Science.gov

Sample records for large-scale multi-dimensional phenomena

  1. A Regression Algorithm for Model Reduction of Large-Scale Multi-Dimensional Problems

    NASA Astrophysics Data System (ADS)

    Rasekh, Ehsan

    2011-11-01

    Model reduction is an approach for fast and cost-efficient modelling of large-scale systems governed by Ordinary Differential Equations (ODEs). Multi-dimensional model reduction has been suggested for reduction of the linear systems simultaneously with respect to frequency and any other parameter of interest. Multi-dimensional model reduction is also used to reduce the weakly nonlinear systems based on Volterra theory. Multiple dimensions degrade the efficiency of reduction by increasing the size of the projection matrix. In this paper a new methodology is proposed to efficiently build the reduced model based on regression analysis. A numerical example confirms the validity of the proposed regression algorithm for model reduction.

  2. Evaluating the use of HILIC in large-scale, multi dimensional proteomics: Horses for courses?

    PubMed Central

    Bensaddek, Dalila; Nicolas, Armel; Lamond, Angus I.

    2015-01-01

    Despite many recent advances in instrumentation, the sheer complexity of biological samples remains a major challenge in large-scale proteomics experiments, reflecting both the large number of protein isoforms and the wide dynamic range of their expression levels. However, while the dynamic range of expression levels for different components of the proteome is estimated to be ∼107–8, the equivalent dynamic range of LC–MS is currently limited to ∼106. Sample pre-fractionation has therefore become routinely used in large-scale proteomics to reduce sample complexity during MS analysis and thus alleviate the problem of ion suppression and undersampling. There is currently a wide range of chromatographic techniques that can be applied as a first dimension separation. Here, we systematically evaluated the use of hydrophilic interaction liquid chromatography (HILIC), in comparison with hSAX, as a first dimension for peptide fractionation in a bottom-up proteomics workflow. The data indicate that in addition to its role as a useful pre-enrichment method for PTM analysis, HILIC can provide a robust, orthogonal and high-resolution method for increasing the depth of proteome coverage in large-scale proteomics experiments. The data also indicate that the choice of using either HILIC, hSAX, or other methods, is best made taking into account the specific types of biological analyses being performed. PMID:26869852

  3. Moon-based Earth Observation for Large Scale Geoscience Phenomena

    NASA Astrophysics Data System (ADS)

    Guo, Huadong; Liu, Guang; Ding, Yixing

    2016-07-01

    The capability of Earth observation for large-global-scale natural phenomena needs to be improved and new observing platform are expected. We have studied the concept of Moon as an Earth observation in these years. Comparing with manmade satellite platform, Moon-based Earth observation can obtain multi-spherical, full-band, active and passive information,which is of following advantages: large observation range, variable view angle, long-term continuous observation, extra-long life cycle, with the characteristics of longevity ,consistency, integrity, stability and uniqueness. Moon-based Earth observation is suitable for monitoring the large scale geoscience phenomena including large scale atmosphere change, large scale ocean change,large scale land surface dynamic change,solid earth dynamic change,etc. For the purpose of establishing a Moon-based Earth observation platform, we already have a plan to study the five aspects as follows: mechanism and models of moon-based observing earth sciences macroscopic phenomena; sensors' parameters optimization and methods of moon-based Earth observation; site selection and environment of moon-based Earth observation; Moon-based Earth observation platform; and Moon-based Earth observation fundamental scientific framework.

  4. Are Critical Phenomena Relevant to Large-Scale Evolution?

    NASA Astrophysics Data System (ADS)

    Sole, Ricard V.; Bascompte, Jordi

    1996-02-01

    Recent theoretical studies, based on the theory of self-organized critical systems, seem to suggest that the dynamical patterns of macroevolution could belong to such class of critical phenomena. Two basic approaches have been proposed: the Kauffman-Johnsen model (based on the use of coupled fitness landscapes) and the Bak-Sneppen model. Both are reviewed here. These models are oversimplified pictures of biological evolution, but the (possible) validity of them is based on the concept of universality, i.e. that apparently very different systems sharing some few common properties should also behave in a very similar way. In this paper we explore the current evidence from the fossil record, showing that some properties that are suggestive of critical dynamics would also be the result of random phenomema. Some general properties of the large-scale pattern of evolution, which should be reproduced by these models, are discussed.

  5. Steps Toward a Large-Scale Solar Image Data Analysis to Differentiate Solar Phenomena

    NASA Astrophysics Data System (ADS)

    Banda, J. M.; Angryk, R. A.; Martens, P. C. H.

    2013-11-01

    We detail the investigation of the first application of several dissimilarity measures for large-scale solar image data analysis. Using a solar-domain-specific benchmark dataset that contains multiple types of phenomena, we analyzed combinations of image parameters with different dissimilarity measures to determine the combinations that will allow us to differentiate between the multiple solar phenomena from both intra-class and inter-class perspectives, where by class we refer to the same types of solar phenomena. We also investigate the problem of reducing data dimensionality by applying multi-dimensional scaling to the dissimilarity matrices that we produced using the previously mentioned combinations. As an early investigation into dimensionality reduction, we investigate by applying multidimensional scaling (MDS) how many MDS components are needed to maintain a good representation of our data (in a new artificial data space) and how many can be discarded to enhance our querying performance. Finally, we present a comparative analysis of several classifiers to determine the quality of the dimensionality reduction achieved with this combination of image parameters, similarity measures, and MDS.

  6. International Halley Watch: Discipline specialists for large scale phenomena

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Niedner, M. B., Jr.

    1986-01-01

    The largest scale structures of comets, their tails, are extremely interesting from a physical point of view, and some of their properties are among the most spectacular displayed by comets. Because the tail(s) is an important component part of a comet, the Large-Scale Phenomena (L-SP) Discipline was created as one of eight different observational methods in which Halley data would be encouraged and collected from all around the world under the aspices of the International Halley Watch (IHW). The L-SP Discipline Specialist (DS) Team resides at NASA/Goddard Space Flight Center under the leadership of John C. Brandt, Malcolm B. Niedner, and their team of image-processing and computer specialists; Jurgan Rahe at NASA Headquarters completes the formal DS science staff. The team has adopted the study of disconnection events (DE) as its principal science target, and it is because of the rapid changes which occur in connection with DE's that such extensive global coverage was deemed necessary to assemble a complete record.

  7. Large-scale phenomena, chapter 3, part D

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Oceanic phenomena with horizontal scales from approximately 100 km up to the widths of the oceans themselves are examined. Data include: shape of geoid, quasi-stationary anomalies due to spatial variations in sea density and steady current systems, and the time dependent variations due to tidal and meteorological forces and to varying currents.

  8. Exploring large-scale phenomena in composite membranes through an efficient implicit-solvent model

    NASA Astrophysics Data System (ADS)

    Laradji, Mohamed; Kumar, P. B. Sunil; Spangler, Eric J.

    2016-07-01

    Several microscopic and mesoscale models have been introduced in the past to investigate various phenomena in lipid membranes. Most of these models account for the solvent explicitly. Since in a typical molecular dynamics simulation, the majority of particles belong to the solvent, much of the computational effort in these simulations is devoted for calculating forces between solvent particles. To overcome this problem, several implicit-solvent mesoscale models for lipid membranes have been proposed during the last few years. In the present article, we review an efficient coarse-grained implicit-solvent model we introduced earlier for studies of lipid membranes. In this model, lipid molecules are coarse-grained into short semi-flexible chains of beads with soft interactions. Through molecular dynamics simulations, the model is used to investigate the thermal, structural and elastic properties of lipid membranes. We will also review here few studies, based on this model, of the phase behavior of nanoscale liposomes, cytoskeleton-induced blebbing in lipid membranes, as well as nanoparticles wrapping and endocytosis by tensionless lipid membranes. Topical Review article submitted to the Journal of Physics D: Applied Physics, May 9, 2016

  9. Large scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Doolin, B. F.

    1975-01-01

    Classes of large scale dynamic systems were discussed in the context of modern control theory. Specific examples discussed were in the technical fields of aeronautics, water resources and electric power.

  10. Large Scale Computing

    NASA Astrophysics Data System (ADS)

    Capiluppi, Paolo

    2005-04-01

    Large Scale Computing is acquiring an important role in the field of data analysis and treatment for many Sciences and also for some Social activities. The present paper discusses the characteristics of Computing when it becomes "Large Scale" and the current state of the art for some particular application needing such a large distributed resources and organization. High Energy Particle Physics (HEP) Experiments are discussed in this respect; in particular the Large Hadron Collider (LHC) Experiments are analyzed. The Computing Models of LHC Experiments represent the current prototype implementation of Large Scale Computing and describe the level of maturity of the possible deployment solutions. Some of the most recent results on the measurements of the performances and functionalities of the LHC Experiments' testing are discussed.

  11. Large-Scale Disasters

    NASA Astrophysics Data System (ADS)

    Gad-El-Hak, Mohamed

    "Extreme" events - including climatic events, such as hurricanes, tornadoes, and drought - can cause massive disruption to society, including large death tolls and property damage in the billions of dollars. Events in recent years have shown the importance of being prepared and that countries need to work together to help alleviate the resulting pain and suffering. This volume presents a review of the broad research field of large-scale disasters. It establishes a common framework for predicting, controlling and managing both manmade and natural disasters. There is a particular focus on events caused by weather and climate change. Other topics include air pollution, tsunamis, disaster modeling, the use of remote sensing and the logistics of disaster management. It will appeal to scientists, engineers, first responders and health-care professionals, in addition to graduate students and researchers who have an interest in the prediction, prevention or mitigation of large-scale disasters.

  12. Large scale tracking algorithms.

    SciTech Connect

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  13. Large scale traffic simulations

    SciTech Connect

    Nagel, K.; Barrett, C.L.; Rickert, M.

    1997-04-01

    Large scale microscopic (i.e. vehicle-based) traffic simulations pose high demands on computational speed in at least two application areas: (i) real-time traffic forecasting, and (ii) long-term planning applications (where repeated {open_quotes}looping{close_quotes} between the microsimulation and the simulated planning of individual person`s behavior is necessary). As a rough number, a real-time simulation of an area such as Los Angeles (ca. 1 million travellers) will need a computational speed of much higher than 1 million {open_quotes}particle{close_quotes} (= vehicle) updates per second. This paper reviews how this problem is approached in different projects and how these approaches are dependent both on the specific questions and on the prospective user community. The approaches reach from highly parallel and vectorizable, single-bit implementations on parallel supercomputers for Statistical Physics questions, via more realistic implementations on coupled workstations, to more complicated driving dynamics implemented again on parallel supercomputers. 45 refs., 9 figs., 1 tab.

  14. Large-Scale Multi-Dimensional Document Clustering on GPU Clusters

    SciTech Connect

    Cui, Xiaohui; Mueller, Frank; Zhang, Yongpeng; Potok, Thomas E

    2010-01-01

    Document clustering plays an important role in data mining systems. Recently, a flocking-based document clustering algorithm has been proposed to solve the problem through simulation resembling the flocking behavior of birds in nature. This method is superior to other clustering algorithms, including k-means, in the sense that the outcome is not sensitive to the initial state. One limitation of this approach is that the algorithmic complexity is inherently quadratic in the number of documents. As a result, execution time becomes a bottleneck with large number of documents. In this paper, we assess the benefits of exploiting the computational power of Beowulf-like clusters equipped with contemporary Graphics Processing Units (GPUs) as a means to significantly reduce the runtime of flocking-based document clustering. Our framework scales up to over one million documents processed simultaneously in a sixteennode GPU cluster. Results are also compared to a four-node cluster with higher-end GPUs. On these clusters, we observe 30X-50X speedups, which demonstrates the potential of GPU clusters to efficiently solve massive data mining problems. Such speedups combined with the scalability potential and accelerator-based parallelization are unique in the domain of document-based data mining, to the best of our knowledge.

  15. Multi-dimensional laser radars

    NASA Astrophysics Data System (ADS)

    Molebny, Vasyl; Steinvall, Ove

    2014-06-01

    We introduce the term "multi-dimensional laser radar", where the dimensions mean not only the coordinates of the object in space, but its velocity and orientation, parameters of the media: scattering, refraction, temperature, humidity, wind velocity, etc. The parameters can change in time and can be combined. For example, rendezvous and docking missions, autonomous planetary landing, along with laser ranging, laser altimetry, laser Doppler velocimetry, are thought to have aboard also the 3D ladar imaging. Operating in combinations, they provide more accurate and safer navigation, docking or landing, hazard avoidance capabilities. Combination with Doppler-based measurements provides more accurate navigation for both space and cruise missile applications. Critical is the information identifying the snipers based on combination of polarization and fluctuation parameters with data from other sources. Combination of thermal imaging and vibrometry can unveil the functionality of detected targets. Hyperspectral probing with laser reveals even more parameters. Different algorithms and architectures of ladar-based target acquisition, reconstruction of 3D images from point cloud, information fusion and displaying is discussed with special attention to the technologies of flash illumination and single-photon focal-plane-array detection.

  16. Statistical Downscaling in Multi-dimensional Wave Climate Forecast

    NASA Astrophysics Data System (ADS)

    Camus, P.; Méndez, F. J.; Medina, R.; Losada, I. J.; Cofiño, A. S.; Gutiérrez, J. M.

    2009-04-01

    Wave climate at a particular site is defined by the statistical distribution of sea state parameters, such as significant wave height, mean wave period, mean wave direction, wind velocity, wind direction and storm surge. Nowadays, long-term time series of these parameters are available from reanalysis databases obtained by numerical models. The Self-Organizing Map (SOM) technique is applied to characterize multi-dimensional wave climate, obtaining the relevant "wave types" spanning the historical variability. This technique summarizes multi-dimension of wave climate in terms of a set of clusters projected in low-dimensional lattice with a spatial organization, providing Probability Density Functions (PDFs) on the lattice. On the other hand, wind and storm surge depend on instantaneous local large-scale sea level pressure (SLP) fields while waves depend on the recent history of these fields (say, 1 to 5 days). Thus, these variables are associated with large-scale atmospheric circulation patterns. In this work, a nearest-neighbors analog method is used to predict monthly multi-dimensional wave climate. This method establishes relationships between the large-scale atmospheric circulation patterns from numerical models (SLP fields as predictors) with local wave databases of observations (monthly wave climate SOM PDFs as predictand) to set up statistical models. A wave reanalysis database, developed by Puertos del Estado (Ministerio de Fomento), is considered as historical time series of local variables. The simultaneous SLP fields calculated by NCEP atmospheric reanalysis are used as predictors. Several applications with different size of sea level pressure grid and with different temporal domain resolution are compared to obtain the optimal statistical model that better represents the monthly wave climate at a particular site. In this work we examine the potential skill of this downscaling approach considering perfect-model conditions, but we will also analyze the

  17. Anonymous voting for multi-dimensional CV quantum system

    NASA Astrophysics Data System (ADS)

    Rong-Hua, Shi; Yi, Xiao; Jin-Jing, Shi; Ying, Guo; Moon-Ho, Lee

    2016-06-01

    We investigate the design of anonymous voting protocols, CV-based binary-valued ballot and CV-based multi-valued ballot with continuous variables (CV) in a multi-dimensional quantum cryptosystem to ensure the security of voting procedure and data privacy. The quantum entangled states are employed in the continuous variable quantum system to carry the voting information and assist information transmission, which takes the advantage of the GHZ-like states in terms of improving the utilization of quantum states by decreasing the number of required quantum states. It provides a potential approach to achieve the efficient quantum anonymous voting with high transmission security, especially in large-scale votes. Project supported by the National Natural Science Foundation of China (Grant Nos. 61272495, 61379153, and 61401519), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130162110012), and the MEST-NRF of Korea (Grant No. 2012-002521).

  18. Semantic overlay network for large-scale spatial information indexing

    NASA Astrophysics Data System (ADS)

    Zou, Zhiqiang; Wang, Yue; Cao, Kai; Qu, Tianshan; Wang, Zhongmin

    2013-08-01

    The increased demand for online services of spatial information poses new challenges to the combined filed of Computer Science and Geographic Information Science. Amongst others, these include fast indexing of spatial data in distributed networks. In this paper we propose a novel semantic overlay network for large-scale multi-dimensional spatial information indexing, called SON_LSII, which has a hybrid structure integrating a semantic quad-tree and Chord ring. The SON_LSII is a small world overlay network that achieves a very competitive trade-off between indexing efficiency and maintenance overhead. To create SON_LSII, we use an effective semantic clustering strategy that considers two aspects, i.e., the semantic of spatial information that peer holds in overlay network and physical network performances. Based on SON_LSII, a mapping method is used to reduce the multi-dimensional features into a single dimension and an efficient indexing algorithm is presented to support complex range queries of the spatial information with a massive number of concurrent users. The results from extensive experiments demonstrate that SON_LSII is superior to existing overlay networks in various respects, including scalability, maintenance, rate of indexing hits, indexing logical hops, and adaptability. Thus, the proposed SON_LSII can be used for large-scale spatial information indexing.

  19. Galaxy clustering on large scales.

    PubMed

    Efstathiou, G

    1993-06-01

    I describe some recent observations of large-scale structure in the galaxy distribution. The best constraints come from two-dimensional galaxy surveys and studies of angular correlation functions. Results from galaxy redshift surveys are much less precise but are consistent with the angular correlations, provided the distortions in mapping between real-space and redshift-space are relatively weak. The galaxy two-point correlation function, rich-cluster two-point correlation function, and galaxy-cluster cross-correlation function are all well described on large scales ( greater, similar 20h-1 Mpc, where the Hubble constant, H0 = 100h km.s-1.Mpc; 1 pc = 3.09 x 10(16) m) by the power spectrum of an initially scale-invariant, adiabatic, cold-dark-matter Universe with Gamma = Omegah approximately 0.2. I discuss how this fits in with the Cosmic Background Explorer (COBE) satellite detection of large-scale anisotropies in the microwave background radiation and other measures of large-scale structure in the Universe. PMID:11607400

  20. Very Large Scale Integration (VLSI).

    ERIC Educational Resources Information Center

    Yeaman, Andrew R. J.

    Very Large Scale Integration (VLSI), the state-of-the-art production techniques for computer chips, promises such powerful, inexpensive computing that, in the future, people will be able to communicate with computer devices in natural language or even speech. However, before full-scale VLSI implementation can occur, certain salient factors must be…

  1. Homogenization of Large-Scale Movement Models in Ecology

    USGS Publications Warehouse

    Garlick, M.J.; Powell, J.A.; Hooten, M.B.; McFarlane, L.R.

    2011-01-01

    A difficulty in using diffusion models to predict large scale animal population dispersal is that individuals move differently based on local information (as opposed to gradients) in differing habitat types. This can be accommodated by using ecological diffusion. However, real environments are often spatially complex, limiting application of a direct approach. Homogenization for partial differential equations has long been applied to Fickian diffusion (in which average individual movement is organized along gradients of habitat and population density). We derive a homogenization procedure for ecological diffusion and apply it to a simple model for chronic wasting disease in mule deer. Homogenization allows us to determine the impact of small scale (10-100 m) habitat variability on large scale (10-100 km) movement. The procedure generates asymptotic equations for solutions on the large scale with parameters defined by small-scale variation. The simplicity of this homogenization procedure is striking when compared to the multi-dimensional homogenization procedure for Fickian diffusion,and the method will be equally straightforward for more complex models. ?? 2010 Society for Mathematical Biology.

  2. Microfluidic large-scale integration.

    PubMed

    Thorsen, Todd; Maerkl, Sebastian J; Quake, Stephen R

    2002-10-18

    We developed high-density microfluidic chips that contain plumbing networks with thousands of micromechanical valves and hundreds of individually addressable chambers. These fluidic devices are analogous to electronic integrated circuits fabricated using large-scale integration. A key component of these networks is the fluidic multiplexor, which is a combinatorial array of binary valve patterns that exponentially increases the processing power of a network by allowing complex fluid manipulations with a minimal number of inputs. We used these integrated microfluidic networks to construct the microfluidic analog of a comparator array and a microfluidic memory storage device whose behavior resembles random-access memory. PMID:12351675

  3. Large-scale Globally Propagating Coronal Waves

    NASA Astrophysics Data System (ADS)

    Warmuth, Alexander

    2015-09-01

    Large-scale, globally propagating wave-like disturbances have been observed in the solar chromosphere and by inference in the corona since the 1960s. However, detailed analysis of these phenomena has only been conducted since the late 1990s. This was prompted by the availability of high-cadence coronal imaging data from numerous spaced-based instruments, which routinely show spectacular globally propagating bright fronts. Coronal waves, as these perturbations are usually referred to, have now been observed in a wide range of spectral channels, yielding a wealth of information. Many findings have supported the "classical" interpretation of the disturbances: fast-mode MHD waves or shocks that are propagating in the solar corona. However, observations that seemed inconsistent with this picture have stimulated the development of alternative models in which "pseudo waves" are generated by magnetic reconfiguration in the framework of an expanding coronal mass ejection. This has resulted in a vigorous debate on the physical nature of these disturbances. This review focuses on demonstrating how the numerous observational findings of the last one and a half decades can be used to constrain our models of large-scale coronal waves, and how a coherent physical understanding of these disturbances is finally emerging.

  4. Large scale topography of Io

    NASA Technical Reports Server (NTRS)

    Gaskell, R. W.; Synnott, S. P.

    1987-01-01

    To investigate the large scale topography of the Jovian satellite Io, both limb observations and stereographic techniques applied to landmarks are used. The raw data for this study consists of Voyager 1 images of Io, 800x800 arrays of picture elements each of which can take on 256 possible brightness values. In analyzing this data it was necessary to identify and locate landmarks and limb points on the raw images, remove the image distortions caused by the camera electronics and translate the corrected locations into positions relative to a reference geoid. Minimizing the uncertainty in the corrected locations is crucial to the success of this project. In the highest resolution frames, an error of a tenth of a pixel in image space location can lead to a 300 m error in true location. In the lowest resolution frames, the same error can lead to an uncertainty of several km.

  5. Challenges for Large Scale Simulations

    NASA Astrophysics Data System (ADS)

    Troyer, Matthias

    2010-03-01

    With computational approaches becoming ubiquitous the growing impact of large scale computing on research influences both theoretical and experimental work. I will review a few examples in condensed matter physics and quantum optics, including the impact of computer simulations in the search for supersolidity, thermometry in ultracold quantum gases, and the challenging search for novel phases in strongly correlated electron systems. While only a decade ago such simulations needed the fastest supercomputers, many simulations can now be performed on small workstation clusters or even a laptop: what was previously restricted to a few experts can now potentially be used by many. Only part of the gain in computational capabilities is due to Moore's law and improvement in hardware. Equally impressive is the performance gain due to new algorithms - as I will illustrate using some recently developed algorithms. At the same time modern peta-scale supercomputers offer unprecedented computational power and allow us to tackle new problems and address questions that were impossible to solve numerically only a few years ago. While there is a roadmap for future hardware developments to exascale and beyond, the main challenges are on the algorithmic and software infrastructure side. Among the problems that face the computational physicist are: the development of new algorithms that scale to thousands of cores and beyond, a software infrastructure that lifts code development to a higher level and speeds up the development of new simulation programs for large scale computing machines, tools to analyze the large volume of data obtained from such simulations, and as an emerging field provenance-aware software that aims for reproducibility of the complete computational workflow from model parameters to the final figures. Interdisciplinary collaborations and collective efforts will be required, in contrast to the cottage-industry culture currently present in many areas of computational

  6. Large Scale Homing in Honeybees

    PubMed Central

    Pahl, Mario; Zhu, Hong; Tautz, Jürgen; Zhang, Shaowu

    2011-01-01

    Honeybee foragers frequently fly several kilometres to and from vital resources, and communicate those locations to their nest mates by a symbolic dance language. Research has shown that they achieve this feat by memorizing landmarks and the skyline panorama, using the sun and polarized skylight as compasses and by integrating their outbound flight paths. In order to investigate the capacity of the honeybees' homing abilities, we artificially displaced foragers to novel release spots at various distances up to 13 km in the four cardinal directions. Returning bees were individually registered by a radio frequency identification (RFID) system at the hive entrance. We found that homing rate, homing speed and the maximum homing distance depend on the release direction. Bees released in the east were more likely to find their way back home, and returned faster than bees released in any other direction, due to the familiarity of global landmarks seen from the hive. Our findings suggest that such large scale homing is facilitated by global landmarks acting as beacons, and possibly the entire skyline panorama. PMID:21602920

  7. ICM: a web server for integrated clustering of multi-dimensional biomedical data.

    PubMed

    He, Song; He, Haochen; Xu, Wenjian; Huang, Xin; Jiang, Shuai; Li, Fei; He, Fuchu; Bo, Xiaochen

    2016-07-01

    Large-scale efforts for parallel acquisition of multi-omics profiling continue to generate extensive amounts of multi-dimensional biomedical data. Thus, integrated clustering of multiple types of omics data is essential for developing individual-based treatments and precision medicine. However, while rapid progress has been made, methods for integrated clustering are lacking an intuitive web interface that facilitates the biomedical researchers without sufficient programming skills. Here, we present a web tool, named Integrated Clustering of Multi-dimensional biomedical data (ICM), that provides an interface from which to fuse, cluster and visualize multi-dimensional biomedical data and knowledge. With ICM, users can explore the heterogeneity of a disease or a biological process by identifying subgroups of patients. The results obtained can then be interactively modified by using an intuitive user interface. Researchers can also exchange the results from ICM with collaborators via a web link containing a Project ID number that will directly pull up the analysis results being shared. ICM also support incremental clustering that allows users to add new sample data into the data of a previous study to obtain a clustering result. Currently, the ICM web server is available with no login requirement and at no cost at http://biotech.bmi.ac.cn/icm/. PMID:27131784

  8. Vlasov multi-dimensional model dispersion relation

    SciTech Connect

    Lushnikov, Pavel M.; Rose, Harvey A.; Silantyev, Denis A.; Vladimirova, Natalia

    2014-07-15

    A hybrid model of the Vlasov equation in multiple spatial dimension D > 1 [H. A. Rose and W. Daughton, Phys. Plasmas 18, 122109 (2011)], the Vlasov multi dimensional model (VMD), consists of standard Vlasov dynamics along a preferred direction, the z direction, and N flows. At each z, these flows are in the plane perpendicular to the z axis. They satisfy Eulerian-type hydrodynamics with coupling by self-consistent electric and magnetic fields. Every solution of the VMD is an exact solution of the original Vlasov equation. We show approximate convergence of the VMD Langmuir wave dispersion relation in thermal plasma to that of Vlasov-Landau as N increases. Departure from strict rotational invariance about the z axis for small perpendicular wavenumber Langmuir fluctuations in 3D goes to zero like θ{sup N}, where θ is the polar angle and flows are arranged uniformly over the azimuthal angle.

  9. Large Scale Nanolaminate Deformable Mirror

    SciTech Connect

    Papavasiliou, A; Olivier, S; Barbee, T; Miles, R; Chang, K

    2005-11-30

    This work concerns the development of a technology that uses Nanolaminate foils to form light-weight, deformable mirrors that are scalable over a wide range of mirror sizes. While MEMS-based deformable mirrors and spatial light modulators have considerably reduced the cost and increased the capabilities of adaptive optic systems, there has not been a way to utilize the advantages of lithography and batch-fabrication to produce large-scale deformable mirrors. This technology is made scalable by using fabrication techniques and lithography that are not limited to the sizes of conventional MEMS devices. Like many MEMS devices, these mirrors use parallel plate electrostatic actuators. This technology replicates that functionality by suspending a horizontal piece of nanolaminate foil over an electrode by electroplated nickel posts. This actuator is attached, with another post, to another nanolaminate foil that acts as the mirror surface. Most MEMS devices are produced with integrated circuit lithography techniques that are capable of very small line widths, but are not scalable to large sizes. This technology is very tolerant of lithography errors and can use coarser, printed circuit board lithography techniques that can be scaled to very large sizes. These mirrors use small, lithographically defined actuators and thin nanolaminate foils allowing them to produce deformations over a large area while minimizing weight. This paper will describe a staged program to develop this technology. First-principles models were developed to determine design parameters. Three stages of fabrication will be described starting with a 3 x 3 device using conventional metal foils and epoxy to a 10-across all-metal device with nanolaminate mirror surfaces.

  10. Large-Scale Information Systems

    SciTech Connect

    D. M. Nicol; H. R. Ammerlahn; M. E. Goldsby; M. M. Johnson; D. E. Rhodes; A. S. Yoshimura

    2000-12-01

    Large enterprises are ever more dependent on their Large-Scale Information Systems (LSLS), computer systems that are distinguished architecturally by distributed components--data sources, networks, computing engines, simulations, human-in-the-loop control and remote access stations. These systems provide such capabilities as workflow, data fusion and distributed database access. The Nuclear Weapons Complex (NWC) contains many examples of LSIS components, a fact that motivates this research. However, most LSIS in use grew up from collections of separate subsystems that were not designed to be components of an integrated system. For this reason, they are often difficult to analyze and control. The problem is made more difficult by the size of a typical system, its diversity of information sources, and the institutional complexities associated with its geographic distribution across the enterprise. Moreover, there is no integrated approach for analyzing or managing such systems. Indeed, integrated development of LSIS is an active area of academic research. This work developed such an approach by simulating the various components of the LSIS and allowing the simulated components to interact with real LSIS subsystems. This research demonstrated two benefits. First, applying it to a particular LSIS provided a thorough understanding of the interfaces between the system's components. Second, it demonstrated how more rapid and detailed answers could be obtained to questions significant to the enterprise by interacting with the relevant LSIS subsystems through simulated components designed with those questions in mind. In a final, added phase of the project, investigations were made on extending this research to wireless communication networks in support of telemetry applications.

  11. Multi-dimensionally encoded magnetic resonance imaging

    PubMed Central

    Lin, Fa-Hsuan

    2013-01-01

    Magnetic resonance imaging typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here we propose the multi-dimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel RF coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. PMID:22926830

  12. Large-Scale Statistics for Cu Electromigration

    NASA Astrophysics Data System (ADS)

    Hauschildt, M.; Gall, M.; Hernandez, R.

    2009-06-01

    Even after the successful introduction of Cu-based metallization, the electromigration failure risk has remained one of the important reliability concerns for advanced process technologies. The observation of strong bimodality for the electron up-flow direction in dual-inlaid Cu interconnects has added complexity, but is now widely accepted. The failure voids can occur both within the via ("early" mode) or within the trench ("late" mode). More recently, bimodality has been reported also in down-flow electromigration, leading to very short lifetimes due to small, slit-shaped voids under vias. For a more thorough investigation of these early failure phenomena, specific test structures were designed based on the Wheatstone Bridge technique. The use of these structures enabled an increase of the tested sample size close to 675000, allowing a direct analysis of electromigration failure mechanisms at the single-digit ppm regime. Results indicate that down-flow electromigration exhibits bimodality at very small percentage levels, not readily identifiable with standard testing methods. The activation energy for the down-flow early failure mechanism was determined to be 0.83±0.02 eV. Within the small error bounds of this large-scale statistical experiment, this value is deemed to be significantly lower than the usually reported activation energy of 0.90 eV for electromigration-induced diffusion along Cu/SiCN interfaces. Due to the advantages of the Wheatstone Bridge technique, we were also able to expand the experimental temperature range down to 150° C, coming quite close to typical operating conditions up to 125° C. As a result of the lowered activation energy, we conclude that the down-flow early failure mode may control the chip lifetime at operating conditions. The slit-like character of the early failure void morphology also raises concerns about the validity of the Blech-effect for this mechanism. A very small amount of Cu depletion may cause failure even before a

  13. The effect of background turbulence on the propagation of large-scale flames

    NASA Astrophysics Data System (ADS)

    Matalon, Moshe

    2008-12-01

    This paper is based on an invited presentation at the Conference on Turbulent Mixing and Beyond held in the Abdus Salam International Center for Theoretical Physics, Trieste, Italy (August 2007). It consists of a summary of recent investigations aimed at understanding the nature and consequences of the Darrieus-Landau instability that is prominent in premixed combustion. It describes rigorous asymptotic methodologies used to simplify the propagation problem of multi-dimensional and time-dependent premixed flames in order to understand the nonlinear evolution of hydrodynamically unstable flames. In particular, it addresses the effect of background turbulent noise on the structure and propagation of large-scale flames.

  14. Large-Scale Reform Comes of Age

    ERIC Educational Resources Information Center

    Fullan, Michael

    2009-01-01

    This article reviews the history of large-scale education reform and makes the case that large-scale or whole system reform policies and strategies are becoming increasingly evident. The review briefly addresses the pre 1997 period concluding that while the pressure for reform was mounting that there were very few examples of deliberate or…

  15. Large-scale infrared scene projectors

    NASA Astrophysics Data System (ADS)

    Murray, Darin A.

    1999-07-01

    Large-scale infrared scene projectors, typically have unique opto-mechanical characteristics associated to their application. This paper outlines two large-scale zoom lens assemblies with different environmental and package constraints. Various challenges and their respective solutions are discussed and presented.

  16. Scalable pattern recognition for large-scale scientific data mining

    SciTech Connect

    Kamath, C.; Musick, R.

    1998-03-23

    Our ability to generate data far outstrips our ability to explore and understand it. The true value of this data lies not in its final size or complexity, but rather in our ability to exploit the data to achieve scientific goals. The data generated by programs such as ASCI have such a large scale that it is impractical to manually analyze, explore, and understand it. As a result, useful information is overlooked, and the potential benefits of increased computational and data gathering capabilities are only partially realized. The difficulties that will be faced by ASCI applications in the near future are foreshadowed by the challenges currently facing astrophysicists in making full use of the data they have collected over the years. For example, among other difficulties, astrophysicists have expressed concern that the sheer size of their data restricts them to looking at very small, narrow portions at any one time. This narrow focus has resulted in the loss of ``serendipitous`` discoveries which have been so vital to progress in the area in the past. To solve this problem, a new generation of computational tools and techniques is needed to help automate the exploration and management of large scientific data. This whitepaper proposes applying and extending ideas from the area of data mining, in particular pattern recognition, to improve the way in which scientists interact with large, multi-dimensional, time-varying data.

  17. Towards a genuinely multi-dimensional upwind scheme

    NASA Technical Reports Server (NTRS)

    Powell, Kenneth G.; Vanleer, Bram; Roe, Philip L.

    1990-01-01

    Methods of incorporating multi-dimensional ideas into algorithms for the solution of Euler equations are presented. Three schemes are developed and tested: a scheme based on a downwind distribution, a scheme based on a rotated Riemann solver and a scheme based on a generalized Riemann solver. The schemes show an improvement over first-order, grid-aligned upwind schemes, but the higher-order performance is less impressive. An outlook for the future of multi-dimensional upwind schemes is given.

  18. Central Schemes for Multi-Dimensional Hamilton-Jacobi Equations

    NASA Technical Reports Server (NTRS)

    Bryson, Steve; Levy, Doron; Biegel, Bryan (Technical Monitor)

    2002-01-01

    We present new, efficient central schemes for multi-dimensional Hamilton-Jacobi equations. These non-oscillatory, non-staggered schemes are first- and second-order accurate and are designed to scale well with an increasing dimension. Efficiency is obtained by carefully choosing the location of the evolution points and by using a one-dimensional projection step. First-and second-order accuracy is verified for a variety of multi-dimensional, convex and non-convex problems.

  19. Multi-dimensional tunnelling and complex momentum

    NASA Technical Reports Server (NTRS)

    Bowcock, Peter; Gregory, Ruth

    1991-01-01

    The problem of modeling tunneling phenomena in more than one dimension is examined. It is found that existing techniques are inadequate in a wide class of situations, due to their inability to deal with concurrent classical motion. The generalization of these methods to allow for complex momenta is shown, and improved techniques are demonstrated with a selection of illustrative examples. Possible applications are presented.

  20. Synthesis of small and large scale dynamos

    NASA Astrophysics Data System (ADS)

    Subramanian, Kandaswamy

    Using a closure model for the evolution of magnetic correlations, we uncover an interesting plausible saturated state of the small-scale fluctuation dynamo (SSD) and a novel analogy between quantum mechanical tunnelling and the generation of large-scale fields. Large scale fields develop via the α-effect, but as magnetic helicity can only change on a resistive timescale, the time it takes to organize the field into large scales increases with magnetic Reynolds number. This is very similar to the results which obtain from simulations using the full MHD equations.

  1. Estimating large-scale fracture permeability of unsaturatedrockusing barometric pressure data

    SciTech Connect

    Wu, Yu-Shu; Zhang, Keni; Liu, Hui-Hai

    2005-05-17

    We present a three-dimensional modeling study of gas flow inthe unsaturated fractured rock of Yucca Mountain. Our objective is toestimate large-scale fracture permeability, using the changes insubsurface pneumatic pressure in response to barometric pressure changesat the land surface. We incorporate the field-measured pneumatic datainto a multiphase flow model for describing the coupled processes ofliquid and gas flow under ambient geothermal conditions. Comparison offield-measured pneumatic data with model-predicted gas pressures is foundto be a powerful technique for estimating the fracture permeability ofthe unsaturated fractured rock, which is otherwise extremely difficult todetermine on the large scales of interest. In addition, this studydemonstrates that the multi-dimensional-flow effect on estimatedpermeability values is significant and should be included whendetermining fracture permeability in heterogeneous fracturedmedia.

  2. Large-scale regions of antimatter

    SciTech Connect

    Grobov, A. V. Rubin, S. G.

    2015-07-15

    Amodified mechanism of the formation of large-scale antimatter regions is proposed. Antimatter appears owing to fluctuations of a complex scalar field that carries a baryon charge in the inflation era.

  3. Large-scale quantum effects in biological systems

    NASA Astrophysics Data System (ADS)

    Mesquita, Marcus V.; Vasconcellos, Áurea R.; Luzzi, Roberto; Mascarenhas, Sergio

    Particular aspects of large-scale quantum effects in biological systems, such as biopolymers and also microtubules in the cytoskeleton of neurons which can have relevance in brain functioning, are discussed. The microscopic (quantum mechanical) and macroscopic (quantum statistical mechanical) aspects, and the emergence of complex behavior, are described. This phenomena consists of the large-scale coherent process of Fröhlich-Bose-Einstein condensation in open and sufficiently far-from-equilibrium biopolymers. Associated with this phenomenon is the presence of Schrödinger-Davydov solitons, which propagate, undistorted and undamped, when embedded in the Fröhlich-Bose-Einstein condensate, thus allowing for the transmission of signals at long distances, involving a question relevant to bioenergetics.

  4. Fast Packet Classification Using Multi-Dimensional Encoding

    NASA Astrophysics Data System (ADS)

    Huang, Chi Jia; Chen, Chien

    Internet routers need to classify incoming packets quickly into flows in order to support features such as Internet security, virtual private networks and Quality of Service (QoS). Packet classification uses information contained in the packet header, and a predefined rule table in the routers. Packet classification of multiple fields is generally a difficult problem. Hence, researchers have proposed various algorithms. This study proposes a multi-dimensional encoding method in which parameters such as the source IP address, destination IP address, source port, destination port and protocol type are placed in a multi-dimensional space. Similar to the previously best known algorithm, i.e., bitmap intersection, multi-dimensional encoding is based on the multi-dimensional range lookup approach, in which rules are divided into several multi-dimensional collision-free rule sets. These sets are then used to form the new coding vector to replace the bit vector of the bitmap intersection algorithm. The average memory storage of this encoding is Θ (L · N · log N) for each dimension, where L denotes the number of collision-free rule sets, and N represents the number of rules. The multi-dimensional encoding practically requires much less memory than bitmap intersection algorithm. Additionally, the computation needed for this encoding is as simple as bitmap intersection algorithm. The low memory requirement of the proposed scheme means that it not only decreases the cost of packet classification engine, but also increases the classification performance, since memory represents the performance bottleneck in the packet classification engine implementation using a network processor.

  5. Large-scale inhomogeneities and galaxy statistics

    NASA Technical Reports Server (NTRS)

    Schaeffer, R.; Silk, J.

    1984-01-01

    The density fluctuations associated with the formation of large-scale cosmic pancake-like and filamentary structures are evaluated using the Zel'dovich approximation for the evolution of nonlinear inhomogeneities in the expanding universe. It is shown that the large-scale nonlinear density fluctuations in the galaxy distribution due to pancakes modify the standard scale-invariant correlation function xi(r) at scales comparable to the coherence length of adiabatic fluctuations. The typical contribution of pancakes and filaments to the J3 integral, and more generally to the moments of galaxy counts in a volume of approximately (15-40 per h Mpc)exp 3, provides a statistical test for the existence of large scale inhomogeneities. An application to several recent three dimensional data sets shows that despite large observational uncertainties over the relevant scales characteristic features may be present that can be attributed to pancakes in most, but not all, of the various galaxy samples.

  6. Survey on large scale system control methods

    NASA Technical Reports Server (NTRS)

    Mercadal, Mathieu

    1987-01-01

    The problem inherent to large scale systems such as power network, communication network and economic or ecological systems were studied. The increase in size and flexibility of future spacecraft has put those dynamical systems into the category of large scale systems, and tools specific to the class of large systems are being sought to design control systems that can guarantee more stability and better performance. Among several survey papers, reference was found to a thorough investigation on decentralized control methods. Especially helpful was the classification made of the different existing approaches to deal with large scale systems. A very similar classification is used, even though the papers surveyed are somehow different from the ones reviewed in other papers. Special attention is brought to the applicability of the existing methods to controlling large mechanical systems like large space structures. Some recent developments are added to this survey.

  7. The large-scale distribution of galaxies

    NASA Technical Reports Server (NTRS)

    Geller, Margaret J.

    1989-01-01

    The spatial distribution of galaxies in the universe is characterized on the basis of the six completed strips of the Harvard-Smithsonian Center for Astrophysics redshift-survey extension. The design of the survey is briefly reviewed, and the results are presented graphically. Vast low-density voids similar to the void in Bootes are found, almost completely surrounded by thin sheets of galaxies. Also discussed are the implications of the results for the survey sampling problem, the two-point correlation function of the galaxy distribution, the possibility of detecting large-scale coherent flows, theoretical models of large-scale structure, and the identification of groups and clusters of galaxies.

  8. New Large-scale Control Strategies for Turbulent Boundary Layers

    NASA Astrophysics Data System (ADS)

    Schoppa, Wade; Hussain, Fazle

    1997-11-01

    Using direct numerical simulations of turbulent channel flow, we present robust strategies for drag reduction by prevention of streamwise vortex formation near the wall. Instability of lifted, vortex-free low-speed streaks is shown to generate new streamwise vortices, which dominate near-wall turbulence phenomena. The newly-found instability mechanism initiates streak waviness in the (x,z) plane which leads to ωx sheets. Streak waviness induces positive partial u/partial x (i.e. positive VISA) which causes these sheets to then collapse via stretching (rather than roll up) into streamwise vortices. Significantly, the 3D features of the (instantaneous) instability-generated vortices agree well with the coherent structures educed (i.e. ensemble-averaged) from fully turbulent flow, suggesting the prevalence of this instability mechanism. The new control via large-scale streak manipulation exploits this crucial role of streak instability in vortex generation. An x-independent forcing with a z wavelength of 4 streak spacings, with an amplitude of only 5% of the centerline velocity, produces a significant sustained drag reduction: 20% for imposed counterrotating large-scale swirls and 50% for colliding spanwise wall jet-like forcing. These results suggest promising drag reduction strategies, involving large-scale (hence more durable) actuation and requiring no wall sensors or feedback logic.

  9. Large Scale Commodity Clusters for Lattice QCD

    SciTech Connect

    A. Pochinsky; W. Akers; R. Brower; J. Chen; P. Dreher; R. Edwards; S. Gottlieb; D. Holmgren; P. Mackenzie; J. Negele; D. Richards; J. Simone; W. Watson

    2002-06-01

    We describe the construction of large scale clusters for lattice QCD computing being developed under the umbrella of the U.S. DoE SciDAC initiative. We discuss the study of floating point and network performance that drove the design of the cluster, and present our plans for future multi-Terascale facilities.

  10. Management of large-scale technology

    NASA Technical Reports Server (NTRS)

    Levine, A.

    1985-01-01

    Two major themes are addressed in this assessment of the management of large-scale NASA programs: (1) how a high technology agency was a decade marked by a rapid expansion of funds and manpower in the first half and almost as rapid contraction in the second; and (2) how NASA combined central planning and control with decentralized project execution.

  11. A Large Scale Computer Terminal Output Controller.

    ERIC Educational Resources Information Center

    Tucker, Paul Thomas

    This paper describes the design and implementation of a large scale computer terminal output controller which supervises the transfer of information from a Control Data 6400 Computer to a PLATO IV data network. It discusses the cost considerations leading to the selection of educational television channels rather than telephone lines for…

  12. Large-scale CFB combustion demonstration project

    SciTech Connect

    Nielsen, P.T.; Hebb, J.L.; Aquino, R.

    1998-07-01

    The Jacksonville Electric Authority's large-scale CFB demonstration project is described. Given the early stage of project development, the paper focuses on the project organizational structure, its role within the Department of Energy's Clean Coal Technology Demonstration Program, and the projected environmental performance. A description of the CFB combustion process in included.

  13. Large-scale CFB combustion demonstration project

    SciTech Connect

    Nielsen, P.T.; Hebb, J.L.; Aquino, R.

    1998-04-01

    The Jacksonville Electric Authority`s large-scale CFB demonstration project is described. Given the early stage of project development, the paper focuses on the project organizational structure, its role within the Department of Energy`s Clean Coal Technology Demonstration Program, and the projected environmental performance. A description of the CFB combustion process is included.

  14. Evaluating Large-Scale Interactive Radio Programmes

    ERIC Educational Resources Information Center

    Potter, Charles; Naidoo, Gordon

    2009-01-01

    This article focuses on the challenges involved in conducting evaluations of interactive radio programmes in South Africa with large numbers of schools, teachers, and learners. It focuses on the role such large-scale evaluation has played during the South African radio learning programme's development stage, as well as during its subsequent…

  15. ARPACK: Solving large scale eigenvalue problems

    NASA Astrophysics Data System (ADS)

    Lehoucq, Rich; Maschhoff, Kristi; Sorensen, Danny; Yang, Chao

    2013-11-01

    ARPACK is a collection of Fortran77 subroutines designed to solve large scale eigenvalue problems. The package is designed to compute a few eigenvalues and corresponding eigenvectors of a general n by n matrix A. It is most appropriate for large sparse or structured matrices A where structured means that a matrix-vector product w

  16. Population generation for large-scale simulation

    NASA Astrophysics Data System (ADS)

    Hannon, Andrew C.; King, Gary; Morrison, Clayton; Galstyan, Aram; Cohen, Paul

    2005-05-01

    Computer simulation is used to research phenomena ranging from the structure of the space-time continuum to population genetics and future combat.1-3 Multi-agent simulations in particular are now commonplace in many fields.4, 5 By modeling populations whose complex behavior emerges from individual interactions, these simulations help to answer questions about effects where closed form solutions are difficult to solve or impossible to derive.6 To be useful, simulations must accurately model the relevant aspects of the underlying domain. In multi-agent simulation, this means that the modeling must include both the agents and their relationships. Typically, each agent can be modeled as a set of attributes drawn from various distributions (e.g., height, morale, intelligence and so forth). Though these can interact - for example, agent height is related to agent weight - they are usually independent. Modeling relations between agents, on the other hand, adds a new layer of complexity, and tools from graph theory and social network analysis are finding increasing application.7, 8 Recognizing the role and proper use of these techniques, however, remains the subject of ongoing research. We recently encountered these complexities while building large scale social simulations.9-11 One of these, the Hats Simulator, is designed to be a lightweight proxy for intelligence analysis problems. Hats models a "society in a box" consisting of many simple agents, called hats. Hats gets its name from the classic spaghetti western, in which the heroes and villains are known by the color of the hats they wear. The Hats society also has its heroes and villains, but the challenge is to identify which color hat they should be wearing based on how they behave. There are three types of hats: benign hats, known terrorists, and covert terrorists. Covert terrorists look just like benign hats but act like terrorists. Population structure can make covert hat identification significantly more

  17. Application of Multi-Dimensional Sensing Technologies in Production Systems

    NASA Astrophysics Data System (ADS)

    Shibuya, Hisae; Kimachi, Akira; Suwa, Masaki; Niwakawa, Makoto; Okuda, Haruhisa; Hashimoto, Manabu

    Multi-dimensional sensing has been used for various purposes in the field of production systems. The members of the IEEJ MDS committee investigated the trends in sensing technologies and their applications. In this paper, the result of investigations of auto-guided vehicles, cell manufacturing robots, safety, maintenance, worker monitoring, and sensor networks are discussed.

  18. The Multi-Dimensional Demands of Reading in the Disciplines

    ERIC Educational Resources Information Center

    Lee, Carol D.

    2014-01-01

    This commentary addresses the complexities of reading comprehension with an explicit focus on reading in the disciplines. The author proposes reading as entailing multi-dimensional demands of the reader and posing complex challenges for teachers. These challenges are intensified by restrictive conceptions of relevant prior knowledge and experience…

  19. Image matrix processor for fast multi-dimensional computations

    DOEpatents

    Roberson, G.P.; Skeate, M.F.

    1996-10-15

    An apparatus for multi-dimensional computation is disclosed which comprises a computation engine, including a plurality of processing modules. The processing modules are configured in parallel and compute respective contributions to a computed multi-dimensional image of respective two dimensional data sets. A high-speed, parallel access storage system is provided which stores the multi-dimensional data sets, and a switching circuit routes the data among the processing modules in the computation engine and the storage system. A data acquisition port receives the two dimensional data sets representing projections through an image, for reconstruction algorithms such as encountered in computerized tomography. The processing modules include a programmable local host, by which they may be configured to execute a plurality of different types of multi-dimensional algorithms. The processing modules thus include an image manipulation processor, which includes a source cache, a target cache, a coefficient table, and control software for executing image transformation routines using data in the source cache and the coefficient table and loading resulting data in the target cache. The local host processor operates to load the source cache with a two dimensional data set, loads the coefficient table, and transfers resulting data out of the target cache to the storage system, or to another destination. 10 figs.

  20. Image matrix processor for fast multi-dimensional computations

    DOEpatents

    Roberson, George P.; Skeate, Michael F.

    1996-01-01

    An apparatus for multi-dimensional computation which comprises a computation engine, including a plurality of processing modules. The processing modules are configured in parallel and compute respective contributions to a computed multi-dimensional image of respective two dimensional data sets. A high-speed, parallel access storage system is provided which stores the multi-dimensional data sets, and a switching circuit routes the data among the processing modules in the computation engine and the storage system. A data acquisition port receives the two dimensional data sets representing projections through an image, for reconstruction algorithms such as encountered in computerized tomography. The processing modules include a programmable local host, by which they may be configured to execute a plurality of different types of multi-dimensional algorithms. The processing modules thus include an image manipulation processor, which includes a source cache, a target cache, a coefficient table, and control software for executing image transformation routines using data in the source cache and the coefficient table and loading resulting data in the target cache. The local host processor operates to load the source cache with a two dimensional data set, loads the coefficient table, and transfers resulting data out of the target cache to the storage system, or to another destination.

  1. Large-scale negative polarity magnetic fields on the sun and particle-emitting flares

    NASA Technical Reports Server (NTRS)

    Bumba, V.

    1972-01-01

    Some observational facts about the large-scale patterns formed by solar negative polarity magnetic fields during the 19th and 20th cycles of solar activity are presented. The close relation of the position of occurrence of very large flares accompanied by cosmic ray and PCA events as well as other phenomena of solar activity during the declining part of the 19th cycle of the regularities in the internal structure of large scale negative polarity features are demonstrated.

  2. Fractals and cosmological large-scale structure

    NASA Technical Reports Server (NTRS)

    Luo, Xiaochun; Schramm, David N.

    1992-01-01

    Observations of galaxy-galaxy and cluster-cluster correlations as well as other large-scale structure can be fit with a 'limited' fractal with dimension D of about 1.2. This is not a 'pure' fractal out to the horizon: the distribution shifts from power law to random behavior at some large scale. If the observed patterns and structures are formed through an aggregation growth process, the fractal dimension D can serve as an interesting constraint on the properties of the stochastic motion responsible for limiting the fractal structure. In particular, it is found that the observed fractal should have grown from two-dimensional sheetlike objects such as pancakes, domain walls, or string wakes. This result is generic and does not depend on the details of the growth process.

  3. Condition Monitoring of Large-Scale Facilities

    NASA Technical Reports Server (NTRS)

    Hall, David L.

    1999-01-01

    This document provides a summary of the research conducted for the NASA Ames Research Center under grant NAG2-1182 (Condition-Based Monitoring of Large-Scale Facilities). The information includes copies of view graphs presented at NASA Ames in the final Workshop (held during December of 1998), as well as a copy of a technical report provided to the COTR (Dr. Anne Patterson-Hine) subsequent to the workshop. The material describes the experimental design, collection of data, and analysis results associated with monitoring the health of large-scale facilities. In addition to this material, a copy of the Pennsylvania State University Applied Research Laboratory data fusion visual programming tool kit was also provided to NASA Ames researchers.

  4. Large scale processes in the solar nebula.

    NASA Astrophysics Data System (ADS)

    Boss, A. P.

    Most proposed chondrule formation mechanisms involve processes occurring inside the solar nebula, so the large scale (roughly 1 to 10 AU) structure of the nebula is of general interest for any chrondrule-forming mechanism. Chondrules and Ca, Al-rich inclusions (CAIs) might also have been formed as a direct result of the large scale structure of the nebula, such as passage of material through high temperature regions. While recent nebula models do predict the existence of relatively hot regions, the maximum temperatures in the inner planet region may not be high enough to account for chondrule or CAI thermal processing, unless the disk mass is considerably greater than the minimum mass necessary to restore the planets to solar composition. Furthermore, it does not seem to be possible to achieve both rapid heating and rapid cooling of grain assemblages in such a large scale furnace. However, if the accretion flow onto the nebula surface is clumpy, as suggested by observations of variability in young stars, then clump-disk impacts might be energetic enough to launch shock waves which could propagate through the nebula to the midplane, thermally processing any grain aggregates they encounter, and leaving behind a trail of chondrules.

  5. Large-scale extraction of proteins.

    PubMed

    Cunha, Teresa; Aires-Barros, Raquel

    2002-01-01

    The production of foreign proteins using selected host with the necessary posttranslational modifications is one of the key successes in modern biotechnology. This methodology allows the industrial production of proteins that otherwise are produced in small quantities. However, the separation and purification of these proteins from the fermentation media constitutes a major bottleneck for the widespread commercialization of recombinant proteins. The major production costs (50-90%) for typical biological product resides in the purification strategy. There is a need for efficient, effective, and economic large-scale bioseparation techniques, to achieve high purity and high recovery, while maintaining the biological activity of the molecule. Aqueous two-phase systems (ATPS) allow process integration as simultaneously separation and concentration of the target protein is achieved, with posterior removal and recycle of the polymer. The ease of scale-up combined with the high partition coefficients obtained allow its potential application in large-scale downstream processing of proteins produced by fermentation. The equipment and the methodology for aqueous two-phase extraction of proteins on a large scale using mixer-settlerand column contractors are described. The operation of the columns, either stagewise or differential, are summarized. A brief description of the methods used to account for mass transfer coefficients, hydrodynamics parameters of hold-up, drop size, and velocity, back mixing in the phases, and flooding performance, required for column design, is also provided. PMID:11876297

  6. CTH: A software family for multi-dimensional shock physics analysis

    SciTech Connect

    Hertel, E.S. Jr.; Bell, R.L.; Elrick, M.G.; Farnsworth, A.V.; Kerley, G.I.; McGlaun, J.M.; Petney, S.V.; Silling, S.A.; Taylor, P.A.; Yarrington, L.

    1992-12-31

    CTH is a family of codes developed at Sandia National Laboratories for modeling complex multi-dimensional, multi-material problems that are characterized by large deformations and/or strong shocks. A two-step, second-order accurate Eulerian solution algorithm is used to solve the mass, momentum, and energy conservation equations. CTH includes models for material strength, fracture, porous materials, and high explosive detonation and initiation. Viscoplastic or rate-dependent models of material strength have been added recently. The formulations of Johnson-Cook, Zerilli-Armstrong, and Steinberg-Guinan-Lund are standard options within CTH. These models rely on using an internal state variable to account for the history dependence of material response. The implementation of internal state variable models will be discussed and several sample calculations will be presented. Comparison with experimental data will be made among the various material strength models. The advancements made in modelling material response have significantly improved the ability of CTH to model complex large-deformation, plastic-flow dominated phenomena. Detonation of energetic material under shock loading conditions has been of great interest. A recently developed model of reactive burn for high explosives (HE) has been added to CTH. This model along with newly developed tabular equations-of-state for the HE reaction by-products has been compared to one- and two-dimensional explosive detonation experiments. These comparisons indicate excellent agreement of CTH predictions with experimental results. The new reactive burn model coupled with the advances in equation-of-state modeling make it possible to predict multi-dimensional burn phenomena without modifying the model parameters for different dimensionality. Examples of the features of CTH will be given. The emphasis in simulations shown will be in comparison with well characterized experiments covering key phenomena of shock physics.

  7. Continuation and bifurcation analysis of large-scale dynamical systems with LOCA.

    SciTech Connect

    Salinger, Andrew Gerhard; Phipps, Eric Todd; Pawlowski, Roger Patrick

    2010-06-01

    Dynamical systems theory provides a powerful framework for understanding the behavior of complex evolving systems. However applying these ideas to large-scale dynamical systems such as discretizations of multi-dimensional PDEs is challenging. Such systems can easily give rise to problems with billions of dynamical variables, requiring specialized numerical algorithms implemented on high performance computing architectures with thousands of processors. This talk will describe LOCA, the Library of Continuation Algorithms, a suite of scalable continuation and bifurcation tools optimized for these types of systems that is part of the Trilinos software collection. In particular, we will describe continuation and bifurcation analysis techniques designed for large-scale dynamical systems that are based on specialized parallel linear algebra methods for solving augmented linear systems. We will also discuss several other Trilinos tools providing nonlinear solvers (NOX), eigensolvers (Anasazi), iterative linear solvers (AztecOO and Belos), preconditioners (Ifpack, ML, Amesos) and parallel linear algebra data structures (Epetra and Tpetra) that LOCA can leverage for efficient and scalable analysis of large-scale dynamical systems.

  8. Advanced numerics for multi-dimensional fluid flow calculations

    NASA Technical Reports Server (NTRS)

    Vanka, S. P.

    1984-01-01

    In recent years, there has been a growing interest in the development and use of mathematical models for the simulation of fluid flow, heat transfer and combustion processes in engineering equipment. The equations representing the multi-dimensional transport of mass, momenta and species are numerically solved by finite-difference or finite-element techniques. However despite the multiude of differencing schemes and solution algorithms, and the advancement of computing power, the calculation of multi-dimensional flows, especially three-dimensional flows, remains a mammoth task. The following discussion is concerned with the author's recent work on the construction of accurate discretization schemes for the partial derivatives, and the efficient solution of the set of nonlinear algebraic equations resulting after discretization. The present work has been jointly supported by the Ramjet Engine Division of the Wright Patterson Air Force Base, Ohio, and the NASA Lewis Research Center.

  9. Large-Scale PV Integration Study

    SciTech Connect

    Lu, Shuai; Etingov, Pavel V.; Diao, Ruisheng; Ma, Jian; Samaan, Nader A.; Makarov, Yuri V.; Guo, Xinxin; Hafen, Ryan P.; Jin, Chunlian; Kirkham, Harold; Shlatz, Eugene; Frantzis, Lisa; McClive, Timothy; Karlson, Gregory; Acharya, Dhruv; Ellis, Abraham; Stein, Joshua; Hansen, Clifford; Chadliev, Vladimir; Smart, Michael; Salgo, Richard; Sorensen, Rahn; Allen, Barbara; Idelchik, Boris

    2011-07-29

    This research effort evaluates the impact of large-scale photovoltaic (PV) and distributed generation (DG) output on NV Energy’s electric grid system in southern Nevada. It analyzes the ability of NV Energy’s generation to accommodate increasing amounts of utility-scale PV and DG, and the resulting cost of integrating variable renewable resources. The study was jointly funded by the United States Department of Energy and NV Energy, and conducted by a project team comprised of industry experts and research scientists from Navigant Consulting Inc., Sandia National Laboratories, Pacific Northwest National Laboratory and NV Energy.

  10. Large-scale planar lightwave circuits

    NASA Astrophysics Data System (ADS)

    Bidnyk, Serge; Zhang, Hua; Pearson, Matt; Balakrishnan, Ashok

    2011-01-01

    By leveraging advanced wafer processing and flip-chip bonding techniques, we have succeeded in hybrid integrating a myriad of active optical components, including photodetectors and laser diodes, with our planar lightwave circuit (PLC) platform. We have combined hybrid integration of active components with monolithic integration of other critical functions, such as diffraction gratings, on-chip mirrors, mode-converters, and thermo-optic elements. Further process development has led to the integration of polarization controlling functionality. Most recently, all these technological advancements have been combined to create large-scale planar lightwave circuits that comprise hundreds of optical elements integrated on chips less than a square inch in size.

  11. Neutrinos and large-scale structure

    SciTech Connect

    Eisenstein, Daniel J.

    2015-07-15

    I review the use of cosmological large-scale structure to measure properties of neutrinos and other relic populations of light relativistic particles. With experiments to measure the anisotropies of the cosmic microwave anisotropies and the clustering of matter at low redshift, we now have securely measured a relativistic background with density appropriate to the cosmic neutrino background. Our limits on the mass of the neutrino continue to shrink. Experiments coming in the next decade will greatly improve the available precision on searches for the energy density of novel relativistic backgrounds and the mass of neutrinos.

  12. Experimental Simulations of Large-Scale Collisions

    NASA Technical Reports Server (NTRS)

    Housen, Kevin R.

    2002-01-01

    This report summarizes research on the effects of target porosity on the mechanics of impact cratering. Impact experiments conducted on a centrifuge provide direct simulations of large-scale cratering on porous asteroids. The experiments show that large craters in porous materials form mostly by compaction, with essentially no deposition of material into the ejecta blanket that is a signature of cratering in less-porous materials. The ratio of ejecta mass to crater mass is shown to decrease with increasing crater size or target porosity. These results are consistent with the observation that large closely-packed craters on asteroid Mathilde appear to have formed without degradation to earlier craters.

  13. Colloquium: Large scale simulations on GPU clusters

    NASA Astrophysics Data System (ADS)

    Bernaschi, Massimo; Bisson, Mauro; Fatica, Massimiliano

    2015-06-01

    Graphics processing units (GPU) are currently used as a cost-effective platform for computer simulations and big-data processing. Large scale applications require that multiple GPUs work together but the efficiency obtained with cluster of GPUs is, at times, sub-optimal because the GPU features are not exploited at their best. We describe how it is possible to achieve an excellent efficiency for applications in statistical mechanics, particle dynamics and networks analysis by using suitable memory access patterns and mechanisms like CUDA streams, profiling tools, etc. Similar concepts and techniques may be applied also to other problems like the solution of Partial Differential Equations.

  14. Nonthermal Components in the Large Scale Structure

    NASA Astrophysics Data System (ADS)

    Miniati, Francesco

    2004-12-01

    I address the issue of nonthermal processes in the large scale structure of the universe. After reviewing the properties of cosmic shocks and their role as particle accelerators, I discuss the main observational results, from radio to γ-ray and describe the processes that are thought be responsible for the observed nonthermal emissions. Finally, I emphasize the important role of γ-ray astronomy for the progress in the field. Non detections at these photon energies have already allowed us important conclusions. Future observations will tell us more about the physics of the intracluster medium, shocks dissipation and CR acceleration.

  15. Large scale phononic metamaterials for seismic isolation

    SciTech Connect

    Aravantinos-Zafiris, N.; Sigalas, M. M.

    2015-08-14

    In this work, we numerically examine structures that could be characterized as large scale phononic metamaterials. These novel structures could have band gaps in the frequency spectrum of seismic waves when their dimensions are chosen appropriately, thus raising the belief that they could be serious candidates for seismic isolation structures. Different and easy to fabricate structures were examined made from construction materials such as concrete and steel. The well-known finite difference time domain method is used in our calculations in order to calculate the band structures of the proposed metamaterials.

  16. Statistical Modeling of Large-Scale Scientific Simulation Data

    SciTech Connect

    Eliassi-Rad, T; Baldwin, C; Abdulla, G; Critchlow, T

    2003-11-15

    With the advent of massively parallel computer systems, scientists are now able to simulate complex phenomena (e.g., explosions of a stars). Such scientific simulations typically generate large-scale data sets over the spatio-temporal space. Unfortunately, the sheer sizes of the generated data sets make efficient exploration of them impossible. Constructing queriable statistical models is an essential step in helping scientists glean new insight from their computer simulations. We define queriable statistical models to be descriptive statistics that (1) summarize and describe the data within a user-defined modeling error, and (2) are able to answer complex range-based queries over the spatiotemporal dimensions. In this chapter, we describe systems that build queriable statistical models for large-scale scientific simulation data sets. In particular, we present our Ad-hoc Queries for Simulation (AQSim) infrastructure, which reduces the data storage requirements and query access times by (1) creating and storing queriable statistical models of the data at multiple resolutions, and (2) evaluating queries on these models of the data instead of the entire data set. Within AQSim, we focus on three simple but effective statistical modeling techniques. AQSim's first modeling technique (called univariate mean modeler) computes the ''true'' (unbiased) mean of systematic partitions of the data. AQSim's second statistical modeling technique (called univariate goodness-of-fit modeler) uses the Andersen-Darling goodness-of-fit method on systematic partitions of the data. Finally, AQSim's third statistical modeling technique (called multivariate clusterer) utilizes the cosine similarity measure to cluster the data into similar groups. Our experimental evaluations on several scientific simulation data sets illustrate the value of using these statistical models on large-scale simulation data sets.

  17. Ionizing shocks in argon. Part II: Transient and multi-dimensional effects

    SciTech Connect

    Kapper, M. G.; Cambier, J.-L.

    2011-06-01

    We extend the computations of ionizing shocks in argon to the unsteady and multi-dimensional, using a collisional-radiative model and a single-fluid, two-temperature formulation of the conservation equations. It is shown that the fluctuations of the shock structure observed in shock-tube experiments can be reproduced by the numerical simulations and explained on the basis of the coupling of the nonlinear kinetics of the collisional-radiative model with wave propagation within the induction zone. The mechanism is analogous to instabilities of detonation waves and also produces a cellular structure commonly observed in gaseous detonations. We suggest that detailed simulations of such unsteady phenomena can yield further information for the validation of nonequilibrium kinetics.

  18. Local gravity and large-scale structure

    NASA Technical Reports Server (NTRS)

    Juszkiewicz, Roman; Vittorio, Nicola; Wyse, Rosemary F. G.

    1990-01-01

    The magnitude and direction of the observed dipole anisotropy of the galaxy distribution can in principle constrain the amount of large-scale power present in the spectrum of primordial density fluctuations. This paper confronts the data, provided by a recent redshift survey of galaxies detected by the IRAS satellite, with the predictions of two cosmological models with very different levels of large-scale power: the biased Cold Dark Matter dominated model (CDM) and a baryon-dominated model (BDM) with isocurvature initial conditions. Model predictions are investigated for the Local Group peculiar velocity, v(R), induced by mass inhomogeneities distributed out to a given radius, R, for R less than about 10,000 km/s. Several convergence measures for v(R) are developed, which can become powerful cosmological tests when deep enough samples become available. For the present data sets, the CDM and BDM predictions are indistinguishable at the 2 sigma level and both are consistent with observations. A promising discriminant between cosmological models is the misalignment angle between v(R) and the apex of the dipole anisotropy of the microwave background.

  19. Large-scale velocity fields. [of solar rotation

    NASA Technical Reports Server (NTRS)

    Howard, Robert F.; Kichatinov, L. L.; Bogart, Richard S.; Ribes, Elizabeth

    1991-01-01

    The present evaluation of recent observational results bearing on the nature and characteristics of solar rotation gives attention to the status of current understanding on such large-scale velocity-field-associated phenomena as solar supergranulation, mesogranulation, and giant-scale convection. Also noted are theoretical suggestions reconciling theory and observations of giant-scale solar convection. The photosphere's global meridional circulation is suggested by solar rotation models requiring pole-to-equator flows of a few m/sec, as well as by the observed migration of magnetic activity over the solar cycle. The solar rotation exhibits a latitude and cycle dependence which can be understood in terms of a time-dependent convective toroidal roll pattern.

  20. Large-Scale Advanced Prop-Fan (LAP) blade design

    NASA Technical Reports Server (NTRS)

    Violette, John A.; Sullivan, William E.; Turnberg, Jay E.

    1984-01-01

    This report covers the design analysis of a very thin, highly swept, propeller blade to be used in the Large-Scale Advanced Prop-Fan (LAP) test program. The report includes: design requirements and goals, a description of the blade configuration which meets requirements, a description of the analytical methods utilized/developed to demonstrate compliance with the requirements, and the results of these analyses. The methods described include: finite element modeling, predicted aerodynamic loads and their application to the blade, steady state and vibratory response analyses, blade resonant frequencies and mode shapes, bird impact analysis, and predictions of stalled and unstalled flutter phenomena. Summarized results include deflections, retention loads, stress/strength comparisons, foreign object damage resistance, resonant frequencies and critical speed margins, resonant vibratory mode shapes, calculated boundaries of stalled and unstalled flutter, and aerodynamic and acoustic performance calculations.

  1. Large scale water lens for solar concentration.

    PubMed

    Mondol, A S; Vogel, B; Bastian, G

    2015-06-01

    Properties of large scale water lenses for solar concentration were investigated. These lenses were built from readily available materials, normal tap water and hyper-elastic linear low density polyethylene foil. Exposed to sunlight, the focal lengths and light intensities in the focal spot were measured and calculated. Their optical properties were modeled with a raytracing software based on the lens shape. We have achieved a good match of experimental and theoretical data by considering wavelength dependent concentration factor, absorption and focal length. The change in light concentration as a function of water volume was examined via the resulting load on the foil and the corresponding change of shape. The latter was extracted from images and modeled by a finite element simulation. PMID:26072893

  2. Large Scale Quantum Simulations of Nuclear Pasta

    NASA Astrophysics Data System (ADS)

    Fattoyev, Farrukh J.; Horowitz, Charles J.; Schuetrumpf, Bastian

    2016-03-01

    Complex and exotic nuclear geometries collectively referred to as ``nuclear pasta'' are expected to naturally exist in the crust of neutron stars and in supernovae matter. Using a set of self-consistent microscopic nuclear energy density functionals we present the first results of large scale quantum simulations of pasta phases at baryon densities 0 . 03 < ρ < 0 . 10 fm-3, proton fractions 0 . 05

  3. Large-scale simulations of reionization

    SciTech Connect

    Kohler, Katharina; Gnedin, Nickolay Y.; Hamilton, Andrew J.S.; /JILA, Boulder

    2005-11-01

    We use cosmological simulations to explore the large-scale effects of reionization. Since reionization is a process that involves a large dynamic range--from galaxies to rare bright quasars--we need to be able to cover a significant volume of the universe in our simulation without losing the important small scale effects from galaxies. Here we have taken an approach that uses clumping factors derived from small scale simulations to approximate the radiative transfer on the sub-cell scales. Using this technique, we can cover a simulation size up to 1280h{sup -1} Mpc with 10h{sup -1} Mpc cells. This allows us to construct synthetic spectra of quasars similar to observed spectra of SDSS quasars at high redshifts and compare them to the observational data. These spectra can then be analyzed for HII region sizes, the presence of the Gunn-Peterson trough, and the Lyman-{alpha} forest.

  4. Large-scale databases of proper names.

    PubMed

    Conley, P; Burgess, C; Hage, D

    1999-05-01

    Few tools for research in proper names have been available--specifically, there is no large-scale corpus of proper names. Two corpora of proper names were constructed, one based on U.S. phone book listings, the other derived from a database of Usenet text. Name frequencies from both corpora were compared with human subjects' reaction times (RTs) to the proper names in a naming task. Regression analysis showed that the Usenet frequencies contributed to predictions of human RT, whereas phone book frequencies did not. In addition, semantic neighborhood density measures derived from the HAL corpus were compared with the subjects' RTs and found to be a better predictor of RT than was frequency in either corpus. These new corpora are freely available on line for download. Potentials for these corpora range from using the names as stimuli in experiments to using the corpus data in software applications. PMID:10495803

  5. Estimation of large-scale dimension densities.

    PubMed

    Raab, C; Kurths, J

    2001-07-01

    We propose a technique to calculate large-scale dimension densities in both higher-dimensional spatio-temporal systems and low-dimensional systems from only a few data points, where known methods usually have an unsatisfactory scaling behavior. This is mainly due to boundary and finite-size effects. With our rather simple method, we normalize boundary effects and get a significant correction of the dimension estimate. This straightforward approach is based on rather general assumptions. So even weak coherent structures obtained from small spatial couplings can be detected with this method, which is impossible by using the Lyapunov-dimension density. We demonstrate the efficiency of our technique for coupled logistic maps, coupled tent maps, the Lorenz attractor, and the Roessler attractor. PMID:11461376

  6. The challenge of large-scale structure

    NASA Astrophysics Data System (ADS)

    Gregory, S. A.

    1996-03-01

    The tasks that I have assumed for myself in this presentation include three separate parts. The first, appropriate to the particular setting of this meeting, is to review the basic work of the founding of this field; the appropriateness comes from the fact that W. G. Tifft made immense contributions that are not often realized by the astronomical community. The second task is to outline the general tone of the observational evidence for large scale structures. (Here, in particular, I cannot claim to be complete. I beg forgiveness from any workers who are left out by my oversight for lack of space and time.) The third task is to point out some of the major aspects of the field that may represent the clues by which some brilliant sleuth will ultimately figure out how galaxies formed.

  7. Engineering management of large scale systems

    NASA Technical Reports Server (NTRS)

    Sanders, Serita; Gill, Tepper L.; Paul, Arthur S.

    1989-01-01

    The organization of high technology and engineering problem solving, has given rise to an emerging concept. Reasoning principles for integrating traditional engineering problem solving with system theory, management sciences, behavioral decision theory, and planning and design approaches can be incorporated into a methodological approach to solving problems with a long range perspective. Long range planning has a great potential to improve productivity by using a systematic and organized approach. Thus, efficiency and cost effectiveness are the driving forces in promoting the organization of engineering problems. Aspects of systems engineering that provide an understanding of management of large scale systems are broadly covered here. Due to the focus and application of research, other significant factors (e.g., human behavior, decision making, etc.) are not emphasized but are considered.

  8. Large scale cryogenic fluid systems testing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA Lewis Research Center's Cryogenic Fluid Systems Branch (CFSB) within the Space Propulsion Technology Division (SPTD) has the ultimate goal of enabling the long term storage and in-space fueling/resupply operations for spacecraft and reusable vehicles in support of space exploration. Using analytical modeling, ground based testing, and on-orbit experimentation, the CFSB is studying three primary categories of fluid technology: storage, supply, and transfer. The CFSB is also investigating fluid handling, advanced instrumentation, and tank structures and materials. Ground based testing of large-scale systems is done using liquid hydrogen as a test fluid at the Cryogenic Propellant Tank Facility (K-site) at Lewis' Plum Brook Station in Sandusky, Ohio. A general overview of tests involving liquid transfer, thermal control, pressure control, and pressurization is given.

  9. Batteries for Large Scale Energy Storage

    SciTech Connect

    Soloveichik, Grigorii L.

    2011-07-15

    In recent years, with the deployment of renewable energy sources, advances in electrified transportation, and development in smart grids, the markets for large-scale stationary energy storage have grown rapidly. Electrochemical energy storage methods are strong candidate solutions due to their high energy density, flexibility, and scalability. This review provides an overview of mature and emerging technologies for secondary and redox flow batteries. New developments in the chemistry of secondary and flow batteries as well as regenerative fuel cells are also considered. Advantages and disadvantages of current and prospective electrochemical energy storage options are discussed. The most promising technologies in the short term are high-temperature sodium batteries with β”-alumina electrolyte, lithium-ion batteries, and flow batteries. Regenerative fuel cells and lithium metal batteries with high energy density require further research to become practical.

  10. Grid sensitivity capability for large scale structures

    NASA Technical Reports Server (NTRS)

    Nagendra, Gopal K.; Wallerstein, David V.

    1989-01-01

    The considerations and the resultant approach used to implement design sensitivity capability for grids into a large scale, general purpose finite element system (MSC/NASTRAN) are presented. The design variables are grid perturbations with a rather general linking capability. Moreover, shape and sizing variables may be linked together. The design is general enough to facilitate geometric modeling techniques for generating design variable linking schemes in an easy and straightforward manner. Test cases have been run and validated by comparison with the overall finite difference method. The linking of a design sensitivity capability for shape variables in MSC/NASTRAN with an optimizer would give designers a powerful, automated tool to carry out practical optimization design of real life, complicated structures.

  11. Large-Scale Astrophysical Visualization on Smartphones

    NASA Astrophysics Data System (ADS)

    Becciani, U.; Massimino, P.; Costa, A.; Gheller, C.; Grillo, A.; Krokos, M.; Petta, C.

    2011-07-01

    Nowadays digital sky surveys and long-duration, high-resolution numerical simulations using high performance computing and grid systems produce multidimensional astrophysical datasets in the order of several Petabytes. Sharing visualizations of such datasets within communities and collaborating research groups is of paramount importance for disseminating results and advancing astrophysical research. Moreover educational and public outreach programs can benefit greatly from novel ways of presenting these datasets by promoting understanding of complex astrophysical processes, e.g., formation of stars and galaxies. We have previously developed VisIVO Server, a grid-enabled platform for high-performance large-scale astrophysical visualization. This article reviews the latest developments on VisIVO Web, a custom designed web portal wrapped around VisIVO Server, then introduces VisIVO Smartphone, a gateway connecting VisIVO Web and data repositories for mobile astrophysical visualization. We discuss current work and summarize future developments.

  12. The XMM Large Scale Structure Survey

    NASA Astrophysics Data System (ADS)

    Pierre, Marguerite

    2005-10-01

    We propose to complete, by an additional 5 deg2, the XMM-LSS Survey region overlying the Spitzer/SWIRE field. This field already has CFHTLS and Integral coverage, and will encompass about 10 deg2. The resulting multi-wavelength medium-depth survey, which complements XMM and Chandra deep surveys, will provide a unique view of large-scale structure over a wide range of redshift, and will show active galaxies in the full range of environments. The complete coverage by optical and IR surveys provides high-quality photometric redshifts, so that cosmological results can quickly be extracted. In the spirit of a Legacy survey, we will make the raw X-ray data immediately public. Multi-band catalogues and images will also be made available on short time scales.

  13. Estimation of large-scale dimension densities

    NASA Astrophysics Data System (ADS)

    Raab, Corinna; Kurths, Jürgen

    2001-07-01

    We propose a technique to calculate large-scale dimension densities in both higher-dimensional spatio-temporal systems and low-dimensional systems from only a few data points, where known methods usually have an unsatisfactory scaling behavior. This is mainly due to boundary and finite-size effects. With our rather simple method, we normalize boundary effects and get a significant correction of the dimension estimate. This straightforward approach is based on rather general assumptions. So even weak coherent structures obtained from small spatial couplings can be detected with this method, which is impossible by using the Lyapunov-dimension density. We demonstrate the efficiency of our technique for coupled logistic maps, coupled tent maps, the Lorenz attractor, and the Roessler attractor.

  14. Large-Scale Organization of Glycosylation Networks

    NASA Astrophysics Data System (ADS)

    Kim, Pan-Jun; Lee, Dong-Yup; Jeong, Hawoong

    2009-03-01

    Glycosylation is a highly complex process to produce a diverse repertoire of cellular glycans that are frequently attached to proteins and lipids. Glycans participate in fundamental biological processes including molecular trafficking and clearance, cell proliferation and apoptosis, developmental biology, immune response, and pathogenesis. N-linked glycans found on proteins are formed by sequential attachments of monosaccharides with the help of a relatively small number of enzymes. Many of these enzymes can accept multiple N-linked glycans as substrates, thus generating a large number of glycan intermediates and their intermingled pathways. Motivated by the quantitative methods developed in complex network research, we investigate the large-scale organization of such N-glycosylation pathways in a mammalian cell. The uncovered results give the experimentally-testable predictions for glycosylation process, and can be applied to the engineering of therapeutic glycoproteins.

  15. Large-scale sequential quadratic programming algorithms

    SciTech Connect

    Eldersveld, S.K.

    1992-09-01

    The problem addressed is the general nonlinear programming problem: finding a local minimizer for a nonlinear function subject to a mixture of nonlinear equality and inequality constraints. The methods studied are in the class of sequential quadratic programming (SQP) algorithms, which have previously proved successful for problems of moderate size. Our goal is to devise an SQP algorithm that is applicable to large-scale optimization problems, using sparse data structures and storing less curvature information but maintaining the property of superlinear convergence. The main features are: 1. The use of a quasi-Newton approximation to the reduced Hessian of the Lagrangian function. Only an estimate of the reduced Hessian matrix is required by our algorithm. The impact of not having available the full Hessian approximation is studied and alternative estimates are constructed. 2. The use of a transformation matrix Q. This allows the QP gradient to be computed easily when only the reduced Hessian approximation is maintained. 3. The use of a reduced-gradient form of the basis for the null space of the working set. This choice of basis is more practical than an orthogonal null-space basis for large-scale problems. The continuity condition for this choice is proven. 4. The use of incomplete solutions of quadratic programming subproblems. Certain iterates generated by an active-set method for the QP subproblem are used in place of the QP minimizer to define the search direction for the nonlinear problem. An implementation of the new algorithm has been obtained by modifying the code MINOS. Results and comparisons with MINOS and NPSOL are given for the new algorithm on a set of 92 test problems.

  16. Supporting large-scale computational science

    SciTech Connect

    Musick, R

    1998-10-01

    A study has been carried out to determine the feasibility of using commercial database management systems (DBMSs) to support large-scale computational science. Conventional wisdom in the past has been that DBMSs are too slow for such data. Several events over the past few years have muddied the clarity of this mindset: 1. 2. 3. 4. Several commercial DBMS systems have demonstrated storage and ad-hoc quer access to Terabyte data sets. Several large-scale science teams, such as EOSDIS [NAS91], high energy physics [MM97] and human genome [Kin93] have adopted (or make frequent use of) commercial DBMS systems as the central part of their data management scheme. Several major DBMS vendors have introduced their first object-relational products (ORDBMSs), which have the potential to support large, array-oriented data. In some cases, performance is a moot issue. This is true in particular if the performance of legacy applications is not reduced while new, albeit slow, capabilities are added to the system. The basic assessment is still that DBMSs do not scale to large computational data. However, many of the reasons have changed, and there is an expiration date attached to that prognosis. This document expands on this conclusion, identifies the advantages and disadvantages of various commercial approaches, and describes the studies carried out in exploring this area. The document is meant to be brief, technical and informative, rather than a motivational pitch. The conclusions within are very likely to become outdated within the next 5-7 years, as market forces will have a significant impact on the state of the art in scientific data management over the next decade.

  17. Supporting large-scale computational science

    SciTech Connect

    Musick, R., LLNL

    1998-02-19

    Business needs have driven the development of commercial database systems since their inception. As a result, there has been a strong focus on supporting many users, minimizing the potential corruption or loss of data, and maximizing performance metrics like transactions per second, or TPC-C and TPC-D results. It turns out that these optimizations have little to do with the needs of the scientific community, and in particular have little impact on improving the management and use of large-scale high-dimensional data. At the same time, there is an unanswered need in the scientific community for many of the benefits offered by a robust DBMS. For example, tying an ad-hoc query language such as SQL together with a visualization toolkit would be a powerful enhancement to current capabilities. Unfortunately, there has been little emphasis or discussion in the VLDB community on this mismatch over the last decade. The goal of the paper is to identify the specific issues that need to be resolved before large-scale scientific applications can make use of DBMS products. This topic is addressed in the context of an evaluation of commercial DBMS technology applied to the exploration of data generated by the Department of Energy`s Accelerated Strategic Computing Initiative (ASCI). The paper describes the data being generated for ASCI as well as current capabilities for interacting with and exploring this data. The attraction of applying standard DBMS technology to this domain is discussed, as well as the technical and business issues that currently make this an infeasible solution.

  18. Introducing Large-Scale Innovation in Schools

    NASA Astrophysics Data System (ADS)

    Sotiriou, Sofoklis; Riviou, Katherina; Cherouvis, Stephanos; Chelioti, Eleni; Bogner, Franz X.

    2016-08-01

    Education reform initiatives tend to promise higher effectiveness in classrooms especially when emphasis is given to e-learning and digital resources. Practical changes in classroom realities or school organization, however, are lacking. A major European initiative entitled Open Discovery Space (ODS) examined the challenge of modernizing school education via a large-scale implementation of an open-scale methodology in using technology-supported innovation. The present paper describes this innovation scheme which involved schools and teachers all over Europe, embedded technology-enhanced learning into wider school environments and provided training to teachers. Our implementation scheme consisted of three phases: (1) stimulating interest, (2) incorporating the innovation into school settings and (3) accelerating the implementation of the innovation. The scheme's impact was monitored for a school year using five indicators: leadership and vision building, ICT in the curriculum, development of ICT culture, professional development support, and school resources and infrastructure. Based on about 400 schools, our study produced four results: (1) The growth in digital maturity was substantial, even for previously high scoring schools. This was even more important for indicators such as vision and leadership" and "professional development." (2) The evolution of networking is presented graphically, showing the gradual growth of connections achieved. (3) These communities became core nodes, involving numerous teachers in sharing educational content and experiences: One out of three registered users (36 %) has shared his/her educational resources in at least one community. (4) Satisfaction scores ranged from 76 % (offer of useful support through teacher academies) to 87 % (good environment to exchange best practices). Initiatives such as ODS add substantial value to schools on a large scale.

  19. Introducing Large-Scale Innovation in Schools

    NASA Astrophysics Data System (ADS)

    Sotiriou, Sofoklis; Riviou, Katherina; Cherouvis, Stephanos; Chelioti, Eleni; Bogner, Franz X.

    2016-02-01

    Education reform initiatives tend to promise higher effectiveness in classrooms especially when emphasis is given to e-learning and digital resources. Practical changes in classroom realities or school organization, however, are lacking. A major European initiative entitled Open Discovery Space (ODS) examined the challenge of modernizing school education via a large-scale implementation of an open-scale methodology in using technology-supported innovation. The present paper describes this innovation scheme which involved schools and teachers all over Europe, embedded technology-enhanced learning into wider school environments and provided training to teachers. Our implementation scheme consisted of three phases: (1) stimulating interest, (2) incorporating the innovation into school settings and (3) accelerating the implementation of the innovation. The scheme's impact was monitored for a school year using five indicators: leadership and vision building, ICT in the curriculum, development of ICT culture, professional development support, and school resources and infrastructure. Based on about 400 schools, our study produced four results: (1) The growth in digital maturity was substantial, even for previously high scoring schools. This was even more important for indicators such as vision and leadership" and "professional development." (2) The evolution of networking is presented graphically, showing the gradual growth of connections achieved. (3) These communities became core nodes, involving numerous teachers in sharing educational content and experiences: One out of three registered users (36 %) has shared his/her educational resources in at least one community. (4) Satisfaction scores ranged from 76 % (offer of useful support through teacher academies) to 87 % (good environment to exchange best practices). Initiatives such as ODS add substantial value to schools on a large scale.

  20. Multi-Scale Multi-Dimensional Ion Battery Performance Model

    Energy Science and Technology Software Center (ESTSC)

    2007-05-07

    The Multi-Scale Multi-Dimensional (MSMD) Lithium Ion Battery Model allows for computer prediction and engineering optimization of thermal, electrical, and electrochemical performance of lithium ion cells with realistic geometries. The model introduces separate simulation domains for different scale physics, achieving much higher computational efficiency compared to the single domain approach. It solves a one dimensional electrochemistry model in a micro sub-grid system, and captures the impacts of macro-scale battery design factors on cell performance and materialmore » usage by solving cell-level electron and heat transports in a macro grid system.« less

  1. Implicit solvers for large-scale nonlinear problems

    SciTech Connect

    Keyes, D E; Reynolds, D; Woodward, C S

    2006-07-13

    Computational scientists are grappling with increasingly complex, multi-rate applications that couple such physical phenomena as fluid dynamics, electromagnetics, radiation transport, chemical and nuclear reactions, and wave and material propagation in inhomogeneous media. Parallel computers with large storage capacities are paving the way for high-resolution simulations of coupled problems; however, hardware improvements alone will not prove enough to enable simulations based on brute-force algorithmic approaches. To accurately capture nonlinear couplings between dynamically relevant phenomena, often while stepping over rapid adjustments to quasi-equilibria, simulation scientists are increasingly turning to implicit formulations that require a discrete nonlinear system to be solved for each time step or steady state solution. Recent advances in iterative methods have made fully implicit formulations a viable option for solution of these large-scale problems. In this paper, we overview one of the most effective iterative methods, Newton-Krylov, for nonlinear systems and point to software packages with its implementation. We illustrate the method with an example from magnetically confined plasma fusion and briefly survey other areas in which implicit methods have bestowed important advantages, such as allowing high-order temporal integration and providing a pathway to sensitivity analyses and optimization. Lastly, we overview algorithm extensions under development motivated by current SciDAC applications.

  2. Gravity and large-scale nonlocal bias

    NASA Astrophysics Data System (ADS)

    Chan, Kwan Chuen; Scoccimarro, Román; Sheth, Ravi K.

    2012-04-01

    For Gaussian primordial fluctuations the relationship between galaxy and matter overdensities, bias, is most often assumed to be local at the time of observation in the large-scale limit. This hypothesis is however unstable under time evolution, we provide proofs under several (increasingly more realistic) sets of assumptions. In the simplest toy model galaxies are created locally and linearly biased at a single formation time, and subsequently move with the dark matter (no velocity bias) conserving their comoving number density (no merging). We show that, after this formation time, the bias becomes unavoidably nonlocal and nonlinear at large scales. We identify the nonlocal gravitationally induced fields in which the galaxy overdensity can be expanded, showing that they can be constructed out of the invariants of the deformation tensor (Galileons), the main signature of which is a quadrupole field in second-order perturbation theory. In addition, we show that this result persists if we include an arbitrary evolution of the comoving number density of tracers. We then include velocity bias, and show that new contributions appear; these are related to the breaking of Galilean invariance of the bias relation, a dipole field being the signature at second order. We test these predictions by studying the dependence of halo overdensities in cells of fixed dark matter density: measurements in simulations show that departures from the mean bias relation are strongly correlated with the nonlocal gravitationally induced fields identified by our formalism, suggesting that the halo distribution at the present time is indeed more closely related to the mass distribution at an earlier rather than present time. However, the nonlocality seen in the simulations is not fully captured by assuming local bias in Lagrangian space. The effects on nonlocal bias seen in the simulations are most important for the most biased halos, as expected from our predictions. Accounting for these

  3. Curvature constraints from large scale structure

    NASA Astrophysics Data System (ADS)

    Di Dio, Enea; Montanari, Francesco; Raccanelli, Alvise; Durrer, Ruth; Kamionkowski, Marc; Lesgourgues, Julien

    2016-06-01

    We modified the CLASS code in order to include relativistic galaxy number counts in spatially curved geometries; we present the formalism and study the effect of relativistic corrections on spatial curvature. The new version of the code is now publicly available. Using a Fisher matrix analysis, we investigate how measurements of the spatial curvature parameter ΩK with future galaxy surveys are affected by relativistic effects, which influence observations of the large scale galaxy distribution. These effects include contributions from cosmic magnification, Doppler terms and terms involving the gravitational potential. As an application, we consider angle and redshift dependent power spectra, which are especially well suited for model independent cosmological constraints. We compute our results for a representative deep, wide and spectroscopic survey, and our results show the impact of relativistic corrections on spatial curvature parameter estimation. We show that constraints on the curvature parameter may be strongly biased if, in particular, cosmic magnification is not included in the analysis. Other relativistic effects turn out to be subdominant in the studied configuration. We analyze how the shift in the estimated best-fit value for the curvature and other cosmological parameters depends on the magnification bias parameter, and find that significant biases are to be expected if this term is not properly considered in the analysis.

  4. Large scale digital atlases in neuroscience

    NASA Astrophysics Data System (ADS)

    Hawrylycz, M.; Feng, D.; Lau, C.; Kuan, C.; Miller, J.; Dang, C.; Ng, L.

    2014-03-01

    Imaging in neuroscience has revolutionized our current understanding of brain structure, architecture and increasingly its function. Many characteristics of morphology, cell type, and neuronal circuitry have been elucidated through methods of neuroimaging. Combining this data in a meaningful, standardized, and accessible manner is the scope and goal of the digital brain atlas. Digital brain atlases are used today in neuroscience to characterize the spatial organization of neuronal structures, for planning and guidance during neurosurgery, and as a reference for interpreting other data modalities such as gene expression and connectivity data. The field of digital atlases is extensive and in addition to atlases of the human includes high quality brain atlases of the mouse, rat, rhesus macaque, and other model organisms. Using techniques based on histology, structural and functional magnetic resonance imaging as well as gene expression data, modern digital atlases use probabilistic and multimodal techniques, as well as sophisticated visualization software to form an integrated product. Toward this goal, brain atlases form a common coordinate framework for summarizing, accessing, and organizing this knowledge and will undoubtedly remain a key technology in neuroscience in the future. Since the development of its flagship project of a genome wide image-based atlas of the mouse brain, the Allen Institute for Brain Science has used imaging as a primary data modality for many of its large scale atlas projects. We present an overview of Allen Institute digital atlases in neuroscience, with a focus on the challenges and opportunities for image processing and computation.

  5. Large-scale carbon fiber tests

    NASA Technical Reports Server (NTRS)

    Pride, R. A.

    1980-01-01

    A realistic release of carbon fibers was established by burning a minimum of 45 kg of carbon fiber composite aircraft structural components in each of five large scale, outdoor aviation jet fuel fire tests. This release was quantified by several independent assessments with various instruments developed specifically for these tests. The most likely values for the mass of single carbon fibers released ranged from 0.2 percent of the initial mass of carbon fiber for the source tests (zero wind velocity) to a maximum of 0.6 percent of the initial carbon fiber mass for dissemination tests (5 to 6 m/s wind velocity). Mean fiber lengths for fibers greater than 1 mm in length ranged from 2.5 to 3.5 mm. Mean diameters ranged from 3.6 to 5.3 micrometers which was indicative of significant oxidation. Footprints of downwind dissemination of the fire released fibers were measured to 19.1 km from the fire.

  6. Large-scale wind turbine structures

    NASA Technical Reports Server (NTRS)

    Spera, David A.

    1988-01-01

    The purpose of this presentation is to show how structural technology was applied in the design of modern wind turbines, which were recently brought to an advanced stage of development as sources of renewable power. Wind turbine structures present many difficult problems because they are relatively slender and flexible; subject to vibration and aeroelastic instabilities; acted upon by loads which are often nondeterministic; operated continuously with little maintenance in all weather; and dominated by life-cycle cost considerations. Progress in horizontal-axis wind turbines (HAWT) development was paced by progress in the understanding of structural loads, modeling of structural dynamic response, and designing of innovative structural response. During the past 15 years a series of large HAWTs was developed. This has culminated in the recent completion of the world's largest operating wind turbine, the 3.2 MW Mod-5B power plane installed on the island of Oahu, Hawaii. Some of the applications of structures technology to wind turbine will be illustrated by referring to the Mod-5B design. First, a video overview will be presented to provide familiarization with the Mod-5B project and the important components of the wind turbine system. Next, the structural requirements for large-scale wind turbines will be discussed, emphasizing the difficult fatigue-life requirements. Finally, the procedures used to design the structure will be presented, including the use of the fracture mechanics approach for determining allowable fatigue stresses.

  7. Large-scale wind turbine structures

    NASA Astrophysics Data System (ADS)

    Spera, David A.

    1988-05-01

    The purpose of this presentation is to show how structural technology was applied in the design of modern wind turbines, which were recently brought to an advanced stage of development as sources of renewable power. Wind turbine structures present many difficult problems because they are relatively slender and flexible; subject to vibration and aeroelastic instabilities; acted upon by loads which are often nondeterministic; operated continuously with little maintenance in all weather; and dominated by life-cycle cost considerations. Progress in horizontal-axis wind turbines (HAWT) development was paced by progress in the understanding of structural loads, modeling of structural dynamic response, and designing of innovative structural response. During the past 15 years a series of large HAWTs was developed. This has culminated in the recent completion of the world's largest operating wind turbine, the 3.2 MW Mod-5B power plane installed on the island of Oahu, Hawaii. Some of the applications of structures technology to wind turbine will be illustrated by referring to the Mod-5B design. First, a video overview will be presented to provide familiarization with the Mod-5B project and the important components of the wind turbine system. Next, the structural requirements for large-scale wind turbines will be discussed, emphasizing the difficult fatigue-life requirements. Finally, the procedures used to design the structure will be presented, including the use of the fracture mechanics approach for determining allowable fatigue stresses.

  8. Food appropriation through large scale land acquisitions

    NASA Astrophysics Data System (ADS)

    Rulli, Maria Cristina; D'Odorico, Paolo

    2014-05-01

    The increasing demand for agricultural products and the uncertainty of international food markets has recently drawn the attention of governments and agribusiness firms toward investments in productive agricultural land, mostly in the developing world. The targeted countries are typically located in regions that have remained only marginally utilized because of lack of modern technology. It is expected that in the long run large scale land acquisitions (LSLAs) for commercial farming will bring the technology required to close the existing crops yield gaps. While the extent of the acquired land and the associated appropriation of freshwater resources have been investigated in detail, the amount of food this land can produce and the number of people it could feed still need to be quantified. Here we use a unique dataset of land deals to provide a global quantitative assessment of the rates of crop and food appropriation potentially associated with LSLAs. We show how up to 300-550 million people could be fed by crops grown in the acquired land, should these investments in agriculture improve crop production and close the yield gap. In contrast, about 190-370 million people could be supported by this land without closing of the yield gap. These numbers raise some concern because the food produced in the acquired land is typically exported to other regions, while the target countries exhibit high levels of malnourishment. Conversely, if used for domestic consumption, the crops harvested in the acquired land could ensure food security to the local populations.

  9. Large Scale Computer Simulation of Erthocyte Membranes

    NASA Astrophysics Data System (ADS)

    Harvey, Cameron; Revalee, Joel; Laradji, Mohamed

    2007-11-01

    The cell membrane is crucial to the life of the cell. Apart from partitioning the inner and outer environment of the cell, they also act as a support of complex and specialized molecular machinery, important for both the mechanical integrity of the cell, and its multitude of physiological functions. Due to its relative simplicity, the red blood cell has been a favorite experimental prototype for investigations of the structural and functional properties of the cell membrane. The erythrocyte membrane is a composite quasi two-dimensional structure composed essentially of a self-assembled fluid lipid bilayer and a polymerized protein meshwork, referred to as the cytoskeleton or membrane skeleton. In the case of the erythrocyte, the polymer meshwork is mainly composed of spectrin, anchored to the bilayer through specialized proteins. Using a coarse-grained model, recently developed by us, of self-assembled lipid membranes with implicit solvent and using soft-core potentials, we simulated large scale red-blood-cells bilayers with dimensions ˜ 10-1 μm^2, with explicit cytoskeleton. Our aim is to investigate the renormalization of the elastic properties of the bilayer due to the underlying spectrin meshwork.

  10. Extended Darknet: Multi-Dimensional Internet Threat Monitoring System

    NASA Astrophysics Data System (ADS)

    Shimoda, Akihiro; Mori, Tatsuya; Goto, Shigeki

    Internet threats caused by botnets/worms are one of the most important security issues to be addressed. Darknet, also called a dark IP address space, is one of the best solutions for monitoring anomalous packets sent by malicious software. However, since darknet is deployed only on an inactive IP address space, it is an inefficient way for monitoring a working network that has a considerable number of active IP addresses. The present paper addresses this problem. We propose a scalable, light-weight malicious packet monitoring system based on a multi-dimensional IP/port analysis. Our system significantly extends the monitoring scope of darknet. In order to extend the capacity of darknet, our approach leverages the active IP address space without affecting legitimate traffic. Multi-dimensional monitoring enables the monitoring of TCP ports with firewalls enabled on each of the IP addresses. We focus on delays of TCP syn/ack responses in the traffic. We locate syn/ack delayed packets and forward them to sensors or honeypots for further analysis. We also propose a policy-based flow classification and forwarding mechanism and develop a prototype of a monitoring system that implements our proposed architecture. We deploy our system on a campus network and perform several experiments for the evaluation of our system. We verify that our system can cover 89% of the IP addresses while darknet-based monitoring only covers 46%. On our campus network, our system monitors twice as many IP addresses as darknet.

  11. Spatial Indexing and Visualization of Large Multi-Dimensional Databases

    NASA Astrophysics Data System (ADS)

    Dobos, L.; Csabai, I.; Trencséni, M.; Herczegh, G.; Józsa, P.; Purger, N.

    2007-10-01

    Scientific endeavors such as large astronomical surveys generate databases on the terabyte scale. These usually multi-dimensional databases must be visualized and mined in order to find interesting objects or to extract meaningful and qualitatively new relationships. Many statistical algorithms required for these tasks run reasonably fast when operating on small sets of in-memory data, but take noticeable performance hits when operating on large databases that do not fit into memory. We utilize new software technologies to develop and evaluate fast multi-dimensional, spatial indexing schemes that inherently follow the underlying highly non-uniform distribution of the data: one of them is hierarchical binary space partitioning; the other is sampled flat Voronoi partitioning of the data. Our working database is the 5-dimensional magnitude space of the Sloan Digital Sky Survey with more than 250 million data points. We show that these techniques can dramatically speed up data mining operations such as finding similar objects by example, classifying objects or comparing extensive simulation sets with observations. We are also developing tools to interact with the spatial database and visualize the data real-time at multiple resolutions at different zoom levels in an adaptive manner.

  12. An information model for managing multi-dimensional gridded data in a GIS

    NASA Astrophysics Data System (ADS)

    Xu, H.; Abdul-Kadar, F.; Gao, P.

    2016-04-01

    Earth observation agencies like NASA and NOAA produce huge volumes of historical, near real-time, and forecasting data representing terrestrial, atmospheric, and oceanic phenomena. The data drives climatological and meteorological studies, and underpins operations ranging from weather pattern prediction and forest fire monitoring to global vegetation analysis. These gridded data sets are distributed mostly as files in HDF, GRIB, or netCDF format and quantify variables like precipitation, soil moisture, or sea surface temperature, along one or more dimensions like time and depth. Although the data cube is a well-studied model for storing and analyzing multi-dimensional data, the GIS community remains in need of a solution that simplifies interactions with the data, and elegantly fits with existing database schemas and dissemination protocols. This paper presents an information model that enables Geographic Information Systems (GIS) to efficiently catalog very large heterogeneous collections of geospatially-referenced multi-dimensional rasters—towards providing unified access to the resulting multivariate hypercubes. We show how the implementation of the model encapsulates format-specific variations and provides unified access to data along any dimension. We discuss how this framework lends itself to familiar GIS concepts like image mosaics, vector field visualization, layer animation, distributed data access via web services, and scientific computing. Global data sources like MODIS from USGS and HYCOM from NOAA illustrate how one would employ this framework for cataloging, querying, and intuitively visualizing such hypercubes. ArcGIS—an established platform for processing, analyzing, and visualizing geospatial data—serves to demonstrate how this integration brings the full power of GIS to the scientific community.

  13. An informal paper on large-scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Ho, Y. C.

    1975-01-01

    Large scale systems are defined as systems requiring more than one decision maker to control the system. Decentralized control and decomposition are discussed for large scale dynamic systems. Information and many-person decision problems are analyzed.

  14. Sensitivity technologies for large scale simulation.

    SciTech Connect

    Collis, Samuel Scott; Bartlett, Roscoe Ainsworth; Smith, Thomas Michael; Heinkenschloss, Matthias; Wilcox, Lucas C.; Hill, Judith C.; Ghattas, Omar; Berggren, Martin Olof; Akcelik, Volkan; Ober, Curtis Curry; van Bloemen Waanders, Bart Gustaaf; Keiter, Eric Richard

    2005-01-01

    Sensitivity analysis is critically important to numerous analysis algorithms, including large scale optimization, uncertainty quantification,reduced order modeling, and error estimation. Our research focused on developing tools, algorithms and standard interfaces to facilitate the implementation of sensitivity type analysis into existing code and equally important, the work was focused on ways to increase the visibility of sensitivity analysis. We attempt to accomplish the first objective through the development of hybrid automatic differentiation tools, standard linear algebra interfaces for numerical algorithms, time domain decomposition algorithms and two level Newton methods. We attempt to accomplish the second goal by presenting the results of several case studies in which direct sensitivities and adjoint methods have been effectively applied, in addition to an investigation of h-p adaptivity using adjoint based a posteriori error estimation. A mathematical overview is provided of direct sensitivities and adjoint methods for both steady state and transient simulations. Two case studies are presented to demonstrate the utility of these methods. A direct sensitivity method is implemented to solve a source inversion problem for steady state internal flows subject to convection diffusion. Real time performance is achieved using novel decomposition into offline and online calculations. Adjoint methods are used to reconstruct initial conditions of a contamination event in an external flow. We demonstrate an adjoint based transient solution. In addition, we investigated time domain decomposition algorithms in an attempt to improve the efficiency of transient simulations. Because derivative calculations are at the root of sensitivity calculations, we have developed hybrid automatic differentiation methods and implemented this approach for shape optimization for gas dynamics using the Euler equations. The hybrid automatic differentiation method was applied to a first

  15. Towards Semantic Web Services on Large, Multi-Dimensional Coverages

    NASA Astrophysics Data System (ADS)

    Baumann, P.

    2009-04-01

    Observed and simulated data in the Earth Sciences often come as coverages, the general term for space-time varying phenomena as set forth by standardization bodies like the Open GeoSpatial Consortium (OGC) and ISO. Among such data are 1-d time series, 2-D surface data, 3-D surface data time series as well as x/y/z geophysical and oceanographic data, and 4-D metocean simulation results. With increasing dimensionality the data sizes grow exponentially, up to Petabyte object sizes. Open standards for exploiting coverage archives over the Web are available to a varying extent. The OGC Web Coverage Service (WCS) standard defines basic extraction operations: spatio-temporal and band subsetting, scaling, reprojection, and data format encoding of the result - a simple interoperable interface for coverage access. More processing functionality is available with products like Matlab, Grid-type interfaces, and the OGC Web Processing Service (WPS). However, these often lack properties known as advantageous from databases: declarativeness (describe results rather than the algorithms), safe in evaluation (no request can keep a server busy infinitely), and optimizable (enable the server to rearrange the request so as to produce the same result faster). WPS defines a geo-enabled SOAP interface for remote procedure calls. This allows to webify any program, but does not allow for semantic interoperability: a function is identified only by its function name and parameters while the semantics is encoded in the (only human readable) title and abstract. Hence, another desirable property is missing, namely an explicit semantics which allows for machine-machine communication and reasoning a la Semantic Web. The OGC Web Coverage Processing Service (WCPS) language, which has been adopted as an international standard by OGC in December 2008, defines a flexible interface for the navigation, extraction, and ad-hoc analysis of large, multi-dimensional raster coverages. It is abstract in that it

  16. Towards Semantic Web Services on Large, Multi-Dimensional Coverages

    NASA Astrophysics Data System (ADS)

    Baumann, P.

    2009-04-01

    Observed and simulated data in the Earth Sciences often come as coverages, the general term for space-time varying phenomena as set forth by standardization bodies like the Open GeoSpatial Consortium (OGC) and ISO. Among such data are 1-d time series, 2-D surface data, 3-D surface data time series as well as x/y/z geophysical and oceanographic data, and 4-D metocean simulation results. With increasing dimensionality the data sizes grow exponentially, up to Petabyte object sizes. Open standards for exploiting coverage archives over the Web are available to a varying extent. The OGC Web Coverage Service (WCS) standard defines basic extraction operations: spatio-temporal and band subsetting, scaling, reprojection, and data format encoding of the result - a simple interoperable interface for coverage access. More processing functionality is available with products like Matlab, Grid-type interfaces, and the OGC Web Processing Service (WPS). However, these often lack properties known as advantageous from databases: declarativeness (describe results rather than the algorithms), safe in evaluation (no request can keep a server busy infinitely), and optimizable (enable the server to rearrange the request so as to produce the same result faster). WPS defines a geo-enabled SOAP interface for remote procedure calls. This allows to webify any program, but does not allow for semantic interoperability: a function is identified only by its function name and parameters while the semantics is encoded in the (only human readable) title and abstract. Hence, another desirable property is missing, namely an explicit semantics which allows for machine-machine communication and reasoning a la Semantic Web. The OGC Web Coverage Processing Service (WCPS) language, which has been adopted as an international standard by OGC in December 2008, defines a flexible interface for the navigation, extraction, and ad-hoc analysis of large, multi-dimensional raster coverages. It is abstract in that it

  17. International space station. Large scale integration approach

    NASA Astrophysics Data System (ADS)

    Cohen, Brad

    The International Space Station is the most complex large scale integration program in development today. The approach developed for specification, subsystem development, and verification lay a firm basis on which future programs of this nature can be based. International Space Station is composed of many critical items, hardware and software, built by numerous International Partners, NASA Institutions, and U.S. Contractors and is launched over a period of five years. Each launch creates a unique configuration that must be safe, survivable, operable, and support ongoing assembly (assemblable) to arrive at the assembly complete configuration in 2003. The approaches to integrating each of the modules into a viable spacecraft and continue the assembly is a challenge in itself. Added to this challenge are the severe schedule constraints and lack of an "Iron Bird", which prevents assembly and checkout of each on-orbit configuration prior to launch. This paper will focus on the following areas: 1) Specification development process explaining how the requirements and specifications were derived using a modular concept driven by launch vehicle capability. Each module is composed of components of subsystems versus completed subsystems. 2) Approach to stage (each stage consists of the launched module added to the current on-orbit spacecraft) specifications. Specifically, how each launched module and stage ensures support of the current and future elements of the assembly. 3) Verification approach, due to the schedule constraints, is primarily analysis supported by testing. Specifically, how are the interfaces ensured to mate and function on-orbit when they cannot be mated before launch. 4) Lessons learned. Where can we improve this complex system design and integration task?

  18. Large Scale Flame Spread Environmental Characterization Testing

    NASA Technical Reports Server (NTRS)

    Clayman, Lauren K.; Olson, Sandra L.; Gokoghi, Suleyman A.; Brooker, John E.; Ferkul, Paul V.; Kacher, Henry F.

    2013-01-01

    Under the Advanced Exploration Systems (AES) Spacecraft Fire Safety Demonstration Project (SFSDP), as a risk mitigation activity in support of the development of a large-scale fire demonstration experiment in microgravity, flame-spread tests were conducted in normal gravity on thin, cellulose-based fuels in a sealed chamber. The primary objective of the tests was to measure pressure rise in a chamber as sample material, burning direction (upward/downward), total heat release, heat release rate, and heat loss mechanisms were varied between tests. A Design of Experiments (DOE) method was imposed to produce an array of tests from a fixed set of constraints and a coupled response model was developed. Supplementary tests were run without experimental design to additionally vary select parameters such as initial chamber pressure. The starting chamber pressure for each test was set below atmospheric to prevent chamber overpressure. Bottom ignition, or upward propagating burns, produced rapid acceleratory turbulent flame spread. Pressure rise in the chamber increases as the amount of fuel burned increases mainly because of the larger amount of heat generation and, to a much smaller extent, due to the increase in gaseous number of moles. Top ignition, or downward propagating burns, produced a steady flame spread with a very small flat flame across the burning edge. Steady-state pressure is achieved during downward flame spread as the pressure rises and plateaus. This indicates that the heat generation by the flame matches the heat loss to surroundings during the longer, slower downward burns. One heat loss mechanism included mounting a heat exchanger directly above the burning sample in the path of the plume to act as a heat sink and more efficiently dissipate the heat due to the combustion event. This proved an effective means for chamber overpressure mitigation for those tests producing the most total heat release and thusly was determined to be a feasible mitigation

  19. Synchronization of coupled large-scale Boolean networks

    SciTech Connect

    Li, Fangfei

    2014-03-15

    This paper investigates the complete synchronization and partial synchronization of two large-scale Boolean networks. First, the aggregation algorithm towards large-scale Boolean network is reviewed. Second, the aggregation algorithm is applied to study the complete synchronization and partial synchronization of large-scale Boolean networks. Finally, an illustrative example is presented to show the efficiency of the proposed results.

  20. Computing the universe: how large-scale simulations illuminate galaxies and dark energy

    NASA Astrophysics Data System (ADS)

    O'Shea, Brian

    2015-04-01

    High-performance and large-scale computing is absolutely to understanding astronomical objects such as stars, galaxies, and the cosmic web. This is because these are structures that operate on physical, temporal, and energy scales that cannot be reasonably approximated in the laboratory, and whose complexity and nonlinearity often defies analytic modeling. In this talk, I show how the growth of computing platforms over time has facilitated our understanding of astrophysical and cosmological phenomena, focusing primarily on galaxies and large-scale structure in the Universe.

  1. Multi-dimensional structure of accreting young stars

    NASA Astrophysics Data System (ADS)

    Geroux, C.; Baraffe, I.; Viallet, M.; Goffrey, T.; Pratt, J.; Constantino, T.; Folini, D.; Popov, M. V.; Walder, R.

    2016-04-01

    This work is the first attempt to describe the multi-dimensional structure of accreting young stars based on fully compressible time implicit multi-dimensional hydrodynamics simulations. One major motivation is to analyse the validity of accretion treatment used in previous 1D stellar evolution studies. We analyse the effect of accretion on the structure of a realistic stellar model of the young Sun. Our work is inspired by the numerical work of Kley & Lin (1996, ApJ, 461, 933) devoted to the structure of the boundary layer in accretion disks, which provides the outer boundary conditions for our simulations. We analyse the redistribution of accreted material with a range of values of specific entropy relative to the bulk specific entropy of the material in the accreting object's convective envelope. Low specific entropy accreted material characterises the so-called cold accretion process, whereas high specific entropy is relevant to hot accretion. A primary goal is to understand whether and how accreted energy deposited onto a stellar surface is redistributed in the interior. This study focusses on the high accretion rates characteristic of FU Ori systems. We find that the highest entropy cases produce a distinctive behaviour in the mass redistribution, rms velocities, and enthalpy flux in the convective envelope. This change in behaviour is characterised by the formation of a hot layer on the surface of the accreting object, which tends to suppress convection in the envelope. We analyse the long-term effect of such a hot buffer zone on the structure and evolution of the accreting object with 1D stellar evolution calculations. We study the relevance of the assumption of redistribution of accreted energy into the stellar interior used in the literature. We compare results obtained with the latter treatment and those obtained with a more physical accretion boundary condition based on the formation of a hot surface layer suggested by present multi-dimensional

  2. Large-Scale Spacecraft Fire Safety Tests

    NASA Technical Reports Server (NTRS)

    Urban, David; Ruff, Gary A.; Ferkul, Paul V.; Olson, Sandra; Fernandez-Pello, A. Carlos; T'ien, James S.; Torero, Jose L.; Cowlard, Adam J.; Rouvreau, Sebastien; Minster, Olivier; Toth, Balazs; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu; Jomaas, Grunde

    2014-01-01

    An international collaborative program is underway to address open issues in spacecraft fire safety. Because of limited access to long-term low-gravity conditions and the small volume generally allotted for these experiments, there have been relatively few experiments that directly study spacecraft fire safety under low-gravity conditions. Furthermore, none of these experiments have studied sample sizes and environment conditions typical of those expected in a spacecraft fire. The major constraint has been the size of the sample, with prior experiments limited to samples of the order of 10 cm in length and width or smaller. This lack of experimental data forces spacecraft designers to base their designs and safety precautions on 1-g understanding of flame spread, fire detection, and suppression. However, low-gravity combustion research has demonstrated substantial differences in flame behavior in low-gravity. This, combined with the differences caused by the confined spacecraft environment, necessitates practical scale spacecraft fire safety research to mitigate risks for future space missions. To address this issue, a large-scale spacecraft fire experiment is under development by NASA and an international team of investigators. This poster presents the objectives, status, and concept of this collaborative international project (Saffire). The project plan is to conduct fire safety experiments on three sequential flights of an unmanned ISS re-supply spacecraft (the Orbital Cygnus vehicle) after they have completed their delivery of cargo to the ISS and have begun their return journeys to earth. On two flights (Saffire-1 and Saffire-3), the experiment will consist of a flame spread test involving a meter-scale sample ignited in the pressurized volume of the spacecraft and allowed to burn to completion while measurements are made. On one of the flights (Saffire-2), 9 smaller (5 x 30 cm) samples will be tested to evaluate NASAs material flammability screening tests

  3. Review of multi-dimensional large-scale kinetic simulation and physics validation of ion acceleration in relativistic laser-matter interaction

    SciTech Connect

    Wu, Hui-Chun; Hegelich, B.M.; Fernandez, J.C.; Shah, R.C.; Palaniyappan, S.; Jung, D.; Yin, L; Albright, B.J.; Bowers, K.; Huang, C.; Kwan, T.J.

    2012-06-19

    Two new experimental technologies enabled realization of Break-out afterburner (BOA) - High quality Trident laser and free-standing C nm-targets. VPIC is an powerful tool for fundamental research of relativistic laser-matter interaction. Predictions from VPIC are validated - Novel BOA and Solitary ion acceleration mechanisms. VPIC is a fully explicit Particle In Cell (PIC) code: models plasma as billions of macro-particles moving on a computational mesh. VPIC particle advance (which typically dominates computation) has been optimized extensively for many different supercomputers. Laser-driven ions lead to realization promising applications - Ion-based fast ignition; active interrogation, hadron therapy.

  4. A Multi-Dimensional Classification Model for Scientific Workflow Characteristics

    SciTech Connect

    Ramakrishnan, Lavanya; Plale, Beth

    2010-04-05

    Workflows have been used to model repeatable tasks or operations in manufacturing, business process, and software. In recent years, workflows are increasingly used for orchestration of science discovery tasks that use distributed resources and web services environments through resource models such as grid and cloud computing. Workflows have disparate re uirements and constraints that affects how they might be managed in distributed environments. In this paper, we present a multi-dimensional classification model illustrated by workflow examples obtained through a survey of scientists from different domains including bioinformatics and biomedical, weather and ocean modeling, astronomy detailing their data and computational requirements. The survey results and classification model contribute to the high level understandingof scientific workflows.

  5. The Multi-Dimensional Character of Core-Collapse Supernovae

    SciTech Connect

    Hix, William Raphael; Lentz, E. J.; Bruenn, S. W.; Mezzacappa, Anthony; Messer, Bronson; Endeve, Eirik; Blondin, J. M.; Harris, James Austin; Marronetti, Pedro; Yakunin, Konstantin N

    2016-01-01

    Core-collapse supernovae, the culmination of massive stellar evolution, are spectacular astronomical events and the principle actors in the story of our elemental origins. Our understanding of these events, while still incomplete, centers around a neutrino-driven central engine that is highly hydrodynamically unstable. Increasingly sophisticated simulations reveal a shock that stalls for hundreds of milliseconds before reviving. Though brought back to life by neutrino heating, the development of the supernova explosion is inextricably linked to multi-dimensional fluid flows. In this paper, the outcomes of three-dimensional simulations that include sophisticated nuclear physics and spectral neutrino transport are juxtaposed to learn about the nature of the three dimensional fluid flow that shapes the explosion. Comparison is also made between the results of simulations in spherical symmetry from several groups, to give ourselves confidence in the understanding derived from this juxtaposition.

  6. Concurrent Validity and Feasibility of Short Tests Currently Used to Measure Early Childhood Development in Large Scale Studies.

    PubMed

    Rubio-Codina, Marta; Araujo, M Caridad; Attanasio, Orazio; Muñoz, Pablo; Grantham-McGregor, Sally

    2016-01-01

    In low- and middle-income countries (LIMCs), measuring early childhood development (ECD) with standard tests in large scale surveys and evaluations of interventions is difficult and expensive. Multi-dimensional screeners and single-domain tests ('short tests') are frequently used as alternatives. However, their validity in these circumstances is unknown. We examined the feasibility, reliability, and concurrent validity of three multi-dimensional screeners (Ages and Stages Questionnaires (ASQ-3), Denver Developmental Screening Test (Denver-II), Battelle Developmental Inventory screener (BDI-2)) and two single-domain tests (MacArthur-Bates Short-Forms (SFI and SFII), WHO Motor Milestones (WHO-Motor)) in 1,311 children 6-42 months in Bogota, Colombia. The scores were compared with those on the Bayley Scales of Infant and Toddler Development (Bayley-III), taken as the 'gold standard'. The Bayley-III was given at a center by psychologists; whereas the short tests were administered in the home by interviewers, as in a survey setting. Findings indicated good internal validity of all short tests except the ASQ-3. The BDI-2 took long to administer and was expensive, while the single-domain tests were quickest and cheapest and the Denver-II and ASQ-3 were intermediate. Concurrent validity of the multi-dimensional tests' cognitive, language, and fine motor scales with the corresponding Bayley-III scale was low below 19 months. However, it increased with age, becoming moderate-to-high over 30 months. In contrast, gross motor scales' concurrence was high under 19 months and then decreased. Of the single-domain tests, the WHO-Motor had high validity with gross motor under 16 months, and the SFI and SFII expressive scales showed moderate correlations with language under 30 months. Overall, the Denver-II was the most feasible and valid multi-dimensional test and the ASQ-3 performed poorly under 31 months. By domain, gross motor development had the highest concurrence below 19

  7. Concurrent Validity and Feasibility of Short Tests Currently Used to Measure Early Childhood Development in Large Scale Studies

    PubMed Central

    Rubio-Codina, Marta; Araujo, M. Caridad; Attanasio, Orazio; Muñoz, Pablo; Grantham-McGregor, Sally

    2016-01-01

    In low- and middle-income countries (LIMCs), measuring early childhood development (ECD) with standard tests in large scale surveys and evaluations of interventions is difficult and expensive. Multi-dimensional screeners and single-domain tests (‘short tests’) are frequently used as alternatives. However, their validity in these circumstances is unknown. We examined the feasibility, reliability, and concurrent validity of three multi-dimensional screeners (Ages and Stages Questionnaires (ASQ-3), Denver Developmental Screening Test (Denver-II), Battelle Developmental Inventory screener (BDI-2)) and two single-domain tests (MacArthur-Bates Short-Forms (SFI and SFII), WHO Motor Milestones (WHO-Motor)) in 1,311 children 6–42 months in Bogota, Colombia. The scores were compared with those on the Bayley Scales of Infant and Toddler Development (Bayley-III), taken as the ‘gold standard’. The Bayley-III was given at a center by psychologists; whereas the short tests were administered in the home by interviewers, as in a survey setting. Findings indicated good internal validity of all short tests except the ASQ-3. The BDI-2 took long to administer and was expensive, while the single-domain tests were quickest and cheapest and the Denver-II and ASQ-3 were intermediate. Concurrent validity of the multi-dimensional tests’ cognitive, language, and fine motor scales with the corresponding Bayley-III scale was low below 19 months. However, it increased with age, becoming moderate-to-high over 30 months. In contrast, gross motor scales’ concurrence was high under 19 months and then decreased. Of the single-domain tests, the WHO-Motor had high validity with gross motor under 16 months, and the SFI and SFII expressive scales showed moderate correlations with language under 30 months. Overall, the Denver-II was the most feasible and valid multi-dimensional test and the ASQ-3 performed poorly under 31 months. By domain, gross motor development had the highest concurrence

  8. Graph theoretic modeling of large-scale semantic networks.

    PubMed

    Bales, Michael E; Johnson, Stephen B

    2006-08-01

    During the past several years, social network analysis methods have been used to model many complex real-world phenomena, including social networks, transportation networks, and the Internet. Graph theoretic methods, based on an elegant representation of entities and relationships, have been used in computational biology to study biological networks; however they have not yet been adopted widely by the greater informatics community. The graphs produced are generally large, sparse, and complex, and share common global topological properties. In this review of research (1998-2005) on large-scale semantic networks, we used a tailored search strategy to identify articles involving both a graph theoretic perspective and semantic information. Thirty-one relevant articles were retrieved. The majority (28, 90.3%) involved an investigation of a real-world network. These included corpora, thesauri, dictionaries, large computer programs, biological neuronal networks, word association networks, and files on the Internet. Twenty-two of the 28 (78.6%) involved a graph comprised of words or phrases. Fifteen of the 28 (53.6%) mentioned evidence of small-world characteristics in the network investigated. Eleven (39.3%) reported a scale-free topology, which tends to have a similar appearance when examined at varying scales. The results of this review indicate that networks generated from natural language have topological properties common to other natural phenomena. It has not yet been determined whether artificial human-curated terminology systems in biomedicine share these properties. Large network analysis methods have potential application in a variety of areas of informatics, such as in development of controlled vocabularies and for characterizing a given domain. PMID:16442849

  9. Large-scale assembly of colloidal particles

    NASA Astrophysics Data System (ADS)

    Yang, Hongta

    This study reports a simple, roll-to-roll compatible coating technology for producing three-dimensional highly ordered colloidal crystal-polymer composites, colloidal crystals, and macroporous polymer membranes. A vertically beveled doctor blade is utilized to shear align silica microsphere-monomer suspensions to form large-area composites in a single step. The polymer matrix and the silica microspheres can be selectively removed to create colloidal crystals and self-standing macroporous polymer membranes. The thickness of the shear-aligned crystal is correlated with the viscosity of the colloidal suspension and the coating speed, and the correlations can be qualitatively explained by adapting the mechanisms developed for conventional doctor blade coating. Five important research topics related to the application of large-scale three-dimensional highly ordered macroporous films by doctor blade coating are covered in this study. The first topic describes the invention in large area and low cost color reflective displays. This invention is inspired by the heat pipe technology. The self-standing macroporous polymer films exhibit brilliant colors which originate from the Bragg diffractive of visible light form the three-dimensional highly ordered air cavities. The colors can be easily changed by tuning the size of the air cavities to cover the whole visible spectrum. When the air cavities are filled with a solvent which has the same refractive index as that of the polymer, the macroporous polymer films become completely transparent due to the index matching. When the solvent trapped in the cavities is evaporated by in-situ heating, the sample color changes back to brilliant color. This process is highly reversible and reproducible for thousands of cycles. The second topic reports the achievement of rapid and reversible vapor detection by using 3-D macroporous photonic crystals. Capillary condensation of a condensable vapor in the interconnected macropores leads to the

  10. Large Scale Obscuration and Related Climate Effects Workshop: Proceedings

    SciTech Connect

    Zak, B.D.; Russell, N.A.; Church, H.W.; Einfeld, W.; Yoon, D.; Behl, Y.K.

    1994-05-01

    A Workshop on Large Scale Obsurcation and Related Climate Effects was held 29--31 January, 1992, in Albuquerque, New Mexico. The objectives of the workshop were: to determine through the use of expert judgement the current state of understanding of regional and global obscuration and related climate effects associated with nuclear weapons detonations; to estimate how large the uncertainties are in the parameters associated with these phenomena (given specific scenarios); to evaluate the impact of these uncertainties on obscuration predictions; and to develop an approach for the prioritization of further work on newly-available data sets to reduce the uncertainties. The workshop consisted of formal presentations by the 35 participants, and subsequent topical working sessions on: the source term; aerosol optical properties; atmospheric processes; and electro-optical systems performance and climatic impacts. Summaries of the conclusions reached in the working sessions are presented in the body of the report. Copies of the transparencies shown as part of each formal presentation are contained in the appendices (microfiche).

  11. Safety aspects of large-scale combustion of hydrogen

    SciTech Connect

    Edeskuty, F.J.; Haugh, J.J.; Thompson, R.T.

    1986-01-01

    Recent hydrogen-safety investigations have studied the possible large-scale effects from phenomena such as the accumulation of combustible hydrogen-air mixtures in large, confined volumes. Of particular interest are safe methods for the disposal of the hydrogen and the pressures which can arise from its confined combustion. Consequently, tests of the confined combustion of hydrogen-air mixtures were conducted in a 2100 m/sup 3/ volume. These tests show that continuous combustion, as the hydrogen is generated, is a safe method for its disposal. It also has been seen that, for hydrogen concentrations up to 13 vol %, it is possible to predict maximum pressures that can occur upon ignition of premixed hydrogen-air atmospheres. In addition information has been obtained concerning the survivability of the equipment that is needed to recover from an accident involving hydrogen combustion. An accident that involved the inadvertent mixing of hydrogen and oxygen gases in a tube trailer gave evidence that under the proper conditions hydrogen combustion can transit to a detonation. If detonation occurs the pressures which can be experienced are much higher although short in duration.

  12. Multi-Resolution Modeling of Large Scale Scientific Simulation Data

    SciTech Connect

    Baldwin, C; Abdulla, G; Critchlow, T

    2003-01-31

    This paper discusses using the wavelets modeling technique as a mechanism for querying large-scale spatio-temporal scientific simulation data. Wavelets have been used successfully in time series analysis and in answering surprise and trend queries. Our approach however is driven by the need for compression, which is necessary for viable throughput given the size of the targeted data, along with the end user requirements from the discovery process. Our users would like to run fast queries to check the validity of the simulation algorithms used. In some cases users are welling to accept approximate results if the answer comes back within a reasonable time. In other cases they might want to identify a certain phenomena and track it over time. We face a unique problem because of the data set sizes. It may take months to generate one set of the targeted data; because of its shear size, the data cannot be stored on disk for long and thus needs to be analyzed immediately before it is sent to tape. We integrated wavelets within AQSIM, a system that we are developing to support exploration and analyses of tera-scale size data sets. We will discuss the way we utilized wavelets decomposition in our domain to facilitate compression and in answering a specific class of queries that is harder to answer with any other modeling technique. We will also discuss some of the shortcomings of our implementation and how to address them.

  13. On Multi-Dimensional Vocabulary Teaching Mode for College English Teaching

    ERIC Educational Resources Information Center

    Zhou, Li-na

    2010-01-01

    This paper analyses the major approaches in EFL (English as a Foreign Language) vocabulary teaching from historical perspective and puts forward multi-dimensional vocabulary teaching mode for college English. The author stresses that multi-dimensional approaches of communicative vocabulary teaching, lexical phrase teaching method, the grammar…

  14. A one-dimensional shock capturing finite element method and multi-dimensional generalizations

    NASA Technical Reports Server (NTRS)

    Hughes, T. J. R.; Mallet, M.; Zanutta, R.; Taki, Y.; Tezduyar, T. E.

    1985-01-01

    Multi-dimensional generalizations of a one-dimensional finite element shock capturing scheme are proposed. A scalar model problem is used to emphasize that 'preferred directions' are important in multi-dimensional applications. Schemes are developed for the two-dimensional Euler equations. One, based upon characteristics, employs the Mach lines and streamlines as preferred directions.

  15. Multitree Algorithms for Large-Scale Astrostatistics

    NASA Astrophysics Data System (ADS)

    March, William B.; Ozakin, Arkadas; Lee, Dongryeol; Riegel, Ryan; Gray, Alexander G.

    2012-03-01

    this number every week, resulting in billions of objects. At such scales, even linear-time analysis operations present challenges, particularly since statistical analyses are inherently interactive processes, requiring that computations complete within some reasonable human attention span. The quadratic (or worse) runtimes of straightforward implementations become quickly unbearable. Examples of applications. These analysis subroutines occur ubiquitously in astrostatistical work. We list just a few examples. The need to cross-match objects across different catalogs has led to various algorithms, which at some point perform an AllNN computation. 2-point and higher-order spatial correlations for the basis of spatial statistics, and are utilized in astronomy to compare the spatial structures of two datasets, such as an observed sample and a theoretical sample, for example, forming the basis for two-sample hypothesis testing. Friends-of-friends clustering is often used to identify halos in data from astrophysical simulations. Minimum spanning tree properties have also been proposed as statistics of large-scale structure. Comparison of the distributions of different kinds of objects requires accurate density estimation, for which KDE is the overall statistical method of choice. The prediction of redshifts from optical data requires accurate regression, for which kernel regression is a powerful method. The identification of objects of various types in astronomy, such as stars versus galaxies, requires accurate classification, for which KDA is a powerful method. Overview. In this chapter, we will briefly sketch the main ideas behind recent fast algorithms which achieve, for example, linear runtimes for pairwise-distance problems, or similarly dramatic reductions in computational growth. In some cases, the runtime orders for these algorithms are mathematically provable statements, while in others we have only conjectures backed by experimental observations for the time being

  16. Probes of large-scale structure in the universe

    NASA Technical Reports Server (NTRS)

    Suto, Yasushi; Gorski, Krzysztof; Juszkiewicz, Roman; Silk, Joseph

    1988-01-01

    A general formalism is developed which shows that the gravitational instability theory for the origin of the large-scale structure of the universe is now capable of critically confronting observational results on cosmic background radiation angular anisotropies, large-scale bulk motions, and large-scale clumpiness in the galaxy counts. The results indicate that presently advocated cosmological models will have considerable difficulty in simultaneously explaining the observational results.

  17. Large-Scale Numerical Modeling of Melt and Solution Crystal Growth

    NASA Astrophysics Data System (ADS)

    Derby, Jeffrey J.; Chelikowsky, James R.; Sinno, Talid; Dai, Bing; Kwon, Yong-Il; Lun, Lisa; Pandy, Arun; Yeckel, Andrew

    2007-06-01

    We present an overview of mathematical models and their large-scale numerical solution for simulating different phenomena and scales in melt and solution crystal growth. Samples of both classical analyses and state-of-the-art computations are presented. It is argued that the fundamental multi-scale nature of crystal growth precludes any one approach for modeling, rather successful crystal growth modeling relies on an artful blend of rigor and practicality.

  18. Wildfire Detection using by Multi Dimensional Histogram in Boreal Forest

    NASA Astrophysics Data System (ADS)

    Honda, K.; Kimura, K.; Honma, T.

    2008-12-01

    forest in Kalimantan, Indonesia and around Chiang Mai, Thailand. But the ground truth data in these areas is lesser than the one in Alaska. Our method needs lots of accurate observed data to make multi-dimensional histogram in the same area. In this study, we can show the system to select wildfire data efficiently from satellite imagery. Furthermore, the development of multi-dimensional histogram from past fire data makes it possible to detect wildfires accurately.

  19. Large Scale, High Resolution, Mantle Dynamics Modeling

    NASA Astrophysics Data System (ADS)

    Geenen, T.; Berg, A. V.; Spakman, W.

    2007-12-01

    To model the geodynamic evolution of plate convergence, subduction and collision and to allow for a connection to various types of observational data, geophysical, geodetical and geological, we developed a 4D (space-time) numerical mantle convection code. The model is based on a spherical 3D Eulerian fem model, with quadratic elements, on top of which we constructed a 3D Lagrangian particle in cell(PIC) method. We use the PIC method to transport material properties and to incorporate a viscoelastic rheology. Since capturing small scale processes associated with localization phenomena require a high resolution, we spend a considerable effort on implementing solvers suitable to solve for models with over 100 million degrees of freedom. We implemented Additive Schwartz type ILU based methods in combination with a Krylov solver, GMRES. However we found that for problems with over 500 thousend degrees of freedom the convergence of the solver degraded severely. This observation is known from the literature [Saad, 2003] and results from the local character of the ILU preconditioner resulting in a poor approximation of the inverse of A for large A. The size of A for which ILU is no longer usable depends on the condition of A and on the amount of fill in allowed for the ILU preconditioner. We found that for our problems with over 5×105 degrees of freedom convergence became to slow to solve the system within an acceptable amount of walltime, one minute, even when allowing for considerable amount of fill in. We also implemented MUMPS and found good scaling results for problems up to 107 degrees of freedom for up to 32 CPU¡¯s. For problems with over 100 million degrees of freedom we implemented Algebraic Multigrid type methods (AMG) from the ML library [Sala, 2006]. Since multigrid methods are most effective for single parameter problems, we rebuild our model to use the SIMPLE method in the Stokes solver [Patankar, 1980]. We present scaling results from these solvers for 3D

  20. Distribution of entanglement in large-scale quantum networks

    NASA Astrophysics Data System (ADS)

    Perseguers, S.; Lapeyre, G. J., Jr.; Cavalcanti, D.; Lewenstein, M.; Acín, A.

    2013-09-01

    The concentration and distribution of quantum entanglement is an essential ingredient in emerging quantum information technologies. Much theoretical and experimental effort has been expended in understanding how to distribute entanglement in one-dimensional networks. However, as experimental techniques in quantum communication develop, protocols for multi-dimensional systems become essential. Here, we focus on recent theoretical developments in protocols for distributing entanglement in regular and complex networks, with particular attention to percolation theory and network-based error correction.

  1. Relaxation-time limit in the multi-dimensional bipolar nonisentropic Euler-Poisson systems

    NASA Astrophysics Data System (ADS)

    Li, Yeping; Zhou, Zhiming

    2015-05-01

    In this paper, we consider the multi-dimensional bipolar nonisentropic Euler-Poisson systems, which model various physical phenomena in semiconductor devices, plasmas and channel proteins. We mainly study the relaxation-time limit of the initial value problem for the bipolar full Euler-Poisson equations with well-prepared initial data. Inspired by the Maxwell iteration, we construct the different approximation states for the case τσ = 1 and σ = 1, respectively, and show that periodic initial-value problems of the certain scaled bipolar nonisentropic Euler-Poisson systems in the case τσ = 1 and σ = 1 have unique smooth solutions in the time interval where the classical energy transport equation and the drift-diffusive equation have smooth solution. Moreover, it is also obtained that the smooth solutions converge to those of energy-transport models at the rate of τ2 and those of the drift-diffusive models at the rate of τ, respectively. The proof of these results is based on the continuation principle and the error estimates.

  2. Multi-Dimensional Dynamics of Human Electromagnetic Brain Activity

    PubMed Central

    Kida, Tetsuo; Tanaka, Emi; Kakigi, Ryusuke

    2016-01-01

    Magnetoencephalography (MEG) and electroencephalography (EEG) are invaluable neuroscientific tools for unveiling human neural dynamics in three dimensions (space, time, and frequency), which are associated with a wide variety of perceptions, cognition, and actions. MEG/EEG also provides different categories of neuronal indices including activity magnitude, connectivity, and network properties along the three dimensions. In the last 20 years, interest has increased in inter-regional connectivity and complex network properties assessed by various sophisticated scientific analyses. We herein review the definition, computation, short history, and pros and cons of connectivity and complex network (graph-theory) analyses applied to MEG/EEG signals. We briefly describe recent developments in source reconstruction algorithms essential for source-space connectivity and network analyses. Furthermore, we discuss a relatively novel approach used in MEG/EEG studies to examine the complex dynamics represented by human brain activity. The correct and effective use of these neuronal metrics provides a new insight into the multi-dimensional dynamics of the neural representations of various functions in the complex human brain. PMID:26834608

  3. Multi-Dimensional Calibration of Impact Dynamic Models

    NASA Technical Reports Server (NTRS)

    Horta, Lucas G.; Reaves, Mercedes C.; Annett, Martin S.; Jackson, Karen E.

    2011-01-01

    NASA Langley, under the Subsonic Rotary Wing Program, recently completed two helicopter tests in support of an in-house effort to study crashworthiness. As part of this effort, work is on-going to investigate model calibration approaches and calibration metrics for impact dynamics models. Model calibration of impact dynamics problems has traditionally assessed model adequacy by comparing time histories from analytical predictions to test at only a few critical locations. Although this approach provides for a direct measure of the model predictive capability, overall system behavior is only qualitatively assessed using full vehicle animations. In order to understand the spatial and temporal relationships of impact loads as they migrate throughout the structure, a more quantitative approach is needed. In this work impact shapes derived from simulated time history data are used to recommend sensor placement and to assess model adequacy using time based metrics and orthogonality multi-dimensional metrics. An approach for model calibration is presented that includes metric definitions, uncertainty bounds, parameter sensitivity, and numerical optimization to estimate parameters to reconcile test with analysis. The process is illustrated using simulated experiment data.

  4. Multi-Dimensional Dynamics of Human Electromagnetic Brain Activity.

    PubMed

    Kida, Tetsuo; Tanaka, Emi; Kakigi, Ryusuke

    2015-01-01

    Magnetoencephalography (MEG) and electroencephalography (EEG) are invaluable neuroscientific tools for unveiling human neural dynamics in three dimensions (space, time, and frequency), which are associated with a wide variety of perceptions, cognition, and actions. MEG/EEG also provides different categories of neuronal indices including activity magnitude, connectivity, and network properties along the three dimensions. In the last 20 years, interest has increased in inter-regional connectivity and complex network properties assessed by various sophisticated scientific analyses. We herein review the definition, computation, short history, and pros and cons of connectivity and complex network (graph-theory) analyses applied to MEG/EEG signals. We briefly describe recent developments in source reconstruction algorithms essential for source-space connectivity and network analyses. Furthermore, we discuss a relatively novel approach used in MEG/EEG studies to examine the complex dynamics represented by human brain activity. The correct and effective use of these neuronal metrics provides a new insight into the multi-dimensional dynamics of the neural representations of various functions in the complex human brain. PMID:26834608

  5. Developing a Multi-Dimensional Hydrodynamics Code with Astrochemical Reactions

    NASA Astrophysics Data System (ADS)

    Kwak, Kyujin; Yang, Seungwon

    2015-08-01

    The Atacama Large Millimeter/submillimeter Array (ALMA) revealed high resolution molecular lines some of which are still unidentified yet. Because formation of these astrochemical molecules has been seldom studied in traditional chemistry, observations of new molecular lines drew a lot of attention from not only astronomers but also chemists both experimental and theoretical. Theoretical calculations for the formation of these astrochemical molecules have been carried out providing reaction rates for some important molecules, and some of theoretical predictions have been measured in laboratories. The reaction rates for the astronomically important molecules are now collected to form databases some of which are publically available. By utilizing these databases, we develop a multi-dimensional hydrodynamics code that includes the reaction rates of astrochemical molecules. Because this type of hydrodynamics code is able to trace the molecular formation in a non-equilibrium fashion, it is useful to study the formation history of these molecules that affects the spatial distribution of some specific molecules. We present the development procedure of this code and some test problems in order to verify and validate the developed code.

  6. The Challenge of Large-Scale Literacy Improvement

    ERIC Educational Resources Information Center

    Levin, Ben

    2010-01-01

    This paper discusses the challenge of making large-scale improvements in literacy in schools across an entire education system. Despite growing interest and rhetoric, there are very few examples of sustained, large-scale change efforts around school-age literacy. The paper reviews 2 instances of such efforts, in England and Ontario. After…

  7. INTERNATIONAL WORKSHOP ON LARGE-SCALE REFORESTATION: PROCEEDINGS

    EPA Science Inventory

    The purpose of the workshop was to identify major operational and ecological considerations needed to successfully conduct large-scale reforestation projects throughout the forested regions of the world. Large-scale" for this workshop means projects where, by human effort, approx...

  8. Using Large-Scale Assessment Scores to Determine Student Grades

    ERIC Educational Resources Information Center

    Miller, Tess

    2013-01-01

    Many Canadian provinces provide guidelines for teachers to determine students' final grades by combining a percentage of students' scores from provincial large-scale assessments with their term scores. This practice is thought to hold students accountable by motivating them to put effort into completing the large-scale assessment, thereby…

  9. Accessing Multi-Dimensional Images and Data Cubes in the Virtual Observatory

    NASA Astrophysics Data System (ADS)

    Tody, Douglas; Plante, R. L.; Berriman, G. B.; Cresitello-Dittmar, M.; Good, J.; Graham, M.; Greene, G.; Hanisch, R. J.; Jenness, T.; Lazio, J.; Norris, P.; Pevunova, O.; Rots, A. H.

    2014-01-01

    Telescopes across the spectrum are routinely producing multi-dimensional images and datasets, such as Doppler velocity cubes, polarization datasets, and time-resolved “movies.” Examples of current telescopes producing such multi-dimensional images include the JVLA, ALMA, and the IFU instruments on large optical and near-infrared wavelength telescopes. In the near future, both the LSST and JWST will also produce such multi-dimensional images routinely. High-energy instruments such as Chandra produce event datasets that are also a form of multi-dimensional data, in effect being a very sparse multi-dimensional image. Ensuring that the data sets produced by these telescopes can be both discovered and accessed by the community is essential and is part of the mission of the Virtual Observatory (VO). The Virtual Astronomical Observatory (VAO, http://www.usvao.org/), in conjunction with its international partners in the International Virtual Observatory Alliance (IVOA), has developed a protocol and an initial demonstration service designed for the publication, discovery, and access of arbitrarily large multi-dimensional images. The protocol describing multi-dimensional images is the Simple Image Access Protocol, version 2, which provides the minimal set of metadata required to characterize a multi-dimensional image for its discovery and access. A companion Image Data Model formally defines the semantics and structure of multi-dimensional images independently of how they are serialized, while providing capabilities such as support for sparse data that are essential to deal effectively with large cubes. A prototype data access service has been deployed and tested, using a suite of multi-dimensional images from a variety of telescopes. The prototype has demonstrated the capability to discover and remotely access multi-dimensional data via standard VO protocols. The prototype informs the specification of a protocol that will be submitted to the IVOA for approval, with an

  10. Chemistry and Transport in a Multi-Dimensional Model

    NASA Technical Reports Server (NTRS)

    Yung, Yuk L.

    2004-01-01

    Our work has two primary scientific goals, the interannual variability (IAV) of stratospheric ozone and the hydrological cycle of the upper troposphere and lower stratosphere. Our efforts are aimed at integrating new information obtained by spacecraft and aircraft measurements to achieve a better understanding of the chemical and dynamical processes that are needed for realistic evaluations of human impact on the global environment. A primary motivation for studying the ozone layer is to separate the anthropogenic perturbations of the ozone layer from natural variability. Using the recently available merged ozone data (MOD), we have carried out an empirical orthogonal function EOF) study of the temporal and spatial patterns of the IAV of total column ozone in the tropics. The outstanding problem about water in the stratosphere is its secular increase in the last few decades. The Caltech/PL multi-dimensional chemical transport model (CTM) photochemical model is used to simulate the processes that control the water vapor and its isotopic composition in the stratosphere. Datasets we will use for comparison with model results include those obtained by the Total Ozone Mapping Spectrometer (TOMS), the Solar Backscatter Ultraviolet (SBUV and SBUV/2), Stratosphere Aerosol and Gas Experiment (SAGE I and II), the Halogen Occultation Experiment (HALOE), the Atmospheric Trace Molecular Spectroscopy (ATMOS) and those soon to be obtained by the Cirrus Regional Study of Tropical Anvils and Cirrus Layers Florida Area Cirrus Experiment (CRYSTAL-FACE) mission. The focus of the investigations is the exchange between the stratosphere and the troposphere, and between the troposphere and the biosphere.

  11. Distribution probability of large-scale landslides in central Nepal

    NASA Astrophysics Data System (ADS)

    Timilsina, Manita; Bhandary, Netra P.; Dahal, Ranjan Kumar; Yatabe, Ryuichi

    2014-12-01

    Large-scale landslides in the Himalaya are defined as huge, deep-seated landslide masses that occurred in the geological past. They are widely distributed in the Nepal Himalaya. The steep topography and high local relief provide high potential for such failures, whereas the dynamic geology and adverse climatic conditions play a key role in the occurrence and reactivation of such landslides. The major geoscientific problems related with such large-scale landslides are 1) difficulties in their identification and delineation, 2) sources of small-scale failures, and 3) reactivation. Only a few scientific publications have been published concerning large-scale landslides in Nepal. In this context, the identification and quantification of large-scale landslides and their potential distribution are crucial. Therefore, this study explores the distribution of large-scale landslides in the Lesser Himalaya. It provides simple guidelines to identify large-scale landslides based on their typical characteristics and using a 3D schematic diagram. Based on the spatial distribution of landslides, geomorphological/geological parameters and logistic regression, an equation of large-scale landslide distribution is also derived. The equation is validated by applying it to another area. For the new area, the area under the receiver operating curve of the landslide distribution probability in the new area is 0.699, and a distribution probability value could explain > 65% of existing landslides. Therefore, the regression equation can be applied to areas of the Lesser Himalaya of central Nepal with similar geological and geomorphological conditions.

  12. Exploring the feasibility of using copy number variants as genetic markers through large-scale whole genome sequencing experiments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Copy number variants (CNV) are large scale duplications or deletions of genomic sequence that are caused by a diverse set of molecular phenomena that are distinct from single nucleotide polymorphism (SNP) formation. Due to their different mechanisms of formation, CNVs are often difficult to track us...

  13. Needs, opportunities, and options for large scale systems research

    SciTech Connect

    Thompson, G.L.

    1984-10-01

    The Office of Energy Research was recently asked to perform a study of Large Scale Systems in order to facilitate the development of a true large systems theory. It was decided to ask experts in the fields of electrical engineering, chemical engineering and manufacturing/operations research for their ideas concerning large scale systems research. The author was asked to distribute a questionnaire among these experts to find out their opinions concerning recent accomplishments and future research directions in large scale systems research. He was also requested to convene a conference which included three experts in each area as panel members to discuss the general area of large scale systems research. The conference was held on March 26--27, 1984 in Pittsburgh with nine panel members, and 15 other attendees. The present report is a summary of the ideas presented and the recommendations proposed by the attendees.

  14. Interpretation of large-scale deviations from the Hubble flow

    NASA Astrophysics Data System (ADS)

    Grinstein, B.; Politzer, H. David; Rey, S.-J.; Wise, Mark B.

    1987-03-01

    The theoretical expectation for large-scale streaming velocities relative to the Hubble flow is expressed in terms of statistical correlation functions. Only for objects that trace the mass would these velocities have a simple cosmological interpretation. If some biasing effects the objects' formation, then nonlinear gravitational evolution is essential to predicting the expected large-scale velocities, which also depend on the nature of the biasing.

  15. Large scale suppression of scalar power on a spatial condensation

    NASA Astrophysics Data System (ADS)

    Kouwn, Seyen; Kwon, O.-Kab; Oh, Phillial

    2015-03-01

    We consider a deformed single-field inflation model in terms of three SO(3) symmetric moduli fields. We find that spatially linear solutions for the moduli fields induce a phase transition during the early stage of the inflation and the suppression of scalar power spectrum at large scales. This suppression can be an origin of anomalies for large-scale perturbation modes in the cosmological observation.

  16. Large-scale motions in a plane wall jet

    NASA Astrophysics Data System (ADS)

    Gnanamanickam, Ebenezer; Jonathan, Latim; Shibani, Bhatt

    2015-11-01

    The dynamic significance of large-scale motions in turbulent boundary layers have been the focus of several recent studies, primarily focussing on canonical flows - zero pressure gradient boundary layers, flows within pipes and channels. This work presents an investigation into the large-scale motions in a boundary layer that is used as the prototypical flow field for flows with large-scale mixing and reactions, the plane wall jet. An experimental investigation is carried out in a plane wall jet facility designed to operate at friction Reynolds numbers Reτ > 1000 , which allows for the development of a significant logarithmic region. The streamwise turbulent intensity across the boundary layer is decomposed into small-scale (less than one integral length-scale δ) and large-scale components. The small-scale energy has a peak in the near-wall region associated with the near-wall turbulent cycle as in canonical boundary layers. However, eddies of large-scales are the dominating eddies having significantly higher energy, than the small-scales across almost the entire boundary layer even at the low to moderate Reynolds numbers under consideration. The large-scales also appear to amplitude and frequency modulate the smaller scales across the entire boundary layer.

  17. Large scale meteorological phenomena, ENSO and ITCZ, define the Paraná River isotope composition

    NASA Astrophysics Data System (ADS)

    Panarello, Héctor O.; Dapeña, Cristina

    2009-02-01

    SummaryThe Paraná River, the second in discharge in South America after the Amazon River and the fifth all over the world, releases an average of more than 17 000 m 3 s -1 into the Del Plata Estuary. In order to assess the causes of variations in its stable isotope composition, 120 monthly grab samples of the Paraná River, acquired on a period of 10 years at the river mouth, near Ciudad Universitaria, Buenos Aires, Argentina have been analysed for oxygen and hydrogen stable isotopes. Both, 2H and 18O showed periodic variations ( δ18O between -7‰ and -3‰; δ2H between -44‰ and -15‰) that follow, shifted in ca. 4 months (average transit time of the river), the southward excursions of the intertropical convergence zone (ITCZ). Deuterium excess values ( δ2H - 8 δ18O) also exhibited large variations (3-18‰) and showed a positive correlation with the El Niño South Oscillation Phenomenon (ENSO) index. ENSO affects the kinetic of the evaporation process of water and modifies the degree in which ITCZ shifts southwards capturing variable amounts of deuterium-rich recycled moisture from the Amazon's basin, then precipitating on the catchment's areas of the Paraná River.

  18. Large-scale flows and coherent structure phenomena in flute turbulence

    SciTech Connect

    Sandberg, I.; Andrushchenko, Zh.N.; Pavlenko, V.P.

    2005-04-15

    The properties of zonal and streamer flows in the flute mode turbulence are investigated. The stability criteria and the frequency of these flows are determined in terms of the spectra of turbulent fluctuations. Furthermore, it is shown that zonal flows can undergo a further nonlinear evolution leading to the formation of long-lived coherent structures which consist of self-bound wave packets supporting stationary shear layers, and thus can be characterized as regions with a reduced level of anomalous transport.

  19. Background-Oriented Schlieren for Large-Scale and High-Speed Aerodynamic Phenomena

    NASA Technical Reports Server (NTRS)

    Mizukaki, Toshiharu; Borg, Stephen; Danehy, Paul M.; Murman, Scott M.; Matsumura, Tomoharu; Wakabayashi, Kunihiko; Nakayama, Yoshio

    2015-01-01

    Visualization of the flow field around a generic re-entry capsule in subsonic flow and shock wave visualization with cylindrical explosives have been conducted to demonstrate sensitivity and applicability of background-oriented schlieren (BOS) for field experiments. The wind tunnel experiment suggests that BOS with a fine-pixel imaging device has a density change detection sensitivity on the order of 10(sup -5) in subsonic flow. In a laboratory setup, the structure of the shock waves generated by explosives have been successfully reconstructed by a computed tomography method combined with BOS.

  20. Foreshocks and Premonitory Slip during Large Scale Friction Experiments

    NASA Astrophysics Data System (ADS)

    Fukuyama, E.; Yamashita, F.; Xu, S.; Kawakata, H.; Mizoguchi, K.

    2014-12-01

    Fukuyama et al. (2013, AGU Fall Meeting) reported that using large-scale biaxial apparatus at NIED with a loading rate of 0.1mm/s, many foreshocks were observed and pre-slip was not evident under 2.6MPa normal stress (LB04-003), but pre-slip was always recognized prior to each stick slip and foreshocks were not common under 6.7MPa normal stress (LB04-005). To further investigate these phenomena to understand what controls the foreshock activity, we conducted another series of experiments using similar rock specimens made of gabbro. We conducted a series of ten experiments whose normal stress was 6.7MPa in the first seven experiments and was lowered to 3.4MPa in the rest of three. We could not find any foreshocks in 9 experiments and the only experiments we found foreshocks was the fifth one (LB09-005), which was under 6.7MPa normal stress with loading rate of 0.1mm/s and 0.01mm/s (loading rate was changed at the middle). It seems that foreshock activity does not depend only on the normal stress but is also related to the detailed fault surface condition, which was created by previous slip history. In Fukuyama et al. (2013), initial roughness of the simulated fault surface was #600 while in the present experiment it was #2000. These differences in initial condition might affect the foreshock generation. In the present cases, a most serious experiment with 1mm/s for 400mm slip (LB09-004) was included, which was a previous experiment of LB09-005. We think LB09-004 provided a damage distribution and that could help generate the foreshocks. It should be noted that foreshock hypocenters, estimated from the PZT array, are located on the grooves. And amount of grooves generated during the experiment was the largest for LB09-005. These features suggest the change in surface condition prior to LB09-005, which might facilitate the generation of foreshocks.

  1. Symmetry-guided large-scale shell-model theory

    NASA Astrophysics Data System (ADS)

    Launey, Kristina D.; Dytrych, Tomas; Draayer, Jerry P.

    2016-07-01

    In this review, we present a symmetry-guided strategy that utilizes exact as well as partial symmetries for enabling a deeper understanding of and advancing ab initio studies for determining the microscopic structure of atomic nuclei. These symmetries expose physically relevant degrees of freedom that, for large-scale calculations with QCD-inspired interactions, allow the model space size to be reduced through a very structured selection of the basis states to physically relevant subspaces. This can guide explorations of simple patterns in nuclei and how they emerge from first principles, as well as extensions of the theory beyond current limitations toward heavier nuclei and larger model spaces. This is illustrated for the ab initio symmetry-adapted no-core shell model (SA-NCSM) and two significant underlying symmetries, the symplectic Sp(3 , R) group and its deformation-related SU(3) subgroup. We review the broad scope of nuclei, where these symmetries have been found to play a key role-from the light p-shell systems, such as 6Li, 8B, 8Be, 12C, and 16O, and sd-shell nuclei exemplified by 20Ne, based on first-principle explorations; through the Hoyle state in 12C and enhanced collectivity in intermediate-mass nuclei, within a no-core shell-model perspective; up to strongly deformed species of the rare-earth and actinide regions, as investigated in earlier studies. A complementary picture, driven by symmetries dual to Sp(3 , R) , is also discussed. We briefly review symmetry-guided techniques that prove useful in various nuclear-theory models, such as Elliott model, ab initio SA-NCSM, symplectic model, pseudo- SU(3) and pseudo-symplectic models, ab initio hyperspherical harmonics method, ab initio lattice effective field theory, exact pairing-plus-shell model approaches, and cluster models, including the resonating-group method. Important implications of these approaches that have deepened our understanding of emergent phenomena in nuclei, such as enhanced

  2. The INTERGROWTH-21st Project Neurodevelopment Package: A Novel Method for the Multi-Dimensional Assessment of Neurodevelopment in Pre-School Age Children

    PubMed Central

    Fernandes, Michelle; Stein, Alan; Newton, Charles R.; Cheikh-Ismail, Leila; Kihara, Michael; Wulff, Katharina; de León Quintana, Enrique; Aranzeta, Luis; Soria-Frisch, Aureli; Acedo, Javier; Ibanez, David; Abubakar, Amina; Giuliani, Francesca; Lewis, Tamsin; Kennedy, Stephen; Villar, Jose

    2014-01-01

    Background The International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st) Project is a population-based, longitudinal study describing early growth and development in an optimally healthy cohort of 4607 mothers and newborns. At 24 months, children are assessed for neurodevelopmental outcomes with the INTERGROWTH-21st Neurodevelopment Package. This paper describes neurodevelopment tools for preschoolers and the systematic approach leading to the development of the Package. Methods An advisory panel shortlisted project-specific criteria (such as multi-dimensional assessments and suitability for international populations) to be fulfilled by a neurodevelopment instrument. A literature review of well-established tools for preschoolers revealed 47 candidates, none of which fulfilled all the project's criteria. A multi-dimensional assessment was, therefore, compiled using a package-based approach by: (i) categorizing desired outcomes into domains, (ii) devising domain-specific criteria for tool selection, and (iii) selecting the most appropriate measure for each domain. Results The Package measures vision (Cardiff tests); cortical auditory processing (auditory evoked potentials to a novelty oddball paradigm); and cognition, language skills, behavior, motor skills and attention (the INTERGROWTH-21st Neurodevelopment Assessment) in 35–45 minutes. Sleep-wake patterns (actigraphy) are also assessed. Tablet-based applications with integrated quality checks and automated, wireless electroencephalography make the Package easy to administer in the field by non-specialist staff. The Package is in use in Brazil, India, Italy, Kenya and the United Kingdom. Conclusions The INTERGROWTH-21st Neurodevelopment Package is a multi-dimensional instrument measuring early child development (ECD). Its developmental approach may be useful to those involved in large-scale ECD research and surveillance efforts. PMID:25423589

  3. The large-scale landslide risk classification in catchment scale

    NASA Astrophysics Data System (ADS)

    Liu, Che-Hsin; Wu, Tingyeh; Chen, Lien-Kuang; Lin, Sheng-Chi

    2013-04-01

    The landslide disasters caused heavy casualties during Typhoon Morakot, 2009. This disaster is defined as largescale landslide due to the casualty numbers. This event also reflects the survey on large-scale landslide potential is so far insufficient and significant. The large-scale landslide potential analysis provides information about where should be focused on even though it is very difficult to distinguish. Accordingly, the authors intend to investigate the methods used by different countries, such as Hong Kong, Italy, Japan and Switzerland to clarify the assessment methodology. The objects include the place with susceptibility of rock slide and dip slope and the major landslide areas defined from historical records. Three different levels of scales are confirmed necessarily from country to slopeland, which are basin, catchment, and slope scales. Totally ten spots were classified with high large-scale landslide potential in the basin scale. The authors therefore focused on the catchment scale and employ risk matrix to classify the potential in this paper. The protected objects and large-scale landslide susceptibility ratio are two main indexes to classify the large-scale landslide risk. The protected objects are the constructions and transportation facilities. The large-scale landslide susceptibility ratio is based on the data of major landslide area and dip slope and rock slide areas. Totally 1,040 catchments are concerned and are classified into three levels, which are high, medium, and low levels. The proportions of high, medium, and low levels are 11%, 51%, and 38%, individually. This result represents the catchments with high proportion of protected objects or large-scale landslide susceptibility. The conclusion is made and it be the base material for the slopeland authorities when considering slopeland management and the further investigation.

  4. Landsat 7 Reveals Large-scale Fractal Motion of Clouds

    NASA Technical Reports Server (NTRS)

    2002-01-01

    get carried along within the vortices, but these are soon mixed into the surrounding clouds. Landsat is unique in its ability to image both the small-scale eddies that mix clear and cloudy air, down to the 30 meter pixel size of Landsat, but also having a wide enough field-of-view, 180 km, to reveal the connection of the turbulence to large-scale flows such as the subtropical oceanic gyres. Landsat 7, with its new onboard digital recorder, has extended this capability away from the few Landsat ground stations to remote areas such as Alejandro Island, and thus is gradually providing a global dynamic picture of evolving human-scale phenomena. (For more details on von Karman vortices, refer to http://climate.gsfc.nasa.gov/cahalan) Image and caption courtesy Bob Cahalan, NASA GSFC

  5. Multi-Dimensional Damage Detection for Surfaces and Structures

    NASA Technical Reports Server (NTRS)

    Williams, Martha; Lewis, Mark; Roberson, Luke; Medelius, Pedro; Gibson, Tracy; Parks, Steen; Snyder, Sarah

    2013-01-01

    Current designs for inflatable or semi-rigidized structures for habitats and space applications use a multiple-layer construction, alternating thin layers with thicker, stronger layers, which produces a layered composite structure that is much better at resisting damage. Even though such composite structures or layered systems are robust, they can still be susceptible to penetration damage. The ability to detect damage to surfaces of inflatable or semi-rigid habitat structures is of great interest to NASA. Damage caused by impacts of foreign objects such as micrometeorites can rupture the shell of these structures, causing loss of critical hardware and/or the life of the crew. While not all impacts will have a catastrophic result, it will be very important to identify and locate areas of the exterior shell that have been damaged by impacts so that repairs (or other provisions) can be made to reduce the probability of shell wall rupture. This disclosure describes a system that will provide real-time data regarding the health of the inflatable shell or rigidized structures, and information related to the location and depth of impact damage. The innovation described here is a method of determining the size, location, and direction of damage in a multilayered structure. In the multi-dimensional damage detection system, layers of two-dimensional thin film detection layers are used to form a layered composite, with non-detection layers separating the detection layers. The non-detection layers may be either thicker or thinner than the detection layers. The thin-film damage detection layers are thin films of materials with a conductive grid or striped pattern. The conductive pattern may be applied by several methods, including printing, plating, sputtering, photolithography, and etching, and can include as many detection layers that are necessary for the structure construction or to afford the detection detail level required. The damage is detected using a detector or

  6. Unsaturated Hydraulic Conductivity for Evaporation in Large scale Heterogeneous Soils

    NASA Astrophysics Data System (ADS)

    Sun, D.; Zhu, J.

    2014-12-01

    In this study we aim to provide some practical guidelines of how the commonly used simple averaging schemes (arithmetic, geometric, or harmonic mean) perform in simulating large scale evaporation in a large scale heterogeneous landscape. Previous studies on hydraulic property upscaling focusing on steady state flux exchanges illustrated that an effective hydraulic property is usually more difficult to define for evaporation. This study focuses on upscaling hydraulic properties of large scale transient evaporation dynamics using the idea of the stream tube approach. Specifically, the two main objectives are: (1) if the three simple averaging schemes (i.e., arithmetic, geometric and harmonic means) of hydraulic parameters are appropriate in representing large scale evaporation processes, and (2) how the applicability of these simple averaging schemes depends on the time scale of evaporation processes in heterogeneous soils. Multiple realizations of local evaporation processes are carried out using HYDRUS-1D computational code (Simunek et al, 1998). The three averaging schemes of soil hydraulic parameters were used to simulate the cumulative flux exchange, which is then compared with the large scale average cumulative flux. The sensitivity of the relative errors to the time frame of evaporation processes is also discussed.

  7. EINSTEIN'S SIGNATURE IN COSMOLOGICAL LARGE-SCALE STRUCTURE

    SciTech Connect

    Bruni, Marco; Hidalgo, Juan Carlos; Wands, David

    2014-10-10

    We show how the nonlinearity of general relativity generates a characteristic nonGaussian signal in cosmological large-scale structure that we calculate at all perturbative orders in a large-scale limit. Newtonian gravity and general relativity provide complementary theoretical frameworks for modeling large-scale structure in ΛCDM cosmology; a relativistic approach is essential to determine initial conditions, which can then be used in Newtonian simulations studying the nonlinear evolution of the matter density. Most inflationary models in the very early universe predict an almost Gaussian distribution for the primordial metric perturbation, ζ. However, we argue that it is the Ricci curvature of comoving-orthogonal spatial hypersurfaces, R, that drives structure formation at large scales. We show how the nonlinear relation between the spatial curvature, R, and the metric perturbation, ζ, translates into a specific nonGaussian contribution to the initial comoving matter density that we calculate for the simple case of an initially Gaussian ζ. Our analysis shows the nonlinear signature of Einstein's gravity in large-scale structure.

  8. Toward Improved Support for Loosely Coupled Large Scale Simulation Workflows

    SciTech Connect

    Boehm, Swen; Elwasif, Wael R; Naughton, III, Thomas J; Vallee, Geoffroy R

    2014-01-01

    High-performance computing (HPC) workloads are increasingly leveraging loosely coupled large scale simula- tions. Unfortunately, most large-scale HPC platforms, including Cray/ALPS environments, are designed for the execution of long-running jobs based on coarse-grained launch capabilities (e.g., one MPI rank per core on all allocated compute nodes). This assumption limits capability-class workload campaigns that require large numbers of discrete or loosely coupled simulations, and where time-to-solution is an untenable pacing issue. This paper describes the challenges related to the support of fine-grained launch capabilities that are necessary for the execution of loosely coupled large scale simulations on Cray/ALPS platforms. More precisely, we present the details of an enhanced runtime system to support this use case, and report on initial results from early testing on systems at Oak Ridge National Laboratory.

  9. Acoustic Studies of the Large Scale Ocean Circulation

    NASA Technical Reports Server (NTRS)

    Menemenlis, Dimitris

    1999-01-01

    Detailed knowledge of ocean circulation and its transport properties is prerequisite to an understanding of the earth's climate and of important biological and chemical cycles. Results from two recent experiments, THETIS-2 in the Western Mediterranean and ATOC in the North Pacific, illustrate the use of ocean acoustic tomography for studies of the large scale circulation. The attraction of acoustic tomography is its ability to sample and average the large-scale oceanic thermal structure, synoptically, along several sections, and at regular intervals. In both studies, the acoustic data are compared to, and then combined with, general circulation models, meteorological analyses, satellite altimetry, and direct measurements from ships. Both studies provide complete regional descriptions of the time-evolving, three-dimensional, large scale circulation, albeit with large uncertainties. The studies raise serious issues about existing ocean observing capability and provide guidelines for future efforts.

  10. A relativistic signature in large-scale structure

    NASA Astrophysics Data System (ADS)

    Bartolo, Nicola; Bertacca, Daniele; Bruni, Marco; Koyama, Kazuya; Maartens, Roy; Matarrese, Sabino; Sasaki, Misao; Verde, Licia; Wands, David

    2016-09-01

    In General Relativity, the constraint equation relating metric and density perturbations is inherently nonlinear, leading to an effective non-Gaussianity in the dark matter density field on large scales-even if the primordial metric perturbation is Gaussian. Intrinsic non-Gaussianity in the large-scale dark matter overdensity in GR is real and physical. However, the variance smoothed on a local physical scale is not correlated with the large-scale curvature perturbation, so that there is no relativistic signature in the galaxy bias when using the simplest model of bias. It is an open question whether the observable mass proxies such as luminosity or weak lensing correspond directly to the physical mass in the simple halo bias model. If not, there may be observables that encode this relativistic signature.

  11. Coupling between convection and large-scale circulation

    NASA Astrophysics Data System (ADS)

    Becker, T.; Stevens, B. B.; Hohenegger, C.

    2014-12-01

    The ultimate drivers of convection - radiation, tropospheric humidity and surface fluxes - are altered both by the large-scale circulation and by convection itself. A quantity to which all drivers of convection contribute is moist static energy, or gross moist stability, respectively. Therefore, a variance analysis of the moist static energy budget in radiative-convective equilibrium helps understanding the interaction of precipitating convection and the large-scale environment. In addition, this method provides insights concerning the impact of convective aggregation on this coupling. As a starting point, the interaction is analyzed with a general circulation model, but a model intercomparison study using a hierarchy of models is planned. Effective coupling parameters will be derived from cloud resolving models and these will in turn be related to assumptions used to parameterize convection in large-scale models.

  12. Large-scale current systems in the dayside Venus ionosphere

    NASA Technical Reports Server (NTRS)

    Luhmann, J. G.; Elphic, R. C.; Brace, L. H.

    1981-01-01

    The occasional observation of large-scale horizontal magnetic fields within the dayside ionosphere of Venus by the flux gate magnetometer on the Pioneer Venus orbiter suggests the presence of large-scale current systems. Using the measured altitude profiles of the magnetic field and the electron density and temperature, together with the previously reported neutral atmosphere density and composition, it is found that the local ionosphere can be described at these times by a simple steady state model which treats the unobserved quantities, such as the electric field, as parameters. When the model is appropriate, the altitude profiles of the ion and electron velocities and the currents along the satellite trajectory can be inferred. These results elucidate the configurations and sources of the ionospheric current systems which produce the observed large-scale magnetic fields, and in particular illustrate the effect of ion-neutral coupling in the determination of the current system at low altitudes.

  13. Do Large-Scale Topological Features Correlate with Flare Properties?

    NASA Astrophysics Data System (ADS)

    DeRosa, Marc L.; Barnes, Graham

    2016-05-01

    In this study, we aim to identify whether the presence or absence of particular topological features in the large-scale coronal magnetic field are correlated with whether a flare is confined or eruptive. To this end, we first determine the locations of null points, spine lines, and separatrix surfaces within the potential fields associated with the locations of several strong flares from the current and previous sunspot cycles. We then validate the topological skeletons against large-scale features in observations, such as the locations of streamers and pseudostreamers in coronagraph images. Finally, we characterize the topological environment in the vicinity of the flaring active regions and identify the trends involving their large-scale topologies and the properties of the associated flares.

  14. Magnetic Helicity and Large Scale Magnetic Fields: A Primer

    NASA Astrophysics Data System (ADS)

    Blackman, Eric G.

    2015-05-01

    Magnetic fields of laboratory, planetary, stellar, and galactic plasmas commonly exhibit significant order on large temporal or spatial scales compared to the otherwise random motions within the hosting system. Such ordered fields can be measured in the case of planets, stars, and galaxies, or inferred indirectly by the action of their dynamical influence, such as jets. Whether large scale fields are amplified in situ or a remnant from previous stages of an object's history is often debated for objects without a definitive magnetic activity cycle. Magnetic helicity, a measure of twist and linkage of magnetic field lines, is a unifying tool for understanding large scale field evolution for both mechanisms of origin. Its importance stems from its two basic properties: (1) magnetic helicity is typically better conserved than magnetic energy; and (2) the magnetic energy associated with a fixed amount of magnetic helicity is minimized when the system relaxes this helical structure to the largest scale available. Here I discuss how magnetic helicity has come to help us understand the saturation of and sustenance of large scale dynamos, the need for either local or global helicity fluxes to avoid dynamo quenching, and the associated observational consequences. I also discuss how magnetic helicity acts as a hindrance to turbulent diffusion of large scale fields, and thus a helper for fossil remnant large scale field origin models in some contexts. I briefly discuss the connection between large scale fields and accretion disk theory as well. The goal here is to provide a conceptual primer to help the reader efficiently penetrate the literature.

  15. The Evolution of Baryons in Cosmic Large Scale Structure

    NASA Astrophysics Data System (ADS)

    Snedden, Ali; Arielle Phillips, Lara; Mathews, Grant James; Coughlin, Jared; Suh, In-Saeng; Bhattacharya, Aparna

    2015-01-01

    The environments of galaxies play a critical role in their formation and evolution. We study these environments using cosmological simulations with star formation and supernova feedback included. From these simulations, we parse the large scale structure into clusters, filaments and voids using a segmentation algorithm adapted from medical imaging. We trace the star formation history, gas phase and metal evolution of the baryons in the intergalactic medium as function of structure. We find that our algorithm reproduces the baryon fraction in the intracluster medium and that the majority of star formation occurs in cold, dense filaments. We present the consequences this large scale environment has for galactic halos and galaxy evolution.

  16. Corridors Increase Plant Species Richness at Large Scales

    SciTech Connect

    Damschen, Ellen I.; Haddad, Nick M.; Orrock,John L.; Tewksbury, Joshua J.; Levey, Douglas J.

    2006-09-01

    Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

  17. Large-scale ER-damper for seismic protection

    NASA Astrophysics Data System (ADS)

    McMahon, Scott; Makris, Nicos

    1997-05-01

    A large scale electrorheological (ER) damper has been designed, constructed, and tested. The damper consists of a main cylinder and a piston rod that pushes an ER-fluid through a number of stationary annular ducts. This damper is a scaled- up version of a prototype ER-damper which has been developed and extensively studied in the past. In this paper, results from comprehensive testing of the large-scale damper are presented, and the proposed theory developed for predicting the damper response is validated.

  18. Survey of decentralized control methods. [for large scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Athans, M.

    1975-01-01

    An overview is presented of the types of problems that are being considered by control theorists in the area of dynamic large scale systems with emphasis on decentralized control strategies. Approaches that deal directly with decentralized decision making for large scale systems are discussed. It is shown that future advances in decentralized system theory are intimately connected with advances in the stochastic control problem with nonclassical information pattern. The basic assumptions and mathematical tools associated with the latter are summarized, and recommendations concerning future research are presented.

  19. Clearing and Labeling Techniques for Large-Scale Biological Tissues

    PubMed Central

    Seo, Jinyoung; Choe, Minjin; Kim, Sung-Yon

    2016-01-01

    Clearing and labeling techniques for large-scale biological tissues enable simultaneous extraction of molecular and structural information with minimal disassembly of the sample, facilitating the integration of molecular, cellular and systems biology across different scales. Recent years have witnessed an explosive increase in the number of such methods and their applications, reflecting heightened interest in organ-wide clearing and labeling across many fields of biology and medicine. In this review, we provide an overview and comparison of existing clearing and labeling techniques and discuss challenges and opportunities in the investigations of large-scale biological systems. PMID:27239813

  20. Large-scale liquid scintillation detectors for solar neutrinos

    NASA Astrophysics Data System (ADS)

    Benziger, Jay B.; Calaprice, Frank P.

    2016-04-01

    Large-scale liquid scintillation detectors are capable of providing spectral yields of the low energy solar neutrinos. These detectors require > 100 tons of liquid scintillator with high optical and radiopurity. In this paper requirements for low-energy neutrino detection by liquid scintillation are specified and the procedures to achieve low backgrounds in large-scale liquid scintillation detectors for solar neutrinos are reviewed. The designs, operations and achievements of Borexino, KamLAND and SNO+ in measuring the low-energy solar neutrino fluxes are reviewed.

  1. Contribution of peculiar shear motions to large-scale structure

    NASA Technical Reports Server (NTRS)

    Mueler, Hans-Reinhard; Treumann, Rudolf A.

    1994-01-01

    Self-gravitating shear flow instability simulations in a cold dark matter-dominated expanding Einstein-de Sitter universe have been performed. When the shear flow speed exceeds a certain threshold, self-gravitating Kelvin-Helmoholtz instability occurs, forming density voids and excesses along the shear flow layer which serve as seeds for large-scale structure formation. A possible mechanism for generating shear peculiar motions are velocity fluctuations induced by the density perturbations of the postinflation era. In this scenario, short scales grow earlier than large scales. A model of this kind may contribute to the cellular structure of the luminous mass distribution in the universe.

  2. Clearing and Labeling Techniques for Large-Scale Biological Tissues.

    PubMed

    Seo, Jinyoung; Choe, Minjin; Kim, Sung-Yon

    2016-06-30

    Clearing and labeling techniques for large-scale biological tissues enable simultaneous extraction of molecular and structural information with minimal disassembly of the sample, facilitating the integration of molecular, cellular and systems biology across different scales. Recent years have witnessed an explosive increase in the number of such methods and their applications, reflecting heightened interest in organ-wide clearing and labeling across many fields of biology and medicine. In this review, we provide an overview and comparison of existing clearing and labeling techniques and discuss challenges and opportunities in the investigations of large-scale biological systems. PMID:27239813

  3. The Extraction of One-Dimensional Flow Properties from Multi-Dimensional Data Sets

    NASA Technical Reports Server (NTRS)

    Baurle, Robert A.; Gaffney, Richard L., Jr.

    2007-01-01

    The engineering design and analysis of air-breathing propulsion systems relies heavily on zero- or one-dimensional properties (e.g. thrust, total pressure recovery, mixing and combustion efficiency, etc.) for figures of merit. The extraction of these parameters from experimental data sets and/or multi-dimensional computational data sets is therefore an important aspect of the design process. A variety of methods exist for extracting performance measures from multi-dimensional data sets. Some of the information contained in the multi-dimensional flow is inevitably lost when any one-dimensionalization technique is applied. Hence, the unique assumptions associated with a given approach may result in one-dimensional properties that are significantly different than those extracted using alternative approaches. The purpose of this effort is to examine some of the more popular methods used for the extraction of performance measures from multi-dimensional data sets, reveal the strengths and weaknesses of each approach, and highlight various numerical issues that result when mapping data from a multi-dimensional space to a space of one dimension.

  4. The Art of Extracting One-Dimensional Flow Properties from Multi-Dimensional Data Sets

    NASA Technical Reports Server (NTRS)

    Baurle, R. A.; Gaffney, R. L.

    2007-01-01

    The engineering design and analysis of air-breathing propulsion systems relies heavily on zero- or one-dimensional properties (e:g: thrust, total pressure recovery, mixing and combustion efficiency, etc.) for figures of merit. The extraction of these parameters from experimental data sets and/or multi-dimensional computational data sets is therefore an important aspect of the design process. A variety of methods exist for extracting performance measures from multi-dimensional data sets. Some of the information contained in the multi-dimensional flow is inevitably lost when any one-dimensionalization technique is applied. Hence, the unique assumptions associated with a given approach may result in one-dimensional properties that are significantly different than those extracted using alternative approaches. The purpose of this effort is to examine some of the more popular methods used for the extraction of performance measures from multi-dimensional data sets, reveal the strengths and weaknesses of each approach, and highlight various numerical issues that result when mapping data from a multi-dimensional space to a space of one dimension.

  5. Iterative methods for large scale nonlinear and linear systems. Final report, 1994--1996

    SciTech Connect

    Walker, H.F.

    1997-09-01

    The major goal of this research has been to develop improved numerical methods for the solution of large-scale systems of linear and nonlinear equations, such as occur almost ubiquitously in the computational modeling of physical phenomena. The numerical methods of central interest have been Krylov subspace methods for linear systems, which have enjoyed great success in many large-scale applications, and newton-Krylov methods for nonlinear problems, which use Krylov subspace methods to solve approximately the linear systems that characterize Newton steps. Krylov subspace methods have undergone a remarkable development over the last decade or so and are now very widely used for the iterative solution of large-scale linear systems, particularly those that arise in the discretization of partial differential equations (PDEs) that occur in computational modeling. Newton-Krylov methods have enjoyed parallel success and are currently used in many nonlinear applications of great scientific and industrial importance. In addition to their effectiveness on important problems, Newton-Krylov methods also offer a nonlinear framework within which to transfer to the nonlinear setting any advances in Krylov subspace methods or preconditioning techniques, or new algorithms that exploit advanced machine architectures. This research has resulted in a number of improved Krylov and Newton-Krylov algorithms together with applications of these to important linear and nonlinear problems.

  6. Assuring Quality in Large-Scale Online Course Development

    ERIC Educational Resources Information Center

    Parscal, Tina; Riemer, Deborah

    2010-01-01

    Student demand for online education requires colleges and universities to rapidly expand the number of courses and programs offered online while maintaining high quality. This paper outlines two universities respective processes to assure quality in large-scale online programs that integrate instructional design, eBook custom publishing, Quality…

  7. Large-scale search for dark-matter axions

    SciTech Connect

    Hagmann, C.A., LLNL; Kinion, D.; Stoeffl, W.; Van Bibber, K.; Daw, E.J.; McBride, J.; Peng, H.; Rosenberg, L.J.; Xin, H.; Laveigne, J.; Sikivie, P.; Sullivan, N.S.; Tanner, D.B.; Moltz, D.M.; Powell, J.; Clarke, J.; Nezrick, F.A.; Turner, M.S.; Golubev, N.A.; Kravchuk, L.V.

    1998-01-01

    Early results from a large-scale search for dark matter axions are presented. In this experiment, axions constituting our dark-matter halo may be resonantly converted to monochromatic microwave photons in a high-Q microwave cavity permeated by a strong magnetic field. Sensitivity at the level of one important axion model (KSVZ) has been demonstrated.

  8. DESIGN OF LARGE-SCALE AIR MONITORING NETWORKS

    EPA Science Inventory

    The potential effects of air pollution on human health have received much attention in recent years. In the U.S. and other countries, there are extensive large-scale monitoring networks designed to collect data to inform the public of exposure risks to air pollution. A major crit...

  9. Over-driven control for large-scale MR dampers

    NASA Astrophysics Data System (ADS)

    Friedman, A. J.; Dyke, S. J.; Phillips, B. M.

    2013-04-01

    As semi-active electro-mechanical control devices increase in scale for use in real-world civil engineering applications, their dynamics become increasingly complicated. Control designs that are able to take these characteristics into account will be more effective in achieving good performance. Large-scale magnetorheological (MR) dampers exhibit a significant time lag in their force-response to voltage inputs, reducing the efficacy of typical controllers designed for smaller scale devices where the lag is negligible. A new control algorithm is presented for large-scale MR devices that uses over-driving and back-driving of the commands to overcome the challenges associated with the dynamics of these large-scale MR dampers. An illustrative numerical example is considered to demonstrate the controller performance. Via simulations of the structure using several seismic ground motions, the merits of the proposed control strategy to achieve reductions in various response parameters are examined and compared against several accepted control algorithms. Experimental evidence is provided to validate the improved capabilities of the proposed controller in achieving the desired control force levels. Through real-time hybrid simulation (RTHS), the proposed controllers are also examined and experimentally evaluated in terms of their efficacy and robust performance. The results demonstrate that the proposed control strategy has superior performance over typical control algorithms when paired with a large-scale MR damper, and is robust for structural control applications.

  10. Large-scale search for dark-matter axions

    SciTech Connect

    Kinion, D; van Bibber, K

    2000-08-30

    We review the status of two ongoing large-scale searches for axions which may constitute the dark matter of our Milky Way halo. The experiments are based on the microwave cavity technique proposed by Sikivie, and marks a ''second-generation'' to the original experiments performed by the Rochester-Brookhaven-Fermilab collaboration, and the University of Florida group.

  11. Large-Scale Innovation and Change in UK Higher Education

    ERIC Educational Resources Information Center

    Brown, Stephen

    2013-01-01

    This paper reflects on challenges universities face as they respond to change. It reviews current theories and models of change management, discusses why universities are particularly difficult environments in which to achieve large scale, lasting change and reports on a recent attempt by the UK JISC to enable a range of UK universities to employ…

  12. Global smoothing and continuation for large-scale molecular optimization

    SciTech Connect

    More, J.J.; Wu, Zhijun

    1995-10-01

    We discuss the formulation of optimization problems that arise in the study of distance geometry, ionic systems, and molecular clusters. We show that continuation techniques based on global smoothing are applicable to these molecular optimization problems, and we outline the issues that must be resolved in the solution of large-scale molecular optimization problems.

  13. The Large-Scale Structure of Scientific Method

    ERIC Educational Resources Information Center

    Kosso, Peter

    2009-01-01

    The standard textbook description of the nature of science describes the proposal, testing, and acceptance of a theoretical idea almost entirely in isolation from other theories. The resulting model of science is a kind of piecemeal empiricism that misses the important network structure of scientific knowledge. Only the large-scale description of…

  14. Individual Skill Differences and Large-Scale Environmental Learning

    ERIC Educational Resources Information Center

    Fields, Alexa W.; Shelton, Amy L.

    2006-01-01

    Spatial skills are known to vary widely among normal individuals. This project was designed to address whether these individual differences are differentially related to large-scale environmental learning from route (ground-level) and survey (aerial) perspectives. Participants learned two virtual environments (route and survey) with limited…

  15. Mixing Metaphors: Building Infrastructure for Large Scale School Turnaround

    ERIC Educational Resources Information Center

    Peurach, Donald J.; Neumerski, Christine M.

    2015-01-01

    The purpose of this analysis is to increase understanding of the possibilities and challenges of building educational infrastructure--the basic, foundational structures, systems, and resources--to support large-scale school turnaround. Building educational infrastructure often exceeds the capacity of schools, districts, and state education…

  16. Large-scale drift and Rossby wave turbulence

    NASA Astrophysics Data System (ADS)

    Harper, K. L.; Nazarenko, S. V.

    2016-08-01

    We study drift/Rossby wave turbulence described by the large-scale limit of the Charney–Hasegawa–Mima equation. We define the zonal and meridional regions as Z:= \\{{k} :| {k}y| \\gt \\sqrt{3}{k}x\\} and M:= \\{{k} :| {k}y| \\lt \\sqrt{3}{k}x\\} respectively, where {k}=({k}x,{k}y) is in a plane perpendicular to the magnetic field such that k x is along the isopycnals and k y is along the plasma density gradient. We prove that the only types of resonant triads allowed are M≤ftrightarrow M+Z and Z≤ftrightarrow Z+Z. Therefore, if the spectrum of weak large-scale drift/Rossby turbulence is initially in Z it will remain in Z indefinitely. We present a generalised Fjørtoft’s argument to find transfer directions for the quadratic invariants in the two-dimensional {k}-space. Using direct numerical simulations, we test and confirm our theoretical predictions for weak large-scale drift/Rossby turbulence, and establish qualitative differences with cases when turbulence is strong. We demonstrate that the qualitative features of the large-scale limit survive when the typical turbulent scale is only moderately greater than the Larmor/Rossby radius.

  17. Large Scale Field Campaign Contributions to Soil Moisture Remote Sensing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Large-scale field experiments have been an essential component of soil moisture remote sensing for over two decades. They have provided test beds for both the technology and science necessary to develop and refine satellite mission concepts. The high degree of spatial variability of soil moisture an...

  18. Large-scale V/STOL testing. [in wind tunnels

    NASA Technical Reports Server (NTRS)

    Koenig, D. G.; Aiken, T. N.; Aoyagi, K.; Falarski, M. D.

    1977-01-01

    Several facets of large-scale testing of V/STOL aircraft configurations are discussed with particular emphasis on test experience in the Ames 40- by 80-foot wind tunnel. Examples of powered-lift test programs are presented in order to illustrate tradeoffs confronting the planner of V/STOL test programs. It is indicated that large-scale V/STOL wind-tunnel testing can sometimes compete with small-scale testing in the effort required (overall test time) and program costs because of the possibility of conducting a number of different tests with a single large-scale model where several small-scale models would be required. The benefits of both high- and full-scale Reynolds numbers, more detailed configuration simulation, and number and type of onboard measurements increase rapidly with scale. Planning must be more detailed at large scale in order to balance the trade-offs between the increased costs, as number of measurements and model configuration variables increase and the benefits of larger amounts of information coming out of one test.

  19. Current Scientific Issues in Large Scale Atmospheric Dynamics

    NASA Technical Reports Server (NTRS)

    Miller, T. L. (Compiler)

    1986-01-01

    Topics in large scale atmospheric dynamics are discussed. Aspects of atmospheric blocking, the influence of transient baroclinic eddies on planetary-scale waves, cyclogenesis, the effects of orography on planetary scale flow, small scale frontal structure, and simulations of gravity waves in frontal zones are discussed.

  20. Large-Scale Machine Learning for Classification and Search

    ERIC Educational Resources Information Center

    Liu, Wei

    2012-01-01

    With the rapid development of the Internet, nowadays tremendous amounts of data including images and videos, up to millions or billions, can be collected for training machine learning models. Inspired by this trend, this thesis is dedicated to developing large-scale machine learning techniques for the purpose of making classification and nearest…

  1. Considerations for Managing Large-Scale Clinical Trials.

    ERIC Educational Resources Information Center

    Tuttle, Waneta C.; And Others

    1989-01-01

    Research management strategies used effectively in a large-scale clinical trial to determine the health effects of exposure to Agent Orange in Vietnam are discussed, including pre-project planning, organization according to strategy, attention to scheduling, a team approach, emphasis on guest relations, cross-training of personnel, and preparing…

  2. Ecosystem resilience despite large-scale altered hydro climatic conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Climate change is predicted to increase both drought frequency and duration, and when coupled with substantial warming, will establish a new hydroclimatological paradigm for many regions. Large-scale, warm droughts have recently impacted North America, Africa, Europe, Amazonia, and Australia result...

  3. Lessons from Large-Scale Renewable Energy Integration Studies: Preprint

    SciTech Connect

    Bird, L.; Milligan, M.

    2012-06-01

    In general, large-scale integration studies in Europe and the United States find that high penetrations of renewable generation are technically feasible with operational changes and increased access to transmission. This paper describes other key findings such as the need for fast markets, large balancing areas, system flexibility, and the use of advanced forecasting.

  4. Probabilistic Cuing in Large-Scale Environmental Search

    ERIC Educational Resources Information Center

    Smith, Alastair D.; Hood, Bruce M.; Gilchrist, Iain D.

    2010-01-01

    Finding an object in our environment is an important human ability that also represents a critical component of human foraging behavior. One type of information that aids efficient large-scale search is the likelihood of the object being in one location over another. In this study we investigated the conditions under which individuals respond to…

  5. Extracting Useful Semantic Information from Large Scale Corpora of Text

    ERIC Educational Resources Information Center

    Mendoza, Ray Padilla, Jr.

    2012-01-01

    Extracting and representing semantic information from large scale corpora is at the crux of computer-assisted knowledge generation. Semantic information depends on collocation extraction methods, mathematical models used to represent distributional information, and weighting functions which transform the space. This dissertation provides a…

  6. Efficient On-Demand Operations in Large-Scale Infrastructures

    ERIC Educational Resources Information Center

    Ko, Steven Y.

    2009-01-01

    In large-scale distributed infrastructures such as clouds, Grids, peer-to-peer systems, and wide-area testbeds, users and administrators typically desire to perform "on-demand operations" that deal with the most up-to-date state of the infrastructure. However, the scale and dynamism present in the operating environment make it challenging to…

  7. Large-Scale Environmental Influences on Aquatic Animal Health

    EPA Science Inventory

    In the latter portion of the 20th century, North America experienced numerous large-scale mortality events affecting a broad diversity of aquatic animals. Short-term forensic investigations of these events have sometimes characterized a causative agent or condition, but have rare...

  8. Newton iterative methods for large scale nonlinear systems

    SciTech Connect

    Walker, H.F.; Turner, K.

    1993-01-01

    Objective is to develop robust, efficient Newton iterative methods for general large scale problems well suited for discretizations of partial differential equations, integral equations, and other continuous problems. A concomitant objective is to develop improved iterative linear algebra methods. We first outline research on Newton iterative methods and then review work on iterative linear algebra methods. (DLC)

  9. Implicit solution of large-scale radiation diffusion problems

    SciTech Connect

    Brown, P N; Graziani, F; Otero, I; Woodward, C S

    2001-01-04

    In this paper, we present an efficient solution approach for fully implicit, large-scale, nonlinear radiation diffusion problems. The fully implicit approach is compared to a semi-implicit solution method. Accuracy and efficiency are shown to be better for the fully implicit method on both one- and three-dimensional problems with tabular opacities taken from the LEOS opacity library.

  10. Resilience of Florida Keys coral communities following large scale disturbances

    EPA Science Inventory

    The decline of coral reefs in the Caribbean over the last 40 years has been attributed to multiple chronic stressors and episodic large-scale disturbances. This study assessed the resilience of coral communities in two different regions of the Florida Keys reef system between 199...

  11. Large Scale Survey Data in Career Development Research

    ERIC Educational Resources Information Center

    Diemer, Matthew A.

    2008-01-01

    Large scale survey datasets have been underutilized but offer numerous advantages for career development scholars, as they contain numerous career development constructs with large and diverse samples that are followed longitudinally. Constructs such as work salience, vocational expectations, educational expectations, work satisfaction, and…

  12. Polymers in 2D Turbulence: Suppression of Large Scale Fluctuations

    NASA Astrophysics Data System (ADS)

    Amarouchene, Y.; Kellay, H.

    2002-08-01

    Small quantities of a long chain molecule or polymer affect two-dimensional turbulence in unexpected ways. Their presence inhibits the transfers of energy to large scales causing their suppression in the energy density spectrum. This also leads to the change of the spectral properties of a passive scalar which turns out to be highly sensitive to the presence of energy transfers.

  13. Creating a Large-Scale, Third Generation, Distance Education Course.

    ERIC Educational Resources Information Center

    Weller, Martin James

    2000-01-01

    Outlines the course development of an introductory large-scale distance education course offered via the World Wide Web at the Open University in the United Kingdom. Topics include developing appropriate student skills; maintaining quality control; facilitating easy updating of material; ensuring student interaction; and making materials…

  14. Cosmic strings and the large-scale structure

    NASA Technical Reports Server (NTRS)

    Stebbins, Albert

    1988-01-01

    A possible problem for cosmic string models of galaxy formation is presented. If very large voids are common and if loop fragmentation is not much more efficient than presently believed, then it may be impossible for string scenarios to produce the observed large-scale structure with Omega sub 0 = 1 and without strong environmental biasing.

  15. International Large-Scale Assessments: What Uses, What Consequences?

    ERIC Educational Resources Information Center

    Johansson, Stefan

    2016-01-01

    Background: International large-scale assessments (ILSAs) are a much-debated phenomenon in education. Increasingly, their outcomes attract considerable media attention and influence educational policies in many jurisdictions worldwide. The relevance, uses and consequences of these assessments are often the focus of research scrutiny. Whilst some…

  16. Measurement, Sampling, and Equating Errors in Large-Scale Assessments

    ERIC Educational Resources Information Center

    Wu, Margaret

    2010-01-01

    In large-scale assessments, such as state-wide testing programs, national sample-based assessments, and international comparative studies, there are many steps involved in the measurement and reporting of student achievement. There are always sources of inaccuracies in each of the steps. It is of interest to identify the source and magnitude of…

  17. A bibliographical surveys of large-scale systems

    NASA Technical Reports Server (NTRS)

    Corliss, W. R.

    1970-01-01

    A limited, partly annotated bibliography was prepared on the subject of large-scale system control. Approximately 400 references are divided into thirteen application areas, such as large societal systems and large communication systems. A first-author index is provided.

  18. Large-Scale Networked Virtual Environments: Architecture and Applications

    ERIC Educational Resources Information Center

    Lamotte, Wim; Quax, Peter; Flerackers, Eddy

    2008-01-01

    Purpose: Scalability is an important research topic in the context of networked virtual environments (NVEs). This paper aims to describe the ALVIC (Architecture for Large-scale Virtual Interactive Communities) approach to NVE scalability. Design/methodology/approach: The setup and results from two case studies are shown: a 3-D learning environment…

  19. Decomposition and coordination of large-scale operations optimization

    NASA Astrophysics Data System (ADS)

    Cheng, Ruoyu

    Nowadays, highly integrated manufacturing has resulted in more and more large-scale industrial operations. As one of the most effective strategies to ensure high-level operations in modern industry, large-scale engineering optimization has garnered a great amount of interest from academic scholars and industrial practitioners. Large-scale optimization problems frequently occur in industrial applications, and many of them naturally present special structure or can be transformed to taking special structure. Some decomposition and coordination methods have the potential to solve these problems at a reasonable speed. This thesis focuses on three classes of large-scale optimization problems: linear programming, quadratic programming, and mixed-integer programming problems. The main contributions include the design of structural complexity analysis for investigating scaling behavior and computational efficiency of decomposition strategies, novel coordination techniques and algorithms to improve the convergence behavior of decomposition and coordination methods, as well as the development of a decentralized optimization framework which embeds the decomposition strategies in a distributed computing environment. The complexity study can provide fundamental guidelines to practical applications of the decomposition and coordination methods. In this thesis, several case studies imply the viability of the proposed decentralized optimization techniques for real industrial applications. A pulp mill benchmark problem is used to investigate the applicability of the LP/QP decentralized optimization strategies, while a truck allocation problem in the decision support of mining operations is used to study the MILP decentralized optimization strategies.

  20. AstroMD: A Multi Dimensional Visualization and Analysis Toolkit for Astrophysics

    NASA Astrophysics Data System (ADS)

    Becciani, U.; Antonuccio-Delogu, V.; Gheller, C.; Calori, L.; Buonomo, F.; Imboden, S.

    2010-10-01

    Over the past few years, the role of visualization for scientific purpose has grown up enormously. Astronomy makes an extended use of visualization techniques to analyze data, and scientific visualization has became a fundamental part of modern researches in Astronomy. With the evolution of high performance computers, numerical simulations have assumed a great role in the scientific investigation, allowing the user to run simulation with higher and higher resolution. Data produced in these simulations are often multi-dimensional arrays with several physical quantities. These data are very hard to manage and to analyze efficiently. Consequently the data analysis and visualization tools must follow the new requirements of the research. AstroMD is a tool for data analysis and visualization of astrophysical data and can manage different physical quantities and multi-dimensional data sets. The tool uses virtual reality techniques by which the user has the impression of travelling through a computer-based multi-dimensional model.

  1. Data Mining in Multi-Dimensional Functional Data for Manufacturing Fault Diagnosis

    SciTech Connect

    Jeong, Myong K; Kong, Seong G; Omitaomu, Olufemi A

    2008-09-01

    Multi-dimensional functional data, such as time series data and images from manufacturing processes, have been used for fault detection and quality improvement in many engineering applications such as automobile manufacturing, semiconductor manufacturing, and nano-machining systems. Extracting interesting and useful features from multi-dimensional functional data for manufacturing fault diagnosis is more difficult than extracting the corresponding patterns from traditional numeric and categorical data due to the complexity of functional data types, high correlation, and nonstationary nature of the data. This chapter discusses accomplishments and research issues of multi-dimensional functional data mining in the following areas: dimensionality reduction for functional data, multi-scale fault diagnosis, misalignment prediction of rotating machinery, and agricultural product inspection based on hyperspectral image analysis.

  2. Multi-dimensional high-order numerical schemes for Lagrangian hydrodynamics

    SciTech Connect

    Dai, William W; Woodward, Paul R

    2009-01-01

    An approximate solver for multi-dimensional Riemann problems at grid points of unstructured meshes, and a numerical scheme for multi-dimensional hydrodynamics have been developed in this paper. The solver is simple, and is developed only for the use in numerical schemes for hydrodynamics. The scheme is truely multi-dimensional, is second order accurate in both space and time, and satisfies conservation laws exactly for mass, momentum, and total energy. The scheme has been tested through numerical examples involving strong shocks. It has been shown that the scheme offers the principle advantages of high-order Codunov schemes; robust operation in the presence of very strong shocks and thin shock fronts.

  3. Some theorems and properties of multi-dimensional fractional Laplace transforms

    NASA Astrophysics Data System (ADS)

    Ahmood, Wasan Ajeel; Kiliçman, Adem

    2016-06-01

    The aim of this work is to study theorems and properties for the one-dimensional fractional Laplace transform, generalize some properties for the one-dimensional fractional Lapalce transform to be valid for the multi-dimensional fractional Lapalce transform and is to give the definition of the multi-dimensional fractional Lapalce transform. This study includes: dedicate the one-dimensional fractional Laplace transform for functions of only one independent variable with some of important theorems and properties and develop of some properties for the one-dimensional fractional Laplace transform to multi-dimensional fractional Laplace transform. Also, we obtain a fractional Laplace inversion theorem after a short survey on fractional analysis based on the modified Riemann-Liouville derivative.

  4. Response of Tradewind Cumuli to Large-Scale Processes.

    NASA Astrophysics Data System (ADS)

    Soong, S.-T.; Ogura, Y.

    1980-09-01

    The two-dimensional slab-symmetric numerical cloud model used by Soong and Ogura (1973) for studying the evolution of an isolated cumulus cloud is extended to investigate the statistical properties of cumulus clouds which would be generated under a given large-scale forcing composed of the horizontal advection of temperature and water vapor mixing ratio, vertical velocity, sea surface temperature and radiative cooling. Random disturbances of small amplitude are introduced into the model at low levels to provide random motion for cloud formation.The model is applied to a case of suppressed weather conditions during BOMEX for the period 22-23 June 1969 when a nearly steady state prevailed. The composited temperature and mixing ratio profiles of these two days are used as initial conditions and the time-independent large-scale forcing terms estimated from the observations are applied to the model. The result of numerical integration shows that a number of small clouds start developing after 1 h. Some of them decay quickly, but some of them develop and reach the tradewind inversion. After a few hours of simulation, the vertical profiles of the horizontally averaged temperature and moisture are found to deviate only slightly from the observed profiles, indicating that the large-scale effect and the feedback effects of clouds on temperature and mixing ratio reach an equilibrium state. The three major components of the cloud feedback effect, i.e., condensation, evaporation and vertical fluxes associated with the clouds, are determined from the model output. The vertical profiles of vertical heat and moisture fluxes in the subcloud layer in the model are found to be in general agreement with the observations.Sensitivity tests of the model are made for different magnitudes of the large-scale vertical velocity. The most striking result is that the temperature and humidity in the cloud layer below the inversion do not change significantly in spite of a relatively large

  5. Large-scale solar wind streams: Average temporal evolution of parameters

    NASA Astrophysics Data System (ADS)

    Yermolaev, Yuri; Lodkina, Irina; Yermolaev, Michael; Nikolaeva, Nadezhda

    2016-07-01

    In the report we describe the average temporal profiles of plasma and field parameters in the disturbed large-scale types of solar wind (SW): corotating interaction regions (CIR), interplanetary coronal mass ejections (ICME) (both magnetic cloud (MC) and Ejecta), and Sheath as well as the interplanetary shock (IS) on the basis of OMNI database and our Catalog of large-scale solar wind phenomena during 1976-2000 (see website ftp://ftp.iki.rssi.ru/pub/omni/ and paper [Yermolaev et al., 2009]). To consider influence of both the surrounding undisturbed solar wind, and the interaction of the disturbed types of the solar wind on the parameters, we separately analyze the following sequences of the phenomena: (1) SW/CIR/SW, (2) SW/IS/CIR/SW, (3) SW/Ejecta/SW, (4) SW/Sheath/Ejecta/SW, (5) SW/IS/Sheath/Ejecta/SW, (6) SW/MC/SW, (7) SW/Sheath/MC/SW, and (8) SW/IS/Sheath/MC/SW. To take into account the different durations of SW types, we use the double superposed epoch analysis (DSEA) method: rescaling the duration of the interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide [Yermolaev et al., 2010; 2015]. Obtained data allow us to suggest that (1) the behavior of parameters in Sheath and in CIR is very similar not only qualitatively but also quantitatively, and (2) the speed angle phi in ICME changes from 2 to -2deg. while in CIR and Sheath it changes from -2 to 2 deg., i.e., the streams in CIR/Sheath and ICME deviate in the opposite side. The work was supported by the Russian Foundation for Basic Research, project 16-02-00125 and by Program of Presidium of the Russian Academy of Sciences. References: Yermolaev, Yu. I., N. S. Nikolaeva, I. G. Lodkina, and M. Yu. Yermolaev (2009), Catalog of Large-Scale Solar Wind Phenomena during 1976-2000, Cosmic Research, , Vol. 47, No. 2, pp. 81-94. Yermolaev, Y. I., N. S. Nikolaeva, I. G. Lodkina, and M. Y. Yermolaev (2010), Specific interplanetary conditions for CIR

  6. Development of multi-dimensional body image scale for malaysian female adolescents.

    PubMed

    Chin, Yit Siew; Taib, Mohd Nasir Mohd; Shariff, Zalilah Mohd; Khor, Geok Lin

    2008-01-01

    The present study was conducted to develop a Multi-dimensional Body Image Scale for Malaysian female adolescents. Data were collected among 328 female adolescents from a secondary school in Kuantan district, state of Pahang, Malaysia by using a self-administered questionnaire and anthropometric measurements. The self-administered questionnaire comprised multiple measures of body image, Eating Attitude Test (EAT-26; Garner & Garfinkel, 1979) and Rosenberg Self-esteem Inventory (Rosenberg, 1965). The 152 items from selected multiple measures of body image were examined through factor analysis and for internal consistency. Correlations between Multi-dimensional Body Image Scale and body mass index (BMI), risk of eating disorders and self-esteem were assessed for construct validity. A seven factor model of a 62-item Multi-dimensional Body Image Scale for Malaysian female adolescents with construct validity and good internal consistency was developed. The scale encompasses 1) preoccupation with thinness and dieting behavior, 2) appearance and body satisfaction, 3) body importance, 4) muscle increasing behavior, 5) extreme dieting behavior, 6) appearance importance, and 7) perception of size and shape dimensions. Besides, a multidimensional body image composite score was proposed to screen negative body image risk in female adolescents. The result found body image was correlated with BMI, risk of eating disorders and self-esteem in female adolescents. In short, the present study supports a multi-dimensional concept for body image and provides a new insight into its multi-dimensionality in Malaysian female adolescents with preliminary validity and reliability of the scale. The Multi-dimensional Body Image Scale can be used to identify female adolescents who are potentially at risk of developing body image disturbance through future intervention programs. PMID:20126371

  7. Development of multi-dimensional body image scale for malaysian female adolescents

    PubMed Central

    Taib, Mohd Nasir Mohd; Shariff, Zalilah Mohd; Khor, Geok Lin

    2008-01-01

    The present study was conducted to develop a Multi-dimensional Body Image Scale for Malaysian female adolescents. Data were collected among 328 female adolescents from a secondary school in Kuantan district, state of Pahang, Malaysia by using a self-administered questionnaire and anthropometric measurements. The self-administered questionnaire comprised multiple measures of body image, Eating Attitude Test (EAT-26; Garner & Garfinkel, 1979) and Rosenberg Self-esteem Inventory (Rosenberg, 1965). The 152 items from selected multiple measures of body image were examined through factor analysis and for internal consistency. Correlations between Multi-dimensional Body Image Scale and body mass index (BMI), risk of eating disorders and self-esteem were assessed for construct validity. A seven factor model of a 62-item Multi-dimensional Body Image Scale for Malaysian female adolescents with construct validity and good internal consistency was developed. The scale encompasses 1) preoccupation with thinness and dieting behavior, 2) appearance and body satisfaction, 3) body importance, 4) muscle increasing behavior, 5) extreme dieting behavior, 6) appearance importance, and 7) perception of size and shape dimensions. Besides, a multidimensional body image composite score was proposed to screen negative body image risk in female adolescents. The result found body image was correlated with BMI, risk of eating disorders and self-esteem in female adolescents. In short, the present study supports a multi-dimensional concept for body image and provides a new insight into its multi-dimensionality in Malaysian female adolescents with preliminary validity and reliability of the scale. The Multi-dimensional Body Image Scale can be used to identify female adolescents who are potentially at risk of developing body image disturbance through future intervention programs. PMID:20126371

  8. Emotional competencies in geriatric nursing: empirical evidence from a computer based large scale assessment calibration study.

    PubMed

    Kaspar, Roman; Hartig, Johannes

    2016-03-01

    The care of older people was described as involving substantial emotion-related affordances. Scholars in vocational training and nursing disagree whether emotion-related skills could be conceptualized and assessed as a professional competence. Studies on emotion work and empathy regularly neglect the multidimensionality of these phenomena and their relation to the care process, and are rarely conclusive with respect to nursing behavior in practice. To test the status of emotion-related skills as a facet of client-directed geriatric nursing competence, 402 final-year nursing students from 24 German schools responded to a 62-item computer-based test. 14 items were developed to represent emotion-related affordances. Multi-dimensional IRT modeling was employed to assess a potential subdomain structure. Emotion-related test items did not form a separate subdomain, and were found to be discriminating across the whole competence continuum. Tasks concerning emotion work and empathy are reliable indicators for various levels of client-directed nursing competence. Claims for a distinct emotion-related competence in geriatric nursing, however, appear excessive with a process-oriented perspective. PMID:26108300

  9. Global Magnetic Topology and Large-Scale Dynamics of the Solar Corona

    NASA Astrophysics Data System (ADS)

    Titov, Viacheslav; Linker, Jon; Mikic, Zoran; Riley, Pete; Lionello, Roberto; Downs, Cooper; Torok, Tibor

    We consider the global topology of the coronal magnetic field in relation to the large-scale dynamics of the solar corona. Our consideration includes recent results on the structural analysis of this field determined in two different approximations, namely, potential field source surface model and solar magnetohydrodynamic model. We identify similarities and differences between structural features of the magnetic field obtained in these two models and discuss their implications for understanding various large-scale phenomena in the solar corona. The underlying magnetic topology manifests itself in a variety of observed morphological features such as streamers, pseudo-streamers or unipolar streamers, EUV dimmings, flare ribbons, coronal holes, and jets. For each of them, the related magnetic configuration has specific structural features, whose presence has to be not only identified but also verified on its independence from the used field model in order to reliably predict the impact of such features on physical processes in the corona. Among them are magnetic null points and minima, bald patches, separatrix surfaces and quasi-separatrix layers, and open and closed separator field lines. These features form a structural skeleton of the coronal magnetic field and are directly involved through the ubiquitous process of magnetic reconnection in many solar dynamic phenomena such as coronal mass ejections, solar wind, acceleration and transport of energetic particles. We will pinpoint and elucidate in our overview some of such involvements that have recently received a considerable attention in our ongoing projects at Predictive Science.

  10. Large-scale quantification of CVD graphene surface coverage

    NASA Astrophysics Data System (ADS)

    Ambrosi, Adriano; Bonanni, Alessandra; Sofer, Zdeněk; Pumera, Martin

    2013-02-01

    The extraordinary properties demonstrated for graphene and graphene-related materials can be fully exploited when a large-scale fabrication procedure is made available. Chemical vapor deposition (CVD) of graphene on Cu and Ni substrates is one of the most promising procedures to synthesize large-area and good quality graphene films. Parallel to the fabrication process, a large-scale quality monitoring technique is equally crucial. We demonstrate here a rapid and simple methodology that is able to probe the effectiveness of the growth process over a large substrate area for both Ni and Cu substrates. This method is based on inherent electrochemical signals generated by the underlying metal catalysts when fractures or discontinuities of the graphene film are present. The method can be applied immediately after the CVD growth process without the need for any graphene transfer step and represents a powerful quality monitoring technique for the assessment of large-scale fabrication of graphene by the CVD process.The extraordinary properties demonstrated for graphene and graphene-related materials can be fully exploited when a large-scale fabrication procedure is made available. Chemical vapor deposition (CVD) of graphene on Cu and Ni substrates is one of the most promising procedures to synthesize large-area and good quality graphene films. Parallel to the fabrication process, a large-scale quality monitoring technique is equally crucial. We demonstrate here a rapid and simple methodology that is able to probe the effectiveness of the growth process over a large substrate area for both Ni and Cu substrates. This method is based on inherent electrochemical signals generated by the underlying metal catalysts when fractures or discontinuities of the graphene film are present. The method can be applied immediately after the CVD growth process without the need for any graphene transfer step and represents a powerful quality monitoring technique for the assessment of large-scale

  11. Large-scale Coronal Propagating Fronts During the Rising Phase of Solar Cycle 24

    NASA Astrophysics Data System (ADS)

    Nitta, N. V.; Liu, W.; Schrijver, C. J.; Title, A. M.; Lemen, J. R.

    2011-12-01

    With increasing solar activity, the AIA on SDO has observed a number of large-scale coronal propagating fronts, which are often called "EIT waves." Although their nature is still actively debated, these propagating fronts usually accompany CMEs, and, in certain cases, may signify CME-related shock waves important for particle acceleration. Using the unprecedented temporal resolution and broad temperature coverage of the AIA, it is possible to characterize the propagating fronts in the corona far better than before, as demonstrated in the literature for a yet small number of cases. We study the properties of more than 40 propagating fronts as observed by AIA, and discuss the key properties for them to be associated with other phenomena such as type II radio bursts, flares, CMEs, ICMEs, and SEP events. We make use of data, both remote-sensing and in-situ, from STEREO which provides two additional vantage points, to make the associations more solid. For the associated phenomena, their basic properties are correlated with those of the propagating fronts. We also revisit the association of EIT waves with other phenomena during the similar phase of Solar Cycle 23 and discuss possible differences in terms of global magnetic field. Understanding their relation with other phenomena, we can have a more complete picture of the coronal propagating fronts in the context of CME acceleration and deceleration.

  12. Theme section: Multi-dimensional modelling, analysis and visualization

    NASA Astrophysics Data System (ADS)

    Guilbert, Éric; Çöltekin, Arzu; Castro, Francesc Antón; Pettit, Chris

    2016-07-01

    Spatial data are now collected and processed in larger amounts, and used by larger populations than ever before. While most geospatial data have traditionally been recorded as two-dimensional data, the evolution of data collection methods and user demands have led to data beyond the two dimensions describing complex multidimensional phenomena. An example of the relevance of multidimensional modelling is seen with the development of urban modelling where several dimensions have been added to the traditional 2D map representation (Sester et al., 2011). These include obviously the third spatial dimension (Biljecki et al., 2015) as well as the temporal, but also the scale dimension (Van Oosterom and Stoter, 2010) or, as mentioned by (Lu et al., 2016), multi-spectral and multi-sensor data. Such a view provides an organisation of multidimensional data around these different axes and it is time to explore each axis as the availability of unprecedented amounts of new data demands new solutions. The availability of such large amounts of data induces an acute need for developing new approaches to assist with their dissemination, visualisation, and analysis by end users. Several issues need to be considered in order to provide a meaningful representation and assist in data visualisation and mining, modelling and analysis; such as data structures allowing representation at different scales or in different contexts of thematic information.

  13. LARGE-SCALE MOTIONS IN THE PERSEUS GALAXY CLUSTER

    SciTech Connect

    Simionescu, A.; Werner, N.; Urban, O.; Allen, S. W.; Fabian, A. C.; Sanders, J. S.; Mantz, A.; Nulsen, P. E. J.; Takei, Y.

    2012-10-01

    By combining large-scale mosaics of ROSAT PSPC, XMM-Newton, and Suzaku X-ray observations, we present evidence for large-scale motions in the intracluster medium of the nearby, X-ray bright Perseus Cluster. These motions are suggested by several alternating and interleaved X-ray bright, low-temperature, low-entropy arcs located along the east-west axis, at radii ranging from {approx}10 kpc to over a Mpc. Thermodynamic features qualitatively similar to these have previously been observed in the centers of cool-core clusters, and were successfully modeled as a consequence of the gas sloshing/swirling motions induced by minor mergers. Our observations indicate that such sloshing/swirling can extend out to larger radii than previously thought, on scales approaching the virial radius.

  14. Generating Large-Scale Longitudinal Data Resources for Aging Research

    PubMed Central

    Hofer, Scott M.

    2011-01-01

    Objectives. The need for large studies and the types of large-scale data resources (LSDRs) are discussed along with their general scientific utility, role in aging research, and affordability. The diversification of approaches to large-scale data resourcing is described in order to facilitate their use in aging research. Methods. The need for LSDRs is discussed in terms of (a) large sample size; (b) longitudinal design; (c) as platforms for additional investigator-initiated research projects; and (d) broad-based access to core genetic, biological, and phenotypic data. Discussion. It is concluded that a “lite-touch, lo-tech, lo-cost” approach to LSDRs is a viable strategy for the development of LSDRs and would enhance the likelihood of LSDRs being established which are dedicated to the wide range of important aging-related issues. PMID:21743049

  15. Lagrangian space consistency relation for large scale structure

    NASA Astrophysics Data System (ADS)

    Horn, Bart; Hui, Lam; Xiao, Xiao

    2015-09-01

    Consistency relations, which relate the squeezed limit of an (N+1)-point correlation function to an N-point function, are non-perturbative symmetry statements that hold even if the associated high momentum modes are deep in the nonlinear regime and astrophysically complex. Recently, Kehagias & Riotto and Peloso & Pietroni discovered a consistency relation applicable to large scale structure. We show that this can be recast into a simple physical statement in Lagrangian space: that the squeezed correlation function (suitably normalized) vanishes. This holds regardless of whether the correlation observables are at the same time or not, and regardless of whether multiple-streaming is present. The simplicity of this statement suggests that an analytic understanding of large scale structure in the nonlinear regime may be particularly promising in Lagrangian space.

  16. Instrumentation Development for Large Scale Hypersonic Inflatable Aerodynamic Decelerator Characterization

    NASA Technical Reports Server (NTRS)

    Swanson, Gregory T.; Cassell, Alan M.

    2011-01-01

    Hypersonic Inflatable Aerodynamic Decelerator (HIAD) technology is currently being considered for multiple atmospheric entry applications as the limitations of traditional entry vehicles have been reached. The Inflatable Re-entry Vehicle Experiment (IRVE) has successfully demonstrated this technology as a viable candidate with a 3.0 m diameter vehicle sub-orbital flight. To further this technology, large scale HIADs (6.0 8.5 m) must be developed and tested. To characterize the performance of large scale HIAD technology new instrumentation concepts must be developed to accommodate the flexible nature inflatable aeroshell. Many of the concepts that are under consideration for the HIAD FY12 subsonic wind tunnel test series are discussed below.

  17. The Large Scale Synthesis of Aligned Plate Nanostructures.

    PubMed

    Zhou, Yang; Nash, Philip; Liu, Tian; Zhao, Naiqin; Zhu, Shengli

    2016-01-01

    We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ' phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential. PMID:27439672

  18. Large-scale processes in the solar nebula

    NASA Technical Reports Server (NTRS)

    Boss, A. P.

    1994-01-01

    Theoretical models of the structure of a minimum mass solar nebula should be able to provide the physical context to help evaluate the efficacy of any mechanism proposed for the formation of chondrules or Ca, Al-rich inclusions (CAI's). These models generally attempt to use the equations of radiative hydrodynamics to calculate the large-scale structure of the solar nebula throughout the planet-forming region. In addition, it has been suggested that chondrules and CAI's (=Ch&CAI's) may have been formed as a direct result of large-scale nebula processing such as passage of material through high-temperature regions associated with the global structure of the nebula. In this report we assess the status of global models of solar nebula structure and of various related mechanisms that have been suggested for Ch and CAI formation.

  19. Planar Doppler Velocimetry for Large-Scale Wind Tunnel Applications

    NASA Technical Reports Server (NTRS)

    McKenzie, Robert L.

    1998-01-01

    Planar Doppler Velocimetry (PDV) concepts using a pulsed laser are described and the obtainable minimum resolved velocities in large-scale wind tunnels are evaluated. Velocity-field measurements are shown to be possible at ranges of tens of meters and with single pulse resolutions as low as 2 m/s. Velocity measurements in the flow of a low-speed, turbulent jet are reported that demonstrate the ability of PDV to acquire both average velocity fields and their fluctuation amplitudes, using procedures that are compatible with large-scale facility operations. The advantages of PDV over current Laser Doppler Anemometry and Particle Image Velocimetry techniques appear to be significant for applications to large facilities.

  20. Transparent and Flexible Large-scale Graphene-based Heater

    NASA Astrophysics Data System (ADS)

    Kang, Junmo; Lee, Changgu; Kim, Young-Jin; Choi, Jae-Boong; Hong, Byung Hee

    2011-03-01

    We report the application of transparent and flexible heater with high optical transmittance and low sheet resistance using graphene films, showing outstanding thermal and electrical properties. The large-scale graphene films were grown on Cu foil by chemical vapor deposition methods, and transferred to transparent substrates by multiple stacking. The wet chemical doping process enhanced the electrical properties, showing a sheet resistance as low as 35 ohm/sq with 88.5 % transmittance. The temperature response usually depends on the dimension and the sheet resistance of the graphene-based heater. We show that a 4x4 cm2 heater can reach 80& circ; C within 40 seconds and large-scale (9x9 cm2) heater shows uniformly heating performance, which was measured using thermocouple and infra-red camera. These heaters would be very useful for defogging systems and smart windows.

  1. Large Scale Diffuse X-ray Emission from Abell 3571

    NASA Technical Reports Server (NTRS)

    Molnar, Sandor M.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    Observations of the Luman alpha forest suggest that there are many more baryons at high redshift than we can find in the Universe nearby. The largest known concentration of baryons in the nearby Universe is the Shapley supercluster. We scanned the Shapley supercluster to search for large scale diffuse emission with the Rossi X-ray Timing Explorer (RXTE), and found some evidence for such emission. Large scale diffuse emission may be associated to the supercluster, or the clusters of galaxies within the supercluster. In this paper we present results of scans near Abell 3571. We found that the sum of a cooling flow and an isothermal beta model adequately describes the X-ray emission from the cluster. Our results suggest that diffuse emission from A3571 extends out to about two virial radii. We briefly discuss the importance of the determination of the cut off radius of the beta model.

  2. Large Scale Deformation of the Western US Cordillera

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.

    2001-01-01

    Destructive earthquakes occur throughout the western US Cordillera (WUSC), not just within the San Andreas fault zone. But because we do not understand the present-day large-scale deformations of the crust throughout the WUSC, our ability to assess the potential for seismic hazards in this region remains severely limited. To address this problem, we are using a large collection of Global Positioning System (GPS) networks which spans the WUSC to precisely quantify present-day large-scale crustal deformations in a single uniform reference frame. Our work can roughly be divided into an analysis of the GPS observations to infer the deformation field across and within the entire plate boundary zone and an investigation of the implications of this deformation field regarding plate boundary dynamics.

  3. The Large Scale Synthesis of Aligned Plate Nanostructures

    PubMed Central

    Zhou, Yang; Nash, Philip; Liu, Tian; Zhao, Naiqin; Zhu, Shengli

    2016-01-01

    We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ′ phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential. PMID:27439672

  4. Large scale meteorological influence during the Geysers 1979 field experiment

    SciTech Connect

    Barr, S.

    1980-01-01

    A series of meteorological field measurements conducted during July 1979 near Cobb Mountain in Northern California reveals evidence of several scales of atmospheric circulation consistent with the climatic pattern of the area. The scales of influence are reflected in the structure of wind and temperature in vertically stratified layers at a given observation site. Large scale synoptic gradient flow dominates the wind field above about twice the height of the topographic ridge. Below that there is a mixture of effects with evidence of a diurnal sea breeze influence and a sublayer of katabatic winds. The July observations demonstrate that weak migratory circulations in the large scale synoptic meteorological pattern have a significant influence on the day-to-day gradient winds and must be accounted for in planning meteorological programs including tracer experiments.

  5. GAIA: A WINDOW TO LARGE-SCALE MOTIONS

    SciTech Connect

    Nusser, Adi; Branchini, Enzo; Davis, Marc E-mail: branchin@fis.uniroma3.it

    2012-08-10

    Using redshifts as a proxy for galaxy distances, estimates of the two-dimensional (2D) transverse peculiar velocities of distant galaxies could be obtained from future measurements of proper motions. We provide the mathematical framework for analyzing 2D transverse motions and show that they offer several advantages over traditional probes of large-scale motions. They are completely independent of any intrinsic relations between galaxy properties; hence, they are essentially free of selection biases. They are free from homogeneous and inhomogeneous Malmquist biases that typically plague distance indicator catalogs. They provide additional information to traditional probes that yield line-of-sight peculiar velocities only. Further, because of their 2D nature, fundamental questions regarding vorticity of large-scale flows can be addressed. Gaia, for example, is expected to provide proper motions of at least bright galaxies with high central surface brightness, making proper motions a likely contender for traditional probes based on current and future distance indicator measurements.

  6. Large-scale objective phenotyping of 3D facial morphology

    PubMed Central

    Hammond, Peter; Suttie, Michael

    2012-01-01

    Abnormal phenotypes have played significant roles in the discovery of gene function, but organized collection of phenotype data has been overshadowed by developments in sequencing technology. In order to study phenotypes systematically, large-scale projects with standardized objective assessment across populations are considered necessary. The report of the 2006 Human Variome Project meeting recommended documentation of phenotypes through electronic means by collaborative groups of computational scientists and clinicians using standard, structured descriptions of disease-specific phenotypes. In this report, we describe progress over the past decade in 3D digital imaging and shape analysis of the face, and future prospects for large-scale facial phenotyping. Illustrative examples are given throughout using a collection of 1107 3D face images of healthy controls and individuals with a range of genetic conditions involving facial dysmorphism. PMID:22434506

  7. Electron drift in a large scale solid xenon

    SciTech Connect

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor two faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.

  8. Electron drift in a large scale solid xenon

    DOE PAGESBeta

    Yoo, J.; Jaskierny, W. F.

    2015-08-21

    A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor twomore » faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.« less

  9. Large-scale micropropagation system of plant cells.

    PubMed

    Honda, Hiroyuki; Kobayashi, Takeshi

    2004-01-01

    Plant micropropagation is an efficient method of propagating disease-free, genetically uniform and massive amounts of plants in vitro. The scale-up of the whole process for plant micropropagation should be established by an economically feasible technology for large-scale production of them in appropriate bioreactors. It is necessary to design suitable bioreactor configuration which can provide adequate mixing and mass transfer while minimizing the intensity of shear stress and hydrodynamic pressure. Automatic selection of embryogenic calli and regenerated plantlets using image analysis system should be associated with the system. The aim of this chapter is to identify the problems related to large-scale plant micropropagation via somatic embryogenesis, and to summarize the micropropagation technology and computer-aided image analysis. Viscous additive supplemented culture, which is including the successful results obtained by us for callus regeneration, is also introduced. PMID:15453194

  10. Individual skill differences and large-scale environmental learning.

    PubMed

    Fields, Alexa W; Shelton, Amy L

    2006-05-01

    Spatial skills are known to vary widely among normal individuals. This project was designed to address whether these individual differences are differentially related to large-scale environmental learning from route (ground-level) and survey (aerial) perspectives. Participants learned two virtual environments (route and survey) with limited exposure and tested on judgments about relative locations of objects. They also performed a series of spatial and nonspatial component skill tests. With limited learning, performance after route encoding was worse than performance after survey encoding. Furthermore, performance after route and survey encoding appeared to be preferentially linked to perspective and object-based transformations, respectively. Together, the results provide clues to how different skills might be engaged by different individuals for the same goal of learning a large-scale environment. PMID:16719662

  11. Quantum Noise in Large-Scale Coherent Nonlinear Photonic Circuits

    NASA Astrophysics Data System (ADS)

    Santori, Charles; Pelc, Jason S.; Beausoleil, Raymond G.; Tezak, Nikolas; Hamerly, Ryan; Mabuchi, Hideo

    2014-06-01

    A semiclassical simulation approach is presented for studying quantum noise in large-scale photonic circuits incorporating an ideal Kerr nonlinearity. A circuit solver is used to generate matrices defining a set of stochastic differential equations, in which the resonator field variables represent random samplings of the Wigner quasiprobability distributions. Although the semiclassical approach involves making a large-photon-number approximation, tests on one- and two-resonator circuits indicate satisfactory agreement between the semiclassical and full-quantum simulation results in the parameter regime of interest. The semiclassical model is used to simulate random errors in a large-scale circuit that contains 88 resonators and hundreds of components in total and functions as a four-bit ripple counter. The error rate as a function of on-state photon number is examined, and it is observed that the quantum fluctuation amplitudes do not increase as signals propagate through the circuit, an important property for scalability.

  12. Large-scale flow generation in turbulent convection

    PubMed Central

    Krishnamurti, Ruby; Howard, Louis N.

    1981-01-01

    In a horizontal layer of fluid heated from below and cooled from above, cellular convection with horizontal length scale comparable to the layer depth occurs for small enough values of the Rayleigh number. As the Rayleigh number is increased, cellular flow disappears and is replaced by a random array of transient plumes. Upon further increase, these plumes drift in one direction near the bottom and in the opposite direction near the top of the layer with the axes of plumes tilted in such a way that horizontal momentum is transported upward via the Reynolds stress. With the onset of this large-scale flow, the largest scale of motion has increased from that comparable to the layer depth to a scale comparable to the layer width. The conditions for occurrence and determination of the direction of this large-scale circulation are described. Images PMID:16592996

  13. The Large Scale Synthesis of Aligned Plate Nanostructures

    NASA Astrophysics Data System (ADS)

    Zhou, Yang; Nash, Philip; Liu, Tian; Zhao, Naiqin; Zhu, Shengli

    2016-07-01

    We propose a novel technique for the large-scale synthesis of aligned-plate nanostructures that are self-assembled and self-supporting. The synthesis technique involves developing nanoscale two-phase microstructures through discontinuous precipitation followed by selective etching to remove one of the phases. The method may be applied to any alloy system in which the discontinuous precipitation transformation goes to completion. The resulting structure may have many applications in catalysis, filtering and thermal management depending on the phase selection and added functionality through chemical reaction with the retained phase. The synthesis technique is demonstrated using the discontinuous precipitation of a γ‧ phase, (Ni, Co)3Al, followed by selective dissolution of the γ matrix phase. The production of the nanostructure requires heat treatments on the order of minutes and can be performed on a large scale making this synthesis technique of great economic potential.

  14. Large-scale behavior and statistical equilibria in rotating flows

    NASA Astrophysics Data System (ADS)

    Mininni, P. D.; Dmitruk, P.; Matthaeus, W. H.; Pouquet, A.

    2011-01-01

    We examine long-time properties of the ideal dynamics of three-dimensional flows, in the presence or not of an imposed solid-body rotation and with or without helicity (velocity-vorticity correlation). In all cases, the results agree with the isotropic predictions stemming from statistical mechanics. No accumulation of excitation occurs in the large scales, although, in the dissipative rotating case, anisotropy and accumulation, in the form of an inverse cascade of energy, are known to occur. We attribute this latter discrepancy to the linearity of the term responsible for the emergence of inertial waves. At intermediate times, inertial energy spectra emerge that differ somewhat from classical wave-turbulence expectations and with a trace of large-scale excitation that goes away for long times. These results are discussed in the context of partial two dimensionalization of the flow undergoing strong rotation as advocated by several authors.

  15. The workshop on iterative methods for large scale nonlinear problems

    SciTech Connect

    Walker, H.F.; Pernice, M.

    1995-12-01

    The aim of the workshop was to bring together researchers working on large scale applications with numerical specialists of various kinds. Applications that were addressed included reactive flows (combustion and other chemically reacting flows, tokamak modeling), porous media flows, cardiac modeling, chemical vapor deposition, image restoration, macromolecular modeling, and population dynamics. Numerical areas included Newton iterative (truncated Newton) methods, Krylov subspace methods, domain decomposition and other preconditioning methods, large scale optimization and optimal control, and parallel implementations and software. This report offers a brief summary of workshop activities and information about the participants. Interested readers are encouraged to look into an online proceedings available at http://www.usi.utah.edu/logan.proceedings. In this, the material offered here is augmented with hypertext abstracts that include links to locations such as speakers` home pages, PostScript copies of talks and papers, cross-references to related talks, and other information about topics addresses at the workshop.

  16. Prototype Vector Machine for Large Scale Semi-Supervised Learning

    SciTech Connect

    Zhang, Kai; Kwok, James T.; Parvin, Bahram

    2009-04-29

    Practicaldataminingrarelyfalls exactlyinto the supervisedlearning scenario. Rather, the growing amount of unlabeled data poses a big challenge to large-scale semi-supervised learning (SSL). We note that the computationalintensivenessofgraph-based SSLarises largely from the manifold or graph regularization, which in turn lead to large models that are dificult to handle. To alleviate this, we proposed the prototype vector machine (PVM), a highlyscalable,graph-based algorithm for large-scale SSL. Our key innovation is the use of"prototypes vectors" for effcient approximation on both the graph-based regularizer and model representation. The choice of prototypes are grounded upon two important criteria: they not only perform effective low-rank approximation of the kernel matrix, but also span a model suffering the minimum information loss compared with the complete model. We demonstrate encouraging performance and appealing scaling properties of the PVM on a number of machine learning benchmark data sets.

  17. Large-Scale Optimization for Bayesian Inference in Complex Systems

    SciTech Connect

    Willcox, Karen; Marzouk, Youssef

    2013-11-12

    The SAGUARO (Scalable Algorithms for Groundwater Uncertainty Analysis and Robust Optimization) Project focused on the development of scalable numerical algorithms for large-scale Bayesian inversion in complex systems that capitalize on advances in large-scale simulation-based optimization and inversion methods. The project was a collaborative effort among MIT, the University of Texas at Austin, Georgia Institute of Technology, and Sandia National Laboratories. The research was directed in three complementary areas: efficient approximations of the Hessian operator, reductions in complexity of forward simulations via stochastic spectral approximations and model reduction, and employing large-scale optimization concepts to accelerate sampling. The MIT--Sandia component of the SAGUARO Project addressed the intractability of conventional sampling methods for large-scale statistical inverse problems by devising reduced-order models that are faithful to the full-order model over a wide range of parameter values; sampling then employs the reduced model rather than the full model, resulting in very large computational savings. Results indicate little effect on the computed posterior distribution. On the other hand, in the Texas--Georgia Tech component of the project, we retain the full-order model, but exploit inverse problem structure (adjoint-based gradients and partial Hessian information of the parameter-to-observation map) to implicitly extract lower dimensional information on the posterior distribution; this greatly speeds up sampling methods, so that fewer sampling points are needed. We can think of these two approaches as ``reduce then sample'' and ``sample then reduce.'' In fact, these two approaches are complementary, and can be used in conjunction with each other. Moreover, they both exploit deterministic inverse problem structure, in the form of adjoint-based gradient and Hessian information of the underlying parameter-to-observation map, to achieve their

  18. Analysis plan for 1985 large-scale tests. Technical report

    SciTech Connect

    McMullan, F.W.

    1983-01-01

    The purpose of this effort is to assist DNA in planning for large-scale (upwards of 5000 tons) detonations of conventional explosives in the 1985 and beyond time frame. Primary research objectives were to investigate potential means to increase blast duration and peak pressures. This report identifies and analyzes several candidate explosives. It examines several charge designs and identifies advantages and disadvantages of each. Other factors including terrain and multiburst techniques are addressed as are test site considerations.

  19. Large-scale Alfvén vortices

    NASA Astrophysics Data System (ADS)

    Onishchenko, O. G.; Pokhotelov, O. A.; Horton, W.; Scullion, E.; Fedun, V.

    2015-12-01

    The new type of large-scale vortex structures of dispersionless Alfvén waves in collisionless plasma is investigated. It is shown that Alfvén waves can propagate in the form of Alfvén vortices of finite characteristic radius and characterised by magnetic flux ropes carrying orbital angular momentum. The structure of the toroidal and radial velocity, fluid and magnetic field vorticity, the longitudinal electric current in the plane orthogonal to the external magnetic field are discussed.

  20. Large-Scale Weather Disturbances in Mars’ Southern Extratropics

    NASA Astrophysics Data System (ADS)

    Hollingsworth, Jeffery L.; Kahre, Melinda A.

    2015-11-01

    Between late autumn and early spring, Mars’ middle and high latitudes within its atmosphere support strong mean thermal gradients between the tropics and poles. Observations from both the Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) indicate that this strong baroclinicity supports intense, large-scale eastward traveling weather systems (i.e., transient synoptic-period waves). These extratropical weather disturbances are key components of the global circulation. Such wave-like disturbances act as agents in the transport of heat and momentum, and generalized scalar/tracer quantities (e.g., atmospheric dust, water-vapor and ice clouds). The character of large-scale, traveling extratropical synoptic-period disturbances in Mars' southern hemisphere during late winter through early spring is investigated using a moderately high-resolution Mars global climate model (Mars GCM). This Mars GCM imposes interactively lifted and radiatively active dust based on a threshold value of the surface stress. The model exhibits a reasonable "dust cycle" (i.e., globally averaged, a dustier atmosphere during southern spring and summer occurs). Compared to their northern-hemisphere counterparts, southern synoptic-period weather disturbances and accompanying frontal waves have smaller meridional and zonal scales, and are far less intense. Influences of the zonally asymmetric (i.e., east-west varying) topography on southern large-scale weather are examined. Simulations that adapt Mars’ full topography compared to simulations that utilize synthetic topographies emulating key large-scale features of the southern middle latitudes indicate that Mars’ transient barotropic/baroclinic eddies are highly influenced by the great impact basins of this hemisphere (e.g., Argyre and Hellas). The occurrence of a southern storm zone in late winter and early spring appears to be anchored to the western hemisphere via orographic influences from the Tharsis highlands, and the Argyre

  1. The Phoenix series large scale LNG pool fire experiments.

    SciTech Connect

    Simpson, Richard B.; Jensen, Richard Pearson; Demosthenous, Byron; Luketa, Anay Josephine; Ricks, Allen Joseph; Hightower, Marion Michael; Blanchat, Thomas K.; Helmick, Paul H.; Tieszen, Sheldon Robert; Deola, Regina Anne; Mercier, Jeffrey Alan; Suo-Anttila, Jill Marie; Miller, Timothy J.

    2010-12-01

    The increasing demand for natural gas could increase the number and frequency of Liquefied Natural Gas (LNG) tanker deliveries to ports across the United States. Because of the increasing number of shipments and the number of possible new facilities, concerns about the potential safety of the public and property from an accidental, and even more importantly intentional spills, have increased. While improvements have been made over the past decade in assessing hazards from LNG spills, the existing experimental data is much smaller in size and scale than many postulated large accidental and intentional spills. Since the physics and hazards from a fire change with fire size, there are concerns about the adequacy of current hazard prediction techniques for large LNG spills and fires. To address these concerns, Congress funded the Department of Energy (DOE) in 2008 to conduct a series of laboratory and large-scale LNG pool fire experiments at Sandia National Laboratories (Sandia) in Albuquerque, New Mexico. This report presents the test data and results of both sets of fire experiments. A series of five reduced-scale (gas burner) tests (yielding 27 sets of data) were conducted in 2007 and 2008 at Sandia's Thermal Test Complex (TTC) to assess flame height to fire diameter ratios as a function of nondimensional heat release rates for extrapolation to large-scale LNG fires. The large-scale LNG pool fire experiments were conducted in a 120 m diameter pond specially designed and constructed in Sandia's Area III large-scale test complex. Two fire tests of LNG spills of 21 and 81 m in diameter were conducted in 2009 to improve the understanding of flame height, smoke production, and burn rate and therefore the physics and hazards of large LNG spills and fires.

  2. Cosmic string and formation of large scale structure.

    NASA Astrophysics Data System (ADS)

    Fang, L.-Z.; Xiang, S.-P.

    Cosmic string formed due to phase transition in the early universe may be the cause of galaxy formation and clustering. The advantage of string model is that it can give a consistent explanation of all observed results related to large scale structure, such as correlation functions of galaxies, clusters and superclusters, the existence of voids and/or bubbles, anisotropy of cosmic background radiation. A systematic review on string model has been done.

  3. Large-scale Alfvén vortices

    SciTech Connect

    Onishchenko, O. G.; Horton, W.; Scullion, E.; Fedun, V.

    2015-12-15

    The new type of large-scale vortex structures of dispersionless Alfvén waves in collisionless plasma is investigated. It is shown that Alfvén waves can propagate in the form of Alfvén vortices of finite characteristic radius and characterised by magnetic flux ropes carrying orbital angular momentum. The structure of the toroidal and radial velocity, fluid and magnetic field vorticity, the longitudinal electric current in the plane orthogonal to the external magnetic field are discussed.

  4. Climate: large-scale warming is not urban.

    PubMed

    Parker, David E

    2004-11-18

    Controversy has persisted over the influence of urban warming on reported large-scale surface-air temperature trends. Urban heat islands occur mainly at night and are reduced in windy conditions. Here we show that, globally, temperatures over land have risen as much on windy nights as on calm nights, indicating that the observed overall warming is not a consequence of urban development. PMID:15549087

  5. Relic vector field and CMB large scale anomalies

    SciTech Connect

    Chen, Xingang; Wang, Yi E-mail: yw366@cam.ac.uk

    2014-10-01

    We study the most general effects of relic vector fields on the inflationary background and density perturbations. Such effects are observable if the number of inflationary e-folds is close to the minimum requirement to solve the horizon problem. We show that this can potentially explain two CMB large scale anomalies: the quadrupole-octopole alignment and the quadrupole power suppression. We discuss its effect on the parity anomaly. We also provide analytical template for more detailed data comparison.

  6. Turbulent large-scale structure effects on wake meandering

    NASA Astrophysics Data System (ADS)

    Muller, Y.-A.; Masson, C.; Aubrun, S.

    2015-06-01

    This work studies effects of large-scale turbulent structures on wake meandering using Large Eddy Simulations (LES) over an actuator disk. Other potential source of wake meandering such as the instablility mechanisms associated with tip vortices are not treated in this study. A crucial element of the efficient, pragmatic and successful simulations of large-scale turbulent structures in Atmospheric Boundary Layer (ABL) is the generation of the stochastic turbulent atmospheric flow. This is an essential capability since one source of wake meandering is these large - larger than the turbine diameter - turbulent structures. The unsteady wind turbine wake in ABL is simulated using a combination of LES and actuator disk approaches. In order to dedicate the large majority of the available computing power in the wake, the ABL ground region of the flow is not part of the computational domain. Instead, mixed Dirichlet/Neumann boundary conditions are applied at all the computational surfaces except at the outlet. Prescribed values for Dirichlet contribution of these boundary conditions are provided by a stochastic turbulent wind generator. This allows to simulate large-scale turbulent structures - larger than the computational domain - leading to an efficient simulation technique of wake meandering. Since the stochastic wind generator includes shear, the turbulence production is included in the analysis without the necessity of resolving the flow near the ground. The classical Smagorinsky sub-grid model is used. The resulting numerical methodology has been implemented in OpenFOAM. Comparisons with experimental measurements in porous-disk wakes have been undertaken, and the agreements are good. While temporal resolution in experimental measurements is high, the spatial resolution is often too low. LES numerical results provide a more complete spatial description of the flow. They tend to demonstrate that inflow low frequency content - or large- scale turbulent structures - is

  7. Space transportation booster engine thrust chamber technology, large scale injector

    NASA Technical Reports Server (NTRS)

    Schneider, J. A.

    1993-01-01

    The objective of the Large Scale Injector (LSI) program was to deliver a 21 inch diameter, 600,000 lbf thrust class injector to NASA/MSFC for hot fire testing. The hot fire test program would demonstrate the feasibility and integrity of the full scale injector, including combustion stability, chamber wall compatibility (thermal management), and injector performance. The 21 inch diameter injector was delivered in September of 1991.

  8. Supporting large scale applications on networks of workstations

    NASA Technical Reports Server (NTRS)

    Cooper, Robert; Birman, Kenneth P.

    1989-01-01

    Distributed applications on networks of workstations are an increasingly common way to satisfy computing needs. However, existing mechanisms for distributed programming exhibit poor performance and reliability as application size increases. Extension of the ISIS distributed programming system to support large scale distributed applications by providing hierarchical process groups is discussed. Incorporation of hierarchy in the program structure and exploitation of this to limit the communication and storage required in any one component of the distributed system is examined.

  9. Dispersal Mutualism Incorporated into Large-Scale, Infrequent Disturbances

    PubMed Central

    Parker, V. Thomas

    2015-01-01

    Because of their influence on succession and other community interactions, large-scale, infrequent natural disturbances also should play a major role in mutualistic interactions. Using field data and experiments, I test whether mutualisms have been incorporated into large-scale wildfire by whether the outcomes of a mutualism depend on disturbance. In this study a seed dispersal mutualism is shown to depend on infrequent, large-scale disturbances. A dominant shrubland plant (Arctostaphylos species) produces seeds that make up a persistent soil seed bank and requires fire to germinate. In post-fire stands, I show that seedlings emerging from rodent caches dominate sites experiencing higher fire intensity. Field experiments show that rodents (Perimyscus californicus, P. boylii) do cache Arctostaphylos fruit and bury most seed caches to a sufficient depth to survive a killing heat pulse that a fire might drive into the soil. While the rodent dispersal and caching behavior itself has not changed compared to other habitats, the environmental transformation caused by wildfire converts the caching burial of seed from a dispersal process to a plant fire adaptive trait, and provides the context for stimulating subsequent life history evolution in the plant host. PMID:26151560

  10. Reliability assessment for components of large scale photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Ahadi, Amir; Ghadimi, Noradin; Mirabbasi, Davar

    2014-10-01

    Photovoltaic (PV) systems have significantly shifted from independent power generation systems to a large-scale grid-connected generation systems in recent years. The power output of PV systems is affected by the reliability of various components in the system. This study proposes an analytical approach to evaluate the reliability of large-scale, grid-connected PV systems. The fault tree method with an exponential probability distribution function is used to analyze the components of large-scale PV systems. The system is considered in the various sequential and parallel fault combinations in order to find all realistic ways in which the top or undesired events can occur. Additionally, it can identify areas that the planned maintenance should focus on. By monitoring the critical components of a PV system, it is possible not only to improve the reliability of the system, but also to optimize the maintenance costs. The latter is achieved by informing the operators about the system component's status. This approach can be used to ensure secure operation of the system by its flexibility in monitoring system applications. The implementation demonstrates that the proposed method is effective and efficient and can conveniently incorporate more system maintenance plans and diagnostic strategies.

  11. Robust regression for large-scale neuroimaging studies.

    PubMed

    Fritsch, Virgile; Da Mota, Benoit; Loth, Eva; Varoquaux, Gaël; Banaschewski, Tobias; Barker, Gareth J; Bokde, Arun L W; Brühl, Rüdiger; Butzek, Brigitte; Conrod, Patricia; Flor, Herta; Garavan, Hugh; Lemaitre, Hervé; Mann, Karl; Nees, Frauke; Paus, Tomas; Schad, Daniel J; Schümann, Gunter; Frouin, Vincent; Poline, Jean-Baptiste; Thirion, Bertrand

    2015-05-01

    Multi-subject datasets used in neuroimaging group studies have a complex structure, as they exhibit non-stationary statistical properties across regions and display various artifacts. While studies with small sample sizes can rarely be shown to deviate from standard hypotheses (such as the normality of the residuals) due to the poor sensitivity of normality tests with low degrees of freedom, large-scale studies (e.g. >100 subjects) exhibit more obvious deviations from these hypotheses and call for more refined models for statistical inference. Here, we demonstrate the benefits of robust regression as a tool for analyzing large neuroimaging cohorts. First, we use an analytic test based on robust parameter estimates; based on simulations, this procedure is shown to provide an accurate statistical control without resorting to permutations. Second, we show that robust regression yields more detections than standard algorithms using as an example an imaging genetics study with 392 subjects. Third, we show that robust regression can avoid false positives in a large-scale analysis of brain-behavior relationships with over 1500 subjects. Finally we embed robust regression in the Randomized Parcellation Based Inference (RPBI) method and demonstrate that this combination further improves the sensitivity of tests carried out across the whole brain. Altogether, our results show that robust procedures provide important advantages in large-scale neuroimaging group studies. PMID:25731989

  12. Large-scale flow experiments for managing river systems

    USGS Publications Warehouse

    Konrad, C.P.; Olden, J.D.; Lytle, D.A.; Melis, T.S.; Schmidt, J.C.; Bray, E.N.; Freeman, Mary C.; Gido, K.B.; Hemphill, N.P.; Kennard, M.J.; McMullen, L.E.; Mims, M.C.; Pyron, M.; Robinson, C.T.; Williams, J.G.

    2011-01-01

    Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments have both scientific and social value when they help to resolve specific questions about the ecological action of flow with a clear nexus to water policies and decisions. Water managers must integrate new information into operating policies for large-scale experiments to be effective. Modeling and monitoring can be integrated with experiments to analyze long-term ecological responses. Experimental design should include spatially extensive observations and well-defined, repeated treatments. Large-scale flow manipulations are only a part of dam operations that affect river systems. Scientists can ensure that experimental manipulations continue to be a valuable approach for the scientifically based management of river systems. ?? 2011 by American Institute of Biological Sciences. All rights reserved.

  13. Large-scale flow experiments for managing river systems

    USGS Publications Warehouse

    Konrad, Christopher P.; Olden, Julian D.; Lytle, David A.; Melis, Theodore S.; Schmidt, John C.; Bray, Erin N.; Freeman, Mary C.; Gido, Keith B.; Hemphill, Nina P.; Kennard, Mark J.; McMullen, Laura E.; Mims, Meryl C.; Pyron, Mark; Robinson, Christopher T.; Williams, John G.

    2011-01-01

    Experimental manipulations of streamflow have been used globally in recent decades to mitigate the impacts of dam operations on river systems. Rivers are challenging subjects for experimentation, because they are open systems that cannot be isolated from their social context. We identify principles to address the challenges of conducting effective large-scale flow experiments. Flow experiments have both scientific and social value when they help to resolve specific questions about the ecological action of flow with a clear nexus to water policies and decisions. Water managers must integrate new information into operating policies for large-scale experiments to be effective. Modeling and monitoring can be integrated with experiments to analyze long-term ecological responses. Experimental design should include spatially extensive observations and well-defined, repeated treatments. Large-scale flow manipulations are only a part of dam operations that affect river systems. Scientists can ensure that experimental manipulations continue to be a valuable approach for the scientifically based management of river systems.

  14. Large-scale flow generation by inhomogeneous helicity

    NASA Astrophysics Data System (ADS)

    Yokoi, N.; Brandenburg, A.

    2016-03-01

    The effect of kinetic helicity (velocity-vorticity correlation) on turbulent momentum transport is investigated. The turbulent kinetic helicity (pseudoscalar) enters the Reynolds stress (mirror-symmetric tensor) expression in the form of a helicity gradient as the coupling coefficient for the mean vorticity and/or the angular velocity (axial vector), which suggests the possibility of mean-flow generation in the presence of inhomogeneous helicity. This inhomogeneous helicity effect, which was previously confirmed at the level of a turbulence- or closure-model simulation, is examined with the aid of direct numerical simulations of rotating turbulence with nonuniform helicity sustained by an external forcing. The numerical simulations show that the spatial distribution of the Reynolds stress is in agreement with the helicity-related term coupled with the angular velocity, and that a large-scale flow is generated in the direction of angular velocity. Such a large-scale flow is not induced in the case of homogeneous turbulent helicity. This result confirms the validity of the inhomogeneous helicity effect in large-scale flow generation and suggests that a vortex dynamo is possible even in incompressible turbulence where there is no baroclinicity effect.

  15. Dispersal Mutualism Incorporated into Large-Scale, Infrequent Disturbances.

    PubMed

    Parker, V Thomas

    2015-01-01

    Because of their influence on succession and other community interactions, large-scale, infrequent natural disturbances also should play a major role in mutualistic interactions. Using field data and experiments, I test whether mutualisms have been incorporated into large-scale wildfire by whether the outcomes of a mutualism depend on disturbance. In this study a seed dispersal mutualism is shown to depend on infrequent, large-scale disturbances. A dominant shrubland plant (Arctostaphylos species) produces seeds that make up a persistent soil seed bank and requires fire to germinate. In post-fire stands, I show that seedlings emerging from rodent caches dominate sites experiencing higher fire intensity. Field experiments show that rodents (Perimyscus californicus, P. boylii) do cache Arctostaphylos fruit and bury most seed caches to a sufficient depth to survive a killing heat pulse that a fire might drive into the soil. While the rodent dispersal and caching behavior itself has not changed compared to other habitats, the environmental transformation caused by wildfire converts the caching burial of seed from a dispersal process to a plant fire adaptive trait, and provides the context for stimulating subsequent life history evolution in the plant host. PMID:26151560

  16. Large-scale quantification of CVD graphene surface coverage.

    PubMed

    Ambrosi, Adriano; Bonanni, Alessandra; Sofer, Zdeněk; Pumera, Martin

    2013-03-21

    The extraordinary properties demonstrated for graphene and graphene-related materials can be fully exploited when a large-scale fabrication procedure is made available. Chemical vapor deposition (CVD) of graphene on Cu and Ni substrates is one of the most promising procedures to synthesize large-area and good quality graphene films. Parallel to the fabrication process, a large-scale quality monitoring technique is equally crucial. We demonstrate here a rapid and simple methodology that is able to probe the effectiveness of the growth process over a large substrate area for both Ni and Cu substrates. This method is based on inherent electrochemical signals generated by the underlying metal catalysts when fractures or discontinuities of the graphene film are present. The method can be applied immediately after the CVD growth process without the need for any graphene transfer step and represents a powerful quality monitoring technique for the assessment of large-scale fabrication of graphene by the CVD process. PMID:23396554

  17. Photorealistic large-scale urban city model reconstruction.

    PubMed

    Poullis, Charalambos; You, Suya

    2009-01-01

    The rapid and efficient creation of virtual environments has become a crucial part of virtual reality applications. In particular, civil and defense applications often require and employ detailed models of operations areas for training, simulations of different scenarios, planning for natural or man-made events, monitoring, surveillance, games, and films. A realistic representation of the large-scale environments is therefore imperative for the success of such applications since it increases the immersive experience of its users and helps reduce the difference between physical and virtual reality. However, the task of creating such large-scale virtual environments still remains a time-consuming and manual work. In this work, we propose a novel method for the rapid reconstruction of photorealistic large-scale virtual environments. First, a novel, extendible, parameterized geometric primitive is presented for the automatic building identification and reconstruction of building structures. In addition, buildings with complex roofs containing complex linear and nonlinear surfaces are reconstructed interactively using a linear polygonal and a nonlinear primitive, respectively. Second, we present a rendering pipeline for the composition of photorealistic textures, which unlike existing techniques, can recover missing or occluded texture information by integrating multiple information captured from different optical sensors (ground, aerial, and satellite). PMID:19423889

  18. Large scale structure in universes dominated by cold dark matter

    NASA Technical Reports Server (NTRS)

    Bond, J. Richard

    1986-01-01

    The theory of Gaussian random density field peaks is applied to a numerical study of the large-scale structure developing from adiabatic fluctuations in models of biased galaxy formation in universes with Omega = 1, h = 0.5 dominated by cold dark matter (CDM). The angular anisotropy of the cross-correlation function demonstrates that the far-field regions of cluster-scale peaks are asymmetric, as recent observations indicate. These regions will generate pancakes or filaments upon collapse. One-dimensional singularities in the large-scale bulk flow should arise in these CDM models, appearing as pancakes in position space. They are too rare to explain the CfA bubble walls, but pancakes that are just turning around now are sufficiently abundant and would appear to be thin walls normal to the line of sight in redshift space. Large scale streaming velocities are significantly smaller than recent observations indicate. To explain the reported 700 km/s coherent motions, mass must be significantly more clustered than galaxies with a biasing factor of less than 0.4 and a nonlinear redshift at cluster scales greater than one for both massive neutrino and cold models.

  19. Line segment extraction for large scale unorganized point clouds

    NASA Astrophysics Data System (ADS)

    Lin, Yangbin; Wang, Cheng; Cheng, Jun; Chen, Bili; Jia, Fukai; Chen, Zhonggui; Li, Jonathan

    2015-04-01

    Line segment detection in images is already a well-investigated topic, although it has received considerably less attention in 3D point clouds. Benefiting from current LiDAR devices, large-scale point clouds are becoming increasingly common. Most human-made objects have flat surfaces. Line segments that occur where pairs of planes intersect give important information regarding the geometric content of point clouds, which is especially useful for automatic building reconstruction and segmentation. This paper proposes a novel method that is capable of accurately extracting plane intersection line segments from large-scale raw scan points. The 3D line-support region, namely, a point set near a straight linear structure, is extracted simultaneously. The 3D line-support region is fitted by our Line-Segment-Half-Planes (LSHP) structure, which provides a geometric constraint for a line segment, making the line segment more reliable and accurate. We demonstrate our method on the point clouds of large-scale, complex, real-world scenes acquired by LiDAR devices. We also demonstrate the application of 3D line-support regions and their LSHP structures on urban scene abstraction.

  20. Geospatial Optimization of Siting Large-Scale Solar Projects

    SciTech Connect

    Macknick, J.; Quinby, T.; Caulfield, E.; Gerritsen, M.; Diffendorfer, J.; Haines, S.

    2014-03-01

    Recent policy and economic conditions have encouraged a renewed interest in developing large-scale solar projects in the U.S. Southwest. However, siting large-scale solar projects is complex. In addition to the quality of the solar resource, solar developers must take into consideration many environmental, social, and economic factors when evaluating a potential site. This report describes a proof-of-concept, Web-based Geographical Information Systems (GIS) tool that evaluates multiple user-defined criteria in an optimization algorithm to inform discussions and decisions regarding the locations of utility-scale solar projects. Existing siting recommendations for large-scale solar projects from governmental and non-governmental organizations are not consistent with each other, are often not transparent in methods, and do not take into consideration the differing priorities of stakeholders. The siting assistance GIS tool we have developed improves upon the existing siting guidelines by being user-driven, transparent, interactive, capable of incorporating multiple criteria, and flexible. This work provides the foundation for a dynamic siting assistance tool that can greatly facilitate siting decisions among multiple stakeholders.

  1. Large-scale data mining pilot project in human genome

    SciTech Connect

    Musick, R.; Fidelis, R.; Slezak, T.

    1997-05-01

    This whitepaper briefly describes a new, aggressive effort in large- scale data Livermore National Labs. The implications of `large- scale` will be clarified Section. In the short term, this effort will focus on several @ssion-critical questions of Genome project. We will adapt current data mining techniques to the Genome domain, to quantify the accuracy of inference results, and lay the groundwork for a more extensive effort in large-scale data mining. A major aspect of the approach is that we will be fully-staffed data warehousing effort in the human Genome area. The long term goal is strong applications- oriented research program in large-@e data mining. The tools, skill set gained will be directly applicable to a wide spectrum of tasks involving a for large spatial and multidimensional data. This includes applications in ensuring non-proliferation, stockpile stewardship, enabling Global Ecology (Materials Database Industrial Ecology), advancing the Biosciences (Human Genome Project), and supporting data for others (Battlefield Management, Health Care).

  2. How Large Scales Flows May Influence Solar Activity

    NASA Technical Reports Server (NTRS)

    Hathaway, D. H.

    2004-01-01

    Large scale flows within the solar convection zone are the primary drivers of the Sun's magnetic activity cycle and play important roles in shaping the Sun's magnetic field. Differential rotation amplifies the magnetic field through its shearing action and converts poloidal field into toroidal field. Poleward meridional flow near the surface carries magnetic flux that reverses the magnetic poles at about the time of solar maximum. The deeper, equatorward meridional flow can carry magnetic flux back toward the lower latitudes where it erupts through the surface to form tilted active regions that convert toroidal fields into oppositely directed poloidal fields. These axisymmetric flows are themselves driven by large scale convective motions. The effects of the Sun's rotation on convection produce velocity correlations that can maintain both the differential rotation and the meridional circulation. These convective motions can also influence solar activity directly by shaping the magnetic field pattern. While considerable theoretical advances have been made toward understanding these large scale flows, outstanding problems in matching theory to observations still remain.

  3. Lateral stirring of large-scale tracer fields by altimetry

    NASA Astrophysics Data System (ADS)

    Dencausse, Guillaume; Morrow, Rosemary; Rogé, Marine; Fleury, Sara

    2014-01-01

    Ocean surface fronts and filaments have a strong impact on the global ocean circulation and biogeochemistry. Surface Lagrangian advection with time-evolving altimetric geostrophic velocities can be used to simulate the submesoscale front and filament structures in large-scale tracer fields. We study this technique in the Southern Ocean region south of Tasmania, a domain marked by strong meso- to submesoscale features such as the fronts of the Antarctic Circumpolar Current (ACC). Starting with large-scale surface tracer fields that we stir with altimetric velocities, we determine `advected' fields which compare well with high-resolution in situ or satellite tracer data. We find that fine scales are best represented in a statistical sense after an optimal advection time of ˜2 weeks, with enhanced signatures of the ACC fronts and better spectral energy. The technique works best in moderate to high EKE regions where lateral advection dominates. This technique may be used to infer the distribution of unresolved small scales in any physical or biogeochemical surface tracer that is dominated by lateral advection. Submesoscale dynamics also impact the subsurface of the ocean, and the Lagrangian advection at depth shows promising results. Finally, we show that climatological tracer fields computed from the advected large-scale fields display improved fine-scale mean features, such as the ACC fronts, which can be useful in the context of ocean modelling.

  4. Large scale anisotropy of UHECRs for the Telescope Array

    SciTech Connect

    Kido, E.

    2011-09-22

    The origin of Ultra High Energy Cosmic Rays (UHECRs) is one of the most interesting questions in astroparticle physics. Despite of the efforts by other previous measurements, there is no consensus of both of the origin and the mechanism of UHECRs generation and propagation yet. In this context, Telescope Array (TA) experiment is expected to play an important role as the largest detector in the northern hemisphere which consists of an array of surface particle detectors (SDs) and fluorescence detectors (FDs) and other important calibration devices. We searched for large scale anisotropy using SD data of TA. UHECRs are expected to be restricted in GZK horizon when the composition of UHECRs is proton, so the observed arrival directions are expected to exhibit local large scale anisotropy if UHECR sources are some astrophysical objects. We used the SD data set from 11 May 2008 to 7 September 2010 to search for large-scale anisotropy. The discrimination power between LSS and isotropy is not enough yet, but the statistics in TA is expected to discriminate between those in about 95% confidence level on average in near future.

  5. Large-scale functional connectivity networks in the rodent brain.

    PubMed

    Gozzi, Alessandro; Schwarz, Adam J

    2016-02-15

    Resting-state functional Magnetic Resonance Imaging (rsfMRI) of the human brain has revealed multiple large-scale neural networks within a hierarchical and complex structure of coordinated functional activity. These distributed neuroanatomical systems provide a sensitive window on brain function and its disruption in a variety of neuropathological conditions. The study of macroscale intrinsic connectivity networks in preclinical species, where genetic and environmental conditions can be controlled and manipulated with high specificity, offers the opportunity to elucidate the biological determinants of these alterations. While rsfMRI methods are now widely used in human connectivity research, these approaches have only relatively recently been back-translated into laboratory animals. Here we review recent progress in the study of functional connectivity in rodent species, emphasising the ability of this approach to resolve large-scale brain networks that recapitulate neuroanatomical features of known functional systems in the human brain. These include, but are not limited to, a distributed set of regions identified in rats and mice that may represent a putative evolutionary precursor of the human default mode network (DMN). The impact and control of potential experimental and methodological confounds are also critically discussed. Finally, we highlight the enormous potential and some initial application of connectivity mapping in transgenic models as a tool to investigate the neuropathological underpinnings of the large-scale connectional alterations associated with human neuropsychiatric and neurological conditions. We conclude by discussing the translational potential of these methods in basic and applied neuroscience. PMID:26706448

  6. Multiresolution comparison of precipitation datasets for large-scale models

    NASA Astrophysics Data System (ADS)

    Chun, K. P.; Sapriza Azuri, G.; Davison, B.; DeBeer, C. M.; Wheater, H. S.

    2014-12-01

    Gridded precipitation datasets are crucial for driving large-scale models which are related to weather forecast and climate research. However, the quality of precipitation products is usually validated individually. Comparisons between gridded precipitation products along with ground observations provide another avenue for investigating how the precipitation uncertainty would affect the performance of large-scale models. In this study, using data from a set of precipitation gauges over British Columbia and Alberta, we evaluate several widely used North America gridded products including the Canadian Gridded Precipitation Anomalies (CANGRD), the National Center for Environmental Prediction (NCEP) reanalysis, the Water and Global Change (WATCH) project, the thin plate spline smoothing algorithms (ANUSPLIN) and Canadian Precipitation Analysis (CaPA). Based on verification criteria for various temporal and spatial scales, results provide an assessment of possible applications for various precipitation datasets. For long-term climate variation studies (~100 years), CANGRD, NCEP, WATCH and ANUSPLIN have different comparative advantages in terms of their resolution and accuracy. For synoptic and mesoscale precipitation patterns, CaPA provides appealing performance of spatial coherence. In addition to the products comparison, various downscaling methods are also surveyed to explore new verification and bias-reduction methods for improving gridded precipitation outputs for large-scale models.

  7. Upscaling of elastic properties for large scale geomechanical simulations

    NASA Astrophysics Data System (ADS)

    Chalon, F.; Mainguy, M.; Longuemare, P.; Lemonnier, P.

    2004-09-01

    Large scale geomechanical simulations are being increasingly used to model the compaction of stress dependent reservoirs, predict the long term integrity of under-ground radioactive waste disposals, and analyse the viability of hot-dry rock geothermal sites. These large scale simulations require the definition of homogenous mechanical properties for each geomechanical cell whereas the rock properties are expected to vary at a smaller scale. Therefore, this paper proposes a new methodology that makes possible to define the equivalent mechanical properties of the geomechanical cells using the fine scale information given in the geological model. This methodology is implemented on a synthetic reservoir case and two upscaling procedures providing the effective elastic properties of the Hooke's law are tested. The first upscaling procedure is an analytical method for perfectly stratified rock mass, whereas the second procedure computes lower and upper bounds of the equivalent properties with no assumption on the small scale heterogeneity distribution. Both procedures are applied to one geomechanical cell extracted from the reservoir structure. The results show that the analytical and numerical upscaling procedures provide accurate estimations of the effective parameters. Furthermore, a large scale simulation using the homogenized properties of each geomechanical cell calculated with the analytical method demonstrates that the overall behaviour of the reservoir structure is well reproduced for two different loading cases. Copyright

  8. Impact of Malaysian Polytechnics' Head of Department Multi-Dimensional Leadership Orientation towards Lecturers Work Commitment

    ERIC Educational Resources Information Center

    Ibrahim, Mohammed Sani; Mujir, Siti Junaidah Mohd

    2012-01-01

    The purpose of this study is to determine if the multi-dimensional leadership orientation of the heads of departments in Malaysian polytechnics affects their leadership effectiveness and the lecturers' commitment to work as perceived by the lecturers. The departmental heads' leadership orientation was determined by five leadership dimensions…

  9. A Multi-Dimensional Cognitive Analysis of Undergraduate Physics Students' Understanding of Heat Conduction

    ERIC Educational Resources Information Center

    Chiou, Guo-Li; Anderson, O. Roger

    2010-01-01

    This study proposes a multi-dimensional approach to investigate, represent, and categorize students' in-depth understanding of complex physics concepts. Clinical interviews were conducted with 30 undergraduate physics students to probe their understanding of heat conduction. Based on the data analysis, six aspects of the participants' responses…

  10. The application of a multi-dimensional assessment approach to talent identification in Australian football.

    PubMed

    Woods, Carl T; Raynor, Annette J; Bruce, Lyndell; McDonald, Zane; Robertson, Sam

    2016-07-01

    This study investigated whether a multi-dimensional assessment could assist with talent identification in junior Australian football (AF). Participants were recruited from an elite under 18 (U18) AF competition and classified into two groups; talent identified (State U18 Academy representatives; n = 42; 17.6 ± 0.4 y) and non-talent identified (non-State U18 Academy representatives; n = 42; 17.4 ± 0.5 y). Both groups completed a multi-dimensional assessment, which consisted of physical (standing height, dynamic vertical jump height and 20 m multistage fitness test), technical (kicking and handballing tests) and perceptual-cognitive (video decision-making task) performance outcome tests. A multivariate analysis of variance tested the main effect of status on the test criterions, whilst a receiver operating characteristic curve assessed the discrimination provided from the full assessment. The talent identified players outperformed their non-talent identified peers in each test (P < 0.05). The receiver operating characteristic curve reflected near perfect discrimination (AUC = 95.4%), correctly classifying 95% and 86% of the talent identified and non-talent identified participants, respectively. When compared to single assessment approaches, this multi-dimensional assessment reflects a more comprehensive means of talent identification in AF. This study further highlights the importance of assessing multi-dimensional performance qualities when identifying talented team sports. PMID:26862858

  11. Developing Multi-Dimensional Evaluation Criteria for English Learning Websites with University Students and Professors

    ERIC Educational Resources Information Center

    Liu, Gi-Zen; Liu, Zih-Hui; Hwang, Gwo-Jen

    2011-01-01

    Many English learning websites have been developed worldwide, but little research has been conducted concerning the development of comprehensive evaluation criteria. The main purpose of this study is thus to construct a multi-dimensional set of criteria to help learners and teachers evaluate the quality of English learning websites. These…

  12. Kullback-Leibler Information and Its Applications in Multi-Dimensional Adaptive Testing

    ERIC Educational Resources Information Center

    Wang, Chun; Chang, Hua-Hua; Boughton, Keith A.

    2011-01-01

    This paper first discusses the relationship between Kullback-Leibler information (KL) and Fisher information in the context of multi-dimensional item response theory and is further interpreted for the two-dimensional case, from a geometric perspective. This explication should allow for a better understanding of the various item selection methods…

  13. Evidencing Learning Outcomes: A Multi-Level, Multi-Dimensional Course Alignment Model

    ERIC Educational Resources Information Center

    Sridharan, Bhavani; Leitch, Shona; Watty, Kim

    2015-01-01

    This conceptual framework proposes a multi-level, multi-dimensional course alignment model to implement a contextualised constructive alignment of rubric design that authentically evidences and assesses learning outcomes. By embedding quality control mechanisms at each level for each dimension, this model facilitates the development of an aligned…

  14. Developing a Hypothetical Multi-Dimensional Learning Progression for the Nature of Matter

    ERIC Educational Resources Information Center

    Stevens, Shawn Y.; Delgado, Cesar; Krajcik, Joseph S.

    2010-01-01

    We describe efforts toward the development of a hypothetical learning progression (HLP) for the growth of grade 7-14 students' models of the structure, behavior and properties of matter, as it relates to nanoscale science and engineering (NSE). This multi-dimensional HLP, based on empirical research and standards documents, describes how students…

  15. Stability of shock waves for multi-dimensional hyperbolic-parabolic conservation laws

    NASA Astrophysics Data System (ADS)

    Li, Dening

    1988-01-01

    The uniform linear stability of shock waves is considerd for quasilinear hyperbolic-parabolic coupled conservation laws in multi-dimensional space. As an example, the stability condition and its dynamic meaning for isothermal shock wave in radiative hydrodynamics are analyzed.

  16. Continuous Energy, Multi-Dimensional Transport Calculations for Problem Dependent Resonance Self-Shielding

    SciTech Connect

    T. Downar

    2009-03-31

    The overall objective of the work here has been to eliminate the approximations used in current resonance treatments by developing continuous energy multi-dimensional transport calculations for problem dependent self-shielding calculations. The work here builds on the existing resonance treatment capabilities in the ORNL SCALE code system.

  17. Development of a Multi-Dimensional Scale for PDD and ADHD

    ERIC Educational Resources Information Center

    Funabiki, Yasuko; Kawagishi, Hisaya; Uwatoko, Teruhisa; Yoshimura, Sayaka; Murai, Toshiya

    2011-01-01

    A novel assessment scale, the multi-dimensional scale for pervasive developmental disorder (PDD) and attention-deficit/hyperactivity disorder (ADHD) (MSPA), is reported. Existing assessment scales are intended to establish each diagnosis. However, the diagnosis by itself does not always capture individual characteristics or indicate the level of…

  18. Methodological Issues in Developing a Multi-Dimensional Coding Procedure for Small-Group Chat Communication

    ERIC Educational Resources Information Center

    Strijbos, Jan-Willem; Stahl, Gerry

    2007-01-01

    In CSCL research, collaboration through chat has primarily been studied in dyadic settings. This article discusses three issues that emerged during the development of a multi-dimensional coding procedure for small-group chat communication: (a) the unit of analysis and unit fragmentation, (b) the reconstruction of the response structure and (c)…

  19. The Relation Between Large-Scale Coronal Propagating Fronts and Type II Radio Bursts

    NASA Astrophysics Data System (ADS)

    Nitta, Nariaki V.; Liu, Wei; Gopalswamy, Nat; Yashiro, Seiji

    2014-12-01

    Large-scale, wave-like disturbances in extreme-ultraviolet (EUV) and type II radio bursts are often associated with coronal mass ejections (CMEs). Both phenomena may signify shock waves driven by CMEs. Taking EUV full-disk images at an unprecedented cadence, the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory has observed the so-called EIT waves or large-scale coronal propagating fronts (LCPFs) from their early evolution, which coincides with the period when most metric type II bursts occur. This article discusses the relation of LCPFs as captured by AIA with metric type II bursts. We show examples of type II bursts without a clear LCPF and fast LCPFs without a type II burst. Part of the disconnect between the two phenomena may be due to the difficulty in identifying them objectively. Furthermore, it is possible that the individual LCPFs and type II bursts may reflect different physical processes and external factors. In particular, the type II bursts that start at low frequencies and high altitudes tend to accompany an extended arc-shaped feature, which probably represents the 3D structure of the CME and the shock wave around it, and not just its near-surface track, which has usually been identified with EIT waves. This feature expands and propagates toward and beyond the limb. These events may be characterized by stretching of field lines in the radial direction and may be distinct from other LCPFs, which may be explained in terms of sudden lateral expansion of the coronal volume. Neither LCPFs nor type II bursts by themselves serve as necessary conditions for coronal shock waves, but these phenomena may provide useful information on the early evolution of the shock waves in 3D when both are clearly identified in eruptive events.

  20. Pedagogical Factors Stimulating the Self-Development of Students' Multi-Dimensional Thinking in Terms of Subject-Oriented Teaching

    ERIC Educational Resources Information Center

    Andreev, Valentin I.

    2014-01-01

    The main aim of this research is to disclose the essence of students' multi-dimensional thinking, also to reveal the rating of factors which stimulate the raising of effectiveness of self-development of students' multi-dimensional thinking in terms of subject-oriented teaching. Subject-oriented learning is characterized as a type of learning where…

  1. Robust large-scale parallel nonlinear solvers for simulations.

    SciTech Connect

    Bader, Brett William; Pawlowski, Roger Patrick; Kolda, Tamara Gibson

    2005-11-01

    This report documents research to develop robust and efficient solution techniques for solving large-scale systems of nonlinear equations. The most widely used method for solving systems of nonlinear equations is Newton's method. While much research has been devoted to augmenting Newton-based solvers (usually with globalization techniques), little has been devoted to exploring the application of different models. Our research has been directed at evaluating techniques using different models than Newton's method: a lower order model, Broyden's method, and a higher order model, the tensor method. We have developed large-scale versions of each of these models and have demonstrated their use in important applications at Sandia. Broyden's method replaces the Jacobian with an approximation, allowing codes that cannot evaluate a Jacobian or have an inaccurate Jacobian to converge to a solution. Limited-memory methods, which have been successful in optimization, allow us to extend this approach to large-scale problems. We compare the robustness and efficiency of Newton's method, modified Newton's method, Jacobian-free Newton-Krylov method, and our limited-memory Broyden method. Comparisons are carried out for large-scale applications of fluid flow simulations and electronic circuit simulations. Results show that, in cases where the Jacobian was inaccurate or could not be computed, Broyden's method converged in some cases where Newton's method failed to converge. We identify conditions where Broyden's method can be more efficient than Newton's method. We also present modifications to a large-scale tensor method, originally proposed by Bouaricha, for greater efficiency, better robustness, and wider applicability. Tensor methods are an alternative to Newton-based methods and are based on computing a step based on a local quadratic model rather than a linear model. The advantage of Bouaricha's method is that it can use any existing linear solver, which makes it simple to write

  2. Foundational perspectives on causality in large-scale brain networks.

    PubMed

    Mannino, Michael; Bressler, Steven L

    2015-12-01

    A profusion of recent work in cognitive neuroscience has been concerned with the endeavor to uncover causal influences in large-scale brain networks. However, despite the fact that many papers give a nod to the important theoretical challenges posed by the concept of causality, this explosion of research has generally not been accompanied by a rigorous conceptual analysis of the nature of causality in the brain. This review provides both a descriptive and prescriptive account of the nature of causality as found within and between large-scale brain networks. In short, it seeks to clarify the concept of causality in large-scale brain networks both philosophically and scientifically. This is accomplished by briefly reviewing the rich philosophical history of work on causality, especially focusing on contributions by David Hume, Immanuel Kant, Bertrand Russell, and Christopher Hitchcock. We go on to discuss the impact that various interpretations of modern physics have had on our understanding of causality. Throughout all this, a central focus is the distinction between theories of deterministic causality (DC), whereby causes uniquely determine their effects, and probabilistic causality (PC), whereby causes change the probability of occurrence of their effects. We argue that, given the topological complexity of its large-scale connectivity, the brain should be considered as a complex system and its causal influences treated as probabilistic in nature. We conclude that PC is well suited for explaining causality in the brain for three reasons: (1) brain causality is often mutual; (2) connectional convergence dictates that only rarely is the activity of one neuronal population uniquely determined by another one; and (3) the causal influences exerted between neuronal populations may not have observable effects. A number of different techniques are currently available to characterize causal influence in the brain. Typically, these techniques quantify the statistical

  3. Large-scale magnetic topologies of early M dwarfs

    NASA Astrophysics Data System (ADS)

    Donati, J.-F.; Morin, J.; Petit, P.; Delfosse, X.; Forveille, T.; Aurière, M.; Cabanac, R.; Dintrans, B.; Fares, R.; Gastine, T.; Jardine, M. M.; Lignières, F.; Paletou, F.; Ramirez Velez, J. C.; Théado, S.

    2008-10-01

    We present here additional results of a spectropolarimetric survey of a small sample of stars ranging from spectral type M0 to M8 aimed at investigating observationally how dynamo processes operate in stars on both sides of the full convection threshold (spectral type M4). The present paper focuses on early M stars (M0-M3), that is above the full convection threshold. Applying tomographic imaging techniques to time series of rotationally modulated circularly polarized profiles collected with the NARVAL spectropolarimeter, we determine the rotation period and reconstruct the large-scale magnetic topologies of six early M dwarfs. We find that early-M stars preferentially host large-scale fields with dominantly toroidal and non-axisymmetric poloidal configurations, along with significant differential rotation (and long-term variability); only the lowest-mass star of our subsample is found to host an almost fully poloidal, mainly axisymmetric large-scale field resembling those found in mid-M dwarfs. This abrupt change in the large-scale magnetic topologies of M dwarfs (occurring at spectral type M3) has no related signature on X-ray luminosities (measuring the total amount of magnetic flux); it thus suggests that underlying dynamo processes become more efficient at producing large-scale fields (despite producing the same flux) at spectral types later than M3. We suspect that this change relates to the rapid decrease in the radiative cores of low-mass stars and to the simultaneous sharp increase of the convective turnover times (with decreasing stellar mass) that models predict to occur at M3; it may also be (at least partly) responsible for the reduced magnetic braking reported for fully convective stars. Based on observations obtained at the Télescope Bernard Lyot (TBL), operated by the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique of France. E-mail: donati@ast.obs-mip.fr (J-FD); jmorin@ast.obs-mip.fr (JM); petit

  4. Foundational perspectives on causality in large-scale brain networks

    NASA Astrophysics Data System (ADS)

    Mannino, Michael; Bressler, Steven L.

    2015-12-01

    A profusion of recent work in cognitive neuroscience has been concerned with the endeavor to uncover causal influences in large-scale brain networks. However, despite the fact that many papers give a nod to the important theoretical challenges posed by the concept of causality, this explosion of research has generally not been accompanied by a rigorous conceptual analysis of the nature of causality in the brain. This review provides both a descriptive and prescriptive account of the nature of causality as found within and between large-scale brain networks. In short, it seeks to clarify the concept of causality in large-scale brain networks both philosophically and scientifically. This is accomplished by briefly reviewing the rich philosophical history of work on causality, especially focusing on contributions by David Hume, Immanuel Kant, Bertrand Russell, and Christopher Hitchcock. We go on to discuss the impact that various interpretations of modern physics have had on our understanding of causality. Throughout all this, a central focus is the distinction between theories of deterministic causality (DC), whereby causes uniquely determine their effects, and probabilistic causality (PC), whereby causes change the probability of occurrence of their effects. We argue that, given the topological complexity of its large-scale connectivity, the brain should be considered as a complex system and its causal influences treated as probabilistic in nature. We conclude that PC is well suited for explaining causality in the brain for three reasons: (1) brain causality is often mutual; (2) connectional convergence dictates that only rarely is the activity of one neuronal population uniquely determined by another one; and (3) the causal influences exerted between neuronal populations may not have observable effects. A number of different techniques are currently available to characterize causal influence in the brain. Typically, these techniques quantify the statistical

  5. Paranormal phenomena

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    1996-08-01

    Critical analysis is given of some paranormal phenomena events (UFO, healers, psychokinesis (telekinesis))reported in Moldova. It is argued that correct analysis of paranormal phenomena should be made in the framework of electromagnetism.

  6. Large-scale smart passive system for civil engineering applications

    NASA Astrophysics Data System (ADS)

    Jung, Hyung-Jo; Jang, Dong-Doo; Lee, Heon-Jae; Cho, Sang-Won

    2008-03-01

    The smart passive system consisting of a magnetorheological (MR) damper and an electromagnetic induction (EMI) part has been recently proposed. An EMI part can generate the input current for an MR damper from vibration of a structure according to Faraday's law of electromagnetic induction. The control performance of the smart passive system has been demonstrated mainly by numerical simulations. It was verified from the numerical results that the system could be effective to reduce the structural responses in the cases of civil engineering structures such as buildings and bridges. On the other hand, the experimental validation of the system is not sufficiently conducted yet. In this paper, the feasibility of the smart passive system to real-scale structures is investigated. To do this, the large-scale smart passive system is designed, manufactured, and tested. The system consists of the large-capacity MR damper, which has a maximum force level of approximately +/-10,000N, a maximum stroke level of +/-35mm and the maximum current level of 3 A, and the large-scale EMI part, which is designed to generate sufficient induced current for the damper. The applicability of the smart passive system to large real-scale structures is examined through a series of shaking table tests. The magnitudes of the induced current of the EMI part with various sinusoidal excitation inputs are measured. According to the test results, the large-scale EMI part shows the possibility that it could generate the sufficient current or power for changing the damping characteristics of the large-capacity MR damper.

  7. Constraints on large-scale dark acoustic oscillations from cosmology

    NASA Astrophysics Data System (ADS)

    Cyr-Racine, Francis-Yan; de Putter, Roland; Raccanelli, Alvise; Sigurdson, Kris

    2014-03-01

    If all or a fraction of the dark matter (DM) were coupled to a bath of dark radiation (DR) in the early Universe, we expect the combined DM-DR system to give rise to acoustic oscillations of the dark matter until it decouples from the DR. Much like the standard baryon acoustic oscillations, these dark acoustic oscillations (DAO) imprint a characteristic scale, the sound horizon of dark matter, on the matter power spectrum. We compute in detail how the microphysics of the DM-DR interaction affects the clustering of matter in the Universe and show that the DAO physics also gives rise to unique signatures in the temperature and polarization spectra of the cosmic microwave background (CMB). We use cosmological data from the CMB, baryon acoustic oscillations, and large-scale structure to constrain the possible fraction of interacting DM as well as the strength of its interaction with DR. Like nearly all knowledge we have gleaned about DM since inferring its existence this constraint rests on the betrayal by gravity of the location of otherwise invisible DM. Although our results can be straightforwardly applied to a broad class of models that couple dark matter particles to various light relativistic species, in order to make quantitative predictions, we model the interacting component as dark atoms coupled to a bath of dark photons. We find that linear cosmological data and CMB lensing put strong constraints on the existence of DAO features in the CMB and the large-scale structure of the Universe. Interestingly, we find that at most ˜5% of all DM can be very strongly interacting with DR. We show that our results are surprisingly constraining for the recently proposed double-disk DM model, a novel example of how large-scale precision cosmological data can be used to constrain galactic physics and subgalactic structure.

  8. Solving large scale structure in ten easy steps with COLA

    NASA Astrophysics Data System (ADS)

    Tassev, Svetlin; Zaldarriaga, Matias; Eisenstein, Daniel J.

    2013-06-01

    We present the COmoving Lagrangian Acceleration (COLA) method: an N-body method for solving for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in Lagrangian Perturbation Theory (LPT). Unlike standard N-body methods, the COLA method can straightforwardly trade accuracy at small-scales in order to gain computational speed without sacrificing accuracy at large scales. This is especially useful for cheaply generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing, as those catalogs are essential for performing detailed error analysis for ongoing and future surveys of LSS. As an illustration, we ran a COLA-based N-body code on a box of size 100 Mpc/h with particles of mass ≈ 5 × 109Msolar/h. Running the code with only 10 timesteps was sufficient to obtain an accurate description of halo statistics down to halo masses of at least 1011Msolar/h. This is only at a modest speed penalty when compared to mocks obtained with LPT. A standard detailed N-body run is orders of magnitude slower than our COLA-based code. The speed-up we obtain with COLA is due to the fact that we calculate the large-scale dynamics exactly using LPT, while letting the N-body code solve for the small scales, without requiring it to capture exactly the internal dynamics of halos. Achieving a similar level of accuracy in halo statistics without the COLA method requires at least 3 times more timesteps than when COLA is employed.

  9. Large-Scale Hybrid Motor Testing. Chapter 10

    NASA Technical Reports Server (NTRS)

    Story, George

    2006-01-01

    Hybrid rocket motors can be successfully demonstrated at a small scale virtually anywhere. There have been many suitcase sized portable test stands assembled for demonstration of hybrids. They show the safety of hybrid rockets to the audiences. These small show motors and small laboratory scale motors can give comparative burn rate data for development of different fuel/oxidizer combinations, however questions that are always asked when hybrids are mentioned for large scale applications are - how do they scale and has it been shown in a large motor? To answer those questions, large scale motor testing is required to verify the hybrid motor at its true size. The necessity to conduct large-scale hybrid rocket motor tests to validate the burn rate from the small motors to application size has been documented in several place^'^^.^. Comparison of small scale hybrid data to that of larger scale data indicates that the fuel burn rate goes down with increasing port size, even with the same oxidizer flux. This trend holds for conventional hybrid motors with forward oxidizer injection and HTPB based fuels. While the reason this is occurring would make a great paper or study or thesis, it is not thoroughly understood at this time. Potential causes include the fact that since hybrid combustion is boundary layer driven, the larger port sizes reduce the interaction (radiation, mixing and heat transfer) from the core region of the port. This chapter focuses on some of the large, prototype sized testing of hybrid motors. The largest motors tested have been AMROC s 250K-lbf thrust motor at Edwards Air Force Base and the Hybrid Propulsion Demonstration Program s 250K-lbf thrust motor at Stennis Space Center. Numerous smaller tests were performed to support the burn rate, stability and scaling concepts that went into the development of those large motors.

  10. LARGE-SCALE CO2 TRANSPORTATION AND DEEP OCEAN SEQUESTRATION

    SciTech Connect

    Hamid Sarv

    1999-03-01

    Technical and economical feasibility of large-scale CO{sub 2} transportation and ocean sequestration at depths of 3000 meters or grater was investigated. Two options were examined for transporting and disposing the captured CO{sub 2}. In one case, CO{sub 2} was pumped from a land-based collection center through long pipelines laid on the ocean floor. Another case considered oceanic tanker transport of liquid carbon dioxide to an offshore floating structure for vertical injection to the ocean floor. In the latter case, a novel concept based on subsurface towing of a 3000-meter pipe, and attaching it to the offshore structure was considered. Budgetary cost estimates indicate that for distances greater than 400 km, tanker transportation and offshore injection through a 3000-meter vertical pipe provides the best method for delivering liquid CO{sub 2} to deep ocean floor depressions. For shorter distances, CO{sub 2} delivery by parallel-laid, subsea pipelines is more cost-effective. Estimated costs for 500-km transport and storage at a depth of 3000 meters by subsea pipelines and tankers were 1.5 and 1.4 dollars per ton of stored CO{sub 2}, respectively. At these prices, economics of ocean disposal are highly favorable. Future work should focus on addressing technical issues that are critical to the deployment of a large-scale CO{sub 2} transportation and disposal system. Pipe corrosion, structural design of the transport pipe, and dispersion characteristics of sinking CO{sub 2} effluent plumes have been identified as areas that require further attention. Our planned activities in the next Phase include laboratory-scale corrosion testing, structural analysis of the pipeline, analytical and experimental simulations of CO{sub 2} discharge and dispersion, and the conceptual economic and engineering evaluation of large-scale implementation.

  11. Solving large scale structure in ten easy steps with COLA

    SciTech Connect

    Tassev, Svetlin; Zaldarriaga, Matias; Eisenstein, Daniel J. E-mail: matiasz@ias.edu

    2013-06-01

    We present the COmoving Lagrangian Acceleration (COLA) method: an N-body method for solving for Large Scale Structure (LSS) in a frame that is comoving with observers following trajectories calculated in Lagrangian Perturbation Theory (LPT). Unlike standard N-body methods, the COLA method can straightforwardly trade accuracy at small-scales in order to gain computational speed without sacrificing accuracy at large scales. This is especially useful for cheaply generating large ensembles of accurate mock halo catalogs required to study galaxy clustering and weak lensing, as those catalogs are essential for performing detailed error analysis for ongoing and future surveys of LSS. As an illustration, we ran a COLA-based N-body code on a box of size 100 Mpc/h with particles of mass ≈ 5 × 10{sup 9}M{sub s}un/h. Running the code with only 10 timesteps was sufficient to obtain an accurate description of halo statistics down to halo masses of at least 10{sup 11}M{sub s}un/h. This is only at a modest speed penalty when compared to mocks obtained with LPT. A standard detailed N-body run is orders of magnitude slower than our COLA-based code. The speed-up we obtain with COLA is due to the fact that we calculate the large-scale dynamics exactly using LPT, while letting the N-body code solve for the small scales, without requiring it to capture exactly the internal dynamics of halos. Achieving a similar level of accuracy in halo statistics without the COLA method requires at least 3 times more timesteps than when COLA is employed.

  12. Infectious diseases in large-scale cat hoarding investigations.

    PubMed

    Polak, K C; Levy, J K; Crawford, P C; Leutenegger, C M; Moriello, K A

    2014-08-01

    Animal hoarders accumulate animals in over-crowded conditions without adequate nutrition, sanitation, and veterinary care. As a result, animals rescued from hoarding frequently have a variety of medical conditions including respiratory infections, gastrointestinal disease, parasitism, malnutrition, and other evidence of neglect. The purpose of this study was to characterize the infectious diseases carried by clinically affected cats and to determine the prevalence of retroviral infections among cats in large-scale cat hoarding investigations. Records were reviewed retrospectively from four large-scale seizures of cats from failed sanctuaries from November 2009 through March 2012. The number of cats seized in each case ranged from 387 to 697. Cats were screened for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) in all four cases and for dermatophytosis in one case. A subset of cats exhibiting signs of upper respiratory disease or diarrhea had been tested for infections by PCR and fecal flotation for treatment planning. Mycoplasma felis (78%), calicivirus (78%), and Streptococcus equi subspecies zooepidemicus (55%) were the most common respiratory infections. Feline enteric coronavirus (88%), Giardia (56%), Clostridium perfringens (49%), and Tritrichomonas foetus (39%) were most common in cats with diarrhea. The seroprevalence of FeLV and FIV were 8% and 8%, respectively. In the one case in which cats with lesions suspicious for dermatophytosis were cultured for Microsporum canis, 69/76 lesional cats were culture-positive; of these, half were believed to be truly infected and half were believed to be fomite carriers. Cats from large-scale hoarding cases had high risk for enteric and respiratory infections, retroviruses, and dermatophytosis. Case responders should be prepared for mass treatment of infectious diseases and should implement protocols to prevent transmission of feline or zoonotic infections during the emergency response and when

  13. Improving Design Efficiency for Large-Scale Heterogeneous Circuits

    NASA Astrophysics Data System (ADS)

    Gregerson, Anthony

    Despite increases in logic density, many Big Data applications must still be partitioned across multiple computing devices in order to meet their strict performance requirements. Among the most demanding of these applications is high-energy physics (HEP), which uses complex computing systems consisting of thousands of FPGAs and ASICs to process the sensor data created by experiments at particles accelerators such as the Large Hadron Collider (LHC). Designing such computing systems is challenging due to the scale of the systems, the exceptionally high-throughput and low-latency performance constraints that necessitate application-specific hardware implementations, the requirement that algorithms are efficiently partitioned across many devices, and the possible need to update the implemented algorithms during the lifetime of the system. In this work, we describe our research to develop flexible architectures for implementing such large-scale circuits on FPGAs. In particular, this work is motivated by (but not limited in scope to) high-energy physics algorithms for the Compact Muon Solenoid (CMS) experiment at the LHC. To make efficient use of logic resources in multi-FPGA systems, we introduce Multi-Personality Partitioning, a novel form of the graph partitioning problem, and present partitioning algorithms that can significantly improve resource utilization on heterogeneous devices while also reducing inter-chip connections. To reduce the high communication costs of Big Data applications, we also introduce Information-Aware Partitioning, a partitioning method that analyzes the data content of application-specific circuits, characterizes their entropy, and selects circuit partitions that enable efficient compression of data between chips. We employ our information-aware partitioning method to improve the performance of the hardware validation platform for evaluating new algorithms for the CMS experiment. Together, these research efforts help to improve the efficiency

  14. Solving Large-scale Eigenvalue Problems in SciDACApplications

    SciTech Connect

    Yang, Chao

    2005-06-29

    Large-scale eigenvalue problems arise in a number of DOE applications. This paper provides an overview of the recent development of eigenvalue computation in the context of two SciDAC applications. We emphasize the importance of Krylov subspace methods, and point out its limitations. We discuss the value of alternative approaches that are more amenable to the use of preconditioners, and report the progression using the multi-level algebraic sub-structuring techniques to speed up eigenvalue calculation. In addition to methods for linear eigenvalue problems, we also examine new approaches to solving two types of non-linear eigenvalue problems arising from SciDAC applications.

  15. Towards large scale production and separation of carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Alvarez, Noe T.

    Since their discovery, carbon nanotubes (CNTs) have boosted the research and applications of nanotechnology; however, many applications of CNTs are inaccessible because they depend upon large-scale CNT production and separations. Type, chirality and diameter control of CNTs determine many of their physical properties, and such control is still not accesible. This thesis studies the fundamentals for scalable selective reactions of HiPCo CNTs as well as the early phase of routes to an inexpensive approach for large-scale CNT production. In the growth part, this thesis covers a complete wet-chemistry process of catalyst and catalyst support deposition for growth of vertically aligned (VA) CNTs. A wet-chemistry preparation process has significant importance for CNT synthesis through chemical vapor deposition (CVD). CVD is by far, the most suitable and inexpensive process for large-scale CNT production when compared to other common processes such as laser ablation and arc discharge. However, its potential has been limited by low-yielding and difficult preparation processes of catalyst and its support, therefore its competitiveness has been reduced. The wet-chemistry process takes advantage of current nanoparticle technology to deposit the catalyst and the catalyst support as a thin film of nanoparticles, making the protocol simple compared to electron beam evaporation and sputtering processes. In the CNT selective reactions part, this thesis studies UV irradiation of individually dispersed HiPCo CNTs that generates auto-selective reactions in the liquid phase with good control over their diameter and chirality. This technique is ideal for large-scale and continuous-process of separations of CNTs by diameter and type. Additionally, an innovative simple catalyst deposition through abrasion is demonstrated. Simple friction between the catalyst and the substrates deposit a high enough density of metal catalyst particles for successful CNT growth. This simple approach has

  16. Why large-scale seasonal streamflow forecasts are feasible

    NASA Astrophysics Data System (ADS)

    Bierkens, M. F.; Candogan Yossef, N.; Van Beek, L. P.

    2011-12-01

    Seasonal forecasts of precipitation and temperature, using either statistical or dynamic prediction, have been around for almost 2 decades. The skill of these forecasts differ both in space and time, with highest skill in areas heavily influenced by SST anomalies such as El Nino or areas where land surface properties have a major impact on e.g. Monsoon strength, such as the vegetation cover of the Sahel region or the snow cover of the Tibetan plateau. However, the skill of seasonal forecasts is limited in most regions, with anomaly correlation coefficients varying between 0.2 and 0.5 for 1-3 month precipitation totals. This raises the question whether seasonal hydrological forecasting is feasible. Here, we make the case that it is. Using the example of statistical forecasts of NAO-strength and related precipitation anomalies over Europe, we show that the skill of large-scale streamflow forecasts is generally much higher than the precipitation forecasts itself, provided that the initial state of the system is accurately estimated. In the latter case, even the precipitation climatology can produce skillful results. This is due to the inertia of the hydrological system rooted in the storage of soil moisture, groundwater and snow pack, as corroborated by a recent study using snow observations for seasonal streamflow forecasting in the Western US. These examples seem to suggest that for accurate seasonal hydrological forecasting, correct state estimation is more important than accurate seasonal meteorological forecasts. However, large-scale estimation of hydrological states is difficult and validation of large-scale hydrological models often reveals large biases in e.g. streamflow estimates. Fortunately, as shown with a validation study of the global model PCR-GLOBWB, these biases are of less importance when seasonal forecasts are evaluated in terms of their ability to reproduce anomalous flows and extreme events, i.e. by anomaly correlations or categorical quantile

  17. Quantum computation for large-scale image classification

    NASA Astrophysics Data System (ADS)

    Ruan, Yue; Chen, Hanwu; Tan, Jianing; Li, Xi

    2016-07-01

    Due to the lack of an effective quantum feature extraction method, there is currently no effective way to perform quantum image classification or recognition. In this paper, for the first time, a global quantum feature extraction method based on Schmidt decomposition is proposed. A revised quantum learning algorithm is also proposed that will classify images by computing the Hamming distance of these features. From the experimental results derived from the benchmark database Caltech 101, and an analysis of the algorithm, an effective approach to large-scale image classification is derived and proposed against the background of big data.

  18. UAV Data Processing for Large Scale Topographical Mapping

    NASA Astrophysics Data System (ADS)

    Tampubolon, W.; Reinhardt, W.

    2014-06-01

    Large scale topographical mapping in the third world countries is really a prominent challenge in geospatial industries nowadays. On one side the demand is significantly increasing while on the other hand it is constrained by limited budgets available for mapping projects. Since the advent of Act Nr.4/yr.2011 about Geospatial Information in Indonesia, large scale topographical mapping has been on high priority for supporting the nationwide development e.g. detail spatial planning. Usually large scale topographical mapping relies on conventional aerial survey campaigns in order to provide high resolution 3D geospatial data sources. Widely growing on a leisure hobby, aero models in form of the so-called Unmanned Aerial Vehicle (UAV) bring up alternative semi photogrammetric aerial data acquisition possibilities suitable for relatively small Area of Interest (AOI) i.e. <5,000 hectares. For detail spatial planning purposes in Indonesia this area size can be used as a mapping unit since it usually concentrates on the basis of sub district area (kecamatan) level. In this paper different camera and processing software systems will be further analyzed for identifying the best optimum UAV data acquisition campaign components in combination with the data processing scheme. The selected AOI is covering the cultural heritage of Borobudur Temple as one of the Seven Wonders of the World. A detailed accuracy assessment will be concentrated within the object feature of the temple at the first place. Feature compilation involving planimetric objects (2D) and digital terrain models (3D) will be integrated in order to provide Digital Elevation Models (DEM) as the main interest of the topographic mapping activity. By doing this research, incorporating the optimum amount of GCPs in the UAV photo data processing will increase the accuracy along with its high resolution in 5 cm Ground Sampling Distance (GSD). Finally this result will be used as the benchmark for alternative geospatial

  19. Inflation in de Sitter spacetime and CMB large scale anomaly

    NASA Astrophysics Data System (ADS)

    Zhao, Dong; Li, Ming-Hua; Wang, Ping; Chang, Zhe

    2015-09-01

    The influence of cosmological constant-type dark energy in the early universe is investigated. This is accommodated by a new dispersion relation in de Sitter spacetime. We perform a global fit to explore the cosmological parameter space by using the CosmoMC package with the recently released Planck TT and WMAP polarization datasets. Using the results from the global fit, we compute a new CMB temperature-temperature (TT) spectrum. The obtained TT spectrum has lower power compared with that based on the ACDM model at large scales. Supported by National Natural Science Foundation of China (11375203)

  20. Large scale obscuration and related climate effects open literature bibliography

    SciTech Connect

    Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.

    1994-05-01

    Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ``Nuclear Winter Controversy`` in the early 1980`s. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest.

  1. Large-scale genotoxicity assessments in the marine environment.

    PubMed

    Hose, J E

    1994-12-01

    There are a number of techniques for detecting genotoxicity in the marine environment, and many are applicable to large-scale field assessments. Certain tests can be used to evaluate responses in target organisms in situ while others utilize surrogate organisms exposed to field samples in short-term laboratory bioassays. Genotoxicity endpoints appear distinct from traditional toxicity endpoints, but some have chemical or ecotoxicologic correlates. One versatile end point, the frequency of anaphase aberrations, has been used in several large marine assessments to evaluate genotoxicity in the New York Bight, in sediment from San Francisco Bay, and following the Exxon Valdez oil spill. PMID:7713029

  2. Synthesis and sensing application of large scale bilayer graphene

    NASA Astrophysics Data System (ADS)

    Hong, Sung Ju; Yoo, Jung Hoon; Baek, Seung Jae; Park, Yung Woo

    2012-02-01

    We have synthesized large scale bilayer graphene by using Chemical Vapor Deposition (CVD) in atmospheric pressure. Bilayer graphene was grown by using CH4, H2 and Ar gases. The growth temperature was 1050^o. Conventional FET measurement shows ambipolar transfer characteristics. Results of Raman spectroscopy, Atomic Force microscope (AFM) and Transmission Electron Microscope (TEM) indicate the film is bilayer graphene. Especially, adlayer structure which interrupt uniformity was reduced in low methane flow condition. Furthermore, large size CVD bilayer graphene film can be investigated to apply sensor devices. By using conventional photolithography process, we have fabricated device array structure and studied sensing behavior.

  3. Implementation of Large Scale Integrated (LSI) circuit design software

    NASA Technical Reports Server (NTRS)

    Kuehlthau, R. L.; Pitts, E. R.

    1976-01-01

    Portions of the Computer Aided Design and Test system, a collection of Large Scale Integrated (LSI) circuit design programs were modified and upgraded. Major modifications were made to the Mask Analysis Program in the form of additional operating commands and file processing options. Modifications were also made to the Artwork Interactive Design System to correct some deficiencies in the original program as well as to add several new command features related to improving the response of AIDS when dealing with large files. The remaining work was concerned with updating various programs within CADAT to incorporate the silicon on sapphire silicon gate technology.

  4. Large-scale sodium spray fire code validation (SOFICOV) test

    SciTech Connect

    Jeppson, D.W.; Muhlestein, L.D.

    1985-01-01

    A large-scale, sodium, spray fire code validation test was performed in the HEDL 850-m/sup 3/ Containment System Test Facility (CSTF) as part of the Sodium Spray Fire Code Validation (SOFICOV) program. Six hundred fifty eight kilograms of sodium spray was sprayed in an air atmosphere for a period of 2400 s. The sodium spray droplet sizes and spray pattern distribution were estimated. The containment atmosphere temperature and pressure response, containment wall temperature response and sodium reaction rate with oxygen were measured. These results are compared to post-test predictions using SPRAY and NACOM computer codes.

  5. Radiative shocks on large scale lasers. Preliminary results

    NASA Astrophysics Data System (ADS)

    Leygnac, S.; Bouquet, S.; Stehle, C.; Barroso, P.; Batani, D.; Benuzzi, A.; Cathala, B.; Chièze, J.-P.; Fleury, X.; Grandjouan, N.; Grenier, J.; Hall, T.; Henry, E.; Koenig, M.; Lafon, J. P. J.; Malka, V.; Marchet, B.; Merdji, H.; Michaut, C.; Poles, L.; Thais, F.

    2001-05-01

    Radiative shocks, those structure is strongly influenced by the radiation field, are present in various astrophysical objects (circumstellar envelopes of variable stars, supernovae ...). Their modeling is very difficult and thus will take benefit from experimental informations. This approach is now possible using large scale lasers. Preliminary experiments have been performed with the nanosecond LULI laser at Ecole Polytechnique (France) in 2000. A radiative shock has been obtained in a low pressure xenon cell. The preparation of such experiments and their interpretation is performed using analytical calculations and numerical simulations.

  6. On the analysis of large-scale genomic structures.

    PubMed

    Oiwa, Nestor Norio; Goldman, Carla

    2005-01-01

    We apply methods from statistical physics (histograms, correlation functions, fractal dimensions, and singularity spectra) to characterize large-scale structure of the distribution of nucleotides along genomic sequences. We discuss the role of the extension of noncoding segments ("junk DNA") for the genomic organization, and the connection between the coding segment distribution and the high-eukaryotic chromatin condensation. The following sequences taken from GenBank were analyzed: complete genome of Xanthomonas campestri, complete genome of yeast, chromosome V of Caenorhabditis elegans, and human chromosome XVII around gene BRCA1. The results are compared with the random and periodic sequences and those generated by simple and generalized fractal Cantor sets. PMID:15858230

  7. Large-scale genotoxicity assessments in the marine environment

    SciTech Connect

    Hose, J.E.

    1994-12-01

    There are a number of techniques for detecting genotoxicity in the marine environment, and many are applicable to large-scale field assessments. Certain tests can be used to evaluate responses in target organisms in situ while others utilize surrogate organisms exposed to field samples in short-term laboratory bioassays. Genotoxicity endpoints appear distinct from traditional toxicity endpoints, but some have chemical or ecotoxicologic correlates. One versatile end point, the frequency of anaphase aberrations, has been used in several large marine assessments to evaluate genotoxicity in the New York Bight, in sediment from San Francisco Bay, and following the Exxon Valdez oil spill. 31 refs., 2 tabs.

  8. Floodplain management in Africa: Large scale analysis of flood data

    NASA Astrophysics Data System (ADS)

    Padi, Philip Tetteh; Baldassarre, Giuliano Di; Castellarin, Attilio

    2011-01-01

    To mitigate a continuously increasing flood risk in Africa, sustainable actions are urgently needed. In this context, we describe a comprehensive statistical analysis of flood data in the African continent. The study refers to quality-controlled, large and consistent databases of flood data, i.e. maximum discharge value and times series of annual maximum flows. Probabilistic envelope curves are derived for the African continent by means of a large scale regional analysis. Moreover, some initial insights on the statistical characteristics of African floods are provided. The results of this study are relevant and can be used to get some indications to support flood management in Africa.

  9. Novel algorithm of large-scale simultaneous linear equations.

    PubMed

    Fujiwara, T; Hoshi, T; Yamamoto, S; Sogabe, T; Zhang, S-L

    2010-02-24

    We review our recently developed methods of solving large-scale simultaneous linear equations and applications to electronic structure calculations both in one-electron theory and many-electron theory. This is the shifted COCG (conjugate orthogonal conjugate gradient) method based on the Krylov subspace, and the most important issue for applications is the shift equation and the seed switching method, which greatly reduce the computational cost. The applications to nano-scale Si crystals and the double orbital extended Hubbard model are presented. PMID:21386384

  10. Large Scale Composite Manufacturing for Heavy Lift Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Stavana, Jacob; Cohen, Leslie J.; Houseal, Keth; Pelham, Larry; Lort, Richard; Zimmerman, Thomas; Sutter, James; Western, Mike; Harper, Robert; Stuart, Michael

    2012-01-01

    Risk reduction for the large scale composite manufacturing is an important goal to produce light weight components for heavy lift launch vehicles. NASA and an industry team successfully employed a building block approach using low-cost Automated Tape Layup (ATL) of autoclave and Out-of-Autoclave (OoA) prepregs. Several large, curved sandwich panels were fabricated at HITCO Carbon Composites. The aluminum honeycomb core sandwich panels are segments of a 1/16th arc from a 10 meter cylindrical barrel. Lessons learned highlight the manufacturing challenges required to produce light weight composite structures such as fairings for heavy lift launch vehicles.

  11. A multilevel optimization of large-scale dynamic systems

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.; Sundareshan, M. K.

    1976-01-01

    A multilevel feedback control scheme is proposed for optimization of large-scale systems composed of a number of (not necessarily weakly coupled) subsystems. Local controllers are used to optimize each subsystem, ignoring the interconnections. Then, a global controller may be applied to minimize the effect of interconnections and improve the performance of the overall system. At the cost of suboptimal performance, this optimization strategy ensures invariance of suboptimality and stability of the systems under structural perturbations whereby subsystems are disconnected and again connected during operation.

  12. Design of a large-scale CFB boiler

    SciTech Connect

    Darling, S.; Li, S.

    1997-12-31

    Many CFB boilers sized 100--150 MWe are in operation, and several others sized 150--250 MWe are in operation or under construction. The next step for CFB technology is the 300--400 MWe size range. This paper will describe Foster Wheeler`s large-scale CFB boiler experience and the design for a 300 MWe CFB boiler. The authors will show how the design incorporates Foster Wheeler`s unique combination of extensive utility experience and CFB boiler experience. All the benefits of CFB technology which include low emissions, fuel flexibility, low maintenance and competitive cost are now available in the 300--400 MWe size range.

  13. [National Strategic Promotion for Large-Scale Clinical Cancer Research].

    PubMed

    Toyama, Senya

    2016-04-01

    The number of clinical research by clinical cancer study groups has been decreasing this year in Japan. They say the reason is the abolition of donations to the groups from the pharmaceutical companies after the Diovan scandal. But I suppose fundamental problem is that government-supported large-scale clinical cancer study system for evidence based medicine (EBM) has not been fully established. An urgent establishment of the system based on the national strategy is needed for the cancer patients and the public health promotion. PMID:27220800

  14. Large-Scale periodic solar velocities: An observational study

    NASA Technical Reports Server (NTRS)

    Dittmer, P. H.

    1977-01-01

    Observations of large-scale solar velocities were made using the mean field telescope and Babcock magnetograph of the Stanford Solar Observatory. Observations were made in the magnetically insensitive ion line at 5124 A, with light from the center (limb) of the disk right (left) circularly polarized, so that the magnetograph measures the difference in wavelength between center and limb. Computer calculations are made of the wavelength difference produced by global pulsations for spherical harmonics up to second order and of the signal produced by displacing the solar image relative to polarizing optics or diffraction grating.

  15. Laser Welding of Large Scale Stainless Steel Aircraft Structures

    NASA Astrophysics Data System (ADS)

    Reitemeyer, D.; Schultz, V.; Syassen, F.; Seefeld, T.; Vollertsen, F.

    In this paper a welding process for large scale stainless steel structures is presented. The process was developed according to the requirements of an aircraft application. Therefore, stringers are welded on a skin sheet in a t-joint configuration. The 0.6 mm thickness parts are welded with a thin disc laser, seam length up to 1920 mm are demonstrated. The welding process causes angular distortions of the skin sheet which are compensated by a subsequent laser straightening process. Based on a model straightening process parameters matching the induced welding distortion are predicted. The process combination is successfully applied to stringer stiffened specimens.

  16. Enabling Large-Scale Biomedical Analysis in the Cloud

    PubMed Central

    Lin, Ying-Chih; Yu, Chin-Sheng; Lin, Yen-Jen

    2013-01-01

    Recent progress in high-throughput instrumentations has led to an astonishing growth in both volume and complexity of biomedical data collected from various sources. The planet-size data brings serious challenges to the storage and computing technologies. Cloud computing is an alternative to crack the nut because it gives concurrent consideration to enable storage and high-performance computing on large-scale data. This work briefly introduces the data intensive computing system and summarizes existing cloud-based resources in bioinformatics. These developments and applications would facilitate biomedical research to make the vast amount of diversification data meaningful and usable. PMID:24288665

  17. Generation of Large-Scale Winds in Horizontally Anisotropic Convection.

    PubMed

    von Hardenberg, J; Goluskin, D; Provenzale, A; Spiegel, E A

    2015-09-25

    We simulate three-dimensional, horizontally periodic Rayleigh-Bénard convection, confined between free-slip horizontal plates and rotating about a distant horizontal axis. When both the temperature difference between the plates and the rotation rate are sufficiently large, a strong horizontal wind is generated that is perpendicular to both the rotation vector and the gravity vector. The wind is turbulent, large-scale, and vertically sheared. Horizontal anisotropy, engendered here by rotation, appears necessary for such wind generation. Most of the kinetic energy of the flow resides in the wind, and the vertical turbulent heat flux is much lower on average than when there is no wind. PMID:26451558

  18. Large-Scale Purification of Peroxisomes for Preparative Applications.

    PubMed

    Cramer, Jana; Effelsberg, Daniel; Girzalsky, Wolfgang; Erdmann, Ralf

    2015-09-01

    This protocol is designed for large-scale isolation of highly purified peroxisomes from Saccharomyces cerevisiae using two consecutive density gradient centrifugations. Instructions are provided for harvesting up to 60 g of oleic acid-induced yeast cells for the preparation of spheroplasts and generation of organellar pellets (OPs) enriched in peroxisomes and mitochondria. The OPs are loaded onto eight continuous 36%-68% (w/v) sucrose gradients. After centrifugation, the peak peroxisomal fractions are determined by measurement of catalase activity. These fractions are subsequently pooled and subjected to a second density gradient centrifugation using 20%-40% (w/v) Nycodenz. PMID:26330621

  19. Enabling large-scale biomedical analysis in the cloud.

    PubMed

    Lin, Ying-Chih; Yu, Chin-Sheng; Lin, Yen-Jen

    2013-01-01

    Recent progress in high-throughput instrumentations has led to an astonishing growth in both volume and complexity of biomedical data collected from various sources. The planet-size data brings serious challenges to the storage and computing technologies. Cloud computing is an alternative to crack the nut because it gives concurrent consideration to enable storage and high-performance computing on large-scale data. This work briefly introduces the data intensive computing system and summarizes existing cloud-based resources in bioinformatics. These developments and applications would facilitate biomedical research to make the vast amount of diversification data meaningful and usable. PMID:24288665

  20. Monochromatic waves induced by large-scale parametric forcing.

    PubMed

    Nepomnyashchy, A; Abarzhi, S I

    2010-03-01

    We study the formation and stability of monochromatic waves induced by large-scale modulations in the framework of the complex Ginzburg-Landau equation with parametric nonresonant forcing dependent on the spatial coordinate. In the limiting case of forcing with very large characteristic length scale, analytical solutions for the equation are found and conditions of their existence are outlined. Stability analysis indicates that the interval of existence of a monochromatic wave can contain a subinterval where the wave is stable. We discuss potential applications of the model in rheology, fluid dynamics, and optics. PMID:20365907

  1. POLARIZED LINE FORMATION IN MULTI-DIMENSIONAL MEDIA. I. DECOMPOSITION OF STOKES PARAMETERS IN ARBITRARY GEOMETRIES

    SciTech Connect

    Anusha, L. S.; Nagendra, K. N.

    2011-01-01

    The solution of the polarized line radiative transfer (RT) equation in multi-dimensional geometries has been rarely addressed and only under the approximation that the changes of frequencies at each scattering are uncorrelated (complete frequency redistribution). With the increase in the resolution power of telescopes, being able to handle RT in multi-dimensional structures becomes absolutely necessary. In the present paper, our first aim is to formulate the polarized RT equation for resonance scattering in multi-dimensional media, using the elegant technique of irreducible spherical tensors T{sub Q}{sup K}(i, {Omega}). Our second aim is to develop a numerical method of a solution based on the polarized approximate lambda iteration (PALI) approach. We consider both complete frequency redistribution and partial frequency redistribution (PRD) in the line scattering. In a multi-dimensional geometry, the radiation field is non-axisymmetrical even in the absence of a symmetry breaking mechanism such as an oriented magnetic field. We generalize here to the three-dimensional (3D) case, the decomposition technique developed for the Hanle effect in a one-dimensional (1D) medium which allows one to represent the Stokes parameters I, Q, U by a set of six cylindrically symmetrical functions. The scattering phase matrix is expressed in terms of T{sub Q}{sup K}(i, {Omega}) (i=0,1,2, K=0,1,2, -K {<=} Q {<=} +K), with {Omega} being the direction of the outgoing ray. Starting from the definition of the source vector, we show that it can be represented in terms of six components S{sup K}{sub Q} independent of {Omega}. The formal solution of the multi-dimensional transfer equation shows that the Stokes parameters can also be expanded in terms of T{sub Q}{sup K}(i, {Omega}). Because of the 3D geometry, the expansion coefficients I{sup K}{sub Q} remain {Omega}-dependent. We show that each I{sup K}{sub Q} satisfies a simple transfer equation with a source term S{sup K}{sub Q} and that

  2. Scaling up explanation generation: Large-scale knowledge bases and empirical studies

    SciTech Connect

    Lester, J.C.; Porter, B.W.

    1996-12-31

    To explain complex phenomena, an explanation system must be able to select information from a formal representation of domain knowledge, organize the selected information into multisentential discourse plans, and realize the discourse plans in text. Although recent years have witnessed significant progress in the development of sophisticated computational mechanisms for explanation, empirical results have been limited. This paper reports on a seven year effort to empirically study explanation generation from semantically rich, large-scale knowledge bases. We first describe Knight, a robust explanation system that constructs multi-sentential and multi-paragraph explanations from the Biology Knowledge Base, a large-scale knowledge base in the domain of botanical anatomy, physiology, and development. We then introduce the Two Panel evaluation methodology and describe how Knight`s performance was assessed with this methodology in the most extensive empirical evaluation conducted on an explanation system. In this evaluation, Knight scored within {open_quotes}half a grade{close_quote} of domain experts, and its performance exceeded that of one of the domain experts.

  3. Large-Scale Transportation Network Congestion Evolution Prediction Using Deep Learning Theory

    PubMed Central

    Ma, Xiaolei; Yu, Haiyang; Wang, Yunpeng; Wang, Yinhai

    2015-01-01

    Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS) and Internet of Things (IoT), transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS) data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU)-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation. PMID:25780910

  4. Large-scale transportation network congestion evolution prediction using deep learning theory.

    PubMed

    Ma, Xiaolei; Yu, Haiyang; Wang, Yunpeng; Wang, Yinhai

    2015-01-01

    Understanding how congestion at one location can cause ripples throughout large-scale transportation network is vital for transportation researchers and practitioners to pinpoint traffic bottlenecks for congestion mitigation. Traditional studies rely on either mathematical equations or simulation techniques to model traffic congestion dynamics. However, most of the approaches have limitations, largely due to unrealistic assumptions and cumbersome parameter calibration process. With the development of Intelligent Transportation Systems (ITS) and Internet of Things (IoT), transportation data become more and more ubiquitous. This triggers a series of data-driven research to investigate transportation phenomena. Among them, deep learning theory is considered one of the most promising techniques to tackle tremendous high-dimensional data. This study attempts to extend deep learning theory into large-scale transportation network analysis. A deep Restricted Boltzmann Machine and Recurrent Neural Network architecture is utilized to model and predict traffic congestion evolution based on Global Positioning System (GPS) data from taxi. A numerical study in Ningbo, China is conducted to validate the effectiveness and efficiency of the proposed method. Results show that the prediction accuracy can achieve as high as 88% within less than 6 minutes when the model is implemented in a Graphic Processing Unit (GPU)-based parallel computing environment. The predicted congestion evolution patterns can be visualized temporally and spatially through a map-based platform to identify the vulnerable links for proactive congestion mitigation. PMID:25780910

  5. Formation and disruption of tonotopy in a large-scale model of the auditory cortex.

    PubMed

    Tomková, Markéta; Tomek, Jakub; Novák, Ondřej; Zelenka, Ondřej; Syka, Josef; Brom, Cyril

    2015-10-01

    There is ample experimental evidence describing changes of tonotopic organisation in the auditory cortex due to environmental factors. In order to uncover the underlying mechanisms, we designed a large-scale computational model of the auditory cortex. The model has up to 100 000 Izhikevich's spiking neurons of 17 different types, almost 21 million synapses, which are evolved according to Spike-Timing-Dependent Plasticity (STDP) and have an architecture akin to existing observations. Validation of the model revealed alternating synchronised/desynchronised states and different modes of oscillatory activity. We provide insight into these phenomena via analysing the activity of neuronal subtypes and testing different causal interventions into the simulation. Our model is able to produce experimental predictions on a cell type basis. To study the influence of environmental factors on the tonotopy, different types of auditory stimulations during the evolution of the network were modelled and compared. We found that strong white noise resulted in completely disrupted tonotopy, which is consistent with in vivo experimental observations. Stimulation with pure tones or spontaneous activity led to a similar degree of tonotopy as in the initial state of the network. Interestingly, weak white noise led to a substantial increase in tonotopy. As the STDP was the only mechanism of plasticity in our model, our results suggest that STDP is a sufficient condition for the emergence and disruption of tonotopy under various types of stimuli. The presented large-scale model of the auditory cortex and the core simulator, SUSNOIMAC, have been made publicly available. PMID:26344164

  6. Large-scale interaction of the solar wind with comets Halley and Giacobini-Zinner

    NASA Technical Reports Server (NTRS)

    Brandt, John C.; Niedner, Malcolm B., Jr.

    1987-01-01

    In-situ measurements of comets Halley and Giacobini-Zinner have confirmed the accepted basic physics of comet/solar wind interaction. The solar wind magnetic field is captured by the comet through the mechanism of field-line loading by cometary ions and the field lines drape around the cometary ionosphere. With this basic model in hand, the large-scale structure of the plasma tail as revealed by submissions to the Large Scale Phenomena Network of the International Halley Watch is reviewed. The turn-on and turn-off of plasma activity seem consistent with theory. Some 16 obvious disconnection events (DEs) have been recorded. Preliminary results showed agreement with the sector-boundary model; a detailed analysis of all DEs will be required in order to make a definitive statement. A study of plasma activity around the time of the VEGA encounters provides strong support for the sector-boundary model and illustrates once again the power of simultaneous remote and in-situ measurements.

  7. Topographically Engineered Large Scale Nanostructures for Plasmonic Biosensing

    NASA Astrophysics Data System (ADS)

    Xiao, Bo; Pradhan, Sangram K.; Santiago, Kevin C.; Rutherford, Gugu N.; Pradhan, Aswini K.

    2016-04-01

    We demonstrate that a nanostructured metal thin film can achieve enhanced transmission efficiency and sharp resonances and use a large-scale and high-throughput nanofabrication technique for the plasmonic structures. The fabrication technique combines the features of nanoimprint and soft lithography to topographically construct metal thin films with nanoscale patterns. Metal nanogratings developed using this method show significantly enhanced optical transmission (up to a one-order-of-magnitude enhancement) and sharp resonances with full width at half maximum (FWHM) of ~15nm in the zero-order transmission using an incoherent white light source. These nanostructures are sensitive to the surrounding environment, and the resonance can shift as the refractive index changes. We derive an analytical method using a spatial Fourier transformation to understand the enhancement phenomenon and the sensing mechanism. The use of real-time monitoring of protein-protein interactions in microfluidic cells integrated with these nanostructures is demonstrated to be effective for biosensing. The perpendicular transmission configuration and large-scale structures provide a feasible platform without sophisticated optical instrumentation to realize label-free surface plasmon resonance (SPR) sensing.

  8. THE LARGE-SCALE MAGNETIC FIELDS OF THIN ACCRETION DISKS

    SciTech Connect

    Cao Xinwu; Spruit, Hendrik C. E-mail: henk@mpa-garching.mpg.de

    2013-03-10

    Large-scale magnetic field threading an accretion disk is a key ingredient in the jet formation model. The most attractive scenario for the origin of such a large-scale field is the advection of the field by the gas in the accretion disk from the interstellar medium or a companion star. However, it is realized that outward diffusion of the accreted field is fast compared with the inward accretion velocity in a geometrically thin accretion disk if the value of the Prandtl number P{sub m} is around unity. In this work, we revisit this problem considering the angular momentum of the disk to be removed predominantly by the magnetically driven outflows. The radial velocity of the disk is significantly increased due to the presence of the outflows. Using a simplified model for the vertical disk structure, we find that even moderately weak fields can cause sufficient angular momentum loss via a magnetic wind to balance outward diffusion. There are two equilibrium points, one at low field strengths corresponding to a plasma-beta at the midplane of order several hundred, and one for strong accreted fields, {beta} {approx} 1. We surmise that the first is relevant for the accretion of weak, possibly external, fields through the outer parts of the disk, while the latter one could explain the tendency, observed in full three-dimensional numerical simulations, of strong flux bundles at the centers of disk to stay confined in spite of strong magnetororational instability turbulence surrounding them.

  9. Development of large-scale functional brain networks in children.

    PubMed

    Supekar, Kaustubh; Musen, Mark; Menon, Vinod

    2009-07-01

    The ontogeny of large-scale functional organization of the human brain is not well understood. Here we use network analysis of intrinsic functional connectivity to characterize the organization of brain networks in 23 children (ages 7-9 y) and 22 young-adults (ages 19-22 y). Comparison of network properties, including path-length, clustering-coefficient, hierarchy, and regional connectivity, revealed that although children and young-adults' brains have similar "small-world" organization at the global level, they differ significantly in hierarchical organization and interregional connectivity. We found that subcortical areas were more strongly connected with primary sensory, association, and paralimbic areas in children, whereas young-adults showed stronger cortico-cortical connectivity between paralimbic, limbic, and association areas. Further, combined analysis of functional connectivity with wiring distance measures derived from white-matter fiber tracking revealed that the development of large-scale brain networks is characterized by weakening of short-range functional connectivity and strengthening of long-range functional connectivity. Importantly, our findings show that the dynamic process of over-connectivity followed by pruning, which rewires connectivity at the neuronal level, also operates at the systems level, helping to reconfigure and rebalance subcortical and paralimbic connectivity in the developing brain. Our study demonstrates the usefulness of network analysis of brain connectivity to elucidate key principles underlying functional brain maturation, paving the way for novel studies of disrupted brain connectivity in neurodevelopmental disorders such as autism. PMID:19621066

  10. Topographically Engineered Large Scale Nanostructures for Plasmonic Biosensing.

    PubMed

    Xiao, Bo; Pradhan, Sangram K; Santiago, Kevin C; Rutherford, Gugu N; Pradhan, Aswini K

    2016-01-01

    We demonstrate that a nanostructured metal thin film can achieve enhanced transmission efficiency and sharp resonances and use a large-scale and high-throughput nanofabrication technique for the plasmonic structures. The fabrication technique combines the features of nanoimprint and soft lithography to topographically construct metal thin films with nanoscale patterns. Metal nanogratings developed using this method show significantly enhanced optical transmission (up to a one-order-of-magnitude enhancement) and sharp resonances with full width at half maximum (FWHM) of ~15nm in the zero-order transmission using an incoherent white light source. These nanostructures are sensitive to the surrounding environment, and the resonance can shift as the refractive index changes. We derive an analytical method using a spatial Fourier transformation to understand the enhancement phenomenon and the sensing mechanism. The use of real-time monitoring of protein-protein interactions in microfluidic cells integrated with these nanostructures is demonstrated to be effective for biosensing. The perpendicular transmission configuration and large-scale structures provide a feasible platform without sophisticated optical instrumentation to realize label-free surface plasmon resonance (SPR) sensing. PMID:27072067

  11. NIC-based Reduction Algorithms for Large-scale Clusters

    SciTech Connect

    Petrini, F; Moody, A T; Fernandez, J; Frachtenberg, E; Panda, D K

    2004-07-30

    Efficient algorithms for reduction operations across a group of processes are crucial for good performance in many large-scale, parallel scientific applications. While previous algorithms limit processing to the host CPU, we utilize the programmable processors and local memory available on modern cluster network interface cards (NICs) to explore a new dimension in the design of reduction algorithms. In this paper, we present the benefits and challenges, design issues and solutions, analytical models, and experimental evaluations of a family of NIC-based reduction algorithms. Performance and scalability evaluations were conducted on the ASCI Linux Cluster (ALC), a 960-node, 1920-processor machine at Lawrence Livermore National Laboratory, which uses the Quadrics QsNet interconnect. We find NIC-based reductions on modern interconnects to be more efficient than host-based implementations in both scalability and consistency. In particular, at large-scale--1812 processes--NIC-based reductions of small integer and floating-point arrays provided respective speedups of 121% and 39% over the host-based, production-level MPI implementation.

  12. Alignment of quasar polarizations with large-scale structures

    NASA Astrophysics Data System (ADS)

    Hutsemékers, D.; Braibant, L.; Pelgrims, V.; Sluse, D.

    2014-12-01

    We have measured the optical linear polarization of quasars belonging to Gpc scale quasar groups at redshift z ~ 1.3. Out of 93 quasars observed, 19 are significantly polarized. We found that quasar polarization vectors are either parallel or perpendicular to the directions of the large-scale structures to which they belong. Statistical tests indicate that the probability that this effect can be attributed to randomly oriented polarization vectors is on the order of 1%. We also found that quasars with polarization perpendicular to the host structure preferentially have large emission line widths while objects with polarization parallel to the host structure preferentially have small emission line widths. Considering that quasar polarization is usually either parallel or perpendicular to the accretion disk axis depending on the inclination with respect to the line of sight, and that broader emission lines originate from quasars seen at higher inclinations, we conclude that quasar spin axes are likely parallel to their host large-scale structures. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 092.A-0221.Table 1 is available in electronic form at http://www.aanda.org

  13. Evaluating Unmanned Aerial Platforms for Cultural Heritage Large Scale Mapping

    NASA Astrophysics Data System (ADS)

    Georgopoulos, A.; Oikonomou, C.; Adamopoulos, E.; Stathopoulou, E. K.

    2016-06-01

    When it comes to large scale mapping of limited areas especially for cultural heritage sites, things become critical. Optical and non-optical sensors are developed to such sizes and weights that can be lifted by such platforms, like e.g. LiDAR units. At the same time there is an increase in emphasis on solutions that enable users to get access to 3D information faster and cheaper. Considering the multitude of platforms, cameras and the advancement of algorithms in conjunction with the increase of available computing power this challenge should and indeed is further investigated. In this paper a short review of the UAS technologies today is attempted. A discussion follows as to their applicability and advantages, depending on their specifications, which vary immensely. The on-board cameras available are also compared and evaluated for large scale mapping. Furthermore a thorough analysis, review and experimentation with different software implementations of Structure from Motion and Multiple View Stereo algorithms, able to process such dense and mostly unordered sequence of digital images is also conducted and presented. As test data set, we use a rich optical and thermal data set from both fixed wing and multi-rotor platforms over an archaeological excavation with adverse height variations and using different cameras. Dense 3D point clouds, digital terrain models and orthophotos have been produced and evaluated for their radiometric as well as metric qualities.

  14. Exploring Cloud Computing for Large-scale Scientific Applications

    SciTech Connect

    Lin, Guang; Han, Binh; Yin, Jian; Gorton, Ian

    2013-06-27

    This paper explores cloud computing for large-scale data-intensive scientific applications. Cloud computing is attractive because it provides hardware and software resources on-demand, which relieves the burden of acquiring and maintaining a huge amount of resources that may be used only once by a scientific application. However, unlike typical commercial applications that often just requires a moderate amount of ordinary resources, large-scale scientific applications often need to process enormous amount of data in the terabyte or even petabyte range and require special high performance hardware with low latency connections to complete computation in a reasonable amount of time. To address these challenges, we build an infrastructure that can dynamically select high performance computing hardware across institutions and dynamically adapt the computation to the selected resources to achieve high performance. We have also demonstrated the effectiveness of our infrastructure by building a system biology application and an uncertainty quantification application for carbon sequestration, which can efficiently utilize data and computation resources across several institutions.

  15. The combustion behavior of large scale lithium titanate battery

    PubMed Central

    Huang, Peifeng; Wang, Qingsong; Li, Ke; Ping, Ping; Sun, Jinhua

    2015-01-01

    Safety problem is always a big obstacle for lithium battery marching to large scale application. However, the knowledge on the battery combustion behavior is limited. To investigate the combustion behavior of large scale lithium battery, three 50 Ah Li(NixCoyMnz)O2/Li4Ti5O12 batteries under different state of charge (SOC) were heated to fire. The flame size variation is depicted to analyze the combustion behavior directly. The mass loss rate, temperature and heat release rate are used to analyze the combustion behavior in reaction way deeply. Based on the phenomenon, the combustion process is divided into three basic stages, even more complicated at higher SOC with sudden smoke flow ejected. The reason is that a phase change occurs in Li(NixCoyMnz)O2 material from layer structure to spinel structure. The critical temperatures of ignition are at 112–121°C on anode tab and 139 to 147°C on upper surface for all cells. But the heating time and combustion time become shorter with the ascending of SOC. The results indicate that the battery fire hazard increases with the SOC. It is analyzed that the internal short and the Li+ distribution are the main causes that lead to the difference. PMID:25586064

  16. Large scale reconstruction of the solar coronal magnetic field

    NASA Astrophysics Data System (ADS)

    Amari, T.; Aly, J.-J.; Chopin, P.; Canou, A.; Mikic, Z.

    2014-10-01

    It is now becoming necessary to access the global magnetic structure of the solar low corona at a large scale in order to understand its physics and more particularly the conditions of energization of the magnetic fields and the multiple connections between distant active regions (ARs) which may trigger eruptive events in an almost coordinated way. Various vector magnetographs, either on board spacecraft or ground-based, currently allow to obtain vector synoptic maps, composite magnetograms made of multiple interactive ARs, and full disk magnetograms. We present a method recently developed for reconstructing the global solar coronal magnetic field as a nonlinear force-free magnetic field in spherical geometry, generalizing our previous results in Cartesian geometry. This method is implemented in the new code XTRAPOLS, which thus appears as an extension of our active region scale code XTRAPOL. We apply our method by performing a reconstruction at a specific time for which we dispose of a set of composite data constituted of a vector magnetogram provided by SDO/HMI, embedded in a larger full disk vector magnetogram provided by the same instrument, finally embedded in a synoptic map provided by SOLIS. It turns out to be possible to access the large scale structure of the corona and its energetic contents, and also the AR scale, at which we recover the presence of a twisted flux rope in equilibrium.

  17. High Speed Networking and Large-scale Simulation in Geodynamics

    NASA Technical Reports Server (NTRS)

    Kuang, Weijia; Gary, Patrick; Seablom, Michael; Truszkowski, Walt; Odubiyi, Jide; Jiang, Weiyuan; Liu, Dong

    2004-01-01

    Large-scale numerical simulation has been one of the most important approaches for understanding global geodynamical processes. In this approach, peta-scale floating point operations (pflops) are often required to carry out a single physically-meaningful numerical experiment. For example, to model convective flow in the Earth's core and generation of the geomagnetic field (geodynamo), simulation for one magnetic free-decay time (approximately 15000 years) with a modest resolution of 150 in three spatial dimensions would require approximately 0.2 pflops. If such a numerical model is used to predict geomagnetic secular variation over decades and longer, with e.g. an ensemble Kalman filter assimilation approach, approximately 30 (and perhaps more) independent simulations of similar scales would be needed for one data assimilation analysis. Obviously, such a simulation would require an enormous computing resource that exceeds the capacity of a single facility currently available at our disposal. One solution is to utilize a very fast network (e.g. 10Gb optical networks) and available middleware (e.g. Globus Toolkit) to allocate available but often heterogeneous resources for such large-scale computing efforts. At NASA GSFC, we are experimenting with such an approach by networking several clusters for geomagnetic data assimilation research. We shall present our initial testing results in the meeting.

  18. Large-scale anisotropy in stably stratified rotating flows

    SciTech Connect

    Marino, R.; Mininni, P. D.; Rosenberg, D. L.; Pouquet, A.

    2014-08-28

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up to $1024^3$ grid points and Reynolds numbers of $\\approx 1000$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $\\sim k_\\perp^{-5/3}$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.

  19. Online education in a large scale rehabilitation institution.

    PubMed

    Mazzoleni, M Cristina; Rognoni, Carla; Pagani, Marco; Imbriani, Marcello

    2012-01-01

    Large scale multiple venue institutions face problems when delivering educations to their healthcare staff. The present study is aimed at evaluating the feasibility of relying on e-learning for at least part of the training of the Salvatore Maugeri Foundation healthcare staff. The paper reports the results of the delivery of e-learning courses to the personnel during a span of time of 7 months in order to assess the attitude to online courses attendance, the proportion between administered online education and administered traditional education, the economic sustainability of the online education delivery process. 37% of the total healthcare staff have attended online courses and 46% of nurses have proved to be the very active. The ratio between total number of credits and total number of courses for online and traditional education are respectively 18268/5 and 20354/96. These results point out that eLearning is not at all a niche tool used (or usable) by a limited number of people. Economic sustainability, assessed via personnel work hour saving, has been demonstrated. When distance learning is appropriate, online education is an effective, sustainable, well accepted mean to support and promote healthcare staff's education in a large scale institution. PMID:22491113

  20. Systematic renormalization of the effective theory of Large Scale Structure

    NASA Astrophysics Data System (ADS)

    Akbar Abolhasani, Ali; Mirbabayi, Mehrdad; Pajer, Enrico

    2016-05-01

    A perturbative description of Large Scale Structure is a cornerstone of our understanding of the observed distribution of matter in the universe. Renormalization is an essential and defining step to make this description physical and predictive. Here we introduce a systematic renormalization procedure, which neatly associates counterterms to the UV-sensitive diagrams order by order, as it is commonly done in quantum field theory. As a concrete example, we renormalize the one-loop power spectrum and bispectrum of both density and velocity. In addition, we present a series of results that are valid to all orders in perturbation theory. First, we show that while systematic renormalization requires temporally non-local counterterms, in practice one can use an equivalent basis made of local operators. We give an explicit prescription to generate all counterterms allowed by the symmetries. Second, we present a formal proof of the well-known general argument that the contribution of short distance perturbations to large scale density contrast δ and momentum density π(k) scale as k2 and k, respectively. Third, we demonstrate that the common practice of introducing counterterms only in the Euler equation when one is interested in correlators of δ is indeed valid to all orders.

  1. The large-scale morphology of IRAS galaxies

    NASA Technical Reports Server (NTRS)

    Babul, Arif; Starkman, Glenn D.; Strauss, Michael A.

    1993-01-01

    At present, visual inspection is the only method for comparing the large-scale morphologies in the distribution of galaxies to those in model universes generated by N-body simulations. To remedy the situation, we have developed a set of three structure functions (S1, S2, S3) that quantify the degree of large-scale prolateness, oblateness, and sphericity/uniformity of a 3-D particle distribution and have applied them to a volume-limited (less than = 4000 km/s) sample of 699 IRAS galaxies with f sub 60 greater than 1.2 Jy. To determine the structure functions, we randomly select 500 galaxies as origins of spherical windows of radius R sub w, locate the centroid of the galaxies in the window (assuming all galaxies have equal mass) and then, compute the principal moments of inertia (I sub 1, I sub 2, I sub 3) about the centroid. Each S sub i is a function of (I sub 2)/(I sub 1) and (I sub 3)/I sub 1). S1, S2, and S3 tend to unity for highly prolate, oblate, and uniform distributions, respectively and tend to zero otherwise. The resulting 500 values of S sub i at each scale R sub w are used to construct a histogram.

  2. Simulating the large-scale structure of HI intensity maps

    NASA Astrophysics Data System (ADS)

    Seehars, Sebastian; Paranjape, Aseem; Witzemann, Amadeus; Refregier, Alexandre; Amara, Adam; Akeret, Joel

    2016-03-01

    Intensity mapping of neutral hydrogen (HI) is a promising observational probe of cosmology and large-scale structure. We present wide field simulations of HI intensity maps based on N-body simulations of a 2.6 Gpc / h box with 20483 particles (particle mass 1.6 × 1011 Msolar / h). Using a conditional mass function to populate the simulated dark matter density field with halos below the mass resolution of the simulation (108 Msolar / h < Mhalo < 1013 Msolar / h), we assign HI to those halos according to a phenomenological halo to HI mass relation. The simulations span a redshift range of 0.35 lesssim z lesssim 0.9 in redshift bins of width Δ z ≈ 0.05 and cover a quarter of the sky at an angular resolution of about 7'. We use the simulated intensity maps to study the impact of non-linear effects and redshift space distortions on the angular clustering of HI. Focusing on the autocorrelations of the maps, we apply and compare several estimators for the angular power spectrum and its covariance. We verify that these estimators agree with analytic predictions on large scales and study the validity of approximations based on Gaussian random fields, particularly in the context of the covariance. We discuss how our results and the simulated maps can be useful for planning and interpreting future HI intensity mapping surveys.

  3. IP over optical multicasting for large-scale video delivery

    NASA Astrophysics Data System (ADS)

    Jin, Yaohui; Hu, Weisheng; Sun, Weiqiang; Guo, Wei

    2007-11-01

    In the IPTV systems, multicasting will play a crucial role in the delivery of high-quality video services, which can significantly improve bandwidth efficiency. However, the scalability and the signal quality of current IPTV can barely compete with the existing broadcast digital TV systems since it is difficult to implement large-scale multicasting with end-to-end guaranteed quality of service (QoS) in packet-switched IP network. China 3TNet project aimed to build a high performance broadband trial network to support large-scale concurrent streaming media and interactive multimedia services. The innovative idea of 3TNet is that an automatic switched optical networks (ASON) with the capability of dynamic point-to-multipoint (P2MP) connections replaces the conventional IP multicasting network in the transport core, while the edge remains an IP multicasting network. In this paper, we will introduce the network architecture and discuss challenges in such IP over Optical multicasting for video delivery.

  4. Maestro: an orchestration framework for large-scale WSN simulations.

    PubMed

    Riliskis, Laurynas; Osipov, Evgeny

    2014-01-01

    Contemporary wireless sensor networks (WSNs) have evolved into large and complex systems and are one of the main technologies used in cyber-physical systems and the Internet of Things. Extensive research on WSNs has led to the development of diverse solutions at all levels of software architecture, including protocol stacks for communications. This multitude of solutions is due to the limited computational power and restrictions on energy consumption that must be accounted for when designing typical WSN systems. It is therefore challenging to develop, test and validate even small WSN applications, and this process can easily consume significant resources. Simulations are inexpensive tools for testing, verifying and generally experimenting with new technologies in a repeatable fashion. Consequently, as the size of the systems to be tested increases, so does the need for large-scale simulations. This article describes a tool called Maestro for the automation of large-scale simulation and investigates the feasibility of using cloud computing facilities for such task. Using tools that are built into Maestro, we demonstrate a feasible approach for benchmarking cloud infrastructure in order to identify cloud Virtual Machine (VM)instances that provide an optimal balance of performance and cost for a given simulation. PMID:24647123

  5. Simulating subsurface heterogeneity improves large-scale water resources predictions

    NASA Astrophysics Data System (ADS)

    Hartmann, A. J.; Gleeson, T.; Wagener, T.; Wada, Y.

    2014-12-01

    Heterogeneity is abundant everywhere across the hydrosphere. It exists in the soil, the vadose zone and the groundwater. In large-scale hydrological models, subsurface heterogeneity is usually not considered. Instead average or representative values are chosen for each of the simulated grid cells, not incorporating any sub-grid variability. This may lead to unreliable predictions when the models are used for assessing future water resources availability, floods or droughts, or when they are used for recommendations for more sustainable water management. In this study we use a novel, large-scale model that takes into account sub-grid heterogeneity for the simulation of groundwater recharge by using statistical distribution functions. We choose all regions over Europe that are comprised by carbonate rock (~35% of the total area) because the well understood dissolvability of carbonate rocks (karstification) allows for assessing the strength of subsurface heterogeneity. Applying the model with historic data and future climate projections we show that subsurface heterogeneity lowers the vulnerability of groundwater recharge on hydro-climatic extremes and future changes of climate. Comparing our simulations with the PCR-GLOBWB model we can quantify the deviations of simulations for different sub-regions in Europe.

  6. Evaluating large scale orthophotos derived from high resolution satellite imagery

    NASA Astrophysics Data System (ADS)

    Ioannou, Maria Teresa; Georgopoulos, Andreas

    2013-08-01

    For the purposes of a research project, for the compilation of the archaeological and environmental digital map of the island of Antiparos, the production of updated large scale orthophotos was required. Hence suitable stereoscopic high resolution satellite imagery was acquired. Two Geoeye-1 stereopairs were enough to cover this small island of the Cyclades complex in the central Aegean. For the orientation of the two stereopairs numerous ground control points were determined using GPS observations. Some of them would also serve as check points. The images were processed using commercial stereophotogrammetric software suitable to process satellite stereoscopic imagery. The results of the orientations are evaluated and the digital terrain model was produced using automated and manual procedures. The DTM was checked both internally and externally with comparison to other available DTMs. In this paper the procedures for producing the desired orthophotography are critically presented and the final result is compared and evaluated for its accuracy, completeness and efficiency. The final product is also compared against the orthophotography produced by Ktimatologio S.A. using aerial images in 2007. The orthophotography produced has been evaluated metrically using the available check points, while qualitative evaluation has also been performed. The results are presented and a critical approach for the usability of satellite imagery for the production of large scale orthophotos is attempted.

  7. Large-Scale Low-Boom Inlet Test Overview

    NASA Technical Reports Server (NTRS)

    Hirt, Stefanie

    2011-01-01

    This presentation provides a high level overview of the Large-Scale Low-Boom Inlet Test and was presented at the Fundamental Aeronautics 2011 Technical Conference. In October 2010 a low-boom supersonic inlet concept with flow control was tested in the 8'x6' supersonic wind tunnel at NASA Glenn Research Center (GRC). The primary objectives of the test were to evaluate the inlet stability and operability of a large-scale low-boom supersonic inlet concept by acquiring performance and flowfield validation data, as well as evaluate simple, passive, bleedless inlet boundary layer control options. During this effort two models were tested: a dual stream inlet intended to model potential flight hardware and a single stream design to study a zero-degree external cowl angle and to permit surface flow visualization of the vortex generator flow control on the internal centerbody surface. The tests were conducted by a team of researchers from NASA GRC, Gulfstream Aerospace Corporation, University of Illinois at Urbana-Champaign, and the University of Virginia

  8. New methods for large scale local and global optimization

    NASA Astrophysics Data System (ADS)

    Byrd, Richard; Schnabel, Robert

    1994-07-01

    We have pursued all three topics described in the proposal during this research period. A large amount of effort has gone into the development of large scale global optimization methods for molecular configuration problems. We have developed new general purpose methods that combine efficient stochastic global optimization techniques with several new, more deterministic techniques that account for most of the computational effort, and the success, of the methods. We have applied our methods to Lennard-Jones problems with up to 75 atoms, to water clusters with up to 31, molecules, and polymers with up to 58 amino acids. The results appear to be the best so far by general purpose optimization methods, and appear to be leading to some interesting chemistry issues. Our research on the second topic, tensor methods, has addressed several areas. We have designed and implemented tensor methods for large sparse systems of nonlinear equations and nonlinear least squares, and have obtained excellent test results on a wide range of problems. We have also developed new tensor methods for nonlinearly constrained optimization problem, and have obtained promising theoretical and preliminary computational results. Finally, on the third topic, limited memory methods for large scale optimization, we have developed and implemented new, extremely efficient limited memory methods for bound constrained problems, and new limited memory trust regions methods, both using our-recently developed compact representations for quasi-Newton matrices. Computational test results for both methods are promising.

  9. Maestro: An Orchestration Framework for Large-Scale WSN Simulations

    PubMed Central

    Riliskis, Laurynas; Osipov, Evgeny

    2014-01-01

    Contemporary wireless sensor networks (WSNs) have evolved into large and complex systems and are one of the main technologies used in cyber-physical systems and the Internet of Things. Extensive research on WSNs has led to the development of diverse solutions at all levels of software architecture, including protocol stacks for communications. This multitude of solutions is due to the limited computational power and restrictions on energy consumption that must be accounted for when designing typical WSN systems. It is therefore challenging to develop, test and validate even small WSN applications, and this process can easily consume significant resources. Simulations are inexpensive tools for testing, verifying and generally experimenting with new technologies in a repeatable fashion. Consequently, as the size of the systems to be tested increases, so does the need for large-scale simulations. This article describes a tool called Maestro for the automation of large-scale simulation and investigates the feasibility of using cloud computing facilities for such task. Using tools that are built into Maestro, we demonstrate a feasible approach for benchmarking cloud infrastructure in order to identify cloud Virtual Machine (VM)instances that provide an optimal balance of performance and cost for a given simulation. PMID:24647123

  10. Power suppression at large scales in string inflation

    SciTech Connect

    Cicoli, Michele; Downes, Sean; Dutta, Bhaskar E-mail: sddownes@physics.tamu.edu

    2013-12-01

    We study a possible origin of the anomalous suppression of the power spectrum at large angular scales in the cosmic microwave background within the framework of explicit string inflationary models where inflation is driven by a closed string modulus parameterizing the size of the extra dimensions. In this class of models the apparent power loss at large scales is caused by the background dynamics which involves a sharp transition from a fast-roll power law phase to a period of Starobinsky-like slow-roll inflation. An interesting feature of this class of string inflationary models is that the number of e-foldings of inflation is inversely proportional to the string coupling to a positive power. Therefore once the string coupling is tuned to small values in order to trust string perturbation theory, enough e-foldings of inflation are automatically obtained without the need of extra tuning. Moreover, in the less tuned cases the sharp transition responsible for the power loss takes place just before the last 50-60 e-foldings of inflation. We illustrate these general claims in the case of Fibre Inflation where we study the strength of this transition in terms of the attractor dynamics, finding that it induces a pivot from a blue to a redshifted power spectrum which can explain the apparent large scale power loss. We compute the effects of this pivot for example cases and demonstrate how magnitude and duration of this effect depend on model parameters.

  11. Detecting differential protein expression in large-scale population proteomics

    SciTech Connect

    Ryu, Soyoung; Qian, Weijun; Camp, David G.; Smith, Richard D.; Tompkins, Ronald G.; Davis, Ronald W.; Xiao, Wenzhong

    2014-06-17

    Mass spectrometry-based high-throughput quantitative proteomics shows great potential in clinical biomarker studies, identifying and quantifying thousands of proteins in biological samples. However, methods are needed to appropriately handle issues/challenges unique to mass spectrometry data in order to detect as many biomarker proteins as possible. One issue is that different mass spectrometry experiments generate quite different total numbers of quantified peptides, which can result in more missing peptide abundances in an experiment with a smaller total number of quantified peptides. Another issue is that the quantification of peptides is sometimes absent, especially for less abundant peptides and such missing values contain the information about the peptide abundance. Here, we propose a Significance Analysis for Large-scale Proteomics Studies (SALPS) that handles missing peptide intensity values caused by the two mechanisms mentioned above. Our model has a robust performance in both simulated data and proteomics data from a large clinical study. Because varying patients’ sample qualities and deviating instrument performances are not avoidable for clinical studies performed over the course of several years, we believe that our approach will be useful to analyze large-scale clinical proteomics data.

  12. Large-scale anisotropy in stably stratified rotating flows

    DOE PAGESBeta

    Marino, R.; Mininni, P. D.; Rosenberg, D. L.; Pouquet, A.

    2014-08-28

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up tomore » $1024^3$ grid points and Reynolds numbers of $$\\approx 1000$$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $$\\sim k_\\perp^{-5/3}$$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.« less

  13. Ecohydrological modeling for large-scale environmental impact assessment.

    PubMed

    Woznicki, Sean A; Nejadhashemi, A Pouyan; Abouali, Mohammad; Herman, Matthew R; Esfahanian, Elaheh; Hamaamin, Yaseen A; Zhang, Zhen

    2016-02-01

    Ecohydrological models are frequently used to assess the biological integrity of unsampled streams. These models vary in complexity and scale, and their utility depends on their final application. Tradeoffs are usually made in model scale, where large-scale models are useful for determining broad impacts of human activities on biological conditions, and regional-scale (e.g. watershed or ecoregion) models provide stakeholders greater detail at the individual stream reach level. Given these tradeoffs, the objective of this study was to develop large-scale stream health models with reach level accuracy similar to regional-scale models thereby allowing for impacts assessments and improved decision-making capabilities. To accomplish this, four measures of biological integrity (Ephemeroptera, Plecoptera, and Trichoptera taxa (EPT), Family Index of Biotic Integrity (FIBI), Hilsenhoff Biotic Index (HBI), and fish Index of Biotic Integrity (IBI)) were modeled based on four thermal classes (cold, cold-transitional, cool, and warm) of streams that broadly dictate the distribution of aquatic biota in Michigan. The Soil and Water Assessment Tool (SWAT) was used to simulate streamflow and water quality in seven watersheds and the Hydrologic Index Tool was used to calculate 171 ecologically relevant flow regime variables. Unique variables were selected for each thermal class using a Bayesian variable selection method. The variables were then used in development of adaptive neuro-fuzzy inference systems (ANFIS) models of EPT, FIBI, HBI, and IBI. ANFIS model accuracy improved when accounting for stream thermal class rather than developing a global model. PMID:26595397

  14. Large scale CMB anomalies from thawing cosmic strings

    NASA Astrophysics Data System (ADS)

    Ringeval, Christophe; Yamauchi, Daisuke; Yokoyama, Jun'ichi; Bouchet, François R.

    2016-02-01

    Cosmic strings formed during inflation are expected to be either diluted over super-Hubble distances, i.e., invisible today, or to have crossed our past light cone very recently. We discuss the latter situation in which a few strings imprint their signature in the Cosmic Microwave Background (CMB) Anisotropies after recombination. Being almost frozen in the Hubble flow, these strings are quasi static and evade almost all of the previously derived constraints on their tension while being able to source large scale anisotropies in the CMB sky. Using a local variance estimator on thousand of numerically simulated Nambu-Goto all sky maps, we compute the expected signal and show that it can mimic a dipole modulation at large angular scales while being negligible at small angles. Interestingly, such a scenario generically produces one cold spot from the thawing of a cosmic string loop. Mixed with anisotropies of inflationary origin, we find that a few strings of tension GU = Script O(1) × 10-6 match the amplitude of the dipole modulation reported in the Planck satellite measurements and could be at the origin of other large scale anomalies.

  15. The combustion behavior of large scale lithium titanate battery

    NASA Astrophysics Data System (ADS)

    Huang, Peifeng; Wang, Qingsong; Li, Ke; Ping, Ping; Sun, Jinhua

    2015-01-01

    Safety problem is always a big obstacle for lithium battery marching to large scale application. However, the knowledge on the battery combustion behavior is limited. To investigate the combustion behavior of large scale lithium battery, three 50 Ah Li(NixCoyMnz)O2/Li4Ti5O12 batteries under different state of charge (SOC) were heated to fire. The flame size variation is depicted to analyze the combustion behavior directly. The mass loss rate, temperature and heat release rate are used to analyze the combustion behavior in reaction way deeply. Based on the phenomenon, the combustion process is divided into three basic stages, even more complicated at higher SOC with sudden smoke flow ejected. The reason is that a phase change occurs in Li(NixCoyMnz)O2 material from layer structure to spinel structure. The critical temperatures of ignition are at 112-121°C on anode tab and 139 to 147°C on upper surface for all cells. But the heating time and combustion time become shorter with the ascending of SOC. The results indicate that the battery fire hazard increases with the SOC. It is analyzed that the internal short and the Li+ distribution are the main causes that lead to the difference.

  16. Large-scale magnetic fields in magnetohydrodynamic turbulence.

    PubMed

    Alexakis, Alexandros

    2013-02-22

    High Reynolds number magnetohydrodynamic turbulence in the presence of zero-flux large-scale magnetic fields is investigated as a function of the magnetic field strength. For a variety of flow configurations, the energy dissipation rate [symbol: see text] follows the scaling [Symbol: see text] proportional U(rms)(3)/ℓ even when the large-scale magnetic field energy is twenty times larger than the kinetic energy. A further increase of the magnetic energy showed a transition to the [Symbol: see text] proportional U(rms)(2) B(rms)/ℓ scaling implying that magnetic shear becomes more efficient at this point at cascading the energy than the velocity fluctuations. Strongly helical configurations form nonturbulent helicity condensates that deviate from these scalings. Weak turbulence scaling was absent from the investigation. Finally, the magnetic energy spectra support the Kolmogorov spectrum k(-5/3) while kinetic energy spectra are closer to the Iroshnikov-Kraichnan spectrum k(-3/2) as observed in the solar wind. PMID:23473153

  17. Exact-Differential Large-Scale Traffic Simulation

    SciTech Connect

    Hanai, Masatoshi; Suzumura, Toyotaro; Theodoropoulos, Georgios; Perumalla, Kalyan S

    2015-01-01

    Analyzing large-scale traffics by simulation needs repeating execution many times with various patterns of scenarios or parameters. Such repeating execution brings about big redundancy because the change from a prior scenario to a later scenario is very minor in most cases, for example, blocking only one of roads or changing the speed limit of several roads. In this paper, we propose a new redundancy reduction technique, called exact-differential simulation, which enables to simulate only changing scenarios in later execution while keeping exactly same results as in the case of whole simulation. The paper consists of two main efforts: (i) a key idea and algorithm of the exact-differential simulation, (ii) a method to build large-scale traffic simulation on the top of the exact-differential simulation. In experiments of Tokyo traffic simulation, the exact-differential simulation shows 7.26 times as much elapsed time improvement in average and 2.26 times improvement even in the worst case as the whole simulation.

  18. Large-scale mapping of mutations affecting zebrafish development

    PubMed Central

    Geisler, Robert; Rauch, Gerd-Jörg; Geiger-Rudolph, Silke; Albrecht, Andrea; van Bebber, Frauke; Berger, Andrea; Busch-Nentwich, Elisabeth; Dahm, Ralf; Dekens, Marcus PS; Dooley, Christopher; Elli, Alexandra F; Gehring, Ines; Geiger, Horst; Geisler, Maria; Glaser, Stefanie; Holley, Scott; Huber, Matthias; Kerr, Andy; Kirn, Anette; Knirsch, Martina; Konantz, Martina; Küchler, Axel M; Maderspacher, Florian; Neuhauss, Stephan C; Nicolson, Teresa; Ober, Elke A; Praeg, Elke; Ray, Russell; Rentzsch, Brit; Rick, Jens M; Rief, Eva; Schauerte, Heike E; Schepp, Carsten P; Schönberger, Ulrike; Schonthaler, Helia B; Seiler, Christoph; Sidi, Samuel; Söllner, Christian; Wehner, Anja; Weiler, Christian; Nüsslein-Volhard, Christiane

    2007-01-01

    Background Large-scale mutagenesis screens in the zebrafish employing the mutagen ENU have isolated several hundred mutant loci that represent putative developmental control genes. In order to realize the potential of such screens, systematic genetic mapping of the mutations is necessary. Here we report on a large-scale effort to map the mutations generated in mutagenesis screening at the Max Planck Institute for Developmental Biology by genome scanning with microsatellite markers. Results We have selected a set of microsatellite markers and developed methods and scoring criteria suitable for efficient, high-throughput genome scanning. We have used these methods to successfully obtain a rough map position for 319 mutant loci from the Tübingen I mutagenesis screen and subsequent screening of the mutant collection. For 277 of these the corresponding gene is not yet identified. Mapping was successful for 80 % of the tested loci. By comparing 21 mutation and gene positions of cloned mutations we have validated the correctness of our linkage group assignments and estimated the standard error of our map positions to be approximately 6 cM. Conclusion By obtaining rough map positions for over 300 zebrafish loci with developmental phenotypes, we have generated a dataset that will be useful not only for cloning of the affected genes, but also to suggest allelism of mutations with similar phenotypes that will be identified in future screens. Furthermore this work validates the usefulness of our methodology for rapid, systematic and inexpensive microsatellite mapping of zebrafish mutations. PMID:17212827

  19. The effective field theory of cosmological large scale structures

    SciTech Connect

    Carrasco, John Joseph M.; Hertzberg, Mark P.; Senatore, Leonardo

    2012-09-20

    Large scale structure surveys will likely become the next leading cosmological probe. In our universe, matter perturbations are large on short distances and small at long scales, i.e. strongly coupled in the UV and weakly coupled in the IR. To make precise analytical predictions on large scales, we develop an effective field theory formulated in terms of an IR effective fluid characterized by several parameters, such as speed of sound and viscosity. These parameters, determined by the UV physics described by the Boltzmann equation, are measured from N-body simulations. We find that the speed of sound of the effective fluid is c2s ≈ 10–6c2 and that the viscosity contributions are of the same order. The fluid describes all the relevant physics at long scales k and permits a manifestly convergent perturbative expansion in the size of the matter perturbations δ(k) for all the observables. As an example, we calculate the correction to the power spectrum at order δ(k)4. As a result, the predictions of the effective field theory are found to be in much better agreement with observation than standard cosmological perturbation theory, already reaching percent precision at this order up to a relatively short scale k ≃ 0.24h Mpc–1.

  20. Halo detection via large-scale Bayesian inference

    NASA Astrophysics Data System (ADS)

    Merson, Alexander I.; Jasche, Jens; Abdalla, Filipe B.; Lahav, Ofer; Wandelt, Benjamin; Jones, D. Heath; Colless, Matthew

    2016-08-01

    We present a proof-of-concept of a novel and fully Bayesian methodology designed to detect haloes of different masses in cosmological observations subject to noise and systematic uncertainties. Our methodology combines the previously published Bayesian large-scale structure inference algorithm, HAmiltonian Density Estimation and Sampling algorithm (HADES), and a Bayesian chain rule (the Blackwell-Rao estimator), which we use to connect the inferred density field to the properties of dark matter haloes. To demonstrate the capability of our approach, we construct a realistic galaxy mock catalogue emulating the wide-area 6-degree Field Galaxy Survey, which has a median redshift of approximately 0.05. Application of HADES to the catalogue provides us with accurately inferred three-dimensional density fields and corresponding quantification of uncertainties inherent to any cosmological observation. We then use a cosmological simulation to relate the amplitude of the density field to the probability of detecting a halo with mass above a specified threshold. With this information, we can sum over the HADES density field realisations to construct maps of detection probabilities and demonstrate the validity of this approach within our mock scenario. We find that the probability of successful detection of haloes in the mock catalogue increases as a function of the signal to noise of the local galaxy observations. Our proposed methodology can easily be extended to account for more complex scientific questions and is a promising novel tool to analyse the cosmic large-scale structure in observations.

  1. A competitive swarm optimizer for large scale optimization.

    PubMed

    Cheng, Ran; Jin, Yaochu

    2015-02-01

    In this paper, a novel competitive swarm optimizer (CSO) for large scale optimization is proposed. The algorithm is fundamentally inspired by the particle swarm optimization but is conceptually very different. In the proposed CSO, neither the personal best position of each particle nor the global best position (or neighborhood best positions) is involved in updating the particles. Instead, a pairwise competition mechanism is introduced, where the particle that loses the competition will update its position by learning from the winner. To understand the search behavior of the proposed CSO, a theoretical proof of convergence is provided, together with empirical analysis of its exploration and exploitation abilities showing that the proposed CSO achieves a good balance between exploration and exploitation. Despite its algorithmic simplicity, our empirical results demonstrate that the proposed CSO exhibits a better overall performance than five state-of-the-art metaheuristic algorithms on a set of widely used large scale optimization problems and is able to effectively solve problems of dimensionality up to 5000. PMID:24860047

  2. Large-scale electromagnetic modeling for multiple inhomogeneous domains

    NASA Astrophysics Data System (ADS)

    Zhdanov, M. S.; Endo, M.; Cuma, M.

    2008-12-01

    We develop a new formulation of the integral equation (IE) method for three-dimensional (3D) electromagnetic (EM) field computation in large-scale models with multiple inhomogeneous domains. This problem arises in many practical applications including modeling the EM fields within the complex geoelectrical structures in geophysical exploration. In geophysical applications, it is difficult to describe an earth structure using a horizontally layered background conductivity model, which is required for the efficient implementation of the conventional IE approach. As a result, a large domain of interest with anomalous conductivity distribution needs to be discretized, which complicates the computations. The new method allows us to consider multiple inhomogeneous domains, where the conductivity distribution is different from that of the background, and to use independent discretizations for different domains. This reduces dramatically the computational resources required for large-scale modeling. In addition, by using this method, we can analyze the response of each domain separately without an inappropriate use of the superposition principle for the EM field calculations. The method was carefully tested for modeling the marine controlled-source electromagnetic (MCSEM) fields for complex geoelectrical structures with multiple inhomogeneous domains, such as a seafloor with rough bathymetry, salt domes, and reservoirs. We have also used this technique to investigate the return induction effects from regional geoelectrical structures, e.g., seafloor bathymetry and salt domes, which can distort the EM response from the geophysical exploration target.

  3. Large-scale network-level processes during entrainment.

    PubMed

    Lithari, Chrysa; Sánchez-García, Carolina; Ruhnau, Philipp; Weisz, Nathan

    2016-03-15

    Visual rhythmic stimulation evokes a robust power increase exactly at the stimulation frequency, the so-called steady-state response (SSR). Localization of visual SSRs normally shows a very focal modulation of power in visual cortex and led to the treatment and interpretation of SSRs as a local phenomenon. Given the brain network dynamics, we hypothesized that SSRs have additional large-scale effects on the brain functional network that can be revealed by means of graph theory. We used rhythmic visual stimulation at a range of frequencies (4-30 Hz), recorded MEG and investigated source level connectivity across the whole brain. Using graph theoretical measures we observed a frequency-unspecific reduction of global density in the alpha band "disconnecting" visual cortex from the rest of the network. Also, a frequency-specific increase of connectivity between occipital cortex and precuneus was found at the stimulation frequency that exhibited the highest resonance (30 Hz). In conclusion, we showed that SSRs dynamically re-organized the brain functional network. These large-scale effects should be taken into account not only when attempting to explain the nature of SSRs, but also when used in various experimental designs. PMID:26835557

  4. Large-scale network-level processes during entrainment

    PubMed Central

    Lithari, Chrysa; Sánchez-García, Carolina; Ruhnau, Philipp; Weisz, Nathan

    2016-01-01

    Visual rhythmic stimulation evokes a robust power increase exactly at the stimulation frequency, the so-called steady-state response (SSR). Localization of visual SSRs normally shows a very focal modulation of power in visual cortex and led to the treatment and interpretation of SSRs as a local phenomenon. Given the brain network dynamics, we hypothesized that SSRs have additional large-scale effects on the brain functional network that can be revealed by means of graph theory. We used rhythmic visual stimulation at a range of frequencies (4–30 Hz), recorded MEG and investigated source level connectivity across the whole brain. Using graph theoretical measures we observed a frequency-unspecific reduction of global density in the alpha band “disconnecting” visual cortex from the rest of the network. Also, a frequency-specific increase of connectivity between occipital cortex and precuneus was found at the stimulation frequency that exhibited the highest resonance (30 Hz). In conclusion, we showed that SSRs dynamically re-organized the brain functional network. These large-scale effects should be taken into account not only when attempting to explain the nature of SSRs, but also when used in various experimental designs. PMID:26835557

  5. Effects of subsurface heterogeneity on large-scale hydrological predictions

    NASA Astrophysics Data System (ADS)

    Hartmann, Andreas; Gleeson, Tom; Wagener, Thorsten; Wada, Yoshihide

    2015-04-01

    Heterogeneity is abundant everywhere across the hydrosphere. It exists in the soil, the vadose zone and the groundwater producing preferential flow and complex threshold behavior. In large-scale hydrological models, subsurface heterogeneity is usually not considered. Instead average or representative values are chosen for each of the simulated grid cells, not incorporating any sub-grid variability. This may lead to unreliable predictions when the models are used for assessing future water resources availability, floods or droughts, or when they are used for recommendations for more sustainable water management. In this study we use a novel, large-scale model that takes into account sub-grid heterogeneity for the simulation of groundwater recharge by using statistical distribution functions. We choose all regions over Europe that are comprised by carbonate rock (~35% of the total area) because the well understood dissolvability of carbonate rocks (karstification) allows for assessing the strength of subsurface heterogeneity. Applying the model with historic data and future climate projections we show that subsurface heterogeneity results (1) in larger present-day groundwater recharge and (2) a greater vulnerability to climate in terms of long-term decrease and hydrological extremes.

  6. Topographically Engineered Large Scale Nanostructures for Plasmonic Biosensing

    PubMed Central

    Xiao, Bo; Pradhan, Sangram K.; Santiago, Kevin C.; Rutherford, Gugu N.; Pradhan, Aswini K.

    2016-01-01

    We demonstrate that a nanostructured metal thin film can achieve enhanced transmission efficiency and sharp resonances and use a large-scale and high-throughput nanofabrication technique for the plasmonic structures. The fabrication technique combines the features of nanoimprint and soft lithography to topographically construct metal thin films with nanoscale patterns. Metal nanogratings developed using this method show significantly enhanced optical transmission (up to a one-order-of-magnitude enhancement) and sharp resonances with full width at half maximum (FWHM) of ~15nm in the zero-order transmission using an incoherent white light source. These nanostructures are sensitive to the surrounding environment, and the resonance can shift as the refractive index changes. We derive an analytical method using a spatial Fourier transformation to understand the enhancement phenomenon and the sensing mechanism. The use of real-time monitoring of protein-protein interactions in microfluidic cells integrated with these nanostructures is demonstrated to be effective for biosensing. The perpendicular transmission configuration and large-scale structures provide a feasible platform without sophisticated optical instrumentation to realize label-free surface plasmon resonance (SPR) sensing. PMID:27072067

  7. Very large-scale motions in a turbulent pipe flow

    NASA Astrophysics Data System (ADS)

    Lee, Jae Hwa; Jang, Seong Jae; Sung, Hyung Jin

    2011-11-01

    Direct numerical simulation of a turbulent pipe flow with ReD=35000 was performed to investigate the spatially coherent structures associated with very large-scale motions. The corresponding friction Reynolds number, based on pipe radius R, is R+=934, and the computational domain length is 30 R. The computed mean flow statistics agree well with previous DNS data at ReD=44000 and 24000. Inspection of the instantaneous fields and two-point correlation of the streamwise velocity fluctuations showed that the very long meandering motions exceeding 25R exist in logarithmic and wake regions, and the streamwise length scale is almost linearly increased up to y/R ~0.3, while the structures in the turbulent boundary layer only reach up to the edge of the log-layer. Time-resolved instantaneous fields revealed that the hairpin packet-like structures grow with continuous stretching along the streamwise direction and create the very large-scale structures with meandering in the spanwise direction, consistent with the previous conceptual model of Kim & Adrian (1999). This work was supported by the Creative Research Initiatives of NRF/MEST of Korea (No. 2011-0000423).

  8. Molten Pb as a catalyst for large-scale growth of highly aligned silicon oxide nanowires

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Jiang, Feihong; Yang, Yongdong; Li, Jianping

    2007-09-01

    Low melting point metal Pb can be used as an effective catalyst for the large-scale growth of highly aligned silicon oxide nanowire balls. Unlike any previously observed results using Au or Fe as catalyst, the molten Pb-catalyzed vapor-liquid-solid (VLS) growth exhibits many amazing growth phenomena. The scan electron microscopy (SEM) data indicate that the silicon oxide nanowires grow out perpendicularly from the surface of the metal Pb balls. For each ball, numerous nanowires simultaneously nucleate, grow at nearly the same rate and direction, and simultaneously stop growing. The pear-like, flower-like, chrysanthemum-like, and echinus-like SiO 2 nanostructures were formed. A growth model was proposed. The experimental results further expand the low melting point metal-catalyzed VLS mechanism to a broader range.

  9. Large-scale climatic control on European precipitation

    NASA Astrophysics Data System (ADS)

    Lavers, David; Prudhomme, Christel; Hannah, David

    2010-05-01

    Precipitation variability has a significant impact on society. Sectors such as agriculture and water resources management are reliant on predictable and reliable precipitation supply with extreme variability having potentially adverse socio-economic impacts. Therefore, understanding the climate drivers of precipitation is of human relevance. This research examines the strength, location and seasonality of links between precipitation and large-scale Mean Sea Level Pressure (MSLP) fields across Europe. In particular, we aim to evaluate whether European precipitation is correlated with the same atmospheric circulation patterns or if there is a strong spatial and/or seasonal variation in the strength and location of centres of correlations. The work exploits time series of gridded ERA-40 MSLP on a 2.5˚×2.5˚ grid (0˚N-90˚N and 90˚W-90˚E) and gridded European precipitation from the Ensemble project on a 0.5°×0.5° grid (36.25˚N-74.25˚N and 10.25˚W-24.75˚E). Monthly Spearman rank correlation analysis was performed between MSLP and precipitation. During winter, a significant MSLP-precipitation correlation dipole pattern exists across Europe. Strong negative (positive) correlation located near the Icelandic Low and positive (negative) correlation near the Azores High pressure centres are found in northern (southern) Europe. These correlation dipoles resemble the structure of the North Atlantic Oscillation (NAO). The reversal in the correlation dipole patterns occurs at the latitude of central France, with regions to the north (British Isles, northern France, Scandinavia) having a positive relationship with the NAO, and regions to the south (Italy, Portugal, southern France, Spain) exhibiting a negative relationship with the NAO. In the lee of mountain ranges of eastern Britain and central Sweden, correlation with North Atlantic MSLP is reduced, reflecting a reduced influence of westerly flow on precipitation generation as the mountains act as a barrier to moist

  10. Nearly incompressible fluids: hydrodynamics and large scale inhomogeneity.

    PubMed

    Hunana, P; Zank, G P; Shaikh, D

    2006-08-01

    A system of hydrodynamic equations in the presence of large-scale inhomogeneities for a high plasma beta solar wind is derived. The theory is derived under the assumption of low turbulent Mach number and is developed for the flows where the usual incompressible description is not satisfactory and a full compressible treatment is too complex for any analytical studies. When the effects of compressibility are incorporated only weakly, a new description, referred to as "nearly incompressible hydrodynamics," is obtained. The nearly incompressible theory, was originally applied to homogeneous flows. However, large-scale gradients in density, pressure, temperature, etc., are typical in the solar wind and it was unclear how inhomogeneities would affect the usual incompressible and nearly incompressible descriptions. In the homogeneous case, the lowest order expansion of the fully compressible equations leads to the usual incompressible equations, followed at higher orders by the nearly incompressible equations, as introduced by Zank and Matthaeus. With this work we show that the inclusion of large-scale inhomogeneities (in this case time-independent and radially symmetric background solar wind) modifies the leading-order incompressible description of solar wind flow. We find, for example, that the divergence of velocity fluctuations is nonsolenoidal and that density fluctuations can be described to leading order as a passive scalar. Locally (for small lengthscales), this system of equations converges to the usual incompressible equations and we therefore use the term "locally incompressible" to describe the equations. This term should be distinguished from the term "nearly incompressible," which is reserved for higher-order corrections. Furthermore, we find that density fluctuations scale with Mach number linearly, in contrast to the original homogeneous nearly incompressible theory, in which density fluctuations scale with the square of Mach number. Inhomogeneous nearly

  11. A Shell Multi-dimensional Hierarchical Cubing Approach for High-Dimensional Cube

    NASA Astrophysics Data System (ADS)

    Zou, Shuzhi; Zhao, Li; Hu, Kongfa

    The pre-computation of data cubes is critical for improving the response time of OLAP systems and accelerating data mining tasks in large data warehouses. However, as the sizes of data warehouses grow, the time it takes to perform this pre-computation becomes a significant performance bottleneck. In a high dimensional data warehouse, it might not be practical to build all these cuboids and their indices. In this paper, we propose a shell multi-dimensional hierarchical cubing algorithm, based on an extension of the previous minimal cubing approach. This method partitions the high dimensional data cube into low multi-dimensional hierarchical cube. Experimental results show that the proposed method is significantly more efficient than other existing cubing methods.

  12. An extension of the TV-HLL scheme for multi-dimensional compressible flows

    NASA Astrophysics Data System (ADS)

    Tiam Kapen, Pascalin; Tchuen, Ghislain

    2015-03-01

    This paper investigates a very simple method to numerically approximate the solution of the multi-dimensional Riemann problem for gas dynamics, using the literal extension of the Toro Vazquez-Harten Lax Leer (TV-HLL) scheme as its basis. Indeed, the present scheme is obtained by following the Toro-Vazquez splitting, and using the HLL algorithm with modified wave speeds for the pressure system. An essential feature of the TV-HLL scheme is its simplicity and its accuracy in computing multi-dimensional flows. The proposed scheme is carefully designed to simplify its eventual numerical implementation. It has been applied to numerical tests and its performances are demonstrated for some two-dimensional and three-dimensional test problems.

  13. Penetration of Large Scale Electric Field to Inner Magnetosphere

    NASA Astrophysics Data System (ADS)

    Chen, S. H.; Fok, M. C. H.; Sibeck, D. G.; Wygant, J. R.; Spence, H. E.; Larsen, B.; Reeves, G. D.; Funsten, H. O.

    2015-12-01

    The direct penetration of large scale global electric field to the inner magnetosphere is a critical element in controlling how the background thermal plasma populates within the radiation belts. These plasma populations provide the source of particles and free energy needed for the generation and growth of various plasma waves that, at critical points of resonances in time and phase space, can scatter or energize radiation belt particles to regulate the flux level of the relativistic electrons in the system. At high geomagnetic activity levels, the distribution of large scale electric fields serves as an important indicator of how prevalence of strong wave-particle interactions extend over local times and radial distances. To understand the complex relationship between the global electric fields and thermal plasmas, particularly due to the ionospheric dynamo and the magnetospheric convection effects, and their relations to the geomagnetic activities, we analyze the electric field and cold plasma measurements from Van Allen Probes over more than two years period and simulate a geomagnetic storm event using Coupled Inner Magnetosphere-Ionosphere Model (CIMI). Our statistical analysis of the measurements from Van Allan Probes and CIMI simulations of the March 17, 2013 storm event indicate that: (1) Global dawn-dusk electric field can penetrate the inner magnetosphere inside the inner belt below L~2. (2) Stronger convections occurred in the dusk and midnight sectors than those in the noon and dawn sectors. (3) Strong convections at multiple locations exist at all activity levels but more complex at higher activity levels. (4) At the high activity levels, strongest convections occur in the midnight sectors at larger distances from the Earth and in the dusk sector at closer distances. (5) Two plasma populations of distinct ion temperature isotropies divided at L-Shell ~2, indicating distinct heating mechanisms between inner and outer radiation belts. (6) CIMI

  14. Autonomic Computing Paradigm For Large Scale Scientific And Engineering Applications

    NASA Astrophysics Data System (ADS)

    Hariri, S.; Yang, J.; Zhang, Y.

    2005-12-01

    Large-scale distributed scientific applications are highly adaptive and heterogeneous in terms of their computational requirements. The computational complexity associated with each computational region or domain varies continuously and dramatically both in space and time throughout the whole life cycle of the application execution. Furthermore, the underlying distributed computing environment is similarly complex and dynamic in the availabilities and capacities of the computing resources. These challenges combined together make the current paradigms, which are based on passive components and static compositions, ineffectual. Autonomic Computing paradigm is an approach that efficiently addresses the complexity and dynamism of large scale scientific and engineering applications and realizes the self-management of these applications. In this presentation, we present an Autonomic Runtime Manager (ARM) that supports the development of autonomic applications. The ARM includes two modules: online monitoring and analysis module and autonomic planning and scheduling module. The ARM behaves as a closed-loop control system that dynamically controls and manages the execution of the applications at runtime. It regularly senses the state changes of both the applications and the underlying computing resources. It then uses these runtime information and prior knowledge about the application behavior and its physics to identify the appropriate solution methods as well as the required computing and storage resources. Consequently this approach enables us to develop autonomic applications, which are capable of self-management and self-optimization. We have developed and implemented the autonomic computing paradigms for several large scale applications such as wild fire simulations, simulations of flow through variably saturated geologic formations, and life sciences. The distributed wildfire simulation models the wildfire spread behavior by considering such factors as fuel

  15. Climatological context for large-scale coral bleaching

    NASA Astrophysics Data System (ADS)

    Barton, A. D.; Casey, K. S.

    2005-12-01

    Large-scale coral bleaching was first observed in 1979 and has occurred throughout virtually all of the tropics since that time. Severe bleaching may result in the loss of live coral and in a decline of the integrity of the impacted coral reef ecosystem. Despite the extensive scientific research and increased public awareness of coral bleaching, uncertainties remain about the past and future of large-scale coral bleaching. In order to reduce these uncertainties and place large-scale coral bleaching in the longer-term climatological context, specific criteria and methods for using historical sea surface temperature (SST) data to examine coral bleaching-related thermal conditions are proposed by analyzing three, 132 year SST reconstructions: ERSST, HadISST1, and GISST2.3b. These methodologies are applied to case studies at Discovery Bay, Jamaica (77.27°W, 18.45°N), Sombrero Reef, Florida, USA (81.11°W, 24.63°N), Academy Bay, Galápagos, Ecuador (90.31°W, 0.74°S), Pearl and Hermes Reef, Northwest Hawaiian Islands, USA (175.83°W, 27.83°N), Midway Island, Northwest Hawaiian Islands, USA (177.37°W, 28.25°N), Davies Reef, Australia (147.68°E, 18.83°S), and North Male Atoll, Maldives (73.35°E, 4.70°N). The results of this study show that (1) The historical SST data provide a useful long-term record of thermal conditions in reef ecosystems, giving important insight into the thermal history of coral reefs and (2) While coral bleaching and anomalously warm SSTs have occurred over much of the world in recent decades, case studies in the Caribbean, Northwest Hawaiian Islands, and parts of other regions such as the Great Barrier Reef exhibited SST conditions and cumulative thermal stress prior to 1979 that were comparable to those conditions observed during the strong, frequent coral bleaching events since 1979. This climatological context and knowledge of past environmental conditions in reef ecosystems may foster a better understanding of how coral reefs will

  16. Large-scale dimension densities for heart rate variability analysis

    NASA Astrophysics Data System (ADS)

    Raab, Corinna; Wessel, Niels; Schirdewan, Alexander; Kurths, Jürgen

    2006-04-01

    In this work, we reanalyze the heart rate variability (HRV) data from the 2002 Computers in Cardiology (CiC) Challenge using the concept of large-scale dimension densities and additionally apply this technique to data of healthy persons and of patients with cardiac diseases. The large-scale dimension density (LASDID) is estimated from the time series using a normalized Grassberger-Procaccia algorithm, which leads to a suitable correction of systematic errors produced by boundary effects in the rather large scales of a system. This way, it is possible to analyze rather short, nonstationary, and unfiltered data, such as HRV. Moreover, this method allows us to analyze short parts of the data and to look for differences between day and night. The circadian changes in the dimension density enable us to distinguish almost completely between real data and computer-generated data from the CiC 2002 challenge using only one parameter. In the second part we analyzed the data of 15 patients with atrial fibrillation (AF), 15 patients with congestive heart failure (CHF), 15 elderly healthy subjects (EH), as well as 18 young and healthy persons (YH). With our method we are able to separate completely the AF (ρlsμ=0.97±0.02) group from the others and, especially during daytime, the CHF patients show significant differences from the young and elderly healthy volunteers (CHF, 0.65±0.13 ; EH, 0.54±0.05 ; YH, 0.57±0.05 ; p<0.05 for both comparisons). Moreover, for the CHF patients we find no circadian changes in ρlsμ (day, 0.65±0.13 ; night, 0.66±0.12 ; n.s.) in contrast to healthy controls (day, 0.54±0.05 ; night, 0.61±0.05 ; p=0.002 ). Correlation analysis showed no statistical significant relation between standard HRV and circadian LASDID, demonstrating a possibly independent application of our method for clinical risk stratification.

  17. Large-scale dimension densities for heart rate variability analysis.

    PubMed

    Raab, Corinna; Wessel, Niels; Schirdewan, Alexander; Kurths, Jürgen

    2006-04-01

    In this work, we reanalyze the heart rate variability (HRV) data from the 2002 Computers in Cardiology (CiC) Challenge using the concept of large-scale dimension densities and additionally apply this technique to data of healthy persons and of patients with cardiac diseases. The large-scale dimension density (LASDID) is estimated from the time series using a normalized Grassberger-Procaccia algorithm, which leads to a suitable correction of systematic errors produced by boundary effects in the rather large scales of a system. This way, it is possible to analyze rather short, nonstationary, and unfiltered data, such as HRV. Moreover, this method allows us to analyze short parts of the data and to look for differences between day and night. The circadian changes in the dimension density enable us to distinguish almost completely between real data and computer-generated data from the CiC 2002 challenge using only one parameter. In the second part we analyzed the data of 15 patients with atrial fibrillation (AF), 15 patients with congestive heart failure (CHF), 15 elderly healthy subjects (EH), as well as 18 young and healthy persons (YH). With our method we are able to separate completely the AF (rho (mu/ls) = 0.97 +/- 0.02) group from the others and, especially during daytime, the CHF patients show significant differences from the young and elderly healthy volunteers (CHF, 0.65 +/- 0.13; EH, 0.54 +/- 0.05; YH, 0.57 +/- 0.05; p < 0.05 for both comparisons). Moreover, for the CHF patients we find no circadian changes in rho (mu/ls) (day, 0.65 +/- 0.13; night, 0.66 +/- 0.12; n.s.) in contrast to healthy controls (day, 0.54 +/- 0.05; night, 0.61 +/- 0.05; p=0.002). Correlation analysis showed no statistical significant relation between standard HRV and circadian LASDID, demonstrating a possibly independent application of our method for clinical risk stratification. PMID:16711836

  18. Large-Scale Graphene Film Deposition for Monolithic Device Fabrication

    NASA Astrophysics Data System (ADS)

    Al-shurman, Khaled

    Since 1958, the concept of integrated circuit (IC) has achieved great technological developments and helped in shrinking electronic devices. Nowadays, an IC consists of more than a million of compacted transistors. The majority of current ICs use silicon as a semiconductor material. According to Moore's law, the number of transistors built-in on a microchip can be double every two years. However, silicon device manufacturing reaches its physical limits. To explain, there is a new trend to shrinking circuitry to seven nanometers where a lot of unknown quantum effects such as tunneling effect can not be controlled. Hence, there is an urgent need for a new platform material to replace Si. Graphene is considered a promising material with enormous potential applications in many electronic and optoelectronics devices due to its superior properties. There are several techniques to produce graphene films. Among these techniques, chemical vapor deposition (CVD) offers a very convenient method to fabricate films for large-scale graphene films. Though CVD method is suitable for large area growth of graphene, the need for transferring a graphene film to silicon-based substrates is required. Furthermore, the graphene films thus achieved are, in fact, not single crystalline. Also, graphene fabrication utilizing Cu and Ni at high growth temperature contaminates the substrate that holds Si CMOS circuitry and CVD chamber as well. So, lowering the deposition temperature is another technological milestone for the successful adoption of graphene in integrated circuits fabrication. In this research, direct large-scale graphene film fabrication on silicon based platform (i.e. SiO2 and Si3N4) at low temperature was achieved. With a focus on low-temperature graphene growth, hot-filament chemical vapor deposition (HF-CVD) was utilized to synthesize graphene film using 200 nm thick nickel film. Raman spectroscopy was utilized to examine graphene formation on the bottom side of the Ni film

  19. Multi-dimensional modelling of gas turbine combustion using a flame sheet model in KIVA II

    NASA Technical Reports Server (NTRS)

    Cheng, W. K.; Lai, M.-C.; Chue, T.-H.

    1991-01-01

    A flame sheet model for heat release is incorporated into a multi-dimensional fluid mechanical simulation for gas turbine application. The model assumes that the chemical reaction takes place in thin sheets compared to the length scale of mixing, which is valid for the primary combustion zone in a gas turbine combustor. In this paper, the details of the model are described and computational results are discussed.

  20. High-value energy storage for the grid: a multi-dimensional look

    SciTech Connect

    Culver, Walter J.

    2010-12-15

    The conceptual attractiveness of energy storage in the electrical power grid has grown in recent years with Smart Grid initiatives. But cost is a problem, interwoven with the complexity of quantifying the benefits of energy storage. This analysis builds toward a multi-dimensional picture of storage that is offered as a step toward identifying and removing the gaps and ''friction'' that permeate the delivery chain from research laboratory to grid deployment. (author)

  1. Multi-dimensional option pricing using radial basis functions and the generalized Fourier transform

    NASA Astrophysics Data System (ADS)

    Larsson, Elisabeth; Ahlander, Krister; Hall, Andreas

    2008-12-01

    We show that the generalized Fourier transform can be used for reducing the computational cost and memory requirements of radial basis function methods for multi-dimensional option pricing. We derive a general algorithm, including a transformation of the Black-Scholes equation into the heat equation, that can be used in any number of dimensions. Numerical experiments in two and three dimensions show that the gain is substantial even for small problem sizes. Furthermore, the gain increases with the number of dimensions.

  2. High-Level Waste Tanks Multi-Dimensional Contaminant Transport Model Development Enhancements for 2000

    SciTech Connect

    Collard, L.B.

    2001-09-21

    A suite of multi-dimensional computer models was developed in 1999 (Collard and Flach) to analyze the transport of residual contamination from high-level waste tanks through the subsurface to seeplines. Enhancements in 2000 to those models include investigate the effect of numerical dispersion, develop a solubility-limited case for U and Pu, and develop a plan for a database as part of the Rapid Screening Tool and start to implement that plan.

  3. DYVIPAC: an integrated analysis and visualisation framework to probe multi-dimensional biological networks

    PubMed Central

    Nguyen, Lan K.; Degasperi, Andrea; Cotter, Philip; Kholodenko, Boris N.

    2015-01-01

    Biochemical networks are dynamic and multi-dimensional systems, consisting of tens or hundreds of molecular components. Diseases such as cancer commonly arise due to changes in the dynamics of signalling and gene regulatory networks caused by genetic alternations. Elucidating the network dynamics in health and disease is crucial to better understand the disease mechanisms and derive effective therapeutic strategies. However, current approaches to analyse and visualise systems dynamics can often provide only low-dimensional projections of the network dynamics, which often does not present the multi-dimensional picture of the system behaviour. More efficient and reliable methods for multi-dimensional systems analysis and visualisation are thus required. To address this issue, we here present an integrated analysis and visualisation framework for high-dimensional network behaviour which exploits the advantages provided by parallel coordinates graphs. We demonstrate the applicability of the framework, named “Dynamics Visualisation based on Parallel Coordinates” (DYVIPAC), to a variety of signalling networks ranging in topological wirings and dynamic properties. The framework was proved useful in acquiring an integrated understanding of systems behaviour. PMID:26220783

  4. Engineering large-scale agent-based systems with consensus

    NASA Technical Reports Server (NTRS)

    Bokma, A.; Slade, A.; Kerridge, S.; Johnson, K.

    1994-01-01

    The paper presents the consensus method for the development of large-scale agent-based systems. Systems can be developed as networks of knowledge based agents (KBA) which engage in a collaborative problem solving effort. The method provides a comprehensive and integrated approach to the development of this type of system. This includes a systematic analysis of user requirements as well as a structured approach to generating a system design which exhibits the desired functionality. There is a direct correspondence between system requirements and design components. The benefits of this approach are that requirements are traceable into design components and code thus facilitating verification. The use of the consensus method with two major test applications showed it to be successful and also provided valuable insight into problems typically associated with the development of large systems.

  5. MODELING THE LARGE-SCALE BIAS OF NEUTRAL HYDROGEN

    SciTech Connect

    MarIn, Felipe A.; Gnedin, Nickolay Y.; Seo, Hee-Jong; Vallinotto, Alberto E-mail: gnedin@fnal.go E-mail: avalli@fnal.go

    2010-08-01

    We present new analytical estimates of the large-scale bias of neutral hydrogen (H I). We use a simple, non-parametric model which monotonically relates the total mass of a halo M{sub tot} with its H I mass M{sub HI} at zero redshift; for earlier times we assume limiting models for the {Omega}{sub HI} evolution consistent with the data presently available, as well as two main scenarios for the evolution of our M{sub HI}-M{sub tot} relation. We find that both the linear and the first nonlinear bias terms exhibit a strong evolution with redshift, regardless of the specific limiting model assumed for the H I density over time. These analytical predictions are then shown to be consistent with measurements performed on the Millennium Simulation. Additionally, we show that this strong bias evolution does not sensibly affect the measurement of the H I power spectrum.

  6. Mass Efficiencies for Common Large-Scale Precision Space Structures

    NASA Technical Reports Server (NTRS)

    Williams, R. Brett; Agnes, Gregory S.

    2005-01-01

    This paper presents a mass-based trade study for large-scale deployable triangular trusses, where the longerons can be monocoque tubes, isogrid tubes, or coilable longeron trusses. Such structures are typically used to support heavy reflectors, solar panels, or other instruments, and are subject to thermal gradients that can vary a great deal based on orbital altitude, location in orbit, and self-shadowing. While multi layer insulation (MLI) blankets are commonly used to minimize the magnitude of these thermal disturbances, they subject the truss to a nonstructural mass penalty. This paper investigates the impact of these add-on thermal protection layers on selecting the lightest precision structure for a given loading scenario.

  7. Nuclear-pumped lasers for large-scale applications

    SciTech Connect

    Anderson, R.E.; Leonard, E.M.; Shea, R.F.; Berggren, R.R.

    1989-05-01

    Efficient initiation of large-volume chemical lasers may be achieved by neutron induced reactions which produce charged particles in the final state. When a burst mode nuclear reactor is used as the neutron source, both a sufficiently intense neutron flux and a sufficiently short initiation pulse may be possible. Proof-of-principle experiments are planned to demonstrate lasing in a direct nuclear-pumped large-volume system; to study the effects of various neutron absorbing materials on laser performance; to study the effects of long initiation pulse lengths; to demonstrate the performance of large-scale optics and the beam quality that may be obtained; and to assess the performance of alternative designs of burst systems that increase the neutron output and burst repetition rate. 21 refs., 8 figs., 5 tabs.

  8. Large scale simulations of the great 1906 San Francisco earthquake

    NASA Astrophysics Data System (ADS)

    Nilsson, S.; Petersson, A.; Rodgers, A.; Sjogreen, B.; McCandless, K.

    2006-12-01

    As part of a multi-institutional simulation effort, we present large scale computations of the ground motion during the great 1906 San Francisco earthquake using a new finite difference code called WPP. The material data base for northern California provided by USGS together with the rupture model by Song et al. is demonstrated to lead to a reasonable match with historical data. In our simulations, the computational domain covered 550 km by 250 km of northern California down to 40 km depth, so a 125 m grid size corresponds to about 2.2 Billion grid points. To accommodate these large grids, the simulations were run on 512-1024 processors on one of the supercomputers at Lawrence Livermore National Lab. A wavelet compression algorithm enabled storage of time-dependent volumetric data. Nevertheless, the first 45 seconds of the earthquake still generated 1.2 TByte of disk space and the 3-D post processing was done in parallel.

  9. A large-scale evaluation of computational protein function prediction

    PubMed Central

    Radivojac, Predrag; Clark, Wyatt T; Ronnen Oron, Tal; Schnoes, Alexandra M; Wittkop, Tobias; Sokolov, Artem; Graim, Kiley; Funk, Christopher; Verspoor, Karin; Ben-Hur, Asa; Pandey, Gaurav; Yunes, Jeffrey M; Talwalkar, Ameet S; Repo, Susanna; Souza, Michael L; Piovesan, Damiano; Casadio, Rita; Wang, Zheng; Cheng, Jianlin; Fang, Hai; Gough, Julian; Koskinen, Patrik; Törönen, Petri; Nokso-Koivisto, Jussi; Holm, Liisa; Cozzetto, Domenico; Buchan, Daniel W A; Bryson, Kevin; Jones, David T; Limaye, Bhakti; Inamdar, Harshal; Datta, Avik; Manjari, Sunitha K; Joshi, Rajendra; Chitale, Meghana; Kihara, Daisuke; Lisewski, Andreas M; Erdin, Serkan; Venner, Eric; Lichtarge, Olivier; Rentzsch, Robert; Yang, Haixuan; Romero, Alfonso E; Bhat, Prajwal; Paccanaro, Alberto; Hamp, Tobias; Kassner, Rebecca; Seemayer, Stefan; Vicedo, Esmeralda; Schaefer, Christian; Achten, Dominik; Auer, Florian; Böhm, Ariane; Braun, Tatjana; Hecht, Maximilian; Heron, Mark; Hönigschmid, Peter; Hopf, Thomas; Kaufmann, Stefanie; Kiening, Michael; Krompass, Denis; Landerer, Cedric; Mahlich, Yannick; Roos, Manfred; Björne, Jari; Salakoski, Tapio; Wong, Andrew; Shatkay, Hagit; Gatzmann, Fanny; Sommer, Ingolf; Wass, Mark N; Sternberg, Michael J E; Škunca, Nives; Supek, Fran; Bošnjak, Matko; Panov, Panče; Džeroski, Sašo; Šmuc, Tomislav; Kourmpetis, Yiannis A I; van Dijk, Aalt D J; ter Braak, Cajo J F; Zhou, Yuanpeng; Gong, Qingtian; Dong, Xinran; Tian, Weidong; Falda, Marco; Fontana, Paolo; Lavezzo, Enrico; Di Camillo, Barbara; Toppo, Stefano; Lan, Liang; Djuric, Nemanja; Guo, Yuhong; Vucetic, Slobodan; Bairoch, Amos; Linial, Michal; Babbitt, Patricia C; Brenner, Steven E; Orengo, Christine; Rost, Burkhard; Mooney, Sean D; Friedberg, Iddo

    2013-01-01

    Automated annotation of protein function is challenging. As the number of sequenced genomes rapidly grows, the overwhelming majority of protein products can only be annotated computationally. If computational predictions are to be relied upon, it is crucial that the accuracy of these methods be high. Here we report the results from the first large-scale community-based Critical Assessment of protein Function Annotation (CAFA) experiment. Fifty-four methods representing the state-of-the-art for protein function prediction were evaluated on a target set of 866 proteins from eleven organisms. Two findings stand out: (i) today’s best protein function prediction algorithms significantly outperformed widely-used first-generation methods, with large gains on all types of targets; and (ii) although the top methods perform well enough to guide experiments, there is significant need for improvement of currently available tools. PMID:23353650

  10. Optimal Wind Energy Integration in Large-Scale Electric Grids

    NASA Astrophysics Data System (ADS)

    Albaijat, Mohammad H.

    The major concern in electric grid operation is operating under the most economical and reliable fashion to ensure affordability and continuity of electricity supply. This dissertation investigates the effects of such challenges, which affect electric grid reliability and economic operations. These challenges are: 1. Congestion of transmission lines, 2. Transmission lines expansion, 3. Large-scale wind energy integration, and 4. Phaser Measurement Units (PMUs) optimal placement for highest electric grid observability. Performing congestion analysis aids in evaluating the required increase of transmission line capacity in electric grids. However, it is necessary to evaluate expansion of transmission line capacity on methods to ensure optimal electric grid operation. Therefore, the expansion of transmission line capacity must enable grid operators to provide low-cost electricity while maintaining reliable operation of the electric grid. Because congestion affects the reliability of delivering power and increases its cost, the congestion analysis in electric grid networks is an important subject. Consequently, next-generation electric grids require novel methodologies for studying and managing congestion in electric grids. We suggest a novel method of long-term congestion management in large-scale electric grids. Owing to the complication and size of transmission line systems and the competitive nature of current grid operation, it is important for electric grid operators to determine how many transmission lines capacity to add. Traditional questions requiring answers are "Where" to add, "How much of transmission line capacity" to add, and "Which voltage level". Because of electric grid deregulation, transmission lines expansion is more complicated as it is now open to investors, whose main interest is to generate revenue, to build new transmission lines. Adding a new transmission capacity will help the system to relieve the transmission system congestion, create

  11. Large-scale quantum networks based on graphs

    NASA Astrophysics Data System (ADS)

    Epping, Michael; Kampermann, Hermann; Bruß, Dagmar

    2016-05-01

    Society relies and depends increasingly on information exchange and communication. In the quantum world, security and privacy is a built-in feature for information processing. The essential ingredient for exploiting these quantum advantages is the resource of entanglement, which can be shared between two or more parties. The distribution of entanglement over large distances constitutes a key challenge for current research and development. Due to losses of the transmitted quantum particles, which typically scale exponentially with the distance, intermediate quantum repeater stations are needed. Here we show how to generalise the quantum repeater concept to the multipartite case, by describing large-scale quantum networks, i.e. network nodes and their long-distance links, consistently in the language of graphs and graph states. This unifying approach comprises both the distribution of multipartite entanglement across the network, and the protection against errors via encoding. The correspondence to graph states also provides a tool for optimising the architecture of quantum networks.

  12. Large Scale Bacterial Colony Screening of Diversified FRET Biosensors

    PubMed Central

    Litzlbauer, Julia; Schifferer, Martina; Ng, David; Fabritius, Arne; Thestrup, Thomas; Griesbeck, Oliver

    2015-01-01

    Biosensors based on Förster Resonance Energy Transfer (FRET) between fluorescent protein mutants have started to revolutionize physiology and biochemistry. However, many types of FRET biosensors show relatively small FRET changes, making measurements with these probes challenging when used under sub-optimal experimental conditions. Thus, a major effort in the field currently lies in designing new optimization strategies for these types of sensors. Here we describe procedures for optimizing FRET changes by large scale screening of mutant biosensor libraries in bacterial colonies. We describe optimization of biosensor expression, permeabilization of bacteria, software tools for analysis, and screening conditions. The procedures reported here may help in improving FRET changes in multiple suitable classes of biosensors. PMID:26061878

  13. Towards Online Multiresolution Community Detection in Large-Scale Networks

    PubMed Central

    Huang, Jianbin; Sun, Heli; Liu, Yaguang; Song, Qinbao; Weninger, Tim

    2011-01-01

    The investigation of community structure in networks has aroused great interest in multiple disciplines. One of the challenges is to find local communities from a starting vertex in a network without global information about the entire network. Many existing methods tend to be accurate depending on a priori assumptions of network properties and predefined parameters. In this paper, we introduce a new quality function of local community and present a fast local expansion algorithm for uncovering communities in large-scale networks. The proposed algorithm can detect multiresolution community from a source vertex or communities covering the whole network. Experimental results show that the proposed algorithm is efficient and well-behaved in both real-world and synthetic networks. PMID:21887325

  14. Policy Driven Development: Flexible Policy Insertion for Large Scale Systems

    PubMed Central

    Demchak, Barry; Krüger, Ingolf

    2014-01-01

    The success of a software system depends critically on how well it reflects and adapts to stakeholder requirements. Traditional development methods often frustrate stakeholders by creating long latencies between requirement articulation and system deployment, especially in large scale systems. One source of latency is the maintenance of policy decisions encoded directly into system workflows at development time, including those involving access control and feature set selection. We created the Policy Driven Development (PDD) methodology to address these development latencies by enabling the flexible injection of decision points into existing workflows at runtime, thus enabling policy composition that integrates requirements furnished by multiple, oblivious stakeholder groups. Using PDD, we designed and implemented a production cyberinfrastructure that demonstrates policy and workflow injection that quickly implements stakeholder requirements, including features not contemplated in the original system design. PDD provides a path to quickly and cost effectively evolve such applications over a long lifetime. PMID:25383258

  15. Nonzero Density-Velocity Consistency Relations for Large Scale Structures.

    PubMed

    Rizzo, Luca Alberto; Mota, David F; Valageas, Patrick

    2016-08-19

    We present exact kinematic consistency relations for cosmological structures that do not vanish at equal times and can thus be measured in surveys. These rely on cross correlations between the density and velocity, or momentum, fields. Indeed, the uniform transport of small-scale structures by long-wavelength modes, which cannot be detected at equal times by looking at density correlations only, gives rise to a shift in the amplitude of the velocity field that could be measured. These consistency relations only rely on the weak equivalence principle and Gaussian initial conditions. They remain valid in the nonlinear regime and for biased galaxy fields. They can be used to constrain nonstandard cosmological scenarios or the large-scale galaxy bias. PMID:27588842

  16. Self-* and Adaptive Mechanisms for Large Scale Distributed Systems

    NASA Astrophysics Data System (ADS)

    Fragopoulou, P.; Mastroianni, C.; Montero, R.; Andrjezak, A.; Kondo, D.

    Large-scale distributed computing systems and infrastructure, such as Grids, P2P systems and desktop Grid platforms, are decentralized, pervasive, and composed of a large number of autonomous entities. The complexity of these systems is such that human administration is nearly impossible and centralized or hierarchical control is highly inefficient. These systems need to run on highly dynamic environments, where content, network topologies and workloads are continuously changing. Moreover, they are characterized by the high degree of volatility of their components and the need to provide efficient service management and to handle efficiently large amounts of data. This paper describes some of the areas for which adaptation emerges as a key feature, namely, the management of computational Grids, the self-management of desktop Grid platforms and the monitoring and healing of complex applications. It also elaborates on the use of bio-inspired algorithms to achieve self-management. Related future trends and challenges are described.

  17. Large-scale testing of structural clay tile infilled frames

    SciTech Connect

    Flanagan, R.D.; Bennett, R.M.

    1993-03-18

    A summary of large-scale cyclic static tests of structural clay tile infilled frames is given. In-plane racking tests examined the effects of varying frame stiffness, varying infill size, infill offset from frame centerline, and single and double wythe infill construction. Out-of-plane tests examined infilled frame response to inertial loadings and inter-story drift loadings. Sequential in-plane and out-of-plane loadings were performed to determine the effects of orthogonal damage and degradation on both strength and stiffness. A combined out-of-plane inertial and in-plane racking test was conducted to investigate the interaction of multi-directional loading. To determine constitutive properties of the infills, prism compression, mortar compression and various unit tile tests were performed.

  18. Large scale CO emission in the Orion Nebula

    NASA Astrophysics Data System (ADS)

    Marcelino, N.; Berne, O.; Cernicharo, J.

    2011-11-01

    We present 12CO and 13CO J=2-1 large scale maps of Orion A observed with the IRAM 30-m radiotelescope. The size of the maps is 1x0.8 deg^2 at its largest extent, and their angular and velocity resolutions (11" and about 0.4 km/s, respectively) are higher than those used in previous extended CO maps of Orion. Besides a very complex velocity structure, these maps show numerous filaments and gas condensations, cometary globules and cavities (or tunnels). All these are signatures of the feedback action of massive star formation on the preexisting molecular gas. Among them, the detection of periodic structures on the surface of an elongated molecular cloud, provide evidence of the development of hydrodynamical instabilities shaping the molecular cloud. The discovery of these ``waves'' shows the high angular and spectral resolution required to understand star formation processes.

  19. Phase Correlations and Topological Measures of Large-Scale Structure

    NASA Astrophysics Data System (ADS)

    Coles, P.

    The process of gravitational instability initiated by small primordial density perturbations is a vital ingredient of cosmological models that attempt to explain how galaxies and large-scale structure formed in the Universe. In the standard picture (the "concordance" model), a period of accelerated expansion ("inflation") generated density fluctuations with simple statistical properties through quantum processes (Starobinsky [82], [83], [84]; Guth [39]; Guth & Pi [40]; Albrecht & Steinhardt [2]; Linde [55]). In this scenario the primordial density field is assumed to form a statistically homogeneous and isotropic Gaussian random field (GRF). Over years of observational scrutiny this paradigm has strengthened its hold in the minds of cosmologists and has survived many tests, culminating in those furnished by the Wilkinson Microwave Anisotropy Probe (WMAP; Bennett et al. [7]; Hinshaw et al. [45].

  20. Grid infrastructure to support science portals for large scale instruments.

    SciTech Connect

    von Laszewski, G.; Foster, I.

    1999-09-29

    Soon, a new generation of scientific workbenches will be developed as a collaborative effort among various research institutions in the US. These scientific workbenches will be accessed in the Web via portals. Reusable components are needed to build such portals for different scientific disciplines, allowing uniform desktop access to remote resources. Such components will include tools and services enabling easy collaboration, job submission, job monitoring, component discovery, and persistent object storage. Based on experience gained from Grand Challenge applications for large-scale instruments, we demonstrate how Grid infrastructure components can be used to support the implementation of science portals. The availability of these components will simplify the prototype implementation of a common portal architecture.

  1. Roary: rapid large-scale prokaryote pan genome analysis

    PubMed Central

    Page, Andrew J.; Cummins, Carla A.; Hunt, Martin; Wong, Vanessa K.; Reuter, Sandra; Holden, Matthew T.G.; Fookes, Maria; Falush, Daniel; Keane, Jacqueline A.; Parkhill, Julian

    2015-01-01

    Summary: A typical prokaryote population sequencing study can now consist of hundreds or thousands of isolates. Interrogating these datasets can provide detailed insights into the genetic structure of prokaryotic genomes. We introduce Roary, a tool that rapidly builds large-scale pan genomes, identifying the core and accessory genes. Roary makes construction of the pan genome of thousands of prokaryote samples possible on a standard desktop without compromising on the accuracy of results. Using a single CPU Roary can produce a pan genome consisting of 1000 isolates in 4.5 hours using 13 GB of RAM, with further speedups possible using multiple processors. Availability and implementation: Roary is implemented in Perl and is freely available under an open source GPLv3 license from http://sanger-pathogens.github.io/Roary Contact: roary@sanger.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26198102

  2. Large scale Hugoniot material properties for Danby Marble

    SciTech Connect

    Rinehart, E.J.

    1993-11-01

    This paper presents the results of simulation experiments of nuclear underground testing carried out using the HYDROPLUS methodology for yield verifications of non-standard tests. The objective of this test series was to demonstrate the accuracy of stress and velocity measurements in hard, low porosity rock, to obtain comparisons of large-scale material properties with those obtained from laboratory testing of the same material, and to address the problems posed by a material having a clear precursor wave preceding the main shock wave. The test series consisted of three individual experimental tests. The first established material properties of the Danby marble selected for use in the experiments. The second and third tests looked at stress and velocity gage errors obtained when gages were placed in boreholes and grouted into place.

  3. Nonzero Density-Velocity Consistency Relations for Large Scale Structures

    NASA Astrophysics Data System (ADS)

    Rizzo, Luca Alberto; Mota, David F.; Valageas, Patrick

    2016-08-01

    We present exact kinematic consistency relations for cosmological structures that do not vanish at equal times and can thus be measured in surveys. These rely on cross correlations between the density and velocity, or momentum, fields. Indeed, the uniform transport of small-scale structures by long-wavelength modes, which cannot be detected at equal times by looking at density correlations only, gives rise to a shift in the amplitude of the velocity field that could be measured. These consistency relations only rely on the weak equivalence principle and Gaussian initial conditions. They remain valid in the nonlinear regime and for biased galaxy fields. They can be used to constrain nonstandard cosmological scenarios or the large-scale galaxy bias.

  4. Star formation associated with a large-scale infrared bubble

    NASA Astrophysics Data System (ADS)

    Xu, Jin-Long; Ju, Bing-Gang

    2014-09-01

    Aims: To investigate how a large-scale infrared bubble centered at l = 53.9° and b = 0.2° forms, and to study if star formation is taking place at the periphery of the bubble, we performed a multiwavelength study. Methods: Using the data from the Galactic Ring Survey (GRS) and Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE), we performed a study of a large-scale infrared bubble with a size of about 16 pc at a distance of 2.0 kpc. We present the 12CO J = 1-0, 13CO J = 1-0, and C18O J = 1-0 observations of HII region G53.54-0.01 (Sh2-82) obtained at the Purple Mountain Observation (PMO) 13.7 m radio telescope to investigate the detailed distribution of associated molecular material. In addition, we also used radiorecombination line and VLA data. To select young stellar objects (YSOs) consistent with this region, we used the GLIMPSE I catalog. Results: The large-scale infrared bubble shows a half-shell morphology at 8 μm. The H II regions of G53.54-0.01, G53.64+0.24, and G54.09-0.06 are situated on the bubble. Comparing the radio recombination line velocities and associated 13CO J = 1-0 components of the three H II regions, we found that the 8 μm emission associated with H II region G53.54-0.01 should belong to the foreground emission, and only overlap with the large-scale infrared bubble in the line of sight. Three extended green objects (EGOs, the candidate massive young stellar objects), as well as three H II regions and two small-scale bubbles are found located in the G54.09-0.06 complex, indicating an active massive star-forming region. Emission from C18O at J = 1-0 presents four cloud clumps on the northeastern border of H II region G53.54-0.01. By comparing the spectral profiles of 12CO J = 1-0, 13CO J = 1-0, and C18O J = 1-0 at the peak position of each clump, we found the collected gas in the three clumps, except for the clump coinciding with a massive YSO (IRAS 19282+1814). Using the evolutive model of the H II region, we derived that

  5. Theoretical expectations for bulk flows in large-scale surveys

    NASA Technical Reports Server (NTRS)

    Feldman, Hume A.; Watkins, Richard

    1994-01-01

    We calculate the theoretical expectation for the bulk motion of a large-scale survey of the type recently carried out by Lauer and Postman. Included are the effects of survey geometry, errors in the distance measurements, clustering properties of the sample, and different assumed power spectra. We considered the power spectrum calculated from the Infrared Astronomy Satellite (IRAS)-QDOT survey, as well as spectra from hot + cold and standard cold dark matter models. We find that measurement uncertainty, sparse sampling, and clustering can lead to a much larger expectation for the bulk motion of a cluster sample than for the volume as a whole. However, our results suggest that the expected bulk motion is still inconsistent with that reported by Lauer and Postman at the 95%-97% confidence level.

  6. Jet noise generated by large-scale coherent motion

    NASA Technical Reports Server (NTRS)

    Tam, Christopher K. W.

    1991-01-01

    The noise generated by large scale turbulence structures and instability waves of jets is discussed. Emphasis is placed on supersonic jets with moderate to high Reynolds numbers. This is because it is in these jets that unambiguous experimental and theoretical evidence is found indicating that large turbulence structures and instability waves are directly responsible for generating the dominant part of the noise. For subsonic jets similar large turbulence structures and instability waves do play a crucial role in the dynamics, spread, and mixing of the jet fluid. However, at subsonic convection speeds, they do not appear to be efficient noise generators. Many investigators believe that the dominant noise source of subsonic jets is, in fact, the small scale turbulence. As yet, this belief has not yet received universal acceptance. The issues involved are complicated and are not easy to resolve.

  7. Large-Scale All-Dielectric Metamaterial Perfect Reflectors

    SciTech Connect

    Moitra, Parikshit; Slovick, Brian A.; li, Wei; Kravchencko, Ivan I.; Briggs, Dayrl P.; Krishnamurthy, S.; Valentine, Jason

    2015-05-08

    All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances can be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.

  8. Large scale rigidity-based flexibility analysis of biomolecules

    PubMed Central

    Streinu, Ileana

    2016-01-01

    KINematics And RIgidity (KINARI) is an on-going project for in silico flexibility analysis of proteins. The new version of the software, Kinari-2, extends the functionality of our free web server KinariWeb, incorporates advanced web technologies, emphasizes the reproducibility of its experiments, and makes substantially improved tools available to the user. It is designed specifically for large scale experiments, in particular, for (a) very large molecules, including bioassemblies with high degree of symmetry such as viruses and crystals, (b) large collections of related biomolecules, such as those obtained through simulated dilutions, mutations, or conformational changes from various types of dynamics simulations, and (c) is intended to work as seemlessly as possible on the large, idiosyncratic, publicly available repository of biomolecules, the Protein Data Bank. We describe the system design, along with the main data processing, computational, mathematical, and validation challenges underlying this phase of the KINARI project. PMID:26958583

  9. Large-scale characterization of the murine cardiac proteome.

    PubMed

    Cosme, Jake; Emili, Andrew; Gramolini, Anthony O

    2013-01-01

    Cardiomyopathies are diseases of the heart that result in impaired cardiac muscle function. This dysfunction can progress to an inability to supply blood to the body. Cardiovascular diseases play a large role in overall global morbidity. Investigating the protein changes in the heart during disease can uncover pathophysiological mechanisms and potential therapeutic targets. Establishing a global protein expression "footprint" can facilitate more targeted studies of diseases of the heart.In the technical review presented here, we present methods to elucidate the heart's proteome through subfractionation of the cellular compartments to reduce sample complexity and improve detection of lower abundant proteins during multidimensional protein identification technology analysis. Analysis of the cytosolic, microsomal, and mitochondrial subproteomes separately in order to characterize the murine cardiac proteome is advantageous by simplifying complex cardiac protein mixtures. In combination with bioinformatic analysis and genome correlation, large-scale protein changes can be identified at the cellular compartment level in this animal model. PMID:23606244

  10. Computational solutions to large-scale data management and analysis

    PubMed Central

    Schadt, Eric E.; Linderman, Michael D.; Sorenson, Jon; Lee, Lawrence; Nolan, Garry P.

    2011-01-01

    Today we can generate hundreds of gigabases of DNA and RNA sequencing data in a week for less than US$5,000. The astonishing rate of data generation by these low-cost, high-throughput technologies in genomics is being matched by that of other technologies, such as real-time imaging and mass spectrometry-based flow cytometry. Success in the life sciences will depend on our ability to properly interpret the large-scale, high-dimensional data sets that are generated by these technologies, which in turn requires us to adopt advances in informatics. Here we discuss how we can master the different types of computational environments that exist — such as cloud and heterogeneous computing — to successfully tackle our big data problems. PMID:20717155

  11. Large-Scale Chaos and Fluctuations in Active Nematics

    NASA Astrophysics Data System (ADS)

    Ngo, Sandrine; Peshkov, Anton; Aranson, Igor S.; Bertin, Eric; Ginelli, Francesco; Chaté, Hugues

    2014-07-01

    We show that dry active nematics, e.g., collections of shaken elongated granular particles, exhibit large-scale spatiotemporal chaos made of interacting dense, ordered, bandlike structures in a parameter region including the linear onset of nematic order. These results are obtained from the study of both the well-known (deterministic) hydrodynamic equations describing these systems and of the self-propelled particle model they were derived from. We prove, in particular, that the chaos stems from the generic instability of the band solution of the hydrodynamic equations. Revisiting the status of the strong fluctuations and long-range correlations in the particle model, we show that the giant number fluctuations observed in the chaotic phase are a trivial consequence of density segregation. However anomalous, curvature-driven number fluctuations are present in the homogeneous quasiordered nematic phase and characterized by a nontrivial scaling exponent.

  12. Reconstructing a Large-Scale Population for Social Simulation

    NASA Astrophysics Data System (ADS)

    Fan, Zongchen; Meng, Rongqing; Ge, Yuanzheng; Qiu, Xiaogang

    The advent of social simulation has provided an opportunity to research on social systems. More and more researchers tend to describe the components of social systems in a more detailed level. Any simulation needs the support of population data to initialize and implement the simulation systems. However, it's impossible to get the data which provide full information about individuals and households. We propose a two-step method to reconstruct a large-scale population for a Chinese city according to Chinese culture. Firstly, a baseline population is generated through gathering individuals into households one by one; secondly, social relationships such as friendship are assigned to the baseline population. Through a case study, a population of 3,112,559 individuals gathered in 1,133,835 households is reconstructed for Urumqi city, and the results show that the generated data can respect the real data quite well. The generated data can be applied to support modeling of some social phenomenon.

  13. Large Scale Deformation of the Western U.S. Cordillera

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.

    2002-01-01

    Over the past couple of years, with support from NASA, we used a large collection of data from GPS, VLBI, SLR, and DORIS networks which span the Westem U.S. Cordillera (WUSC) to precisely quantify present-day large-scale crustal deformations in a single uniform reference frame. Our work was roughly divided into an analysis of these space geodetic observations to infer the deformation field across and within the entire plate boundary zone, and an investigation of the implications of this deformation field regarding plate boundary dynamics. Following the determination of the first generation WUSC velocity solution, we placed high priority on the dissemination of the velocity estimates. With in-kind support from the Smithsonian Astrophysical Observatory, we constructed a web-site which allows anyone to access the data, and to determine their own velocity reference frame.

  14. Large Scale Deformation of the Western U.S. Cordillera

    NASA Technical Reports Server (NTRS)

    Bennett, Richard A.

    2002-01-01

    Over the past couple of years, with support from NASA, we used a large collection of data from GPS, VLBI, SLR, and DORIS networks which span the Western U.S. Cordillera (WUSC) to precisely quantify present-day large-scale crustal deformations in a single uniform reference frame. Our work was roughly divided into an analysis of these space geodetic observations to infer the deformation field across and within the entire plate boundary zone, and an investigation of the implications of this deformation field regarding plate boundary dynamics. Following the determination of the first generation WUSC velocity solution, we placed high priority on the dissemination of the velocity estimates. With in-kind support from the Smithsonian Astrophysical Observatory, we constructed a web-site which allows anyone to access the data, and to determine their own velocity reference frame.

  15. Large-scale cortical correlation structure of spontaneous oscillatory activity

    PubMed Central

    Hipp, Joerg F.; Hawellek, David J.; Corbetta, Maurizio; Siegel, Markus; Engel, Andreas K.

    2013-01-01

    Little is known about the brain-wide correlation of electrophysiological signals. Here we show that spontaneous oscillatory neuronal activity exhibits frequency-specific spatial correlation structure in the human brain. We developed an analysis approach that discounts spurious correlation of signal power caused by the limited spatial resolution of electrophysiological measures. We applied this approach to source estimates of spontaneous neuronal activity reconstructed from magnetoencephalography (MEG). Overall, correlation of power across cortical regions was strongest in the alpha to beta frequency range (8–32 Hz) and correlation patterns depended on the underlying oscillation frequency. Global hubs resided in the medial temporal lobe in the theta frequency range (4–6 Hz), in lateral parietal areas in the alpha to beta frequency range (8–23 Hz), and in sensorimotor areas for higher frequencies (32–45 Hz). Our data suggest that interactions in various large-scale cortical networks may be reflected in frequency specific power-envelope correlations. PMID:22561454

  16. Efficient multiobjective optimization scheme for large scale structures

    NASA Astrophysics Data System (ADS)

    Grandhi, Ramana V.; Bharatram, Geetha; Venkayya, V. B.

    1992-09-01

    This paper presents a multiobjective optimization algorithm for an efficient design of large scale structures. The algorithm is based on generalized compound scaling techniques to reach the intersection of multiple functions. Multiple objective functions are treated similar to behavior constraints. Thus, any number of objectives can be handled in the formulation. Pseudo targets on objectives are generated at each iteration in computing the scale factors. The algorithm develops a partial Pareto set. This method is computationally efficient due to the fact that it does not solve many single objective optimization problems in reaching the Pareto set. The computational efficiency is compared with other multiobjective optimization methods, such as the weighting method and the global criterion method. Trusses, plate, and wing structure design cases with stress and frequency considerations are presented to demonstrate the effectiveness of the method.

  17. Solving large scale traveling salesman problems by chaotic neurodynamics.

    PubMed

    Hasegawa, Mikio; Ikeguch, Tohru; Aihara, Kazuyuki

    2002-03-01

    We propose a novel approach for solving large scale traveling salesman problems (TSPs) by chaotic dynamics. First, we realize the tabu search on a neural network, by utilizing the refractory effects as the tabu effects. Then, we extend it to a chaotic neural network version. We propose two types of chaotic searching methods, which are based on two different tabu searches. While the first one requires neurons of the order of n2 for an n-city TSP, the second one requires only n neurons. Moreover, an automatic parameter tuning method of our chaotic neural network is presented for easy application to various problems. Last, we show that our method with n neurons is applicable to large TSPs such as an 85,900-city problem and exhibits better performance than the conventional stochastic searches and the tabu searches. PMID:12022514

  18. Applications of large-scale density functional theory in biology

    NASA Astrophysics Data System (ADS)

    Cole, Daniel J.; Hine, Nicholas D. M.

    2016-10-01

    Density functional theory (DFT) has become a routine tool for the computation of electronic structure in the physics, materials and chemistry fields. Yet the application of traditional DFT to problems in the biological sciences is hindered, to a large extent, by the unfavourable scaling of the computational effort with system size. Here, we review some of the major software and functionality advances that enable insightful electronic structure calculations to be performed on systems comprising many thousands of atoms. We describe some of the early applications of large-scale DFT to the computation of the electronic properties and structure of biomolecules, as well as to paradigmatic problems in enzymology, metalloproteins, photosynthesis and computer-aided drug design. With this review, we hope to demonstrate that first principles modelling of biological structure-function relationships are approaching a reality.

  19. Proteomics beyond large-scale protein expression analysis.

    PubMed

    Boersema, Paul J; Kahraman, Abdullah; Picotti, Paola

    2015-08-01

    Proteomics is commonly referred to as the application of high-throughput approaches to protein expression analysis. Typical results of proteomics studies are inventories of the protein content of a sample or lists of differentially expressed proteins across multiple conditions. Recently, however, an explosion of novel proteomics workflows has significantly expanded proteomics beyond the analysis of protein expression. Targeted proteomics methods, for example, enable the analysis of the fine dynamics of protein systems, such as a specific pathway or a network of interacting proteins, and the determination of protein complex stoichiometries. Structural proteomics tools allow extraction of restraints for structural modeling and identification of structurally altered proteins on a proteome-wide scale. Other variations of the proteomic workflow can be applied to the large-scale analysis of protein activity, location, degradation and turnover. These exciting developments provide new tools for multi-level 'omics' analysis and for the modeling of biological networks in the context of systems biology studies. PMID:25636126

  20. Applications of large-scale density functional theory in biology.

    PubMed

    Cole, Daniel J; Hine, Nicholas D M

    2016-10-01

    Density functional theory (DFT) has become a routine tool for the computation of electronic structure in the physics, materials and chemistry fields. Yet the application of traditional DFT to problems in the biological sciences is hindered, to a large extent, by the unfavourable scaling of the computational effort with system size. Here, we review some of the major software and functionality advances that enable insightful electronic structure calculations to be performed on systems comprising many thousands of atoms. We describe some of the early applications of large-scale DFT to the computation of the electronic properties and structure of biomolecules, as well as to paradigmatic problems in enzymology, metalloproteins, photosynthesis and computer-aided drug design. With this review, we hope to demonstrate that first principles modelling of biological structure-function relationships are approaching a reality. PMID:27494095

  1. Large scale radio/X-ray jets in microquasars

    NASA Astrophysics Data System (ADS)

    Corbel, Stephane; Tzioumis, Anastasios; Fender, Rob; Kaaret, Philip; Orosz, Jerry; Tomsick, John

    2012-10-01

    The discovery with ATCA of large scale radio lobes around the microquasar XTE J1550-564 has led to the discovery with Chandra (for the first time) of moving relativistic X-ray jets in a galactic accreting source. The lobes are likely due to the interaction of relativistic plasma with the ISM. This ATCA proposal has allowed similar discovery in H 1743-322, and therefore that it maybe a common occurrence in the Galaxy. Recently, we have witnessed with ATCA the formation of similar lobes in the black hole GX 339-4. We propose to use the Compact Array to continue our search for radio lobes in microquasars that have been active in the past years.

  2. Large scale radio/X-ray jets in microquasars

    NASA Astrophysics Data System (ADS)

    Corbel, Stephane; Tzioumis, Anastasios; Fender, Rob; Kaaret, Philip; Tomsick, John; Orosz, Jerry

    2011-10-01

    The discovery with ATCA of large scale radio lobes around the microquasar XTE J1550-564 has led to the discovery with Chandra (for the first time) of moving relativistic X-ray jets in a galactic accreting source. The lobes are likely due to the interaction of relativistic plasma with the ISM. This ATCA proposal has allowed similar discovery in H 1743-322, and therefore that it maybe a common occurrence in the Galaxy. Recently, we have witnessed with ATCA the formation of similar lobes in the black hole GX 339-4. We propose to use the Compact Array to continue our search for radio lobes in microquasars that have been active in the past years.

  3. Large scale radio/X-ray jets in microquasars

    NASA Astrophysics Data System (ADS)

    Corbel, Stephane; Tzioumis, Anastasios; Fender, Rob; Kaaret, Philip; Orosz, Jerry; Tomsick, John

    2013-10-01

    The discovery with ATCA of large scale radio lobes around the microquasar XTE J1550-564 has led to the discovery with Chandra (for the first time) of moving relativistic X-ray jets in a galactic accreting source. The lobes are likely due to the interaction of relativistic plasma with the ISM. This ATCA proposal has allowed similar discovery in H 1743-322, and therefore that it maybe a common occurrence in the Galaxy. Recently, we have witnessed with ATCA the formation of similar lobes in the black hole GX 339-4. We propose to use the Compact Array to continue our search for radio lobes in microquasars that have been active in the past years.

  4. Large scale radio/X-ray jets in microquasars

    NASA Astrophysics Data System (ADS)

    Corbel, Stephane; Tzioumis, Anastasios; Fender, Rob; Kaaret, Philip; Tomsick, John; Orosz, Jerry

    2011-04-01

    The discovery with ATCA of large scale radio lobes around the microquasar XTE J1550-564 has led to the discovery with Chandra (for the first time) of moving relativistic X-ray jets in a galactic accreting source. The lobes are likely due to the interaction of relativistic plasma with the ISM. This ATCA proposal has allowed similar discovery in H 1743-322, and therefore that it maybe a common occurrence in the Galaxy. Recently, we have witnessed with ATCA the formation of similar lobes in the black hole GX 339-4. We propose to use the Compact Array to continue our search for radio lobes in microquasars that have been active in the past years.

  5. Large scale radio/X-ray jets in microquasars

    NASA Astrophysics Data System (ADS)

    Corbel, Stephane; Tzioumis, Anastasios; Fender, Rob; Kaaret, Philip; Orosz, Jerry; Tomsick, John

    2013-04-01

    The discovery with ATCA of large scale radio lobes around the microquasar XTE J1550-564 has led to the discovery with Chandra (for the first time) of moving relativistic X-ray jets in a galactic accreting source. The lobes are likely due to the interaction of relativistic plasma with the ISM. This ATCA proposal has allowed similar discovery in H 1743-322, and therefore that it maybe a common occurrence in the Galaxy. Recently, we have witnessed with ATCA the formation of similar lobes in the black hole GX 339-4. We propose to use the Compact Array to continue our search for radio lobes in microquasars that have been active in the past years.

  6. Large scale radio/X-ray jets in microquasars

    NASA Astrophysics Data System (ADS)

    Corbel, Stephane; Tzioumis, Anastasios; Fender, Rob; Kaaret, Philip; Tomsick, John; Orosz, Jerry

    2012-04-01

    The discovery with ATCA of large scale radio lobes around the microquasar XTE J1550-564 has led to the discovery with Chandra (for the first time) of moving relativistic X-ray jets in a galactic accreting source. The lobes are likely due to the interaction of relativistic plasma with the ISM. This ATCA proposal has allowed similar discovery in H 1743-322, and therefore that it maybe a common occurrence in the Galaxy. Recently, we have witnessed with ATCA the formation of similar lobes in the black hole GX 339-4. We propose to use the Compact Array to continue our search for radio lobes in microquasars that have been active in the past years.

  7. Impact of Parallel Computing on Large Scale Aeroelastic Computations

    NASA Technical Reports Server (NTRS)

    Guruswamy, Guru P.; Kwak, Dochan (Technical Monitor)

    2000-01-01

    Aeroelasticity is computationally one of the most intensive fields in aerospace engineering. Though over the last three decades the computational speed of supercomputers have substantially increased, they are still inadequate for large scale aeroelastic computations using high fidelity flow and structural equations. In addition to reaching a saturation in computational speed because of changes in economics, computer manufactures are stopping the manufacturing of mainframe type supercomputers. This has led computational aeroelasticians to face the gigantic task of finding alternate approaches for fulfilling their needs. The alternate path to over come speed and availability limitations of mainframe type supercomputers is to use parallel computers. During this decade several different architectures have evolved. In FY92 the US Government started the High Performance Computing and Communication (HPCC) program. As a participant in this program NASA developed several parallel computational tools for aeroelastic applications. This talk describes the impact of those application tools on high fidelity based multidisciplinary analysis.

  8. Lightweight computational steering of very large scale molecular dynamics simulations

    SciTech Connect

    Beazley, D.M.; Lomdahl, P.S.

    1996-09-01

    We present a computational steering approach for controlling, analyzing, and visualizing very large scale molecular dynamics simulations involving tens to hundreds of millions of atoms. Our approach relies on extensible scripting languages and an easy to use tool for building extensions and modules. The system is extremely easy to modify, works with existing C code, is memory efficient, and can be used from inexpensive workstations and networks. We demonstrate how we have used this system to manipulate data from production MD simulations involving as many as 104 million atoms running on the CM-5 and Cray T3D. We also show how this approach can be used to build systems that integrate common scripting languages (including Tcl/Tk, Perl, and Python), simulation code, user extensions, and commercial data analysis packages.

  9. Performance Health Monitoring of Large-Scale Systems

    SciTech Connect

    Rajamony, Ram

    2014-11-20

    This report details the progress made on the ASCR funded project Performance Health Monitoring for Large Scale Systems. A large-­‐scale application may not achieve its full performance potential due to degraded performance of even a single subsystem. Detecting performance faults, isolating them, and taking remedial action is critical for the scale of systems on the horizon. PHM aims to develop techniques and tools that can be used to identify and mitigate such performance problems. We accomplish this through two main aspects. The PHM framework encompasses diagnostics, system monitoring, fault isolation, and performance evaluation capabilities that indicates when a performance fault has been detected, either due to an anomaly present in the system itself or due to contention for shared resources between concurrently executing jobs. Software components called the PHM Control system then build upon the capabilities provided by the PHM framework to mitigate degradation caused by performance problems.

  10. A large-scale crop protection bioassay data set.

    PubMed

    Gaulton, Anna; Kale, Namrata; van Westen, Gerard J P; Bellis, Louisa J; Bento, A Patrícia; Davies, Mark; Hersey, Anne; Papadatos, George; Forster, Mark; Wege, Philip; Overington, John P

    2015-01-01

    ChEMBL is a large-scale drug discovery database containing bioactivity information primarily extracted from scientific literature. Due to the medicinal chemistry focus of the journals from which data are extracted, the data are currently of most direct value in the field of human health research. However, many of the scientific use-cases for the current data set are equally applicable in other fields, such as crop protection research: for example, identification of chemical scaffolds active against a particular target or endpoint, the de-convolution of the potential targets of a phenotypic assay, or the potential targets/pathways for safety liabilities. In order to broaden the applicability of the ChEMBL database and allow more widespread use in crop protection research, an extensive data set of bioactivity data of insecticidal, fungicidal and herbicidal compounds and assays was collated and added to the database. PMID:26175909

  11. Monitoring large-scale precipitation over the globe

    SciTech Connect

    Xie, Pingping; Arkin, P.A.

    1997-11-01

    A previously developed algorithm was used to produce global monthly precipitation analysis on a 2.5{degrees} latitude/longitude grid for a 17-year period from 1979 to 1995. This paper reports the construction of the data set and describes some of its applications. Seven kinds of individual data sources were used, including gauge observations, estimates inferred from satellite observations, and the National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) reanalysis. The merged analysis was applied to investigate the annual and interannual variability in large-scale precipitation. The mean distribution and the annual cycle of the 17-year merged analysis exhibited reasonable agreements with existing long-term means but with major differences over the eastern Pacific. The interannual variability associated with the El Nino-Southern Oscillation is similar to previous findings, but with substantial details over the ocean. 13 refs., 4 figs.

  12. Towards online multiresolution community detection in large-scale networks.

    PubMed

    Huang, Jianbin; Sun, Heli; Liu, Yaguang; Song, Qinbao; Weninger, Tim

    2011-01-01

    The investigation of community structure in networks has aroused great interest in multiple disciplines. One of the challenges is to find local communities from a starting vertex in a network without global information about the entire network. Many existing methods tend to be accurate depending on a priori assumptions of network properties and predefined parameters. In this paper, we introduce a new quality function of local community and present a fast local expansion algorithm for uncovering communities in large-scale networks. The proposed algorithm can detect multiresolution community from a source vertex or communities covering the whole network. Experimental results show that the proposed algorithm is efficient and well-behaved in both real-world and synthetic networks. PMID:21887325

  13. Scalable Parallel Distance Field Construction for Large-Scale Applications.

    PubMed

    Yu, Hongfeng; Xie, Jinrong; Ma, Kwan-Liu; Kolla, Hemanth; Chen, Jacqueline H

    2015-10-01

    Computing distance fields is fundamental to many scientific and engineering applications. Distance fields can be used to direct analysis and reduce data. In this paper, we present a highly scalable method for computing 3D distance fields on massively parallel distributed-memory machines. A new distributed spatial data structure, named parallel distance tree, is introduced to manage the level sets of data and facilitate surface tracking over time, resulting in significantly reduced computation and communication costs for calculating the distance to the surface of interest from any spatial locations. Our method supports several data types and distance metrics from real-world applications. We demonstrate its efficiency and scalability on state-of-the-art supercomputers using both large-scale volume datasets and surface models. We also demonstrate in-situ distance field computation on dynamic turbulent flame surfaces for a petascale combustion simulation. Our work greatly extends the usability of distance fields for demanding applications. PMID:26357251

  14. Thermophoretically induced large-scale deformations around microscopic heat centers

    NASA Astrophysics Data System (ADS)

    Puljiz, Mate; Orlishausen, Michael; Köhler, Werner; Menzel, Andreas M.

    2016-05-01

    Selectively heating a microscopic colloidal particle embedded in a soft elastic matrix is a situation of high practical relevance. For instance, during hyperthermic cancer treatment, cell tissue surrounding heated magnetic colloidal particles is destroyed. Experiments on soft elastic polymeric matrices suggest a very long-ranged, non-decaying radial component of the thermophoretically induced displacement fields around the microscopic heat centers. We theoretically confirm this conjecture using a macroscopic hydrodynamic two-fluid description. Both thermophoretic and elastic effects are included in this theory. Indeed, we find that the elasticity of the environment can cause the experimentally observed large-scale radial displacements in the embedding matrix. Additional experiments confirm the central role of elasticity. Finally, a linearly decaying radial component of the displacement field in the experiments is attributed to the finite size of the experimental sample. Similar results are obtained from our theoretical analysis under modified boundary conditions.

  15. Large-Scale Quantitative Analysis of Painting Arts

    PubMed Central

    Kim, Daniel; Son, Seung-Woo; Jeong, Hawoong

    2014-01-01

    Scientists have made efforts to understand the beauty of painting art in their own languages. As digital image acquisition of painting arts has made rapid progress, researchers have come to a point where it is possible to perform statistical analysis of a large-scale database of artistic paints to make a bridge between art and science. Using digital image processing techniques, we investigate three quantitative measures of images – the usage of individual colors, the variety of colors, and the roughness of the brightness. We found a difference in color usage between classical paintings and photographs, and a significantly low color variety of the medieval period. Interestingly, moreover, the increment of roughness exponent as painting techniques such as chiaroscuro and sfumato have advanced is consistent with historical circumstances. PMID:25501877

  16. A mini review: photobioreactors for large scale algal cultivation.

    PubMed

    Gupta, Prabuddha L; Lee, Seung-Mok; Choi, Hee-Jeong

    2015-09-01

    Microalgae cultivation has gained much interest in terms of the production of foods, biofuels, and bioactive compounds and offers a great potential option for cleaning the environment through CO2 sequestration and wastewater treatment. Although open pond cultivation is most affordable option, there tends to be insufficient control on growth conditions and the risk of contamination. In contrast, while providing minimal risk of contamination, closed photobioreactors offer better control on culture conditions, such as: CO2 supply, water supply, optimal temperatures, efficient exposure to light, culture density, pH levels, and mixing rates. For a large scale production of biomass, efficient photobioreactors are required. This review paper describes general design considerations pertaining to photobioreactor systems, in order to cultivate microalgae for biomass production. It also discusses the current challenges in designing of photobioreactors for the production of low-cost biomass. PMID:26085485

  17. Successful Physician Training Program for Large Scale EMR Implementation

    PubMed Central

    Stevens, L.A.; Mailes, E.S.; Goad, B.A.; Longhurst, C.A.

    2015-01-01

    Summary End-user training is an essential element of electronic medical record (EMR) implementation and frequently suffers from minimal institutional investment. In addition, discussion of successful EMR training programs for physicians is limited in the literature. The authors describe a successful physician-training program at Stanford Children’s Health as part of a large scale EMR implementation. Evaluations of classroom training, obtained at the conclusion of each class, revealed high physician satisfaction with the program. Free-text comments from learners focused on duration and timing of training, the learning environment, quality of the instructors, and specificity of training to their role or department. Based upon participant feedback and institutional experience, best practice recommendations, including physician engagement, curricular design, and assessment of proficiency and recognition, are suggested for future provider EMR training programs. The authors strongly recommend the creation of coursework to group providers by common workflow. PMID:25848415

  18. Automated Sequence Preprocessing in a Large-Scale Sequencing Environment

    PubMed Central

    Wendl, Michael C.; Dear, Simon; Hodgson, Dave; Hillier, LaDeana

    1998-01-01

    A software system for transforming fragments from four-color fluorescence-based gel electrophoresis experiments into assembled sequence is described. It has been developed for large-scale processing of all trace data, including shotgun and finishing reads, regardless of clone origin. Design considerations are discussed in detail, as are programming implementation and graphic tools. The importance of input validation, record tracking, and use of base quality values is emphasized. Several quality analysis metrics are proposed and applied to sample results from recently sequenced clones. Such quantities prove to be a valuable aid in evaluating modifications of sequencing protocol. The system is in full production use at both the Genome Sequencing Center and the Sanger Centre, for which combined weekly production is ∼100,000 sequencing reads per week. PMID:9750196

  19. Large-scale asymmetric synthesis of a cathepsin S inhibitor.

    PubMed

    Lorenz, Jon C; Busacca, Carl A; Feng, XuWu; Grinberg, Nelu; Haddad, Nizar; Johnson, Joe; Kapadia, Suresh; Lee, Heewon; Saha, Anjan; Sarvestani, Max; Spinelli, Earl M; Varsolona, Rich; Wei, Xudong; Zeng, Xingzhong; Senanayake, Chris H

    2010-02-19

    A potent reversible inhibitor of the cysteine protease cathepsin-S was prepared on large scale using a convergent synthetic route, free of chromatography and cryogenics. Late-stage peptide coupling of a chiral urea acid fragment with a functionalized aminonitrile was employed to prepare the target, using 2-hydroxypyridine as a robust, nonexplosive replacement for HOBT. The two key intermediates were prepared using a modified Strecker reaction for the aminonitrile and a phosphonation-olefination-rhodium-catalyzed asymmetric hydrogenation sequence for the urea. A palladium-catalyzed vinyl transfer coupled with a Claisen reaction was used to produce the aldehyde required for the side chain. Key scale up issues, safety calorimetry, and optimization of all steps for multikilogram production are discussed. PMID:20102230

  20. Scalable parallel distance field construction for large-scale applications

    SciTech Connect

    Yu, Hongfeng; Xie, Jinrong; Ma, Kwan -Liu; Kolla, Hemanth; Chen, Jacqueline H.

    2015-10-01

    Computing distance fields is fundamental to many scientific and engineering applications. Distance fields can be used to direct analysis and reduce data. In this paper, we present a highly scalable method for computing 3D distance fields on massively parallel distributed-memory machines. Anew distributed spatial data structure, named parallel distance tree, is introduced to manage the level sets of data and facilitate surface tracking overtime, resulting in significantly reduced computation and communication costs for calculating the distance to the surface of interest from any spatial locations. Our method supports several data types and distance metrics from real-world applications. We demonstrate its efficiency and scalability on state-of-the-art supercomputers using both large-scale volume datasets and surface models. We also demonstrate in-situ distance field computation on dynamic turbulent flame surfaces for a petascale combustion simulation. In conclusion, our work greatly extends the usability of distance fields for demanding applications.

  1. Computational Issues in Damping Identification for Large Scale Problems

    NASA Technical Reports Server (NTRS)

    Pilkey, Deborah L.; Roe, Kevin P.; Inman, Daniel J.

    1997-01-01

    Two damping identification methods are tested for efficiency in large-scale applications. One is an iterative routine, and the other a least squares method. Numerical simulations have been performed on multiple degree-of-freedom models to test the effectiveness of the algorithm and the usefulness of parallel computation for the problems. High Performance Fortran is used to parallelize the algorithm. Tests were performed using the IBM-SP2 at NASA Ames Research Center. The least squares method tested incurs high communication costs, which reduces the benefit of high performance computing. This method's memory requirement grows at a very rapid rate meaning that larger problems can quickly exceed available computer memory. The iterative method's memory requirement grows at a much slower pace and is able to handle problems with 500+ degrees of freedom on a single processor. This method benefits from parallelization, and significant speedup can he seen for problems of 100+ degrees-of-freedom.

  2. Atypical Behavior Identification in Large Scale Network Traffic

    SciTech Connect

    Best, Daniel M.; Hafen, Ryan P.; Olsen, Bryan K.; Pike, William A.

    2011-10-23

    Cyber analysts are faced with the daunting challenge of identifying exploits and threats within potentially billions of daily records of network traffic. Enterprise-wide cyber traffic involves hundreds of millions of distinct IP addresses and results in data sets ranging from terabytes to petabytes of raw data. Creating behavioral models and identifying trends based on those models requires data intensive architectures and techniques that can scale as data volume increases. Analysts need scalable visualization methods that foster interactive exploration of data and enable identification of behavioral anomalies. Developers must carefully consider application design, storage, processing, and display to provide usability and interactivity with large-scale data. We present an application that highlights atypical behavior in enterprise network flow records. This is accomplished by utilizing data intensive architectures to store the data, aggregation techniques to optimize data access, statistical techniques to characterize behavior, and a visual analytic environment to render the behavioral trends, highlight atypical activity, and allow for exploration.

  3. The large-scale radio structure of R Aquarii

    NASA Technical Reports Server (NTRS)

    Hollis, J. M.; Michalitsianos, A. G.; Oliversen, R. J.; Yusef-Zadeh, F.; Kafatos, M.

    1987-01-01

    Radio continuum observations of the R Aqr symbiotic star system, using the compact D configuration of the VLA at 6-cm wavelength, reveal a large-scale about 2-arcmin structure engulfing the binary, which has long been known to have a similar optical nebula. This optical/radio nebula possesses about 4 x 10 to the 42nd ergs of kinetic energy which is typical of a recurrent nova outburst. Moreover, a cluster of a dozen additional 6-cm radio sources were observed in proximity to R Aqr, most of these discrete sources lie about 3 arcmin south and/or west of R Aqr and, coupled with previous 20-cm data, spectral indices limits suggest a thermal nature for some of these sources. If the thermal members of the cluster are associated with R Aqr, it may indicate a prehistoric eruption of the system's suspected recurrent nova. The nonthermal cluster members may be extragalactic background radio sources.

  4. Large-Scale All-Dielectric Metamaterial Perfect Reflectors

    DOE PAGESBeta

    Moitra, Parikshit; Slovick, Brian A.; li, Wei; Kravchencko, Ivan I.; Briggs, Dayrl P.; Krishnamurthy, S.; Valentine, Jason

    2015-05-08

    All-dielectric metamaterials offer a potential low-loss alternative to plasmonic metamaterials at optical frequencies. In this paper, we take advantage of the low absorption loss as well as the simple unit cell geometry to demonstrate large-scale (centimeter-sized) all-dielectric metamaterial perfect reflectors made from silicon cylinder resonators. These perfect reflectors, operating in the telecommunications band, were fabricated using self-assembly based nanosphere lithography. In spite of the disorder originating from the self-assembly process, the average reflectance of the metamaterial perfect reflectors is 99.7% at 1530 nm, surpassing the reflectance of metallic mirrors. Moreover, the spectral separation of the electric and magnetic resonances canmore » be chosen to achieve the required reflection bandwidth while maintaining a high tolerance to disorder. Finally, the scalability of this design could lead to new avenues of manipulating light for low-loss and large-area photonic applications.« less

  5. Large-scale coastal evolution of Louisiana's barrier islands

    USGS Publications Warehouse

    List, Jeffrey H.; Jaffe, Bruce E.; Sallenger,, Asbury H., Jr.

    1991-01-01

    The prediction of large-scale coastal change is an extremely important, but distant goal. Here we describe some of our initial efforts in this direction, using historical bathymetric information along a 150 km reach of the rapidly evolving barrier island coast of Louisiana. Preliminary results suggest that the relative sea level rise rate, though extremely high in the area, has played a secondary role in coastal erosion over the last 100 years, with longshore transport of sand-sized sediment being the primary cause. Prediction of future conditions is hampered by a general lack of erosion processes understanding; however, an examination of the changing volumes of sand stored in a large ebb-tidal delta system suggests a continued high rate of shoreline retreat driven by the longshore re-distribution of sand.

  6. Modeling and Dynamic Simulation of a Large Scale Helium Refrigerator

    NASA Astrophysics Data System (ADS)

    Lv, C.; Qiu, T. N.; Wu, J. H.; Xie, X. J.; Li, Q.

    In order to simulate the transient behaviors of a newly developed 2 kW helium refrigerator, a numerical model of the critical equipment including a screw compressor with variable-frequency drive, plate-fin heat exchangers, a turbine expander, and pneumatic valves wasdeveloped. In the simulation,the calculation of the helium thermodynamic properties arebased on 32-parameter modified Benedict-Webb-Rubin (MBWR) state equation.The start-up process of the warm compressor station with gas management subsystem, and the cool-down process of cold box in an actual operation, were dynamically simulated. The developed model was verified by comparing the simulated results with the experimental data.Besides, system responses of increasing heat load were simulated. This model can also be used to design and optimize other large scale helium refrigerators.

  7. Ocean fertilization experiments may initiate a large scale phytoplankton bloom

    NASA Astrophysics Data System (ADS)

    Neufeld, Zoltán; Haynes, Peter H.; Garçon, Véronique; Sudre, Joël

    2002-06-01

    Oceanic plankton plays an important role in the marine food chain and through its significant contribution to the global carbon cycle can also influence the climate. Plankton bloom is a sudden rapid increase of the population. It occurs naturally in the North Atlantic as a result of seasonal changes. Ocean fertilization experiments have shown that supply of iron, an important trace element, can trigger a phytoplankton bloom in oceanic regions with low natural phytoplankton density. Here we use a simple mathematical model of the combined effects of stirring by ocean eddies and plankton evolution to consider the impact of a transient local perturbation, e.g. in the form of iron enrichment as in recent `ocean fertilization' experiments. The model not only explains aspects of the bloom observed in such experiments but predicts the unexpected outcome of a large scale bloom that in its extent could be comparable to the spring bloom in the North Atlantic.

  8. Planning under uncertainty solving large-scale stochastic linear programs

    SciTech Connect

    Infanger, G. . Dept. of Operations Research Technische Univ., Vienna . Inst. fuer Energiewirtschaft)

    1992-12-01

    For many practical problems, solutions obtained from deterministic models are unsatisfactory because they fail to hedge against certain contingencies that may occur in the future. Stochastic models address this shortcoming, but up to recently seemed to be intractable due to their size. Recent advances both in solution algorithms and in computer technology now allow us to solve important and general classes of practical stochastic problems. We show how large-scale stochastic linear programs can be efficiently solved by combining classical decomposition and Monte Carlo (importance) sampling techniques. We discuss the methodology for solving two-stage stochastic linear programs with recourse, present numerical results of large problems with numerous stochastic parameters, show how to efficiently implement the methodology on a parallel multi-computer and derive the theory for solving a general class of multi-stage problems with dependency of the stochastic parameters within a stage and between different stages.

  9. Hierarchical features of large-scale cortical connectivity

    NASA Astrophysics Data System (ADS)

    da F. Costa, L.; Sporns, O.

    2005-12-01

    The analysis of complex networks has revealed patterns of organization in a variety of natural and artificial systems, including neuronal networks of the brain at multiple scales. In this paper, we describe a novel analysis of the large-scale connectivity between regions of the mammalian cerebral cortex, utilizing a set of hierarchical measurements proposed recently. We examine previously identified functional clusters of brain regions in macaque visual cortex and cat cortex and find significant differences between such clusters in terms of several hierarchical measures, revealing differences in how these clusters are embedded in the overall cortical architecture. For example, the ventral cluster of visual cortex maintains structurally more segregated, less divergent connections than the dorsal cluster, which may point to functionally different roles of their constituent brain regions.

  10. Scaling and Criticality in Large-Scale Neuronal Activity

    NASA Astrophysics Data System (ADS)

    Linkenkaer-Hansen, K.

    The human brain during wakeful rest spontaneously generates large-scale neuronal network oscillations at around 10 and 20 Hz that can be measured non-invasively using magnetoencephalography (MEG) or electroencephalography (EEG). In this chapter, spontaneous oscillations are viewed as the outcome of a self-organizing stochastic process. The aim is to introduce the general prerequisites for stochastic systems to evolve to the critical state and to explain their neurophysiological equivalents. I review the recent evidence that the theory of self-organized criticality (SOC) may provide a unifying explanation for the large variability in amplitude, duration, and recurrence of spontaneous network oscillations, as well as the high susceptibility to perturbations and the long-range power-law temporal correlations in their amplitude envelope.

  11. Complex modular structure of large-scale brain networks

    NASA Astrophysics Data System (ADS)

    Valencia, M.; Pastor, M. A.; Fernández-Seara, M. A.; Artieda, J.; Martinerie, J.; Chavez, M.

    2009-06-01

    Modular structure is ubiquitous among real-world networks from related proteins to social groups. Here we analyze the modular organization of brain networks at a large scale (voxel level) extracted from functional magnetic resonance imaging signals. By using a random-walk-based method, we unveil the modularity of brain webs and show modules with a spatial distribution that matches anatomical structures with functional significance. The functional role of each node in the network is studied by analyzing its patterns of inter- and intramodular connections. Results suggest that the modular architecture constitutes the structural basis for the coexistence of functional integration of distant and specialized brain areas during normal brain activities at rest.

  12. Large scale motions of thermal transport in a turbulent channel

    NASA Astrophysics Data System (ADS)

    Dharmarathne, Suranga; Tutkun, Murat; Araya, Guillermo; Leonardi, Stefano; Castillo, Luciano

    2015-11-01

    The importance of large scale motions (LSMs) on thermal transport in a turbulent channel flow at friction number of 394 is investigated. Two-point correlation analysis reveals that LSM which significantly contribute to turbulence kinetic energy and scalar transport is a reminiscent of a hairpin packet. Low-order mode representation of the original fields using proper orthogonal decomposition (POD) unveils that the most dominant mode that transports is 3-4 channel half-heights long and such structure which contribute to scalar transport is 2-4 channel half-heights long. Consequently, the study discloses that LSMs are effective in transporting both streamwise component of turbulence kinetic energy and scalar variances.

  13. A large-scale evaluation of computational protein function prediction.

    PubMed

    Radivojac, Predrag; Clark, Wyatt T; Oron, Tal Ronnen; Schnoes, Alexandra M; Wittkop, Tobias; Sokolov, Artem; Graim, Kiley; Funk, Christopher; Verspoor, Karin; Ben-Hur, Asa; Pandey, Gaurav; Yunes, Jeffrey M; Talwalkar, Ameet S; Repo, Susanna; Souza, Michael L; Piovesan, Damiano; Casadio, Rita; Wang, Zheng; Cheng, Jianlin; Fang, Hai; Gough, Julian; Koskinen, Patrik; Törönen, Petri; Nokso-Koivisto, Jussi; Holm, Liisa; Cozzetto, Domenico; Buchan, Daniel W A; Bryson, Kevin; Jones, David T; Limaye, Bhakti; Inamdar, Harshal; Datta, Avik; Manjari, Sunitha K; Joshi, Rajendra; Chitale, Meghana; Kihara, Daisuke; Lisewski, Andreas M; Erdin, Serkan; Venner, Eric; Lichtarge, Olivier; Rentzsch, Robert; Yang, Haixuan; Romero, Alfonso E; Bhat, Prajwal; Paccanaro, Alberto; Hamp, Tobias; Kaßner, Rebecca; Seemayer, Stefan; Vicedo, Esmeralda; Schaefer, Christian; Achten, Dominik; Auer, Florian; Boehm, Ariane; Braun, Tatjana; Hecht, Maximilian; Heron, Mark; Hönigschmid, Peter; Hopf, Thomas A; Kaufmann, Stefanie; Kiening, Michael; Krompass, Denis; Landerer, Cedric; Mahlich, Yannick; Roos, Manfred; Björne, Jari; Salakoski, Tapio; Wong, Andrew; Shatkay, Hagit; Gatzmann, Fanny; Sommer, Ingolf; Wass, Mark N; Sternberg, Michael J E; Škunca, Nives; Supek, Fran; Bošnjak, Matko; Panov, Panče; Džeroski, Sašo; Šmuc, Tomislav; Kourmpetis, Yiannis A I; van Dijk, Aalt D J; ter Braak, Cajo J F; Zhou, Yuanpeng; Gong, Qingtian; Dong, Xinran; Tian, Weidong; Falda, Marco; Fontana, Paolo; Lavezzo, Enrico; Di Camillo, Barbara; Toppo, Stefano; Lan, Liang; Djuric, Nemanja; Guo, Yuhong; Vucetic, Slobodan; Bairoch, Amos; Linial, Michal; Babbitt, Patricia C; Brenner, Steven E; Orengo, Christine; Rost, Burkhard; Mooney, Sean D; Friedberg, Iddo

    2013-03-01

    Automated annotation of protein function is challenging. As the number of sequenced genomes rapidly grows, the overwhelming majority of protein products can only be annotated computationally. If computational predictions are to be relied upon, it is crucial that the accuracy of these methods be high. Here we report the results from the first large-scale community-based critical assessment of protein function annotation (CAFA) experiment. Fifty-four methods representing the state of the art for protein function prediction were evaluated on a target set of 866 proteins from 11 organisms. Two findings stand out: (i) today's best protein function prediction algorithms substantially outperform widely used first-generation methods, with large gains on all types of targets; and (ii) although the top methods perform well enough to guide experiments, there is considerable need for improvement of currently available tools. PMID:23353650

  14. Large-scale polarimetry of large optical galaxies

    NASA Astrophysics Data System (ADS)

    Sholomitskii, G. B.; Maslov, I. A.; Vitrichenko, E. A.

    1999-11-01

    We present preliminary results of wide-field visual CCD polarimetry for large optical galaxies through a concentric multisector radial-tangential polaroid analyzer mounted at the intermediate focus of a Zeiss-1000 telescope. The mean degree of tangential polarization in a 13-arcmin field, which was determined by processing images with imprinted ``orthogonal'' sectors, ranges from several percent (M 82) and 0.51% (the spirals M 51, M 81) to lower values for elliptical galaxies (M 49, M 87). It is emphasized that the parameters of large-scale polarization can be properly determined by using physical models for galaxies; inclination and azimuthal dependences of the degree of polarization are given for spirals.

  15. Large-Scale Quantitative Analysis of Painting Arts

    NASA Astrophysics Data System (ADS)

    Kim, Daniel; Son, Seung-Woo; Jeong, Hawoong

    2014-12-01

    Scientists have made efforts to understand the beauty of painting art in their own languages. As digital image acquisition of painting arts has made rapid progress, researchers have come to a point where it is possible to perform statistical analysis of a large-scale database of artistic paints to make a bridge between art and science. Using digital image processing techniques, we investigate three quantitative measures of images - the usage of individual colors, the variety of colors, and the roughness of the brightness. We found a difference in color usage between classical paintings and photographs, and a significantly low color variety of the medieval period. Interestingly, moreover, the increment of roughness exponent as painting techniques such as chiaroscuro and sfumato have advanced is consistent with historical circumstances.

  16. Large-scale signal detection: A unified perspective.

    PubMed

    Mukhopadhyay, Subhadeep

    2016-06-01

    There is an overwhelmingly large literature and algorithms already available on "large-scale inference problems" based on different modeling techniques and cultures. Our primary goal in this article is not to add one more new methodology to the existing toolbox but instead (i) to clarify the mystery how these different simultaneous inference methods are connected, (ii) to provide an alternative more intuitive derivation of the formulas that leads to simpler expressions in order (iii) to develop a unified algorithm for practitioners. A detailed discussion on representation, estimation, inference, and model selection is given. Applications to a variety of real and simulated datasets show promise. We end with several future research directions. PMID:26433744

  17. Large scale magnetic fields in galaxies at high redshifts

    NASA Astrophysics Data System (ADS)

    Bernet, M. L.; Miniati, F.; Lilly, S. J.; Kronberg, P. P.; Dessauges-Zavadsky, M.

    2012-09-01

    In a recent study we have used a large sample of extragalactic radio sources to investigate the redshift evolution of the Rotation Measure (RM) of polarized quasars up to z ≈ 3.0. We found that the dispersion in the RM distribution of quasars increases at higher redshifts and hypothesized that MgII intervening systems were responsible for the observed trend. To test this hypothesis, we have recently obtained high-resolution UVES/VLT spectra for 76 quasars in our sample and in the redshift range 0.6 < z < 2.0. We found a clear correlation between the presence of strong MgII systems and large RMs. This implies that normal galaxies at z ≈ 1 already had large-scale magnetic fields comparable to those seen today.

  18. Large scale oil lease automation and electronic custody transfer

    SciTech Connect

    Price, C.R.; Elmer, D.C.

    1995-12-31

    Typically, oil field production operations have only been automated at fields with long term production profiles and enhanced recovery. The automation generally consists of monitoring and control at the wellhead and centralized facilities. However, Union Pacific Resources Co. (UPRC) has successfully implemented a large scale automation program for rapid-decline primary recovery Austin Chalk wells where purchasers buy and transport oil from each individual wellsite. This project has resulted in two significant benefits. First, operators are using the system to re-engineer their work processes. Second, an inter-company team created a new electronic custody transfer method. This paper will describe: the progression of the company`s automation objectives in the area; the field operator`s interaction with the system, and the related benefits; the research and development of the new electronic custody transfer method.

  19. Galaxy clustering and the origin of large-scale flows

    NASA Technical Reports Server (NTRS)

    Juszkiewicz, R.; Yahil, A.

    1989-01-01

    Peebles's 'cosmic virial theorem' is extended from its original range of validity at small separations, where hydrostatic equilibrium holds, to large separations, in which linear gravitational stability theory applies. The rms pairwise velocity difference at separation r is shown to depend on the spatial galaxy correlation function xi(x) only for x less than r. Gravitational instability theory can therefore be tested by comparing the two up to the maximum separation for which both can reliably be determined, and there is no dependence on the poorly known large-scale density and velocity fields. With the expected improvement in the data over the next few years, however, this method should yield a reliable determination of omega.

  20. Large-scale experience with biological treatment of contaminated soil

    SciTech Connect

    Schulz-Berendt, V.; Poetzsch, E.

    1995-12-31

    The efficiency of biological methods for the cleanup of soil contaminated with total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) was demonstrated by a large-scale example in which 38,000 tons of TPH- and PAH-polluted soil was treated onsite with the TERRAFERM{reg_sign} degradation system to reach the target values of 300 mg/kg TPH and 5 mg/kg PAH. Detection of the ecotoxicological potential (Microtox{reg_sign} assay) showed a significant decrease during the remediation. Low concentrations of PAH in the ground were treated by an in situ technology. The in situ treatment was combined with mechanical measures (slurry wall) to prevent the contamination from dispersing from the site.

  1. Measuring Large-Scale Social Networks with High Resolution

    PubMed Central

    Stopczynski, Arkadiusz; Sekara, Vedran; Sapiezynski, Piotr; Cuttone, Andrea; Madsen, Mette My; Larsen, Jakob Eg; Lehmann, Sune

    2014-01-01

    This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years—the Copenhagen Networks Study. Specifically, we collect data on face-to-face interactions, telecommunication, social networks, location, and background information (personality, demographics, health, politics) for a densely connected population of 1 000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation and research agenda driving the study. Additionally, the paper details the data-types measured, and the technical infrastructure in terms of both backend and phone software, as well as an outline of the deployment procedures. We document the participant privacy procedures and their underlying principles. The paper is concluded with early results from data analysis, illustrating the importance of multi-channel high-resolution approach to data collection. PMID:24770359

  2. Large-scale structure in f(T) gravity

    SciTech Connect

    Li Baojiu; Sotiriou, Thomas P.; Barrow, John D.

    2011-05-15

    In this work we study the cosmology of the general f(T) gravity theory. We express the modified Einstein equations using covariant quantities, and derive the gauge-invariant perturbation equations in covariant form. We consider a specific choice of f(T), designed to explain the observed late-time accelerating cosmic expansion without including an exotic dark energy component. Our numerical solution shows that the extra degree of freedom of such f(T) gravity models generally decays as one goes to smaller scales, and consequently its effects on scales such as galaxies and galaxies clusters are small. But on large scales, this degree of freedom can produce large deviations from the standard {Lambda}CDM scenario, leading to severe constraints on the f(T) gravity models as an explanation to the cosmic acceleration.

  3. Honeycomb: Visual Analysis of Large Scale Social Networks

    NASA Astrophysics Data System (ADS)

    van Ham, Frank; Schulz, Hans-Jörg; Dimicco, Joan M.

    The rise in the use of social network sites allows us to collect large amounts of user reported data on social structures and analysis of this data could provide useful insights for many of the social sciences. This analysis is typically the domain of Social Network Analysis, and visualization of these structures often proves invaluable in understanding them. However, currently available visual analysis tools are not very well suited to handle the massive scale of this network data, and often resolve to displaying small ego networks or heavily abstracted networks. In this paper, we present Honeycomb, a visualization tool that is able to deal with much larger scale data (with millions of connections), which we illustrate by using a large scale corporate social networking site as an example. Additionally, we introduce a new probability based network metric to guide users to potentially interesting or anomalous patterns and discuss lessons learned during design and implementation.

  4. Recovery Act - Large Scale SWNT Purification and Solubilization

    SciTech Connect

    Michael Gemano; Dr. Linda B. McGown

    2010-10-07

    The goal of this Phase I project was to establish a quantitative foundation for development of binary G-gels for large-scale, commercial processing of SWNTs and to develop scientific insight into the underlying mechanisms of solubilization, selectivity and alignment. In order to accomplish this, we performed systematic studies to determine the effects of G-gel composition and experimental conditions that will enable us to achieve our goals that include (1) preparation of ultra-high purity SWNTs from low-quality, commercial SWNT starting materials, (2) separation of MWNTs from SWNTs, (3) bulk, non-destructive solubilization of individual SWNTs in aqueous solution at high concentrations (10-100 mg/mL) without sonication or centrifugation, (4) tunable enrichment of subpopulations of the SWNTs based on metallic vs. semiconductor properties, diameter, or chirality and (5) alignment of individual SWNTs.

  5. Large-scale reconstruction and phylogenetic analysis of metabolic environments

    PubMed Central

    Borenstein, Elhanan; Kupiec, Martin; Feldman, Marcus W.; Ruppin, Eytan

    2008-01-01

    The topology of metabolic networks may provide important insights not only into the metabolic capacity of species, but also into the habitats in which they evolved. Here we introduce the concept of a metabolic network's “seed set”—the set of compounds that, based on the network topology, are exogenously acquired—and provide a methodological framework to computationally infer the seed set of a given network. Such seed sets form ecological “interfaces” between metabolic networks and their surroundings, approximating the effective biochemical environment of each species. Analyzing the metabolic networks of 478 species and identifying the seed set of each species, we present a comprehensive large-scale reconstruction of such predicted metabolic environments. The seed sets' composition significantly correlates with several basic properties characterizing the species' environments and agrees with biological observations concerning major adaptations. Species whose environments are highly predictable (e.g., obligate parasites) tend to have smaller seed sets than species living in variable environments. Phylogenetic analysis of the seed sets reveals the complex dynamics governing gain and loss of seeds across the phylogenetic tree and the process of transition between seed and non-seed compounds. Our findings suggest that the seed state is transient and that seeds tend either to be dropped completely from the network or to become non-seed compounds relatively fast. The seed sets also permit a successful reconstruction of a phylogenetic tree of life. The “reverse ecology” approach presented lays the foundations for studying the evolutionary interplay between organisms and their habitats on a large scale. PMID:18787117

  6. Making Large-Scale Networks from fMRI Data

    PubMed Central

    Schmittmann, Verena D.; Jahfari, Sara; Borsboom, Denny; Savi, Alexander O.; Waldorp, Lourens J.

    2015-01-01

    Pairwise correlations are currently a popular way to estimate a large-scale network (> 1000 nodes) from functional magnetic resonance imaging data. However, this approach generally results in a poor representation of the true underlying network. The reason is that pairwise correlations cannot distinguish between direct and indirect connectivity. As a result, pairwise correlation networks can lead to fallacious conclusions; for example, one may conclude that a network is a small-world when it is not. In a simulation study and an application to resting-state fMRI data, we compare the performance of pairwise correlations in large-scale networks (2000 nodes) against three other methods that are designed to filter out indirect connections. Recovery methods are evaluated in four simulated network topologies (small world or not, scale-free or not) in scenarios where the number of observations is very small compared to the number of nodes. Simulations clearly show that pairwise correlation networks are fragmented into separate unconnected components with excessive connectedness within components. This often leads to erroneous estimates of network metrics, like small-world structures or low betweenness centrality, and produces too many low-degree nodes. We conclude that using partial correlations, informed by a sparseness penalty, results in more accurate networks and corresponding metrics than pairwise correlation networks. However, even with these methods, the presence of hubs in the generating network can be problematic if the number of observations is too small. Additionally, we show for resting-state fMRI that partial correlations are more robust than correlations to different parcellation sets and to different lengths of time-series. PMID:26325185

  7. The Large-scale Component of Mantle Convection

    NASA Astrophysics Data System (ADS)

    Cserepes, L.

    Circulation in the Earth's mantle occurs on multiple spatial scales: this review dis- cusses the character of its large-scale or global components. Direct and strong evi- dence concerning the global flow comes, first of all, from the pattern of plate motion. Further indirect observational data which can be transformed into flow velocities by the equation of motion are the internal density heterogeneities revealed by seismic to- mography, and the geoid can also be used as an observational constraint. Due to their limited spatial resolution, global tomographic data automatically filter out the small- scale features and are therefore relevant to the global flow pattern. Flow solutions obtained from tomographic models, using the plate motion as boundary condition, re- veal that subduction is the downwelling of the global mantle circulation and that the deep-rooted upwellings are concentrated in 2-3 superplumes. Spectral analysis of the tomographic heterogeneities shows that the power of global flow appears dominantly in the lowest spherical harmonic orders 2-5. Theoretical convection calculations con- tribute substantially to the understanding of global flow. If basal heating of the mantle is significant, numerical models can reproduce the basic 2 to 5 cell pattern of con- vection even without the inclusion of surface plates. If plates are superimposed on the solution with their present arrangement and motion, the dominance of these low spherical harmonic orders is more pronounced. The cells are not necessarily closed, rather they show chaotic time-dependence, but they are normally bordered by long downwelling features, and they have usually a single superplume in the cell interior. Swarms of small plumes can develop in the large cells, especially when convection is partially layered due to an internal boundary such as the 670 km discontinuity (source of small plumes). These small plumes are usually tilted by the background large-scale flow which shows that they are

  8. Nanomaterials processing toward large-scale flexible/stretchable electronics

    NASA Astrophysics Data System (ADS)

    Takahashi, Toshitake

    In recent years, there has been tremendous progress in large-scale mechanically flexible electronics, where electrical components are fabricated on non-crystalline substrates such as plastics and glass. These devices are currently serving as the basis for various applications such as flat-panel displays, smart cards, and wearable electronics. In this thesis, a promising approach using chemically synthesized nanomaterials is explored to overcome various obstacles current technology faces in this field. Here, we use chemically synthesized semiconducting nanowires (NWs) including group IV (Si, Ge), III-V (InAs) and II-IV (CdS, CdSe) NWs, and semiconductor-enriched SWNTs (99 % purity), and developed reliable, controllable, and more importantly uniform assembly methods on 4-inch wafer-scale flexible substrates in the form of either parallel NW arrays or SWNT random networks, which act as the active components in thin film transistors (TFTs). Thusly obtained TFTs composed of nanomaterials show respectable electrical and optical properties such as 1) cut-off frequency, ft ~ 1 GHz and maximum frequency of oscillation, fmax ~ 1.8 GHz from InAs parallel NW array TFTs with channel length of ~ 1.5 μm, 2) photodetectors covering visible wavelengths (500-700 nm) using compositionally graded CdSxSe1-x (0 < x < 1) parallel NW arrays, and 3) carrier mobility of ~ 20 cm2/Vs, which is an order of magnitude larger than conventional TFT materials such as a-Si and organic semiconductors, without sacrificing current on/off ratio (Ion/Ioff ~ 104) from SWNT network TFTs. The capability to uniformly assemble nanomaterials over large-scale flexible substrates enables us to use them for more sophisticated applications. Artificial electronic skin (e-skin) is demonstrated by laminating pressure sensitive rubber on top of nanomaterial-based active matrix backplanes. Furthermore, an x-ray imaging device is also achieved by combining organic photodiodes with this backplane technology.

  9. High Fidelity Simulations of Large-Scale Wireless Networks

    SciTech Connect

    Onunkwo, Uzoma; Benz, Zachary

    2015-11-01

    The worldwide proliferation of wireless connected devices continues to accelerate. There are 10s of billions of wireless links across the planet with an additional explosion of new wireless usage anticipated as the Internet of Things develops. Wireless technologies do not only provide convenience for mobile applications, but are also extremely cost-effective to deploy. Thus, this trend towards wireless connectivity will only continue and Sandia must develop the necessary simulation technology to proactively analyze the associated emerging vulnerabilities. Wireless networks are marked by mobility and proximity-based connectivity. The de facto standard for exploratory studies of wireless networks is discrete event simulations (DES). However, the simulation of large-scale wireless networks is extremely difficult due to prohibitively large turnaround time. A path forward is to expedite simulations with parallel discrete event simulation (PDES) techniques. The mobility and distance-based connectivity associated with wireless simulations, however, typically doom PDES and fail to scale (e.g., OPNET and ns-3 simulators). We propose a PDES-based tool aimed at reducing the communication overhead between processors. The proposed solution will use light-weight processes to dynamically distribute computation workload while mitigating communication overhead associated with synchronizations. This work is vital to the analytics and validation capabilities of simulation and emulation at Sandia. We have years of experience in Sandia’s simulation and emulation projects (e.g., MINIMEGA and FIREWHEEL). Sandia’s current highly-regarded capabilities in large-scale emulations have focused on wired networks, where two assumptions prevent scalable wireless studies: (a) the connections between objects are mostly static and (b) the nodes have fixed locations.

  10. Large-scale mass distribution in the Illustris simulation

    NASA Astrophysics Data System (ADS)

    Haider, M.; Steinhauser, D.; Vogelsberger, M.; Genel, S.; Springel, V.; Torrey, P.; Hernquist, L.

    2016-04-01

    Observations at low redshifts thus far fail to account for all of the baryons expected in the Universe according to cosmological constraints. A large fraction of the baryons presumably resides in a thin and warm-hot medium between the galaxies, where they are difficult to observe due to their low densities and high temperatures. Cosmological simulations of structure formation can be used to verify this picture and provide quantitative predictions for the distribution of mass in different large-scale structure components. Here we study the distribution of baryons and dark matter at different epochs using data from the Illustris simulation. We identify regions of different dark matter density with the primary constituents of large-scale structure, allowing us to measure mass and volume of haloes, filaments and voids. At redshift zero, we find that 49 per cent of the dark matter and 23 per cent of the baryons are within haloes more massive than the resolution limit of 2 × 108 M⊙. The filaments of the cosmic web host a further 45 per cent of the dark matter and 46 per cent of the baryons. The remaining 31 per cent of the baryons reside in voids. The majority of these baryons have been transported there through active galactic nuclei feedback. We note that the feedback model of Illustris is too strong for heavy haloes, therefore it is likely that we are overestimating this amount. Categorizing the baryons according to their density and temperature, we find that 17.8 per cent of them are in a condensed state, 21.6 per cent are present as cold, diffuse gas, and 53.9 per cent are found in the state of a warm-hot intergalactic medium.

  11. Disinformative data in large-scale hydrological modelling

    NASA Astrophysics Data System (ADS)

    Kauffeldt, Anna; Halldin, Sven; Rodhe, Allan; Xu, Chong-Yu; Westerberg, Ida

    2013-04-01

    Large-scale hydrological modelling has become an important tool for the study of global and regional water resources, climate impacts, and water-resources management. However, modelling efforts over large spatial domains are fraught with problems of data scarcity, uncertainties and inconsistencies between forcing and evaluation data. Model-independent methods to screen and analyse data for such problems are needed. This study aims at identifying two types of data inconsistencies in global datasets using a pre-modelling analysis, inconsistencies that can be disinformative for subsequent modelling. Firstly, four hydrographic datasets were examined in terms of how well basin areas were represented in the flow networks. It was found that most basins could be well represented in both gridded basin delineations and polygon-based ones, but some basins exhibited large area discrepancies between hydrographic datasets and archived basin areas. Secondly, the consistency between climate data (precipitation and potential evaporation) and discharge data was examined for the possibility of water-balance closure. It was found that basins exhibiting too high runoff coefficients were abundant in areas where precipitation data were likely affected by snow undercatch, and that the occurrence of basins exhibiting losses exceeding the energy limit were strongly dependent on the potential-evaporation data, both in terms of numbers and geographical distribution. These results emphasise the need for pre-modelling data analysis to identify dataset inconsistencies as an important first step in any large-scale study. Applying data-screening methods before modelling increases our chances to draw robust conclusions from subsequent model simulations.

  12. Tools for Large-Scale Mobile Malware Analysis

    SciTech Connect

    Bierma, Michael

    2014-01-01

    Analyzing mobile applications for malicious behavior is an important area of re- search, and is made di cult, in part, by the increasingly large number of appli- cations available for the major operating systems. There are currently over 1.2 million apps available in both the Google Play and Apple App stores (the respec- tive o cial marketplaces for the Android and iOS operating systems)[1, 2]. Our research provides two large-scale analysis tools to aid in the detection and analysis of mobile malware. The rst tool we present, Andlantis, is a scalable dynamic analysis system capa- ble of processing over 3000 Android applications per hour. Traditionally, Android dynamic analysis techniques have been relatively limited in scale due to the compu- tational resources required to emulate the full Android system to achieve accurate execution. Andlantis is the most scalable Android dynamic analysis framework to date, and is able to collect valuable forensic data, which helps reverse-engineers and malware researchers identify and understand anomalous application behavior. We discuss the results of running 1261 malware samples through the system, and provide examples of malware analysis performed with the resulting data. While techniques exist to perform static analysis on a large number of appli- cations, large-scale analysis of iOS applications has been relatively small scale due to the closed nature of the iOS ecosystem, and the di culty of acquiring appli- cations for analysis. The second tool we present, iClone, addresses the challenges associated with iOS research in order to detect application clones within a dataset of over 20,000 iOS applications.

  13. Biased galaxy formation and large-scale structure

    NASA Astrophysics Data System (ADS)

    Berlind, Andreas Alan

    The biased relation between the galaxy and mass distributions lies at the intersection of large scale structure in the universe and the process of galaxy formation. I study the nature of galaxy bias and its connections to galaxy clustering and galaxy formation physics. Galaxy bias has traditionally been viewed as an obstacle to constraining cosmological parameters by studying galaxy clustering. I examine the effect of bias on measurements of the cosmological density parameter Wm by techniques that exploit the gravity-induced motions of galaxies. Using a variety of environmental bias models applied to N-body simulations, I find that, in most cases, the quantity estimated by these techniques is the value of W0.6m/bs , where bs is the ratio of rms galaxy fluctuations to rms mass fluctuations on large scales. Moreover, I find that different methods should, in principle, agree with each other and it is thus unlikely that non-linear or scale-dependent bias is responsible for the discrepancies that exist among current measurements. One can also view the influence of bias on galaxy clustering as a strength rather than a weakness, since it provides us with a potentially powerful way to constrain galaxy formation theories. With this goal in mind, I develop the "Halo Occupation Distribution" (HOD), a physically motivated and complete formulation of bias that is based on the distribution of galaxies within virialized dark matter halos. I explore the sensitivity of galaxy clustering statistics to features of the HOD and focus on how the HOD may be empirically constrained from galaxy clustering data. I make the connection to the physics of galaxy formation by studying the HOD predicted by the two main theoretical methods of modeling galaxy formation. I find that, despite many differences between them, the two methods predict the same HOD, suggesting that galaxy bias is determined by robust features of the hierarchical galaxy formation process rather than details of gas cooling

  14. Identifying Large-Scale Brain Networks in Fragile X Syndrome

    PubMed Central

    Hall, Scott S.; Jiang, Heidi; Reiss, Allan L.; Greicius, Michael D.

    2014-01-01

    IMPORTANCE Fragile X syndrome (FXS) is an X-linked neurogenetic disorder characterized by a cognitive and behavioral phenotype resembling features of autism spectrum disorder. Until now, research has focused largely on identifying regional differences in brain structure and function between individuals with FXS and various control groups. Very little is known about the large-scale brain networks that may underlie the cognitive and behavioral symptoms of FXS. OBJECTIVE To identify large-scale, resting-state networks in FXS that differ from control individuals matched on age, IQ, and severity of behavioral and cognitive symptoms. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional, in vivo neuroimaging study conducted in an academic medical center. Participants (aged 10–23 years) included 17 males and females with FXS and 16 males and females serving as controls. MAIN OUTCOMES AND MEASURES Univariate voxel-based morphometric analyses, fractional amplitude of low-frequency fluctuations (fALFF) analysis, and group-independent component analysis with dual regression. RESULTS Patients with FXS showed decreased functional connectivity in the salience, precuneus, left executive control, language, and visuospatial networks compared with controls. Decreased fALFF in the bilateral insular, precuneus, and anterior cingulate cortices also was found in patients with FXS compared with control participants. Furthermore, fALFF in the left insular cortex was significantly positively correlated with IQ in patients with FXS. Decreased gray matter density, resting-state connectivity, and fALFF converged in the left insular cortex in patients with FXS. CONCLUSIONS AND RELEVANCE Fragile X syndrome results in widespread reductions in functional connectivity across multiple cognitive and affective brain networks. Converging structural and functional abnormalities in the left insular cortex, a region also implicated in individuals diagnosed with autism spectrum disorder, suggests that

  15. Large Scale Archaeological Satellite Classification and Data Mining Tools

    NASA Astrophysics Data System (ADS)

    Canham, Kelly

    Archaeological applications routinely use many different forms of remote sensing imagery, the exception being hyperspectral imagery (HSI). HSI tends to be utilized in a similar fashion as multispectral imagery (MSI) or processed to the point that it can be utilized similarly to MSI, thus reducing the benefits of HSI. However, for large scale archaeological surveys, HSI data can be used to differentiate materials more accurately than MSI because of HSI's larger number of spectral bands. HSI also has the ability to identify multiple materials found within a single pixel (sub-pixel material mixing), which is traditionally not possible with MSI. The Zapotec people of Oaxaca, Mexico, lived in an environment that isolates the individual settlements by rugged mountain ranges and dramatically different ecosystems. The rugged mountains of Oaxaca make large scale ground based archaeological surveys expensive in terms of both time and money. The diverse ecosystems of Oaxaca make multispectral satellite imagery inadequate for local material identification. For these reasons hyperspectral imagery was collected over Oaxaca, Mexico. Using HSI, investigations were conducted into how the Zapotec statehood was impacted by the environment, and conversely, how the environment impacted the statehood. Emphasis in this research is placed on identifying the number of pure materials present in the imagery, what these materials are, and identifying archaeological regions of interest using image processing techniques. The HSI processing techniques applied include a new spatially adaptive spectral unmixing approach (LoGlo) to identify pure materials across broad regions of Oaxaca, vegetation indices analysis, and spectral change detection algorithms. Verification of identified archaeological sites is completed using Geospatial Information System (GIS) tools, ground truth data, and high-resolution satellite MSI. GIS tools are also used to analyze spatial trends in lost archaeological sites due

  16. Visualization of Multi-dimensional MISR Datasets Using Self-Organizing Map

    NASA Astrophysics Data System (ADS)

    Li, P.; Jacob, J.; Braverman, A.; Block, G.

    2003-12-01

    Many techniques exist for visualization of high dimensional datasets including Parallel Coordinates, Projection Pursuit, and Self-Organizing Map (SOM), but none of these are particularly well suited to satellite data. Remote sensing datasets are typically highly multivariate, but also have spatial structure. In analyzing such data, it is critical to maintain the spatial context within which multivariate relationships exist. Only then can we begin to investigate how those relationships change spatially, and connect observed phenomena to physical processes that may explain them. We present an analysis and visualization system called SOM_VIS that applies an enhanced SOM algorithm proposed by Todd & Kirby [1] to multi-dimensional image datasets in a way that maintains spatial context. We first use SOM to project high-dimensional data into a non-uniform 3D lattice structure. The lattice structure is then mapped to a color space to serve as a colormap for the image. The Voronoi cell refinement algorithm is then used to map the SOM lattice structure to various levels of color resolution. The final result is a false color image with similar colors representing similar characteristics across all its data dimensions. We demonstrate this system using data from JPL's Multi-angle Imaging Spectro-Radiometer (MISR), which looks at Earth and its atmosphere in 36 channels: all combinations of four spectral bands and nine view angles. The SOM_VIS tool consists of a data control panel for users to select a subset from MISR's Level 1B Radiance data products, and a training control panel for users to choose various parameters for SOM training. These include the size of the SOM lattice, the method used to modify the control vectors towards the input training vector, convergence rate, and number of Voronoi regions. Also, the SOM_VIS system contains a multi-window display system allowing users to view false color SOM images and the corresponding color maps for trained SOM lattices. In

  17. Large-scale simulations of layered double hydroxide nanocomposite materials

    NASA Astrophysics Data System (ADS)

    Thyveetil, Mary-Ann

    Layered double hydroxides (LDHs) have the ability to intercalate a multitude of anionic species. Atomistic simulation techniques such as molecular dynamics have provided considerable insight into the behaviour of these materials. We review these techniques and recent algorithmic advances which considerably improve the performance of MD applications. In particular, we discuss how the advent of high performance computing and computational grids has allowed us to explore large scale models with considerable ease. Our simulations have been heavily reliant on computational resources on the UK's NGS (National Grid Service), the US TeraGrid and the Distributed European Infrastructure for Supercomputing Applications (DEISA). In order to utilise computational grids we rely on grid middleware to launch, computationally steer and visualise our simulations. We have integrated the RealityGrid steering library into the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) 1 . which has enabled us to perform re mote computational steering and visualisation of molecular dynamics simulations on grid infrastruc tures. We also use the Application Hosting Environment (AHE) 2 in order to launch simulations on remote supercomputing resources and we show that data transfer rates between local clusters and super- computing resources can be considerably enhanced by using optically switched networks. We perform large scale molecular dynamics simulations of MgiAl-LDHs intercalated with either chloride ions or a mixture of DNA and chloride ions. The systems exhibit undulatory modes, which are suppressed in smaller scale simulations, caused by the collective thermal motion of atoms in the LDH layers. Thermal undulations provide elastic properties of the system including the bending modulus, Young's moduli and Poisson's ratios. To explore the interaction between LDHs and DNA. we use molecular dynamics techniques to per form simulations of double stranded, linear and plasmid DNA up

  18. Planar Doppler Velocimetry for Large-Scale Wind Tunnel Testing

    NASA Technical Reports Server (NTRS)

    McKenzie, Robert L.

    1997-01-01

    Recently, Planar Doppler Velocimetry (PDV) has been shown by several laboratories to offer an attractive means for measuring three-dimensional velocity vectors everywhere in a light sheet placed in a flow. Unlike other optical means of measuring flow velocities, PDV is particularly attractive for use in large wind tunnels where distances to the sample region may be several meters, because it does not require the spatial resolution and tracking of individual scattering particles or the alignment of crossed beams at large distances. To date, demonstrations of PDV have been made either in low speed flows without quantitative comparison to other measurements, or in supersonic flows where the Doppler shift is large and its measurement is relatively insensitive to instrumental errors. Moreover, most reported applications have relied on the use of continuous-wave lasers, which limit the measurement to time-averaged velocity fields. This work summarizes the results of two previous studies of PDV in which the use of pulsed lasers to obtain instantaneous velocity vector fields is evaluated. The objective has been to quantitatively define and demonstrate PDV capabilities for applications in large-scale wind tunnels that are intended primarily for the production testing of subsonic aircraft. For such applications, the adequate resolution of low-speed flow fields requires accurate measurements of small Doppler shifts that are obtained at distances of several meters from the sample region. The use of pulsed lasers provides the unique capability to obtain not only time-averaged fields, but also their statistical fluctuation amplitudes and the spatial excursions of unsteady flow regions such as wakes and separations. To accomplish the objectives indicated, the PDV measurement process is first modeled and its performance evaluated computationally. The noise sources considered include those related to the optical and electronic properties of Charge-Coupled Device (CCD) arrays and to

  19. Strategies for Interactive Visualization of Large Scale Climate Simulations

    NASA Astrophysics Data System (ADS)

    Xie, J.; Chen, C.; Ma, K.; Parvis

    2011-12-01

    With the advances in computational methods and supercomputing technology, climate scientists are able to perform large-scale simulations at unprecedented resolutions. These simulations produce data that are time-varying, multivariate, and volumetric, and the data may contain thousands of time steps with each time step having billions of voxels and each voxel recording dozens of variables. Visualizing such time-varying 3D data to examine correlations between different variables thus becomes a daunting task. We have been developing strategies for interactive visualization and correlation analysis of multivariate data. The primary task is to find connection and correlation among data. Given the many complex interactions among the Earth's oceans, atmosphere, land, ice and biogeochemistry, and the sheer size of observational and climate model data sets, interactive exploration helps identify which processes matter most for a particular climate phenomenon. We may consider time-varying data as a set of samples (e.g., voxels or blocks), each of which is associated with a vector of representative or collective values over time. We refer to such a vector as a temporal curve. Correlation analysis thus operates on temporal curves of data samples. A temporal curve can be treated as a two-dimensional function where the two dimensions are time and data value. It can also be treated as a point in the high-dimensional space. In this case, to facilitate effective analysis, it is often necessary to transform temporal curve data from the original space to a space of lower dimensionality. Clustering and segmentation of temporal curve data in the original or transformed space provides us a way to categorize and visualize data of different patterns, which reveals connection or correlation of data among different variables or at different spatial locations. We have employed the power of GPU to enable interactive correlation visualization for studying the variability and correlations of a

  20. Can global hydrological models reproduce large scale river flood regimes?

    NASA Astrophysics Data System (ADS)

    Eisner, Stephanie; Flörke, Martina

    2013-04-01

    River flooding remains one of the most severe natural hazards. On the one hand, major flood events pose a serious threat to human well-being, causing deaths and considerable economic damage. On the other hand, the periodic occurrence of flood pulses is crucial to maintain the functioning of riverine floodplains and wetlands, and to preserve the ecosystem services the latter provide. In many regions, river floods reveal a distinct seasonality, i.e. they occur at a particular time during the year. This seasonality is related to regionally dominant flood generating processes which can be expressed in river flood types. While in data-rich regions (esp. Europe and North America) the analysis of flood regimes can be based on observed river discharge time series, this data is sparse or lacking in many other regions of the world. This gap of knowledge can be filled by global modeling approaches. However, to date most global modeling studies have focused on mean annual or monthly water availability and their change over time while simulating discharge extremes, both floods and droughts, still remains a challenge for large scale hydrological models. This study will explore the ability of the global hydrological model WaterGAP3 to simulate the large scale patterns of river flood regimes, represented by seasonal pattern and the dominant flood type. WaterGAP3 simulates the global terrestrial water balance on a 5 arc minute spatial grid (excluding Greenland and Antarctica) at a daily time step. The model accounts for human interference on river flow, i.e. water abstraction for various purposes, e.g. irrigation, and flow regulation by large dams and reservoirs. Our analysis will provide insight in the general ability of global hydrological models to reproduce river flood regimes and thus will promote the creation of a global map of river flood regimes to provide a spatially inclusive and comprehensive picture. Understanding present-day flood regimes can support both flood risk