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Sample records for complexes model experiments

  1. Modeling Complex Equilibria in ITC Experiments: Thermodynamic Parameters Estimation for a Three Binding Site Model

    PubMed Central

    Le, Vu H.; Buscaglia, Robert; Chaires, Jonathan B.; Lewis, Edwin A.

    2013-01-01

    Isothermal Titration Calorimetry, ITC, is a powerful technique that can be used to estimate a complete set of thermodynamic parameters (e.g. Keq (or ΔG), ΔH, ΔS, and n) for a ligand binding interaction described by a thermodynamic model. Thermodynamic models are constructed by combination of equilibrium constant, mass balance, and charge balance equations for the system under study. Commercial ITC instruments are supplied with software that includes a number of simple interaction models, for example one binding site, two binding sites, sequential sites, and n-independent binding sites. More complex models for example, three or more binding sites, one site with multiple binding mechanisms, linked equilibria, or equilibria involving macromolecular conformational selection through ligand binding need to be developed on a case by case basis by the ITC user. In this paper we provide an algorithm (and a link to our MATLAB program) for the non-linear regression analysis of a multiple binding site model with up to four overlapping binding equilibria. Error analysis demonstrates that fitting ITC data for multiple parameters (e.g. up to nine parameters in the three binding site model) yields thermodynamic parameters with acceptable accuracy. PMID:23262283

  2. Model complexity in carbon sequestration:A design of experiment and response surface uncertainty analysis

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Li, S.

    2014-12-01

    Geologic carbon sequestration (GCS) is proposed for the Nugget Sandstone in Moxa Arch, a regional saline aquifer with a large storage potential. For a proposed storage site, this study builds a suite of increasingly complex conceptual "geologic" model families, using subsets of the site characterization data: a homogeneous model family, a stationary petrophysical model family, a stationary facies model family with sub-facies petrophysical variability, and a non-stationary facies model family (with sub-facies variability) conditioned to soft data. These families, representing alternative conceptual site models built with increasing data, were simulated with the same CO2 injection test (50 years at 1/10 Mt per year), followed by 2950 years of monitoring. Using the Design of Experiment, an efficient sensitivity analysis (SA) is conducted for all families, systematically varying uncertain input parameters. Results are compared among the families to identify parameters that have 1st order impact on predicting the CO2 storage ratio (SR) at both end of injection and end of monitoring. At this site, geologic modeling factors do not significantly influence the short-term prediction of the storage ratio, although they become important over monitoring time, but only for those families where such factors are accounted for. Based on the SA, a response surface analysis is conducted to generate prediction envelopes of the storage ratio, which are compared among the families at both times. Results suggest a large uncertainty in the predicted storage ratio given the uncertainties in model parameters and modeling choices: SR varies from 5-60% (end of injection) to 18-100% (end of monitoring), although its variation among the model families is relatively minor. Moreover, long-term leakage risk is considered small at the proposed site. In the lowest-SR scenarios, all families predict gravity-stable supercritical CO2 migrating toward the bottom of the aquifer. In the highest

  3. Photochemistry of iron(III)-carboxylato complexes in aqueous atmospheric particles - Laboratory experiments and modeling studies

    NASA Astrophysics Data System (ADS)

    Weller, C.; Tilgner, A.; Herrmann, H.

    2010-12-01

    Iron is always present in the atmosphere in concentrations from ~10-9 M (clouds, rain) up to ~10-3 M (fog, particles). Sources are mainly mineral dust emissions. Iron complexes are very good absorbers in the UV-VIS actinic region and therefore photo-chemically reactive. Iron complex photolysis leads to radical production and can initiate radical chain reactions, which is related to the oxidizing capacity of the atmosphere. These radical chain reactions are involved in the decomposition and transformation of a variety of chemical compounds in cloud droplets and deliquescent particles. Additionally, the photochemical reaction itself can be a degradation pathway for organic compounds with the ability to bind iron. Iron-complexes of atmospherically relevant coordination compounds like oxalate, malonate, succinate, glutarate, tartronate, gluconate, pyruvate and glyoxalate have been investigated in laboratory experiments. Iron speciation depends on the iron-ligand ratio and the pH. The most suitable experimental conditions were calculated with a speciation program (Visual Minteq). The solutions were prepared accordingly and transferred to a 1 cm quartz cuvette and flash-photolyzed with an excimer laser at wavelengths 308 or 351 nm. Photochemically produced Fe2+ has been measured by spectrometry at 510 nm as Fe(phenantroline)32+. Fe2+ overall effective quantum yields have been calculated with the concentration of photochemically produced Fe2+ and the measured energy of the excimer laser pulse. The laser pulse energy was measured with a pyroelectric sensor. For some iron-carboxylate systems the experimental parameters like the oxygen content of the solution, the initial Iron concentration and the incident laser energy were systematically altered to observe an effect on the overall quantum yield. The dependence of some quantum yields on these parameters allows in some cases an interpretation of the underlying photochemical reaction mechanism. Quantum yields of malonate

  4. A business process modeling experience in a complex information system re-engineering.

    PubMed

    Bernonville, Stéphanie; Vantourout, Corinne; Fendeler, Geneviève; Beuscart, Régis

    2013-01-01

    This article aims to share a business process modeling experience in a re-engineering project of a medical records department in a 2,965-bed hospital. It presents the modeling strategy, an extract of the results and the feedback experience.

  5. Circular Dichroism of Carotenoids in Bacterial Light-Harvesting Complexes: Experiments and Modeling

    PubMed Central

    Georgakopoulou, S.; van Grondelle, R.; van der Zwan, G.

    2004-01-01

    In this work we investigate the origin and characteristics of the circular dichroism (CD) spectrum of rhodopin glucoside and lycopene in the light-harvesting 2 complex of Rhodopseudomonas acidophila and Rhodospirillum molischianum, respectively. We successfully model their absorption and CD spectra based on the high-resolution structures. We assume that these spectra originate from seven interacting transition dipole moments: the first corresponds to the 0-0 transition of the carotenoid, whereas the remaining six represent higher vibronic components of the S2 state. From the absorption spectra we get an estimate of the Franck-Condon factors of these transitions. Furthermore, we investigate the broadening mechanisms that lead to the final shape of the spectra and get an insight into the interaction energy between carotenoids. Finally, we examine the consequences of rotations of the carotenoid transition dipole moment and of deformations in the light-harvesting 2 complex rings. Comparison of the modeled carotenoid spectra with modeled spectra of the bacteriochlorophyll QY region leads to a refinement of the modeling procedure and an improvement of all calculated results. We therefore propose that the combined carotenoid and bacteriochlorophyll CD can be used as an accurate reflection of the overall structure of the light-harvesting complexes. PMID:15326029

  6. Toward Technological Application of Non-Newtonian Fluids & Complex Materials/Modeling, Simulation, & Design of Experiments

    DTIC Science & Technology

    2007-11-02

    34Therrmanechanical Equations Governing a Material with Prescribed Temperature-Dependent Density, with Applications to Nonisothernal Plane Poiseuille Flow ", D...1-0431 Materials/Modeling, Simulation , & Design of Experiments 6. AUTHORS M. Gregory Forest & Stephen E. Bechtel 7. PERFORMING ORGANIZATION NAME(S...made significant progress in each of these general areas. We produced high resolution models and codes that simulate molten fiber manufacturing

  7. A computational methodology for learning low-complexity surrogate models of process from experiments or simulations. (Paper 679a)

    SciTech Connect

    Cozad, A.; Sahinidis, N.; Miller, D.

    2011-01-01

    Costly and/or insufficiently robust simulations or experiments can often pose difficulties when their use extends well beyond a single evaluation. This is case with the numerous evaluations of uncertainty quantification, when an algebraic model is needed for optimization, as well as numerous other areas. To overcome these difficulties, we generate an accurate set of algebraic surrogate models of disaggregated process blocks of the experiment or simulation. We developed a method that uses derivative-based and derivative-free optimization alongside machine learning and statistical techniques to generate the set of surrogate models using data sampled from experiments or detailed simulations. Our method begins by building a low-complexity surrogate model for each block from an initial sample set. The model is built using a best subset technique that leverages a mixed-integer linear problem formulation to allow for very large initial basis sets. The models are then tested, exploited, and improved through the use of derivative-free solvers to adaptively sample new simulation or experimental points. The sets of surrogate models from each disaggregated process block are then combined with heat and mass balances around each disaggregated block to generate a full algebraic model of the process. The full model can be used for cheap and accurate evaluations of the original simulation or experiment or combined with design specifications and an objective for nonlinear optimization.

  8. Complexities in Barrier Island Response to Sea-Level Rise: Insights from Model Experiments

    NASA Astrophysics Data System (ADS)

    Moore, L. J.; List, J. H.; Williams, S. J.

    2008-12-01

    As sea level rises, a barrier island will respond either by migrating landward across the underlying substrate to higher elevations or by disintegrating if there is no longer sufficient sand volume and relief above sea level to prevent inundation during storms. Using the morphological-behavior model GEOMBEST, we investigate the sea-level rise response of a complex coastal environment to changes in variety of factors, thus yielding insights into barrier island evolution. Our base case is a simplified Holocene run which simulates a possible scenario for the evolution of a 25-km stretch of the North Carolina Outer Banks over the last 8500 years. Varying one parameter at a time, we explore the degree to which changes in sea-level rise rate, sediment supply/loss rate, offshore limits to sediment transport, substrate erodibility, substrate composition and depth- dependent response rate produce changes in average landward barrier island migration rate, average depth of substrate erosion, and final barrier island volume. As expected, sensitivity analyses reveal that within the range of possible values for the North Carolina coast, sea-level rise rate, followed by sediment supply rate, is the most important factor in determining barrier island response to sea-level rise. More surprisingly, the analyses in aggregate indicate that barrier island evolution is highly sensitive to the range of substrate slopes encountered throughout landward migration (i.e., the slope history); as a barrier encounters a continually changing substrate slope, island volume constantly changes, moving toward equilibrium with the current average slope. Through this process, steeper average slope histories produce smaller barrier islands while shallower average slope histories produce larger barrier islands. In both cases, secondary effects on substrate erosion depth and migration rate also result. Notably, similar geometric effects explain an insensitivity of simulation results to changes in offshore

  9. Cadmium sorption onto Natural Red Earth - An assessment using batch experiments and surface complexation modeling

    NASA Astrophysics Data System (ADS)

    Mahatantila, K.; Minoru, O.; Seike, Y.; Vithanage, M. S.

    2010-12-01

    Natural red earth (NRE), an iron coated sand found in north western part of Sri Lanka was used to examine its retention behavior of cadmium, a heavy metal postulated as a factor of chronic kidney disease in Sri Lanka. Adsorption studies were examined in batch experiments as a function of pH, ionic strength and initial cadmium loading. Proton binding sites on NRE were characterized by potentiometric titration yielding a pHzpc around 6.6. The cadmium adsorption increased from 6% to 99% along with a pH increase from 4 to 8.5. In addition, the maximum adsorption was observed when pH is greater than 7.5. Ionic strength dependency of cadmium adsorption for 100 fold variation of NaNO3 evidences the dominance of an inner-sphere bonding mechanism for 10 fold variation of initial cadmium loadings (4.44 and 44.4 µmol/L). Adsorption edges were quantified with a 2pK generalized diffuse double layer model considering two site types, >FeOH and >AlOH, for Cd2+ binding. From modeling, we introduced a monodentate chemical bonding mechanism for cadmium binding on to NRE and this finding was further verified with FTIR spectroscopy. Intrinsic constants determined were log KFeOCd = 8.543 and log KAlOCd = 13.917. Isotherm data implies the heterogeneity of NRE surface and the sorption maximum of 9.418 x10-6 mol/g and 1.3x10-4 mol/g for Langmuir and Freundlich isotherm models. The study suggested the potential of NRE as a material in decontaminating environmental water polluted with cadmium.

  10. Reduction of U(VI) Complexes by Anthraquinone Disulfonate: Experiment and Molecular Modeling

    SciTech Connect

    Ainsworth, C.C.; Wang, Z.; Rosso, K.M.; Wagnon, K.; Fredrickson, J.K.

    2004-03-17

    Past studies demonstrate that complexation will limit abiotic and biotic U(VI) reduction rates and the overall extent of reduction. However, the underlying basis for this behavior is not understood and presently unpredictable across species and ligand structure. The central tenets of these investigations are: (1) reduction of U(VI) follows the electron-transfer (ET) mechanism developed by Marcus; (2) the ET rate is the rate-limiting step in U(VI) reduction and is the step that is most affected by complexation; and (3) Marcus theory can be used to unify the apparently disparate U(VI) reduction rate data and as a computational tool to construct a predictive relationship.

  11. Prediction of homoprotein and heteroprotein complexes by protein docking and template-based modeling: A CASP-CAPRI experiment.

    PubMed

    Lensink, Marc F; Velankar, Sameer; Kryshtafovych, Andriy; Huang, Shen-You; Schneidman-Duhovny, Dina; Sali, Andrej; Segura, Joan; Fernandez-Fuentes, Narcis; Viswanath, Shruthi; Elber, Ron; Grudinin, Sergei; Popov, Petr; Neveu, Emilie; Lee, Hasup; Baek, Minkyung; Park, Sangwoo; Heo, Lim; Rie Lee, Gyu; Seok, Chaok; Qin, Sanbo; Zhou, Huan-Xiang; Ritchie, David W; Maigret, Bernard; Devignes, Marie-Dominique; Ghoorah, Anisah; Torchala, Mieczyslaw; Chaleil, Raphaël A G; Bates, Paul A; Ben-Zeev, Efrat; Eisenstein, Miriam; Negi, Surendra S; Weng, Zhiping; Vreven, Thom; Pierce, Brian G; Borrman, Tyler M; Yu, Jinchao; Ochsenbein, Françoise; Guerois, Raphaël; Vangone, Anna; Rodrigues, João P G L M; van Zundert, Gydo; Nellen, Mehdi; Xue, Li; Karaca, Ezgi; Melquiond, Adrien S J; Visscher, Koen; Kastritis, Panagiotis L; Bonvin, Alexandre M J J; Xu, Xianjin; Qiu, Liming; Yan, Chengfei; Li, Jilong; Ma, Zhiwei; Cheng, Jianlin; Zou, Xiaoqin; Shen, Yang; Peterson, Lenna X; Kim, Hyung-Rae; Roy, Amit; Han, Xusi; Esquivel-Rodriguez, Juan; Kihara, Daisuke; Yu, Xiaofeng; Bruce, Neil J; Fuller, Jonathan C; Wade, Rebecca C; Anishchenko, Ivan; Kundrotas, Petras J; Vakser, Ilya A; Imai, Kenichiro; Yamada, Kazunori; Oda, Toshiyuki; Nakamura, Tsukasa; Tomii, Kentaro; Pallara, Chiara; Romero-Durana, Miguel; Jiménez-García, Brian; Moal, Iain H; Férnandez-Recio, Juan; Joung, Jong Young; Kim, Jong Yun; Joo, Keehyoung; Lee, Jooyoung; Kozakov, Dima; Vajda, Sandor; Mottarella, Scott; Hall, David R; Beglov, Dmitri; Mamonov, Artem; Xia, Bing; Bohnuud, Tanggis; Del Carpio, Carlos A; Ichiishi, Eichiro; Marze, Nicholas; Kuroda, Daisuke; Roy Burman, Shourya S; Gray, Jeffrey J; Chermak, Edrisse; Cavallo, Luigi; Oliva, Romina; Tovchigrechko, Andrey; Wodak, Shoshana J

    2016-09-01

    We present the results for CAPRI Round 30, the first joint CASP-CAPRI experiment, which brought together experts from the protein structure prediction and protein-protein docking communities. The Round comprised 25 targets from amongst those submitted for the CASP11 prediction experiment of 2014. The targets included mostly homodimers, a few homotetramers, and two heterodimers, and comprised protein chains that could readily be modeled using templates from the Protein Data Bank. On average 24 CAPRI groups and 7 CASP groups submitted docking predictions for each target, and 12 CAPRI groups per target participated in the CAPRI scoring experiment. In total more than 9500 models were assessed against the 3D structures of the corresponding target complexes. Results show that the prediction of homodimer assemblies by homology modeling techniques and docking calculations is quite successful for targets featuring large enough subunit interfaces to represent stable associations. Targets with ambiguous or inaccurate oligomeric state assignments, often featuring crystal contact-sized interfaces, represented a confounding factor. For those, a much poorer prediction performance was achieved, while nonetheless often providing helpful clues on the correct oligomeric state of the protein. The prediction performance was very poor for genuine tetrameric targets, where the inaccuracy of the homology-built subunit models and the smaller pair-wise interfaces severely limited the ability to derive the correct assembly mode. Our analysis also shows that docking procedures tend to perform better than standard homology modeling techniques and that highly accurate models of the protein components are not always required to identify their association modes with acceptable accuracy. Proteins 2016; 84(Suppl 1):323-348. © 2016 Wiley Periodicals, Inc.

  12. Prediction of homoprotein and heteroprotein complexes by protein docking and template‐based modeling: A CASP‐CAPRI experiment

    PubMed Central

    Velankar, Sameer; Kryshtafovych, Andriy; Huang, Shen‐You; Schneidman‐Duhovny, Dina; Sali, Andrej; Segura, Joan; Fernandez‐Fuentes, Narcis; Viswanath, Shruthi; Elber, Ron; Grudinin, Sergei; Popov, Petr; Neveu, Emilie; Lee, Hasup; Baek, Minkyung; Park, Sangwoo; Heo, Lim; Rie Lee, Gyu; Seok, Chaok; Qin, Sanbo; Zhou, Huan‐Xiang; Ritchie, David W.; Maigret, Bernard; Devignes, Marie‐Dominique; Ghoorah, Anisah; Torchala, Mieczyslaw; Chaleil, Raphaël A.G.; Bates, Paul A.; Ben‐Zeev, Efrat; Eisenstein, Miriam; Negi, Surendra S.; Weng, Zhiping; Vreven, Thom; Pierce, Brian G.; Borrman, Tyler M.; Yu, Jinchao; Ochsenbein, Françoise; Guerois, Raphaël; Vangone, Anna; Rodrigues, João P.G.L.M.; van Zundert, Gydo; Nellen, Mehdi; Xue, Li; Karaca, Ezgi; Melquiond, Adrien S.J.; Visscher, Koen; Kastritis, Panagiotis L.; Bonvin, Alexandre M.J.J.; Xu, Xianjin; Qiu, Liming; Yan, Chengfei; Li, Jilong; Ma, Zhiwei; Cheng, Jianlin; Zou, Xiaoqin; Shen, Yang; Peterson, Lenna X.; Kim, Hyung‐Rae; Roy, Amit; Han, Xusi; Esquivel‐Rodriguez, Juan; Kihara, Daisuke; Yu, Xiaofeng; Bruce, Neil J.; Fuller, Jonathan C.; Wade, Rebecca C.; Anishchenko, Ivan; Kundrotas, Petras J.; Vakser, Ilya A.; Imai, Kenichiro; Yamada, Kazunori; Oda, Toshiyuki; Nakamura, Tsukasa; Tomii, Kentaro; Pallara, Chiara; Romero‐Durana, Miguel; Jiménez‐García, Brian; Moal, Iain H.; Férnandez‐Recio, Juan; Joung, Jong Young; Kim, Jong Yun; Joo, Keehyoung; Lee, Jooyoung; Kozakov, Dima; Vajda, Sandor; Mottarella, Scott; Hall, David R.; Beglov, Dmitri; Mamonov, Artem; Xia, Bing; Bohnuud, Tanggis; Del Carpio, Carlos A.; Ichiishi, Eichiro; Marze, Nicholas; Kuroda, Daisuke; Roy Burman, Shourya S.; Gray, Jeffrey J.; Chermak, Edrisse; Cavallo, Luigi; Oliva, Romina; Tovchigrechko, Andrey

    2016-01-01

    ABSTRACT We present the results for CAPRI Round 30, the first joint CASP‐CAPRI experiment, which brought together experts from the protein structure prediction and protein–protein docking communities. The Round comprised 25 targets from amongst those submitted for the CASP11 prediction experiment of 2014. The targets included mostly homodimers, a few homotetramers, and two heterodimers, and comprised protein chains that could readily be modeled using templates from the Protein Data Bank. On average 24 CAPRI groups and 7 CASP groups submitted docking predictions for each target, and 12 CAPRI groups per target participated in the CAPRI scoring experiment. In total more than 9500 models were assessed against the 3D structures of the corresponding target complexes. Results show that the prediction of homodimer assemblies by homology modeling techniques and docking calculations is quite successful for targets featuring large enough subunit interfaces to represent stable associations. Targets with ambiguous or inaccurate oligomeric state assignments, often featuring crystal contact‐sized interfaces, represented a confounding factor. For those, a much poorer prediction performance was achieved, while nonetheless often providing helpful clues on the correct oligomeric state of the protein. The prediction performance was very poor for genuine tetrameric targets, where the inaccuracy of the homology‐built subunit models and the smaller pair‐wise interfaces severely limited the ability to derive the correct assembly mode. Our analysis also shows that docking procedures tend to perform better than standard homology modeling techniques and that highly accurate models of the protein components are not always required to identify their association modes with acceptable accuracy. Proteins 2016; 84(Suppl 1):323–348. © 2016 The Authors Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc. PMID:27122118

  13. The Mentoring Relationship as a Complex Adaptive System: Finding a Model for Our Experience

    ERIC Educational Resources Information Center

    Jones, Rachel; Brown, Dot

    2011-01-01

    Mentoring theory and practice has evolved significantly during the past 40 years. Early mentoring models were characterized by the top-down flow of information and benefits to the protege. This framework was reconceptualized as a reciprocal model when scholars realized mentoring was a mutually beneficial process. Recently, in response to rapidly…

  14. Complexities in barrier island response to sea level rise: Insights from numerical model experiments, North Carolina Outer Banks

    NASA Astrophysics Data System (ADS)

    Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

    2010-09-01

    Using a morphological-behavior model to conduct sensitivity experiments, we investigate the sea level rise response of a complex coastal environment to changes in a variety of factors. Experiments reveal that substrate composition, followed in rank order by substrate slope, sea level rise rate, and sediment supply rate, are the most important factors in determining barrier island response to sea level rise. We find that geomorphic threshold crossing, defined as a change in state (e.g., from landward migrating to drowning) that is irreversible over decadal to millennial time scales, is most likely to occur in muddy coastal systems where the combination of substrate composition, depth-dependent limitations on shoreface response rates, and substrate erodibility may prevent sand from being liberated rapidly enough, or in sufficient quantity, to maintain a subaerial barrier. Analyses indicate that factors affecting sediment availability such as low substrate sand proportions and high sediment loss rates cause a barrier to migrate landward along a trajectory having a lower slope than average barrier island slope, thereby defining an "effective" barrier island slope. Other factors being equal, such barriers will tend to be smaller and associated with a more deeply incised shoreface, thereby requiring less migration per sea level rise increment to liberate sufficient sand to maintain subaerial exposure than larger, less incised barriers. As a result, the evolution of larger/less incised barriers is more likely to be limited by shoreface erosion rates or substrate erodibility making them more prone to disintegration related to increasing sea level rise rates than smaller/more incised barriers. Thus, the small/deeply incised North Carolina barriers are likely to persist in the near term (although their long-term fate is less certain because of the low substrate slopes that will soon be encountered). In aggregate, results point to the importance of system history (e

  15. Concept model of the formation process of humic acid-kaolin complexes deduced by trichloroethylene sorption experiments and various characterizations.

    PubMed

    Zhu, Xiaojing; He, Jiangtao; Su, Sihui; Zhang, Xiaoliang; Wang, Fei

    2016-05-01

    To explore the interactions between soil organic matter and minerals, humic acid (HA, as organic matter), kaolin (as a mineral component) and Ca(2+) (as metal ions) were used to prepare HA-kaolin and Ca-HA-kaolin complexes. These complexes were used in trichloroethylene (TCE) sorption experiments and various characterizations. Interactions between HA and kaolin during the formation of their complexes were confirmed by the obvious differences between the Qe (experimental sorbed TCE) and Qe_p (predicted sorbed TCE) values of all detected samples. The partition coefficient kd obtained for the different samples indicated that both the organic content (fom) and Ca(2+) could significantly impact the interactions. Based on experimental results and various characterizations, a concept model was developed. In the absence of Ca(2+), HA molecules first patched onto charged sites of kaolin surfaces, filling the pores. Subsequently, as the HA content increased and the first HA layer reached saturation, an outer layer of HA began to form, compressing the inner HA layer. As HA loading continued, the second layer reached saturation, such that an outer-third layer began to form, compressing the inner layers. In the presence of Ca(2+), which not only can promote kaolin self-aggregation but can also boost HA attachment to kaolin, HA molecules were first surrounded by kaolin. Subsequently, first and second layers formed (with inner layer compression) via the same process as described above in the absence of Ca(2+), except that the second layer continued to load rather than reach saturation, within the investigated conditions, because of enhanced HA aggregation caused by Ca(2+).

  16. Numerical Modeling of Complex Targets for High-Energy- Density Experiments with Ion Beams and other Drivers

    DOE PAGES

    Koniges, Alice; Liu, Wangyi; Lidia, Steven; ...

    2016-04-01

    We explore the simulation challenges and requirements for experiments planned on facilities such as the NDCX-II ion accelerator at LBNL, currently undergoing commissioning. Hydrodynamic modeling of NDCX-II experiments include certain lower temperature effects, e.g., surface tension and target fragmentation, that are not generally present in extreme high-energy laser facility experiments, where targets are completely vaporized in an extremely short period of time. Target designs proposed for NDCX-II range from metal foils of order one micron thick (thin targets) to metallic foam targets several tens of microns thick (thick targets). These high-energy-density experiments allow for the study of fracture as wellmore » as the process of bubble and droplet formation. We incorporate these physics effects into a code called ALE-AMR that uses a combination of Arbitrary Lagrangian Eulerian hydrodynamics and Adaptive Mesh Refinement. Inclusion of certain effects becomes tricky as we must deal with non-orthogonal meshes of various levels of refinement in three dimensions. A surface tension model used for droplet dynamics is implemented in ALE-AMR using curvature calculated from volume fractions. Thick foam target experiments provide information on how ion beam induced shock waves couple into kinetic energy of fluid flow. Although NDCX-II is not fully commissioned, experiments are being conducted that explore material defect production and dynamics.« less

  17. Numerical Modeling of Complex Targets for High-Energy- Density Experiments with Ion Beams and other Drivers

    SciTech Connect

    Koniges, Alice; Liu, Wangyi; Lidia, Steven; Schenkel, Thomas; Barnard, John; Friedman, Alex; Eder, David; Fisher, Aaron; Masters, Nathan

    2016-04-01

    We explore the simulation challenges and requirements for experiments planned on facilities such as the NDCX-II ion accelerator at LBNL, currently undergoing commissioning. Hydrodynamic modeling of NDCX-II experiments include certain lower temperature effects, e.g., surface tension and target fragmentation, that are not generally present in extreme high-energy laser facility experiments, where targets are completely vaporized in an extremely short period of time. Target designs proposed for NDCX-II range from metal foils of order one micron thick (thin targets) to metallic foam targets several tens of microns thick (thick targets). These high-energy-density experiments allow for the study of fracture as well as the process of bubble and droplet formation. We incorporate these physics effects into a code called ALE-AMR that uses a combination of Arbitrary Lagrangian Eulerian hydrodynamics and Adaptive Mesh Refinement. Inclusion of certain effects becomes tricky as we must deal with non-orthogonal meshes of various levels of refinement in three dimensions. A surface tension model used for droplet dynamics is implemented in ALE-AMR using curvature calculated from volume fractions. Thick foam target experiments provide information on how ion beam induced shock waves couple into kinetic energy of fluid flow. Although NDCX-II is not fully commissioned, experiments are being conducted that explore material defect production and dynamics.

  18. Numerical Modeling of Complex Targets for High-Energy- Density Experiments with Ion Beams and other Drivers

    NASA Astrophysics Data System (ADS)

    Koniges, Alice; Liu, Wangyi; Lidia, Steven; Schenkel, Thomas; Barnard, John; Friedman, Alex; Eder, David; Fisher, Aaron; Masters, Nathan

    2016-03-01

    We explore the simulation challenges and requirements for experiments planned on facilities such as the NDCX-II ion accelerator at LBNL, currently undergoing commissioning. Hydrodynamic modeling of NDCX-II experiments include certain lower temperature effects, e.g., surface tension and target fragmentation, that are not generally present in extreme high-energy laser facility experiments, where targets are completely vaporized in an extremely short period of time. Target designs proposed for NDCX-II range from metal foils of order one micron thick (thin targets) to metallic foam targets several tens of microns thick (thick targets). These high-energy-density experiments allow for the study of fracture as well as the process of bubble and droplet formation. We incorporate these physics effects into a code called ALE-AMR that uses a combination of Arbitrary Lagrangian Eulerian hydrodynamics and Adaptive Mesh Refinement. Inclusion of certain effects becomes tricky as we must deal with non-orthogonal meshes of various levels of refinement in three dimensions. A surface tension model used for droplet dynamics is implemented in ALE-AMR using curvature calculated from volume fractions. Thick foam target experiments provide information on how ion beam induced shock waves couple into kinetic energy of fluid flow. Although NDCX-II is not fully commissioned, experiments are being conducted that explore material defect production and dynamics.

  19. Surface complexation modeling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adsorption-desorption reactions are important processes that affect the transport of contaminants in the environment. Surface complexation models are chemical models that can account for the effects of variable chemical conditions, such as pH, on adsorption reactions. These models define specific ...

  20. Modelling multi-protein complexes using PELDOR distance measurements for rigid body minimisation experiments using XPLOR-NIH

    PubMed Central

    Hammond, Colin M.; Owen-Hughes, Tom; Norman, David G.

    2014-01-01

    Crystallographic and NMR approaches have provided a wealth of structural information about protein domains. However, often these domains are found as components of larger multi domain polypeptides or complexes. Orienting domains within such contexts can provide powerful new insight into their function. The combination of site specific spin labelling and Pulsed Electron Double Resonance (PELDOR) provide a means of obtaining structural measurements that can be used to generate models describing how such domains are oriented. Here we describe a pipeline for modelling the location of thio-reactive nitroxyl spin locations to engineered sties on the histone chaperone Vps75. We then use a combination of experimentally determined measurements and symmetry constraints to model the orientation in which homodimers of Vps75 associate to form homotetramers using the XPLOR-NIH platform. This provides a working example of how PELDOR measurements can be used to generate a structural model. PMID:25448300

  1. Complexity and Animal Models

    DTIC Science & Technology

    2015-01-01

    SEP 2015 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Complexity and animal models 5a. CONTRACT NUMBER 5b. GRANT NUMBER...decrease W/Wmax, thereby maintaining the relationship between variability and W/Wmax. doi:10.1016/j.jcrc.2010.05.012 Complexity and animal models...may not be possible during mass casualty and natural disaster situations or may need to be postponed during combat to avoid danger to the medic’s life

  2. From Metaphors to Models: Broadening the Lens of the Hunter Warrior Experiment with a Complex Adaptive System Tool

    DTIC Science & Technology

    1999-01-01

    complexity and complex adaptive systems, self-organizing criticality, cellular automata , and so on, because they all globally share this property...distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT Same...four categories: Artificial Life, Evolution and Complexity, Classification , Heuristic Search and Computation, Neural Networks, Chaos and Fractals. 14

  3. Sporadic meteoroid complex: Modeling

    NASA Astrophysics Data System (ADS)

    Andreev, V.

    2014-07-01

    The distribution of the sporadic meteoroids flux density over the celestial sphere is the common form of representation of the meteoroids distribution in the vicinity of the Earth's orbit. The determination of the flux density of sporadic meteor bodies is Q(V,e,f) = Q_0 P_e(V) P(e,f) where V is the meteoroid velocity, e,f are the radiant coordinates, Q_0 is the meteoroid flux over whole celestial sphere, P_e(V) is the conditional velocity distributions and P(e,f) is the radiant distribution over the celestial sphere. The sporadic meteoroid complex model is analytical and based on heliocentric velocities and radiant distributions. The multi-mode character of the heliocentric velocity and radiant distributions follows from the analysis of meteor observational data. This fact points to a complicated structure of the sporadic meteoroid complex. It is the consequence of the plurality of the parent bodies and the origin mechanisms of the meteoroids. The meteoroid complex was divided into four groups for that reason and with a goal of more accurate modelling of velocities and radiant distributions. As the classifying parameter to determine the meteoroid membership in any group, we adopt the Tisserand invariant relative to Jupiter T_J = 1/a + 2 A_J^{-3/2} √{a (1 - e^2)} cos i and the meteoroid orbit inclination i. Two meteoroid groups relate to long-period and short-period comets. One meteoroid group is related to asteroids. The relationship to the last, fourth group is a problematic one. Then, we construct models of radiant and velocity distributions for each group. The analytical model for the whole sporadic meteoroid complex is the sum of the ones for each group.

  4. Predictive Surface Complexation Modeling

    SciTech Connect

    Sverjensky, Dimitri A.

    2016-11-29

    Surface complexation plays an important role in the equilibria and kinetics of processes controlling the compositions of soilwaters and groundwaters, the fate of contaminants in groundwaters, and the subsurface storage of CO2 and nuclear waste. Over the last several decades, many dozens of individual experimental studies have addressed aspects of surface complexation that have contributed to an increased understanding of its role in natural systems. However, there has been no previous attempt to develop a model of surface complexation that can be used to link all the experimental studies in order to place them on a predictive basis. Overall, my research has successfully integrated the results of the work of many experimentalists published over several decades. For the first time in studies of the geochemistry of the mineral-water interface, a practical predictive capability for modeling has become available. The predictive correlations developed in my research now enable extrapolations of experimental studies to provide estimates of surface chemistry for systems not yet studied experimentally and for natural and anthropogenically perturbed systems.

  5. Model Experiments and Model Descriptions

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Ko, Malcolm K. W.; Weisenstein, Debra; Scott, Courtney J.; Shia, Run-Lie; Rodriguez, Jose; Sze, N. D.; Vohralik, Peter; Randeniya, Lakshman; Plumb, Ian

    1999-01-01

    The Second Workshop on Stratospheric Models and Measurements Workshop (M&M II) is the continuation of the effort previously started in the first Workshop (M&M I, Prather and Remsberg [1993]) held in 1992. As originally stated, the aim of M&M is to provide a foundation for establishing the credibility of stratospheric models used in environmental assessments of the ozone response to chlorofluorocarbons, aircraft emissions, and other climate-chemistry interactions. To accomplish this, a set of measurements of the present day atmosphere was selected. The intent was that successful simulations of the set of measurements should become the prerequisite for the acceptance of these models as having a reliable prediction for future ozone behavior. This section is divided into two: model experiment and model descriptions. In the model experiment, participant were given the charge to design a number of experiments that would use observations to test whether models are using the correct mechanisms to simulate the distributions of ozone and other trace gases in the atmosphere. The purpose is closely tied to the needs to reduce the uncertainties in the model predicted responses of stratospheric ozone to perturbations. The specifications for the experiments were sent out to the modeling community in June 1997. Twenty eight modeling groups responded to the requests for input. The first part of this section discusses the different modeling group, along with the experiments performed. Part two of this section, gives brief descriptions of each model as provided by the individual modeling groups.

  6. Debating complexity in modeling

    USGS Publications Warehouse

    Hunt, Randall J.; Zheng, Chunmiao

    1999-01-01

    As scientists trying to understand the natural world, how should our effort be apportioned? We know that the natural world is characterized by complex and interrelated processes. Yet do we need to explicitly incorporate these intricacies to perform the tasks we are charged with? In this era of expanding computer power and development of sophisticated preprocessors and postprocessors, are bigger machines making better models? Put another way, do we understand the natural world better now with all these advancements in our simulation ability? Today the public's patience for long-term projects producing indeterminate results is wearing thin. This increases pressure on the investigator to use the appropriate technology efficiently. On the other hand, bringing scientific results into the legal arena opens up a new dimension to the issue: to the layperson, a tool that includes more of the complexity known to exist in the real world is expected to provide the more scientifically valid answer.

  7. Network dynamics: quantitative analysis of complex behavior in metabolism, organelles, and cells, from experiments to models and back.

    PubMed

    Kurz, Felix T; Kembro, Jackelyn M; Flesia, Ana G; Armoundas, Antonis A; Cortassa, Sonia; Aon, Miguel A; Lloyd, David

    2017-01-01

    Advancing from two core traits of biological systems: multilevel network organization and nonlinearity, we review a host of novel and readily available techniques to explore and analyze their complex dynamic behavior within the framework of experimental-computational synergy. In the context of concrete biological examples, analytical methods such as wavelet, power spectra, and metabolomics-fluxomics analyses, are presented, discussed, and their strengths and limitations highlighted. Further shown is how time series from stationary and nonstationary biological variables and signals, such as membrane potential, high-throughput metabolomics, O2 and CO2 levels, bird locomotion, at the molecular, (sub)cellular, tissue, and whole organ and animal levels, can reveal important information on the properties of the underlying biological networks. Systems biology-inspired computational methods start to pave the way for addressing the integrated functional dynamics of metabolic, organelle and organ networks. As our capacity to unravel the control and regulatory properties of these networks and their dynamics under normal or pathological conditions broadens, so is our ability to address endogenous rhythms and clocks to improve health-span in human aging, and to manage complex metabolic disorders, neurodegeneration, and cancer. WIREs Syst Biol Med 2017, 9:e1352. doi: 10.1002/wsbm.1352 For further resources related to this article, please visit the WIREs website.

  8. Analysis of designed experiments with complex aliasing

    SciTech Connect

    Hamada, M.; Wu, C.F.J. )

    1992-07-01

    Traditionally, Plackett-Burman (PB) designs have been used in screening experiments for identifying important main effects. The PB designs whose run sizes are not a power of two have been criticized for their complex aliasing patterns, which according to conventional wisdom gives confusing results. This paper goes beyond the traditional approach by proposing the analysis strategy that entertains interactions in addition to main effects. Based on the precepts of effect sparsity and effect heredity, the proposed procedure exploits the designs' complex aliasing patterns, thereby turning their 'liability' into an advantage. Demonstration of the procedure on three real experiments shows the potential for extracting important information available in the data that has, until now, been missed. Some limitations are discussed, and extentions to overcome them are given. The proposed procedure also applies to more general mixed level designs that have become increasingly popular. 16 refs.

  9. Turbulence modeling and experiments

    NASA Technical Reports Server (NTRS)

    Shabbir, Aamir

    1992-01-01

    The best way of verifying turbulence is to do a direct comparison between the various terms and their models. The success of this approach depends upon the availability of the data for the exact correlations (both experimental and DNS). The other approach involves numerically solving the differential equations and then comparing the results with the data. The results of such a computation will depend upon the accuracy of all the modeled terms and constants. Because of this it is sometimes difficult to find the cause of a poor performance by a model. However, such a calculation is still meaningful in other ways as it shows how a complete Reynolds stress model performs. Thirteen homogeneous flows are numerically computed using the second order closure models. We concentrate only on those models which use a linear (or quasi-linear) model for the rapid term. This, therefore, includes the Launder, Reece and Rodi (LRR) model; the isotropization of production (IP) model; and the Speziale, Sarkar, and Gatski (SSG) model. Which of the three models performs better is examined along with what are their weaknesses, if any. The other work reported deal with the experimental balances of the second moment equations for a buoyant plume. Despite the tremendous amount of activity toward the second order closure modeling of turbulence, very little experimental information is available about the budgets of the second moment equations. Part of the problem stems from our inability to measure the pressure correlations. However, if everything else appearing in these equations is known from the experiment, pressure correlations can be obtained as the closing terms. This is the closest we can come to in obtaining these terms from experiment, and despite the measurement errors which might be present in such balances, the resulting information will be extremely useful for the turbulence modelers. The purpose of this part of the work was to provide such balances of the Reynolds stress and heat

  10. CFD [computational fluid dynamics] And Safety Factors. Computer modeling of complex processes needs old-fashioned experiments to stay in touch with reality.

    SciTech Connect

    Leishear, Robert A.; Lee, Si Y.; Poirier, Michael R.; Steeper, Timothy J.; Ervin, Robert C.; Giddings, Billy J.; Stefanko, David B.; Harp, Keith D.; Fowley, Mark D.; Van Pelt, William B.

    2012-10-07

    Computational fluid dynamics (CFD) is recognized as a powerful engineering tool. That is, CFD has advanced over the years to the point where it can now give us deep insight into the analysis of very complex processes. There is a danger, though, that an engineer can place too much confidence in a simulation. If a user is not careful, it is easy to believe that if you plug in the numbers, the answer comes out, and you are done. This assumption can lead to significant errors. As we discovered in the course of a study on behalf of the Department of Energy's Savannah River Site in South Carolina, CFD models fail to capture some of the large variations inherent in complex processes. These variations, or scatter, in experimental data emerge from physical tests and are inadequately captured or expressed by calculated mean values for a process. This anomaly between experiment and theory can lead to serious errors in engineering analysis and design unless a correction factor, or safety factor, is experimentally validated. For this study, blending times for the mixing of salt solutions in large storage tanks were the process of concern under investigation. This study focused on the blending processes needed to mix salt solutions to ensure homogeneity within waste tanks, where homogeneity is required to control radioactivity levels during subsequent processing. Two of the requirements for this task were to determine the minimum number of submerged, centrifugal pumps required to blend the salt mixtures in a full-scale tank in half a day or less, and to recommend reasonable blending times to achieve nearly homogeneous salt mixtures. A full-scale, low-flow pump with a total discharge flow rate of 500 to 800 gpm was recommended with two opposing 2.27-inch diameter nozzles. To make this recommendation, both experimental and CFD modeling were performed. Lab researchers found that, although CFD provided good estimates of an average blending time, experimental blending times varied

  11. Molecular modeling of polynucleotide complexes.

    PubMed

    Meneksedag-Erol, Deniz; Tang, Tian; Uludağ, Hasan

    2014-08-01

    Delivery of polynucleotides into patient cells is a promising strategy for treatment of genetic disorders. Gene therapy aims to either synthesize desired proteins (DNA delivery) or suppress expression of endogenous genes (siRNA delivery). Carriers constitute an important part of gene therapeutics due to limitations arising from the pharmacokinetics of polynucleotides. Non-viral carriers such as polymers and lipids protect polynucleotides from intra and extracellular threats and facilitate formation of cell-permeable nanoparticles through shielding and/or bridging multiple polynucleotide molecules. Formation of nanoparticulate systems with optimal features, their cellular uptake and intracellular trafficking are crucial steps for an effective gene therapy. Despite the great amount of experimental work pursued, critical features of the nanoparticles as well as their processing mechanisms are still under debate due to the lack of instrumentation at atomic resolution. Molecular modeling based computational approaches can shed light onto the atomic level details of gene delivery systems, thus provide valuable input that cannot be readily obtained with experimental techniques. Here, we review the molecular modeling research pursued on critical gene therapy steps, highlight the knowledge gaps in the field and providing future perspectives. Existing modeling studies revealed several important aspects of gene delivery, such as nanoparticle formation dynamics with various carriers, effect of carrier properties on complexation, carrier conformations in endosomal stages, and release of polynucleotides from carriers. Rate-limiting steps related to cellular events (i.e. internalization, endosomal escape, and nuclear uptake) are now beginning to be addressed by computational approaches. Limitations arising from current computational power and accuracy of modeling have been hindering the development of more realistic models. With the help of rapidly-growing computational power

  12. Hydraulic Fracturing Mineback Experiment in Complex Media

    NASA Astrophysics Data System (ADS)

    Green, S. J.; McLennan, J. D.

    2012-12-01

    Hydraulic fracturing (or "fracking") for the recovery of gas and liquids from tight shale formations has gained much attention. This operation which involves horizontal well drilling and massive hydraulic fracturing has been developed over the last decade to produce fluids from extremely low permeability mudstone and siltstone rocks with high organic content. Nearly thirteen thousand wells and about one hundred and fifty thousand stages within the wells were fractured in the US in 2011. This operation has proven to be successful, causing hundreds of billions of dollars to be invested and has produced an abundance of natural gas and is making billions of barrels of hydrocarbon liquids available for the US. But, even with this commercial success, relatively little is clearly known about the complexity--or lack of complexity--of the hydraulic fracture, the extent that the newly created surface area contacts the high Reservoir Quality rock, nor the connectivity and conductivity of the hydraulic fractures created. To better understand this phenomena in order to improve efficiency, a large-scale mine-back experiment is progressing. The mine-back experiment is a full-scale hydraulic fracture carried out in a well-characterized environment, with comprehensive instrumentation deployed to measure fracture growth. A tight shale mudstone rock geologic setting is selected, near the edge of a formation where one to two thousand feet difference in elevation occurs. From the top of the formation, drilling, well logging, and hydraulic fracture pumping will occur. From the bottom of the formation a horizontal tunnel will be mined using conventional mining techniques into the rock formation towards the drilled well. Certain instrumentation will be located within this tunnel for observations during the hydraulic fracturing. After the hydraulic fracturing, the tunnel will be extended toward the well, with careful mapping of the created hydraulic fracture. Fracturing fluid will be

  13. Surface complexation modeling of groundwater arsenic mobility: Results of a forced gradient experiment in a Red River flood plain aquifer, Vietnam

    NASA Astrophysics Data System (ADS)

    Jessen, Søren; Postma, Dieke; Larsen, Flemming; Nhan, Pham Quy; Hoa, Le Quynh; Trang, Pham Thi Kim; Long, Tran Vu; Viet, Pham Hung; Jakobsen, Rasmus

    2012-12-01

    Three surface complexation models (SCMs) developed for, respectively, ferrihydrite, goethite and sorption data for a Pleistocene oxidized aquifer sediment from Bangladesh were used to explore the effect of multicomponent adsorption processes on As mobility in a reduced Holocene floodplain aquifer along the Red River, Vietnam. The SCMs for ferrihydrite and goethite yielded very different results. The ferrihydrite SCM favors As(III) over As(V) and has carbonate and silica species as the main competitors for surface sites. In contrast, the goethite SCM has a greater affinity for As(V) over As(III) while PO43- and Fe(II) form the predominant surface species. The SCM for Pleistocene aquifer sediment resembles most the goethite SCM but shows more Si sorption. Compiled As(III) adsorption data for Holocene sediment was also well described by the SCM determined for Pleistocene aquifer sediment, suggesting a comparable As(III) affinity of Holocene and Pleistocene aquifer sediments. A forced gradient field experiment was conducted in a bank aquifer adjacent to a tributary channel to the Red River, and the passage in the aquifer of mixed groundwater containing up to 74% channel water was observed. The concentrations of As (<0.013 μM) and major ions in the channel water are low compared to those in the pristine groundwater in the adjacent bank aquifer, which had an As concentration of ˜3 μM. Calculations for conservative mixing of channel and groundwater could explain the observed variation in concentration for most elements. However, the mixed waters did contain an excess of As(III), PO43- and Si which is attributed to desorption from the aquifer sediment. The three SCMs were tested on their ability to model the desorption of As(III), PO43- and Si. Qualitatively, the ferrihydrite SCM correctly predicts desorption for As(III) but for Si and PO43- it predicts an increased adsorption instead of desorption. The goethite SCM correctly predicts desorption of both As(III) and PO43

  14. Barrier experiment: Shock initiation under complex loading

    SciTech Connect

    Menikoff, Ralph

    2016-01-12

    The barrier experiments are a variant of the gap test; a detonation wave in a donor HE impacts a barrier and drives a shock wave into an acceptor HE. The question we ask is: What is the trade-off between the barrier material and threshold barrier thickness to prevent the acceptor from detonating. This can be viewed from the perspective of shock initiation of the acceptor subject to a complex pressure drive condition. Here we consider key factors which affect whether or not the acceptor undergoes a shock-to-detonation transition. These include the following: shock impedance matches for the donor detonation wave into the barrier and then the barrier shock into the acceptor, the pressure gradient behind the donor detonation wave, and the curvature of detonation front in the donor. Numerical simulations are used to illustrate how these factors affect the reaction in the acceptor.

  15. Complex terrain experiments in the New European Wind Atlas

    PubMed Central

    Angelou, N.; Callies, D.; Cantero, E.; Arroyo, R. Chávez; Courtney, M.; Cuxart, J.; Dellwik, E.; Gottschall, J.; Ivanell, S.; Kühn, P.; Lea, G.; Matos, J. C.; Palma, J. M. L. M.; Peña, A.; Rodrigo, J. Sanz; Söderberg, S.; Vasiljevic, N.; Rodrigues, C. Veiga

    2017-01-01

    The New European Wind Atlas project will create a freely accessible wind atlas covering Europe and Turkey, develop the model chain to create the atlas and perform a series of experiments on flow in many different kinds of complex terrain to validate the models. This paper describes the experiments of which some are nearly completed while others are in the planning stage. All experiments focus on the flow properties that are relevant for wind turbines, so the main focus is the mean flow and the turbulence at heights between 40 and 300 m. Also extreme winds, wind shear and veer, and diurnal and seasonal variations of the wind are of interest. Common to all the experiments is the use of Doppler lidar systems to supplement and in some cases replace completely meteorological towers. Many of the lidars will be equipped with scan heads that will allow for arbitrary scan patterns by several synchronized systems. Two pilot experiments, one in Portugal and one in Germany, show the value of using multiple synchronized, scanning lidar, both in terms of the accuracy of the measurements and the atmospheric physical processes that can be studied. The experimental data will be used for validation of atmospheric flow models and will by the end of the project be freely available. This article is part of the themed issue ‘Wind energy in complex terrains’. PMID:28265025

  16. Complex terrain experiments in the New European Wind Atlas.

    PubMed

    Mann, J; Angelou, N; Arnqvist, J; Callies, D; Cantero, E; Arroyo, R Chávez; Courtney, M; Cuxart, J; Dellwik, E; Gottschall, J; Ivanell, S; Kühn, P; Lea, G; Matos, J C; Palma, J M L M; Pauscher, L; Peña, A; Rodrigo, J Sanz; Söderberg, S; Vasiljevic, N; Rodrigues, C Veiga

    2017-04-13

    The New European Wind Atlas project will create a freely accessible wind atlas covering Europe and Turkey, develop the model chain to create the atlas and perform a series of experiments on flow in many different kinds of complex terrain to validate the models. This paper describes the experiments of which some are nearly completed while others are in the planning stage. All experiments focus on the flow properties that are relevant for wind turbines, so the main focus is the mean flow and the turbulence at heights between 40 and 300 m. Also extreme winds, wind shear and veer, and diurnal and seasonal variations of the wind are of interest. Common to all the experiments is the use of Doppler lidar systems to supplement and in some cases replace completely meteorological towers. Many of the lidars will be equipped with scan heads that will allow for arbitrary scan patterns by several synchronized systems. Two pilot experiments, one in Portugal and one in Germany, show the value of using multiple synchronized, scanning lidar, both in terms of the accuracy of the measurements and the atmospheric physical processes that can be studied. The experimental data will be used for validation of atmospheric flow models and will by the end of the project be freely available.This article is part of the themed issue 'Wind energy in complex terrains'.

  17. Trends in modeling Biomedical Complex Systems

    PubMed Central

    Milanesi, Luciano; Romano, Paolo; Castellani, Gastone; Remondini, Daniel; Liò, Petro

    2009-01-01

    In this paper we provide an introduction to the techniques for multi-scale complex biological systems, from the single bio-molecule to the cell, combining theoretical modeling, experiments, informatics tools and technologies suitable for biological and biomedical research, which are becoming increasingly multidisciplinary, multidimensional and information-driven. The most important concepts on mathematical modeling methodologies and statistical inference, bioinformatics and standards tools to investigate complex biomedical systems are discussed and the prominent literature useful to both the practitioner and the theoretician are presented. PMID:19828068

  18. Modelling Canopy Flows over Complex Terrain

    NASA Astrophysics Data System (ADS)

    Grant, Eleanor R.; Ross, Andrew N.; Gardiner, Barry A.

    2016-12-01

    Recent studies of flow over forested hills have been motivated by a number of important applications including understanding CO_2 and other gaseous fluxes over forests in complex terrain, predicting wind damage to trees, and modelling wind energy potential at forested sites. Current modelling studies have focussed almost exclusively on highly idealized, and usually fully forested, hills. Here, we present model results for a site on the Isle of Arran, Scotland with complex terrain and heterogeneous forest canopy. The model uses an explicit representation of the canopy and a 1.5-order turbulence closure for flow within and above the canopy. The validity of the closure scheme is assessed using turbulence data from a field experiment before comparing predictions of the full model with field observations. For near-neutral stability, the results compare well with the observations, showing that such a relatively simple canopy model can accurately reproduce the flow patterns observed over complex terrain and realistic, variable forest cover, while at the same time remaining computationally feasible for real case studies. The model allows closer examination of the flow separation observed over complex forested terrain. Comparisons with model simulations using a roughness length parametrization show significant differences, particularly with respect to flow separation, highlighting the need to explicitly model the forest canopy if detailed predictions of near-surface flow around forests are required.

  19. "Computational Modeling of Actinide Complexes"

    SciTech Connect

    Balasubramanian, K

    2007-03-07

    We will present our recent studies on computational actinide chemistry of complexes which are not only interesting from the standpoint of actinide coordination chemistry but also of relevance to environmental management of high-level nuclear wastes. We will be discussing our recent collaborative efforts with Professor Heino Nitsche of LBNL whose research group has been actively carrying out experimental studies on these species. Computations of actinide complexes are also quintessential to our understanding of the complexes found in geochemical, biochemical environments and actinide chemistry relevant to advanced nuclear systems. In particular we have been studying uranyl, plutonyl, and Cm(III) complexes are in aqueous solution. These studies are made with a variety of relativistic methods such as coupled cluster methods, DFT, and complete active space multi-configuration self-consistent-field (CASSCF) followed by large-scale CI computations and relativistic CI (RCI) computations up to 60 million configurations. Our computational studies on actinide complexes were motivated by ongoing EXAFS studies of speciated complexes in geo and biochemical environments carried out by Prof Heino Nitsche's group at Berkeley, Dr. David Clark at Los Alamos and Dr. Gibson's work on small actinide molecules at ORNL. The hydrolysis reactions of urnayl, neputyl and plutonyl complexes have received considerable attention due to their geochemical and biochemical importance but the results of free energies in solution and the mechanism of deprotonation have been topic of considerable uncertainty. We have computed deprotonating and migration of one water molecule from the first solvation shell to the second shell in UO{sub 2}(H{sub 2}O){sub 5}{sup 2+}, UO{sub 2}(H{sub 2}O){sub 5}{sup 2+}NpO{sub 2}(H{sub 2}O){sub 6}{sup +}, and PuO{sub 2}(H{sub 2}O){sub 5}{sup 2+} complexes. Our computed Gibbs free energy(7.27 kcal/m) in solution for the first time agrees with the experiment (7.1 kcal

  20. Atmospheric modeling in complex terrain

    SciTech Connect

    Williams, M. D.; Streit, G. E.

    1990-05-01

    Los Alamos investigators have developed several models which are relevant to modeling Mexico City air quality. The collection of models includes: meteorological models, dispersion models, air chemistry models, and visibility models. The models have been applied in several different contexts. They have been developed primarily to address the complexities posed by complex terrain. HOTMAC is the meteorological model which requires terrain and limited meteorological information. HOTMAC incorporates a relatively complete description of atmospheric physics to give good descriptions of the wind, temperature, and turbulence fields. RAPTAD is a dispersion code which uses random particle transport and kernel representations to efficiently provide accurate pollutant concentration fields. RAPTAD provides a much better description of tracer dispersion than do Gaussian puff models which fail to properly represent the effects of the wind profile near the surface. ATMOS and LAVM treat photochemistry and visibility respectively. ATMOS has been used to describe wintertime chemistry of the Denver brown cloud. Its description provided reasonable agreement with measurements for the high altitude of Denver. LAVM can provide both numerical indices or pictoral representations of visibility effects of pollutants. 15 refs., 74 figs.

  1. Complex Networks in Psychological Models

    NASA Astrophysics Data System (ADS)

    Wedemann, R. S.; Carvalho, L. S. A. V. D.; Donangelo, R.

    We develop schematic, self-organizing, neural-network models to describe mechanisms associated with mental processes, by a neurocomputational substrate. These models are examples of real world complex networks with interesting general topological structures. Considering dopaminergic signal-to-noise neuronal modulation in the central nervous system, we propose neural network models to explain development of cortical map structure and dynamics of memory access, and unify different mental processes into a single neurocomputational substrate. Based on our neural network models, neurotic behavior may be understood as an associative memory process in the brain, and the linguistic, symbolic associative process involved in psychoanalytic working-through can be mapped onto a corresponding process of reconfiguration of the neural network. The models are illustrated through computer simulations, where we varied dopaminergic modulation and observed the self-organizing emergent patterns at the resulting semantic map, interpreting them as different manifestations of mental functioning, from psychotic through to normal and neurotic behavior, and creativity.

  2. Numerical Modeling Experiments

    DTIC Science & Technology

    1974-09-01

    presence of clouds is associated with the occurvence of condensation in the atmospheric models. Cloudiness 3t a particulat grid point is introduced -4...when saturation is predicted as a result of either large-scale moisture flux convergence or vertical convective adjustment. In most models such clouds ... cloud top, cloud thickness, and liquid-water content. In some general circulation models the local fractional convective cloud amountv tre taken

  3. Diagnosis in Complex Plasmas for Microgravity Experiments (PK-3 plus)

    SciTech Connect

    Takahashi, Kazuo; Hayashi, Yasuaki; Thomas, Hubertus M.; Morfill, Gregor E.; Ivlev, Alexei V.; Adachi, Satoshi

    2008-09-07

    Microgravity gives the complex (dusty) plasmas, where dust particles are embedded in complete charge neutral region of bulk plasma. The dust clouds as an uncompressed strongly coupled Coulomb system correspond to atomic model with several physical phenomena, crystallization, phase transition, and so on. As the phenomena tightly connect to plasma states, it is significant to understand plasma parameters such as electron density and temperature. The present work shows the electron density in the setup for microgravity experiments currently onboard on the International Space Station.

  4. The Hidden Complexities of a "Simple" Experiment.

    ERIC Educational Resources Information Center

    Caplan, Jeremy B.; And Others

    1994-01-01

    Provides two experiments that do not give the expected results. One involves burning a candle in an air-filled beaker under water and the other burns the candle in pure oxygen. Provides methodology, suggestions, and theory. (MVL)

  5. Numerical Experiments In Strongly Coupled Complex (Dusty) Plasmas

    NASA Astrophysics Data System (ADS)

    Hou, L. J.; Ivlev A.; Hubertus M. T.; Morfill, G. E.

    2010-07-01

    Complex (dusty) plasma is a suspension of micron-sized charged dust particles in a weakly ionized plasma with electrons, ions, and neutral atoms or molecules. Therein, dust particles acquire a few thousand electron charges by absorbing surrounding electrons and ions, and consequently interact with each other via a dynamically screened Coulomb potential while undergoing Brownian motion due primarily to frequent collisions with the neutral molecules. When the interaction potential energy between charged dust particles significantly exceeds their kinetic energy, they become strongly coupled and can form ordered structures comprising liquid and solid states. Since the motion of charged dust particles in complex (dusty) plasmas can be directly observed in real time by using a video camera, such systems have been generally regarded as a promising model system to study many phenomena occurring in solids, liquids and other strongly-coupled systems at the kinetic level, such as phase transitions, transport processes, and collective dynamics. Complex plasma physics has now grown into a mature research field with a very broad range of interdisciplinary facets. In addition to usual experimental and theoretical study, computer simulation in complex plasma plays an important role in bridging experimental observations and theories and in understanding many interesting phenomena observed in laboratory. The present talk will focus on a class of computer simulations that are usually non-equilibrium ones with external perturbation and that mimic the real complex plasma experiments (i. e., numerical experiment). The simulation method, i. e., the so-called Brownian Dynamics methods, will be firstly reviewed and then examples, such as simulations of heat transfer and shock wave propagation, will be present.

  6. Tuberous sclerosis complex; single center experience

    PubMed Central

    Erol, İlknur; Savaş, Tülin; Şekerci, Sevda; Yazıcı, Nalan; Erbay, Ayşe; Demir, Şenay; Saygı, Semra; Alkan, Özlem

    2015-01-01

    Aim: This study was planned with the aim of retrospectively reviewing the clinical and laboratory findings and therapies of our patients diagnosed with tuberous sclerosis and redefining the patients according to the diagnostic criteria revised by the 2012 International Tuberous Sclerosis Complex Consensus Group and comparing them with the literature. Materials and Method: Twenty patients diagnosed with tuberous sclerosis complex in the Pediatric Neurology Clinic were examined retrospectively in terms of clinical findings and therapies. The diagnoses were compared again according to 1998 and 2012 criteria. Results: It was observed that the complaint at presentation was seizure in 17 of 20 patients and hypopigmented spots on the skin in 3 of 20 patients. On the initial physical examination, findings related with the disease were found in the skin in 17 of the patients, in the eye in 5, in the kidneys in 7 and in the brain with imaging in 17. No cardiac involvement was observed in the patients. Infantile spasm was observed in 7 of the patients who presented because of seizure (n=17), partial seizure was observed in 7 and multiple seizure types were observed in 3. It was found that sirolimus treatment was given to 9 of 20 patients because of different reasons, 7 of these 9 patients had epileptic seizures and sirolimus treatment had no effect on epileptic seizures. According to 2012 diagnostic criteria, no marked change occured in the diagnoses of our patients. Conclusions: It was observed that the signs and symptoms of our patients were compatible with the literature. Molecular genetic examination was planned for the patients who were being followed up because of probable tuberous sclerosis complex. It was observed that sirolimus treatment had no marked effect on the seizure frequency of our patients. PMID:26078697

  7. Modelling biological complexity: a physical scientist's perspective

    PubMed Central

    Coveney, Peter V; Fowler, Philip W

    2005-01-01

    integration of molecular and more coarse-grained representations of matter. The scope of such integrative approaches to complex systems research is circumscribed by the computational resources available. Computational grids should provide a step jump in the scale of these resources; we describe the tools that RealityGrid, a major UK e-Science project, has developed together with our experience of deploying complex models on nascent grids. We also discuss the prospects for mathematical approaches to reducing the dimensionality of complex networks in the search for universal systems-level properties, illustrating our approach with a description of the origin of life according to the RNA world view. PMID:16849185

  8. Modelling biological complexity: a physical scientist's perspective.

    PubMed

    Coveney, Peter V; Fowler, Philip W

    2005-09-22

    integration of molecular and more coarse-grained representations of matter. The scope of such integrative approaches to complex systems research is circumscribed by the computational resources available. Computational grids should provide a step jump in the scale of these resources; we describe the tools that RealityGrid, a major UK e-Science project, has developed together with our experience of deploying complex models on nascent grids. We also discuss the prospects for mathematical approaches to reducing the dimensionality of complex networks in the search for universal systems-level properties, illustrating our approach with a description of the origin of life according to the RNA world view.

  9. Extracting Models in Single Molecule Experiments

    NASA Astrophysics Data System (ADS)

    Presse, Steve

    2013-03-01

    Single molecule experiments can now monitor the journey of a protein from its assembly near a ribosome to its proteolytic demise. Ideally all single molecule data should be self-explanatory. However data originating from single molecule experiments is particularly challenging to interpret on account of fluctuations and noise at such small scales. Realistically, basic understanding comes from models carefully extracted from the noisy data. Statistical mechanics, and maximum entropy in particular, provide a powerful framework for accomplishing this task in a principled fashion. Here I will discuss our work in extracting conformational memory from single molecule force spectroscopy experiments on large biomolecules. One clear advantage of this method is that we let the data tend towards the correct model, we do not fit the data. I will show that the dynamical model of the single molecule dynamics which emerges from this analysis is often more textured and complex than could otherwise come from fitting the data to a pre-conceived model.

  10. A Practical Philosophy of Complex Climate Modelling

    NASA Technical Reports Server (NTRS)

    Schmidt, Gavin A.; Sherwood, Steven

    2014-01-01

    We give an overview of the practice of developing and using complex climate models, as seen from experiences in a major climate modelling center and through participation in the Coupled Model Intercomparison Project (CMIP).We discuss the construction and calibration of models; their evaluation, especially through use of out-of-sample tests; and their exploitation in multi-model ensembles to identify biases and make predictions. We stress that adequacy or utility of climate models is best assessed via their skill against more naive predictions. The framework we use for making inferences about reality using simulations is naturally Bayesian (in an informal sense), and has many points of contact with more familiar examples of scientific epistemology. While the use of complex simulations in science is a development that changes much in how science is done in practice, we argue that the concepts being applied fit very much into traditional practices of the scientific method, albeit those more often associated with laboratory work.

  11. "Long, Boring, and Tedious": Youths' Experiences with Complex, Religious Texts

    ERIC Educational Resources Information Center

    Rackley, Eric D.; Kwok, Michelle

    2016-01-01

    Growing out of the renewed attention to text complexity in the United States and the large population of youth who are deeply committed to reading scripture, this study explores 16 Latter-day Saint and Methodist youths' experiences with complex, religious texts. The study took place in the Midwestern United States. Data consisted of an academic…

  12. Teacher Modeling Using Complex Informational Texts

    ERIC Educational Resources Information Center

    Fisher, Douglas; Frey, Nancy

    2015-01-01

    Modeling in complex texts requires that teachers analyze the text for factors of qualitative complexity and then design lessons that introduce students to that complexity. In addition, teachers can model the disciplinary nature of content area texts as well as word solving and comprehension strategies. Included is a planning guide for think aloud.

  13. Iron-Sulfur-Carbonyl and -Nitrosyl Complexes: A Laboratory Experiment.

    ERIC Educational Resources Information Center

    Glidewell, Christopher; And Others

    1985-01-01

    Background information, materials needed, procedures used, and typical results obtained, are provided for an experiment on iron-sulfur-carbonyl and -nitrosyl complexes. The experiment involved (1) use of inert atmospheric techniques and thin-layer and flexible-column chromatography and (2) interpretation of infrared, hydrogen and carbon-13 nuclear…

  14. Assessment and Computerized Modeling of the Environmental Deposition of Military Smokes. Characterization of the Atmospheric Boundary Layer in Complex Terrain and Results from the Amadeus Smoke Dispersion Experiments

    DTIC Science & Technology

    1991-12-01

    empirical relation. The appro- 3 priate scaling parameters for this region are w. and h (Smith and Blackall , 1979), and several empirical forms using these...Slope Flows in a tributary Conyon During the 1984 ASCOT Experiment," Journal of Applied Meteorology, 28, 569-577. 168 I I Smith, F. B. and R. M. Blackall

  15. Capturing Complexity through Maturity Modelling

    ERIC Educational Resources Information Center

    Underwood, Jean; Dillon, Gayle

    2004-01-01

    The impact of information and communication technologies (ICT) on the process and products of education is difficult to assess for a number of reasons. In brief, education is a complex system of interrelationships, of checks and balances. This context is not a neutral backdrop on which teaching and learning are played out. Rather, it may help, or…

  16. The Complex Experience of Learning to Do Research

    ERIC Educational Resources Information Center

    Emo, Kenneth; Emo, Wendy; Kimn, Jung-Han; Gent, Stephen

    2015-01-01

    This article examines how student learning is a product of the experiential interaction between person and environment. We draw from the theoretical perspective of complexity to shed light on the emergent, adaptive, and unpredictable nature of students' learning experiences. To understand the relationship between the environment and the student…

  17. School Experiences of an Adolescent with Medical Complexities Involving Incontinence

    ERIC Educational Resources Information Center

    Filce, Hollie Gabler; Bishop, John B.

    2014-01-01

    The educational implications of chronic illnesses which involve incontinence are not well represented in the literature. The experiences of an adolescent with multiple complex illnesses, including incontinence, were explored via an intrinsic case study. Data were gathered from the adolescent, her mother, and teachers through interviews, email…

  18. Facing up to Complexity: Implications for Our Social Experiments.

    PubMed

    Hawkins, Ronnie

    2016-06-01

    Biological systems are highly complex, and for this reason there is a considerable degree of uncertainty as to the consequences of making significant interventions into their workings. Since a number of new technologies are already impinging on living systems, including our bodies, many of us have become participants in large-scale "social experiments". I will discuss biological complexity and its relevance to the technologies that brought us BSE/vCJD and the controversy over GM foods. Then I will consider some of the complexities of our social dynamics, and argue for making a shift from using the precautionary principle to employing the approach of evaluating the introduction of new technologies by conceiving of them as social experiments.

  19. Molecular simulation and modeling of complex I.

    PubMed

    Hummer, Gerhard; Wikström, Mårten

    2016-07-01

    Molecular modeling and molecular dynamics simulations play an important role in the functional characterization of complex I. With its large size and complicated function, linking quinone reduction to proton pumping across a membrane, complex I poses unique modeling challenges. Nonetheless, simulations have already helped in the identification of possible proton transfer pathways. Simulations have also shed light on the coupling between electron and proton transfer, thus pointing the way in the search for the mechanistic principles underlying the proton pump. In addition to reviewing what has already been achieved in complex I modeling, we aim here to identify pressing issues and to provide guidance for future research to harness the power of modeling in the functional characterization of complex I. This article is part of a Special Issue entitled Respiratory complex I, edited by Volker Zickermann and Ulrich Brandt.

  20. Hierarchical Models of the Nearshore Complex System

    DTIC Science & Technology

    2004-01-01

    unclassified unclassified /,andard Form 7 7Qien. -pii Prescrbed by ANS Sid 239-18 zgB -10z Hierarchical Models of the Nearshore Complex System: Final...TITLE AND SUBTITLE S. FUNDING NUMBERS Hierarchical Models of the Nearshore Complex System N00014-02-1-0358 6. AUTHOR(S) Brad Werner 7. PERFORMING...8217 ........... The long-term goal of this reasearch was to develop and test predictive models for nearshore processes. This grant was terminaton funding for the

  1. Reducing Spatial Data Complexity for Classification Models

    NASA Astrophysics Data System (ADS)

    Ruta, Dymitr; Gabrys, Bogdan

    2007-11-01

    Intelligent data analytics gradually becomes a day-to-day reality of today's businesses. However, despite rapidly increasing storage and computational power current state-of-the-art predictive models still can not handle massive and noisy corporate data warehouses. What is more adaptive and real-time operational environment requires multiple models to be frequently retrained which further hinders their use. Various data reduction techniques ranging from data sampling up to density retention models attempt to address this challenge by capturing a summarised data structure, yet they either do not account for labelled data or degrade the classification performance of the model trained on the condensed dataset. Our response is a proposition of a new general framework for reducing the complexity of labelled data by means of controlled spatial redistribution of class densities in the input space. On the example of Parzen Labelled Data Compressor (PLDC) we demonstrate a simulatory data condensation process directly inspired by the electrostatic field interaction where the data are moved and merged following the attracting and repelling interactions with the other labelled data. The process is controlled by the class density function built on the original data that acts as a class-sensitive potential field ensuring preservation of the original class density distributions, yet allowing data to rearrange and merge joining together their soft class partitions. As a result we achieved a model that reduces the labelled datasets much further than any competitive approaches yet with the maximum retention of the original class densities and hence the classification performance. PLDC leaves the reduced dataset with the soft accumulative class weights allowing for efficient online updates and as shown in a series of experiments if coupled with Parzen Density Classifier (PDC) significantly outperforms competitive data condensation methods in terms of classification performance at the

  2. Reducing Spatial Data Complexity for Classification Models

    SciTech Connect

    Ruta, Dymitr; Gabrys, Bogdan

    2007-11-29

    Intelligent data analytics gradually becomes a day-to-day reality of today's businesses. However, despite rapidly increasing storage and computational power current state-of-the-art predictive models still can not handle massive and noisy corporate data warehouses. What is more adaptive and real-time operational environment requires multiple models to be frequently retrained which further hinders their use. Various data reduction techniques ranging from data sampling up to density retention models attempt to address this challenge by capturing a summarised data structure, yet they either do not account for labelled data or degrade the classification performance of the model trained on the condensed dataset. Our response is a proposition of a new general framework for reducing the complexity of labelled data by means of controlled spatial redistribution of class densities in the input space. On the example of Parzen Labelled Data Compressor (PLDC) we demonstrate a simulatory data condensation process directly inspired by the electrostatic field interaction where the data are moved and merged following the attracting and repelling interactions with the other labelled data. The process is controlled by the class density function built on the original data that acts as a class-sensitive potential field ensuring preservation of the original class density distributions, yet allowing data to rearrange and merge joining together their soft class partitions. As a result we achieved a model that reduces the labelled datasets much further than any competitive approaches yet with the maximum retention of the original class densities and hence the classification performance. PLDC leaves the reduced dataset with the soft accumulative class weights allowing for efficient online updates and as shown in a series of experiments if coupled with Parzen Density Classifier (PDC) significantly outperforms competitive data condensation methods in terms of classification performance at the

  3. Scaffolding in Complex Modelling Situations

    ERIC Educational Resources Information Center

    Stender, Peter; Kaiser, Gabriele

    2015-01-01

    The implementation of teacher-independent realistic modelling processes is an ambitious educational activity with many unsolved problems so far. Amongst others, there hardly exists any empirical knowledge about efficient ways of possible teacher support with students' activities, which should be mainly independent from the teacher. The research…

  4. Emulator-assisted data assimilation in complex models

    NASA Astrophysics Data System (ADS)

    Margvelashvili, Nugzar Yu; Herzfeld, Mike; Rizwi, Farhan; Mongin, Mathieu; Baird, Mark E.; Jones, Emlyn; Schaffelke, Britta; King, Edward; Schroeder, Thomas

    2016-09-01

    Emulators are surrogates of complex models that run orders of magnitude faster than the original model. The utility of emulators for the data assimilation into ocean models is still not well understood. High complexity of ocean models translates into high uncertainty of the corresponding emulators which may undermine the quality of the assimilation schemes based on such emulators. Numerical experiments with a chaotic Lorenz-95 model are conducted to illustrate this point and suggest a strategy to alleviate this problem through the localization of the emulation and data assimilation procedures. Insights gained through these experiments are used to design and implement data assimilation scenario for a 3D fine-resolution sediment transport model of the Great Barrier Reef (GBR), Australia.

  5. Complex Parameter Landscape for a Complex Neuron Model

    PubMed Central

    Achard, Pablo; De Schutter, Erik

    2006-01-01

    The electrical activity of a neuron is strongly dependent on the ionic channels present in its membrane. Modifying the maximal conductances from these channels can have a dramatic impact on neuron behavior. But the effect of such modifications can also be cancelled out by compensatory mechanisms among different channels. We used an evolution strategy with a fitness function based on phase-plane analysis to obtain 20 very different computational models of the cerebellar Purkinje cell. All these models produced very similar outputs to current injections, including tiny details of the complex firing pattern. These models were not completely isolated in the parameter space, but neither did they belong to a large continuum of good models that would exist if weak compensations between channels were sufficient. The parameter landscape of good models can best be described as a set of loosely connected hyperplanes. Our method is efficient in finding good models in this complex landscape. Unraveling the landscape is an important step towards the understanding of functional homeostasis of neurons. PMID:16848639

  6. Role models for complex networks

    NASA Astrophysics Data System (ADS)

    Reichardt, J.; White, D. R.

    2007-11-01

    We present a framework for automatically decomposing (“block-modeling”) the functional classes of agents within a complex network. These classes are represented by the nodes of an image graph (“block model”) depicting the main patterns of connectivity and thus functional roles in the network. Using a first principles approach, we derive a measure for the fit of a network to any given image graph allowing objective hypothesis testing. From the properties of an optimal fit, we derive how to find the best fitting image graph directly from the network and present a criterion to avoid overfitting. The method can handle both two-mode and one-mode data, directed and undirected as well as weighted networks and allows for different types of links to be dealt with simultaneously. It is non-parametric and computationally efficient. The concepts of structural equivalence and modularity are found as special cases of our approach. We apply our method to the world trade network and analyze the roles individual countries play in the global economy.

  7. Agent-based modeling of complex infrastructures

    SciTech Connect

    North, M. J.

    2001-06-01

    Complex Adaptive Systems (CAS) can be applied to investigate complex infrastructures and infrastructure interdependencies. The CAS model agents within the Spot Market Agent Research Tool (SMART) and Flexible Agent Simulation Toolkit (FAST) allow investigation of the electric power infrastructure, the natural gas infrastructure and their interdependencies.

  8. Modeling the complex bromate-iodine reaction.

    PubMed

    Machado, Priscilla B; Faria, Roberto B

    2009-05-07

    In this article, it is shown that the FLEK model (ref 5 ) is able to model the experimental results of the bromate-iodine clock reaction. Five different complex chemical systems, the bromate-iodide clock and oscillating reactions, the bromite-iodide clock and oscillating reactions, and now the bromate-iodine clock reaction are adequately accounted for by the FLEK model.

  9. Numerical models of complex diapirs

    NASA Astrophysics Data System (ADS)

    Podladchikov, Yu.; Talbot, C.; Poliakov, A. N. B.

    1993-12-01

    Numerically modelled diapirs that rise into overburdens with viscous rheology produce a large variety of shapes. This work uses the finite-element method to study the development of diapirs that rise towards a surface on which a diapir-induced topography creeps flat or disperses ("erodes") at different rates. Slow erosion leads to diapirs with "mushroom" shapes, moderate erosion rate to "wine glass" diapirs and fast erosion to "beer glass"- and "column"-shaped diapirs. The introduction of a low-viscosity layer at the top of the overburden causes diapirs to develop into structures resembling a "Napoleon hat". These spread lateral sheets.

  10. Slip complexity in earthquake fault models.

    PubMed

    Rice, J R; Ben-Zion, Y

    1996-04-30

    We summarize studies of earthquake fault models that give rise to slip complexities like those in natural earthquakes. For models of smooth faults between elastically deformable continua, it is critical that the friction laws involve a characteristic distance for slip weakening or evolution of surface state. That results in a finite nucleation size, or coherent slip patch size, h*. Models of smooth faults, using numerical cell size properly small compared to h*, show periodic response or complex and apparently chaotic histories of large events but have not been found to show small event complexity like the self-similar (power law) Gutenberg-Richter frequency-size statistics. This conclusion is supported in the present paper by fully inertial elastodynamic modeling of earthquake sequences. In contrast, some models of locally heterogeneous faults with quasi-independent fault segments, represented approximately by simulations with cell size larger than h* so that the model becomes "inherently discrete," do show small event complexity of the Gutenberg-Richter type. Models based on classical friction laws without a weakening length scale or for which the numerical procedure imposes an abrupt strength drop at the onset of slip have h* = 0 and hence always fall into the inherently discrete class. We suggest that the small-event complexity that some such models show will not survive regularization of the constitutive description, by inclusion of an appropriate length scale leading to a finite h*, and a corresponding reduction of numerical grid size.

  11. Governance of complex systems: results of a sociological simulation experiment.

    PubMed

    Adelt, Fabian; Weyer, Johannes; Fink, Robin D

    2014-01-01

    Social sciences have discussed the governance of complex systems for a long time. The following paper tackles the issue by means of experimental sociology, in order to investigate the performance of different modes of governance empirically. The simulation framework developed is based on Esser's model of sociological explanation as well as on Kroneberg's model of frame selection. The performance of governance has been measured by means of three macro and two micro indicators. Surprisingly, central control mostly performs better than decentralised coordination. However, results not only depend on the mode of governance, but there is also a relation between performance and the composition of actor populations, which has yet not been investigated sufficiently. Practitioner Summary: Practitioners can gain insights into the functioning of complex systems and learn how to better manage them. Additionally, they are provided with indicators to measure the performance of complex systems.

  12. Preferential urn model and nongrowing complex networks.

    PubMed

    Ohkubo, Jun; Yasuda, Muneki; Tanaka, Kazuyuki

    2005-12-01

    A preferential urn model, which is based on the concept "the rich get richer," is proposed. From a relationship between a nongrowing model for complex networks and the preferential urn model in regard to degree distributions, it is revealed that a fitness parameter in the nongrowing model is interpreted as an inverse local temperature in the preferential urn model. Furthermore, it is clarified that the preferential urn model with randomness generates a fat-tailed occupation distribution; the concept of the local temperature enables us to understand the fat-tailed occupation distribution intuitively. Since the preferential urn model is a simple stochastic model, it can be applied to research on not only the nongrowing complex networks, but also many other fields such as econophysics and social sciences.

  13. Combustion, Complex Fluids, and Fluid Physics Experiments on the ISS

    NASA Technical Reports Server (NTRS)

    Motil, Brian; Urban, David

    2012-01-01

    multiphase flows, capillary phenomena, and heat pipes. Finally in complex fluids, experiments in rheology and soft condensed materials will be presented.

  14. Combustion, Complex Fluids, and Fluid Physics Experiments on the ISS

    NASA Technical Reports Server (NTRS)

    Motil, Brian; Urban, David

    2012-01-01

    From the very early days of human spaceflight, NASA has been conducting experiments in space to understand the effect of weightlessness on physical and chemically reacting systems. NASA Glenn Research Center (GRC) in Cleveland, Ohio has been at the forefront of this research looking at both fundamental studies in microgravity as well as experiments targeted at reducing the risks to long duration human missions to the moon, Mars, and beyond. In the current International Space Station (ISS) era, we now have an orbiting laboratory that provides the highly desired condition of long-duration microgravity. This allows continuous and interactive research similar to Earth-based laboratories. Because of these capabilities, the ISS is an indispensible laboratory for low gravity research. NASA GRC has been actively involved in developing and operating facilities and experiments on the ISS since the beginning of a permanent human presence on November 2, 2000. As the lead Center for combustion, complex fluids, and fluid physics; GRC has led the successful implementation of the Combustion Integrated Rack (CIR) and the Fluids Integrated Rack (FIR) as well as the continued use of other facilities on the ISS. These facilities have supported combustion experiments in fundamental droplet combustion; fire detection; fire extinguishment; soot phenomena; flame liftoff and stability; and material flammability. The fluids experiments have studied capillary flow; magneto-rheological fluids; colloidal systems; extensional rheology; pool and nucleate boiling phenomena. In this paper, we provide an overview of the experiments conducted on the ISS over the past 12 years.

  15. Complex system modelling for veterinary epidemiology.

    PubMed

    Lanzas, Cristina; Chen, Shi

    2015-02-01

    The use of mathematical models has a long tradition in infectious disease epidemiology. The nonlinear dynamics and complexity of pathogen transmission pose challenges in understanding its key determinants, in identifying critical points, and designing effective mitigation strategies. Mathematical modelling provides tools to explicitly represent the variability, interconnectedness, and complexity of systems, and has contributed to numerous insights and theoretical advances in disease transmission, as well as to changes in public policy, health practice, and management. In recent years, our modelling toolbox has considerably expanded due to the advancements in computing power and the need to model novel data generated by technologies such as proximity loggers and global positioning systems. In this review, we discuss the principles, advantages, and challenges associated with the most recent modelling approaches used in systems science, the interdisciplinary study of complex systems, including agent-based, network and compartmental modelling. Agent-based modelling is a powerful simulation technique that considers the individual behaviours of system components by defining a set of rules that govern how individuals ("agents") within given populations interact with one another and the environment. Agent-based models have become a recent popular choice in epidemiology to model hierarchical systems and address complex spatio-temporal dynamics because of their ability to integrate multiple scales and datasets.

  16. Discrete Element Modeling of Complex Granular Flows

    NASA Astrophysics Data System (ADS)

    Movshovitz, N.; Asphaug, E. I.

    2010-12-01

    Granular materials occur almost everywhere in nature, and are actively studied in many fields of research, from food industry to planetary science. One approach to the study of granular media, the continuum approach, attempts to find a constitutive law that determines the material's flow, or strain, under applied stress. The main difficulty with this approach is that granular systems exhibit different behavior under different conditions, behaving at times as an elastic solid (e.g. pile of sand), at times as a viscous fluid (e.g. when poured), or even as a gas (e.g. when shaken). Even if all these physics are accounted for, numerical implementation is made difficult by the wide and often discontinuous ranges in continuum density and sound speed. A different approach is Discrete Element Modeling (DEM). Here the goal is to directly model every grain in the system as a rigid body subject to various body and surface forces. The advantage of this method is that it treats all of the above regimes in the same way, and can easily deal with a system moving back and forth between regimes. But as a granular system typically contains a multitude of individual grains, the direct integration of the system can be very computationally expensive. For this reason most DEM codes are limited to spherical grains of uniform size. However, spherical grains often cannot replicate the behavior of real world granular systems. A simple pile of spherical grains, for example, relies on static friction alone to keep its shape, while in reality a pile of irregular grains can maintain a much steeper angle by interlocking force chains. In the present study we employ a commercial DEM, nVidia's PhysX Engine, originally designed for the game and animation industry, to simulate complex granular flows with irregular, non-spherical grains. This engine runs as a multi threaded process and can be GPU accelerated. We demonstrate the code's ability to physically model granular materials in the three regimes

  17. Model validation for karst flow using sandbox experiments

    NASA Astrophysics Data System (ADS)

    Ye, M.; Pacheco Castro, R. B.; Tao, X.; Zhao, J.

    2015-12-01

    The study of flow in karst is complex due of the high heterogeneity of the porous media. Several approaches have been proposed in the literature to study overcome the natural complexity of karst. Some of those methods are the single continuum, double continuum and the discrete network of conduits coupled with the single continuum. Several mathematical and computing models are available in the literature for each approach. In this study one computer model has been selected for each category to validate its usefulness to model flow in karst using a sandbox experiment. The models chosen are: Modflow 2005, Modflow CFPV1 and Modflow CFPV2. A sandbox experiment was implemented in such way that all the parameters required for each model can be measured. The sandbox experiment was repeated several times under different conditions. The model validation will be carried out by comparing the results of the model simulation and the real data. This model validation will allows ud to compare the accuracy of each model and the applicability in Karst. Also we will be able to evaluate if the results of the complex models improve a lot compared to the simple models specially because some models require complex parameters that are difficult to measure in the real world.

  18. From Complex to Simple: Interdisciplinary Stochastic Models

    ERIC Educational Resources Information Center

    Mazilu, D. A.; Zamora, G.; Mazilu, I.

    2012-01-01

    We present two simple, one-dimensional, stochastic models that lead to a qualitative understanding of very complex systems from biology, nanoscience and social sciences. The first model explains the complicated dynamics of microtubules, stochastic cellular highways. Using the theory of random walks in one dimension, we find analytical expressions…

  19. Modeling the chemistry of complex petroleum mixtures.

    PubMed

    Quann, R J

    1998-12-01

    Determining the complete molecular composition of petroleum and its refined products is not feasible with current analytical techniques because of the astronomical number of molecular components. Modeling the composition and behavior of such complex mixtures in refinery processes has accordingly evolved along a simplifying concept called lumping. Lumping reduces the complexity of the problem to a manageable form by grouping the entire set of molecular components into a handful of lumps. This traditional approach does not have a molecular basis and therefore excludes important aspects of process chemistry and molecular property fundamentals from the model's formulation. A new approach called structure-oriented lumping has been developed to model the composition and chemistry of complex mixtures at a molecular level. The central concept is to represent an individual molecular or a set of closely related isomers as a mathematical construct of certain specific and repeating structural groups. A complex mixture such as petroleum can then be represented as thousands of distinct molecular components, each having a mathematical identity. This enables the automated construction of large complex reaction networks with tens of thousands of specific reactions for simulating the chemistry of complex mixtures. Further, the method provides a convenient framework for incorporating molecular physical property correlations, existing group contribution methods, molecular thermodynamic properties, and the structure--activity relationships of chemical kinetics in the development of models.

  20. Modeling the chemistry of complex petroleum mixtures.

    PubMed Central

    Quann, R J

    1998-01-01

    Determining the complete molecular composition of petroleum and its refined products is not feasible with current analytical techniques because of the astronomical number of molecular components. Modeling the composition and behavior of such complex mixtures in refinery processes has accordingly evolved along a simplifying concept called lumping. Lumping reduces the complexity of the problem to a manageable form by grouping the entire set of molecular components into a handful of lumps. This traditional approach does not have a molecular basis and therefore excludes important aspects of process chemistry and molecular property fundamentals from the model's formulation. A new approach called structure-oriented lumping has been developed to model the composition and chemistry of complex mixtures at a molecular level. The central concept is to represent an individual molecular or a set of closely related isomers as a mathematical construct of certain specific and repeating structural groups. A complex mixture such as petroleum can then be represented as thousands of distinct molecular components, each having a mathematical identity. This enables the automated construction of large complex reaction networks with tens of thousands of specific reactions for simulating the chemistry of complex mixtures. Further, the method provides a convenient framework for incorporating molecular physical property correlations, existing group contribution methods, molecular thermodynamic properties, and the structure--activity relationships of chemical kinetics in the development of models. PMID:9860903

  1. Coherent operation of detector systems and their readout electronics in a complex experiment control environment

    NASA Astrophysics Data System (ADS)

    Koestner, Stefan

    2009-09-01

    With the increasing size and degree of complexity of today's experiments in high energy physics the required amount of work and complexity to integrate a complete subdetector into an experiment control system is often underestimated. We report here on the layered software structure and protocols used by the LHCb experiment to control its detectors and readout boards. The experiment control system of LHCb is based on the commercial SCADA system PVSS II. Readout boards which are outside the radiation area are accessed via embedded credit card sized PCs which are connected to a large local area network. The SPECS protocol is used for control of the front end electronics. Finite state machines are introduced to facilitate the control of a large number of electronic devices and to model the whole experiment at the level of an expert system.

  2. Updating the debate on model complexity

    USGS Publications Warehouse

    Simmons, Craig T.; Hunt, Randall J.

    2012-01-01

    As scientists who are trying to understand a complex natural world that cannot be fully characterized in the field, how can we best inform the society in which we live? This founding context was addressed in a special session, “Complexity in Modeling: How Much is Too Much?” convened at the 2011 Geological Society of America Annual Meeting. The session had a variety of thought-provoking presentations—ranging from philosophy to cost-benefit analyses—and provided some areas of broad agreement that were not evident in discussions of the topic in 1998 (Hunt and Zheng, 1999). The session began with a short introduction during which model complexity was framed borrowing from an economic concept, the Law of Diminishing Returns, and an example of enjoyment derived by eating ice cream. Initially, there is increasing satisfaction gained from eating more ice cream, to a point where the gain in satisfaction starts to decrease, ending at a point when the eater sees no value in eating more ice cream. A traditional view of model complexity is similar—understanding gained from modeling can actually decrease if models become unnecessarily complex. However, oversimplified models—those that omit important aspects of the problem needed to make a good prediction—can also limit and confound our understanding. Thus, the goal of all modeling is to find the “sweet spot” of model sophistication—regardless of whether complexity was added sequentially to an overly simple model or collapsed from an initial highly parameterized framework that uses mathematics and statistics to attain an optimum (e.g., Hunt et al., 2007). Thus, holistic parsimony is attained, incorporating “as simple as possible,” as well as the equally important corollary “but no simpler.”

  3. Multifaceted Modelling of Complex Business Enterprises.

    PubMed

    Chakraborty, Subrata; Mengersen, Kerrie; Fidge, Colin; Ma, Lin; Lassen, David

    2015-01-01

    We formalise and present a new generic multifaceted complex system approach for modelling complex business enterprises. Our method has a strong focus on integrating the various data types available in an enterprise which represent the diverse perspectives of various stakeholders. We explain the challenges faced and define a novel approach to converting diverse data types into usable Bayesian probability forms. The data types that can be integrated include historic data, survey data, and management planning data, expert knowledge and incomplete data. The structural complexities of the complex system modelling process, based on various decision contexts, are also explained along with a solution. This new application of complex system models as a management tool for decision making is demonstrated using a railway transport case study. The case study demonstrates how the new approach can be utilised to develop a customised decision support model for a specific enterprise. Various decision scenarios are also provided to illustrate the versatility of the decision model at different phases of enterprise operations such as planning and control.

  4. Multifaceted Modelling of Complex Business Enterprises

    PubMed Central

    2015-01-01

    We formalise and present a new generic multifaceted complex system approach for modelling complex business enterprises. Our method has a strong focus on integrating the various data types available in an enterprise which represent the diverse perspectives of various stakeholders. We explain the challenges faced and define a novel approach to converting diverse data types into usable Bayesian probability forms. The data types that can be integrated include historic data, survey data, and management planning data, expert knowledge and incomplete data. The structural complexities of the complex system modelling process, based on various decision contexts, are also explained along with a solution. This new application of complex system models as a management tool for decision making is demonstrated using a railway transport case study. The case study demonstrates how the new approach can be utilised to develop a customised decision support model for a specific enterprise. Various decision scenarios are also provided to illustrate the versatility of the decision model at different phases of enterprise operations such as planning and control. PMID:26247591

  5. Complex quantum network model of energy transfer in photosynthetic complexes.

    PubMed

    Ai, Bao-Quan; Zhu, Shi-Liang

    2012-12-01

    The quantum network model with real variables is usually used to describe the excitation energy transfer (EET) in the Fenna-Matthews-Olson (FMO) complexes. In this paper we add the quantum phase factors to the hopping terms and find that the quantum phase factors play an important role in the EET. The quantum phase factors allow us to consider the space structure of the pigments. It is found that phase coherence within the complexes would allow quantum interference to affect the dynamics of the EET. There exist some optimal phase regions where the transfer efficiency takes its maxima, which indicates that when the pigments are optimally spaced, the exciton can pass through the FMO with perfect efficiency. Moreover, the optimal phase regions almost do not change with the environments. In addition, we find that the phase factors are useful in the EET just in the case of multiple pathways. Therefore, we demonstrate that the quantum phases may bring the other two factors, the optimal space of the pigments and multiple pathways, together to contribute the EET in photosynthetic complexes with perfect efficiency.

  6. Slip complexity in earthquake fault models.

    PubMed Central

    Rice, J R; Ben-Zion, Y

    1996-01-01

    We summarize studies of earthquake fault models that give rise to slip complexities like those in natural earthquakes. For models of smooth faults between elastically deformable continua, it is critical that the friction laws involve a characteristic distance for slip weakening or evolution of surface state. That results in a finite nucleation size, or coherent slip patch size, h*. Models of smooth faults, using numerical cell size properly small compared to h*, show periodic response or complex and apparently chaotic histories of large events but have not been found to show small event complexity like the self-similar (power law) Gutenberg-Richter frequency-size statistics. This conclusion is supported in the present paper by fully inertial elastodynamic modeling of earthquake sequences. In contrast, some models of locally heterogeneous faults with quasi-independent fault segments, represented approximately by simulations with cell size larger than h* so that the model becomes "inherently discrete," do show small event complexity of the Gutenberg-Richter type. Models based on classical friction laws without a weakening length scale or for which the numerical procedure imposes an abrupt strength drop at the onset of slip have h* = 0 and hence always fall into the inherently discrete class. We suggest that the small-event complexity that some such models show will not survive regularization of the constitutive description, by inclusion of an appropriate length scale leading to a finite h*, and a corresponding reduction of numerical grid size. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:11607669

  7. Minimum-complexity helicopter simulation math model

    NASA Technical Reports Server (NTRS)

    Heffley, Robert K.; Mnich, Marc A.

    1988-01-01

    An example of a minimal complexity simulation helicopter math model is presented. Motivating factors are the computational delays, cost, and inflexibility of the very sophisticated math models now in common use. A helicopter model form is given which addresses each of these factors and provides better engineering understanding of the specific handling qualities features which are apparent to the simulator pilot. The technical approach begins with specification of features which are to be modeled, followed by a build up of individual vehicle components and definition of equations. Model matching and estimation procedures are given which enable the modeling of specific helicopters from basic data sources such as flight manuals. Checkout procedures are given which provide for total model validation. A number of possible model extensions and refinement are discussed. Math model computer programs are defined and listed.

  8. The Kuramoto model in complex networks

    NASA Astrophysics Data System (ADS)

    Rodrigues, Francisco A.; Peron, Thomas K. DM.; Ji, Peng; Kurths, Jürgen

    2016-01-01

    Synchronization of an ensemble of oscillators is an emergent phenomenon present in several complex systems, ranging from social and physical to biological and technological systems. The most successful approach to describe how coherent behavior emerges in these complex systems is given by the paradigmatic Kuramoto model. This model has been traditionally studied in complete graphs. However, besides being intrinsically dynamical, complex systems present very heterogeneous structure, which can be represented as complex networks. This report is dedicated to review main contributions in the field of synchronization in networks of Kuramoto oscillators. In particular, we provide an overview of the impact of network patterns on the local and global dynamics of coupled phase oscillators. We cover many relevant topics, which encompass a description of the most used analytical approaches and the analysis of several numerical results. Furthermore, we discuss recent developments on variations of the Kuramoto model in networks, including the presence of noise and inertia. The rich potential for applications is discussed for special fields in engineering, neuroscience, physics and Earth science. Finally, we conclude by discussing problems that remain open after the last decade of intensive research on the Kuramoto model and point out some promising directions for future research.

  9. Modeling of Protein Binary Complexes Using Structural Mass Spectrometry Data

    SciTech Connect

    Amisha Kamal,J.; Chance, M.

    2008-01-01

    In this article, we describe a general approach to modeling the structure of binary protein complexes using structural mass spectrometry data combined with molecular docking. In the first step, hydroxyl radical mediated oxidative protein footprinting is used to identify residues that experience conformational reorganization due to binding or participate in the binding interface. In the second step, a three-dimensional atomic structure of the complex is derived by computational modeling. Homology modeling approaches are used to define the structures of the individual proteins if footprinting detects significant conformational reorganization as a function of complex formation. A three-dimensional model of the complex is constructed from these binary partners using the ClusPro program, which is composed of docking, energy filtering, and clustering steps. Footprinting data are used to incorporate constraints--positive and/or negative--in the docking step and are also used to decide the type of energy filter--electrostatics or desolvation--in the successive energy-filtering step. By using this approach, we examine the structure of a number of binary complexes of monomeric actin and compare the results to crystallographic data. Based on docking alone, a number of competing models with widely varying structures are observed, one of which is likely to agree with crystallographic data. When the docking steps are guided by footprinting data, accurate models emerge as top scoring. We demonstrate this method with the actin/gelsolin segment-1 complex. We also provide a structural model for the actin/cofilin complex using this approach which does not have a crystal or NMR structure.

  10. Experiment Design for Complex VTOL Aircraft with Distributed Propulsion and Tilt Wing

    NASA Technical Reports Server (NTRS)

    Murphy, Patrick C.; Landman, Drew

    2015-01-01

    Selected experimental results from a wind tunnel study of a subscale VTOL concept with distributed propulsion and tilt lifting surfaces are presented. The vehicle complexity and automated test facility were ideal for use with a randomized designed experiment. Design of Experiments and Response Surface Methods were invoked to produce run efficient, statistically rigorous regression models with minimized prediction error. Static tests were conducted at the NASA Langley 12-Foot Low-Speed Tunnel to model all six aerodynamic coefficients over a large flight envelope. This work supports investigations at NASA Langley in developing advanced configurations, simulations, and advanced control systems.

  11. Comparing flood loss models of different complexity

    NASA Astrophysics Data System (ADS)

    Schröter, Kai; Kreibich, Heidi; Vogel, Kristin; Riggelsen, Carsten; Scherbaum, Frank; Merz, Bruno

    2013-04-01

    Any deliberation on flood risk requires the consideration of potential flood losses. In particular, reliable flood loss models are needed to evaluate cost-effectiveness of mitigation measures, to assess vulnerability, for comparative risk analysis and financial appraisal during and after floods. In recent years, considerable improvements have been made both concerning the data basis and the methodological approaches used for the development of flood loss models. Despite of that, flood loss models remain an important source of uncertainty. Likewise the temporal and spatial transferability of flood loss models is still limited. This contribution investigates the predictive capability of different flood loss models in a split sample cross regional validation approach. For this purpose, flood loss models of different complexity, i.e. based on different numbers of explaining variables, are learned from a set of damage records that was obtained from a survey after the Elbe flood in 2002. The validation of model predictions is carried out for different flood events in the Elbe and Danube river basins in 2002, 2005 and 2006 for which damage records are available from surveys after the flood events. The models investigated are a stage-damage model, the rule based model FLEMOps+r as well as novel model approaches which are derived using data mining techniques of regression trees and Bayesian networks. The Bayesian network approach to flood loss modelling provides attractive additional information concerning the probability distribution of both model predictions and explaining variables.

  12. Modeling Electromagnetic Scattering From Complex Inhomogeneous Objects

    NASA Technical Reports Server (NTRS)

    Deshpande, Manohar; Reddy, C. J.

    2011-01-01

    This software innovation is designed to develop a mathematical formulation to estimate the electromagnetic scattering characteristics of complex, inhomogeneous objects using the finite-element-method (FEM) and method-of-moments (MoM) concepts, as well as to develop a FORTRAN code called FEMOM3DS (Finite Element Method and Method of Moments for 3-Dimensional Scattering), which will implement the steps that are described in the mathematical formulation. Very complex objects can be easily modeled, and the operator of the code is not required to know the details of electromagnetic theory to study electromagnetic scattering.

  13. Flowgraph Models for Complex Multistate System Reliabiliy.

    SciTech Connect

    Williams, B. J.; Huzurbazar, A. V.

    2005-01-01

    This chapter reviews flowgraph models for complex multistate systems. The focus is on modeling data from semi-Markov processes and constructing likelihoods when different portions of the system data are censored and incomplete. Semi-Markov models play an important role in the analysis of time to event data. However, in practice, data analysis for semi-Markov processes can be quite difficult and many simplifying assumptions are made. Flowgraph models are multistate models that provide a data analytic method for semi-Markov processes. Flowgraphs are useful for estimating Bayes predictive densities, predictive reliability functions, and predictive hazard functions for waiting times of interest in the presence of censored and incomplete data. This chapter reviews data analysis for flowgraph models and then presents methods for constructing likelihoods when portions of the system data are missing.

  14. Complexity.

    PubMed

    Gómez-Hernández, J Jaime

    2006-01-01

    It is difficult to define complexity in modeling. Complexity is often associated with uncertainty since modeling uncertainty is an intrinsically difficult task. However, modeling uncertainty does not require, necessarily, complex models, in the sense of a model requiring an unmanageable number of degrees of freedom to characterize the aquifer. The relationship between complexity, uncertainty, heterogeneity, and stochastic modeling is not simple. Aquifer models should be able to quantify the uncertainty of their predictions, which can be done using stochastic models that produce heterogeneous realizations of aquifer parameters. This is the type of complexity addressed in this article.

  15. Experiments on a Model Eye

    ERIC Educational Resources Information Center

    Arell, Antti; Kolari, Samuli

    1978-01-01

    Explains a laboratory experiment dealing with the optical features of the human eye. Shows how to measure the magnification of the retina and the refractive anomaly of the eye could be used to measure the refractive power of the observer's eye. (GA)

  16. Human driven transitions in complex model ecosystems

    NASA Astrophysics Data System (ADS)

    Harfoot, Mike; Newbold, Tim; Tittinsor, Derek; Purves, Drew

    2015-04-01

    Human activities have been observed to be impacting ecosystems across the globe, leading to reduced ecosystem functioning, altered trophic and biomass structure and ultimately ecosystem collapse. Previous attempts to understand global human impacts on ecosystems have usually relied on statistical models, which do not explicitly model the processes underlying the functioning of ecosystems, represent only a small proportion of organisms and do not adequately capture complex non-linear and dynamic responses of ecosystems to perturbations. We use a mechanistic ecosystem model (1), which simulates the underlying processes structuring ecosystems and can thus capture complex and dynamic interactions, to investigate boundaries of complex ecosystems to human perturbation. We explore several drivers including human appropriation of net primary production and harvesting of animal biomass. We also present an analysis of the key interactions between biotic, societal and abiotic earth system components, considering why and how we might think about these couplings. References: M. B. J. Harfoot et al., Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model., PLoS Biol. 12, e1001841 (2014).

  17. BDI-modelling of complex intracellular dynamics.

    PubMed

    Jonker, C M; Snoep, J L; Treur, J; Westerhoff, H V; Wijngaards, W C A

    2008-03-07

    A BDI-based continuous-time modelling approach for intracellular dynamics is presented. It is shown how temporalized BDI-models make it possible to model intracellular biochemical processes as decision processes. By abstracting from some of the details of the biochemical pathways, the model achieves understanding in nearly intuitive terms, without losing veracity: classical intentional state properties such as beliefs, desires and intentions are founded in reality through precise biochemical relations. In an extensive example, the complex regulation of Escherichia coli vis-à-vis lactose, glucose and oxygen is simulated as a discrete-state, continuous-time temporal decision manager. Thus a bridge is introduced between two different scientific areas: the area of BDI-modelling and the area of intracellular dynamics.

  18. Intrinsic Uncertainties in Modeling Complex Systems.

    SciTech Connect

    Cooper, Curtis S; Bramson, Aaron L.; Ames, Arlo L.

    2014-09-01

    Models are built to understand and predict the behaviors of both natural and artificial systems. Because it is always necessary to abstract away aspects of any non-trivial system being modeled, we know models can potentially leave out important, even critical elements. This reality of the modeling enterprise forces us to consider the prospective impacts of those effects completely left out of a model - either intentionally or unconsidered. Insensitivity to new structure is an indication of diminishing returns. In this work, we represent a hypothetical unknown effect on a validated model as a finite perturba- tion whose amplitude is constrained within a control region. We find robustly that without further constraints, no meaningful bounds can be placed on the amplitude of a perturbation outside of the control region. Thus, forecasting into unsampled regions is a very risky proposition. We also present inherent difficulties with proper time discretization of models and representing in- herently discrete quantities. We point out potentially worrisome uncertainties, arising from math- ematical formulation alone, which modelers can inadvertently introduce into models of complex systems. Acknowledgements This work has been funded under early-career LDRD project #170979, entitled "Quantify- ing Confidence in Complex Systems Models Having Structural Uncertainties", which ran from 04/2013 to 09/2014. We wish to express our gratitude to the many researchers at Sandia who con- tributed ideas to this work, as well as feedback on the manuscript. In particular, we would like to mention George Barr, Alexander Outkin, Walt Beyeler, Eric Vugrin, and Laura Swiler for provid- ing invaluable advice and guidance through the course of the project. We would also like to thank Steven Kleban, Amanda Gonzales, Trevor Manzanares, and Sarah Burwell for their assistance in managing project tasks and resources.

  19. Different Epidemic Models on Complex Networks

    NASA Astrophysics Data System (ADS)

    Zhang, Hai-Feng; Small, Michael; Fu, Xin-Chu

    2009-07-01

    Models for diseases spreading are not just limited to SIS or SIR. For instance, for the spreading of AIDS/HIV, the susceptible individuals can be classified into different cases according to their immunity, and similarly, the infected individuals can be sorted into different classes according to their infectivity. Moreover, some diseases may develop through several stages. Many authors have shown that the individuals' relation can be viewed as a complex network. So in this paper, in order to better explain the dynamical behavior of epidemics, we consider different epidemic models on complex networks, and obtain the epidemic threshold for each case. Finally, we present numerical simulations for each case to verify our results.

  20. Noncommutative complex Grosse-Wulkenhaar model

    SciTech Connect

    Hounkonnou, Mahouton Norbert; Samary, Dine Ousmane

    2008-11-18

    This paper stands for an application of the noncommutative (NC) Noether theorem, given in our previous work [AIP Proc 956(2007) 55-60], for the NC complex Grosse-Wulkenhaar model. It provides with an extension of a recent work [Physics Letters B 653(2007) 343-345]. The local conservation of energy-momentum tensors (EMTs) is recovered using improvement procedures based on Moyal algebraic techniques. Broken dilatation symmetry is discussed. NC gauge currents are also explicitly computed.

  1. Predictive modelling of complex agronomic and biological systems.

    PubMed

    Keurentjes, Joost J B; Molenaar, Jaap; Zwaan, Bas J

    2013-09-01

    Biological systems are tremendously complex in their functioning and regulation. Studying the multifaceted behaviour and describing the performance of such complexity has challenged the scientific community for years. The reduction of real-world intricacy into simple descriptive models has therefore convinced many researchers of the usefulness of introducing mathematics into biological sciences. Predictive modelling takes such an approach another step further in that it takes advantage of existing knowledge to project the performance of a system in alternating scenarios. The ever growing amounts of available data generated by assessing biological systems at increasingly higher detail provide unique opportunities for future modelling and experiment design. Here we aim to provide an overview of the progress made in modelling over time and the currently prevalent approaches for iterative modelling cycles in modern biology. We will further argue for the importance of versatility in modelling approaches, including parameter estimation, model reduction and network reconstruction. Finally, we will discuss the difficulties in overcoming the mathematical interpretation of in vivo complexity and address some of the future challenges lying ahead.

  2. Complex Constructivism: A Theoretical Model of Complexity and Cognition

    ERIC Educational Resources Information Center

    Doolittle, Peter E.

    2014-01-01

    Education has long been driven by its metaphors for teaching and learning. These metaphors have influenced both educational research and educational practice. Complexity and constructivism are two theories that provide functional and robust metaphors. Complexity provides a metaphor for the structure of myriad phenomena, while constructivism…

  3. Magnetic modeling of the Bushveld Igneous Complex

    NASA Astrophysics Data System (ADS)

    Webb, S. J.; Cole, J.; Letts, S. A.; Finn, C.; Torsvik, T. H.; Lee, M. D.

    2009-12-01

    Magnetic modeling of the 2.06 Ga Bushveld Complex presents special challenges due a variety of magnetic effects. These include strong remanence in the Main Zone and extremely high magnetic susceptibilities in the Upper Zone, which exhibit self-demagnetization. Recent palaeomagnetic results have resolved a long standing discrepancy between age data, which constrain the emplacement to within 1 million years, and older palaeomagnetic data which suggested ~50 million years for emplacement. The new palaeomagnetic results agree with the age data and present a single consistent pole, as opposed to a long polar wander path, for the Bushveld for all of the Zones and all of the limbs. These results also pass a fold test indicating the Bushveld Complex was emplaced horizontally lending support to arguments for connectivity. The magnetic signature of the Bushveld Complex provides an ideal mapping tool as the UZ has high susceptibility values and is well layered showing up as distinct anomalies on new high resolution magnetic data. However, this signature is similar to the highly magnetic BIFs found in the Transvaal and in the Witwatersrand Supergroups. Through careful mapping using new high resolution aeromagnetic data, we have been able to map the Bushveld UZ in complicated geological regions and identify a characteristic signature with well defined layers. The Main Zone, which has a more subdued magnetic signature, does have a strong remanent component and exhibits several magnetic reversals. The magnetic layers of the UZ contain layers of magnetitite with as much as 80-90% pure magnetite with large crystals (1-2 cm). While these layers are not strongly remanent, they have extremely high magnetic susceptibilities, and the self demagnetization effect must be taken into account when modeling these layers. Because the Bushveld Complex is so large, the geometry of the Earth’s magnetic field relative to the layers of the UZ Bushveld Complex changes orientation, creating

  4. Sandia National Laboratories ASCOT (atmospheric studies in complex terrain) field experiment, September 1980

    NASA Astrophysics Data System (ADS)

    Woods, R. O.

    1982-04-01

    During the period September 8 through September 25, 1980, Sandia National Laboratories, Division 4774, participated in a series of experiments held in the Geysers area of California. These experiments, aimed at providing data on nighttime drainage flow in complex terrain, were intended to provide a reliable basis for mathematical fow modeling. Tracers were released at several points on a valley rim and sampled by a large number of stations at ground level. Sandia's contribution was to make it possible to derive vertical tracer profiles. This was done by taking air samples from a captive balloon at chosen altitudes between the surface and 450 meters above ground.

  5. An experiment with interactive planning models

    NASA Technical Reports Server (NTRS)

    Beville, J.; Wagner, J. H.; Zannetos, Z. S.

    1970-01-01

    Experiments on decision making in planning problems are described. Executives were tested in dealing with capital investments and competitive pricing decisions under conditions of uncertainty. A software package, the interactive risk analysis model system, was developed, and two controlled experiments were conducted. It is concluded that planning models can aid management, and predicted uses of the models are as a central tool, as an educational tool, to improve consistency in decision making, to improve communications, and as a tool for consensus decision making.

  6. Modeling of microgravity combustion experiments

    NASA Technical Reports Server (NTRS)

    Buckmaster, John

    1995-01-01

    This program started in February 1991, and is designed to improve our understanding of basic combustion phenomena by the modeling of various configurations undergoing experimental study by others. Results through 1992 were reported in the second workshop. Work since that time has examined the following topics: Flame-balls; Intrinsic and acoustic instabilities in multiphase mixtures; Radiation effects in premixed combustion; Smouldering, both forward and reverse, as well as two dimensional smoulder.

  7. The database for reaching experiments and models.

    PubMed

    Walker, Ben; Kording, Konrad

    2013-01-01

    Reaching is one of the central experimental paradigms in the field of motor control, and many computational models of reaching have been published. While most of these models try to explain subject data (such as movement kinematics, reaching performance, forces, etc.) from only a single experiment, distinct experiments often share experimental conditions and record similar kinematics. This suggests that reaching models could be applied to (and falsified by) multiple experiments. However, using multiple datasets is difficult because experimental data formats vary widely. Standardizing data formats promises to enable scientists to test model predictions against many experiments and to compare experimental results across labs. Here we report on the development of a new resource available to scientists: a database of reaching called the Database for Reaching Experiments And Models (DREAM). DREAM collects both experimental datasets and models and facilitates their comparison by standardizing formats. The DREAM project promises to be useful for experimentalists who want to understand how their data relates to models, for modelers who want to test their theories, and for educators who want to help students better understand reaching experiments, models, and data analysis.

  8. Structured analysis and modeling of complex systems

    NASA Technical Reports Server (NTRS)

    Strome, David R.; Dalrymple, Mathieu A.

    1992-01-01

    The Aircrew Evaluation Sustained Operations Performance (AESOP) facility at Brooks AFB, Texas, combines the realism of an operational environment with the control of a research laboratory. In recent studies we collected extensive data from the Airborne Warning and Control Systems (AWACS) Weapons Directors subjected to high and low workload Defensive Counter Air Scenarios. A critical and complex task in this environment involves committing a friendly fighter against a hostile fighter. Structured Analysis and Design techniques and computer modeling systems were applied to this task as tools for analyzing subject performance and workload. This technology is being transferred to the Man-Systems Division of NASA Johnson Space Center for application to complex mission related tasks, such as manipulating the Shuttle grappler arm.

  9. Project trades model for complex space missions

    NASA Technical Reports Server (NTRS)

    Girerd, Andre R.; Shishko, Roberto

    2003-01-01

    A Project Trades Model (PTM) is a collection of tools/simulations linked together to rapidly perform integrated system trade studies of performance, cost, risk, and mission effectiveness. An operating PTM captures the interactions between various targeted systems and subsystems through an exchange of computed variables of the constituent models. Selection and implementation of the order, method of interaction, model type, and envisioned operation of the ensemble of tools rpresents the key system engineering challenge of the approach. This paper describes an approach to building a PTM and using it to perform top-level system trades for a complex space mission. In particular, the PTM discussed here is for a future Mars mission involving a large rover.

  10. In Vivo Experiments with Dental Pulp Stem Cells for Pulp-Dentin Complex Regeneration

    PubMed Central

    Kim, Sunil; Shin, Su-Jung; Song, Yunjung; Kim, Euiseong

    2015-01-01

    In recent years, many studies have examined the pulp-dentin complex regeneration with DPSCs. While it is important to perform research on cells, scaffolds, and growth factors, it is also critical to develop animal models for preclinical trials. The development of a reproducible animal model of transplantation is essential for obtaining precise and accurate data in vivo. The efficacy of pulp regeneration should be assessed qualitatively and quantitatively using animal models. This review article sought to introduce in vivo experiments that have evaluated the potential of dental pulp stem cells for pulp-dentin complex regeneration. According to a review of various researches about DPSCs, the majority of studies have used subcutaneous mouse and dog teeth for animal models. There is no way to know which animal model will reproduce the clinical environment. If an animal model is developed which is easier to use and is useful in more situations than the currently popular models, it will be a substantial aid to studies examining pulp-dentin complex regeneration. PMID:26688616

  11. A summary of computational experience at GE Aircraft Engines for complex turbulent flows in gas turbines

    NASA Technical Reports Server (NTRS)

    Zerkle, Ronald D.; Prakash, Chander

    1995-01-01

    This viewgraph presentation summarizes some CFD experience at GE Aircraft Engines for flows in the primary gaspath of a gas turbine engine and in turbine blade cooling passages. It is concluded that application of the standard k-epsilon turbulence model with wall functions is not adequate for accurate CFD simulation of aerodynamic performance and heat transfer in the primary gas path of a gas turbine engine. New models are required in the near-wall region which include more physics than wall functions. The two-layer modeling approach appears attractive because of its computational complexity. In addition, improved CFD simulation of film cooling and turbine blade internal cooling passages will require anisotropic turbulence models. New turbulence models must be practical in order to have a significant impact on the engine design process. A coordinated turbulence modeling effort between NASA centers would be beneficial to the gas turbine industry.

  12. Multicomponent reactive transport modeling of uranium bioremediation field experiments

    NASA Astrophysics Data System (ADS)

    Fang, Yilin; Yabusaki, Steven B.; Morrison, Stan J.; Amonette, James P.; Long, Philip E.

    2009-10-01

    A reaction network integrating abiotic and microbially mediated reactions has been developed to simulate biostimulation field experiments at a former Uranium Mill Tailings Remedial Action (UMTRA) site in Rifle, Colorado. The reaction network was calibrated using data from the 2002 field experiment, after which it was applied without additional calibration to field experiments performed in 2003 and 2007. The robustness of the model specification is significant in that (1) the 2003 biostimulation field experiment was performed with 3 times higher acetate concentrations than the previous biostimulation in the same field plot (i.e., the 2002 experiment), and (2) the 2007 field experiment was performed in a new unperturbed plot on the same site. The biogeochemical reactive transport simulations accounted for four terminal electron-accepting processes (TEAPs), two distinct functional microbial populations, two pools of bioavailable Fe(III) minerals (iron oxides and phyllosilicate iron), uranium aqueous and surface complexation, mineral precipitation and dissolution. The conceptual model for bioavailable iron reflects recent laboratory studies with sediments from the UMTRA site that demonstrated that the bulk (˜90%) of initial Fe(III) bioreduction is associated with phyllosilicate rather than oxide forms of iron. The uranium reaction network includes a U(VI) surface complexation model based on laboratory studies with Rifle site sediments and aqueous complexation reactions that include ternary complexes (e.g., calcium-uranyl-carbonate). The bioreduced U(IV), Fe(II), and sulfide components produced during the experiments are strongly associated with the solid phases and may play an important role in long-term uranium immobilization.

  13. Lateral organization of complex lipid mixtures from multiscale modeling

    NASA Astrophysics Data System (ADS)

    Tumaneng, Paul W.; Pandit, Sagar A.; Zhao, Guijun; Scott, H. L.

    2010-02-01

    The organizational properties of complex lipid mixtures can give rise to functionally important structures in cell membranes. In model membranes, ternary lipid-cholesterol (CHOL) mixtures are often used as representative systems to investigate the formation and stabilization of localized structural domains ("rafts"). In this work, we describe a self-consistent mean-field model that builds on molecular dynamics simulations to incorporate multiple lipid components and to investigate the lateral organization of such mixtures. The model predictions reveal regions of bimodal order on ternary plots that are in good agreement with experiment. Specifically, we have applied the model to ternary mixtures composed of dioleoylphosphatidylcholine:18:0 sphingomyelin:CHOL. This work provides insight into the specific intermolecular interactions that drive the formation of localized domains in these mixtures. The model makes use of molecular dynamics simulations to extract interaction parameters and to provide chain configuration order parameter libraries.

  14. On Complexity of the Quantum Ising Model

    NASA Astrophysics Data System (ADS)

    Bravyi, Sergey; Hastings, Matthew

    2017-01-01

    We study complexity of several problems related to the Transverse field Ising Model (TIM). First, we consider the problem of estimating the ground state energy known as the Local Hamiltonian Problem (LHP). It is shown that the LHP for TIM on degree-3 graphs is equivalent modulo polynomial reductions to the LHP for general k-local `stoquastic' Hamiltonians with any constant {k ≥ 2}. This result implies that estimating the ground state energy of TIM on degree-3 graphs is a complete problem for the complexity class {StoqMA} —an extension of the classical class {MA}. As a corollary, we complete the complexity classification of 2-local Hamiltonians with a fixed set of interactions proposed recently by Cubitt and Montanaro. Secondly, we study quantum annealing algorithms for finding ground states of classical spin Hamiltonians associated with hard optimization problems. We prove that the quantum annealing with TIM Hamiltonians is equivalent modulo polynomial reductions to the quantum annealing with a certain subclass of k-local stoquastic Hamiltonians. This subclass includes all Hamiltonians representable as a sum of a k-local diagonal Hamiltonian and a 2-local stoquastic Hamiltonian.

  15. Evaluation of a puff dispersion model in complex terrain

    SciTech Connect

    Thuillier, R.H. )

    1992-03-01

    California's Pacific Gas and Electric Company has many power plant operations situated in complex terrain, prominent examples being the Geysers geothermal plant in Lake and Sonoma Counties, and the Diablo Canyon nuclear plant in San Luis Obispo County. Procedures ranging from plant licensing to emergency response require a dispersion modeling capability in a complex terrain environment. This paper describes the performance evaluation of such a capability, the Pacific Gas and Electric Company Modeling System (PGEMS), a fast response Gaussian puff model with a three-dimensional wind field generator. Performance of the model was evaluated for ground level and short stack elevated release on the basis of a special intensive tracer experiment in the complex coastal terrain surrounding the Diablo Canyon Nuclear Power Plant in San Luis Obispo County, California. The model performed well under a variety of meteorological and release conditions within the test region of 20-kilometer radius surrounding the nuclear plant, and turned in a superior performance in the wake of the nuclear plant, using a new wake correction algorithm for ground level and roof-vent releases a that location.

  16. Lattice Boltzmann model for the complex Ginzburg-Landau equation.

    PubMed

    Zhang, Jianying; Yan, Guangwu

    2010-06-01

    A lattice Boltzmann model with complex distribution function for the complex Ginzburg-Landau equation (CGLE) is proposed. By using multiscale technique and the Chapman-Enskog expansion on complex variables, we obtain a series of complex partial differential equations. Then, complex equilibrium distribution function and its complex moments are obtained. Based on this model, the rotation and oscillation properties of stable spiral waves and the breaking-up behavior of unstable spiral waves in CGLE are investigated in detail.

  17. Turbulence modeling needs of commercial CFD codes: Complex flows in the aerospace and automotive industries

    NASA Technical Reports Server (NTRS)

    Befrui, Bizhan A.

    1995-01-01

    This viewgraph presentation discusses the following: STAR-CD computational features; STAR-CD turbulence models; common features of industrial complex flows; industry-specific CFD development requirements; applications and experiences of industrial complex flows, including flow in rotating disc cavities, diffusion hole film cooling, internal blade cooling, and external car aerodynamics; and conclusions on turbulence modeling needs.

  18. Complex Educational Design: A Course Design Model Based on Complexity

    ERIC Educational Resources Information Center

    Freire, Maximina Maria

    2013-01-01

    Purpose: This article aims at presenting a conceptual framework which, theoretically grounded on complexity, provides the basis to conceive of online language courses that intend to respond to the needs of students and society. Design/methodology/approach: This paper is introduced by reflections on distance education and on the paradigmatic view…

  19. Delineating parameter unidentifiabilities in complex models

    NASA Astrophysics Data System (ADS)

    Raman, Dhruva V.; Anderson, James; Papachristodoulou, Antonis

    2017-03-01

    Scientists use mathematical modeling as a tool for understanding and predicting the properties of complex physical systems. In highly parametrized models there often exist relationships between parameters over which model predictions are identical, or nearly identical. These are known as structural or practical unidentifiabilities, respectively. They are hard to diagnose and make reliable parameter estimation from data impossible. They furthermore imply the existence of an underlying model simplification. We describe a scalable method for detecting unidentifiabilities, as well as the functional relations defining them, for generic models. This allows for model simplification, and appreciation of which parameters (or functions thereof) cannot be estimated from data. Our algorithm can identify features such as redundant mechanisms and fast time-scale subsystems, as well as the regimes in parameter space over which such approximations are valid. We base our algorithm on a quantification of regional parametric sensitivity that we call `multiscale sloppiness'. Traditionally, the link between parametric sensitivity and the conditioning of the parameter estimation problem is made locally, through the Fisher information matrix. This is valid in the regime of infinitesimal measurement uncertainty. We demonstrate the duality between multiscale sloppiness and the geometry of confidence regions surrounding parameter estimates made where measurement uncertainty is non-negligible. Further theoretical relationships are provided linking multiscale sloppiness to the likelihood-ratio test. From this, we show that a local sensitivity analysis (as typically done) is insufficient for determining the reliability of parameter estimation, even with simple (non)linear systems. Our algorithm can provide a tractable alternative. We finally apply our methods to a large-scale, benchmark systems biology model of necrosis factor (NF)-κ B , uncovering unidentifiabilities.

  20. Using Perspective to Model Complex Processes

    SciTech Connect

    Kelsey, R.L.; Bisset, K.R.

    1999-04-04

    The notion of perspective, when supported in an object-based knowledge representation, can facilitate better abstractions of reality for modeling and simulation. The object modeling of complex physical and chemical processes is made more difficult in part due to the poor abstractions of state and phase changes available in these models. The notion of perspective can be used to create different views to represent the different states of matter in a process. These techniques can lead to a more understandable model. Additionally, the ability to record the progress of a process from start to finish is problematic. It is desirable to have a historic record of the entire process, not just the end result of the process. A historic record should facilitate backtracking and re-start of a process at different points in time. The same representation structures and techniques can be used to create a sequence of process markers to represent a historic record. By using perspective, the sequence of markers can have multiple and varying views tailored for a particular user's context of interest.

  1. Mathematical modelling of complex contagion on clustered networks

    NASA Astrophysics Data System (ADS)

    O'sullivan, David J.; O'Keeffe, Gary; Fennell, Peter; Gleeson, James

    2015-09-01

    The spreading of behavior, such as the adoption of a new innovation, is influenced bythe structure of social networks that interconnect the population. In the experiments of Centola (Science, 2010), adoption of new behavior was shown to spread further and faster across clustered-lattice networks than across corresponding random networks. This implies that the “complex contagion” effects of social reinforcement are important in such diffusion, in contrast to “simple” contagion models of disease-spread which predict that epidemics would grow more efficiently on random networks than on clustered networks. To accurately model complex contagion on clustered networks remains a challenge because the usual assumptions (e.g. of mean-field theory) regarding tree-like networks are invalidated by the presence of triangles in the network; the triangles are, however, crucial to the social reinforcement mechanism, which posits an increased probability of a person adopting behavior that has been adopted by two or more neighbors. In this paper we modify the analytical approach that was introduced by Hebert-Dufresne et al. (Phys. Rev. E, 2010), to study disease-spread on clustered networks. We show how the approximation method can be adapted to a complex contagion model, and confirm the accuracy of the method with numerical simulations. The analytical results of the model enable us to quantify the level of social reinforcement that is required to observe—as in Centola’s experiments—faster diffusion on clustered topologies than on random networks.

  2. An Experiment on Isomerism in Metal-Amino Acid Complexes.

    ERIC Educational Resources Information Center

    Harrison, R. Graeme; Nolan, Kevin B.

    1982-01-01

    Background information, laboratory procedures, and discussion of results are provided for syntheses of cobalt (III) complexes, I-III, illustrating three possible bonding modes of glycine to a metal ion (the complex cations II and III being linkage/geometric isomers). Includes spectrophotometric and potentiometric methods to distinguish among the…

  3. CALIBRATION OF SUBSURFACE BATCH AND REACTIVE-TRANSPORT MODELS INVOLVING COMPLEX BIOGEOCHEMICAL PROCESSES

    EPA Science Inventory

    In this study, the calibration of subsurface batch and reactive-transport models involving complex biogeochemical processes was systematically evaluated. Two hypothetical nitrate biodegradation scenarios were developed and simulated in numerical experiments to evaluate the perfor...

  4. Surface Complexation Modelling in Metal-Mineral-Bacteria Systems

    NASA Astrophysics Data System (ADS)

    Johnson, K. J.; Fein, J. B.

    2002-12-01

    The reactive surfaces of bacteria and minerals can determine the fate, transport, and bioavailability of aqueous heavy metal cations. Geochemical models are instrumental in accurately accounting for the partitioning of the metals between mineral surfaces and bacteria cell walls. Previous research has shown that surface complexation modelling (SCM) is accurate in two-component systems (metal:mineral and metal:bacteria); however, the ability of SCMs to account for metal distribution in mixed metal-mineral-bacteria systems has not been tested. In this study, we measure aqueous Cd distributions in water-bacteria-mineral systems, and compare these observations with predicted distributions based on a surface complexation modelling approach. We measured Cd adsorption in 2- and 3-component batch adsorption experiments. In the 2-component experiments, we measured the extent of adsorption of 10 ppm aqueous Cd onto either a bacterial or hydrous ferric oxide sorbent. The metal:bacteria experiments contained 1 g/L (wet wt.) of B. subtilis, and were conducted as a function of pH; the metal:mineral experiments were conducted as a function of both pH and HFO content. Two types of 3-component Cd adsorption experiments were also conducted in which both mineral powder and bacteria were present as sorbents: 1) one in which the HFO was physically but not chemically isolated from the system using sealed dialysis tubing, and 2) others where the HFO, Cd and B. subtilis were all in physical contact. The dialysis tubing approach enabled the direct determination of the concentration of Cd on each sorbing surface, after separation and acidification of each sorbent. The experiments indicate that both bacteria and mineral surfaces can dominate adsorption in the system, depending on pH and bacteria:mineral ratio. The stability constants, determined using the data from the 2-component systems, along with those for other surface and aqueous species in the systems, were used with FITEQL to

  5. Argonne Bubble Experiment Thermal Model Development

    SciTech Connect

    Buechler, Cynthia Eileen

    2015-12-03

    This report will describe the Computational Fluid Dynamics (CFD) model that was developed to calculate the temperatures and gas volume fractions in the solution vessel during the irradiation. It is based on the model used to calculate temperatures and volume fractions in an annular vessel containing an aqueous solution of uranium . The experiment was repeated at several electron beam power levels, but the CFD analysis was performed only for the 12 kW irradiation, because this experiment came the closest to reaching a steady-state condition. The aim of the study is to compare results of the calculation with experimental measurements to determine the validity of the CFD model.

  6. Modeling choice and valuation in decision experiments.

    PubMed

    Loomes, Graham

    2010-07-01

    This article develops a parsimonious descriptive model of individual choice and valuation in the kinds of experiments that constitute a substantial part of the literature relating to decision making under risk and uncertainty. It suggests that many of the best known "regularities" observed in those experiments may arise from a tendency for participants to perceive probabilities and payoffs in a particular way. This model organizes more of the data than any other extant model and generates a number of novel testable implications which are examined with new data.

  7. Using Ecosystem Experiments to Improve Vegetation Models

    SciTech Connect

    Medlyn, Belinda; Zaehle, S; DeKauwe, Martin G.; Walker, Anthony P.; Dietze, Michael; Hanson, Paul J.; Hickler, Thomas; Jain, Atul; Luo, Yiqi; Parton, William; Prentice, I. Collin; Thornton, Peter E.; Wang, Shusen; Wang, Yingping; Weng, Ensheng; Iversen, Colleen M.; McCarthy, Heather R.; Warren, Jeffrey; Oren, Ram; Norby, Richard J

    2015-05-21

    Ecosystem responses to rising CO2 concentrations are a major source of uncertainty in climate change projections. Data from ecosystem-scale Free-Air CO2 Enrichment (FACE) experiments provide a unique opportunity to reduce this uncertainty. The recent FACE Model–Data Synthesis project aimed to use the information gathered in two forest FACE experiments to assess and improve land ecosystem models. A new 'assumption-centred' model intercomparison approach was used, in which participating models were evaluated against experimental data based on the ways in which they represent key ecological processes. Identifying and evaluating the main assumptions caused differences among models, and the assumption-centered approach produced a clear roadmap for reducing model uncertainty. We explain this approach and summarize the resulting research agenda. We encourage the application of this approach in other model intercomparison projects to fundamentally improve predictive understanding of the Earth system.

  8. Using Ecosystem Experiments to Improve Vegetation Models

    DOE PAGES

    Medlyn, Belinda; Zaehle, S; DeKauwe, Martin G.; ...

    2015-05-21

    Ecosystem responses to rising CO2 concentrations are a major source of uncertainty in climate change projections. Data from ecosystem-scale Free-Air CO2 Enrichment (FACE) experiments provide a unique opportunity to reduce this uncertainty. The recent FACE Model–Data Synthesis project aimed to use the information gathered in two forest FACE experiments to assess and improve land ecosystem models. A new 'assumption-centred' model intercomparison approach was used, in which participating models were evaluated against experimental data based on the ways in which they represent key ecological processes. Identifying and evaluating the main assumptions caused differences among models, and the assumption-centered approach produced amore » clear roadmap for reducing model uncertainty. We explain this approach and summarize the resulting research agenda. We encourage the application of this approach in other model intercomparison projects to fundamentally improve predictive understanding of the Earth system.« less

  9. Finding the right balance between groundwater model complexity and experimental effort via Bayesian model selection

    NASA Astrophysics Data System (ADS)

    Schöniger, Anneli; Illman, Walter A.; Wöhling, Thomas; Nowak, Wolfgang

    2015-12-01

    Groundwater modelers face the challenge of how to assign representative parameter values to the studied aquifer. Several approaches are available to parameterize spatial heterogeneity in aquifer parameters. They differ in their conceptualization and complexity, ranging from homogeneous models to heterogeneous random fields. While it is common practice to invest more effort into data collection for models with a finer resolution of heterogeneities, there is a lack of advice which amount of data is required to justify a certain level of model complexity. In this study, we propose to use concepts related to Bayesian model selection to identify this balance. We demonstrate our approach on the characterization of a heterogeneous aquifer via hydraulic tomography in a sandbox experiment (Illman et al., 2010). We consider four increasingly complex parameterizations of hydraulic conductivity: (1) Effective homogeneous medium, (2) geology-based zonation, (3) interpolation by pilot points, and (4) geostatistical random fields. First, we investigate the shift in justified complexity with increasing amount of available data by constructing a model confusion matrix. This matrix indicates the maximum level of complexity that can be justified given a specific experimental setup. Second, we determine which parameterization is most adequate given the observed drawdown data. Third, we test how the different parameterizations perform in a validation setup. The results of our test case indicate that aquifer characterization via hydraulic tomography does not necessarily require (or justify) a geostatistical description. Instead, a zonation-based model might be a more robust choice, but only if the zonation is geologically adequate.

  10. Troposphere-lower-stratosphere connection in an intermediate complexity model.

    NASA Astrophysics Data System (ADS)

    Ruggieri, Paolo; King, Martin; Kucharski, Fred; Buizza, Roberto; Visconti, Guido

    2016-04-01

    The dynamical coupling between the troposphere and the lower stratosphere has been investigated using a low-top, intermediate complexity model provided by the Abdus Salam International Centre for Theoretical Physics (SPEEDY). The key question that we wanted to address is whether a simple model like SPEEDY can be used to understand troposphere-stratosphere interactions, e.g. forced by changes of sea-ice concentration in polar arctic regions. Three sets of experiments have been performed. Firstly, a potential vorticity perspective has been applied to understand the wave-like forcing of the troposphere on the stratosphere and to provide quantitative information on the sub seasonal variability of the coupling. Then, the zonally asymmetric, near-surface response to a lower-stratospheric forcing has been analysed in a set of forced experiments with an artificial heating imposed in the extra-tropical lower stratosphere. Finally, the lower-stratosphere response sensitivity to tropospheric initial conditions has been examined. Results indicate how SPEEDY captures the physics of the troposphere-stratosphere connection but also show the lack of stratospheric variability. Results also suggest that intermediate-complexity models such as SPEEDY could be used to investigate the effects that surface forcing (e.g. due to sea-ice concentration changes) have on the troposphere and the lower stratosphere.

  11. Advanced Combustion Modeling for Complex Turbulent Flows

    NASA Technical Reports Server (NTRS)

    Ham, Frank Stanford

    2005-01-01

    The next generation of aircraft engines will need to pass stricter efficiency and emission tests. NASA's Ultra-Efficient Engine Technology (UEET) program has set an ambitious goal of 70% reduction of NO(x) emissions and a 15% increase in fuel efficiency of aircraft engines. We will demonstrate the state-of-the-art combustion tools developed a t Stanford's Center for Turbulence Research (CTR) as part of this program. In the last decade, CTR has spear-headed a multi-physics-based combustion modeling program. Key technologies have been transferred to the aerospace industry and are currently being used for engine simulations. In this demo, we will showcase the next-generation combustion modeling tools that integrate a very high level of detailed physics into advanced flow simulation codes. Combustor flows involve multi-phase physics with liquid fuel jet breakup, evaporation, and eventual combustion. Individual components of the simulation are verified against complex test cases and show excellent agreement with experimental data.

  12. The Experience of Strategic Thinking in a Volatile, Complex, Uncertain & Ambiguous (VUCA) Environment

    DTIC Science & Technology

    2014-08-01

    Dale L. Moore, Aug., 2014 The Experience of Strategic Thinking in a Volatile, Complex, Uncertain & Ambiguous (VUCA) Environment Dr. Dale L...TITLE AND SUBTITLE The Experience of Strategic Thinking in a Volatile, Complex, Uncertain & Ambiguous (VUCA) Environment 5a. CONTRACT NUMBER 5b...Title: The Experience of Strategic Thinking in VUCA Environments Purpose of the Study: To understand the experience of leaders when they think

  13. Recent "Ground Testing" Experiences in the National Full-Scale Aerodynamics Complex

    NASA Technical Reports Server (NTRS)

    Zell, Peter; Stich, Phil; Sverdrup, Jacobs; George, M. W. (Technical Monitor)

    2002-01-01

    The large test sections of the National Full-scale Aerodynamics Complex (NFAC) wind tunnels provide ideal controlled wind environments to test ground-based objects and vehicles. Though this facility was designed and provisioned primarily for aeronautical testing requirements, several experiments have been designed to utilize existing model mount structures to support "non-flying" systems. This presentation will discuss some of the ground-based testing capabilities of the facility and provide examples of groundbased tests conducted in the facility to date. It will also address some future work envisioned and solicit input from the SATA membership on ways to improve the service that NASA makes available to customers.

  14. Investigations and experiments of a new multi-layer complex liquid-cooled mirror

    NASA Astrophysics Data System (ADS)

    Lu, Yuling; Cheng, Zuhai; Zhang, Yaoning; Sun, Feng; Yu, Wenfeng

    2004-07-01

    This paper describes a new multi-layer complex liquid-cooled Si mirror with 3 cooling ducts in Archimedes spirals. Utilizing the ANSYS program, the structure of the mirror is optimized and the thermal deformation model of the mirror is simulated. The simulation results show that the mirror has the following advantages: very small amount of surface deformation, uniform distribution of temperature and surface deformation, and fast surface shape restoration. The results of the experiments of thermal deformation and the surface restoration are accurately mapped to the simulation results.

  15. Solar models, neutrino experiments, and helioseismology

    NASA Technical Reports Server (NTRS)

    Bahcall, John N.; Ulrich, Roger K.

    1988-01-01

    The event rates and their recognized uncertainties are calculated for 11 solar neutrino experiments using accurate solar models. These models are also used to evaluate the frequency spectrum of the p and g oscillations modes of the sun. It is shown that the discrepancy between the predicted and observed event rates in the Cl-37 and Kamiokande II experiments cannot be explained by a 'likely' fluctuation in input parameters with the best estimates and uncertainties given in the present study. It is suggested that, whatever the correct solution to the solar neutrino problem, it is unlikely to be a 'trival' error.

  16. The Meduza experiment: An orbital complex ten weeks in flight

    NASA Technical Reports Server (NTRS)

    Ovcharov, V.

    1979-01-01

    The newspaper article discusses the contribution of space research to understanding the origin of life on Earth. Part of this basic research involves studying amino acids, ribonucleic acid and DNA molecules subjected to cosmic radiation. The results from the Meduza experiment are not all analyzed as yet. The article also discusses the psychological changes in cosmonauts as evidenced by their attitude towards biology experiments in space.

  17. Multicomponent reactive transport modeling of uranium bioremediation field experiments

    SciTech Connect

    Fang, Yilin; Yabusaki, Steven B.; Morrison, Stan J.; Amonette, James E.; Long, Philip E.

    2009-10-15

    Biostimulation field experiments with acetate amendment are being performed at a former uranium mill tailings site in Rifle, Colorado, to investigate subsurface processes controlling in situ bioremediation of uranium-contaminated groundwater. An important part of the research is identifying and quantifying field-scale models of the principal terminal electron-accepting processes (TEAPs) during biostimulation and the consequent biogeochemical impacts to the subsurface receiving environment. Integrating abiotic chemistry with the microbially mediated TEAPs in the reaction network brings into play geochemical observations (e.g., pH, alkalinity, redox potential, major ions, and secondary minerals) that the reactive transport model must recognize. These additional constraints provide for a more systematic and mechanistic interpretation of the field behaviors during biostimulation. The reaction network specification developed for the 2002 biostimulation field experiment was successfully applied without additional calibration to the 2003 and 2007 field experiments. The robustness of the model specification is significant in that 1) the 2003 biostimulation field experiment was performed with 3 times higher acetate concentrations than the previous biostimulation in the same field plot (i.e., the 2002 experiment), and 2) the 2007 field experiment was performed in a new unperturbed plot on the same site. The biogeochemical reactive transport simulations accounted for four TEAPs, two distinct functional microbial populations, two pools of bioavailable Fe(III) minerals (iron oxides and phyllosilicate iron), uranium aqueous and surface complexation, mineral precipitation, and dissolution. The conceptual model for bioavailable iron reflects recent laboratory studies with sediments from the Old Rifle Uranium Mill Tailings Remedial Action (UMTRA) site that demonstrated that the bulk (~90%) of Fe(III) bioreduction is associated with the phyllosilicates rather than the iron oxides

  18. Modelling of Rare Earth Elements Complexation With Humic Acid

    NASA Astrophysics Data System (ADS)

    Pourret, O.; Davranche, M.; Gruau, G.; Dia, A.

    2006-12-01

    The binding of rare earth elements (REE) to humic acid (HA) was studied by combining Ultrafiltration and ICP- MS techniques. REE-HA complexation experiments were performed at various pH conditions (ranging from 2 to 10.5) using a standard batch equilibration method. Results show that the amount of REE bound to HA strongly increase with increasing pH. Moreover, a Middle REE (MREE) downward concavity is evidenced by REE distribution patterns at acidic pH. Modelling of the experimental data using Humic Ion Binding Model VI provided a set of log KMA values (i.e. the REE-HA complexation constants specific to Model VI) for the entire REE series. The log KMA pattern obtained displays a MREE downward concavity. Log KMA values range from 2.42 to 2.79. These binding constants are in good agreement with the few existing datasets quantifying the binding of REE with humic substances except a recently published study which evidence a lanthanide contraction effect (i.e. continuous increase of the constant from La to Lu). The MREE downward concavity displayed by REE-HA complexation pattern determined in this study compares well with results from REE-fulvic acid (FA) and REE-acetic acid complexation studies. This similarity in the REE complexation pattern shapes suggests that carboxylic groups are the main binding sites of REE in HA. This conclusion is further supported by a detailed review of published studies for natural, organic-rich, river- and ground-waters which show no evidence of a lanthanide contraction effect in REE pattern shape. Finally, application of Model VI using the new, experimentally determined log KMA values to World Average River Water confirms earlier suggestions that REE occur predominantly as organic complexes (> 60 %) in the pH range between 5-5.5 and 7-8.5 (i.e. in circumneutral pH waters). The only significant difference as compared to earlier model predictions made using estimated log KMA values is that the experimentally determined log KMA values

  19. Surface complexation model of uranyl sorption on Georgia kaolinite

    USGS Publications Warehouse

    Payne, T.E.; Davis, J.A.; Lumpkin, G.R.; Chisari, R.; Waite, T.D.

    2004-01-01

    The adsorption of uranyl on standard Georgia kaolinites (KGa-1 and KGa-1B) was studied as a function of pH (3-10), total U (1 and 10 ??mol/l), and mass loading of clay (4 and 40 g/l). The uptake of uranyl in air-equilibrated systems increased with pH and reached a maximum in the near-neutral pH range. At higher pH values, the sorption decreased due to the presence of aqueous uranyl carbonate complexes. One kaolinite sample was examined after the uranyl uptake experiments by transmission electron microscopy (TEM), using energy dispersive X-ray spectroscopy (EDS) to determine the U content. It was found that uranium was preferentially adsorbed by Ti-rich impurity phases (predominantly anatase), which are present in the kaolinite samples. Uranyl sorption on the Georgia kaolinites was simulated with U sorption reactions on both titanol and aluminol sites, using a simple non-electrostatic surface complexation model (SCM). The relative amounts of U-binding >TiOH and >AlOH sites were estimated from the TEM/EDS results. A ternary uranyl carbonate complex on the titanol site improved the fit to the experimental data in the higher pH range. The final model contained only three optimised log K values, and was able to simulate adsorption data across a wide range of experimental conditions. The >TiOH (anatase) sites appear to play an important role in retaining U at low uranyl concentrations. As kaolinite often contains trace TiO2, its presence may need to be taken into account when modelling the results of sorption experiments with radionuclides or trace metals on kaolinite. ?? 2004 Elsevier B.V. All rights reserved.

  20. Metal powder absorptivity: Modeling and experiment

    DOE PAGES

    Boley, C. D.; Mitchell, S. C.; Rubenchik, A. M.; ...

    2016-08-10

    Here, we present results of numerical modeling and direct calorimetric measurements of the powder absorptivity for a number of metals. The modeling results generally correlate well with experiment. We show that the powder absorptivity is determined, to a great extent, by the absorptivity of a flat surface at normal incidence. Our results allow the prediction of the powder absorptivity from normal flat-surface absorptivity measurements.

  1. Modeling and minimizing CAPRI round 30 symmetrical protein complexes from CASP-11 structural models.

    PubMed

    El Houasli, Marwa; Maigret, Bernard; Devignes, Marie-Dominique; Ghoorah, Anisah W; Grudinin, Sergei; Ritchie, David W

    2017-03-01

    Many of the modeling targets in the blind CASP-11/CAPRI-30 experiment were protein homo-dimers and homo-tetramers. Here, we perform a retrospective docking-based analysis of the perfectly symmetrical CAPRI Round 30 targets whose crystal structures have been published. Starting from the CASP "stage-2" fold prediction models, we show that using our recently developed "SAM" polar Fourier symmetry docking algorithm combined with NAMD energy minimization often gives acceptable or better 3D models of the target complexes. We also use SAM to analyze the overall quality of all CASP structural models for the selected targets from a docking-based perspective. We demonstrate that docking only CASP "center" structures for the selected targets provides a fruitful and economical docking strategy. Furthermore, our results show that many of the CASP models are dockable in the sense that they can lead to acceptable or better models of symmetrical complexes. Even though SAM is very fast, using docking and NAMD energy minimization to pull out acceptable docking models from a large ensemble of docked CASP models is computationally expensive. Nonetheless, thanks to our SAM docking algorithm, we expect that applying our docking protocol on a modern computer cluster will give us the ability to routinely model 3D structures of symmetrical protein complexes from CASP-quality models. Proteins 2017; 85:463-469. © 2016 Wiley Periodicals, Inc.

  2. Graduate Social Work Education and Cognitive Complexity: Does Prior Experience Really Matter?

    ERIC Educational Resources Information Center

    Simmons, Chris

    2014-01-01

    This study examined the extent to which age, education, and practice experience among social work graduate students (N = 184) predicted cognitive complexity, an essential aspect of critical thinking. In the regression analysis, education accounted for more of the variance associated with cognitive complexity than age and practice experience. When…

  3. Ultrasonic ray models for complex geometries

    NASA Astrophysics Data System (ADS)

    Schumm, A.

    2000-05-01

    Computer Aided Design techniques have become an inherent part of many industrial applications and are also gaining popularity in Nondestructive Testing. In sound field calculations, CAD representations can contribute to one of the generic problem in ultrasonic modeling, the wave propagation in complex geometries. Ray tracing codes were the first to take account of the geometry, providing qualitative information on beam propagation, such as geometrical echoes, multiple sound paths and possible conversions between wave modes. The forward ray tracing approach is intuitive and straightforward and can evolve towards a more quantitative code if transmission, divergence and polarization information is added. If used to evaluate the impulse response of a given geometry, an approximated time-dependent received signal can be obtained after convolution with the excitation signal. The more accurate reconstruction of a sound field after interaction with a geometrical interface according to ray theory requires inverse (or Fermat) ray-tracing to obtain the contribution of each elementary point source to the field at a given observation point. The resulting field of a finite transducer can then be obtained after integration over all point sources. While conceptionally close to classical ray tracing, this approach puts more stringent requirements on the CAD representation employed and is more difficult to extend towards multiple interfaces. In this communication we present examples for both approaches. In a prospective step, the link between both ray techniques is shown, and we illustrate how a combination of both approaches contributes to the solution of an industrial problem.

  4. Modeling competitive substitution in a polyelectrolyte complex

    SciTech Connect

    Peng, B.; Muthukumar, M.

    2015-12-28

    We have simulated the invasion of a polyelectrolyte complex made of a polycation chain and a polyanion chain, by another longer polyanion chain, using the coarse-grained united atom model for the chains and the Langevin dynamics methodology. Our simulations reveal many intricate details of the substitution reaction in terms of conformational changes of the chains and competition between the invading chain and the chain being displaced for the common complementary chain. We show that the invading chain is required to be sufficiently longer than the chain being displaced for effecting the substitution. Yet, having the invading chain to be longer than a certain threshold value does not reduce the substitution time much further. While most of the simulations were carried out in salt-free conditions, we show that presence of salt facilitates the substitution reaction and reduces the substitution time. Analysis of our data shows that the dominant driving force for the substitution process involving polyelectrolytes lies in the release of counterions during the substitution.

  5. High precision modeling for fundamental physics experiments

    NASA Astrophysics Data System (ADS)

    Rievers, Benny; Nesemann, Leo; Costea, Adrian; Andres, Michael; Stephan, Ernst P.; Laemmerzahl, Claus

    With growing experimental accuracies and high precision requirements for fundamental physics space missions the needs for accurate numerical modeling techniques are increasing. Motivated by the challenge of length stability in cavities and optical resonators we propose the develop-ment of a high precision modeling tool for the simulation of thermomechanical effects up to a numerical precision of 10-20 . Exemplary calculations for simplified test cases demonstrate the general feasibility of high precision calculations and point out the high complexity of the task. A tool for high precision analysis of complex geometries will have to use new data types, advanced FE solver routines and implement new methods for the evaluation of numerical precision.

  6. Management of Complex Ovarian Cysts in Newborns – Our Experience

    PubMed Central

    Manjiri, S; Padmalatha, SK; Shetty, J

    2017-01-01

    Aims: To analyse the clinical presentation, clinicopathological correlation and management of complex ovarian cysts in newborn and infants. Materials and Methods: Over a period of 6 years (2009-2015), 25 newborns who were diagnosed to have ovarian cyst on antenatal ultrasound, were followed up. We collected data in the form of clinical features, radiological findings, pathology and mode of treatment. Results: Of the 25 fetuses who were diagnosed to have ovarian cysts, fourteen (56%) underwent spontaneous regression by 6-8 months. Eight were operated in newborn period while 3 were operated in early infancy. Seven had ovarian cyst on right side, 4 had on left side. Eight babies underwent laparoscopy while 3 underwent laparotomy. Histopathology showed varied features of hemorrhagic cyst with necrosis and calcification, serous cystadenoma with hemorrhage, benign serous cyst with hemorrhage and simple serous cyst. Post-operative recovery was uneventful in all. Conclusion: All the ovarian cysts detected antenatally in female fetuses need close follow-up after birth. Since spontaneous regression is known, only complex or larger cysts need surgical intervention, preferably by laparoscopy. Majority of the complex cysts show atrophic ovarian tissue hence end up in oophorectomy but simple cysts can be removed preserving normal ovarian tissue whenever possible. PMID:28083489

  7. The Effect of Complex Formation upon the Redox Potentials of Metallic Ions. Cyclic Voltammetry Experiments.

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; And Others

    1988-01-01

    Describes experiments in which students prepare in situ soluble complexes of metal ions with different ligands and observe and estimate the change in formal potential that the ion undergoes upon complexation. Discusses student formation and analysis of soluble complexes of two different metal ions with the same ligand. (CW)

  8. Complexation Effect on Redox Potential of Iron(III)-Iron(II) Couple: A Simple Potentiometric Experiment

    ERIC Educational Resources Information Center

    Rizvi, Masood Ahmad; Syed, Raashid Maqsood; Khan, Badruddin

    2011-01-01

    A titration curve with multiple inflection points results when a mixture of two or more reducing agents with sufficiently different reduction potentials are titrated. In this experiment iron(II) complexes are combined into a mixture of reducing agents and are oxidized to the corresponding iron(III) complexes. As all of the complexes involve the…

  9. A Computer Simulated Experiment in Complex Order Kinetics

    ERIC Educational Resources Information Center

    Merrill, J. C.; And Others

    1975-01-01

    Describes a computer simulation experiment in which physical chemistry students can determine all of the kinetic parameters of a reaction, such as order of the reaction with respect to each reagent, forward and reverse rate constants for the overall reaction, and forward and reverse activation energies. (MLH)

  10. Industrial processing of complex fluids: Formulation and modeling

    SciTech Connect

    Scovel, J.C.; Bleasdale, S.; Forest, G.M.; Bechtel, S.

    1997-08-01

    The production of many important commercial materials involves the evolution of a complex fluid through a cooling phase into a hardened product. Textile fibers, high-strength fibers(KEVLAR, VECTRAN), plastics, chopped-fiber compounds, and fiber optical cable are such materials. Industry desires to replace experiments with on-line, real time models of these processes. Solutions to the problems are not just a matter of technology transfer, but require a fundamental description and simulation of the processes. Goals of the project are to develop models that can be used to optimize macroscopic properties of the solid product, to identify sources of undesirable defects, and to seek boundary-temperature and flow-and-material controls to optimize desired properties.

  11. Data production models for the CDF experiment

    SciTech Connect

    Antos, J.; Babik, M.; Benjamin, D.; Cabrera, S.; Chan, A.W.; Chen, Y.C.; Coca, M.; Cooper, B.; Genser, K.; Hatakeyama, K.; Hou, S.; Hsieh, T.L.; Jayatilaka, B.; Kraan, A.C.; Lysak, R.; Mandrichenko, I.V.; Robson, A.; Siket, M.; Stelzer, B.; Syu, J.; Teng, P.K.; /Kosice, IEF /Duke U. /Taiwan, Inst. Phys. /University Coll. London /Fermilab /Rockefeller U. /Michigan U. /Pennsylvania U. /Glasgow U. /UCLA /Tsukuba U. /New Mexico U.

    2006-06-01

    The data production for the CDF experiment is conducted on a large Linux PC farm designed to meet the needs of data collection at a maximum rate of 40 MByte/sec. We present two data production models that exploits advances in computing and communication technology. The first production farm is a centralized system that has achieved a stable data processing rate of approximately 2 TByte per day. The recently upgraded farm is migrated to the SAM (Sequential Access to data via Metadata) data handling system. The software and hardware of the CDF production farms has been successful in providing large computing and data throughput capacity to the experiment.

  12. Model-scale sound propagation experiment

    NASA Technical Reports Server (NTRS)

    Willshire, William L., Jr.

    1988-01-01

    The results of a scale model propagation experiment to investigate grazing propagation above a finite impedance boundary are reported. In the experiment, a 20 x 25 ft ground plane was installed in an anechoic chamber. Propagation tests were performed over the plywood surface of the ground plane and with the ground plane covered with felt, styrofoam, and fiberboard. Tests were performed with discrete tones in the frequency range of 10 to 15 kHz. The acoustic source and microphones varied in height above the test surface from flush to 6 in. Microphones were located in a linear array up to 18 ft from the source. A preliminary experiment using the same ground plane, but only testing the plywood and felt surfaces was performed. The results of this first experiment were encouraging, but data variability and repeatability were poor, particularly, for the felt surface, making comparisons with theoretical predictions difficult. In the main experiment the sound source, microphones, microphone positioning, data acquisition, quality of the anechoic chamber, and environmental control of the anechoic chamber were improved. High-quality, repeatable acoustic data were measured in the main experiment for all four test surfaces. Comparisons with predictions are good, but limited by uncertainties of the impedance values of the test surfaces.

  13. Clinical complexity in medicine: A measurement model of task and patient complexity

    PubMed Central

    Islam, R.; Weir, C.; Fiol, G. Del

    2016-01-01

    Summary Background Complexity in medicine needs to be reduced to simple components in a way that is comprehensible to researchers and clinicians. Few studies in the current literature propose a measurement model that addresses both task and patient complexity in medicine. Objective The objective of this paper is to develop an integrated approach to understand and measure clinical complexity by incorporating both task and patient complexity components focusing on infectious disease domain. The measurement model was adapted and modified to healthcare domain. Methods Three clinical Infectious Disease teams were observed, audio-recorded and transcribed. Each team included an Infectious Diseases expert, one Infectious Diseases fellow, one physician assistant and one pharmacy resident fellow. The transcripts were parsed and the authors independently coded complexity attributes. This baseline measurement model of clinical complexity was modified in an initial set of coding process and further validated in a consensus-based iterative process that included several meetings and email discussions by three clinical experts from diverse backgrounds from the Department of Biomedical Informatics at the University of Utah. Inter-rater reliability was calculated using Cohen’s kappa. Results The proposed clinical complexity model consists of two separate components. The first is a clinical task complexity model with 13 clinical complexity-contributing factors and 7 dimensions. The second is the patient complexity model with 11 complexity-contributing factors and 5 dimensions. Conclusion The measurement model for complexity encompassing both task and patient complexity will be a valuable resource for future researchers and industry to measure and understand complexity in healthcare. PMID:26404626

  14. Modeling Complex Chemical Systems: Problems and Solutions

    NASA Astrophysics Data System (ADS)

    van Dijk, Jan

    2016-09-01

    Non-equilibrium plasmas in complex gas mixtures are at the heart of numerous contemporary technologies. They typically contain dozens to hundreds of species, involved in hundreds to thousands of reactions. Chemists and physicists have always been interested in what are now called chemical reduction techniques (CRT's). The idea of such CRT's is that they reduce the number of species that need to be considered explicitly without compromising the validity of the model. This is usually achieved on the basis of an analysis of the reaction time scales of the system under study, which identifies species that are in partial equilibrium after a given time span. The first such CRT that has been widely used in plasma physics was developed in the 1960's and resulted in the concept of effective ionization and recombination rates. It was later generalized to systems in which multiple levels are effected by transport. In recent years there has been a renewed interest in tools for chemical reduction and reaction pathway analysis. An example of the latter is the PumpKin tool. Another trend is that techniques that have previously been developed in other fields of science are adapted as to be able to handle the plasma state of matter. Examples are the Intrinsic Low Dimension Manifold (ILDM) method and its derivatives, which originate from combustion engineering, and the general-purpose Principle Component Analysis (PCA) technique. In this contribution we will provide an overview of the most common reduction techniques, then critically assess the pros and cons of the methods that have gained most popularity in recent years. Examples will be provided for plasmas in argon and carbon dioxide.

  15. Modeling the propagation of mobile phone virus under complex network.

    PubMed

    Yang, Wei; Wei, Xi-liang; Guo, Hao; An, Gang; Guo, Lei; Yao, Yu

    2014-01-01

    Mobile phone virus is a rogue program written to propagate from one phone to another, which can take control of a mobile device by exploiting its vulnerabilities. In this paper the propagation model of mobile phone virus is tackled to understand how particular factors can affect its propagation and design effective containment strategies to suppress mobile phone virus. Two different propagation models of mobile phone viruses under the complex network are proposed in this paper. One is intended to describe the propagation of user-tricking virus, and the other is to describe the propagation of the vulnerability-exploiting virus. Based on the traditional epidemic models, the characteristics of mobile phone viruses and the network topology structure are incorporated into our models. A detailed analysis is conducted to analyze the propagation models. Through analysis, the stable infection-free equilibrium point and the stability condition are derived. Finally, considering the network topology, the numerical and simulation experiments are carried out. Results indicate that both models are correct and suitable for describing the spread of two different mobile phone viruses, respectively.

  16. Modeling Hemispheric Detonation Experiments in 2-Dimensions

    SciTech Connect

    Howard, W M; Fried, L E; Vitello, P A; Druce, R L; Phillips, D; Lee, R; Mudge, S; Roeske, F

    2006-06-22

    Experiments have been performed with LX-17 (92.5% TATB and 7.5% Kel-F 800 binder) to study scaling of detonation waves using a dimensional scaling in a hemispherical divergent geometry. We model these experiments using an arbitrary Lagrange-Eulerian (ALE3D) hydrodynamics code, with reactive flow models based on the thermo-chemical code, Cheetah. The thermo-chemical code Cheetah provides a pressure-dependent kinetic rate law, along with an equation of state based on exponential-6 fluid potentials for individual detonation product species, calibrated to high pressures ({approx} few Mbars) and high temperatures (20000K). The parameters for these potentials are fit to a wide variety of experimental data, including shock, compression and sound speed data. For the un-reacted high explosive equation of state we use a modified Murnaghan form. We model the detonator (including the flyer plate) and initiation system in detail. The detonator is composed of LX-16, for which we use a program burn model. Steinberg-Guinan models5 are used for the metal components of the detonator. The booster and high explosive are LX-10 and LX-17, respectively. For both the LX-10 and LX-17, we use a pressure dependent rate law, coupled with a chemical equilibrium equation of state based on Cheetah. For LX-17, the kinetic model includes carbon clustering on the nanometer size scale.

  17. Design and modeling of small scale multiple fracturing experiments

    SciTech Connect

    Cuderman, J F

    1981-12-01

    Recent experiments at the Nevada Test Site (NTS) have demonstrated the existence of three distinct fracture regimes. Depending on the pressure rise time in a borehole, one can obtain hydraulic, multiple, or explosive fracturing behavior. The use of propellants rather than explosives in tamped boreholes permits tailoring of the pressure risetime over a wide range since propellants having a wide range of burn rates are available. This technique of using the combustion gases from a full bore propellant charge to produce controlled borehole pressurization is termed High Energy Gas Fracturing (HEGF). Several series of HEGF, in 0.15 m and 0.2 m diameter boreholes at 12 m depths, have been completed in a tunnel complex at NTS where mineback permitted direct observation of fracturing obtained. Because such large experiments are costly and time consuming, smaller scale experiments are desirable, provided results from small experiments can be used to predict fracture behavior in larger boreholes. In order to design small scale gas fracture experiments, the available data from previous HEGF experiments were carefully reviewed, analytical elastic wave modeling was initiated, and semi-empirical modeling was conducted which combined predictions for statically pressurized boreholes with experimental data. The results of these efforts include (1) the definition of what constitutes small scale experiments for emplacement in a tunnel complex at the Nevada Test Site, (2) prediction of average crack radius, in ash fall tuff, as a function of borehole size and energy input per unit length, (3) definition of multiple-hydraulic and multiple-explosive fracture boundaries as a function of boreholes size and surface wave velocity, (4) semi-empirical criteria for estimating stress and acceleration, and (5) a proposal that multiple fracture orientations may be governed by in situ stresses.

  18. Power Curve Modeling in Complex Terrain Using Statistical Models

    NASA Astrophysics Data System (ADS)

    Bulaevskaya, V.; Wharton, S.; Clifton, A.; Qualley, G.; Miller, W.

    2014-12-01

    Traditional power output curves typically model power only as a function of the wind speed at the turbine hub height. While the latter is an essential predictor of power output, wind speed information in other parts of the vertical profile, as well as additional atmospheric variables, are also important determinants of power. The goal of this work was to determine the gain in predictive ability afforded by adding wind speed information at other heights, as well as other atmospheric variables, to the power prediction model. Using data from a wind farm with a moderately complex terrain in the Altamont Pass region in California, we trained three statistical models, a neural network, a random forest and a Gaussian process model, to predict power output from various sets of aforementioned predictors. The comparison of these predictions to the observed power data revealed that considerable improvements in prediction accuracy can be achieved both through the addition of predictors other than the hub-height wind speed and the use of statistical models. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344 and was funded by Wind Uncertainty Quantification Laboratory Directed Research and Development Project at LLNL under project tracking code 12-ERD-069.

  19. Molecular modeling of the neurophysin I/oxytocin complex

    NASA Astrophysics Data System (ADS)

    Kazmierkiewicz, R.; Czaplewski, C.; Lammek, B.; Ciarkowski, J.

    1997-01-01

    Neurophysins I and II (NPI and NPII) act in the neurosecretory granules as carrier proteinsfor the neurophyseal hormones oxytocin (OT) and vasopressin (VP), respectively. The NPI/OTfunctional unit, believed to be an (NPI/OT)2 heterotetramer, was modeled using low-resolution structure information, viz. the Cα carbon atom coordinates of the homologousNPII/dipeptide complex (file 1BN2 in the Brookhaven Protein Databank) as a template. Itsall-atom representation was obtained using standard modeling tools available within theINSIGHT/Biopolymer modules supplied by Biosym Technologies Inc. A conformation of theNPI-bound OT, similar to that recently proposed in a transfer NOE experiment, was dockedinto the ligand-binding site by a superposition of its Cys1-Tyr2 fragment onto the equivalentportion of the dipeptide in the template. The starting complex for the initial refinements wasprepared by two alternative strategies, termed Model I and Model II, each ending with a˜100 ps molecular dynamics (MD) simulation in water using the AMBER 4.1 force field. The freehomodimer NPI2 was obtained by removal of the two OT subunits from their sites, followedby a similar structure refinement. The use of Model I, consisting of a constrained simulatedannealing, resulted in a structure remarkably similar to both the NPII/dipeptide complex anda recently published solid-state structure of the NPII/OT complex. Thus, Model I isrecommended as the method of choice for the preparation of the starting all-atom data forMD. The MD simulations indicate that, both in the homodimer and in the heterotetramer, the310-helices demonstrate an increased mobility relative to the remaining body of the protein.Also, the C-terminal domains in the NPI2 homodimer are more mobile than the N-terminalones. Finally, a distinct intermonomer interaction is identified, concentrated around its mostprominent, although not unique, contribution provided by an H-bond from Ser25Oγ in one NPI unit to Glu81 Oɛ in the other

  20. Cell motility: Combining experiments with modeling

    NASA Astrophysics Data System (ADS)

    Rappel, Wouter-Jan

    2013-03-01

    Cell migration and motility is a pervasive process in many biology systems. It involves intra-cellular signal transduction pathways that eventually lead to membrane extension and contraction. Here we describe our efforts to combine quantitative experiments with theoretical and computational modeling to gain fundamental insights into eukaryotic cell motion. In particular, we will focus on the amoeboid motion of Dictyostelium discoideum cells. This work is supported by the National Institutes of Health (P01 GM078586)

  1. Background modeling for the GERDA experiment

    SciTech Connect

    Becerici-Schmidt, N.; Collaboration: GERDA Collaboration

    2013-08-08

    The neutrinoless double beta (0νββ) decay experiment GERDA at the LNGS of INFN has started physics data taking in November 2011. This paper presents an analysis aimed at understanding and modeling the observed background energy spectrum, which plays an essential role in searches for a rare signal like 0νββ decay. A very promising preliminary model has been obtained, with the systematic uncertainties still under study. Important information can be deduced from the model such as the expected background and its decomposition in the signal region. According to the model the main background contributions around Q{sub ββ} come from {sup 214}Bi, {sup 228}Th, {sup 42}K, {sup 60}Co and α emitting isotopes in the {sup 226}Ra decay chain, with a fraction depending on the assumed source positions.

  2. Data Assimilation and Model Evaluation Experiment Datasets.

    NASA Astrophysics Data System (ADS)

    Lai, Chung-Chieng A.; Qian, Wen; Glenn, Scott M.

    1994-05-01

    The Institute for Naval Oceanography, in cooperation with Naval Research Laboratories and universities, executed the Data Assimilation and Model Evaluation Experiment (DAMÉE) for the Gulf Stream region during fiscal years 1991-1993. Enormous effort has gone into the preparation of several high-quality and consistent datasets for model initialization and verification. This paper describes the preparation process, the temporal and spatial scopes, the contents, the structure, etc., of these datasets.The goal of DAMEE and the need of data for the four phases of experiment are briefly stated. The preparation of DAMEE datasets consisted of a series of processes: 1)collection of observational data; 2) analysis and interpretation; 3) interpolation using the Optimum Thermal Interpolation System package; 4) quality control and re-analysis; and 5) data archiving and software documentation.The data products from these processes included a time series of 3D fields of temperature and salinity, 2D fields of surface dynamic height and mixed-layer depth, analysis of the Gulf Stream and rings system, and bathythermograph profiles. To date, these are the most detailed and high-quality data for mesoscale ocean modeling, data assimilation, and forecasting research. Feedback from ocean modeling groups who tested this data was incorporated into its refinement.Suggestions for DAMEE data usages include 1) ocean modeling and data assimilation studies, 2) diagnosis and theorectical studies, and 3) comparisons with locally detailed observations.

  3. Data assimilation and model evaluation experiment datasets

    NASA Technical Reports Server (NTRS)

    Lai, Chung-Cheng A.; Qian, Wen; Glenn, Scott M.

    1994-01-01

    The Institute for Naval Oceanography, in cooperation with Naval Research Laboratories and universities, executed the Data Assimilation and Model Evaluation Experiment (DAMEE) for the Gulf Stream region during fiscal years 1991-1993. Enormous effort has gone into the preparation of several high-quality and consistent datasets for model initialization and verification. This paper describes the preparation process, the temporal and spatial scopes, the contents, the structure, etc., of these datasets. The goal of DAMEE and the need of data for the four phases of experiment are briefly stated. The preparation of DAMEE datasets consisted of a series of processes: (1) collection of observational data; (2) analysis and interpretation; (3) interpolation using the Optimum Thermal Interpolation System package; (4) quality control and re-analysis; and (5) data archiving and software documentation. The data products from these processes included a time series of 3D fields of temperature and salinity, 2D fields of surface dynamic height and mixed-layer depth, analysis of the Gulf Stream and rings system, and bathythermograph profiles. To date, these are the most detailed and high-quality data for mesoscale ocean modeling, data assimilation, and forecasting research. Feedback from ocean modeling groups who tested this data was incorporated into its refinement. Suggestions for DAMEE data usages include (1) ocean modeling and data assimilation studies, (2) diagnosis and theoretical studies, and (3) comparisons with locally detailed observations.

  4. Design of Experiments, Model Calibration and Data Assimilation

    SciTech Connect

    Williams, Brian J.

    2014-07-30

    This presentation provides an overview of emulation, calibration and experiment design for computer experiments. Emulation refers to building a statistical surrogate from a carefully selected and limited set of model runs to predict unsampled outputs. The standard kriging approach to emulation of complex computer models is presented. Calibration refers to the process of probabilistically constraining uncertain physics/engineering model inputs to be consistent with observed experimental data. An initial probability distribution for these parameters is updated using the experimental information. Markov chain Monte Carlo (MCMC) algorithms are often used to sample the calibrated parameter distribution. Several MCMC algorithms commonly employed in practice are presented, along with a popular diagnostic for evaluating chain behavior. Space-filling approaches to experiment design for selecting model runs to build effective emulators are discussed, including Latin Hypercube Design and extensions based on orthogonal array skeleton designs and imposed symmetry requirements. Optimization criteria that further enforce space-filling, possibly in projections of the input space, are mentioned. Designs to screen for important input variations are summarized and used for variable selection in a nuclear fuels performance application. This is followed by illustration of sequential experiment design strategies for optimization, global prediction, and rare event inference.

  5. Anatomy of a Metamorphic Core Complex: Preliminary Results of Ruby Mountains Seismic Experiment, Northeastern Nevada

    NASA Astrophysics Data System (ADS)

    Schiltz, K. K.; Litherland, M.; Klemperer, S. L.

    2010-12-01

    The Ruby Mountains Seismic Experiment is a 50-station deployment of Earthscope’s Flexible Array installed in June 2010 to study the Ruby Mountain metamorphic core complex, northeastern Nevada. Competing theories of metamorphic core complexes stress the importance of either (1) low-angle detachment faulting and lateral crustal flow, likely leading to horizontal shearing and anisotropy, or (2) vertical diapirism creating dominantly vertical shearing and anisotropy. Our experiment aims to distinguish between these two hypotheses using densely spaced (5 to 10 km) broadband seismometers along two WNW-ESE transects across the Ruby Range and one NNE-SSW transect along the axis of the range. When data acquisition is complete we will image crustal structures and measure velocity and anisotropy with a range of receiver function, shear-wave splitting and surface-wave tomographic methods. In addition to the newly acquired data, existing data can also be used to build understanding of the region. Previous regional studies have interpreted shear-wave splitting in terms of single-layer anisotropy in the mantle, related to a complex flow structure, but previous controlled source studies have identified measurable crustal anisotropy. We therefore attempted to fit existing data to a two-layer model consisting of a weakly anisotropic crustal layer and a more dominant mantle layer. We used “SplitLab” to measure apparent splitting parameters from ELK (a USGS permanent station) and 3 Earthscope Transportable Array stations. There is a clear variation in the splitting parameters with back-azimuth, but existing data do not provide a stable inversion for a two-layer model. Our best forward-model solution is a crustal layer with a fast axis orientation of 357° and 0.3 second delay time and a mantle layer with a 282° fast axis and 1.3 s delay time. Though the direction of the fast axis is consistent with previously published regional results, the 1.3 s delay time is larger than

  6. Evaluation of a Neuromechanical Walking Control Model Using Disturbance Experiments

    PubMed Central

    Song, Seungmoon; Geyer, Hartmut

    2017-01-01

    Neuromechanical simulations have been used to study the spinal control of human locomotion which involves complex mechanical dynamics. So far, most neuromechanical simulation studies have focused on demonstrating the capability of a proposed control model in generating normal walking. As many of these models with competing control hypotheses can generate human-like normal walking behaviors, a more in-depth evaluation is required. Here, we conduct the more in-depth evaluation on a spinal-reflex-based control model using five representative gait disturbances, ranging from electrical stimulation to mechanical perturbation at individual leg joints and at the whole body. The immediate changes in muscle activations of the model are compared to those of humans across different gait phases and disturbance magnitudes. Remarkably similar response trends for the majority of investigated muscles and experimental conditions reinforce the plausibility of the reflex circuits of the model. However, the model's responses lack in amplitude for two experiments with whole body disturbances suggesting that in these cases the proposed reflex circuits need to be amplified by additional control structures such as location-specific cutaneous reflexes. A model that captures these selective amplifications would be able to explain both steady and reactive spinal control of human locomotion. Neuromechanical simulations that investigate hypothesized control models are complementary to gait experiments in better understanding the control of human locomotion. PMID:28381996

  7. Modeling the evolution of complex conductivity during calcite precipitation on glass beads

    NASA Astrophysics Data System (ADS)

    Leroy, Philippe; Li, Shuai; Jougnot, Damien; Revil, André; Wu, Yuxin

    2017-01-01

    SUMMARYWhen pH and alkalinity increase, calcite frequently precipitates and hence modifies the petrophysical properties of porous media. The <span class="hlt">complex</span> conductivity method can be used to directly monitor calcite precipitation in porous media because it is sensitive to the evolution of the mineralogy, pore structure and its connectivity. We have developed a mechanistic grain polarization <span class="hlt">model</span> considering the electrochemical polarization of the Stern and diffuse layer surrounding calcite particles. Our <span class="hlt">complex</span> conductivity <span class="hlt">model</span> depends on the surface charge density of the Stern layer and on the electrical potential at the onset of the diffuse layer, which are computed using a basic Stern <span class="hlt">model</span> of the calcite/water interface. The <span class="hlt">complex</span> conductivity measurements of Wu et al. (2010) on a column packed with glass beads where calcite precipitation occurs are reproduced by our surface <span class="hlt">complexation</span> and <span class="hlt">complex</span> conductivity <span class="hlt">models</span>. The evolution of the size and shape of calcite particles during the calcite precipitation <span class="hlt">experiment</span> is estimated by our <span class="hlt">complex</span> conductivity <span class="hlt">model</span>. At the early stage of the calcite precipitation <span class="hlt">experiment</span>, <span class="hlt">modeled</span> particles sizes increase and calcite particles flatten with time because calcite crystals nucleate at the surface of glass beads and grow into larger calcite grains around glass beads. At the later stage of the calcite precipitation <span class="hlt">experiment</span>, <span class="hlt">modeled</span> sizes and cementation exponents of calcite particles decrease with time because large calcite grains aggregate over multiple glass beads, a percolation threshold is achieved, and small and discrete calcite crystals polarize.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993JAG....29..301D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993JAG....29..301D"><span><span class="hlt">Experience</span> from the ECORS program in regions of <span class="hlt">complex</span> geology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Damotte, B.</p> <p>1993-04-01</p> <p>The French ECORS program was launched in 1983 by a cooperation agreement between universities and petroleum companies. Crustal surveys have tried to find explanations for the formation of geological features, such as rifts, mountains ranges or subsidence in sedimentary basins. Several seismic surveys were carried out, some across areas with <span class="hlt">complex</span> geological structures. The seismic techniques and equipment used were those developed by petroleum geophysicists, adapted to the depth aimed at (30-50 km) and to various physical constraints encountered in the field. In France, ECORS has recorded 850 km of deep seismic lines onshore across plains and mountains, on various kinds of geological formations. Different variations of the seismic method (reflection, refraction, long-offset seismic) were used, often simultaneously. Multiple coverage profiling constitutes the essential part of this data acquisition. Vibrators and dynamite shots were employed with a spread generally 15 km long, but sometimes 100 km long. Some typical seismic examples show that obtaining crustal reflections essentialy depends on two factors: (1) the type and structure of shallow formations, and (2) the sources used. Thus, when seismic energy is strongly absorbed across the first kilometers in shallow formations, or when these formations are highly structured, standard multiple-coverage profiling is not able to provide results beyond a few seconds. In this case, it is recommended to simultaneously carry out long-offset seismic in low multiple coverage. Other more methodological examples show: how the impact on the crust of a surface fault may be evaluated according to the seismic method implemented ( VIBROSEIS 96-fold coverage or single dynamite shot); that vibrators make it possible to implement wide-angle seismic surveying with an offset 80 km long; how to implement the seismic reflection method on <span class="hlt">complex</span> formations in high mountains. All data were processed using industrial seismic software</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910007189','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910007189"><span>Observation simulation <span class="hlt">experiments</span> with regional prediction <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Diak, George; Perkey, Donald J.; Kalb, Michael; Robertson, Franklin R.; Jedlovec, Gary</p> <p>1990-01-01</p> <p>Research efforts in FY 1990 included studies employing regional scale numerical <span class="hlt">models</span> as aids in evaluating potential contributions of specific satellite observing systems (current and future) to numerical prediction. One study involves Observing System Simulation <span class="hlt">Experiments</span> (OSSEs) which mimic operational initialization/forecast cycles but incorporate simulated Advanced Microwave Sounding Unit (AMSU) radiances as input data. The objective of this and related studies is to anticipate the potential value of data from these satellite systems, and develop applications of remotely sensed data for the benefit of short range forecasts. Techniques are also being used that rely on numerical <span class="hlt">model</span>-based synthetic satellite radiances to interpret the information content of various types of remotely sensed image and sounding products. With this approach, evolution of simulated channel radiance image features can be directly interpreted in terms of the atmospheric dynamical processes depicted by a <span class="hlt">model</span>. Progress is being made in a study using the internal consistency of a regional prediction <span class="hlt">model</span> to simplify the assessment of forced diabatic heating and moisture initialization in reducing <span class="hlt">model</span> spinup times. Techniques for <span class="hlt">model</span> initialization are being examined, with focus on implications for potential applications of remote microwave observations, including AMSU and Special Sensor Microwave Imager (SSM/I), in shortening <span class="hlt">model</span> spinup time for regional prediction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20726125','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20726125"><span>Design of <span class="hlt">experiments</span> and springback prediction for AHSS automotive components with <span class="hlt">complex</span> geometry</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Asgari, A.; Pereira, M.; Rolfe, B.; Dingle, M.; Hodgson, P.</p> <p>2005-08-05</p> <p>With the drive towards implementing Advanced High Strength Steels (AHSS) in the automotive industry; stamping engineers need to quickly answer questions about forming these strong materials into elaborate shapes. Commercially available codes have been successfully used to accurately predict formability, thickness and strains in <span class="hlt">complex</span> parts. However, springback and twisting are still challenging subjects in numerical simulations of AHSS components. Design of <span class="hlt">Experiments</span> (DOE) has been used in this paper to study the sensitivity of the implicit and explicit numerical results with respect to certain arrays of user input parameters in the forming of an AHSS component. Numerical results were compared to experimental measurements of the parts stamped in an industrial production line. The forming predictions of the implicit and explicit codes were in good agreement with the experimental measurements for the conventional steel grade, while lower accuracies were observed for the springback predictions. The forming predictions of the <span class="hlt">complex</span> component with an AHSS material were also in good correlation with the respective experimental measurements. However, much lower accuracies were observed in its springback predictions. The number of integration points through the thickness and tool offset were found to be of significant importance, while coefficient of friction and Young's modulus (<span class="hlt">modeling</span> input parameters) have no significant effect on the accuracy of the predictions for the <span class="hlt">complex</span> geometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMS...165..139M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMS...165..139M"><span>Simple parameter estimation for <span class="hlt">complex</span> <span class="hlt">models</span> — Testing evolutionary techniques on 3-dimensional biogeochemical ocean <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mattern, Jann Paul; Edwards, Christopher A.</p> <p>2017-01-01</p> <p>Parameter estimation is an important part of numerical <span class="hlt">modeling</span> and often required when a coupled physical-biogeochemical ocean <span class="hlt">model</span> is first deployed. However, 3-dimensional ocean <span class="hlt">model</span> simulations are computationally expensive and <span class="hlt">models</span> typically contain upwards of 10 parameters suitable for estimation. Hence, manual parameter tuning can be lengthy and cumbersome. Here, we present four easy to implement and flexible parameter estimation techniques and apply them to two 3-dimensional biogeochemical <span class="hlt">models</span> of different <span class="hlt">complexities</span>. Based on a Monte Carlo <span class="hlt">experiment</span>, we first develop a cost function measuring the <span class="hlt">model</span>-observation misfit based on multiple data types. The parameter estimation techniques are then applied and yield a substantial cost reduction over ∼ 100 simulations. Based on the outcome of multiple replicate <span class="hlt">experiments</span>, they perform on average better than random, uninformed parameter search but performance declines when more than 40 parameters are estimated together. Our results emphasize the <span class="hlt">complex</span> cost function structure for biogeochemical parameters and highlight dependencies between different parameters as well as different cost function formulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD0768928','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD0768928"><span>Experimente ueber den Einflusse von Metaboliten und Antimetaboliten am <span class="hlt">Modell</span> von Trichomonas Vaginalis. I. Mitteilung Experimente mit dem Vitamin B2-Komplex (<span class="hlt">Experiments</span> on the Influence of Metabolites and Antimetabolites on the <span class="hlt">Model</span> of Trichomonas vaginalis. I. Communication: <span class="hlt">Experiments</span> with the Vitamin-B2-<span class="hlt">Complex</span>),</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p></p> <p>pathogenic protozoa Trichomonas vaginalis have been studied. Material and methods are described in the paper. The efficacy of the individual admixtures from the vitamin-B2-<span class="hlt">complex</span> is subsequently discussed. (Author)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001APS..SHK.C5002O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001APS..SHK.C5002O"><span>Ballistic Response of Fabrics: <span class="hlt">Model</span> and <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Orphal, Dennis L.; Walker Anderson, James D., Jr.</p> <p>2001-06-01</p> <p>Walker (1999)developed an analytical <span class="hlt">model</span> for the dynamic response of fabrics to ballistic impact. From this <span class="hlt">model</span> the force, F, applied to the projectile by the fabric is derived to be F = 8/9 (ET*)h^3/R^2, where E is the Young's modulus of the fabric, T* is the "effective thickness" of the fabric and equal to the ratio of the areal density of the fabric to the fiber density, h is the displacement of the fabric on the axis of impact and R is the radius of the fabric deformation or "bulge". Ballistic tests against Zylon^TM fabric have been performed to measure h and R as a function of time. The results of these <span class="hlt">experiments</span> are presented and analyzed in the context of the Walker <span class="hlt">model</span>. Walker (1999), Proceedings of the 18th International Symposium on Ballistics, pp. 1231.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2797718','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2797718"><span><span class="hlt">Modeling</span> <span class="hlt">Complex</span> Workflow in Molecular Diagnostics</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gomah, Mohamed E.; Turley, James P.; Lu, Huimin; Jones, Dan</p> <p>2010-01-01</p> <p>One of the hurdles to achieving personalized medicine has been implementing the laboratory processes for performing and reporting <span class="hlt">complex</span> molecular tests. The rapidly changing test rosters and <span class="hlt">complex</span> analysis platforms in molecular diagnostics have meant that many clinical laboratories still use labor-intensive manual processing and testing without the level of automation seen in high-volume chemistry and hematology testing. We provide here a discussion of design requirements and the results of implementation of a suite of lab management tools that incorporate the many elements required for use of molecular diagnostics in personalized medicine, particularly in cancer. These applications provide the functionality required for sample accessioning and tracking, material generation, and testing that are particular to the evolving needs of individualized molecular diagnostics. On implementation, the applications described here resulted in improvements in the turn-around time for reporting of more <span class="hlt">complex</span> molecular test sets, and significant changes in the workflow. Therefore, careful mapping of workflow can permit design of software applications that simplify even the <span class="hlt">complex</span> demands of specialized molecular testing. By incorporating design features for order review, software tools can permit a more personalized approach to sample handling and test selection without compromising efficiency. PMID:20007844</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920000894','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920000894"><span>Process <span class="hlt">modelling</span> for Space Station <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Alexander, J. Iwan D.; Rosenberger, Franz; Nadarajah, Arunan; Ouazzani, Jalil; Amiroudine, Sakir</p> <p>1990-01-01</p> <p>Examined here is the sensitivity of a variety of space <span class="hlt">experiments</span> to residual accelerations. In all the cases discussed the sensitivity is related to the dynamic response of a fluid. In some cases the sensitivity can be defined by the magnitude of the response of the velocity field. This response may involve motion of the fluid associated with internal density gradients, or the motion of a free liquid surface. For fluids with internal density gradients, the type of acceleration to which the <span class="hlt">experiment</span> is sensitive will depend on whether buoyancy driven convection must be small in comparison to other types of fluid motion, or fluid motion must be suppressed or eliminated. In the latter case, the <span class="hlt">experiments</span> are sensitive to steady and low frequency accelerations. For <span class="hlt">experiments</span> such as the directional solidification of melts with two or more components, determination of the velocity response alone is insufficient to assess the sensitivity. The effect of the velocity on the composition and temperature field must be considered, particularly in the vicinity of the melt-crystal interface. As far as the response to transient disturbances is concerned, the sensitivity is determined by both the magnitude and frequency of the acceleration and the characteristic momentum and solute diffusion times. The microgravity environment, a numerical analysis of low gravity tolerance of the Bridgman-Stockbarger technique, and <span class="hlt">modeling</span> crystal growth by physical vapor transport in closed ampoules are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011LNCS.6589....1T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011LNCS.6589....1T"><span>Using <span class="hlt">Models</span> to Inform Policy: Insights from <span class="hlt">Modeling</span> the <span class="hlt">Complexities</span> of Global Polio Eradication</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Thompson, Kimberly M.</p> <p></p> <p>Drawing on over 20 years of <span class="hlt">experience</span> <span class="hlt">modeling</span> risks in <span class="hlt">complex</span> systems, this talk will challenge SBP participants to develop <span class="hlt">models</span> that provide timely and useful answers to critical policy questions when decision makers need them. The talk will include reflections on the opportunities and challenges associated with developing integrated <span class="hlt">models</span> for <span class="hlt">complex</span> problems and communicating their results effectively. Dr. Thompson will focus the talk largely on collaborative <span class="hlt">modeling</span> related to global polio eradication and the application of system dynamics tools. After successful global eradication of wild polioviruses, live polioviruses will still present risks that could potentially lead to paralytic polio cases. This talk will present the insights of efforts to use integrated dynamic, probabilistic risk, decision, and economic <span class="hlt">models</span> to address critical policy questions related to managing global polio risks. Using a dynamic disease transmission <span class="hlt">model</span> combined with probabilistic <span class="hlt">model</span> inputs that characterize uncertainty for a stratified world to account for variability, we find that global health leaders will face some difficult choices, but that they can take actions that will manage the risks effectively. The talk will emphasize the need for true collaboration between <span class="hlt">modelers</span> and subject matter experts, and the importance of working with decision makers as partners to ensure the development of useful <span class="hlt">models</span> that actually get used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED476861.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED476861.pdf"><span>Specifying and Refining a <span class="hlt">Complex</span> Measurement <span class="hlt">Model</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Levy, Roy; Mislevy, Robert J.</p> <p></p> <p>This paper aims to describe a Bayesian approach to <span class="hlt">modeling</span> and estimating cognitive <span class="hlt">models</span> both in terms of statistical machinery and actual instrument development. Such a method taps the knowledge of experts to provide initial estimates for the probabilistic relationships among the variables in a multivariate latent variable <span class="hlt">model</span> and refines…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Complex+AND+adaptive+AND+system&pg=5&id=EJ691535','ERIC'); return false;" href="http://eric.ed.gov/?q=Complex+AND+adaptive+AND+system&pg=5&id=EJ691535"><span>Acquisition of <span class="hlt">Complex</span> Systemic Thinking: Mental <span class="hlt">Models</span> of Evolution</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>d'Apollonia, Sylvia T.; Charles, Elizabeth S.; Boyd, Gary M.</p> <p>2004-01-01</p> <p>We investigated the impact of introducing college students to <span class="hlt">complex</span> adaptive systems on their subsequent mental <span class="hlt">models</span> of evolution compared to those of students taught in the same manner but with no reference to <span class="hlt">complex</span> systems. The students' mental <span class="hlt">models</span> (derived from similarity ratings of 12 evolutionary terms using the pathfinder algorithm)…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1260366','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1260366"><span>Argonne Bubble <span class="hlt">Experiment</span> Thermal <span class="hlt">Model</span> Development II</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Buechler, Cynthia Eileen</p> <p>2016-07-01</p> <p>This report describes the continuation of the work reported in “Argonne Bubble <span class="hlt">Experiment</span> Thermal <span class="hlt">Model</span> Development”. The <span class="hlt">experiment</span> was performed at Argonne National Laboratory (ANL) in 2014. A rastered 35 MeV electron beam deposited power in a solution of uranyl sulfate, generating heat and radiolytic gas bubbles. Irradiations were performed at three beam power levels, 6, 12 and 15 kW. Solution temperatures were measured by thermocouples, and gas bubble behavior was observed. This report will describe the Computational Fluid Dynamics (CFD) <span class="hlt">model</span> that was developed to calculate the temperatures and gas volume fractions in the solution vessel during the irradiations. The previous report described an initial analysis performed on a geometry that had not been updated to reflect the as-built solution vessel. Here, the as-built geometry is used. Monte-Carlo N-Particle (MCNP) calculations were performed on the updated geometry, and these results were used to define the power deposition profile for the CFD analyses, which were performed using Fluent, Ver. 16.2. CFD analyses were performed for the 12 and 15 kW irradiations, and further improvements to the <span class="hlt">model</span> were incorporated, including the consideration of power deposition in nearby vessel components, gas mixture composition, and bubble size distribution. The temperature results of the CFD calculations are compared to experimental measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.A44D..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.A44D..07B"><span>Wind Tunnel <span class="hlt">Modeling</span> Of Wind Flow Over <span class="hlt">Complex</span> Terrain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Banks, D.; Cochran, B.</p> <p>2010-12-01</p> <p>This presentation will describe the finding of an atmospheric boundary layer (ABL) wind tunnel study conducted as part of the Bolund <span class="hlt">Experiment</span>. This <span class="hlt">experiment</span> was sponsored by Risø DTU (National Laboratory for Sustainable Energy, Technical University of Denmark) during the fall of 2009 to enable a blind comparison of various air flow <span class="hlt">models</span> in an attempt to validate their performance in predicting airflow over <span class="hlt">complex</span> terrain. Bohlund hill sits 12 m above the water level at the end of a narrow isthmus. The island features a steep escarpment on one side, over which the airflow can be expected to separate. The island was equipped with several anemometer towers, and the approach flow over the water was well characterized. This study was one of only two only physical <span class="hlt">model</span> studies included in the blind <span class="hlt">model</span> comparison, the other being a water plume study. The remainder were computational fluid dynamics (CFD) simulations, including both RANS and LES. Physical <span class="hlt">modeling</span> of air flow over topographical features has been used since the middle of the 20th century, and the methods required are well understood and well documented. Several books have been written describing how to properly perform ABL wind tunnel studies, including ASCE manual of engineering practice 67. Boundary layer wind tunnel tests are the only <span class="hlt">modelling</span> method deemed acceptable in ASCE 7-10, the most recent edition of the American Society of Civil Engineers standard that provides wind loads for buildings and other structures for buildings codes across the US. Since the 1970’s, most tall structures undergo testing in a boundary layer wind tunnel to accurately determine the wind induced loading. When compared to CFD, the US EPA considers a properly executed wind tunnel study to be equivalent to a CFD <span class="hlt">model</span> with infinitesimal grid resolution and near infinite memory. One key reason for this widespread acceptance is that properly executed ABL wind tunnel studies will accurately simulate flow separation</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/941408','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/941408"><span><span class="hlt">Experiments</span> for foam <span class="hlt">model</span> development and validation.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bourdon, Christopher Jay; Cote, Raymond O.; Moffat, Harry K.; Grillet, Anne Mary; Mahoney, James F.; Russick, Edward Mark; Adolf, Douglas Brian; Rao, Rekha Ranjana; Thompson, Kyle Richard; Kraynik, Andrew Michael; Castaneda, Jaime N.; Brotherton, Christopher M.; Mondy, Lisa Ann; Gorby, Allen D.</p> <p>2008-09-01</p> <p>A series of <span class="hlt">experiments</span> has been performed to allow observation of the foaming process and the collection of temperature, rise rate, and microstructural data. Microfocus video is used in conjunction with particle image velocimetry (PIV) to elucidate the boundary condition at the wall. Rheology, reaction kinetics and density measurements complement the flow visualization. X-ray computed tomography (CT) is used to examine the cured foams to determine density gradients. These data provide input to a continuum level finite element <span class="hlt">model</span> of the blowing process.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA593318','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA593318"><span><span class="hlt">Complex</span> Systems and Human Performance <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2013-12-01</p> <p>human communication patterns can be implemented in a task network <span class="hlt">modeling</span> tool. Although queues are a basic feature in many task network <span class="hlt">modeling</span>...time. <span class="hlt">MODELING</span> COMMUNICATIVE BEHAVIOR Barabasi (2010) argues that human communication patterns are “bursty”; that is, the inter-event arrival...Having implemented the methods advocated by Clauset et al. in C3TRACE, we have grown more confident that the human communication data discussed above</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.5613O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.5613O"><span>Induced polarization of clay-sand mixtures. <span class="hlt">Experiments</span> and <span class="hlt">modelling</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Okay, G.; Leroy, P.</p> <p>2012-04-01</p> <p>The <span class="hlt">complex</span> conductivity of saturated unconsolidated sand-clay mixtures was experimentally investigated using two types of clay minerals, kaolinite and smectite (mainly Na-Montmorillonite) in the frequency range 1.4 mHz - 12 kHz. The <span class="hlt">experiments</span> were performed with various clay contents (1, 5, 20, and 100 % in volume of the sand-clay mixture) and salinities (distilled water, 0.1 g/L, 1 g/L, and 10 g/L NaCl solution). Induced polarization measurements were performed with a cylindrical four-electrode sample-holder associated with a SIP-Fuchs II impedance meter and non-polarizing Cu/CuSO4 electrodes. The results illustrate the strong impact of the CEC of the clay minerals upon the <span class="hlt">complex</span> conductivity. The quadrature conductivity increases steadily with the clay content. We observe that the dependence on frequency of the quadrature conductivity of sand-kaolinite mixtures is more important than for sand-bentonite mixtures. For both types of clay, the quadrature conductivity seems to be fairly independent on the pore fluid salinity except at very low clay contents. The experimental data show good agreement with predicted values given by our SIP <span class="hlt">model</span>. This <span class="hlt">complex</span> conductivity <span class="hlt">model</span> considers the electrochemical polarization of the Stern layer coating the clay particles and the Maxwell-Wagner polarization. We use the differential effective medium theory to calculate the <span class="hlt">complex</span> conductivity of the porous medium constituted of the grains and the electrolyte. The SIP <span class="hlt">model</span> includes also the effect of the grain size distribution upon the <span class="hlt">complex</span> conductivity spectra.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EJPh...38b5202G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EJPh...38b5202G"><span>Forces between permanent magnets: <span class="hlt">experiments</span> and <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>González, Manuel I.</p> <p>2017-03-01</p> <p>This work describes a very simple, low-cost experimental setup designed for measuring the force between permanent magnets. The <span class="hlt">experiment</span> consists of placing one of the magnets on a balance, attaching the other magnet to a vertical height gauge, aligning carefully both magnets and measuring the load on the balance as a function of the gauge reading. A theoretical <span class="hlt">model</span> is proposed to compute the force, assuming uniform magnetisation and based on laws and techniques accessible to undergraduate students. A comparison between the <span class="hlt">model</span> and the experimental results is made, and good agreement is found at all distances investigated. In particular, it is also found that the force behaves as r -4 at large distances, as expected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SMaS...22b5034G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SMaS...22b5034G"><span>Bucky gel actuator displacement: <span class="hlt">experiment</span> and <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ghamsari, A. K.; Jin, Y.; Zegeye, E.; Woldesenbet, E.</p> <p>2013-02-01</p> <p>Bucky gel actuator (BGA) is a dry electroactive nanocomposite which is driven with a few volts. BGA’s remarkable features make this tri-layered actuator a potential candidate for morphing applications. However, most of these applications would require a better understanding of the effective parameters that influence the BGA displacement. In this study, various sets of <span class="hlt">experiments</span> were designed to investigate the effect of several parameters on the maximum lateral displacement of BGA. Two input parameters, voltage and frequency, and three material/design parameters, carbon nanotube type, thickness, and weight fraction of constituents were selected. A new thickness ratio term was also introduced to study the role of individual layers on BGA displacement. A <span class="hlt">model</span> was established to predict BGA maximum displacement based on the effect of these parameters. This <span class="hlt">model</span> showed good agreement with reported results from the literature. In addition, an important factor in the design of BGA-based devices, lifetime, was investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3970111','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3970111"><span>Multiscale Computational <span class="hlt">Models</span> of <span class="hlt">Complex</span> Biological Systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Walpole, Joseph; Papin, Jason A.; Peirce, Shayn M.</p> <p>2014-01-01</p> <p>Integration of data across spatial, temporal, and functional scales is a primary focus of biomedical engineering efforts. The advent of powerful computing platforms, coupled with quantitative data from high-throughput experimental platforms, has allowed multiscale <span class="hlt">modeling</span> to expand as a means to more comprehensively investigate biological phenomena in experimentally relevant ways. This review aims to highlight recently published multiscale <span class="hlt">models</span> of biological systems while using their successes to propose the best practices for future <span class="hlt">model</span> development. We demonstrate that coupling continuous and discrete systems best captures biological information across spatial scales by selecting <span class="hlt">modeling</span> techniques that are suited to the task. Further, we suggest how to best leverage these multiscale <span class="hlt">models</span> to gain insight into biological systems using quantitative, biomedical engineering methods to analyze data in non-intuitive ways. These topics are discussed with a focus on the future of the field, the current challenges encountered, and opportunities yet to be realized. PMID:23642247</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/373738','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/373738"><span>Information, <span class="hlt">complexity</span> and efficiency: The automobile <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Allenby, B. |</p> <p>1996-08-08</p> <p>The new, rapidly evolving field of industrial ecology - the objective, multidisciplinary study of industrial and economic systems and their linkages with fundamental natural systems - provides strong ground for believing that a more environmentally and economically efficient economy will be more information intensive and <span class="hlt">complex</span>. Information and intellectual capital will be substituted for the more traditional inputs of materials and energy in producing a desirable, yet sustainable, quality of life. While at this point this remains a strong hypothesis, the evolution of the automobile industry can be used to illustrate how such substitution may, in fact, already be occurring in an environmentally and economically critical sector.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012APS..DFDH32006Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012APS..DFDH32006Z"><span>A resistive force <span class="hlt">model</span> for <span class="hlt">complex</span> intrusion in granular media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Tingnan; Li, Chen; Goldman, Daniel</p> <p>2012-11-01</p> <p>Intrusion forces in granular media (GM) are best understood for simple shapes (like disks and rods) undergoing vertical penetration and horizontal drag. Inspired by a resistive force theory for sand-swimming, we develop a new two-dimensional resistive force <span class="hlt">model</span> for intruders of arbitrary shape and intrusion path into GM in the vertical plane. We divide an intruder of <span class="hlt">complex</span> geometry into small segments and approximate segmental forces by measuring forces on small flat plates in <span class="hlt">experiments</span>. Both lift and drag forces on the plates are proportional to penetration depth, and depend sensitively on the angle of attack and the direction of motion. Summation of segmental forces over the intruder predicts the net forces on a c-leg, a flat leg, and a reversed c-leg rotated into GM about a fixed axle. The stress profiles are similar for GM of different particle sizes, densities, coefficients of friction, and volume fractions. We propose a universal scaling law applicable to all tested GM. By combining the new force <span class="hlt">model</span> with a multi-body simulator, we can also predict the locomotion dynamics of a small legged robot on GM. Our force laws can provide a strict test of hydrodynamic-like approaches to <span class="hlt">model</span> dense granular flows. Also affiliated to: School of Physics, Georgia Institute of Technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=negotiation&pg=4&id=EJ1084186','ERIC'); return false;" href="http://eric.ed.gov/?q=negotiation&pg=4&id=EJ1084186"><span><span class="hlt">Complex</span> Perceptions of Identity: The <span class="hlt">Experiences</span> of Student Combat Veterans in Community College</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Hammond, Shane Patrick</p> <p>2016-01-01</p> <p>This qualitative study illustrates how <span class="hlt">complex</span> perceptions of identity influence the community college <span class="hlt">experience</span> for student veterans who have been in combat, creating barriers to their overall persistence. The collective <span class="hlt">experiences</span> of student combat veterans at two community colleges in northwestern Massachusetts are presented, and a Combat…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Cerebral+AND+palsy&id=EJ924150','ERIC'); return false;" href="http://eric.ed.gov/?q=Cerebral+AND+palsy&id=EJ924150"><span>Communicating about Loss: <span class="hlt">Experiences</span> of Older Australian Adults with Cerebral Palsy and <span class="hlt">Complex</span> Communication Needs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dark, Leigha; Balandin, Susan; Clemson, Lindy</p> <p>2011-01-01</p> <p>Loss and grief is a universal human <span class="hlt">experience</span>, yet little is known about how older adults with a lifelong disability, such as cerebral palsy, and <span class="hlt">complex</span> communication needs (CCN) <span class="hlt">experience</span> loss and manage the grieving process. In-depth interviews were conducted with 20 Australian participants with cerebral palsy and CCN to determine the types…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=light+AND+table+AND+primary+AND+school&pg=2&id=EJ1002230','ERIC'); return false;" href="http://eric.ed.gov/?q=light+AND+table+AND+primary+AND+school&pg=2&id=EJ1002230"><span>Woven into the Fabric of <span class="hlt">Experience</span>: Residential Adventure Education and <span class="hlt">Complexity</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Williams, Randall</p> <p>2013-01-01</p> <p>Residential adventure education is a surprisingly powerful developmental <span class="hlt">experience</span>. This paper reports on a mixed-methods study focused on English primary school pupils aged 9-11, which used <span class="hlt">complexity</span> theory to throw light on the synergistic inter-relationships between the different aspects of that <span class="hlt">experience</span>. Broadly expressed, the research…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=39443','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=39443"><span>Slip <span class="hlt">complexity</span> in dynamic <span class="hlt">models</span> of earthquake faults.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Langer, J S; Carlson, J M; Myers, C R; Shaw, B E</p> <p>1996-01-01</p> <p>We summarize recent evidence that <span class="hlt">models</span> of earthquake faults with dynamically unstable friction laws but no externally imposed heterogeneities can exhibit slip <span class="hlt">complexity</span>. Two <span class="hlt">models</span> are described here. The first is a one-dimensional <span class="hlt">model</span> with velocity-weakening stick-slip friction; the second is a two-dimensional elastodynamic <span class="hlt">model</span> with slip-weakening friction. Both exhibit small-event <span class="hlt">complexity</span> and chaotic sequences of large characteristic events. The large events in both <span class="hlt">models</span> are composed of Heaton pulses. We argue that the key ingredients of these <span class="hlt">models</span> are reasonably accurate representations of the properties of real faults. PMID:11607671</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/877087','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/877087"><span><span class="hlt">Modeling</span> Power Systems as <span class="hlt">Complex</span> Adaptive Systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chassin, David P.; Malard, Joel M.; Posse, Christian; Gangopadhyaya, Asim; Lu, Ning; Katipamula, Srinivas; Mallow, J V.</p> <p>2004-12-30</p> <p>Physical analogs have shown considerable promise for understanding the behavior of <span class="hlt">complex</span> adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today's most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This report explores the state-of-the-art physical analogs for understanding the behavior of some econophysical systems and deriving stable and robust control strategies for using them. We review and discuss applications of some analytic methods based on a thermodynamic metaphor, according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of <span class="hlt">complex</span> systems that cannot be otherwise understood. We apply these methods to the question of how power markets can be expected to behave under a variety of conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8336E....A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8336E....A"><span>Integrated <span class="hlt">Modeling</span> of <span class="hlt">Complex</span> Optomechanical Systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andersen, Torben; Enmark, Anita</p> <p>2011-09-01</p> <p>Mathematical <span class="hlt">modeling</span> and performance simulation are playing an increasing role in large, high-technology projects. There are two reasons; first, projects are now larger than they were before, and the high cost calls for detailed performance prediction before construction. Second, in particular for space-related designs, it is often difficult to test systems under realistic conditions beforehand, and mathematical <span class="hlt">modeling</span> is then needed to verify in advance that a system will work as planned. Computers have become much more powerful, permitting calculations that were not possible before. At the same time mathematical tools have been further developed and found acceptance in the community. Particular progress has been made in the fields of structural mechanics, optics and control engineering, where new methods have gained importance over the last few decades. Also, methods for combining optical, structural and control system <span class="hlt">models</span> into global <span class="hlt">models</span> have found widespread use. Such combined <span class="hlt">models</span> are usually called integrated <span class="hlt">models</span> and were the subject of this symposium. The objective was to bring together people working in the fields of groundbased optical telescopes, ground-based radio telescopes, and space telescopes. We succeeded in doing so and had 39 interesting presentations and many fruitful discussions during coffee and lunch breaks and social arrangements. We are grateful that so many top ranked specialists found their way to Kiruna and we believe that these proceedings will prove valuable during much future work.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9675E..1KZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9675E..1KZ"><span>Research on the optimal selection method of image <span class="hlt">complexity</span> assessment <span class="hlt">model</span> index parameter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Yong; Duan, Jin; Qian, Xiaofei; Xiao, Bo</p> <p>2015-10-01</p> <p>Target recognition is widely used in national economy, space technology and national defense and other fields. There is great difference between the difficulty of the target recognition and target extraction. The image <span class="hlt">complexity</span> is evaluating the difficulty level of extracting the target from background. It can be used as a prior evaluation index of the target recognition algorithm's effectiveness. The paper, from the perspective of the target and background characteristics measurement, describe image <span class="hlt">complexity</span> metrics parameters using quantitative, accurate mathematical relationship. For the collinear problems between each measurement parameters, image <span class="hlt">complexity</span> metrics parameters are clustered with gray correlation method. It can realize the metrics parameters of extraction and selection, improve the reliability and validity of image <span class="hlt">complexity</span> description and representation, and optimize the image the <span class="hlt">complexity</span> assessment calculation <span class="hlt">model</span>. <span class="hlt">Experiment</span> results demonstrate that when gray system theory is applied to the image <span class="hlt">complexity</span> analysis, target characteristics image <span class="hlt">complexity</span> can be measured more accurately and effectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5302026','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5302026"><span>Fatigue Damage of Collagenous Tissues: <span class="hlt">Experiment</span>, <span class="hlt">Modeling</span> and Simulation Studies</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Martin, Caitlin; Sun, Wei</p> <p>2017-01-01</p> <p>Mechanical fatigue damage is a critical issue for soft tissues and tissue-derived materials, particularly for musculoskeletal and cardiovascular applications; yet, our understanding of the fatigue damage process is incomplete. Soft tissue fatigue <span class="hlt">experiments</span> are often difficult and time-consuming to perform, which has hindered progress in this area. However, the recent development of soft-tissue fatigue-damage constitutive <span class="hlt">models</span> has enabled simulation-based fatigue analyses of tissues under various conditions. Computational simulations facilitate highly controlled and quantitative analyses to study the distinct effects of various loading conditions and design features on tissue durability; thus, they are advantageous over <span class="hlt">complex</span> fatigue <span class="hlt">experiments</span>. Although significant work to calibrate the constitutive <span class="hlt">models</span> from fatigue <span class="hlt">experiments</span> and to validate predictability remains, further development in these areas will add to our knowledge of soft-tissue fatigue damage and will facilitate the design of durable treatments and devices. In this review, the experimental, <span class="hlt">modeling</span>, and simulation efforts to study collagenous tissue fatigue damage are summarized and critically assessed. PMID:25955007</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23402624','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23402624"><span>Using machine learning tools to <span class="hlt">model</span> <span class="hlt">complex</span> toxic interactions with limited sampling regimes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bertin, Matthew J; Moeller, Peter; Guillette, Louis J; Chapman, Robert W</p> <p>2013-03-19</p> <p>A major impediment to understanding the impact of environmental stress, including toxins and other pollutants, on organisms, is that organisms are rarely challenged by one or a few stressors in natural systems. Thus, linking laboratory <span class="hlt">experiments</span> that are limited by practical considerations to a few stressors and a few levels of these stressors to real world conditions is constrained. In addition, while the existence of <span class="hlt">complex</span> interactions among stressors can be identified by current statistical methods, these methods do not provide a means to construct mathematical <span class="hlt">models</span> of these interactions. In this paper, we offer a two-step process by which <span class="hlt">complex</span> interactions of stressors on biological systems can be <span class="hlt">modeled</span> in an experimental design that is within the limits of practicality. We begin with the notion that environment conditions circumscribe an n-dimensional hyperspace within which biological processes or end points are embedded. We then randomly sample this hyperspace to establish experimental conditions that span the range of the relevant parameters and conduct the <span class="hlt">experiment(s</span>) based upon these selected conditions. <span class="hlt">Models</span> of the <span class="hlt">complex</span> interactions of the parameters are then extracted using machine learning tools, specifically artificial neural networks. This approach can rapidly generate highly accurate <span class="hlt">models</span> of biological responses to <span class="hlt">complex</span> interactions among environmentally relevant toxins, identify critical subspaces where nonlinear responses exist, and provide an expedient means of designing traditional <span class="hlt">experiments</span> to test the impact of <span class="hlt">complex</span> mixtures on biological responses. Further, this can be accomplished with an astonishingly small sample size.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17205386','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17205386"><span><span class="hlt">Complex</span> emotions, <span class="hlt">complex</span> problems: understanding the <span class="hlt">experiences</span> of perinatal depression among new mothers in urban Indonesia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Andajani-Sutjahjo, Sari; Manderson, Lenore; Astbury, Jill</p> <p>2007-03-01</p> <p>In this article, we explore how Javanese women identify and speak of symptoms of depression in late pregnancy and early postpartum and describe their subjective accounts of mood disorders. The study, conducted in the East Java region of Indonesia in 2000, involved in-depth interviews with a subgroup of women (N = 41) who scored above the cutoff score of 12/13 on the Edinburgh Postnatal Depression Scale (EPDS) during pregnancy, at six weeks postpartum, or on both occasions. This sample was taken from a larger cohort study (N cohort = 488) researching the sociocultural factors that contribute to women's emotional well-being in early motherhood. The women used a variety of Indonesian and Javanese terms to explain their emotional states during pregnancy and in early postpartum, some of which coincided with the feelings described on the EPDS and others of which did not. Women attributed their mood variations to multiple causes including: premarital pregnancy, chronic illness in the family, marital problems, lack of support from partners or family networks, their husband's unemployment, and insufficient family income due to giving up their own paid work. We argue for the importance of understanding the context of childbearing in order to interpret the meaning of depression within <span class="hlt">complex</span> social, cultural, and economic contexts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA435841','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA435841"><span>Reduced-<span class="hlt">Complexity</span> <span class="hlt">Models</span> for Network Performance Prediction</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2005-05-01</p> <p>traffic over the network . To understand such a <span class="hlt">complex</span> system it is necessary to develop accurate, yet simple, <span class="hlt">models</span> to describe the performance...interconnected in <span class="hlt">complex</span> ways, with millions of users sending traffic over the network . To understand such a <span class="hlt">complex</span> system, it is necessary to develop...number of downloaders . . . . . . . . . . . . . . . . . 17 11 A network of ISP clouds. In this figure, the ISPs are connected via peering points, denoted</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145283','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4145283"><span>A simple <span class="hlt">model</span> clarifies the complicated relationships of <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zheng, Bojin; Wu, Hongrun; Kuang, Li; Qin, Jun; Du, Wenhua; Wang, Jianmin; Li, Deyi</p> <p>2014-01-01</p> <p>Real-world networks such as the Internet and WWW have many common traits. Until now, hundreds of <span class="hlt">models</span> were proposed to characterize these traits for understanding the networks. Because different <span class="hlt">models</span> used very different mechanisms, it is widely believed that these traits origin from different causes. However, we find that a simple <span class="hlt">model</span> based on optimisation can produce many traits, including scale-free, small-world, ultra small-world, Delta-distribution, compact, fractal, regular and random networks. Moreover, by revising the proposed <span class="hlt">model</span>, the community-structure networks are generated. By this <span class="hlt">model</span> and the revised versions, the complicated relationships of <span class="hlt">complex</span> networks are illustrated. The <span class="hlt">model</span> brings a new universal perspective to the understanding of <span class="hlt">complex</span> networks and provide a universal method to <span class="hlt">model</span> <span class="hlt">complex</span> networks from the viewpoint of optimisation. PMID:25160506</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998SPIE.3390..511J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998SPIE.3390..511J"><span><span class="hlt">Complex</span> Chebyshev-polynomial-based unified <span class="hlt">model</span> (CCPBUM) neural networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jeng, Jin-Tsong; Lee, Tsu-Tian</p> <p>1998-03-01</p> <p>In this paper, we propose <span class="hlt">complex</span> Chebyshev Polynomial Based unified <span class="hlt">model</span> neural network for the approximation of <span class="hlt">complex</span>- valued function. Based on this approximate transformable technique, we have derived the relationship between the single-layered neural network and multi-layered perceptron neural network. It is shown that the <span class="hlt">complex</span> Chebyshev Polynomial Based unified <span class="hlt">model</span> neural network can be represented as a functional link network that are based on Chebyshev polynomial. We also derived a new learning algorithm for the proposed network. It turns out that the <span class="hlt">complex</span> Chebyshev Polynomial Based unified <span class="hlt">model</span> neural network not only has the same capability of universal approximator, but also has faster learning speed than conventional <span class="hlt">complex</span> feedforward/recurrent neural network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19950006857','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19950006857"><span>A musculoskeletal <span class="hlt">model</span> of the elbow joint <span class="hlt">complex</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gonzalez, Roger V.; Barr, Ronald E.; Abraham, Lawrence D.</p> <p>1993-01-01</p> <p>This paper describes a musculoskeletal <span class="hlt">model</span> that represents human elbow flexion-extension and forearm pronation-supination. Musculotendon parameters and the skeletal geometry were determined for the musculoskeletal <span class="hlt">model</span> in the analysis of ballistic elbow joint <span class="hlt">complex</span> movements. The key objective was to develop a computational <span class="hlt">model</span>, guided by optimal control, to investigate the relationship among patterns of muscle excitation, individual muscle forces, and movement kinematics. The <span class="hlt">model</span> was verified using experimental kinematic, torque, and electromyographic data from volunteer subjects performing both isometric and ballistic elbow joint <span class="hlt">complex</span> movements. In general, the <span class="hlt">model</span> predicted kinematic and muscle excitation patterns similar to what was experimentally measured.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/8432645','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/8432645"><span>An elementary method for implementing <span class="hlt">complex</span> biokinetic <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Leggett, R W; Eckerman, K F; Williams, L R</p> <p>1993-03-01</p> <p>Recent efforts to incorporate greater anatomical and physiological realism into biokinetic <span class="hlt">models</span> have resulted in many cases in mathematically <span class="hlt">complex</span> formulations that limit routine application of the <span class="hlt">models</span>. This paper describes an elementary, computer-efficient technique for implementing <span class="hlt">complex</span> compartmental <span class="hlt">models</span>, with attention focused primarily on biokinetic <span class="hlt">models</span> involving time-dependent transfer rates and recycling. The technique applies, in particular, to the physiologically based, age-specific biokinetic <span class="hlt">models</span> recommended in Publication No. 56 of the International Commission on Radiological Protection, Age-Dependent Doses to Members of the Public from Intake of Radionuclides.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15013776','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15013776"><span>Full-Scale Cookoff <span class="hlt">Model</span> Validation <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>McClelland, M A; Rattanapote, M K; Heimdahl, E R; Erikson, W E; Curran, P O; Atwood, A I</p> <p>2003-11-25</p> <p>This paper presents the experimental results of the third and final phase of a cookoff <span class="hlt">model</span> validation effort. In this phase of the work, two generic Heavy Wall Penetrators (HWP) were tested in two heating orientations. Temperature and strain gage data were collected over the entire test period. Predictions for time and temperature of reaction were made prior to release of the live data. Predictions were comparable to the measured values and were highly dependent on the established boundary conditions. Both HWP tests failed at a weld located near the aft closure of the device. More than 90 percent of unreacted explosive was recovered in the end heated <span class="hlt">experiment</span> and less than 30 percent recovered in the side heated test.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......155G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......155G"><span>Nanofluid Drop Evaporation: <span class="hlt">Experiment</span>, Theory, and <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gerken, William James</p> <p></p> <p>Nanofluids, stable colloidal suspensions of nanoparticles in a base fluid, have potential applications in the heat transfer, combustion and propulsion, manufacturing, and medical fields. <span class="hlt">Experiments</span> were conducted to determine the evaporation rate of room temperature, millimeter-sized pendant drops of ethanol laden with varying amounts (0-3% by weight) of 40-60 nm aluminum nanoparticles (nAl). Time-resolved high-resolution drop images were collected for the determination of early-time evaporation rate (D2/D 02 > 0.75), shown to exhibit D-square law behavior, and surface tension. Results show an asymptotic decrease in pendant drop evaporation rate with increasing nAl loading. The evaporation rate decreases by approximately 15% at around 1% to 3% nAl loading relative to the evaporation rate of pure ethanol. Surface tension was observed to be unaffected by nAl loading up to 3% by weight. A <span class="hlt">model</span> was developed to describe the evaporation of the nanofluid pendant drops based on D-square law analysis for the gas domain and a description of the reduction in liquid fraction available for evaporation due to nanoparticle agglomerate packing near the evaporating drop surface. <span class="hlt">Model</span> predictions are in relatively good agreement with <span class="hlt">experiment</span>, within a few percent of measured nanofluid pendant drop evaporation rate. The evaporation of pinned nanofluid sessile drops was also considered via <span class="hlt">modeling</span>. It was found that the same mechanism for nanofluid evaporation rate reduction used to explain pendant drops could be used for sessile drops. That mechanism is a reduction in evaporation rate due to a reduction in available ethanol for evaporation at the drop surface caused by the packing of nanoparticle agglomerates near the drop surface. Comparisons of the present <span class="hlt">modeling</span> predictions with sessile drop evaporation rate measurements reported for nAl/ethanol nanofluids by Sefiane and Bennacer [11] are in fairly good agreement. Portions of this abstract previously appeared as: W. J</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ940653.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ940653.pdf"><span>Classrooms as <span class="hlt">Complex</span> Adaptive Systems: A Relational <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Burns, Anne; Knox, John S.</p> <p>2011-01-01</p> <p>In this article, we describe and <span class="hlt">model</span> the language classroom as a <span class="hlt">complex</span> adaptive system (see Logan & Schumann, 2005). We argue that linear, categorical descriptions of classroom processes and interactions do not sufficiently explain the <span class="hlt">complex</span> nature of classrooms, and cannot account for how classroom change occurs (or does not occur), over…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011CoPhC.182...43S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011CoPhC.182...43S"><span>Realistic <span class="hlt">modeling</span> of <span class="hlt">complex</span> oxide materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Solovyev, I. V.</p> <p>2011-01-01</p> <p>Since electronic and magnetic properties of many transition-metal oxides can be efficiently controlled by external factors such as the temperature, pressure, electric or magnetic field, they are regarded as promising materials for various applications. From the viewpoint of the electronic structure, these phenomena are frequently related to the behavior of a small group of states located near the Fermi level. The basic idea of this project is to construct a <span class="hlt">model</span> for the low-energy states, derive all the parameters rigorously on the basis of density functional theory (DFT), and to study this <span class="hlt">model</span> by modern techniques. After a brief review of the method, the abilities of this approach will be illustrated on a number of examples, including multiferroic manganites and spin-orbital-lattice coupled phenomena in RVO 3 (where R is the three-valent element).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA570616','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA570616"><span><span class="hlt">Complex</span> Network <span class="hlt">Modeling</span> with an Emulab HPC</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2012-09-01</p> <p>field. Actual Joint Tactical Radio System (JTRS) radios, Operations Network ( OPNET ) emulations, and GNU (recursive definition for GNU is Not Unix...open-source software-defined-radio software/ firmware/ hardware emulations can be accommodated. Index Terms—network emulation, Emulab, OPNET I...other hand, simulation tools such as MATLAB, Optimized Network Engineering Tools ( OPNET ), NS2, and CORE (a <span class="hlt">modeling</span> environment from Vitech</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4101697','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4101697"><span>STATegra EMS: an <span class="hlt">Experiment</span> Management System for <span class="hlt">complex</span> next-generation omics <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>High-throughput sequencing assays are now routinely used to study different aspects of genome organization. As decreasing costs and widespread availability of sequencing enable more laboratories to use sequencing assays in their research projects, the number of samples and replicates in these <span class="hlt">experiments</span> can quickly grow to several dozens of samples and thus require standardized annotation, storage and management of preprocessing steps. As a part of the STATegra project, we have developed an <span class="hlt">Experiment</span> Management System (EMS) for high throughput omics data that supports different types of sequencing-based assays such as RNA-seq, ChIP-seq, Methyl-seq, etc, as well as proteomics and metabolomics data. The STATegra EMS provides metadata annotation of experimental design, samples and processing pipelines, as well as storage of different types of data files, from raw data to ready-to-use measurements. The system has been developed to provide research laboratories with a freely-available, integrated system that offers a simple and effective way for <span class="hlt">experiment</span> annotation and tracking of analysis procedures. PMID:25033091</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15007540','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15007540"><span>Computational <span class="hlt">Modeling</span> of Uranium Hydriding and <span class="hlt">Complexes</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Balasubramanian, K; Siekhaus, W J; McLean, W</p> <p>2003-02-03</p> <p>Uranium hydriding is one of the most important processes that has received considerable attention over many years. Although many experimental and <span class="hlt">modeling</span> studies have been carried out concerning thermochemistry, diffusion kinetics and mechanisms of U-hydriding, very little is known about the electronic structure and electronic features that govern the U-hydriding process. Yet it is the electronic feature that controls the activation barrier and thus the rate of hydriding. Moreover the role of impurities and the role of the product UH{sub 3} on hydriding rating are not fully understood. An early study by Condon and Larson concerns with the kinetics of U-hydrogen system and a mathematical <span class="hlt">model</span> for the U-hydriding process. They proposed that diffusion in the reactant phase by hydrogen before nucleation to form hydride phase and that the reaction is first order for hydriding and zero order for dehydriding. Condon has also calculated and measures the reaction rates of U-hydriding and proposed a diffusion <span class="hlt">model</span> for the U-hydriding. This <span class="hlt">model</span> was found to be in excellent agreement with the experimental reaction rates. From the slopes of the Arrhenius plot the activation energy was calculated as 6.35 kcal/mole. In a subsequent study Kirkpatrick formulated a close-form for approximate solution to Condon's equation. Bloch and Mintz have proposed the kinetics and mechanism for the U-H reaction over a wide range of pressures and temperatures. They have discussed their results through two <span class="hlt">models</span>, one, which considers hydrogen diffusion through a protective UH{sub 3} product layer, and the second where hydride growth occurs at the hydride-metal interface. These authors obtained two-dimensional fits of experimental data to the pressure-temperature reactions. Kirkpatrick and Condon have obtained a linear solution to hydriding of uranium. These authors showed that the calculated reaction rates compared quite well with the experimental data at a hydrogen pressure of 1 atm. Powell</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006PrOce..70...27R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006PrOce..70...27R"><span><span class="hlt">Model</span> <span class="hlt">complexity</span> and performance: How far can we simplify?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raick, C.; Soetaert, K.; Grégoire, M.</p> <p>2006-07-01</p> <p>Handling <span class="hlt">model</span> <span class="hlt">complexity</span> and reliability is a key area of research today. While <span class="hlt">complex</span> <span class="hlt">models</span> containing sufficient detail have become possible due to increased computing power, they often lead to too much uncertainty. On the other hand, very simple <span class="hlt">models</span> often crudely oversimplify the real ecosystem and can not be used for management purposes. Starting from a <span class="hlt">complex</span> and validated 1D pelagic ecosystem <span class="hlt">model</span> of the Ligurian Sea (NW Mediterranean Sea), we derived simplified aggregated <span class="hlt">models</span> in which either the unbalanced algal growth, the functional group diversity or the explicit description of the microbial loop was sacrificed. To overcome the problem of data availability with adequate spatial and temporal resolution, the outputs of the <span class="hlt">complex</span> <span class="hlt">model</span> are used as the baseline of perfect knowledge to calibrate the simplified <span class="hlt">models</span>. Objective criteria of <span class="hlt">model</span> performance were used to compare the simplified models’ results to the <span class="hlt">complex</span> <span class="hlt">model</span> output and to the available data at the DYFAMED station in the central Ligurian Sea. We show that even the simplest (NPZD) <span class="hlt">model</span> is able to represent the global ecosystem features described by the <span class="hlt">complex</span> <span class="hlt">model</span> (e.g. primary and secondary productions, particulate organic matter export flux, etc.). However, a certain degree of sophistication in the formulation of some biogeochemical processes is required to produce realistic behaviors (e.g. the phytoplankton competition, the potential carbon or nitrogen limitation of the zooplankton ingestion, the <span class="hlt">model</span> trophic closure, etc.). In general, a 9 state-variable <span class="hlt">model</span> that has the functional group diversity removed, but which retains the bacterial loop and the unbalanced algal growth, performs best.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20617104','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20617104"><span>Prequential Analysis of <span class="hlt">Complex</span> Data with Adaptive <span class="hlt">Model</span> Reselection.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Clarke, Jennifer; Clarke, Bertrand</p> <p>2009-11-01</p> <p>In Prequential analysis, an inference method is viewed as a forecasting system, and the quality of the inference method is based on the quality of its predictions. This is an alternative approach to more traditional statistical methods that focus on the inference of parameters of the data generating distribution. In this paper, we introduce adaptive combined average predictors (ACAPs) for the Prequential analysis of <span class="hlt">complex</span> data. That is, we use convex combinations of two different <span class="hlt">model</span> averages to form a predictor at each time step in a sequence. A novel feature of our strategy is that the <span class="hlt">models</span> in each average are re-chosen adaptively at each time step. To assess the <span class="hlt">complexity</span> of a given data set, we introduce measures of data <span class="hlt">complexity</span> for continuous response data. We validate our measures in several simulated contexts prior to using them in real data examples. The performance of ACAPs is compared with the performances of predictors based on stacking or likelihood weighted averaging in several <span class="hlt">model</span> classes and in both simulated and real data sets. Our results suggest that ACAPs achieve a better trade off between <span class="hlt">model</span> list bias and <span class="hlt">model</span> list variability in cases where the data is very <span class="hlt">complex</span>. This implies that the choices of <span class="hlt">model</span> class and averaging method should be guided by a concept of <span class="hlt">complexity</span> matching, i.e. the analysis of a <span class="hlt">complex</span> data set may require a more <span class="hlt">complex</span> <span class="hlt">model</span> class and averaging strategy than the analysis of a simpler data set. We propose that <span class="hlt">complexity</span> matching is akin to a bias-variance tradeoff in statistical <span class="hlt">modeling</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/511976','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/511976"><span>Vacuum membrane distillation: <span class="hlt">Experiments</span> and <span class="hlt">modeling</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bandini, S.; Saavedra, A.; Sarti, G.C.</p> <p>1997-02-01</p> <p>Vacuum membrane distillation is a membrane-based separation process considered here to remove volatile organic compounds from aqueous streams. Microporous hydrophobic membranes are used to separate the aqueous stream from a gas phase kept under vacuum. The evaporation of the liquid stream takes place on one side of the membrane, and mass transfer occurs through the vapor phase inside the membrane. The role of operative conditions on the process performance is widely investigated in the case of dilute binary aqueous mixtures containing acetone, ethanol, isopropanol, ethylacetate, methylacetate, or methylterbutyl ether. Temperature, composition, flow rate of the liquid feed, and pressure downstream the membrane are the main operative variables. Among these, the vacuum-side pressure is the major design factor since it greatly affects the separation efficiency. A mathematical <span class="hlt">model</span> description of the process is developed, and the results are compared with the <span class="hlt">experiments</span>. The <span class="hlt">model</span> is finally used to predict the best operative conditions in which the process can work for the case of benzene removal from waste waters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhDT.......144H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhDT.......144H"><span><span class="hlt">Experiment</span>-Driven <span class="hlt">Modeling</span> of Plasmonic Nanostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hryn, Alexander John</p> <p></p> <p>Plasmonic nanostructures can confine light at their surface in the form of surface plasmon polaritons (SPPs) or localized surface plasmons (LSPs) depending on their geometry. SPPs are excited on nano- and micropatterned surfaces, where the typical feature size is on the order of the wavelength of light. LSPs, on the other hand, can be excited on nanoparticles much smaller than the diffraction limit. In both cases, far-field optical measurements are used to infer the excited plasmonic modes, and theoretical <span class="hlt">models</span> are used to verify those results. Typically, these theoretical <span class="hlt">models</span> are tailored to match the experimental nanostructures in order to explain observed phenomena. In this thesis, I explore incorporating components of experimental procedures into the <span class="hlt">models</span> to increase the accuracy of the simulated result, and to inform the design of future <span class="hlt">experiments</span>. First, I examine SPPs on nanostructured metal films in the form of low-symmetry moire plasmonic crystals. I created a general Bragg <span class="hlt">model</span> to understand and predict the excited SPP modes in moire plasmonic crystals based on the nanolithography masks used in their fabrication. This <span class="hlt">model</span> makes use of experimental parameters such as periodicity, azimuthal rotation, and number of sequential exposures to predict the energies of excited SPP modes and the opening of plasmonic band gaps. The <span class="hlt">model</span> is further expanded to apply to multiscale gratings, which have patterns that contain hierarchical periodicities: a sub-micron primary periodicity, and microscale superperiodicity. A new set of rules was established to determine how superlattice SPPs are excited, and informed development of a new fabrication technique to create superlattices with multiple primary periodicities that absorb light over a wider spectral range than other plasmonic structures. The second half of the thesis is based on development of finite-difference time-domain (FDTD) simulations of plasmonic nanoparticles. I created a new technique to <span class="hlt">model</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003Ap%26SS.287...69G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003Ap%26SS.287...69G"><span>MHD <span class="hlt">Models</span> and Laboratory <span class="hlt">Experiments</span> of Jets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gardiner, T. A.; Frank, A.; Blackman, E. G.; Lebedev, S. V.; Chittenden, J. P.; Ampleford, D.; Bland, S. N.; Ciardi, A.; Sherlock, M.; Haines, M. G.</p> <p></p> <p>Jet research has long relied upon a combination of analytical, observational and numerical studies to elucidate the <span class="hlt">complex</span> phenomena involved. One element missing from these studies (which other physical sciences utilize) is the controlled experimental investigation of such systems. With the advent of high-power lasers and fast Z-pinch machines it is now possible to experimentally study similar systems in a laboratory setting. Such investigations can contribute in two useful ways. They can be used for comparison with numerical simulations as a means to validate simulation codes. More importantly, however, such investigations can also be used to complement other jet research, leading to fundamentally new knowledge. In the first part of this article, we analyze the evolution of magnetized wide-angle winds in a collapsing environment. We track the ambient and wind mass separately and describe a physical mechanism by which an ionized central wind can entrain the ambient gas giving rise to internal shells of molecular material on short time scales. The formation of internal shells in molecular outflows has been found to be an important ingredient in describing the observations of convex spurs in P-V diagrams (Hubble wedges in M-V diagrams). In the second part, we present astrophysically relevant <span class="hlt">experiments</span> in which supersonic jets are created using a conical wire array Z-pinch. The conically convergent flow generates a standing shock around the axis which collimates the flow into a Mach ~ 30 jet. The jet formation process is closely related to the work of Cantó et al. (1988) for hydrodynamic jet collimation. The influence of radiative cooling on collimation and stability is studied by varying the wire material (Al, Fe, and W).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21563020','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21563020"><span>Do <span class="hlt">complex</span> <span class="hlt">models</span> increase prediction of <span class="hlt">complex</span> behaviours? Predicting driving ability in people with brain disorders.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Innes, Carrie R H; Lee, Dominic; Chen, Chen; Ponder-Sutton, Agate M; Melzer, Tracy R; Jones, Richard D</p> <p>2011-09-01</p> <p>Prediction of <span class="hlt">complex</span> behavioural tasks via relatively simple <span class="hlt">modelling</span> techniques, such as logistic regression and discriminant analysis, often has limited success. We hypothesized that to more accurately <span class="hlt">model</span> <span class="hlt">complex</span> behaviour, more <span class="hlt">complex</span> <span class="hlt">models</span>, such as kernel-based methods, would be needed. To test this hypothesis, we assessed the value of six <span class="hlt">modelling</span> approaches for predicting driving ability based on performance on computerized sensory-motor and cognitive tests (SMCTests™) in 501 people with brain disorders. The <span class="hlt">models</span> included three <span class="hlt">models</span> previously used to predict driving ability (discriminant analysis, DA; binary logistic regression, BLR; and nonlinear causal resource analysis, NCRA) and three kernel methods (support vector machine, SVM; product kernel density, PK; and kernel product density, KP). At the classification level, two kernel methods were substantially more accurate at classifying on-road pass or fail (SVM 99.6%, PK 99.8%) than the other <span class="hlt">models</span> (DA 76%, BLR 78%, NCRA 74%, KP 81%). However, accuracy decreased substantially for all of the kernel <span class="hlt">models</span> when cross-validation techniques were used to estimate prediction of on-road pass or fail in an independent referral group (SVM 73-76%, PK 72-73%, KP 71-72%) but decreased only slightly for DA (74-75%) and BLR (75-76%). Cross-validation of NCRA was not possible. In conclusion, while kernel-based <span class="hlt">models</span> are successful at <span class="hlt">modelling</span> <span class="hlt">complex</span> data at a classification level, this is likely to be due to overfitting of the data, which does not lead to an improvement in accuracy in independent data over and above the accuracy of other less <span class="hlt">complex</span> <span class="hlt">modelling</span> techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.717a2081S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.717a2081S"><span>Multi-scale <span class="hlt">modelling</span> for HEDP <span class="hlt">experiments</span> on Orion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sircombe, N. J.; Ramsay, M. G.; Hughes, S. J.; Hoarty, D. J.</p> <p>2016-05-01</p> <p>The Orion laser at AWE couples high energy long-pulse lasers with high intensity short-pulses, allowing material to be compressed beyond solid density and heated isochorically. This experimental capability has been demonstrated as a platform for conducting High Energy Density Physics material properties <span class="hlt">experiments</span>. A clear understanding of the physics in <span class="hlt">experiments</span> at this scale, combined with a robust, flexible and predictive <span class="hlt">modelling</span> capability, is an important step towards more <span class="hlt">complex</span> experimental platforms and ICF schemes which rely on high power lasers to achieve ignition. These <span class="hlt">experiments</span> present a significant <span class="hlt">modelling</span> challenge, the system is characterised by hydrodynamic effects over nanoseconds, driven by long-pulse lasers or the pre-pulse of the petawatt beams, and fast electron generation, transport, and heating effects over picoseconds, driven by short-pulse high intensity lasers. We describe the approach taken at AWE; to integrate a number of codes which capture the detailed physics for each spatial and temporal scale. Simulations of the heating of buried aluminium microdot targets are discussed and we consider the role such tools can play in understanding the impact of changes to the laser parameters, such as frequency and pre-pulse, as well as understanding effects which are difficult to observe experimentally.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1013915','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1013915"><span>Investigation of Statistical Inference Methodologies Through Scale <span class="hlt">Model</span> Propagation <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2015-09-30</p> <p>Investigation of Statistical Inference Methodologies Through Scale <span class="hlt">Model</span> Propagation <span class="hlt">Experiments</span> Jason D. Sagers Applied Research Laboratories...statistical inference methodologies for ocean-acoustic problems by investigating and applying statistical methods to data collected from scale -<span class="hlt">model...experiments</span> over a translationally invariant wedge, (2) to plan and conduct 3D propagation <span class="hlt">experiments</span> over the Hudson Canyon scale -<span class="hlt">model</span> bathymetry, and (3</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPhCS.803a2057I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPhCS.803a2057I"><span>Simulation <span class="hlt">modelling</span> as a tool to diagnose the <span class="hlt">complex</span> networks of security systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iskhakov, S. Y.; Shelupanov, A. A.; Meshcheryakov, R. V.</p> <p>2017-01-01</p> <p>In the article, the questions of <span class="hlt">modelling</span> of <span class="hlt">complex</span> security system networks are considered. The simulation <span class="hlt">model</span> of operation of similar <span class="hlt">complexes</span> and approbation of the offered approach to identification of the incidents are presented. The approach is based on detection of uncharacteristic alterations of the network operation mode. The results of the <span class="hlt">experiment</span> allow one to draw a conclusion on possibility of the offered <span class="hlt">model</span> application to analyse the current status of heterogeneous security systems. Also, it is confirmed that the application of short-term forecasting methods for the analysis of monitoring system data allows one to automate the process of formation the criteria to reveal the incidents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4269775','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4269775"><span><span class="hlt">Modeling</span> a Ca2+ Channel/BKCa Channel <span class="hlt">Complex</span> at the Single-<span class="hlt">Complex</span> Level</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cox, Daniel H.</p> <p>2014-01-01</p> <p>BKCa-channel activity often affects the firing properties of neurons, the shapes of neuronal action potentials (APs), and in some cases the extent of neurotransmitter release. It has become clear that BKCa channels often form <span class="hlt">complexes</span> with voltage-gated Ca2+ channels (CaV channels) such that when a CaV channel is activated, the ensuing influx of Ca2+ activates its closely associated BKCa channel. Thus, in <span class="hlt">modeling</span> the electrical properties of neurons, it would be useful to have quantitative <span class="hlt">models</span> of CaV/BKCa <span class="hlt">complexes</span>. Furthermore, in a population of CaV/BKCa <span class="hlt">complexes</span>, all BKCa channels are not exposed to the same Ca2+ concentration at the same time. Thus, stochastic rather than deterministic <span class="hlt">models</span> are required. To date, however, no such <span class="hlt">models</span> have been described. Here, however, I present a stochastic <span class="hlt">model</span> of a CaV2.1/BKCa(α-only) <span class="hlt">complex</span>, as might be found in a central nerve terminal. The CaV2.1/BKCa <span class="hlt">model</span> is based on kinetic <span class="hlt">modeling</span> of its two component channels at physiological temperature. Surprisingly, The CaV2.1/BKCa <span class="hlt">model</span> predicts that although the CaV channel will open nearly every time during a typical cortical AP, its associated BKCa channel is expected to open in only 30% of trials, and this percentage is very sensitive to the duration of the AP, the distance between the two channels in the <span class="hlt">complex</span>, and the presence of fast internal Ca2+ buffers. Also, the <span class="hlt">model</span> predicts that the kinetics of the BKCa currents of a population of CaV2.1/BKCa <span class="hlt">complexes</span> will not be limited by the kinetics of the CaV2.1 channel, and during a train of APs, the current response of the <span class="hlt">complex</span> is expected to faithfully follow even very rapid trains. Aside from providing insight into how these <span class="hlt">complexes</span> are likely to behave in vivo, the <span class="hlt">models</span> presented here could also be of use more generally as components of higher-level <span class="hlt">models</span> of neural function. PMID:25517147</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V43C..05G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V43C..05G"><span>Analogue <span class="hlt">experiments</span> as benchmarks for <span class="hlt">models</span> of lava flow emplacement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garel, F.; Kaminski, E. C.; Tait, S.; Limare, A.</p> <p>2013-12-01</p> <p> experimental observations of the effect of wind the surface thermal structure of a viscous flow, that could be used to benchmark a thermal heat loss <span class="hlt">model</span>. We will also briefly present more <span class="hlt">complex</span> analogue <span class="hlt">experiments</span> using wax material. These <span class="hlt">experiments</span> present discontinuous advance behavior, and a dual surface thermal structure with low (solidified) vs. high (hot liquid exposed at the surface) surface temperatures regions. Emplacement <span class="hlt">models</span> should tend to reproduce these two features, also observed on lava flows, to better predict the hazard of lava inundation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23091020','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23091020"><span>Size and <span class="hlt">complexity</span> in <span class="hlt">model</span> financial systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Arinaminpathy, Nimalan; Kapadia, Sujit; May, Robert M</p> <p>2012-11-06</p> <p>The global financial crisis has precipitated an increasing appreciation of the need for a systemic perspective toward financial stability. For example: What role do large banks play in systemic risk? How should capital adequacy standards recognize this role? How is stability shaped by concentration and diversification in the financial system? We explore these questions using a deliberately simplified, dynamic <span class="hlt">model</span> of a banking system that combines three different channels for direct transmission of contagion from one bank to another: liquidity hoarding, asset price contagion, and the propagation of defaults via counterparty credit risk. Importantly, we also introduce a mechanism for capturing how swings in "confidence" in the system may contribute to instability. Our results highlight that the importance of relatively large, well-connected banks in system stability scales more than proportionately with their size: the impact of their collapse arises not only from their connectivity, but also from their effect on confidence in the system. Imposing tougher capital requirements on larger banks than smaller ones can thus enhance the resilience of the system. Moreover, these effects are more pronounced in more concentrated systems, and continue to apply, even when allowing for potential diversification benefits that may be realized by larger banks. We discuss some tentative implications for policy, as well as conceptual analogies in ecosystem stability and in the control of infectious diseases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3494937','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3494937"><span>Size and <span class="hlt">complexity</span> in <span class="hlt">model</span> financial systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Arinaminpathy, Nimalan; Kapadia, Sujit; May, Robert M.</p> <p>2012-01-01</p> <p>The global financial crisis has precipitated an increasing appreciation of the need for a systemic perspective toward financial stability. For example: What role do large banks play in systemic risk? How should capital adequacy standards recognize this role? How is stability shaped by concentration and diversification in the financial system? We explore these questions using a deliberately simplified, dynamic <span class="hlt">model</span> of a banking system that combines three different channels for direct transmission of contagion from one bank to another: liquidity hoarding, asset price contagion, and the propagation of defaults via counterparty credit risk. Importantly, we also introduce a mechanism for capturing how swings in “confidence” in the system may contribute to instability. Our results highlight that the importance of relatively large, well-connected banks in system stability scales more than proportionately with their size: the impact of their collapse arises not only from their connectivity, but also from their effect on confidence in the system. Imposing tougher capital requirements on larger banks than smaller ones can thus enhance the resilience of the system. Moreover, these effects are more pronounced in more concentrated systems, and continue to apply, even when allowing for potential diversification benefits that may be realized by larger banks. We discuss some tentative implications for policy, as well as conceptual analogies in ecosystem stability and in the control of infectious diseases. PMID:23091020</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1987365','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1987365"><span>MatOFF: A Tool For Analyzing Behaviorally-<span class="hlt">Complex</span> Neurophysiological <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Genovesio, Aldo; Mitz, Andrew R.</p> <p>2007-01-01</p> <p>The simple operant conditioning originally used in behavioral neurophysiology 30 years ago has given way to <span class="hlt">complex</span> and sophisticated behavioral paradigms; so much so, that early general purpose programs for analyzing neurophysiological data are ill-suited for <span class="hlt">complex</span> <span class="hlt">experiments</span>. The trend has been to develop custom software for each class of <span class="hlt">experiment</span>, but custom software can have serious drawbacks. We describe here a general purpose software tool for behavioral and electrophysiological studies, called MatOFF, that is especially suited for processing neurophysiological data gathered during the execution of <span class="hlt">complex</span> behaviors. Written in the MATLAB programming language, MatOFF solves the problem of handling <span class="hlt">complex</span> analysis requirements in a unique and powerful way. While other neurophysiological programs are either a loose collection of tools or append MATLAB as a post-processing step, MatOFF is an integrated environment that supports MATLAB scripting within the event search engine safely isolated in programming sandbox. The results from scripting are stored separately, but in parallel with the raw data, and thus available to all subsequent MatOFF analysis and display processing. An example from a recently published <span class="hlt">experiment</span> shows how all the features of MatOFF work together to analyze <span class="hlt">complex</span> <span class="hlt">experiments</span> and mine neurophysiological data in efficient ways. PMID:17604115</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4093748','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4093748"><span>Characterization of <span class="hlt">Complex</span> Systems Using the Design of <span class="hlt">Experiments</span> Approach: Transient Protein Expression in Tobacco as a Case Study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Buyel, Johannes Felix; Fischer, Rainer</p> <p>2014-01-01</p> <p>Plants provide multiple benefits for the production of biopharmaceuticals including low costs, scalability, and safety. Transient expression offers the additional advantage of short development and production times, but expression levels can vary significantly between batches thus giving rise to regulatory concerns in the context of good manufacturing practice. We used a design of <span class="hlt">experiments</span> (DoE) approach to determine the impact of major factors such as regulatory elements in the expression construct, plant growth and development parameters, and the incubation conditions during expression, on the variability of expression between batches. We tested plants expressing a <span class="hlt">model</span> anti-HIV monoclonal antibody (2G12) and a fluorescent marker protein (DsRed). We discuss the rationale for selecting certain properties of the <span class="hlt">model</span> and identify its potential limitations. The general approach can easily be transferred to other problems because the principles of the <span class="hlt">model</span> are broadly applicable: knowledge-based parameter selection, <span class="hlt">complexity</span> reduction by splitting the initial problem into smaller modules, software-guided setup of optimal <span class="hlt">experiment</span> combinations and step-wise design augmentation. Therefore, the methodology is not only useful for characterizing protein expression in plants but also for the investigation of other <span class="hlt">complex</span> systems lacking a mechanistic description. The predictive equations describing the interconnectivity between parameters can be used to establish mechanistic <span class="hlt">models</span> for other <span class="hlt">complex</span> systems. PMID:24514765</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.5396B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.5396B"><span>Real-data Calibration <span class="hlt">Experiments</span> On A Distributed Hydrologic <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brath, A.; Montanari, A.; Toth, E.</p> <p></p> <p>The increasing availability of extended information on the study watersheds does not generally overcome the need for the determination through calibration of at least a part of the parameters of distributed hydrologic <span class="hlt">models</span>. The <span class="hlt">complexity</span> of such <span class="hlt">models</span>, making the computations highly intensive, has often prevented an extensive analysis of calibration issues. The purpose of this study is an evaluation of the validation results of a series of automatic calibration <span class="hlt">experiments</span> (using the shuffled <span class="hlt">complex</span> evolu- tion method, Duan et al., 1992) performed with a highly conceptualised, continuously simulating, distributed hydrologic <span class="hlt">model</span> applied on the real data of a mid-sized Ital- ian watershed. Major flood events occurred in the 1990-2000 decade are simulated with the parameters obtained by the calibration of the <span class="hlt">model</span> against discharge data observed at the closure section of the watershed and the hydrological features (overall agreement, volumes, peaks and times to peak) of the discharges obtained both in the closure and in an interior stream-gauge are analysed for validation purposes. A first set of calibrations investigates the effect of the variability of the calibration periods, using the data from several single flood events and from longer, continuous periods. Another analysis regards the influence of rainfall input and it is carried out varying the size and distribution of the raingauge network, in order to examine the relation between the spatial pattern of observed rainfall and the variability of <span class="hlt">modelled</span> runoff. Lastly, a comparison of the hydrographs obtained for the flood events with the <span class="hlt">model</span> parameterisation resulting when modifying the objective function to be minimised in the automatic calibration procedure is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JHEP...03..022Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JHEP...03..022Z"><span>Generalized <span class="hlt">complex</span> geometry, generalized branes and the Hitchin sigma <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zucchini, Roberto</p> <p>2005-03-01</p> <p>Hitchin's generalized <span class="hlt">complex</span> geometry has been shown to be relevant in compactifications of superstring theory with fluxes and is expected to lead to a deeper understanding of mirror symmetry. Gualtieri's notion of generalized <span class="hlt">complex</span> submanifold seems to be a natural candidate for the description of branes in this context. Recently, we introduced a Batalin-Vilkovisky field theoretic realization of generalized <span class="hlt">complex</span> geometry, the Hitchin sigma <span class="hlt">model</span>, extending the well known Poisson sigma <span class="hlt">model</span>. In this paper, exploiting Gualtieri's formalism, we incorporate branes into the <span class="hlt">model</span>. A detailed study of the boundary conditions obeyed by the world sheet fields is provided. Finally, it is found that, when branes are present, the classical Batalin-Vilkovisky cohomology contains an extra sector that is related non trivially to a novel cohomology associated with the branes as generalized <span class="hlt">complex</span> submanifolds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5352923','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5352923"><span>Experimental porcine <span class="hlt">model</span> of <span class="hlt">complex</span> fistula-in-ano</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>A Ba-Bai-Ke-Re, Ma-Mu-Ti-Jiang; Chen, Hui; Liu, Xue; Wang, Yun-Hai</p> <p>2017-01-01</p> <p>AIM To establish and evaluate an experimental porcine <span class="hlt">model</span> of fistula-in-ano. METHODS Twelve healthy pigs were randomly divided into two groups. Under general anesthesia, the experimental group underwent rubber band ligation surgery, and the control group underwent an artificial damage technique. Clinical magnetic resonance imaging (MRI) and histopathological evaluation were performed on the 38th d and 48th d after surgery in both groups, respectively. RESULTS There were no significant differences between the experimental group and the control group in general characteristics such as body weight, gender, and the number of fistula (P > 0.05). In the experimental group, 15 fistulas were confirmed clinically, 13 <span class="hlt">complex</span> fistulas were confirmed by MRI, and 11 <span class="hlt">complex</span> fistulas were confirmed by histopathology. The success rate in the porcine <span class="hlt">complex</span> fistula <span class="hlt">model</span> establishment was 83.33%. Among the 18 fistulas in the control group, 5 fistulas were confirmed clinically, 4 <span class="hlt">complex</span> fistulas were confirmed by MRI, and 3 fistulas were confirmed by histopathology. The success rate in the porcine fistula <span class="hlt">model</span> establishment was 27.78%. Thus, the success rate of the rubber band ligation group was significantly higher than the control group (P < 0.05). CONCLUSION Rubber band ligation is a stable and reliable method to establish <span class="hlt">complex</span> fistula-in-ano <span class="hlt">models</span>. Large animal <span class="hlt">models</span> of <span class="hlt">complex</span> anal fistulas can be used for the diagnosis and treatment of anal fistulas. PMID:28348488</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24904177','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24904177"><span>Finite element analysis to <span class="hlt">model</span> <span class="hlt">complex</span> mitral valve repair.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Labrosse, Michel; Mesana, Thierry; Baxter, Ian; Chan, Vincent</p> <p>2016-01-01</p> <p>Although finite element analysis has been used to <span class="hlt">model</span> simple mitral repair, it has not been used to <span class="hlt">model</span> <span class="hlt">complex</span> repair. A virtual mitral valve <span class="hlt">model</span> was successful in simulating normal and abnormal valve function. <span class="hlt">Models</span> were then developed to simulate an edge-to-edge repair and repair employing quadrangular resection. Stress contour plots demonstrated increased stresses along the mitral annulus, corresponding to the annuloplasty. The role of finite element analysis in guiding clinical practice remains undetermined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/764683','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/764683"><span>Theoretical Simulations and Ultrafast Pump-probe Spectroscopy <span class="hlt">Experiments</span> in Pigment-protein Photosynthetic <span class="hlt">Complexes</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Buck, D. R.</p> <p>2000-09-12</p> <p>Theoretical simulations and ultrafast pump-probe laser spectroscopy <span class="hlt">experiments</span> were used to study photosynthetic pigment-protein <span class="hlt">complexes</span> and antennae found in green sulfur bacteria such as Prosthecochloris aestuarii, Chloroflexus aurantiacus, and Chlorobium tepidum. The work focused on understanding structure-function relationships in energy transfer processes in these <span class="hlt">complexes</span> through <span class="hlt">experiments</span> and trying to <span class="hlt">model</span> that data as we tested our theoretical assumptions with calculations. Theoretical exciton calculations on tubular pigment aggregates yield electronic absorption spectra that are superimpositions of linear J-aggregate spectra. The electronic spectroscopy of BChl c/d/e antennae in light harvesting chlorosomes from Chloroflexus aurantiacus differs considerably from J-aggregate spectra. Strong symmetry breaking is needed if we hope to simulate the absorption spectra of the BChl c antenna. The theory for simulating absorption difference spectra in strongly coupled photosynthetic antenna is described, first for a relatively simple heterodimer, then for the general N-pigment system. The theory is applied to the Fenna-Matthews-Olson (FMO) BChl a protein trimers from Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from Chlorobium tepidum. Circular dichroism spectra of the FMO trimer are unusually sensitive to diagonal energy disorder. Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Anisotropic absorption difference spectroscopy measurements are less consistent with 21-pigment trimer simulations than 7-pigment monomer simulations which assume that the laser-prepared states are localized within a subunit of the trimer. Experimental anisotropies from real samples likely arise from statistical averaging over states with diagonal energies shifted by</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/5354017','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/5354017"><span>Multiwell <span class="hlt">experiment</span>: reservoir <span class="hlt">modeling</span> analysis, Volume II</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Horton, A.I.</p> <p>1985-05-01</p> <p>This report updates an ongoing analysis by reservoir <span class="hlt">modelers</span> at the Morgantown Energy Technology Center (METC) of well test data from the Department of Energy's Multiwell <span class="hlt">Experiment</span> (MWX). Results of previous efforts were presented in a recent METC Technical Note (Horton 1985). Results included in this report pertain to the poststimulation well tests of Zones 3 and 4 of the Paludal Sandstone Interval and the prestimulation well tests of the Red and Yellow Zones of the Coastal Sandstone Interval. The following results were obtained by using a reservoir <span class="hlt">model</span> and history matching procedures: (1) Post-minifracture analysis indicated that the minifracture stimulation of the Paludal Interval did not produce an induced fracture, and extreme formation damage did occur, since a 65% permeability reduction around the wellbore was estimated. The design for this minifracture was from 200 to 300 feet on each side of the wellbore; (2) Post full-scale stimulation analysis for the Paludal Interval also showed that extreme formation damage occurred during the stimulation as indicated by a 75% permeability reduction 20 feet on each side of the induced fracture. Also, an induced fracture half-length of 100 feet was determined to have occurred, as compared to a designed fracture half-length of 500 to 600 feet; and (3) Analysis of prestimulation well test data from the Coastal Interval agreed with previous well-to-well interference tests that showed extreme permeability anisotropy was not a factor for this zone. This lack of permeability anisotropy was also verified by a nitrogen injection test performed on the Coastal Red and Yellow Zones. 8 refs., 7 figs., 2 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15778439','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15778439"><span>Braiding DNA: <span class="hlt">experiments</span>, simulations, and <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Charvin, G; Vologodskii, A; Bensimon, D; Croquette, V</p> <p>2005-06-01</p> <p>DNA encounters topological problems in vivo because of its extended double-helical structure. As a consequence, the semiconservative mechanism of DNA replication leads to the formation of DNA braids or catenanes, which have to be removed for the completion of cell division. To get a better understanding of these structures, we have studied the elastic behavior of two braided nicked DNA molecules using a magnetic trap apparatus. The experimental data let us identify and characterize three regimes of braiding: a slightly twisted regime before the formation of the first crossing, followed by genuine braids which, at large braiding number, buckle to form plectonemes. Two different approaches support and quantify this characterization of the data. First, Monte Carlo (MC) simulations of braided DNAs yield a full description of the molecules' behavior and their buckling transition. Second, <span class="hlt">modeling</span> the braids as a twisted swing provides a good approximation of the elastic response of the molecules as they are intertwined. Comparisons of the <span class="hlt">experiments</span> and the MC simulations with this analytical <span class="hlt">model</span> allow for a measurement of the diameter of the braids and its dependence upon entropic and electrostatic repulsive interactions. The MC simulations allow for an estimate of the effective torsional constant of the braids (at a stretching force F = 2 pN): C(b) approximately 48 nm (as compared with C approximately 100 nm for a single unnicked DNA). Finally, at low salt concentrations and for sufficiently large number of braids, the diameter of the braided molecules is observed to collapse to that of double-stranded DNA. We suggest that this collapse is due to the partial melting and fraying of the two nicked molecules and the subsequent right- or left-handed intertwining of the stretched single strands.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100027331','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100027331"><span>The Use of Behavior <span class="hlt">Models</span> for Predicting <span class="hlt">Complex</span> Operations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gore, Brian F.</p> <p>2010-01-01</p> <p><span class="hlt">Modeling</span> and simulation (M&S) plays an important role when <span class="hlt">complex</span> human-system notions are being proposed, developed and tested within the system design process. National Aeronautics and Space Administration (NASA) as an agency uses many different types of M&S approaches for predicting human-system interactions, especially when it is early in the development phase of a conceptual design. NASA Ames Research Center possesses a number of M&S capabilities ranging from airflow, flight path <span class="hlt">models</span>, aircraft <span class="hlt">models</span>, scheduling <span class="hlt">models</span>, human performance <span class="hlt">models</span> (HPMs), and bioinformatics <span class="hlt">models</span> among a host of other kinds of M&S capabilities that are used for predicting whether the proposed designs will benefit the specific mission criteria. The Man-Machine Integration Design and Analysis System (MIDAS) is a NASA ARC HPM software tool that integrates many <span class="hlt">models</span> of human behavior with environment <span class="hlt">models</span>, equipment <span class="hlt">models</span>, and procedural / task <span class="hlt">models</span>. The challenge to <span class="hlt">model</span> comprehensibility is heightened as the number of <span class="hlt">models</span> that are integrated and the requisite fidelity of the procedural sets are increased. <span class="hlt">Model</span> transparency is needed for some of the more <span class="hlt">complex</span> HPMs to maintain comprehensibility of the integrated <span class="hlt">model</span> performance. This will be exemplified in a recent MIDAS v5 application <span class="hlt">model</span> and plans for future <span class="hlt">model</span> refinements will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23212797','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23212797"><span>Geometric <span class="hlt">modeling</span> of subcellular structures, organelles, and multiprotein <span class="hlt">complexes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Feng, Xin; Xia, Kelin; Tong, Yiying; Wei, Guo-Wei</p> <p>2012-12-01</p> <p>Recently, the structure, function, stability, and dynamics of subcellular structures, organelles, and multiprotein <span class="hlt">complexes</span> have emerged as a leading interest in structural biology. Geometric <span class="hlt">modeling</span> not only provides visualizations of shapes for large biomolecular <span class="hlt">complexes</span> but also fills the gap between structural information and theoretical <span class="hlt">modeling</span>, and enables the understanding of function, stability, and dynamics. This paper introduces a suite of computational tools for volumetric data processing, information extraction, surface mesh rendering, geometric measurement, and curvature estimation of biomolecular <span class="hlt">complexes</span>. Particular emphasis is given to the <span class="hlt">modeling</span> of cryo-electron microscopy data. Lagrangian-triangle meshes are employed for the surface presentation. On the basis of this representation, algorithms are developed for surface area and surface-enclosed volume calculation, and curvature estimation. Methods for volumetric meshing have also been presented. Because the technological development in computer science and mathematics has led to multiple choices at each stage of the geometric <span class="hlt">modeling</span>, we discuss the rationales in the design and selection of various algorithms. Analytical <span class="hlt">models</span> are designed to test the computational accuracy and convergence of proposed algorithms. Finally, we select a set of six cryo-electron microscopy data representing typical subcellular <span class="hlt">complexes</span> to demonstrate the efficacy of the proposed algorithms in handling biomolecular surfaces and explore their capability of geometric characterization of binding targets. This paper offers a comprehensive protocol for the geometric <span class="hlt">modeling</span> of subcellular structures, organelles, and multiprotein <span class="hlt">complexes</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20160005732&hterms=Acids&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DAcids','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20160005732&hterms=Acids&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DAcids"><span>Humic Acid <span class="hlt">Complexation</span> of Th, Hf and Zr in Ligand Competition <span class="hlt">Experiments</span>: Metal Loading and Ph Effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stern, Jennifer C.; Foustoukos, Dionysis I.; Sonke, Jeroen E.; Salters, Vincent J. M.</p> <p>2014-01-01</p> <p>The mobility of metals in soils and subsurface aquifers is strongly affected by sorption and <span class="hlt">complexation</span> with dissolved organic matter, oxyhydroxides, clay minerals, and inorganic ligands. Humic substances (HS) are organic macromolecules with functional groups that have a strong affinity for binding metals, such as actinides. Thorium, often studied as an analog for tetravalent actinides, has also been shown to strongly associate with dissolved and colloidal HS in natural waters. The effects of HS on the mobilization dynamics of actinides are of particular interest in risk assessment of nuclear waste repositories. Here, we present conditional equilibrium binding constants (Kc, MHA) of thorium, hafnium, and zirconium-humic acid <span class="hlt">complexes</span> from ligand competition <span class="hlt">experiments</span> using capillary electrophoresis coupled with ICP-MS (CE- ICP-MS). Equilibrium dialysis ligand exchange (EDLE) <span class="hlt">experiments</span> using size exclusion via a 1000 Damembrane were also performed to validate the CE-ICP-MS analysis. <span class="hlt">Experiments</span> were performed at pH 3.5-7 with solutions containing one tetravalent metal (Th, Hf, or Zr), Elliot soil humic acid (EHA) or Pahokee peat humic acid (PHA), and EDTA. CE-ICP-MS and EDLE <span class="hlt">experiments</span> yielded nearly identical binding constants for the metal- humic acid <span class="hlt">complexes</span>, indicating that both methods are appropriate for examining metal speciation at conditions lower than neutral pH. We find that tetravalent metals form strong <span class="hlt">complexes</span> with humic acids, with Kc, MHA several orders of magnitude above REE-humic <span class="hlt">complexes</span>. <span class="hlt">Experiments</span> were conducted at a range of dissolved HA concentrations to examine the effect of [HA]/[Th] molar ratio on Kc, MHA. At low metal loading conditions (i.e. elevated [HA]/[Th] ratios) the ThHA binding constant reached values that were not affected by the relative abundance of humic acid and thorium. The importance of [HA]/[Th] molar ratios on constraining the equilibrium of MHA <span class="hlt">complexation</span> is apparent when our estimated Kc, MHA values</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/991290','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/991290"><span>Implementation of a <span class="hlt">complex</span> multi-phase equation of state for cerium and its correlation with <span class="hlt">experiment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cherne, Frank J; Jensen, Brian J; Elkin, Vyacheslav M</p> <p>2009-01-01</p> <p>The <span class="hlt">complexity</span> of cerium combined with its interesting material properties makes it a desirable material to examine dynamically. Characteristics such as the softening of the material before the phase change, low pressure solid-solid phase change, predicted low pressure melt boundary, and the solid-solid critical point add <span class="hlt">complexity</span> to the construction of its equation of state. Currently, we are incorporating a feedback loop between a theoretical understanding of the material and an experimental understanding. Using a <span class="hlt">model</span> equation of state for cerium we compare calculated wave profiles with experimental wave profiles for a number of front surface impact (cerium impacting a plated window) <span class="hlt">experiments</span>. Using the calculated release isentrope we predict the temperature of the observed rarefaction shock. These <span class="hlt">experiments</span> showed that the release state occurs at different magnitudes, thus allowing us to infer where dynamic {gamma} - {alpha} phase boundary is.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014IJMPB..2850144W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014IJMPB..2850144W"><span>Network <span class="hlt">model</span> of bilateral power markets based on <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yang; Liu, Junyong; Li, Furong; Yan, Zhanxin; Zhang, Li</p> <p>2014-06-01</p> <p>The bilateral power transaction (BPT) mode becomes a typical market organization with the restructuring of electric power industry, the proper <span class="hlt">model</span> which could capture its characteristics is in urgent need. However, the <span class="hlt">model</span> is lacking because of this market organization's <span class="hlt">complexity</span>. As a promising approach to <span class="hlt">modeling</span> <span class="hlt">complex</span> systems, <span class="hlt">complex</span> networks could provide a sound theoretical framework for developing proper simulation <span class="hlt">model</span>. In this paper, a <span class="hlt">complex</span> network <span class="hlt">model</span> of the BPT market is proposed. In this <span class="hlt">model</span>, price advantage mechanism is a precondition. Unlike other general commodity transactions, both of the financial layer and the physical layer are considered in the <span class="hlt">model</span>. Through simulation analysis, the feasibility and validity of the <span class="hlt">model</span> are verified. At same time, some typical statistical features of BPT network are identified. Namely, the degree distribution follows the power law, the clustering coefficient is low and the average path length is a bit long. Moreover, the topological stability of the BPT network is tested. The results show that the network displays a topological robustness to random market member's failures while it is fragile against deliberate attacks, and the network could resist cascading failure to some extent. These features are helpful for making decisions and risk management in BPT markets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=brain+AND+mapping&pg=7&id=EJ820982','ERIC'); return false;" href="http://eric.ed.gov/?q=brain+AND+mapping&pg=7&id=EJ820982"><span>Using fMRI to Test <span class="hlt">Models</span> of <span class="hlt">Complex</span> Cognition</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Anderson, John R.; Carter, Cameron S.; Fincham, Jon M.; Qin, Yulin; Ravizza, Susan M.; Rosenberg-Lee, Miriam</p> <p>2008-01-01</p> <p>This article investigates the potential of fMRI to test assumptions about different components in <span class="hlt">models</span> of <span class="hlt">complex</span> cognitive tasks. If the components of a <span class="hlt">model</span> can be associated with specific brain regions, one can make predictions for the temporal course of the BOLD response in these regions. An event-locked procedure is described for dealing…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=CAD&pg=2&id=EJ788402','ERIC'); return false;" href="http://eric.ed.gov/?q=CAD&pg=2&id=EJ788402"><span>Tips on Creating <span class="hlt">Complex</span> Geometry Using Solid <span class="hlt">Modeling</span> Software</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gow, George</p> <p>2008-01-01</p> <p>Three-dimensional computer-aided drafting (CAD) software, sometimes referred to as "solid <span class="hlt">modeling</span>" software, is easy to learn, fun to use, and becoming the standard in industry. However, many users have difficulty creating <span class="hlt">complex</span> geometry with the solid <span class="hlt">modeling</span> software. And the problem is not entirely a student problem. Even some teachers and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1001000','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1001000"><span>Dynamic crack initiation toughness : <span class="hlt">experiments</span> and peridynamic <span class="hlt">modeling</span>.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Foster, John T.</p> <p>2009-10-01</p> <p>This is a dissertation on research conducted studying the dynamic crack initiation toughness of a 4340 steel. Researchers have been conducting experimental testing of dynamic crack initiation toughness, K{sub Ic}, for many years, using many experimental techniques with vastly different trends in the results when reporting K{sub Ic} as a function of loading rate. The dissertation describes a novel experimental technique for measuring K{sub Ic} in metals using the Kolsky bar. The method borrows from improvements made in recent years in traditional Kolsky bar testing by using pulse shaping techniques to ensure a constant loading rate applied to the sample before crack initiation. Dynamic crack initiation measurements were reported on a 4340 steel at two different loading rates. The steel was shown to exhibit a rate dependence, with the recorded values of K{sub Ic} being much higher at the higher loading rate. Using the knowledge of this rate dependence as a motivation in attempting to <span class="hlt">model</span> the fracture events, a viscoplastic constitutive <span class="hlt">model</span> was implemented into a peridynamic computational mechanics code. Peridynamics is a newly developed theory in solid mechanics that replaces the classical partial differential equations of motion with integral-differential equations which do not require the existence of spatial derivatives in the displacement field. This allows for the straightforward <span class="hlt">modeling</span> of unguided crack initiation and growth. To date, peridynamic implementations have used severely restricted constitutive <span class="hlt">models</span>. This research represents the first implementation of a <span class="hlt">complex</span> material <span class="hlt">model</span> and its validation. After showing results comparing deformations to experimental Taylor anvil impact for the viscoplastic material <span class="hlt">model</span>, a novel failure criterion is introduced to <span class="hlt">model</span> the dynamic crack initiation toughness <span class="hlt">experiments</span>. The failure <span class="hlt">model</span> is based on an energy criterion and uses the K{sub Ic} values recorded experimentally as an input. The failure <span class="hlt">model</span></p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhyA..392.3654S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhyA..392.3654S"><span>Between <span class="hlt">complexity</span> of <span class="hlt">modelling</span> and <span class="hlt">modelling</span> of <span class="hlt">complexity</span>: An essay on econophysics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schinckus, C.</p> <p>2013-09-01</p> <p>Econophysics is an emerging field dealing with <span class="hlt">complex</span> systems and emergent properties. A deeper analysis of themes studied by econophysicists shows that research conducted in this field can be decomposed into two different computational approaches: “statistical econophysics” and “agent-based econophysics”. This methodological scission complicates the definition of the <span class="hlt">complexity</span> used in econophysics. Therefore, this article aims to clarify what kind of emergences and <span class="hlt">complexities</span> we can find in econophysics in order to better understand, on one hand, the current scientific modes of reasoning this new field provides; and on the other hand, the future methodological evolution of the field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3913794','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3913794"><span>Zebrafish as an emerging <span class="hlt">model</span> for studying <span class="hlt">complex</span> brain disorders</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kalueff, Allan V.; Stewart, Adam Michael; Gerlai, Robert</p> <p>2014-01-01</p> <p>The zebrafish (Danio rerio) is rapidly becoming a popular <span class="hlt">model</span> organism in pharmacogenetics and neuropharmacology. Both larval and adult zebrafish are currently used to increase our understanding of brain function, dysfunction, and their genetic and pharmacological modulation. Here we review the developing utility of zebrafish in the analysis of <span class="hlt">complex</span> brain disorders (including, for example, depression, autism, psychoses, drug abuse and cognitive disorders), also covering zebrafish applications towards the goal of <span class="hlt">modeling</span> major human neuropsychiatric and drug-induced syndromes. We argue that zebrafish <span class="hlt">models</span> of <span class="hlt">complex</span> brain disorders and drug-induced conditions have become a rapidly emerging critical field in translational neuropharmacology research. PMID:24412421</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26827296','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26827296"><span><span class="hlt">Complexation</span> and molecular <span class="hlt">modeling</span> studies of europium(III)-gallic acid-amino acid <span class="hlt">complexes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Taha, Mohamed; Khan, Imran; Coutinho, João A P</p> <p>2016-04-01</p> <p>With many metal-based drugs extensively used today in the treatment of cancer, attention has focused on the development of new coordination compounds with antitumor activity with europium(III) <span class="hlt">complexes</span> recently introduced as novel anticancer drugs. The aim of this work is to design new Eu(III) <span class="hlt">complexes</span> with gallic acid, an antioxida'nt phenolic compound. Gallic acid was chosen because it shows anticancer activity without harming health cells. As antioxidant, it helps to protect human cells against oxidative damage that implicated in DNA damage, cancer, and accelerated cell aging. In this work, the formation of binary and ternary <span class="hlt">complexes</span> of Eu(III) with gallic acid, primary ligand, and amino acids alanine, leucine, isoleucine, and tryptophan was studied by glass electrode potentiometry in aqueous solution containing 0.1M NaNO3 at (298.2 ± 0.1) K. Their overall stability constants were evaluated and the concentration distributions of the <span class="hlt">complex</span> species in solution were calculated. The protonation constants of gallic acid and amino acids were also determined at our experimental conditions and compared with those predicted by using conductor-like screening <span class="hlt">model</span> for realistic solvation (COSMO-RS) <span class="hlt">model</span>. The geometries of Eu(III)-gallic acid <span class="hlt">complexes</span> were characterized by the density functional theory (DFT). The spectroscopic UV-visible and photoluminescence measurements are carried out to confirm the formation of Eu(III)-gallic acid <span class="hlt">complexes</span> in aqueous solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ACN&id=EJ969286','ERIC'); return false;" href="http://eric.ed.gov/?q=ACN&id=EJ969286"><span>Deaf Children with <span class="hlt">Complex</span> Needs: Parental <span class="hlt">Experience</span> of Access to Cochlear Implants and Ongoing Support</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>McCracken, Wendy; Turner, Oliver</p> <p>2012-01-01</p> <p>This paper discusses the <span class="hlt">experiences</span> of parents of deaf children with additional <span class="hlt">complex</span> needs (ACN) in accessing cochlear implant (CI) services and achieving ongoing support. Of a total study group of fifty-one children with ACN, twelve had been fitted with a CI. The parental accounts provide a rich and varied picture of service access. For some…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Relativity&pg=6&id=EJ1108615','ERIC'); return false;" href="http://eric.ed.gov/?q=Relativity&pg=6&id=EJ1108615"><span>Board Games and Board Game Design as Learning Tools for <span class="hlt">Complex</span> Scientific Concepts: Some <span class="hlt">Experiences</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Chiarello, Fabio; Castellano, Maria Gabriella</p> <p>2016-01-01</p> <p>In this paper the authors report different <span class="hlt">experiences</span> in the use of board games as learning tools for <span class="hlt">complex</span> and abstract scientific concepts such as Quantum Mechanics, Relativity or nano-biotechnologies. In particular we describe "Quantum Race," designed for the introduction of Quantum Mechanical principles, "Lab on a chip,"…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26738810','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26738810"><span>Multiscale <span class="hlt">Model</span> for the Assembly Kinetics of Protein <span class="hlt">Complexes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xie, Zhong-Ru; Chen, Jiawen; Wu, Yinghao</p> <p>2016-02-04</p> <p>The assembly of proteins into high-order <span class="hlt">complexes</span> is a general mechanism for these biomolecules to implement their versatile functions in cells. Natural evolution has developed various assembling pathways for specific protein <span class="hlt">complexes</span> to maintain their stability and proper activities. Previous studies have provided numerous examples of the misassembly of protein <span class="hlt">complexes</span> leading to severe biological consequences. Although the research focusing on protein <span class="hlt">complexes</span> has started to move beyond the static representation of quaternary structures to the dynamic aspect of their assembly, the current understanding of the assembly mechanism of protein <span class="hlt">complexes</span> is still largely limited. To tackle this problem, we developed a new multiscale <span class="hlt">modeling</span> framework. This framework combines a lower-resolution rigid-body-based simulation with a higher-resolution Cα-based simulation method so that protein <span class="hlt">complexes</span> can be assembled with both structural details and computational efficiency. We applied this <span class="hlt">model</span> to a homotrimer and a heterotetramer as simple test systems. Consistent with experimental observations, our simulations indicated very different kinetics between protein oligomerization and dimerization. The formation of protein oligomers is a multistep process that is much slower than dimerization but thermodynamically more stable. Moreover, we showed that even the same protein quaternary structure can have very diverse assembly pathways under different binding constants between subunits, which is important for regulating the functions of protein <span class="hlt">complexes</span>. Finally, we revealed that the binding between subunits in a <span class="hlt">complex</span> can be synergistically strengthened during assembly without considering allosteric regulation or conformational changes. Therefore, our <span class="hlt">model</span> provides a useful tool to understand the general principles of protein <span class="hlt">complex</span> assembly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5428918','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5428918"><span>Pedigree <span class="hlt">models</span> for <span class="hlt">complex</span> human traits involving the mitochrondrial genome</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schork, N.J.; Guo, S.W. )</p> <p>1993-12-01</p> <p>Recent biochemical and molecular-genetic discoveries concerning variations in human mtDNA have suggested a role for mtDNA mutations in a number of human traits and disorders. Although the importance of these discoveries cannot be emphasized enough, the <span class="hlt">complex</span> natures of mitochondrial biogenesis, mutant mtDNA phenotype expression, and the maternal inheritance pattern exhibited by mtDNA transmission make it difficult to develop <span class="hlt">models</span> that can be used routinely in pedigree analyses to quantify and test hypotheses about the role of mtDNA in the expression of a trait. In the present paper, the authors describe <span class="hlt">complexities</span> inherent in mitochondrial biogenesis and genetic transmission and show how these <span class="hlt">complexities</span> can be incorporated into appropriate mathematical <span class="hlt">models</span>. The authors offer a variety of likelihood-based <span class="hlt">models</span> which account for the <span class="hlt">complexities</span> discussed. The derivation of the <span class="hlt">models</span> is meant to stimulate the construction of statistical tests for putative mtDNA contribution to a trait. Results of simulation studies which make use of the proposed <span class="hlt">models</span> are described. The results of the simulation studies suggest that, although pedigree <span class="hlt">models</span> of mtDNA effects can be reliable, success in mapping chromosomal determinants of a trait does not preclude the possibility that mtDNA determinants exist for the trait as well. Shortcomings inherent in the proposed <span class="hlt">models</span> are described in an effort to expose areas in need of additional research. 58 refs., 5 figs., 2 tabs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970014722','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970014722"><span>Systems Engineering Metrics: Organizational <span class="hlt">Complexity</span> and Product Quality <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mog, Robert A.</p> <p>1997-01-01</p> <p>Innovative organizational <span class="hlt">complexity</span> and product quality <span class="hlt">models</span> applicable to performance metrics for NASA-MSFC's Systems Analysis and Integration Laboratory (SAIL) missions and objectives are presented. An intensive research effort focuses on the synergistic combination of stochastic process <span class="hlt">modeling</span>, nodal and spatial decomposition techniques, organizational and computational <span class="hlt">complexity</span>, systems science and metrics, chaos, and proprietary statistical tools for accelerated risk assessment. This is followed by the development of a preliminary <span class="hlt">model</span>, which is uniquely applicable and robust for quantitative purposes. Exercise of the preliminary <span class="hlt">model</span> using a generic system hierarchy and the AXAF-I architectural hierarchy is provided. The Kendall test for positive dependence provides an initial verification and validation of the <span class="hlt">model</span>. Finally, the research and development of the innovation is revisited, prior to peer review. This research and development effort results in near-term, measurable SAIL organizational and product quality methodologies, enhanced organizational risk assessment and evolutionary <span class="hlt">modeling</span> results, and 91 improved statistical quantification of SAIL productivity interests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=187424&keyword=Space+AND+exploration&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90723169&CFTOKEN=11522722','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=187424&keyword=Space+AND+exploration&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=90723169&CFTOKEN=11522722"><span>Calibration of <span class="hlt">Complex</span> Subsurface Reaction <span class="hlt">Models</span> Using a Surrogate-<span class="hlt">Model</span> Approach</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Application of <span class="hlt">model</span> assessment techniques to <span class="hlt">complex</span> subsurface reaction <span class="hlt">models</span> involves numerous difficulties, including non-trivial <span class="hlt">model</span> selection, parameter non-uniqueness, and excessive computational burden. To overcome these difficulties, this study introduces SAMM (Simult...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150016950','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150016950"><span>Electrostatic <span class="hlt">Model</span> Applied to ISS Charged Water Droplet <span class="hlt">Experiment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stevenson, Daan; Schaub, Hanspeter; Pettit, Donald R.</p> <p>2015-01-01</p> <p>The electrostatic force can be used to create novel relative motion between charged bodies if it can be isolated from the stronger gravitational and dissipative forces. Recently, Coulomb orbital motion was demonstrated on the International Space Station by releasing charged water droplets in the vicinity of a charged knitting needle. In this investigation, the Multi-Sphere Method, an electrostatic <span class="hlt">model</span> developed to study active spacecraft position control by Coulomb charging, is used to simulate the <span class="hlt">complex</span> orbital motion of the droplets. When atmospheric drag is introduced, the simulated motion closely mimics that seen in the video footage of the <span class="hlt">experiment</span>. The electrostatic force's inverse dependency on separation distance near the center of the needle lends itself to analytic predictions of the radial motion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA457738','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA457738"><span><span class="hlt">Modeling</span> of <span class="hlt">Complex</span> Adaptive Systems in Air Operations</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2006-09-01</p> <p>control of C3 in an increasingly <span class="hlt">complex</span> military environment. Control theory is a multidisciplinary science associated with dynamic systems and, while...AFRL-IF-RS-TR-2006-282 In- House Final Technical Report September 2006 <span class="hlt">MODELING</span> OF <span class="hlt">COMPLEX</span> ADAPTIVE SYSTEMS IN AIR OPERATIONS...NOTICE AND SIGNATURE PAGE Using Government drawings, specifications, or other data included in this document for any purpose other than Government</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70157405','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70157405"><span>Improving a regional <span class="hlt">model</span> using reduced <span class="hlt">complexity</span> and parameter estimation</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Kelson, Victor A.; Hunt, Randall J.; Haitjema, Henk M.</p> <p>2002-01-01</p> <p>The availability of powerful desktop computers and graphical user interfaces for ground water flow <span class="hlt">models</span> makes possible the construction of ever more <span class="hlt">complex</span> <span class="hlt">models</span>. A proposed copper-zinc sulfide mine in northern Wisconsin offers a unique case in which the same hydrologic system has been <span class="hlt">modeled</span> using a variety of techniques covering a wide range of sophistication and <span class="hlt">complexity</span>. Early in the permitting process, simple numerical <span class="hlt">models</span> were used to evaluate the necessary amount of water to be pumped from the mine, reductions in streamflow, and the drawdowns in the regional aquifer. More <span class="hlt">complex</span> <span class="hlt">models</span> have subsequently been used in an attempt to refine the predictions. Even after so much <span class="hlt">modeling</span> effort, questions regarding the accuracy and reliability of the predictions remain. We have performed a new analysis of the proposed mine using the two-dimensional analytic element code GFLOW coupled with the nonlinear parameter estimation code UCODE. The new <span class="hlt">model</span> is parsimonious, containing fewer than 10 parameters, and covers a region several times larger in areal extent than any of the previous <span class="hlt">models</span>. The <span class="hlt">model</span> demonstrates the suitability of analytic element codes for use with parameter estimation codes. The simplified <span class="hlt">model</span> results are similar to the more <span class="hlt">complex</span> <span class="hlt">models</span>; predicted mine inflows and UCODE-derived 95% confidence intervals are consistent with the previous predictions. More important, the large areal extent of the <span class="hlt">model</span> allowed us to examine hydrological features not included in the previous <span class="hlt">models</span>, resulting in new insights about the effects that far-field boundary conditions can have on near-field <span class="hlt">model</span> calibration and parameterization. In this case, the addition of surface water runoff into a lake in the headwaters of a stream while holding recharge constant moved a regional ground watershed divide and resulted in some of the added water being captured by the adjoining basin. Finally, a simple analytical solution was used to clarify the GFLOW <span class="hlt">model</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930006292','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930006292"><span>On explicit algebraic stress <span class="hlt">models</span> for <span class="hlt">complex</span> turbulent flows</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gatski, T. B.; Speziale, C. G.</p> <p>1992-01-01</p> <p>Explicit algebraic stress <span class="hlt">models</span> that are valid for three-dimensional turbulent flows in noninertial frames are systematically derived from a hierarchy of second-order closure <span class="hlt">models</span>. This represents a generalization of the <span class="hlt">model</span> derived by Pope who based his analysis on the Launder, Reece, and Rodi <span class="hlt">model</span> restricted to two-dimensional turbulent flows in an inertial frame. The relationship between the new <span class="hlt">models</span> and traditional algebraic stress <span class="hlt">models</span> -- as well as anistropic eddy visosity <span class="hlt">models</span> -- is theoretically established. The need for regularization is demonstrated in an effort to explain why traditional algebraic stress <span class="hlt">models</span> have failed in <span class="hlt">complex</span> flows. It is also shown that these explicit algebraic stress <span class="hlt">models</span> can shed new light on what second-order closure <span class="hlt">models</span> predict for the equilibrium states of homogeneous turbulent flows and can serve as a useful alternative in practical computations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AIPC..574....1A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AIPC..574....1A"><span><span class="hlt">Modeling</span> active memory: <span class="hlt">Experiment</span>, theory and simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amit, Daniel J.</p> <p>2001-06-01</p> <p>Neuro-physiological <span class="hlt">experiments</span> on cognitively performing primates are described to argue that strong evidence exists for localized, non-ergodic (stimulus specific) attractor dynamics in the cortex. The specific phenomena are delay activity distributions-enhanced spike-rate distributions resulting from training, which we associate with working memory. The anatomy of the relevant cortex region and the physiological characteristics of the participating elements (neural cells) are reviewed to provide a substrate for <span class="hlt">modeling</span> the observed phenomena. <span class="hlt">Modeling</span> is based on the properties of the integrate-and-fire neural element in presence of an input current of Gaussian distribution. Theory of stochastic processes provides an expression for the spike emission rate as a function of the mean and the variance of the current distribution. Mean-field theory is then based on the assumption that spike emission processes in different neurons in the network are independent, and hence the input current to a neuron is Gaussian. Consequently, the dynamics of the interacting network is reduced to the computation of the mean and the variance of the current received by a cell of a given population in terms of the constitutive parameters of the network and the emission rates of the neurons in the different populations. Within this logic we analyze the stationary states of an unstructured network, corresponding to spontaneous activity, and show that it can be stable only if locally the net input current of a neuron is inhibitory. This is then tested against simulations and it is found that agreement is excellent down to great detail. A confirmation of the independence hypothesis. On top of stable spontaneous activity, keeping all parameters fixed, training is described by (Hebbian) modification of synapses between neurons responsive to a stimulus and other neurons in the module-synapses are potentiated between two excited neurons and depressed between an excited and a quiescent neuron</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25337455','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25337455"><span><span class="hlt">Complex</span> groundwater flow systems as traveling agent <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>López Corona, Oliver; Padilla, Pablo; Escolero, Oscar; González, Tomas; Morales-Casique, Eric; Osorio-Olvera, Luis</p> <p>2014-01-01</p> <p>Analyzing field data from pumping tests, we show that as with many other natural phenomena, groundwater flow exhibits <span class="hlt">complex</span> dynamics described by 1/f power spectrum. This result is theoretically studied within an agent perspective. Using a traveling agent <span class="hlt">model</span>, we prove that this statistical behavior emerges when the medium is <span class="hlt">complex</span>. Some heuristic reasoning is provided to justify both spatial and dynamic <span class="hlt">complexity</span>, as the result of the superposition of an infinite number of stochastic processes. Even more, we show that this implies that non-Kolmogorovian probability is needed for its study, and provide a set of new partial differential equations for groundwater flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4203025','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4203025"><span><span class="hlt">Complex</span> groundwater flow systems as traveling agent <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Padilla, Pablo; Escolero, Oscar; González, Tomas; Morales-Casique, Eric; Osorio-Olvera, Luis</p> <p>2014-01-01</p> <p>Analyzing field data from pumping tests, we show that as with many other natural phenomena, groundwater flow exhibits <span class="hlt">complex</span> dynamics described by 1/f power spectrum. This result is theoretically studied within an agent perspective. Using a traveling agent <span class="hlt">model</span>, we prove that this statistical behavior emerges when the medium is <span class="hlt">complex</span>. Some heuristic reasoning is provided to justify both spatial and dynamic <span class="hlt">complexity</span>, as the result of the superposition of an infinite number of stochastic processes. Even more, we show that this implies that non-Kolmogorovian probability is needed for its study, and provide a set of new partial differential equations for groundwater flow. PMID:25337455</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27744217','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27744217"><span>Is there <span class="hlt">Complex</span> Trauma <span class="hlt">Experience</span> typology for Australian's experiencing extreme social disadvantage and low housing stability?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Keane, Carol A; Magee, Christopher A; Kelly, Peter J</p> <p>2016-11-01</p> <p>Traumatic childhood <span class="hlt">experiences</span> predict many adverse outcomes in adulthood including <span class="hlt">Complex</span>-PTSD. Understanding <span class="hlt">complex</span> trauma within socially disadvantaged populations has important implications for policy development and intervention implementation. This paper examined the nature of <span class="hlt">complex</span> trauma experienced by disadvantaged individuals using a latent class analysis (LCA) approach. Data were collected through the large-scale Journeys Home Study (N=1682), utilising a representative sample of individuals experiencing low housing stability. Data on adverse childhood <span class="hlt">experiences</span>, adulthood interpersonal trauma and relevant covariates were collected through interviews at baseline (Wave 1). Latent class analysis (LCA) was conducted to identify distinct classes of childhood trauma history, which included physical assault, neglect, and sexual abuse. Multinomial logistic regression investigated childhood relevant factors associated with class membership such as biological relationship of primary carer at age 14 years and number of times in foster care. Of the total sample (N=1682), 99% reported traumatic adverse childhood <span class="hlt">experiences</span>. The most common included witnessing of violence, threat/<span class="hlt">experience</span> of physical abuse, and sexual assault. LCA identified six distinct childhood trauma history classes including high violence and multiple traumas. Significant covariate differences between classes included: gender, biological relationship of primary carer at age 14 years, and time in foster care. Identification of six distinct childhood trauma history profiles suggests there might be unique treatment implications for individuals living in extreme social disadvantage. Further research is required to examine the relationship between these classes of <span class="hlt">experience</span>, consequent impact on adulthood engagement, and future transitions though homelessness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70027801','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70027801"><span>A <span class="hlt">Complex</span> Systems <span class="hlt">Model</span> Approach to Quantified Mineral Resource Appraisal</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Gettings, M.E.; Bultman, M.W.; Fisher, F.S.</p> <p>2004-01-01</p> <p>For federal and state land management agencies, mineral resource appraisal has evolved from value-based to outcome-based procedures wherein the consequences of resource development are compared with those of other management options. <span class="hlt">Complex</span> systems <span class="hlt">modeling</span> is proposed as a general framework in which to build <span class="hlt">models</span> that can evaluate outcomes. Three frequently used methods of mineral resource appraisal (subjective probabilistic estimates, weights of evidence <span class="hlt">modeling</span>, and fuzzy logic <span class="hlt">modeling</span>) are discussed to obtain insight into methods of incorporating <span class="hlt">complexity</span> into mineral resource appraisal <span class="hlt">models</span>. Fuzzy logic and weights of evidence are most easily utilized in <span class="hlt">complex</span> systems <span class="hlt">models</span>. A fundamental product of new appraisals is the production of reusable, accessible databases and methodologies so that appraisals can easily be repeated with new or refined data. The data are representations of <span class="hlt">complex</span> systems and must be so regarded if all of their information content is to be utilized. The proposed generalized <span class="hlt">model</span> framework is applicable to mineral assessment and other geoscience problems. We begin with a (fuzzy) cognitive map using (+1,0,-1) values for the links and evaluate the map for various scenarios to obtain a ranking of the importance of various links. Fieldwork and <span class="hlt">modeling</span> studies identify important links and help identify unanticipated links. Next, the links are given membership functions in accordance with the data. Finally, processes are associated with the links; ideally, the controlling physical and chemical events and equations are found for each link. After calibration and testing, this <span class="hlt">complex</span> systems <span class="hlt">model</span> is used for predictions under various scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20060111','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20060111"><span>Extensive video-game <span class="hlt">experience</span> alters cortical networks for <span class="hlt">complex</span> visuomotor transformations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Granek, Joshua A; Gorbet, Diana J; Sergio, Lauren E</p> <p>2010-10-01</p> <p>Using event-related functional magnetic resonance imaging (fMRI), we examined the effect of video-game <span class="hlt">experience</span> on the neural control of increasingly <span class="hlt">complex</span> visuomotor tasks. Previously, skilled individuals have demonstrated the use of a more efficient movement control brain network, including the prefrontal, premotor, primary sensorimotor and parietal cortices. Our results extend and generalize this finding by documenting additional prefrontal cortex activity in experienced video gamers planning for <span class="hlt">complex</span> eye-hand coordination tasks that are distinct from actual video-game play. These changes in activation between non-gamers and extensive gamers are putatively related to the increased online control and spatial attention required for <span class="hlt">complex</span> visually guided reaching. These data suggest that the basic cortical network for processing <span class="hlt">complex</span> visually guided reaching is altered by extensive video-game play.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JSMTE..05.4031M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JSMTE..05.4031M"><span>Kinetic <span class="hlt">modeling</span> of molecular motors: pause <span class="hlt">model</span> and parameter determination from single-molecule <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Morin, José A.; Ibarra, Borja; Cao, Francisco J.</p> <p>2016-05-01</p> <p>Single-molecule manipulation <span class="hlt">experiments</span> of molecular motors provide essential information about the rate and conformational changes of the steps of the reaction located along the manipulation coordinate. This information is not always sufficient to define a particular kinetic cycle. Recent single-molecule <span class="hlt">experiments</span> with optical tweezers showed that the DNA unwinding activity of a Phi29 DNA polymerase mutant presents a <span class="hlt">complex</span> pause behavior, which includes short and long pauses. Here we show that different kinetic <span class="hlt">models</span>, considering different connections between the active and the pause states, can explain the experimental pause behavior. Both the two independent pause <span class="hlt">model</span> and the two connected pause <span class="hlt">model</span> are able to describe the pause behavior of a mutated Phi29 DNA polymerase observed in an optical tweezers single-molecule <span class="hlt">experiment</span>. For the two independent pause <span class="hlt">model</span> all parameters are fixed by the observed data, while for the more general two connected pause <span class="hlt">model</span> there is a range of values of the parameters compatible with the observed data (which can be expressed in terms of two of the rates and their force dependencies). This general <span class="hlt">model</span> includes <span class="hlt">models</span> with indirect entry and exit to the long-pause state, and also <span class="hlt">models</span> with cycling in both directions. Additionally, assuming that detailed balance is verified, which forbids cycling, this reduces the ranges of the values of the parameters (which can then be expressed in terms of one rate and its force dependency). The resulting <span class="hlt">model</span> interpolates between the independent pause <span class="hlt">model</span> and the indirect entry and exit to the long-pause state <span class="hlt">model</span></p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25698434','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25698434"><span>Evaluation of soil flushing of <span class="hlt">complex</span> contaminated soil: an experimental and <span class="hlt">modeling</span> simulation study.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yun, Sung Mi; Kang, Christina S; Kim, Jonghwa; Kim, Han S</p> <p>2015-04-28</p> <p>The removal of heavy metals (Zn and Pb) and heavy petroleum oils (HPOs) from a soil with <span class="hlt">complex</span> contamination was examined by soil flushing. Desorption and transport behaviors of the <span class="hlt">complex</span> contaminants were assessed by batch and continuous flow reactor <span class="hlt">experiments</span> and through <span class="hlt">modeling</span> simulations. Flushing a one-dimensional flow column packed with <span class="hlt">complex</span> contaminated soil sequentially with citric acid then a surfactant resulted in the removal of 85.6% of Zn, 62% of Pb, and 31.6% of HPO. The desorption distribution coefficients, KUbatch and KLbatch, converged to constant values as Ce increased. An equilibrium <span class="hlt">model</span> (ADR) and nonequilibrium <span class="hlt">models</span> (TSNE and TRNE) were used to predict the desorption and transport of <span class="hlt">complex</span> contaminants. The nonequilibrium <span class="hlt">models</span> demonstrated better fits with the experimental values obtained from the column test than the equilibrium <span class="hlt">model</span>. The ranges of KUbatch and KLbatch were very close to those of KUfit and KLfit determined from <span class="hlt">model</span> simulations. The parameters (R, β, ω, α, and f) determined from <span class="hlt">model</span> simulations were useful for characterizing the transport of contaminants within the soil matrix. The results of this study provide useful information for the operational parameters of the flushing process for soils with <span class="hlt">complex</span> contamination.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989JApMe..28..665L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989JApMe..28..665L"><span>Transferability of a Three-Dimensional Air Quality <span class="hlt">Model</span> between Two Different Sites in <span class="hlt">Complex</span> Terrain.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lange, Rolf</p> <p>1989-07-01</p> <p>The three-dimensional, diagnostic, particle-in-cell transport and diffusion <span class="hlt">model</span> MATHEW/ADPIC is used to test its transferability from one site in <span class="hlt">complex</span> terrain to another with different characteristics, under stable nighttime drainage flow conditions. The two sites were subject to extensive drainage flow tracer <span class="hlt">experiments</span> under the multilaboratory Atmospheric Studies in <span class="hlt">Complex</span> Terrain (ASCOT) program: the first being a valley in the Geysers geothermal region of northern California, and the second a canyon in western Colorado. The domain in each case is approximately 10 × 10 km. The 1980 Geysers <span class="hlt">model</span> evaluation is only quoted. The 1984 Brush Creek <span class="hlt">model</span> evaluation is described in detail.Results from comparing computed with measured concentrations from a variety of tracer releases indicate that 52% of the 4531 samples from five <span class="hlt">experiments</span> in Brush Creek and 50% of the 831 samples from four <span class="hlt">experiments</span> in the Geysers agreed within a factor of 5. When an angular 10° uncertainty, consistent with anemometer reliability limits in <span class="hlt">complex</span> terrain, was allowed to be applied to the <span class="hlt">model</span> results, <span class="hlt">model</span> performance improved such that 78% of samples compared within a factor of 5 for Brush Creek and 77% for the Geysers. Looking at the range of other factors of concentration ratios, results indicate that the <span class="hlt">model</span> is satisfactorily transferable without tuning it to a specific site.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/942063','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/942063"><span>Mathematical approaches for <span class="hlt">complexity</span>/predictivity trade-offs in <span class="hlt">complex</span> system <span class="hlt">models</span> : LDRD final report.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Goldsby, Michael E.; Mayo, Jackson R.; Bhattacharyya, Arnab; Armstrong, Robert C.; Vanderveen, Keith</p> <p>2008-09-01</p> <p>The goal of this research was to examine foundational methods, both computational and theoretical, that can improve the veracity of entity-based <span class="hlt">complex</span> system <span class="hlt">models</span> and increase confidence in their predictions for emergent behavior. The strategy was to seek insight and guidance from simplified yet realistic <span class="hlt">models</span>, such as cellular automata and Boolean networks, whose properties can be generalized to production entity-based simulations. We have explored the usefulness of renormalization-group methods for finding reduced <span class="hlt">models</span> of such idealized <span class="hlt">complex</span> systems. We have prototyped representative <span class="hlt">models</span> that are both tractable and relevant to Sandia mission applications, and quantified the effect of computational renormalization on the predictive accuracy of these <span class="hlt">models</span>, finding good predictivity from renormalized versions of cellular automata and Boolean networks. Furthermore, we have theoretically analyzed the robustness properties of certain Boolean networks, relevant for characterizing organic behavior, and obtained precise mathematical constraints on systems that are robust to failures. In combination, our results provide important guidance for more rigorous construction of entity-based <span class="hlt">models</span>, which currently are often devised in an ad-hoc manner. Our results can also help in designing <span class="hlt">complex</span> systems with the goal of predictable behavior, e.g., for cybersecurity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....51.8677S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....51.8677S"><span>Introduction to a special section on ecohydrology of semiarid environments: Confronting mathematical <span class="hlt">models</span> with ecosystem <span class="hlt">complexity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Svoray, Tal; Assouline, Shmuel; Katul, Gabriel</p> <p>2015-11-01</p> <p>Current literature provides large number of publications about ecohydrological processes and their effect on the biota in drylands. Given the limited laboratory and field <span class="hlt">experiments</span> in such systems, many of these publications are based on mathematical <span class="hlt">models</span> of varying <span class="hlt">complexity</span>. The underlying implicit assumption is that the data set used to evaluate these <span class="hlt">models</span> covers the parameter space of conditions that characterize drylands and that the <span class="hlt">models</span> represent the actual processes with acceptable certainty. However, a question raised is to what extent these mathematical <span class="hlt">models</span> are valid when confronted with observed ecosystem <span class="hlt">complexity</span>? This Introduction reviews the 16 papers that comprise the Special Section on Eco-hydrology of Semiarid Environments: Confronting Mathematical <span class="hlt">Models</span> with Ecosystem <span class="hlt">Complexity</span>. The subjects studied in these papers include rainfall regime, infiltration and preferential flow, evaporation and evapotranspiration, annual net primary production, dispersal and invasion, and vegetation greening. The findings in the papers published in this Special Section show that innovative mathematical <span class="hlt">modeling</span> approaches can represent actual field measurements. Hence, there are strong grounds for suggesting that mathematical <span class="hlt">models</span> can contribute to greater understanding of ecosystem <span class="hlt">complexity</span> through characterization of space-time dynamics of biomass and water storage as well as their multiscale interactions. However, the generality of the <span class="hlt">models</span> and their low-dimensional representation of many processes may also be a "curse" that results in failures when particulars of an ecosystem are required. It is envisaged that the search for a unifying "general" <span class="hlt">model</span>, while seductive, may remain elusive in the foreseeable future. It is for this reason that improving the merger between <span class="hlt">experiments</span> and <span class="hlt">models</span> of various degrees of <span class="hlt">complexity</span> continues to shape the future research agenda.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017CNSNS..42..324N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017CNSNS..42..324N"><span>The general theory of the Quasi-reproducible <span class="hlt">experiments</span>: How to describe the measured data of <span class="hlt">complex</span> systems?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nigmatullin, Raoul R.; Maione, Guido; Lino, Paolo; Saponaro, Fabrizio; Zhang, Wei</p> <p>2017-01-01</p> <p>In this paper, we suggest a general theory that enables to describe <span class="hlt">experiments</span> associated with reproducible or quasi-reproducible data reflecting the dynamical and self-similar properties of a wide class of <span class="hlt">complex</span> systems. Under <span class="hlt">complex</span> system we understand a system when the <span class="hlt">model</span> based on microscopic principles and suppositions about the nature of the matter is absent. This microscopic <span class="hlt">model</span> is usually determined as "the best fit" <span class="hlt">model</span>. The behavior of the <span class="hlt">complex</span> system relatively to a control variable (time, frequency, wavelength, etc.) can be described in terms of the so-called intermediate <span class="hlt">model</span> (IM). One can prove that the fitting parameters of the IM are associated with the amplitude-frequency response of the segment of the Prony series. The segment of the Prony series including the set of the decomposition coefficients and the set of the exponential functions (with k = 1,2,…,K) is limited by the final mode K. The exponential functions of this decomposition depend on time and are found by the original algorithm described in the paper. This approach serves as a logical continuation of the results obtained earlier in paper [Nigmatullin RR, W. Zhang and Striccoli D. General theory of <span class="hlt">experiment</span> containing reproducible data: The reduction to an ideal <span class="hlt">experiment</span>. Commun Nonlinear Sci Numer Simul, 27, (2015), pp 175-192] for reproducible <span class="hlt">experiments</span> and includes the previous results as a partial case. In this paper, we consider a more <span class="hlt">complex</span> case when the available data can create short samplings or exhibit some instability during the process of measurements. We give some justified evidences and conditions proving the validity of this theory for the description of a wide class of <span class="hlt">complex</span> systems in terms of the reduced set of the fitting parameters belonging to the segment of the Prony series. The elimination of uncontrollable factors expressed in the form of the apparatus function is discussed. To illustrate how to apply the theory and take advantage of its</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4937570','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4937570"><span>Multikernel linear mixed <span class="hlt">models</span> for <span class="hlt">complex</span> phenotype prediction</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Weissbrod, Omer; Geiger, Dan; Rosset, Saharon</p> <p>2016-01-01</p> <p>Linear mixed <span class="hlt">models</span> (LMMs) and their extensions have recently become the method of choice in phenotype prediction for <span class="hlt">complex</span> traits. However, LMM use to date has typically been limited by assuming simple genetic architectures. Here, we present multikernel linear mixed <span class="hlt">model</span> (MKLMM), a predictive <span class="hlt">modeling</span> framework that extends the standard LMM using multiple-kernel machine learning approaches. MKLMM can <span class="hlt">model</span> genetic interactions and is particularly suitable for <span class="hlt">modeling</span> <span class="hlt">complex</span> local interactions between nearby variants. We additionally present MKLMM-Adapt, which automatically infers interaction types across multiple genomic regions. In an analysis of eight case-control data sets from the Wellcome Trust Case Control Consortium and more than a hundred mouse phenotypes, MKLMM-Adapt consistently outperforms competing methods in phenotype prediction. MKLMM is as computationally efficient as standard LMMs and does not require storage of genotypes, thus achieving state-of-the-art predictive power without compromising computational feasibility or genomic privacy. PMID:27302636</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017GMD....10..945U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017GMD....10..945U"><span>A cloud feedback emulator (CFE, version 1.0) for an intermediate <span class="hlt">complexity</span> <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ullman, David J.; Schmittner, Andreas</p> <p>2017-02-01</p> <p>The dominant source of inter-<span class="hlt">model</span> differences in comprehensive global climate <span class="hlt">models</span> (GCMs) are cloud radiative effects on Earth's energy budget. Intermediate <span class="hlt">complexity</span> <span class="hlt">models</span>, while able to run more efficiently, often lack cloud feedbacks. Here, we describe and evaluate a method for applying GCM-derived shortwave and longwave cloud feedbacks from 4 × CO2 and Last Glacial Maximum <span class="hlt">experiments</span> to the University of Victoria Earth System Climate <span class="hlt">Model</span>. The method generally captures the spread in top-of-the-atmosphere radiative feedbacks between the original GCMs, which impacts the magnitude and spatial distribution of surface temperature changes and climate sensitivity. These results suggest that the method is suitable to incorporate multi-<span class="hlt">model</span> cloud feedback uncertainties in ensemble simulations with a single intermediate <span class="hlt">complexity</span> <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4742534','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4742534"><span>A Compact <span class="hlt">Model</span> for the <span class="hlt">Complex</span> Plant Circadian Clock</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>De Caluwé, Joëlle; Xiao, Qiying; Hermans, Christian; Verbruggen, Nathalie; Leloup, Jean-Christophe; Gonze, Didier</p> <p>2016-01-01</p> <p>The circadian clock is an endogenous timekeeper that allows organisms to anticipate and adapt to the daily variations of their environment. The plant clock is an intricate network of interlocked feedback loops, in which transcription factors regulate each other to generate oscillations with expression peaks at specific times of the day. Over the last decade, mathematical <span class="hlt">modeling</span> approaches have been used to understand the inner workings of the clock in the <span class="hlt">model</span> plant Arabidopsis thaliana. Those efforts have produced a number of <span class="hlt">models</span> of ever increasing <span class="hlt">complexity</span>. Here, we present an alternative <span class="hlt">model</span> that combines a low number of equations and parameters, similar to the very earliest <span class="hlt">models</span>, with the <span class="hlt">complex</span> network structure found in more recent ones. This simple <span class="hlt">model</span> describes the temporal evolution of the abundance of eight clock gene mRNA/protein and captures key features of the clock on a qualitative level, namely the entrained and free-running behaviors of the wild type clock, as well as the defects found in knockout mutants (such as altered free-running periods, lack of entrainment, or changes in the expression of other clock genes). Additionally, our <span class="hlt">model</span> produces <span class="hlt">complex</span> responses to various light cues, such as extreme photoperiods and non-24 h environmental cycles, and can describe the control of hypocotyl growth by the clock. Our <span class="hlt">model</span> constitutes a useful tool to probe dynamical properties of the core clock as well as clock-dependent processes. PMID:26904049</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/12293578','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/12293578"><span>Further thoughts on simplicity and <span class="hlt">complexity</span> in population projection <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smith, S K</p> <p>1997-12-01</p> <p>"This article is a review of--and response to--a special issue of Mathematical Population Studies that focused on the relative performance of simpler vs. more <span class="hlt">complex</span> population projection <span class="hlt">models</span>. I do not attempt to summarize or comment on each of the articles in the special issue, but rather present an additional perspective on several points: definitions of simplicity and <span class="hlt">complexity</span>, empirical evidence regarding population forecast accuracy, the costs and benefits of disaggregation, the potential benefits of combining forecasts, criteria for evaluating projection <span class="hlt">models</span>, and issues of economic efficiency in the production of population projections."</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhRvD..94i6011F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhRvD..94i6011F"><span>Vacuum structure of the Higgs <span class="hlt">complex</span> singlet-doublet <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferreira, P. M.</p> <p>2016-11-01</p> <p>The <span class="hlt">complex</span> singlet-doublet <span class="hlt">model</span> is a popular theory to account for dark matter and electroweak baryogenesis, wherein the Standard <span class="hlt">Model</span> particle content is supplemented by a <span class="hlt">complex</span> scalar gauge singlet, with certain discrete symmetries imposed. The scalar potential which results thereof can have seven different types of minima at tree level, which may coexist for specific choices of parameters. There is therefore the possibility that a given minimum is not global but rather a local one, and may tunnel to a deeper extremum, thus causing vacuum instability. This rich vacuum structure is explained and discussed in detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AdAtS..22..142X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AdAtS..22..142X"><span>Optimal parameter and uncertainty estimation of a land surface <span class="hlt">model</span>: Sensitivity to parameter ranges and <span class="hlt">model</span> <span class="hlt">complexities</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xia, Youlong; Yang, Zong-Liang; Stoffa, Paul L.; Sen, Mrinal K.</p> <p>2005-01-01</p> <p>Most previous land-surface <span class="hlt">model</span> calibration studies have defined global ranges for their parameters to search for optimal parameter sets. Little work has been conducted to study the impacts of realistic versus global ranges as well as <span class="hlt">model</span> <span class="hlt">complexities</span> on the calibration and uncertainty estimates. The primary purpose of this paper is to investigate these impacts by employing Bayesian Stochastic Inversion (BSI) to the Chameleon Surface <span class="hlt">Model</span> (CHASM). The CHASM was designed to explore the general aspects of land-surface energy balance representation within a common <span class="hlt">modeling</span> framework that can be run from a simple energy balance formulation to a <span class="hlt">complex</span> mosaic type structure. The BSI is an uncertainty estimation technique based on Bayes theorem, importance sampling, and very fast simulated annealing. The <span class="hlt">model</span> forcing data and surface flux data were collected at seven sites representing a wide range of climate and vegetation conditions. For each site, four <span class="hlt">experiments</span> were performed with simple and <span class="hlt">complex</span> CHASM formulations as well as realistic and global parameter ranges. Twenty eight <span class="hlt">experiments</span> were conducted and 50 000 parameter sets were used for each run. The results show that the use of global and realistic ranges gives similar simulations for both modes for most sites, but the global ranges tend to produce some unreasonable optimal parameter values. Comparison of simple and <span class="hlt">complex</span> modes shows that the simple mode has more parameters with unreasonable optimal values. Use of parameter ranges and <span class="hlt">model</span> <span class="hlt">complexities</span> have significant impacts on frequency distribution of parameters, marginal posterior probability density functions, and estimates of uncertainty of simulated sensible and latent heat fluxes. Comparison between <span class="hlt">model</span> <span class="hlt">complexity</span> and parameter ranges shows that the former has more significant impacts on parameter and uncertainty estimations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/768084','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/768084"><span>Coupled Thermal-Chemical-Mechanical <span class="hlt">Modeling</span> of Validation Cookoff <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>ERIKSON,WILLIAM W.; SCHMITT,ROBERT G.; ATWOOD,A.I.; CURRAN,P.D.</p> <p>2000-11-27</p> <p>-dominated failure mode experienced in the tests. High-pressure burning rates are needed for more detailed post-ignition studies. Sub-<span class="hlt">models</span> for chemistry, mechanical response and burn dynamics need to be validated against data from less <span class="hlt">complex</span> <span class="hlt">experiments</span>. The sub-<span class="hlt">models</span> can then be used in integrated analysis for comparison with experimental data taken during integrated tests.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760004550','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760004550"><span>Investigation of <span class="hlt">models</span> for large-scale meteorological prediction <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spar, J.</p> <p>1975-01-01</p> <p>The feasibility of extended and long-range weather prediction by means of global atmospheric <span class="hlt">models</span> was studied. A number of computer <span class="hlt">experiments</span> were conducted at GISS with the GISS global general circulation <span class="hlt">model</span>. Topics discussed include atmospheric response to sea-surface temperature anomalies, and monthly mean forecast <span class="hlt">experiments</span> with the global <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Taxonomy&id=EJ1112599','ERIC'); return false;" href="http://eric.ed.gov/?q=Taxonomy&id=EJ1112599"><span>Assessing <span class="hlt">Complexity</span> in Learning Outcomes--A Comparison between the SOLO Taxonomy and the <span class="hlt">Model</span> of Hierarchical <span class="hlt">Complexity</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stålne, Kristian; Kjellström, Sofia; Utriainen, Jukka</p> <p>2016-01-01</p> <p>An important aspect of higher education is to educate students who can manage <span class="hlt">complex</span> relationships and solve <span class="hlt">complex</span> problems. Teachers need to be able to evaluate course content with regard to <span class="hlt">complexity</span>, as well as evaluate students' ability to assimilate <span class="hlt">complex</span> content and express it in the form of a learning outcome. One <span class="hlt">model</span> for evaluating…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ThEng..60..835K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ThEng..60..835K"><span>Computer <span class="hlt">models</span> of <span class="hlt">complex</span> multiloop branched pipeline systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kudinov, I. V.; Kolesnikov, S. V.; Eremin, A. V.; Branfileva, A. N.</p> <p>2013-11-01</p> <p>This paper describes the principal theoretical concepts of the method used for constructing computer <span class="hlt">models</span> of <span class="hlt">complex</span> multiloop branched pipeline networks, and this method is based on the theory of graphs and two Kirchhoff's laws applied to electrical circuits. The <span class="hlt">models</span> make it possible to calculate velocities, flow rates, and pressures of a fluid medium in any section of pipeline networks, when the latter are considered as single hydraulic systems. On the basis of multivariant calculations the reasons for existing problems can be identified, the least costly methods of their elimination can be proposed, and recommendations for planning the modernization of pipeline systems and construction of their new sections can be made. The results obtained can be applied to <span class="hlt">complex</span> pipeline systems intended for various purposes (water pipelines, petroleum pipelines, etc.). The operability of the <span class="hlt">model</span> has been verified on an example of designing a unified computer <span class="hlt">model</span> of the heat network for centralized heat supply of the city of Samara.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016CNSNS..37..249L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016CNSNS..37..249L"><span><span class="hlt">Modeling</span> the propagation of mobile malware on <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Wanping; Liu, Chao; Yang, Zheng; Liu, Xiaoyang; Zhang, Yihao; Wei, Zuxue</p> <p>2016-08-01</p> <p>In this paper, the spreading behavior of malware across mobile devices is addressed. By introducing <span class="hlt">complex</span> networks to <span class="hlt">model</span> mobile networks, which follows the power-law degree distribution, a novel epidemic <span class="hlt">model</span> for mobile malware propagation is proposed. The spreading threshold that guarantees the dynamics of the <span class="hlt">model</span> is calculated. Theoretically, the asymptotic stability of the malware-free equilibrium is confirmed when the threshold is below the unity, and the global stability is further proved under some sufficient conditions. The influences of different <span class="hlt">model</span> parameters as well as the network topology on malware propagation are also analyzed. Our theoretical studies and numerical simulations show that networks with higher heterogeneity conduce to the diffusion of malware, and <span class="hlt">complex</span> networks with lower power-law exponents benefit malware spreading.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.S51F..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.S51F..02B"><span>Slip <span class="hlt">complexity</span> and frictional heterogeneities in dynamic fault <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bizzarri, A.</p> <p>2005-12-01</p> <p>The numerical <span class="hlt">modeling</span> of earthquake rupture requires the specification of the fault system geometry, the mechanical properties of the media surrounding the fault, the initial conditions and the constitutive law for fault friction. The latter accounts for the fault zone properties and allows for the description of processes of nucleation, propagation, healing and arrest of a spontaneous rupture. In this work I solve the fundamental elasto-dynamic equation for a planar fault, adopting different constitutive equations (slip-dependent and rate- and state-dependent friction laws). We show that the slip patterns may be complicated by different causes. The spatial heterogeneities of constitutive parameters are able to cause the healing of slip, like barrier-healing or slip pulses. Our numerical <span class="hlt">experiments</span> show that the heterogeneities of the parameter L affect the dynamic rupture propagation and weakly modify the dynamic stress drop and the rupture velocity. The heterogeneity of a and b parameters affects the dynamic rupture propagation in a more <span class="hlt">complex</span> way: a velocity strengthening area (a > b) can arrest a dynamic rupture, but can be driven to an instability if suddenly loaded by the dynamic rupture front. Our simulations provide a picture of the <span class="hlt">complex</span> interactions between fault patches having different frictional properties. Moreover, the slip distribution on the fault plane is complicated considering the effects of the rake rotation during the propagation: depending on the position on the fault plane, the orientation of instantaneous total dynamic traction can change with time with respect to the imposed initial stress direction. These temporal rake rotations depend on the amplitude of the initial stress and on its distribution. They also depend on the curvature and direction of the rupture front with respect to the imposed initial stress direction: this explains why rake rotations are mostly located near the rupture front and within the cohesive zone, where the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/352703','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/352703"><span>Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> or organic acid sorption to goethite</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Evanko, C.R.; Dzombak, D.A.</p> <p>1999-06-15</p> <p>Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> was performed using the Generalized Two-Layer <span class="hlt">Model</span> for a series of low molecular weight organic acids. Sorption of these organic acids to goethite was investigated in a previous study to assess the influence of particular structural features on sorption. Here, the ability to describe the observed sorption behavior for compounds with similar structural features using surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> was investigated. A set of surface reactions and equilibrium constants yielding optimal data fits was obtained for each organic acid over a range of total sorbate concentrations. Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> successfully described sorption of a number of the simple organic acids, but an additional hydrophobic component was needed to describe sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior that was inconsistent with ligand exchange mechanisms since sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior that was inconsistent with ligand exchange mechanisms since sorption did not decrease with increasing total sorbate concentration and/or exceeded surface site saturation. Hydrophobic interactions appeared to be most significant for the compound containing a 5-carbon aliphatic chain. Comparison of optimized equilibrium constants for similar surface species showed that <span class="hlt">model</span> results were consistent with observed sorption behavior: equilibrium constants were highest for compounds having adjacent carboxylic groups, lower for compounds with adjacent phenolic groups, and lowest for compounds with phenolic groups in the ortho position relative to a carboxylic group. Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> was also performed to fit sorption data for Suwannee River fulvic acid. The data could be described well using reactions and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/10339359','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/10339359"><span>Surface <span class="hlt">Complexation</span> <span class="hlt">Modeling</span> of Organic Acid Sorption to Goethite.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Evanko; Dzombak</p> <p>1999-06-15</p> <p>Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> was performed using the Generalized Two-Layer <span class="hlt">Model</span> for a series of low molecular weight organic acids. Sorption of these organic acids to goethite was investigated in a previous study to assess the influence of particular structural features on sorption. Here, the ability to describe the observed sorption behavior for compounds with similar structural features using surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> was investigated. A set of surface reactions and equilibrium constants yielding optimal data fits was obtained for each organic acid over a range of total sorbate concentrations. Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> successfully described sorption of a number of the simple organic acids, but an additional hydrophobic component was needed to describe sorption behavior of some compounds with significant hydrophobic character. These compounds exhibited sorption behavior that was inconsistent with ligand exchange mechanisms since sorption did not decrease with increasing total sorbate concentration and/or exceeded surface site saturation. Hydrophobic interactions appeared to be most significant for the compound containing a 5-carbon aliphatic chain. Comparison of optimized equilibrium constants for similar surface species showed that <span class="hlt">model</span> results were consistent with observed sorption behavior: equilibrium constants were highest for compounds having adjacent carboxylic groups, lower for compounds with adjacent phenolic groups, and lowest for compounds with phenolic groups in the ortho position relative to a carboxylic group. Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> was also performed to fit sorption data for Suwannee River fulvic acid. The data could be described well using reactions and constants similar to those for pyromellitic acid. This four-carboxyl group compound may be useful as a <span class="hlt">model</span> for fulvic acid with respect to sorption. Other simple organic acids having multiple carboxylic and phenolic functional groups were identified as potential <span class="hlt">models</span> for humic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870043929&hterms=petri+nets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpetri%2Bnets','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870043929&hterms=petri+nets&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dpetri%2Bnets"><span>Petri net <span class="hlt">model</span> for analysis of concurrently processed <span class="hlt">complex</span> algorithms</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stoughton, John W.; Mielke, Roland R.</p> <p>1986-01-01</p> <p>This paper presents a Petri-net <span class="hlt">model</span> suitable for analyzing the concurrent processing of computationally <span class="hlt">complex</span> algorithms. The decomposed operations are to be processed in a multiple processor, data driven architecture. Of particular interest is the application of the <span class="hlt">model</span> to both the description of the data/control flow of a particular algorithm, and to the general specification of the data driven architecture. A candidate architecture is also presented.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24963803','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24963803"><span>Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> of americium sorption onto volcanic tuff.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ding, M; Kelkar, S; Meijer, A</p> <p>2014-10-01</p> <p>Results of a surface <span class="hlt">complexation</span> <span class="hlt">model</span> (SCM) for americium sorption on volcanic rocks (devitrified and zeolitic tuff) are presented. The <span class="hlt">model</span> was developed using PHREEQC and based on laboratory data for americium sorption on quartz. Available data for sorption of americium on quartz as a function of pH in dilute groundwater can be <span class="hlt">modeled</span> with two surface reactions involving an americium sulfate and an americium carbonate <span class="hlt">complex</span>. It was assumed in applying the <span class="hlt">model</span> to volcanic rocks from Yucca Mountain, that the surface properties of volcanic rocks can be represented by a quartz surface. Using groundwaters compositionally representative of Yucca Mountain, americium sorption distribution coefficient (Kd, L/Kg) values were calculated as function of pH. These Kd values are close to the experimentally determined Kd values for americium sorption on volcanic rocks, decreasing with increasing pH in the pH range from 7 to 9. The surface <span class="hlt">complexation</span> constants, derived in this study, allow prediction of sorption of americium in a natural <span class="hlt">complex</span> system, taking into account the inherent uncertainty associated with geochemical conditions that occur along transport pathways.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=estimator&pg=3&id=EJ915404','ERIC'); return false;" href="http://eric.ed.gov/?q=estimator&pg=3&id=EJ915404"><span>Performance of Random Effects <span class="hlt">Model</span> Estimators under <span class="hlt">Complex</span> Sampling Designs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jia, Yue; Stokes, Lynne; Harris, Ian; Wang, Yan</p> <p>2011-01-01</p> <p>In this article, we consider estimation of parameters of random effects <span class="hlt">models</span> from samples collected via <span class="hlt">complex</span> multistage designs. Incorporation of sampling weights is one way to reduce estimation bias due to unequal probabilities of selection. Several weighting methods have been proposed in the literature for estimating the parameters of…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=b+AND+cells&pg=2&id=EJ1109001','ERIC'); return false;" href="http://eric.ed.gov/?q=b+AND+cells&pg=2&id=EJ1109001"><span>Fitting Meta-Analytic Structural Equation <span class="hlt">Models</span> with <span class="hlt">Complex</span> Datasets</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wilson, Sandra Jo; Polanin, Joshua R.; Lipsey, Mark W.</p> <p>2016-01-01</p> <p>A modification of the first stage of the standard procedure for two-stage meta-analytic structural equation <span class="hlt">modeling</span> for use with large <span class="hlt">complex</span> datasets is presented. This modification addresses two common problems that arise in such meta-analyses: (a) primary studies that provide multiple measures of the same construct and (b) the correlation…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=%22Process+model%22&pg=6&id=EJ940837','ERIC'); return false;" href="http://eric.ed.gov/?q=%22Process+model%22&pg=6&id=EJ940837"><span>The <span class="hlt">Complexity</span> of Developmental Predictions from Dual Process <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Stanovich, Keith E.; West, Richard F.; Toplak, Maggie E.</p> <p>2011-01-01</p> <p>Drawing developmental predictions from dual-process theories is more <span class="hlt">complex</span> than is commonly realized. Overly simplified predictions drawn from such <span class="hlt">models</span> may lead to premature rejection of the dual process approach as one of many tools for understanding cognitive development. Misleading predictions can be avoided by paying attention to several…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Carbon&id=EJ1079266','ERIC'); return false;" href="http://eric.ed.gov/?q=Carbon&id=EJ1079266"><span>Fischer and Schrock Carbene <span class="hlt">Complexes</span>: A Molecular <span class="hlt">Modeling</span> Exercise</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Montgomery, Craig D.</p> <p>2015-01-01</p> <p>An exercise in molecular <span class="hlt">modeling</span> that demonstrates the distinctive features of Fischer and Schrock carbene <span class="hlt">complexes</span> is presented. Semi-empirical calculations (PM3) demonstrate the singlet ground electronic state, restricted rotation about the C-Y bond, the positive charge on the carbon atom, and hence, the electrophilic nature of the Fischer…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED073965.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED073965.pdf"><span>Conceptual <span class="hlt">Complexity</span>, Teaching Style and <span class="hlt">Models</span> of Teaching.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Joyce, Bruce; Weil, Marsha</p> <p></p> <p>The focus of this paper is on the relative roles of personality and training in enabling teachers to carry out the kinds of <span class="hlt">complex</span> learning <span class="hlt">models</span> which are envisioned by curriculum reformers in the social sciences. The paper surveys some of the major research done in this area and concludes that: 1) Most teachers do not manifest the complex…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013NIMPA.732..397F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013NIMPA.732..397F"><span>Development of liquid scintillator containing a zirconium <span class="hlt">complex</span> for neutrinoless double beta decay <span class="hlt">experiment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fukuda, Yoshiyuki; Moriyama, Shigetaka; Ogawa, Izumi</p> <p>2013-12-01</p> <p>An organic liquid scintillator containing a zirconium <span class="hlt">complex</span> has been developed for a new neutrinoless double beta decay <span class="hlt">experiment</span>. In order to produce a detector that has good energy resolution (4% at 2.5 MeV) and low background (0.1 counts/(t·year)) and that can monitor tons of target isotope, we chose a zirconium β-diketone <span class="hlt">complex</span> having high solubility (over 10 wt%) in anisole. However, the absorption peak of the diketone ligand overlaps with the luminescence of anisole. Therefore, the light yield of the liquid scintillator decreases in proportion to the concentration of the <span class="hlt">complex</span>. To avoid this problem, we synthesized a β-keto ester <span class="hlt">complex</span> introducing -OC3H7 or -OC2H5 substituent groups in the β-diketone ligand, which shifted the absorption peak to around 245 nm, which is shorter than the emission peak of anisole (275 nm). However, the shift of the absorption peak depends on the polarity of the scintillation solvent. Therefore we must choose a low polarity solvent for the liquid scintillator. We also synthesized a Zr-ODZ <span class="hlt">complex</span>, which has a high quantum yield (30%) and good emission wavelength (425 nm) with a solubility 5 wt% in benzonitrile. However, the absorption peak of the Zr-ODZ <span class="hlt">complex</span> was around 240 nm. Therefore, it is better to use the scintillation solvent which has shorter luminescence wavelength than that of the aromatic solvent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4676066','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4676066"><span>A random interacting network <span class="hlt">model</span> for <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Goswami, Bedartha; Shekatkar, Snehal M.; Rheinwalt, Aljoscha; Ambika, G.; Kurths, Jürgen</p> <p>2015-01-01</p> <p>We propose a RAndom Interacting Network (RAIN) <span class="hlt">model</span> to study the interactions between a pair of <span class="hlt">complex</span> networks. The <span class="hlt">model</span> involves two major steps: (i) the selection of a pair of nodes, one from each network, based on intra-network node-based characteristics, and (ii) the placement of a link between selected nodes based on the similarity of their relative importance in their respective networks. Node selection is based on a selection fitness function and node linkage is based on a linkage probability defined on the linkage scores of nodes. The <span class="hlt">model</span> allows us to relate within-network characteristics to between-network structure. We apply the <span class="hlt">model</span> to the interaction between the USA and Schengen airline transportation networks (ATNs). Our results indicate that two mechanisms: degree-based preferential node selection and degree-assortative link placement are necessary to replicate the observed inter-network degree distributions as well as the observed inter-network assortativity. The RAIN <span class="hlt">model</span> offers the possibility to test multiple hypotheses regarding the mechanisms underlying network interactions. It can also incorporate <span class="hlt">complex</span> interaction topologies. Furthermore, the framework of the RAIN <span class="hlt">model</span> is general and can be potentially adapted to various real-world <span class="hlt">complex</span> systems. PMID:26657032</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23346354','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23346354"><span>APG: an Active Protein-Gene network <span class="hlt">model</span> to quantify regulatory signals in <span class="hlt">complex</span> biological systems.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Jiguang; Sun, Yidan; Zheng, Si; Zhang, Xiang-Sun; Zhou, Huarong; Chen, Luonan</p> <p>2013-01-01</p> <p>Synergistic interactions among transcription factors (TFs) and their cofactors collectively determine gene expression in <span class="hlt">complex</span> biological systems. In this work, we develop a novel graphical <span class="hlt">model</span>, called Active Protein-Gene (APG) network <span class="hlt">model</span>, to quantify regulatory signals of transcription in <span class="hlt">complex</span> biomolecular networks through integrating both TF upstream-regulation and downstream-regulation high-throughput data. Firstly, we theoretically and computationally demonstrate the effectiveness of APG by comparing with the traditional strategy based only on TF downstream-regulation information. We then apply this <span class="hlt">model</span> to study spontaneous type 2 diabetic Goto-Kakizaki (GK) and Wistar control rats. Our biological <span class="hlt">experiments</span> validate the theoretical results. In particular, SP1 is found to be a hidden TF with changed regulatory activity, and the loss of SP1 activity contributes to the increased glucose production during diabetes development. APG <span class="hlt">model</span> provides theoretical basis to quantitatively elucidate transcriptional regulation by <span class="hlt">modelling</span> TF combinatorial interactions and exploiting multilevel high-throughput information.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20365129','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20365129"><span>Data-driven approach to decomposing <span class="hlt">complex</span> enzyme kinetics with surrogate <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Calderon, Christopher P</p> <p>2009-12-01</p> <p>The temporal autocorrelation (AC) function associated with monitoring order parameters characterizing conformational fluctuations of an enzyme is analyzed using a collection of surrogate <span class="hlt">models</span>. The surrogates considered are phenomenological stochastic differential equation (SDE) <span class="hlt">models</span>. It is demonstrated how an ensemble of such surrogate <span class="hlt">models</span>, each surrogate being calibrated from a single trajectory, indirectly contains information about unresolved conformational degrees of freedom. This ensemble can be used to construct <span class="hlt">complex</span> temporal ACs associated with a "non-Markovian" process. The ensemble of surrogates approach allows researchers to consider <span class="hlt">models</span> more flexible than a mixture of exponentials to describe relaxation times and at the same time gain physical information about the system. The relevance of this type of analysis to matching single-molecule <span class="hlt">experiments</span> to computer simulations and how more <span class="hlt">complex</span> stochastic processes can emerge from a mixture of simpler processes is also discussed. The ideas are illustrated on a toy SDE <span class="hlt">model</span> and on molecular-dynamics simulations of the enzyme dihydrofolate reductase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8336E..02A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8336E..02A"><span>A perspective on <span class="hlt">modeling</span> and simulation of <span class="hlt">complex</span> dynamical systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Åström, K. J.</p> <p>2011-09-01</p> <p>There has been an amazing development of <span class="hlt">modeling</span> and simulation from its beginning in the 1920s, when the technology was available only at a handful of University groups who had access to a mechanical differential analyzer. Today, tools for <span class="hlt">modeling</span> and simulation are available for every student and engineer. This paper gives a perspective on the development with particular emphasis on technology and paradigm shifts. <span class="hlt">Modeling</span> is increasingly important for design and operation of <span class="hlt">complex</span> natural and man-made systems. Because of the increased use of <span class="hlt">model</span> based control such as Kalman filters and <span class="hlt">model</span> predictive control, <span class="hlt">models</span> are also appearing as components of feedback systems. <span class="hlt">Modeling</span> and simulation are multidisciplinary, it is used in a wide variety of fields and their development have been strongly influenced by mathematics, numerics, computer science and computer technology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4500159','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4500159"><span>Bayesian Case-deletion <span class="hlt">Model</span> <span class="hlt">Complexity</span> and Information Criterion</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhu, Hongtu; Ibrahim, Joseph G.; Chen, Qingxia</p> <p>2015-01-01</p> <p>We establish a connection between Bayesian case influence measures for assessing the influence of individual observations and Bayesian predictive methods for evaluating the predictive performance of a <span class="hlt">model</span> and comparing different <span class="hlt">models</span> fitted to the same dataset. Based on such a connection, we formally propose a new set of Bayesian case-deletion <span class="hlt">model</span> <span class="hlt">complexity</span> (BCMC) measures for quantifying the effective number of parameters in a given statistical <span class="hlt">model</span>. Its properties in linear <span class="hlt">models</span> are explored. Adding some functions of BCMC to a conditional deviance function leads to a Bayesian case-deletion information criterion (BCIC) for comparing <span class="hlt">models</span>. We systematically investigate some properties of BCIC and its connection with other information criteria, such as the Deviance Information Criterion (DIC). We illustrate the proposed methodology on linear mixed <span class="hlt">models</span> with simulations and a real data example. PMID:26180578</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23750914','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23750914"><span><span class="hlt">Complexity</span> vs. simplicity: groundwater <span class="hlt">model</span> ranking using information criteria.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Engelhardt, I; De Aguinaga, J G; Mikat, H; Schüth, C; Liedl, R</p> <p>2014-01-01</p> <p>A groundwater <span class="hlt">model</span> characterized by a lack of field data about hydraulic <span class="hlt">model</span> parameters and boundary conditions combined with many observation data sets for calibration purpose was investigated concerning <span class="hlt">model</span> uncertainty. Seven different conceptual <span class="hlt">models</span> with a stepwise increase from 0 to 30 adjustable parameters were calibrated using PEST. Residuals, sensitivities, the Akaike information criterion (AIC and AICc), Bayesian information criterion (BIC), and Kashyap's information criterion (KIC) were calculated for a set of seven inverse calibrated <span class="hlt">models</span> with increasing <span class="hlt">complexity</span>. Finally, the likelihood of each <span class="hlt">model</span> was computed. Comparing only residuals of the different conceptual <span class="hlt">models</span> leads to an overparameterization and certainty loss in the conceptual <span class="hlt">model</span> approach. The <span class="hlt">model</span> employing only uncalibrated hydraulic parameters, estimated from sedimentological information, obtained the worst AIC, BIC, and KIC values. Using only sedimentological data to derive hydraulic parameters introduces a systematic error into the simulation results and cannot be recommended for generating a valuable <span class="hlt">model</span>. For numerical investigations with high numbers of calibration data the BIC and KIC select as optimal a simpler <span class="hlt">model</span> than the AIC. The <span class="hlt">model</span> with 15 adjusted parameters was evaluated by AIC as the best option and obtained a likelihood of 98%. The AIC disregards the potential <span class="hlt">model</span> structure error and the selection of the KIC is, therefore, more appropriate. Sensitivities to piezometric heads were highest for the <span class="hlt">model</span> with only five adjustable parameters and sensitivity coefficients were directly influenced by the changes in extracted groundwater volumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/183675','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/183675"><span>Nuclear reaction <span class="hlt">modeling</span>, verification <span class="hlt">experiments</span>, and applications</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dietrich, F.S.</p> <p>1995-10-01</p> <p>This presentation summarized the recent accomplishments and future promise of the neutron nuclear physics program at the Manuel Lujan Jr. Neutron Scatter Center (MLNSC) and the Weapons Neutron Research (WNR) facility. The unique capabilities of the spallation sources enable a broad range of <span class="hlt">experiments</span> in weapons-related physics, basic science, nuclear technology, industrial applications, and medical physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=cooperation+AND+Interagency&id=ED559589','ERIC'); return false;" href="http://eric.ed.gov/?q=cooperation+AND+Interagency&id=ED559589"><span>On Using Meta-<span class="hlt">Modeling</span> and Multi-<span class="hlt">Modeling</span> to Address <span class="hlt">Complex</span> Problems</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Abu Jbara, Ahmed</p> <p>2013-01-01</p> <p><span class="hlt">Models</span>, created using different <span class="hlt">modeling</span> techniques, usually serve different purposes and provide unique insights. While each <span class="hlt">modeling</span> technique might be capable of answering specific questions, <span class="hlt">complex</span> problems require multiple <span class="hlt">models</span> interoperating to complement/supplement each other; we call this Multi-<span class="hlt">Modeling</span>. To address the syntactic and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B21I..03N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B21I..03N"><span>Accelerating the connection between <span class="hlt">experiments</span> and <span class="hlt">models</span>: The FACE-MDS <span class="hlt">experience</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Norby, R. J.; Medlyn, B. E.; De Kauwe, M. G.; Zaehle, S.; Walker, A. P.</p> <p>2014-12-01</p> <p>The mandate is clear for improving communication between <span class="hlt">models</span> and <span class="hlt">experiments</span> to better evaluate terrestrial responses to atmospheric and climatic change. Unfortunately, progress in linking experimental and <span class="hlt">modeling</span> approaches has been slow and sometimes frustrating. Recent successes in linking results from the Duke and Oak Ridge free-air CO2 enrichment (FACE) <span class="hlt">experiments</span> with ecosystem and land surface <span class="hlt">models</span> - the FACE <span class="hlt">Model</span>-Data Synthesis (FACE-MDS) project - came only after a period of slow progress, but the <span class="hlt">experience</span> points the way to future <span class="hlt">model-experiment</span> interactions. As the FACE <span class="hlt">experiments</span> were approaching their termination, the FACE research community made an explicit attempt to work together with the <span class="hlt">modeling</span> community to synthesize and deliver experimental data to benchmark <span class="hlt">models</span> and to use <span class="hlt">models</span> to supply appropriate context for the experimental results. Initial problems that impeded progress were: measurement protocols were not consistent across different <span class="hlt">experiments</span>; data were not well organized for <span class="hlt">model</span> input; and parameterizing and spinning up <span class="hlt">models</span> that were not designed for simulating a specific site was difficult. Once these problems were worked out, the FACE-MDS project has been very successful in using data from the Duke and ORNL FACE <span class="hlt">experiment</span> to test critical assumptions in the <span class="hlt">models</span>. The project showed, for example, that the stomatal conductance <span class="hlt">model</span> most widely used in <span class="hlt">models</span> was supported by experimental data, but <span class="hlt">models</span> did not capture important responses such as increased leaf mass per unit area in elevated CO2, and did not appropriately represent foliar nitrogen allocation. We now have an opportunity to learn from this <span class="hlt">experience</span>. New FACE <span class="hlt">experiments</span> that have recently been initiated, or are about to be initiated, include a eucalyptus forest in Australia; the AmazonFACE <span class="hlt">experiment</span> in a primary, tropical forest in Brazil; and a mature oak woodland in England. Cross-site science questions are being developed that will have a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=cesium&id=EJ627112','ERIC'); return false;" href="http://eric.ed.gov/?q=cesium&id=EJ627112"><span><span class="hlt">Modeling</span> the Classic Meselson and Stahl <span class="hlt">Experiment</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>D'Agostino, JoBeth</p> <p>2001-01-01</p> <p>Points out the importance of molecular <span class="hlt">models</span> in biology and chemistry. Presents a laboratory activity on DNA. Uses different colored wax strips to represent "heavy" and "light" DNA, cesium chloride for identification of small density differences, and three different liquids with varying densities to <span class="hlt">model</span> gradient…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060026070','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060026070"><span><span class="hlt">Experience</span> With Bayesian Image Based Surface <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Stutz, John C.</p> <p>2005-01-01</p> <p>Bayesian surface <span class="hlt">modeling</span> from images requires <span class="hlt">modeling</span> both the surface and the image generation process, in order to optimize the <span class="hlt">models</span> by comparing actual and generated images. Thus it differs greatly, both conceptually and in computational difficulty, from conventional stereo surface recovery techniques. But it offers the possibility of using any number of images, taken under quite different conditions, and by different instruments that provide independent and often complementary information, to generate a single surface <span class="hlt">model</span> that fuses all available information. I describe an implemented system, with a brief introduction to the underlying mathematical <span class="hlt">models</span> and the compromises made for computational efficiency. I describe successes and failures achieved on actual imagery, where we went wrong and what we did right, and how our approach could be improved. Lastly I discuss how the same approach can be extended to distinct types of instruments, to achieve true sensor fusion.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H44A..08M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H44A..08M"><span>Uranium transport <span class="hlt">experiments</span> at the intermediate scale: Do more heterogeneous systems create more <span class="hlt">complex</span> behaviors?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Miller, A. W.; Rodriguez, D.; Honeyman, B.</p> <p>2010-12-01</p> <p>With respect to <span class="hlt">complexity</span>, two things occur as experimental scale increases. The first is that as total system size increases, the heterogeneities at smaller scales are explicitly included while simultaneously allowing for a general increase in total <span class="hlt">complexity</span>. The second is that <span class="hlt">model</span> constraining measurements become more difficult to make. Bench scale systems limit total <span class="hlt">complexity</span>; field scale systems are limited in the amount of characterization that can be completed. Intermediate scale systems can bridge this gap, allowing for increased <span class="hlt">complexity</span> relative to the bench scale and better characterization ability relative to the field scale. We have completed three intermediate scale <span class="hlt">experiments</span> with a uranium contaminated sediment from a former uranium mill site near Naturita in southwestern Colorado, USA. Three tanks were packed with various particle size distributions of this sediment. The first two tanks were 2-D in nature and had dimensions of 2.44m x 1.22m x 7.62cm (tank #1, LxHxW), and 2.44m x 0.61m x 7.62cm (tank #2, LxHxW). Tank #3 was 3-D in nature with dimensions of 2.44m x 0.61m x 0.61m (LxHxW). Tank #1 was packed in a homogenous manner with only the <2mm size fraction of sediment. For tank #2 the <2mm fraction was split into <0.250mm and >0.250mm fractions, and these two fractions allowed for a physically heterogeneous packing. Using all three of the previously mentioned size fractions as well as a 0.125-0.250mm and a 4-12mm fraction, tank #3 was also packed in a heterogeneous fashion. The masses of sediment used in the three tanks are: tank #1 ~280kg, tank #2 - 163kg, and tank #3 - 1160kg. Flow through all three systems was comparable, and controlled by constant head boundaries. Three different artificial ground waters (AGW) were used with ionic compositions similar to that found at the field site. The major distinctions are that AGW #1 was in equilibrium with atmospheric CO2 and had no Si; AGW#2 was in equilibrium with 2%CO2 and had no Si; AGW#3</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ACP....16.5091S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ACP....16.5091S"><span>Cloud chamber <span class="hlt">experiments</span> on the origin of ice crystal <span class="hlt">complexity</span> in cirrus clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schnaiter, Martin; Järvinen, Emma; Vochezer, Paul; Abdelmonem, Ahmed; Wagner, Robert; Jourdan, Olivier; Mioche, Guillaume; Shcherbakov, Valery N.; Schmitt, Carl G.; Tricoli, Ugo; Ulanowski, Zbigniew; Heymsfield, Andrew J.</p> <p>2016-04-01</p> <p>This study reports on the origin of small-scale ice crystal <span class="hlt">complexity</span> and its influence on the angular light scattering properties of cirrus clouds. Cloud simulation <span class="hlt">experiments</span> were conducted at the AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber of the Karlsruhe Institute of Technology (KIT). A new experimental procedure was applied to grow and sublimate ice particles at defined super- and subsaturated ice conditions and for temperatures in the -40 to -60 °C range. The <span class="hlt">experiments</span> were performed for ice clouds generated via homogeneous and heterogeneous initial nucleation. Small-scale ice crystal <span class="hlt">complexity</span> was deduced from measurements of spatially resolved single particle light scattering patterns by the latest version of the Small Ice Detector (SID-3). It was found that a high crystal <span class="hlt">complexity</span> dominates the microphysics of the simulated clouds and the degree of this <span class="hlt">complexity</span> is dependent on the available water vapor during the crystal growth. Indications were found that the small-scale crystal <span class="hlt">complexity</span> is influenced by unfrozen H2SO4 / H2O residuals in the case of homogeneous initial ice nucleation. Angular light scattering functions of the simulated ice clouds were measured by the two currently available airborne polar nephelometers: the polar nephelometer (PN) probe of Laboratoire de Métérologie et Physique (LaMP) and the Particle Habit Imaging and Polar Scattering (PHIPS-HALO) probe of KIT. The measured scattering functions are featureless and flat in the side and backward scattering directions. It was found that these functions have a rather low sensitivity to the small-scale crystal <span class="hlt">complexity</span> for ice clouds that were grown under typical atmospheric conditions. These results have implications for the microphysical properties of cirrus clouds and for the radiative transfer through these clouds.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ACPD...1530511S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ACPD...1530511S"><span>Cloud chamber <span class="hlt">experiments</span> on the origin of ice crystal <span class="hlt">complexity</span> in cirrus clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schnaiter, M.; Järvinen, E.; Vochezer, P.; Abdelmonem, A.; Wagner, R.; Jourdan, O.; Mioche, G.; Shcherbakov, V. N.; Schmitt, C. G.; Tricoli, U.; Ulanowski, Z.; Heymsfield, A. J.</p> <p>2015-11-01</p> <p>This study reports on the origin of ice crystal <span class="hlt">complexity</span> and its influence on the angular light scattering properties of cirrus clouds. Cloud simulation <span class="hlt">experiments</span> were conducted at the AIDA (Aerosol Interactions and Dynamics in the Atmosphere) cloud chamber of the Karlsruhe Institute of Technology (KIT). A new experimental procedure was applied to grow and sublimate ice particles at defined super- and subsaturated ice conditions and for temperatures in the -40 to -60 °C range. The <span class="hlt">experiments</span> were performed for ice clouds generated via homogeneous and heterogeneous initial nucleation. Ice crystal <span class="hlt">complexity</span> was deduced from measurements of spatially resolved single particle light scattering patterns by the latest version of the Small Ice Detector (SID-3). It was found that a high ice crystal <span class="hlt">complexity</span> is dominating the microphysics of the simulated clouds and the degree of this <span class="hlt">complexity</span> is dependent on the available water vapour during the crystal growth. Indications were found that the crystal <span class="hlt">complexity</span> is influenced by unfrozen H2SO4/H2O residuals in the case of homogeneous initial ice nucleation. Angular light scattering functions of the simulated ice clouds were measured by the two currently available airborne polar nephelometers; the Polar Nephelometer (PN) probe of LaMP and the Particle Habit Imaging and Polar Scattering (PHIPS-HALO) probe of KIT. The measured scattering functions are featureless and flat in the side- and backward scattering directions resulting in low asymmetry parameters g around 0.78. It was found that these functions have a rather low sensitivity to the crystal <span class="hlt">complexity</span> for ice clouds that were grown under typical atmospheric conditions. These results have implications for the microphysical properties of cirrus clouds and for the radiative transfer through these clouds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050215642&hterms=Complex+Variables&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DComplex%2BVariables','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050215642&hterms=Complex+Variables&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DComplex%2BVariables"><span>Probabilistic Analysis Techniques Applied to <span class="hlt">Complex</span> Spacecraft Power System <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hojnicki, Jeffrey S.; Rusick, Jeffrey J.</p> <p>2005-01-01</p> <p>Electric power system performance predictions are critical to spacecraft, such as the International Space Station (ISS), to ensure that sufficient power is available to support all the spacecraft s power needs. In the case of the ISS power system, analyses to date have been deterministic, meaning that each analysis produces a single-valued result for power capability because of the <span class="hlt">complexity</span> and large size of the <span class="hlt">model</span>. As a result, the deterministic ISS analyses did not account for the sensitivity of the power capability to uncertainties in <span class="hlt">model</span> input variables. Over the last 10 years, the NASA Glenn Research Center has developed advanced, computationally fast, probabilistic analysis techniques and successfully applied them to large (thousands of nodes) <span class="hlt">complex</span> structural analysis <span class="hlt">models</span>. These same techniques were recently applied to large, <span class="hlt">complex</span> ISS power system <span class="hlt">models</span>. This new application enables probabilistic power analyses that account for input uncertainties and produce results that include variations caused by these uncertainties. Specifically, N&R Engineering, under contract to NASA, integrated these advanced probabilistic techniques with Glenn s internationally recognized ISS power system <span class="hlt">model</span>, System Power Analysis for Capability Evaluation (SPACE).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19119812','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19119812"><span>New macrocyclic terbium(III) <span class="hlt">complex</span> for use in RNA footprinting <span class="hlt">experiments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Belousoff, Matthew J; Ung, Phuc; Forsyth, Craig M; Tor, Yitzhak; Spiccia, Leone; Graham, Bim</p> <p>2009-01-28</p> <p>Reaction of terbium triflate with a heptadentate ligand derivative of cyclen, L1 = 2-[7-ethyl-4,10-bis(isopropylcarbamoylmethyl)-1,4,7,10-tetraazacyclododec-1-yl]-N-isopropyl-acetamide, produced a new synthetic ribonuclease, [Tb(L1)(OTf)(OH(2))](OTf)(2).MeCN (C1). X-ray crystal structure analysis indicates that the terbium(III) center in C1 is 9-coordinate, with a capped square-antiprism geometry. While the terbium(III) center is tightly bound by the L1 ligand, two of the coordination sites are occupied by labile water and triflate ligands. In water, the triflate ligand is likely to be displaced, forming [Tb(L1)(OH(2))(2)](3+), which is able to effectively promote RNA cleavage. This <span class="hlt">complex</span> greatly accelerates the rate of intramolecular transesterification of an activated <span class="hlt">model</span> RNA phosphodiester, uridine-3'-p-nitrophenylphosphate (UpNP), with k(obs) = 5.5(1) x 10(-2) s(-1) at 21 degrees C and pH 7.5, corresponding to an apparent second-order rate constant of 277(5) M(-1) s(-1). By contrast, the analogous <span class="hlt">complex</span> of an octadentate derivative of cyclen featuring only a single labile coordination site, [Tb(L2)(OH(2))](OTf)(3) (C2), where L2 = 2-[4,7,10-tris(isopropylcarbamoylmethyl)-1,4,7,10-tetraazacyclododec-1-yl]-N-isopropyl-acetamide, is inactive. [Tb(L1)(OH(2))(2)](3+) is also capable of hydrolyzing short transcripts of the HIV-1 transactivation response (TAR) element, HIV-1 dimerization initiation site (DIS) and ribosomal A-site, as well as formyl methionine tRNA (tRNA(fMet)), albeit at a considerably slower rate than UpNP transesterification (k(obs) = 2.78(8) x 10(-5) s(-1) for TAR cleavage at 37 degrees C, pH 6.5, corresponding to an apparent second-order rate constant of 0.56(2) M(-1)s(-1)). Cleavage is concentrated at the single-stranded "bulge" regions of these RNA motifs. Exploiting this selectivity, [Tb(L1)(OH(2))(2)](3+) was successfully employed in footprinting <span class="hlt">experiments</span>, in which binding of the Tat peptide and neomycin B to the bulge region of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2633772','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2633772"><span>A new macrocyclic terbium(III) <span class="hlt">complex</span> for use in RNA footprinting <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Belousoff, Matthew J.; Ung, Phuc; Forsyth, Craig M.; Tor, Yitzhak; Spiccia, Leone; Graham, Bim</p> <p>2009-01-01</p> <p>Reaction of terbium triflate with a heptadentate ligand derivative of cyclen, L1 = 2-[7-ethyl-4,10-bis(isopropylcarbamoylmethyl)-1,4,7,10-tetraazacyclododec-1-yl]-N-isopropylacetamide, produced a new synthetic ribonuclease, [Tb(L1)(OTf)(OH2)](OTf)2·MeCN (C1). X-ray crystal structure analysis indicates that the terbium(III) centre in C1 is 9-coordinate, with a capped square-antiprism geometry. Whilst the terbium(III) center is tightly bound by the L1 ligand, two of the coordination sites are occupied by labile water and triflate ligands. In water, the triflate ligand is likely to be displaced, forming [Tb(L1)(OH2)2]3+, which is able to effectively promote RNA cleavage. This <span class="hlt">complex</span> greatly accelerates the rate of intramolecular transesterification of an activated <span class="hlt">model</span> RNA phosphodiester, uridine-3′-p-nitrophenylphosphate (UpNP), with kobs = 5.5(1) × 10-2 s-1 at 21°C and pH 7.5, corresponding to an apparent second-order rate constant of 277(5) M-1s-1. By contrast, the analogous <span class="hlt">complex</span> of an octadentate derivative of cyclen featuring only a single labile coordination site, [Tb(L2)(OH2)](OTf)3 (C2), where L2 = 2-[4,7,10-tris(isopropylcarbamoylmethyl)-1,4,7,10-tetraazacyclododec-1-yl]-N-isopropyl-acetamide, is inactive. [Tb(L1)(OH2)2]3+ is also capable of hydrolyzing short transcripts of the HIV-1 transactivation response (TAR) element, HIV-1 dimerization initiation site (DIS) and ribosomal A-site, as well as formyl methionine transfer RNA (tRNAfMet), albeit at a considerably slower rate than UpNP transesterification (kobs = 2.78(8) × 10-5 M-1s-1 for TAR cleavage at 37°C, pH 6.5, corresponding to an apparent second-order rate constant of 0.56(2) M-1s-1). Cleavage is concentrated at the single-stranded “bulge” regions of these RNA motifs. Exploiting this selectivity, [Tb(L1)(OH2)23+ was successfully employed in footprinting <span class="hlt">experiments</span>, in which binding of the Tat peptide and neomycin B to the bulge region of the TAR stem-loop was confirmed. PMID:19119812</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2718684','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2718684"><span>Boolean <span class="hlt">modeling</span> of collective effects in <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Norrell, Johannes; Socolar, Joshua E. S.</p> <p>2009-01-01</p> <p><span class="hlt">Complex</span> systems are often <span class="hlt">modeled</span> as Boolean networks in attempts to capture their logical structure and reveal its dynamical consequences. Approximating the dynamics of continuous variables by discrete values and Boolean logic gates may, however, introduce dynamical possibilities that are not accessible to the original system. We show that large random networks of variables coupled through continuous transfer functions often fail to exhibit the <span class="hlt">complex</span> dynamics of corresponding Boolean <span class="hlt">models</span> in the disordered (chaotic) regime, even when each individual function appears to be a good candidate for Boolean idealization. A suitably modified Boolean theory explains the behavior of systems in which information does not propagate faithfully down certain chains of nodes. <span class="hlt">Model</span> networks incorporating calculated or directly measured transfer functions reported in the literature on transcriptional regulation of genes are described by the modified theory. PMID:19658525</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3314197','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3314197"><span>Activity-Dependent Neuronal <span class="hlt">Model</span> on <span class="hlt">Complex</span> Networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>de Arcangelis, Lucilla; Herrmann, Hans J.</p> <p>2012-01-01</p> <p>Neuronal avalanches are a novel mode of activity in neuronal networks, experimentally found in vitro and in vivo, and exhibit a robust critical behavior: these avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of <span class="hlt">complex</span> systems. We present a recent <span class="hlt">model</span> inspired in self-organized criticality, which consists of an electrical network with threshold firing, refractory period, and activity-dependent synaptic plasticity. The <span class="hlt">model</span> reproduces the critical behavior of the distribution of avalanche sizes and durations measured experimentally. Moreover, the power spectra of the electrical signal reproduce very robustly the power law behavior found in human electroencephalogram (EEG) spectra. We implement this <span class="hlt">model</span> on a variety of <span class="hlt">complex</span> networks, i.e., regular, small-world, and scale-free and verify the robustness of the critical behavior. PMID:22470347</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17337784','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17337784"><span>Deciphering the <span class="hlt">complexity</span> of acute inflammation using mathematical <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vodovotz, Yoram</p> <p>2006-01-01</p> <p>Various stresses elicit an acute, <span class="hlt">complex</span> inflammatory response, leading to healing but sometimes also to organ dysfunction and death. We constructed both equation-based <span class="hlt">models</span> (EBM) and agent-based <span class="hlt">models</span> (ABM) of various degrees of granularity--which encompass the dynamics of relevant cells, cytokines, and the resulting global tissue dysfunction--in order to begin to unravel these inflammatory interactions. The EBMs describe and predict various features of septic shock and trauma/hemorrhage (including the response to anthrax, preconditioning phenomena, and irreversible hemorrhage) and were used to simulate anti-inflammatory strategies in clinical trials. The ABMs that describe the interrelationship between inflammation and wound healing yielded insights into intestinal healing in necrotizing enterocolitis, vocal fold healing during phonotrauma, and skin healing in the setting of diabetic foot ulcers. <span class="hlt">Modeling</span> may help in understanding the <span class="hlt">complex</span> interactions among the components of inflammation and response to stress, and therefore aid in the development of novel therapies and diagnostics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21038919','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21038919"><span>Fundamental efficiency of nanothermophones: <span class="hlt">modeling</span> and <span class="hlt">experiments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vesterinen, V; Niskanen, A O; Hassel, J; Helistö, P</p> <p>2010-12-08</p> <p>Scaling down the dimensions of thermoacoustic sound sources (thermophones) improves efficiency by means of reducing speaker heat capacity. Recent <span class="hlt">experiments</span> with nanoscale thermophones have revealed properties which are not fully understood theoretically. We develop a Green's function formalism which quantitatively explains some observed discrepancies, e.g., the effect of a heat-absorbing substrate in the proximity of the sound source. We also find a generic ultimate limit for thermophone efficiency. We verify the theory with <span class="hlt">experiments</span> and finite difference method simulations which deal with thermoacoustically operated suspended arrays of nanowires. The efficiency of our devices is measured to be 1 order of magnitude below the ultimate bound. At low frequencies this mainly results from the presence of a substrate. At high frequencies, on the other hand, the efficiency is limited by the heat capacity of the nanowires. Measured sound pressure level and efficiency are in good agreement with simulations. We discuss the feasibility of reaching the ultimate limit in practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25523357','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25523357"><span>Entropy, <span class="hlt">complexity</span>, and Markov diagrams for random walk cancer <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Newton, Paul K; Mason, Jeremy; Hurt, Brian; Bethel, Kelly; Bazhenova, Lyudmila; Nieva, Jorge; Kuhn, Peter</p> <p>2014-12-19</p> <p>The notion of entropy is used to compare the <span class="hlt">complexity</span> associated with 12 common cancers based on metastatic tumor distribution autopsy data. We characterize power-law distributions, entropy, and Kullback-Liebler divergence associated with each primary cancer as compared with data for all cancer types aggregated. We then correlate entropy values with other measures of <span class="hlt">complexity</span> associated with Markov chain dynamical systems <span class="hlt">models</span> of progression. The Markov transition matrix associated with each cancer is associated with a directed graph <span class="hlt">model</span> where nodes are anatomical locations where a metastatic tumor could develop, and edge weightings are transition probabilities of progression from site to site. The steady-state distribution corresponds to the autopsy data distribution. Entropy correlates well with the overall <span class="hlt">complexity</span> of the reduced directed graph structure for each cancer and with a measure of systemic interconnectedness of the graph, called graph conductance. The <span class="hlt">models</span> suggest that grouping cancers according to their entropy values, with skin, breast, kidney, and lung cancers being prototypical high entropy cancers, stomach, uterine, pancreatic and ovarian being mid-level entropy cancers, and colorectal, cervical, bladder, and prostate cancers being prototypical low entropy cancers, provides a potentially useful framework for viewing metastatic cancer in terms of predictability, <span class="hlt">complexity</span>, and metastatic potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatSR...4E7558N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatSR...4E7558N"><span>Entropy, <span class="hlt">complexity</span>, and Markov diagrams for random walk cancer <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Newton, Paul K.; Mason, Jeremy; Hurt, Brian; Bethel, Kelly; Bazhenova, Lyudmila; Nieva, Jorge; Kuhn, Peter</p> <p>2014-12-01</p> <p>The notion of entropy is used to compare the <span class="hlt">complexity</span> associated with 12 common cancers based on metastatic tumor distribution autopsy data. We characterize power-law distributions, entropy, and Kullback-Liebler divergence associated with each primary cancer as compared with data for all cancer types aggregated. We then correlate entropy values with other measures of <span class="hlt">complexity</span> associated with Markov chain dynamical systems <span class="hlt">models</span> of progression. The Markov transition matrix associated with each cancer is associated with a directed graph <span class="hlt">model</span> where nodes are anatomical locations where a metastatic tumor could develop, and edge weightings are transition probabilities of progression from site to site. The steady-state distribution corresponds to the autopsy data distribution. Entropy correlates well with the overall <span class="hlt">complexity</span> of the reduced directed graph structure for each cancer and with a measure of systemic interconnectedness of the graph, called graph conductance. The <span class="hlt">models</span> suggest that grouping cancers according to their entropy values, with skin, breast, kidney, and lung cancers being prototypical high entropy cancers, stomach, uterine, pancreatic and ovarian being mid-level entropy cancers, and colorectal, cervical, bladder, and prostate cancers being prototypical low entropy cancers, provides a potentially useful framework for viewing metastatic cancer in terms of predictability, <span class="hlt">complexity</span>, and metastatic potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015LaPhL..12l5201A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015LaPhL..12l5201A"><span>Quantum scattering <span class="hlt">model</span> of energy transfer in photosynthetic <span class="hlt">complexes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ai, Bao-quan; Zhu, Shi-Liang</p> <p>2015-12-01</p> <p>We develop a quantum scattering <span class="hlt">model</span> to describe the exciton transport through the Fenna-Matthews-Olson (FMO) <span class="hlt">complex</span>. It is found that the exciton transport involving the optimal quantum coherence is more efficient than that involving classical behaviour alone. Furthermore, we also find that the quantum resonance condition is easier to be fulfilled in multiple pathways than that in one pathway. We then definitely demonstrate that the optimal distribution of the pigments, the multitude of energy delivery pathways and the quantum effects are combined together to contribute to the perfect energy transport in the FMO <span class="hlt">complex</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006CPL...423...54H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006CPL...423...54H"><span><span class="hlt">Complex</span> reaction noise in a molecular quasispecies <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hochberg, David; Zorzano, María-Paz; Morán, Federico</p> <p>2006-05-01</p> <p>We have derived exact Langevin equations for a <span class="hlt">model</span> of quasispecies dynamics. The inherent multiplicative reaction noise is <span class="hlt">complex</span> and its statistical properties are specified completely. The numerical simulation of the <span class="hlt">complex</span> Langevin equations is carried out using the Cholesky decomposition for the noise covariance matrix. This internal noise, which is due to diffusion-limited reactions, produces unavoidable spatio-temporal density fluctuations about the mean field value. In two dimensions, this noise strictly vanishes only in the perfectly mixed limit, a situation difficult to attain in practice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007SHPMP..38...97H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007SHPMP..38...97H"><span>Annual modulation <span class="hlt">experiments</span>, galactic <span class="hlt">models</span> and WIMPs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hudson, Robert G.</p> <p></p> <p>Our task in the paper is to examine some recent <span class="hlt">experiments</span> (in the period 1996-2002) bearing on the issue of whether there is dark matter in the universe in the form of neutralino WIMPs (weakly interacting massive particles). Our main focus is an <span class="hlt">experiment</span> performed by the DAMA group that claims to have found an 'annual modulation signature' for the WIMP. DAMA's result has been hotly contested by two other groups, EDELWEISS and CDMS, and we study the details of the <span class="hlt">experiments</span> performed by all three groups. Our goal is to investigate the philosophic and sociological implications of this controversy. Particularly, using an innovative theoretical strategy suggested by (Copi, C. and L. M. Krauss (2003). Comparing interaction rate detectors for weakly interacting massive particles with annual modulation detectors. Physical Review D, 67, 103 507), we suggest a new way of resolving discordant experimental data (extending a previous analysis by (Franklin, A. (2002). Selectivity and discord. Pittsburgh: University of Pittsburgh Press). In addition, we are in a position to contribute substantively to the debate between realists and constructive empiricists. Finally, from a sociological standpoint, we remark that DAMA's work has been valuable in mobilizing other research teams and providing them with a critical focus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9809E..0DM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9809E..0DM"><span>Vortex microscope: analytical <span class="hlt">model</span> and <span class="hlt">experiment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Masajada, Jan; Popiołek-Masajada, Agnieszka; Szatkowski, Mateusz; Plociniczak, Łukasz</p> <p>2015-11-01</p> <p>We present the analytical <span class="hlt">model</span> describing the Gaussian beam propagation through the off axis vortex lens and the set of axially positioned ideal lenses. The <span class="hlt">model</span> is derived on the base of Fresnel diffraction integral. The <span class="hlt">model</span> is extended to the case of vortex lens with any topological charge m. We have shown that the Gaussian beam propagation can be represented by function G which depends on four coefficients. When propagating from one lens to another the function holds its form but the coefficient changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1150221','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1150221"><span><span class="hlt">Modeling</span> and Algorithmic Approaches to Constitutively-<span class="hlt">Complex</span>, Microstructured Fluids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Miller, Gregory H.; Forest, Gregory</p> <p>2014-05-01</p> <p>We present a new multiscale <span class="hlt">model</span> for <span class="hlt">complex</span> fluids based on three scales: microscopic, kinetic, and continuum. We choose the microscopic level as Kramers' bead-rod <span class="hlt">model</span> for polymers, which we describe as a system of stochastic differential equations with an implicit constraint formulation. The associated Fokker-Planck equation is then derived, and adiabatic elimination removes the fast momentum coordinates. Approached in this way, the kinetic level reduces to a dispersive drift equation. The continuum level is <span class="hlt">modeled</span> with a finite volume Godunov-projection algorithm. We demonstrate computation of viscoelastic stress divergence using this multiscale approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009IJMPC..20.1387R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009IJMPC..20.1387R"><span><span class="hlt">Complex</span> Behavior in Simple <span class="hlt">Models</span> of Biological Coevolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rikvold, Per Arne</p> <p></p> <p>We explore the <span class="hlt">complex</span> dynamical behavior of simple predator-prey <span class="hlt">models</span> of biological coevolution that account for interspecific and intraspecific competition for resources, as well as adaptive foraging behavior. In long kinetic Monte Carlo simulations of these <span class="hlt">models</span> we find quite robust 1/f-like noise in species diversity and population sizes, as well as power-law distributions for the lifetimes of individual species and the durations of quiet periods of relative evolutionary stasis. In one <span class="hlt">model</span>, based on the Holling Type II functional response, adaptive foraging produces a metastable low-diversity phase and a stable high-diversity phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1087230','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1087230"><span><span class="hlt">Modeling</span> of Carbohydrate Binding Modules <span class="hlt">Complexed</span> to Cellulose</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nimlos, M. R.; Beckham, G. T.; Bu, L.; Himmel, M. E.; Crowley, M. F.; Bomble, Y. J.</p> <p>2012-01-01</p> <p><span class="hlt">Modeling</span> results are presented for the interaction of two carbohydrate binding modules (CBMs) with cellulose. The family 1 CBM from Trichoderma reesei's Cel7A cellulase was <span class="hlt">modeled</span> using molecular dynamics to confirm that this protein selectively binds to the hydrophobic (100) surface of cellulose fibrils and to determine the energetics and mechanisms for locating this surface. <span class="hlt">Modeling</span> was also conducted of binding of the family 4 CBM from the CbhA <span class="hlt">complex</span> from Clostridium thermocellum. There is a cleft in this protein, which may accommodate a cellulose chain that is detached from crystalline cellulose. This possibility is explored using molecular dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H52E..05H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H52E..05H"><span>Development of Conceptual Benchmark <span class="hlt">Models</span> to Evaluate <span class="hlt">Complex</span> Hydrologic <span class="hlt">Model</span> Calibration in Managed Basins Using Python</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hughes, J. D.; White, J.</p> <p>2013-12-01</p> <p>For many numerical hydrologic <span class="hlt">models</span> it is a challenge to quantitatively demonstrate that <span class="hlt">complex</span> <span class="hlt">models</span> are preferable to simpler <span class="hlt">models</span>. Typically, a decision is made to develop and calibrate a <span class="hlt">complex</span> <span class="hlt">model</span> at the beginning of a study. The value of selecting a <span class="hlt">complex</span> <span class="hlt">model</span> over simpler <span class="hlt">models</span> is commonly inferred from use of a <span class="hlt">model</span> with fewer simplifications of the governing equations because it can be time consuming to develop another numerical code with data processing and parameter estimation functionality. High-level programming languages like Python can greatly reduce the effort required to develop and calibrate simple <span class="hlt">models</span> that can be used to quantitatively demonstrate the increased value of a <span class="hlt">complex</span> <span class="hlt">model</span>. We have developed and calibrated a spatially-distributed surface-water/groundwater flow <span class="hlt">model</span> for managed basins in southeast Florida, USA, to (1) evaluate the effect of municipal groundwater pumpage on surface-water/groundwater exchange, (2) investigate how the study area will respond to sea-level rise, and (3) explore combinations of these forcing functions. To demonstrate the increased value of this <span class="hlt">complex</span> <span class="hlt">model</span>, we developed a two-parameter conceptual-benchmark-discharge <span class="hlt">model</span> for each basin in the study area. The conceptual-benchmark-discharge <span class="hlt">model</span> includes seasonal scaling and lag parameters and is driven by basin rainfall. The conceptual-benchmark-discharge <span class="hlt">models</span> were developed in the Python programming language and used weekly rainfall data. Calibration was implemented with the Broyden-Fletcher-Goldfarb-Shanno method available in the Scientific Python (SciPy) library. Normalized benchmark efficiencies calculated using output from the <span class="hlt">complex</span> <span class="hlt">model</span> and the corresponding conceptual-benchmark-discharge <span class="hlt">model</span> indicate that the <span class="hlt">complex</span> <span class="hlt">model</span> has more explanatory power than the simple <span class="hlt">model</span> driven only by rainfall.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JChEd..76.1277I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JChEd..76.1277I"><span>Determination of Equilibrium Constants of Metal <span class="hlt">Complexes</span> from Spectrophotometric Measurements. An Undergraduate Laboratory <span class="hlt">Experiment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ibañez, Gabriela A.; Olivieri, Alejandro C.; Escandar*, Graciela M.</p> <p>1999-09-01</p> <p>We describe an undergraduate laboratory practice involving the determination of <span class="hlt">complex</span> equilibrium constants by spectrophotometric techniques. The results are obtained through <span class="hlt">model</span> fitting using a computer program. As an example of these determinations, salicylic acid was selected and evaluated in the presence of copper(II) ion. The experimental conditions, general procedures, and computational strategem are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1064264.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1064264.pdf"><span>Tutoring and Multi-Agent Systems: <span class="hlt">Modeling</span> from <span class="hlt">Experiences</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Bennane, Abdellah</p> <p>2010-01-01</p> <p>Tutoring systems become <span class="hlt">complex</span> and are offering varieties of pedagogical software as course modules, exercises, simulators, systems online or offline, for single user or multi-user. This <span class="hlt">complexity</span> motivates new forms and approaches to the design and the <span class="hlt">modelling</span>. Studies and research in this field introduce emergent concepts that allow the…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015215','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015215"><span>Design of Low <span class="hlt">Complexity</span> <span class="hlt">Model</span> Reference Adaptive Controllers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hanson, Curt; Schaefer, Jacob; Johnson, Marcus; Nguyen, Nhan</p> <p>2012-01-01</p> <p>Flight research <span class="hlt">experiments</span> have demonstrated that adaptive flight controls can be an effective technology for improving aircraft safety in the event of failures or damage. However, the nonlinear, timevarying nature of adaptive algorithms continues to challenge traditional methods for the verification and validation testing of safety-critical flight control systems. Increasingly <span class="hlt">complex</span> adaptive control theories and designs are emerging, but only make testing challenges more difficult. A potential first step toward the acceptance of adaptive flight controllers by aircraft manufacturers, operators, and certification authorities is a very simple design that operates as an augmentation to a non-adaptive baseline controller. Three such controllers were developed as part of a National Aeronautics and Space Administration flight research <span class="hlt">experiment</span> to determine the appropriate level of <span class="hlt">complexity</span> required to restore acceptable handling qualities to an aircraft that has suffered failures or damage. The controllers consist of the same basic design, but incorporate incrementally-increasing levels of <span class="hlt">complexity</span>. Derivations of the controllers and their adaptive parameter update laws are presented along with details of the controllers implementations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/812409','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/812409"><span>Uncertainty Analysis with Site Specific Groundwater <span class="hlt">Models</span>: <span class="hlt">Experiences</span> and Observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brewer, K.</p> <p>2003-07-15</p> <p>Groundwater flow and transport predictions are a major component of remedial action evaluations for contaminated groundwater at the Savannah River Site. Because all groundwater <span class="hlt">modeling</span> results are subject to uncertainty from various causes; quantification of the level of uncertainty in the <span class="hlt">modeling</span> predictions is beneficial to project decision makers. <span class="hlt">Complex</span> site-specific <span class="hlt">models</span> present formidable challenges for implementing an uncertainty analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920075801&hterms=experimental+fluid+dynamics&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dexperimental%2Bfluid%2Bdynamics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920075801&hterms=experimental+fluid+dynamics&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dexperimental%2Bfluid%2Bdynamics"><span>Experimental fluid dynamics. Part 1: Brief overview. Part 2: Flow <span class="hlt">modeling</span> and verification <span class="hlt">experiments</span>: RFE</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marvin, Joseph G.</p> <p>1987-01-01</p> <p>The role of <span class="hlt">experiment</span> in Computational Fluid Dynamics (CFD) is discussed. Flow <span class="hlt">modeling</span> of <span class="hlt">complex</span> physics and determination of accuracy limits (confidence) are two ways in which experimentation can be used to develop CFD. The results of this discussion are presented in viewgraph form.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28183024','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28183024"><span>High field hyperpolarization-EXSY <span class="hlt">experiment</span> for fast determination of dissociation rates in SABRE <span class="hlt">complexes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hermkens, Niels K J; Feiters, Martin C; Rutjes, Floris P J T; Wijmenga, Sybren S; Tessari, Marco</p> <p>2017-03-01</p> <p>SABRE (Signal Amplification By Reversible Exchange) is a nuclear spin hyperpolarization technique based on the reversible concurrent binding of small molecules and para-hydrogen (p-H2) to an iridium metal <span class="hlt">complex</span> in solution. At low magnetic field, spontaneous conversion of p-H2 spin order to enhanced longitudinal magnetization of the nuclear spins of the other ligands occurs. Subsequent <span class="hlt">complex</span> dissociation results in hyperpolarized substrate molecules in solution. The lifetime of this <span class="hlt">complex</span> plays a crucial role in attained SABRE NMR signal enhancements. Depending on the ligands, vastly different dissociation rates have been previously measured using EXSY or selective inversion <span class="hlt">experiments</span>. However, both these approaches are generally time-consuming due to the long recycle delays (up to 2min) necessary to reach thermal equilibrium for the nuclear spins of interest. In the cases of dilute solutions, signal averaging aggravates the problem, further extending the experimental time. Here, a new approach is proposed based on coherent hyperpolarization transfer to substrate protons in asymmetric <span class="hlt">complexes</span> at high magnetic field. We have previously shown that such asymmetric <span class="hlt">complexes</span> are important for application of SABRE to dilute substrates. Our results demonstrate that a series of high sensitivity EXSY spectra can be collected in a short experimental time thanks to the NMR signal enhancement and much shorter recycle delay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JMagR.276..122H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JMagR.276..122H"><span>High field hyperpolarization-EXSY <span class="hlt">experiment</span> for fast determination of dissociation rates in SABRE <span class="hlt">complexes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hermkens, Niels K. J.; Feiters, Martin C.; Rutjes, Floris P. J. T.; Wijmenga, Sybren S.; Tessari, Marco</p> <p>2017-03-01</p> <p>SABRE (Signal Amplification By Reversible Exchange) is a nuclear spin hyperpolarization technique based on the reversible concurrent binding of small molecules and para-hydrogen (p-H2) to an iridium metal <span class="hlt">complex</span> in solution. At low magnetic field, spontaneous conversion of p-H2 spin order to enhanced longitudinal magnetization of the nuclear spins of the other ligands occurs. Subsequent <span class="hlt">complex</span> dissociation results in hyperpolarized substrate molecules in solution. The lifetime of this <span class="hlt">complex</span> plays a crucial role in attained SABRE NMR signal enhancements. Depending on the ligands, vastly different dissociation rates have been previously measured using EXSY or selective inversion <span class="hlt">experiments</span>. However, both these approaches are generally time-consuming due to the long recycle delays (up to 2 min) necessary to reach thermal equilibrium for the nuclear spins of interest. In the cases of dilute solutions, signal averaging aggravates the problem, further extending the experimental time. Here, a new approach is proposed based on coherent hyperpolarization transfer to substrate protons in asymmetric <span class="hlt">complexes</span> at high magnetic field. We have previously shown that such asymmetric <span class="hlt">complexes</span> are important for application of SABRE to dilute substrates. Our results demonstrate that a series of high sensitivity EXSY spectra can be collected in a short experimental time thanks to the NMR signal enhancement and much shorter recycle delay.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760023161','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760023161"><span>Apollo <span class="hlt">Experiment</span> Report: Lunar-Sample Processing in the Lunar Receiving Laboratory High-Vacuum <span class="hlt">Complex</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>White, D. R.</p> <p>1976-01-01</p> <p>A high-vacuum <span class="hlt">complex</span> composed of an atmospheric decontamination system, sample-processing chambers, storage chambers, and a transfer system was built to process and examine lunar material while maintaining quarantine status. Problems identified, equipment modifications, and procedure changes made for Apollo 11 and 12 sample processing are presented. The sample processing <span class="hlt">experiences</span> indicate that only a few operating personnel are required to process the sample efficiently, safely, and rapidly in the high-vacuum <span class="hlt">complex</span>. The high-vacuum <span class="hlt">complex</span> was designed to handle the many contingencies, both quarantine and scientific, associated with handling an unknown entity such as the lunar sample. Lunar sample handling necessitated a <span class="hlt">complex</span> system that could not respond rapidly to changing scientific requirements as the characteristics of the lunar sample were better defined. Although the <span class="hlt">complex</span> successfully handled the processing of Apollo 11 and 12 lunar samples, the scientific requirement for vacuum samples was deleted after the Apollo 12 mission just as the vacuum system was reaching its full potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4871498','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4871498"><span>Bridging Mechanistic and Phenomenological <span class="hlt">Models</span> of <span class="hlt">Complex</span> Biological Systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Transtrum, Mark K.; Qiu, Peng</p> <p>2016-01-01</p> <p>The inherent <span class="hlt">complexity</span> of biological systems gives rise to complicated mechanistic <span class="hlt">models</span> with a large number of parameters. On the other hand, the collective behavior of these systems can often be characterized by a relatively small number of phenomenological parameters. We use the Manifold Boundary Approximation Method (MBAM) as a tool for deriving simple phenomenological <span class="hlt">models</span> from complicated mechanistic <span class="hlt">models</span>. The resulting <span class="hlt">models</span> are not black boxes, but remain expressed in terms of the microscopic parameters. In this way, we explicitly connect the macroscopic and microscopic descriptions, characterize the equivalence class of distinct systems exhibiting the same range of collective behavior, and identify the combinations of components that function as tunable control knobs for the behavior. We demonstrate the procedure for adaptation behavior exhibited by the EGFR pathway. From a 48 parameter mechanistic <span class="hlt">model</span>, the system can be effectively described by a single adaptation parameter τ characterizing the ratio of time scales for the initial response and recovery time of the system which can in turn be expressed as a combination of microscopic reaction rates, Michaelis-Menten constants, and biochemical concentrations. The situation is not unlike <span class="hlt">modeling</span> in physics in which microscopically <span class="hlt">complex</span> processes can often be renormalized into simple phenomenological <span class="hlt">models</span> with only a few effective parameters. The proposed method additionally provides a mechanistic explanation for non-universal features of the behavior. PMID:27187545</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5366773','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5366773"><span>Mathematical and Computational <span class="hlt">Modeling</span> in <span class="hlt">Complex</span> Biological Systems</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Wenyang; Zhu, Xiaoliang</p> <p>2017-01-01</p> <p>The biological process and molecular functions involved in the cancer progression remain difficult to understand for biologists and clinical doctors. Recent developments in high-throughput technologies urge the systems biology to achieve more precise <span class="hlt">models</span> for <span class="hlt">complex</span> diseases. Computational and mathematical <span class="hlt">models</span> are gradually being used to help us understand the omics data produced by high-throughput experimental techniques. The use of computational <span class="hlt">models</span> in systems biology allows us to explore the pathogenesis of <span class="hlt">complex</span> diseases, improve our understanding of the latent molecular mechanisms, and promote treatment strategy optimization and new drug discovery. Currently, it is urgent to bridge the gap between the developments of high-throughput technologies and systemic <span class="hlt">modeling</span> of the biological process in cancer research. In this review, we firstly studied several typical mathematical <span class="hlt">modeling</span> approaches of biological systems in different scales and deeply analyzed their characteristics, advantages, applications, and limitations. Next, three potential research directions in systems <span class="hlt">modeling</span> were summarized. To conclude, this review provides an update of important solutions using computational <span class="hlt">modeling</span> approaches in systems biology. PMID:28386558</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ruthenium&id=EJ717054','ERIC'); return false;" href="http://eric.ed.gov/?q=ruthenium&id=EJ717054"><span>Syntheses and Characterization of Ruthenium(II) Tetrakis(pyridine)<span class="hlt">complexes</span>: An Advanced Coordination Chemistry <span class="hlt">Experiment</span> or Mini-Project</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Coe, Benjamin J.</p> <p>2004-01-01</p> <p>An <span class="hlt">experiment</span> for third-year undergraduate a student is designed which provides synthetic <span class="hlt">experience</span> and qualitative interpretation of the spectroscopic properties of the ruthenium <span class="hlt">complexes</span>. It involves the syntheses and characterization of several coordination <span class="hlt">complexes</span> of ruthenium, the element found directly beneath iron in the middle of the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/6248720','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/6248720"><span><span class="hlt">Modeling</span> of modification <span class="hlt">experiments</span> involving neutral-gas release</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bernhardt, P.A.</p> <p>1983-01-01</p> <p>Many <span class="hlt">experiments</span> involve the injection of neutral gases into the upper atmosphere. Examples are critical velocity <span class="hlt">experiments</span>, MHD wave generation, ionospheric hole production, plasma striation formation, and ion tracing. Many of these <span class="hlt">experiments</span> are discussed in other sessions of the Active <span class="hlt">Experiments</span> Conference. This paper limits its discussion to: (1) the <span class="hlt">modeling</span> of the neutral gas dynamics after injection, (2) subsequent formation of ionosphere holes, and (3) use of such holes as experimental tools.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=plot&pg=2&id=EJ1028290','ERIC'); return false;" href="http://eric.ed.gov/?q=plot&pg=2&id=EJ1028290"><span>Teaching "Instant <span class="hlt">Experience</span>" with Graphical <span class="hlt">Model</span> Validation Techniques</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ekstrøm, Claus Thorn</p> <p>2014-01-01</p> <p>Graphical <span class="hlt">model</span> validation techniques for linear normal <span class="hlt">models</span> are often used to check the assumptions underlying a statistical <span class="hlt">model</span>. We describe an approach to provide "instant <span class="hlt">experience</span>" in looking at a graphical <span class="hlt">model</span> validation plot, so it becomes easier to validate if any of the underlying assumptions are violated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2733151','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2733151"><span>An Adaptive <span class="hlt">Complex</span> Network <span class="hlt">Model</span> for Brain Functional Networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gomez Portillo, Ignacio J.; Gleiser, Pablo M.</p> <p>2009-01-01</p> <p>Brain functional networks are graph representations of activity in the brain, where the vertices represent anatomical regions and the edges their functional connectivity. These networks present a robust small world topological structure, characterized by highly integrated modules connected sparsely by long range links. Recent studies showed that other topological properties such as the degree distribution and the presence (or absence) of a hierarchical structure are not robust, and show different intriguing behaviors. In order to understand the basic ingredients necessary for the emergence of these <span class="hlt">complex</span> network structures we present an adaptive <span class="hlt">complex</span> network <span class="hlt">model</span> for human brain functional networks. The microscopic units of the <span class="hlt">model</span> are dynamical nodes that represent active regions of the brain, whose interaction gives rise to <span class="hlt">complex</span> network structures. The links between the nodes are chosen following an adaptive algorithm that establishes connections between dynamical elements with similar internal states. We show that the <span class="hlt">model</span> is able to describe topological characteristics of human brain networks obtained from functional magnetic resonance imaging studies. In particular, when the dynamical rules of the <span class="hlt">model</span> allow for integrated processing over the entire network scale-free non-hierarchical networks with well defined communities emerge. On the other hand, when the dynamical rules restrict the information to a local neighborhood, communities cluster together into larger ones, giving rise to a hierarchical structure, with a truncated power law degree distribution. PMID:19738902</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22347859','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22347859"><span>The use of workflows in the design and implementation of <span class="hlt">complex</span> <span class="hlt">experiments</span> in macromolecular crystallography</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brockhauser, Sandor; Svensson, Olof; Bowler, Matthew W.; Nanao, Max; Gordon, Elspeth; Leal, Ricardo M. F.; Popov, Alexander; Gerring, Matthew; McCarthy, Andrew A.; Gotz, Andy</p> <p>2012-08-01</p> <p>A powerful and easy-to-use workflow environment has been developed at the ESRF for combining <span class="hlt">experiment</span> control with online data analysis on synchrotron beamlines. This tool provides the possibility of automating <span class="hlt">complex</span> <span class="hlt">experiments</span> without the need for expertise in instrumentation control and programming, but rather by accessing defined beamline services. The automation of beam delivery, sample handling and data analysis, together with increasing photon flux, diminishing focal spot size and the appearance of fast-readout detectors on synchrotron beamlines, have changed the way that many macromolecular crystallography <span class="hlt">experiments</span> are planned and executed. Screening for the best diffracting crystal, or even the best diffracting part of a selected crystal, has been enabled by the development of microfocus beams, precise goniometers and fast-readout detectors that all require rapid feedback from the initial processing of images in order to be effective. All of these advances require the coupling of data feedback to the experimental control system and depend on immediate online data-analysis results during the <span class="hlt">experiment</span>. To facilitate this, a Data Analysis WorkBench (DAWB) for the flexible creation of <span class="hlt">complex</span> automated protocols has been developed. Here, example workflows designed and implemented using DAWB are presented for enhanced multi-step crystal characterizations, <span class="hlt">experiments</span> involving crystal reorientation with kappa goniometers, crystal-burning <span class="hlt">experiments</span> for empirically determining the radiation sensitivity of a crystal system and the application of mesh scans to find the best location of a crystal to obtain the highest diffraction quality. Beamline users interact with the prepared workflows through a specific brick within the beamline-control GUI MXCuBE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/fs/2009/3105/','USGSPUBS'); return false;" href="https://pubs.usgs.gov/fs/2009/3105/"><span>U.S. Geological Survey Groundwater <span class="hlt">Modeling</span> Software: Making Sense of a <span class="hlt">Complex</span> Natural Resource</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Provost, Alden M.; Reilly, Thomas E.; Harbaugh, Arlen W.; Pollock, David W.</p> <p>2009-01-01</p> <p>Computer <span class="hlt">models</span> of groundwater systems simulate the flow of groundwater, including water levels, and the transport of chemical constituents and thermal energy. Groundwater <span class="hlt">models</span> afford hydrologists a framework on which to organize their knowledge and understanding of groundwater systems, and they provide insights water-resources managers need to plan effectively for future water demands. Building on decades of <span class="hlt">experience</span>, the U.S. Geological Survey (USGS) continues to lead in the development and application of computer software that allows groundwater <span class="hlt">models</span> to address scientific and management questions of increasing <span class="hlt">complexity</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1077158','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1077158"><span>Silicon Carbide Derived Carbons: <span class="hlt">Experiments</span> and <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kertesz, Miklos</p> <p>2011-02-28</p> <p>The main results of the computational <span class="hlt">modeling</span> was: 1. Development of a new genealogical algorithm to generate vacancy clusters in diamond starting from monovacancies combined with energy criteria based on TBDFT energetics. The method revealed that for smaller vacancy clusters the energetically optimal shapes are compact but for larger sizes they tend to show graphitized regions. In fact smaller clusters of the size as small as 12 already show signatures of this graphitization. The <span class="hlt">modeling</span> gives firm basis for the slit-pore <span class="hlt">modeling</span> of porous carbon materials and explains some of their properties. 2. We discovered small vacancy clusters and their physical characteristics that can be used to spectroscopically identify them. 3. We found low barrier pathways for vacancy migration in diamond-like materials by obtaining for the first time optimized reaction pathways.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120013093','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120013093"><span>Fundamental Rotorcraft Acoustic <span class="hlt">Modeling</span> From <span class="hlt">Experiments</span> (FRAME)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Greenwood, Eric</p> <p>2011-01-01</p> <p>A new methodology is developed for the construction of helicopter source noise <span class="hlt">models</span> for use in mission planning tools from experimental measurements of helicopter external noise radiation. The <span class="hlt">models</span> are constructed by employing a parameter identification method to an assumed analytical <span class="hlt">model</span> of the rotor harmonic noise sources. This new method allows for the identification of individual rotor harmonic noise sources and allows them to be characterized in terms of their individual non-dimensional governing parameters. The method is applied to both wind tunnel measurements and ground noise measurements of two-bladed rotors. The method is shown to match the parametric trends of main rotor harmonic noise, allowing accurate estimates of the dominant rotorcraft noise sources to be made for operating conditions based on a small number of measurements taken at different operating conditions. The ability of this method to estimate changes in noise radiation due to changes in ambient conditions is also demonstrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970005632','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970005632"><span><span class="hlt">Experiences</span> Using Formal Methods for Requirements <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Easterbrook, Steve; Lutz, Robyn; Covington, Rick; Kelly, John; Ampo, Yoko; Hamilton, David</p> <p>1996-01-01</p> <p>This paper describes three cases studies in the lightweight application of formal methods to requirements <span class="hlt">modeling</span> for spacecraft fault protection systems. The case studies differ from previously reported applications of formal methods in that formal methods were applied very early in the requirements engineering process, to validate the evolving requirements. The results were fed back into the projects, to improve the informal specifications. For each case study, we describe what methods were applied, how they were applied, how much effort was involved, and what the findings were. In all three cases, the formal <span class="hlt">modeling</span> provided a cost effective enhancement of the existing verification and validation processes. We conclude that the benefits gained from early <span class="hlt">modeling</span> of unstable requirements more than outweigh the effort needed to maintain multiple representations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19920051859&hterms=testing+Localization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtesting%2BLocalization','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19920051859&hterms=testing+Localization&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dtesting%2BLocalization"><span><span class="hlt">Model</span> localization <span class="hlt">experiments</span> on a ribbed antenna</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Levine-West, M. B.; Salama, M. A.</p> <p>1992-01-01</p> <p>In this paper, the <span class="hlt">model</span> localization (ML) phenomenon is investigated experimentally and analytically to determine the influence of its parameters. For this purpose, a full-scale 12-rib loosely-coupled antenna testbed with small imperfections is dynamically tested for various levels of inter-rib coupling stiffness and excitation force. The experimental results are described herein. Using a simplified numerical <span class="hlt">model</span> of the structure, a sensitivity analysis of the modal behavior is also performed. The numerical and experimental results are shown to agree remarkably well, thereby providing conclusive validation of the ML phenomenon on a testbed having the dynamic characteristics of space structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110003562','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110003562"><span>A Hardware <span class="hlt">Model</span> Validation Tool for Use in <span class="hlt">Complex</span> Space Systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Davies, Misty Dawn; Gundy-Burlet, Karen L.; Limes, Gregory L.</p> <p>2010-01-01</p> <p>One of the many technological hurdles that must be overcome in future missions is the challenge of validating as-built systems against the <span class="hlt">models</span> used for design. We propose a technique composed of intelligent parameter exploration in concert with automated failure analysis as a scalable method for the validation of <span class="hlt">complex</span> space systems. The technique is impervious to discontinuities and linear dependencies in the data, and can handle dimensionalities consisting of hundreds of variables over tens of thousands of <span class="hlt">experiments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ffcd.confE..81S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ffcd.confE..81S"><span>Fog Forecasting using Synergy between <span class="hlt">Models</span> of different <span class="hlt">Complexity</span>: Large-Eddy Simulation, Column <span class="hlt">modelling</span> and Limited Area <span class="hlt">Modelling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steeneveld, G. J.; Masbou, M.; van Heerwaarden, C. C.; Mohr, C.; Schneider, W.; Müller, M.; Bott, A.; Holtslag, A. A. M.</p> <p>2010-07-01</p> <p>Fog is a hazardous weather phenomenon with a large impact on the environment and human life. In particular the transportation sector is vulnerable to fog; but fog is also important for agriculture, for leaf-wetness duration in particular, and for humans with asthma or related diseases. In addition, fog and low level clouds govern to a large extent the radiation balance of the polar regions in summer, and as such fog also influences the regional climate. Hence a thorough understanding of the fog governing processes is essential. However, due to the <span class="hlt">complexity</span> and small scale nature of the relevant physical processes, the current understanding is relatively poor, as is our ability to forecast fog. In order to improve our knowledge, and to identify key deficiencies in the current state of the art fog forecasting <span class="hlt">models</span>, we present an <span class="hlt">experiment</span> in which the synergy between <span class="hlt">models</span> of different <span class="hlt">complexity</span> and observations is used to evaluate <span class="hlt">model</span> skill. Therefore, an observed case study (Cabauw; The Netherlands) of a well developed radiation fog will be innovatively run with a large eddy simulation <span class="hlt">model</span> which allows us to evaluate the key issue of turbulent mixing. In addition, operational and research column <span class="hlt">models</span> (PAFOG; Duynkerke, 1991) will be employed to evaluate their skill on the local scale, while at the limited area <span class="hlt">models</span> WRF-NMMFOG (Mueller et al 2010) and COSMO-FOG will be evaluated on their skill for the regional scale. Special focus will be given to the representation of the boundary-layer vertical structure and turbulence in the latter two <span class="hlt">model</span> types versus the LES results with its solid physical ground.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/962188','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/962188"><span>RHIC injector <span class="hlt">complex</span> online <span class="hlt">model</span> status and plans</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schoefer,V.; Ahrens, L.; Brown, K.; Morris, J.; Nemesure, S.</p> <p>2009-05-04</p> <p>An online <span class="hlt">modeling</span> system is being developed for the RHIC injector <span class="hlt">complex</span>, which consists of the Booster, the AGS and the transfer lines connecting the Booster to the AGS and the AGS to RHIC. Historically the injectors have been operated using static values from design specifications or offline <span class="hlt">model</span> runs, but tighter beam optics constraints required by polarized proton operations (e.g, accelerating with near-integer tunes) have necessitated a more dynamic system. An online <span class="hlt">model</span> server for the AGS has been implemented using MAD-X [1] as the <span class="hlt">model</span> engine, with plans to extend the system to the Booster and the injector transfer lines and to add the option of calculating optics using the Polymorphic Tracking Code (PTC [2]) as the <span class="hlt">model</span> engine.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25954573','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25954573"><span>Simplifying <span class="hlt">complex</span> clinical element <span class="hlt">models</span> to encourage adoption.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Freimuth, Robert R; Zhu, Qian; Pathak, Jyotishman; Chute, Christopher G</p> <p>2014-01-01</p> <p>Clinical Element <span class="hlt">Models</span> (CEMs) were developed to provide a normalized form for the exchange of clinical data. The CEM specification is quite <span class="hlt">complex</span> and specialized knowledge is required to understand and implement the <span class="hlt">models</span>, which presents a significant barrier to investigators and study designers. To encourage the adoption of CEMs at the time of data collection and reduce the need for retrospective normalization efforts, we developed an approach that provides a simplified view of CEMs for non-experts while retaining the full semantic detail of the underlying logical <span class="hlt">models</span>. This allows investigators to approach CEMs through generalized representations that are intended to be more intuitive than the native <span class="hlt">models</span>, and it permits them to think conceptually about their data elements without worrying about details related to the CEM logical <span class="hlt">models</span> and syntax. We demonstrate our approach using data elements from the Pharmacogenomics Research Network (PGRN).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25368428','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25368428"><span>Mechanistic <span class="hlt">modeling</span> confronts the <span class="hlt">complexity</span> of molecular cell biology.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Phair, Robert D</p> <p>2014-11-05</p> <p>Mechanistic <span class="hlt">modeling</span> has the potential to transform how cell biologists contend with the inescapable <span class="hlt">complexity</span> of modern biology. I am a physiologist-electrical engineer-systems biologist who has been working at the level of cell biology for the past 24 years. This perspective aims 1) to convey why we build <span class="hlt">models</span>, 2) to enumerate the major approaches to <span class="hlt">modeling</span> and their philosophical differences, 3) to address some recurrent concerns raised by experimentalists, and then 4) to imagine a future in which teams of experimentalists and <span class="hlt">modelers</span> build-and subject to exhaustive experimental tests-<span class="hlt">models</span> covering the entire spectrum from molecular cell biology to human pathophysiology. There is, in my view, no technical obstacle to this future, but it will require some plasticity in the biological research mind-set.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://pubs.usgs.gov/of/2003/0364/pdf/OF03-364.pdf','USGSPUBS'); return false;" href="https://pubs.usgs.gov/of/2003/0364/pdf/OF03-364.pdf"><span>Cx-02 Program, workshop on <span class="hlt">modeling</span> <span class="hlt">complex</span> systems</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Mossotti, Victor G.; Barragan, Jo Ann; Westergard, Todd D.</p> <p>2003-01-01</p> <p>This publication contains the abstracts and program for the workshop on <span class="hlt">complex</span> systems that was held on November 19-21, 2002, in Reno, Nevada. <span class="hlt">Complex</span> systems are ubiquitous within the realm of the earth sciences. Geological systems consist of a multiplicity of linked components with nested feedback loops; the dynamics of these systems are non-linear, iterative, multi-scale, and operate far from equilibrium. That notwithstanding, It appears that, with the exception of papers on seismic studies, geology and geophysics work has been disproportionally underrepresented at regional and national meetings on <span class="hlt">complex</span> systems relative to papers in the life sciences. This is somewhat puzzling because geologists and geophysicists are, in many ways, preadapted to thinking of <span class="hlt">complex</span> system mechanisms. Geologists and geophysicists think about processes involving large volumes of rock below the sunlit surface of Earth, the accumulated consequence of processes extending hundreds of millions of years in the past. Not only do geologists think in the abstract by virtue of the vast time spans, most of the evidence is out-of-sight. A primary goal of this workshop is to begin to bridge the gap between the Earth sciences and life sciences through demonstration of the universality of <span class="hlt">complex</span> systems science, both philosophically and in <span class="hlt">model</span> structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17259279','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17259279"><span>Computational and analytical <span class="hlt">modeling</span> of cationic lipid-DNA <span class="hlt">complexes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Farago, Oded; Grønbech-Jensen, Niels</p> <p>2007-05-01</p> <p>We present a theoretical study of the physical properties of cationic lipid-DNA (CL-DNA) <span class="hlt">complexes</span>--a promising synthetically based nonviral carrier of DNA for gene therapy. The study is based on a coarse-grained molecular <span class="hlt">model</span>, which is used in Monte Carlo simulations of mesoscopically large systems over timescales long enough to address experimental reality. In the present work, we focus on the statistical-mechanical behavior of lamellar <span class="hlt">complexes</span>, which in Monte Carlo simulations self-assemble spontaneously from a disordered random initial state. We measure the DNA-interaxial spacing, d(DNA), and the local cationic area charge density, sigma(M), for a wide range of values of the parameter (c) representing the fraction of cationic lipids. For weakly charged <span class="hlt">complexes</span> (low values of (c)), we find that d(DNA) has a linear dependence on (c)(-1), which is in excellent agreement with x-ray diffraction experimental data. We also observe, in qualitative agreement with previous Poisson-Boltzmann calculations of the system, large fluctuations in the local area charge density with a pronounced minimum of sigma(M) halfway between adjacent DNA molecules. For highly-charged <span class="hlt">complexes</span> (large (c)), we find moderate charge density fluctuations and observe deviations from linear dependence of d(DNA) on (c)(-1). This last result, together with other findings such as the decrease in the effective stretching modulus of the <span class="hlt">complex</span> and the increased rate at which pores are formed in the <span class="hlt">complex</span> membranes, are indicative of the gradual loss of mechanical stability of the <span class="hlt">complex</span>, which occurs when (c) becomes large. We suggest that this may be the origin of the recently observed enhanced transfection efficiency of lamellar CL-DNA <span class="hlt">complexes</span> at high charge densities, because the completion of the transfection process requires the disassembly of the <span class="hlt">complex</span> and the release of the DNA into the cytoplasm. Some of the structural properties of the system are also predicted by a continuum</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DNP.EA099C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DNP.EA099C"><span>Computational <span class="hlt">Model</span> of Fluorine-20 <span class="hlt">Experiment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chuna, Thomas; Voytas, Paul; George, Elizabeth; Naviliat-Cuncic, Oscar; Gade, Alexandra; Hughes, Max; Huyan, Xueying; Liddick, Sean; Minamisono, Kei; Weisshaar, Dirk; Paulauskas, Stanley; Ban, Gilles; Flechard, Xavier; Lienard, Etienne</p> <p>2015-10-01</p> <p>The Conserved Vector Current (CVC) hypothesis of the standard <span class="hlt">model</span> of the electroweak interaction predicts there is a contribution to the shape of the spectrum in the beta-minus decay of 20F related to a property of the analogous gamma decay of excited 20Ne. To provide a strong test of the CVC hypothesis, a precise measurement of the 20F beta decay spectrum will be taken at the National Superconducting Cyclotron Laboratory. This measurement uses unconventional measurement techniques in that 20F will be implanted directly into a scintillator. As the emitted electrons interact with the detector material, bremsstrahlung interactions occur and the escape of the resultant photons will distort the measured spectrum. Thus, a Monte Carlo simulation has been constructed using EGSnrc radiation transport software. This computational <span class="hlt">model</span>'s intended use is to quantify and correct for distortion in the observed beta spectrum due, primarily, to the aforementioned bremsstrahlung. The focus of this presentation is twofold: the analysis of the computational <span class="hlt">model</span> itself and the results produced by the <span class="hlt">model</span>. Wittenberg University.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9344H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9344H"><span>Mathematic <span class="hlt">modeling</span> of <span class="hlt">complex</span> aquifer: Evian Natural Mineral Water case study considering lumped and distributed <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Henriot, abel; Blavoux, bernard; Travi, yves; Lachassagne, patrick; Beon, olivier; Dewandel, benoit; Ladouche, bernard</p> <p>2013-04-01</p> <p>The Evian Natural Mineral Water (NMW) aquifer is a highly heterogeneous Quaternary glacial deposits <span class="hlt">complex</span> composed of three main units, from bottom to top: - The "Inferior <span class="hlt">Complex</span>" mainly composed of basal and impermeable till lying on the Alpine rocks. It outcrops only at the higher altitudes but is known in depth through drilled holes. - The "Gavot Plateau <span class="hlt">Complex</span>" is an interstratified <span class="hlt">complex</span> of mainly basal and lateral till up to 400 m thick. It outcrops at heights above approximately 850 m a.m.s.l. and up to 1200 m a.m.s.l. over a 30 km² area. It is the main recharge area known for the hydromineral system. - The "Terminal <span class="hlt">Complex</span>" from which the Evian NMW is emerging at 410 m a.m.s.l. It is composed of sand and gravel Kame terraces that allow water to flow from the deep "Gavot Plateau <span class="hlt">Complex</span>" permeable layers to the "Terminal <span class="hlt">Complex</span>". A thick and impermeable terminal till caps and seals the system. Aquifer is then confined at its downstream area. Because of heterogeneity and <span class="hlt">complexity</span> of this hydrosystem, distributed <span class="hlt">modeling</span> tools are difficult to implement at the whole system scale: important hypothesis would have to be made about geometry, hydraulic properties, boundary conditions for example and extrapolation would lead with no doubt to unacceptable errors. Consequently a <span class="hlt">modeling</span> strategy is being developed and leads also to improve the conceptual <span class="hlt">model</span> of the hydrosystem. Lumped <span class="hlt">models</span> mainly based on tritium time series allow the whole hydrosystem to be <span class="hlt">modeled</span> combining in series: an exponential <span class="hlt">model</span> (superficial aquifers of the "Gavot Plateau <span class="hlt">Complex</span>"), a dispersive <span class="hlt">model</span> (Gavot Plateau interstratified <span class="hlt">complex</span>) and a piston flow <span class="hlt">model</span> (sand and gravel from the Kame terraces) respectively 8, 60 and 2.5 years of mean transit time. These <span class="hlt">models</span> provide insight on the governing parameters for the whole mineral aquifer. They help improving the current conceptual <span class="hlt">model</span> and are to be improved with other environmental tracers such as CFC, SF6. A</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3172241','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3172241"><span>A Corticothalamic Circuit <span class="hlt">Model</span> for Sound Identification in <span class="hlt">Complex</span> Scenes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Otazu, Gonzalo H.; Leibold, Christian</p> <p>2011-01-01</p> <p>The identification of the sound sources present in the environment is essential for the survival of many animals. However, these sounds are not presented in isolation, as natural scenes consist of a superposition of sounds originating from multiple sources. The identification of a source under these circumstances is a <span class="hlt">complex</span> computational problem that is readily solved by most animals. We present a <span class="hlt">model</span> of the thalamocortical circuit that performs level-invariant recognition of auditory objects in <span class="hlt">complex</span> auditory scenes. The circuit identifies the objects present from a large dictionary of possible elements and operates reliably for real sound signals with multiple concurrently active sources. The key <span class="hlt">model</span> assumption is that the activities of some cortical neurons encode the difference between the observed signal and an internal estimate. Reanalysis of awake auditory cortex recordings revealed neurons with patterns of activity corresponding to such an error signal. PMID:21931668</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009LNCS.5872..564W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009LNCS.5872..564W"><span>An Ontology for <span class="hlt">Modeling</span> <span class="hlt">Complex</span> Inter-relational Organizations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wautelet, Yves; Neysen, Nicolas; Kolp, Manuel</p> <p></p> <p>This paper presents an ontology for organizational <span class="hlt">modeling</span> through multiple complementary aspects. The primary goal of the ontology is to dispose of an adequate set of related concepts for studying <span class="hlt">complex</span> organizations involved in a lot of relationships at the same time. In this paper, we define <span class="hlt">complex</span> organizations as networked organizations involved in a market eco-system that are playing several roles simultaneously. In such a context, traditional approaches focus on the macro analytic level of transactions; this is supplemented here with a micro analytic study of the actors' rationale. At first, the paper overviews enterprise ontologies literature to position our proposal and exposes its contributions and limitations. The ontology is then brought to an advanced level of formalization: a meta-<span class="hlt">model</span> in the form of a UML class diagram allows to overview the ontology concepts and their relationships which are formally defined. Finally, the paper presents the case study on which the ontology has been validated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/447373','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/447373"><span>Plasma gun pellet acceleration <span class="hlt">modeling</span> and <span class="hlt">experiment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kincaid, R.W.; Bourham, M.A.; Gilligan, J.G.</p> <p>1996-12-31</p> <p>Modifications to the electrothermal plasma gun SIRENS have been completed to allow for acceleration <span class="hlt">experiments</span> using plastic pellets. Modifications have been implemented to the 1-D, time dependent code ODIN to include pellet friction, momentum, and kinetic energy with options of variable barrel length. The code results in the new version, POSEIDON, compare favorably with experimental data and with code results from ODIN. Predicted values show an increased pellet velocity along the barrel length, achieving 2 km/s exit velocity. Measured velocity, at three locations along the barrel length, showed good correlation with predicted values. The code has also been used to investigate the effectiveness of longer pulse length on pellet velocity using simulated ramp up and down currents with flat top, and triangular current pulses with early and late peaking. 16 refs., 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005SurSc.576..197D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005SurSc.576..197D"><span><span class="hlt">Model</span> <span class="hlt">experiments</span> of superlubricity of graphite</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dienwiebel, Martin; Pradeep, Namboodiri; Verhoeven, Gertjan S.; Zandbergen, Henny W.; Frenken, Joost W. M.</p> <p>2005-02-01</p> <p>Graphite is known to be a good solid lubricant. The low-friction behavior is traditionally ascribed to the low resistance to shear. We have recently observed that the ultra-low friction found in friction force microscopy <span class="hlt">experiments</span> on graphite is due to a effect called superlubricity [M. Dienwiebel, G. S. Verhoeven, N. Pradeep, J.W.M. Frenken, J.A. Heimberg, H.W. Zandbergen, Phys. Rev. Lett. 92 (2004) 126101]. Here, we provide additional experimental evidence that superlubricity has been taken place between a small graphite flake attached to the scanning tip and the graphite surface. Finally, we speculate about the significance of this for the lubricating properties of graphite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ISPAr.XL5..387B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ISPAr.XL5..387B"><span>Polygonal Shapes Detection in 3d <span class="hlt">Models</span> of <span class="hlt">Complex</span> Architectures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Benciolini, G. B.; Vitti, A.</p> <p>2015-02-01</p> <p>A sequential application of two global <span class="hlt">models</span> defined on a variational framework is proposed for the detection of polygonal shapes in 3D <span class="hlt">models</span> of <span class="hlt">complex</span> architectures. As a first step, the procedure involves the use of the Mumford and Shah (1989) 1st-order variational <span class="hlt">model</span> in dimension two (gridded height data are processed). In the Mumford-Shah <span class="hlt">model</span> an auxiliary function detects the sharp changes, i.e., the discontinuities, of a piecewise smooth approximation of the data. The Mumford-Shah <span class="hlt">model</span> requires the global minimization of a specific functional to simultaneously produce both the smooth approximation and its discontinuities. In the proposed procedure, the edges of the smooth approximation derived by a specific processing of the auxiliary function are then processed using the Blake and Zisserman (1987) 2nd-order variational <span class="hlt">model</span> in dimension one (edges are processed in the plane). This second step permits to describe the edges of an object by means of piecewise almost-linear approximation of the input edges themselves and to detects sharp changes of the first-derivative of the edges so to detect corners. The Mumford-Shah variational <span class="hlt">model</span> is used in two dimensions accepting the original data as primary input. The Blake-Zisserman variational <span class="hlt">model</span> is used in one dimension for the refinement of the description of the edges. The selection among all the boundaries detected by the Mumford-Shah <span class="hlt">model</span> of those that present a shape close to a polygon is performed by considering only those boundaries for which the Blake-Zisserman <span class="hlt">model</span> identified discontinuities in their first derivative. The output of the procedure are hence shapes, coming from 3D geometric data, that can be considered as polygons. The application of the procedure is suitable for, but not limited to, the detection of objects such as foot-print of polygonal buildings, building facade boundaries or windows contours. v The procedure is applied to a height <span class="hlt">model</span> of the building of the Engineering</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22262582','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22262582"><span>A radio-frequency sheath <span class="hlt">model</span> for <span class="hlt">complex</span> waveforms</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Turner, M. M.; Chabert, P.</p> <p>2014-04-21</p> <p>Plasma sheaths driven by radio-frequency voltages occur in contexts ranging from plasma processing to magnetically confined fusion <span class="hlt">experiments</span>. An analytical understanding of such sheaths is therefore important, both intrinsically and as an element in more elaborate theoretical structures. Radio-frequency sheaths are commonly excited by highly anharmonic waveforms, but no analytical <span class="hlt">model</span> exists for this general case. We present a mathematically simple sheath <span class="hlt">model</span> that is in good agreement with earlier <span class="hlt">models</span> for single frequency excitation, yet can be solved for arbitrary excitation waveforms. As examples, we discuss dual-frequency and pulse-like waveforms. The <span class="hlt">model</span> employs the ansatz that the time-averaged electron density is a constant fraction of the ion density. In the cases we discuss, the error introduced by this approximation is small, and in general it can be quantified through an internal consistency condition of the <span class="hlt">model</span>. This simple and accurate <span class="hlt">model</span> is likely to have wide application.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003Sci...302..419P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003Sci...302..419P"><span>A Hybridization <span class="hlt">Model</span> for the Plasmon Response of <span class="hlt">Complex</span> Nanostructures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prodan, E.; Radloff, C.; Halas, N. J.; Nordlander, P.</p> <p>2003-10-01</p> <p>We present a simple and intuitive picture, an electromagnetic analog of molecular orbital theory, that describes the plasmon response of <span class="hlt">complex</span> nanostructures of arbitrary shape. Our <span class="hlt">model</span> can be understood as the interaction or ``hybridization'' of elementary plasmons supported by nanostructures of elementary geometries. As an example, the approach is applied to the important case of a four-layer concentric nanoshell, where the hybridization of the plasmons of the inner and outer nanoshells determines the resonant frequencies of the multilayer nanostructure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/14564001','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/14564001"><span>A hybridization <span class="hlt">model</span> for the plasmon response of <span class="hlt">complex</span> nanostructures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prodan, E; Radloff, C; Halas, N J; Nordlander, P</p> <p>2003-10-17</p> <p>We present a simple and intuitive picture, an electromagnetic analog of molecular orbital theory, that describes the plasmon response of <span class="hlt">complex</span> nanostructures of arbitrary shape. Our <span class="hlt">model</span> can be understood as the interaction or "hybridization" of elementary plasmons supported by nanostructures of elementary geometries. As an example, the approach is applied to the important case of a four-layer concentric nanoshell, where the hybridization of the plasmons of the inner and outer nanoshells determines the resonant frequencies of the multilayer nanostructure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19860021335','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19860021335"><span><span class="hlt">Modeling</span> and analysis of pinhole occulter <span class="hlt">experiment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ring, J. R.</p> <p>1986-01-01</p> <p>The objectives were to improve pointing control system implementation by converting the dynamic compensator from a continuous domain representation to a discrete one; to determine pointing stability sensitivites to sensor and actuator errors by adding sensor and actuator error <span class="hlt">models</span> to treetops and by developing an error budget for meeting pointing stability requirements; and to determine pointing performance for alternate mounting bases (space station for example).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19900000788','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19900000788"><span>Flexible robot control: <span class="hlt">Modeling</span> and <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Oppenheim, Irving J.; Shimoyama, Isao</p> <p>1989-01-01</p> <p>Described here is a <span class="hlt">model</span> and its use in experimental studies of flexible manipulators. The analytical <span class="hlt">model</span> uses the equivalent of Rayleigh's method to approximate the displaced shape of a flexible link as the static elastic displacement which would occur under end rotations as applied at the joints. The generalized coordinates are thereby expressly compatible with joint motions and rotations in serial link manipulators, because the amplitude variables are simply the end rotations between the flexible link and the chord connecting the end points. The equations for the system dynamics are quite simple and can readily be formulated for the multi-link, three-dimensional case. When the flexible links possess mass and (polar moment of) inertia which are small compared to the concentrated mass and inertia at the joints, the analytical <span class="hlt">model</span> is exact and displays the additional advantage of reduction in system dimension for the governing equations. Four series of pilot tests have been completed. Studies on a planar single-link system were conducted at Carnegie-Mellon University, and tests conducted at Toshiba Corporation on a planar two-link system were then incorporated into the study. A single link system under three-dimensional motion, displaying biaxial flexure, was then tested at Carnegie-Mellon.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010LNCS.6508....1L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010LNCS.6508....1L"><span>Termination of Multipartite Graph Series Arising from <span class="hlt">Complex</span> Network <span class="hlt">Modelling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Latapy, Matthieu; Phan, Thi Ha Duong; Crespelle, Christophe; Nguyen, Thanh Qui</p> <p></p> <p>An intense activity is nowadays devoted to the definition of <span class="hlt">models</span> capturing the properties of <span class="hlt">complex</span> networks. Among the most promising approaches, it has been proposed to <span class="hlt">model</span> these graphs via their clique incidence bipartite graphs. However, this approach has, until now, severe limitations resulting from its incapacity to reproduce a key property of this object: the overlapping nature of cliques in <span class="hlt">complex</span> networks. In order to get rid of these limitations we propose to encode the structure of clique overlaps in a network thanks to a process consisting in iteratively factorising the maximal bicliques between the upper level and the other levels of a multipartite graph. We show that the most natural definition of this factorising process leads to infinite series for some instances. Our main result is to design a restriction of this process that terminates for any arbitrary graph. Moreover, we show that the resulting multipartite graph has remarkable combinatorial properties and is closely related to another fundamental combinatorial object. Finally, we show that, in practice, this multipartite graph is computationally tractable and has a size that makes it suitable for <span class="hlt">complex</span> network <span class="hlt">modelling</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000Sci...287..667E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000Sci...287..667E"><span>A Simple <span class="hlt">Model</span> for <span class="hlt">Complex</span> Dynamical Transitions in Epidemics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Earn, David J. D.; Rohani, Pejman; Bolker, Benjamin M.; Grenfell, Bryan T.</p> <p>2000-01-01</p> <p>Dramatic changes in patterns of epidemics have been observed throughout this century. For childhood infectious diseases such as measles, the major transitions are between regular cycles and irregular, possibly chaotic epidemics, and from regionally synchronized oscillations to <span class="hlt">complex</span>, spatially incoherent epidemics. A simple <span class="hlt">model</span> can explain both kinds of transitions as the consequences of changes in birth and vaccination rates. Measles is a natural ecological system that exhibits different dynamical transitions at different times and places, yet all of these transitions can be predicted as bifurcations of a single nonlinear <span class="hlt">model</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19900023475&hterms=Semantic+representation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSemantic%2Brepresentation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19900023475&hterms=Semantic+representation&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSemantic%2Brepresentation"><span>The evaluative imaging of mental <span class="hlt">models</span> - Visual representations of <span class="hlt">complexity</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dede, Christopher</p> <p>1989-01-01</p> <p>The paper deals with some design issues involved in building a system that could visually represent the semantic structures of training materials and their underlying mental <span class="hlt">models</span>. In particular, hypermedia-based semantic networks that instantiate classification problem solving strategies are thought to be a useful formalism for such representations; the <span class="hlt">complexity</span> of these web structures can be best managed through visual depictions. It is also noted that a useful approach to implement in these hypermedia <span class="hlt">models</span> would be some metrics of conceptual distance.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050210038','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050210038"><span><span class="hlt">Experiments</span> and <span class="hlt">Models</span> for Polymeric Microsphere Foams</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pipes, R. Byrona; Kyu, Thein</p> <p>2005-01-01</p> <p>The current project was performed under the direction of Dr. Byron Pipes as its lead investigator from January 2001 to August 2004. With the permission of the NASA, the project was transferred to Dr. Thein Kyu as the principle investigator for the period of September 2004 - June 2005. There were two major thrust areas in the original proposal; (1) experimental characterization and kinematics of foam structure formation and (2) determination of the mechanical, physical, and thermal properties, although these thrust areas were further sub- divided into 7 tasks. The present project has been directed primarily to elucidate kinematics of micro-foam formation (tasks 1 and 3) and to characterize micro-foam structures, since the control of the micro-structure of these foams is of paramount importance in determining their physical, mechanical and thermal properties. The first thrust area was accomplished in a timely manner; however, the second thrust area of foam properties (tasks 2,4-7) has yet to be completed because the area of kinematics of foam structure formation turned out to be extremely <span class="hlt">complex</span> and thus consumed more time than what have been anticipated. As will be reported in what follows, the present studies have greatly enhances the in-depth understanding of mechanisms and kinematics of the micro-foam formation from solid powders. However, in order to implement all objectives of the second thrust areas regarding investigations of mechanical, physical, and thermal properties and establishment of the correlation of structure - properties of the foams, the project needs additional time and resources. The technical highlights of the accomplishment are summarized as follows. The present study represents a first approach to understanding the <span class="hlt">complexities</span> that act together in the powder foaming process to achieve the successful inflation of polyimide microstructures. This type of study is novel as no prior work had dissected the fundamentals that govern the inflation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007JSV...306..580K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007JSV...306..580K"><span>Nonlinear vibrations of shallow shells with <span class="hlt">complex</span> boundary: R-functions method and <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kurpa, Lidia; Pilgun, Galina; Amabili, Marco</p> <p>2007-10-01</p> <p>Geometrically nonlinear vibrations of shallow circular cylindrical panels with <span class="hlt">complex</span> shape of the boundary are considered. The R-functions theory and variational methods are used to study the problem. The R-functions method (RFM) allows constructing in analytical form the sequence of basis functions satisfying the given boundary conditions in case of <span class="hlt">complex</span> shape of the boundary. The problem is reduced to a single second-order differential equation with quadratic and cubic nonlinear terms. The method developed has been initially applied to study free vibrations of shallow circular cylindrical panels with rectangular base for different boundary conditions: (i) clamped edges, (ii) in-plane immovable simply supported edges, (iii) classically simply supported edges, and (iv) in-plane free simply supported edges. Then, the same approach is applied to a shell with <span class="hlt">complex</span> shape of the boundary. <span class="hlt">Experiments</span> have been conducted on an aluminum panel with <span class="hlt">complex</span> shape of the boundary in order to identify the nonlinear response of the fundamental mode; these experimental results have been compared to numerical results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.V43E4939N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.V43E4939N"><span><span class="hlt">Complex</span> tephra dispersion from 3D plume <span class="hlt">modeling</span> using ATHAM</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nicholson, B. C.; Kobs-Nawotniak, S. E.</p> <p>2014-12-01</p> <p>Most volcanic hazard assessments are based on a classic inversion tool for tephra deposits that relies on a simple integral <span class="hlt">model</span> to explain the eruption plume. While this tool is adequate for first-order predictions of tephra deposition under no-wind conditions, the simplifying assumptions make it unreliable for ambient winds >10 m/s. Advances in computational power now make it possible to improve the inversion tool using 3D fluid dynamics. We do this with the physics-based Active Tracer High-resolution Atmospheric <span class="hlt">Model</span> (ATHAM) to <span class="hlt">model</span> tephra dispersion and deposition from volcanic eruption columns. The <span class="hlt">model</span>, when run in 3D, is able to capture the <span class="hlt">complex</span> morphology of bent plumes. Tephra distributions produced by these morphologies differ significantly from distributions created by idealized advection solutions, reflecting the effects of counter-rotating vortex pairs, puffing modes, or plume bifurcation. The <span class="hlt">modeled</span> tephra deposition better captures the <span class="hlt">complex</span> effects of wind-plume interaction, allowing us to update classic inversion tools with more realistic weak plume conditions consistent with typical historical explosive eruptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930011047','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930011047"><span>Process <span class="hlt">modelling</span> for materials preparation <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rosenberger, Franz; Alexander, J. Iwan D.</p> <p>1993-01-01</p> <p>The main goals of the research under this grant consist of the development of mathematical tools and measurement of transport properties necessary for high fidelity <span class="hlt">modeling</span> of crystal growth from the melt and solution, in particular, for the Bridgman-Stockbarger growth of mercury cadmium telluride (MCT) and the solution growth of triglycine sulphate (TGS). Of the tasks described in detail in the original proposal, two remain to be worked on: (1) development of a spectral code for moving boundary problems; and (2) diffusivity measurements on concentrated and supersaturated TGS solutions. Progress made during this seventh half-year period is reported.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920009864','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920009864"><span>Process <span class="hlt">modelling</span> for materials preparation <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rosenberger, Franz; Alexander, J. Iwan D.</p> <p>1992-01-01</p> <p>The development is examined of mathematical tools and measurement of transport properties necessary for high fidelity <span class="hlt">modeling</span> of crystal growth from the melt and solution, in particular for the Bridgman-Stockbarger growth of mercury cadmium telluride (MCT) and the solution growth of triglycine sulphate (TGS). The tasks include development of a spectral code for moving boundary problems, kinematic viscosity measurements on liquid MCT at temperatures close to the melting point, and diffusivity measurements on concentrated and supersaturated TGS solutions. A detailed description is given of the work performed for these tasks, together with a summary of the resulting publications and presentations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940008116','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940008116"><span>Process <span class="hlt">modelling</span> for materials preparation <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rosenberger, Franz; Alexander, J. Iwan D.</p> <p>1993-01-01</p> <p>The main goals of the research consist of the development of mathematical tools and measurement of transport properties necessary for high fidelity <span class="hlt">modeling</span> of crystal growth from the melt and solution, in particular for the Bridgman-Stockbarger growth of mercury cadmium telluride (MCT) and the solution growth of triglycine sulphate (TGS). Of the tasks described in detail in the original proposal, two remain to be worked on: development of a spectral code for moving boundary problems, and diffusivity measurements on concentrated and supersaturated TGS solutions. During this eighth half-year period, good progress was made on these tasks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20217033','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20217033"><span>Characterizing nanoparticle interactions: Linking <span class="hlt">models</span> to <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ramakrishnan, S.; Zukoski, C. F.</p> <p>2000-07-15</p> <p>Self-assembly of nanoparticles involves manipulating particle interactions such that attractions are on the order of the average thermal energy in the system. If the self-assembly is to result in an ordered packing, an understanding of their phase behavior is necessary. Here we test the ability of simple pair potentials to characterize the interactions and phase behavior of silico tungstic acid (STA), a 1.2 nm particle. The strength of interaction is controlled by dispersing STA in different background salt concentrations. The experimental variables used in characterizing the interactions are the osmotic compressibility (d{pi}/d{rho}), the second virial coefficient (B{sub 2}), relative solution viscosity ({eta}/{eta}{sub c}), and the solubility ({rho}{sigma}{sup 3}){sub sat}. Various techniques are then developed to extract the parameters of square well, the adhesive hard sphere (AHS), and the Yukawa pair potentials that best describe the experimental data. The AHS <span class="hlt">model</span> describes the solution thermodynamic behavior only where the system is weakly attractive but, as would be expected, fails when long range repulsions or nonmonotonic pair potentials become important. <span class="hlt">Model</span> free representations are presented which offer the opportunity to extract pair potential parameters. (c) 2000 American Institute of Physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007ASPC..377..405P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007ASPC..377..405P"><span>Indian Consortia <span class="hlt">Models</span>: FORSA Libraries' <span class="hlt">Experiences</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Patil, Y. M.; Birdie, C.; Bawdekar, N.; Barve, S.; Anilkumar, N.</p> <p>2007-10-01</p> <p>With increases in prices of journals, shrinking library budgets and cuts in subscriptions to journals over the years, there has been a big challenge facing Indian library professionals to cope with the proliferation of electronic information resources. There have been sporadic efforts by different groups of libraries in forming consortia at different levels. The types of consortia identified are generally based on various <span class="hlt">models</span> evolved in India in a variety of forms depending upon the participants' affiliations and funding sources. Indian astronomy library professionals have formed a group called Forum for Resource Sharing in Astronomy and Astrophysics (FORSA), which falls under `Open Consortia', wherein participants are affiliated to different government departments. This is a <span class="hlt">model</span> where professionals willingly come forward and actively support consortia formation; thereby everyone benefits. As such, FORSA has realized four consortia, viz. Nature Online Consortium; Indian Astrophysics Consortium for physics/astronomy journals of Springer/Kluwer; Consortium for Scientific American Online Archive (EBSCO); and Open Consortium for Lecture Notes in Physics (Springer), which are discussed briefly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AIPC..823.1095D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AIPC..823.1095D"><span><span class="hlt">Experiments</span> and Valve <span class="hlt">Modelling</span> in Thermoacoustic Device</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Duthil, P.; Baltean Carlès, D.; Bétrancourt, A.; François, M. X.; Yu, Z. B.; Thermeau, J. P.</p> <p>2006-04-01</p> <p>In a so called heat driven thermoacoustic refrigerator, using either a pulse tube or a lumped boost configuration, heat pumping is induced by Stirling type thermodynamic cycles within the regenerator. The time phase between acoustic pressure and flow rate throughout must then be close to that met for a purely progressive wave. The study presented here relates the experimental characterization of passive elements such as valves, tubes and tanks which are likely to act on this phase relationship when included in the propagation line of the wave resonator. In order to carry out a characterization — from the acoustic point of view — of these elements, systematic measurements of the acoustic field are performed varying various parameters: mean pressure, oscillations frequency, supplied heat power. Acoustic waves are indeed generated by use of a thermoacoustic prime mover driving a pulse tube refrigerator. The experimental results are then compared with the solutions obtained with various one-dimensional linear <span class="hlt">models</span> including non linear correction factors. It turns out that when using a non symmetrical valve, and for large dissipative effects, the measurements disagree with the linear <span class="hlt">modelling</span> and non linear behaviour of this particular element is shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999ApJ...510..795S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999ApJ...510..795S"><span>Hierarchical <span class="hlt">Model</span> for the Evolution of Cloud <span class="hlt">Complexes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez D., Néstor M.; Parravano, Antonio</p> <p>1999-01-01</p> <p>The structure of cloud <span class="hlt">complexes</span> appears to be well described by a tree structure (i.e., a simplified ``stick man'') representation when the image is partitioned into ``clouds.'' In this representation, the parent-child relationships are assigned according to containment. Based on this picture, a hierarchical <span class="hlt">model</span> for the evolution of cloud <span class="hlt">complexes</span>, including star formation, is constructed. The <span class="hlt">model</span> follows the mass evolution of each substructure by computing its mass exchange with its parent and children. The parent-child mass exchange (evaporation or condensation) depends on the radiation density at the interphase. At the end of the ``lineage,'' stars may be born or die, so that there is a nonstationary mass flow in the hierarchical structure. For a variety of parameter sets the system follows the same series of steps to transform diffuse gas into stars, and the regulation of the mass flux in the tree by previously formed stars dominates the evolution of the star formation. For the set of parameters used here as a reference <span class="hlt">model</span>, the system tends to produce initial mass functions (IMFs) that have a maximum at a mass that is too high (~2 Msolar) and the characteristic times for evolution seem too long. We show that these undesired properties can be improved by adjusting the <span class="hlt">model</span> parameters. The <span class="hlt">model</span> requires further physics (e.g., allowing for multiple stellar systems and clump collisions) before a definitive comparison with observations can be made. Instead, the emphasis here is to illustrate some general properties of this kind of <span class="hlt">complex</span> nonlinear <span class="hlt">model</span> for the star formation process. Notwithstanding the simplifications involved, the <span class="hlt">model</span> reveals an essential feature that will likely remain if additional physical processes are included, that is, the detailed behavior of the system is very sensitive to the variations on the initial and external conditions, suggesting that a ``universal'' IMF is very unlikely. When an ensemble of IMFs corresponding to a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890001551','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890001551"><span>Process <span class="hlt">modelling</span> for space station <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rosenberger, Franz; Alexander, J. Iwan D.</p> <p>1988-01-01</p> <p>The work performed during the first year 1 Oct. 1987 to 30 Sept. 1988 involved analyses of crystal growth from the melt and from solution. The particular melt growth technique under investigation is directional solidification by the Bridgman-Stockbarger method. Two types of solution growth systems are also being studied. One involves growth from solution in a closed container, the other concerns growth of protein crystals by the hanging drop method. Following discussions with Dr. R. J. Naumann of the Low Gravity Science Division at MSFC it was decided to tackle the analysis of crystal growth from the melt earlier than originally proposed. Rapid progress was made in this area. Work is on schedule and full calculations were underway for some time. Progress was also made in the formulation of the two solution growth <span class="hlt">models</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18510656','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18510656"><span>Differential equation <span class="hlt">modeling</span> of HIV viral fitness <span class="hlt">experiments</span>: <span class="hlt">model</span> identification, <span class="hlt">model</span> selection, and multimodel inference.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Miao, Hongyu; Dykes, Carrie; Demeter, Lisa M; Wu, Hulin</p> <p>2009-03-01</p> <p>Many biological processes and systems can be described by a set of differential equation (DE) <span class="hlt">models</span>. However, literature in statistical inference for DE <span class="hlt">models</span> is very sparse. We propose statistical estimation, <span class="hlt">model</span> selection, and multimodel averaging methods for HIV viral fitness <span class="hlt">experiments</span> in vitro that can be described by a set of nonlinear ordinary differential equations (ODE). The parameter identifiability of the ODE <span class="hlt">models</span> is also addressed. We apply the proposed methods and techniques to experimental data of viral fitness for HIV-1 mutant 103N. We expect that the proposed <span class="hlt">modeling</span> and inference approaches for the DE <span class="hlt">models</span> can be widely used for a variety of biomedical studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=user+AND+profile&pg=6&id=EJ420361','ERIC'); return false;" href="http://eric.ed.gov/?q=user+AND+profile&pg=6&id=EJ420361"><span>Integration of User Profiles: <span class="hlt">Models</span> and <span class="hlt">Experiments</span> in Information Retrieval.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Myaeng, Sung H.; Korfhage, Robert R.</p> <p>1990-01-01</p> <p>Discussion of the interpretation of user queries in information retrieval highlights theoretical <span class="hlt">models</span> that utilize user characteristics maintained in the form of a user profile. Various query/profile interaction <span class="hlt">models</span> are identified, and an <span class="hlt">experiment</span> is described that tested the relevance of retrieved documents based on various <span class="hlt">models</span>. (29…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23185058','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23185058"><span>Elementary <span class="hlt">models</span> for turbulent diffusion with <span class="hlt">complex</span> physical features: eddy diffusivity, spectrum and intermittency.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Majda, Andrew J; Gershgorin, Boris</p> <p>2013-01-13</p> <p>This paper motivates, develops and reviews elementary <span class="hlt">models</span> for turbulent tracers with a background mean gradient which, despite their simplicity, have <span class="hlt">complex</span> statistical features mimicking crucial aspects of laboratory <span class="hlt">experiments</span> and atmospheric observations. These statistical features include exact formulas for tracer eddy diffusivity which is non-local in space and time, exact formulas and simple numerics for the tracer variance spectrum in a statistical steady state, and the transition to intermittent scalar probability density functions with fat exponential tails as certain variances of the advecting mean velocity are increased while satisfying important physical constraints. The recent use of such simple <span class="hlt">models</span> with <span class="hlt">complex</span> statistics as unambiguous test <span class="hlt">models</span> for central contemporary issues in both climate change science and the real-time filtering of turbulent tracers from sparse noisy observations is highlighted throughout the paper.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1005538','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1005538"><span>Hybrid Structural <span class="hlt">Model</span> of the Complete Human ESCRT-0 <span class="hlt">Complex</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ren, Xuefeng; Kloer, Daniel P.; Kim, Young C.; Ghirlando, Rodolfo; Saidi, Layla F.; Hummer, Gerhard; Hurley, James H.</p> <p>2009-03-31</p> <p>The human Hrs and STAM proteins comprise the ESCRT-0 <span class="hlt">complex</span>, which sorts ubiquitinated cell surface receptors to lysosomes for degradation. Here we report a <span class="hlt">model</span> for the complete ESCRT-0 <span class="hlt">complex</span> based on the crystal structure of the Hrs-STAM core <span class="hlt">complex</span>, previously solved domain structures, hydrodynamic measurements, and Monte Carlo simulations. ESCRT-0 expressed in insect cells has a hydrodynamic radius of R{sub H} = 7.9 nm and is a 1:1 heterodimer. The 2.3 {angstrom} crystal structure of the ESCRT-0 core <span class="hlt">complex</span> reveals two domain-swapped GAT domains and an antiparallel two-stranded coiled-coil, similar to yeast ESCRT-0. ESCRT-0 typifies a class of biomolecular assemblies that combine structured and unstructured elements, and have dynamic and open conformations to ensure versatility in target recognition. Coarse-grained Monte Carlo simulations constrained by experimental R{sub H} values for ESCRT-0 reveal a dynamic ensemble of conformations well suited for diverse functions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.A51C0122R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.A51C0122R"><span>FIELD <span class="hlt">EXPERIMENTS</span> AND <span class="hlt">MODELING</span> AT CDG AIRPORTS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramaroson, R.</p> <p>2009-12-01</p> <p>Richard Ramaroson1,4, Klaus Schaefer2, Stefan Emeis2, Carsten Jahn2, Gregor Schürmann2, Maria Hoffmann2, Mikhael Zatevakhin3, Alexandre Ignatyev3. 1ONERA, Châtillon, France; 4SEAS, Harvard University, Cambridge, USA; 2FZK, Garmisch, Germany; (3)FSUE SPbAEP, St Petersburg, Russia. 2-month field campaigns have been organized at CDG airports in autumn 2004 and summer 2005. Air quality and ground air traffic emissions have been monitored continuously at terminals and taxi-runways, along with meteorological parameters onboard trucks and with a SODAR. This paper analyses the commercial engine emissions characteristics at airports and their effects on gas pollutants and airborne particles coupled to meteorology. LES <span class="hlt">model</span> results for PM dispersion coupled to microphysics in the PBL are compared to measurements. Winds and temperature at the surface and their vertical profiles have been stored with turbulence. SODAR observations show the time-development of the mixing layer depth and turbulent mixing in summer up to 800m. Active low level jets and their regional extent have been observed and analyzed. PM number and mass size distribution, morphology and chemical contents are investigated. Formation of new ultra fine volatile (UFV) particles in the ambient plume downstream of running engines is observed. Soot particles are mostly observed at significant level at high power thrusts at take-off (TO) and on touch-down whereas at lower thrusts at taxi and aprons ultra the UFV PM emissions become higher. Ambient airborne PM1/2.5 is closely correlated to air traffic volume and shows a maximum beside runways. PM number distribution at airports is composed mainly by volatile UF PM abundant at apron. Ambient PM mass in autumn is higher than in summer. The expected differences between TO and taxi emissions are confirmed for NO, NO2, speciated VOC and CO. NO/NO2 emissions are larger at runways due to higher power. Reactive VOC and CO are more produced at low powers during idling at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyA..436..499P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyA..436..499P"><span>Context dependent preferential attachment <span class="hlt">model</span> for <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pandey, Pradumn Kumar; Adhikari, Bibhas</p> <p>2015-10-01</p> <p>In this paper, we propose a growing random <span class="hlt">complex</span> network <span class="hlt">model</span>, which we call context dependent preferential attachment <span class="hlt">model</span> (CDPAM), when the preference of a new node to get attached to old nodes is determined by the local and global property of the old nodes. We consider that local and global properties of a node as the degree and relative average degree of the node respectively. We prove that the degree distribution of <span class="hlt">complex</span> networks generated by CDPAM follow power law with exponent lies in the interval [2,3] and the expected diameter grows logarithmically with the size of new nodes added to the initial small network. Numerical results show that the expected diameter stabilizes when alike weights to the local and global properties are assigned by the new nodes. Computing various measures including clustering coefficient, assortativity, number of triangles, algebraic connectivity, spectral radius, we show that the proposed <span class="hlt">model</span> replicates properties of real networks when alike weights are given to local and global property. Finally, we observe that the BA <span class="hlt">model</span> is a limiting case of CDPAM when new nodes tend to give large weight to the local property compared to the weight given to the global property during link formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/431137','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/431137"><span>Semiotic aspects of control and <span class="hlt">modeling</span> relations in <span class="hlt">complex</span> systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Joslyn, C.</p> <p>1996-08-01</p> <p>A conceptual analysis of the semiotic nature of control is provided with the goal of elucidating its nature in <span class="hlt">complex</span> systems. Control is identified as a canonical form of semiotic relation of a system to its environment. As a form of constraint between a system and its environment, its necessary and sufficient conditions are established, and the stabilities resulting from control are distinguished from other forms of stability. These result from the presence of semantic coding relations, and thus the class of control systems is hypothesized to be equivalent to that of semiotic systems. Control systems are contrasted with <span class="hlt">models</span>, which, while they have the same measurement functions as control systems, do not necessarily require semantic relations because of the lack of the requirement of an interpreter. A hybrid construction of <span class="hlt">models</span> in control systems is detailed. Towards the goal of considering the nature of control in <span class="hlt">complex</span> systems, the possible relations among collections of control systems are considered. Powers arguments on conflict among control systems and the possible nature of control in social systems are reviewed, and reconsidered based on our observations about hierarchical control. Finally, we discuss the necessary semantic functions which must be present in <span class="hlt">complex</span> systems for control in this sense to be present at all.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940025737','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940025737"><span>Process <span class="hlt">modelling</span> for materials preparation <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rosenberger, Franz; Alexander, J. Iwan D.</p> <p>1994-01-01</p> <p>The main goals of the research under this grant consist of the development of mathematical tools and measurement techniques for transport properties necessary for high fidelity <span class="hlt">modelling</span> of crystal growth from the melt and solution. Of the tasks described in detail in the original proposal, two remain to be worked on: development of a spectral code for moving boundary problems, and development of an expedient diffusivity measurement technique for concentrated and supersaturated solutions. We have focused on developing a code to solve for interface shape, heat and species transport during directional solidification. The work involved the computation of heat, mass and momentum transfer during Bridgman-Stockbarger solidification of compound semiconductors. Domain decomposition techniques and preconditioning methods were used in conjunction with Chebyshev spectral methods to accelerate convergence while retaining the high-order spectral accuracy. During the report period we have further improved our experimental setup. These improvements include: temperature control of the measurement cell to 0.1 C between 10 and 60 C; enclosure of the optical measurement path outside the ZYGO interferometer in a metal housing that is temperature controlled to the same temperature setting as the measurement cell; simultaneous dispensing and partial removal of the lower concentration (lighter) solution above the higher concentration (heavier) solution through independently motor-driven syringes; three-fold increase in data resolution by orientation of the interferometer with respect to diffusion direction; and increase of the optical path length in the solution cell to 12 mm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRA..12110481S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRA..12110481S"><span>Laboratory <span class="hlt">modeling</span> of ionospheric heating <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Starodubtsev, M. V.; Nazarov, V. V.; Gushchin, M. E.; Kostrov, A. V.</p> <p>2016-10-01</p> <p>Turbulent plasma processes, such as those which occur in the Earth's ionosphere during ionospheric heating by powerful radio waves, were studied under laboratory conditions, and new physical <span class="hlt">models</span> of small-scale ionospheric turbulence are proposed as a result of these studies. It is shown here that the mechanism of small-scale plasma filamentation can be connected with the thermal self-channeling of Langmuir waves. During this process, Langmuir waves are guided by a plasma channel, which in turn is formed by the guided waves through a thermal plasma nonlinearity. The spectrum of the self-guided Langmuir waves exhibits sidebands whose features are similar to stimulated electromagnetic emission. We present two mechanisms of sideband generation. The first mechanism can be observed during the formation of the plasma channel and is connected with the parametric shift in the frequency of the self-channeling wave. The second mechanism is connected with the scattering of the self-channeling wave on the low-frequency eigenmodes of the plasma irregularity.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18027371','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18027371"><span><span class="hlt">Complexity</span> in <span class="hlt">modeling</span> and understanding protonation states: computational titration of HIV-1-protease-inhibitor <span class="hlt">complexes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tripathi, Ashutosh; Fornabaio, Micaela; Spyrakis, Francesca; Mozzarelli, Andrea; Cozzini, Pietro; Kellogg, Glen E</p> <p>2007-11-01</p> <p>The computational-titration (CT) algorithm based on the 'natural' Hydropathic INTeractions (HINT) force field is described. The HINT software <span class="hlt">model</span> is an empirical, non-Newtonian force field derived from experimentally measured partition coefficients for solvent transfer between octanol and H(2)O (log P(o/w)). The CT algorithm allows the identification, <span class="hlt">modeling</span>, and optimization of multiple protonation states of residues and ligand functional groups at the protein-ligand active site. The importance of taking into account pH and ionization states of residues, which strongly affect the process of ligand binding, for correctly predicting binding free energies is discussed. The application of the CT protocol to a set of six cyclic inhibitors in their <span class="hlt">complexes</span> with HIV-1 protease is presented, and the advance of HINT as a virtual-screening tool is outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3400659','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3400659"><span>Neural Repetition Effects in the Medial Temporal Lobe <span class="hlt">Complex</span> are Modulated by Previous Encoding <span class="hlt">Experience</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Greene, Ciara M.; Soto, David</p> <p>2012-01-01</p> <p>It remains an intriguing question why the medial temporal lobe (MTL) can display either attenuation or enhancement of neural activity following repetition of previously studied items. To isolate the role of encoding <span class="hlt">experience</span> itself, we assessed neural repetition effects in the absence of any ongoing task demand or intentional orientation to retrieve. <span class="hlt">Experiment</span> 1 showed that the hippocampus and surrounding MTL regions displayed neural repetition suppression (RS) upon repetition of past items that were merely attended during an earlier study phase but this was not the case following re-occurrence of items that had been encoded into working memory (WM). In this latter case a trend toward neural repetition enhancement (RE) was observed, though this was highly variable across individuals. Interestingly, participants with a higher degree of neural RE in the MTL <span class="hlt">complex</span> displayed higher memory sensitivity in a later, surprise recognition test. <span class="hlt">Experiment</span> 2 showed that massive exposure at encoding effected a change in the neural architecture supporting incidental repetition effects, with regions of the posterior parietal and ventral-frontal cortex in addition to the hippocampus displaying neural RE, while no neural RS was observed. The nature of encoding <span class="hlt">experience</span> therefore modulates the expression of neural repetition effects in the MTL and the neocortex in the absence of memory goals. PMID:22829892</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3413211','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3413211"><span>The use of workflows in the design and implementation of <span class="hlt">complex</span> <span class="hlt">experiments</span> in macromolecular crystallography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Brockhauser, Sandor; Svensson, Olof; Bowler, Matthew W.; Nanao, Max; Gordon, Elspeth; Leal, Ricardo M. F.; Popov, Alexander; Gerring, Matthew; McCarthy, Andrew A.; Gotz, Andy</p> <p>2012-01-01</p> <p>The automation of beam delivery, sample handling and data analysis, together with increasing photon flux, diminishing focal spot size and the appearance of fast-readout detectors on synchrotron beamlines, have changed the way that many macromolecular crystallography <span class="hlt">experiments</span> are planned and executed. Screening for the best diffracting crystal, or even the best diffracting part of a selected crystal, has been enabled by the development of microfocus beams, precise goniometers and fast-readout detectors that all require rapid feedback from the initial processing of images in order to be effective. All of these advances require the coupling of data feedback to the experimental control system and depend on immediate online data-analysis results during the <span class="hlt">experiment</span>. To facilitate this, a Data Analysis WorkBench (DAWB) for the flexible creation of <span class="hlt">complex</span> automated protocols has been developed. Here, example workflows designed and implemented using DAWB are presented for enhanced multi-step crystal characterizations, <span class="hlt">experiments</span> involving crystal re­orientation with kappa goniometers, crystal-burning <span class="hlt">experiments</span> for empirically determining the radiation sensitivity of a crystal system and the application of mesh scans to find the best location of a crystal to obtain the highest diffraction quality. Beamline users interact with the prepared workflows through a specific brick within the beamline-control GUI MXCuBE. PMID:22868763</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3946009','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3946009"><span>Optimal <span class="hlt">experiment</span> design for <span class="hlt">model</span> selection in biochemical networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background Mathematical <span class="hlt">modeling</span> is often used to formalize hypotheses on how a biochemical network operates by discriminating between competing <span class="hlt">models</span>. Bayesian <span class="hlt">model</span> selection offers a way to determine the amount of evidence that data provides to support one <span class="hlt">model</span> over the other while favoring simple <span class="hlt">models</span>. In practice, the amount of experimental data is often insufficient to make a clear distinction between competing <span class="hlt">models</span>. Often one would like to perform a new <span class="hlt">experiment</span> which would discriminate between competing hypotheses. Results We developed a novel method to perform Optimal <span class="hlt">Experiment</span> Design to predict which <span class="hlt">experiments</span> would most effectively allow <span class="hlt">model</span> selection. A Bayesian approach is applied to infer <span class="hlt">model</span> parameter distributions. These distributions are sampled and used to simulate from multivariate predictive densities. The method is based on a k-Nearest Neighbor estimate of the Jensen Shannon divergence between the multivariate predictive densities of competing <span class="hlt">models</span>. Conclusions We show that the method successfully uses predictive differences to enable <span class="hlt">model</span> selection by applying it to several test cases. Because the design criterion is based on predictive distributions, which can be computed for a wide range of <span class="hlt">model</span> quantities, the approach is very flexible. The method reveals specific combinations of <span class="hlt">experiments</span> which improve discriminability even in cases where data is scarce. The proposed approach can be used in conjunction with existing Bayesian methodologies where (approximate) posteriors have been determined, making use of relations that exist within the inferred posteriors. PMID:24555498</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NHESS..17..305S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NHESS..17..305S"><span>Spatio-temporal <span class="hlt">modelling</span> of lightning climatologies for <span class="hlt">complex</span> terrain</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Simon, Thorsten; Umlauf, Nikolaus; Zeileis, Achim; Mayr, Georg J.; Schulz, Wolfgang; Diendorfer, Gerhard</p> <p>2017-03-01</p> <p>This study develops methods for estimating lightning climatologies on the day-1 km-2 scale for regions with <span class="hlt">complex</span> terrain and applies them to summertime observations (2010-2015) of the lightning location system ALDIS in the Austrian state of Carinthia in the Eastern Alps. Generalized additive <span class="hlt">models</span> (GAMs) are used to <span class="hlt">model</span> both the probability of occurrence and the intensity of lightning. Additive effects are set up for altitude, day of the year (season) and geographical location (longitude/latitude). The performance of the <span class="hlt">models</span> is verified by 6-fold cross-validation. The altitude effect of the occurrence <span class="hlt">model</span> suggests higher probabilities of lightning for locations on higher elevations. The seasonal effect peaks in mid-July. The spatial effect <span class="hlt">models</span> several local features, but there is a pronounced minimum in the north-west and a clear maximum in the eastern part of Carinthia. The estimated effects of the intensity <span class="hlt">model</span> reveal similar features, though they are not equal. The main difference is that the spatial effect varies more strongly than the analogous effect of the occurrence <span class="hlt">model</span>. A major asset of the introduced method is that the resulting climatological information varies smoothly over space, time and altitude. Thus, the climatology is capable of serving as a useful tool in quantitative applications, i.e. risk assessment and weather prediction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20550909','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20550909"><span>Wrapped-around <span class="hlt">models</span> for the lac operon <span class="hlt">complex</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>La Penna, Giovanni; Perico, Angelo</p> <p>2010-06-16</p> <p>The protein-DNA <span class="hlt">complex</span>, involved in the lac operon of enteric bacteria, is paradigmatic in understanding the extent of DNA bending and plasticity due to interactions with protein assemblies acting as DNA regulators. For the lac operon, two classes of structures have been proposed: 1), with the protein tetramer lying away from the DNA loop (wrapped-away <span class="hlt">model</span>); and 2), with the protein tetramer lying inside the DNA loop (wrapped-around <span class="hlt">model</span>). A recently developed electrostatic analytical <span class="hlt">model</span> shows that the size and net charge of the Lac protein tetramer allow the bending of DNA, which is consistent with another wrapped-around <span class="hlt">model</span> from the literature. Coarse-grained <span class="hlt">models</span>, designed based on this observation, are extensively investigated and show three kinds of wrapped-around arrangements of DNA and a lower propensity for wrapped-away configurations. Molecular dynamics simulations of an all-atom <span class="hlt">model</span>, built on the basis of the most tightly collapsed coarse-grained <span class="hlt">model</span>, show that most of the DNA double-helical architecture is maintained in the region between O3 and O1 DNA operators, that the DNA distortion is concentrated in the chain beyond the O1 operator, and that the protein tetramer can adapt the N-terminal domains to the DNA tension.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.A22A..01T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.A22A..01T"><span>How much <span class="hlt">complexity</span> is needed in global <span class="hlt">model</span> organic aerosol simulations?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsigaridis, K.; Daskalakis, N.; Kanakidou, M.</p> <p>2014-12-01</p> <p>The skill in simulating the global atmospheric distribution and fate of organic aerosols (OA) of thirty-one global chemistry/transport and general circulation <span class="hlt">models</span> of various <span class="hlt">complexities</span> will be presented. Significant differences between <span class="hlt">models</span> are identified in the magnitude of primary emissions, secondary OA (SOA) formation, the number of OA species used, the <span class="hlt">complexity</span> of OA parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, aerosol microphysics), and the OA physical, chemical and optical properties. The diversity of the global OA simulation results has increased since earlier AeroCom <span class="hlt">experiments</span>, mainly due to the increasing <span class="hlt">complexity</span> of the SOA parameterization in <span class="hlt">models</span>, and the implementation of new, highly uncertain, OA sources. Diversity of over an order of magnitude exists in the <span class="hlt">modeled</span> vertical distribution of OA concentrations pointing to uncertainties in the parameterization of the semi-volatile character of OA and its temperature dependence, as well as OA long-range transport. Fine aerosol organic carbon (OC) and OA observations from continuous monitoring networks and individual field campaigns have been used for <span class="hlt">model</span> evaluation. Τhe combined <span class="hlt">model</span>/measurements analysis suggests the existence of increased OA levels during summer due to biogenic SOA formation over large areas of the USA that can be of the same order of magnitude as the POA, even at urban locations, and contribute to the observed urban seasonal pattern. The global <span class="hlt">models</span> are able to simulate the high secondary character of OA observed in the atmosphere as a result of SOA formation and of POA aging, although, the amount of OA present in the atmosphere remains largely underestimated. The <span class="hlt">models</span> skill with increasing <span class="hlt">model</span> <span class="hlt">complexity</span> with regard to OC or OA mass concentration will be presented and thoroughly discussed. This work is part of AeroCom phase II.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22199777','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22199777"><span>3D <span class="hlt">model</span> of amphioxus steroid receptor <span class="hlt">complexed</span> with estradiol</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Baker, Michael E.; Chang, David J.</p> <p>2009-08-28</p> <p>The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen-binding to steroid receptors, we constructed a 3D <span class="hlt">model</span> of amphioxus SR <span class="hlt">complexed</span> with estradiol. This 3D <span class="hlt">model</span> indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER{alpha} are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER{alpha} in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D <span class="hlt">model</span> predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid-binding to nuclear receptors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhyA..388.2435Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhyA..388.2435Y"><span>A two-level <span class="hlt">complex</span> network <span class="hlt">model</span> and its application</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Jianmei; Wang, Wenjie; Chen, Guanrong</p> <p>2009-06-01</p> <p>This paper investigates the competitive relationship and rivalry of industrial markets, using Chinese household electrical appliance firms as a platform for the study. The common <span class="hlt">complex</span> network <span class="hlt">models</span> belong to one-level networks in layered classification, while this paper formulates and evaluates a new two-level network <span class="hlt">model</span>, in which the first level is the whole unweighted-undirected network useful for macro-analyzing the industrial market structure while the second level is a local weighted-directed network capable of micro-analyzing the inter-firm rivalry in the market. It is believed that the relationship is determined by objective factors whereas the action is rather subjective, and the idea in this paper lies in that the objective relationship and the subjective action subjected to this relationship are being simultaneously considered but at deferent levels of the <span class="hlt">model</span> which may be applicable to many real applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=power&pg=4&id=EJ1104733','ERIC'); return false;" href="http://eric.ed.gov/?q=power&pg=4&id=EJ1104733"><span>A Community Mentoring <span class="hlt">Model</span> for STEM Undergraduate Research <span class="hlt">Experiences</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kobulnicky, Henry A.; Dale, Daniel A.</p> <p>2016-01-01</p> <p>This article describes a community mentoring <span class="hlt">model</span> for UREs that avoids some of the common pitfalls of the traditional paradigm while harnessing the power of learning communities to provide young scholars a stimulating collaborative STEM research <span class="hlt">experience</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/992299','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/992299"><span>Underwater Blast <span class="hlt">Experiments</span> and <span class="hlt">Modeling</span> for Shock Mitigation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Glascoe, L; McMichael, L; Vandersall, K; Margraf, J</p> <p>2010-03-07</p> <p>A simple but novel mitigation concept to enforce standoff distance and reduce shock loading on a vertical, partially-submerged structure is evaluated using scaled aquarium <span class="hlt">experiments</span> and numerical <span class="hlt">modeling</span>. Scaled, water tamped explosive <span class="hlt">experiments</span> were performed using three gallon aquariums. The effectiveness of different mitigation configurations, including air-filled media and an air gap, is assessed relative to an unmitigated detonation using the same charge weight and standoff distance. <span class="hlt">Experiments</span> using an air-filled media mitigation concept were found to effectively dampen the explosive response of the aluminum plate and reduce the final displacement at plate center by approximately half. The finite element <span class="hlt">model</span> used for the initial experimental design compares very well to the experimental DIC results both spatially and temporally. Details of the <span class="hlt">experiment</span> and finite element aquarium <span class="hlt">models</span> are described including the boundary conditions, Eulerian and Lagrangian techniques, detonation <span class="hlt">models</span>, experimental design and test diagnostics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820021920','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820021920"><span>Applying <span class="hlt">modeling</span> Results in designing a global tropospheric <span class="hlt">experiment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1982-01-01</p> <p>A set of field <span class="hlt">experiments</span> and advanced <span class="hlt">modeling</span> studies which provide a strategy for a program of global tropospheric <span class="hlt">experiments</span> was identified. An expanded effort to develop space applications for trospheric air quality monitoring and studies was recommended. The tropospheric ozone, carbon, nitrogen, and sulfur cycles are addressed. Stratospheric-tropospheric exchange is discussed. Fast photochemical processes in the free troposphere are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21325793','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21325793"><span>Characterizing and <span class="hlt">Modeling</span> the Noise and <span class="hlt">Complex</span> Impedance of Feedhorn-Coupled TES Polarimeters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Appel, J. W.; Beall, J. A.; Essinger-Hileman, T.; Parker, L. P.; Staggs, S. T.; Visnjic, C.; Zhao, Y.; Austermann, J. E.; Halverson, N. W.; Henning, J. W.; Simon, S. M.; Becker, D.; Britton, J.; Cho, H. M.; Hilton, G. C.; Irwin, K. D.; Niemack, M. D.; Yoon, K. W.; Benson, B. A.; Bleem, L. E.</p> <p>2009-12-16</p> <p>We present results from <span class="hlt">modeling</span> the electrothermal performance of feedhorn-coupled transition edge sensor (TES) polarimeters under development for use in cosmic microwave background (CMB) polarization <span class="hlt">experiments</span>. Each polarimeter couples radiation from a corrugated feedhorn through a planar orthomode transducer, which transmits power from orthogonal polarization modes to two TES bolometers. We <span class="hlt">model</span> our TES with two- and three-block thermal architectures. We fit the <span class="hlt">complex</span> impedance data at multiple points in the TES transition. From the fits, we predict the noise spectra. We present comparisons of these predictions to the data for two TESes on a prototype polarimeter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1130460','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1130460"><span><span class="hlt">Modeling</span> and Algorithmic Approaches to Constitutively-<span class="hlt">Complex</span>, Micro-structured Fluids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Forest, Mark Gregory</p> <p>2014-05-06</p> <p>The team for this Project made significant progress on <span class="hlt">modeling</span> and algorithmic approaches to hydrodynamics of fluids with <span class="hlt">complex</span> microstructure. Our advances are broken down into <span class="hlt">modeling</span> and algorithmic approaches. In <span class="hlt">experiments</span> a driven magnetic bead in a <span class="hlt">complex</span> fluid accelerates out of the Stokes regime and settles into another apparent linear response regime. The <span class="hlt">modeling</span> explains the take-off as a deformation of entanglements, and the longtime behavior is a nonlinear, far-from-equilibrium property. Furthermore, the <span class="hlt">model</span> has predictive value, as we can tune microstructural properties relative to the magnetic force applied to the bead to exhibit all possible behaviors. Wave-theoretic probes of <span class="hlt">complex</span> fluids have been extended in two significant directions, to small volumes and the nonlinear regime. Heterogeneous stress and strain features that lie beyond experimental capability were studied. It was shown that nonlinear penetration of boundary stress in confined viscoelastic fluids is not monotone, indicating the possibility of interlacing layers of linear and nonlinear behavior, and thus layers of variable viscosity. <span class="hlt">Models</span>, algorithms, and codes were developed and simulations performed leading to phase diagrams of nanorod dispersion hydrodynamics in parallel shear cells and confined cavities representative of film and membrane processing conditions. Hydrodynamic codes for polymeric fluids are extended to include coupling between microscopic and macroscopic <span class="hlt">models</span>, and to the strongly nonlinear regime.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25147853','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25147853"><span>A novel prediction method about single components of analog circuits based on <span class="hlt">complex</span> field <span class="hlt">modeling</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Jingyu; Tian, Shulin; Yang, Chenglin</p> <p>2014-01-01</p> <p>Few researches pay attention to prediction about analog circuits. The few methods lack the correlation with circuit analysis during extracting and calculating features so that FI (fault indicator) calculation often lack rationality, thus affecting prognostic performance. To solve the above problem, this paper proposes a novel prediction method about single components of analog circuits based on <span class="hlt">complex</span> field <span class="hlt">modeling</span>. Aiming at the feature that faults of single components hold the largest number in analog circuits, the method starts with circuit structure, analyzes transfer function of circuits, and implements <span class="hlt">complex</span> field <span class="hlt">modeling</span>. Then, by an established parameter scanning <span class="hlt">model</span> related to <span class="hlt">complex</span> field, it analyzes the relationship between parameter variation and degeneration of single components in the <span class="hlt">model</span> in order to obtain a more reasonable FI feature set via calculation. According to the obtained FI feature set, it establishes a novel <span class="hlt">model</span> about degeneration trend of analog circuits' single components. At last, it uses particle filter (PF) to update parameters for the <span class="hlt">model</span> and predicts remaining useful performance (RUP) of analog circuits' single components. Since calculation about the FI feature set is more reasonable, accuracy of prediction is improved to some extent. Finally, the foregoing conclusions are verified by <span class="hlt">experiments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25352538','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25352538"><span><span class="hlt">Experiences</span> of parenting a child with medical <span class="hlt">complexity</span> in need of acute hospital care.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hagvall, Monica; Ehnfors, Margareta; Anderzén-Carlsson, Agneta</p> <p>2016-03-01</p> <p>Parents of children with medical <span class="hlt">complexity</span> have described being responsible for providing advanced care for the child. When the child is acutely ill, they must rely on the health-care services during short or long periods of hospitalization. The purpose of this study was to describe parental <span class="hlt">experiences</span> of caring for their child with medical <span class="hlt">complexity</span> during hospitalization for acute deterioration, specifically focussing on parental needs and their <span class="hlt">experiences</span> of the attitudes of staff. Data were gathered through individual interviews and analyzed using qualitative content analysis. The care period can be interpreted as a balancing act between acting as a caregiver and being in need of care. The parents needed skilled staff who could relieve them of medical responsibility, but they wanted to be involved in the care and in the decisions taken. They needed support, including relief, in order to meet their own needs and to be able to take care of their children. It was important that the child was treated with respect in order for the parent to trust the staff. An approach where staff view parents and children as a single unit, as recipients of care, would probably make the situation easier for these parents and children.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JMoSt1088...56K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JMoSt1088...56K"><span>The first naphthosemiquinone <span class="hlt">complex</span> of K+ with vitamin K3 analog: <span class="hlt">Experiment</span> and density functional theory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kathawate, Laxmi; Gejji, Shridhar P.; Yeole, Sachin D.; Verma, Prakash L.; Puranik, Vedavati G.; Salunke-Gawali, Sunita</p> <p>2015-05-01</p> <p>Synthesis and characterization of potassium <span class="hlt">complex</span> of 2-hydroxy-3-methyl-1,4-naphthoquinone (phthiocol), the vitamin K3 analog, has been carried out using FT-IR, UV-Vis, 1H and 13C NMR, EPR, cyclic voltammetry and single crystal X-ray diffraction <span class="hlt">experiments</span> combined with the density functional theory. It has been observed that naphthosemiquinone binds to two K+ ions extending the polymeric chain through bridging oxygens O(2) and O(3). The crystal network possesses hydrogen bonding interactions from coordinated water molecules showing water channels along the c-axis. 13C NMR spectra revealed that the <span class="hlt">complexation</span> of phthiocol with potassium ion engenders deshielding of C(2) signals, which appear at δ = ∼14.6 ppm whereas those of C(3) exhibit up-field signals near δ ∼ 6.9 ppm. These inferences are supported by the M06-2x based density functional theory. Electrochemical <span class="hlt">experiments</span> further suggest that reduction of naphthosemiquinone results in only a cathodic peak from catechol. A triplet state arising from interactions between neighboring phthiocol anion lead to a half field signal at g = 4.1 in the polycrystalline X-band EPR spectra at 133 K.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AIPC.1145..771C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AIPC.1145..771C"><span>Granular Medium Impacted by a Projectile: <span class="hlt">Experiment</span> and <span class="hlt">Model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crassous, J.; Valance, A.</p> <p>2009-06-01</p> <p>We present an <span class="hlt">experiment</span> and a simple <span class="hlt">model</span> of a granular projectile on a granular medium. <span class="hlt">Experiment</span> consists in impacting an half space of PVC beads with a single bead. Numerous beads are then ejected around the impact point. The loci of ejection and velocities of the ejecta were measured. The experimental data were compared with the predictions of a simple discrete <span class="hlt">model</span>. In this <span class="hlt">model</span>, the energy is transferred from grain to grain on a frozen disordered medium following the law of binary collisions. This theoretical description is in remarkable agreement with the experimental observations. Besides, the present <span class="hlt">model</span> provides a clear picture of the mechanism of energy propagation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11...53G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11...53G"><span>Engineering teacher training <span class="hlt">models</span> and <span class="hlt">experiences</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>González-Tirados, R. M.</p> <p>2009-04-01</p> <p> Education Area, we renewed the programme, content and methodology, teaching the course under the name of "Initial Teacher Training Course within the framework of the European Higher Education Area". Continuous Training means learning throughout one's life as an Engineering teacher. They are actions designed to update and improve teaching staff, and are systematically offered on the current issues of: Teaching Strategies, training for research, training for personal development, classroom innovations, etc. They are activities aimed at conceptual change, changing the way of teaching and bringing teaching staff up-to-date. At the same time, the Institution is at the disposal of all teaching staff as a meeting point to discuss issues in common, attend conferences, department meetings, etc. In this Congress we present a justification of both training <span class="hlt">models</span> and their design together with some results obtained on: training needs, participation, how it is developing and to what extent students are profiting from it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008PhyA..387.5279G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008PhyA..387.5279G"><span>A computational <span class="hlt">model</span> for cancer growth by using <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Galvão, Viviane; Miranda, José G. V.</p> <p>2008-09-01</p> <p>In this work we propose a computational <span class="hlt">model</span> to investigate the proliferation of cancerous cell by using <span class="hlt">complex</span> networks. In our <span class="hlt">model</span> the network represents the structure of available space in the cancer propagation. The computational scheme considers a cancerous cell randomly included in the <span class="hlt">complex</span> network. When the system evolves the cells can assume three states: proliferative, non-proliferative, and necrotic. Our results were compared with experimental data obtained from three human lung carcinoma cell lines. The computational simulations show that the cancerous cells have a Gompertzian growth. Also, our <span class="hlt">model</span> simulates the formation of necrosis, increase of density, and resources diffusion to regions of lower nutrient concentration. We obtain that the cancer growth is very similar in random and small-world networks. On the other hand, the topological structure of the small-world network is more affected. The scale-free network has the largest rates of cancer growth due to hub formation. Finally, our results indicate that for different average degrees the rate of cancer growth is related to the available space in the network.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NJPh...17i3003C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NJPh...17i3003C"><span>Multiagent <span class="hlt">model</span> and mean field theory of <span class="hlt">complex</span> auction dynamics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Qinghua; Huang, Zi-Gang; Wang, Yougui; Lai, Ying-Cheng</p> <p>2015-09-01</p> <p>Recent years have witnessed a growing interest in analyzing a variety of socio-economic phenomena using methods from statistical and nonlinear physics. We study a class of <span class="hlt">complex</span> systems arising from economics, the lowest unique bid auction (LUBA) systems, which is a recently emerged class of online auction game systems. Through analyzing large, empirical data sets of LUBA, we identify a general feature of the bid price distribution: an inverted J-shaped function with exponential decay in the large bid price region. To account for the distribution, we propose a multi-agent <span class="hlt">model</span> in which each agent bids stochastically in the field of winner’s attractiveness, and develop a theoretical framework to obtain analytic solutions of the <span class="hlt">model</span> based on mean field analysis. The theory produces bid-price distributions that are in excellent agreement with those from the real data. Our <span class="hlt">model</span> and theory capture the essential features of human behaviors in the competitive environment as exemplified by LUBA, and may provide significant quantitative insights into <span class="hlt">complex</span> socio-economic phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JCoPh.231...82P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JCoPh.231...82P"><span>Preconditioning the bidomain <span class="hlt">model</span> with almost linear <span class="hlt">complexity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pierre, Charles</p> <p>2012-01-01</p> <p>The bidomain <span class="hlt">model</span> is widely used in electro-cardiology to simulate spreading of excitation in the myocardium and electrocardiograms. It consists of a system of two parabolic reaction diffusion equations coupled with an ODE system. Its discretisation displays an ill-conditioned system matrix to be inverted at each time step: simulations based on the bidomain <span class="hlt">model</span> therefore are associated with high computational costs. In this paper we propose a preconditioning for the bidomain <span class="hlt">model</span> either for an isolated heart or in an extended framework including a coupling with the surrounding tissues (the torso). The preconditioning is based on a formulation of the discrete problem that is shown to be symmetric positive semi-definite. A block LU decomposition of the system together with a heuristic approximation (referred to as the monodomain approximation) are the key ingredients for the preconditioning definition. Numerical results are provided for two test cases: a 2D test case on a realistic slice of the thorax based on a segmented heart medical image geometry, a 3D test case involving a small cubic slab of tissue with orthotropic anisotropy. The analysis of the resulting computational cost (both in terms of CPU time and of iteration number) shows an almost linear <span class="hlt">complexity</span> with the problem size, i.e. of type nlog α( n) (for some constant α) which is optimal <span class="hlt">complexity</span> for such problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5613607','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5613607"><span>NMR-derived <span class="hlt">model</span> for a peptide-antibody <span class="hlt">complex</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zilber, B.; Scherf, T.; Anglister, J. ); Levitt, M. )</p> <p>1990-10-01</p> <p>The TE34 monoclonal antibody against cholera toxin peptide 3 (CTP3; VEVPGSQHIDSQKKA) was sequenced and investigated by two-dimensional transferred NOE difference spectroscopy and molecular <span class="hlt">modeling</span>. The V{sub H} sequence of TE34, which does not bind cholera toxin, shares remarkable homology to that of TE32 and TE33, which are both anti-CTP3 antibodies that bind the toxin. However, due to a shortened heavy chain CDR3, TE34 assumes a radically different combining site structure. The assignment of the combining site interactions to specific peptide residues was completed by use of AcIDSQRKA, a truncated peptide analogue in which lysine-13 was substituted by arginine, specific deuteration of individual polypeptide chains of the antibody, and a computer <span class="hlt">model</span> for the Fv fragment of TE34. NMR-derived distance restraints were then applied to the calculated <span class="hlt">model</span> of the Fv to generate a three-dimensional structure of the TE34/CTP3 <span class="hlt">complex</span>. The combining site was found to be a very hydrophobic cavity composed of seven aromatic residues. Charged residues are found in the periphery of the combining site. The peptide residues HIDSQKKA form a {beta}-turn inside the combining site. The contact area between the peptide and the TE34 antibody is 388 {Angstrom}{sup 2}, about half of the contact area observed in protein-antibody <span class="hlt">complexes</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25681884','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25681884"><span>Bloch-Redfield equations for <span class="hlt">modeling</span> light-harvesting <span class="hlt">complexes</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jeske, Jan; Ing, David J; Plenio, Martin B; Huelga, Susana F; Cole, Jared H</p> <p>2015-02-14</p> <p>We challenge the misconception that Bloch-Redfield equations are a less powerful tool than phenomenological Lindblad equations for <span class="hlt">modeling</span> exciton transport in photosynthetic <span class="hlt">complexes</span>. This view predominantly originates from an indiscriminate use of the secular approximation. We provide a detailed description of how to <span class="hlt">model</span> both coherent oscillations and several types of noise, giving explicit examples. All issues with non-positivity are overcome by a consistent straightforward physical noise <span class="hlt">model</span>. Herein also lies the strength of the Bloch-Redfield approach because it facilitates the analysis of noise-effects by linking them back to physical parameters of the noise environment. This includes temporal and spatial correlations and the strength and type of interaction between the noise and the system of interest. Finally, we analyze a prototypical dimer system as well as a 7-site Fenna-Matthews-Olson <span class="hlt">complex</span> in regards to spatial correlation length of the noise, noise strength, temperature, and their connection to the transfer time and transfer probability.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....51.3695H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....51.3695H"><span>A revised <span class="hlt">model</span> for microbially induced calcite precipitation: Improvements and new insights based on recent <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hommel, Johannes; Lauchnor, Ellen; Phillips, Adrienne; Gerlach, Robin; Cunningham, Alfred B.; Helmig, Rainer; Ebigbo, Anozie; Class, Holger</p> <p>2015-05-01</p> <p>The <span class="hlt">model</span> for microbially induced calcite precipitation (MICP) published by Ebigbo et al. (2012) has been improved based on new insights obtained from <span class="hlt">experiments</span> and <span class="hlt">model</span> calibration. The challenge in constructing a predictive <span class="hlt">model</span> for permeability reduction in the underground with MICP is the quantification of the <span class="hlt">complex</span> interaction between flow, transport, biofilm growth, and reaction kinetics. New data from Lauchnor et al. (2015) on whole-cell ureolysis kinetics from batch <span class="hlt">experiments</span> were incorporated into the <span class="hlt">model</span>, which has allowed for a more precise quantification of the relevant parameters as well as a simplification of the reaction kinetics in the equations of the <span class="hlt">model</span>. Further, the <span class="hlt">model</span> has been calibrated objectively by inverse <span class="hlt">modeling</span> using quasi-1D column <span class="hlt">experiments</span> and a radial flow <span class="hlt">experiment</span>. From the postprocessing of the inverse <span class="hlt">modeling</span>, a comprehensive sensitivity analysis has been performed with focus on the <span class="hlt">model</span> input parameters that were fitted in the course of the <span class="hlt">model</span> calibration. It reveals that calcite precipitation and concentrations of NH4+ and Ca2+ are particularly sensitive to parameters associated with the ureolysis rate and the attachment behavior of biomass. Based on the determined sensitivities and the ranges of values for the estimated parameters in the inversion, it is possible to identify focal areas where further research can have a high impact toward improving the understanding and engineering of MICP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ESD.....7..397N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ESD.....7..397N"><span>An ice sheet <span class="hlt">model</span> of reduced <span class="hlt">complexity</span> for paleoclimate studies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neff, Basil; Born, Andreas; Stocker, Thomas F.</p> <p>2016-04-01</p> <p>IceBern2D is a vertically integrated ice sheet <span class="hlt">model</span> to investigate the ice distribution on long timescales under different climatic conditions. It is forced by simulated fields of surface temperature and precipitation of the Last Glacial Maximum and present-day climate from a comprehensive climate <span class="hlt">model</span>. This constant forcing is adjusted to changes in ice elevation. Due to its reduced <span class="hlt">complexity</span> and computational efficiency, the <span class="hlt">model</span> is well suited for extensive sensitivity studies and ensemble simulations on extensive temporal and spatial scales. It shows good quantitative agreement with standardized benchmarks on an artificial domain (EISMINT). Present-day and Last Glacial Maximum ice distributions in the Northern Hemisphere are also simulated with good agreement. Glacial ice volume in Eurasia is underestimated due to the lack of ice shelves in our <span class="hlt">model</span>. The efficiency of the <span class="hlt">model</span> is utilized by running an ensemble of 400 simulations with perturbed <span class="hlt">model</span> parameters and two different estimates of the climate at the Last Glacial Maximum. The sensitivity to the imposed climate boundary conditions and the positive degree-day factor β, i.e., the surface mass balance, outweighs the influence of parameters that disturb the flow of ice. This justifies the use of simplified dynamics as a means to achieve computational efficiency for simulations that cover several glacial cycles. Hysteresis simulations over 5 million years illustrate the stability of the simulated ice sheets to variations in surface air temperature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23778160','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23778160"><span>When do evolutionary food web <span class="hlt">models</span> generate <span class="hlt">complex</span> networks?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Allhoff, Korinna T; Drossel, Barbara</p> <p>2013-10-07</p> <p>Evolutionary foodweb <span class="hlt">models</span> are used to build food webs by the repeated addition of new species. Population dynamics leads to the extinction or establishment of a newly added species, and possibly to the extinction of other species. The food web structure that emerges after some time is a highly nontrivial result of the evolutionary and dynamical rules. We investigate the evolutionary food web <span class="hlt">model</span> introduced by Loeuille and Loreau (2005), which characterizes species by their body mass as the only evolving trait. Our goal is to find the reasons behind the <span class="hlt">model</span>'s remarkable robustness and its capability to generate various and stable networks. In contrast to other evolutionary food web <span class="hlt">models</span>, this <span class="hlt">model</span> requires neither adaptive foraging nor allometric scaling of metabolic rates with body mass in order to produce <span class="hlt">complex</span> networks that do not eventually collapse to trivial structures. Our study shows that this is essentially due to the fact that the difference in niche value between predator and prey as well as the feeding range are constrained so that they remain within narrow limits under evolution. Furthermore, competition between similar species is sufficiently strong, so that a trophic level can accommodate several species. We discuss the implications of these findings and argue that the conditions that stabilize other evolutionary food web <span class="hlt">models</span> have similar effects because they also prevent the occurrence of extreme specialists or extreme generalists that have in general a higher fitness than species with a moderate niche width.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.2592H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.2592H"><span>Process Consistency in <span class="hlt">Models</span>: the Importance of System Signatures, Expert Knowledge and Process <span class="hlt">Complexity</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hrachowitz, Markus; Fovet, Ophelie; Ruiz, Laurent; Gascuel-Odoux, Chantal; Savenije, Hubert</p> <p>2014-05-01</p> <p>Hydrological <span class="hlt">models</span> are frequently characterized by what is often considered to be adequate calibration performances. In many cases, however, these <span class="hlt">models</span> <span class="hlt">experience</span> a substantial uncertainty and performance decrease in validation periods, thus resulting in poor predictive power. Besides the likely presence of data errors, this observation can point towards wrong or insufficient representations of the underlying processes and their heterogeneity. In other words, right results are generated for the wrong reasons. Thus ways are sought to increase <span class="hlt">model</span> consistency and to thereby satisfy the contrasting priorities of the need a) to increase <span class="hlt">model</span> <span class="hlt">complexity</span> and b) to limit <span class="hlt">model</span> equifinality. In this study a stepwise <span class="hlt">model</span> development approach is chosen to test the value of an exhaustive and systematic combined use of hydrological signatures, expert knowledge and readily available, yet anecdotal and rarely exploited, hydrological information for increasing <span class="hlt">model</span> consistency towards generating the right answer for the right reasons. A simple 3-box, 7 parameter, conceptual HBV-type <span class="hlt">model</span>, constrained by 4 calibration objective functions was able to adequately reproduce the hydrograph with comparatively high values for the 4 objective functions in the 5-year calibration period. However, closer inspection of the results showed a dramatic decrease of <span class="hlt">model</span> performance in the 5-year validation period. In addition, assessing the <span class="hlt">model</span>'s skill to reproduce a range of 20 hydrological signatures including, amongst others, the flow duration curve, the autocorrelation function and the rising limb density, showed that it could not adequately reproduce the vast majority of these signatures, indicating a lack of <span class="hlt">model</span> consistency. Subsequently <span class="hlt">model</span> <span class="hlt">complexity</span> was increased in a stepwise way to allow for more process heterogeneity. To limit <span class="hlt">model</span> equifinality, increase in <span class="hlt">complexity</span> was counter-balanced by a stepwise application of "realism constraints", inferred from expert</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5020081','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5020081"><span><span class="hlt">Model</span> <span class="hlt">Complexity</span> in Diffusion <span class="hlt">Modeling</span>: Benefits of Making the <span class="hlt">Model</span> More Parsimonious</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lerche, Veronika; Voss, Andreas</p> <p>2016-01-01</p> <p>The diffusion <span class="hlt">model</span> (Ratcliff, 1978) takes into account the reaction time distributions of both correct and erroneous responses from binary decision tasks. This high degree of information usage allows the estimation of different parameters mapping cognitive components such as speed of information accumulation or decision bias. For three of the four main parameters (drift rate, starting point, and non-decision time) trial-to-trial variability is allowed. We investigated the influence of these variability parameters both drawing on simulation studies and on data from an empirical test-retest study using different optimization criteria and different trial numbers. Our results suggest that less <span class="hlt">complex</span> <span class="hlt">models</span> (fixing intertrial variabilities of the drift rate and the starting point at zero) can improve the estimation of the psychologically most interesting parameters (drift rate, threshold separation, starting point, and non-decision time). PMID:27679585</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20050182784&hterms=dispersing+agent&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddispersing%2Bagent','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20050182784&hterms=dispersing+agent&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Ddispersing%2Bagent"><span><span class="hlt">Modeling</span> and Visualizing Flow of Chemical Agents Across <span class="hlt">Complex</span> Terrain</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kao, David; Kramer, Marc; Chaderjian, Neal</p> <p>2005-01-01</p> <p>Release of chemical agents across <span class="hlt">complex</span> terrain presents a real threat to homeland security. <span class="hlt">Modeling</span> and visualization tools are being developed that capture flow fluid terrain interaction as well as point dispersal downstream flow paths. These analytic tools when coupled with UAV atmospheric observations provide predictive capabilities to allow for rapid emergency response as well as developing a comprehensive preemptive counter-threat evacuation plan. The visualization tools involve high-end computing and massive parallel processing combined with texture mapping. We demonstrate our approach across a mountainous portion of North California under two contrasting meteorological conditions. Animations depicting flow over this geographical location provide immediate assistance in decision support and crisis management.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.5211N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5211N"><span>The Eemian climate simulated by two <span class="hlt">models</span> of different <span class="hlt">complexities</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nikolova, Irina; Yin, Qiuzhen; Berger, Andre; Singh, Umesh; Karami, Pasha</p> <p>2013-04-01</p> <p>The Eemian period, also known as MIS-5, experienced warmer than today climate, reduction in ice sheets and important sea-level rise. These interesting features have made the Eemian appropriate to evaluate climate <span class="hlt">models</span> when forced with astronomical and greenhouse gas forcings different from today. In this work, we present the simulated Eemian climate by two climate <span class="hlt">models</span> of different <span class="hlt">complexities</span>, LOVECLIM (LLN Earth system <span class="hlt">model</span> of intermediate <span class="hlt">complexity</span>) and CCSM3 (NCAR atmosphere-ocean general circulation <span class="hlt">model</span>). Feedbacks from sea ice, vegetation, monsoon and ENSO phenomena are discussed to explain the regional similarities/dissimilarities in both <span class="hlt">models</span> with respect to the pre-industrial (PI) climate. Significant warming (cooling) over almost all the continents during boreal summer (winter) leads to a largely increased (reduced) seasonal contrast in the northern (southern) hemisphere, mainly due to the much higher (lower) insolation received by the whole Earth in boreal summer (winter). The arctic is warmer than at PI through the whole year, resulting from its much higher summer insolation and its remnant effect in the following fall-winter through the interactions between atmosphere, ocean and sea ice. Regional discrepancies exist in the sea-ice formation zones between the two <span class="hlt">models</span>. Excessive sea-ice formation in CCSM3 results in intense regional cooling. In both <span class="hlt">models</span> intensified African monsoon and vegetation feedback are responsible for the cooling during summer in North Africa and on the Arabian Peninsula. Over India precipitation maximum is found further west, while in Africa the precipitation maximum migrates further north. Trees and grassland expand north in Sahel/Sahara, trees being more abundant in the results from LOVECLIM than from CCSM3. A mix of forest and grassland occupies continents and expand deep in the high northern latitudes in line with proxy records. Desert areas reduce significantly in Northern Hemisphere, but increase in North</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011ISPAr3816W.191A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011ISPAr3816W.191A"><span>a Range Based Method for <span class="hlt">Complex</span> Facade <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adami, A.; Fregonese, L.; Taffurelli, L.</p> <p>2011-09-01</p> <p>3d <span class="hlt">modelling</span> of Architectural Heritage does not follow a very well-defined way, but it goes through different algorithms and digital form according to the shape <span class="hlt">complexity</span> of the object, to the main goal of the representation and to the starting data. Even if the process starts from the same data, such as a pointcloud acquired by laser scanner, there are different possibilities to realize a digital <span class="hlt">model</span>. In particular we can choose between two different attitudes: the mesh and the solid <span class="hlt">model</span>. In the first case the <span class="hlt">complexity</span> of architecture is represented by a dense net of triangular surfaces which approximates the real surface of the object. In the other -opposite- case the 3d digital <span class="hlt">model</span> can be realized by the use of simple geometrical shapes, by the use of sweeping algorithm and the Boolean operations. Obviously these two <span class="hlt">models</span> are not the same and each one is characterized by some peculiarities concerning the way of <span class="hlt">modelling</span> (the choice of a particular triangulation algorithm or the quasi-automatic <span class="hlt">modelling</span> by known shapes) and the final results (a more detailed and <span class="hlt">complex</span> mesh versus an approximate and more simple solid <span class="hlt">model</span>). Usually the expected final representation and the possibility of publishing lead to one way or the other. In this paper we want to suggest a semiautomatic process to build 3d digital <span class="hlt">models</span> of the facades of <span class="hlt">complex</span> architecture to be used for example in city <span class="hlt">models</span> or in other large scale representations. This way of <span class="hlt">modelling</span> guarantees also to obtain small files to be published on the web or to be transmitted. The <span class="hlt">modelling</span> procedure starts from laser scanner data which can be processed in the well known way. Usually more than one scan is necessary to describe a <span class="hlt">complex</span> architecture and to avoid some shadows on the facades. These have to be registered in a single reference system by the use of targets which are surveyed by topography and then to be filtered in order to obtain a well controlled and homogeneous point cloud of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2000APS..DFD.JL006Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2000APS..DFD.JL006Z"><span><span class="hlt">Complex</span> Wall Boundary Conditions for <span class="hlt">Modeling</span> Combustion in Catalytic Channels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Huayang; Jackson, Gregory</p> <p>2000-11-01</p> <p>Monolith catalytic reactors for exothermic oxidation are being used in automobile exhaust clean-up and ultra-low emissions combustion systems. The reactors present a unique coupling between mass, heat, and momentum transport in a channel flow configuration. The use of porous catalytic coatings along the channel wall presents a <span class="hlt">complex</span> boundary condition when <span class="hlt">modeled</span> with the two-dimensional channel flow. This current work presents a 2-D transient <span class="hlt">model</span> for predicting the performance of catalytic combustion systems for methane oxidation on Pd catalysts. The <span class="hlt">model</span> solves the 2-D compressible transport equations for momentum, species, and energy, which are solved with a porous washcoat <span class="hlt">model</span> for the wall boundary conditions. A time-splitting algorithm is used to separate the stiff chemical reactions from the convective/diffusive equations for the channel flow. A detailed surface chemistry mechanism is incorporated for the catalytic wall <span class="hlt">model</span> and is used to predict transient ignition and steady-state conversion of CH4-air flows in the catalytic reactor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/413548','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/413548"><span>3-D physical <span class="hlt">modeling</span> of a <span class="hlt">complex</span> salt canopy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wiley, R.W.; Sekharan, K.K.</p> <p>1996-12-31</p> <p>Recent drilling has confirmed both significant reservoir potential and the presence of commercial hydrocarbons below salt structures in the Gulf of Mexico. Obtaining definitive seismic images with standard processing schemes beneath these salt structures is very difficult if not impossible. Because of the complicated seismic behavior of these structures, full volume 3-D prestack depth migration is required. Unfortunately, carrying out the multitude of calculations needed to create a proper image requires the largest and fastest supercomputers and rather <span class="hlt">complex</span> numerical algorithms. Furthermore, developing and testing the imaging algorithms is quite involved and requires appropriate test data sets. To better understand the problems and issues of subsalt imaging, Marathon Oil Company and Louisiana Land and Exploration Company contracted with the University of Houston`s Allied Geophysical Laboratories (AGL) to construct a salt canopy physical <span class="hlt">model</span>. The <span class="hlt">model</span> is patterned after the SEG/EAEG Salt <span class="hlt">Model</span> and is made from synthetic materials. It is a full three-dimensional <span class="hlt">model</span> with an irregularly shaped, lateral salt structure embedded in five distinct sedimentary layers. The <span class="hlt">model</span> was used to acquire a multi-offset 3-D marine-style survey. These data are being used to address problems of subsalt imaging. In addition to standard processing techniques, the authors investigate algorithms for multiple removal and prestack depth migration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMEP42B..07N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMEP42B..07N"><span>A subsurface <span class="hlt">model</span> of the beaver meadow <span class="hlt">complex</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nash, C.; Grant, G.; Flinchum, B. A.; Lancaster, J.; Holbrook, W. S.; Davis, L. G.; Lewis, S.</p> <p>2015-12-01</p> <p>Wet meadows are a vital component of arid and semi-arid environments. These valley spanning, seasonally inundated wetlands provide critical habitat and refugia for wildlife, and may potentially mediate catchment-scale hydrology in otherwise "water challenged" landscapes. In the last 150 years, these meadows have begun incising rapidly, causing the wetlands to drain and much of the ecological benefit to be lost. The mechanisms driving this incision are poorly understood, with proposed means ranging from cattle grazing to climate change, to the removal of beaver. There is considerable interest in identifying cost-effective strategies to restore the hydrologic and ecological conditions of these meadows at a meaningful scale, but effective process based restoration first requires a thorough understanding of the constructional history of these ubiquitous features. There is emerging evidence to suggest that the North American beaver may have had a considerable role in shaping this landscape through the building of dams. This "beaver meadow <span class="hlt">complex</span> hypothesis" posits that as beaver dams filled with fine-grained sediments, they became large wet meadows on which new dams, and new <span class="hlt">complexes</span>, were formed, thereby aggrading valley bottoms. A pioneering study done in Yellowstone indicated that 32-50% of the alluvial sediment was deposited in ponded environments. The observed aggradation rates were highly heterogeneous, suggesting spatial variability in the depositional process - all consistent with the beaver meadow <span class="hlt">complex</span> hypothesis (Polvi and Wohl, 2012). To expand on this initial work, we have probed deeper into these meadow <span class="hlt">complexes</span> using a combination of geophysical techniques, coring methods and numerical <span class="hlt">modeling</span> to create a 3-dimensional representation of the subsurface environments. This imaging has given us a unique view into the patterns and processes responsible for the landforms, and may shed further light on the role of beaver in shaping these landscapes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4235124','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4235124"><span><span class="hlt">Modeling</span> Pedestrian's Conformity Violation Behavior: A <span class="hlt">Complex</span> Network Based Approach</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhou, Zhuping; Hu, Qizhou; Wang, Wei</p> <p>2014-01-01</p> <p>Pedestrian injuries and fatalities present a problem all over the world. Pedestrian conformity violation behaviors, which lead to many pedestrian crashes, are common phenomena at the signalized intersections in China. The concepts and metrics of <span class="hlt">complex</span> networks are applied to analyze the structural characteristics and evolution rules of pedestrian network about the conformity violation crossings. First, a network of pedestrians crossing the street is established, and the network's degree distributions are analyzed. Then, by using the basic idea of SI <span class="hlt">model</span>, a spreading <span class="hlt">model</span> of pedestrian illegal crossing behavior is proposed. Finally, through simulation analysis, pedestrian's illegal crossing behavior trends are obtained in different network structures and different spreading rates. Some conclusions are drawn: as the waiting time increases, more pedestrians will join in the violation crossing once a pedestrian crosses on red firstly. And pedestrian's conformity violation behavior will increase as the spreading rate increases. PMID:25530755</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25530755','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25530755"><span><span class="hlt">Modeling</span> pedestrian's conformity violation behavior: a <span class="hlt">complex</span> network based approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhou, Zhuping; Hu, Qizhou; Wang, Wei</p> <p>2014-01-01</p> <p>Pedestrian injuries and fatalities present a problem all over the world. Pedestrian conformity violation behaviors, which lead to many pedestrian crashes, are common phenomena at the signalized intersections in China. The concepts and metrics of <span class="hlt">complex</span> networks are applied to analyze the structural characteristics and evolution rules of pedestrian network about the conformity violation crossings. First, a network of pedestrians crossing the street is established, and the network's degree distributions are analyzed. Then, by using the basic idea of SI <span class="hlt">model</span>, a spreading <span class="hlt">model</span> of pedestrian illegal crossing behavior is proposed. Finally, through simulation analysis, pedestrian's illegal crossing behavior trends are obtained in different network structures and different spreading rates. Some conclusions are drawn: as the waiting time increases, more pedestrians will join in the violation crossing once a pedestrian crosses on red firstly. And pedestrian's conformity violation behavior will increase as the spreading rate increases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27730243','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27730243"><span>Uncertainty quantification for quantum chemical <span class="hlt">models</span> of <span class="hlt">complex</span> reaction networks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Proppe, Jonny; Husch, Tamara; Simm, Gregor N; Reiher, Markus</p> <p>2016-12-22</p> <p>For the quantitative understanding of <span class="hlt">complex</span> chemical reaction mechanisms, it is, in general, necessary to accurately determine the corresponding free energy surface and to solve the resulting continuous-time reaction rate equations for a continuous state space. For a general (<span class="hlt">complex</span>) reaction network, it is computationally hard to fulfill these two requirements. However, it is possible to approximately address these challenges in a physically consistent way. On the one hand, it may be sufficient to consider approximate free energies if a reliable uncertainty measure can be provided. On the other hand, a highly resolved time evolution may not be necessary to still determine quantitative fluxes in a reaction network if one is interested in specific time scales. In this paper, we present discrete-time kinetic simulations in discrete state space taking free energy uncertainties into account. The method builds upon thermo-chemical data obtained from electronic structure calculations in a condensed-phase <span class="hlt">model</span>. Our kinetic approach supports the analysis of general reaction networks spanning multiple time scales, which is here demonstrated for the example of the formose reaction. An important application of our approach is the detection of regions in a reaction network which require further investigation, given the uncertainties introduced by both approximate electronic structure methods and kinetic <span class="hlt">models</span>. Such cases can then be studied in greater detail with more sophisticated first-principles calculations and kinetic simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDC34001L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDC34001L"><span>Fish locomotion: insights from both simple and <span class="hlt">complex</span> mechanical <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lauder, George</p> <p>2015-11-01</p> <p>Fishes are well-known for their ability to swim and maneuver effectively in the water, and recent years have seen great progress in understanding the hydrodynamics of aquatic locomotion. But studying freely-swimming fishes is challenging due to difficulties in controlling fish behavior. Mechanical <span class="hlt">models</span> of aquatic locomotion have many advantages over studying live animals, including the ability to manipulate and control individual structural or kinematic factors, easier measurement of forces and torques, and the ability to abstract <span class="hlt">complex</span> animal designs into simpler components. Such simplifications, while not without their drawbacks, facilitate interpretation of how individual traits alter swimming performance and the discovery of underlying physical principles. In this presentation I will discuss the use of a variety of mechanical <span class="hlt">models</span> for fish locomotion, ranging from simple flexing panels to <span class="hlt">complex</span> biomimetic designs incorporating flexible, actively moved, fin rays on multiple fins. Mechanical devices have provided great insight into the dynamics of aquatic propulsion and, integrated with studies of locomotion in freely-swimming fishes, provide new insights into how fishes move through the water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5366872','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5366872"><span>Mutual information <span class="hlt">model</span> for link prediction in heterogeneous <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shakibian, Hadi; Moghadam Charkari, Nasrollah</p> <p>2017-01-01</p> <p>Recently, a number of meta-path based similarity indices like PathSim, HeteSim, and random walk have been proposed for link prediction in heterogeneous <span class="hlt">complex</span> networks. However, these indices suffer from two major drawbacks. Firstly, they are primarily dependent on the connectivity degrees of node pairs without considering the further information provided by the given meta-path. Secondly, most of them are required to use a single and usually symmetric meta-path in advance. Hence, employing a set of different meta-paths is not straightforward. To tackle with these problems, we propose a mutual information <span class="hlt">model</span> for link prediction in heterogeneous <span class="hlt">complex</span> networks. The proposed <span class="hlt">model</span>, called as Meta-path based Mutual Information Index (MMI), introduces meta-path based link entropy to estimate the link likelihood and could be carried on a set of available meta-paths. This estimation measures the amount of information through the paths instead of measuring the amount of connectivity between the node pairs. The experimental results on a Bibliography network show that the MMI obtains high prediction accuracy compared with other popular similarity indices. PMID:28344326</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Complex&pg=3&id=EJ1035056','ERIC'); return false;" href="http://eric.ed.gov/?q=Complex&pg=3&id=EJ1035056"><span>Staff <span class="hlt">Experiences</span> of Supported Employment with the Sustainable Hub of Innovative Employment for People with <span class="hlt">Complex</span> Needs</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gore, Nick J.; Forrester-Jones, Rachel; Young, Rhea</p> <p>2014-01-01</p> <p>Whilst the value of supported employment for people with learning disabilities is well substantiated, the <span class="hlt">experiences</span> of supporting individuals into work are less well documented. The Sustainable Hub of Innovative Employment for people with <span class="hlt">Complex</span> needs aims to support people with learning disabilities and <span class="hlt">complex</span> needs to find paid employment.…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17107967','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17107967"><span>Dynamic <span class="hlt">modelling</span> and analysis of biochemical networks: mechanism-based <span class="hlt">models</span> and <span class="hlt">model</span>-based <span class="hlt">experiments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Riel, Natal A W</p> <p>2006-12-01</p> <p>Systems biology applies quantitative, mechanistic <span class="hlt">modelling</span> to study genetic networks, signal transduction pathways and metabolic networks. Mathematical <span class="hlt">models</span> of biochemical networks can look very different. An important reason is that the purpose and application of a <span class="hlt">model</span> are essential for the selection of the best mathematical framework. Fundamental aspects of selecting an appropriate <span class="hlt">modelling</span> framework and a strategy for <span class="hlt">model</span> building are discussed. Concepts and methods from system and control theory provide a sound basis for the further development of improved and dedicated computational tools for systems biology. Identification of the network components and rate constants that are most critical to the output behaviour of the system is one of the major problems raised in systems biology. Current approaches and methods of parameter sensitivity analysis and parameter estimation are reviewed. It is shown how these methods can be applied in the design of <span class="hlt">model</span>-based <span class="hlt">experiments</span> which iteratively yield <span class="hlt">models</span> that are decreasingly wrong and increasingly gain predictive power.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24804451','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24804451"><span>Assessing nutrient limitation in <span class="hlt">complex</span> forested ecosystems: alternatives to large-scale fertilization <span class="hlt">experiments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sullivan, Benjamin W; Alvarez-Clare, Silvia; Castle, Sarah C; Porder, Stephen; Reed, Sasha C; Schreeg, Laura; Townsend, Alan R; Cleveland, Cory C</p> <p>2014-03-01</p> <p>Quantifying nutrient limitation of primary productivity is a fundamental task of terrestrial ecosystem ecology, but in a high carbon dioxide environment it is even more critical that we understand potential nutrient constraints on plant growth. Ecologists often manipulate nutrients with fertilizer to assess nutrient limitation, yet for a variety of reasons, nutrient fertilization <span class="hlt">experiments</span> are either impractical or incapable of resolving ecosystem responses to some global changes. The challenges of conducting large, in situ fertilization <span class="hlt">experiments</span> are magnified in forests, especially the high-diversity forests common throughout the lowland tropics. A number of methods, including fertilization <span class="hlt">experiments</span>, could be seen as tools in a toolbox that ecologists may use to attempt to assess nutrient limitation, but there has been no compilation or synthetic discussion of those methods in the literature. Here, we group these methods into one of three categories (indicators of soil nutrient supply, organismal indicators of nutrient limitation, and lab-based <span class="hlt">experiments</span> and nutrient depletions), and discuss some of the strengths and limitations of each. Next, using a case study, we compare nutrient limitation assessed using these methods to results obtained using large-scale fertilizations across the Hawaiian Archipelago. We then explore the application of these methods in high-diversity tropical forests. In the end, we suggest that, although no single method is likely to predict nutrient limitation in all ecosystems and at all scales, by simultaneously utilizing a number of the methods we describe, investigators may begin to understand nutrient limitation in <span class="hlt">complex</span> and diverse ecosystems such as tropical forests. In combination, these methods represent our best hope for understanding nutrient constraints on the global carbon cycle, especially in tropical forest ecosystems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJBC...2550046W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJBC...2550046W"><span>Stochastic Path <span class="hlt">Model</span> of Polaroid Polarizer for Bell's Theorem and Triphoton <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Werbos, Paul J.</p> <p></p> <p>Depending on the outcome of the triphoton <span class="hlt">experiment</span> now underway, it is possible that the new local realistic Markov Random Field (MRF) <span class="hlt">models</span> will be the only <span class="hlt">models</span> now available to correctly predict both that <span class="hlt">experiment</span> and Bell's theorem <span class="hlt">experiments</span>. The MRF <span class="hlt">models</span> represent the <span class="hlt">experiments</span> as graphs of discrete events over space-time. This paper extends the MRF approach to continuous time, by defining a new class of realistic <span class="hlt">model</span>, the stochastic path <span class="hlt">model</span>, and showing how it can be applied to ideal polaroid type polarizers in such <span class="hlt">experiments</span>. The final section discusses possibilities for future research, ranging from uses in other <span class="hlt">experiments</span> or novel quantum communication systems, to extensions involving stochastic paths in the space of functions over continuous space. As part of this, it derives a new Boltzmann-like density operator over Fock space, which predicts the emergent statistical equilibria of nonlinear Hamiltonian field theories, based on our previous work of extending the Glauber-Sudarshan P mapping from the case of classical systems described by a <span class="hlt">complex</span> state variable α to the case of classical continuous fields. This extension may explain the stochastic aspects of quantum theory as the emergent outcome of nonlinear PDE in a time-symmetric universe.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PhDT.......549M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PhDT.......549M"><span>Informing education policy in Afghanistan: Using design of <span class="hlt">experiments</span> and data envelopment analysis to provide transparency in <span class="hlt">complex</span> simulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marlin, Benjamin</p> <p></p> <p>Education planning provides the policy maker and the decision maker a logical framework in which to develop and implement education policy. At the international level, education planning is often confounded by both internal and external <span class="hlt">complexities</span>, making the development of education policy difficult. This research presents a discrete event simulation in which individual students and teachers flow through the system across a variable time horizon. This simulation is then used with advancements in design of <span class="hlt">experiments</span>, multivariate statistical analysis, and data envelopment analysis, to provide a methodology designed to assist the international education planning community. We propose that this methodology will provide the education planner with insights into the <span class="hlt">complexity</span> of the education system, the effects of both endogenous and exogenous factors upon the system, and the implications of policies as they pertain to potential futures of the system. We do this recognizing that there are multiple actors and stochastic events in play, which although cannot be accurately forecasted, must be accounted for within the education <span class="hlt">model</span>. To both test the implementation and usefulness of such a <span class="hlt">model</span> and to prove its relevance, we chose the Afghan education system as the focal point of this research. The Afghan education system is a <span class="hlt">complex</span>, real world system with competing actors, dynamic requirements, and ambiguous states. At the time of this writing, Afghanistan is at a pivotal point as a nation, and has been the recipient of a tremendous amount of international support and attention. Finally, Afghanistan is a fragile state, and the proliferation of the current disparity in education across gender, districts, and ethnicity could provide the catalyst to drive the country into hostility. In order to prevent the failure of the current government, it is essential that the education system is able to meet the demands of the Afghan people. This work provides insights into</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B11C0441C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B11C0441C"><span>Assessing <span class="hlt">model</span> sensitivity and uncertainty across multiple Free-Air CO2 Enrichment <span class="hlt">experiments</span>.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cowdery, E.; Dietze, M.</p> <p>2015-12-01</p> <p>As atmospheric levels of carbon dioxide levels continue to increase, it is critical that terrestrial ecosystem <span class="hlt">models</span> can accurately predict ecological responses to the changing environment. Current predictions of net primary productivity (NPP) in response to elevated atmospheric CO2 concentrations are highly variable and contain a considerable amount of uncertainty. It is necessary that we understand which factors are driving this uncertainty. The Free-Air CO2 Enrichment (FACE) <span class="hlt">experiments</span> have equipped us with a rich data source that can be used to calibrate and validate these <span class="hlt">model</span> predictions. To identify and evaluate the assumptions causing inter-<span class="hlt">model</span> differences we performed <span class="hlt">model</span> sensitivity and uncertainty analysis across ambient and elevated CO2 treatments using the Data Assimilation Linked Ecosystem Carbon (DALEC) <span class="hlt">model</span> and the Ecosystem Demography <span class="hlt">Model</span> (ED2), two process-based <span class="hlt">models</span> ranging from low to high <span class="hlt">complexity</span> respectively. These <span class="hlt">modeled</span> process responses were compared to experimental data from the Kennedy Space Center Open Top Chamber <span class="hlt">Experiment</span>, the Nevada Desert Free Air CO2 Enrichment Facility, the Rhinelander FACE <span class="hlt">experiment</span>, the Wyoming Prairie Heating and CO2 Enrichment <span class="hlt">Experiment</span>, the Duke Forest Face <span class="hlt">experiment</span> and the Oak Ridge <span class="hlt">Experiment</span> on CO2 Enrichment. By leveraging data access proxy and data tilling services provided by the BrownDog data curation project alongside analysis modules available in the Predictive Ecosystem Analyzer (PEcAn), we produced automated, repeatable benchmarking workflows that are generalized to incorporate different sites and ecological <span class="hlt">models</span>. Combining the observed patterns of uncertainty between the two <span class="hlt">models</span> with results of the recent FACE-<span class="hlt">model</span> data synthesis project (FACE-MDS) can help identify which processes need further study and additional data constraints. These findings can be used to inform future experimental design and in turn can provide informative starting point for data assimilation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT........87R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT........87R"><span>A <span class="hlt">modeling</span> process to understand <span class="hlt">complex</span> system architectures</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robinson, Santiago Balestrini</p> <p>2009-12-01</p> <p>In recent decades, several tools have been developed by the armed forces, and their contractors, to test the capability of a force. These campaign level analysis tools, often times characterized as constructive simulations are generally expensive to create and execute, and at best they are extremely difficult to verify and validate. This central observation, that the analysts are relying more and more on constructive simulations to predict the performance of future networks of systems, leads to the two central objectives of this thesis: (1) to enable the quantitative comparison of architectures in terms of their ability to satisfy a capability without resorting to constructive simulations, and (2) when constructive simulations must be created, to quantitatively determine how to spend the <span class="hlt">modeling</span> effort amongst the different system classes. The first objective led to Hypothesis A, the first main hypotheses, which states that by studying the relationships between the entities that compose an architecture, one can infer how well it will perform a given capability. The method used to test the hypothesis is based on two assumptions: (1) the capability can be defined as a cycle of functions, and that it (2) must be possible to estimate the probability that a function-based relationship occurs between any two types of entities. If these two requirements are met, then by creating random functional networks, different architectures can be compared in terms of their ability to satisfy a capability. In order to test this hypothesis, a novel process for creating representative functional networks of large-scale system architectures was developed. The process, named the Digraph <span class="hlt">Modeling</span> for Architectures (DiMA), was tested by comparing its results to those of <span class="hlt">complex</span> constructive simulations. Results indicate that if the inputs assigned to DiMA are correct (in the tests they were based on time-averaged data obtained from the ABM), DiMA is able to identify which of any two</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19820009870','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19820009870"><span>Investigation of <span class="hlt">models</span> for large scale meteorological prediction <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Spar, J.</p> <p>1982-01-01</p> <p>Long-range numerical prediction and climate simulation <span class="hlt">experiments</span> with various global atmospheric general circulation <span class="hlt">models</span> are reported. A chronological listing of the titles of all publications and technical reports already distributed is presented together with an account of the most recent reseach. Several reports on a series of perpetual January climate simulations with the GISS coarse mesh climate <span class="hlt">model</span> are listed. A set of perpetual July climate simulations with the same <span class="hlt">model</span> is presented and the results are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008GeoRL..3512601K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008GeoRL..3512601K"><span>Organic iron (III) <span class="hlt">complexing</span> ligands during an iron enrichment <span class="hlt">experiment</span> in the western subarctic North Pacific</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kondo, Yoshiko; Takeda, Shigenobu; Nishioka, Jun; Obata, Hajime; Furuya, Ken; Johnson, William Keith; Wong, C. S.</p> <p>2008-06-01</p> <p><span class="hlt">Complexation</span> of iron (III) with natural organic ligands was investigated during a mesoscale iron enrichment <span class="hlt">experiment</span> in the western subarctic North Pacific (SEEDS II). After the iron infusions, ligand concentrations increased rapidly with subsequent decreases. While the increases of ligands might have been partly influenced by amorphous iron colloids formation (12-29%), most in-situ increases were attributable to the <200 kDa fraction. Dilution of the fertilized patch may have contributed to the rapid decreases of the ligands. During the bloom decline, ligand concentration increased again, and the high concentrations persisted for 10 days. The conditional stability constant was not different between inside and outside of the fertilized patch. These results suggest that the chemical speciation of the released iron was strongly affected by formation of the ligands; the production of ligands observed during the bloom decline will strongly impact the iron cycle and bioavailability in the surface water.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJWC.13202020S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJWC.13202020S"><span><span class="hlt">Experiment</span> and computation: a combined approach to study the van der Waals <span class="hlt">complexes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Surin, L. A.</p> <p>2016-12-01</p> <p>A review of recent results on the millimetre-wave spectroscopy of weakly bound van der Waals <span class="hlt">complexes</span>, mostly those which contain H2 and He, is presented. In our work, we compared the experimental spectra to the theoretical bound state results, thus providing a critical test of the quality of the M-H2 and M-He potential energy surfaces (PESs) which are a key issue for reliable computations of the collisional excitation and de-excitation of molecules (M = CO, NH3, H2O) in the dense interstellar medium. The intermolecular interactions with He and H2 play also an important role for high resolution spectroscopy of helium or para-hydrogen clusters doped by a probe molecule (CO, HCN). Such <span class="hlt">experiments</span> are directed on the detection of superfluid response of molecular rotation in the He and p-H2 clusters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyA..471..427R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..471..427R"><span>Coevolving <span class="hlt">complex</span> networks in the <span class="hlt">model</span> of social interactions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raducha, Tomasz; Gubiec, Tomasz</p> <p>2017-04-01</p> <p>We analyze Axelrod's <span class="hlt">model</span> of social interactions on coevolving <span class="hlt">complex</span> networks. We introduce four extensions with different mechanisms of edge rewiring. The <span class="hlt">models</span> are intended to catch two kinds of interactions-preferential attachment, which can be observed in scientists or actors collaborations, and local rewiring, which can be observed in friendship formation in everyday relations. Numerical simulations show that proposed dynamics can lead to the power-law distribution of nodes' degree and high value of the clustering coefficient, while still retaining the small-world effect in three <span class="hlt">models</span>. All <span class="hlt">models</span> are characterized by two phase transitions of a different nature. In case of local rewiring we obtain order-disorder discontinuous phase transition even in the thermodynamic limit, while in case of long-distance switching discontinuity disappears in the thermodynamic limit, leaving one continuous phase transition. In addition, we discover a new and universal characteristic of the second transition point-an abrupt increase of the clustering coefficient, due to formation of many small complete subgraphs inside the network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4337231','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4337231"><span>Lupus Nephritis: Animal <span class="hlt">Modeling</span> of a <span class="hlt">Complex</span> Disease Syndrome Pathology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McGaha, Tracy L; Madaio, Michael P.</p> <p>2014-01-01</p> <p>Nephritis as a result of autoimmunity is a common morbidity associated with Systemic Lupus Erythematosus (SLE). There is substantial clinical and industry interest in medicinal intervention in the SLE nephritic process; however, clinical trials to specifically treat lupus nephritis have not resulted in complete and sustained remission in all patients. Multiple mouse <span class="hlt">models</span> have been used to investigate the pathologic interactions between autoimmune reactivity and SLE pathology. While several <span class="hlt">models</span> bear a remarkable similarity to SLE-driven nephritis, there are limitations for each that can make the task of choosing the appropriate <span class="hlt">model</span> for a particular aspect of SLE pathology challenging. This is not surprising given the variable and diverse nature of human disease. In many respects, features among murine strains mimic some (but never all) of the autoimmune and pathologic features of lupus patients. Although the diversity often limits universal conclusions relevant to pathogenesis, they provide insights into the <span class="hlt">complex</span> process that result in phenotypic manifestations of nephritis. Thus nephritis represents a microcosm of systemic disease, with variable lesions and clinical features. In this review, we discuss some of the most commonly used <span class="hlt">models</span> of lupus nephritis (LN) and immune-mediated glomerular damage examining their relative strengths and weaknesses, which may provide insight in the human condition. PMID:25722732</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1183543','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1183543"><span>Wind Power Curve <span class="hlt">Modeling</span> in Simple and <span class="hlt">Complex</span> Terrain</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bulaevskaya, V.; Wharton, S.; Irons, Z.; Qualley, G.</p> <p>2015-02-09</p> <p>Our previous work on wind power curve <span class="hlt">modeling</span> using statistical <span class="hlt">models</span> focused on a location with a moderately <span class="hlt">complex</span> terrain in the Altamont Pass region in northern California (CA). The work described here is the follow-up to that work, but at a location with a simple terrain in northern Oklahoma (OK). The goal of the present analysis was to determine the gain in predictive ability afforded by adding information beyond the hub-height wind speed, such as wind speeds at other heights, as well as other atmospheric variables, to the power prediction <span class="hlt">model</span> at this new location and compare the results to those obtained at the CA site in the previous study. While we reach some of the same conclusions at both sites, many results reported for the CA site do not hold at the OK site. In particular, using the entire vertical profile of wind speeds improves the accuracy of wind power prediction relative to using the hub-height wind speed alone at both sites. However, in contrast to the CA site, the rotor equivalent wind speed (REWS) performs almost as well as the entire profile at the OK site. Another difference is that at the CA site, adding wind veer as a predictor significantly improved the power prediction accuracy. The same was true for that site when air density was added to the <span class="hlt">model</span> separately instead of using the standard air density adjustment. At the OK site, these additional variables result in no significant benefit for the prediction accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1027837','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1027837"><span><span class="hlt">Complex</span> Geometry Creation and Turbulent Conjugate Heat Transfer <span class="hlt">Modeling</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bodey, Isaac T; Arimilli, Rao V; Freels, James D</p> <p>2011-01-01</p> <p>The multiphysics capabilities of COMSOL provide the necessary tools to simulate the turbulent thermal-fluid aspects of the High Flux Isotope Reactor (HFIR). Version 4.1, and later, of COMSOL provides three different turbulence <span class="hlt">models</span>: the standard k-{var_epsilon} closure <span class="hlt">model</span>, the low Reynolds number (LRN) k-{var_epsilon} <span class="hlt">model</span>, and the Spalart-Allmaras <span class="hlt">model</span>. The LRN meets the needs of the nominal HFIR thermal-hydraulic requirements for 2D and 3D simulations. COMSOL also has the capability to create <span class="hlt">complex</span> geometries. The circular involute fuel plates used in the HFIR require the use of algebraic equations to generate an accurate geometrical representation in the simulation environment. The best-estimate simulation results show that the maximum fuel plate clad surface temperatures are lower than those predicted by the legacy thermal safety code used at HFIR by approximately 17 K. The best-estimate temperature distribution determined by COMSOL was then used to determine the necessary increase in the magnitude of the power density profile (PDP) to produce a similar clad surface temperature as compared to the legacy thermal safety code. It was determined and verified that a 19% power increase was sufficient to bring the two temperature profiles to relatively good agreement.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ909840.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ909840.pdf"><span><span class="hlt">Model</span>-Driven Design: Systematically Building Integrated Blended Learning <span class="hlt">Experiences</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Laster, Stephen</p> <p>2010-01-01</p> <p>Developing and delivering curricula that are integrated and that use blended learning techniques requires a highly orchestrated design. While institutions have demonstrated the ability to design <span class="hlt">complex</span> curricula on an ad-hoc basis, these projects are generally successful at a great human and capital cost. <span class="hlt">Model</span>-driven design provides a…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1234874','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1234874"><span>Initial <span class="hlt">experience</span> with transluminally placed endovascular grafts for the treatment of <span class="hlt">complex</span> vascular lesions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Marin, M L; Veith, F J; Cynamon, J; Sanchez, L A; Lyon, R T; Levine, B A; Bakal, C W; Suggs, W D; Wengerter, K R; Rivers, S P</p> <p>1995-01-01</p> <p>OBJECTIVES: <span class="hlt">Complex</span> arterial occlusive, traumatic, and aneurysmal lesions may be difficult or impossible to treat successfully by standard surgical techniques when severe medical or surgical comorbidities exist. The authors describe a single center's <span class="hlt">experience</span> over a 2 1/2-year period with 96 endovascular graft procedures performed to treat 100 arterial lesions in 92 patients. PATIENTS AND METHODS: Thirty-three patients had 36 large aortic and/or peripheral artery aneurysms, 48 had 53 multilevel limb-threatening aortoiliac and/or femoropopliteal occlusive lesions, and 11 had traumatic arterial injuries (false aneurysms and arteriovenous fistulas). Endovascular grafts were placed through remote arteriotomies under local (16[17%]), epidural (42[43%]), or general (38[40%]) anesthesia. RESULTS: Technical and clinical successes were achieved in 91% of the patients with aneurysms, 91% with occlusive lesions, and 100% with traumatic arterial lesions. These patients and grafts have been followed from 1 to 30 months (mean, 13 months). The primary and secondary patency rates at 18 months for aortoiliac occlusions were 77% and 95%, respectively. The 18-month limb salvage rate was 98%. Immediately after aortic aneurysm exclusion, a total of 6 (33%) perigraft channels were detected; 3 of these closed within 8 weeks. Endovascular stented graft procedures were associated with a 10% major and a 14% minor complication rate. The overall 30-day mortality rate for this entire series was 6%. CONCLUSIONS: This initial <span class="hlt">experience</span> with endovascular graft repair of <span class="hlt">complex</span> arterial lesions justifies further use and careful evaluation of this technique for major arterial reconstruction. Images Figure 1. Figure 4. Figure 5. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 11. PMID:7574926</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24508723','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24508723"><span>Spectroscopic properties of photosystem II core <span class="hlt">complexes</span> from Thermosynechococcus elongatus revealed by single-molecule <span class="hlt">experiments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Brecht, Marc; Skandary, Sepideh; Hellmich, Julia; Glöckner, Carina; Konrad, Alexander; Hussels, Martin; Meixner, Alfred J; Zouni, Athina; Schlodder, Eberhard</p> <p>2014-06-01</p> <p>In this study we use a combination of absorption, fluorescence and low temperature single-molecule spectroscopy to elucidate the spectral properties, heterogeneities and dynamics of the chlorophyll a (Chla) molecules responsible for the fluorescence emission of photosystem II core <span class="hlt">complexes</span> (PS II cc) from the cyanobacterium Thermosynechococcus elongatus. At the ensemble level, the absorption and fluorescence spectra show a temperature dependence similar to plant PS II. We report emission spectra of single PS II cc for the first time; the spectra are dominated by zero-phonon lines (ZPLs) in the range between 680 and 705nm. The single-molecule <span class="hlt">experiments</span> show unambiguously that different emitters and not only the lowest energy trap contribute to the low temperature emission spectrum. The average emission spectrum obtained from more than hundred single <span class="hlt">complexes</span> shows three main contributions that are in good agreement with the reported bands F685, F689 and F695. The intensity of F695 is found to be lower than in conventional ensemble spectroscopy. The reason for the deviation might be due to the accumulation of triplet states on the red-most chlorophylls (e.g. Chl29 in CP47) or on carotenoids close to these long-wavelength traps by the high excitation power used in the single-molecule <span class="hlt">experiments</span>. The red-most emitter will not contribute to the fluorescence spectrum as long as it is in the triplet state. In addition, quenching of fluorescence by the triplet state may lead to a decrease of long-wavelength emission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011MMTB...42..144K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011MMTB...42..144K"><span>Numerical Simulation and Cold <span class="hlt">Modeling</span> <span class="hlt">experiments</span> on Centrifugal Casting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Keerthiprasad, Kestur Sadashivaiah; Murali, Mysore Seetharam; Mukunda, Pudukottah Gopaliengar; Majumdar, Sekhar</p> <p>2011-02-01</p> <p>In a centrifugal casting process, the fluid flow eventually determines the quality and characteristics of the final product. It is difficult to study the fluid behavior here because of the opaque nature of melt and mold. In the current investigation, numerical simulations of the flow field and visualization <span class="hlt">experiments</span> on cold <span class="hlt">models</span> have been carried out for a centrifugal casting system using horizontal molds and fluids of different viscosities to study the effect of different process variables on the flow pattern. The effects of the thickness of the cylindrical fluid annulus formed inside the mold and the effects of fluid viscosity, diameter, and rotational speed of the mold on the hollow fluid cylinder formation process have been investigated. The numerical simulation results are compared with corresponding data obtained from the cold <span class="hlt">modeling</span> <span class="hlt">experiments</span>. The influence of rotational speed in a real-life centrifugal casting system has also been studied using an aluminum-silicon alloy. Cylinders of different thicknesses are cast at different rotational speeds, and the flow patterns observed visually in the actual castings are found to be similar to those recorded in the corresponding cold <span class="hlt">modeling</span> <span class="hlt">experiments</span>. Reasonable agreement is observed between the results of numerical simulation and the results of cold <span class="hlt">modeling</span> <span class="hlt">experiments</span> with different fluids. The visualization study on the hollow cylinders produced in an actual centrifugal casting process also confirm the conclusions arrived at from the cold <span class="hlt">modeling</span> <span class="hlt">experiments</span> and numerical simulation in a qualitative sense.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DPPJP2011B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DPPJP2011B"><span>The Entropy and <span class="hlt">Complexity</span> of Drift waves in a LAPTAG Plasma Physics <span class="hlt">Experiment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Birge-Lee, Henry; Gekelman, Walter; Pribyl, Patrick; Wise, Joe; Katz, Cami; Baker, Bob; Marmie, Ken; Thomas, Sam; Buckley-Bonnano, Samuel</p> <p>2015-11-01</p> <p>Drift waves grow from noise on a density gradient in a narrow (dia = 3 cm, L = 1.5 m) magnetized (Boz = 160G) plasma column. A two-dimensional probe drive measured fluctuations in the plasma column in a plane transverse to the background magnetic field. Correlation techniques determined that the fluctuations were that of electrostatic drift waves. The time series data was used to generate the Bandt-Pompe/Shannon entropy, H, and Jensen-Shannon <span class="hlt">complexity</span>, CJS. C-H diagrams can be used to tell the difference between deterministic chaos, random noise and stochastic processes and simple waves, which makes it a powerful tool in nonlinear dynamics. The C-H diagram in this <span class="hlt">experiment</span>, reveal that the combination of drift waves and other background fluctuations is a deterministically chaotic system. The PDF of the time series, the wave spectra the spatial dependence of the entropy wave <span class="hlt">complexity</span> will be presented. LAPTAG is a university-high school alliance outreach program, which has been in existence for over 20 years. Work done at BaPSF at UCLA and supported by NSF and DOE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19449693','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19449693"><span><span class="hlt">Complex</span> equilibria in the maintenance of boundaries: <span class="hlt">experiments</span> with mussel beds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Robles, Carlos D; Desharnais, Robert A; Garza, Corey; Donahue, Megan J; Martinez, Carlos A</p> <p>2009-04-01</p> <p>Stationary boundaries of sedentary species may belie dynamic processes that form them. Our aim was to test an implication of an evolving body of theory, that such boundaries are manifestations of <span class="hlt">complex</span> regulatory dynamics. On rocky shores of British Columbia, large-scale field <span class="hlt">experiments</span> altered the densities of predatory sea stars (Pisaster ochraceus), causing shifts in the location of the lower vertical boundaries of their prey, sea mussels (Mytilus californianus). While control mussel beds remained unchanged, experimental reductions of sea star densities caused the downward extension of the lower boundaries, and experimental increases in sea stars densities caused the upward recession of the lower boundary well into the zone presumed to be a spatial refuge from predation. Cleared plots prepared within the initial boundaries were recolonized to varying degrees, depending on predator densities. After 30 months, plots on sea star removal sites showed high densities of adult mussels, control plots showed intermediate densities, and sea star addition plots showed only a sparse cover of alternative prey. Observations by divers at high tide showed that as small prey were depleted progressively from removal, to control, to addition sites, correspondingly larger mussels were attacked, including very large individuals comprising the lower boundary of addition sites. The findings contradict classic theory of zonation based on static prey refuges and support an alternative theory in which boundaries are maintained by <span class="hlt">complex</span>, spatially structured equilibria.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18930649','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18930649"><span>Social epidemiology and <span class="hlt">complex</span> system dynamic <span class="hlt">modelling</span> as applied to health behaviour and drug use research.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Galea, Sandro; Hall, Chris; Kaplan, George A</p> <p>2009-05-01</p> <p>A social epidemiologic perspective considers factors at multiple levels of influence (e.g., social networks, neighbourhoods, states) that may individually or jointly affect health and health behaviour. This provides a useful lens through which to understand the production of health behaviours in general, and drug use in particular. However, the analytic <span class="hlt">models</span> that are commonly applied in population health sciences limit the inference we are able to draw about the determination of health behaviour by factors, likely interrelated, across levels of influence. <span class="hlt">Complex</span> system dynamic <span class="hlt">modelling</span> techniques may be useful in enabling the adoption of a social epidemiologic approach in health behaviour and drug use research. We provide an example of a <span class="hlt">model</span> that aims to incorporate factors at multiple levels of influence in understanding drug dependence. We conclude with suggestions about future directions in the field and how such <span class="hlt">models</span> may serve as virtual laboratories for policy <span class="hlt">experiments</span> aimed at improving health behaviour.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4560026','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4560026"><span>Designing <span class="hlt">Experiments</span> to Discriminate Families of Logic <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Videla, Santiago; Konokotina, Irina; Alexopoulos, Leonidas G.; Saez-Rodriguez, Julio; Schaub, Torsten; Siegel, Anne; Guziolowski, Carito</p> <p>2015-01-01</p> <p>Logic <span class="hlt">models</span> of signaling pathways are a promising way of building effective in silico functional <span class="hlt">models</span> of a cell, in particular of signaling pathways. The automated learning of Boolean logic <span class="hlt">models</span> describing signaling pathways can be achieved by training to phosphoproteomics data, which is particularly useful if it is measured upon different combinations of perturbations in a high-throughput fashion. However, in practice, the number and type of allowed perturbations are not exhaustive. Moreover, experimental data are unavoidably subjected to noise. As a result, the learning process results in a family of feasible logical networks rather than in a single <span class="hlt">model</span>. This family is composed of logic <span class="hlt">models</span> implementing different internal wirings for the system and therefore the predictions of <span class="hlt">experiments</span> from this family may present a significant level of variability, and hence uncertainty. In this paper, we introduce a method based on Answer Set Programming to propose an optimal experimental design that aims to narrow down the variability (in terms of input–output behaviors) within families of logical <span class="hlt">models</span> learned from experimental data. We study how the fitness with respect to the data can be improved after an optimal selection of signaling perturbations and how we learn optimal logic <span class="hlt">models</span> with minimal number of <span class="hlt">experiments</span>. The methods are applied on signaling pathways in human liver cells and phosphoproteomics experimental data. Using 25% of the <span class="hlt">experiments</span>, we obtained logical <span class="hlt">models</span> with fitness scores (mean square error) 15% close to the ones obtained using all <span class="hlt">experiments</span>, illustrating the impact that our approach can have on the design of <span class="hlt">experiments</span> for efficient <span class="hlt">model</span> calibration. PMID:26389116</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.S23A2470L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.S23A2470L"><span>A successive three-point scheme for fast ray tracing in <span class="hlt">complex</span> 3D geological <span class="hlt">models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, F.; Xu, T.; Zhang, M.; Zhang, Z.</p> <p>2013-12-01</p> <p>We present a new 3D ray-tracing method that can be applied to computations of traveltime and ray-paths of seismic transmitted, reflected and turning waves in <span class="hlt">complex</span> geologic <span class="hlt">models</span>, which consist of arbitrarily shaped blocks whose boundaries are matched by triangulated interfaces for computational efficiency. The new ray-tracing scheme combines the segmentally iterative ray tracing (SIRT) method and the pseudo-bending scheme so as to become a robust and fast ray-tracing method for seismic waves. The new method is extension of our previous constant block <span class="hlt">models</span> and constant gradient block <span class="hlt">models</span> to generally heterogeneous block <span class="hlt">models</span>, and incorporates triangulated interfaces defining boundaries of <span class="hlt">complex</span> geological bodies, so that it becomes applicable for practical problems. A successive three-point perturbation scheme is formulated that iteratively updates the midpoints of a segment based on an initial ray-path. The corrections of the midpoints are accomplished by first-order analytic formulae according to locations of the midpoint inside the block or on the boundaries of the blocks, to which the updating formulae of the pseudo-bending method and SIRT algorithm are applied instead of the traditional iterative methods. Numerical <span class="hlt">experiments</span>, including an example in the Bohemian Massif, demonstrate that successive three-point scheme is effective and capable for kinematic ray tracing in <span class="hlt">complex</span> 3D heterogeneous media.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ237473.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ237473.pdf"><span>Electronic Transitions as a Probe of Tetrahedral versus Octahedral Coordination in Nickel(II) <span class="hlt">Complexes</span>: An Undergraduate Inorganic Chemistry <span class="hlt">Experiment</span>.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Filgueiras, Carlos A. L.; Carazza, Fernando</p> <p>1980-01-01</p> <p>Discusses procedures, theoretical considerations, and results of an <span class="hlt">experiment</span> involving the preparation of a tetrahedral nickel(II) <span class="hlt">complex</span> and its transformation into an octahedral species. Suggests that fundamental aspects of coordination chemistry can be demonstrated by simple <span class="hlt">experiments</span> performed in introductory level courses. (Author/JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17955469','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17955469"><span><span class="hlt">Modeling</span> relations in nature and eco-informatics: a practical application of rosennean <span class="hlt">complexity</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kineman, John J</p> <p>2007-10-01</p> <p>The purpose of eco-informatics is to communicate critical information about organisms and ecosystems. To accomplish this, it must reflect the <span class="hlt">complexity</span> of natural systems. Present information systems are designed around mechanistic concepts that do not capture <span class="hlt">complexity</span>. Robert Rosen's relational theory offers a way of representing <span class="hlt">complexity</span> in terms of information entailments that are part of an ontologically implicit '<span class="hlt">modeling</span> relation'. This relation has corresponding epistemological components that can be captured empirically, the components being structure (associated with <span class="hlt">model</span> encoding) and function (associated with <span class="hlt">model</span> decoding). Relational <span class="hlt">complexity</span>, thus, provides a long-awaited theoretical underpinning for these concepts that ecology has found indispensable. Structural information pertains to the material organization of a system, which can be represented by data. Functional information specifies potential change, which can be inferred from <span class="hlt">experiment</span> and represented as <span class="hlt">models</span> or descriptions of state transformations. Contextual dependency (of structure or function) implies meaning. Biological functions imply internalized or system-dependent laws. <span class="hlt">Complexity</span> can be represented epistemologically by relating structure and function in two different ways. One expresses the phenomenal relation that exists in any present or past instance, and the other draws the ontology of a system into the empirical world in terms of multiple potentials subject to natural forms of selection and optimality. These act as system attractors. Implementing these components and their theoretical relations in an informatics system will provide more-complete ecological informatics than is possible from a strictly mechanistic point of view. This approach will enable many new possibilities for supporting science and decision making.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002EGSGA..27.2424B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002EGSGA..27.2424B"><span>Water Balance <span class="hlt">Modelling</span> - Does The Required <span class="hlt">Model</span> <span class="hlt">Complexity</span> Change With Scale?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blöschl, G.; Merz, R.</p> <p></p> <p>An important issue in <span class="hlt">modelling</span> the water balance of catchments is what is the suitable <span class="hlt">model</span> <span class="hlt">complexity</span>. Anecdotal evidence suggests that the <span class="hlt">model</span> <span class="hlt">complexity</span> required to <span class="hlt">model</span> the water balance accurately decreases with catchment scale but so far very few studies have quantified these possible effects. In this paper we examine the <span class="hlt">model</span> per- formance as a function of catchment scale for a given <span class="hlt">model</span> <span class="hlt">complexity</span> which allows us to infer, whether the required <span class="hlt">model</span> <span class="hlt">complexity</span> changes with scale. We also exam- ine whether the calibrated parameter values change with scale or are scale invariant. In a case study we analysed 700 catchments in Austria with catchment sizes ranging from 10 to 100 000 km2. 30 years of daily data (runoff, precipitation, air temperature, air humidity) were analysed. A spatially lumped, conceptual, HBV style soil mois- ture accounting scheme was used which involved fifteen <span class="hlt">model</span> parameters including snow processes. Five parameters were preset and ten parameters were calibrated on observed daily streamflow. The calibration period was about 10 years and the verifi- cation period was about 20 years. <span class="hlt">Model</span> performance (in terms of Nash-Sutcliffe effi- ciency) was examined both for the calibration and the verification periods. The mean efficiency over all catchments only decreased slightly when moving from the calibra- tion to the verification (from R2 = 0.65 to 0.60). The results suggest that the <span class="hlt">model</span> efficiencies (both for the calibration and the verification) do not change which catch- ment scale for scales smaller than 10 000 km2 but beyond this scale there is a slight decrease in <span class="hlt">model</span> performance. This means that for these very large scales, a spatial subdivision of the lumped <span class="hlt">model</span> is needed to allow for spatial differences in rainfall. The results also suggest that the <span class="hlt">model</span> parameters are not scale dependent. We con- clude that the <span class="hlt">complexity</span> required for water balance <span class="hlt">models</span> of catchments does not change with scale for catchment sizes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016BoLMe.158..183C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016BoLMe.158..183C"><span>Experimental and Numerical <span class="hlt">Modelling</span> of Flow over <span class="hlt">Complex</span> Terrain: The Bolund Hill</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Conan, Boris; Chaudhari, Ashvinkumar; Aubrun, Sandrine; van Beeck, Jeroen; Hämäläinen, Jari; Hellsten, Antti</p> <p>2016-02-01</p> <p>In the wind-energy sector, wind-power forecasting, turbine siting, and turbine-design selection are all highly dependent on a precise evaluation of atmospheric wind conditions. On-site measurements provide reliable data; however, in <span class="hlt">complex</span> terrain and at the scale of a wind farm, local measurements may be insufficient for a detailed site description. On highly variable terrain, numerical <span class="hlt">models</span> are commonly used but still constitute a challenge regarding simulation and interpretation. We propose a joint state-of-the-art study of two approaches to <span class="hlt">modelling</span> atmospheric flow over the Bolund hill: a wind-tunnel test and a large-eddy simulation (LES). The approach has the particularity of describing both methods in parallel in order to highlight their similarities and differences. The work provides a first detailed comparison between field measurements, wind-tunnel <span class="hlt">experiments</span> and numerical simulations. The systematic and quantitative approach used for the comparison contributes to a better understanding of the strengths and weaknesses of each <span class="hlt">model</span> and, therefore, to their enhancement. Despite fundamental <span class="hlt">modelling</span> differences, both techniques result in only a 5 % difference in the mean wind speed and 15 % in the turbulent kinetic energy (TKE). The joint comparison makes it possible to identify the most difficult features to <span class="hlt">model</span>: the near-ground flow and the wake of the hill. When compared to field data, both <span class="hlt">models</span> reach 11 % error for the mean wind speed, which is close to the best performance reported in the literature. For the TKE, a great improvement is found using the LES <span class="hlt">model</span> compared to previous studies (20 % error). Wind-tunnel results are in the low range of error when compared to <span class="hlt">experiments</span> reported previously (40 % error). This comparison highlights the potential of such approaches and gives directions for the improvement of <span class="hlt">complex</span> flow <span class="hlt">modelling</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100012847','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100012847"><span>Cognitive <span class="hlt">Modeling</span> of Video Game Player User <span class="hlt">Experience</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bohil, Corey J.; Biocca, Frank A.</p> <p>2010-01-01</p> <p>This paper argues for the use of cognitive <span class="hlt">modeling</span> to gain a detailed and dynamic look into user <span class="hlt">experience</span> during game play. Applying cognitive <span class="hlt">models</span> to game play data can help researchers understand a player's attentional focus, memory status, learning state, and decision strategies (among other things) as these cognitive processes occurred throughout game play. This is a stark contrast to the common approach of trying to assess the long-term impact of games on cognitive functioning after game play has ended. We describe what cognitive <span class="hlt">models</span> are, what they can be used for and how game researchers could benefit by adopting these methods. We also provide details of a single <span class="hlt">model</span> - based on decision field theory - that has been successfUlly applied to data sets from memory, perception, and decision making <span class="hlt">experiments</span>, and has recently found application in real world scenarios. We examine possibilities for applying this <span class="hlt">model</span> to game-play data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4782801','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4782801"><span>Disulfide Trapping for <span class="hlt">Modeling</span> and Structure Determination of Receptor:Chemokine <span class="hlt">Complexes</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kufareva, Irina; Gustavsson, Martin; Holden, Lauren G.; Qin, Ling; Zheng, Yi; Handel, Tracy M.</p> <p>2016-01-01</p> <p>Despite the recent breakthrough advances in GPCR crystallography, structure determination of protein-protein <span class="hlt">complexes</span> involving chemokine receptors and their endogenous chemokine ligands remains challenging. Here we describe disulfide trapping, a methodology for generating irreversible covalent binary protein <span class="hlt">complexes</span> from unbound protein partners by introducing two cysteine residues, one per interaction partner, at selected positions within their interaction interface. Disulfide trapping can serve at least two distinct purposes: (i) stabilization of the <span class="hlt">complex</span> to assist structural studies, and/or (ii) determination of pairwise residue proximities to guide molecular <span class="hlt">modeling</span>. Methods for characterization of disulfide-trapped <span class="hlt">complexes</span> are described and evaluated in terms of throughput, sensitivity, and specificity towards the most energetically favorable cross-links. Due to abundance of native disulfide bonds at receptor:chemokine interfaces, disulfide trapping of their <span class="hlt">complexes</span> can be associated with intramolecular disulfide shuffling and result in misfolding of the component proteins; because of this, evidence from several <span class="hlt">experiments</span> is typically needed to firmly establish a positive disulfide crosslink. An optimal pipeline that maximizes throughput and minimizes time and costs by early triage of unsuccessful candidate constructs is proposed. PMID:26921956</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24889376','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24889376"><span>Neutral null <span class="hlt">models</span> for diversity in serial transfer evolution <span class="hlt">experiments</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Harpak, Arbel; Sella, Guy</p> <p>2014-09-01</p> <p>Evolution <span class="hlt">experiments</span> with microorganisms coupled with genome-wide sequencing now allow for the systematic study of population genetic processes under a wide range of conditions. In learning about these processes in natural, sexual populations, neutral <span class="hlt">models</span> that describe the behavior of diversity and divergence summaries have played a pivotal role. It is therefore natural to ask whether neutral <span class="hlt">models</span>, suitably modified, could be useful in the context of evolution <span class="hlt">experiments</span>. Here, we introduce coalescent <span class="hlt">models</span> for polymorphism and divergence under the most common experimental evolution assay, a serial transfer <span class="hlt">experiment</span>. This relatively simple setting allows us to address several issues that could affect diversity patterns in evolution <span class="hlt">experiments</span>, whether selection is operating or not: the transient behavior of neutral polymorphism in an <span class="hlt">experiment</span> beginning from a single clone, the effects of randomness in the timing of cell division and noisiness in population size in the dilution stage. In our analyses and discussion, we emphasize the implications for <span class="hlt">experiments</span> aimed at measuring diversity patterns and making inferences about population genetic processes based on these measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22243872','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22243872"><span>Adsorption of mercury on lignin: combined surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> and X-ray absorption spectroscopy studies.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lv, Jitao; Luo, Lei; Zhang, Jing; Christie, Peter; Zhang, Shuzhen</p> <p>2012-03-01</p> <p>Adsorption of mercury (Hg) on lignin was studied at a range of pH values using a combination of batch adsorption <span class="hlt">experiments</span>, a surface <span class="hlt">complexation</span> <span class="hlt">model</span> (SCM) and synchrotron X-ray absorption spectroscopy (XAS). Surface <span class="hlt">complexation</span> <span class="hlt">modeling</span> indicates that three types of acid sites on lignin surfaces, namely aliphatic carboxylic-, aromatic carboxylic- and phenolic-type surface groups, contributed to Hg(II) adsorption. The bond distance and coordination number of Hg(II) adsorption samples at pH 3.0, 4.0 and 5.5 were obtained from extended X-ray absorption fine structure (EXAFS) spectroscopy analysis. The results of SCM and XAS combined reveal that the predominant adsorption species of Hg(II) on lignin changes from HgCl(2)(0) to monodentate <span class="hlt">complex</span> -C-O-HgCl and then bidentate <span class="hlt">complex</span> -C-O-Hg-O-C- with increasing pH value from 2.0 to 6.0. The good agreement between SCM and XAS results provides new insight into understanding the mechanisms of Hg(II) adsorption on lignin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AIPC..863..214S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AIPC..863..214S"><span>Harmonic Oscillator <span class="hlt">Model</span> for Radin's Markov-Chain <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sheehan, D. P.; Wright, J. H.</p> <p>2006-10-01</p> <p>The conscious observer stands as a central figure in the measurement problem of quantum mechanics. Recent <span class="hlt">experiments</span> by Radin involving linear Markov chains driven by random number generators illuminate the role and temporal dynamics of observers interacting with quantum mechanically labile systems. In this paper a Lagrangian interpretation of these <span class="hlt">experiments</span> indicates that the evolution of Markov chain probabilities can be <span class="hlt">modeled</span> as damped harmonic oscillators. The results are best interpreted in terms of symmetric equicausal determinism rather than strict retrocausation, as posited by Radin. Based on the present analysis, suggestions are made for more advanced <span class="hlt">experiments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20891710','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20891710"><span>Harmonic Oscillator <span class="hlt">Model</span> for Radin's Markov-Chain <span class="hlt">Experiments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sheehan, D. P.; Wright, J. H.</p> <p>2006-10-16</p> <p>The conscious observer stands as a central figure in the measurement problem of quantum mechanics. Recent <span class="hlt">experiments</span> by Radin involving linear Markov chains driven by random number generators illuminate the role and temporal dynamics of observers interacting with quantum mechanically labile systems. In this paper a Lagrangian interpretation of these <span class="hlt">experiments</span> indicates that the evolution of Markov chain probabilities can be <span class="hlt">modeled</span> as damped harmonic oscillators. The results are best interpreted in terms of symmetric equicausal determinism rather than strict retrocausation, as posited by Radin. Based on the present analysis, suggestions are made for more advanced <span class="hlt">experiments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPA....5i2402A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPA....5i2402A"><span><span class="hlt">Modeling</span> Cu2+-Aβ <span class="hlt">complexes</span> from computational approaches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alí-Torres, Jorge; Mirats, Andrea; Maréchal, Jean-Didier; Rodríguez-Santiago, Luis; Sodupe, Mariona</p> <p>2015-09-01</p> <p>Amyloid plaques formation and oxidative stress are two key events in the pathology of the Alzheimer disease (AD), in which metal cations have been shown to play an important role. In particular, the interaction of the redox active Cu2+ metal cation with Aβ has been found to interfere in amyloid aggregation and to lead to reactive oxygen species (ROS). A detailed knowledge of the electronic and molecular structure of Cu2+-Aβ <span class="hlt">complexes</span> is thus important to get a better understanding of the role of these <span class="hlt">complexes</span> in the development and progression of the AD disease. The computational treatment of these systems requires a combination of several available computational methodologies, because two fundamental aspects have to be addressed: the metal coordination sphere and the conformation adopted by the peptide upon copper binding. In this paper we review the main computational strategies used to deal with the Cu2+-Aβ coordination and build plausible Cu2+-Aβ <span class="hlt">models</span> that will afterwards allow determining physicochemical properties of interest, such as their redox potential.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20060047496','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20060047496"><span>Cryogenic Tank <span class="hlt">Modeling</span> for the Saturn AS-203 <span class="hlt">Experiment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Grayson, Gary D.; Lopez, Alfredo; Chandler, Frank O.; Hastings, Leon J.; Tucker, Stephen P.</p> <p>2006-01-01</p> <p>A computational fluid dynamics (CFD) <span class="hlt">model</span> is developed for the Saturn S-IVB liquid hydrogen (LH2) tank to simulate the 1966 AS-203 flight <span class="hlt">experiment</span>. This significant <span class="hlt">experiment</span> is the only known, adequately-instrumented, low-gravity, cryogenic self pressurization test that is well suited for CFD <span class="hlt">model</span> validation. A 4000-cell, axisymmetric <span class="hlt">model</span> predicts motion of the LH2 surface including boil-off and thermal stratification in the liquid and gas phases. The <span class="hlt">model</span> is based on a modified version of the commercially available FLOW3D software. During the <span class="hlt">experiment</span>, heat enters the LH2 tank through the tank forward dome, side wall, aft dome, and common bulkhead. In both <span class="hlt">model</span> and test the liquid and gases thermally stratify in the low-gravity natural convection environment. LH2 boils at the free surface which in turn increases the pressure within the tank during the 5360 second <span class="hlt">experiment</span>. The Saturn S-IVB tank <span class="hlt">model</span> is shown to accurately simulate the self pressurization and thermal stratification in the 1966 AS-203 test. The average predicted pressurization rate is within 4% of the pressure rise rate suggested by test data. Ullage temperature results are also in good agreement with the test where the <span class="hlt">model</span> predicts an ullage temperature rise rate within 6% of the measured data. The <span class="hlt">model</span> is based on first principles only and includes no adjustments to bring the predictions closer to the test data. Although quantitative <span class="hlt">model</span> validation is achieved or one specific case, a significant step is taken towards demonstrating general use of CFD for low-gravity cryogenic fluid <span class="hlt">modeling</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNS43A3852F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNS43A3852F"><span>Simulation and Processing Seismic Data in <span class="hlt">Complex</span> Geological <span class="hlt">Models</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Forestieri da Gama Rodrigues, S.; Moreira Lupinacci, W.; Martins de Assis, C. A.</p> <p>2014-12-01</p> <p>Seismic simulations in <span class="hlt">complex</span> geological <span class="hlt">models</span> are interesting to verify some limitations of seismic data. In this project, different geological <span class="hlt">models</span> were designed to analyze some difficulties encountered in the interpretation of seismic data. Another idea is these data become available for LENEP/UENF students to test new tools to assist in seismic data processing. The geological <span class="hlt">models</span> were created considering some characteristics found in oil exploration. We simulated geological medium with volcanic intrusions, salt domes, fault, pinch out and layers more distante from surface (Kanao, 2012). We used the software Tesseral Pro to simulate the seismic acquisitions. The acquisition geometries simulated were of the type common offset, end-on and split-spread. (Figure 1) Data acquired with constant offset require less processing routines. The processing flow used with tools available in Seismic Unix package (for more details, see Pennington et al., 2005) was geometric spreading correction, deconvolution, attenuation correction and post-stack depth migration. In processing of the data acquired with end-on and split-spread geometries, we included velocity analysis and NMO correction routines. Although we analyze synthetic data and carefully applied each processing routine, we can observe some limitations of the seismic reflection in imaging thin layers, great surface depth layers, layers with low impedance contrast and faults.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1260839','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1260839"><span>Deposition parameterizations for the Industrial Source <span class="hlt">Complex</span> (ISC3) <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wesely, Marvin L.; Doskey, Paul V.; Shannon, J. D.</p> <p>2002-06-01</p> <p>Improved algorithms have been developed to simulate the dry and wet deposition of hazardous air pollutants (HAPs) with the Industrial Source <span class="hlt">Complex</span> version 3 (ISC3) <span class="hlt">model</span> system. The dry deposition velocities (concentrations divided by downward flux at a specified height) of the gaseous HAPs are <span class="hlt">modeled</span> with algorithms adapted from existing dry deposition modules. The dry deposition velocities are described in a conventional resistance scheme, for which micrometeorological formulas are applied to describe the aerodynamic resistances above the surface. Pathways to uptake at the ground and in vegetative canopies are depicted with several resistances that are affected by variations in air temperature, humidity, solar irradiance, and soil moisture. The role of soil moisture variations in affecting the uptake of gases through vegetative plant leaf stomata is assessed with the relative available soil moisture, which is estimated with a rudimentary budget of soil moisture content. Some of the procedures and equations are simplified to be commensurate with the type and extent of information on atmospheric and surface conditions available to the ISC3 <span class="hlt">model</span> system user. For example, standardized land use types and seasonal categories provide sets of resistances to uptake by various components of the surface. To describe the dry deposition of the large number of gaseous organic HAPS, a new technique based on laboratory study results and theoretical considerations has been developed providing a means of evaluating the role of lipid solubility in uptake by the waxy outer cuticle of vegetative plant leaves.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4777878','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4777878"><span>Neurocomputational <span class="hlt">Model</span> of EEG <span class="hlt">Complexity</span> during Mind Wandering</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ibáñez-Molina, Antonio J.; Iglesias-Parro, Sergio</p> <p>2016-01-01</p> <p>Mind wandering (MW) can be understood as a transient state in which attention drifts from an external task to internal self-generated thoughts. MW has been associated with the activation of the Default Mode Network (DMN). In addition, it has been shown that the activity of the DMN is anti-correlated with activation in brain networks related to the processing of external events (e.g., Salience network, SN). In this study, we present a mean field <span class="hlt">model</span> based on weakly coupled Kuramoto oscillators. We simulated the oscillatory activity of the entire brain and explored the role of the interaction between the nodes from the DMN and SN in MW states. External stimulation was added to the network <span class="hlt">model</span> in two opposite conditions. Stimuli could be presented when oscillators in the SN showed more internal coherence (synchrony) than in the DMN, or, on the contrary, when the coherence in the SN was lower than in the DMN. The resulting phases of the oscillators were analyzed and used to simulate EEG signals. Our results showed that the structural <span class="hlt">complexity</span> from both simulated and real data was higher when the <span class="hlt">model</span> was stimulated during periods in which DMN was more coherent than the SN. Overall, our results provided a plausible mechanistic explanation to MW as a state in which high coherence in the DMN partially suppresses the capacity of the system to process external stimuli. PMID:26973505</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19930004692','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19930004692"><span>Integrated <span class="hlt">modeling</span> tool for performance engineering of <span class="hlt">complex</span> computer systems</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wright, Gary; Ball, Duane; Hoyt, Susan; Steele, Oscar</p> <p>1989-01-01</p> <p>This report summarizes Advanced System Technologies' accomplishments on the Phase 2 SBIR contract NAS7-995. The technical objectives of the report are: (1) to develop an evaluation version of a graphical, integrated <span class="hlt">modeling</span> language according to the specification resulting from the Phase 2 research; and (2) to determine the degree to which the language meets its objectives by evaluating ease of use, utility of two sets of performance predictions, and the power of the language constructs. The technical approach followed to meet these objectives was to design, develop, and test an evaluation prototype of a graphical, performance prediction tool. The utility of the prototype was then evaluated by applying it to a variety of test cases found in the literature and in AST case histories. Numerous <span class="hlt">models</span> were constructed and successfully tested. The major conclusion of this Phase 2 SBIR research and development effort is that <span class="hlt">complex</span>, real-time computer systems can be specified in a non-procedural manner using combinations of icons, windows, menus, and dialogs. Such a specification technique provides an interface that system designers and architects find natural and easy to use. In addition, PEDESTAL's multiview approach provides system engineers with the capability to perform the trade-offs necessary to produce a design that meets timing performance requirements. Sample system designs analyzed during the development effort showed that <span class="hlt">models</span> could be constructed in a fraction of the time required by non-visual system design capture tools.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/2764150','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/2764150"><span>Beyond pure parasystole: promises and problems in <span class="hlt">modeling</span> <span class="hlt">complex</span> arrhythmias.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Courtemanche, M; Glass, L; Rosengarten, M D; Goldberger, A L</p> <p>1989-08-01</p> <p>The dynamics of pure parasystole, a cardiac arrhythmia in which two competing pacemakers fire independently, have recently been fully characterized. This <span class="hlt">model</span> is now extended in an attempt to account for the more <span class="hlt">complex</span> dynamics occurring with modulated parasystole, in which there exists nonlinear interaction between the sinus node and the ectopic ventricular focus. Theoretical analysis of modulated parasystole reveals three types of dynamics: entrainment, quasiperiodicity, and chaos. Rhythms associated with quasiperiodicity obey a set of rules derived from pure parasystole. This <span class="hlt">model</span> is applied to the interpretation of continuous electrocardiographic data sets from three patients with complicated patterns of ventricular ectopic activity. We describe several new statistical properties of these records, related to the number of intervening sinus beats between ectopic events, that are essential in characterizing the dynamics and testing mathematical <span class="hlt">models</span>. Detailed comparison between data and theory in these cases show substantial areas of agreement as well as potentially important discrepancies. These findings have implications for understanding the dynamics of the heartbeat in normal and pathological conditions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EPJP..132...72F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EPJP..132...72F"><span>Evolution of <span class="hlt">complexity</span> in a resource-based <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernández, Lenin; Campos, Paulo R. A.</p> <p>2017-02-01</p> <p>Through a resource-based <span class="hlt">modelling</span> the evolution of organismal <span class="hlt">complexity</span> is studied. In the <span class="hlt">model</span>, the cells are characterized by their metabolic rates which, together with the availability of resource, determine the rate at which they divide. The population is structured in groups. Groups are also autonomous entities regarding reproduction and propagation, and so they correspond to a higher biological organization level. The <span class="hlt">model</span> assumes reproductive altruism as there exists a fitness transfer from the cell level to the group level. Reproductive altruism comes about by inflicting a higher energetic cost to cells belonging to larger groups. On the other hand, larger groups are less prone to extinction. The strength of this benefit arising from group augmentation can be tuned by the synergistic parameter γ. Through extensive computer simulations we make a thorough exploration of the parameter space to find out the domain in which the formation of larger groups is allowed. We show that formation of small groups can be obtained for a low level of synergy. Larger group sizes can only be attained as synergistic interactions surpass a given level of strength. Although the total resource influx rate plays a key role in determining the number of groups coexisting at the equilibrium, its function on driving group size is minor. On the other hand, how the resource is seized by the groups matters.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JChPh.145l4902J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JChPh.145l4902J"><span>Atomic level insights into realistic molecular <span class="hlt">models</span> of dendrimer-drug <span class="hlt">complexes</span> through MD simulations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jain, Vaibhav; Maiti, Prabal K.; Bharatam, Prasad V.</p> <p>2016-09-01</p> <p>Computational studies performed on dendrimer-drug <span class="hlt">complexes</span> usually consider 1:1 stoichiometry, which is far from reality, since in <span class="hlt">experiments</span> more number of drug molecules get encapsulated inside a dendrimer. In the present study, molecular dynamic (MD) simulations were implemented to characterize the more realistic molecular <span class="hlt">models</span> of dendrimer-drug <span class="hlt">complexes</span> (1:n stoichiometry) in order to understand the effect of high drug loading on the structural properties and also to unveil the atomistic level details. For this purpose, possible inclusion <span class="hlt">complexes</span> of <span class="hlt">model</span> drug Nateglinide (Ntg) (antidiabetic, belongs to Biopharmaceutics Classification System class II) with amine- and acetyl-terminated G4 poly(amidoamine) (G4 PAMAM(NH2) and G4 PAMAM(Ac)) dendrimers at neutral and low pH conditions are explored in this work. MD simulation analysis on dendrimer-drug <span class="hlt">complexes</span> revealed that the drug encapsulation efficiency of G4 PAMAM(NH2) and G4 PAMAM(Ac) dendrimers at neutral pH was 6 and 5, respectively, while at low pH it was 12 and 13, respectively. Center-of-mass distance analysis showed that most of the drug molecules are located in the interior hydrophobic pockets of G4 PAMAM(NH2) at both the pH; while in the case of G4 PAMAM(Ac), most of them are distributed near to the surface at neutral pH and in the interior hydrophobic pockets at low pH. Structural properties such as radius of gyration, shape, radial density distribution, and solvent accessible surface area of dendrimer-drug <span class="hlt">complexes</span> were also assessed and compared with that of the drug unloaded dendrimers. Further, binding energy calculations using molecular mechanics Poisson-Boltzmann surface area approach revealed that the location of drug molecules in the dendrimer is not the decisive factor for the higher and lower binding affinity of the <span class="hlt">complex</span>, but the charged state of dendrimer and drug, intermolecular interactions, pH-induced conformational changes, and surface groups of dendrimer do play an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EPJST.225.1271D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EPJST.225.1271D"><span>Methods of Information Geometry to <span class="hlt">model</span> <span class="hlt">complex</span> shapes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>De Sanctis, A.; Gattone, S. A.</p> <p>2016-09-01</p> <p>In this paper, a new statistical method to <span class="hlt">model</span> patterns emerging in <span class="hlt">complex</span> systems is proposed. A framework for shape analysis of 2- dimensional landmark data is introduced, in which each landmark is represented by a bivariate Gaussian distribution. From Information Geometry we know that Fisher-Rao metric endows the statistical manifold of parameters of a family of probability distributions with a Riemannian metric. Thus this approach allows to reconstruct the intermediate steps in the evolution between observed shapes by computing the geodesic, with respect to the Fisher-Rao metric, between the corresponding distributions. Furthermore, the geodesic path can be used for shape predictions. As application, we study the evolution of the rat skull shape. A future application in Ophthalmology is introduced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JSP...166..230F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JSP...166..230F"><span>A Deep Stochastic <span class="hlt">Model</span> for Detecting Community in <span class="hlt">Complex</span> Networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, Jingcheng; Wu, Jianliang</p> <p>2017-01-01</p> <p>Discovering community structures is an important step to understanding the structure and dynamics of real-world networks in social science, biology and technology. In this paper, we develop a deep stochastic <span class="hlt">model</span> based on non-negative matrix factorization to identify communities, in which there are two sets of parameters. One is the community membership matrix, of which the elements in a row correspond to the probabilities of the given node belongs to each of the given number of communities in our <span class="hlt">model</span>, another is the community-community connection matrix, of which the element in the i-th row and j-th column represents the probability of there being an edge between a randomly chosen node from the i-th community and a randomly chosen node from the j-th community. The parameters can be evaluated by an efficient updating rule, and its convergence can be guaranteed. The community-community connection matrix in our <span class="hlt">model</span> is more precise than the community-community connection matrix in traditional non-negative matrix factorization methods. Furthermore, the method called symmetric nonnegative matrix factorization, is a special case of our <span class="hlt">model</span>. Finally, based on the <span class="hlt">experiments</span> on both synthetic and real-world networks data, it can be demonstrated that our algorithm is highly effective in detecting communities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25811335','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25811335"><span>Construction of Lyapunov functions for some <span class="hlt">models</span> of infectious diseases in vivo: from simple <span class="hlt">models</span> to <span class="hlt">complex</span> <span class="hlt">models</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kajiwara, Tsuyoshi; Sasaki, Toru; Takeuchi, Yasuhiro</p> <p>2015-02-01</p> <p>We present a constructive method for Lyapunov functions for ordinary differential equation <span class="hlt">models</span> of infectious diseases in vivo. We consider <span class="hlt">models</span> derived from the Nowak-Bangham <span class="hlt">models</span>. We construct Lyapunov functions for <span class="hlt">complex</span> <span class="hlt">models</span> using those of simpler <span class="hlt">models</span>. Especially, we construct Lyapunov functions for <span class="hlt">models</span> with an immune variable from those for <span class="hlt">models</span> without an immune variable, a Lyapunov functions of a <span class="hlt">model</span> with absorption effect from that for a <span class="hlt">model</span> without absorption effect. We make the construction clear for Lyapunov functions proposed previously, and present new results with our method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA289014','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA289014"><span>Data Assimilation and <span class="hlt">Model</span> Evaluation <span class="hlt">Experiments</span> - North Atlantic Basin; Preliminary <span class="hlt">Experiment</span> Plan.</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>1994-12-01</p> <p>and will be allowed to evolve as the <span class="hlt">experiment</span> proceeds. A brief description by participants of <span class="hlt">models</span> and data assimilation methods are included....describes the approach to implement a comparative environment in which to assess numerical ocean <span class="hlt">model</span> nowcast/forecast capabilities and data assimilation ... methods and techniques. Goals are stated which provide direction for the long term, the next five years, and specifically for the next two years. A</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMNG51A1196D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMNG51A1196D"><span>Earthquake nucleation mechanisms and periodic loading: <span class="hlt">Models</span>, <span class="hlt">Experiments</span>, and Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dahmen, K.; Brinkman, B.; Tsekenis, G.; Ben-Zion, Y.; Uhl, J.</p> <p>2010-12-01</p> <p>The project has two main goals: (a) Improve the understanding of how earthquakes are nucleated ¬ with specific focus on seismic response to periodic stresses (such as tidal or seasonal variations) (b) Use the results of (a) to infer on the possible existence of precursory activity before large earthquakes. A number of mechanisms have been proposed for the nucleation of earthquakes, including frictional nucleation (Dieterich 1987) and fracture (Lockner 1999, Beeler 2003). We study the relation between the observed rates of triggered seismicity, the period and amplitude of cyclic loadings and whether the observed seismic activity in response to periodic stresses can be used to identify the correct nucleation mechanism (or combination of mechanisms). A generalized version of the Ben-Zion and Rice <span class="hlt">model</span> for disordered fault zones and results from related recent studies on dislocation dynamics and magnetization avalanches in slowly magnetized materials are used in the analysis (Ben-Zion et al. 2010; Dahmen et al. 2009). The analysis makes predictions for the statistics of macroscopic failure events of sheared materials in the presence of added cyclic loading, as a function of the period, amplitude, and noise in the system. The employed tools include analytical methods from statistical physics, the theory of phase transitions, and numerical simulations. The results will be compared to laboratory <span class="hlt">experiments</span> and observations. References: Beeler, N.M., D.A. Lockner (2003). Why earthquakes correlate weakly with the solid Earth tides: effects of periodic stress on the rate and probability of earthquake occurrence. J. Geophys. Res.-Solid Earth 108, 2391-2407. Ben-Zion, Y. (2008). Collective Behavior of Earthquakes and Faults: Continuum-Discrete Transitions, Evolutionary Changes and Corresponding Dynamic Regimes, Rev. Geophysics, 46, RG4006, doi:10.1029/2008RG000260. Ben-Zion, Y., Dahmen, K. A. and J. T. Uhl (2010). A unifying phase diagram for the dynamics of sheared solids</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNS53A..02B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNS53A..02B"><span>Inverse Problems in <span class="hlt">Complex</span> <span class="hlt">Models</span> and Applications to Earth Sciences</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bosch, M. E.</p> <p>2015-12-01</p> <p>The inference of the subsurface earth structure and properties requires the integration of different types of data, information and knowledge, by combined processes of analysis and synthesis. To support the process of integrating information, the regular concept of data inversion is evolving to expand its application to <span class="hlt">models</span> with multiple inner components (properties, scales, structural parameters) that explain multiple data (geophysical survey data, well-logs, core data). The probabilistic inference methods provide the natural framework for the formulation of these problems, considering a posterior probability density function (PDF) that combines the information from a prior information PDF and the new sets of observations. To formulate the posterior PDF in the context of multiple datasets, the data likelihood functions are factorized assuming independence of uncertainties for data originating across different surveys. A realistic description of the earth medium requires <span class="hlt">modeling</span> several properties and structural parameters, which relate to each other according to dependency and independency notions. Thus, conditional probabilities across <span class="hlt">model</span> components also factorize. A common setting proceeds by structuring the <span class="hlt">model</span> parameter space in hierarchical layers. A primary layer (e.g. lithology) conditions a secondary layer (e.g. physical medium properties), which conditions a third layer (e.g. geophysical data). In general, less structured relations within <span class="hlt">model</span> components and data emerge from the analysis of other inverse problems. They can be described with flexibility via direct acyclic graphs, which are graphs that map dependency relations between the <span class="hlt">model</span> components. Examples of inverse problems in <span class="hlt">complex</span> <span class="hlt">models</span> can be shown at various scales. At local scale, for example, the distribution of gas saturation is inferred from pre-stack seismic data and a calibrated rock-physics <span class="hlt">model</span>. At regional scale, joint inversion of gravity and magnetic data is applied</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PEPI..257..115D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PEPI..257..115D"><span><span class="hlt">Complex</span> events in a fault <span class="hlt">model</span> with interacting asperities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dragoni, Michele; Tallarico, Andrea</p> <p>2016-08-01</p> <p>The dynamics of a fault with heterogeneous friction is studied by employing a discrete fault <span class="hlt">model</span> with two asperities of different strengths. The average values of stress, friction and slip on each asperity are considered and the state of the fault is described by the slip deficits of the asperities as functions of time. The fault has three different slipping modes, corresponding to the asperities slipping one at a time or simultaneously. Any seismic event produced by the fault is a sequence of n slipping modes. According to initial conditions, seismic events can be different sequences of slipping modes, implying different moment rates and seismic moments. Each event can be represented geometrically in the state space by an orbit that is the union of n damped Lissajous curves. We focus our interest on events that are sequences of two or more slipping modes: they show a <span class="hlt">complex</span> stress interchange between the asperities and a <span class="hlt">complex</span> temporal pattern of slip rate. The initial stress distribution producing these events is not uniform on the fault. We calculate the stress drop, the moment rate and the frequency spectrum of the events, showing how these quantities depend on initial conditions. These events have the greatest seismic moments that can be produced by fault slip. As an example, we <span class="hlt">model</span> the moment rate of the 1992 Landers, California, earthquake that can be described as the consecutive failure of two asperities, one of which has a double strength than the other, and evaluate the evolution of stress distribution on the fault during the event.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PhyA..463..282J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PhyA..463..282J"><span>Dynamical <span class="hlt">complexity</span> in the perception-based network formation <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jo, Hang-Hyun; Moon, Eunyoung</p> <p>2016-12-01</p> <p>Many link formation mechanisms for the evolution of social networks have been successful to reproduce various empirical findings in social networks. However, they have largely ignored the fact that individuals make decisions on whether to create links to other individuals based on cost and benefit of linking, and the fact that individuals may use perception of the network in their decision making. In this paper, we study the evolution of social networks in terms of perception-based strategic link formation. Here each individual has her own perception of the actual network, and uses it to decide whether to create a link to another individual. An individual with the least perception accuracy can benefit from updating her perception using that of the most accurate individual via a new link. This benefit is compared to the cost of linking in decision making. Once a new link is created, it affects the accuracies of other individuals' perceptions, leading to a further evolution of the actual network. As for initial actual networks, we consider both homogeneous and heterogeneous cases. The homogeneous initial actual network is <span class="hlt">modeled</span> by Erdős-Rényi (ER) random networks, while we take a star network for the heterogeneous case. In any cases, individual perceptions of the actual network are <span class="hlt">modeled</span> by ER random networks with controllable linking probability. Then the stable link density of the actual network is found to show discontinuous transitions or jumps according to the cost of linking. As the number of jumps is the consequence of the dynamical <span class="hlt">complexity</span>, we discuss the effect of initial conditions on the number of jumps to find that the dynamical <span class="hlt">complexity</span> strongly depends on how much individuals initially overestimate or underestimate the link density of the actual network. For the heterogeneous case, the role of the highly connected individual as an information spreader is also discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA567141','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA567141"><span>Cellular Shape Memory Alloy Structures: <span class="hlt">Experiments</span> & <span class="hlt">Modeling</span> (Part 1)</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2012-08-01</p> <p>AFOSR  Grant  #FA9550-­‐08-­‐1-­‐0313 Cellular  Shape  Memory   Alloy  Structures:   <span class="hlt">Experiments</span>  &  <span class="hlt">Modeling</span> J.  Shaw  (UM...2012 4. TITLE AND SUBTITLE Cellular Shape Memory Alloy Structures: <span class="hlt">Experiments</span> & <span class="hlt">Modeling</span> (Part 1) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...dense,  0.37  g/cc) Combine benefits of light-weight cellular structures with Shape Memory Alloy (SMA) adaptive behavior CombinaKon •Amplified</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.5104D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.5104D"><span><span class="hlt">Model</span> slope infiltration <span class="hlt">experiments</span> for shallow landslides early warning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Damiano, E.; Greco, R.; Guida, A.; Olivares, L.; Picarelli, L.</p> <p>2009-04-01</p> <p> simple empirical <span class="hlt">models</span> [Versace et al., 2003] based on correlation between some features of rainfall records (cumulated height, duration, season etc.) and the correspondent observed landslides. Laboratory <span class="hlt">experiments</span> on instrumented small scale slope <span class="hlt">models</span> represent an effective way to provide data sets [Eckersley, 1990; Wang and Sassa, 2001] useful for building up more <span class="hlt">complex</span> <span class="hlt">models</span> of landslide triggering prediction. At the Geotechnical Laboratory of C.I.R.I.AM. an instrumented flume to investigate on the mechanics of landslides in unsaturated deposits of granular soils is available [Olivares et al. 2003; Damiano, 2004; Olivares et al., 2007]. In the flume a <span class="hlt">model</span> slope is reconstituted by a moist-tamping technique and subjected to an artificial uniform rainfall since failure happens. The state of stress and strain of the slope is monitored during the entire test starting from the infiltration process since the early post-failure stage: the monitoring system is constituted by several mini-tensiometers placed at different locations and depths, to measure suction, mini-transducers to measure positive pore pressures, laser sensors, to measure settlements of the ground surface, and high definition video-cameras to obtain, through a software (PIV) appositely dedicated, the overall horizontal displacement field. Besides, TDR sensors, used with an innovative technique [Greco, 2006], allow to reconstruct the water content profile of soil along the entire thickness of the investigated deposit and to monitor its continuous changes during infiltration. In this paper a series of laboratory tests carried out on <span class="hlt">model</span> slopes in granular pyroclastic soils taken in the mountainous area north-eastern of Napoli, are presented. The experimental results demonstrate the completeness of information provided by the various sensors installed. In particular, very useful information is given by the coupled measurements of soil water content by TDR and suction by tensiometers. Knowledge of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4991K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4991K"><span><span class="hlt">Complex</span> Environmental Data <span class="hlt">Modelling</span> Using Adaptive General Regression Neural Networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kanevski, Mikhail</p> <p>2015-04-01</p> <p>The research deals with an adaptation and application of Adaptive General Regression Neural Networks (GRNN) to high dimensional environmental data. GRNN [1,2,3] are efficient <span class="hlt">modelling</span> tools both for spatial and temporal data and are based on nonparametric kernel methods closely related to classical Nadaraya-Watson estimator. Adaptive GRNN, using anisotropic kernels, can be also applied for features selection tasks when working with high dimensional data [1,3]. In the present research Adaptive GRNN are used to study geospatial data predictability and relevant feature selection using both simulated and real data case studies. The original raw data were either three dimensional monthly precipitation data or monthly wind speeds embedded into 13 dimensional space constructed by geographical coordinates and geo-features calculated from digital elevation <span class="hlt">model</span>. GRNN were applied in two different ways: 1) adaptive GRNN with the resulting list of features ordered according to their relevancy; and 2) adaptive GRNN applied to evaluate all possible <span class="hlt">models</span> N [in case of wind fields N=(2^13 -1)=8191] and rank them according to the cross-validation error. In both cases training were carried out applying leave-one-out procedure. An important result of the study is that the set of the most relevant features depends on the month (strong seasonal effect) and year. The predictabilities of precipitation and wind field patterns, estimated using the cross-validation and testing errors of raw and shuffled data, were studied in detail. The results of both approaches were qualitatively and quantitatively compared. In conclusion, Adaptive GRNN with their ability to select features and efficient <span class="hlt">modelling</span> of <span class="hlt">complex</span> high dimensional data can be widely used in automatic/on-line mapping and as an integrated part of environmental decision support systems. 1. Kanevski M., Pozdnoukhov A., Timonin V. Machine Learning for Spatial Environmental Data. Theory, applications and software. EPFL Press</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/514895','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/514895"><span><span class="hlt">Modeling</span> a set of heavy oil aqueous pyrolysis <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Thorsness, C.B.; Reynolds, J.G.</p> <p>1996-11-01</p> <p>Aqueous pyrolysis <span class="hlt">experiments</span>, aimed at mild upgrading of heavy oil, were analyzed using various computer <span class="hlt">models</span>. The primary focus of the analysis was the pressure history of the closed autoclave reactors obtained during the heating of the autoclave to desired reaction temperatures. The <span class="hlt">models</span> used included a means of estimating nonideal behavior of primary components with regard to vapor liquid equilibrium. The <span class="hlt">modeling</span> indicated that to match measured autoclave pressures, which often were well below the vapor pressure of water at a given temperature, it was necessary to incorporate water solubility in the oil phase and an activity <span class="hlt">model</span> for the water in the oil phase which reduced its fugacity below that of pure water. Analysis also indicated that the mild to moderate upgrading of the oil which occurred in <span class="hlt">experiments</span> that reached 400{degrees}C or more using a FE(III) 2-ethylhexanoate could be reasonably well characterized by a simple first order rate constant of 1.7xl0{sup 8} exp(-20000/T)s{sup {minus}l}. Both gas production and API gravity increase were characterized by this rate constant. <span class="hlt">Models</span> were able to match the complete pressure history of the autoclave <span class="hlt">experiments</span> fairly well with relatively simple equilibria <span class="hlt">models</span>. However, a consistent lower than measured buildup in pressure at peak temperatures was noted in the <span class="hlt">model</span> calculations. This phenomena was tentatively attributed to an increase in the amount of water entering the vapor phase caused by a change in its activity in the oil phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.2705S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.2705S"><span>Simulating pollutant transport in <span class="hlt">complex</span> terrain with a Lagrangian particle dispersion <span class="hlt">model</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Szintai, B.; Kaufmann, P.; Rotach, M. W.</p> <p>2009-04-01</p> <p>Lagrangian particle dispersion <span class="hlt">models</span> (LPDMs) are among the most sophisticated tools to simulate atmospheric dispersion of pollutants, and are widely used in emergency response systems. In these systems, LPDMs should be coupled with a numerical weather prediction (NWP) <span class="hlt">model</span>, which provides information from the mean wind as well as from the turbulence state of the atmosphere. Mean wind can directly be used from the NWP <span class="hlt">model</span>, while turbulence characteristics have to be parameterized by a so-called meteorological pre-processor. In most cases, to diagnose turbulence variables, meteorological pre-processors use similarity theory approaches, which are based on turbulence datasets over flat and homogeneous surface. However, turbulence structure in <span class="hlt">complex</span> terrain, such as in steep and narrow Alpine valleys, can be substantially different from flat conditions. In this study a new scaling approach from Weigel et al. (2007), based on measurements and <span class="hlt">model</span> simulations of the Riviera Project in the framework of the Mesoscale Alpine Program (MAP), is investigated with respect to pollutant dispersion. In the Riviera Project, analysis of turbulence measurements in a steep and narrow Alpine valley showed that daytime profiles of Turbulent Kinetic Energy (TKE) scale very well if the convective velocity scale w* is obtained from the sunlit eastern slope rather than from the surface directly under the measured profiles. This scaling behaviour was also reproduced by high-resolution Large Eddy Simulation runs. To improve the performance of the dispersion <span class="hlt">model</span> in <span class="hlt">complex</span> terrain, this new scaling approach is introduced in the meteorological pre-processor of the LPDM and results are validated with a real tracer <span class="hlt">experiment</span>. For the evaluation of the dispersion <span class="hlt">model</span>, the TRANSALP tracer <span class="hlt">experiment</span> is used. During this <span class="hlt">experiment</span> passive tracers were released and detected in an Alpine valley in Southern Switzerland on two days in October 1989. To simulate this case the operational</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1077203','SCIGOV-DOEDE'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1077203"><span>Community Climate System <span class="hlt">Model</span> (CCSM) <span class="hlt">Experiments</span> and Output Data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/dataexplorer">DOE Data Explorer</a></p> <p></p> <p></p> <p>The National Center for Atmospheric Research (NCAR) created the first version of the Community Climate <span class="hlt">Model</span> (CCM) in 1983 as a global atmosphere <span class="hlt">model</span>. It was improved in 1994 when NCAR, with support from the National Science Foundation (NSF), developed and incorporated a Climate System <span class="hlt">Model</span> (CSM) that included atmosphere, land surface, ocean, and sea ice. As the capabilities of the <span class="hlt">model</span> grew, so did interest in its applications and changes in how it would be managed. A workshop in 1996 set the future management structure, marked the beginning of the second phase of the <span class="hlt">model</span>, a phase that included full participation of the scientific community, and also saw additional financial support, including support from the Department of Energy. In recognition of these changes, the <span class="hlt">model</span> was renamed to the Community Climate System <span class="hlt">Model</span> (CCSM). It began to function as a <span class="hlt">model</span> with the interactions of land, sea, and air fully coupled, providing computer simulations of Earth's past climate, its present climate, and its possible future climate. The CCSM website at http://www2.cesm.ucar.edu/ describes some of the research that has been done since then: A 300-year run has been performed using the CSM, and results from this <span class="hlt">experiment</span> have appeared in a special issue of theJournal of Climate, 11, June, 1998. A 125-year <span class="hlt">experiment</span> has been carried out in which carbon dioxide was described to increase at 1% per year from its present concentration to approximately three times its present concentration. More recently, the Climate of the 20th Century <span class="hlt">experiment</span> was run, with carbon dioxide and other greenhouse gases and sulfate aerosols prescribed to evolve according to our best knowledge from 1870 to the present. Three scenarios for the 21st century were developed: a "business as usual" <span class="hlt">experiment</span>, in which greenhouse gases are assumed to increase with no economic constraints; an <span class="hlt">experiment</span> using the Intergovernmental Panel on Climate Change (IPCC) Scenario A1; and a "policy</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70020152','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70020152"><span>Molybdate transport in a chemically <span class="hlt">complex</span> aquifer: Field measurements compared with solute-transport <span class="hlt">model</span> predictions</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stollenwerk, K.G.</p> <p>1998-01-01</p> <p>A natural-gradient tracer test was conducted in an unconfined sand and gravel aquifer on Cape Cod, Massachusetts. Molybdate was included in the injectate to study the effects of variable groundwater chemistry on its aqueous distribution and to evaluate the reliability of laboratory <span class="hlt">experiments</span> for identifying and quantifying reactions that control the transport of reactive solutes in groundwater. Transport of molybdate in this aquifer was controlled by adsorption. The amount adsorbed varied with aqueous chemistry that changed with depth as freshwater recharge mixed with a plume of sewage-contaminated groundwater. Molybdate adsorption was strongest near the water table where pH (5.7) and the concentration of the competing solutes phosphate (2.3 micromolar) and sulfate (86 micromolar) were low. Adsorption of molybdate decreased with depth as pH increased to 6.5, phosphate increased to 40 micromolar, and sulfate increased to 340 micromolar. A one-site diffuse-layer surface-<span class="hlt">complexation</span> <span class="hlt">model</span> and a two-site diffuse-layer surface-<span class="hlt">complexation</span> <span class="hlt">model</span> were used to simulate adsorption. Reactions and equilibrium constants for both <span class="hlt">models</span> were determined in laboratory <span class="hlt">experiments</span> and used in the reactive-transport <span class="hlt">model</span> PHAST to simulate the two-dimensional transport of molybdate during the tracer test. No geochemical parameters were adjusted in the simulation to improve the fit between <span class="hlt">model</span> and field data. Both <span class="hlt">models</span> simulated the travel distance of the molybdate cloud to within 10% during the 2-year tracer test; however, the two-site diffuse-layer <span class="hlt">model</span> more accurately simulated the molybdate concentration distribution within the cloud.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015DPS....4721304C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015DPS....4721304C"><span>Thermophysical <span class="hlt">Model</span> of S-<span class="hlt">complex</span> NEAs: 1627 Ivar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crowell, Jenna L.; Howell, Ellen S.; Magri, Christopher; Fernandez, Yan R.; Marshall, Sean E.; Warner, Brian D.; Vervack, Ronald J.</p> <p>2015-11-01</p> <p>We present updates to the thermophysical <span class="hlt">model</span> of asteroid 1627 Ivar. Ivar is an Amor class near Earth asteroid (NEA) with a taxonomic type of Sqw [1] and a rotation rate of 4.795162 ± 5.4 * 10-6 hours [2]. In 2013, our group observed Ivar in radar, in CCD lightcurves, and in the near-IR’s reflected and thermal regimes (0.8 - 4.1 µm) using the Arecibo Observatory’s 2380 MHz radar, the Palmer Divide Station’s 0.35m telescope, and the SpeX instrument at the NASA IRTF respectively. Using these radar and lightcurve data, we generated a detailed shape <span class="hlt">model</span> of Ivar using the software SHAPE [3,4]. Our shape <span class="hlt">model</span> reveals more surface detail compared to earlier <span class="hlt">models</span> [5] and we found Ivar to be an elongated asteroid with the maximum extended length along the three body-fixed coordinates being 12 x 11.76 x 6 km. For our thermophysical <span class="hlt">modeling</span>, we have used SHERMAN [6,7] with input parameters such as the asteroid’s IR emissivity, optical scattering law and thermal inertia, in order to complete thermal computations based on our shape <span class="hlt">model</span> and the known spin state. We then create synthetic near-IR spectra that can be compared to our observed spectra, which cover a wide range of Ivar’s rotational longitudes and viewing geometries. As has been noted [6,8], the use of an accurate shape <span class="hlt">model</span> is often crucial for correctly interpreting multi-epoch thermal emission observations. We will present what SHERMAN has let us determine about the reflective, thermal, and surface properties for Ivar that best reproduce our spectra. From our derived best-fit thermal parameters, we will learn more about the regolith, surface properties, and heterogeneity of Ivar and how those properties compare to those of other S-<span class="hlt">complex</span> asteroids. References: [1] DeMeo et al. 2009, Icarus 202, 160-180 [2] Crowell, J. et al. 2015, LPSC 46 [3] Magri C. et al. 2007, Icarus 186, 152-177 [4] Crowell, J. et al. 2014, AAS/DPS 46 [5] Kaasalainen, M. et al. 2004, Icarus 167, 178-196 [6] Crowell, J. et</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3946900','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3946900"><span>Compartmental <span class="hlt">models</span> for apical efflux by P-glycoprotein. Part 1. Evaluation of <span class="hlt">model</span> <span class="hlt">complexity</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nagar, Swati; Tucker, Jalia; Weiskircher, Erica A.; Bhoopathy, Siddhartha; Hidalgo, Ismael J.; Korzekwa, Ken</p> <p>2013-01-01</p> <p>Purpose With the goal of quantifying P-gp transport kinetics, Part 1 of these manuscripts evaluates different compartmental <span class="hlt">models</span> and Part 2 applies these <span class="hlt">models</span> to kinetic data. Methods <span class="hlt">Models</span> were developed to simulate the effect of apical efflux transporters on intracellular concentrations of six drugs. The effect of experimental variability on <span class="hlt">model</span> predictions was evaluated. Several <span class="hlt">models</span> were evaluated, and characteristics including membrane configuration, lipid content, and apical surface area (asa) were varied. Results Passive permeabilities from MDCK-MDR1 cells in the presence of cyclosporine gave lower <span class="hlt">model</span> errors than from MDCK control cells. Consistent with the results in Part 2, <span class="hlt">model</span> configuration had little impact on calculated <span class="hlt">model</span> errors. The 5-compartment <span class="hlt">model</span> was the simplest <span class="hlt">model</span> that reproduced experimental lag times. Lipid content and asa had minimal effect on <span class="hlt">model</span> errors, predicted lag times, and intracellular concentrations. Including endogenous basolateral uptake activity can decrease <span class="hlt">model</span> errors. <span class="hlt">Models</span> with and without explicit membrane barriers differed markedly in their predicted intracellular concentrations for basolateral drug exposure. Single point data resulted in clearances similar to time course data. Conclusions Compartmental <span class="hlt">models</span> are useful to evaluate the impact of efflux transporters on intracellular concentrations. Whereas a 3-compartment <span class="hlt">model</span> may be sufficient to predict the impact of transporters that efflux drugs from the cell, a 5-compartment <span class="hlt">model</span> with explicit membranes may be required to predict intracellular concentrations when efflux occurs from the membrane. More <span class="hlt">complex</span> <span class="hlt">models</span> including additional compartments may be unnecessary. PMID:24019023</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4782058','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4782058"><span>Amblypygids: <span class="hlt">Model</span> Organisms for the Study of Arthropod Navigation Mechanisms in <span class="hlt">Complex</span> Environments?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wiegmann, Daniel D.; Hebets, Eileen A.; Gronenberg, Wulfila; Graving, Jacob M.; Bingman, Verner P.</p> <p>2016-01-01</p> <p>Navigation is an ideal behavioral <span class="hlt">model</span> for the study of sensory system integration and the neural substrates associated with <span class="hlt">complex</span> behavior. For this broader purpose, however, it may be profitable to develop new <span class="hlt">model</span> systems that are both tractable and sufficiently <span class="hlt">complex</span> to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement <span class="hlt">experiments</span> under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, albeit on a smaller spatial scale, of true-navigating vertebrates. Specialized legs, called antenniform legs, which possess hundreds of olfactory and tactile sensory hairs, and vision appear to be involved. These animals also have enormous mushroom bodies, higher-order brain regions that, in insects, integrate contextual cues and may be involved in spatial memory. In amblypygids, the <span class="hlt">complexity</span> of a nocturnal rainforest may impose navigational challenges that favor the integration of information derived from multimodal cues. Moreover, the movement of these animals is easily studied in the laboratory and putative neural integration sites of sensory information can be manipulated. Thus, amblypygids could serve as <span class="hlt">model</span> organisms for the discovery of neural substrates associated with a unique and potentially sophisticated navigational capability. The diversity of habitats in which amblypygids are found also offers an opportunity for comparative studies of sensory integration and ecological selection pressures on navigation mechanisms. PMID:27014008</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/15011824','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/15011824"><span>An Aqueous Thermodynamic <span class="hlt">Model</span> for the <span class="hlt">Complexation</span> of Nickel with EDTA Valid to high Base Concentration</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Felmy, Andrew R.; Qafoku, Odeta</p> <p>2004-09-01</p> <p>An aqueous thermodynamic <span class="hlt">model</span> is developed which accurately describes the effects of high base concentration on the <span class="hlt">complexation</span> of Ni2+ by ethylenedinitrilotetraacetic acid (EDTA). The <span class="hlt">model</span> is primarily developed from an extensive data on the solubility of Ni(OH)2(c) in the presence of EDTA and in the presence and absence of Ca2+ as the competing metal ion. The solubility data for Ni(OH)2(c) were obtained in solutions ranging in NaOH concentration from 0.01 to 11.6m, and in Ca 2+ concentrations extending to saturation with respect to portlandite, Ca(OH)2. Owing to the inert nature of the Ni-EDTA <span class="hlt">complexation</span> reactions, solubility <span class="hlt">experiments</span> were approached from both the oversaturation and undersaturation direction and over time frames extending to 413 days. The final aqueous thermodynamic <span class="hlt">model</span> is based upon the equations of Pitzer, accurately predicts the observed solubilities to concentrations as high as 11.6m NaOH, and is consistent with UV-Vis spectroscopic studies of the <span class="hlt">complexes</span> in solution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22043622','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22043622"><span>Determination of the levitation limits of dust particles within the sheath in <span class="hlt">complex</span> plasma <span class="hlt">experiments</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Douglass, Angela; Land, Victor; Qiao Ke; Matthews, Lorin; Hyde, Truell</p> <p>2012-01-15</p> <p><span class="hlt">Experiments</span> are performed in which dust particles are levitated at varying heights above the powered electrode in a radio frequency plasma discharge by changing the discharge power. The trajectories of particles dropped from the top of the discharge chamber are used to reconstruct the vertical electric force acting on the particles. The resulting data, together with the results from a self-consistent fluid <span class="hlt">model</span>, are used to determine the lower levitation limit for dust particles in the discharge and the approximate height above the lower electrode where quasineutrality is attained, locating the sheath edge. These results are then compared with current sheath <span class="hlt">models</span>. It is also shown that particles levitated within a few electron Debye lengths of the sheath edge are located outside the linearly increasing portion of the electric field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24218213','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24218213"><span>Mathematical <span class="hlt">modeling</span> of isotope labeling <span class="hlt">experiments</span> for metabolic flux analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nargund, Shilpa; Sriram, Ganesh</p> <p>2014-01-01</p> <p>Isotope labeling <span class="hlt">experiments</span> (ILEs) offer a powerful methodology to perform metabolic flux analysis. However, the task of interpreting data from these <span class="hlt">experiments</span> to evaluate flux values requires significant mathematical <span class="hlt">modeling</span> skills. Toward this, this chapter provides background information and examples to enable the reader to (1) <span class="hlt">model</span> metabolic networks, (2) simulate ILEs, and (3) understand the optimization and statistical methods commonly used for flux evaluation. A compartmentalized <span class="hlt">model</span> of plant glycolysis and pentose phosphate pathway illustrates the reconstruction of a typical metabolic network, whereas a simpler example network illustrates the underlying metabolite and isotopomer balancing techniques. We also discuss the salient features of commonly used flux estimation software 13CFLUX2, Metran, NMR2Flux+, FiatFlux, and OpenFLUX. Furthermore, we briefly discuss methods to improve flux estimates. A graphical checklist at the end of the chapter provides a reader a quick reference to the mathematical <span class="hlt">modeling</span> concepts and resources.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1265991-modeling-detachment-experiments-diii','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1265991-modeling-detachment-experiments-diii"><span><span class="hlt">Modeling</span> of detachment <span class="hlt">experiments</span> at DIII-D</span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Canik, John M.; Briesemeister, Alexis R.; Lasnier, C. J.; ...</p> <p>2014-11-26</p> <p>Edge fluid–plasma/kinetic–neutral <span class="hlt">modeling</span> of well-diagnosed DIII-D <span class="hlt">experiments</span> is performed in order to document in detail how well certain aspects of experimental measurements are reproduced within the <span class="hlt">model</span> as the transition to detachment is approached. Results indicate, that at high densities near detachment onset, the poloidal temperature profile produced in the simulations agrees well with that measured in <span class="hlt">experiment</span>. However, matching the heat flux in the <span class="hlt">model</span> requires a significant increase in the radiated power compared to what is predicted using standard chemical sputtering rates. Lastly, these results suggest that the <span class="hlt">model</span> is adequate to predict the divertor temperature, provided thatmore » the discrepancy in radiated power level can be resolved.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1265991','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1265991"><span><span class="hlt">Modeling</span> of detachment <span class="hlt">experiments</span> at DIII-D</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Canik, John M.; Briesemeister, Alexis R.; Lasnier, C. J.; Leonard, A. W.; Lore, J. D.; McLean, A. G.; Watkins, J. G.</p> <p>2014-11-26</p> <p>Edge fluid–plasma/kinetic–neutral <span class="hlt">modeling</span> of well-diagnosed DIII-D <span class="hlt">experiments</span> is performed in order to document in detail how well certain aspects of experimental measurements are reproduced within the <span class="hlt">model</span> as the transition to detachment is approached. Results indicate, that at high densities near detachment onset, the poloidal temperature profile produced in the simulations agrees well with that measured in <span class="hlt">experiment</span>. However, matching the heat flux in the <span class="hlt">model</span> requires a significant increase in the radiated power compared to what is predicted using standard chemical sputtering rates. Lastly, these results suggest that the <span class="hlt">model</span> is adequate to predict the divertor temperature, provided that the discrepancy in radiated power level can be resolved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020052625&hterms=Mechanics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMechanics','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020052625&hterms=Mechanics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DMechanics"><span><span class="hlt">Experiments</span> and <span class="hlt">Modeling</span> of G-Jitter Fluid Mechanics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Leslie, F. W.; Ramachandran, N.; Whitaker, Ann F. (Technical Monitor)</p> <p>2002-01-01</p> <p>While there is a general understanding of the acceleration environment onboard an orbiting spacecraft, past research efforts in the <span class="hlt">modeling</span> and analysis area have still not produced a general theory that predicts the effects of multi-spectral periodic accelerations on a general class of <span class="hlt">experiments</span> nor have they produced scaling laws that a prospective experimenter can use to assess how an <span class="hlt">experiment</span> might be affected by this acceleration environment. Furthermore, there are no actual flight experimental data that correlates heat or mass transport with measurements of the periodic acceleration environment. The present investigation approaches this problem with carefully conducted terrestrial <span class="hlt">experiments</span> and rigorous numerical <span class="hlt">modeling</span> for better understanding the effect of residual gravity and gentler on <span class="hlt">experiments</span>. The approach is to use magnetic fluids that respond to an imposed magnetic field gradient in much the same way as fluid density responds to a gravitational field. By utilizing a programmable power source in conjunction with an electromagnet, both static and dynamic body forces can be simulated in lab <span class="hlt">experiments</span>. The paper provides an overview of the technique and includes recent results from the <span class="hlt">experiments</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017PhyA..469..750Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017PhyA..469..750Z"><span>Rumor spreading <span class="hlt">model</span> with noise interference in <span class="hlt">complex</span> social networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Liang; Wang, Youguo</p> <p>2017-03-01</p> <p>In this paper, a modified susceptible-infected-removed (SIR) <span class="hlt">model</span> has been proposed to explore rumor diffusion on <span class="hlt">complex</span> social networks. We take variation of connectivity into consideration and assume the variation as noise. On the basis of related literature on virus networks, the noise is described as standard Brownian motion while stochastic differential equations (SDE) have been derived to characterize dynamics of rumor diffusion both on homogeneous networks and heterogeneous networks. Then, theoretical analysis on homogeneous networks has been demonstrated to investigate the solution of SDE <span class="hlt">model</span> and the steady state of rumor diffusion. Simulations both on Barabási-Albert (BA) network and Watts-Strogatz (WS) network display that the addition of noise accelerates rumor diffusion and expands diffusion size, meanwhile, the spreading speed on BA network is much faster than on WS network under the same noise intensity. In addition, there exists a rumor diffusion threshold in statistical average meaning on homogeneous network which is absent on heterogeneous network. Finally, we find a positive correlation between peak value of infected individuals and noise intensity while a negative correlation between rumor lifecycle and noise intensity overall.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009JSMTE..08..023D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009JSMTE..08..023D"><span>A minimal <span class="hlt">model</span> for congestion phenomena on <span class="hlt">complex</span> networks</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>DeMartino, Daniele; Dall'Asta, Luca; Bianconi, Ginestra; Marsili, Matteo</p> <p>2009-08-01</p> <p>We study a minimal <span class="hlt">model</span> of traffic flows in <span class="hlt">complex</span> networks, simple enough for getting analytical results, but with a very rich phenomenology, presenting continuous, discontinuous as well as hybrid phase transitions between a free-flow phase and a congested phase, critical points and different behaviors of scaling with the system size. It consists of random walkers on a queuing network with one-range repulsion, where particles can be destroyed only if they can move. We focus on the dependence on the topology as well as on the level of traffic control. We are able to obtain transition curves and phase diagrams at an analytical level for the ensemble of uncorrelated networks and numerically for single instances. We find that traffic control improves global performance, enlarging the free-flow region in parameter space only in heterogeneous networks. Traffic control introduces non-linear effects and, beyond a critical strength, may trigger the appearance of a congested phase in a discontinuous manner. The <span class="hlt">model</span> also reproduces the crossover in the scaling of traffic fluctuations empirically observed in the Internet, and moreover, a conserved version can reproduce qualitatively some stylized facts of traffic in transportation networks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1616421P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1616421P"><span>Electromagnetic <span class="hlt">modelling</span> of Ground Penetrating Radar responses to <span class="hlt">complex</span> targets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pajewski, Lara; Giannopoulos, Antonis</p> <p>2014-05-01</p> <p>This work deals with the electromagnetic <span class="hlt">modelling</span> of composite structures for Ground Penetrating Radar (GPR) applications. It was developed within the Short-Term Scientific Mission ECOST-STSM-TU1208-211013-035660, funded by COST Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar". The Authors define a set of test concrete structures, hereinafter called cells. The size of each cell is 60 x 100 x 18 cm and the content varies with growing <span class="hlt">complexity</span>, from a simple cell with few rebars of different diameters embedded in concrete at increasing depths, to a final cell with a quite complicated pattern, including a layer of tendons between two overlying meshes of rebars. Other cells, of intermediate <span class="hlt">complexity</span>, contain pvc ducts (air filled or hosting rebars), steel objects commonly used in civil engineering (as a pipe, an angle bar, a box section and an u-channel), as well as void and honeycombing defects. One of the cells has a steel mesh embedded in it, overlying two rebars placed diagonally across the comers of the structure. Two cells include a couple of rebars bent into a right angle and placed on top of each other, with a square/round circle lying at the base of the concrete slab. Inspiration for some of these cells is taken from the very interesting experimental work presented in Ref. [1]. For each cell, a subset of <span class="hlt">models</span> with growing <span class="hlt">complexity</span> is defined, starting from a simple representation of the cell and ending with a more realistic one. In particular, the <span class="hlt">model</span>'s <span class="hlt">complexity</span> increases from the geometrical point of view, as well as in terms of how the constitutive parameters of involved media and GPR antennas are described. Some cells can be simulated in both two and three dimensions; the concrete slab can be approximated as a finite-thickness layer having infinite extension on the transverse plane, thus neglecting how edges affect radargrams, or else its finite size can be fully taken into account. The permittivity of concrete can be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5132223','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5132223"><span>Analysis of a Mouse Skin <span class="hlt">Model</span> of Tuberous Sclerosis <span class="hlt">Complex</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Guo, Yanan; Dreier, John R.; Cao, Juxiang; Du, Heng; Granter, Scott R.; Kwiatkowski, David J.</p> <p>2016-01-01</p> <p>Tuberous Sclerosis <span class="hlt">Complex</span> (TSC) is an autosomal dominant tumor suppressor gene syndrome in which patients develop several types of tumors, including facial angiofibroma, subungual fibroma, Shagreen patch, angiomyolipomas, and lymphangioleiomyomatosis. It is due to inactivating mutations in TSC1 or TSC2. We sought to generate a mouse <span class="hlt">model</span> of one or more of these tumor types by targeting deletion of the Tsc1 gene to fibroblasts using the Fsp-Cre allele. Mutant, Tsc1ccFsp-Cre+ mice survived a median of nearly a year, and developed tumors in multiple sites but did not develop angiomyolipoma or lymphangioleiomyomatosis. They did develop a prominent skin phenotype with marked thickening of the dermis with accumulation of mast cells, that was minimally responsive to systemic rapamycin therapy, and was quite different from the pathology seen in human TSC skin lesions. Recombination and loss of Tsc1 was demonstrated in skin fibroblasts in vivo and in cultured skin fibroblasts. Loss of Tsc1 in fibroblasts in mice does not lead to a <span class="hlt">model</span> of angiomyolipoma or lymphangioleiomyomatosis. PMID:27907099</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27286899','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27286899"><span>Fitting meta-analytic structural equation <span class="hlt">models</span> with <span class="hlt">complex</span> datasets.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wilson, Sandra Jo; Polanin, Joshua R; Lipsey, Mark W</p> <p>2016-06-01</p> <p>A modification of the first stage of the standard procedure for two-stage meta-analytic structural equation <span class="hlt">modeling</span> for use with large <span class="hlt">complex</span> datasets is presented. This modification addresses two common problems that arise in such meta-analyses: (a) primary studies that provide multiple measures of the same construct and (b) the correlation coefficients that exhibit substantial heterogeneity, some of which obscures the relationships between the constructs of interest or undermines the comparability of the correlations across the cells. One component of this approach is a three-level random effects <span class="hlt">model</span> capable of synthesizing a pooled correlation matrix with dependent correlation coefficients. Another component is a meta-regression that can be used to generate covariate-adjusted correlation coefficients that reduce the influence of selected unevenly distributed moderator variables. A non-technical presentation of these techniques is given, along with an illustration of the procedures with a meta-analytic dataset. Copyright © 2016 John Wiley & Sons, Ltd.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/430709','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/430709"><span>The <span class="hlt">complexity</span> of <span class="hlt">model</span> checking for belief revision and update</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liberatore, P.; Schaerf, M.</p> <p>1996-12-31</p> <p>One of the main challenges in the formal <span class="hlt">modeling</span> of common-sense reasoning is the ability to cope with the dynamic nature of the world. Among the approaches put forward to address this problem are belief revision and update. Given a knowledge base T, representing our knowledge of the {open_quotes}state of affairs{close_quotes} of the world of interest, it is possible that we are lead to trust another piece of information P, possibly inconsistent with the old one T. The aim of revision and update operators is to characterize the revised knowledge base T{prime} that incorporates the new formula P into the old one T while preserving consistency and, at the same time, avoiding the loss of too much information in this process. In this paper we study the computational <span class="hlt">complexity</span> of one of the main computational problems of belief revision and update: deciding if an interpretation M is a <span class="hlt">model</span> of the revised knowledge base.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JChPh.139c4301T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JChPh.139c4301T"><span>Reliable <span class="hlt">modeling</span> of the electronic spectra of realistic uranium <span class="hlt">complexes</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tecmer, Paweł; Govind, Niranjan; Kowalski, Karol; de Jong, Wibe A.; Visscher, Lucas</p> <p>2013-07-01</p> <p>We present an EOMCCSD (equation of motion coupled cluster with singles and doubles) study of excited states of the small [UO2]2+ and [UO2]+ <span class="hlt">model</span> systems as well as the larger UVIO2(saldien) <span class="hlt">complex</span>. In addition, the triples contribution within the EOMCCSDT and CR-EOMCCSD(T) (completely renormalized EOMCCSD with non-iterative triples) approaches for the [UO2]2+ and [UO2]+ systems as well as the active-space variant of the CR-EOMCCSD(T) method—CR-EOMCCSd(t)—for the UVIO2(saldien) molecule are investigated. The coupled cluster data were employed as benchmark to choose the "best" appropriate exchange-correlation functional for subsequent time-dependent density functional (TD-DFT) studies on the transition energies for closed-shell species. Furthermore, the influence of the saldien ligands on the electronic structure and excitation energies of the [UO2]+ molecule is discussed. The electronic excitations as well as their oscillator dipole strengths <span class="hlt">modeled</span> with TD-DFT approach using the CAM-B3LYP exchange-correlation functional for the [UVO2(saldien)]- with explicit inclusion of two dimethyl sulfoxide molecules are in good agreement with the experimental data of Takao et al. [Inorg. Chem. 49, 2349 (2010), 10.1021/ic902225f].</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70020336','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70020336"><span>A controlled <span class="hlt">experiment</span> in ground water flow <span class="hlt">model</span> calibration</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hill, M.C.; Cooley, R.L.; Pollock, D.W.</p> <p>1998-01-01</p> <p>Nonlinear regression was introduced to ground water <span class="hlt">modeling</span> in the 1970s, but has been used very little to calibrate numerical <span class="hlt">models</span> of complicated ground water systems. Apparently, nonlinear regression is thought by many to be incapable of addressing such <span class="hlt">complex</span> problems. With what we believe to be the most complicated synthetic test case used for such a study, this work investigates using nonlinear regression in ground water <span class="hlt">model</span> calibration. Results of the study fall into two categories. First, the study demonstrates how systematic use of a well designed nonlinear regression method can indicate the importance of different types of data and can lead to successive improvement of <span class="hlt">models</span> and their parameterizations. Our method differs from previous methods presented in the ground water literature in that (1) weighting is more closely related to expected data errors than is usually the case; (2) defined diagnostic statistics allow for more effective evaluation of the available data, the <span class="hlt">model</span>, and their interaction; and (3) prior information is used more cautiously. Second, our results challenge some commonly held beliefs about <span class="hlt">model</span> calibration. For the test case considered, we show that (1) field measured values of hydraulic conductivity are not as directly applicable to <span class="hlt">models</span> as their use in some geostatistical methods imply; (2) a unique <span class="hlt">model</span> does not necessarily need to be identified to obtain accurate predictions; and (3) in the absence of obvious <span class="hlt">model</span> bias, <span class="hlt">model</span> error was normally distributed. The <span class="hlt">complexity</span> of the test case involved implies that the methods used and conclusions drawn are likely to be powerful in practice.Nonlinear regression was introduced to ground water <span class="hlt">modeling</span> in the 1970s, but has been used very little to calibrate numerical <span class="hlt">models</span> of complicated ground water systems. Apparently, nonlinear regression is thought by many to be incapable of addressing such <span class="hlt">complex</span> problems. With what we believe to be the most complicated synthetic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1122127','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1122127"><span>A <span class="hlt">Complex</span>-Geometry Validation <span class="hlt">Experiment</span> for Advanced Neutron Transport Codes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>David W. Nigg; Anthony W. LaPorta; Joseph W. Nielsen; James Parry; Mark D. DeHart; Samuel E. Bays; William F. Skerjanc</p> <p>2013-11-01</p> <p>The Idaho National Laboratory (INL) has initiated a focused effort to upgrade legacy computational reactor physics software tools and protocols used for support of core fuel management and <span class="hlt">experiment</span> management in the Advanced Test Reactor (ATR) and its companion critical facility (ATRC) at the INL.. This will be accomplished through the introduction of modern high-fidelity computational software and protocols, with appropriate new Verification and Validation (V&V) protocols, over the next 12-18 months. Stochastic and deterministic transport theory based reactor physics codes and nuclear data packages that support this effort include MCNP5[1], SCALE/KENO6[2], HELIOS[3], SCALE/NEWT[2], and ATTILA[4]. Furthermore, a capability for sensitivity analysis and uncertainty quantification based on the TSUNAMI[5] system has also been implemented. Finally, we are also evaluating the Serpent[6] and MC21[7] codes, as additional verification tools in the near term as well as for possible applications to full three-dimensional Monte Carlo based fuel management <span class="hlt">modeling</span> in the longer term. On the experimental side, several new benchmark-quality code validation measurements based on neutron activation spectrometry have been conducted using the ATRC. Results for the first four <span class="hlt">experiments</span>, focused on neutron spectrum measurements within the Northwest Large In-Pile Tube (NW LIPT) and in the core fuel elements surrounding the NW LIPT and the diametrically opposite Southeast IPT have been reported [8,9]. A fifth, very recent, <span class="hlt">experiment</span> focused on detailed measurements of the element-to-element core power distribution is summarized here and examples of the use of the measured data for validation of corresponding MCNP5, HELIOS, NEWT, and Serpent computational <span class="hlt">models</span> using modern least-square adjustment methods are provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B41F0494T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B41F0494T"><span>The Impact of Organo-Mineral <span class="hlt">Complexation</span> on Mineral Weathering in the Soil Zone: Column <span class="hlt">Experiment</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, F.; Dever, S.; Yoo, K.; Imhoff, P. T.; Michael, H. A.</p> <p>2015-12-01</p> <p>While it is well known that organo-mineral <span class="hlt">complexes</span> can protect organic matter (OM) from degradation, its impact on soil mineral weathering is not clear. Strong evidence has shown that the adsorption of OM to mineral surface accelerates the dissolution of some minerals, but these observations are limited to bench-scale <span class="hlt">experiments</span> that focus on specific OM and minerals. In this study, soil samples prepared from an undisturbed forest site were used to determine mineral weathering rates under differing OM sorption on minerals. Soil samples from two depths, 0-6cm and 84-100cm, were chosen to represent different soil OM content and soil mineralogy. Soil OM was removed stepwise by heating samples to 350℃ for different durations (0-6cm: 100% removed, ~50% removed, and no removal; 84-100cm: 100% removed and no removal). Pretreated soil samples were subjected to flow-through, saturated column <span class="hlt">experiments</span> using 0.01M LiCl and 5%CO2/95%air gas saturated (pH = 4.5) influent solution. Each column treatment was run in duplicate under a constant flow rate (Darcy velocity ≈ 8cm/hr). All columns reached a steady state after 600~700 pore volumes at which effluent pH, dissolved organic carbon (DOC) and element concentrations were constant. At the 95% significance level, the DOC from OM-present columns was significantly higher, as expected. Correspondingly, effluent pH was lower in higher OM content columns. The chemical denudation rates were calculated from the effluent concentrations of the elements of interest. For the soil columns from both depths, silicon (Si) leaching rate showed that dissolution of silicate minerals was 2-3 times higher in OM-removed columns, suggesting that organo-mineral <span class="hlt">complexes</span> suppress mineral dissolution. The N2-BET specific surface area (SSA) measurement also showed that the removal of OM increased SSA, which supported the idea that OM adsorption had decreased mineral exposure and thus decreased mineral dissolution. The leaching rates of some</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/231193','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/231193"><span>Design of spatial <span c