Science.gov

Sample records for physical modeling improvements

  1. Improving the physics models in the Space Weather Modeling Framework

    NASA Astrophysics Data System (ADS)

    Toth, G.; Fang, F.; Frazin, R. A.; Gombosi, T. I.; Ilie, R.; Liemohn, M. W.; Manchester, W. B.; Meng, X.; Pawlowski, D. J.; Ridley, A. J.; Sokolov, I.; van der Holst, B.; Vichare, G.; Yigit, E.; Yu, Y.; Buzulukova, N.; Fok, M. H.; Glocer, A.; Jordanova, V. K.; Welling, D. T.; Zaharia, S. G.

    2010-12-01

    The success of physics based space weather forecasting depends on several factors: we need sufficient amount and quality of timely observational data, we have to understand the physics of the Sun-Earth system well enough, we need sophisticated computational models, and the models have to run faster than real time on the available computational resources. This presentation will focus on a single ingredient, the recent improvements of the mathematical and numerical models in the Space Weather Modeling Framework. We have developed a new physics based CME initiation code using flux emergence from the convection zone solving the equations of radiative magnetohydrodynamics (MHD). Our new lower corona and solar corona models use electron heat conduction, Alfven wave heating, and boundary conditions based on solar tomography. We can obtain a physically consistent solar wind model from the surface of the Sun all the way to the L1 point without artificially changing the polytropic index. The global magnetosphere model can now solve the multi-ion MHD equations and take into account the oxygen outflow from the polar wind model. We have also added the options of solving for Hall MHD and anisotropic pressure. Several new inner magnetosphere models have been added to the framework: CRCM, HEIDI and RAM-SCB. These new models resolve the pitch angle distribution of the trapped particles. The upper atmosphere model GITM has been improved by including a self-consistent equatorial electrodynamics and the effects of solar flares. This presentation will very briefly describe the developments and highlight some results obtained with the improved and new models.

  2. A Model for Improving "Advanced" Courses in Physics

    ERIC Educational Resources Information Center

    Friedman, Charles P.

    1972-01-01

    Individualized instruction similar to the Keller plan with two additional features: (1) student freedom in selecting his own procedure for mastering the course material; (2) some variety in topics studied by each student. Describes two successful trials of this plan in an atomic physics course at MIT. (Author/DF)

  3. Physics Students' Performance Using Computational Modelling Activities to Improve Kinematics Graphs Interpretation

    ERIC Educational Resources Information Center

    Araujo, Ives Solano; Veit, Eliane Angela; Moreira, Marco Antonio

    2008-01-01

    The purpose of this study was to investigate undergraduate students' performance while exposed to complementary computational modelling activities to improve physics learning, using the software "Modellus." Interpretation of kinematics graphs was the physics topic chosen for investigation. The theoretical framework adopted was based on Halloun's…

  4. Improved Characters and Student Learning Outcomes through Development of Character Education Based General Physics Learning Model

    ERIC Educational Resources Information Center

    Derlina; Sabani; Mihardi, Satria

    2015-01-01

    Education Research in Indonesia has begun to lead to the development of character education and is no longer fixated on the outcomes of cognitive learning. This study purposed to produce character education based general physics learning model (CEBGP Learning Model) and with valid, effective and practical peripheral devices to improve character…

  5. Improving flood forecasting capability of physically based distributed hydrological models by parameter optimization

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Li, J.; Xu, H.

    2016-01-01

    Physically based distributed hydrological models (hereafter referred to as PBDHMs) divide the terrain of the whole catchment into a number of grid cells at fine resolution and assimilate different terrain data and precipitation to different cells. They are regarded to have the potential to improve the catchment hydrological process simulation and prediction capability. In the early stage, physically based distributed hydrological models are assumed to derive model parameters from the terrain properties directly, so there is no need to calibrate model parameters. However, unfortunately the uncertainties associated with this model derivation are very high, which impacted their application in flood forecasting, so parameter optimization may also be necessary. There are two main purposes for this study: the first is to propose a parameter optimization method for physically based distributed hydrological models in catchment flood forecasting by using particle swarm optimization (PSO) algorithm and to test its competence and to improve its performances; the second is to explore the possibility of improving physically based distributed hydrological model capability in catchment flood forecasting by parameter optimization. In this paper, based on the scalar concept, a general framework for parameter optimization of the PBDHMs for catchment flood forecasting is first proposed that could be used for all PBDHMs. Then, with the Liuxihe model as the study model, which is a physically based distributed hydrological model proposed for catchment flood forecasting, the improved PSO algorithm is developed for the parameter optimization of the Liuxihe model in catchment flood forecasting. The improvements include adoption of the linearly decreasing inertia weight strategy to change the inertia weight and the arccosine function strategy to adjust the acceleration coefficients. This method has been tested in two catchments in southern China with different sizes, and the results show

  6. CFD modeling of entrained-flow coal gasifiers with improved physical and chemical sub-models

    SciTech Connect

    Ma, J.; Zitney, S.

    2012-01-01

    Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. While the turbulent multiphase reacting flow inside entrained-flow gasifiers has been modeled through computational fluid dynamic (CFD), the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented here include a moisture vaporization model with consideration of high mass transfer rate, a coal devolatilization model with more species to represent coal volatiles and heating rate effect on volatile yield, and careful selection of global gas phase reaction kinetics. The enhanced CFD model is applied to simulate two typical oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here indicate that the gasifier models reported in this paper are reliable and accurate enough to be incorporated into process/CFD co-simulations of IGCC power plants for systemwide design and optimization.

  7. Improving flood forecasting capability of physically based distributed hydrological model by parameter optimization

    NASA Astrophysics Data System (ADS)

    Chen, Y.; Li, J.; Xu, H.

    2015-10-01

    Physically based distributed hydrological models discrete the terrain of the whole catchment into a number of grid cells at fine resolution, and assimilate different terrain data and precipitation to different cells, and are regarded to have the potential to improve the catchment hydrological processes simulation and prediction capability. In the early stage, physically based distributed hydrological models are assumed to derive model parameters from the terrain properties directly, so there is no need to calibrate model parameters, but unfortunately, the uncertanties associated with this model parameter deriving is very high, which impacted their application in flood forecasting, so parameter optimization may also be necessary. There are two main purposes for this study, the first is to propose a parameter optimization method for physically based distributed hydrological models in catchment flood forecasting by using PSO algorithm and to test its competence and to improve its performances, the second is to explore the possibility of improving physically based distributed hydrological models capability in cathcment flood forecasting by parameter optimization. In this paper, based on the scalar concept, a general framework for parameter optimization of the PBDHMs for catchment flood forecasting is first proposed that could be used for all PBDHMs. Then, with Liuxihe model as the study model, which is a physically based distributed hydrological model proposed for catchment flood forecasting, the improverd Particle Swarm Optimization (PSO) algorithm is developed for the parameter optimization of Liuxihe model in catchment flood forecasting, the improvements include to adopt the linear decreasing inertia weight strategy to change the inertia weight, and the arccosine function strategy to adjust the acceleration coefficients. This method has been tested in two catchments in southern China with different sizes, and the results show that the improved PSO algorithm could be

  8. [An improved physical model to correct topographic effects in remotely sensed imagery].

    PubMed

    Zhang, Zhao-ming; He, Guo-jin; Liu, Ding-sheng; Wang, Xiao-qin; Jiang, Hong

    2010-07-01

    Topographic correction for remotely sensed imagery is an important preprocessing step in order to improve the retrieval accuracy of land surface spectral reflectance in mountainous area. Various kinds of topographic correction models have been proposed in the literature. Each model has its advantages and limitations. In consideration of the limitations of the topographic correction models in the literature, an improved Shepherd topographic correction model is proposed in this paper. Diffuse irradiance is an essential factor in the physically based topographic correction model. While in the Shepherd model (originally proposed by Shepherd et al. in 2003), accuracy of the method to compute the diffuse irradiance is relatively low; therefore, the accuracy of the land surface spectral reflectance retrieved with the Shepherd model is impacted. In order to improve the accuracy of diffuse irradiance, hence the accuracy of land surface spectral reflectance, a different method (named the Perez model), is used to obtain the diffuse irradiance with higher accuracy in the improved Shepherd model. Landsat 5 Thematic Mapper (TM) imagery acquired on July 12th 2006, over the mountainous areas in the north of Beijing city, was employed to retrieve land surface spectral reflectance with the improved Shepherd topographic correction model and 6S (Second Simulation of the Satellite Signal in the Solar Spectrum) atmospheric radiative transfer model. Correction results were tested with three different methods. Testing result shows that the improved Shepherd topographic correction model can achieve a good correction result and is better than Shepherd and C topographic correction model. What is more, this improved model is physically based and can be applied to all kinds of optical satellite imagery. PMID:20827982

  9. Improved Uncertainty Quantification for Physics-Based Atmospheric Models via Generalized Polynomial Chaos

    NASA Astrophysics Data System (ADS)

    Vittaldev, V.; Linares, R.; Godinez, H. C.; Koller, J.; Russell, R. P.

    2013-12-01

    Recent events in space, including the collision of Russia's Cosmos 2251 satellite with Iridium 33 and China's Feng Yun 1C anti-satellite demonstration, have stressed the capabilities of the Space Surveillance Network and its ability to provide accurate and actionable impact probability estimates. In particular low-Earth orbiting satellites are heavily influenced by upper atmospheric density, due to drag, which is very difficult to model accurately. This work focuses on the generalized Polynomial Chaos (gPC) technique for Uncertainty Quantification (UQ) in physics-based atmospheric models. The advantage of the gPC approach is that it can efficiently model non-Gaussian probability distribution functions (pdfs). The gPC approach is used to create a polynomial chaos in F10.7, AP, and solar wind parameters; this chaos is used to perform UQ on future atmospheric conditions. A number of physics-based models are used as test cases, including GITM and TIE-GCM, and the gPC is shown to have good performance in modeling non-Gaussian pdfs. Los Alamos National Laboratory (LANL) has established a research effort, called IMPACT (Integrated Modeling of Perturbations in Atmospheres for Conjunction Tracking), to improve impact assessment via improved physics-based modeling. A number of atmospheric models exist which can be classified as either empirical or physics-based. Physics-based models can be used to provide a forward prediction which is required for accurate collision assessments. As part of this effort, accurate and consistent UQ is required for the atmospheric models used. One of the primary sources of uncertainty is input parameter uncertainty. These input parameters, which include F10.7, AP, and solar wind parameters, are measured constantly. In turn, these measurements are used to provide a prediction for future parameter values. Therefore, the uncertainty of the atmospheric model forecast, due to potential error in the input parameters, must be correctly characterized to

  10. Toward Improving Water Supply Forecasts on the Carson River with a Physically Based Hydrologic Model

    NASA Astrophysics Data System (ADS)

    Rajagopal, S.; Boyle, D. P.; Lamorey, G.; Bassett, S.; Coors, S.; Mann, M.

    2005-12-01

    Researchers at the Desert Research Institute and the USBR are conducting research aimed at improving water supply forecasts on the Carson River as part of the Water 2025 initiative. The primary goal of the effort is to improve short, seasonal, and long term streamflow forecasts through the use of a physically based hydrologic model (MMS-PRMS) coupled with an operational river routing model (Riverware). Streamflow from high-altitude headwater basins is simulated with MMS-PRMS model and routed with the Riverware model through the Carson valley where a number of ungauged agricultural diversions and returns complicate the real system. The water supply forecasts made with the coupled model are evaluated through comparison with forecasts made by the National Weather Service, the Natural Resources Conservation Service, and historic streamflow using multiple objective measures

  11. Improvements made to simulated tropical variability in climate models by stochastic physics

    NASA Astrophysics Data System (ADS)

    Watson, Peter; Palmer, Tim

    2016-04-01

    Many climate models have too little variability in the tropics on daily to weekly time scales. This degrades their ability to simulate extreme events and how they will change with global warming. Stochastic parameterisations, which include a physically-based representation of the uncertainty in unresolved processes, have the potential to alleviate this problem by including variability associated with unresolved processes that is left out of deterministic models. The stochastic physics scheme used operationally by ECMWF has been shown to increase their weather forecast skill. Here we show that in an atmospheric GCM, the scheme makes the simulated tropical variability more consistent with observations by increasing daily precipitation variance, reducing its autocorrelation, and increasing the frequency of heavy-rainfall events. Stochastic physics may therefore be important for improving the model simulations and predicting how the statistics of extreme tropical events will change in the future. We also show also that even when the model's horizontal resolution is increased to that of a weather forecast model, there is still too little simulated tropical variability, so stochastic physics is likely to remain important even as computational power increases.

  12. Linking Statistically- and Physically-Based Models for Improved Streamflow Simulation in Gaged and Ungaged Areas

    NASA Astrophysics Data System (ADS)

    Lafontaine, J.; Hay, L.; Archfield, S. A.; Farmer, W. H.; Kiang, J. E.

    2014-12-01

    The U.S. Geological Survey (USGS) has developed a National Hydrologic Model (NHM) to support coordinated, comprehensive and consistent hydrologic model development, and facilitate the application of hydrologic simulations within the continental US. The portion of the NHM located within the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO LCC) is being used to test the feasibility of improving streamflow simulations in gaged and ungaged watersheds by linking statistically- and physically-based hydrologic models. The GCPO LCC covers part or all of 12 states and 5 sub-geographies, totaling approximately 726,000 km2, and is centered on the lower Mississippi Alluvial Valley. A total of 346 USGS streamgages in the GCPO LCC region were selected to evaluate the performance of this new calibration methodology for the period 1980 to 2013. Initially, the physically-based models are calibrated to measured streamflow data to provide a baseline for comparison. An enhanced calibration procedure then is used to calibrate the physically-based models in the gaged and ungaged areas of the GCPO LCC using statistically-based estimates of streamflow. For this application, the calibration procedure is adjusted to address the limitations of the statistically generated time series to reproduce measured streamflow in gaged basins, primarily by incorporating error and bias estimates. As part of this effort, estimates of uncertainty in the model simulations are also computed for the gaged and ungaged watersheds.

  13. Improving Physical Activity and Metabolic Syndrome Indicators in Women: A Transtheoretical Model-Based Intervention

    PubMed Central

    Mostafavi, Firoozeh; Ghofranipour, Fazllolah; Feizi, Awat; Pirzadeh, Asiyeh

    2015-01-01

    Background: This study aimed at investigating the impact of an educational intervention based on transtheoretical model to increase physical activity and improve metabolic syndrome indicators in women. Methods: In this quasi-experimental study, 142 women with metabolic syndrome were randomly assigned to the case and control group (each group 71 participants). SECQ (Marcus), processes of change (Marcus), decisional balance (Bandura) and self-efficacy (Nigg) questionnaires and International Physical Activities Standard Questionnaire in preintervention, 3 and 6 months after intervention were completed. Furthermore, abdominal obesity, triglycerides (TG), and high-density lipoprotein (HDL) were measured. Physical activity intervention based on transtheoretical model (TTM) was performed in the case group. Finally, data were analyzed by SPSS (16) (SPSS Inc., Chicago, IL, USA) and repeated measure ANOVA, independent t-test and Freidman was used. A two-tailed P value, lower than 0.05, was considered to be statistically significant. Results: After the intervention, physical activity level increased in the intervention group, and they also progressed in stages of change, but the people in the control group had regressed. All changes in TTM constructs were significant in the intervention group during the time and differences in pros and cons were not significant in the control group. Abdominal obesity and TG has significantly reduced, and HDL has increased in the intervention group. In the control group, there was a significant increase in TGs and a decrease in HDL. Conclusions: Physical activity training based on TTM can improve physical activity and metabolic syndrome indicators in women. PMID:25949778

  14. The physics of energy transfer toward improved subgrid-scale models

    NASA Astrophysics Data System (ADS)

    Cimarelli, Andrea; De Angelis, Elisabetta

    2014-05-01

    Starting from physical insight on the energy transfer phenomena in wall turbulent flows, it is shown how modeling of subgrid stresses in large-eddy simulations can be improved. Each model should aim at reproducing the double feature of energy sink and source of the small scales of wall flows which become relevant when large filter lengths are considered. Here we propose one possible choice where the main ingredient is the coupling of the classical linear formulation of eddy viscosity with the nonlinear anisotropic features of the velocity increments tensor. This approach, which actually presents most of the features of the mixed models, captures the near-wall dynamics for very large filter lengths reproducing the small scales source physics responsible for backward energy transfer. A posteriori tests show excellent agreement with direct numerical simulation of turbulent channel flows even when very coarse grids are considered. The capability of the balance of the filtered second order structure function as a post-processing tool to evaluate the physics of any model is also shown.

  15. Wind-US Code Physical Modeling Improvements to Complement Hypersonic Testing and Evaluation

    NASA Technical Reports Server (NTRS)

    Georgiadis, Nicholas J.; Yoder, Dennis A.; Towne, Charles S.; Engblom, William A.; Bhagwandin, Vishal A.; Power, Greg D.; Lankford, Dennis W.; Nelson, Christopher C.

    2009-01-01

    This report gives an overview of physical modeling enhancements to the Wind-US flow solver which were made to improve the capabilities for simulation of hypersonic flows and the reliability of computations to complement hypersonic testing. The improvements include advanced turbulence models, a bypass transition model, a conjugate (or closely coupled to vehicle structure) conduction-convection heat transfer capability, and an upgraded high-speed combustion solver. A Mach 5 shock-wave boundary layer interaction problem is used to investigate the benefits of k- s and k-w based explicit algebraic stress turbulence models relative to linear two-equation models. The bypass transition model is validated using data from experiments for incompressible boundary layers and a Mach 7.9 cone flow. The conjugate heat transfer method is validated for a test case involving reacting H2-O2 rocket exhaust over cooled calorimeter panels. A dual-mode scramjet configuration is investigated using both a simplified 1-step kinetics mechanism and an 8-step mechanism. Additionally, variations in the turbulent Prandtl and Schmidt numbers are considered for this scramjet configuration.

  16. Cross-flow turbines: physical and numerical model studies towards improved array simulations

    NASA Astrophysics Data System (ADS)

    Wosnik, M.; Bachant, P.

    2015-12-01

    Cross-flow, or vertical-axis turbines, show potential in marine hydrokinetic (MHK) and wind energy applications. As turbine designs mature, the research focus is shifting from individual devices towards improving turbine array layouts for maximizing overall power output, i.e., minimizing wake interference for axial-flow turbines, or taking advantage of constructive wake interaction for cross-flow turbines. Numerical simulations are generally better suited to explore the turbine array design parameter space, as physical model studies of large arrays at large model scale would be expensive. However, since the computing power available today is not sufficient to conduct simulations of the flow in and around large arrays of turbines with fully resolved turbine geometries, the turbines' interaction with the energy resource needs to be parameterized, or modeled. Most models in use today, e.g. actuator disk, are not able to predict the unique wake structure generated by cross-flow turbines. Experiments were carried out using a high-resolution turbine test bed in a large cross-section tow tank, designed to achieve sufficiently high Reynolds numbers for the results to be Reynolds number independent with respect to turbine performance and wake statistics, such that they can be reliably extrapolated to full scale and used for model validation. To improve parameterization in array simulations, an actuator line model (ALM) was developed to provide a computationally feasible method for simulating full turbine arrays inside Navier--Stokes models. The ALM predicts turbine loading with the blade element method combined with sub-models for dynamic stall and flow curvature. The open-source software is written as an extension library for the OpenFOAM CFD package, which allows the ALM body force to be applied to their standard RANS and LES solvers. Turbine forcing is also applied to volume of fluid (VOF) models, e.g., for predicting free surface effects on submerged MHK devices. An

  17. Towards more accurate wind and solar power prediction by improving NWP model physics

    NASA Astrophysics Data System (ADS)

    Steiner, Andrea; Köhler, Carmen; von Schumann, Jonas; Ritter, Bodo

    2014-05-01

    The growing importance and successive expansion of renewable energies raise new challenges for decision makers, economists, transmission system operators, scientists and many more. In this interdisciplinary field, the role of Numerical Weather Prediction (NWP) is to reduce the errors and provide an a priori estimate of remaining uncertainties associated with the large share of weather-dependent power sources. For this purpose it is essential to optimize NWP model forecasts with respect to those prognostic variables which are relevant for wind and solar power plants. An improved weather forecast serves as the basis for a sophisticated power forecasts. Consequently, a well-timed energy trading on the stock market, and electrical grid stability can be maintained. The German Weather Service (DWD) currently is involved with two projects concerning research in the field of renewable energy, namely ORKA*) and EWeLiNE**). Whereas the latter is in collaboration with the Fraunhofer Institute (IWES), the project ORKA is led by energy & meteo systems (emsys). Both cooperate with German transmission system operators. The goal of the projects is to improve wind and photovoltaic (PV) power forecasts by combining optimized NWP and enhanced power forecast models. In this context, the German Weather Service aims to improve its model system, including the ensemble forecasting system, by working on data assimilation, model physics and statistical post processing. This presentation is focused on the identification of critical weather situations and the associated errors in the German regional NWP model COSMO-DE. First steps leading to improved physical parameterization schemes within the NWP-model are presented. Wind mast measurements reaching up to 200 m height above ground are used for the estimation of the (NWP) wind forecast error at heights relevant for wind energy plants. One particular problem is the daily cycle in wind speed. The transition from stable stratification during

  18. Establishing a connection between hydrologic model parameters and physical catchment signatures for improved hierarchical Bayesian modeling in ungauged catchments

    NASA Astrophysics Data System (ADS)

    Marshall, L. A.; Weber, K.; Smith, T. J.; Greenwood, M. C.; Sharma, A.

    2012-12-01

    In an effort to improve hydrologic analysis in areas with limited data, hydrologists often seek to link catchments where little to no data collection occurs to catchments that are gauged. Various metrics and methods have been proposed to identify such relationships, in the hope that "surrogate" catchments might provide information for those catchments that are hydrologically similar. In this study we present a statistical analysis of over 150 catchments located in southeast Australia to examine the relationship between a hydrological model and certain catchment metrics. A conceptual rainfall-runoff model is optimized for each of the catchments and hierarchical clustering is performed to link catchments based on their calibrated model parameters. Clustering has been used in recent hydrologic studies but catchments are often clustered based on physical characteristics alone. Usually there is little evidence to suggest that such "surrogate" data approaches provide sufficiently similar model predictions. Beginning with model parameters and working backwards, we hope to establish if there is a relationship between the model parameters and physical characteristics for improved model predictions in the ungauged catchment. To analyze relationships, permutational multivariate analysis of variance tests are used that suggest which hydrologic metrics are most appropriate for discriminating between calibrated catchment clusters. Additional analysis is performed to determine which cluster pairs show significant differences for various metrics. We further examine the extent to which these results may be insightful for a hierarchical Bayesian modeling approach that is aimed at generating model predictions at an ungauged site. The method, known as Bayes Empirical Bayes (BEB) works to pool information from similar catchments to generate informed probability distributions for each model parameter at a data-limited catchment of interest. We demonstrate the effect of selecting

  19. Analysis of scheme interrelationships for model calibration and improvement using the Noah land surface model with multi-physics options

    NASA Astrophysics Data System (ADS)

    Hong, S.; Park, S. K.; Choi, Y.; Myoung, B.

    2013-12-01

    As the importance of the land surface models (LSMs) has been increasingly magnified due to their pivotal role in the complete Earth environmental system, linking the atmosphere, hydrosphere, and biosphere, modeling accuracy at regional scales has been important to ensure better representations of increased land surface heterogeneities with the increase of spatial resolutions. However, every model has its own weaknesses induced by such problems as the reality of physical schemes by uncertain parameterizing methods and even structural unreality by simplified model designs. One of the major uncertainties is Interrelationships between implemented physical schemes and their impact on simulation accuracy. Using the new version of Noah land surface model with multi-physics option (Noah-MP) that enables to create various scheme combinations, we examined how each scheme in different scheme combinations contributes to better simulations and how their interrelationships vary with uncertain parameter changes. Targeting long term (5 year) monthly surface hydrology of Han River watershed in South Korea, we mainly explored the simulation accuracy of runoff and evapotranspiration, and additionally that of leaf area index in order to see the vegetation impact on surface water partitioning. The result indicates that the primary contributor for simulation accuracies were the schemes of surface heat exchange coefficient. These schemes are very sensitive to vegetation amount due to their different treatment of heat transfer between on bare and vegetated surface. Showing that further improvement through uncertain parameter calibration, this study also demonstrated that the combination of analyses of scheme interrelationships and parameter calibration promises improved model calibration. In addition, revealing remained uncertainty about the vegetation effect on surface energy and water partitioning, this study also showed that the scheme interrelationship analyses is useful for model

  20. Deep sea water improves exercise and inhibits oxidative stress in a physical fatigue mouse model

    PubMed Central

    FAN, HUIJIE; TAN, ZHANGBIN; HUA, YUE; HUANG, XIAOFANG; GAO, YITING; WU, YUTING; LIU, BIN; ZHOU, YINGCHUN

    2016-01-01

    Physical fatigue is extremely common and occurs daily, and is considered to be associated with oxidative stress. The diverse functions of deep sea water (DSW) have recently gained increasing attention. Previous studies have emphasized the anti-fatigue effect of DSW, but the intrinsic mechanism behind the effect remains to be elucidated. In the imprinting control region (ICR) mice model, DSW delayed the exhaustive swimming time. In addition, DSW decreased the area under the blood lactate (BLA) curve, which was associated with the area under the BLA curve of pre-swimming, post-swimming and post-rest. Furthermore, DSW reduced the basal levels of malondialdehyde and the post-swimming concentration of blood urea nitrogen, lactate dehydrogenase and creatine kinase after swimming, along with an increase in the normal level of antioxidant enzyme activity such as superoxide dismutase and glutathione peroxidase. However, no significant effect on body weight, hepatic glycogen and muscle glycogen was observed between any group. In conclusion, DSW can improve the athletic ability and alleviate physical fatigue of ICR mice. This effect is achieved by enhancing the antioxidant capacity. PMID:27284418

  1. Improved Flood Prediction in an Urban Watershed Using a Physically-Based Modeling Approach

    NASA Astrophysics Data System (ADS)

    Adams, R.; Rees, P. L.; Bedient, P. B.; Vieux, B. E.

    2005-05-01

    A modeling strategy has been developed to improve the real-time forecasting of medium to large magnitude floods in an urban watershed, Brays Bayou (260 km2), in Houston, TX. Severe flooding of downstream areas of the watershed around the Texas Medical Center (TMC) has been an increasing problem over the past few decades, particularly during Tropical Storm (TS) Allison in June 2001. Since late 2003, the physically-based distributed hydraulic model, VfloTM, using a relatively coarse (122m) finite element grid, has been run alongside HEC-1 as an ensemble for real-time flood forecasting at strategic locations on the main channel. The models are driven by local NEXRAD L2 radar data. Both VfloTM and HEC-1 are incorporated into the Flood Alert System 2 (FAS2), which was developed for the TMC through Rice University. Both FAS2 and its predecessor FAS have done well in predicting the magnitude and timing of flooding. However, during TS Allison, stormwater in Harris Gully (20.7 km2) overflowed, resulting in millions of dollars in damages. In addition, the City of Houston is currently installing new stormwater conduits which will change the pattern of flow from Harris Gully to the larger Brays Bayou. The SWMM model has been applied to this subcatchment; however its long run-time precludes its use for real-time forecasting. It is intended to develop a more detailed VfloTM model of the smaller Harris Gully subcatchment to explore several questions, including: 1) in order to improve real-time forecasts further for the TMC, highly accurate quantitative precipitation estimate data at the spatial resolution relevant for urban areas (e.g. a city block) and a distributed hydrologic model of the same spatial resolution are necessary, 2) even in heavily urbanized areas, dependence on flood properties on a basin scale derives from the space-time scaling properties of rainfall, 3) urbanization, particularly in small (less than 100 km2) basins, alters traditional scaling theories of flood

  2. Improving image quality in poor visibility conditions using a physical model for contrast degradation.

    PubMed

    Oakley, J P; Satherley, B L

    1998-01-01

    In daylight viewing conditions, image contrast is often significantly degraded by atmospheric aerosols such as haze and fog. This paper introduces a method for reducing this degradation in situations in which the scene geometry is known. Contrast is lost because light is scattered toward the sensor by the aerosol particles and because the light reflected by the terrain is attenuated by the aerosol. This degradation is approximately characterized by a simple, physically based model with three parameters. The method involves two steps: first, an inverse problem is solved in order to recover the three model parameters; then, for each pixel, the relative contributions of scattered and reflected flux are estimated. The estimated scatter contribution is simply subtracted from the pixel value and the remainder is scaled to compensate for aerosol attenuation. This paper describes the image processing algorithm and presents an analysis of the signal-to-noise ratio (SNR) in the resulting enhanced image. This analysis shows that the SNR decreases exponentially with range. A temporal filter structure is proposed to solve this problem. Results are presented for two image sequences taken from an airborne camera in hazy conditions and one sequence in clear conditions. A satisfactory agreement between the model and the experimental data is shown for the haze conditions. A significant improvement in image quality is demonstrated when using the contrast enhancement algorithm in conjuction with a temporal filter. PMID:18267391

  3. Applying Socioecological Model to Improve Women’s Physical Activity: A Randomized Control Trial

    PubMed Central

    Tehrani, Hadi; Majlessi, Fershteh; Shojaeizadeh, Davoud; Sadeghi, Roya; Hasani Kabootarkhani, Marzieh

    2016-01-01

    Background: A sedentary life without sufficient physical activity is recognized as a risk factor for various diseases, and a major modifiable risk factor for noncommunicable diseases. This study was conducted to investigate the effect of intervention using socioecological model in promoting women’s physical activity in the city of Kerman, Iran. Materials and Methods: In this randomized, double-blinded, controlled study, 360 women were studied at health and medical centers of Kerman. This educational intervention was based on socioecological model and conducted on 4 levels of personal, social, organizational, and political. Data collection tool included a researcher-made questionnaire based on constructs of socioecological model and the international physical activity inventory. Results: The results indicated insignificant differences between the two groups in terms of perceived social, physical, and political support and also with regard to level of physical activity before intervention. However after the intervention and according to independent t test, significant differences were observed between two groups in perceived social, physical, and political support and also level of physical activity (P < 0.001). Furthermore, mean values of the above terms increased in the intervention group. Conclusions: According to the results, interventions based on socioecological model can positively affect women’s physical activity. PMID:27247781

  4. Improvements of Physically-Based Hydrological Modelling using the ACRU Agro-Hydrological Modelling System

    NASA Astrophysics Data System (ADS)

    Bonifacio, C. M. T.; Kienzle, S. W.; Xu, W.; Zhang, J.

    2014-12-01

    The uncertainty of future water availability due to climate change in the Upper Oldman River Basin in Alberta, Canada, and downstream users is considered in this study. A changing climate can significantly perturb hydrological response within a region, thereby affecting the available water resources within southern Alberta. The ACRU agro-hydrological modelling system is applied to simulate historical (1950-2010) and future (2041-2070) streamflows and volumes of a major irrigation reservoir. Like many highly complex, process-based distributed models, major limitations include the data availability and data quality at finer spatial resolutions. With the use of a scripting language, certain limitations can be greatly reduced. Three phases of the project will be emphasized. First, the assimilation of solar radiation, relative humidity, sunshine hours and wind speed daily data into the Canadian 10KM daily climate data that contains daily precipitation, maximum and minimum temperature data for the period 1950-2010, so as to enable potential evapotranspiration calculations using the Penman-Monteith equation. Second, the downscaling of five regional climate model (RCM) data to match the 10KM spatial resolution was undertaken. Third, a total of 1722 hydrological response units (HRUs) were delineated within the 4403 km2 large upper Oldman River Basin. In all phases of model input data parameterization and calibration, the automation of known external procedures greatly decreased erroneous model inputs and increased the efficiency of validating the quality of input data to be used within the ACRU model.

  5. Using Hidden Markov Models to Improve Quantifying Physical Activity in Accelerometer Data – A Simulation Study

    PubMed Central

    Witowski, Vitali; Foraita, Ronja; Pitsiladis, Yannis; Pigeot, Iris; Wirsik, Norman

    2014-01-01

    Introduction The use of accelerometers to objectively measure physical activity (PA) has become the most preferred method of choice in recent years. Traditionally, cutpoints are used to assign impulse counts recorded by the devices to sedentary and activity ranges. Here, hidden Markov models (HMM) are used to improve the cutpoint method to achieve a more accurate identification of the sequence of modes of PA. Methods 1,000 days of labeled accelerometer data have been simulated. For the simulated data the actual sedentary behavior and activity range of each count is known. The cutpoint method is compared with HMMs based on the Poisson distribution (HMM[Pois]), the generalized Poisson distribution (HMM[GenPois]) and the Gaussian distribution (HMM[Gauss]) with regard to misclassification rate (MCR), bout detection, detection of the number of activities performed during the day and runtime. Results The cutpoint method had a misclassification rate (MCR) of 11% followed by HMM[Pois] with 8%, HMM[GenPois] with 3% and HMM[Gauss] having the best MCR with less than 2%. HMM[Gauss] detected the correct number of bouts in 12.8% of the days, HMM[GenPois] in 16.1%, HMM[Pois] and the cutpoint method in none. HMM[GenPois] identified the correct number of activities in 61.3% of the days, whereas HMM[Gauss] only in 26.8%. HMM[Pois] did not identify the correct number at all and seemed to overestimate the number of activities. Runtime varied between 0.01 seconds (cutpoint), 2.0 minutes (HMM[Gauss]) and 14.2 minutes (HMM[GenPois]). Conclusions Using simulated data, HMM-based methods were superior in activity classification when compared to the traditional cutpoint method and seem to be appropriate to model accelerometer data. Of the HMM-based methods, HMM[Gauss] seemed to be the most appropriate choice to assess real-life accelerometer data. PMID:25464514

  6. Multi-physics Modeling for Improving Li-Ion Battery Safety; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Pesaran, A.; Kim, G.; Santhanagopalan, S.; Yang, C.

    2015-04-21

    Battery performance, cost, and safety must be further improved for larger market share of HEVs/PEVs and penetration into the grid. Significant investment is being made to develop new materials, fine tune existing ones, improve cell and pack designs, and enhance manufacturing processes to increase performance, reduce cost, and make batteries safer. Modeling, simulation, and design tools can play an important role by providing insight on how to address issues, reducing the number of build-test-break prototypes, and accelerating the development cycle of generating products.

  7. An improved hindcast approach for evaluation and diagnosis of physical processes in global climate models

    SciTech Connect

    Ma, Hsi-Yen; Chuang, C. C.; Klein, Stephen A.; Lo, M. H.; Zhang, Y.; Shaocheng, Xie; Ma, Po-Lun; Phillips, Thomas J.

    2015-10-19

    We present an improved procedure of generating initial conditions (ICs) for climate model hindcast experiments with specified sea surface temperature and sea ice. The motivation is to minimize errors in the ICs and lead to a better evaluation of atmospheric parameterizations' performance in the hindcast mode. We apply state variables (horizontal velocities, temperature and specific humidity) from the operational analysis/reanalysis for the atmospheric initial states. Without a data assimilation system, we apply a two-step process to obtain other necessary variables to initialize both the atmospheric (e.g., aerosols and clouds) and land models (e.g., soil moisture). First, we nudge only the model horizontal velocities towards operational analysis/reanalysis values, given a 6-hour relaxation time scale, to obtain all necessary variables. Compared to the original strategy in which horizontal velocities, temperature and specific humidity are nudged, the revised approach produces a better representation of initial aerosols and cloud fields which are more consistent and closer to observations and model's preferred climatology. Second, we obtain land ICs from an offline land model simulation forced with observed precipitation, winds, and surface fluxes. This approach produces more realistic soil moisture in the land ICs. With this refined procedure, the simulated precipitation, clouds, radiation, and surface air temperature over land are improved in the Day 2 mean hindcasts. Following this procedure, we propose a “Core” integration suite which provides an easily repeatable test allowing model developers to rapidly assess the impacts of various parameterization changes on the fidelity of modelled cloud-associated processes relative to observations. This article is protected by copyright. All rights reserved.

  8. An improved hindcast approach for evaluation and diagnosis of physical processes in global climate models

    NASA Astrophysics Data System (ADS)

    Ma, H.-Y.; Chuang, C. C.; Klein, S. A.; Lo, M.-H.; Zhang, Y.; Xie, S.; Zheng, X.; Ma, P.-L.; Zhang, Y.; Phillips, T. J.

    2015-12-01

    We present an improved procedure of generating initial conditions (ICs) for climate model hindcast experiments with specified sea surface temperature and sea ice. The motivation is to minimize errors in the ICs and lead to a better evaluation of atmospheric parameterizations' performance in the hindcast mode. We apply state variables (horizontal velocities, temperature, and specific humidity) from the operational analysis/reanalysis for the atmospheric initial states. Without a data assimilation system, we apply a two-step process to obtain other necessary variables to initialize both the atmospheric (e.g., aerosols and clouds) and land models (e.g., soil moisture). First, we nudge only the model horizontal velocities toward operational analysis/reanalysis values, given a 6 h relaxation time scale, to obtain all necessary variables. Compared to the original strategy in which horizontal velocities, temperature, and specific humidity are nudged, the revised approach produces a better representation of initial aerosols and cloud fields which are more consistent and closer to observations and model's preferred climatology. Second, we obtain land ICs from an off-line land model simulation forced with observed precipitation, winds, and surface fluxes. This approach produces more realistic soil moisture in the land ICs. With this refined procedure, the simulated precipitation, clouds, radiation, and surface air temperature over land are improved in the Day 2 mean hindcasts. Following this procedure, we propose a "Core" integration suite which provides an easily repeatable test allowing model developers to rapidly assess the impacts of various parameterization changes on the fidelity of modeled cloud-associated processes relative to observations.

  9. Improving predictive power of physically based rainfall-induced shallow landslide models: a probablistic approach

    USGS Publications Warehouse

    Raia, S.; Alvioli, M.; Rossi, M.; Baum, R.L.; Godt, J.W.; Guzzetti, F.

    2013-01-01

    are analyzed statistically, and compared to the original (deterministic) model output. The comparison suggests an improvement of the predictive power of the model of about 10% and 16% in two small test areas, i.e. the Frontignano (Italy) and the Mukilteo (USA) areas, respectively. We discuss the computational requirements of TRIGRS-P to determine the potential use of the numerical model to forecast the spatial and temporal occurrence of rainfall-induced shallow landslides in very large areas, extending for several hundreds or thousands of square kilometers. Parallel execution of the code using a simple process distribution and the Message Passing Interface (MPI) on multi-processor machines was successful, opening the possibly of testing the use of TRIGRS-P for the operational forecasting of rainfall-induced shallow landslides over large regions.

  10. Improving predictive power of physically based rainfall-induced shallow landslide models: a probabilistic approach

    NASA Astrophysics Data System (ADS)

    Raia, S.; Alvioli, M.; Rossi, M.; Baum, R. L.; Godt, J. W.; Guzzetti, F.

    2014-03-01

    runs obtained varying the input parameters are analyzed statistically, and compared to the original (deterministic) model output. The comparison suggests an improvement of the predictive power of the model of about 10% and 16% in two small test areas, that is, the Frontignano (Italy) and the Mukilteo (USA) areas. We discuss the computational requirements of TRIGRS-P to determine the potential use of the numerical model to forecast the spatial and temporal occurrence of rainfall-induced shallow landslides in very large areas, extending for several hundreds or thousands of square kilometers. Parallel execution of the code using a simple process distribution and the message passing interface (MPI) on multi-processor machines was successful, opening the possibly of testing the use of TRIGRS-P for the operational forecasting of rainfall-induced shallow landslides over large regions.

  11. Improved constraint on magmatic systems from geodetic and other data using physics-based eruption models

    NASA Astrophysics Data System (ADS)

    Anderson, K. R.; Segall, P.

    2012-12-01

    Observations of ground deformation at volcanoes can be used with simple kinematic models of idealized magma chambers to place valuable constraints on the location, depth, volume change history, and possibly shape of volcanic source reservoirs, but cannot generally be used to estimate their total volume or the properties of the melt in the chamber (including pressure). Analysis of gas emissions, lava dome growth, and the petrology of extruded rock can provide constraints on melt properties and possibly chamber volume, but considered independently, these observations can paint only an incomplete picture of the volcanic system. We argue that a physics-based model of a volcanic eruption can link realistic magmatic processes with diverse time-evolving observations, and thereby make it possible to use all available information simultaneously to place better constraints on properties of the magmatic system than is possible by considering each independently. We have developed a model of an effusive silicic volcanic eruption that is capable of predicting time-evolving pressures, volatile concentrations, and other properties of melt in the chamber and conduit, and from which observations of ground deformation and lava dome extrusion may be calculated. A Bayesian inverse formulation allows for the incorporation of additional information into the problem and generates probabilistic estimates for model parameters. We have applied the technique to the 2004-2008 eruption of Mount St. Helens (MSH), constraining model parameters using geodetic and extrusive flux time series, as well as independent estimates of chamber pressure (from plagioclase equilibration data) and dissolved water concentration (derived from gas emissions). In contrast to more traditional inversions using only geodetic data and kinematic forward models, we are able to provide constraint on the absolute volume of the magma chamber, properties of the melt including its compressibility and volatile content, and

  12. Improving Advanced High School Physics

    NASA Astrophysics Data System (ADS)

    Spital, Robin David

    2003-04-01

    A National Research Council study committee recently commissioned a "Physics Panel" to evaluate and make recommendations for improving advanced physics education in American high schools [1]. The Physics Panel recommends the creation of a nationally standardized Newtonian Mechanics Unit that would form the foundation of all advanced physics programs. In a one-year program, the Panel recommends that advanced physics students study at most one other major area of physics, so that sufficient time is available to develop the deep conceptual understanding that is the primary goal of advanced study. The Panel emphasizes that final assessments must be improved to focus on depth of understanding, rather than technical problem-solving skill. The Physics Panel strongly endorses the inclusion of meaningful real-world experiences in advanced physics programs, but believes that traditional "cook-book" laboratory exercises are not worth the enormous amount of time and effort spent on them. The Physics Panel believes that the talent and preparation of teachers are the most important ingredients in effective physics instruction; it therefore calls for a concerted effort by all parts of the physics community to remedy the desperate shortage of highly qualified teachers. [1] Jerry P. Gollub and Robin Spital, "Advanced Physics in the High Schools", Physics Today, May 2002.

  13. Physics Lectures and Laboratories. A Model To Improve Preservice Elementary Science Teacher Development. Volume II.

    ERIC Educational Resources Information Center

    Dresser, Miles

    A group of scientists and science educators has developed and pilot tested an integrated physical science program designed for preservice elementary school teachers. This document includes the syllabus and class materials for the Physics block of the physical science courses developed by the group. Included are diagrams, lecture notes, homework…

  14. Towards a More Accurate Solar Power Forecast By Improving NWP Model Physics

    NASA Astrophysics Data System (ADS)

    Köhler, C.; Lee, D.; Steiner, A.; Ritter, B.

    2014-12-01

    The growing importance and successive expansion of renewable energies raise new challenges for decision makers, transmission system operators, scientists and many more. In this interdisciplinary field, the role of Numerical Weather Prediction (NWP) is to reduce the uncertainties associated with the large share of weather-dependent power sources. Precise power forecast, well-timed energy trading on the stock market, and electrical grid stability can be maintained. The research project EWeLiNE is a collaboration of the German Weather Service (DWD), the Fraunhofer Institute (IWES) and three German transmission system operators (TSOs). Together, wind and photovoltaic (PV) power forecasts shall be improved by combining optimized NWP and enhanced power forecast models. The conducted work focuses on the identification of critical weather situations and the associated errors in the German regional NWP model COSMO-DE. Not only the representation of the model cloud characteristics, but also special events like Sahara dust over Germany and the solar eclipse in 2015 are treated and their effect on solar power accounted for. An overview of the EWeLiNE project and results of the ongoing research will be presented.

  15. Development Status of the PEBBLES Code for Pebble Mechanics: Improved Physical Models and Speed-up

    SciTech Connect

    Joshua J. Cogliati; Abderrafi M. Ougouag

    2009-09-01

    PEBBLES is a code for simulating the motion of all the pebbles in a pebble bed reactor. Since pebble bed reactors are packed randomly and not precisely placed, the location of the fuel elements in the reactor is not deterministically known. Instead, when determining operating parameters the motion of the pebbles can be simulated and stochastic locations can be found. The PEBBLES code can output information relevant for other simulations of the pebble bed reactors such as the positions of the pebbles in the reactor, packing fraction change in an earthquake, and velocity profiles created by recirculation. The goal for this level three milestone was to speedup the PEBBLES code through implementation on massively parallel computer. Work on this goal has resulted in speeding up both the single processor version and creation of a new parallel version of PEBBLES. Both the single processor version and the parallel running capability of the PEBBLES code have improved since the fiscal year start. The hybrid MPI/OpenMP PEBBLES version was created this year to run on the increasingly common cluster hardware profile that combines nodes with multiple processors that share memory and a cluster of nodes that are networked together. The OpenMP portions use the Open Multi-Processing shared memory parallel processing model to split the task across processors in a single node that shares memory. The Message Passing Interface (MPI) portion uses messages to communicate between different nodes over a network. The following are wall clock speed up for simulating an NGNP-600 sized reactor. The single processor version runs 1.5 times faster compared to the single processor version at the beginning of the fiscal year. This speedup is primarily due to the improved static friction model described in the report. When running on 64 processors, the new MPI/OpenMP hybrid version has a wall clock speed up of 22 times compared to the current single processor version. When using 88 processors, a

  16. Development Status of the PEBBLES Code for Pebble Mechanics: Improved Physical Models and Speed-up

    SciTech Connect

    Joshua J. Cogliati; Abderrafi M. Ougouag

    2009-12-01

    PEBBLES is a code for simulating the motion of all the pebbles in a pebble bed reactor. Since pebble bed reactors are packed randomly and not precisely placed, the location of the fuel elements in the reactor is not deterministically known. Instead, when determining operating parameters the motion of the pebbles can be simulated and stochastic locations can be found. The PEBBLES code can output information relevant for other simulations of the pebble bed reactors such as the positions of the pebbles in the reactor, packing fraction change in an earthquake, and velocity profiles created by recirculation. The goal for this level three milestone was to speedup the PEBBLES code through implementation on massively parallel computer. Work on this goal has resulted in speeding up both the single processor version and creation of a new parallel version of PEBBLES. Both the single processor version and the parallel running capability of the PEBBLES code have improved since the fiscal year start. The hybrid MPI/OpenMP PEBBLES version was created this year to run on the increasingly common cluster hardware profile that combines nodes with multiple processors that share memory and a cluster of nodes that are networked together. The OpenMP portions use the Open Multi-Processing shared memory parallel processing model to split the task across processors in a single node that shares memory. The Message Passing Interface (MPI) portion uses messages to communicate between different nodes over a network. The following are wall clock speed up for simulating an NGNP-600 sized reactor. The single processor version runs 1.5 times faster compared to the single processor version at the beginning of the fiscal year. This speedup is primarily due to the improved static friction model described in the report. When running on 64 processors, the new MPI/OpenMP hybrid version has a wall clock speed up of 22 times compared to the current single processor version. When using 88 processors, a

  17. Investigation for improving Global Positioning System (GPS) orbits using a discrete sequential estimator and stochastic models of selected physical processes

    NASA Technical Reports Server (NTRS)

    Goad, Clyde C.; Chadwell, C. David

    1993-01-01

    GEODYNII is a conventional batch least-squares differential corrector computer program with deterministic models of the physical environment. Conventional algorithms were used to process differenced phase and pseudorange data to determine eight-day Global Positioning system (GPS) orbits with several meter accuracy. However, random physical processes drive the errors whose magnitudes prevent improving the GPS orbit accuracy. To improve the orbit accuracy, these random processes should be modeled stochastically. The conventional batch least-squares algorithm cannot accommodate stochastic models, only a stochastic estimation algorithm is suitable, such as a sequential filter/smoother. Also, GEODYNII cannot currently model the correlation among data values. Differenced pseudorange, and especially differenced phase, are precise data types that can be used to improve the GPS orbit precision. To overcome these limitations and improve the accuracy of GPS orbits computed using GEODYNII, we proposed to develop a sequential stochastic filter/smoother processor by using GEODYNII as a type of trajectory preprocessor. Our proposed processor is now completed. It contains a correlated double difference range processing capability, first order Gauss Markov models for the solar radiation pressure scale coefficient and y-bias acceleration, and a random walk model for the tropospheric refraction correction. The development approach was to interface the standard GEODYNII output files (measurement partials and variationals) with software modules containing the stochastic estimator, the stochastic models, and a double differenced phase range processing routine. Thus, no modifications to the original GEODYNII software were required. A schematic of the development is shown. The observational data are edited in the preprocessor and the data are passed to GEODYNII as one of its standard data types. A reference orbit is determined using GEODYNII as a batch least-squares processor and the

  18. Improving Regional Climate Modeling of the North American Monsoon Through Physically Consistent Bias Corrected CCSM4 Output

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Jin, J.

    2014-12-01

    The Weather Research and Forecasting (WRF) model was used to simulate a 32-year climatology of the North American Monsoon (NAM) using forcing data provided by 1) the Climate Forecast System Reanalysis (CFSR), and 2) the Community Climate System Model version 4 (CCSM). Systematic biases in the CCSM output such as significant dry biases in the tropics are transmitted into the WRF model through the lateral boundary conditions and degrade the performance of the model when compared to both observations and simulations forced with the CFSR dataset. To improve the ability of CCSM output to appropriately prescribe the NAM, we introduce a process using simple linear regression and the CFSR dataset to perform a mean bias correction that also maintains the physical dependencies across variables. A third NAM climatology was simulated using this bias corrected CCSM output, which showed marked improvement to the NAM precipitation, most notably in the Mexican core of the NAM. Additionally, the climatology of NAM evolutionary characteristics (i.e. onset, intensity, decay) are much better represented in the bias corrected CCSM WRF model than in the original CCSM WRF model, and closely resemble the CFSR simulations. NAM precipitation simulated by each of the three forcing datasets show the bias corrected CCSM simulations produce the most consistent trends when compared to observations, providing confidence for future projections of the NAM.

  19. Improvement of Spatial Ability Using Innovative Tools: Alternative View Screen and Physical Model Rotator

    ERIC Educational Resources Information Center

    Kinsey, Brad L.; Towle, Erick; Onyancha, Richard M.

    2008-01-01

    Spatial ability, which is positively correlated with retention and achievement in engineering, mathematics, and science disciplines, has been shown to improve over the course of a Computer-Aided Design course or through targeted training. However, which type of training provides the most beneficial improvements to spatial ability and whether other…

  20. Physical properties of particulate matter from animal houses-empirical studies to improve emission modelling.

    PubMed

    Mostafa, Ehab; Nannen, Christoph; Henseler, Jessica; Diekmann, Bernd; Gates, Richard; Buescher, Wolfgang

    2016-06-01

    Maintaining and preserving the environment from pollutants are of utmost importance. Particulate matter (PM) is considered one of the main air pollutants. In addition to the harmful effects of PM in the environment, it has also a negative indoor impact on human and animal health. The specific forms of damage of particulate emission from livestock buildings depend on its physical properties. The physical properties of particulates from livestock facilities are largely unknown. Most studies assume the livestock particles to be spherical with a constant density which can result in biased estimations, leading to inaccurate results and errors in the calculation of particle mass concentration in livestock buildings. The physical properties of PM, including difference in density as a function of particle size and shape, can have a significant impact on the predictions of particles' behaviour. The aim of this research was to characterize the physical properties of PM from different animal houses and consequently determine PM mass concentration. The mean densities of collected PM from laying hens, dairy cows and pig barns were 1450, 1520 and 2030 kg m(-3), respectively, whilst the mass factors were 2.17 × 10(-3), 2.18 × 10(-3) and 5.36 × 10(-3) μm, respectively. The highest mass concentration was observed in pig barns generally followed by laying hen barns, and the lowest concentration was in dairy cow buildings. Results are presented in such a way that they can be used in subsequent research for simulation purposes and to form the basis for a data set of PM physical properties. PMID:26976010

  1. Application of a Distributed, Physically Based, Hydrologic Model to Improve Streamflow Forecasts in the Headwaters of the Rio Grande

    NASA Astrophysics Data System (ADS)

    Boyle, D. P.; Viger, R.; Markstrom, S.; Hay, L. E.; McConnell, J. R.; Leavesley, G.; Bardsley, T.

    2001-05-01

    A significant portion of the runoff in the Rio Grande begins as seasonal snowpack in the headwaters above the USGS stream gaging station at Del Norte, CO. Resource managers in the Rio Grande rely on accurate forecasts of water availability and flow at the Del Norte gage to make important decisions aimed at achieving a balance among the many different and competing water uses such as municipal, fish and wildlife, agricultural, and water quality. In this study, a distributed, physically based hydrologic model is used to investigate the degree of spatial and temporal distribution of snow and the processes that control snowmelt necessary to accurately simulate streamflow at the Del Norte gage. Specifically, snow distribution and surface runoff are estimated using a combination of the USGS Modular Modeling System (MMS), GIS Weasel, Precipitation-Runoff Modeling System (PRMS), and XYZ snow distribution model. The work represents a highly collaborative effort between researchers at the Desert Research Institute and the USGS as part of initial Sustainability of semi-Arid Hydrology and Riparian Areas (SAHRA) goals to improve models of snow distribution and snowmelt processes.

  2. Application of a Distributed, Physically Based, Hydrologic Model to Improve Streamflow Forecasts in the Upper Rio Grande Basin

    NASA Astrophysics Data System (ADS)

    Gorham, T. A.; Boyle, D. P.; McConnell, J. R.; Lamorey, G. W.; Markstrom, S.; Viger, R.; Leavesley, G.

    2001-12-01

    Approximately two-thirds of the runoff in the Rio Grande begins as seasonal snowpack in the headwaters above the USGS stream gaging stations at several points (nodes) above Albuquerque, New Mexico. Resource managers in the Rio Grande Basin rely on accurate short and long term forecasts of water availability and flow at these nodes to make important decisions aimed at achieving a balance among many different and competing water uses such as municipal, fish and wildlife, agricultural, and water quality. In this study, a distributed, physically based hydrologic model is used to investigate the degree of spatial and temporal distribution of snow and the processes that control snowmelt necessary to accurately simulate streamflow at seven of these nodes. Specifically, snow distribution and surface runoff are estimated using a combination of the USGS Modular Modeling System (MMS), GIS Weasel, Precipitation-Runoff Modeling System (PRMS), and XYZ snow distribution model. This highly collaborative work between researchers at the Desert Research Institute and the USGS is an important part of SAHRA (Sustainability of semi-Arid Hydrology and Riparian Areas) efforts aimed at improving models of snow distribution and snowmelt processes.

  3. Effect of a physical activity improvement program using the transtheoretical model at a small-scale company.

    PubMed

    Ishii, Atsuko; Nakiri, Makoto; Nagatomi, Kaori; Tsuji, Yoshiyasu; Hoshiko, Michiko; Yamaguchi, Yoshie; Muramoto, Junko; Ishitake, Tatsuya

    2007-01-01

    The present study aimed to investigate the potential use of the transtheoretical model (TTM) by clarifying the program's effects on workers at a small-scale company. Subjects were 22 male workers at a communication system company. They were divided into two physical activity improvement program groups, the TTM-based assistance group (TTM group, n=12) and the control group (n=10). During the study period each subject was asked to wear a calorie counter and to record daily exercise. Changes in number of steps per day and body weight were measured before, immediately after, and 1 month after the intervention ended. Stage of exercise behavior, health protective behavior, and self-efficacy were also examined by means of self-administered questionnaires. In the control group, the number of steps per day tended to increase immediately after the intervention and then decreased at 1 month after the program ended. In both groups, physical activity peaked during commuting and lunch hours. This peak persisted for 1 month after the intervention in the TTM group, but not in the control group. Moreover, the stage of exercise behavior tended to progress in the TTM group, whereas regression in the stage of exercise behavior was observed in the control group. In the control group, although the exercise self-efficacy score after intervention was higher than that before intervention, the health protective behavior score decreased at 1 month after the program ended. This study suggested that physical activity improvement programs based on TTM may be useful for workers at small-scale companies. However, further study of larger numbers of workers will be needed to confirm the validity and usefulness of these results. PMID:18332591

  4. Improving physical realism, stereochemistry and side-chain accuracy in homology modeling: four approaches that performed well in CASP8

    PubMed Central

    Krieger, Elmar; Joo, Keehyoung; Lee, Jinwoo; Lee, Jooyoung; Raman, Srivatsan; Thompson, James; Tyka, Mike; Baker, David; Karplus, Kevin

    2009-01-01

    A correct alignment is an essential requirement in homology modeling. Yet in order to bridge the structural gap between template and target, which may not only involve loop rearrangements, but also shifts of secondary structure elements and repacking of core residues, high-resolution refinement methods with full atomic details are needed. Here we describe four approaches that address this ‘last mile of the protein folding problem’ and have performed well during CASP8, yielding physically realistic models: YASARA, which runs molecular dynamics simulations of models in explicit solvent, using a new partly knowledge-based all atom force field derived from Amber, whose parameters have been optimized to minimize the damage done to protein crystal structures. The LEE-SERVER, which makes extensive use of conformational space annealing to create alignments, to help Modeller build physically realistic models while satisfying input restraints from templates and CHARMM stereochemistry, and to remodel the side-chains. ROSETTA, whose high resolution refinement protocol combines a physically realistic all atom force field with Monte Carlo minimization to allow the large conformational space to be sampled quickly. And finally UNDERTAKER, which creates a pool of candidate models from various templates and then optimizes them with an adaptive genetic algorithm, using a primarily empirical cost function that does not include bond angle, bond length, or other physics-like terms. PMID:19768677

  5. Optimizing the characterization of forest structure with remote sensing to improve physically-based hydrologic modeling (Invited)

    NASA Astrophysics Data System (ADS)

    Varhola, A.; Coops, N.; Teti, P.; Weiler, M.

    2013-12-01

    For more than a decade, the lodgepole pine (Pinus contorta) forests of British Columbia have been affected by mountain pine beetle (MPB) (Dendroctonus ponderosae), constituting one of the most destructive insect outbreaks in North America. In such a snow-dominated environment, a receding forest cover is known to be associated with an increase in snow accumulation during winter, an enhancement in snowmelt rates and the suppression of transpiration during spring. These changes can exacerbate the risk of flooding, with the corresponding threats to infrastructure and society. However, the unprecedented extent of the disturbance (180,000 km2) and the particular nature of the beetles' severe but gradual effect on the forests' structural and physiological integrity have challenged scientists aiming to more confidently quantify the real ecological impacts. Even though hydrologic models remain as the only tool currently available to evaluate the effects of MPB on snow and streamflow dynamics, they are impaired in their present form because they rely on coarse and oversimplified characterizations of forest structure unable to capture the changes caused by MPB on vegetation over large areas. Remote sensing technologies such as Airborne Laser Scanning (ALS) and Landsat Thematic Mapper offer remarkable alternatives to fill this knowledge gap. First, this study presents a novel methodology to calibrate ALS data with in-situ optical hemispherical camera images to obtain the plot-level forest structure metrics that are traditionally used in physically-based hydrologic models. The approach minimizes geometrical differences between these two techniques by transforming the Cartesian coordinates of ALS data to generate synthetic images with a polar projection directly comparable to optical photography. We demonstrate how these new coordinate-transformed ALS metrics, along with additional standard vegetation variables, can be estimated at any individual location within the extent of an

  6. Machine Learning Based Multi-Physical-Model Blending for Enhancing Renewable Energy Forecast -- Improvement via Situation Dependent Error Correction

    SciTech Connect

    Lu, Siyuan; Hwang, Youngdeok; Khabibrakhmanov, Ildar; Marianno, Fernando J.; Shao, Xiaoyan; Zhang, Jie; Hodge, Bri-Mathias; Hamann, Hendrik F.

    2015-07-15

    With increasing penetration of solar and wind energy to the total energy supply mix, the pressing need for accurate energy forecasting has become well-recognized. Here we report the development of a machine-learning based model blending approach for statistically combining multiple meteorological models for improving the accuracy of solar/wind power forecast. Importantly, we demonstrate that in addition to parameters to be predicted (such as solar irradiance and power), including additional atmospheric state parameters which collectively define weather situations as machine learning input provides further enhanced accuracy for the blended result. Functional analysis of variance shows that the error of individual model has substantial dependence on the weather situation. The machine-learning approach effectively reduces such situation dependent error thus produces more accurate results compared to conventional multi-model ensemble approaches based on simplistic equally or unequally weighted model averaging. Validation over an extended period of time results show over 30% improvement in solar irradiance/power forecast accuracy compared to forecasts based on the best individual model.

  7. Building mental models by dissecting physical models.

    PubMed

    Srivastava, Anveshna

    2016-01-01

    When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to ensure focused learning; models that are too constrained require less supervision, but can be constructed mechanically, with little to no conceptual engagement. We propose "model-dissection" as an alternative to "model-building," whereby instructors could make efficient use of supervisory resources, while simultaneously promoting focused learning. We report empirical results from a study conducted with biology undergraduate students, where we demonstrate that asking them to "dissect" out specific conceptual structures from an already built 3D physical model leads to a significant improvement in performance than asking them to build the 3D model from simpler components. Using questionnaires to measure understanding both before and after model-based interventions for two cohorts of students, we find that both the "builders" and the "dissectors" improve in the post-test, but it is the latter group who show statistically significant improvement. These results, in addition to the intrinsic time-efficiency of "model dissection," suggest that it could be a valuable pedagogical tool. PMID:26712513

  8. Towards Improved High-Resolution Land Surface Hydrologic Reanalysis Using a Physically-Based Hydrologic Model and Data Assimilation

    NASA Astrophysics Data System (ADS)

    Shi, Y.; Davis, K. J.; Zhang, F.; Duffy, C.; Yu, X.

    2014-12-01

    A coupled physically based land surface hydrologic model, Flux-PIHM, has been developed by incorporating a land surface scheme into the Penn State Integrated Hydrologic Model (PIHM). The land surface scheme is adapted from the Noah land surface model. Flux-PIHM has been implemented and manually calibrated at the Shale Hills watershed (0.08 km2) in central Pennsylvania. Model predictions of discharge, point soil moisture, point water table depth, sensible and latent heat fluxes, and soil temperature show good agreement with observations. When calibrated only using discharge, and soil moisture and water table depth at one point, Flux-PIHM is able to resolve the observed 101 m scale soil moisture pattern at the Shale Hills watershed when an appropriate map of soil hydraulic properties is provided. A Flux-PIHM data assimilation system has been developed by incorporating EnKF for model parameter and state estimation. Both synthetic and real data assimilation experiments have been performed at the Shale Hills watershed. Synthetic experiment results show that the data assimilation system is able to simultaneously provide accurate estimates of multiple parameters. In the real data experiment, the EnKF estimated parameters and manually calibrated parameters yield similar model performances, but the EnKF method significantly decreases the time and labor required for calibration. The data requirements for accurate Flux-PIHM parameter estimation via data assimilation using synthetic observations have been tested. Results show that by assimilating only in situ outlet discharge, soil water content at one point, and the land surface temperature averaged over the whole watershed, the data assimilation system can provide an accurate representation of watershed hydrology. Observations of these key variables are available with national and even global spatial coverage (e.g., MODIS surface temperature, SMAP soil moisture, and the USGS gauging stations). National atmospheric reanalysis

  9. Beyond Standard Model Physics

    SciTech Connect

    Bellantoni, L.

    2009-11-01

    There are many recent results from searches for fundamental new physics using the TeVatron, the SLAC b-factory and HERA. This talk quickly reviewed searches for pair-produced stop, for gauge-mediated SUSY breaking, for Higgs bosons in the MSSM and NMSSM models, for leptoquarks, and v-hadrons. There is a SUSY model which accommodates the recent astrophysical experimental results that suggest that dark matter annihilation is occurring in the center of our galaxy, and a relevant experimental result. Finally, model-independent searches at D0, CDF, and H1 are discussed.

  10. Ionospheric irregularity physics modelling

    SciTech Connect

    Ossakow, S.L.; Keskinen, M.J.; Zalesak, S.T.

    1982-01-01

    Theoretical and numerical simulation techniques have been employed to study ionospheric F region plasma cloud striation phenomena, equatorial spread F phenomena, and high latitude diffuse auroral F region irregularity phenomena. Each of these phenomena can cause scintillation effects. The results and ideas from these studies are state-of-the-art, agree well with experimental observations, and have induced experimentalists to look for theoretically predicted results. One conclusion that can be drawn from these studies is that ionospheric irregularity phenomena can be modelled from a first principles physics point of view. Theoretical and numerical simulation results from the aforementioned ionospheric irregularity areas will be presented.

  11. Automated Student Model Improvement

    ERIC Educational Resources Information Center

    Koedinger, Kenneth R.; McLaughlin, Elizabeth A.; Stamper, John C.

    2012-01-01

    Student modeling plays a critical role in developing and improving instruction and instructional technologies. We present a technique for automated improvement of student models that leverages the DataShop repository, crowd sourcing, and a version of the Learning Factors Analysis algorithm. We demonstrate this method on eleven educational…

  12. Applying the Model of Goal-Directed Behavior, Including Descriptive Norms, to Physical Activity Intentions: A Contribution to Improving the Theory of Planned Behavior.

    PubMed

    Esposito, Gabriele; van Bavel, René; Baranowski, Tom; Duch-Brown, Néstor

    2016-08-01

    The theory of planned behavior (TPB) has received its fair share of criticism lately, including calls for it to retire. We contribute to improving the theory by testing extensions such as the model of goal-directed behavior (MGDB, which adds desire and anticipated positive and negative emotions) applied to physical activity (PA) intention. We also test the inclusion of a descriptive norms construct as an addition to the subjective norms construct, also applied to PA, resulting in two additional models: TPB including descriptive norms (TPB + DN) and MGDB including descriptive norms (MGDB + DN). The study is based on an online survey of 400 young adult Internet users, previously enrolled in a subject pool. Confirmatory factor analysis (CFA) showed that TPB and TPB + DN were not fit for purpose, while MGDB and MGDB + DN were. Structural equation modelling (SEM) conducted on MGDB and MGDB + DN showed that the inclusion of descriptive norms took over the significance of injunctive norms, and increased the model's account of total variance in intention to be physically active. PMID:27229344

  13. Physical Models of Cognition

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    1994-01-01

    This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor ; a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

  14. Physical models of cognition

    NASA Astrophysics Data System (ADS)

    Zak, Michail

    1994-05-01

    This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor—a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

  15. Improving physics instruction by analyzing video games

    NASA Astrophysics Data System (ADS)

    Beatty, Ian D.

    2013-01-01

    Video games can be very powerful teaching systems, and game designers have become adept at optimizing player engagement while scaffolding development of complex skills and situated knowledge. One implication is that we might create games to teach physics. Another, which I explore here, is that we might learn to improve classroom physics instruction by studying effective games. James Gee, in his book What Video Games Have to Teach Us About Learning and Literacy (2007), articulates 36 principles that make good video games highly effective as learning environments. In this theoretical work, I identify 16 themes running through Gee's principles, and explore how these themes and Gee's principles could be applied to the design of an on-campus physics course. I argue that the process pushes us to confront aspects of learning that physics instructors and even physics education researchers generally neglect, and suggest some novel ideas for course design.

  16. Physical and mathematical cochlear models

    NASA Astrophysics Data System (ADS)

    Lim, Kian-Meng

    2000-10-01

    The cochlea is an intricate organ in the inner ear responsible for our hearing. Besides acting as a transducer to convert mechanical sound vibrations to electrical neural signals, the cochlea also amplifies and separates the sound signal into its spectral components for further processing in the brain. It operates over a broad-band of frequency and a huge dynamic range of input while maintaining a low power consumption. The present research takes the approach of building cochlear models to study and understand the underlying mechanics involved in the functioning of the cochlea. Both physical and mathematical models of the cochlea are constructed. The physical model is a first attempt to build a life- sized replica of the human cochlea using advanced micro- machining techniques. The model takes a modular design, with a removable silicon-wafer based partition membrane encapsulated in a plastic fluid chamber. Preliminary measurements in the model are obtained and they compare roughly with simulation results. Parametric studies on the design parameters of the model leads to an improved design of the model. The studies also revealed that the width and orthotropy of the basilar membrane in the cochlea have significant effects on the sharply tuned responses observed in the biological cochlea. The mathematical model is a physiologically based model that includes three-dimensional viscous fluid flow and a tapered partition with variable properties along its length. A hybrid asymptotic and numerical method provides a uniformly valid and efficient solution to the short and long wave regions in the model. Both linear and non- linear activity are included in the model to simulate the active cochlea. The mathematical model has successfully reproduced many features of the response in the biological cochlea, as observed in experiment measurements performed on animals. These features include sharply tuned frequency responses, significant amplification with inclusion of activity

  17. MODELING PHYSICAL HABITAT PARAMETERS

    EPA Science Inventory

    Salmonid populations can be affected by alterations in stream physical habitat. Fish productivity is determined by the stream's physical habitat structure ( channel form, substrate distribution, riparian vegetation), water quality, flow regime and inputs from the watershed (sedim...

  18. Physical model of kitesurfing

    NASA Astrophysics Data System (ADS)

    Zimoch, Pawel; Paxson, Adam; Obropta, Edward; Peleg, Tom; Parker, Sam; Hosoi, A. E.

    2013-11-01

    Kitesurfing is a popular water sport, similar to windsurfing, utilizing a surfboard-like platform pulled by a large kite operated by the surfer. While the kite generates thrust that propels the surfer across the water, much like a traditional sail, it is also capable of generating vertical forces on the surfer, reducing the hydrodynamic lift generated by the surfboard required to support the surfer's weight. This in turn reduces drag acting on the surfboard, making sailing possible in winds lower than required by other sailing sports. We describe aerodynamic and hydrodynamic models for the forces acting on the kite and the surfboard, and couple them while considering the kite's position in space and the requirement for the kite to support its own weight. We then use these models to quantitatively characterize the significance of the vertical force component generated by the kite on sailing performance (the magnitude of achievable steady-state velocities and the range of headings, relative to the true wind direction, in which sailing is possible), and the degradation in sailing performance with decreasing wind speeds. Finally, we identify the areas of kite and surfboard design whose development could have the greatest impact on improving sailing performance in low wind conditions.

  19. An improved linear ion trap physics package

    NASA Technical Reports Server (NTRS)

    Prestage, J. D.

    1993-01-01

    This article describes an improvement in the architecture of the physics package used in the Linear Ion Trap (LIT)-based frequency standard recently developed at JPL. This new design is based on the observation that ions can be moved along the axis of an LIT by applied dc voltages. The state selection and interrogation region can be separated from the more critical microwave resonance region where the multiplied local oscillator signal is compared with the stable atomic transition. This separation relaxes many of the design constraints of the present units. Improvements include increased frequency stability and a substantial reduction in size, mass, and cost of the final frequency standard.

  20. Building Mental Models by Dissecting Physical Models

    ERIC Educational Resources Information Center

    Srivastava, Anveshna

    2016-01-01

    When students build physical models from prefabricated components to learn about model systems, there is an implicit trade-off between the physical degrees of freedom in building the model and the intensity of instructor supervision needed. Models that are too flexible, permitting multiple possible constructions require greater supervision to…

  1. Multi-initial-conditions and Multi-physics Ensembles in the Weather Research and Forecasting Model to Improve Coastal Stratocumulus Forecasts for Solar Power Integration

    NASA Astrophysics Data System (ADS)

    Yang, H.

    2015-12-01

    In coastal Southern California, variation in solar energy production is predominantly due to the presence of stratocumulus clouds (Sc), as they greatly attenuate surface solar irradiance and cover most distributed photovoltaic systems on summer mornings. Correct prediction of the spatial coverage and lifetime of coastal Sc is therefore vital to the accuracy of solar energy forecasts in California. In Weather Research and Forecasting (WRF) model simulations, underprediction of Sc inherent in the initial conditions directly leads to an underprediction of Sc in the resulting forecasts. Hence, preprocessing methods were developed to create initial conditions more consistent with observational data and reduce spin-up time requirements. Mathiesen et al. (2014) previously developed a cloud data assimilation system to force WRF initial conditions to contain cloud liquid water based on CIMSS GOES Sounder cloud cover. The Well-mixed Preprocessor and Cloud Data Assimilation (WEMPPDA) package merges an initial guess of cloud liquid water content obtained from mixed-layer theory with assimilated CIMSS GOES Sounder cloud cover to more accurately represent the spatial coverage of Sc at initialization. The extent of Sc inland penetration is often constrained topographically; therefore, the low inversion base height (IBH) bias in NAM initial conditions decreases Sc inland penetration. The Inversion Base Height (IBH) package perturbs the initial IBH by the difference between model IBH and the 12Z radiosonde measurement. The performance of these multi-initial-condition configurations was evaluated over June, 2013 against SolarAnywhere satellite-derived surface irradiance data. Four configurations were run: 1) NAM initial conditions, 2) RAP initial conditions, 3) WEMPPDA applied to NAM, and 4) IBH applied to NAM. Both preprocessing methods showed significant improvement in the prediction of both spatial coverage and lifetime of coastal Sc. The best performing configuration was then

  2. Integrated modeling, data transfers, and physical models

    NASA Astrophysics Data System (ADS)

    Brookshire, D. S.; Chermak, J. M.

    2003-04-01

    Difficulties in developing precise economic policy models for water reallocation and re-regulation in various regional and transboundary settings has been exacerbated not only by climate issues but also by institutional changes reflected in the promulgation of environmental laws, changing regional populations, and an increased focus on water quality standards. As complexity of the water issues have increased, model development at a micro-policy level is necessary to capture difficult institutional nuances and represent the differing national, regional and stakeholders' viewpoints. More often than not, adequate "local" or specific micro-data are not available in all settings for modeling and policy decisions. Economic policy analysis increasingly deals with this problem through data transfers (transferring results from one study area to another) and significant progress has been made in understanding the issue of the dimensionality of data transfers. This paper explores the conceptual and empirical dimensions of data transfers in the context of integrated modeling when the transfers are not only from the behavioral, but also from the hard sciences. We begin by exploring the domain of transfer issues associated with policy analyses that directly consider uncertainty in both the behavioral and physical science settings. We then, through a stylized, hybrid, economic-engineering model of water supply and demand in the Middle Rio Grand Valley of New Mexico (USA) analyze the impacts of; (1) the relative uncertainty of data transfers methods, (2) the uncertainty of climate data and, (3) the uncertainly of population growth. These efforts are motivated by the need to address the relative importance of more accurate data both from the physical sciences as well as from demography and economics for policy analyses. We evaluate the impacts by empirically addressing (within the Middle Rio Grand model): (1) How much does the surrounding uncertainty of the benefit transfer

  3. Physical Modeling of the Piano

    NASA Astrophysics Data System (ADS)

    Giordano, N.; Jiang, M.

    2004-12-01

    A project aimed at constructing a physical model of the piano is described. Our goal is to calculate the sound produced by the instrument entirely from Newton's laws. The structure of the model is described along with experiments that augment and test the model calculations. The state of the model and what can be learned from it are discussed.

  4. Improvement of Learning Process and Learning Outcomes in Physics Learning by Using Collaborative Learning Model of Group Investigation at High School (Grade X, SMAN 14 Jakarta)

    ERIC Educational Resources Information Center

    Astra, I. Made; Wahyuni, Citra; Nasbey, Hadi

    2015-01-01

    The aim of this research is to improve the quality of physics learning through application of collaborative learning of group investigation at grade X MIPA 2 SMAN 14 Jakarta. The method used in this research is classroom action research. This research consisted of three cycles was conducted from April to May in 2014. Each cycle consists of…

  5. Using satellite-derived snow cover to assess and improve the snowpack physics of the Noah Land Surface Model of NCEP

    NASA Astrophysics Data System (ADS)

    Mitchell, K.; Wei, H.; Ek, M.; Lohmann, D.; Ramsay, B.; Tarpley, D.; Sheffield, J.; Wood, E.

    During the 1990's and continuing to the present, advances in land surface modeling at NCEP have been an important source of improving prediction skill in NCEP global and regional weather and climate models. Many advancements in NCEP's Noah Land Surface Model (Noah LSM) emerged from two thrusts: 1) NCEP's participation in the several land modeling foci of the Global Energy and Water Cycle Experiment (GEWEX), such as GCIP/GAPP, ISLSCP (GSWP I and II), PILPS (2a, 2c, 2d, 2e), and GLASS (Rhone), and 2) the multi-institution collaboration led by NCEP to develop and execute the North American Land Data Assimilation System (NLDAS). Concurrently, NCEP's advancement of the Noah LSM benefited repeatedly from the succession of advances in various satellite-derived land-surface products, including snow cover, green vegetation cover, land surface skin temperature, and surface albedo. Recently for example, NCEP has improved the performance of the snowpack physics in its Noah LSM by means of multi-year inter-comparisons of model simulations and satellite-based analyses of snow cover over continental scales. The satellite-based fields of snow cover applied by NCEP are those of the NESDIS daily, N. Hemisphere 24-km, Interactive Multi-sensor Snow (IMS) product, which has been operational since January of 1997. The generation of IMS snow-cover utilizes inputs from both polar orbiting (NOAA/AVHRR visible and DMSP/SSMI microwave) and geostationary satellites (GOES, METEOSAT, and GMS). On 23 Feb 2004, the operational resolution of the IMS snow-cover product increased to 4-km (from 24-km). The comparison of the Noah LSM simulations of snow cover with the NESDIS IMS analyses of snow cover over the continental U.S. (CONUS) for three successive winter seasons in the NLDAS project revealed a systematic early bias in the Noah timing of springtime snowpack depletion. Subsequent investigation via model sensitivity tests and intercomparison with other land models revealed a low bias in snow

  6. Integrated Hydrologic Validation to Improve Physical Precipitation Retrievals for GPM

    NASA Astrophysics Data System (ADS)

    Peters-Lidard, C. D.; Harrison, K. W.; Tian, Y.; Kumar, S.

    2011-12-01

    One of the five scientific objectives for GPM is to "Improve hydrological modeling and prediction", including advancing prediction skill for high-impact hazards such as floods, droughts, landslides and landfalling hurricanes. Given the focus on land hydrology, and the range of hydrologic regimes targeted by GPM, it follows that a hydrologically-oriented ground validation program that covers these regimes from both the physical retrieval and the hydrological prediction perspectives is required for the successful application of GPM to land hydrology. In order to investigate the robustness of both hydrologic model predictions and physical precipitation retrievals, this talk will present recent evaluations of skill in land surface hydrologic models forced with TRMM-era multisensor products, with and without land data assimilation. In addition to LSM skill, we will also demonstrate how physical precipitation retrievals can be supported by land surface emissivity and temperature estimates obtained by coupling microwave emission models (e.g., the Joint Center for Satellite Data Assimilation Community Radiative Transfer Model CRTM and the European Center for Medium-Range Weather Forecasting's Community Microwave Emission Model CMEM) to the land surface models in the Land Information System (LIS; http://lis.gsfc.nasa.gov). Evaluation at multiple frequencies, with and without land data assimilation, demonstrates the critical impact of certain real-time ancillary data (e.g., snow cover) on the microwave background states required for physical retrievals.

  7. Sustaining the Progress to Improve Physics Education

    ERIC Educational Resources Information Center

    Abdul-Razzaq, Wathiq

    2010-01-01

    One of the problems we face in teaching introductory physics courses at the college level is that about 2/3 of students never had physics prior coming to college. Thus, many students find it very difficult to learn physics for the first time at the relatively fast-paced teaching of college physics courses. Sometimes the drop/failure/withdrawal…

  8. Physical Modeling of Microtubules Network

    NASA Astrophysics Data System (ADS)

    Allain, Pierre; Kervrann, Charles

    2014-10-01

    Microtubules (MT) are highly dynamic tubulin polymers that are involved in many cellular processes such as mitosis, intracellular cell organization and vesicular transport. Nevertheless, the modeling of cytoskeleton and MT dynamics based on physical properties is difficult to achieve. Using the Euler-Bernoulli beam theory, we propose to model the rigidity of microtubules on a physical basis using forces, mass and acceleration. In addition, we link microtubules growth and shrinkage to the presence of molecules (e.g. GTP-tubulin) in the cytosol. The overall model enables linking cytosol to microtubules dynamics in a constant state space thus allowing usage of data assimilation techniques.

  9. Physical Modeling of Aqueous Solvation

    PubMed Central

    Fennell, Christopher J.

    2014-01-01

    We consider the free energies of solvating molecules in water. Computational modeling usually involves either detailed explicit-solvent simulations, or faster computations, which are based on implicit continuum approximations or additivity assumptions. These simpler approaches often miss microscopic physical details and non-additivities present in experimental data. We review explicit-solvent modeling that identifies the physical bases for the errors in the simpler approaches. One problem is that water molecules that are shared between two substituent groups often behave differently than waters around each substituent individually. One manifestation of non-additivities is that solvation free energies in water can depend not only on surface area or volume, but on other properties, such as the surface curvature. We also describe a new computational approach, called Semi-Explicit Assembly, that aims to repair these flaws and capture more of the physics of explicit water models, but with computational efficiencies approaching those of implicit-solvent models. PMID:25143658

  10. Spray combustion model improvement study, 1

    NASA Technical Reports Server (NTRS)

    Chen, C. P.; Kim, Y. M.; Shang, H. M.

    1993-01-01

    This study involves the development of numerical and physical modeling in spray combustion. These modeling efforts are mainly motivated to improve the physical submodels of turbulence, combustion, atomization, dense spray effects, and group vaporization. The present mathematical formulation can be easily implemented in any time-marching multiple pressure correction methodologies such as MAST code. A sequence of validation cases includes the nonevaporating, evaporating and_burnin dense_sprays.

  11. Physical Models In GPSOMC Software

    NASA Technical Reports Server (NTRS)

    Sovers, Ojars J.; Border, James S.

    1992-01-01

    Report desribes physical models incorporated into GPSOMC, (modeling module of GIPSY software) which processes geodetic measurements in Global Positioning Satellite (GPS) system. Models describe spacecraft orbits and motions of receivers fixed to Earth. Supplies apriori values of computed observables and partial derivatives of computed observables with respect to parameters of models. Describes portion of software modeling locations of receivers and motions of whole Earth and computes observables and partial derivatives. Corrected, expanded, and updated version of JPL Publication 87-21, September 15, 1987.

  12. Applying the model of Goal-Directed Behavior, including descriptive norms, to physical activity intentions: A contribution to improving the Theory of Planned Behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The theory of planned behavior (TPB) has received its fair share of criticism lately, including calls for it to retire. We contributed to improving the theory by testing extensions such as the model of goal-directed behavior (MGDB, which adds desire and anticipated positive and negative emotions) ap...

  13. Accelerator physics and modeling: Proceedings

    SciTech Connect

    Parsa, Z.

    1991-12-31

    This report contains papers on the following topics: Physics of high brightness beams; radio frequency beam conditioner for fast-wave free-electron generators of coherent radiation; wake-field and space-charge effects on high brightness beams. Calculations and measured results for BNL-ATF; non-linear orbit theory and accelerator design; general problems of modeling for accelerators; development and application of dispersive soft ferrite models for time-domain simulation; and bunch lengthening in the SLC damping rings.

  14. Accelerator physics and modeling: Proceedings

    SciTech Connect

    Parsa, Z.

    1991-01-01

    This report contains papers on the following topics: Physics of high brightness beams; radio frequency beam conditioner for fast-wave free-electron generators of coherent radiation; wake-field and space-charge effects on high brightness beams. Calculations and measured results for BNL-ATF; non-linear orbit theory and accelerator design; general problems of modeling for accelerators; development and application of dispersive soft ferrite models for time-domain simulation; and bunch lengthening in the SLC damping rings.

  15. A 30-Minute Physical Education Program Improves Students' Executive Attention

    ERIC Educational Resources Information Center

    Kubesch, Sabine; Walk, Laura; Spitzer, Manfred; Kammer, Thomas; Lainburg, Alyona; Heim, Rudiger; Hille, Katrin

    2009-01-01

    Physical activity is not only beneficial to physical health but also to cognitive functions. In particular, executive functions that are closely related to learning achievement can be improved by acute and recurring physical activity. We examined the effects of a single 30-min physical education program in contrast to a 5-min movement break on…

  16. Recent improvements of reactor physics codes in MHI

    NASA Astrophysics Data System (ADS)

    Kosaka, Shinya; Yamaji, Kazuya; Kirimura, Kazuki; Kamiyama, Yohei; Matsumoto, Hideki

    2015-12-01

    This paper introduces recent improvements for reactor physics codes in Mitsubishi Heavy Industries, Ltd(MHI). MHI has developed a new neutronics design code system Galaxy/Cosmo-S(GCS) for PWR core analysis. After TEPCO's Fukushima Daiichi accident, it is required to consider design extended condition which has not been covered explicitly by the former safety licensing analyses. Under these circumstances, MHI made some improvements for GCS code system. A new resonance calculation model of lattice physics code and homogeneous cross section representative model for core simulator have been developed to apply more wide range core conditions corresponding to severe accident status such like anticipated transient without scram (ATWS) analysis and criticality evaluation of dried-up spent fuel pit. As a result of these improvements, GCS code system has very wide calculation applicability with good accuracy for any core conditions as far as fuel is not damaged. In this paper, the outline of GCS code system is described briefly and recent relevant development activities are presented.

  17. Recent improvements of reactor physics codes in MHI

    SciTech Connect

    Kosaka, Shinya Yamaji, Kazuya; Kirimura, Kazuki; Kamiyama, Yohei; Matsumoto, Hideki

    2015-12-31

    This paper introduces recent improvements for reactor physics codes in Mitsubishi Heavy Industries, Ltd(MHI). MHI has developed a new neutronics design code system Galaxy/Cosmo-S(GCS) for PWR core analysis. After TEPCO’s Fukushima Daiichi accident, it is required to consider design extended condition which has not been covered explicitly by the former safety licensing analyses. Under these circumstances, MHI made some improvements for GCS code system. A new resonance calculation model of lattice physics code and homogeneous cross section representative model for core simulator have been developed to apply more wide range core conditions corresponding to severe accident status such like anticipated transient without scram (ATWS) analysis and criticality evaluation of dried-up spent fuel pit. As a result of these improvements, GCS code system has very wide calculation applicability with good accuracy for any core conditions as far as fuel is not damaged. In this paper, the outline of GCS code system is described briefly and recent relevant development activities are presented.

  18. Improved cosmological model

    NASA Astrophysics Data System (ADS)

    Tsamis, N. C.; Woodard, R. P.

    2016-08-01

    We study a class of nonlocal, action-based, and purely gravitational models. These models seek to describe a cosmology in which inflation is driven by a large, bare cosmological constant that is screened by the self-gravitation between the soft gravitons that inflation rips from the vacuum. Inflation ends with the Universe poised on the verge of gravitational collapse, in an oscillating phase of expansion and contraction that should lead to rapid reheating when matter is included. After the attainment of a hot, dense Universe the nonlocal screening terms become constant as the Universe evolves through a conventional phase of radiation domination. The onset of matter domination triggers a much smaller antiscreening effect that could explain the current phase of acceleration.

  19. Cabin Environment Physics Risk Model

    NASA Technical Reports Server (NTRS)

    Mattenberger, Christopher J.; Mathias, Donovan Leigh

    2014-01-01

    This paper presents a Cabin Environment Physics Risk (CEPR) model that predicts the time for an initial failure of Environmental Control and Life Support System (ECLSS) functionality to propagate into a hazardous environment and trigger a loss-of-crew (LOC) event. This physics-of failure model allows a probabilistic risk assessment of a crewed spacecraft to account for the cabin environment, which can serve as a buffer to protect the crew during an abort from orbit and ultimately enable a safe return. The results of the CEPR model replace the assumption that failure of the crew critical ECLSS functionality causes LOC instantly, and provide a more accurate representation of the spacecraft's risk posture. The instant-LOC assumption is shown to be excessively conservative and, moreover, can impact the relative risk drivers identified for the spacecraft. This, in turn, could lead the design team to allocate mass for equipment to reduce overly conservative risk estimates in a suboptimal configuration, which inherently increases the overall risk to the crew. For example, available mass could be poorly used to add redundant ECLSS components that have a negligible benefit but appear to make the vehicle safer due to poor assumptions about the propagation time of ECLSS failures.

  20. Service Learning In Physics: The Consultant Model

    NASA Astrophysics Data System (ADS)

    Guerra, David

    2005-04-01

    Each year thousands of students across the country and across the academic disciplines participate in service learning. Unfortunately, with no clear model for integrating community service into the physics curriculum, there are very few physics students engaged in service learning. To overcome this shortfall, a consultant based service-learning program has been developed and successfully implemented at Saint Anselm College (SAC). As consultants, students in upper level physics courses apply their problem solving skills in the service of others. Most recently, SAC students provided technical and managerial support to a group from Girl's Inc., a national empowerment program for girls in high-risk, underserved areas, who were participating in the national FIRST Lego League Robotics competition. In their role as consultants the SAC students provided technical information through brainstorming sessions and helped the girls stay on task with project management techniques, like milestone charting. This consultant model of service-learning, provides technical support to groups that may not have a great deal of resources and gives physics students a way to improve their interpersonal skills, test their technical expertise, and better define the marketable skill set they are developing through the physics curriculum.

  1. Excellence in Physics Education Award: Modeling Theory for Physics Instruction

    NASA Astrophysics Data System (ADS)

    Hestenes, David

    2014-03-01

    All humans create mental models to plan and guide their interactions with the physical world. Science has greatly refined and extended this ability by creating and validating formal scientific models of physical things and processes. Research in physics education has found that mental models created from everyday experience are largely incompatible with scientific models. This suggests that the fundamental problem in learning and understanding science is coordinating mental models with scientific models. Modeling Theory has drawn on resources of cognitive science to work out extensive implications of this suggestion and guide development of an approach to science pedagogy and curriculum design called Modeling Instruction. Modeling Instruction has been widely applied to high school physics and, more recently, to chemistry and biology, with noteworthy results.

  2. A Multivariate Model of Physics Problem Solving

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Farley, John

    2013-01-01

    A model of expertise in physics problem solving was tested on undergraduate science, physics, and engineering majors enrolled in an introductory-level physics course. Structural equation modeling was used to test hypothesized relationships among variables linked to expertise in physics problem solving including motivation, metacognitive planning,…

  3. Testing Physical Models of Passive Membrane Permeation

    PubMed Central

    Leung, Siegfried S. F.; Mijalkovic, Jona; Borrelli, Kenneth; Jacobson, Matthew P.

    2012-01-01

    The biophysical basis of passive membrane permeability is well understood, but most methods for predicting membrane permeability in the context of drug design are based on statistical relationships that indirectly capture the key physical aspects. Here, we investigate molecular mechanics-based models of passive membrane permeability and evaluate their performance against different types of experimental data, including parallel artificial membrane permeability assays (PAMPA), cell-based assays, in vivo measurements, and other in silico predictions. The experimental data sets we use in these tests are diverse, including peptidomimetics, congeneric series, and diverse FDA approved drugs. The physical models are not specifically trained for any of these data sets; rather, input parameters are based on standard molecular mechanics force fields, such as partial charges, and an implicit solvent model. A systematic approach is taken to analyze the contribution from each component in the physics-based permeability model. A primary factor in determining rates of passive membrane permeation is the conformation-dependent free energy of desolvating the molecule, and this measure alone provides good agreement with experimental permeability measurements in many cases. Other factors that improve agreement with experimental data include deionization and estimates of entropy losses of the ligand and the membrane, which lead to size-dependence of the permeation rate. PMID:22621168

  4. Improving the status of Iranian women in physics

    NASA Astrophysics Data System (ADS)

    Iraji zad, A.; Roshani, F.; Izadi, D.

    2015-12-01

    Iranian women have shown improving contribution in the field of physics as students and researchers in recent years. More than 60% of BSc and MSc students, 47% of PhD students, and 18% of faculty members in the physics departments in Iran are female. However, in higher levels of academic fields and management, participation by women is still below the expected values. The Women in Physics branch of the Physics Society of Iran studies the related cases to find suitable strategies to improve the situation.

  5. Improving Hydrology in Land Ice Models

    NASA Astrophysics Data System (ADS)

    Price, Stephen; Flowers, Gwenn; Schoof, Christian

    2011-05-01

    Community Earth System Model Land Ice Working Group Meeting; Boulder, Colorado, 13 January 2011 ; Recent observations indicate that mass loss from glaciers and ice sheets (“land ice”) is increasing. The drivers of these changes are not well understood, and modeling the land ice response to them remains challenging. As a result, the Intergovernmental Panel on Climate Change explicitly avoided speculating on 21st-century sea level rise from ice dynamical processes in its fourth assessment report. The mismatch between observations of land ice change and model skill at mimicking those changes is behind recent efforts to develop next-generation land ice models. Necessary improvements to existing models include improved dynamics, coupling to climate models, and better representations of important boundary conditions and physical processes. Basal sliding, the primary control on the rate of land ice delivery to the oceans, is one such boundary condition that is largely controlled by land ice hydrology.

  6. Modeling QCD for Hadron Physics

    NASA Astrophysics Data System (ADS)

    Tandy, P. C.

    2011-10-01

    We review the approach to modeling soft hadron physics observables based on the Dyson-Schwinger equations of QCD. The focus is on light quark mesons and in particular the pseudoscalar and vector ground states, their decays and electromagnetic couplings. We detail the wide variety of observables that can be correlated by a ladder-rainbow kernel with one infrared parameter fixed to the chiral quark condensate. A recently proposed novel perspective in which the quark condensate is contained within hadrons and not the vacuum is mentioned. The valence quark parton distributions, in the pion and kaon, as measured in the Drell Yan process, are investigated with the same ladder-rainbow truncation of the Dyson-Schwinger and Bethe-Salpeter equations.

  7. Modeling QCD for Hadron Physics

    SciTech Connect

    Tandy, P. C.

    2011-10-24

    We review the approach to modeling soft hadron physics observables based on the Dyson-Schwinger equations of QCD. The focus is on light quark mesons and in particular the pseudoscalar and vector ground states, their decays and electromagnetic couplings. We detail the wide variety of observables that can be correlated by a ladder-rainbow kernel with one infrared parameter fixed to the chiral quark condensate. A recently proposed novel perspective in which the quark condensate is contained within hadrons and not the vacuum is mentioned. The valence quark parton distributions, in the pion and kaon, as measured in the Drell Yan process, are investigated with the same ladder-rainbow truncation of the Dyson-Schwinger and Bethe-Salpeter equations.

  8. The "Champions" Program--Behavior Improvement in Physical Education.

    ERIC Educational Resources Information Center

    Carter, Jack

    1989-01-01

    An elementary physical education teacher describes a successful behavior improvement program implemented at his school. Students earned points (tokens) for good behavior and physical education achievement. They lost points for inappropriate behavior. Donated prizes were awarded based on accumulated points. (IAH)

  9. Profiles of Change: Lessons for Improving High School Physical Education

    ERIC Educational Resources Information Center

    Doolittle, Sarah

    2014-01-01

    This feature has told stories of high school physical educators who have refused to accept the status quo of high school physical education programs. They have identified problems, initiated innovations in their own classes, implemented changes beyond their classes, and moved toward institutionalizing improvements throughout their programs and…

  10. Electrical Storm Simulation to Improve the Learning Physics Process

    ERIC Educational Resources Information Center

    Martínez Muñoz, Miriam; Jiménez Rodríguez, María Lourdes; Gutiérrez de Mesa, José Antonio

    2013-01-01

    This work is part of a research project whose main objective is to understand the impact that the use of Information and Communication Technology (ICT) has on the teaching and learning process on the subject of Physics. We will show that, with the use of a storm simulator, physics students improve their learning process on one hand they understand…

  11. Physics modeling support contract: Final report

    SciTech Connect

    Not Available

    1987-09-30

    This document is the final report for the Physics Modeling Support contract between TRW, Inc. and the Lawrence Livermore National Laboratory for fiscal year 1987. It consists of following projects: TIBER physics modeling and systems code development; advanced blanket modeling task; time dependent modeling; and free electron maser for TIBER II.

  12. Model Formulation for Physics Problem Solving. Draft.

    ERIC Educational Resources Information Center

    Novak, Gordon S., Jr.

    The major task in solving a physics problem is to construct an appropriate model of the problem in terms of physical principles. The functions performed by such a model, the information which needs to be represented, and the knowledge used in selecting and instantiating an appropriate model are discussed. An example of a model for a mechanics…

  13. The value of oxygen-isotope data and multiple discharge records in calibrating a fully-distributed, physically-based rainfall-runoff model (CRUM3) to improve predictive capability

    NASA Astrophysics Data System (ADS)

    Neill, Aaron; Reaney, Sim

    2015-04-01

    Fully-distributed, physically-based rainfall-runoff models attempt to capture some of the complexity of the runoff processes that operate within a catchment, and have been used to address a variety of issues including water quality and the effect of climate change on flood frequency. Two key issues are prevalent, however, which call into question the predictive capability of such models. The first is the issue of parameter equifinality which can be responsible for large amounts of uncertainty. The second is whether such models make the right predictions for the right reasons - are the processes operating within a catchment correctly represented, or do the predictive abilities of these models result only from the calibration process? The use of additional data sources, such as environmental tracers, has been shown to help address both of these issues, by allowing for multi-criteria model calibration to be undertaken, and by permitting a greater understanding of the processes operating in a catchment and hence a more thorough evaluation of how well catchment processes are represented in a model. Using discharge and oxygen-18 data sets, the ability of the fully-distributed, physically-based CRUM3 model to represent the runoff processes in three sub-catchments in Cumbria, NW England has been evaluated. These catchments (Morland, Dacre and Pow) are part of the of the River Eden demonstration test catchment project. The oxygen-18 data set was firstly used to derive transit-time distributions and mean residence times of water for each of the catchments to gain an integrated overview of the types of processes that were operating. A generalised likelihood uncertainty estimation procedure was then used to calibrate the CRUM3 model for each catchment based on a single discharge data set from each catchment. Transit-time distributions and mean residence times of water obtained from the model using the top 100 behavioural parameter sets for each catchment were then compared to

  14. Physical modeling of Tibetan bowls

    NASA Astrophysics Data System (ADS)

    Antunes, Jose; Inacio, Octavio

    2001-05-01

    Tibetan bowls produce rich penetrating sounds, used in musical contexts and to induce a state of relaxation for meditation or therapy purposes. To understand the dynamics of these instruments under impact and rubbing excitation, we developed a simulation method based on the modal approach, following our previous papers on physical modeling of plucked/bowed strings and impacted/bowed bars. This technique is based on a compact representation of the system dynamics, in terms of the unconstrained bowl modes. Nonlinear contact/friction interaction forces, between the exciter (puja) and the bowl, are computed at each time step and projected on the bowl modal basis, followed by step integration of the modal equations. We explore the behavior of two different-sized bowls, for extensive ranges of excitation conditions (contact/friction parameters, normal force, and tangential puja velocity). Numerical results and experiments show that various self-excited motions may arise depending on the playing conditions and, mainly, on the contact/friction interaction parameters. Indeed, triggering of a given bowl modal frequency mainly depends on the puja material. Computed animations and experiments demonstrate that self-excited modes spin, following the puja motion. Accordingly, the sensed pressure field pulsates, with frequency controlled by the puja spinning velocity and the spatial pattern of the singing mode.

  15. A qualitative model of physical fields

    SciTech Connect

    Lundell, M.

    1996-12-31

    A qualitative model of the spatio-temporal behaviour of distributed parameter systems based on physical fields is presented. Field-based models differ from the object-based models normally used in qualitative physics by treating parameters as continuous entities instead of as attributes of discrete objects. This is especially suitable for natural physical systems, e.g. in ecology. The model is divided into a static and a dynamic part. The static model describes the distribution of each parameter as a qualitative physical field. Composite fields are constructed from intersection models of pairs of fields. The dynamic model describes processes acting on the fields, and qualitative relationships between parameters. Spatio-temporal behaviour is modelled by interacting temporal processes, influencing single points in space, and spatial processes that gradually spread temporal processes over space. We give an example of a qualitative model of a natural physical system and discuss the ambiguities that arise during simulation.

  16. Using data assimilation for systematic model improvement

    NASA Astrophysics Data System (ADS)

    Lang, Matthew S.; van Leeuwen, Peter Jan; Browne, Phil

    2016-04-01

    In Numerical Weather Prediction parameterisations are used to simulate missing physics in the model. These can be due to a lack of scientific understanding or a lack of computing power available to address all the known physical processes. Parameterisations are sources of large uncertainty in a model as parameter values used in these parameterisations cannot be measured directly and hence are often not well known, and the parameterisations themselves are approximations of the processes present in the true atmosphere. Whilst there are many efficient and effective methods for combined state/parameter estimation in data assimilation, such as state augmentation, these are not effective at estimating the structure of parameterisations. A new method of parameterisation estimation is proposed that uses sequential data assimilation methods to estimate errors in the numerical models at each space-time point for each model equation. These errors are then fitted to predetermined functional forms of missing physics or parameterisations, that are based upon prior information. The method picks out the functional form, or that combination of functional forms, that bests fits the error structure. The prior information typically takes the form of expert knowledge. We applied the method to a one-dimensional advection model with additive model error, and it is shown that the method can accurately estimate parameterisations, with consistent error estimates. It is also demonstrated that state augmentation is not successful. The results indicate that this new method is a powerful tool in systematic model improvement.

  17. Improve SSME power balance model

    NASA Astrophysics Data System (ADS)

    Karr, Gerald R.

    1992-09-01

    Effort was dedicated to development and testing of a formal strategy for reconciling uncertain test data with physically limited computational prediction. Specific weaknesses in the logical structure of the current Power Balance Model (PBM) version are described with emphasis given to the main routing subroutines BAL and DATRED. Selected results from a variational analysis of PBM predictions are compared to Technology Test Bed (TTB) variational study results to assess PBM predictive capability. The motivation for systematic integration of uncertain test data with computational predictions based on limited physical models is provided. The theoretical foundation for the reconciliation strategy developed in this effort is presented, and results of a reconciliation analysis of the Space Shuttle Main Engine (SSME) high pressure fuel side turbopump subsystem are examined.

  18. Improve SSME power balance model

    NASA Technical Reports Server (NTRS)

    Karr, Gerald R.

    1992-01-01

    Effort was dedicated to development and testing of a formal strategy for reconciling uncertain test data with physically limited computational prediction. Specific weaknesses in the logical structure of the current Power Balance Model (PBM) version are described with emphasis given to the main routing subroutines BAL and DATRED. Selected results from a variational analysis of PBM predictions are compared to Technology Test Bed (TTB) variational study results to assess PBM predictive capability. The motivation for systematic integration of uncertain test data with computational predictions based on limited physical models is provided. The theoretical foundation for the reconciliation strategy developed in this effort is presented, and results of a reconciliation analysis of the Space Shuttle Main Engine (SSME) high pressure fuel side turbopump subsystem are examined.

  19. NUMERICAL MODELING OF FINE SEDIMENT PHYSICAL PROCESSES.

    USGS Publications Warehouse

    Schoellhamer, David H.

    1985-01-01

    Fine sediment in channels, rivers, estuaries, and coastal waters undergo several physical processes including flocculation, floc disruption, deposition, bed consolidation, and resuspension. This paper presents a conceptual model and reviews mathematical models of these physical processes. Several general fine sediment models that simulate some of these processes are reviewed. These general models do not directly simulate flocculation and floc disruption, but the conceptual model and existing functions are shown to adequately model these two processes for one set of laboratory data.

  20. A GIS-based Adaptive Management Decision Support System to Develop a Multi-Objective Framework: A case study utilizing GIS technologies and physically-based models to archieve improved decision making for site management.

    SciTech Connect

    Coleman, Andre M.; Wigmosta, Mark S.; Lane, Leonard J.; Tagestad, Jerry D.; Roberts, Damon

    2008-06-26

    The notion of Adaptive Management (AM) allows for the realization and adjustment of management practices in response to elements of uncertainty. In terms of natural resource management, this will typically integrate monitoring, databases, simulation modeling, decision theory, and expert judgment to evaluate management alternatives and adapt them as necessary to continually improve the natural resource condition as defined by the stakeholders. Natural resource management scenarios can often be expressed, viewed, and understood as a spatial and temporal problem. The integration of Geographic Information System (GIS) technologies and physically-based models provide an effective state-of-the-art solution for deriving, understanding, and applying AM scenarios for land use and remediation. A recently developed GIS-based adaptive management decision support system is presented for the U.S. Department of Defense Yakima Training Center near Yakima, Washington.

  1. Evaluating a Model of Youth Physical Activity

    ERIC Educational Resources Information Center

    Heitzler, Carrie D.; Lytle, Leslie A.; Erickson, Darin J.; Barr-Anderson, Daheia; Sirard, John R.; Story, Mary

    2010-01-01

    Objective: To explore the relationship between social influences, self-efficacy, enjoyment, and barriers and physical activity. Methods: Structural equation modeling examined relationships between parent and peer support, parent physical activity, individual perceptions, and objectively measured physical activity using accelerometers among a…

  2. The Role of Exergaming in Improving Physical Activity: A Review

    PubMed Central

    Sween, Jennifer; Wallington, Sherrie Flynnt; Sheppard, Vanessa; Taylor, Teletia; Llanos, Adana A.; Adams-Campbell, Lucile Lauren

    2013-01-01

    Background The high prevalence of obesity in America can be attributed to inadequate energy expenditure as a result of high levels of physical inactivity. This review presents an overview of the current literature on physical activity, specifically through active videogame systems (exergaming) and how these systems can help to increase physical activity levels. Methods The search strategy for this review was to identify previous studies which investigated energy expenditure levels using a single active video game or a combination of active videogames. Results Based on data from 27 studies, a strong correlation exists between exergaming and increased energy expenditure (up to 300% above resting levels). The majority of active videogames tested were found to achieve physical activity levels of moderate intensity, which meet American College of Sports Medicine guidelines for health and fitness. Conclusions Exergaming is a new and exciting strategy to potentially improve physical activity levels and reduce obesity among Americans. PMID:25078529

  3. Improved engineering models for turbulent wall flows

    NASA Astrophysics Data System (ADS)

    She, Zhen-Su; Chen, Xi; Zou, Hong-Yue; Hussain, Fazle

    2015-11-01

    We propose a new approach, called structural ensemble dynamics (SED), involving new concepts to describe the mean quantities in wall-bounded flows, and its application to improving the existing engineering turbulence models, as well as its physical interpretation. First, a revised k - ω model for pipe flows is obtained, which accurately predicts, for the first time, both mean velocity and (streamwise) kinetic energy for a wide range of the Reynolds number (Re), validated by Princeton experimental data. In particular, a multiplicative factor is introduced in the dissipation term to model an anomaly in the energy cascade in a meso-layer, predicting the outer peak of agreeing with data. Secondly, a new one-equation model is obtained for compressible turbulent boundary layers (CTBL), building on a multi-layer formula of the stress length function and a generalized temperature-velocity relation. The former refines the multi-layer description - viscous sublayer, buffer layer, logarithmic layer and a newly defined bulk zone - while the latter characterizes a parabolic relation between the mean velocity and temperature. DNS data show our predictions to have a 99% accuracy for several Mach numbers Ma = 2.25, 4.5, improving, up to 10%, a previous similar one-equation model (Baldwin & Lomax, 1978). Our results promise notable improvements in engineering models.

  4. Comprehensive Physical Education Program Model

    ERIC Educational Resources Information Center

    Kamiya, Artie

    2005-01-01

    In 2004, the Wake County Public School System (North Carolina) received $1.3 million as one of 237 national winners of the $70 million federal Carol M. White Physical Education Program (PEP) Grant competition. The PEP Grant program is funded by the U.S. Department of Education and provides monies to school districts able to demonstrate the…

  5. Improved SPICE electrical model of silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Marano, D.; Bonanno, G.; Belluso, M.; Billotta, S.; Grillo, A.; Garozzo, S.; Romeo, G.; Catalano, O.; La Rosa, G.; Sottile, G.; Impiombato, D.; Giarrusso, S.

    2013-10-01

    The present work introduces an improved SPICE equivalent electrical model of silicon photomultiplier (SiPM) detectors, in order to simulate and predict their transient response to avalanche triggering events. In particular, the developed circuit model provides a careful investigation of the magnitude and timing of the read-out signals and can therefore be exploited to perform reliable circuit-level simulations. The adopted modeling approach is strictly related to the physics of each basic microcell constituting the SiPM device, and allows the avalanche timing as well as the photodiode current and voltage to be accurately simulated. Predictive capabilities of the proposed model are demonstrated by means of experimental measurements on a real SiPM detector. Simulated and measured pulses are found to be in good agreement with the expected results.

  6. Using Physical Education to Improve Literacy Skills in Struggling Students

    ERIC Educational Resources Information Center

    Wachob, David A.

    2014-01-01

    Literacy skills are an essential part of academic performance. When physical educators collaborate with classroom teachers to address these skills, student engagement in the learning process can greatly improve. This article begins by reviewing the growing issues surrounding student literacy and its impact on academic performance. The discussion…

  7. Improving the Monitoring, Verification, and Accounting of CO{sub 2} Sequestered in Geologic Systems with Multicomponent Seismic Technology and Rock Physics Modeling

    SciTech Connect

    Alkan, Engin; DeAngelo, Michael; Hardage, Bob; Sava, Diana; Sullivan, Charlotte; Wagner, Donald

    2012-12-31

    concept that the same weight must be given to S-wave sequences and facies as is given to P-wave sequences and facies. This philosophy differs from the standard practice of depending on only conventional P-wave seismic stratigraphy to characterize reservoir units. The fundamental physics of elastic wavefield seismic stratigraphy is that S- wave modes sense different sequences and facies across some intervals than does a P-wave mode because S-wave displacement vectors are orthogonal to P- wave displacement vectors and thus react to a different rock fabric than do P waves. Although P and S images are different, both images can still be correct in terms of the rock fabric information they reveal.

  8. Introductory physics in biological context: An approach to improve introductory physics for life science students

    NASA Astrophysics Data System (ADS)

    Crouch, Catherine H.; Heller, Kenneth

    2014-05-01

    We describe restructuring the introductory physics for life science students (IPLS) course to better support these students in using physics to understand their chosen fields. Our courses teach physics using biologically rich contexts. Specifically, we use examples in which fundamental physics contributes significantly to understanding a biological system to make explicit the value of physics to the life sciences. This requires selecting the course content to reflect the topics most relevant to biology while maintaining the fundamental disciplinary structure of physics. In addition to stressing the importance of the fundamental principles of physics, an important goal is developing students' quantitative and problem solving skills. Our guiding pedagogical framework is the cognitive apprenticeship model, in which learning occurs most effectively when students can articulate why what they are learning matters to them. In this article, we describe our courses, summarize initial assessment data, and identify needs for future research.

  9. CHEMICAL AND PHYSICAL PROCESS AND MECHANISM MODELING

    EPA Science Inventory

    The goal of this task is to develop and test chemical and physical mechanisms for use in the chemical transport models of EPA's Models-3. The target model for this research is the Community Multiscale Air Quality (CMAQ) model. These mechanisms include gas and aqueous phase ph...

  10. [Increase of physical activity by improvement of the nutritional status].

    PubMed

    Torún, B

    1989-09-01

    Physical activity is affected by nutritional modifications and, in turn, influences growth, cognition, social behavior, work performance and other functions. Studies in preschool children showed that: 1. A decrease in energy intake during four to seven days reduced the time allocated to energy-demanding activities and increased sedentary activities. 2. Children with mild weight deficit were more sedentary than well-nourished counterparts. 3. Children became more active when nutritional status improved. 4. A 10% reduction in energy intake reduced total energy expenditure by 15% without affecting weight gain nor basal metabolism. Studies of men working in non-mechanized agriculture showed that: 1. Dietary improvements led to faster salaried work, reduction of napping time and greater physical activity after work. 2. An increase in energy intake increased total daily energy expenditure, tending to maintain energy balance and relatively stable body weight within the cyclic variations of the agricultural year. 3. Food supplementation did not necessarily improve productivity. Other labor incentives without dietary improvements increased energy expenditure during working hours, which resulted in weight loss. In conclusion, good health and nutrition provide the biological basis for adequate physical activity that may improve cognitive development, social interactions, economic productivity and the quality of life of an individual or a population, but other incentives are required for the optimal expression of that biologic potential. PMID:2518785

  11. Nuclear Physics and the New Standard Model

    SciTech Connect

    Ramsey-Musolf, Michael J.

    2010-08-04

    Nuclear physics studies of fundamental symmetries and neutrino properties have played a vital role in the development and confirmation of the Standard Model of fundamental interactions. With the advent of the CERN Large Hadron Collider, experiments at the high energy frontier promise exciting discoveries about the larger framework in which the Standard Model lies. In this talk, I discuss the complementary opportunities for probing the 'new Standard Model' with nuclear physics experiments at the low-energy high precision frontier.

  12. Improving Climate and Gender Equity in Physics Departments

    NASA Astrophysics Data System (ADS)

    Yennello, Sherry

    2010-02-01

    We need to open the door of science to women and minorities. We need to invite them in and encourage them to succeed. We need to teach them the secret handshake and transfer all the writing on the men's room walls and all-white country clubs into accessible places. We need to promote them to positions of national prominence. We need to do this out of respect to our mothers and the pioneering scientists who have come before us. We need to do this for our daughters and sons, so that our grandchildren may only know this discrimination as a piece of history. We need to do this now -- for the sake of our country, our science, our technical workforce, our economy and because it is the right thing to do. The Committee on the Status of Women in Physics (CSWP) has been helping physics departments improve their climate as a means to enhance gender equity. The CSWP site visit program has been giving departments valuable feedback on their climate for many years. In May 2007, a workshop on ``Gender Equity: Enhancing the Physics Enterprise in Universities and National Laboratories'' was held to address the issue of underrepresentation of women in physics by engaging the stake holders. This fall a new ``Conversation on Gender Equity'' has begun. Successful strategies for improving the climate and increasing the representation of women in physics will be presented. )

  13. Improvements in continuum modeling for biomolecular systems

    NASA Astrophysics Data System (ADS)

    Yu, Qiao; Ben-Zhuo, Lu

    2016-01-01

    Modeling of biomolecular systems plays an essential role in understanding biological processes, such as ionic flow across channels, protein modification or interaction, and cell signaling. The continuum model described by the Poisson- Boltzmann (PB)/Poisson-Nernst-Planck (PNP) equations has made great contributions towards simulation of these processes. However, the model has shortcomings in its commonly used form and cannot capture (or cannot accurately capture) some important physical properties of the biological systems. Considerable efforts have been made to improve the continuum model to account for discrete particle interactions and to make progress in numerical methods to provide accurate and efficient simulations. This review will summarize recent main improvements in continuum modeling for biomolecular systems, with focus on the size-modified models, the coupling of the classical density functional theory and the PNP equations, the coupling of polar and nonpolar interactions, and numerical progress. Project supported by the National Natural Science Foundation of China (Grant No. 91230106) and the Chinese Academy of Sciences Program for Cross & Cooperative Team of the Science & Technology Innovation.

  14. Models of Strategy for Solving Physics Problems.

    ERIC Educational Resources Information Center

    Larkin, Jill H.

    A set of computer implemented models are presented which can assist in developing problem solving strategies. The three levels of expertise which are covered are beginners (those who have completed at least one university physics course), intermediates (university level physics majors in their third year of study), and professionals (university…

  15. Are Physical Education Majors Models for Fitness?

    ERIC Educational Resources Information Center

    Kamla, James; Snyder, Ben; Tanner, Lori; Wash, Pamela

    2012-01-01

    The National Association of Sport and Physical Education (NASPE) (2002) has taken a firm stance on the importance of adequate fitness levels of physical education teachers stating that they have the responsibility to model an active lifestyle and to promote fitness behaviors. Since the NASPE declaration, national initiatives like Let's Move…

  16. DEVELOPMENT OF AN IMPROVED URBAN AIRSHED MODELING SYSTEM

    EPA Science Inventory

    A research and development effort to improve certain physical processes simulated in the Urban Airshed Model (UAM) processor and model programs, and to update the computer software is described. he UAM is an Eulerian photochemical grid model designed to simulate the relevant phys...

  17. The trinucleons: Physical observables and model properties

    SciTech Connect

    Gibson, B.F.

    1992-05-01

    Our progress in understanding the properties of {sup 3}H and {sup 3}He in terms of a nonrelativistic Hamiltonian picture employing realistic nuclear forces is reviewed. Trinucleon model properties are summarized for a number of contemporary force models, and predictions for physical observables are presented. Disagreement between theoretical model results and experimental results are highlighted.

  18. The trinucleons: Physical observables and model properties

    SciTech Connect

    Gibson, B.F.

    1992-01-01

    Our progress in understanding the properties of {sup 3}H and {sup 3}He in terms of a nonrelativistic Hamiltonian picture employing realistic nuclear forces is reviewed. Trinucleon model properties are summarized for a number of contemporary force models, and predictions for physical observables are presented. Disagreement between theoretical model results and experimental results are highlighted.

  19. Modeling Physics with Easy Java Simulations

    ERIC Educational Resources Information Center

    Christian, Wolfgang; Esquembre, Francisco

    2007-01-01

    Modeling has been shown to correct weaknesses of traditional instruction by engaging students in the design of physical models to describe, explain, and predict phenomena. Although the modeling method can be used without computers, the use of computers allows students to study problems that are difficult and time consuming, to visualize their…

  20. Bridging physics and biology teaching through modeling

    NASA Astrophysics Data System (ADS)

    Hoskinson, Anne-Marie; Couch, Brian A.; Zwickl, Benjamin M.; Hinko, Kathleen A.; Caballero, Marcos D.

    2014-05-01

    As the frontiers of biology become increasingly interdisciplinary, the physics education community has engaged in ongoing efforts to make physics classes more relevant to life science majors. These efforts are complicated by the many apparent differences between these fields, including the types of systems that each studies, the behavior of those systems, the kinds of measurements that each makes, and the role of mathematics in each field. Nonetheless, physics and biology are both sciences that rely on observations and measurements to construct models of the natural world. In this article, we propose that efforts to bridge the teaching of these two disciplines must emphasize shared scientific practices, particularly scientific modeling. We define modeling using language common to both disciplines and highlight how an understanding of the modeling process can help reconcile apparent differences between the teaching of physics and biology. We elaborate on how models can be used for explanatory, predictive, and functional purposes and present common models from each discipline demonstrating key modeling principles. By framing interdisciplinary teaching in the context of modeling, we aim to bridge physics and biology teaching and to equip students with modeling competencies applicable in any scientific discipline.

  1. Developing + Using Models in Physics

    ERIC Educational Resources Information Center

    Campbell, Todd; Neilson, Drew; Oh, Phil Seok

    2013-01-01

    Of the eight practices of science identified in "A Framework for K-12 Science Education" (NRC 2012), helping students develop and use models has been identified by many as an anchor (Schwarz and Passmore 2012; Windschitl 2012). In instruction, disciplinary core ideas, crosscutting concepts, and scientific practices can be meaningfully…

  2. Physics of the Quark Model

    ERIC Educational Resources Information Center

    Young, Robert D.

    1973-01-01

    Discusses the charge independence, wavefunctions, magnetic moments, and high-energy scattering of hadrons on the basis of group theory and nonrelativistic quark model with mass spectrum calculated by first-order perturbation theory. The presentation is explainable to advanced undergraduate students. (CC)

  3. Improving Learning by Discussing Controversies in 20th Century Physics.

    ERIC Educational Resources Information Center

    Niaz, Mansoor; Rodriguez, Maria A.

    2002-01-01

    Textbooks rarely emphasize how controversial some physics theories were at the time of their proposal. Makes the case that useful classroom debate can be generated by considering the controversy that arose over models of the atom such as Rutherford's and Bohr's, and ideas about fractional charges put forward by Millikan and arising from quark…

  4. PHYSICAL MODEL FOR RECOGNITION TUNNELING

    PubMed Central

    Krstić, Predrag; Ashcroft, Brian; Lindsay, Stuart

    2015-01-01

    Recognition tunneling (RT) identifies target molecules trapped between tunneling electrodes functionalized with recognition molecules that serve as specific chemical linkages between the metal electrodes and the trapped target molecule. Possible applications include single molecule DNA and protein sequencing. This paper addresses several fundamental aspects of RT by multiscale theory, applying both all-atom and coarse-grained DNA models: (1) We show that the magnitude of the observed currents are consistent with the results of non-equilibrium Green's function calculations carried out on a solvated all-atom model. (2) Brownian fluctuations in hydrogen bond-lengths lead to current spikes that are similar to what is observed experimentally. (3) The frequency characteristics of these fluctuations can be used to identify the trapped molecules with a machine-learning algorithm, giving a theoretical underpinning to this new method of identifying single molecule signals. PMID:25650375

  5. Higgs Physics in Supersymmetric Models

    NASA Astrophysics Data System (ADS)

    Jaiswal, Prerit

    Standard Model (SM) successfully describes the particle spectrum in nature and the interaction between these particles using gauge symmetries. However, in order to give masses to these particles, the electroweak gauge symmetry must be broken. In the SM, this is achieved through the Higgs mechanism where a scalar Higgs field acquires a vacuum expectation value. It is well known that the presence of a scalar field in the SM leads to a hierarchy problem, and therefore the SM by itself can not be the fundamental theory of nature. A well-motivated extension of the SM which addresses this problem is the Minimal Supersymmetric Standard Model (MSSM). The Higgs sector in the MSSM has a rich phenomenology and its predictions can be tested at colliders. In this thesis, I will describe three examples in supersymmetric models where the Higgs phenomenology is significantly different from that in SM. The first example is the MSSM with large tan β where the Higgs coupling to the bottom quarks receives large radiative supersymmetric QCD corrections. As a consequence, bg bh can be a dominant Higgs production mode in certain parameter spaces of the MSSM. A second example is an extension of the MSSM wherein a fourth generation of chiral fermions and their super-partners are added. I will show that the Higgs boson in such models can be as heavy as ˜ 500 GeV. Finally, as a third example, the MSSM with one of the stops lighter than the top quark is considered. Such a scenario is required to generate sufficient baryon asymmetry in the universe through the process of electroweak baryogenesis. By using the correlations between the Higgs production and decay rates, it will be shown that the electroweak baryogenesis in the MSSM is highly constrained.

  6. The Standard Model of Nuclear Physics

    NASA Astrophysics Data System (ADS)

    Detmold, William

    2015-04-01

    At its core, nuclear physics, which describes the properties and interactions of hadrons, such as protons and neutrons, and atomic nuclei, arises from the Standard Model of particle physics. However, the complexities of nuclei result in severe computational difficulties that have historically prevented the calculation of central quantities in nuclear physics directly from this underlying theory. The availability of petascale (and prospect of exascale) high performance computing is changing this situation by enabling us to extend the numerical techniques of lattice Quantum Chromodynamics (LQCD), applied successfully in particle physics, to the more intricate dynamics of nuclear physics. In this talk, I will discuss this revolution and the emerging understanding of hadrons and nuclei within the Standard Model.

  7. Physically-Derived Dynamical Cores in Atmospheric General Circulation Models

    NASA Technical Reports Server (NTRS)

    Rood, Richard B.; Lin, Shian-Kiann

    1999-01-01

    The algorithm chosen to represent the advection in atmospheric models is often used as the primary attribute to classify the model. Meteorological models are generally classified as spectral or grid point, with the term grid point implying discretization using finite differences. These traditional approaches have a number of shortcomings that render them non-physical. That is, they provide approximate solutions to the conservation equations that do not obey the fundamental laws of physics. The most commonly discussed shortcomings are overshoots and undershoots which manifest themselves most overtly in the constituent continuity equation. For this reason many climate models have special algorithms to model water vapor advection. This talk focuses on the development of an atmospheric general circulation model which uses a consistent physically-based advection algorithm in all aspects of the model formulation. The shallow-water model of Lin and Rood (QJRMS, 1997) is generalized to three dimensions and combined with the physics parameterizations of NCAR's Community Climate Model. The scientific motivation for the development is to increase the integrity of the underlying fluid dynamics so that the physics terms can be more effectively isolated, examined, and improved. The expected benefits of the new model are discussed and results from the initial integrations will be presented.

  8. Physically-Derived Dynamical Cores in Atmospheric General Circulation Models

    NASA Technical Reports Server (NTRS)

    Rood, Richard B.; Lin, Shian-Jiann

    1999-01-01

    The algorithm chosen to represent the advection in atmospheric models is often used as the primary attribute to classify the model. Meteorological models are generally classified as spectral or grid point, with the term grid point implying discretization using finite differences. These traditional approaches have a number of shortcomings that render them non-physical. That is, they provide approximate solutions to the conservation equations that do not obey the fundamental laws of physics. The most commonly discussed shortcomings are overshoots and undershoots which manifest themselves most overtly in the constituent continuity equation. For this reason many climate models have special algorithms to model water vapor advection. This talk focuses on the development of an atmospheric general circulation model which uses a consistent physically-based advection algorithm in all aspects of the model formulation. The shallow-water model is generalized to three dimensions and combined with the physics parameterizations of NCAR's Community Climate Model. The scientific motivation for the development is to increase the integrity of the underlying fluid dynamics so that the physics terms can be more effectively isolated, examined, and improved. The expected benefits of the new model are discussed and results from the initial integrations will be presented.

  9. Chicken Essence Improves Exercise Performance and Ameliorates Physical Fatigue

    PubMed Central

    Huang, Wen-Ching; Lin, Ching-I; Chiu, Chien-Chao; Lin, Yi-Ting; Huang, Wei-Kai; Huang, Hui-Yu; Huang, Chi-Chang

    2014-01-01

    Chicken essence (CE) is a liquid nutritional supplement made from cooking whole chickens. In traditional Chinese medicine, CE is used to support health, promote healing, increase metabolism, and relieve fatigue. However, few studies have examined the effect of CE on exercise performance and physical fatigue. We aimed to evaluate the potential beneficial effects of CE on fatigue and ergogenic functions following physical challenge in mice. Male ICR mice were divided into four groups to receive vehicle or CE by oral gavage at 0, 845, 1690, or 4225 mg/kg/day for 4 weeks. Exercise performance and anti-fatigue function were evaluated by forelimb grip strength, exhaustive swimming time, and levels of physical fatigue-related biomarkers serum lactate, ammonia, glucose, and creatine kinase (CK) after physical challenge. CE supplementation dose-dependently elevated endurance and grip strength. CE supplementation significantly decreased lactate, ammonia, and CK levels after physical challenge. Tissue glycogen content, an important energy source for exercise, was significantly increased with CE supplementation. In addition, CE supplementation had few subchronic toxic effects. The supplementation with CE can have a wide spectrum of bioactivities on health promotion, performance improvement and anti-fatigue. PMID:25045938

  10. PHYSICAL MODELING OF CONTRACTED FLOW.

    USGS Publications Warehouse

    Lee, Jonathan K.

    1987-01-01

    Experiments on steady flow over uniform grass roughness through centered single-opening contractions were conducted in the Flood Plain Simulation Facility at the U. S. Geological Survey's Gulf Coast Hydroscience Center near Bay St. Louis, Miss. The experimental series was designed to provide data for calibrating and verifying two-dimensional, vertically averaged surface-water flow models used to simulate flow through openings in highway embankments across inundated flood plains. Water-surface elevations, point velocities, and vertical velocity profiles were obtained at selected locations for design discharges ranging from 50 to 210 cfs. Examples of observed water-surface elevations and velocity magnitudes at basin cross-sections are presented.

  11. Enhancing primary care for persons with spinal cord injury: More than improving physical accessibility.

    PubMed

    Milligan, James; Lee, Joseph

    2016-09-01

    In Ontario, Canada, legislation exists that mandates that all medical practices be fully accessible by 2025, in an effort to improve access to primary care for persons with physical disabilities. The simple removal of physical barriers may not guarantee improved access to appropriate care. In this clinical note, members of an interprofessional primary care-based Mobility Clinic reflect on opportunities to improve primary care beyond just better physical accessibility for persons with spinal cord injury (SCI). The importance of collaborations between funders, researchers, and clinicians are examined. Using a participatory action research model, the unique perspective of consumers and consumer networks are incorporated into the Mobility Clinic's clinical and research efforts to improve primary care for persons with SCI. PMID:26111044

  12. Physical-scale models of engineered log jams in rivers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stream restoration and river engineering projects are employing engineered log jams increasingly for stabilization and in-stream improvements. To further advance the design of these structures and their morphodynamic effects on corridors, the basis for physical-scale models of rivers with engineere...

  13. Physical Modelling of Sedimentary Basin

    SciTech Connect

    Yuen, David A.

    2003-04-24

    The main goals of the first three years have been achieved, i.e., the development of particle-based and continuum-based algorithms for cross-scaleup-scale analysis of complex fluid flows. The U. Minnesota team has focused on particle-based methods, wavelets (Rustad et al., 2001) and visualization and has had great success with the dissipative and fluid particle dynamics algorithms, as applied to colloidal, polymeric and biological systems, wavelet filtering and visualization endeavors. We have organized two sessions in nonlinear geophysics at the A.G.U. Fall Meeting (2000,2002), which have indeed synergetically stimulated the community and promoted cross-disciplinary efforts in the geosciences. The LANL team has succeeded with continuum-based algorithms, in particular, fractal interpolating functions (fif). These have been applied to 1-D flow and transport equations (Travis, 2000; 2002) as a proof of principle, providing solutions that capture dynamics at all scales. In addition, the fif representations can be integrated to provide sub-grid-scale homogenization, which can be used in more traditional finite difference or finite element solutions of porous flow and transport. Another useful tool for fluid flow problems is the ability to solve inverse problems, that is, given present-time observations of a fluid flow, what was the initial state of that fluid system? We have demonstrated this capability for a large-scale problem of 3-D flow in the Earth's crust (Bunge, Hagelberg & Travis, 2002). Use of the adjoint method for sensitivity analysis (Marchuk, 1995) to compute derivatives of models makes the large-scale inversion feasible in 4-D, , space and time. Further, a framework for simulating complex fluid flow in the Earth's crust has been implemented (Dutrow et al, 2001). The remaining task of the first three-year campaign is to extend the implementation of the fif formalism to our 2-D and 3-D computer codes, which is straightforward, but involved.

  14. Waste Feed Evaporation Physical Properties Modeling

    SciTech Connect

    Daniel, W.E.

    2003-08-25

    This document describes the waste feed evaporator modeling work done in the Waste Feed Evaporation and Physical Properties Modeling test specification and in support of the Hanford River Protection Project (RPP) Waste Treatment Plant (WTP) project. A private database (ZEOLITE) was developed and used in this work in order to include the behavior of aluminosilicates such a NAS-gel in the OLI/ESP simulations, in addition to the development of the mathematical models. Mathematical models were developed that describe certain physical properties in the Hanford RPP-WTP waste feed evaporator process (FEP). In particular, models were developed for the feed stream to the first ultra-filtration step characterizing its heat capacity, thermal conductivity, and viscosity, as well as the density of the evaporator contents. The scope of the task was expanded to include the volume reduction factor across the waste feed evaporator (total evaporator feed volume/evaporator bottoms volume). All the physical properties were modeled as functions of the waste feed composition, temperature, and the high level waste recycle volumetric flow rate relative to that of the waste feed. The goal for the mathematical models was to predict the physical property to predicted simulation value. The simulation model approximating the FEP process used to develop the correlations was relatively complex, and not possible to duplicate within the scope of the bench scale evaporation experiments. Therefore, simulants were made of 13 design points (a subset of the points used in the model fits) using the compositions of the ultra-filtration feed streams as predicted by the simulation model. The chemistry and physical properties of the supernate (the modeled stream) as predicted by the simulation were compared with the analytical results of experimental simulant work as a method of validating the simulation software.

  15. Improving hybrid statistical and physical forcefields through local structure enumeration.

    PubMed

    Conway, Patrick; DiMaio, Frank

    2016-08-01

    Forcefields used in biomolecular simulations are comprised of energetic terms that are physical in nature, based on parameter fitting to quantum mechanical simulation or experimental data, or statistical, drawing off high-resolution structural data to describe distributions of molecular features. Combining the two in a single forcefield is challenging, since physical terms describe some, but not all, of the observed statistics, leading to double counting. In this manuscript, we develop a general scheme for correcting statistical potentials used in combination with physical terms. We apply these corrections to the sidechain torsional potential used in the Rosetta all-atom forcefield. We show the approach identifies instances of double-counted interactions, including electrostatic interactions between sidechain and nearby backbone, and steric interactions between neighboring Cβ atoms within secondary structural elements. Moreover, this scheme allows for the inclusion of intraresidue physical terms, previously turned off to avoid overlap with the statistical potential. Combined, these corrections lead to a forcefield with improved performance on several structure prediction tasks, including rotamer prediction and native structure discrimination. PMID:27239808

  16. Diagnosing forecast model errors with a perturbed physics ensemble

    NASA Astrophysics Data System (ADS)

    Mulholland, David; Haines, Keith; Sparrow, Sarah

    2016-04-01

    Perturbed physics ensembles are routinely used to analyse long-timescale climate model behaviour, but have less often been used to study model processes on shorter timescales. We present a method for diagnosing the sources of error in an initialised forecast model by using information from an ensemble of members with known perturbations to model physical parameters. We combine a large perturbed physics ensemble with a set of initialised forecasts to deduce possible process errors present in the standard HadCM3 model, which cause the model to drift from the truth in the early stages of the forecast. It is shown that, even on the sub-seasonal timescale, forecast drifts can be linked to perturbations in individual physical parameters, and that the parameters which exert most influence on forecast drifts vary regionally. Equivalent parameter perturbations are recovered from the initialised forecasts, and used to suggest the physical processes that are most critical to controlling model drifts on a regional basis. It is suggested that this method could be used to improve forecast skill, by reducing model drift through regional tuning of parameter values and targeted parameterisation refinement.

  17. Nanocomposites for Improved Physical Durability of Porous PVDF Membranes

    PubMed Central

    Lai, Chi Yan; Groth, Andrew; Gray, Stephen; Duke, Mikel

    2014-01-01

    Current commercial polymer membranes have shown high performance and durability in water treatment, converting poor quality waters to higher quality suitable for drinking, agriculture and recycling. However, to extend the treatment into more challenging water sources containing abrasive particles, micro and ultrafiltration membranes with enhanced physical durability are highly desirable. This review summarises the current limits of the existing polymeric membranes to treat harsh water sources, followed by the development of nanocomposite poly(vinylidene fluoride) (PVDF) membranes for improved physical durability. Various types of nanofillers including nanoparticles, carbon nanotubes (CNT) and nanoclays were evaluated for their effect on flux, fouling resistance, mechanical strength and abrasion resistance on PVDF membranes. The mechanisms of abrasive wear and how the more durable materials provide resistance was also explored. PMID:24957121

  18. Progress in Geant4 Electromagnetic Physics Modelling and Validation

    NASA Astrophysics Data System (ADS)

    Apostolakis, J.; Asai, M.; Bagulya, A.; Brown, J. M. C.; Burkhardt, H.; Chikuma, N.; Cortes-Giraldo, M. A.; Elles, S.; Grichine, V.; Guatelli, S.; Incerti, S.; Ivanchenko, V. N.; Jacquemier, J.; Kadri, O.; Maire, M.; Pandola, L.; Sawkey, D.; Toshito, T.; Urban, L.; Yamashita, T.

    2015-12-01

    In this work we report on recent improvements in the electromagnetic (EM) physics models of Geant4 and new validations of EM physics. Improvements have been made in models of the photoelectric effect, Compton scattering, gamma conversion to electron and muon pairs, fluctuations of energy loss, multiple scattering, synchrotron radiation, and high energy positron annihilation. The results of these developments are included in the new Geant4 version 10.1 and in patches to previous versions 9.6 and 10.0 that are planned to be used for production for run-2 at LHC. The Geant4 validation suite for EM physics has been extended and new validation results are shown in this work. In particular, the effect of gamma-nuclear interactions on EM shower shape at LHC energies is discussed.

  19. Degradation and Improvement of Argiudolls in Centre Santa Fe (Argentina): Changes in Physical and Chemical Soil Properties and in its Productive Capacity Using a sSmulation Model of Crop Growth

    NASA Astrophysics Data System (ADS)

    Pilatti, M. A.; Marano, R.; Felli, O.; Alesso, A.; Carrizo, M. E.; Miretti, M. C.

    2012-04-01

    Traditional tillage without adequate crop rotation and restoration of nutrients had generated degradation of the soils in Santa Fe. For this reason, it is important to find alternative systems to improve them. The A horizon of a typical Argiudoll of the centre of Santa Fe was chosen in 1983 and 2003 to evaluate: (to) physical and chemical properties of the natural soil (SN), (b) level of deterioration or improvement of those properties due to the management system (LC: traditional till during 50 years with the last 15 years of wheat-soya; RAG: crop-grass rotation under no-till with partial reposition of N, P and S), (c) productive capacity (CP) of the SN and the soil changes according to its management (LC and RAG). Soil data were introduced into a model of crop production (FitoSim), using corn as pattern and 30 years of meteorological data, to evaluate the effect of the soil use on the productive capacity. LC and RAG significantly differ from SN. The former have smaller values of CO, Nt, P e, pH, Ca, K, soil bulk density, relative aggregates stability, least limiting water range and crust infiltration. However the indexes are worse in LC. RAG has greater values of P, Nt and particulate N. The mean potential yield was 16200 kg/ha. The index of production capacity of SN was 75%, i.e. the limitations of the soil and rain only allow taking advantage of 75% of the environment potential capacity. In LC that loss reached 72%. The loss of productive capacity of the evaluated management systems was 21 and 69% for RAG and LC, standing out that although RAG is degraded with regard to the SN, however it is a more conservationist management system that LC. Subsidiado por CA+ID 2009 (UNL) 12/C114; SECTEI- Ley23877-09-04; INTA PNECO-093012

  20. Simplified Models for LHC New Physics Searches

    SciTech Connect

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Chivukula, R.Sekhar; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig, Rouven,; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; /more authors..

    2012-06-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the LHC and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first {approx} 50-500 pb{sup -1} of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  1. Simplified models for LHC new physics searches

    NASA Astrophysics Data System (ADS)

    Alves, Daniele; Arkani-Hamed, Nima; Arora, Sanjay; Bai, Yang; Baumgart, Matthew; Berger, Joshua; Buckley, Matthew; Butler, Bart; Chang, Spencer; Cheng, Hsin-Chia; Cheung, Clifford; Sekhar Chivukula, R.; Cho, Won Sang; Cotta, Randy; D'Alfonso, Mariarosaria; El Hedri, Sonia; Essig (Editor, Rouven; Evans, Jared A.; Fitzpatrick, Liam; Fox, Patrick; Franceschini, Roberto; Freitas, Ayres; Gainer, James S.; Gershtein, Yuri; Gray, Richard; Gregoire, Thomas; Gripaios, Ben; Gunion, Jack; Han, Tao; Haas, Andy; Hansson, Per; Hewett, JoAnne; Hits, Dmitry; Hubisz, Jay; Izaguirre, Eder; Kaplan, Jared; Katz, Emanuel; Kilic, Can; Kim, Hyung-Do; Kitano, Ryuichiro; Koay, Sue Ann; Ko, Pyungwon; Krohn, David; Kuflik, Eric; Lewis, Ian; Lisanti (Editor, Mariangela; Liu, Tao; Liu, Zhen; Lu, Ran; Luty, Markus; Meade, Patrick; Morrissey, David; Mrenna, Stephen; Nojiri, Mihoko; Okui, Takemichi; Padhi, Sanjay; Papucci, Michele; Park, Michael; Park, Myeonghun; Perelstein, Maxim; Peskin, Michael; Phalen, Daniel; Rehermann, Keith; Rentala, Vikram; Roy, Tuhin; Ruderman, Joshua T.; Sanz, Veronica; Schmaltz, Martin; Schnetzer, Stephen; Schuster (Editor, Philip; Schwaller, Pedro; Schwartz, Matthew D.; Schwartzman, Ariel; Shao, Jing; Shelton, Jessie; Shih, David; Shu, Jing; Silverstein, Daniel; Simmons, Elizabeth; Somalwar, Sunil; Spannowsky, Michael; Spethmann, Christian; Strassler, Matthew; Su, Shufang; Tait (Editor, Tim; Thomas, Brooks; Thomas, Scott; Toro (Editor, Natalia; Volansky, Tomer; Wacker (Editor, Jay; Waltenberger, Wolfgang; Yavin, Itay; Yu, Felix; Zhao, Yue; Zurek, Kathryn; LHC New Physics Working Group

    2012-10-01

    This document proposes a collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the ‘Topologies for Early LHC Searches’ workshop, held at SLAC in September of 2010, the purpose of which was to develop a set of representative models that can be used to cover all relevant phase space in experimental searches. Particular emphasis is placed on searches relevant for the first ˜50-500 pb-1 of data and those motivated by supersymmetric models. This note largely summarizes material posted at http://lhcnewphysics.org/, which includes simplified model definitions, Monte Carlo material, and supporting contacts within the theory community. We also comment on future developments that may be useful as more data is gathered and analyzed by the experiments.

  2. Model reduction in the physical coordinate system

    NASA Technical Reports Server (NTRS)

    Yae, K. Harold; Joeng, K. Y.

    1989-01-01

    In the dynamics modeling of a flexible structure, finite element analysis employs reduction techniques, such as Guyan's reduction, to remove some of the insignificant physical coordinates, thus producing a dynamics model that has smaller mass and stiffness matrices. But this reduction is limited in the sense that it removes certain degrees of freedom at a node points themselves in the model. From the standpoint of linear control design, the resultant model is still too large despite the reduction. Thus, some form of the model reduction is frequently used in control design by approximating a large dynamical system with a fewer number of state variables. However, a problem arises from the placement of sensors and actuators in the reduced model, because a model usually undergoes, before being reduced, some form of coordinate transformations that do not preserve the physical meanings of the states. To correct such a problem, a method is developed that expresses a reduced model in terms of a subset of the original states. The proposed method starts with a dynamic model that is originated and reduced in finite element analysis. Then the model is converted to the state space form, and reduced again by the internal balancing method. At this point, being in the balanced coordinate system, the states in the reduced model have no apparent resemblance to those of the original model. Through another coordinate transformation that is developed, however, this reduced model is expressed by a subset of the original states.

  3. A physical analogue of the Schelling model

    NASA Astrophysics Data System (ADS)

    Vinković, Dejan; Kirman, Alan

    2006-12-01

    We present a mathematical link between Schelling's socio-economic model of segregation and the physics of clustering. We replace the economic concept of "utility" by the physics concept of a particle's internal energy. As a result cluster dynamics is driven by the "surface tension" force. The resultant segregated areas can be very large and can behave like spherical "liquid" droplets or as a collection of static clusters in "frozen" form. This model will hopefully provide a useful framework for studying many spatial economic phenomena that involve individuals making location choices as a function of the characteristics and choices of their neighbors.

  4. Waste glass melter numerical and physical modeling

    SciTech Connect

    Eyler, L.L.; Peters, R.D.; Lessor, D.L.; Lowery, P.S.; Elliott, M.L.

    1991-10-01

    Results of physical and numerical simulation modeling of high-level liquid waste vitrification melters are presented. Physical modeling uses simulant fluids in laboratory testing. Visualization results provide insight into convective melt flow patterns from which information is derived to support performance estimation of operating melters and data to support numerical simulation. Numerical simulation results of several melter configurations are presented. These are in support of programs to evaluate melter operation characteristics and performance. Included are investigations into power skewing and alternating current electric field phase angle in a dual electrode pair reference design and bi-modal convective stability in an advanced design. 9 refs., 9 figs., 1 tab.

  5. Method of Improving the Teaching of Particle Physics in a Noncalculus Course of Physics

    NASA Astrophysics Data System (ADS)

    Chen, Robert L. W.

    The Klein Gordon equation-which describes mesons-can be reformulated to suit students who have no calculus background. The method is arrived at from a review and a reinterpretation of the mechanics of small oscillations. It may serve as a model for the design of new instructions for other areas of particle physics.

  6. Topos models for physics and topos theory

    SciTech Connect

    Wolters, Sander

    2014-08-15

    What is the role of topos theory in the topos models for quantum theory as used by Isham, Butterfield, Döring, Heunen, Landsman, Spitters, and others? In other words, what is the interplay between physical motivation for the models and the mathematical framework used in these models? Concretely, we show that the presheaf topos model of Butterfield, Isham, and Döring resembles classical physics when viewed from the internal language of the presheaf topos, similar to the copresheaf topos model of Heunen, Landsman, and Spitters. Both the presheaf and copresheaf models provide a “quantum logic” in the form of a complete Heyting algebra. Although these algebras are natural from a topos theoretic stance, we seek a physical interpretation for the logical operations. Finally, we investigate dynamics. In particular, we describe how an automorphism on the operator algebra induces a homeomorphism (or isomorphism of locales) on the associated state spaces of the topos models, and how elementary propositions and truth values transform under the action of this homeomorphism. Also with dynamics the focus is on the internal perspective of the topos.

  7. Mental Models in Expert Physics Reasoning.

    ERIC Educational Resources Information Center

    Roschelle, Jeremy; Greeno, James G.

    Proposed is a relational framework for characterizing experienced physicists' representations of physics problem situations and the process of constructing these representations. A representation includes a coherent set of relations among: (1) a mental model of the objects in the situation, along with their relevant properties and relations; (2) a…

  8. Mathematical and physical modelling of materials processing

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Mathematical and physical modeling of turbulence phenomena in metals processing, electromagnetically driven flows in materials processing, gas-solid reactions, rapid solidification processes, the electroslag casting process, the role of cathodic depolarizers in the corrosion of aluminum in sea water, and predicting viscoelastic flows are described.

  9. Dilution physics modeling: Dissolution/precipitation chemistry

    SciTech Connect

    Onishi, Y.; Reid, H.C.; Trent, D.S.

    1995-09-01

    This report documents progress made to date on integrating dilution/precipitation chemistry and new physical models into the TEMPEST thermal-hydraulics computer code. Implementation of dissolution/precipitation chemistry models is necessary for predicting nonhomogeneous, time-dependent, physical/chemical behavior of tank wastes with and without a variety of possible engineered remediation and mitigation activities. Such behavior includes chemical reactions, gas retention, solids resuspension, solids dissolution and generation, solids settling/rising, and convective motion of physical and chemical species. Thus this model development is important from the standpoint of predicting the consequences of various engineered activities, such as mitigation by dilution, retrieval, or pretreatment, that can affect safe operations. The integration of a dissolution/precipitation chemistry module allows the various phase species concentrations to enter into the physical calculations that affect the TEMPEST hydrodynamic flow calculations. The yield strength model of non-Newtonian sludge correlates yield to a power function of solids concentration. Likewise, shear stress is concentration-dependent, and the dissolution/precipitation chemistry calculations develop the species concentration evolution that produces fluid flow resistance changes. Dilution of waste with pure water, molar concentrations of sodium hydroxide, and other chemical streams can be analyzed for the reactive species changes and hydrodynamic flow characteristics.

  10. Physical models for classroom teaching in hydrology

    NASA Astrophysics Data System (ADS)

    Rodhe, A.

    2012-09-01

    Hydrology teaching benefits from the fact that many important processes can be illustrated and explained with simple physical models. A set of mobile physical models has been developed and used during many years of lecturing at basic university level teaching in hydrology. One model, with which many phenomena can be demonstrated, consists of a 1.0-m-long plexiglass container containing an about 0.25-m-deep open sand aquifer through which water is circulated. The model can be used for showing the groundwater table and its influence on the water content in the unsaturated zone and for quantitative determination of hydraulic properties such as the storage coefficient and the saturated hydraulic conductivity. It is also well suited for discussions on the runoff process and the significance of recharge and discharge areas for groundwater. The flow paths of water and contaminant dispersion can be illustrated in tracer experiments using fluorescent or colour dye. This and a few other physical models, with suggested demonstrations and experiments, are described in this article. The finding from using models in classroom teaching is that it creates curiosity among the students, promotes discussions and most likely deepens the understanding of the basic processes.

  11. Transforming teacher knowledge: Modeling instruction in physics

    NASA Astrophysics Data System (ADS)

    Cabot, Lloyd H.

    I show that the Modeling physics curriculum is readily accommodated by most teachers in favor of traditional didactic pedagogies. This is so, at least in part, because Modeling focuses on a small set of connected models embedded in a self-consistent theoretical framework and thus is closely congruent with human cognition in this context which is to generate mental models of physical phenomena as both predictive and explanatory devices. Whether a teacher fully implements the Modeling pedagogy depends on the depth of the teacher's commitment to inquiry-based instruction, specifically Modeling instruction, as a means of promoting student understanding of Newtonian mechanics. Moreover, this commitment trumps all other characteristics: teacher educational background, content coverage issues, student achievement data, district or state learning standards, and district or state student assessments. Indeed, distinctive differences exist in how Modeling teachers deliver their curricula and some teachers are measurably more effective than others in their delivery, but they all share an unshakable belief in the efficacy of inquiry-based, constructivist-oriented instruction. The Modeling Workshops' pedagogy, duration, and social interactions impacts teachers' self-identification as members of a professional community. Finally, I discuss the consequences my research may have for the Modeling Instruction program designers and for designers of professional development programs generally.

  12. Investigations of physical model of biological tissue

    NASA Astrophysics Data System (ADS)

    Linkov, Kirill G.; Kisselev, Gennady L.; Loschenov, Victor B.

    1996-12-01

    Physical model of a biological tissue for comparison with earlier created mathematical model of a biological tissue and researches of distribution photosensitizer in a depth was created and investigated. Mathematical model is based on granulated representation of optical medium. The model of a biological tissue was created on the basis of enough thin layers of a special material. For fluorescence excitation laser sources with a various wavelength were used. For investigation of scattering and fluorescent signal laser- fiber spectrum-analyzer LESA-5 was applied. Water solution of aluminum phthalocyanine and oil solution of zinc phthalocyanine were used for receiving of fluorescent signal. Created samples have certain absorbing and fluorescent properties. Scattering properties of samples are close to scattering properties of real human skin. By virtue of layered structure the model permits to simulate as a biological tissue without photosensitizer accumulation in it, as tissue with photosensitizer accumulation with certain distribution in a depth. Dependence of fields distribution on a surface was investigated at change of parameters of a model. Essential changes of distribution on a surface depending on the characteristics of model was revealed. The space and angular characteristics was investigated also. The investigations with physical model correspond to predicted results of theoretical model.

  13. A physical interpretation of hydrologic model complexity

    NASA Astrophysics Data System (ADS)

    Moayeri, MohamadMehdi; Pande, Saket

    2015-04-01

    It is intuitive that instability of hydrological system representation, in the sense of how perturbations in input forcings translate into perturbation in a hydrologic response, may depend on its hydrological characteristics. Responses of unstable systems are thus complex to model. We interpret complexity in this context and define complexity as a measure of instability in hydrological system representation. We provide algorithms to quantify model complexity in this context. We use Sacramento soil moisture accounting model (SAC-SMA) parameterized for MOPEX basins and quantify complexities of corresponding models. Relationships between hydrologic characteristics of MOPEX basins such as location, precipitation seasonality index, slope, hydrologic ratios, saturated hydraulic conductivity and NDVI and respective model complexities are then investigated. We hypothesize that complexities of basin specific SAC-SMA models correspond to aforementioned hydrologic characteristics, thereby suggesting that model complexity, in the context presented here, may have a physical interpretation.

  14. Mathematical Modeling Is Also Physics--Interdisciplinary Teaching between Mathematics and Physics in Danish Upper Secondary Education

    ERIC Educational Resources Information Center

    Michelsen, Claus

    2015-01-01

    Mathematics plays a crucial role in physics. This role is brought about predominantly through the building, employment, and assessment of mathematical models, and teachers and educators should capture this relationship in the classroom in an effort to improve students' achievement and attitude in both physics and mathematics. But although there…

  15. Full-waveform modeling and inversion of physical model data

    NASA Astrophysics Data System (ADS)

    Cai, Jian; Zhang, Jie

    2016-08-01

    Because full elastic waveform inversion requires considerable computation time for forward modeling and inversion, acoustic waveform inversion is often applied to marine data for reducing the computational time. To understand the validity of the acoustic approximation, we study data collected from an ultrasonic laboratory with a known physical model by applying elastic and acoustic waveform modeling and acoustic waveform inversion. This study enables us to evaluate waveform differences quantitatively between synthetics and real data from the same physical model and to understand the effects of different objective functions in addressing the waveform differences for full-waveform inversion. Because the materials used in the physical experiment are viscoelastic, we find that both elastic and acoustic synthetics differ substantially from the physical data over offset in true amplitude. If attenuation is taken into consideration, the amplitude versus offset (AVO) of viscoelastic synthetics more closely approximates the physical data. To mitigate the effect of amplitude differences, we apply trace normalization to both synthetics and physical data in acoustic full-waveform inversion. The objective function is equivalent to minimizing the phase differences with indirect contributions from the amplitudes. We observe that trace normalization helps to stabilize the inversion and obtain more accurate model solutions for both synthetics and physical data.

  16. Modelling Students' Construction of Energy Models in Physics.

    ERIC Educational Resources Information Center

    Devi, Roshni; And Others

    1996-01-01

    Examines students' construction of experimentation models for physics theories in energy storage, transformation, and transfers involving electricity and mechanics. Student problem solving dialogs and artificial intelligence modeling of these processes is analyzed. Construction of models established relations between elements with linear causal…

  17. Source signature and acoustic field of seismic physical modeling

    NASA Astrophysics Data System (ADS)

    Lin, Q.; Jackson, C.; Tang, G.; Burbach, G.

    2004-12-01

    As an important tool of seismic research and exploration, seismic physical modeling simulates the real world data acquisition by scaling the model, acquisition parameters, and some features of the source generated by a transducer. Unlike the numerical simulation where a point source is easily satisfied, the transducer can't be made small enough for approximating the point source in physical modeling, therefore yield different source signature than the sources applied in the field data acquisition. To better understand the physical modeling data, characterizing the wave field generated by ultrasonic transducers is desirable and helpful. In this study, we explode several aspects of source characterization; including their radiation pattern, directivity, sensitivity and frequency response. We also try to figure out how to improve the acquired data quality, such as minimize ambient noise, use encoded chirp to prevent ringing, apply deterministic deconvolution to enhance data resolution and t-P filtering to remove linear events. We found that the transducer and their wave field, the modeling system performance, as well as material properties of the model and their coupling conditions all play roles in the physical modeling data acquisition.

  18. Improving post-intensive care unit neuropsychiatric outcomes: understanding cognitive effects of physical activity.

    PubMed

    Hopkins, Ramona O; Suchyta, Mary R; Farrer, Thomas J; Needham, Dale

    2012-12-15

    Critical illness and its treatment often result in long-term neuropsychiatric morbidities. Consequently, there is a need to focus on means to prevent or ameliorate these morbidities. Animal models provide important data regarding the neurobiological effects of physical activity, including angiogenesis, neurogenesis, and release of neurotrophic factors that enhance plasticity. Studies in noncritically ill patients demonstrate that exercise is associated with increased cerebral blood flow, neurogenesis, and brain volume, which are associated with improved cognition. Clinically, research in both healthy and diseased human subjects suggests that exercise improves neuropsychiatric outcomes. In the critical care setting, early physical rehabilitation and mobilization are safe and feasible, with demonstrated improvements in physical functional outcomes. Such activity may also reduce the duration of delirium in the intensive care unit (ICU) and improve neuropsychiatric outcomes, although data are limited. Barriers exist regarding implementing ICU rehabilitation in routine care, including use of sedatives and lack of awareness of post-ICU cognitive impairments. Further research is necessary to determine whether prior animal and human research, in conjunction with preliminary results from existing ICU studies, can translate into improvements for neuropsychiatric outcomes in critically ill patients. Studies are needed to evaluate biological mechanisms, risk factors, the role of pre-ICU functional level, and the timing, duration, and type of physical activity for optimal patient outcomes. PMID:23065013

  19. Physics Beyond the Standard Model: Supersymmetry

    SciTech Connect

    Nojiri, M.M.; Plehn, T.; Polesello, G.; Alexander, John M.; Allanach, B.C.; Barr, Alan J.; Benakli, K.; Boudjema, F.; Freitas, A.; Gwenlan, C.; Jager, S.; /CERN /LPSC, Grenoble

    2008-02-01

    This collection of studies on new physics at the LHC constitutes the report of the supersymmetry working group at the Workshop 'Physics at TeV Colliders', Les Houches, France, 2007. They cover the wide spectrum of phenomenology in the LHC era, from alternative models and signatures to the extraction of relevant observables, the study of the MSSM parameter space and finally to the interplay of LHC observations with additional data expected on a similar time scale. The special feature of this collection is that while not each of the studies is explicitly performed together by theoretical and experimental LHC physicists, all of them were inspired by and discussed in this particular environment.

  20. Modeling quantum physics with machine learning

    NASA Astrophysics Data System (ADS)

    Lopez-Bezanilla, Alejandro; Arsenault, Louis-Francois; Millis, Andrew; Littlewood, Peter; von Lilienfeld, Anatole

    2014-03-01

    Machine Learning (ML) is a systematic way of inferring new results from sparse information. It directly allows for the resolution of computationally expensive sets of equations by making sense of accumulated knowledge and it is therefore an attractive method for providing computationally inexpensive 'solvers' for some of the important systems of condensed matter physics. In this talk a non-linear regression statistical model is introduced to demonstrate the utility of ML methods in solving quantum physics related problem, and is applied to the calculation of electronic transport in 1D channels. DOE contract number DE-AC02-06CH11357.

  1. Physics Beyond the Standard Model at Colliders

    NASA Astrophysics Data System (ADS)

    Matchev, Konstantin

    These lectures introduce the modern machinery used in searches and studies of new physics Beyond the Standard Model (BSM) at colliders. The first lecture provides an overview of the main simulation tools used in high energy physics, including automated parton-level calculators, general purpose event generators, detector simulators, etc. The second lecture is a brief introduction to low energy supersymmetry (SUSY) as a representative BSM paradigm. The third lecture discusses the main collider signatures of SUSY and methods for measuring the masses of new particles in events with missing energy.

  2. Novel useful sun strategy to improve physical endurance

    NASA Astrophysics Data System (ADS)

    Khramov, R. N.; Fakhranurova, L. I.; Santalova, I. M.; Simonova, N. B.; Vikhlyantsev, I. M.; Karaduleva, E. V.; Podlubnaya, Z. A.; Manokhin, A. A.; Kreslavski, V. D.; Rzhevsky, D. I.; Murashev, A. N.; Vorobiev, V. A.

    2008-04-01

    We propose a "useful sun" strategy with application of a photoluminophore that absorbs a part of the UV component of the sunlight and converts it into the visible light. As a result, the "harmful" UV sun radiation becomes useful. The present study was designed to determine the effect of additional luminescent radiation with λ m=626nm on the physical endurance in 12-week-old male mice. Four groups of animals were used: Control I, intact animals; Control II, exposure to standard artificial day light 5 B T/M2; Control III, exposure to solar radiation with absorbed UV-component; and Experiment, exposure to converted solar radiation with an additional orange-red luminescent component in the range of 603-637 nm (0.11 J/cm2 per day). The experimental group showed a significant increase (by more than 50%) in swimming time to exhaustion as compared to Control III. No significant difference in physical endurance was found between Control III and Control II. These results suggest that improvement in swimming endurance by the solar light is due to an additional orange-red luminescent component in the range of 603-637 nm.

  3. Model-based software process improvement

    NASA Technical Reports Server (NTRS)

    Zettervall, Brenda T.

    1994-01-01

    The activities of a field test site for the Software Engineering Institute's software process definition project are discussed. Products tested included the improvement model itself, descriptive modeling techniques, the CMM level 2 framework document, and the use of process definition guidelines and templates. The software process improvement model represents a five stage cyclic approach for organizational process improvement. The cycles consist of the initiating, diagnosing, establishing, acting, and leveraging phases.

  4. Physical Modeling of the Composting Ecosystem †

    PubMed Central

    Hogan, J. A.; Miller, F. C.; Finstein, M. S.

    1989-01-01

    A composting physical model with an experimental chamber with a working volume of 14 × 103 cm3 (0.5 ft3) was designed to avoid exaggerated conductive heat loss resulting from, relative to field-scale piles, a disproportionately large outer surface-area-to-volume ratio. In the physical model, conductive flux (rate of heat flow through chamber surfaces) was made constant and slight through a combination of insulation and temperature control of the surrounding air. This control was based on the instantaneous conductive flux, as calculated from temperature differentials via a conductive heat flow model. An experiment was performed over a 10-day period in which control of the composting process was based on ventilative heat removal in reference to a microbially favorable temperature ceiling (temperature feedback). By using the conduction control system (surrounding air temperature controlled), 2.4% of the total heat evolved from the chamber was through conduction, whereas the remainder was through the ventilative mechanisms of the latent heat of vaporization and the sensible temperature increase of air. By comparison, with insulation alone (the conduction control system was not used) conduction accounted for 33.5% of the total heat evolved. This difference in conduction resulted in substantial behavioral differences with respect to the temperature of the composting matrix and the amount of water removed. By emphasizing the slight conduction system (2.4% of total heat flow) as being a better representative of field conditions, a comparison was made between composting system behavior in the laboratory physical model and field-scale piles described in earlier reports. Numerous behavioral patterns were qualitatively similar in the laboratory and field (e.g., temperature gradient, O2 content, and water removal). It was concluded that field-scale composting system behavior can be simulated reasonably faithfully in the physical model. Images PMID:16347903

  5. Application of physical parameter identification to finite-element models

    NASA Technical Reports Server (NTRS)

    Bronowicki, Allen J.; Lukich, Michael S.; Kuritz, Steven P.

    1987-01-01

    The time domain parameter identification method described previously is applied to TRW's Large Space Structure Truss Experiment. Only control sensors and actuators are employed in the test procedure. The fit of the linear structural model to the test data is improved by more than an order of magnitude using a physically reasonable parameter set. The electro-magnetic control actuators are found to contribute significant damping due to a combination of eddy current and back electro-motive force (EMF) effects. Uncertainties in both estimated physical parameters and modal behavior variables are given.

  6. Improved model for statistical alignment

    SciTech Connect

    Miklos, I.; Toroczkai, Z.

    2001-01-01

    The statistical approach to molecular sequence evolution involves the stochastic modeling of the substitution, insertion and deletion processes. Substitution has been modeled in a reliable way for more than three decades by using finite Markov-processes. Insertion and deletion, however, seem to be more difficult to model, and thc recent approaches cannot acceptably deal with multiple insertions and deletions. A new method based on a generating function approach is introduced to describe the multiple insertion process. The presented algorithm computes the approximate joint probability of two sequences in 0(13) running time where 1 is the geometric mean of the sequence lengths.

  7. Physical security and vulnerability modeling for infrasturcture facilities.

    SciTech Connect

    Nozick, Linda Karen; Jones, Dean A.; Davis, Chad Edward; Turnquist, Mark Alan

    2006-07-01

    A model of malicious intrusions in infrastructure facilities is developed, using a network representation of the system structure together with Markov models of intruder progress and strategy. This structure provides an explicit mechanism to estimate the probability of successful breaches of physical security, and to evaluate potential improvements. Simulation is used to analyze varying levels of imperfect information on the part of the intruders in planning their attacks. An example of an intruder attempting to place an explosive device on an airplane at an airport gate illustrates the structure and potential application of the model.

  8. Highly physical penumbra solar radiation pressure modeling with atmospheric effects

    NASA Astrophysics Data System (ADS)

    Robertson, Robert; Flury, Jakob; Bandikova, Tamara; Schilling, Manuel

    2015-10-01

    We present a new method for highly physical solar radiation pressure (SRP) modeling in Earth's penumbra. The fundamental geometry and approach mirrors past work, where the solar radiation field is modeled using a number of light rays, rather than treating the Sun as a single point source. However, we aim to clarify this approach, simplify its implementation, and model previously overlooked factors. The complex geometries involved in modeling penumbra solar radiation fields are described in a more intuitive and complete way to simplify implementation. Atmospheric effects are tabulated to significantly reduce computational cost. We present new, more efficient and accurate approaches to modeling atmospheric effects which allow us to consider the high spatial and temporal variability in lower atmospheric conditions. Modeled penumbra SRP accelerations for the Gravity Recovery and Climate Experiment (GRACE) satellites are compared to the sub-nm/s2 precision GRACE accelerometer data. Comparisons to accelerometer data and a traditional penumbra SRP model illustrate the improved accuracy which our methods provide. Sensitivity analyses illustrate the significance of various atmospheric parameters and modeled effects on penumbra SRP. While this model is more complex than a traditional penumbra SRP model, we demonstrate its utility and propose that a highly physical model which considers atmospheric effects should be the basis for any simplified approach to penumbra SRP modeling.

  9. Operational physical models of the ionosphere

    NASA Technical Reports Server (NTRS)

    Nisbet, J. S.

    1978-01-01

    Global models of the neutral constituents are considered relevant to ion density models and improved knowledge of the ion chemistry. Information provided on the pressure gradients that control the wind system and the electric field systems due to balloon, satellite, and incoherent scatter measurements is discussed along with the implication of these results to the development of global ionospheric models. The current state of knowledge of the factors controlling the large day to day variations in the ionosphere and possible approaches for operational models are reviewed.

  10. Intervention in Overweight Children Improves BMI and Physical Activity

    PubMed Central

    Siwik, Violet; Kutob, Randa; Ritenbaugh, Cheryl; Cruz, Luis; Senf, Janet; Aickin, Mikel; Going, Scott; Shatte, Andrew

    2014-01-01

    Background Childhood obesity is a growing epidemic in family medicine with few clinical treatment options. We implemented and evaluated a group office-visit intervention by family physicians emphasizing nutrition and physical activity within a resiliency psychosocial model, for overweight children and their parents. Methods The intervention lasted for 3 months, with half of the children crossing over to intervention after 6 months on study. Participants included 35 children who met eligibility criteria of being in third through fifth grades and having a body mass index above the 85th percentile. The 3-month twelve-session intervention, “Choices”, included topics on nutrition, physical activity, and resiliency. The sessions were developed for delivery by a family physician, and a nutritionist, who all received training in positive psychology and resilience skills. Main outcome measures were body mass index (BMI) z-scores for age-and-gender, and weight-for-age-and-gender z-scores, as well as qualitative interviews to understand individual and family processes. Results The intervention resulted in a significant effect on one primary outcome, BMI z-score (-0.138 per 9 months (p =0.017) and a trend toward significance on the other, weight for age z-score (-0.87 per 9 months (p=0.09). The net shift of activity from the low METS to the high METS had an intervention effect of 2.84 METS (p = 0.037). Families reported lasting changes in behaviors and attitudes. Discussion The innovative approach used in this study demonstrated modest efficacy in reducing BMI z-score, changing physical activity levels, and possibly shifting family dynamics. PMID:23471926

  11. Evaluating nuclear physics inputs in core-collapse supernova models

    SciTech Connect

    Lentz, Eric J; Hix, William Raphael; Baird, Mark L; Messer, Bronson; Mezzacappa, Anthony

    2010-01-01

    Core-collapse supernova models depend on the details of the nuclear and weak interaction physics inputs just as they depend on the details of the macroscopic physics (transport, hydrodynamics, etc.), numerical methods, and progenitors. We present the results of our ongoing comparison studies of nuclear and weak interaction physics inputs to core collapse supernova models using the spherically-symmetric, general relativistic, neutrino radiation hydrodynamics code Agile-Boltztran. We focus on comparisons of the effects of the nuclear EoS and the effects of improving the opacities, particularly neutrino--nucleon interactions. We present the results of our ongoing comparison studies of nuclear and weak interaction physics inputs to core collapse supernova models using the spherically-symmetric, general relativistic, neutrino radiation hydrodynamics code Agile-Boltztran. We focus on comparisons of the effects of the nuclear EoS and the effects of improving the opacities, particularly neutrino--nucleon interactions. We also investigate the feedback between different EoSs and opacities in the context of different progenitors.

  12. A Goddard Multi-Scale Modeling System with Unified Physics

    NASA Technical Reports Server (NTRS)

    Tao, W.K.; Anderson, D.; Atlas, R.; Chern, J.; Houser, P.; Hou, A.; Lang, S.; Lau, W.; Peters-Lidard, C.; Kakar, R.; Kumar, S.; Lapenta, W.; Li, X.; Matsui, T.; Rienecker, M.; Shen, B.W.; Shi, J.J.; Simpson, J.; Zeng, X.

    2008-01-01

    Numerical cloud resolving models (CRMs), which are based the non-hydrostatic equations of motion, have been extensively applied to cloud-scale and mesoscale processes during the past four decades. Recent GEWEX Cloud System Study (GCSS) model comparison projects have indicated that CRMs agree with observations in simulating various types of clouds and cloud systems from different geographic locations. Cloud resolving models now provide statistical information useful for developing more realistic physically based parameterizations for climate models and numerical weather prediction models. It is also expected that Numerical Weather Prediction (NWP) and regional scale model can be run in grid size similar to cloud resolving model through nesting technique. Current and future NASA satellite programs can provide cloud, precipitation, aerosol and other data at very fine spatial and temporal scales. It requires a coupled global circulation model (GCM) and cloud-scale model (termed a szrper-parameterization or multi-scale modeling -framework, MMF) to use these satellite data to improve the understanding of the physical processes that are responsible for the variation in global and regional climate and hydrological systems. The use of a GCM will enable global coverage, and the use of a CRM will allow for better and more sophisticated physical parameterization. NASA satellite and field campaign can provide initial conditions as well as validation through utilizing the Earth Satellite simulators. At Goddard, we have developed a multi-scale modeling system with unified physics. The modeling system consists a coupled GCM-CRM (or MMF); a state-of-the-art weather research forecast model (WRF) and a cloud-resolving model (Goddard Cumulus Ensemble model). In these models, the same microphysical schemes (2ICE, several 3ICE), radiation (including explicitly calculated cloud optical properties), and surface models are applied. In addition, a comprehensive unified Earth Satellite

  13. Physical modelling of failure in composites.

    PubMed

    Talreja, Ramesh

    2016-07-13

    Structural integrity of composite materials is governed by failure mechanisms that initiate at the scale of the microstructure. The local stress fields evolve with the progression of the failure mechanisms. Within the full span from initiation to criticality of the failure mechanisms, the governing length scales in a fibre-reinforced composite change from the fibre size to the characteristic fibre-architecture sizes, and eventually to a structural size, depending on the composite configuration and structural geometry as well as the imposed loading environment. Thus, a physical modelling of failure in composites must necessarily be of multi-scale nature, although not always with the same hierarchy for each failure mode. With this background, the paper examines the currently available main composite failure theories to assess their ability to capture the essential features of failure. A case is made for an alternative in the form of physical modelling and its skeleton is constructed based on physical observations and systematic analysis of the basic failure modes and associated stress fields and energy balances. This article is part of the themed issue 'Multiscale modelling of the structural integrity of composite materials'. PMID:27242307

  14. Demonstrating the improvement of predictive maturity of a computational model

    SciTech Connect

    Hemez, Francois M; Unal, Cetin; Atamturktur, Huriye S

    2010-01-01

    We demonstrate an improvement of predictive capability brought to a non-linear material model using a combination of test data, sensitivity analysis, uncertainty quantification, and calibration. A model that captures increasingly complicated phenomena, such as plasticity, temperature and strain rate effects, is analyzed. Predictive maturity is defined, here, as the accuracy of the model to predict multiple Hopkinson bar experiments. A statistical discrepancy quantifies the systematic disagreement (bias) between measurements and predictions. Our hypothesis is that improving the predictive capability of a model should translate into better agreement between measurements and predictions. This agreement, in turn, should lead to a smaller discrepancy. We have recently proposed to use discrepancy and coverage, that is, the extent to which the physical experiments used for calibration populate the regime of applicability of the model, as basis to define a Predictive Maturity Index (PMI). It was shown that predictive maturity could be improved when additional physical tests are made available to increase coverage of the regime of applicability. This contribution illustrates how the PMI changes as 'better' physics are implemented in the model. The application is the non-linear Preston-Tonks-Wallace (PTW) strength model applied to Beryllium metal. We demonstrate that our framework tracks the evolution of maturity of the PTW model. Robustness of the PMI with respect to the selection of coefficients needed in its definition is also studied.

  15. Inferior mirages: an improved model.

    PubMed

    Young, Andrew T

    2015-02-01

    A quantitative model of the inferior mirage is presented, based on a realistic temperature profile in the convective boundary layer, using Monin-Obukhov similarity theory. The top of the inverted image is determined by the logarithmic part of the profile; the bottom is the apparent horizon, which depends on optical obstruction by roughness elements. These effects of surface roughness are included in the model, which is illustrated with a simulation. The vertical magnification varies throughout the mirage, becoming infinite at Minnaert's ill-named "vanishing line"-which makes green flashes apparent to the naked eye. PMID:25967823

  16. Physical models of polarization mode dispersion

    SciTech Connect

    Menyuk, C.R.; Wai, P.K.A.

    1995-12-31

    The effect of randomly varying birefringence on light propagation in optical fibers is studied theoretically in the parameter regime that will be used for long-distance communications. In this regime, the birefringence is large and varies very rapidly in comparison to the nonlinear and dispersive scale lengths. We determine the polarization mode dispersion, and we show that physically realistic models yield the same result for polarization mode dispersion as earlier heuristic models that were introduced by Poole. We also prove an ergodic theorem.

  17. The Improved Physical Activity Index for Measuring Physical Activity in EPIC Germany

    PubMed Central

    Wientzek, Angelika; Vigl, Matthäus; Steindorf, Karen; Brühmann, Boris; Bergmann, Manuela M.; Harttig, Ulrich; Katzke, Verena; Kaaks, Rudolf; Boeing, Heiner

    2014-01-01

    In the European Investigation into Cancer and Nutrition study (EPIC), physical activity (PA) has been indexed as a cross-tabulation between PA at work and recreational activity. As the proportion of non-working participants increases, other categorization strategies are needed. Therefore, our aim was to develop a valid PA index for this population, which will also be able to express PA continuously. In the German EPIC centers Potsdam and Heidelberg, a clustered sample of 3,766 participants was re-invited to the study center. 1,615 participants agreed to participate and 1,344 participants were finally included in this study. PA was measured by questionnaires on defined activities and a 7-day combined heart rate and acceleration sensor. In a training sample of 433 participants, the Improved Physical Activity Index (IPAI) was developed. Its performance was evaluated in a validation sample of 911 participants and compared with the Cambridge Index and the Total PA Index. The IPAI consists of items covering five areas including PA at work, sport, cycling, television viewing, and computer use. The correlations of the IPAI with accelerometer counts in the training and validation sample ranged r = 0.40–0.43 and with physical activity energy expenditure (PAEE) r = 0.33–0.40 and were higher than for the Cambridge Index and the Total PA Index previously applied in EPIC. In non-working participants the IPAI showed higher correlations than the Cambridge Index and the Total PA Index, with r = 0.34 for accelerometer counts and r = 0.29 for PAEE. In conclusion, we developed a valid physical activity index which is able to express PA continuously as well as to categorize participants according to their PA level. In populations with increasing rates of non-working people the performance of the IPAI is better than the established indices used in EPIC. PMID:24642812

  18. Statistical physical models of cellular motility

    NASA Astrophysics Data System (ADS)

    Banigan, Edward J.

    Cellular motility is required for a wide range of biological behaviors and functions, and the topic poses a number of interesting physical questions. In this work, we construct and analyze models of various aspects of cellular motility using tools and ideas from statistical physics. We begin with a Brownian dynamics model for actin-polymerization-driven motility, which is responsible for cell crawling and "rocketing" motility of pathogens. Within this model, we explore the robustness of self-diffusiophoresis, which is a general mechanism of motility. Using this mechanism, an object such as a cell catalyzes a reaction that generates a steady-state concentration gradient that propels the object in a particular direction. We then apply these ideas to a model for depolymerization-driven motility during bacterial chromosome segregation. We find that depolymerization and protein-protein binding interactions alone are sufficient to robustly pull a chromosome, even against large loads. Next, we investigate how forces and kinetics interact during eukaryotic mitosis with a many-microtubule model. Microtubules exert forces on chromosomes, but since individual microtubules grow and shrink in a force-dependent way, these forces lead to bistable collective microtubule dynamics, which provides a mechanism for chromosome oscillations and microtubule-based tension sensing. Finally, we explore kinematic aspects of cell motility in the context of the immune system. We develop quantitative methods for analyzing cell migration statistics collected during imaging experiments. We find that during chronic infection in the brain, T cells run and pause stochastically, following the statistics of a generalized Levy walk. These statistics may contribute to immune function by mimicking an evolutionarily conserved efficient search strategy. Additionally, we find that naive T cells migrating in lymph nodes also obey non-Gaussian statistics. Altogether, our work demonstrates how physical

  19. Modelling the physics in iterative reconstruction for transmission computed tomography

    PubMed Central

    Nuyts, Johan; De Man, Bruno; Fessler, Jeffrey A.; Zbijewski, Wojciech; Beekman, Freek J.

    2013-01-01

    There is an increasing interest in iterative reconstruction (IR) as a key tool to improve quality and increase applicability of X-ray CT imaging. IR has the ability to significantly reduce patient dose, it provides the flexibility to reconstruct images from arbitrary X-ray system geometries and it allows to include detailed models of photon transport and detection physics, to accurately correct for a wide variety of image degrading effects. This paper reviews discretisation issues and modelling of finite spatial resolution, Compton scatter in the scanned object, data noise and the energy spectrum. Widespread implementation of IR with highly accurate model-based correction, however, still requires significant effort. In addition, new hardware will provide new opportunities and challenges to improve CT with new modelling. PMID:23739261

  20. Systems and models with anticipation in physics and its applications

    NASA Astrophysics Data System (ADS)

    Makarenko, A.

    2012-11-01

    Investigations of recent physics processes and real applications of models require the new more and more improved models which should involved new properties. One of such properties is anticipation (that is taking into accounting some advanced effects).It is considered the special kind of advanced systems - namely a strong anticipatory systems introduced by D. Dubois. Some definitions, examples and peculiarities of solutions are described. The main feature is presumable multivaluedness of the solutions. Presumable physical examples of such systems are proposed: self-organization problems; dynamical chaos; synchronization; advanced potentials; structures in micro-, meso- and macro- levels; cellular automata; computing; neural network theory. Also some applications for modeling social, economical, technical and natural systems are described.

  1. Physical vs. Mathematical Models in Rock Mechanics

    NASA Astrophysics Data System (ADS)

    Morozov, I. B.; Deng, W.

    2013-12-01

    One of the less noted challenges in understanding the mechanical behavior of rocks at both in situ and lab conditions is the character of theoretical approaches being used. Currently, the emphasis is made on spatial averaging theories (homogenization and numerical models of microstructure), empirical models for temporal behavior (material memory, compliance functions and complex moduli), and mathematical transforms (Laplace and Fourier) used to infer the Q-factors and 'relaxation mechanisms'. In geophysical applications, we have to rely on such approaches for very broad spatial and temporal scales which are not available in experiments. However, the above models often make insufficient use of physics and utilize, for example, the simplified 'correspondence principle' instead of the laws of viscosity and friction. As a result, the commonly-used time- and frequency dependent (visco)elastic moduli represent apparent properties related to the measurement procedures and not necessarily to material properties. Predictions made from such models may therefore be inaccurate or incorrect when extrapolated beyond the lab scales. To overcome the above challenge, we need to utilize the methods of micro- and macroscopic mechanics and thermodynamics known in theoretical physics. This description is rigorous and accurate, uses only partial differential equations, and allows straightforward numerical implementations. One important observation from the physical approach is that the analysis should always be done for the specific geometry and parameters of the experiment. Here, we illustrate these methods on axial deformations of a cylindrical rock sample in the lab. A uniform, isotropic elastic rock with a thermoelastic effect is considered in four types of experiments: 1) axial extension with free transverse boundary, 2) pure axial extension with constrained transverse boundary, 3) pure bulk expansion, and 4) axial loading harmonically varying with time. In each of these cases, an

  2. A physical model of Titan's clouds

    NASA Technical Reports Server (NTRS)

    Toon, O. B.; Pollack, J. B.; Turco, R. P.

    1980-01-01

    A physical model of the formation and growth of aerosols in the atmosphere of Titan has been constructed in light of the observed correlation between variations in Titan's albedo and the sunspot cycle. The model was developed to fit spectral observations of deep methane bands, pressures, temperature distributions, and cloud structure, and is based on a one-dimensional physical-chemical model developed to simulate the earth's stratospheric aerosol layer. Sensitivity tests reveal the model parameters to be relatively insensitive to particle shape but sensitive to particle density, with high particle densities requiring larger aerosol mass production rates to produce compatible clouds. Solution of the aerosol continuity equations for particles of sizes 13 A to about 3 microns indicates the importance of a warm upper atmosphere and a high-altitude mass injection layer, and the production of aerosols at very low aerosol optical depths. Limits are obtained for the chemical production of aerosol mass and the eddy diffusion coefficient, and it is found that an increase in mass input causes a decrease in mean particle size.

  3. Material model for physically based rendering

    NASA Astrophysics Data System (ADS)

    Robart, Mathieu; Paulin, Mathias; Caubet, Rene

    1999-09-01

    In computer graphics, a complete knowledge of the interactions between light and a material is essential to obtain photorealistic pictures. Physical measurements allow us to obtain data on the material response, but are limited to industrial surfaces and depend on measure conditions. Analytic models do exist, but they are often inadequate for common use: the empiric ones are too simple to be realistic, and the physically-based ones are often to complex or too specialized to be generally useful. Therefore, we have developed a multiresolution virtual material model, that not only describes the surface of a material, but also its internal structure thanks to distribution functions of microelements, arranged in layers. Each microelement possesses its own response to an incident light, from an elementary reflection to a complex response provided by its inner structure, taking into account geometry, energy, polarization, . . ., of each light ray. This model is virtually illuminated, in order to compute its response to an incident radiance. This directional response is stored in a compressed data structure using spherical wavelets, and is destined to be used in a rendering model such as directional radiosity.

  4. Research as a guide to improving student learning in physics*

    NASA Astrophysics Data System (ADS)

    Heron, Paula R. L.

    1999-05-01

    Investigations of student understanding in courses beyond the introductory level have helped identify some conceptual and reasoning difficulties that have their roots in introductory physics. The results have implications for physics instruction at all levels. Examples will be taken from introductory physics, engineering statics, and special courses for precollege teachers. * This work has been funded in part by NSF Grants DUE 9354501 and DUE 9727648, which include support from other Divisions of EHR and the Physics Division of MPS.

  5. Runway configuration improvement programming model.

    NASA Technical Reports Server (NTRS)

    Yu, J. C.; Gibson, D. R.

    1973-01-01

    The basic objectives of the study were to subject a set of runway configurations to cost analysis and to develop a dynamic programming model which would enable an airport to economically match the ground capacity to its air traffic demand. Quantitative differences in the capacity of runway configurations result from the various aircraft/aircraft and aircraft/air-system interactions. A problem formulation and solution procedure is presented which is intended to be a meaningful technique for the long-range planning of runway expansion programs.

  6. Beyond the standard model of particle physics.

    PubMed

    Virdee, T S

    2016-08-28

    The Large Hadron Collider (LHC) at CERN and its experiments were conceived to tackle open questions in particle physics. The mechanism of the generation of mass of fundamental particles has been elucidated with the discovery of the Higgs boson. It is clear that the standard model is not the final theory. The open questions still awaiting clues or answers, from the LHC and other experiments, include: What is the composition of dark matter and of dark energy? Why is there more matter than anti-matter? Are there more space dimensions than the familiar three? What is the path to the unification of all the fundamental forces? This talk will discuss the status of, and prospects for, the search for new particles, symmetries and forces in order to address the open questions.This article is part of the themed issue 'Unifying physics and technology in light of Maxwell's equations'. PMID:27458261

  7. A Goddard Multi-Scale Modeling System with Unified Physics

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2008-01-01

    A multi-scale modeling system with unified physics has been developed at NASA Goddard Space Flight Center (GSFC). The system consists of an MMF, the coupled NASA Goddard finite-volume GCM (fvGCM) and Goddard Cumulus Ensemble model (GCE, a CRM); the state-of-the-art Weather Research and Forecasting model (WRF) and the stand alone GCE. These models can share the same microphysical schemes, radiation (including explicitly calculated cloud optical properties), and surface models that have been developed, improved and tested for different environments. The following is presented in this report: (1) a brief review of the GCE model and its applications on the impact of aerosols on deep precipitation processes, (2) the Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), and preliminary results (the comparison with traditional GCMs), and (3) a discussion on the Goddard WRF version (its developments and applications).

  8. Improved Systematic Pointing Error Model for the DSN Antennas

    NASA Technical Reports Server (NTRS)

    Rochblatt, David J.; Withington, Philip M.; Richter, Paul H.

    2011-01-01

    New pointing models have been developed for large reflector antennas whose construction is founded on elevation over azimuth mount. At JPL, the new models were applied to the Deep Space Network (DSN) 34-meter antenna s subnet for corrections of their systematic pointing errors; it achieved significant improvement in performance at Ka-band (32-GHz) and X-band (8.4-GHz). The new models provide pointing improvements relative to the traditional models by a factor of two to three, which translate to approximately 3-dB performance improvement at Ka-band. For radio science experiments where blind pointing performance is critical, the new innovation provides a new enabling technology. The model extends the traditional physical models with higher-order mathematical terms, thereby increasing the resolution of the model for a better fit to the underlying systematic imperfections that are the cause of antenna pointing errors. The philosophy of the traditional model was that all mathematical terms in the model must be traced to a physical phenomenon causing antenna pointing errors. The traditional physical terms are: antenna axis tilts, gravitational flexure, azimuth collimation, azimuth encoder fixed offset, azimuth and elevation skew, elevation encoder fixed offset, residual refraction, azimuth encoder scale error, and antenna pointing de-rotation terms for beam waveguide (BWG) antennas. Besides the addition of spherical harmonics terms, the new models differ from the traditional ones in that the coefficients for the cross-elevation and elevation corrections are completely independent and may be different, while in the traditional model, some of the terms are identical. In addition, the new software allows for all-sky or mission-specific model development, and can utilize the previously used model as an a priori estimate for the development of the updated models.

  9. Models in Physics, Models for Physics Learning, and Why the Distinction May Matter in the Case of Electric Circuits

    ERIC Educational Resources Information Center

    Hart, Christina

    2008-01-01

    Models are important both in the development of physics itself and in teaching physics. Historically, the consensus models of physics have come to embody particular ontological assumptions and epistemological commitments. Educators have generally assumed that the consensus models of physics, which have stood the test of time, will also work well…

  10. Impact of improved snowmelt modelling in a monthly hydrological model.

    NASA Astrophysics Data System (ADS)

    Folton, Nathalie; Garcia, Florine

    2016-04-01

    The quantification and the management of water resources at the regional scale require hydrological models that are both easy to implement and efficient. To be reliable and robust, these models must be calibrated and validated on a large number of catchments that are representative of various hydro-meteorological conditions, physiographic contexts, and specific hydrological behavior (e.g. mountainous catchments). The GRLoiEau monthly model, with its simple structure and its two free parameters, answer our need of such a simple model. It required the development of a snow routine to model catchments with temporarily snow-covered areas. The snow routine developed here does not claim to represent physical snowmelt processes but rather to simulate them globally on the catchment. The snowmelt equation is based on the degree-day method which is widely used by the hydrological community, in particular in engineering studies (Etchevers 2000). A potential snowmelt (Schaefli et al. 2005) was computed, and the parameters of the snow routine were regionalized for each mountain area. The GRLoiEau parsimonious structure requires meteorological data. They come from the distributed mesoscale atmospheric analysis system SAFRAN, which provides estimations of daily solid and liquid precipitations and temperatures on a regular square grid at the spatial resolution of 8*8 km², throughout France. Potential evapotranspiration was estimated using the formula by Oudin et al. (2005). The aim of this study is to improve the quality of monthly simulations for ungauged basins, in particular for all types of mountain catchments, without increasing the number of free parameters of the model. By using daily SAFRAN data, the production store and snowmelt can be run at a daily time scale. The question then arises whether simulating the monthly flows using a production function at a finer time step would improve the results. And by using the SAFRAN distributed climate series, a distributed approach

  11. Physical modelling of the nuclear pore complex

    PubMed Central

    Fassati, Ariberto; Ford, Ian J.; Hoogenboom, Bart W.

    2013-01-01

    Physically interesting behaviour can arise when soft matter is confined to nanoscale dimensions. A highly relevant biological example of such a phenomenon is the Nuclear Pore Complex (NPC) found perforating the nuclear envelope of eukaryotic cells. In the central conduit of the NPC, of ∼30–60 nm diameter, a disordered network of proteins regulates all macromolecular transport between the nucleus and the cytoplasm. In spite of a wealth of experimental data, the selectivity barrier of the NPC has yet to be explained fully. Experimental and theoretical approaches are complicated by the disordered and heterogeneous nature of the NPC conduit. Modelling approaches have focused on the behaviour of the partially unfolded protein domains in the confined geometry of the NPC conduit, and have demonstrated that within the range of parameters thought relevant for the NPC, widely varying behaviour can be observed. In this review, we summarise recent efforts to physically model the NPC barrier and function. We illustrate how attempts to understand NPC barrier function have employed many different modelling techniques, each of which have contributed to our understanding of the NPC.

  12. Physical model for membrane protrusions during spreading.

    PubMed

    Chamaraux, F; Ali, O; Keller, S; Bruckert, F; Fourcade, B

    2008-01-01

    During cell spreading onto a substrate, the kinetics of the contact area is an observable quantity. This paper is concerned with a physical approach to modeling this process in the case of ameboid motility where the membrane detaches itself from the underlying cytoskeleton at the leading edge. The physical model we propose is based on previous reports which highlight that membrane tension regulates cell spreading. Using a phenomenological feedback loop to mimic stress-dependent biochemistry, we show that the actin polymerization rate can be coupled to the stress which builds up at the margin of the contact area between the cell and the substrate. In the limit of small variation of membrane tension, we show that the actin polymerization rate can be written in a closed form. Our analysis defines characteristic lengths which depend on elastic properties of the membrane-cytoskeleton complex, such as the membrane-cytoskeleton interaction, and on molecular parameters, the rate of actin polymerization. We discuss our model in the case of axi-symmetric and non-axi-symmetric spreading and we compute the characteristic time scales as a function of fundamental elastic constants such as the strength of membrane-cytoskeleton adherence. PMID:18824791

  13. Ionospheric irregularity physics modelling. Memorandum report

    SciTech Connect

    Ossakow, S.L.; Keskinen, M.J.; Zalesak, S.T.

    1982-02-09

    Theoretical and numerical simulation techniques have been employed to study ionospheric F region plasma cloud striation phenomena, equatorial spread F phenomena, and high latitude diffuse auroral F region irregularity phenomena. Each of these phenomena can cause scintillation effects. The results and ideas from these studies are state-of-the-art, agree well with experimental observations, and have induced experimentalists to look for theoretically predicted results. One conclusion that can be drawn from these studies is that ionospheric irregularity phenomena can be modelled from a first principles physics point of view. Theoretical and numerical simulation results from the aforementioned ionospheric irregularity areas will be presented.

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

    PubMed Central

    Coveney, Peter V; Fowler, Philip W

    2005-01-01

    We discuss the modern approaches of complexity and self-organization to understanding dynamical systems and how these concepts can inform current interest in systems biology. From the perspective of a physical scientist, it is especially interesting to examine how the differing weights given to philosophies of science in the physical and biological sciences impact the application of the study of complexity. We briefly describe how the dynamics of the heart and circadian rhythms, canonical examples of systems biology, are modelled by sets of nonlinear coupled differential equations, which have to be solved numerically. A major difficulty with this approach is that all the parameters within these equations are not usually known. Coupled models that include biomolecular detail could help solve this problem. Coupling models across large ranges of length- and time-scales is central to describing complex systems and therefore to biology. Such coupling may be performed in at least two different ways, which we refer to as hierarchical and hybrid multiscale modelling. While limited progress has been made in the former case, the latter is only beginning to be addressed systematically. These modelling methods are expected to bring numerous benefits to biology, for example, the properties of a system could be studied over a wider range of length- and time-scales, a key aim of systems biology. Multiscale models couple behaviour at the molecular biological level to that at the cellular level, thereby providing a route for calculating many unknown parameters as well as investigating the effects at, for example, the cellular level, of small changes at the biomolecular level, such as a genetic mutation or the presence of a drug. The modelling and simulation of biomolecular systems is itself very computationally intensive; we describe a recently developed hybrid continuum-molecular model, HybridMD, and its associated molecular insertion algorithm, which point the way towards the

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

    PubMed

    Coveney, Peter V; Fowler, Philip W

    2005-09-22

    We discuss the modern approaches of complexity and self-organization to understanding dynamical systems and how these concepts can inform current interest in systems biology. From the perspective of a physical scientist, it is especially interesting to examine how the differing weights given to philosophies of science in the physical and biological sciences impact the application of the study of complexity. We briefly describe how the dynamics of the heart and circadian rhythms, canonical examples of systems biology, are modelled by sets of nonlinear coupled differential equations, which have to be solved numerically. A major difficulty with this approach is that all the parameters within these equations are not usually known. Coupled models that include biomolecular detail could help solve this problem. Coupling models across large ranges of length- and time-scales is central to describing complex systems and therefore to biology. Such coupling may be performed in at least two different ways, which we refer to as hierarchical and hybrid multiscale modelling. While limited progress has been made in the former case, the latter is only beginning to be addressed systematically. These modelling methods are expected to bring numerous benefits to biology, for example, the properties of a system could be studied over a wider range of length- and time-scales, a key aim of systems biology. Multiscale models couple behaviour at the molecular biological level to that at the cellular level, thereby providing a route for calculating many unknown parameters as well as investigating the effects at, for example, the cellular level, of small changes at the biomolecular level, such as a genetic mutation or the presence of a drug. The modelling and simulation of biomolecular systems is itself very computationally intensive; we describe a recently developed hybrid continuum-molecular model, HybridMD, and its associated molecular insertion algorithm, which point the way towards the

  16. Engaging the Community to Improve Nutrition and Physical Activity Among Houses of Worship

    PubMed Central

    Hudson, Shawna V.

    2014-01-01

    Background Obesity, physical inactivity, and poor nutrition have been linked to many chronic diseases. Research indicates that interventions in community-based settings such as houses of worship can build on attendees’ trust to address health issues and help them make behavioral changes. Community Context New Brunswick, New Jersey, has low rates of physical activity and a high prevalence of obesity. An adapted community-based intervention was implemented there to improve nutrition and physical activity among people who attend houses of worship and expand and enhance the network of partners working with Rutgers Cancer Institute of New Jersey. Methods An adapted version of Body & Soul: A Celebration of Healthy Living and Eating was created using a 3-phase model to 1) educate lay members on nutrition and physical activity, 2) provide sustainable change through the development of physical activity programming, and 3) increase access to local produce through collaborations with community partners. Outcome Nineteen houses of worship were selected for participation in this program. Houses of worship provided a questionnaire to a convenience sample of its congregation to assess congregants’ physical activity levels and produce consumption behaviors at baseline using questions from the Health Information National Trends Survey instrument. This information was also used to inform future program activities. Interpretation Community-based health education can be a promising approach when appropriate partnerships are identified, funding is adequate, ongoing information is extracted to inform future action, and there is an expectation from all parties of long-term engagement and capacity building. PMID:24625362

  17. Physics REU sites: What works? How do we know? How do we improve?

    NASA Astrophysics Data System (ADS)

    Mader, Catherine

    2011-04-01

    The NSF Physics REU Leadership Group (NPRLG) is an organization of Physics NSF REU site directors and others committed to enhancing undergraduate student research experiences through cooperative engagement of the Physics REU site directors. The Executive Committee (EC) of the NPRLG is leading efforts to further the goals of the NPRLG through advocacy, data gathering and information sharing. We strive to improve the effectiveness of REU programs by facilitating communication across disciplines and within the physics community. While there is no single model of the ideal REU site, we identify examples of successful sites and share those examples with the Physics community. Several studies have tried to identify the costs and benefits of undergraduate research experiences to the students and faculty mentors. The NPRLG EC strives to keep their members informed of these studies and encourages them to take advantage of the information. The NPRLG EC is working to identify ways to make more undergraduate physics majors and faculty mentors aware of the benefits of participating in undergraduate research. Current initiatives as well as future plans will be shared.

  18. Detailed Physical Trough Model for NREL's Solar Advisor Model: Preprint

    SciTech Connect

    Wagner, M. J.; Blair, N.; Dobos, A.

    2010-10-01

    Solar Advisor Model (SAM) is a free software package made available by the National Renewable Energy Laboratory (NREL), Sandia National Laboratory, and the US Department of Energy. SAM contains hourly system performance and economic models for concentrating solar power (CSP) systems, photovoltaic, solar hot-water, and generic fuel-use technologies. Versions of SAM prior to 2010 included only the parabolic trough model based on Excelergy. This model uses top-level empirical performance curves to characterize plant behavior, and thus is limited in predictive capability for new technologies or component configurations. To address this and other functionality challenges, a new trough model; derived from physical first principles was commissioned to supplement the Excelergy-based empirical model. This new 'physical model' approaches the task of characterizing the performance of the whole parabolic trough plant by replacing empirical curve-fit relationships with more detailed calculations where practical. The resulting model matches the annual performance of the SAM empirical model (which has been previously verified with plant data) while maintaining run-times compatible with parametric analysis, adding additional flexibility in modeled system configurations, and providing more detailed performance calculations in the solar field, power block, piping, and storage subsystems.

  19. Semi-Empirical Modeling of SLD Physics

    NASA Technical Reports Server (NTRS)

    Wright, William B.; Potapczuk, Mark G.

    2004-01-01

    The effects of supercooled large droplets (SLD) in icing have been an area of much interest in recent years. As part of this effort, the assumptions used for ice accretion software have been reviewed. A literature search was performed to determine advances from other areas of research that could be readily incorporated. Experimental data in the SLD regime was also analyzed. A semi-empirical computational model is presented which incorporates first order physical effects of large droplet phenomena into icing software. This model has been added to the LEWICE software. Comparisons are then made to SLD experimental data that has been collected to date. Results will be presented for the comparison of water collection efficiency, ice shape and ice mass.

  20. Physics-based models of the plasmasphere

    SciTech Connect

    Jordanova, Vania K; Pierrard, Vivane; Goldstein, Jerry; Andr'e, Nicolas; Lemaire, Joseph F; Liemohn, Mike W; Matsui, H

    2008-01-01

    We describe recent progress in physics-based models of the plasmasphere using the Auid and the kinetic approaches. Global modeling of the dynamics and inAuence of the plasmasphere is presented. Results from global plasmasphere simulations are used to understand and quantify (i) the electric potential pattern and evolution during geomagnetic storms, and (ii) the inAuence of the plasmasphere on the excitation of electromagnetic ion cyclotron (ElvIIC) waves a.nd precipitation of energetic ions in the inner magnetosphere. The interactions of the plasmasphere with the ionosphere a.nd the other regions of the magnetosphere are pointed out. We show the results of simulations for the formation of the plasmapause and discuss the inAuence of plasmaspheric wind and of ultra low frequency (ULF) waves for transport of plasmaspheric material. Theoretical formulations used to model the electric field and plasma distribution in the plasmasphere are given. Model predictions are compared to recent CLUSTER and MAGE observations, but also to results of earlier models and satellite observations.

  1. New Physics Beyond the Standard Model

    NASA Astrophysics Data System (ADS)

    Cai, Haiying

    In this thesis we discuss several extensons of the standard model, with an emphasis on the hierarchy problem. The hierachy problem related to the Higgs boson mass is a strong indication of new physics beyond the Standard Model. In the literature, several mechanisms, e.g. , supersymmetry (SUSY), the little Higgs and extra dimensions, are proposed to explain why the Higgs mass can be stabilized to the electroweak scale. In the Standard Model, the largest quadratically divergent contribution to the Higgs mass-squared comes from the top quark loop. We consider a few novel possibilities on how this contribution is cancelled. In the standard SUSY scenario, the quadratic divergence from the fermion loops is cancelled by the scalar superpartners and the SUSY breaking scale determines the masses of the scalars. We propose a new SUSY model, where the superpartner of the top quark is spin-1 rather than spin-0. In little Higgs theories, the Higgs field is realized as a psudo goldstone boson in a nonlinear sigma model. The smallness of its mass is protected by the global symmetry. As a variation, we put the little Higgs into an extra dimensional model where the quadratically divergent top loop contribution to the Higgs mass is cancelled by an uncolored heavy "top quirk" charged under a different SU(3) gauge group. Finally, we consider a supersymmetric warped extra dimensional model where the superpartners have continuum mass spectra. We use the holographic boundary action to study how a mass gap can arise to separate the zero modes from continuum modes. Such extensions of the Standard Model have novel signatures at the Large Hadron Collider.

  2. Propulsion Physics Using the Chameleon Density Model

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will require a new theory of propulsion. Specifically one that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. The Chameleon Density Model (CDM) is one such model that could provide new paths in propulsion toward this end. The CDM is based on Chameleon Cosmology a dark matter theory; introduced by Khrouy and Weltman in 2004. Chameleon as it is hidden within known physics, where the Chameleon field represents a scalar field within and about an object; even in the vacuum. The CDM relates to density changes in the Chameleon field, where the density changes are related to matter accelerations within and about an object. These density changes in turn change how an object couples to its environment. Whereby, thrust is achieved by causing a differential in the environmental coupling about an object. As a demonstration to show that the CDM fits within known propulsion physics, this paper uses the model to estimate the thrust from a solid rocket motor. Under the CDM, a solid rocket constitutes a two body system, i.e., the changing density of the rocket and the changing density in the nozzle arising from the accelerated mass. Whereby, the interactions between these systems cause a differential coupling to the local gravity environment of the earth. It is shown that the resulting differential in coupling produces a calculated value for the thrust near equivalent to the conventional thrust model used in Sutton and Ross, Rocket Propulsion Elements. Even though imbedded in the equations are the Universe energy scale factor, the reduced Planck mass and the Planck length, which relates the large Universe scale to the subatomic scale.

  3. 3-D physical models of amitosis (cytokinesis).

    PubMed

    Cheng, Kang; Zou, Changhua

    2005-01-01

    Based on Newton's laws, extended Coulomb's law and published biological data, we develop our 3-D physical models of natural and normal amitosis (cytokinesis), for prokaryotes (bacterial cells) in M phase. We propose following hypotheses: Chromosome rings exclusion: No normally and naturally replicated chromosome rings (RCR) can occupy the same prokaryote, a bacterial cell. The RCR produce spontaneous and strong electromagnetic fields (EMF), that can be alternated environmentally, in protoplasm and cortex. The EMF is approximately a repulsive quasi-static electric (slowly variant and mostly electric) field (EF). The EF forces between the RCR are strong enough, and orderly accumulate contractile proteins that divide the procaryotes in the cell cortex of division plane or directly split the cell compartment envelope longitudinally. The radial component of the EF forces could also make furrows or cleavages of procaryotes. The EF distribution controls the protoplasm partition and completes the amitosis (cytokinesis). After the cytokinesis, the spontaneous and strong EF disappear because the net charge accumulation becomes weak, in the protoplasm. The exclusion is because the two sets of informative objects (RCR) have identical DNA codes information and they are electro magnetically identical, therefore they repulse from each other. We also compare divisions among eukaryotes, prokaryotes, mitochondria and chloroplasts and propose our hypothesis: The principles of our models are applied to divisions of mitochondria and chloroplasts of eucaryotes too because these division mechanisms are closer than others in a view of physics. Though we develop our model using 1 division plane (i.e., 1 cell is divided into 2 cells) as an example, the principle of our model is applied to the cases with multiple division planes (i.e., 1 cell is divided into multiple cells) too. PMID:15533619

  4. Actoprotective effect of ginseng: improving mental and physical performance

    PubMed Central

    Oliynyk, Sergiy; Oh, Seikwan

    2013-01-01

    Actoprotectors are preparations that increase the mental performance and enhance body stability against physical loads without increasing oxygen consumption. Actoprotectors are regarded as a subclass of adaptogens that hold a significant capacity to increase physical performance. The focus of this article is studying adaptogen herbs of genus Panax (P. ginseng in particular) and their capabilities as actoprotectors. Some animal experiments and human studies about actoprotective properties of genus Panax attest that P. ginseng (administered as an extract) significantly increased the physical and intellectual work capacities, and the data provided suggests that ginseng is a natural source of actoprotectors. Preparations of ginseng can be regarded as potential actoprotectors which give way to further research of its influence on physical and mental work capacity, endurance and restoration after exhaustive physical loads while compared with reference actoprotectors. PMID:23717168

  5. Fuzzy modelling of Atlantic salmon physical habitat

    NASA Astrophysics Data System (ADS)

    St-Hilaire, André; Mocq, Julien; Cunjak, Richard

    2015-04-01

    Fish habitat models typically attempt to quantify the amount of available river habitat for a given fish species for various flow and hydraulic conditions. To achieve this, information on the preferred range of values of key physical habitat variables (e.g. water level, velocity, substrate diameter) for the targeted fishs pecies need to be modelled. In this context, we developed several habitat suitability indices sets for three Atlantic salmon life stages (young-of-the-year (YOY), parr, spawning adults) with the help of fuzzy logic modeling. Using the knowledge of twenty-seven experts, from both sides of the Atlantic Ocean, we defined fuzzy sets of four variables (depth, substrate size, velocity and Habitat Suitability Index, or HSI) and associated fuzzy rules. When applied to the Romaine River (Canada), median curves of standardized Weighted Usable Area (WUA) were calculated and a confidence interval was obtained by bootstrap resampling. Despite the large range of WUA covered by the expert WUA curves, confidence intervals were relatively narrow: an average width of 0.095 (on a scale of 0 to 1) for spawning habitat, 0.155 for parr rearing habitat and 0.160 for YOY rearing habitat. When considering an environmental flow value corresponding to 90% of the maximum reached by WUA curve, results seem acceptable for the Romaine River. Generally, this proposed fuzzy logic method seems suitable to model habitat availability for the three life stages, while also providing an estimate of uncertainty in salmon preferences.

  6. A Goddard Multi-Scale Modeling System with Unified Physics

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2010-01-01

    A multi-scale modeling system with unified physics has been developed at NASA Goddard Space Flight Center (GSFC). The system consists of an MMF, the coupled NASA Goddard finite-volume GCM (fvGCM) and Goddard Cumulus Ensemble model (GCE, a CRM); the state-of-the-art Weather Research and Forecasting model (WRF) and the stand alone GCE. These models can share the same microphysical schemes, radiation (including explicitly calculated cloud optical properties), and surface models that have been developed, improved and tested for different environments. In this talk, I will present: (1) A brief review on GCE model and its applications on the impact of the aerosol on deep precipitation processes, (2) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), and preliminary results (the comparison with traditional GCMs), and (3) A discussion on the Goddard WRF version (its developments and applications). We are also performing the inline tracer calculation to comprehend the physical processes (i.e., boundary layer and each quadrant in the boundary layer) related to the development and structure of hurricanes and mesoscale convective systems. In addition, high - resolution (spatial. 2km, and temporal, I minute) visualization showing the model results will be presented.

  7. An Improved Model for the Turbulent PBL

    NASA Technical Reports Server (NTRS)

    Cheng, Y.; Canuto, V. M.; Howard, A. M.; Hansen, James E. (Technical Monitor)

    2001-01-01

    Second order turbulence models of the Mellor and Yamada type have been widely used to simulate the PBL. It is however known that these models have several deficiencies. For example, they all predict a critical Richardson number which is about four times smaller than the Large Eddy Simulation (LES) data, they are unable to match the surface data, and they predict a boundary layer height lower than expected. In the present model, we show that these difficulties are all overcome by a single new physical input: the use of the most complete expression for both the pressure-velocity and the pressure-temperature correlations presently available. Each of the new terms represents a physical process that, was not accounted for by previous models. The new model is presented in three different levels according to Mellor and Yamada's terminology, with new, ready-to-use expressions for the turbulent, moments. We show that the new model reproduces several experimental and LES data better than previous models. As far as the PBL is concerned, we show that the model reproduces both the Kansas data as analyzed by Businger et al. in the context of Monin-Obukhov similarity theory for smaller Richardson numbers, as well as the LES and laboratory data up to Richardson numbers of order unity. We also show that the model yields a higher PBL height than the previous models.

  8. Computer Integrated Manufacturing: Physical Modelling Systems Design. A Personal View.

    ERIC Educational Resources Information Center

    Baker, Richard

    A computer-integrated manufacturing (CIM) Physical Modeling Systems Design project was undertaken in a time of rapid change in the industrial, business, technological, training, and educational areas in Australia. A specification of a manufacturing physical modeling system was drawn up. Physical modeling provides a flexibility and configurability…

  9. Tactile Teaching: Exploring Protein Structure/Function Using Physical Models

    ERIC Educational Resources Information Center

    Herman, Tim; Morris, Jennifer; Colton, Shannon; Batiza, Ann; Patrick, Michael; Franzen, Margaret; Goodsell, David S.

    2006-01-01

    The technology now exists to construct physical models of proteins based on atomic coordinates of solved structures. We review here our recent experiences in using physical models to teach concepts of protein structure and function at both the high school and the undergraduate levels. At the high school level, physical models are used in a…

  10. Using ecosystem experiments to improve vegetation models

    NASA Astrophysics Data System (ADS)

    Medlyn, Belinda E.; Zaehle, Sönke; de Kauwe, Martin G.; Walker, Anthony P.; Dietze, Michael C.; Hanson, Paul J.; Hickler, Thomas; Jain, Atul K.; Luo, Yiqi; Parton, William; Prentice, I. Colin; Thornton, Peter E.; Wang, Shusen; Wang, Ying-Ping; Weng, Ensheng; Iversen, Colleen M.; McCarthy, Heather R.; Warren, Jeffrey M.; Oren, Ram; Norby, Richard J.

    2015-06-01

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

  11. Compass models: Theory and physical motivations

    NASA Astrophysics Data System (ADS)

    Nussinov, Zohar; van den Brink, Jeroen

    2015-01-01

    Compass models are theories of matter in which the couplings between the internal spin (or other relevant field) components are inherently spatially (typically, direction) dependent. A simple illustrative example is furnished by the 90° compass model on a square lattice in which only couplings of the form τixτjx (where {τia}a denote Pauli operators at site i ) are associated with nearest-neighbor sites i and j separated along the x axis of the lattice while τiyτjy couplings appear for sites separated by a lattice constant along the y axis. Similar compass-type interactions can appear in diverse physical systems. For instance, compass models describe Mott insulators with orbital degrees of freedom where interactions sensitively depend on the spatial orientation of the orbitals involved as well as the low-energy effective theories of frustrated quantum magnets, and a host of other systems such as vacancy centers, and cold atomic gases. The fundamental interdependence between internal (spin, orbital, or other) and external (i.e., spatial) degrees of freedom which underlies compass models generally leads to very rich behaviors, including the frustration of (semi-)classical ordered states on nonfrustrated lattices, and to enhanced quantum effects, prompting, in certain cases, the appearance of zero-temperature quantum spin liquids. As a consequence of these frustrations, new types of symmetries and their associated degeneracies may appear. These intermediate symmetries lie midway between the extremes of global symmetries and local gauge symmetries and lead to effective dimensional reductions. In this article, compass models are reviewed in a unified manner, paying close attention to exact consequences of these symmetries and to thermal and quantum fluctuations that stabilize orders via order-out-of-disorder effects. This is complemented by a survey of numerical results. In addition to reviewing past works, a number of other models are introduced and new results

  12. Physical Activity: A Tool for Improving Health (Part 3--Recommended Amounts of Physical Activity for Optimal Health)

    ERIC Educational Resources Information Center

    Gallaway, Patrick J.; Hongu, Nobuko

    2016-01-01

    By promoting physical activities and incorporating them into their community-based programs, Extension professionals are improving the health of individuals, particularly those with limited resources. This article is the third in a three-part series describing the benefits of physical activity for human health: (1) biological health benefits of…

  13. A Holoinformational Model of the Physical Observer

    NASA Astrophysics Data System (ADS)

    Biase, Francisco Di

    2013-09-01

    The author proposes a holoinformational view of the observer based, on the holonomic theory of brain/mind function and quantum brain dynamics developed by Karl Pribram, Sir John Eccles, R.L. Amoroso, Hameroff, Jibu and Yasue, and in the quantumholographic and holomovement theory of David Bohm. This conceptual framework is integrated with nonlocal information properties of the Quantum Field Theory of Umesawa, with the concept of negentropy, order, and organization developed by Shannon, Wiener, Szilard and Brillouin, and to the theories of self-organization and complexity of Prigogine, Atlan, Jantsch and Kauffman. Wheeler's "it from bit" concept of a participatory universe, and the developments of the physics of information made by Zureck and others with the concepts of statistical entropy and algorithmic entropy, related to the number of bits being processed in the mind of the observer are also considered. This new synthesis gives a self-organizing quantum nonlocal informational basis for a new model of awareness in a participatory universe. In this synthesis, awareness is conceived as meaningful quantum nonlocal information interconnecting the brain and the cosmos, by a holoinformational unified field (integrating nonlocal holistic (quantum) and local (Newtonian). We propose that the cosmology of the physical observer is this unified nonlocal quantum-holographic cosmos manifesting itself through awareness, interconnected in a participatory holistic and indivisible way the human mind-brain to all levels of the self-organizing holographic anthropic multiverse.

  14. Using the CLER Model in School Improvement.

    ERIC Educational Resources Information Center

    Lotto, Linda S.

    1982-01-01

    The CLER (configurations, linkages, environments, resources) Model for planned change was evaluated to determine whether it could be applied in school settings, using empirical data from two recent national school improvement studies. While the model was applicable, it did not seem sufficiently precise to be, in itself, a powerful tool for school…

  15. Improving hydrology models for a changing climate

    NASA Astrophysics Data System (ADS)

    Palus, Shannon

    2014-12-01

    Changes over time in the relationship between rainfall and catchment runoff pose a significant challenge for hydrological models, which are often calibrated under the assumption that the future relationship will be consistent with that of the past. In a recent paper, Westra et al. outlined a method for diagnosing, interpreting, and improving the capacity of models to develop predictions under such conditions.

  16. Spectral analysis of walking improvement utilizing AR modeling.

    PubMed

    Tsuruoka, Masako; Tsuruoka, Yuriko

    2008-01-01

    This study analyzes the walking improvement based on 1/f fluctuations and impulse responses utilizing Auto-Regressive (AR) modeling. Once subjects were aware of the correct posture, the fluctuation of subject's both sides of the hip while walking was improved more rhythmic. The analysis of impulse response utilizing AR modeling provided clear results for the evaluation of improvement to walking stability. After the subjects understood their own walking condition, based on 1/f fluctuation, and had received suitable rehabilitation and shoes, their walking stability improved satisfactorily. This study provides a useful method of medical evaluation in rehabilitation and physical fitness, and a means for subjects to maintain a state of well being. PMID:19163860

  17. Statistical physics model of an evolving population

    NASA Astrophysics Data System (ADS)

    Sznajd-Weron, K.; Pȩkalski, A.

    1999-12-01

    There are many possible approaches by a theoretical physicist to problems of biological evolution. Some focus on physically interesting features, like the self-organized criticality (P. Bak, K. Sneppen, Phys. Rev. Lett 71 (1993); N. Vadewalle, M. Ausloos, Physica D 90 (1996) 262). Others put on more effort taking into account factors considered by biologists to be important in determining one or another aspect of biological evolution (D. Derrida, P.G. Higgs, J. Phys. A 24 (1991) L985; I. Mróz, A. Pȩkalski, K. Sznajd-Weron, Phys. Rev. Lett. 76 (1996) 3025; A. Pȩkalski, Physica A 265 (1999) 255). The intrinsic complexity of the problem enforces nevertheless drastic simplifications. Certain consolation may come from the fact that the mathematical models used by biologists themselves are quite often even more “coarse grained”.

  18. Improvements to constitutive material model for fabrics

    NASA Astrophysics Data System (ADS)

    Morea, Mihai I.

    2011-12-01

    The high strength to weight ratio of woven fabric offers a cost effective solution to be used in a containment system for aircraft propulsion engines. Currently, Kevlar is the only Federal Aviation Administration (FAA) approved fabric for usage in systems intended to mitigate fan blade-out events. This research builds on an earlier constitutive model of Kevlar 49 fabric developed at Arizona State University (ASU) with the addition of new and improved modeling details. Latest stress strain experiments provided new and valuable data used to modify the material model post peak behavior. These changes reveal an overall improvement of the Finite Element (FE) model's ability to predict experimental results. First, the steel projectile is modeled using Johnson-Cook material model and provides a more realistic behavior in the FE ballistic models. This is particularly noticeable when comparing FE models with laboratory tests where large deformations in projectiles are observed. Second, follow-up analysis of the results obtained through the new picture frame tests conducted at ASU provides new values for the shear moduli and corresponding strains. The new approach for analysis of data from picture frame tests combines digital image analysis and a two-level factorial optimization formulation. Finally, an additional improvement in the material model for Kevlar involves checking the convergence at variation of mesh density of fabrics. The study performed and described herein shows the converging trend, therefore validating the FE model.

  19. Dynamical and Physical Models of Ecliptic Comets

    NASA Astrophysics Data System (ADS)

    Dones, L.; Boyce, D. C.; Levison, H. F.; Duncan, M. J.

    2005-08-01

    In most simulations of the dynamical evolution of the cometary reservoirs, a comet is removed from the computer only if it is thrown from the Solar System or strikes the Sun or a planet. However, ejection or collision is probably not the fate of most active comets. Some, like 3D/Biela, disintegrate for no apparent reason, and others, such as the Sun-grazers, 16P/Brooks 2, and D/1993 F2 Shoemaker-Levy 9, are pulled apart by the Sun or a planet. Still others, like 107P/Wilson Harrington and D/1819 W1 Blanpain, are lost and then rediscovered as asteroids. Historically, amateurs discovered most comets. However, robotic surveys now dominate the discovery of comets (http://www.comethunter.de/). These surveys include large numbers of comets observed in a standard way, so the process of discovery is amenable to modeling. Understanding the selection effects for discovery of comets is a key problem in constructing models of cometary origin. To address this issue, we are starting new orbital integrations that will provide the best model to date of the population of ecliptic comets as a function of location in the Solar System and the size of the cometary nucleus, which we expect will vary with location. The integrations include the gravitational effects of the terrestrial and giant planets and, in some cases, nongravitational jetting forces. We will incorporate simple parameterizations for mantling and mass loss based upon detailed physical models. This approach will enable us to estimate the fraction of comets in different states (active, extinct, dormant, or disintegrated) and to track how the cometary size distribution changes as a function of distance from the Sun. We will compare the results of these simulations with bias-corrected models of the orbital and absolute magnitude distributions of Jupiter-family comets and Centaurs.

  20. Improvements to the analytical linescan model for SEM metrology

    NASA Astrophysics Data System (ADS)

    Mack, Chris A.; Bunday, Benjamin D.

    2016-03-01

    Critical dimension scanning electron microscope (CD-SEM) metrology has long used empirical approaches to determine edge locations. While such solutions are very flexible, physics-based models offer the potential for improved accuracy and precision for specific applications. Here, Monte Carlo simulation is used to generate theoretical linescans from single step and line/space targets in order to build a physics-based analytical model, including the presence of bottom footing and top corner rounding. The resulting analytical linescan model fits the Monte Carlo simulation results for different feature heights, widths, pitches, sidewall angles, bottom footing, and top corner rounding. This model has also been successfully applied to asymetric features such as sidewall spacers encountered in self-aligned double patterning.

  1. Using Ecosystem Experiments to Improve Vegetation Models

    SciTech Connect

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

    2015-05-21

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

  2. Using Ecosystem Experiments to Improve Vegetation Models

    DOE PAGESBeta

    Medlyn, Belinda; Zaehle, S; DeKauwe, Martin G.; Walker, Anthony P.; Dietze, Michael; Hanson, Paul J.; Hickler, Thomas; Jain, Atul; Luo, Yiqi; Parton, William; et al

    2015-05-21

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

  3. An improved ARIMA model for hydrological simulations

    NASA Astrophysics Data System (ADS)

    Wang, H. R.; Wang, C.; Lin, X.; Kang, J.

    2014-04-01

    Auto Regressive Integrated Moving Average (ARIMA) model is often used to calculate time series data formed by inter-annual variations of monthly data. However, the influence brought about by inter-monthly variations within each year is ignored. Based on the monthly data classified by clustering analysis, the characteristics of time series data are extracted. An improved ARIMA model is developed accounting for both the inter-annual and inter-monthly variation. The correlation between characteristic quantity and monthly data within each year is constructed by regression analysis first. The model can be used for predicting characteristic quantity followed by the stationary treatment for characteristic quantity time series by difference. A case study is conducted to predict the precipitation in Lanzhou precipitation station, China, using the model, and the results show that the accuracy of the improved model is significantly higher than the seasonal model, with the mean residual achieving 9.41 mm and the forecast accuracy increasing by 21%.

  4. Improved virtual surgical cutting based on physical experiments.

    PubMed

    Lim, Yi-Je; Jones, Daniel B; De, Suvranu

    2005-01-01

    Simulation of surgical cutting is one of the most challenging tasks in the development of a surgery simulator. Changes in topology during simulation make any precomputed data meaningless. Moreover, the process is nonlinear and given the complexity of soft tissue mechanics, the underlying physics is not well understood. Therefore, fully realistic procedures for the simulation of surgical cutting at real time rates on single processor machines is possibly out of reach. We developed a geometry-based algorithm that is capable of simulating progressive cutting without increasing the number of primitives and have coupled it to a meshfree physically based simulation scheme. In this paper we enhance a geometrically efficient cutting algorithm by including physical information from actual cutting experiments. PMID:15718749

  5. An innovation in physical modelling for testing marine renewables technology

    NASA Astrophysics Data System (ADS)

    Todd, David; Whitehouse, Richard; Harris, John; Liddiard, Mark

    2015-04-01

    HR Wallingford has undertaken physical modelling of scour around structures since its creation as a government research laboratory in 1947. Since privatisation in 1982 HR Wallingford has carried out a large number of studies for offshore developments including renewable energy developments and offshore wind in particular, looking at scour around offshore foundations and cables. To maintain our position as both a research and consultancy organisation delivering high quality work we have developed a new purpose built physical modelling facility. The Fast Flow Facility is a dual-channel, race track shaped flume and the only large scale physical modelling facility of this kind offering wave, fast tidal current and recirculating sediment capabilities. The 75 m long, 8 m wide and 2.5 m deep Fast Flow Facility has two working channels of 4 m and 2.6 m width. Holding up to a million litres of water the facility can generate waves with significant wave heights, Hs, of up to 0.5 m and maximum wave heights of up to 1 m in combination with flows of up to 2 m/s (~4 knots). This state-of-the-art facility combines fast, reversible currents with wave generation and sediment transport modelling in a single flume, allowing us to further develop our understanding of sediment transport within the marine environment and keep us at the forefront of sediment transport research. The facility has been designed with the marine renewables sector in mind, with a 4 x 4 x 1m deep sediment pit in the centre of the flume allowing investigations to provide improved understanding of the detailed processes which lead to scour, and enabling improvements in prediction capabilities for marine scour in different sediment seabed compositions (non-cohesive and cohesive) for a range of structure types (monopiles, jackets, gravity base foundations, jack-ups etc.). The facility also enables the testing of scour protection methodologies at relatively large scale (typically 1: 10 - 1:20) and allows for

  6. Physical modeling of transverse drainage mechanisms

    NASA Astrophysics Data System (ADS)

    Douglass, J. C.; Schmeeckle, M. W.

    2005-12-01

    Streams that incise across bedrock highlands such as anticlines, upwarps, cuestas, or horsts are termed transverse drainages. Their relevance today involves such diverse matters as highway and dam construction decisions, location of wildlife corridors, better-informed sediment budgets, and detailed studies into developmental histories of late Cenozoic landscapes. The transient conditions responsible for transverse drainage incision have been extensively studied on a case-by-case basis, and the dominate mechanisms proposed include: antecedence, superimposition, overflow, and piracy. Modeling efforts have been limited to antecedence, and such the specific erosional conditions required for transverse drainage incision, with respect to the individual mechanisms, remains poorly understood. In this study, fifteen experiments attempted to simulate the four mechanisms and constructed on a 9.15 m long, 2.1 m wide, and 0.45 m deep stream table. Experiments lasted between 50 and 220 minutes. The stream table was filled with seven tons of sediment consisting of a silt and clay (30%) and a fine to coarse sand (70%) mixture. The physical models highlighted the importance of downstream aggradation with regard to antecedent incision versus possible defeat and diversion. The overflow experiments indicate that retreating knickpoints across a basin outlet produce a high probability of downstream flooding when associated with a deep lake. Misters used in a couple of experiments illustrate a potential complication with regard to headward erosion driven piracy. Relatively level asymmetrically sloped ridges allow for the drainage divide across the ridge to retreat from headward erosion, but hindered when the ridge's apex undulates or when symmetrically sloped. Although these physical models cannot strictly simulate natural transverse drainages, the observed processes, their development over time, and resultant landforms roughly emulate their natural counterparts. Proposed originally from

  7. Improving the physiological realism of experimental models.

    PubMed

    Vinnakota, Kalyan C; Cha, Chae Y; Rorsman, Patrik; Balaban, Robert S; La Gerche, Andre; Wade-Martins, Richard; Beard, Daniel A; Jeneson, Jeroen A L

    2016-04-01

    The Virtual Physiological Human (VPH) project aims to develop integrative, explanatory and predictive computational models (C-Models) as numerical investigational tools to study disease, identify and design effective therapies and provide an in silico platform for drug screening. Ultimately, these models rely on the analysis and integration of experimental data. As such, the success of VPH depends on the availability of physiologically realistic experimental models (E-Models) of human organ function that can be parametrized to test the numerical models. Here, the current state of suitable E-models, ranging from in vitro non-human cell organelles to in vivo human organ systems, is discussed. Specifically, challenges and recent progress in improving the physiological realism of E-models that may benefit the VPH project are highlighted and discussed using examples from the field of research on cardiovascular disease, musculoskeletal disorders, diabetes and Parkinson's disease. PMID:27051507

  8. A Conceptual Model of Observed Physical Literacy

    ERIC Educational Resources Information Center

    Dudley, Dean A.

    2015-01-01

    Physical literacy is a concept that is gaining greater acceptance around the world with the United Nations Educational, Cultural, and Scientific Organization (2013) recognizing it as one of several central tenets in a quality physical education framework. However, previous attempts to understand progression in physical literacy learning have been…

  9. Physical Activity at Daycare: Childcare Providers' Perspectives for Improvements

    ERIC Educational Resources Information Center

    Tucker, Patricia; van Zandvoort, Melissa M.; Burke, Shauna M.; Irwin, Jennifer D.

    2011-01-01

    In London, Ontario, approximately 45 percent of preschoolers are insufficiently active.With the large number of preschoolers who attend childcare (54%), and the low levels of physical activity among preschool-aged children, daycare centers may be an appropriate avenue to intervene. This study sought to collect childcare providers' suggestions for…

  10. Identification of Physically Underdeveloped Pupils: Activities to Improve Their Performance.

    ERIC Educational Resources Information Center

    President's Council on Physical Fitness and Sports, Washington, DC.

    Screening tests consisting of observation procedures and simple physical exercises requiring only a chinning bar, stopwatch, and record forms are suggested for identifying pupils aged ten to seventeen who are underdeveloped in strength, flexibility, agility, or cardiorespiratory endurance. Classes should be divided into pairs with one pupil acting…

  11. Integrating Animations, Narratives and Textual Information for Improving Physics Learning

    ERIC Educational Resources Information Center

    Adegoke, Benson Adesina

    2010-01-01

    Introduction: This article examined the effect of multimedia instruction on students' learning outcomes (achievement and interest) in secondary school physics. Method: The sample comprised of 517 (294 boys and 223 girls) students who came from 12 senior secondary schools in Ibadan Educational Zone 1, Oyo State, Nigeria. Their ages ranged between…

  12. Physical Training Improves Insulin Resistance Syndrome Markers in Obese Adolescents.

    ERIC Educational Resources Information Center

    Kang, Hyun-Sik; Gutin, Bernard; Barbeau, Paule; Owens, Scott; Lemmon, Christian R.; Allison, Jerry; Litaker, Mark S.; Le, Ngoc-Anh

    2002-01-01

    Tested the hypothesis that physical training (PT), especially high-intensity PT, would favorably affect components of the insulin resistance syndrome (IRS) in obese adolescents. Data on teens randomized into lifestyle education (LSE) alone, LSE plus moderate -intensity PT, and LSE plus high-intensity PT indicated that PT, especially high-intensity…

  13. IMPROVED PHYSICAL PROPERTIES OF ZEIN USING GLYOXAL AS A CROSSLINKER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of crosslinkers glyoxal, methylglyoxal and formaldehyde on physical properties of zein films was studied. Zein was solubilized in 90%(v/v) aqueous ethanol and the pH was adjusted with either hydrochloric acid or sodium hydroxide. Crosslinkers were added to 0.3, 1, 3 and 6%(w/w by zein w...

  14. IMPROVED PHYSICAL PROPERTIES OF ZEIN USING GLYOXAL AS A CROSSLINKER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of crosslinkers glyoxal, methylglyoxal and formaldehyde on physical properties of zein films was studied. Crosslinker concentrations varied from 0.3 to 6% by zein weight. Films crosslinked with glyoxal and formaldehyde showed a significant increase in tensile strength under certain pH c...

  15. Models for Curriculum and Pedagogy in Elementary School Physical Education

    ERIC Educational Resources Information Center

    Kulinna, Pamela Hodges

    2008-01-01

    The purpose of this article is to review current models for curriculum and pedagogy used in elementary school physical education programs. Historically, physical educators have developed and used a multiactivity curriculum in order to educate students through physical movement. More recently, a variety of alternative curricular models have been…

  16. A Structural Equation Model of Expertise in College Physics

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Carr, Martha

    2009-01-01

    A model of expertise in physics was tested on a sample of 374 college students in 2 different level physics courses. Structural equation modeling was used to test hypothesized relationships among variables linked to expert performance in physics including strategy use, pictorial representation, categorization skills, and motivation, and these…

  17. A Structural Equation Model of Conceptual Change in Physics

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Sinatra, Gale M.

    2011-01-01

    A model of conceptual change in physics was tested on introductory-level, college physics students. Structural equation modeling was used to test hypothesized relationships among variables linked to conceptual change in physics including an approach goal orientation, need for cognition, motivation, and course grade. Conceptual change in physics…

  18. The Role of Various Curriculum Models on Physical Activity Levels

    ERIC Educational Resources Information Center

    Culpepper, Dean O.; Tarr, Susan J.; Killion, Lorraine E.

    2011-01-01

    Researchers have suggested that physical education curricula can be highly effective in increasing physical activity levels at school (Sallis & Owen, 1999). The purpose of this study was to investigate the impact of various curriculum models on physical activity. Total steps were measured on 1,111 subjects and three curriculum models were studied…

  19. Recent Improvements to the Calibration Models for RXTE/PCA

    NASA Technical Reports Server (NTRS)

    Jahoda, K.

    2008-01-01

    We are updating the calibration of the PCA to correct for slow variations, primarily in energy to channel relationship. We have also improved the physical model in the vicinity of the Xe K-edge, which should increase the reliability of continuum fits above 20 keV. The improvements to the matrix are especially important to simultaneous observations, where the PCA is often used to constrain the continuum while other higher resolution spectrometers are used to study the shape of lines and edges associated with Iron.

  20. Global scale, physical models of the F region ionosphere

    NASA Technical Reports Server (NTRS)

    Sojka, J. J.

    1989-01-01

    Consideration is given to the development and verification of global computer models of the F-region which simulate the interactions between physical processes in the ionosphere. The limitations of the physical models are discussed, focusing on the inputs to the ionospheric system such as magnetospheric electric field and auroral precipitation. The possibility of coupling ionospheric models with thermospheric and magnetospheric models is examined.

  1. IMPROVING PHYSICAL ACTIVITY IN ARTHRITIS CLINICAL TRIAL (IMPAACT): STUDY DESIGN, RATIONALE, RECRUITMENT, AND BASELINE DATA

    PubMed Central

    Chang, Rowland W.; Semanik, Pamela A.; Lee, Jungwha; Feinglass, Joseph; Ehrlich-Jones, Linda; Dunlop, Dorothy D.

    2014-01-01

    Over 21 million Americans report an arthritis-attributable activity limitation. Knee osteoarthritis (OA) and rheumatoid arthritis (RA) are two of the most common/disabling forms of arthritis. Various forms of physical activity (PA) can improve a variety of health outcomes and reduce health care costs, but the proportion of the US population engaging in the recommended amount of PA is low and even lower among those with arthritis. The Improving Motivation for Physical Activity in Arthritis Clinical Trial (IMPAACT) is a randomized clinical trial that studied the effects of a lifestyle PA promotion intervention on pain and physical function outcomes. The IMPAACT intervention was based on a chronic care/disease management model in which allied health professionals promote patient self-management activities outside of traditional physician office encounters. The program was a motivational interviewing-based, individualized counseling and referral intervention, directed by a comprehensive assessment of individual patient barriers and strengths related to PA performance. The specific aims of IMPAACT were to test the efficacy of the IMPAACT intervention for persons with arthritis (N=185 persons with RA and 155 persons with knee OA) in improving arthritis-specific and generic self-reported pain and physical function outcomes, observed measures of function, and objectively measured and self-reported PA levels. Details of the stratified-randomized study design, subject recruitment, and data collection are described. The results from IMPAACT will generate empiric evidence pertaining to increasing PA levels in persons with arthritis and result in widely applicable strategies for health behavior change. PMID:25183043

  2. Increasing Steps/Day Predicts Improvement in Physical Function and Pain Interference in Adults with Fibromyalgia

    PubMed Central

    Kaleth, Anthony S.; Slaven, James E.; Ang, Dennis C.

    2014-01-01

    Objective To examine the concurrent and predictive associations between the number of steps taken per day (steps/day) and clinical outcomes in patients with fibromyalgia (FM). Methods 199 adults with FM [mean age = 46.1 yr; 95% females] enrolled in a randomized clinical trial wore a hip-mounted accelerometer for 1 week and completed self-report measures of physical function [Fibromyalgia Impact Questionnaire-Physical Impairment (FIQ-PI), SF-36 physical component score (SF-36 PCS)], pain intensity and interference (Brief Pain Inventory; BPI), and depressive symptoms (Patient Health Questionnaire-8; PHQ-8) as part of their baseline and follow-up assessments. Associations of steps/day with self-report clinical measures were evaluated from baseline to week 12 using multivariate regression models adjusted for demographic and baseline covariates. Results Study participants were primarily sedentary, averaging 4,019 ± 1,530 steps/day. Our findings demonstrate a linear relationship between the change in steps/day and improvement in health outcomes for FM. Incremental increases on the order of 1,000 steps/day were significantly associated with (and predictive of) improvements in FIQ-PI, SF-36 PCS, BPI pain interference, and PHQ-8 (all p<0.05). Although higher step counts were associated with lower FIQ and BPI pain intensity scores, these were not statistically significant. Conclusion Step counts is an easily obtained and understood objective measure of daily physical activity. An exercise prescription that includes recommendations to gradually accumulate at least 5,000 additional steps/day may result in clinically significant improvements in outcomes relevant to patients with FM. Future studies are needed to elucidate the dose-response relationship between steps/day and patient outcomes in FM. PMID:25049001

  3. Improving the EOTDA ocean background model

    NASA Astrophysics Data System (ADS)

    McGrath, Charles P.; Badzik, Gregory D.

    1997-09-01

    The Electro-Optical Tactical Decision Aid (EOTDA) is a strike warfare mission planning tool originally developed by the US Air Force. The US Navy has added navy sensors and targets to the EOTDA and installed it into current fleet mission planning and support systems. Fleet experience with the EOTDA and previous studies have noted the need for improvement, especially for scenarios involving ocean backgrounds. In order to test and improve the water background model in the EOTDA, a modified version has been created that replaces the existing semi-empirical model with the SeaRad model that was developed by Naval Command, Control and Ocean Surveillance Systems (NRaD). The SeaRad model is a more rigorous solution based on the Cox-Munk wave-slope probabilities. During the April 1996 Electrooptical Propagation Assessment in Coastal Environments (EOPACE) trials, data was collected to evaluate the effects of the SeaRad version of the EOTDA. Data was collected using a calibrated airborne infrared imaging system and operational FUR systems against ship targets. A modified version of MODTRAN also containing the SeaRad model is used to correct the data for the influences of the atmosphere. This report uses these data along with the modified EOTDA to evaluate the effects of the SeaRad model on ocean background predictions under clear and clouded skies. Upon using the more accurate water reflection model, the significance of the sky and cloud radiance contributions become more apparent leading to recommendations for further improvements.

  4. Application of radiation physics to improve dosimetry in early breast cancer radiotherapy

    SciTech Connect

    Donovan, Ellen Mary

    2005-07-15

    Radiotherapy for early breast cancer has been shown to be a highly effective treatment in a number of long term studies. The radiation dose uniformity of the current standard treatments is often poor, however, with dose variations across the breast much higher than those recommended in international guidelines. This work aimed to explore methods for improving this aspect of the radiation dosimetry of early breast cancer radiotherapy. An experimental method was validated by applying it to computed tomography data from 14 patients with a variety of breast shapes and sizes. The volume of the breast receiving the desired dose levels increased by a mean of 6.9% (range -0.8% to 15.9%) and this benefit was shown to increase with breast volume. The quality of reference images in the verification of treatments was improved by introducing differential filtering to the imaging beams on a radiotherapy simulator. The positive results from the first two studies were applied in a clinical trial (which used the experimental technique). The unique set of data from the trial was analyzed and confirmation of dosimetric improvement, and the increased benefit, for larger breasted women were found. In addition, an analysis of the position of high doses showed these occurred in the upper or lower third of the breast and affected 46% and 30% of patients, respectively, with standard treatment but only 1% of patients with the improved method. Other published methods for improving breast dosimetry were explored by building a simple physical model and carrying out a comparative planning study. The physical model was shown to be effective in predicting the dosimetric consequences of each method. The planning study showed that there was little difference between the methods generally but dosimetric improvement could be increased for larger breast volumes by an appropriate choice of technique. A final study explored how breathing control could be used to reduce cardiac doses in patients with

  5. An improved model of direct gauge mediation

    NASA Astrophysics Data System (ADS)

    Agashe, Kaustubh

    1998-09-01

    We present a new, improved model of gauge mediation of dynamical SUSY Breaking: the model does not have gauge messengers or ~10 TeV scalars charged under the Standard Model (SM), thus avoiding the problem of negative (mass)2 for supersymmetric SM (SSM) scalars faced by some earlier models. The gauge mediation is direct, i.e., the messengers which communicate SUSY breaking to the SSM fields carry quantum numbers of the gauge group which breaks SUSY. These messenger fields couple to a modulus field. The model has a very simple particle content: the modulus and the messengers are the only chiral superfields (other than the SSM fields) in the model. The inverted hierarchy mechanism is used to generate a local SUSY breaking minimum for the modulus field in a perturbative regime thus making the model calculable.

  6. An improved model for prediction of resuspension.

    PubMed

    Maxwell, Reed M; Anspaugh, Lynn R

    2011-12-01

    A complete, historical dataset is presented of radionuclide resuspension-factors. These data span six orders of magnitude in time (ranging from 0.1 to 73,000 d), encompass more than 300 individual values, and combine observations from events on three continents. These data were then used to derive improved, empirical models that can be used to predict resuspension of trace materials after their deposit on the ground. Data-fitting techniques were used to derive models of various types and an estimate of uncertainty in model prediction. Two models were found to be suitable: a power law and the modified Anspaugh et al. model, which is a double exponential. Though statistically the power-law model provides the best metrics of fit, the modified Anspaugh model is deemed the more appropriate due to its better fit to data at early times and its ease of implementation in terms of closed analytical integrals. PMID:22048490

  7. A review of recent research on improvement of physical parameterizations in the GLA GCM

    NASA Technical Reports Server (NTRS)

    Sud, Y. C.; Walker, G. K.

    1990-01-01

    A systematic assessment of the effect of a series of improvements in physical parameterizations of the Goddard Laboratory for Atmospheres (GLA) general circulation model (GCM) are summarized. The implementation of the Simple Biosphere Model (SiB) in the GCM is followed by a comparison of SiB GCM simulations with that of the earlier slab soil hydrology GCM (SSH-GCM) simulations. In the Sahelian context, the biogeophysical component of desertification was analyzed for SiB-GCM simulations. Cumulus parameterization is found to be the primary determinant of the organization of the simulated tropical rainfall of the GLA GCM using Arakawa-Schubert cumulus parameterization. A comparison of model simulations with station data revealed excessive shortwave radiation accompanied by excessive drying and heating to the land. The perpetual July simulations with and without interactive soil moisture shows that 30 to 40 day oscillations may be a natural mode of the simulated earth atmosphere system.

  8. Recommendations to improve the accuracy of estimates of physical activity derived from self report

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Assessment of physical activity using self-report has the potential for measurement error that can lead to incorrect inferences about physical activity behaviors and bias study results. To provide recommendations to improve the accuracy of physical activity derived from self report. We provide an ov...

  9. A Physical Model of Electron Radiation Belts of Saturn

    NASA Astrophysics Data System (ADS)

    Lorenzato, L.; Sicard-Piet, A.; Bourdarie, S.

    2012-09-01

    Enrolling on the Cassini age, a physical Salammbô model for the radiation belts of Saturn have been developed including several physical processes governing the kronian magnetosphere. Results have been compared with Cassini MIMI LEMMS data.

  10. Improved reference models for middle atmosphere ozone

    NASA Technical Reports Server (NTRS)

    Keating, G. M.; Pitts, M. C.; Chen, C.

    1990-01-01

    This paper describes the improvements introduced into the original version of ozone reference model of Keating and Young (1985, 1987) which is to be incorporated in the next COSPAR International Reference Atmosphere (CIRA). The ozone reference model will provide information on the global ozone distribution (including the ozone vertical structure as a function of month and latitude from 25 to 90 km) combining data from five recent satellite experiments: the Nimbus 7 LIMS, Nimbus 7 SBUV, AE-2 Stratospheric Aerosol Gas Experiment (SAGE), Solar Mesosphere Explorer (SME) UV Spectrometer, and SME 1.27 Micron Airglow. The improved version of the reference model uses reprocessed AE-2 SAGE data (sunset) and extends the use of SAGE data from 1981 to the 1981-1983 time period. Comparisons are presented between the results of this ozone model and various nonsatellite measurements at different levels in the middle atmosphere.

  11. Improved reference models for middle atmosphere ozone

    NASA Technical Reports Server (NTRS)

    Keating, G. M.; Pitts, M. C.; Chen, C.

    1989-01-01

    Improvements are provided for the ozone reference model which is to be incorporated in the COSPAR International Reference Atmosphere (CIRA). The ozone reference model will provide considerable information on the global ozone distribution, including ozone vertical structure as a function of month and latitude from approximately 25 to 90 km, combining data from five recent satellite experiments (Nimbus 7 LIMS, Nimbus 7 SBUV, AE-2 SAGE, Solar Mesosphere Explorer (SME) UVS, and SME IR). The improved models are described and use reprocessed AE-2 SAGE data (sunset) and extend the use of SAGE data from 1981 to the period 1981-1983. Comparisons are shown between the ozone reference model and various nonsatellite measurements at different levels in the middle atmosphere.

  12. An improved ARIMA model for precipitation simulations

    NASA Astrophysics Data System (ADS)

    Wang, H. R.; Wang, C.; Lin, X.; Kang, J.

    2014-12-01

    Auto regressive integrated moving average (ARIMA) models have been widely used to calculate monthly time series data formed by interannual variations of monthly data or inter-monthly variation. However, the influence brought about by inter-monthly variations within each year is often ignored. An improved ARIMA model is developed in this study accounting for both the interannual and inter-monthly variation. In the present approach, clustering analysis is performed first to hydrologic variable time series. The characteristics of each class are then extracted and the correlation between the hydrologic variable quantity to be predicted and characteristic quantities constructed by linear regression analysis. ARIMA models are built for predicting these characteristics of each class and the hydrologic variable monthly values of year of interest are finally predicted using the modeled values of corresponding characteristics from ARIMA model and the linear regression model. A case study is conducted to predict the monthly precipitation at the Lanzhou precipitation station in Lanzhou, China, using the model, and the results show that the accuracy of the improved model is significantly higher than the seasonal model, with the mean residual achieving 9.41 mm and the forecast accuracy increasing by 21%.

  13. Specifically designed physical exercise programs improve children's motor abilities.

    PubMed

    Chiodera, P; Volta, E; Gobbi, G; Milioli, M A; Mirandola, P; Bonetti, A; Delsignore, R; Bernasconi, S; Anedda, A; Vitale, M

    2008-04-01

    Physical activity in schools is declining in many countries and inactivity in childhood has become a recognized risk factor. Data from a program of professionally guided physical exercise in primary school children were collected before and after the academic year of training. Four thousand five hundred children (6-10 years) were enrolled, and conditional and coordinative motor abilities (speed, trunk flexibility, long jumping, somersault, Harre circuit test) were measured. Anthropometric measurements were focused on body mass index (BMI), weight and height. Females never showed a significant variation of BMI, whereas males in the first and fourth grades showed significant differences. On the contrary, when considering the motor abilities studied, all the comparisons were highly significant. At the end of training, both males and females did better than at the beginning, and males were constantly faster than females. Our data, generated on a large number of children, show that professionally guided programs of physical education in the primary school lead to significant progresses in the development of conditional and coordinative abilities, without altering BMI values, thus not interfering with the balanced progression of body weight and height. PMID:17490452

  14. Physical health nurse consultant role to improve physical health in mental health services: A carer's perspective.

    PubMed

    Happell, Brenda; Wilson, Karen; Platania-Phung, Chris; Stanton, Robert

    2016-06-01

    The physical health of people diagnosed with a mental illness is significantly poorer in comparison with the general population. Awareness of this health disparity is increasing; however, strategies to address the problem are limited. Carers play an important role in the physical health care of people with mental illness, particularly in facilitating navigation of and advocating in the health care system. A specialist physical health nurse consultant position has been suggested as a way to address the physical health care disparity and limited research available suggests that positive outcomes are possible. In the present study, a qualitative exploratory research project was undertaken, involving in-depth interviews with people identifying as mental health carers. Two focus groups and one individual interview were conducted involving a total of 13 carers. The resulting data were analyzed thematically. Views and opinions about the proposed physical health nurse consultant (PHNC) position were sought during these interviews and are reported in this paper. Two main sub-themes were evident relating to characteristics of this role: reliability and consistency; and communication and support. Essentially carers expressed a need for support for themselves and consumers in addressing physical health concerns. Successful implementation of this position would require a consistent and reliable approach. Carers are significant stakeholders in the physical health of consumers of mental health services and their active involvement in identifying and tailoring services, including development of the physical health nurse consultant must be seen as a priority. PMID:26876094

  15. Improving subsurface hydrology in Earth System Models

    NASA Astrophysics Data System (ADS)

    Volk, J. M.; Clark, M. P.; Swenson, S. C.; Lawrence, D. M.; Tyler, S. W.

    2015-12-01

    Hydrologic processes that govern storage and transport of soil water and groundwater can have strong dynamic relationships with biogeochemical and atmospheric processes. This understanding has lead to a push to improve subsurface hydrologic parametrization in Earth System Models. Here we present results related to improving the implementation of soil moisture distribution, groundwater recharge/discharge, and subsurface drainage in the Community Land Model (CLM) which is the land surface model in the Community Earth System Model. First we identified geo-climatically different locations around the world to develop test cases. For each case we compare the vertical soil moisture distribution from the different implementations of 1D Richards equation, considering the boundary conditions, the treatment of the groundwater sink term, the vertical discretization, and the time stepping schemes. Generally, large errors in the hydrologic mass balance within the soil column occur when there is a large vertical gradient in soil moisture or when there is a shallow water table within a soil column. We then test the sensitivity of the algorithmic parameters that control temporal discretization and error tolerance of the adaptive time-stepping scheme to help optimize its computational efficiency. In addition, we vary the spatial discretization of soil layers (i.e. quantity of layers and their thicknesses) to better understand the sensitivity of vertical discretization of soil columns on soil moisture variability in ESMs. We present multivariate and multi-scale evaluation for the different model options and suggest ways to move forward with future model improvements.

  16. An improved approach for tank purge modeling

    NASA Astrophysics Data System (ADS)

    Roth, Jacob R.; Chintalapati, Sunil; Gutierrez, Hector M.; Kirk, Daniel R.

    2013-05-01

    Many launch support processes use helium gas to purge rocket propellant tanks and fill lines to rid them of hazardous contaminants. As an example, the purge of the Space Shuttle's External Tank used approximately 1,100 kg of helium. With the rising cost of helium, initiatives are underway to examine methods to reduce helium consumption. Current helium purge processes have not been optimized using physics-based models, but rather use historical 'rules of thumb'. To develop a more accurate and useful model of the tank purge process, computational fluid dynamics simulations of several tank configurations were completed and used as the basis for the development of an algebraic model of the purge process. The computationally efficient algebraic model of the purge process compares well with a detailed transient, three-dimensional computational fluid dynamics (CFD) simulation as well as with experimental data from two external tank purges.

  17. Improved inland water levels from SAR altimetry using novel empirical and physical retrackers

    NASA Astrophysics Data System (ADS)

    Villadsen, Heidi; Deng, Xiaoli; Andersen, Ole B.; Stenseng, Lars; Nielsen, Karina; Knudsen, Per

    2016-06-01

    Satellite altimetry has proven a valuable resource of information on river and lake levels where in situ data are sparse or non-existent. In this study several new methods for obtaining stable inland water levels from CryoSat-2 Synthetic Aperture Radar (SAR) altimetry are presented and evaluated. In addition, the possible benefits from combining physical and empirical retrackers are investigated. The retracking methods evaluated in this paper include the physical SAR Altimetry MOde Studies and Applications (SAMOSA3) model, a traditional subwaveform threshold retracker, the proposed Multiple Waveform Persistent Peak (MWaPP) retracker, and a method combining the physical and empirical retrackers. Using a physical SAR waveform retracker over inland water has not been attempted before but shows great promise in this study. The evaluation is performed for two medium-sized lakes (Lake Vänern in Sweden and Lake Okeechobee in Florida), and in the Amazon River in Brazil. Comparing with in situ data shows that using the SAMOSA3 retracker generally provides the lowest root-mean-squared-errors (RMSE), closely followed by the MWaPP retracker. For the empirical retrackers, the RMSE values obtained when comparing with in situ data in Lake Vänern and Lake Okeechobee are in the order of 2-5 cm for well-behaved waveforms. Combining the physical and empirical retrackers did not offer significantly improved mean track standard deviations or RMSEs. Based on these studies, it is suggested that future SAR derived water levels are obtained using the SAMOSA3 retracker whenever information about other physical properties apart from range is desired. Otherwise we suggest using the empirical MWaPP retracker described in this paper, which is both easy to implement, computationally efficient, and gives a height estimate for even the most contaminated waveforms.

  18. Guided-Inquiry Experiments for Physical Chemistry: The POGIL-PCL Model

    ERIC Educational Resources Information Center

    Hunnicutt, Sally S.; Grushow, Alexander; Whitnell, Robert

    2015-01-01

    The POGIL-PCL project implements the principles of process-oriented, guided-inquiry learning (POGIL) in order to improve student learning in the physical chemistry laboratory (PCL) course. The inquiry-based physical chemistry experiments being developed emphasize modeling of chemical phenomena. In each experiment, students work through at least…

  19. Hybrid Modeling Improves Health and Performance Monitoring

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Scientific Monitoring Inc. was awarded a Phase I Small Business Innovation Research (SBIR) project by NASA's Dryden Flight Research Center to create a new, simplified health-monitoring approach for flight vehicles and flight equipment. The project developed a hybrid physical model concept that provided a structured approach to simplifying complex design models for use in health monitoring, allowing the output or performance of the equipment to be compared to what the design models predicted, so that deterioration or impending failure could be detected before there would be an impact on the equipment's operational capability. Based on the original modeling technology, Scientific Monitoring released I-Trend, a commercial health- and performance-monitoring software product named for its intelligent trending, diagnostics, and prognostics capabilities, as part of the company's complete ICEMS (Intelligent Condition-based Equipment Management System) suite of monitoring and advanced alerting software. I-Trend uses the hybrid physical model to better characterize the nature of health or performance alarms that result in "no fault found" false alarms. Additionally, the use of physical principles helps I-Trend identify problems sooner. I-Trend technology is currently in use in several commercial aviation programs, and the U.S. Air Force recently tapped Scientific Monitoring to develop next-generation engine health-management software for monitoring its fleet of jet engines. Scientific Monitoring has continued the original NASA work, this time under a Phase III SBIR contract with a joint NASA-Pratt & Whitney aviation security program on propulsion-controlled aircraft under missile-damaged aircraft conditions.

  20. Improving Representational Competence with Concrete Models

    ERIC Educational Resources Information Center

    Stieff, Mike; Scopelitis, Stephanie; Lira, Matthew E.; DeSutter, Dane

    2016-01-01

    Representational competence is a primary contributor to student learning in science, technology, engineering, and math (STEM) disciplines and an optimal target for instruction at all educational levels. We describe the design and implementation of a learning activity that uses concrete models to improve students' representational competence and…

  1. School Improvement Model to Foster Student Learning

    ERIC Educational Resources Information Center

    Rulloda, Rudolfo Barcena

    2011-01-01

    Many classroom teachers are still using the traditional teaching methods. The traditional teaching methods are one-way learning process, where teachers would introduce subject contents such as language arts, English, mathematics, science, and reading separately. However, the school improvement model takes into account that all students have…

  2. Report Critiques Evidence on School Improvement Models

    ERIC Educational Resources Information Center

    Viadero, Debra

    2005-01-01

    Only two of the most popular school improvement models for elementary schools have "moderately strong" evidence to show that they work, according to a consumer-style guide released last week by a Washington-based research group. The federally financed report by the American Institutes for Research rates 22 of the most widely used…

  3. INHALATION EXPOSURE AND INTAKE DOSE MODEL IMPROVEMENTS

    EPA Science Inventory

    This presentation highlights recent human exposure model improvements and products developed by the EMRB in coordination with scientists in the OAQPS and provides insight into how these products are used by the OAQPS in its regulatory process. Besides providing a status report of...

  4. Models To Improve Service Delivery. Chapter 8.

    ERIC Educational Resources Information Center

    1996

    This collection of papers presented at a 1996 conference on children's mental health focuses on models to improve service delivery. Papers have the following titles and authors: (1) "Empirical Evaluation of an Alternative to Hospitalization for Youth Presenting Psychiatric Emergencies" (Scott W. Henggeler); (2) "An Experimental Study of the…

  5. Numerical strategy for model correction using physical constraints

    NASA Astrophysics Data System (ADS)

    He, Yanyan; Xiu, Dongbin

    2016-05-01

    In this paper we present a strategy for correcting model deficiency using observational data. We first present the model correction in a general form, involving both external correction and internal correction. The model correction problem is then parameterized and casted into an optimization problem, from which the parameters are determined. More importantly, we discuss the incorporation of physical constraints from the underlying physical problem. Several representative examples are presented, where the physical constraints take very different forms. Numerical tests demonstrate that the physics constrained model correction is an effective way to address model-form uncertainty.

  6. Modelers and policymakers : improving the relationships.

    SciTech Connect

    Karas, Thomas H.

    2004-06-01

    On April 22 and 23, 2004, a diverse group of 14 policymakers, modelers, analysts, and scholars met with some 22 members of the Sandia National Laboratories staff to explores ways in which the relationships between modelers and policymakers in the energy and environment fields (with an emphasis on energy) could be made more productive for both. This report is not a transcription of that workshop, but draws very heavily on its proceedings. It first describes the concept of modeling, the varying ways in which models are used to support policymaking, and the institutional context for those uses. It then proposes that the goal of modelers and policymakers should be a relationship of mutual trust, built on a foundation of communication, supported by the twin pillars of policy relevance and technical credibility. The report suggests 20 guidelines to help modelers improve the relationship, followed by 10 guidelines to help policymakers toward the same goal.

  7. Real time refractivity from clutter using a best fit approach improved with physical information

    NASA Astrophysics Data System (ADS)

    Douvenot, RéMi; Fabbro, Vincent; Gerstoft, Peter; Bourlier, Christophe; Saillard, Joseph

    2010-02-01

    Refractivity from clutter (RFC) retrieves the radio frequency refractive conditions along a propagation path by inverting the measured radar sea clutter return. In this paper, a real-time RFC technique is proposed called "Improved Best Fit" (IBF). It is based on finding the environment with best fit to one of many precomputed, modeled radar returns for different environments in a database. The method is improved by considering the mean slope of the propagation factor, and physical considerations are added: smooth variations of refractive conditions with azimuth and smooth variations of duct height with range. The approach is tested on data from 1998 Wallops Island, Virginia, measurement campaign with good results on most of the data, and questionable results are detected with a confidence criterion. A comparison between the refractivity structures measured during the measurement campaign and the ones retrieved by inversion shows a good match. Radar coverage simulations obtained from these inverted refractivity structures demonstrate the potential utility of IBF.

  8. Low Complexity Models to improve Incomplete Sensitivities for Shape Optimization

    NASA Astrophysics Data System (ADS)

    Stanciu, Mugurel; Mohammadi, Bijan; Moreau, Stéphane

    2003-01-01

    The present global platform for simulation and design of multi-model configurations treat shape optimization problems in aerodynamics. Flow solvers are coupled with optimization algorithms based on CAD-free and CAD-connected frameworks. Newton methods together with incomplete expressions of gradients are used. Such incomplete sensitivities are improved using reduced models based on physical assumptions. The validity and the application of this approach in real-life problems are presented. The numerical examples concern shape optimization for an airfoil, a business jet and a car engine cooling axial fan.

  9. Improving student learning and views of physics in a large enrollment introductory physics class

    NASA Astrophysics Data System (ADS)

    Salehzadeh Einabad, Omid

    Introductory physics courses often serve as gatekeepers for many scientific and engineering programs and, increasingly, colleges are relying on large, lecture formats for these courses. Many students, however, leave having learned very little physics and with poor views of the subject. In interactive engagement (IE), classroom activities encourage students to engage with each other and with physics concepts and to be actively involved in their own learning. These methods have been shown to be effective in introductory physics classes with small group recitations. This study examined student learning and views of physics in a large enrollment course that included IE methods with no separate, small-group recitations. In this study, a large, lecture-based course included activities that had students explaining their reasoning both verbally and in writing, revise their ideas about physics concepts, and apply their reasoning to various problems. The questions addressed were: (a) What do students learn about physics concepts and how does student learning in this course compare to that reported in the literature for students in a traditional course?, (b) Do students' views of physics change and how do students' views of physics compare to that reported in the literature for students in a traditional course?, and (c) Which of the instructional strategies contribute to student learning in this course? Data included: pre-post administration of the Force Concept Inventory (FCI), classroom exams during the term, pre-post administration of the Colorado Learning Attitudes About Science Survey (CLASS), and student work, interviews, and open-ended surveys. The average normalized gain (=0.32) on the FCI falls within the medium-gain range as reported in the physics education literature, even though the average pre-test score was very low (30%) and this was the instructor's first implementation of IE methods. Students' views of physics remained relatively unchanged by instruction

  10. The impact of improved physics on commercial tokamak reactors

    SciTech Connect

    Galambos, J.D.; Perkins, L.J.; Haney, S.; Mandrekas, J.

    1994-01-01

    Improvements in the confinement and beta capability of tokamak devices have long been a goal of the fusion program. We examine the impact of improvements in present day confinement and beta capabilities on commercial tokamak reactors. We characterize confinement with the achievable enhancement factor (H) over the ITER89 Power scaling confinement time, and beta by the Troyon coefficient g. A surprisingly narrow range of plasma confinement and beta are found to be useful in minimizing the cost of electricity for a tokamak reactor. Improvements in only one of these quantities is not useful beyond some point, without accompanying improvements in the other. For the plasma beta limited by a Troyon coefficient (g) near 4.3 (%mT/MA), confinement levels characterized by H factor enhancements of only 2 are useful for our nominal steady-state driven tokamak. These confinement levels are similar to those observed in present day experiments. If the permissible Troyon beta coefficient is near 6, the useful H factor confinement range increases to 2.5, still close to present day confinement levels. Inductively driven, pulsed reactors have somewhat increased useful ranges of confinement, relative to the steady-state cases. For a Troyon beta limit coefficient g near 4.3, H factors up to 2.5 are useful, and for g near 6, H factors up to 3 are useful.

  11. Improvements in Physical Fitness in Adults with Down Syndrome

    ERIC Educational Resources Information Center

    Rimmer, James H.; Heller, Tamar; Wang, Edward; Valerio, Irene

    2004-01-01

    The effectiveness of an exercise training program for 52 adults with Down syndrome (M age = 39.4 years) was evaluated. The training program consisted of cardiovascular (30 minutes) and strength exercise (15 minutes) for 12 weeks, 3 days a week for 45-minutes per session. Compared to control subjects, the training group improved significantly in…

  12. Leveraging Spatial Model to Improve Indoor Tracking

    NASA Astrophysics Data System (ADS)

    Liu, L.; Xu, W.; Penard, W.; Zlatanova, S.

    2015-05-01

    In this paper, we leverage spatial model to process indoor localization results and then improve the track consisting of measured locations. We elaborate different parts of spatial model such as geometry, topology and semantics, and then present how they contribute to the processing of indoor tracks. The initial results of our experiment reveal that spatial model can support us to overcome problems such as tracks intersecting with obstacles and unstable shifts between two location measurements. In the future, we will investigate more exceptions of indoor tracking results and then develop additional spatial methods to reduce errors of indoor tracks.

  13. Modelling Mathematical Reasoning in Physics Education

    ERIC Educational Resources Information Center

    Uhden, Olaf; Karam, Ricardo; Pietrocola, Mauricio; Pospiech, Gesche

    2012-01-01

    Many findings from research as well as reports from teachers describe students' problem solving strategies as manipulation of formulas by rote. The resulting dissatisfaction with quantitative physical textbook problems seems to influence the attitude towards the role of mathematics in physics education in general. Mathematics is often seen as a…

  14. Assessing Program Learning Objectives to Improve Undergraduate Physics Education

    NASA Astrophysics Data System (ADS)

    Menke, Carrie

    2014-03-01

    Our physics undergraduate program has five program learning objectives (PLOs) focusing on (1) physical principles, (2) mathematical expertise, (3) experimental technique, (4) communication and teamwork, and (5) research proficiency. One PLO is assessed each year, with the results guiding modifications in our curriculum and future assessment practices; we have just completed our first cycle of assessing all PLOs. Our approach strives to maximize the ease and applicability of our assessment practices while maintaining faculty's flexibility in course design and delivery. Objectives are mapped onto our core curriculum with identified coursework collected as direct evidence. We've utilized mostly descriptive rubrics, applying them at the course and program levels as well as sharing them with the students. This has resulted in more efficient assessment that is also applicable to reaccreditation efforts, higher inter-rater reliability than with other rubric types, and higher quality capstone projects. We've also found that the varied quality of student writing can interfere with our assessment of other objectives. This poster outlines our processes, resources, and how we have used PLO assessment to strengthen our undergraduate program.

  15. Engaging Students In Modeling Instruction for Introductory Physics

    NASA Astrophysics Data System (ADS)

    Brewe, Eric

    2016-05-01

    Teaching introductory physics is arguably one of the most important things that a physics department does. It is the primary way that students from other science disciplines engage with physics and it is the introduction to physics for majors. Modeling instruction is an active learning strategy for introductory physics built on the premise that science proceeds through the iterative process of model construction, development, deployment, and revision. We describe the role that participating in authentic modeling has in learning and then explore how students engage in this process in the classroom. In this presentation, we provide a theoretical background on models and modeling and describe how these theoretical elements are enacted in the introductory university physics classroom. We provide both quantitative and video data to link the development of a conceptual model to the design of the learning environment and to student outcomes. This work is supported in part by DUE #1140706.

  16. MEM: A physical-based directional meteoroid model

    NASA Technical Reports Server (NTRS)

    McNamara, H.; Cooke, W.; Suggs, R.

    2004-01-01

    Three years of research conducted by the University of Western Ontario into the nature and distribution of the sporadic sources have been incorporated into a Meteoroid Engineering Model (MEM) by members of the Meteoroid Environments Office at NASA's Marshall Space Flight Center. This paper gives a broad overview of this model, new features of which include: a) identification of the sporadic radiants with real sources of meteoroids, such as comets, b) a physics-based approach which yields accurate fluxes and directionality for interplanetary spacecraft anywhere from 0.2 AU to 2 AU. and c) velocity distributions obtained from theory and validated against observation. Its use and application is also described, along with existing limitations and plans for future improvements.

  17. Advanced in turbulence physics and modeling by direct numerical simulations

    NASA Technical Reports Server (NTRS)

    Reynolds, W. C.

    1987-01-01

    The advent of direct numerical simulations of turbulence has opened avenues for research on turbulence physics and turbulence modeling. Direct numerical simulation provides values for anything that the scientist or modeler would like to know about the flow. An overview of some recent advances in the physical understanding of turbulence and in turbulence modeling obtained through such simulations is presented.

  18. A Path-Analysis Model of Secondary Physics Enrollments

    ERIC Educational Resources Information Center

    Bryant, Lee T.; Doran, Rodney L.

    1977-01-01

    Develops a path-analysis model of critical variables affecting student enrollment in secondary school physics. A test of the model utilizing state provided data of physics enrollment in New York State resulted in the rejection of the model; however, significant critical variable results were obtained. (SL)

  19. Teacher Fidelity to One Physical Education Curricular Model

    ERIC Educational Resources Information Center

    Kloeppel, Tiffany; Kulinna, Pamela Hodges; Stylianou, Michalis; van der Mars, Hans

    2013-01-01

    This study addressed teachers' fidelity to one Physical Education curricular model. The theoretical framework guiding this study included professional development and fidelity to curricular models. In this study, teachers' fidelity to the Dynamic Physical Education (DPE) curricular model was measured for high and nonsupport district groups.…

  20. Supervision Models with Respect to Physical Education Needs.

    ERIC Educational Resources Information Center

    Williams, Lisa G.

    This paper focuses on several models of supervision in public schools with respect to needs in physical education. A literature review examined the traditional, counseling-based, self-analysis, competency-based, and systematic supervision models. Findings include the use of each model and the failure of each in the physical education setting. One…

  1. Improving Student Learning and Views of Physics in a Large Enrollment Introductory Physics Class

    NASA Astrophysics Data System (ADS)

    Shan, Kathy

    2014-03-01

    Interactive engagement (IE) strategies can be helpful for students learning introductory physics with small group recitations. Less is known about their impact for large lecture-based courses. This study examined student learning and views of physics in a large enrollment course that included IE but no small-group recitation. The questions addressed were: (a) What do students learn about physics and how does this compare to reports for traditional courses?, (b) How do students' views of physics change and how does this compare to reports for traditional courses?, and (c) Which instructional strategies contribute to student outcomes? Data included pre-post FCI scores, classroom examinations during the term, pre-post CLASS scores, and student work, interviews, and open-ended surveys. Findings include a FCI average normalized gain of 0.32, which is high for students with low pre-test score (30% for this group) and instructors new to IE methods. Students' views of physics remained relatively unchanged, which is promising given the typical decline for student views. And instructional strategies as a set, not individual strategies, impacted student outcomes. Findings support the recommendation to adopt IE methods in introductory physics classes, particularly when pre-tests are low.

  2. An improved model of equatorial scintillation

    NASA Astrophysics Data System (ADS)

    Secan, J. A.; Bussey, R. M.; Fremouw, E. J.; Basu, Sa.

    1995-05-01

    One of the main limitations of the modeling work that went into the equatorial section of the Wideband ionospheric scintillation model (WBMOD) was that the data set used in the modeling was limited to two stations near the dip equator (Ancon, Peru, and Kwajalein Island, in the North Pacific Ocean) at two fixed local times (nominally 1000 and 2200). Over the past year this section of the WBMOD model has been replaced by a model developed using data from three additional stations (Ascension Island, in the South Atlantic Ocean, Huancayo, Peru, and Manila, Phillipines; data collected under the auspices of the USAF Phillips Laboratory Geophysics Directorate) which provide a greater diversity in both latitude and longitude, as well as cover the entire day. The new model includes variations with latitude, local time, longitude, season, solar epoch, and geomagnetic activity levels. The way in which the irregularity strength parameter CkL is modeled has also been changed. The new model provides the variation of the full probability distribution function (PDF) of log (CkL) rather than simply the average of log (CkL). This permits the user to specify a threshold on scintillation level, and the model will calculate the percent of the time that scintillation will exceed that level in the user-specified scenario. It will also permit calculation of scintillation levels at a user-specified percentile. A final improvement to the WBMOD model is the implementation of a new theory for calculating S4 on a two-way channel.

  3. Double multiple streamtube model with recent improvements

    SciTech Connect

    Paraschivoiu, I.; Delclaux, F.

    1983-05-01

    The objective of the present paper is to show the new capabilities of the double multiple streamtube (DMS) model for predicting the aerodynamic loads and performance of the Darrieus vertical-axis turbine. The original DMS model has been improved (DMSV model) by considering the variation in the upwind and downwind induced velocities as a function of the azimuthal angle for each streamtube. A comparison is made of the rotor performance for several blade geometries (parabola, catenary, troposkien, and Sandia shape). A new formulation is given for an approximate troposkien shape by considering the effect of the gravitational field. The effects of three NACA symmetrical profiles, 0012, 0015 and 0018, on the aerodynamic performance of the turbine are shown. Finally, a semiempirical dynamic-stall model has been incorporated and a better approximation obtained for modeling the local aerodynamic forces and performance for a Darrieus rotor.

  4. Double multiple streamtube model with recent improvements

    SciTech Connect

    Paraschivoiu, I.; Delclaux, F.

    1983-05-01

    The objective is to show the new capabilities of the double multiple streamtube (DMS) model for predicting the aerodynamic loads and performance of the Darrieus vertical-axis turbine. The original DMS model has been improved (DMSV model) by considering the variation in the upwind and downwind induced velocities as a function of the azimuthal angle for each streamtube. A comparison is made of the rotor performance for several blade geometries (parabola, catenary, troposkien, and Sandia shape). A new formulation is given for an approximate troposkien shape by considering the effect of the gravitational field. The effects of three NACA symmetrical profiles, 0012, 0015 and 0018, on the aerodynamic performance of the turbine are shown. Finally, a semiempirical dynamic-stall model has been incorporated and a better approximation obtained for modeling the local aerodynamic forces and performance for a Darrieus rotor.

  5. Improving physical health monitoring for patients with chronic mental health problems who receive antipsychotic medications

    PubMed Central

    Abdallah, Nihad; Conn, Rory; Latif Marini, Abdel

    2016-01-01

    Physical health monitoring is an integral part of caring for patients with mental health problems. It is proven that serious physical health problems are more common among patients with severe mental health illness (SMI), this monitoring can be challenging and there is a need for improvement. The project aimed at improving the physical health monitoring among patients with SMI who are receiving antipsychotic medications. The improvement process focused on ensuring there is a good communication with general practitioners (GPs) as well as patient's education and education of care home staff. GP letters requesting physical health monitoring were updated; care home staff and patients were given more information about the value of regular physical health monitoring. There was an improvement in patients' engagement with the monitoring and the monitoring done by GPs was more adherent to local and national guidelines and was communicated with the mental health service.

  6. Improving physical health monitoring for patients with chronic mental health problems who receive antipsychotic medications.

    PubMed

    Abdallah, Nihad; Conn, Rory; Latif Marini, Abdel

    2016-01-01

    Physical health monitoring is an integral part of caring for patients with mental health problems. It is proven that serious physical health problems are more common among patients with severe mental health illness (SMI), this monitoring can be challenging and there is a need for improvement. The project aimed at improving the physical health monitoring among patients with SMI who are receiving antipsychotic medications. The improvement process focused on ensuring there is a good communication with general practitioners (GPs) as well as patient's education and education of care home staff. GP letters requesting physical health monitoring were updated; care home staff and patients were given more information about the value of regular physical health monitoring. There was an improvement in patients' engagement with the monitoring and the monitoring done by GPs was more adherent to local and national guidelines and was communicated with the mental health service. PMID:27559474

  7. A Goddard Multi-Scale Modeling System with Unified Physics

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo

    2010-01-01

    A multi-scale modeling system with unified physics has been developed at NASA Goddard Space Flight Center (GSFC). The system consists of an MMF, the coupled NASA Goddard finite-volume GCM (fvGCM) and Goddard Cumulus Ensemble model (GCE, a CRM); the state-of-the-art Weather Research and Forecasting model (WRF) and the stand alone GCE. These models can share the same microphysical schemes, radiation (including explicitly calculated cloud optical properties), and surface models that have been developed, improved and tested for different environments. In this talk, I will present: (1) A brief review on GCE model and its applications on the impact of the aerosol on deep precipitation processes, (2) The Goddard MMF and the major difference between two existing MMFs (CSU MMF and Goddard MMF), and preliminary results (the comparison with traditional GCMs), and (3) A discussion on the Goddard WRF version (its developments and applications). We are also performing the inline tracer calculation to comprehend the ph ysical processes (i.e., boundary layer and each quadrant in the boundary layer) related to the development and structure of hurricanes and mesoscale convective systems.

  8. Intentional Development: A Model to Guide Lifelong Physical Activity

    ERIC Educational Resources Information Center

    Cherubini, Jeffrey M.

    2009-01-01

    Framed in the context of researching influences on physical activity and actually working with individuals and groups seeking to initiate, increase or maintain physical activity, the purpose of this review is to present the model of Intentional Development as a multi-theoretical approach to guide research and applied work in physical activity.…

  9. Exercise can improve physical self perceptions in adolescents with low motor competence.

    PubMed

    McIntyre, Fleur; Chivers, Paola; Larkin, Dawne; Rose, Elizabeth; Hands, Beth

    2015-08-01

    Adolescents with low motor competence have diminished perceptions of their physical self and tend to avoid physical activities. This study examined the outcomes of an exercise intervention that focused on improving aerobic fitness, strength, and self-perceptions in the physical domain in adolescents with poor motor coordination. The sample included 35 adolescents with low motor competence, comprising boys (n = 25) and girls (n = 10) ranging in age from 13 to 17 years, who attended two sessions per week in the 13 week exercise intervention study (AMP it up). Physical self-perceptions were measured before and after the intervention using the Physical Self Perception Profile and Perceived Importance Profile. Significant improvements in perceived Physical Condition, Attractive Body and Physical Strength sub domain scores were identified between pre and post-test. Adjusting for age, gender, BMI and attendance, regression analyses revealed that Attractive Body was the strongest predictor of Physical Self Worth at pre-test, joined by Physical Condition at post-test. This exercise intervention had a positive impact on adolescent physical self-perceptions, in particular males, with improvements in those sub domains specifically related to the exercise program. Changes in specific aspects of Physical Self Worth can be facilitated by exercise interventions, after a relatively short period of time, in adolescents with poor motor coordination. PMID:25543182

  10. Implementing active-learning strategies to improve physics learning in Latin America

    NASA Astrophysics Data System (ADS)

    Alarcon, Hugo; Zavala, G.; Fernandez, R.; Benegas, J.

    2006-12-01

    It is evident that the most effective active-learning strategies to improve physics learning at the college level have been developed in the United States. Recently, some universities in Latin America have begun adopting such methods as a part of institutional projects, or motivated by national projects led by education authorities. In this work we will present two cases, a large-scale implementation of Tutorials in Introductory Physics (1) in Mexico supported by the institution as a part of a change in its educational model, and a medium-scale implementation of this method in Chile supported by the national government. In both experiences, the professors involved in the educational experience have previously participated in a training workshop that prepared them for implementing this strategy in the classroom. The training workshop, described elsewhere (2), was designed also under active learning premises, so teachers completed the proposed activities in the same way as their students will do. We will present the first results of these two projects. References: (1) McDermott, L. C., Shaffer, P. S., & PER (1998). "Tutorials in Introductory Physics", Prentice Hall, translated as "Tutoriales para Física Introductoria" (2001) Prentice Hall, Buenos Aires.. (2) Zavala, G., Alarcón, H. and Benegas, J. (2005). "Innovative training of in-service teachers for active learning: A short teacher development course based on Physics Education Research", accepted for publication, J. of Sc. Teach. Ed. This work has been partially supported by Tecnológico de Monterrey through the Chair in Physics Education Research and by MECE Educación Superior Program (Chile).

  11. Possibilities: A framework for modeling students' deductive reasoning in physics

    NASA Astrophysics Data System (ADS)

    Gaffney, Jonathan David Housley

    possibilities framework provides. For example, this framework allows us to detect subtle differences in students' reasoning errors, even when those errors result in the same final answer. It also illuminates how simply mentioning overlooked quantities can instigate new lines of student reasoning. It allows us to better understand how well-known psychological biases, such as the belief bias, affect the reasoning process by preventing reasoners from fleshing out all of the possibilities. The possibilities framework also allows us to track student discussions about physics, revealing the need for all parties in communication to use the same set of possibilities in the conversations to facilitate successful understanding. The framework also suggests some of the influences that affect how reasoners choose between possible solutions to a given problem. This new framework for understanding how students reason when solving conceptual physics problems opens the door to a significant field of research. The framework itself needs to be further tested and developed, but it provides substantial suggestions for instructional interventions. If we hope to improve student reasoning in physics, the possibilities framework suggests that we are perhaps best served by teaching students how to fully flesh out the possibilities in every situation. This implies that we need to ensure students have a deep understanding of all of the implied possibilities afforded by the fundamental principles that are the cornerstones of the models we teach in physics classes.

  12. A Physically Based Runoff Routing Model for Land Surface and Earth System Models

    SciTech Connect

    Li, Hongyi; Wigmosta, Mark S.; Wu, Huan; Huang, Maoyi; Ke, Yinghai; Coleman, Andre M.; Leung, Lai-Yung R.

    2013-06-13

    A new physically based runoff routing model, called the Model for Scale Adaptive River Transport (MOSART), has been developed to be applicable across local, regional, and global scales. Within each spatial unit, surface runoff is first routed across hillslopes and then discharged along with subsurface runoff into a ‘‘tributary subnetwork’’ before entering the main channel. The spatial units are thus linked via routing through the main channel network, which is constructed in a scale-consistent way across different spatial resolutions. All model parameters are physically based, and only a small subset requires calibration.MOSART has been applied to the Columbia River basin at 1/ 168, 1/ 88, 1/ 48, and 1/ 28 spatial resolutions and was evaluated using naturalized or observed streamflow at a number of gauge stations. MOSART is compared to two other routing models widely used with land surface models, the River Transport Model (RTM) in the Community Land Model (CLM) and the Lohmann routing model, included as a postprocessor in the Variable Infiltration Capacity (VIC) model package, yielding consistent performance at multiple resolutions. MOSART is further evaluated using the channel velocities derived from field measurements or a hydraulic model at various locations and is shown to be capable of producing the seasonal variation and magnitude of channel velocities reasonably well at different resolutions. Moreover, the impacts of spatial resolution on model simulations are systematically examined at local and regional scales. Finally, the limitations ofMOSART and future directions for improvements are discussed.

  13. An improved ephemeris and physical elements of ER Vul

    NASA Astrophysics Data System (ADS)

    Harmanec, P.; Božić, H.; Thanjavur, K.; Robb, R. M.; Ruždjak, D.; Sudar, D.

    2004-02-01

    New photoelectric U B{V} and BV RI observations, secured during August-November of 2002 at two observatories distant in local time are analyzed together with two earlier photometric data sets and all available radial velocities to derive the most accurate ephemeris of the binary and to set limits on its basic physical elements. These observations were obtained as a support for a high-dispersion spectroscopic study, results of which will be published separately. It was found that radial velocities and photometric observations spanning 53 years can be reconciled with the linear ephemeris T_prim.min.=HJD 2 440 182.25628(46) + 0698095113(29)d × E, where the rms errors of the last digits are given in brackets. Masses of the stars are 1.02 \\fms and 0.97 \\fms and the binary separation is 4.170 R⊙. There is still a large uncertainty in the stellar radii. We also report the discovery of rapid light variations on a time scale of hours seen in the U band light curve and offer a few thoughts on the future investigation of this binary. This research is based on photoelectric observations from Hvar and University of Victoria Observatories. Table 4 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/415/289

  14. Improving residential miscellaneous electrical load modeling

    NASA Astrophysics Data System (ADS)

    Burgett, Joseph M.

    Over the past 30 years, the intensity of all major energy use categories has decreased in the residential market with the exception of miscellaneous electrical loads (MELs). MELs include primarily 120V plug-loads and some hard wired loads. MELs stand alone as the only category in which energy intensity has steadily increased over time. While MELs constitute approximately 15% - 25% of a typical home's total energy use, it is projected to increase to 36% by 2020. Despite the significant percentage of the home's total load, MELs are the least researched energy end use category and most poorly modeled. The Home Energy Rating System (HERS) index is the most widely used residential energy rating system and uses a simple square foot multiplier to model MELs. This study improves upon the HERS model by including occupant characteristics as part of the MEL model. This "new model" was created by regressing and explanatory equation from the Energy Information Agency's Residential Energy Consumption Survey (RECS). The RECS has a very large sample size of 12,083 respondents who answered over 90 pages of questions related to home structure, appliances they own and demographical information. The information provided by the respondents was used to calculate a MEL for all the RECS households. A stepwise regression process was used to create a model that included size of the home, household income, number of household members and presence of a home business to predict the MEL. The new model was then tested on 24 actual homes to compare its predictive power with the HERS model. The new model more closely predicted the actual MEL for 17 of the 24 test houses (71%). Additionally, the standard deviation or the "tightness of fit" of the new model was less than half of the HERS model when used on the RECS respondents. What this study found was that using occupant characteristics to supplement a square foot multiplier significantly increased the precision of MEL modeling.

  15. A Physically-based Tropical Cyclone Rainfall Model

    NASA Astrophysics Data System (ADS)

    Lu, P.; Lin, N.; Smith, J. A.; Emanuel, K.; Chavas, D. R.

    2015-12-01

    Rainfall from tropical cyclones (TCs) can cause extreme flooding. Predicting and understanding TC rainfall is thus important but has received relatively less attention, compared to the wind and surge. Here we present a simple, physically-based rainfall model, where the rain rate is obtained from estimated vertical velocity and specific humidity in the lower troposphere. The involved rainfall mechanisms include: 1) vertical motion at the top of the boundary layer owing to frictional effects; 2) vertical motion in the middle troposphere resulted from the time evolution of the gradient wind; 3) vertical motion forced by topographic interaction as well as 4) baroclinic effect. The model has been applied to Texas and shown to generate rainfall statistics comparable to observations (Zhu et al, 2013). Here we further evaluate this model on an event basis; case studies include Hurricane Irene (2011) and Isabel (2003). Without any calibration, hourly rainfall estimated from this model compares well with those from full numerical weather prediction model (WRF) as well as rainfall climatology models (R-CLIPPER and PHRaM). This comparison demonstrates the model's ability to capture main TC rainfall mechanisms, and it can be used as an effective tool to study the relative contribution of each rainfall mechanism. Ongoing work includes possibly improving the rainfall model by coupling it with a more accurate boundary layer model. Given its high computational efficiency, this rainfall model can be applied to large numbers of ensemble or synthetic simulations. This study fits into our long-term goal to quantify the risk of inland flooding associated with landfalling TCs.

  16. Improving data transfer for model coupling

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Liu, L.; Yang, G.; Li, R.; Wang, B.

    2015-10-01

    Data transfer, which means transferring data fields between two component models or rearranging data fields among processes of the same component model, is a fundamental operation of a coupler. Most of state-of-the-art coupler versions currently use an implementation based on the point-to-point (P2P) communication of the Message Passing Interface (MPI) (call such an implementation "P2P implementation" for short). In this paper, we reveal the drawbacks of the P2P implementation, including low communication bandwidth due to small message size, variable and big number of MPI messages, and jams during communication. To overcome these drawbacks, we propose a butterfly implementation for data transfer. Although the butterfly implementation can outperform the P2P implementation in many cases, it degrades the performance in some cases because the total message size transferred by the butterfly implementation is larger than that by the P2P implementation. To make the data transfer completely improved, we design and implement an adaptive data transfer library that combines the advantages of both butterfly implementation and P2P implementation. Performance evaluation shows that the adaptive data transfer library significantly improves the performance of data transfer in most cases and does not decrease the performance in any cases. Now the adaptive data transfer library is open to the public and has been imported into a coupler version C-Coupler1 for performance improvement of data transfer. We believe that it can also improve other coupler versions.

  17. An Improved Analytic Model for Microdosimeter Response

    NASA Technical Reports Server (NTRS)

    Shinn, Judy L.; Wilson, John W.; Xapsos, Michael A.

    2001-01-01

    An analytic model used to predict energy deposition fluctuations in a microvolume by ions through direct events is improved to include indirect delta ray events. The new model can now account for the increase in flux at low lineal energy when the ions are of very high energy. Good agreement is obtained between the calculated results and available data for laboratory ion beams. Comparison of GCR (galactic cosmic ray) flux between Shuttle TEPC (tissue equivalent proportional counter) flight data and current calculations draws a different assessment of developmental work required for the GCR transport code (HZETRN) than previously concluded.

  18. Improving Localization Accuracy: Successive Measurements Error Modeling

    PubMed Central

    Abu Ali, Najah; Abu-Elkheir, Mervat

    2015-01-01

    Vehicle self-localization is an essential requirement for many of the safety applications envisioned for vehicular networks. The mathematical models used in current vehicular localization schemes focus on modeling the localization error itself, and overlook the potential correlation between successive localization measurement errors. In this paper, we first investigate the existence of correlation between successive positioning measurements, and then incorporate this correlation into the modeling positioning error. We use the Yule Walker equations to determine the degree of correlation between a vehicle’s future position and its past positions, and then propose a p-order Gauss–Markov model to predict the future position of a vehicle from its past p positions. We investigate the existence of correlation for two datasets representing the mobility traces of two vehicles over a period of time. We prove the existence of correlation between successive measurements in the two datasets, and show that the time correlation between measurements can have a value up to four minutes. Through simulations, we validate the robustness of our model and show that it is possible to use the first-order Gauss–Markov model, which has the least complexity, and still maintain an accurate estimation of a vehicle’s future location over time using only its current position. Our model can assist in providing better modeling of positioning errors and can be used as a prediction tool to improve the performance of classical localization algorithms such as the Kalman filter. PMID:26140345

  19. Improving Agricultural Drought Monitoring in East Africa with Unbiased Rainfall Fields and Detailed Land Surface Physics

    NASA Astrophysics Data System (ADS)

    McNally, A.; Yatheendradas, S.; Peters-Lidard, C. D.; Michaelsen, J.

    2010-12-01

    Monitoring drought is particularly challenging within rainfed agricultural and pastoral systems, where it can serve the greatest need. Such locations often have sparse or non-existent ground based measurements of precipitation, evapotranspiration (ET), and soil moisture. For more effective drought monitoring with limited hydroclimate observations, we simulate land surface states using the Community Noah Land Surface Model forced with different merged rainfall products inside a Land Information System (LIS). Using model outputs we will answer the questions: How sensitive are soil moisture and ET fields to differences in rainfall forcing and model physics? What are acceptable drought-specific tradeoffs between near-real time availability and skill of rainfall data? Preliminary results with the African Rainfall Estimation Algorithm Version 2 (RFE2.0) outperformed global products, suggesting that sub-global rainfall estimates are the way forward for regional drought monitoring. Specifically, the Noah model forced with RFE2.0 better resolved the heterogeneous patterns in crop stress than the Famine Early Warning System Network (FEWS NET) operational Water Requirement Satisfaction Index (WRSI) model. To further investigate the improvement in drought monitoring while maintaining timeliness, we unbias (using Africa specific climatology) the precipitation products from CPC Merged Analysis of Precipitation (CMAP), Tropical Rainfall Measurement Mission (TRMM), and RFE2.0. The skill (relative accuracy) and reliability (average agreement) of the unbiased rainfall are calculated against an unbiased precipitation product augmented with station data from Ethiopia and Kenya. Soil moisture and ET fields from Noah are compared to the operational FEWS NET WRSI, soil water anomaly index, and the World Food Program’s Crop and Food Security Assessment Mission reports. We anticipate that the unbiased rainfall fields will improve the accuracy, spatio-temporal resolution, and

  20. TOWARD EFFICIENT RIPARIAN RESTORATION: INTEGRATING ECONOMIC, PHYSICAL, AND BIOLOGICAL MODELS

    EPA Science Inventory

    This paper integrates economic, biological, and physical models to determine the efficient combination and spatial allocation of conservation efforts for water quality protection and salmonid habitat enhancement in the Grande Ronde basin, Oregon. The integrated modeling system co...

  1. Acute Exercise Improves Physical Sexual Arousal in Women Taking Antidepressants

    PubMed Central

    Lorenz, Tierney A.; Meston, Cindy M.

    2012-01-01

    Background Antidepressants can impair sexual arousal. Exercise increases genital arousal in healthy women, likely due to increasing sympathetic nervous system (SNS) activity. Purpose Test if exercise increases genital arousal in women taking antidepressants, including selective serotonin reuptake inhibitors (SSRIs), which suppress SNS activity, and selective serotonin and norepinephrine reuptake inhibitors (SNRIs), which suppress the SNS less. Method Women reporting antidepressant-related sexual arousal problems (N=47) participated in three counterbalanced sessions where they watched an erotic film while we recorded genital and SNS arousal. In two sessions, women exercised for 20 min, either 5 or 15 min prior to the films. Results During the no-exercise condition, women taking SSRIs showed significantly less genital response than women taking SNRIs. Exercise prior to sexual stimuli increased genital arousal in both groups. Women reporting greater sexual dysfunction had larger increases in genital arousal post-exercise. For women taking SSRIs, genital arousal was linked to SNS activity. Conclusions Exercise may improve antidepressant-related genital arousal problems. PMID:22403029

  2. Improving assessment of daily energy expenditure by identifying types of physical activity with a single accelerometer.

    PubMed

    Bonomi, A G; Plasqui, G; Goris, A H C; Westerterp, K R

    2009-09-01

    Accelerometers are often used to quantify the acceleration of the body in arbitrary units (counts) to measure physical activity (PA) and to estimate energy expenditure. The present study investigated whether the identification of types of PA with one accelerometer could improve the estimation of energy expenditure compared with activity counts. Total energy expenditure (TEE) of 15 subjects was measured with the use of double-labeled water. The physical activity level (PAL) was derived by dividing TEE by sleeping metabolic rate. Simultaneously, PA was measured with one accelerometer. Accelerometer output was processed to calculate activity counts per day (AC(D)) and to determine the daily duration of six types of common activities identified with a classification tree model. A daily metabolic value (MET(D)) was calculated as mean of the MET compendium value of each activity type weighed by the daily duration. TEE was predicted by AC(D) and body weight and by AC(D) and fat-free mass, with a standard error of estimate (SEE) of 1.47 MJ/day, and 1.2 MJ/day, respectively. The replacement in these models of AC(D) with MET(D) increased the explained variation in TEE by 9%, decreasing SEE by 0.14 MJ/day and 0.18 MJ/day, respectively. The correlation between PAL and MET(D) (R(2) = 51%) was higher than that between PAL and AC(D) (R(2) = 46%). We conclude that identification of activity types combined with MET intensity values improves the assessment of energy expenditure compared with activity counts. Future studies could develop models to objectively assess activity type and intensity to further increase accuracy of the energy expenditure estimation. PMID:19556460

  3. An Empirical-Mathematical Modelling Approach to Upper Secondary Physics

    ERIC Educational Resources Information Center

    Angell, Carl; Kind, Per Morten; Henriksen, Ellen K.; Guttersrud, Oystein

    2008-01-01

    In this paper we describe a teaching approach focusing on modelling in physics, emphasizing scientific reasoning based on empirical data and using the notion of multiple representations of physical phenomena as a framework. We describe modelling activities from a project (PHYS 21) and relate some experiences from implementation of the modelling…

  4. Modeling instruction: Positive attitudinal shifts in introductory physics measured with CLASS

    NASA Astrophysics Data System (ADS)

    Brewe, Eric; Kramer, Laird; O'Brien, George

    2009-06-01

    Among the most surprising findings in Physics Education Research is the lack of positive results on attitudinal measures, such as Colorado Learning Attitudes about Science Survey (CLASS) and Maryland Physics Expectations Survey (MPEX). The uniformity with which physics teaching manages to negatively shift attitudes toward physics learning is striking. Strategies which have been shown to improve conceptual learning, such as interactive engagement and studio-format classes, provide more authentic science experiences for students; yet do not seem to be sufficient to produce positive attitudinal results. Florida International University’s Physics Education Research Group has implemented Modeling Instruction in University Physics classes as part of an overall effort toward building a research and learning community. Modeling Instruction is explicitly designed to engage students in scientific practices that include model building, validation, and revision. Results from a preinstruction/postinstruction CLASS measurement show attitudinal improvements through both semesters of an introductory physics sequence, as well as over the entire two-course sequence. In this Brief Report, we report positive shifts from the CLASS in one section of a modeling-based introductory physics sequence, for both mechanics (N=22) and electricity and magnetism (N=23) . Using the CLASS results and follow up interviews, we examine how these results reflect on modeling instruction and the unique student community and population at FIU.

  5. Application of Improved Radiation Modeling to General Circulation Models

    SciTech Connect

    Michael J Iacono

    2011-04-07

    This research has accomplished its primary objectives of developing accurate and efficient radiation codes, validating them with measurements and higher resolution models, and providing these advancements to the global modeling community to enhance the treatment of cloud and radiative processes in weather and climate prediction models. A critical component of this research has been the development of the longwave and shortwave broadband radiative transfer code for general circulation model (GCM) applications, RRTMG, which is based on the single-column reference code, RRTM, also developed at AER. RRTMG is a rigorously tested radiation model that retains a considerable level of accuracy relative to higher resolution models and measurements despite the performance enhancements that have made it possible to apply this radiation code successfully to global dynamical models. This model includes the radiative effects of all significant atmospheric gases, and it treats the absorption and scattering from liquid and ice clouds and aerosols. RRTMG also includes a statistical technique for representing small-scale cloud variability, such as cloud fraction and the vertical overlap of clouds, which has been shown to improve cloud radiative forcing in global models. This development approach has provided a direct link from observations to the enhanced radiative transfer provided by RRTMG for application to GCMs. Recent comparison of existing climate model radiation codes with high resolution models has documented the improved radiative forcing capability provided by RRTMG, especially at the surface, relative to other GCM radiation models. Due to its high accuracy, its connection to observations, and its computational efficiency, RRTMG has been implemented operationally in many national and international dynamical models to provide validated radiative transfer for improving weather forecasts and enhancing the prediction of global climate change.

  6. Improving Distributed Diagnosis Through Structural Model Decomposition

    NASA Technical Reports Server (NTRS)

    Bregon, Anibal; Daigle, Matthew John; Roychoudhury, Indranil; Biswas, Gautam; Koutsoukos, Xenofon; Pulido, Belarmino

    2011-01-01

    Complex engineering systems require efficient fault diagnosis methodologies, but centralized approaches do not scale well, and this motivates the development of distributed solutions. This work presents an event-based approach for distributed diagnosis of abrupt parametric faults in continuous systems, by using the structural model decomposition capabilities provided by Possible Conflicts. We develop a distributed diagnosis algorithm that uses residuals computed by extending Possible Conflicts to build local event-based diagnosers based on global diagnosability analysis. The proposed approach is applied to a multitank system, and results demonstrate an improvement in the design of local diagnosers. Since local diagnosers use only a subset of the residuals, and use subsystem models to compute residuals (instead of the global system model), the local diagnosers are more efficient than previously developed distributed approaches.

  7. Building an advanced climate model: Program plan for the CHAMMP (Computer Hardware, Advanced Mathematics, and Model Physics) Climate Modeling Program

    SciTech Connect

    Not Available

    1990-12-01

    The issue of global warming and related climatic changes from increasing concentrations of greenhouse gases in the atmosphere has received prominent attention during the past few years. The Computer Hardware, Advanced Mathematics, and Model Physics (CHAMMP) Climate Modeling Program is designed to contribute directly to this rapid improvement. The goal of the CHAMMP Climate Modeling Program is to develop, verify, and apply a new generation of climate models within a coordinated framework that incorporates the best available scientific and numerical approaches to represent physical, biogeochemical, and ecological processes, that fully utilizes the hardware and software capabilities of new computer architectures, that probes the limits of climate predictability, and finally that can be used to address the challenging problem of understanding the greenhouse climate issue through the ability of the models to simulate time-dependent climatic changes over extended times and with regional resolution.

  8. An improved gravity model for Mars: Goddard Mars Model 1

    NASA Technical Reports Server (NTRS)

    Smith, D. E.; Lerch, F. J.; Nerem, R. S.; Zuber, M. T.; Patel, G. B.; Fricke, S. K.; Lemoine, F. G.

    1993-01-01

    Doppler tracking data of three orbiting spacecraft have been reanalyzed to develop a new gravitational field model for the planet Mars, Goddard Mars Model 1 (GMM-1). This model employs nearly all available data, consisting of approximately 1100 days of S band tracking data collected by NASA's Deep Space Network from the Mariner 9 and Viking 1 and Viking 2 spacecraft, in seven different orbits, between 1971 and 1979. GMM-1 is complete to spherical harmonic degree and order 50, which corresponds to a half-wavelength spatial resolution of 200-300 km where the data permit. GMM-1 represents satellite orbits with considerably better accuracy than previous Mars gravity models and shows greater resolution of identifiable geological structures. The notable improvement in GMM-1 over previous models is a consequence of several factors: improved computational capabilities, the use of otpimum weighting and least squares collocation solution techniques which stabilized the behavior of the solution at high degree and order, and the use of longer satellite arcs than employed in previous solutions that were made possible by improved force and measurement models. The inclusion of X band tracking data from the 379-km altitude, nnear-polar orbiting Mars Observer spacecraft should provide a significant improvement over GMM-1, particularly at high latitudes where current data poorly resolve the gravitational signature of the planet.

  9. Modeling the Discrimination Power of Physics Items

    ERIC Educational Resources Information Center

    Mesic, Vanes

    2011-01-01

    For the purposes of tailoring physics instruction in accordance with the needs and abilities of the students it is useful to explore the knowledge structure of students of different ability levels. In order to precisely differentiate the successive, characteristic states of student achievement it is necessary to use test items that possess…

  10. Optimization of microtubule affinity regulating kinase (MARK) inhibitors with improved physical properties.

    PubMed

    Sloman, David L; Noucti, Njamkou; Altman, Michael D; Chen, Dapeng; Mislak, Andrea C; Szewczak, Alexander; Hayashi, Mansuo; Warren, Lee; Dellovade, Tammy; Wu, Zhenhua; Marcus, Jacob; Walker, Deborah; Su, Hua-Poo; Edavettal, Suzanne C; Munshi, Sanjeev; Hutton, Michael; Nuthall, Hugh; Stanton, Matthew G

    2016-09-01

    Inhibition of microtubule affinity regulating kinase (MARK) represents a potentially attractive means of arresting neurofibrillary tangle pathology in Alzheimer's disease. This manuscript outlines efforts to optimize a pyrazolopyrimidine series of MARK inhibitors by focusing on improvements in potency, physical properties and attributes amenable to CNS penetration. A unique cylcyclohexyldiamine scaffold was identified that led to remarkable improvements in potency, opening up opportunities to reduce MW, Pgp efflux and improve pharmacokinetic properties while also conferring improved solubility. PMID:27491711

  11. “Using Statistical Comparisons between SPartICus Cirrus Microphysical Measurements, Detailed Cloud Models, and GCM Cloud Parameterizations to Understand Physical Processes Controlling Cirrus Properties and to Improve the Cloud Parameterizations”

    SciTech Connect

    Woods, Sarah

    2015-12-01

    The dual objectives of this project were improving our basic understanding of processes that control cirrus microphysical properties and improvement of the representation of these processes in the parameterizations. A major effort in the proposed research was to integrate, calibrate, and better understand the uncertainties in all of these measurements.

  12. Houttuynia cordata Extract Improves Physical Endurance Performance by Regulating Endothelial Production of Nitric Oxide.

    PubMed

    Yang, Ui-Jeong; Maeng, Hyojin; Park, Tae-Sik; Shim, Soon-Mi

    2015-09-01

    Vascular function is mediated by various regulatory molecules, including endothelial nitric oxide (NO), which regulates the vasodilation of smooth muscle cells. We investigated whether standardized Houttuynia cordata extract (SHCE) could improve physical endurance performance by regulating the endothelial production of NO. For the standardization of Houttuynia cordata (HC) extract, its bioactive components were identified and quantified using ultraperformance liquid chromatography-mass spectrometry. Bioaccessibility and biological activity were measured by the in vitro digestion model system and free radical scavenging capacity, respectively. The vascular function in the endothelium was assessed by the phosphorylation of endothelial nitric oxide synthase (eNOS). A preliminary clinical trial was carried out to assess the physical endurance performance. HC extract was standardized to bioactive components, including chlorogenic acid, rutin, and quercitrin, with the concentration of 5.53, 6.09, and 16.15 mg from 1 g of dry weight, respectively. Bioaccessibility was 33.17%, 31.67%, and 11.18% for chlorogenic acid, rutin, and quercitrin, respectively. Antioxidant activities of SHCE were expressed as vitamin C equivalent antioxidant capacity in 55.81 and 17.23 mg/g of HC extract using ABTS and DPPH scavenging assay, respectively. In human aortic endothelial cells, insulin-mediated phosphorylation of eNOS was increased by SHCE in the presence of palmitate. However, the expression of blood pressure-regulating genes was not altered. The level of blood lactate concentration and the heart rate of subjects who drank SHCE were lower than those of subjects who drank plain water. Oxygen uptake from subjects drinking SHCE was slightly higher than that from those who drank plain water. This study demonstrated that SHCE decreased heart rate and blood lactate, increased oxygen uptake, and improved physical performance, presumably due to the increased NO production. PMID:25923355

  13. Impact Flash Physics: Modeling and Comparisons With Experimental Results

    NASA Astrophysics Data System (ADS)

    Rainey, E.; Stickle, A. M.; Ernst, C. M.; Schultz, P. H.; Mehta, N. L.; Brown, R. C.; Swaminathan, P. K.; Michaelis, C. H.; Erlandson, R. E.

    2015-12-01

    Hypervelocity impacts frequently generate an observable "flash" of light with two components: a short-duration spike due to emissions from vaporized material, and a long-duration peak due to thermal emissions from expanding hot debris. The intensity and duration of these peaks depend on the impact velocity, angle, and the target and projectile mass and composition. Thus remote sensing measurements of planetary impact flashes have the potential to constrain the properties of impacting meteors and improve our understanding of impact flux and cratering processes. Interpreting impact flash measurements requires a thorough understanding of how flash characteristics correlate with impact conditions. Because planetary-scale impacts cannot be replicated in the laboratory, numerical simulations are needed to provide this insight for the solar system. Computational hydrocodes can produce detailed simulations of the impact process, but they lack the radiation physics required to model the optical flash. The Johns Hopkins University Applied Physics Laboratory (APL) developed a model to calculate the optical signature from the hot debris cloud produced by an impact. While the phenomenology of the optical signature is understood, the details required to accurately model it are complicated by uncertainties in material and optical properties and the simplifications required to numerically model radiation from large-scale impacts. Comparisons with laboratory impact experiments allow us to validate our approach and to draw insight regarding processes that occur at all scales in impact events, such as melt generation. We used Sandia National Lab's CTH shock physics hydrocode along with the optical signature model developed at APL to compare with a series of laboratory experiments conducted at the NASA Ames Vertical Gun Range. The experiments used Pyrex projectiles to impact pumice powder targets with velocities ranging from 1 to 6 km/s at angles of 30 and 90 degrees with respect to

  14. Improving Physical Fitness of Individuals with Intellectual and Developmental Disability through a Virtual Reality Intervention Program

    ERIC Educational Resources Information Center

    Lotan, Meir; Yalon-Chamovitz, Shira; Weiss, Patrice L.

    2009-01-01

    Individuals with intellectual and developmental disabilities (IDD) are in need of effective physical fitness training programs. The aim was to test the effectiveness of a Virtual Reality (VR)-based exercise program in improving the physical fitness of adults with IDD. A research group (N = 30; mean age = 52.3 plus or minus 5.8 years; moderate IDD…

  15. Physical Activity: A Tool for Improving Health (Part 2-Mental Health Benefits)

    ERIC Educational Resources Information Center

    Gallaway, Patrick J.; Hongu, Nobuko

    2016-01-01

    By promoting physical activities and incorporating them into their community-based programs, Extension professionals are improving the health of individuals, particularly those with limited resources. This article is the second in a three-part series describing the benefits of physical activity for human health: (1) biological health benefits of…

  16. Physical Activity: A Tool for Improving Health (Part 1--Biological Health Benefits)

    ERIC Educational Resources Information Center

    Gallaway, Patrick J.; Hongu, Nobuko

    2015-01-01

    Extension educators have been promoting and incorporating physical activities into their community-based programs and improving the health of individuals, particularly those with limited resources. This article is the first of a three-part series describing the benefits of physical activity for human health: 1) biological health benefits of…

  17. Community-based strength training improves physical function in older women and arthritis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exercise is recognized as a mainstay treatment of arthritis, yet more than 40% of adults with arthritis report no leisure time physical activity participation. The Centers for Disease Control and Prevention is working to identify and promote evidence-based physical activity programs to improve physi...

  18. Testing a Theoretical Model of Immigration Transition and Physical Activity.

    PubMed

    Chang, Sun Ju; Im, Eun-Ok

    2015-01-01

    The purposes of the study were to develop a theoretical model to explain the relationships between immigration transition and midlife women's physical activity and test the relationships among the major variables of the model. A theoretical model, which was developed based on transitions theory and the midlife women's attitudes toward physical activity theory, consists of 4 major variables, including length of stay in the United States, country of birth, level of acculturation, and midlife women's physical activity. To test the theoretical model, a secondary analysis with data from 127 Hispanic women and 123 non-Hispanic (NH) Asian women in a national Internet study was used. Among the major variables of the model, length of stay in the United States was negatively associated with physical activity in Hispanic women. Level of acculturation in NH Asian women was positively correlated with women's physical activity. Country of birth and level of acculturation were significant factors that influenced physical activity in both Hispanic and NH Asian women. The findings support the theoretical model that was developed to examine relationships between immigration transition and physical activity; it shows that immigration transition can play an essential role in influencing health behaviors of immigrant populations in the United States. The NH theoretical model can be widely used in nursing practice and research that focus on immigrant women and their health behaviors. Health care providers need to consider the influences of immigration transition to promote immigrant women's physical activity. PMID:26502554

  19. Simple universal models capture all classical spin physics.

    PubMed

    De las Cuevas, Gemma; Cubitt, Toby S

    2016-03-11

    Spin models are used in many studies of complex systems because they exhibit rich macroscopic behavior despite their microscopic simplicity. Here, we prove that all the physics of every classical spin model is reproduced in the low-energy sector of certain "universal models," with at most polynomial overhead. This holds for classical models with discrete or continuous degrees of freedom. We prove necessary and sufficient conditions for a spin model to be universal and show that one of the simplest and most widely studied spin models, the two-dimensional Ising model with fields, is universal. Our results may facilitate physical simulations of Hamiltonians with complex interactions. PMID:26965624

  20. Improved laser ablation model for asteroid deflection

    NASA Astrophysics Data System (ADS)

    Vasile, Massimiliano; Gibbings, Alison; Watson, Ian; Hopkins, John-Mark

    2014-10-01

    This paper presents an improved laser ablation model and compares the performance - momentum coupling and deflection system mass - of laser ablation against contactless deflection methods based on ion-propulsion. The deflection of an asteroid through laser ablation is achieved by illuminating the surface of the asteroid with high intensity laser light. The absorbed energy induces the sublimation of the surface material and the generation of a plume of gas and ejecta. Similar to a rocket engine, the flow of expelled material produces a continuous and controllable thrust that could be used to modify the trajectory and tumbling motion of the asteroid. Recent results gained from a series of laser ablation experiments were used to improve the sublimation and deflection models. In each experiment a terrestrial olivine sample was ablated, under vacuum, with a 90 W continuous wave laser. The paper presents a model that better fits the outcomes of the experimental campaign, in particular in terms of mass flow rate and spot temperature.

  1. Mapping fluid distribution in a pinch-out reservoir model: A physical modeling study

    NASA Astrophysics Data System (ADS)

    Assis, Carlos A. M.; Ceia, Marco A. R.; Misságia, Roseane M.; Lupinacci, Wagner M.

    2014-10-01

    This work shows the results obtained from seismic physical modeling experiments that image the non-homogeneous, two-phase distribution of immiscible fluids inside a cavity in a pinch-out model. The main goal of this study was to verify how the seismic sections can be used to observe the fluid distribution in this type of reservoir. A high-resolution deconvolution method was applied to improve the image resolution and depth migration correctly positioned the events. Instantaneous attributes were used to assist data interpretation. The results provided an image of the oil-water interface and revealed a complex fluid compartmentalization pattern that was confirmed by numerical modeling simulations. The results of this study should improve the understanding of mapping fluid distributions from seismic sections in pinch-out reservoirs.

  2. Two is better than one: Physical interactions improve motor performance in humans

    NASA Astrophysics Data System (ADS)

    Ganesh, G.; Takagi, A.; Osu, R.; Yoshioka, T.; Kawato, M.; Burdet, E.

    2014-01-01

    How do physical interactions with others change our own motor behavior? Utilizing a novel motor learning paradigm in which the hands of two - individuals are physically connected without their conscious awareness, we investigated how the interaction forces from a partner adapt the motor behavior in physically interacting humans. We observed the motor adaptations during physical interactions to be mutually beneficial such that both the worse and better of the interacting partners improve motor performance during and after interactive practice. We show that these benefits cannot be explained by multi-sensory integration by an individual, but require physical interaction with a reactive partner. Furthermore, the benefits are determined by both the interacting partner's performance and similarity of the partner's behavior to one's own. Our results demonstrate the fundamental neural processes underlying human physical interactions and suggest advantages of interactive paradigms for sport-training and physical rehabilitation.

  3. Two is better than one: Physical interactions improve motor performance in humans

    PubMed Central

    Ganesh, G.; Takagi, A.; Osu, R.; Yoshioka, T.; Kawato, M.; Burdet, E.

    2014-01-01

    How do physical interactions with others change our own motor behavior? Utilizing a novel motor learning paradigm in which the hands of two - individuals are physically connected without their conscious awareness, we investigated how the interaction forces from a partner adapt the motor behavior in physically interacting humans. We observed the motor adaptations during physical interactions to be mutually beneficial such that both the worse and better of the interacting partners improve motor performance during and after interactive practice. We show that these benefits cannot be explained by multi-sensory integration by an individual, but require physical interaction with a reactive partner. Furthermore, the benefits are determined by both the interacting partner's performance and similarity of the partner's behavior to one's own. Our results demonstrate the fundamental neural processes underlying human physical interactions and suggest advantages of interactive paradigms for sport-training and physical rehabilitation. PMID:24452767

  4. Improving Mass Balance Modeling of Benchmark Glaciers

    NASA Astrophysics Data System (ADS)

    van Beusekom, A. E.; March, R. S.; O'Neel, S.

    2009-12-01

    The USGS monitors long-term glacier mass balance at three benchmark glaciers in different climate regimes. The coastal and continental glaciers are represented by Wolverine and Gulkana Glaciers in Alaska, respectively. Field measurements began in 1966 and continue. We have reanalyzed the published balance time series with more modern methods and recomputed reference surface and conventional balances. Addition of the most recent data shows a continuing trend of mass loss. We compare the updated balances to the previously accepted balances and discuss differences. Not all balance quantities can be determined from the field measurements. For surface processes, we model missing information with an improved degree-day model. Degree-day models predict ablation from the sum of daily mean temperatures and an empirical degree-day factor. We modernize the traditional degree-day model as well as derive new degree-day factors in an effort to closer match the balance time series and thus better predict the future state of the benchmark glaciers. For subsurface processes, we model the refreezing of meltwater for internal accumulation. We examine the sensitivity of the balance time series to the subsurface process of internal accumulation, with the goal of determining the best way to include internal accumulation into balance estimates.

  5. Improved Modeling of Soil Biogeochemistry in Permafrost

    NASA Astrophysics Data System (ADS)

    Schaefer, K. M.; Jafarov, E. E.

    2014-12-01

    Modeling frozen biogeochemistry in permafrost soils is a major challenge because using observed Q10 values from incubation studies results in unrealistically high carbon emissions from permafrost. Incubation studies of frozen soil show a rapid decline in respiration as temperature decreases below freezing. Permafrost soils contain 1700 Gt of carbon, most of it frozen in permafrost below the active layer. Models with permafrost carbon in the frozen soil layers show unrealistic losses during spinup with observed Q10 values. Greatly increasing the frozen Q10 eliminates the unrealistic emissions, but suppresses winter respiration below observed values. We used a more physical approach in the Simple Biosphere/Carnegie-Ames-Stanford Approach (SiBCASA) model by separating the simulated soil carbon into three pools: thawed, thin film, and bulk frozen. Carbon transfers between thawed, thin film, and frozen pools are controlled by a curve fit of observed liquid water content in frozen soils as a function of temperature, eliminating the frozen Q10 function entirely. This restricts respiration only to the thawed pools while the frozen and thin film pools remain inactive. SiBCASA reproduces observed fluxes from incubation studies and observed winter fluxes. This new parameterization eliminated unrealistic fluxes of permafrost carbon during spinup and resulted in global total amount of frozen carbon much closer to observed values.

  6. Improving Flood Damage Assessment Models in Italy

    NASA Astrophysics Data System (ADS)

    Amadio, M.; Mysiak, J.; Carrera, L.; Koks, E.

    2015-12-01

    The use of Stage-Damage Curve (SDC) models is prevalent in ex-ante assessments of flood risk. To assess the potential damage of a flood event, SDCs describe a relation between water depth and the associated potential economic damage over land use. This relation is normally developed and calibrated through site-specific analysis based on ex-post damage observations. In some cases (e.g. Italy) SDCs are transferred from other countries, undermining the accuracy and reliability of simulation results. Against this background, we developed a refined SDC model for Northern Italy, underpinned by damage compensation records from a recent flood event. Our analysis considers both damage to physical assets and production losses from business interruptions. While the first is calculated based on land use information, production losses are measured through the spatial distribution of Gross Value Added (GVA). An additional component of the model assesses crop-specific agricultural losses as a function of flood seasonality. Our results show an overestimation of asset damage from non-calibrated SDC values up to a factor of 4.5 for tested land use categories. Furthermore, we estimate that production losses amount to around 6 per cent of the annual GVA. Also, maximum yield losses are less than a half of the amount predicted by the standard SDC methods.

  7. Improvement of the IAU 2000 precession model

    NASA Astrophysics Data System (ADS)

    Capitaine, N.; Wallace, P. T.; Chapront, J.

    2005-03-01

    The IAU 2000 precession consists of the IAU 1976 ecliptic precession (Lieske et al. [CITE], A&A, 58, 1) and the precession part of the IAU 2000A equator adopted by IAU 2000 Resolution B1.6 (Mathews et al. [CITE], J. Geophys. Res., 107, B4, 10.1029/2001JB000390). In this paper we provide a range of new expressions as possible replacements for the IAU 2000 precession. The new expressions are based upon the so-called P03 solution of Capitaine et al. ([CITE], A&A, 412, 567) for the equator and the ecliptic. In addition an improved model for the precession of the equator is discussed. This improved solution was obtained in exactly the same way as P03 but using a refined model for the contributions of the non-rigid Earth (Mathews [CITE], private communication) and revised integration constants for the precession rates resulting from fits to the most recent VLBI data. The paper reports on the procedure that was used for improving the P03 solution and on the comparisons of this solution with the MHB 2000, IAU 2000 and P03 solutions. It also discusses the choices for the solution to be put forward as a replacement for IAU 2000. We concluded that the existing VLBI data were insufficient to provide convincing evidence that the improved solutions would deliver better accuracy than the existing P03 solution, and we recommend retaining P03 as the replacement for IAU 2000. P03, which unlike the IAU 2000 precession is dynamically consistent, has the advantage of already having been used experimentally by a number of groups; the model is recalled in Tables [see full text]- [see full text]. Due to the strong dependence of the precession expressions on the precession rates and of the precession in longitude (or equivalently the celestial CIP X coordinate) on the J2 rate model, we also provide a parameterized P04 solution for these quantities as functions of those parameters. The expressions include the quantities to be used in both the equinox-based and CIO-based (i.e. referred to

  8. Ultravisible warped model from flavor triviality and improved naturalness

    SciTech Connect

    Delaunay, Cedric; Gedalia, Oram; Lee, Seung J.; Perez, Gilad; Ponton, Eduardo

    2011-06-01

    A warped extra-dimensional model, where the standard model Yukawa hierarchy is set by UV physics, is shown to have a sweet spot of parameters with improved experimental visibility and possibly naturalness. Upon marginalizing over all the model parameters, a Kaluza-Klein scale of 2.1 TeV can be obtained at 2{sigma} (95.4% C.L.) without conflicting with electroweak precision measurements. Fitting all relevant parameters simultaneously can relax this bound to 1.7 TeV. In this bulk version of the Rattazzi-Zaffaroni shining model, flavor violation is also highly suppressed, yielding a bound of 2.4 TeV. Nontrivial flavor physics at the LHC in the form of flavor gauge bosons is predicted. The model is also characterized by a depletion of the third-generation couplings--as predicted by the general minimal flavor violation framework--which can be tested via flavor precision measurements. In particular, sizable CP violation in {Delta}B=2 transitions can be obtained, and there is a natural region where B{sub s} mixing is predicted to be larger than B{sub d} mixing, as favored by recent Tevatron data. Unlike other proposals, the new contributions are not linked to Higgs or any scalar exchange processes.

  9. Morphological Evolution of Physical Robots through Model-Free Phenotype Development

    PubMed Central

    Brodbeck, Luzius; Hauser, Simon; Iida, Fumiya

    2015-01-01

    Artificial evolution of physical systems is a stochastic optimization method in which physical machines are iteratively adapted to a target function. The key for a meaningful design optimization is the capability to build variations of physical machines through the course of the evolutionary process. The optimization in turn no longer relies on complex physics models that are prone to the reality gap, a mismatch between simulated and real-world behavior. We report model-free development and evaluation of phenotypes in the artificial evolution of physical systems, in which a mother robot autonomously designs and assembles locomotion agents. The locomotion agents are automatically placed in the testing environment and their locomotion behavior is analyzed in the real world. This feedback is used for the design of the next iteration. Through experiments with a total of 500 autonomously built locomotion agents, this article shows diversification of morphology and behavior of physical robots for the improvement of functionality with limited resources. PMID:26091255

  10. Physical aggression, compromised social support, and 10-year marital outcomes: Testing a relational spillover model.

    PubMed

    Sullivan, Kieran T; Pasch, Lauri A; Lawrence, Erika; Bradbury, Thomas N

    2015-12-01

    The purpose of the present study was to test a relational spillover model of physical aggression whereby physical aggression affects marital outcomes due to its effects on how spouses ask for and provide support to one another. Newlywed couples (n = 172) reported levels of physical aggression over the past year and engaged in interactions designed to elicit social support; marital adjustment, and stability were assessed periodically over the first 10 years of marriage. Multilevel modeling revealed that negative support behavior mediated the relationship between physical aggression and 10-year marital adjustment levels whereas positive support behavior mediated the relationship between physical aggression and divorce status. These findings emphasize the need to look beyond conflict when explaining how aggression affects relationships and when working with couples with a history of physical aggression who are seeking to improve their relationships. PMID:26168263

  11. Mental, physical, and mathematical models in the teaching and learning of physics

    NASA Astrophysics Data System (ADS)

    Greca, Ileana María; Moreira, Marco Antonio

    2002-01-01

    In this paper, we initially discuss the relationships among physical, mathematical, and mental models in the process of constructing and understanding physical theories. We adopt the assumption that comprehension in a particular field of physics is attained when it is possible to predict a physical phenomenon from its physical models without having to previously refer to the mathematical formalism. The physical models constitute the semantic structure of a physical theory and determine the way the classes of phenomena linked to them should be perceived. Within this framework, the first step in order to understand a phenomenon or a process in physics is to construct mental models that will allow the individual to understand the statements that compose the semantic structure of the theory, being necessary, at the same time, to modify the way of perceiving the phenomena by constructing mental models that will permit him to evaluate as true or false the descriptions the theory makes of them. When this double process is attained concerning a particular phenomenon, in such a way that the results of the constructed mental models (predictions and explanations) match those scientifically accepted, one can say that the individual has constructed an adequate mental model of the physical model of the theory. Then, in the light of this discussion, we attempt to interpret the research findings we have obtained so far with college students, regarding mental models and physics education under the framework of Johnson-Laird's mental model theory. The difficulties faced by the students to achieve the understanding of physical theories did not seem to be all of the same level: some are linked to the constraints imposed to the construction of mental models by students' previous knowledge and others, linked to the ways individuals perceive the world, seem to be much more problematic. We argue that teaching should focus on them, at least at introductory level, considering the explicit

  12. Toward a detailed physical modelling of wildfires: physical considerations and numerical results (Invited)

    NASA Astrophysics Data System (ADS)

    Morvan, D.

    2010-12-01

    In introduction to the elaboration of detailed physical models able to reproduce the behaviour of wildfires, we reviewed the physical phenomena and the length scales, contributing to the interaction between atmosphere and fire, between vegetation and fire, i.e. all physical mechanisms affecting the behaviour of a wildfire propagating through a vegetation layer. Two main mechanisms of heat transfer were clearly identified to control the propagation of a line fire through a fuel layer: the radiation heat transfer coming from soot particles located in the flaming zone and the convection heat transfer between the hot gases and the vegetation. The relative importance of these two modes of heat transfer depends on the ratio between two forces: the buoyancy due to the vertical elevation of hot gases above the burning zone and the horizontal wind flow in pushing the hot gases toward the unburned vegetation. For a surface fire propagating through an horizontal fuel layer, the dominance of one mode of heat transfer compared to the other one, is manisfested by the existence of two regimes of propagation: plume dominated fires (when radiation heat transfer is dominant) and wind driven fire (when convection heat transfer is dominant). From the point of view of the prediction concerning the behaviour of these two classes of fire, these two regimes of propagation are not fully equivalent. In some sense, the second one (wind driven fires) is more easily predictable, because its rate of spread (ROS) varies more or less linearly with the wind speed velocity. The improvement of knowledge concerning the domain of existence of these two regimes of fire propagation and the consequences upon the fire behaviour are at the origin of the development of a new class of fire models, based on a full description of the physics governing the coupling between fire, atmosphere and vegetation. In a second part we developed theoretical bases for a “fully” physical model to simulate in detail the

  13. Improved modeling techniques for turbomachinery flow fields

    SciTech Connect

    Lakshminarayana, B.; Fagan, J.R. Jr.

    1995-12-31

    This program has the objective of developing an improved methodology for modeling turbomachinery flow fields, including the prediction of losses and efficiency. Specifically, the program addresses the treatment of the mixing stress tensor terms attributed to deterministic flow field mechanisms required in steady-state Computational Fluid Dynamic (CFD) models for turbomachinery flow fields. These mixing stress tensors arise due to spatial and temporal fluctuations (in an absolute frame of reference) caused by rotor-stator interaction due to various blade rows and by blade-to-blade variation of flow properties. This will be accomplished in a cooperative program by Penn State University and the Allison Engine Company. These tasks include the acquisition of previously unavailable experimental data in a high-speed turbomachinery environment, the use of advanced techniques to analyze the data, and the development of a methodology to treat the deterministic component of the mixing stress tenor.

  14. Improved geometrical model of fringe projection profilometry.

    PubMed

    Huang, Zhengrong; Xi, Jiangtao; Yu, Yanguang; Guo, Qinghua; Song, Limei

    2014-12-29

    The accuracy performance of fringe projection profilometry (FPP) depends on accurate phase-to-height (PTH) mapping and system calibration. The existing PTH mapping is derived based on the condition that the plane formed by axes of camera and projector is perpendicular to the reference plane, and measurement error occurs when the condition is not met. In this paper, a new geometric model for FPP is presented to lift the condition, resulting in a new PTH mapping relationship. The new model involves seven parameters, and a new system calibration method is proposed to determine their values. Experiments are conducted to verify the performance of the proposed technique, showing a noticeable improvement in the accuracy of 3D shape measurement. PMID:25607188

  15. Coupled Facility/Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael

    2015-01-01

    A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at NASA/GSFC there is an analysis to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combination of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

  16. Coupled Facility-Payload Vibration Modeling Improvements

    NASA Technical Reports Server (NTRS)

    Carnahan, Timothy M.; Kaiser, Michael A.

    2015-01-01

    A major phase of aerospace hardware verification is vibration testing. The standard approach for such testing is to use a shaker to induce loads into the payload. In preparation for vibration testing at National Aeronautics and Space Administration/Goddard Space Flight Center an analysis is performed to assess the responses of the payload. A new method of modeling the test is presented that takes into account dynamic interactions between the facility and the payload. This dynamic interaction has affected testing in the past, but been ignored or adjusted for during testing. By modeling the combined dynamics of the facility and test article (payload) it is possible to improve the prediction of hardware responses. Many aerospace test facilities work in similar way to those at NASA/Goddard Space Flight Center. Lessons learned here should be applicable to other test facilities with similar setups.

  17. Impact of assimilating physical oceanographic data on modeled ecosystem dynamics in the California Current System

    NASA Astrophysics Data System (ADS)

    Raghukumar, Kaustubha; Edwards, Christopher A.; Goebel, Nicole L.; Broquet, Gregoire; Veneziani, Milena; Moore, Andrew M.; Zehr, Jon P.

    2015-11-01

    A method to model ocean ecosystems using data-constrained physical circulation estimates is investigated. Physical oceanographic data is assimilated into a Regional Ocean Modeling System implementation of the California Current System using an incremental 4-Dimensional Variational method. The resulting state estimate drives a complex, self-assembling ocean ecosystem model for the year 2003, and results are evaluated against SeaWiFS surface and CalCOFI subsurface observations and with ecosystem model output driven by an unconstrained physical model. While physical data assimilation improves correlation with observations, this method also drives elevated levels of phytoplankton standing stock, leading to a large bias particularly in regions of low mean concentration. We identify two causes for this increase: biological rectification of fluctuating vertical nutrient transport due to gravity wave generation at assimilation cycle initialization and increased nutrient variance on density surfaces. We investigate one and propose other possible remedies for these deleterious side-effects of this data assimilation method.

  18. Improved modeling techniques for turbomachinery flow fields

    SciTech Connect

    Lakshminarayana, B.; Fagan, J.R. Jr.

    1995-10-01

    This program has the objective of developing an improved methodology for modeling turbomachinery flow fields, including the prediction of losses and efficiency. Specifically, the program addresses the treatment of the mixing stress tensor terms attributed to deterministic flow field mechanisms required in steady-state Computational Fluid Dynamic (CFD) models for turbo-machinery flow fields. These mixing stress tensors arise due to spatial and temporal fluctuations (in an absolute frame of reference) caused by rotor-stator interaction due to various blade rows and by blade-to-blade variation of flow properties. These tasks include the acquisition of previously unavailable experimental data in a high-speed turbomachinery environment, the use of advanced techniques to analyze the data, and the development of a methodology to treat the deterministic component of the mixing stress tensor. Penn State will lead the effort to make direct measurements of the momentum and thermal mixing stress tensors in high-speed multistage compressor flow field in the turbomachinery laboratory at Penn State. They will also process the data by both conventional and conditional spectrum analysis to derive momentum and thermal mixing stress tensors due to blade-to-blade periodic and aperiodic components, revolution periodic and aperiodic components arising from various blade rows and non-deterministic (which includes random components) correlations. The modeling results from this program will be publicly available and generally applicable to steady-state Navier-Stokes solvers used for turbomachinery component (compressor or turbine) flow field predictions. These models will lead to improved methodology, including loss and efficiency prediction, for the design of high-efficiency turbomachinery and drastically reduce the time required for the design and development cycle of turbomachinery.

  19. Relativistic models in nuclear and particle physics

    SciTech Connect

    Coester, F.

    1988-01-01

    A comparative overview is presented of different approaches to the construction of phenomenological dynamical models that respect basic principles of quantum theory and relativity. Wave functions defined as matrix elements of products of field operators on one hand and wave functions that are defined as representatives of state vectors in model Hilbert spaces are related differently to observables and dynamical models for these wave functions have each distinct advantages and disadvantages 34 refs.

  20. Improving carbon model phenology using data assimilation

    NASA Astrophysics Data System (ADS)

    Exrayat, Jean-François; Smallman, T. Luke; Bloom, A. Anthony; Williams, Mathew

    2015-04-01

    drivers. DALEC2-GSI showed a more realistic response to climate variability and fire disturbance than DALEC2. DALEC2-GSI more accurately reproduced the assimilated global LAI time series, particularly in areas with high levels of disturbance. This result is supported by more ecologically consistent trait combinations generated by the DALEC2-GSI calibration. In addition, using DALEC2-GSI we are able to map global information on ecosystem traits such as drought tolerance and adaptation to repeated fire disturbance. This demonstrates that utilizing data assimilation provides a useful means of improving the representation of processes within models.

  1. Modelling transport phenomena in a multi-physics context

    NASA Astrophysics Data System (ADS)

    Marra, Francesco

    2015-01-01

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

  2. Modelling transport phenomena in a multi-physics context

    SciTech Connect

    Marra, Francesco

    2015-01-22

    Innovative heating research on cooking, pasteurization/sterilization, defrosting, thawing and drying, often focuses on areas which include the assessment of processing time, evaluation of heating uniformity, studying the impact on quality attributes of the final product as well as considering the energy efficiency of these heating processes. During the last twenty years, so-called electro-heating-processes (radio-frequency - RF, microwaves - MW and ohmic - OH) gained a wide interest in industrial food processing and many applications using the above mentioned technologies have been developed with the aim of reducing processing time, improving process efficiency and, in many cases, the heating uniformity. In the area of innovative heating, electro-heating accounts for a considerable portion of both the scientific literature and commercial applications, which can be subdivided into either direct electro-heating (as in the case of OH heating) where electrical current is applied directly to the food or indirect electro-heating (e.g. MW and RF heating) where the electrical energy is firstly converted to electromagnetic radiation which subsequently generates heat within a product. New software packages, which make easier solution of PDEs based mathematical models, and new computers, capable of larger RAM and more efficient CPU performances, allowed an increasing interest about modelling transport phenomena in systems and processes - as the ones encountered in food processing - that can be complex in terms of geometry, composition, boundary conditions but also - as in the case of electro-heating assisted applications - in terms of interaction with other physical phenomena such as displacement of electric or magnetic field. This paper deals with the description of approaches used in modelling transport phenomena in a multi-physics context such as RF, MW and OH assisted heating.

  3. Renormalization group improved Yennie-Frautschi-Suura theory for Z/sup 0/ physics

    SciTech Connect

    Ward, B.F.L.

    1987-06-01

    Described is a recently developed renormalization group improved version of the program of Yennie, Frautschi and Suura for the exponentiation of infrared divergences in Abelian gauge theories. Particular attention is paid to the relevance of this renormalization group improved exponentiation to Z/sup 0/ physics at the SLC and LEP.

  4. Physical Activity Strategies for Improved Cognition: The Mind/Body Connection

    ERIC Educational Resources Information Center

    Fede, Marybeth H.

    2012-01-01

    Whether an administrator, faculty member, classroom teacher, or specials teacher (Art, Music, and Physical Education), everyone wants students test scores to improve and know that they contributed to it. These improved scores validate the roles and influence of educators and administrators. The purpose of this article is two-fold: (1) to assist…

  5. Using the Bifocal Modeling Framework to Resolve "Discrepant Events" Between Physical Experiments and Virtual Models in Biology

    NASA Astrophysics Data System (ADS)

    Blikstein, Paulo; Fuhrmann, Tamar; Salehi, Shima

    2016-08-01

    In this paper, we investigate an approach to supporting students' learning in science through a combination of physical experimentation and virtual modeling. We present a study that utilizes a scientific inquiry framework, which we call "bifocal modeling," to link student-designed experiments and computer models in real time. In this study, a group of high school students designed computer models of bacterial growth with reference to a simultaneous physical experiment they were conducting, and were able to validate the correctness of their model against the results of their experiment. Our findings suggest that as the students compared their virtual models with physical experiments, they encountered "discrepant events" that contradicted their existing conceptions and elicited a state of cognitive disequilibrium. This experience of conflict encouraged students to further examine their ideas and to seek more accurate explanations of the observed natural phenomena, improving the design of their computer models.

  6. Using the Bifocal Modeling Framework to Resolve "Discrepant Events" Between Physical Experiments and Virtual Models in Biology

    NASA Astrophysics Data System (ADS)

    Blikstein, Paulo; Fuhrmann, Tamar; Salehi, Shima

    2016-05-01

    In this paper, we investigate an approach to supporting students' learning in science through a combination of physical experimentation and virtual modeling. We present a study that utilizes a scientific inquiry framework, which we call "bifocal modeling," to link student-designed experiments and computer models in real time. In this study, a group of high school students designed computer models of bacterial growth with reference to a simultaneous physical experiment they were conducting, and were able to validate the correctness of their model against the results of their experiment. Our findings suggest that as the students compared their virtual models with physical experiments, they encountered "discrepant events" that contradicted their existing conceptions and elicited a state of cognitive disequilibrium. This experience of conflict encouraged students to further examine their ideas and to seek more accurate explanations of the observed natural phenomena, improving the design of their computer models.

  7. Capitalizing on the Teachable Moment: Osteoarthritis Physical Activity and Exercise Net for Improving Physical Activity in Early Knee Osteoarthritis

    PubMed Central

    Lineker, Sydney; Cibere, Jolanda; Crooks, Valorie A; Jones, Catherine A; Kopec, Jacek A; Lear, Scott A; Pencharz, James; Rhodes, Ryan E; Esdaile, John M

    2013-01-01

    Background Practice guidelines emphasize the use of exercise and weight reduction as the first line of management for knee osteoarthritis (OA). However, less than half of the people with mild OA participate in moderate intensity physical activity. Given that physical activities have been shown to reduce pain, improve quality of life, and have the potential to reduce the progression of joint damage, many people with OA are missing the benefits of this inexpensive intervention. Objective The objectives of this study are (1) to develop a behavioral theory-informed Internet intervention called Osteoarthritis Physical Activity & Exercise Net (OPEN) for people with previously undiagnosed knee OA, and (2) to assess the efficacy of the OPEN website for improving physical activity participation through a proof-of-concept study. Methods OPEN was developed based on the theory of planned behavior. Efficacy of this online intervention is being assessed by an ongoing proof-of-concept, single-blind randomized controlled trial in British Columbia, Canada. We are currently recruiting participants and plan to recruit a total of 252 sedentary people with previously undiagnosed knee OA using a set of validated criteria. Half of the participants will be randomized to use OPEN and receive an OA education pamphlet. The other half only will receive the pamphlet. Participants will complete an online questionnaire at baseline, 3 months, and 6 months about their participation in physical activities, health-related quality of life, and motivational outcomes. In addition, we will perform an aerobic fitness test in a sub-sample of participants (n=20 per study arm). In the primary analysis, we will use logistic regression to compare the proportion of participants reporting being physically active at or above the recommended level in the 2 groups, adjusting for baseline measurement, age, and sex. Results This study evaluates a theory-informed behavioral intervention at a time when people affected

  8. A physically-based Distributed Hydrologic Model for Tropical Catchments

    NASA Astrophysics Data System (ADS)

    Abebe, N. A.; Ogden, F. L.

    2010-12-01

    Hydrological models are mathematical formulations intended to represent observed hydrological processes in a watershed. Simulated watersheds in turn vary in their nature based on their geographic location, altitude, climatic variables and geology and soil formation. Due to these variations, available hydrologic models vary in process formulation, spatial and temporal resolution and data demand. Many tropical watersheds are characterized by extensive and persistent biological activity and a large amount of rain. The Agua Salud catchments located within the Panama Canal Watershed, Panama, are such catchments identified by steep rolling topography, deep soils derived from weathered bedrock, and limited exposed bedrock. Tropical soils are highly affected by soil cracks, decayed tree roots and earthworm burrows forming a network of preferential flow paths that drain to a perched water table, which forms at a depth where the vertical hydraulic conductivity is significantly reduced near the bottom of the bioturbation layer. We have developed a physics-based, spatially distributed, multi-layered hydrologic model to simulate the dominant processes in these tropical watersheds. The model incorporates the major flow processes including overland flow, channel flow, matrix and non-Richards film flow infiltration, lateral downslope saturated matrix and non-Darcian pipe flow in the bioturbation layer, and deep saturated groundwater flow. Emphasis is given to the modeling of subsurface unsaturated zone soil moisture dynamics and the saturated preferential lateral flow from the network of macrospores. Preliminary results indicate that the model has the capability to simulate the complex hydrological processes in the catchment and will be a useful tool in the ongoing comprehensive ecohydrological studies in tropical catchments, and help improve our understanding of the hydrological effects of deforestation and aforestation.

  9. Residential end use demand modeling: Improvements to the ORNL model

    NASA Astrophysics Data System (ADS)

    McMahon, J. E.

    1981-10-01

    The ORNL/LBL Residential Energy Demand Model incorporated major improvements in three areas: efficiency of appliances, current construction practice in new houses, and appliance retirements. The new methodology is more general, and provides energy demand estimates in better agreement with recent data. Key areas for future improvements are indicated, including: quantifying the uncertainty in model simulation, redefining the set of end uses, updating the algorithm, and broadening the model's applicability to different geographic areas. A US Department of Energy survey of appliance manufacturers was used to determine new appliance efficiencies. Similarly, surveys of current housing practices (e.g., ceiling insulation level) were used to estimate changes in heating and cooling energy requirements. Appliances are assumed to retire as a function of their age.

  10. On physical aspects of the Jiles-Atherton hysteresis models

    NASA Astrophysics Data System (ADS)

    Zirka, Sergey E.; Moroz, Yuriy I.; Harrison, Robert G.; Chwastek, Krzysztof

    2012-08-01

    The physical assumptions underlying the static and dynamic Jiles-Atherton (JA) hysteresis models are critically analyzed. It is shown that the energy-balance method used in deriving these models is actually closer to a balance of coenergies, thereby depriving the resulting JA phenomenology of physical meaning. The non-physical basis of its dynamic extension is demonstrated by a sharp contrast between hysteresis loops predicted by the model and those measured for grain-oriented steel under conditions of controlled sinusoidal flux density at frequencies of 50, 100, and 200 Hz.

  11. Engineered Barrier System: Physical and Chemical Environment Model

    SciTech Connect

    D. M. Jolley; R. Jarek; P. Mariner

    2004-02-09

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

  12. Hidden sector DM models and Higgs physics

    SciTech Connect

    Ko, P.

    2014-06-24

    We present an extension of the standard model to dark sector with an unbroken local dark U(1){sub X} symmetry. Including various singlet portal interactions provided by the standard model Higgs, right-handed neutrinos and kinetic mixing, we show that the model can address most of phenomenological issues (inflation, neutrino mass and mixing, baryon number asymmetry, dark matter, direct/indirect dark matter searches, some scale scale puzzles of the standard collisionless cold dark matter, vacuum stability of the standard model Higgs potential, dark radiation) and be regarded as an alternative to the standard model. The Higgs signal strength is equal to one as in the standard model for unbroken U(1){sub X} case with a scalar dark matter, but it could be less than one independent of decay channels if the dark matter is a dark sector fermion or if U(1){sub X} is spontaneously broken, because of a mixing with a new neutral scalar boson in the models.

  13. Towards LHC physics with nonlocal Standard Model

    NASA Astrophysics Data System (ADS)

    Biswas, Tirthabir; Okada, Nobuchika

    2015-09-01

    We take a few steps towards constructing a string-inspired nonlocal extension of the Standard Model. We start by illustrating how quantum loop calculations can be performed in nonlocal scalar field theory. In particular, we show the potential to address the hierarchy problem in the nonlocal framework. Next, we construct a nonlocal abelian gauge model and derive modifications of the gauge interaction vertex and field propagators. We apply the modifications to a toy version of the nonlocal Standard Model and investigate collider phenomenology. We find the lower bound on the scale of nonlocality from the 8 TeV LHC data to be 2.5-3 TeV.

  14. An analytically linearized helicopter model with improved modeling accuracy

    NASA Technical Reports Server (NTRS)

    Jensen, Patrick T.; Curtiss, H. C., Jr.; Mckillip, Robert M., Jr.

    1991-01-01

    An analytically linearized model for helicopter flight response including rotor blade dynamics and dynamic inflow, that was recently developed, was studied with the objective of increasing the understanding, the ease of use, and the accuracy of the model. The mathematical model is described along with a description of the UH-60A Black Hawk helicopter and flight test used to validate the model. To aid in utilization of the model for sensitivity analysis, a new, faster, and more efficient implementation of the model was developed. It is shown that several errors in the mathematical modeling of the system caused a reduction in accuracy. These errors in rotor force resolution, trim force and moment calculation, and rotor inertia terms were corrected along with improvements to the programming style and documentation. Use of a trim input file to drive the model is examined. Trim file errors in blade twist, control input phase angle, coning and lag angles, main and tail rotor pitch, and uniform induced velocity, were corrected. Finally, through direct comparison of the original and corrected model responses to flight test data, the effect of the corrections on overall model output is shown.

  15. Modeling soil water content for vegetation modeling improvement

    NASA Astrophysics Data System (ADS)

    Cianfrani, Carmen; Buri, Aline; Zingg, Barbara; Vittoz, Pascal; Verrecchia, Eric; Guisan, Antoine

    2016-04-01

    Soil water content (SWC) is known to be important for plants as it affects the physiological processes regulating plant growth. Therefore, SWC controls plant distribution over the Earth surface, ranging from deserts and grassland to rain forests. Unfortunately, only a few data on SWC are available as its measurement is very time consuming and costly and needs specific laboratory tools. The scarcity of SWC measurements in geographic space makes it difficult to model and spatially project SWC over larger areas. In particular, it prevents its inclusion in plant species distribution model (SDMs) as predictor. The aims of this study were, first, to test a new methodology allowing problems of the scarcity of SWC measurements to be overpassed and second, to model and spatially project SWC in order to improve plant SDMs with the inclusion of SWC parameter. The study was developed in four steps. First, SWC was modeled by measuring it at 10 different pressures (expressed in pF and ranging from pF=0 to pF=4.2). The different pF represent different degrees of soil water availability for plants. An ensemble of bivariate models was built to overpass the problem of having only a few SWC measurements (n = 24) but several predictors to include in the model. Soil texture (clay, silt, sand), organic matter (OM), topographic variables (elevation, aspect, convexity), climatic variables (precipitation) and hydrological variables (river distance, NDWI) were used as predictors. Weighted ensemble models were built using only bivariate models with adjusted-R2 > 0.5 for each SWC at different pF. The second step consisted in running plant SDMs including modeled SWC jointly with the conventional topo-climatic variable used for plant SDMs. Third, SDMs were only run using the conventional topo-climatic variables. Finally, comparing the models obtained in the second and third steps allowed assessing the additional predictive power of SWC in plant SDMs. SWC ensemble models remained very good, with

  16. Massive Stars: Input Physics and Stellar Models

    NASA Astrophysics Data System (ADS)

    El Eid, M. F.; The, L.-S.; Meyer, B. S.

    2009-10-01

    We present a general overview of the structure and evolution of massive stars of masses ≥12 M ⊙ during their pre-supernova stages. We think it is worth reviewing this topic owing to the crucial role of massive stars in astrophysics, especially in the evolution of galaxies and the universe. We have performed several test computations with the aim to analyze and discuss many physical uncertainties still encountered in massive-star evolution. In particular, we explore the effects of mass loss, convection, rotation, 12C( α, γ)16O reaction and initial metallicity. We also compare and analyze the similarities and differences among various works and ours. Finally, we present useful comments on the nucleosynthesis from massive stars concerning the s-process and the yields for 26Al and 60Fe.

  17. Early Childhood Educators' Experience of an Alternative Physical Education Model

    ERIC Educational Resources Information Center

    Tsangaridou, Niki; Genethliou, Nicholas

    2016-01-01

    Alternative instructional and curricular models are regarded as more comprehensive and suitable approaches to providing quality physical education (Kulinna 2008; Lund and Tannehill 2010; McKenzie and Kahan 2008; Metzler 2011; Quay and Peters 2008). The purpose of this study was to describe the impact of the Early Steps Physical Education…

  18. A Model of Physical Performance for Occupational Tasks.

    ERIC Educational Resources Information Center

    Hogan, Joyce

    This report acknowledges the problems faced by industrial/organizational psychologists who must make personnel decisions involving physically demanding jobs. The scarcity of criterion-related validation studies and the difficulty of generalizing validity are considered, and a model of physical performance that builds on Fleishman's (1984)…

  19. Educational Value and Models-Based Practice in Physical Education

    ERIC Educational Resources Information Center

    Kirk, David

    2013-01-01

    A models-based approach has been advocated as a means of overcoming the serious limitations of the traditional approach to physical education. One of the difficulties with this approach is that physical educators have sought to use it to achieve diverse and sometimes competing educational benefits, and these wide-ranging aspirations are rarely if…

  20. An improved nuclear mass model: FRDM (2012)

    NASA Astrophysics Data System (ADS)

    Moller, Peter

    2011-10-01

    We have developed an improved nuclear mass model which we plan to finalize in 2012, so we designate it FRDM(2012). Relative to our previous mass table in 1995 we do a full four-dimensional variation of the shape coordinates EPS2, EPS3, EPS4, and EPS6, we consider axial asymmetric shape degrees of freedom and we vary the density symmetry parameter L. Other additional features are also implemented. With respect to the Audi 2003 data base we now have an accuracy of 0.57 MeV. We have carefully tested the extrapolation properties of the new mass table by adjusting model parameters to limited data sets and testing on extended data sets and find it is highly reliable in new regions of nuclei. We discuss what the remaining differences between model calculations and experiment tell us about the limitations of the currently used effective single-particle potential and possible extensions. DOE No. DE-AC52-06NA25396.

  1. A Physically Based Coupled Chemical and Physical Weathering Model for Simulating Soilscape Evolution

    NASA Astrophysics Data System (ADS)

    Willgoose, G. R.; Welivitiya, D.; Hancock, G. R.

    2015-12-01

    A critical missing link in existing landscape evolution models is a dynamic soil evolution models where soils co-evolve with the landform. Work by the authors over the last decade has demonstrated a computationally manageable model for soil profile evolution (soilscape evolution) based on physical weathering. For chemical weathering it is clear that full geochemistry models such as CrunchFlow and PHREEQC are too computationally intensive to be couplable to existing soilscape and landscape evolution models. This paper presents a simplification of CrunchFlow chemistry and physics that makes the task feasible, and generalises it for hillslope geomorphology applications. Results from this simplified model will be compared with field data for soil pedogenesis. Other researchers have previously proposed a number of very simple weathering functions (e.g. exponential, humped, reverse exponential) as conceptual models of the in-profile weathering process. The paper will show that all of these functions are possible for specific combinations of in-soil environmental, geochemical and geologic conditions, and the presentation will outline the key variables controlling which of these conceptual models can be realistic models of in-profile processes and under what conditions. The presentation will finish by discussing the coupling of this model with a physical weathering model, and will show sample results from our SSSPAM soilscape evolution model to illustrate the implications of including chemical weathering in the soilscape evolution model.

  2. Flavour physics in the soft wall model

    NASA Astrophysics Data System (ADS)

    Archer, Paul R.; Huber, Stephan J.; Jäger, Sebastian

    2011-12-01

    We extend the description of flavour that exists in the Randall-Sundrum (RS) model to the soft wall (SW) model in which the IR brane is removed and the Higgs is free to propagate in the bulk. It is demonstrated that, like the RS model, one can generate the hierarchy of fermion masses by localising the fermions at different locations throughout the space. However, there are two significant differences. Firstly the possible fermion masses scale down, from the electroweak scale, less steeply than in the RS model and secondly there now exists a minimum fermion mass for fermions sitting towards the UV brane. With a quadratic Higgs VEV, this minimum mass is about fifteen orders of magnitude lower than the electroweak scale. We derive the gauge propagator and despite the KK masses scaling as m_n^2 ˜ n , it is demonstrated that the coefficients of four fermion operators are not divergent at tree level. FCNC's amongst kaons and leptons are considered and compared to calculations in the RS model, with a brane localised Higgs and equivalent levels of tuning. It is found that since the gauge fermion couplings are slightly more universal and the SM fermions typically sit slightly further towards the UV brane, the contributions to observables such as ɛ K and Δ m K , from the exchange of KK gauge fields, are significantly reduced.

  3. Does Further Education in Adulthood Improve Physical and Mental Health among Australian Women? A Longitudinal Study

    PubMed Central

    Tooth, Leigh; Mishra, Gita D.

    2015-01-01

    Objective We analyzed whether further education in young adult and mid-life [adult educational mobility] influences physical functioning and depressive symptoms in women. Methods 14247 women born 1973–78 (younger cohort) and 13715 women born 1946–51 (mid-aged cohort) from the Australian Longitudinal Study on Women’s Health were followed for 14–16 years. Measures were the Short-Form 36 Health Survey physical functioning subscale (SF-36 PF) and Centre for Epidemiologic Studies 10-item Depression Scale (CESD-10). Linear mixed modelling, accounting for time varying covariates, assessed the influence of further education on physical functioning and depressive symptoms over time. Sensitivity analysis to assess the impact of missing data was conducted using multiple imputation. Results Compared to younger women with a pre-existing high level of education, women gaining further education (up to age 39 years) from low levels had lower SF-36 PF scores (poorer physical functioning) (fully adjusted beta estimates (95%CIs) -1.52 (-2.59, -0.44)) while those gaining further education from middle to high levels showed equivalent SF-36 PF scores (-0.08 (-0.61, 0.44)). A similar pattern was shown for CESD-10 scores (0.78 (0.29, 1.25); -0.02 (-0.26, 0.21), respectively) where higher scores represented more depressive symptoms. For mid-age women, further education from a middle to high level resulted in equivalent SF-36 PF scores (-0.61 (-1.93,0.71)) but higher CESD-10 scores (0.49 (0.11, 0.86)), compared to highly educated women. Conclusion Women who delay further education until they are aged between their 40s and 60s can improve or maintain their physical functioning but may have missed the critical time to minimise depressive symptomatology. Public health policy should focus on encouraging women to upgrade their educational qualifications earlier in life in order to potentially offset the negative associations between their initial lower socio-economic position class of

  4. Propulsion Physics Under the Changing Density Field Model

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A.

    2011-01-01

    To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a scalar field within and about an object, even in the vacuum. Whereby, these scalar fields can be viewed as vacuum energy fields with definable densities that permeate all matter; having implications to dark matter/energy with universe acceleration properties; implying a new force mechanism for propulsion physics. Using Chameleon Cosmology, the author has developed a new propulsion physics model, called the Changing Density Field (CDF) Model. This model relates to density changes in these density fields, where the density field density changes are related to the acceleration of matter within an object. These density changes in turn change how an object couples to the surrounding density fields. Whereby, thrust is achieved by causing a differential in the coupling to these density fields about an object. Since the model indicates that the density of the density field in an object can be changed by internal mass acceleration, even without exhausting mass, the CDF model implies a new propellant-less propulsion physics model

  5. A physical model of Titan's aerosols

    NASA Technical Reports Server (NTRS)

    Toon, O. B.; Mckay, C. P.; Griffith, C. A.; Turco, R. P.

    1992-01-01

    A modeling effort is presented for the nature of the stratospheric haze on Titan, under several simplifying assumptions; chief among these is that the aerosols in question are of a single composition, and involatile. It is further assumed that a one-dimensional model is capable of simulating the general characteristics of the aerosol. It is suggested in this light that the detached haze on Titan may be a manifestation of organized, Hadley-type motions above 300 km altitude, with vertical velocities of 1 cm/sec. The hemispherical asymmetry of the visible albedo may be due to organized vertical motions within the upper 150-200 km of the haze.

  6. Multivariate Regression Models for Estimating Journal Usefulness in Physics.

    ERIC Educational Resources Information Center

    Bennion, Bruce C.; Karschamroon, Sunee

    1984-01-01

    This study examines possibility of ranking journals in physics by means of bibliometric regression models that estimate usefulness as it is reported by 167 physicists in United States and Canada. Development of four models, patterns of deviation from models, and validity and application are discussed. Twenty-six references are cited. (EJS)

  7. Kinetic exchange models: From molecular physics to social science

    NASA Astrophysics Data System (ADS)

    Patriarca, Marco; Chakraborti, Anirban

    2013-08-01

    We discuss several multi-agent models that have their origin in the kinetic exchange theory of statistical mechanics and have been recently applied to a variety of problems in the social sciences. This class of models can be easily adapted for simulations in areas other than physics, such as the modeling of income and wealth distributions in economics and opinion dynamics in sociology.

  8. Physical model to predict the ball-burnishing forces

    NASA Astrophysics Data System (ADS)

    González-Rojas, H. A.; Travieso-Rodríguez, J. A.

    2012-04-01

    In this paper, we have developed a physical model to predict the forces of the ball burnishing. The models have been constructed on the basis of the plasticity theory. During the model development we have figured out the dimensionless number B that characterizes the problem of plastic deformation in the ball-burnishing. The experiments performed in steel and aluminum allows to validate the model and to emphasize the correct prediction of behavior patterns that the model describes.

  9. Statistical physics models for nacre fracture simulation

    NASA Astrophysics Data System (ADS)

    Nukala, Phani Kumar V. V.; Šimunović, Srđan

    2005-10-01

    Natural biological materials such as nacre (or mother-of-pearl), exhibit phenomenal fracture strength and toughness properties despite the brittle nature of their constituents. For example, nacre’s work of fracture is three orders of magnitude greater than that of a single crystal of its constituent mineral. This study investigates the fracture properties of nacre using a simple discrete lattice model based on continuous damage random thresholds fuse network. The discrete lattice topology of the proposed model is based on nacre’s unique brick and mortar microarchitecture, and the mechanical behavior of each of the bonds in the discrete lattice model is governed by the characteristic modular damage evolution of the organic matrix that includes the mineral bridges between the aragonite platelets. The analysis indicates that the excellent fracture properties of nacre are a result of their unique microarchitecture, repeated unfolding of protein molecules (modular damage evolution) in the organic polymer, and the presence of fiber bundle of mineral bridges between the aragonite platelets. The numerical results obtained using this simple discrete lattice model are in excellent agreement with the previously obtained experimental results, such as nacre’s stiffness, tensile strength, and work of fracture.

  10. Statistical physics models for nacre fracture simulation.

    PubMed

    Nukala, Phani Kumar V V; Simunović, Srdan

    2005-10-01

    Natural biological materials such as nacre (or mother-of-pearl), exhibit phenomenal fracture strength and toughness properties despite the brittle nature of their constituents. For example, nacre's work of fracture is three orders of magnitude greater than that of a single crystal of its constituent mineral. This study investigates the fracture properties of nacre using a simple discrete lattice model based on continuous damage random thresholds fuse network. The discrete lattice topology of the proposed model is based on nacre's unique brick and mortar microarchitecture, and the mechanical behavior of each of the bonds in the discrete lattice model is governed by the characteristic modular damage evolution of the organic matrix that includes the mineral bridges between the aragonite platelets. The analysis indicates that the excellent fracture properties of nacre are a result of their unique microarchitecture, repeated unfolding of protein molecules (modular damage evolution) in the organic polymer, and the presence of fiber bundle of mineral bridges between the aragonite platelets. The numerical results obtained using this simple discrete lattice model are in excellent agreement with the previously obtained experimental results, such as nacre's stiffness, tensile strength, and work of fracture. PMID:16383432

  11. Do as I Say, Not as I Do: Improving the Image of the Physical Education Profession

    ERIC Educational Resources Information Center

    Baghurst, Timothy; Bryant, Lance C.

    2012-01-01

    Modeling physical fitness and healthy behaviors has been a topic of discussion in the profession for decades. Arguably the most famous research on this topic was conducted by Melville and Maddalozzo (1988) who found that a high school physical educator's body fatness could affect students' ability to retain information and their intent to…

  12. Development of Integrated ASR Model Forcing Data and Their Applications to Improve CAM

    SciTech Connect

    Zhang, Minghua

    2016-01-01

    In this project, we have (1) improved the constrained variational analysis algorithm of ARM model forcing data, and (2) used the ARM forcing data to identify systematic biases in clouds and radiation in the CAM5 and design new physical parameterizations to improve it.

  13. Improving the Ni I atomic model for solar and stellar atmospheric models

    SciTech Connect

    Vieytes, M. C.; Fontenla, J. M. E-mail: johnf@digidyna.com

    2013-06-01

    Neutral nickel (Ni I) is abundant in the solar atmosphere and is one of the important elements that contribute to the emission and absorption of radiation in the spectral range between 1900 and 3900 Å. Previously, the Solar Radiation Physical Modeling (SRPM) models of the solar atmosphere only considered a few levels of this species. Here, we improve the Ni I atomic model by taking into account 61 levels and 490 spectral lines. We compute the populations of these levels in full NLTE using the SRPM code and compare the resulting emerging spectrum with observations. The present atomic model significantly improves the calculation of the solar spectral irradiance at near-UV wavelengths, which is important for Earth atmospheric studies, and particularly for ozone chemistry.

  14. An Improved Degree-day Melt Model Considering Albedo

    NASA Astrophysics Data System (ADS)

    Pellicciotti, F.; Strasser, U.; Burlando, P.; Funk, M.; Brock, B.; Corripio, J.

    Albedo is a major controlling factor for the melting of snow and ice. Here, an en- hanced degree-day melt model for the point scale is presented, in which the classical dependency on temperature is extended by considering albedo and global radiation. Temperature based index melt methods have been widely used due to their good per- formances, the availability of temperature data and the ease of its spatial interpolation. Other authors have recently improved the standard approach by addition of a radiation term. Here, the latter is modified with albedo, which represents a physical property of the material, and accounts for the way the surface reacts to the energy input of global radiation. The formulation adopted is additive, being melt expressed as the sum of two components, one controlled by temperature and the second by short-wave incoming radiation. Such a representation allows to separate in a clear way the two important contributions to melt of long wave and global radiation The model was run at different sites where the necessary meteorological data are measured and melt values are avail- able. In the pre-alpine site of Col de Porte (French Alps, 1340m), melt was computed by use of a highly sophisticated, physically based energy balance model. An ultrasonic device was used at a glacier location on Haut Glacier d'Arolla (Swiss Alps, 2920 m). Both measured short-wave radiation and computed potential direct short-wave radia- tion were used, and different temporal resolutions were tested. Results are discussed with the purpose of evaluating the increased efficiency of the improved degree-day scheme, and in the light of extending it to a distributed model, which accounts for space-time albedo variability.

  15. Tight Binding Models in Cold Atoms Physics

    NASA Astrophysics Data System (ADS)

    Zakrzewski, J.

    2007-05-01

    Cold atomic gases placed in optical lattice potentials offer a unique tool to study simple tight binding models. Both the standard cases known from the condensed matter theory as well as novel situations may be addressed. Cold atoms setting allows for a precise control of parameters of the systems discussed, stimulating new questions and problems. The attempts to treat disorder in a controlled fashion are addressed in detail.

  16. ITER physics-safety interface: models and assessments

    SciTech Connect

    Uckan, N.A.; Putvinski, S.; Wesley, J.; Bartels, H-W.; Honda, T.; Amano, T.; Boucher, D.; Fujisawa, N.; Post, D.; Rosenbluth, M.

    1996-10-01

    Plasma operation conditions and physics requirements to be used as a basis for safety analysis studies are developed and physics results motivated by safety considerations are presented for the ITER design. Physics guidelines and specifications for enveloping plasma dynamic events for Category I (operational event), Category II (likely event), and Category III (unlikely event) are characterized. Safety related physics areas that are considered are: (i) effect of plasma on machined and safety (disruptions, runaway electrons, fast plasma shutdown) and (ii) plasma response to ex-vessel LOCA from first wall providing a potential passive plasma shutdown due to Be evaporation. Physics models and expressions developed are implemented in safety analysis code (SAFALY, couples 0-D dynamic plasma model to thermal response of the in-vessel components). Results from SAFALY are presented.

  17. Improved Shell models for screened Coulomb balls

    NASA Astrophysics Data System (ADS)

    Bonitz, M.; Kaehlert, H.; Henning, C.; Baumgartner, H.; Filinov, A.

    2006-10-01

    Spherical Coulomb crystals in dusty plasmas [1] are well described by an isotropic Yukawa-type pair interaction and an external parabolic confinement as was shown by extensive molecular dynamics simulations [2]. A much simpler description is possible with analytical shell models which have been derived for Yukawas plasmas in [3,4]. Here we analyze improved Yukawa shell models which include correlations along the lines proposed for Coulomb crystals in [5]. The shell configurations are efficiently evaluated using a Monte Carlo procedure. [1] O. Arp, A. Piel and A. Melzer, Phys. Rev. Lett. 93, 165004 (2004). [2] M. Bonitz, D. Block, O. Arp, V. Golunychiy, H. Baumgartner, P. Ludwig, A. Piel and A. Filinov, Phys. Rev. Lett. 96, 075001 (2006). [3] H. Totsuji, C. Totsuji, T. Ogawa, and K. Tsuruta, Phys. Rev. E 71, 045401 (2005). [4] C. Henning, M. Bonitz, A. Piel, P. Ludwig, H. Baumgartner, V. Golubnichiy, and D. Block, submitted to Phys. Rev. E [5] W.D. Kraeft and M. Bonitz, J. Phys. Conf. Ser. 35, 94 (2006).

  18. Studio Physics at the Colorado School of Mines: A model for iterative development and assessment

    NASA Astrophysics Data System (ADS)

    Kohl, Patrick; Kuo, Vincent

    2009-05-01

    The Colorado School of Mines (CSM) has taught its first-semester introductory physics course using a hybrid lecture/Studio Physics format for several years. Based on this previous success, over the past 18 months we have converted the second semester of our traditional calculus-based introductory physics course (Physics II) to a Studio Physics format. In this talk, we describe the recent history of the Physics II course and of Studio at Mines, discuss the PER-based improvements that we are implementing, and characterize our progress via several metrics, including pre/post Conceptual Survey of Electricity and Magnetism (CSEM) scores, Colorado Learning About Science Survey scores (CLASS), failure rates, and exam scores. We also report on recent attempts to involve students in the department's Senior Design program with our course. Our ultimate goal is to construct one possible model for a practical and successful transition from a lecture course to a Studio (or Studio-like) course.

  19. Validation and upgrading of physically based mathematical models

    NASA Technical Reports Server (NTRS)

    Duval, Ronald

    1992-01-01

    The validation of the results of physically-based mathematical models against experimental results was discussed. Systematic techniques are used for: (1) isolating subsets of the simulator mathematical model and comparing the response of each subset to its experimental response for the same input conditions; (2) evaluating the response error to determine whether it is the result of incorrect parameter values, incorrect structure of the model subset, or unmodeled external effects of cross coupling; and (3) modifying and upgrading the model and its parameter values to determine the most physically appropriate combination of changes.

  20. Improved myocardial ischemia detection by combined physical and mental stress testing.

    PubMed

    Hunziker, P R; Gradel, C; Müller-Brand, J; Buser, P; Pfisterer, M

    1998-07-01

    The hypothesis that addition of mental stress to physical exercise would modify the circulation response to stress and improve noninvasive detection of myocardial ischemia was tested in a randomized, crossover radionuclide angiocardiographic study. Compared with physical exercise or mental stress alone, combined stress led to higher heart rates and rate-pressure products in early stress stages, to more pronounced symptoms, and to a better discrimination of subjects with and without coronary artery disease by radionuclide angiography. PMID:9671017

  1. Managing the Learning Quality in Physics by E-Learning Improvement with Collaborative Education

    NASA Astrophysics Data System (ADS)

    Kanenaga, Masahiko; Suzuki, Masaru; Abe, Kohji; Nakamura, Jin; Takada, Tohru; Kokubo, Nobuhito; Fuseya, Yuki

    In 2010, the University of Electro-Communications (UEC) reconstructed the freshmen's curriculum in which all students learn the same contents of introductory physics and take the examination at same time. We had constructed Collaborative Education in order to support the students who had a various learning history in high school and the teachers who had not been experts in physics education. In this article, we show the result of Collaborative Education in UEC and its improvement strategy.

  2. Parameter identification methods for improving structural dynamic models. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lawrence, Charles

    1988-01-01

    There is an increasing need to develop Parameter Identification methods for improving structural dynamic models, based on the inability of engineers to produce mathematical models which correlate with experimental data. This research explores the efficiency of combining Component Mode Synthesis (substructuring) methods with Parameter Identification procedures in order to improve analytical modeling of structural components and their connections. Improvements are computed in terms of physical stiffness and damping parameters in order that the physical characteristics of the model can be better understood. Connections involving both viscous and friction damping are investigated. Substructuring methods are utilized to reduce the complexity of the identification problem. Component and inter-component structural connection properties are evaluated and identified independently, thus simplifying the identification problem. It is shown that modal test data is effective for identifying modeling problems associated with structural components, and for determining the stiffness and damping properties of intercomponent connections. In general, Parameter Identification is improved when greater quantities of experimental data are available.

  3. Catch bonds: physical models and biological functions.

    PubMed

    Zhu, Cheng; McEver, Rodger P

    2005-09-01

    Force can shorten the lifetimes of receptor-ligand bonds by accelerating their dissociation. Perhaps paradoxical at first glance, bond lifetimes can also be prolonged by force. This counterintuitive behavior was named catch bonds, which is in contrast to the ordinary slip bonds that describe the intuitive behavior of lifetimes being shortened by force. Fifteen years after their theoretical proposal, catch bonds have finally been observed. In this article we review recently published data that have demonstrated catch bonds in the selectin system and suggested catch bonds in other systems, the theoretical models for their explanations, and their function as a mechanism for flow-enhanced adhesion. PMID:16708472

  4. Scenarios of physics beyond the standard model

    NASA Astrophysics Data System (ADS)

    Fok, Ricky

    This dissertation discusses three topics on scenarios beyond the Standard Model. Topic one is the effects from a fourth generation of quarks and leptons on electroweak baryogenesis in the early universe. The Standard Model is incapable of electroweak baryogenesis due to an insufficiently strong enough electroweak phase transition (EWPT) as well as insufficient CP violation. We show that the presence of heavy fourth generation fermions solves the first problem but requires additional bosons to be included to stabilize the electroweak vacuum. Introducing supersymmetric partners of the heavy fermions, we find that the EWPT can be made strong enough and new sources of CP violation are present. Topic two relates to the lepton avor problem in supersymmetry. In the Minimal Supersymmetric Standard Model (MSSM), the off-diagonal elements in the slepton mass matrix must be suppressed at the 10-3 level to avoid experimental bounds from lepton avor changing processes. This dissertation shows that an enlarged R-parity can alleviate the lepton avor problem. An analysis of all sensitive parameters was performed in the mass range below 1 TeV, and we find that slepton maximal mixing is possible without violating bounds from the lepton avor changing processes: mu → egamma; mu → e conversion, and mu → 3e. Topic three is the collider phenomenology of quirky dark matter. In this model, quirks are particles that are gauged under the electroweak group, as well as a dark" color SU(2) group. The hadronization scale of this color group is well below the quirk masses. As a result, the dark color strings never break. Quirk and anti-quirk pairs can be produced at the LHC. Once produced, they immediately form a bound state of high angular momentum. The quirk pair rapidly shed angular momentum by emitting soft radiation before they annihilate into observable signals. This dissertation presents the decay branching ratios of quirkonia where quirks obtain their masses through electroweak

  5. Improving the Rapid Refresh and High Resolution Rapid Refresh physics to better perform across a wide range of spatial scales

    NASA Astrophysics Data System (ADS)

    Olson, Joseph; Grell, Georg

    2014-05-01

    Model development at NOAA/GSD spans a wide range of spatial scales: global scale (Flow-following finite-volume Icosohedral Model, FIM; 10-250 km grid spacing), continental scale (RAP; 13 km grid spacing), CONUS scale (HRRR; 3 km grid spacing), and regional modeling (experimental nesting at 1 km grid spacing over complex terrain). As the model resolution changes, the proportion of resolved vs unresolved physical processes changes; therefore, physical parameterizations need to adapt to different model resolutions to more accurately handle the unresolved processes. The Limited Area Model (LAM) component of the Grey Zone Experiment was designed to assess the change in behavior of numerical weather prediction models between 16 and 1 km by simulating a cold-air outbreak over the North Atlantic and North Sea. The RAP and HRRR model physics were tested in this case study in order to examine the change in behavior of the model physics at 16, 8, 4, 2, and 1 km grid spacings with and without the use a convective parameterization. The primary purpose of these tests is to better understand the change in behavior of the boundary layer and convective schemes across the grey zone, such that further targeted modifications can then help improve general performance at various scales. The RAP currently employs a modified form of the Mellor-Yamada-Nakanishi-Niino (MYNN) PBL scheme, which is an improved TKE-based scheme tuned to match large-eddy simulations. Modifications have been performed to better match observations at 13 km (RAP) grid spacing but more multi-scale testing is required before modifications are introduced to make it scale-aware. A scale-aware convective parameterization, the Grell-Freitas scheme (both deep- and shallow-cumulus scheme), has been developed to better handle the transition in behavior of the sub-grid scale convective processes through the grey zone. This study examines the change in behavior of both schemes across the grey zone. Their transitional behavior

  6. Characterizing, modeling, and addressing gender disparities in introductory college physics

    NASA Astrophysics Data System (ADS)

    Kost-Smith, Lauren Elizabeth

    2011-12-01

    The underrepresentation and underperformance of females in physics has been well documented and has long concerned policy-makers, educators, and the physics community. In this thesis, we focus on gender disparities in the first- and second-semester introductory, calculus-based physics courses at the University of Colorado. Success in these courses is critical for future study and careers in physics (and other sciences). Using data gathered from roughly 10,000 undergraduate students, we identify and model gender differences in the introductory physics courses in three areas: student performance, retention, and psychological factors. We observe gender differences on several measures in the introductory physics courses: females are less likely to take a high school physics course than males and have lower standardized mathematics test scores; males outscore females on both pre- and post-course conceptual physics surveys and in-class exams; and males have more expert-like attitudes and beliefs about physics than females. These background differences of males and females account for 60% to 70% of the gender gap that we observe on a post-course survey of conceptual physics understanding. In analyzing underlying psychological factors of learning, we find that female students report lower self-confidence related to succeeding in the introductory courses (self-efficacy) and are less likely to report seeing themselves as a "physics person". Students' self-efficacy beliefs are significant predictors of their performance, even when measures of physics and mathematics background are controlled, and account for an additional 10% of the gender gap. Informed by results from these studies, we implemented and tested a psychological, self-affirmation intervention aimed at enhancing female students' performance in Physics 1. Self-affirmation reduced the gender gap in performance on both in-class exams and the post-course conceptual physics survey. Further, the benefit of the self

  7. A comprehensive track model for the improvement of corrugation models

    NASA Astrophysics Data System (ADS)

    Gómez, J.; Vadillo, E. G.; Santamaría, J.

    2006-06-01

    This paper presents a detailed model of the railway track based on wave propagation, suitable for corrugation studies. The model analyses both the vertical and the transverse dynamics of the track. Using the finite strip method (FSM), only the cross-section of the rail must be meshed, and thus it is not necessary to discretise a whole span in 3D. This model takes into account the discrete nature of the support, introducing concepts pertaining to the theory of periodic structures in the formulation. Wave superposition is enriched taking into account the contribution of residual vectors. In this way, the model obtains accurate results when a finite section of railway track is considered. Results for the infinite track have been compared against those presented by Gry and Müller. Aside from the improvements provided by the model presented in this paper, which Gry's and Müller's models do not contemplate, the results arising from the comparison prove satisfactory. Finally, the calculated receptances are compared against the experimental values obtained by the authors, demonstrating a fair degree of adequacy. Finally, these receptances are used within a linear model of corrugation developed by the authors.

  8. Beyond standard model physics at current and future colliders

    NASA Astrophysics Data System (ADS)

    Liu, Zhen

    The Large Hadron Collider (LHC), a multinational experiment which began running in 2009, is highly expected to discover new physics that will help us understand the nature of the universe and begin to find solutions to many of the unsolved puzzles of particle physics. For over 40 years the Standard Model has been the accepted theory of elementary particle physics, except for one unconfirmed component, the Higgs boson. The experiments at the LHC have recently discovered this Standard-Model-like Higgs boson. This discovery is one of the most exciting achievements in elementary particle physics. Yet, a profound question remains: Is this rather light, weakly-coupled boson nothing but a Standard Model Higgs or a first manifestation of a deeper theory? Also, the recent discoveries of neutrino mass and mixing, experimental evidences of dark matter and dark energy, matter-antimatter asymmetry, indicate that our understanding of fundamental physics is currently incomplete. For the next decade and more, the LHC and future colliders will be at the cutting-edge of particle physics discoveries and will shed light on many of these unanswered questions. There are many promising beyond-Standard-Model theories that may help solve the central puzzles of particle physics. To fill the gaps in our knowledge, we need to know how these theories will manifest themselves in controlled experiments, such as high energy colliders. I discuss how we can probe fundamental physics at current and future colliders directly through searches for new phenomena such as resonances, rare Higgs decays, exotic displaced signatures, and indirectly through precision measurements on Higgs in this work. I explore beyond standard model physics effects from different perspectives, including explicit models such as supersymmetry, generic models in terms of resonances, as well as effective field theory approach in terms of higher dimensional operators. This work provides a generic and broad overview of the physics

  9. Novel models on fluid's variable thermo-physical properties for extensive study on convection heat and mass transfer

    NASA Astrophysics Data System (ADS)

    Shang, De-Yi; Zhong, Liang-Cai

    2016-04-01

    Our novel models for fluid's variable physical properties are improved and reported systematically in this work for enhancement of theoretical and practical value on study of convection heat and mass transfer. It consists of three models, namely (1) temperature parameter model, (2) polynomial model, and (3) weighted-sum model, respectively for treatment of temperature-dependent physical properties of gases, temperature-dependent physical properties of liquids, and concentration- and temperature-dependent physical properties of vapour-gas mixture. Two related components are proposed, and involved in each model for fluid's variable physical properties. They are basic physic property equations and theoretical similarity equations on physical property factors. The former, as the foundation of the latter, is based on the typical experimental data and physical analysis. The latter is built up by similarity analysis and mathematical derivation based on the former basic physical properties equations. These models are available for smooth simulation and treatment of fluid's variable physical properties for assurance of theoretical and practical value of study on convection of heat and mass transfer. Especially, so far, there has been lack of available study on heat and mass transfer of film condensation convection of vapour-gas mixture, and the wrong heat transfer results existed in widespread studies on the related research topics, due to ignorance of proper consideration of the concentration- and temperature-dependent physical properties of vapour-gas mixture. For resolving such difficult issues, the present novel physical property models have their special advantages.

  10. Application of physical parameter identification to finite element models

    NASA Technical Reports Server (NTRS)

    Bronowicki, Allen J.; Lukich, Michael S.; Kuritz, Steven P.

    1986-01-01

    A time domain technique for matching response predictions of a structural dynamic model to test measurements is developed. Significance is attached to prior estimates of physical model parameters and to experimental data. The Bayesian estimation procedure allows confidence levels in predicted physical and modal parameters to be obtained. Structural optimization procedures are employed to minimize an error functional with physical model parameters describing the finite element model as design variables. The number of complete FEM analyses are reduced using approximation concepts, including the recently developed convoluted Taylor series approach. The error function is represented in closed form by converting free decay test data to a time series model using Prony' method. The technique is demonstrated on simulated response of a simple truss structure.

  11. The limitations of mathematical modeling in high school physics education

    NASA Astrophysics Data System (ADS)

    Forjan, Matej

    The theme of the doctoral dissertation falls within the scope of didactics of physics. Theoretical analysis of the key constraints that occur in the transmission of mathematical modeling of dynamical systems into field of physics education in secondary schools is presented. In an effort to explore the extent to which current physics education promotes understanding of models and modeling, we analyze the curriculum and the three most commonly used textbooks for high school physics. We focus primarily on the representation of the various stages of modeling in the solved tasks in textbooks and on the presentation of certain simplifications and idealizations, which are in high school physics frequently used. We show that one of the textbooks in most cases fairly and reasonably presents the simplifications, while the other two half of the analyzed simplifications do not explain. It also turns out that the vast majority of solved tasks in all the textbooks do not explicitly represent model assumptions based on what we can conclude that in high school physics the students do not develop sufficiently a sense of simplification and idealizations, which is a key part of the conceptual phase of modeling. For the introduction of modeling of dynamical systems the knowledge of students is also important, therefore we performed an empirical study on the extent to which high school students are able to understand the time evolution of some dynamical systems in the field of physics. The research results show the students have a very weak understanding of the dynamics of systems in which the feedbacks are present. This is independent of the year or final grade in physics and mathematics. When modeling dynamical systems in high school physics we also encounter the limitations which result from the lack of mathematical knowledge of students, because they don't know how analytically solve the differential equations. We show that when dealing with one-dimensional dynamical systems

  12. Physical activity levels improve following discharge in people admitted to hospital with an acute exacerbation of chronic obstructive pulmonary disease.

    PubMed

    Tsai, Ling Ling Y; Alison, Jennifer A; McKenzie, David K; McKeough, Zoe J

    2016-02-01

    This study aimed to determine the physical activity level of people admitted to hospital with an acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and whether physical activity changed immediately after discharge and 6 weeks post hospital admission. In this prospective observational study, people admitted to hospital with an AECOPD had physical activity levels monitored using the SenseWear(®) Armband (model MF-SW) for 3 days in hospital (T1), during the first week at home following discharge (T2), and at home during the sixth week after admission (T3). Fifty participants (mean age (SD) 71 (10) years) completed the study. There was a linear increase in average steps per day over the three time periods (T1, mean (SD) 1385 (1972) steps/day; T2, 2040 (2680); T3, 2328 (2745); analysis of variance (ANOVA) p = 0.001) and time spent in moderate activity (3.0-6.0 metabolic equivalents; minutes/day) (T1, mean (SD) 16 (27) minutes/day; T2, 32 (46) minutes/day; T3, 35 (58) minutes/day; ANOVA p = 0.008). For both outcomes, post hoc t-tests showed significant improvements from T1 to T2 and from T1 to T3, but not between T2 and T3. Physical activity was low in hospital and significantly improved in the week after discharge but showed no further significant improvement at 6 weeks following a hospitalized AECOPD. PMID:26374299

  13. The importance of behavior theory in control system modeling of physical activity sensor data.

    PubMed

    Riley, William T; Martin, Cesar A; Rivera, Daniel E

    2014-01-01

    Among health behaviors, physical activity has the most extensive record of research using passive sensors. Control systems and other system dynamic approaches have long been considered applicable for understanding human behavior, but only recently has the technology provided the precise and intensive longitudinal data required for these analytic approaches. Although sensors provide intensive data on the patterns and variations of physical activity over time, the influences of these variations are often unmeasured. Health behavior theories provide an explanatory framework of the putative mediators of physical activity changes. Incorporating the intensive longitudinal measurement of these theoretical constructs is critical to improving the fit of control system model of physical activity and for advancing behavioral theory. Theory-based control models also provide guidance on the nature of the controllers which serve as the basis for just-in-time adaptive interventions based on these control system models. PMID:25571577

  14. Peer Assessment with Online Tools to Improve Student Modeling

    NASA Astrophysics Data System (ADS)

    Atkins, Leslie J.

    2012-11-01

    Introductory physics courses often require students to develop precise models of phenomena and represent these with diagrams, including free-body diagrams, light-ray diagrams, and maps of field lines. Instructors expect that students will adopt a certain rigor and precision when constructing these diagrams, but we want that rigor and precision to be an aid to sense-making rather than meeting seemingly arbitrary requirements set by the instructor. By giving students the authority to develop their own models and establish requirements for their diagrams, the sense that these are arbitrary requirements diminishes and students are more likely to see modeling as a sense-making activity. The practice of peer assessment can help students take ownership; however, it can be difficult for instructors to manage. Furthermore, it is not without risk: students can be reluctant to critique their peers, they may view this as the job of the instructor, and there is no guarantee that students will employ greater rigor and precision as a result of peer assessment. In this article, we describe one approach for peer assessment that can establish norms for diagrams in a way that is student driven, where students retain agency and authority in assessing and improving their work. We show that such an approach does indeed improve students' diagrams and abilities to assess their own work, without sacrificing students' authority and agency.

  15. Effects of Park Improvements on Park Use and Physical Activity Policy and Programming Implications

    PubMed Central

    Cohen, Deborah; Golinelli, Daniela; Williamson, Stephanie; Sehgal, Amber; Marsh, Terry; McKenzie, Thomas L

    2009-01-01

    Background Many assume that improving the quality and the perceived safety of facilities in parks and recreation centers are critical to attracting more users and increasing population physical activity. There are few studies in which these assumptions have been tested. Purpose To assess the impact of park improvements on park use and physical activity. Methods Five intervention parks and five matched comparison parks were studied by objectively measuring park use and collecting self reports of park use by residents before and after park improvements. After using the System for Observing Play and Recreation in Communities (SOPARC) to count park users and measure their activity levels and conducting household interviews and intercept surveys with park users, propensity score analyses were used to adjust for differences in respondents’ characteristics between pre- and post-intervention and across conditions. Results Overall park use and physical activity declined in both intervention and control parks, with 39% of the decline directly attributable to fewer scheduled organized activities. Perceptions of park safety increased more in the intervention parks than in the comparison parks. Conclusions Improvements to parks may not automatically result in increased use and physical activity, especially when programming decreases. Multiple factors contribute to park use and need to be accounted for in future community-level interventions. Improving perceptions of safety alone are unlikely to result in increased park use. PMID:19944911

  16. "Let's get physical": advantages of a physical model over 3D computer models and textbooks in learning imaging anatomy.

    PubMed

    Preece, Daniel; Williams, Sarah B; Lam, Richard; Weller, Renate

    2013-01-01

    Three-dimensional (3D) information plays an important part in medical and veterinary education. Appreciating complex 3D spatial relationships requires a strong foundational understanding of anatomy and mental 3D visualization skills. Novel learning resources have been introduced to anatomy training to achieve this. Objective evaluation of their comparative efficacies remains scarce in the literature. This study developed and evaluated the use of a physical model in demonstrating the complex spatial relationships of the equine foot. It was hypothesized that the newly developed physical model would be more effective for students to learn magnetic resonance imaging (MRI) anatomy of the foot than textbooks or computer-based 3D models. Third year veterinary medicine students were randomly assigned to one of three teaching aid groups (physical model; textbooks; 3D computer model). The comparative efficacies of the three teaching aids were assessed through students' abilities to identify anatomical structures on MR images. Overall mean MRI assessment scores were significantly higher in students utilizing the physical model (86.39%) compared with students using textbooks (62.61%) and the 3D computer model (63.68%) (P < 0.001), with no significant difference between the textbook and 3D computer model groups (P = 0.685). Student feedback was also more positive in the physical model group compared with both the textbook and 3D computer model groups. Our results suggest that physical models may hold a significant advantage over alternative learning resources in enhancing visuospatial and 3D understanding of complex anatomical architecture, and that 3D computer models have significant limitations with regards to 3D learning. PMID:23349117

  17. Improving the Physical Health Monitoring of City & Hackney Assertive Outreach Service Patients

    PubMed Central

    Akyuz, Elvan; jain, amit; phelan, declan; Gupta, Susham

    2016-01-01

    Improving physical healthcare to reduce premature mortality in people with SMI (Serious Mental Illness) is a priority for ELFT (East London NHS Foundation Trust) and NHS England. It is well know that people with schizophrenia have a life expectancy which is approximately 20% shorter than that of the general population and a substantial mortality difference exists between people with schizophrenia and the general community.[1–2] Among other risk factors, such as poor diet, physical inactivity, and high rates of smoking, the iatrogenic effects of anti-psychotic medications have been found to increase the risk of metabolic syndrome. This can easily be detected through regular monitoring. Through this project, it was our aim to improve the physical health monitoring of City & Hackney Assertive Outreach Service (AOS) patients with a view to decrease mortality rate, increase life expectancy, increase the quality of life, and reduce harm from medication. This was done using quality improvement methods, including several change ideas, each of which started sequentially over the course of a nine month period from November 2014. Following QI methodology, this utilised cycles of iterative learning using PDSA methods and was supported by the Trust's extensive programme of quality improvement, including training provided by the Institute for Healthcare Improvement. The project involved setting a specific aim which was improving the physical health monitoring of AOS patients to 80% by July 2015 and for our patients to have physical health checks (blood tests, weight, ECG, BP) as a minimum annually. From baseline measurements of between 50–75%, we reached our target of 80% for weight, BP and blood tests monitoring, with 89%, 91%, and 84% achieved respectively by July 2015. Further progress still needs to be made on ECGs, with 77% achieved by July 2015, although the monitoring of ECG nearly doubled from 39% in November 2014 to 77% in July 2015. This project demonstrated that

  18. Improving the Physical Health Monitoring of City & Hackney Assertive Outreach Service Patients.

    PubMed

    Akyuz, Elvan; Jain, Amit; Phelan, Declan; Gupta, Susham

    2016-01-01

    Improving physical healthcare to reduce premature mortality in people with SMI (Serious Mental Illness) is a priority for ELFT (East London NHS Foundation Trust) and NHS England. It is well know that people with schizophrenia have a life expectancy which is approximately 20% shorter than that of the general population and a substantial mortality difference exists between people with schizophrenia and the general community.[1-2] Among other risk factors, such as poor diet, physical inactivity, and high rates of smoking, the iatrogenic effects of anti-psychotic medications have been found to increase the risk of metabolic syndrome. This can easily be detected through regular monitoring. Through this project, it was our aim to improve the physical health monitoring of City & Hackney Assertive Outreach Service (AOS) patients with a view to decrease mortality rate, increase life expectancy, increase the quality of life, and reduce harm from medication. This was done using quality improvement methods, including several change ideas, each of which started sequentially over the course of a nine month period from November 2014. Following QI methodology, this utilised cycles of iterative learning using PDSA methods and was supported by the Trust's extensive programme of quality improvement, including training provided by the Institute for Healthcare Improvement. The project involved setting a specific aim which was improving the physical health monitoring of AOS patients to 80% by July 2015 and for our patients to have physical health checks (blood tests, weight, ECG, BP) as a minimum annually. From baseline measurements of between 50-75%, we reached our target of 80% for weight, BP and blood tests monitoring, with 89%, 91%, and 84% achieved respectively by July 2015. Further progress still needs to be made on ECGs, with 77% achieved by July 2015, although the monitoring of ECG nearly doubled from 39% in November 2014 to 77% in July 2015. This project demonstrated that

  19. Physical microscopic model of proteins under force.

    PubMed

    Dokholyan, Nikolay V

    2012-06-14

    Nature has evolved proteins to counteract forces applied on living cells, and has designed proteins that can sense forces. One can appreciate Nature's ingenuity in evolving these proteins to be highly sensitive to force and to have a high dynamic force range at which they operate. To achieve this level of sensitivity, many of these proteins are composed of multiple domains and linking peptides connecting these domains, each of them having their own force response regimes. Here, using a simple model of a protein, we address the question of how each individual domain responds to force. We also ask how multidomain proteins respond to forces. We find that the end-to-end distance of individual domains under force scales linearly with force. In multidomain proteins, we find that the force response has a rich range: at low force, extension is predominantly governed by "weaker" linking peptides or domain intermediates, while at higher force, the extension is governed by unfolding of individual domains. Overall, the force extension curve comprises multiple sigmoidal transitions governed by unfolding of linking peptides and domains. Our study provides a basic framework for the understanding of protein response to force, and allows for interpretation experiments in which force is used to study the mechanical properties of multidomain proteins. PMID:22375559

  20. Beyond the Fluid Approximation: Improved Modeling of the Intracluster Plasma

    NASA Astrophysics Data System (ADS)

    O'Shea, Brian

    surveys targeting galaxy clusters. This project is innovative due to its novel combination of cosmological simulations of galaxy clusters with physics-rich non-ideal MHD, hybrid gyrokinetic+MHD, and particle-in-cell electrodynamics calculations, which will enable us to reliably explore astrophysical plasma behavior over a far greater range of spatial scales than has been previously possible. The understanding gained by doing this will translate directly to more accurate cosmological simulations of galaxy clusters, and will be transformative in terms of our ability to use clusters as cosmological probes and as laboratories for plasma physics in extreme environments. This work will directly impact current and future X-ray, Sunyaev-Zel'dovich, and radio surveys of galaxy clusters, and will lead to improved modeling of plasma physics in a range of astrophysical situations.

  1. Applying Transtheoretical Model to Promote Physical Activities Among Women

    PubMed Central

    Pirzadeh, Asiyeh; Mostafavi, Firoozeh; Ghofranipour, Fazllolah; Feizi, Awat

    2015-01-01

    Background: Physical activity is one of the most important indicators of health in communities but different studies conducted in the provinces of Iran showed that inactivity is prevalent, especially among women. Objectives: Inadequate regular physical activities among women, the importance of education in promoting the physical activities, and lack of studies on the women using transtheoretical model, persuaded us to conduct this study with the aim of determining the application of transtheoretical model in promoting the physical activities among women of Isfahan. Materials and Methods: This research was a quasi-experimental study which was conducted on 141 women residing in Isfahan, Iran. They were randomly divided into case and control groups. In addition to the demographic information, their physical activities and the constructs of the transtheoretical model (stages of change, processes of change, decisional balance, and self-efficacy) were measured at 3 time points; preintervention, 3 months, and 6 months after intervention. Finally, the obtained data were analyzed through t test and repeated measures ANOVA test using SPSS version 16. Results: The results showed that education based on the transtheoretical model significantly increased physical activities in 2 aspects of intensive physical activities and walking, in the case group over the time. Also, a high percentage of people have shown progress during the stages of change, the mean of the constructs of processes of change, as well as pros and cons. On the whole, a significant difference was observed over the time in the case group (P < 0.01). Conclusions: This study showed that interventions based on the transtheoretical model can promote the physical activity behavior among women. PMID:26834796

  2. Spin-foam models and the physical scalar product

    SciTech Connect

    Alesci, Emanuele; Noui, Karim; Sardelli, Francesco

    2008-11-15

    This paper aims at clarifying the link between loop quantum gravity and spin-foam models in four dimensions. Starting from the canonical framework, we construct an operator P acting on the space of cylindrical functions Cyl({gamma}), where {gamma} is the four-simplex graph, such that its matrix elements are, up to some normalization factors, the vertex amplitude of spin-foam models. The spin-foam models we are considering are the topological model, the Barrett-Crane model, and the Engle-Pereira-Rovelli model. If one of these spin-foam models provides a covariant quantization of gravity, then the associated operator P should be the so-called ''projector'' into physical states and its matrix elements should give the physical scalar product. We discuss the possibility to extend the action of P to any cylindrical functions on the space manifold.

  3. Technical Manual for the SAM Physical Trough Model

    SciTech Connect

    Wagner, M. J.; Gilman, P.

    2011-06-01

    NREL, in conjunction with Sandia National Lab and the U.S Department of Energy, developed the System Advisor Model (SAM) analysis tool for renewable energy system performance and economic analysis. This paper documents the technical background and engineering formulation for one of SAM's two parabolic trough system models in SAM. The Physical Trough model calculates performance relationships based on physical first principles where possible, allowing the modeler to predict electricity production for a wider range of component geometries than is possible in the Empirical Trough model. This document describes the major parabolic trough plant subsystems in detail including the solar field, power block, thermal storage, piping, auxiliary heating, and control systems. This model makes use of both existing subsystem performance modeling approaches, and new approaches developed specifically for SAM.

  4. Snyder-de Sitter model from two-time physics

    SciTech Connect

    Carrisi, M. C.; Mignemi, S.

    2010-11-15

    We show that the symplectic structure of the Snyder model on a de Sitter background can be derived from two-time physics in seven dimensions and propose a Hamiltonian for a free particle consistent with the symmetries of the model.

  5. Partial Possible Models: An Approach To Interpret Students' Physical Representation.

    ERIC Educational Resources Information Center

    Camacho, Fernando Flores; Cazares, Leticia Gallegos

    1998-01-01

    Illustrates the construction of conceptual models on pressure and flotation using high school students' previous ideas on these concepts. Identifies three models and uses them to analyze students' ideas about physical phenomena and to recognize the inferential structure they use. Contains 28 references. (DDR)

  6. Investigating Student Understanding of Quantum Physics: Spontaneous Models of Conductivity.

    ERIC Educational Resources Information Center

    Wittmann, Michael C.; Steinberg, Richard N.; Redish, Edward F.

    2002-01-01

    Investigates student reasoning about models of conduction. Reports that students often are unable to account for the existence of free electrons in a conductor and create models that lead to incorrect predictions and responses contradictory to expert descriptions of the physics involved. (Contains 36 references.) (Author/YDS)

  7. Rock.XML - Towards a library of rock physics models

    NASA Astrophysics Data System (ADS)

    Jensen, Erling Hugo; Hauge, Ragnar; Ulvmoen, Marit; Johansen, Tor Arne; Drottning, Åsmund

    2016-08-01

    Rock physics modelling provides tools for correlating physical properties of rocks and their constituents to the geophysical observations we measure on a larger scale. Many different theoretical and empirical models exist, to cover the range of different types of rocks. However, upon reviewing these, we see that they are all built around a few main concepts. Based on this observation, we propose a format for digitally storing the specifications for rock physics models which we have named Rock.XML. It does not only contain data about the various constituents, but also the theories and how they are used to combine these building blocks to make a representative model for a particular rock. The format is based on the Extensible Markup Language XML, making it flexible enough to handle complex models as well as scalable towards extending it with new theories and models. This technology has great advantages as far as documenting and exchanging models in an unambiguous way between people and between software. Rock.XML can become a platform for creating a library of rock physics models; making them more accessible to everyone.

  8. B-meson decay constants from improved lattice nonrelativistic QCD with physical u, d, s, and c quarks.

    PubMed

    Dowdall, R J; Davies, C T H; Horgan, R R; Monahan, C J; Shigemitsu, J

    2013-05-31

    We present the first lattice QCD calculation of the decay constants f(B) and f(B(s)) with physical light quark masses. We use configurations generated by the MILC Collaboration including the effect of u, d, s, and c highly improved staggered quarks in the sea at three lattice spacings and with three u/d quark mass values going down to the physical value. We use improved nonrelativistic QCD (NRQCD) for the valence b quarks. Our results are f(B)=0.186(4) GeV, f(B(s))=0.224(4) GeV, f(B(s))/f(B)=1.205(7), and M(B(s))-M(B)=85(2) MeV, superseding earlier results with NRQCD b quarks. We discuss the implications of our results for the standard model rates for B((s))→μ(+)μ(-) and B→τν. PMID:23767714

  9. A physical model of Titan's aerosols.

    PubMed

    Toon, O B; McKay, C P; Griffith, C A; Turco, R P

    1992-01-01

    Microphysical simulations of Titan's stratospheric haze show that aerosol microphysics is linked to organized dynamical processes. The detached haze layer may be a manifestation of 1 cm sec-1 vertical velocities at altitudes above 300 km. The hemispherical asymmetry in the visible albedo may be caused by 0.05 cm sec-1 vertical velocities at altitudes of 150 to 200 km, we predict contrast reversal beyond 0.6 micrometer. Tomasko and Smith's (1982, Icarus 51, 65-95) model, in which a layer of large particles above 220 km altitude is responsible for the high forward scattering observed by Rages and Pollack (1983, Icarus 55, 50-62), is a natural outcome of the detached haze layer being produced by rising motions if aerosol mass production occurs primarily below the detached haze layer. The aerosol's electrical charge is critical for the particle size and optical depth of the haze. The geometric albedo, particularly in the ultraviolet and near infrared, requires that the particle size be near 0.15 micrometer down to altitudes below 100 km, which is consistent with polarization observations (Tomasko and Smith 1982, West and Smith 1991, Icarus 90, 330-333). Above about 400 km and below about 150 km Yung et al.'s (1984, Astrophys. J. Suppl. Ser. 55, 465-506) diffusion coefficients are too small. Dynamical processes control the haze particles below about 150 km. The relatively large eddy diffusion coefficients in the lower stratosphere result in a vertically extensive region with nonuniform mixing ratios of condensable gases, so that most hydrocarbons may condense very near the tropopause rather than tens of kilometers above it. The optical depths of hydrocarbon clouds are probably less than one, requiring that abundant gases such as ethane condense on a subset of the haze particles to create relatively large, rapidly removed particles. The wavelength dependence of the optical radius is calculated for use in analyzing observations of the geometric albedo. The lower

  10. How can model comparison help improving species distribution models?

    PubMed

    Gritti, Emmanuel Stephan; Gaucherel, Cédric; Crespo-Perez, Maria-Veronica; Chuine, Isabelle

    2013-01-01

    Today, more than ever, robust projections of potential species range shifts are needed to anticipate and mitigate the impacts of climate change on biodiversity and ecosystem services. Such projections are so far provided almost exclusively by correlative species distribution models (correlative SDMs). However, concerns regarding the reliability of their predictive power are growing and several authors call for the development of process-based SDMs. Still, each of these methods presents strengths and weakness which have to be estimated if they are to be reliably used by decision makers. In this study we compare projections of three different SDMs (STASH, LPJ and PHENOFIT) that lie in the continuum between correlative models and process-based models for the current distribution of three major European tree species, Fagussylvatica L., Quercusrobur L. and Pinussylvestris L. We compare the consistency of the model simulations using an innovative comparison map profile method, integrating local and multi-scale comparisons. The three models simulate relatively accurately the current distribution of the three species. The process-based model performs almost as well as the correlative model, although parameters of the former are not fitted to the observed species distributions. According to our simulations, species range limits are triggered, at the European scale, by establishment and survival through processes primarily related to phenology and resistance to abiotic stress rather than to growth efficiency. The accuracy of projections of the hybrid and process-based model could however be improved by integrating a more realistic representation of the species resistance to water stress for instance, advocating for pursuing efforts to understand and formulate explicitly the impact of climatic conditions and variations on these processes. PMID:23874779

  11. The Effects of a Model-Based Physics Curriculum Program with a Physics First Approach: A Causal-Comparative Study

    ERIC Educational Resources Information Center

    Liang, Ling L.; Fulmer, Gavin W.; Majerich, David M.; Clevenstine, Richard; Howanski, Raymond

    2012-01-01

    The purpose of this study is to examine the effects of a model-based introductory physics curriculum on conceptual learning in a Physics First (PF) Initiative. This is the first comparative study in physics education that applies the Rasch modeling approach to examine the effects of a model-based curriculum program combined with PF in the United…

  12. Modeling of surface roughness: application to physical properties of paper

    NASA Astrophysics Data System (ADS)

    Bloch, Jean-Francis; Butel, Marc

    2000-09-01

    Papermaking process consists in a succession of unit operations having for main objective the expression of water out of the wet paper pad. The three main stages are successively, the forming section, the press section and finally the drying section. Furthermore, another operation (calendering) may be used to improve the surface smoothness. Forming, pressing and drying are not on the scope of this paper, but the influence of formation and calendering on surface roughness is analyzed. The main objective is to characterize the materials and specially its superficial structure. The proposed model is described in order to analyze this topographical aspect. Some experimental results are presented in order to illustrate the interest of this method to better understand physical properties. This work is therefore dedicated to the description of the proposed model: the studied surface is measured at a microscopic scale using for example, a classical stylus profilometry method. Then the obtained surface is transformed using a conformal mapping that retains the surface orientations. Due to the anisotropy of the fiber distribution in the plane of the sheet, the resulting surface is often not isotropic. Hence, the micro facets that identify the interfaces between pores and solid (fibers in the studied case) at the micro level are transformed into a macroscopic equivalent structure. Furthermore, an ellipsoid may be fit to the experimental data in order to obtain a simple model. The ellipticities are proved to be linked for paper to both fiber orientation (through other optical methods) and roughness. These parameters (ellipticities) are shown to be very significant for different end-use properties. Indeed, they shown to be correlated to printing or optical properties, such as gloss for example. We present in a first part the method to obtain a macroscopic description from physical microscopic measurements. Then measurements carried on different paper samples, using a classical

  13. Physically-based landslide susceptibility modelling: geotechnical testing and model evaluation issues

    NASA Astrophysics Data System (ADS)

    Marchesini, Ivan; Mergili, Martin; Schneider-Muntau, Barbara; Alvioli, Massimiliano; Rossi, Mauro; Guzzetti, Fausto

    2015-04-01

    We used the software r.slope.stability for physically-based landslide susceptibility modelling in the 90 km² Collazzone area, Central Italy, exploiting a comprehensive set of lithological, geotechnical, and landslide inventory data. The model results were evaluated against the inventory. r.slope.stability is a GIS-supported tool for modelling shallow and deep-seated slope stability and slope failure probability at comparatively broad scales. Developed as a raster module of the GRASS GIS software, r.slope.stability evaluates the slope stability for a large number of randomly selected ellipsoidal potential sliding surfaces. The bottom of the soil (for shallow slope stability) or the bedding planes of lithological layers (for deep-seated slope stability) are taken as potential sliding surfaces by truncating the ellipsoids, allowing for the analysis of relatively complex geological structures. To take account for the uncertain geotechnical and geometric parameters, r.slope.stability computes the slope failure probability by testing multiple parameter combinations sampled deterministically or stochastically, and evaluating the ratio between the number of parameter combinations yielding a factor of safety below 1 and the total number of tested combinations. Any single raster cell may be intersected by multiple sliding surfaces, each associated with a slope failure probability. The most critical sliding surface is relevant for each pixel. Intensive use of r.slope.stability in the Collazzone Area has opened up two questions elaborated in the present work: (i) To what extent does a larger number of geotechnical tests help to better constrain the geotechnical characteristics of the study area and, consequently, to improve the model results? The ranges of values of cohesion and angle of internal friction obtained through 13 direct shear tests corresponds remarkably well to the range of values suggested by a geotechnical textbook. We elaborate how far an increased number of

  14. Acute physical exercise improves shifting in adolescents at school: evidence for a dopaminergic contribution

    PubMed Central

    Berse, Timo; Rolfes, Kathrin; Barenberg, Jonathan; Dutke, Stephan; Kuhlenbäumer, Gregor; Völker, Klaus; Winter, Bernward; Wittig, Michael; Knecht, Stefan

    2015-01-01

    The executive function of shifting between mental sets demands cognitive flexibility. Based on evidence that physical exercise fostered cognition, we tested whether acute physical exercise can improve shifting in an unselected sample of adolescents. Genetic polymorphisms were analyzed to gain more insight into possibly contributing neurophysiological processes. We examined 297 students aged between 13 and 17 years in their schools. Physical exercise was manipulated by an intense incremental exercise condition using bicycle ergometers and a control condition which involved watching an infotainment cartoon while sitting calm. The order of conditions was counterbalanced between participants. Shifting was assessed by a switching task after both conditions. Acute intense physical exercise significantly improved shifting as indicated by reduced switch costs. Exercise-induced performance gains in switch costs were predicted by a single nucleotide polymorphism (SNP) targeting the Dopamine Transporter (DAT1/SLCA6A3) gene suggesting that the brain dopamine system contributed to the effect. The results demonstrate the potential of acute physical exercise to improve cognitive flexibility in adolescents. The field conditions of the present approach suggest applications in schools. PMID:26283937

  15. Acute physical exercise improves shifting in adolescents at school: evidence for a dopaminergic contribution.

    PubMed

    Berse, Timo; Rolfes, Kathrin; Barenberg, Jonathan; Dutke, Stephan; Kuhlenbäumer, Gregor; Völker, Klaus; Winter, Bernward; Wittig, Michael; Knecht, Stefan

    2015-01-01

    The executive function of shifting between mental sets demands cognitive flexibility. Based on evidence that physical exercise fostered cognition, we tested whether acute physical exercise can improve shifting in an unselected sample of adolescents. Genetic polymorphisms were analyzed to gain more insight into possibly contributing neurophysiological processes. We examined 297 students aged between 13 and 17 years in their schools. Physical exercise was manipulated by an intense incremental exercise condition using bicycle ergometers and a control condition which involved watching an infotainment cartoon while sitting calm. The order of conditions was counterbalanced between participants. Shifting was assessed by a switching task after both conditions. Acute intense physical exercise significantly improved shifting as indicated by reduced switch costs. Exercise-induced performance gains in switch costs were predicted by a single nucleotide polymorphism (SNP) targeting the Dopamine Transporter (DAT1/SLCA6A3) gene suggesting that the brain dopamine system contributed to the effect. The results demonstrate the potential of acute physical exercise to improve cognitive flexibility in adolescents. The field conditions of the present approach suggest applications in schools. PMID:26283937

  16. Body Mass Index, Physical Activity, and Working Memory in a Sample of Children with Down Syndrome: Can Physical Activity Improve Learning in Children with Intellectual Disabilities?

    ERIC Educational Resources Information Center

    Ellis, Geertina Houthuijzen

    2013-01-01

    Research has suggested that in typical developing children a positive relationship exists between physical activity level and cognitive functioning. For some children, academic performance may increase when levels of physical activity are increased. Moreover, some studies have supported the idea that physical activity seems to improve attention.…

  17. Search for Beyond the Standard Model Physics at D0

    SciTech Connect

    Kraus, James

    2011-08-01

    The standard model (SM) of particle physics has been remarkably successful at predicting the outcomes of particle physics experiments, but there are reasons to expect new physics at the electroweak scale. Over the last several years, there have been a number of searches for beyond the standard model (BSM) physics at D0. Here, we limit our focus to three: searches for diphoton events with large missing transverse energy (E{sub T}), searches for leptonic jets and E{sub T}, and searches for single vector-like quarks. We have discussed three recent searches at D0. There are many more, including limits on heavy neutral gauge boson in the ee channel, a search for scalar top quarks, a search for quirks, and limits on a new resonance decaying to WW or WZ.

  18. Strategies to encourage physical activity in patients with hemophilia to improve quality of life

    PubMed Central

    Goto, Miwa; Takedani, Hideyuki; Yokota, Kazuhiko; Haga, Nobuhiko

    2016-01-01

    Hemophilia is a bleeding disorder caused by a congenital abnormality of blood coagulation. Until the mid-1970s, patients with hemophilia (PWH) were advised to refrain from physical activity (PA) because of a perceived increased risk of bleeding. Since then, PA, which is recognized as being essential for health maintenance, is now recommended by the World Federation of Hemophilia. Moreover, a number of studies reported that PA can improve treatment efficacy and prevent bleeding in PWH. Physical assessment and intervention in PA are currently used in clinical practice. However, the necessity of PA is not emphasized, and many PWH generally have low- to- no PA. Therefore, a behavior change approach to encourage patient motivation is becoming ever more important. In this article, we review articles addressing PA in PWH and discuss strategies to encourage PA through a behavior change approach by focusing on factors relevant to hemophilia, such as benefits and bleeding risk of PA, risk management of bleeding, PA characteristics, and difficulty with exercise adherence. The trust relationship between clinicians and patients, a transtheoretical model of behavior change, and motivation theory as approaches to promote PA are introduced. Finally, we review a case report of the clinical success of a behavior change approach to promote PA. Many PWH find it difficult to continue PA because of aging, fear of bleeding, insufficient recognition of PA benefits, and psychological problems. Therefore, it is essential and important to perform prophylaxis with PWH and to heighten their understanding of the benefits and risks of PA, before initiating the exercise regimen. For those patients who find it difficult to participate in PA, it is necessary to plan individual-based behavior change approach and encourage self-efficacy. PMID:27274330

  19. A physical data model for fields and agents

    NASA Astrophysics Data System (ADS)

    de Jong, Kor; de Bakker, Merijn; Karssenberg, Derek

    2016-04-01

    Two approaches exist in simulation modeling: agent-based and field-based modeling. In agent-based (or individual-based) simulation modeling, the entities representing the system's state are represented by objects, which are bounded in space and time. Individual objects, like an animal, a house, or a more abstract entity like a country's economy, have properties representing their state. In an agent-based model this state is manipulated. In field-based modeling, the entities representing the system's state are represented by fields. Fields capture the state of a continuous property within a spatial extent, examples of which are elevation, atmospheric pressure, and water flow velocity. With respect to the technology used to create these models, the domains of agent-based and field-based modeling have often been separate worlds. In environmental modeling, widely used logical data models include feature data models for point, line and polygon objects, and the raster data model for fields. Simulation models are often either agent-based or field-based, even though the modeled system might contain both entities that are better represented by individuals and entities that are better represented by fields. We think that the reason for this dichotomy in kinds of models might be that the traditional object and field data models underlying those models are relatively low level. We have developed a higher level conceptual data model for representing both non-spatial and spatial objects, and spatial fields (De Bakker et al. 2016). Based on this conceptual data model we designed a logical and physical data model for representing many kinds of data, including the kinds used in earth system modeling (e.g. hydrological and ecological models). The goal of this work is to be able to create high level code and tools for the creation of models in which entities are representable by both objects and fields. Our conceptual data model is capable of representing the traditional feature data

  20. Physical and numerical modeling of Joule-heated melters

    NASA Astrophysics Data System (ADS)

    Eyler, L. L.; Skarda, R. J.; Crowder, R. S., III; Trent, D. S.; Reid, C. R.; Lessor, D. L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable.

  1. Physical and numerical modeling of Joule-heated melters

    SciTech Connect

    Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

    1985-10-01

    The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs.

  2. Gravity model improvement investigation. [improved gravity model for determination of ocean geoid

    NASA Technical Reports Server (NTRS)

    Siry, J. W.; Kahn, W. D.; Bryan, J. W.; Vonbun, F. F.

    1973-01-01

    This investigation was undertaken to improve the gravity model and hence the ocean geoid. A specific objective is the determination of the gravity field and geoid with a space resolution of approximately 5 deg and a height resolution of the order of five meters. The concept of the investigation is to utilize both GEOS-C altimeter and satellite-to-satellite tracking data to achieve the gravity model improvement. It is also planned to determine the geoid in selected regions with a space resolution of about a degree and a height resolution of the order of a meter or two. The short term objectives include the study of the gravity field in the GEOS-C calibration area outlined by Goddard, Bermuda, Antigua, and Cape Kennedy, and also in the eastern Pacific area which is viewed by ATS-F.

  3. Physical modeling of geometrically confined disordered protein assemblies

    NASA Astrophysics Data System (ADS)

    Ando, David

    The mental health of soldiers is a growing concern as rates of depression and suicide have increased in soldiers with recently more deaths attributed to suicide than deaths due to combat in Afghanistan in 2012. Previous research has demonstrated the potential for eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), vitamin D, physical activity, and physical fitness to improve and arachidonic acid (AA) to threaten depression/quality of life scores. This study examined whether blood fatty acid levels, vitamin D status and/or physical activity are associated with physical fitness scores, measures of mood, and measures of resiliency in active duty soldiers. 100 active duty males at Fort Hood, TX underwent a battery of psychometric tests, anthropometric, fitness tests, and donated fasting blood samples. Pearson bivariate correlation analysis revealed significant correlations among psychometric tests, anthropometric, physical performance, reported physical inactivity (sitting time), and fatty acid and vitamin D blood levels. Categorical analysis revealed significant difference in levels of fatty acids and vitamin D, anthropometric, physical performance, and psychometric measures. Based on these findings, a regression equation was developed to predict a depressed mood status as determined by the Patient Health Questionnaire-9. The equation accurately predicted 80% of our participants with a sensitivity of 76.9% and a specificity of 80.5%. Results indicate that lack of physical activity and fitness, high levels of AA and low levels of EPA, DHA, and vitamin D could increase the risk of depressed mood and that use of a regression equation may be helpful in identifying soldiers at higher risk for possible intervention. Future studies should evaluate the impact of exercise and diet interventions as a means of improving resiliency and reducing depressed mood in soldiers.

  4. Acute physical exercise under hypoxia improves sleep, mood and reaction time.

    PubMed

    de Aquino-Lemos, Valdir; Santos, Ronaldo Vagner T; Antunes, Hanna Karen Moreira; Lira, Fabio S; Luz Bittar, Irene G; Caris, Aline V; Tufik, Sergio; de Mello, Marco Tulio

    2016-02-01

    This study aimed to assess the effect of two sessions of acute physical exercise at 50% VO2peak performed under hypoxia (equivalent to an altitude of 4500 m for 28 h) on sleep, mood and reaction time. Forty healthy men were randomized into 4 groups: Normoxia (NG) (n = 10); Hypoxia (HG) (n = 10); Exercise under Normoxia (ENG) (n = 10); and Exercise under Hypoxia (EHG) (n = 10). All mood and reaction time assessments were performed 40 min after awakening. Sleep was reassessed on the first day at 14 h after the initiation of hypoxia; mood and reaction time were measured 28 h later. Two sessions of acute physical exercise at 50% VO2peak were performed for 60 min on the first and second days after 3 and 27 h, respectively, after starting to hypoxia. Improved sleep efficiency, stage N3 and REM sleep and reduced wake after sleep onset were observed under hypoxia after acute physical exercise. Tension, anger, depressed mood, vigor and reaction time scores improved after exercise under hypoxia. We conclude that hypoxia impairs sleep, reaction time and mood. Acute physical exercise at 50% VO2peak under hypoxia improves sleep efficiency, reversing the aspects that had been adversely affected under hypoxia, possibly contributing to improved mood and reaction time. PMID:26522742

  5. Improving Students' Revision of Physics Concepts through ICT-Based Co-Construction and Prescriptive Tutoring

    ERIC Educational Resources Information Center

    Soong, Benson; Mercer, Neil

    2011-01-01

    In this paper, we describe and discuss an information and communication technology (ICT)-based intervention designed to improve secondary school students' "revision" (in contrast to "learning") of physics concepts. We show that students' engagement in joint activities via our ICT-based intervention can provide them (and their teachers) with…

  6. Addition of cover crops enhances no-till potential for improving soil physical properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interest in the use of cover crops (CC) is growing. Inclusion of CC may be a potential strategy to boost no-till performance by improving soil physical properties. To assess this potential, we utilized a wheat [Triticum aestivum (L.)]-grain sorghum [Sorghum bicolor (L.) Moench] rotation, four N rate...

  7. Multiple Voices: Improving Participation of Muslim Girls in Physical Education and School Sport

    ERIC Educational Resources Information Center

    Dagkas, Symeon; Benn, Tansin; Jawad, Haifaa

    2011-01-01

    This study reports on data from a larger-scale research project in one city in the West Midlands, England. The study was commissioned by the local education authority because of the rising incidence of parental withdrawal of Muslim girls from physical education. The aim was to provide evidence-based guidance to schools on improving the inclusion…

  8. Female role models in physics education in Ireland

    NASA Astrophysics Data System (ADS)

    Chormaic, Síle Nic; Fee, Sandra; Tobin, Laura; Hennessy, Tara

    2013-03-01

    In this paper we consider the statistics on undergraduate student representation in Irish universities and look at student numbers in secondary (high) schools in one region in Ireland. There seems to be no significant change in female participation in physics from 2002 to 2011. Additionally, we have studied the influence of an educator's gender on the prevalence of girls studying physics in secondary schools in Co. Louth, Ireland, and at the postgraduate level in Irish universities. It would appear that strong female role models have a positive influence and lead to an increase in girls' participation in physics.

  9. Rupture Directivity in a Foam Rubber Physical Model

    NASA Astrophysics Data System (ADS)

    Anooshehpoor, R.; Brune, J. N.

    2003-12-01

    Understanding earthquake rupture dynamics, especially forward rupture directivity (focusing of seismic energy in the direction of rupture propagation), is crucial in determining the seismic hazard for critical structures located near major active faults. We use foam rubber modeling experiments to provide constraints on parameters that control rupture dynamics, and consequently, forward directivity effects. Numerical models currently in use have too many unconstrained parameters to allow confidence in predictions, and may not even be realistic from a physical point of view. The foam rubber model allows us to develop a deep physical understanding of an actual physical model. This in turn will allow us to better specify which physical parameters used in numerical models are critical, and establish a realistic range for their values, and to better understand and qualify particular numerical models. Three-dimensional numerical simulations of earlier experiments with excellent results provided incentive for additional funding from PEER to increase the number of recording channels in the model from 32 to 76. In particular, we have increased the number of recording sites on the fault plane from 12 to 35 to provide a better picture of the slip distribution on the fault during rupture. At the time of meeting we will present waveforms for selected events.

  10. The Pharmacology of Actoprotectors: Practical Application for Improvement of Mental and Physical Performance

    PubMed Central

    Oliynyk, Sergiy; Oh, Seikwan

    2012-01-01

    Actoprotectors are preparations that enhance body stability against physical loads without increasing oxygen consumption or heat production. Or, in short, actoprotectors are synthetic adaptogens with a significant capacity to improve physical performance. This paper explores the history of actoprotectors’development, their pharmacological properties, mechanism of action, and practical application to the improvement of mental and physical performance. A brief summary of the clinico-pharmacological characteristics of the main representatives of this class (bemitil and bromantane) is provided. Some other synthesized compounds, and even natural ones such as ginseng, also are regarded as potential actoprotectors, and these are treated herein as well. Actoprotectors, owing to their wide-ranging pharmacological activities, high efficiency and safety, can be applied under either normal or extreme conditions. PMID:24009833

  11. A Physical Model of Electron Radiation Belts of Saturn

    NASA Astrophysics Data System (ADS)

    Lorenzato, L.; Sicard-Piet, A.; Bourdarie, S.

    2012-04-01

    Radiation belts causes irreversible damages on on-board instruments materials. That's why for two decades, ONERA proposes studies about radiation belts of magnetized planets. First, in the 90's, the development of a physical model, named Salammbô, carried out a model of the radiation belts of the Earth. Then, for few years, analysis of the magnetosphere of Jupiter and in-situ data (Pioneer, Voyager, Galileo) allow to build a physical model of the radiation belts of Jupiter. Enrolling on the Cassini age and thanks to all information collected, this study permits to adapt Salammbô jovian radiation belts model to the case of Saturn environment. Indeed, some physical processes present in the kronian magnetosphere are similar to those present in the magnetosphere of Jupiter (radial diffusion; interaction of energetic electrons with rings, moons, atmosphere; synchrotron emission). However, some physical processes have to be added to the kronian model (compared to the jovian model) because of the particularity of the magnetosphere of Saturn: interaction of energetic electrons with neutral particles from Enceladus, and wave-particle interaction. This last physical process has been studied in details with the analysis of CASSINI/RPWS (Radio and Plasma Waves Science) data. The major importance of the wave particles interaction is now well known in the case of the radiation belts of the Earth but it is important to investigate on its role in the case of Saturn. So, importance of each physical process has been studied and analysis of Cassini MIMI-LEMMS and CAPS data allows to build a model boundary condition (at L = 6). Finally, results of this study lead to a kronian electrons radiation belts model including radial diffusion, interactions of energetic electrons with rings, moons and neutrals particles and wave-particle interaction (interactions of electrons with atmosphere particles and synchrotron emission are too weak to be taken into account in this model). Then, to

  12. Improved molecular collision models for nonequilibrium rarefied gases

    NASA Astrophysics Data System (ADS)

    Parsons, Neal

    -dissociation SO internal energy. Implemented into DSMC, the MD/QCT-based models had a significant effect on simulations of simple, thermal nonequilibrium heat bath and 2D counterflow cases approximating the upper atmospheric conditions of Io. In high-fidelity 1D simulations of the atmosphere of Io, the MD/QCT models predicted approximately half the SO2 atmospheric dissociation due to O and O+ bombardment and a temperature rise due to plasma heating further from the Ionian surface than the existing baseline methodologies. Hypersonic spacecraftre-entering Earth's atmosphere experience significant heating from the post-shock gas. The DSMC method is used to model hypersonic shocks during the early stages of re-entry because of the rarefied nature of the atmosphere at high altitudes. Improved modeling of the N-N 2 and N2-N 2 collision pairs are thus generated with MD/QCT. For the N-N2 pair, a potential energy surface developed at NASA Ames is used and, for the N2-N2 pair, a new potential energy surface is developed using a ReaxFF fit to recent advanced ab initio computations. The MD/QCT-computed total cross sections agreed well with the baseline models, but the MD/QCT reaction probabilities exhibited better physical behavior, a stronger dependence on initial molecular internal energy, and were generally lower than the baseline DSMC chemistry models for strong nonequilibrium conditions, but higher for equilibrium conditions. Furthermore, the MD/QCT results predicted faster rotational-translational energy relaxation for the N-N2 pair and faster vibrational-translational energy relaxation for the N2-N2 pair. The MD/QCT models were tested in DSMC simulations of 2D axisymmetric hypersonic flow over a blunt body and thermal nonequilibrium heat bath cases. The MD/QCT models led to increased post-shock N2 dissociation and faster rates of internal energy relaxation, each of which led to corresponding decreases in translational temperature.

  13. Technique to model and design physical database systems

    SciTech Connect

    Wise, T.E.

    1983-12-01

    Database management systems (DBMSs) allow users to define and manipulate records at a logical level of abstraction. A logical record is not stored as users see it but is mapped into a collection of physical records. Physical records are stored in file structures managed by a DBMS. Likewise, DBMS commands which appear to be directed toward one or more logical records actually correspond to a series of operations on the file structures. The structures and operations of a DBMS (i.e., its physical architecture) are not visible to users at the logical level. Traditionally, logical records and DBMS commands are mapped to physical records and operations in one step. In this report, logical records are mapped to physical records in a series of steps over several levels of abstraction. Each level of abstraction is composed of one or more intermediate record types. A hierarchy of record types results that covers the gap between logical and physical records. The first step of our technique identifies the record types and levels of abstraction that describe a DBMS. The second step maps DBMS commands to physical operations in terms of these records and levels of abstraction. The third step encapsulates each record type and its operations into a programming construct called a module. The applications of our technique include modeling existing DBMSs and designing the physical architectures of new DBMSs. To illustrate one application, we describe in detail the architecture of the commercial DBMS INQUIRE.

  14. Plans for performance and model improvements in the LISE++ software

    NASA Astrophysics Data System (ADS)

    Kuchera, M. P.; Tarasov, O. B.; Bazin, D.; Sherrill, B. M.; Tarasova, K. V.

    2016-06-01

    The LISE++ software for fragment separator simulations is undergoing a major update. LISE++ is the standard software used at in-flight separator facilities for predicting beam intensity and purity. The code simulates nuclear physics experiments where fragments are produced and then selected with a fragment separator. A set of modifications to improve the functionality of the code is discussed in this work. These modifications include transportation to a modern graphics framework and updated compilers to aid in the performance and sustainability of the code. To accommodate the diversity of our users' computer platform preferences, we extend the software from Windows to a cross-platform application. The calculations of beam transport and isotope production are becoming more computationally intense with the new large scale facilities. Planned new features include new types of optimization, for example, optimization of ion optics, improvements in reaction models, and new event generator options. In addition, LISE++ interface with control systems are planned. Computational improvements as well as the schedule for updating this large package will be discussed.

  15. Physically representative atomistic modeling of atomic-scale friction

    NASA Astrophysics Data System (ADS)

    Dong, Yalin

    Nanotribology is a research field to study friction, adhesion, wear and lubrication occurred between two sliding interfaces at nano scale. This study is motivated by the demanding need of miniaturization mechanical components in Micro Electro Mechanical Systems (MEMS), improvement of durability in magnetic storage system, and other industrial applications. Overcoming tribological failure and finding ways to control friction at small scale have become keys to commercialize MEMS with sliding components as well as to stimulate the technological innovation associated with the development of MEMS. In addition to the industrial applications, such research is also scientifically fascinating because it opens a door to understand macroscopic friction from the most bottom atomic level, and therefore serves as a bridge between science and engineering. This thesis focuses on solid/solid atomic friction and its associated energy dissipation through theoretical analysis, atomistic simulation, transition state theory, and close collaboration with experimentalists. Reduced-order models have many advantages for its simplification and capacity to simulating long-time event. We will apply Prandtl-Tomlinson models and their extensions to interpret dry atomic-scale friction. We begin with the fundamental equations and build on them step-by-step from the simple quasistatic one-spring, one-mass model for predicting transitions between friction regimes to the two-dimensional and multi-atom models for describing the effect of contact area. Theoretical analysis, numerical implementation, and predicted physical phenomena are all discussed. In the process, we demonstrate the significant potential for this approach to yield new fundamental understanding of atomic-scale friction. Atomistic modeling can never be overemphasized in the investigation of atomic friction, in which each single atom could play a significant role, but is hard to be captured experimentally. In atomic friction, the

  16. Improving default risk prediction using Bayesian model uncertainty techniques.

    PubMed

    Kazemi, Reza; Mosleh, Ali

    2012-11-01

    Credit risk is the potential exposure of a creditor to an obligor's failure or refusal to repay the debt in principal or interest. The potential of exposure is measured in terms of probability of default. Many models have been developed to estimate credit risk, with rating agencies dating back to the 19th century. They provide their assessment of probability of default and transition probabilities of various firms in their annual reports. Regulatory capital requirements for credit risk outlined by the Basel Committee on Banking Supervision have made it essential for banks and financial institutions to develop sophisticated models in an attempt to measure credit risk with higher accuracy. The Bayesian framework proposed in this article uses the techniques developed in physical sciences and engineering for dealing with model uncertainty and expert accuracy to obtain improved estimates of credit risk and associated uncertainties. The approach uses estimates from one or more rating agencies and incorporates their historical accuracy (past performance data) in estimating future default risk and transition probabilities. Several examples demonstrate that the proposed methodology can assess default probability with accuracy exceeding the estimations of all the individual models. Moreover, the methodology accounts for potentially significant departures from "nominal predictions" due to "upsetting events" such as the 2008 global banking crisis. PMID:23163724

  17. Transport in Polymer-Electrolyte Membranes I. Physical Model

    SciTech Connect

    Weber, Adam Z.; Newman, John

    2003-06-02

    In this paper, a physical model is developed that is semiphenomenological and takes into account Schroeder's paradox. Using the wealth of knowledge contained in the literature regarding polymer-electrolyte membranes as a basis, a novel approach is taken in tying together all of the data into a single coherent theory. This approach involves describing the structural changes of the membrane due to water content, and casting this in terms of capillary phenomena. By treating the membrane in this fashion, Schroeder's paradox can be elucidated. Along with the structural changes, two different transport mechanisms are presented and discussed. These mechanisms, along with the membrane's structural changes, comprise the complete physical model of the membrane. The model is shown to agree qualitatively with different membranes and different membrane forms, and is applicable to modeling perfluorinated sulfonic acid and similar membranes. It is also the first physically based comprehensive model of transport in a membrane that includes a physical description of Schroeder's paradox, and it bridges the gap between the two types of macroscopic models currently in the literature.

  18. Comparing the cognitive differences resulting from modeling instruction: Using computer microworld and physical object instruction to model real world problems

    NASA Astrophysics Data System (ADS)

    Oursland, Mark David

    This study compared the modeling achievement of students receiving mathematical modeling instruction using the computer microworld, Interactive Physics, and students receiving instruction using physical objects. Modeling instruction included activities where students applied the (a) linear model to a variety of situations, (b) linear model to two-rate situations with a constant rate, (c) quadratic model to familiar geometric figures. Both quantitative and qualitative methods were used to analyze achievement differences between students (a) receiving different methods of modeling instruction, (b) with different levels of beginning modeling ability, or (c) with different levels of computer literacy. Student achievement was analyzed quantitatively through a three-factor analysis of variance where modeling instruction, beginning modeling ability, and computer literacy were used as the three independent factors. The SOLO (Structure of the Observed Learning Outcome) assessment framework was used to design written modeling assessment instruments to measure the students' modeling achievement. The same three independent factors were used to collect and analyze the interviews and observations of student behaviors. Both methods of modeling instruction used the data analysis approach to mathematical modeling. The instructional lessons presented problem situations where students were asked to collect data, analyze the data, write a symbolic mathematical equation, and use equation to solve the problem. The researcher recommends the following practice for modeling instruction based on the conclusions of this study. A variety of activities with a common structure are needed to make explicit the modeling process of applying a standard mathematical model. The modeling process is influenced strongly by prior knowledge of the problem context and previous modeling experiences. The conclusions of this study imply that knowledge of the properties about squares improved the students

  19. A mathematical look at a physical power prediction model

    SciTech Connect

    Landberg, L.

    1997-12-31

    This paper takes a mathematical look at a physical model used to predict the power produced from wind farms. The reason is to see whether simple mathematical expressions can replace the original equations, and to give guidelines as to where the simplifications can be made and where they can not. This paper shows that there is a linear dependence between the geostrophic wind and the wind at the surface, but also that great care must be taken in the selection of the models since physical dependencies play a very important role, e.g. through the dependence of the turning of the wind on the wind speed.

  20. Physics-based model for electro-chemical process

    SciTech Connect

    Zhang, Jinsuo

    2013-07-01

    Considering the kinetics of electrochemical reactions and mass transfer at the surface and near-surface of the electrode, a physics-based separation model for separating actinides from fission products in an electro-refiner is developed. The model, taking into account the physical, chemical and electrochemical processes at the electrode surface, can be applied to study electrorefining kinetics. One of the methods used for validation has been to apply the developed model to the computation of the cyclic voltammetry process of PuCl{sub 3} and UCl{sub 3} at a solid electrode in molten KCl-LiCl. The computed results appear to be similar to experimental measures. The separation model can be applied to predict materials flows under normal and abnormal operation conditions. Parametric studies can be conducted based on the model to identify the most important factors that affect the electrorefining processes.

  1. Methods for improved forewarning of condition changes in monitoring physical processes

    DOEpatents

    Hively, Lee M.

    2013-04-09

    This invention teaches further improvements in methods for forewarning of critical events via phase-space dissimilarity analysis of data from biomedical equipment, mechanical devices, and other physical processes. One improvement involves objective determination of a forewarning threshold (U.sub.FW), together with a failure-onset threshold (U.sub.FAIL) corresponding to a normalized value of a composite measure (C) of dissimilarity; and providing a visual or audible indication to a human observer of failure forewarning and/or failure onset. Another improvement relates to symbolization of the data according the binary numbers representing the slope between adjacent data points. Another improvement relates to adding measures of dissimilarity based on state-to-state dynamical changes of the system. And still another improvement relates to using a Shannon entropy as the measure of condition change in lieu of a connected or unconnected phase space.

  2. Comparison and validation of physical wave parameterizations in spectral wave models

    NASA Astrophysics Data System (ADS)

    Stopa, Justin E.; Ardhuin, Fabrice; Babanin, Alexander; Zieger, Stefan

    2016-07-01

    Recent developments in the physical parameterizations available in spectral wave models have already been validated, but there is little information on their relative performance especially with focus on the higher order spectral moments and wave partitions. This study concentrates on documenting their strengths and limitations using satellite measurements, buoy spectra, and a comparison between the different models. It is confirmed that all models perform well in terms of significant wave heights; however higher-order moments have larger errors. The partition wave quantities perform well in terms of direction and frequency but the magnitude and directional spread typically have larger discrepancies. The high-frequency tail is examined through the mean square slope using satellites and buoys. From this analysis it is clear that some models behave better than the others, suggesting their parameterizations match the physical processes reasonably well. However none of the models are entirely satisfactory, pointing to poorly constrained parameterizations or missing physical processes. The major space-time differences between the models are related to the swell field which stresses the importance of describing its evolution. An example swell field confirms the wave heights can be notably different between model configurations while the directional distributions remain similar. It is clear that all models have difficulty describing the directional spread. Therefore, knowledge of the source term directional distributions is paramount to improve the wave model physics in the future.

  3. Physically-based Models For Flood Frequency Analysis

    NASA Astrophysics Data System (ADS)

    Strupczewski, W. G.; Singh, V. P.; Weglarczyk, S.

    Flood frequency models can be broadly classified into: (1) empirical, (2) phenomeno- logical, and (3) physically based. Despite their appeal, physically-based models have yet to become models of choice in hydrologic practice. Along the lines of physically based models and recognizing that channels are the dominant conduits for transmis- sion of flood waters, it is plausible to develop a model that employs the physics of channel flow routing and in which no explicit consideration is given to the hydrologic processes occurring on the land areas of the watershed. It is well accepted that the complete linearized Saint Venant equation and its simplifications provide a reason- able representation of the physics of channel flow. It is then hypothesized that impulse response function (IRF) of such models can be considered as a probability density function (PDF) for FFA. The impulse response of a linear convective-diffusion anal- ogy (LD) model is proposed for perennial rivers and that of a linear kinematic dif- fusion (KD) model for ephemeral streams. Each of them has two parameters which are derived using the method of moments (MOM) and maximum likelihood method (MLM). Also derived are errors in quantiles for both methods. Both distributions show an equivalency of MOM and MLM with respect to the mean U an important property in the case of unknown true distribution function. The LD model was tested using 39 series of Polish rivers showing its superiority over Log-normal - the main competitor among the family of two-parameter PDFs for the analyzed data. In particular, the LD model represents FF-characteristics well when the LD is likely to be the best of all lin- ear flood routing models. The KD distribution was tested on 44 annual peak flows data series containing zero values. A comparison of empirical and KD distributions shows that MOM better reproduces the upper tail of the distribution, while MLM is more ro- bust for higher sample values and more conditioned on the

  4. Subliminal strengthening: improving older individuals' physical function over time with an implicit-age-stereotype intervention.

    PubMed

    Levy, Becca R; Pilver, Corey; Chung, Pil H; Slade, Martin D

    2014-12-01

    Negative age stereotypes that older individuals assimilate from their culture predict detrimental outcomes, including worse physical function. We examined, for the first time, whether positive age stereotypes, presented subliminally across multiple sessions in the community, would lead to improved outcomes. Each of 100 older individuals (age=61-99 years, M=81) was randomly assigned to an implicit-positive-age-stereotype-intervention group, an explicit-positive-age-stereotype-intervention group, a combined implicit- and explicit-positive-age-stereotype-intervention group, or a control group. Interventions occurred at four 1-week intervals. The implicit intervention strengthened positive age stereotypes, which strengthened positive self-perceptions of aging, which, in turn, improved physical function. The improvement in these outcomes continued for 3 weeks after the last intervention session. Further, negative age stereotypes and negative self-perceptions of aging were weakened. For all outcomes, the implicit intervention's impact was greater than the explicit intervention's impact. The physical-function effect of the implicit intervention surpassed a previous study's 6-month-exercise-intervention's effect with participants of similar ages. The current study's findings demonstrate the potential of directing implicit processes toward physical-function enhancement over time. PMID:25326508

  5. Physical Exercise Improves The Functional Capacity and Quality of Life in Patients With Heart Failure

    PubMed Central

    Bocalini, Danilo Sales; dos Santos, Leonardo; Serra, Andrey Jorge

    2008-01-01

    OBJECTIVE The purpose of this study was to investigate the effects of physical exercise on the functional capacity and quality of life in heart failure patients. METHODS Forty-two patients of both sexes with heart failure of NYHA class II and III with different etiologies were randomly divided into untrained or trained groups. The six-month exercise program consisted of aerobic training, muscle strength training, agility and joint flexibility activities. Physical fitness was evaluated by testing the performance on these trained components. Quality of life was evaluated by scored answers to a standardized questionnaire involving multiple domains. RESULTS Baseline values did not differ between groups. Improvement in the trained group was identified in all components of functional capacity when compared to the untrained group (p < 0.001). Quality of life improved in the trained patients concerning physical, psychological, social and environmental domains (p < 0.001), whereas no significant change was found in the untrained patients. CONCLUSIONS Guided and monitored physical exercise is safe and has the potential to improve functional capacity and quality of life in heart failure patients with multiple etiologies. PMID:18719752

  6. Comparison of dietary and smoking habit changes in physical fitness improvers and nonimprovers.

    PubMed

    Blair, S N; Goodyear, N N; Wynne, K L; Saunders, R P

    1984-07-01

    Changes in dietary, smoking, and alcohol intake habits of men who voluntarily increased their physical fitness level (n = 532) were compared with men who did not increase physical fitness (n = 390). These men were middle-aged (average age = 43 years), initially sedentary and free of disease, and had been examined twice at a preventive medicine clinic within a 1- to 6-year period. Subjects were retrospectively assigned to two fitness groups--improvers and nonimprovers--based on changes in treadmill performance between baseline and follow-up examinations. Fifteen lifestyle variables were assessed by questionnaire and evaluated for change. At baseline the two groups were similar in demographic variables and diet, differing significantly only in follow-up interval (P less than 0.001), treadmill time (P less than 0.001), whole milk consumption (P less than 0.003), and smoking (P less than 0.001). At follow-up, positive changes in health habits were seen for both groups. Statistically significant differences in health habit change between the groups were seen only for beef (P less than 0.003) and coffee (P less than 0.003) consumption (consumption of both decreasing in more improvers than nonimprovers). Smokers at baseline were less likely to improve their physical fitness. We concluded that individuals who voluntarily increased their physical fitness level were not more likely to change their dietary and alcohol habits than persons who maintained a more sedentary lifestyle. PMID:6504869

  7. Fusion Education Physical Models for Students and Teachers

    NASA Astrophysics Data System (ADS)

    Nagy, A.; Lee, R. L.

    2002-11-01

    Interactive classroom visits by scientists and engineers in the ``Scientist in the Classroom" program and educator workshops led by Fusion Education team members continue to be the catalyst in the development of low cost, age appropriate, understandable physical demonstration models for use in classroom and workshop environments. Physical models developed for these interactive settings are based on topics in plasma science and technology, vacuum, thermodynamics, light, and electricity and magnetism. The physical models are actual hands-on devices students use to observe specific phenomena. One example uses a piston, a sealed volume, and a vacuum chamber to illustrate the ideal gas law. Another example uses liquid nitrogen to explore how temperature affects changes in states of matter, and, as a third example, magnets are used on simple plasma devices to illustrate the effects a magnetic field has on moving, charged particles. The details of these models will be presented. Three very successful ``build-it" days have been sponsored that enable teachers to build these physics models for use in their own classrooms.

  8. Exergames: neuroplastic hypothesis about cognitive improvement and biological effects on physical function of institutionalized older persons.

    PubMed

    Monteiro-Junior, Renato Sobral; Vaghetti, César Augusto Otero; Nascimento, Osvaldo José M; Laks, Jerson; Deslandes, Andrea Camaz

    2016-02-01

    Exergames can be considered a dual task because the games are performed by a man-videogame interface, requiring cognitive and motor functions simultaneously. Although the literature has shown improvements of cognitive and physical functions due to exergames, the intrinsic mechanisms involved in these functional changes have still not been elucidated. The aims of the present study were (1) to demonstrate the known biological mechanisms of physical exercise regarding muscle adaptation and establish a relationship with exergames; and (2) to present a neurobiological hypothesis about the neuroplastic effects of exergames on the cognitive function of institutionalized older persons. These hypotheses are discussed. PMID:27073355

  9. Energy requirements for methods improving gas detection by modulating physical properties of resistive gas sensors

    NASA Astrophysics Data System (ADS)

    Trawka, M.; Kotarski, M.

    2016-01-01

    One of the most important disadvantage of resistive gas sensors is their limited gas selectivity. Therefore, various methods modulating their physical properties are used to improve gas detection. These methods are usually limited to temperature modulation or UV light irradiation for the layers exhibiting photocatalytic effect. These methods cause increased energy consumption. In our study we consider how much energy has to be supplied to utilize such methods and what kind of additional information can be gathered. We present experimental results of selected resistive gas sensors, including commercial and prototype constructions, and practical solutions of modulating their physical properties.

  10. Osteopenia of Prematurity: Does Physical Activity Improve Bone Mineralization in Preterm Infants?

    PubMed

    Stalnaker, Kelsey A; Poskey, Gail A

    2016-01-01

    Bone mineralization of preterm infants is significantly less than full-term infants at birth, placing preterm infants at risk for osteopenia of prematurity and other metabolic bone diseases. Advances in nutritional supplementation and standard nursing care alone have been unsuccessful in improving bone mineralization postnatally. Research supports a daily physical activity protocol of passive range of motion and gentle joint compression when combined with adequate nutritional supplementation reduces osteopenia of prematurity. This article provides a systematic review of the current evidence surrounding early physical activity and neonatal massage for the treatment of osteopenia and indicates the need for universal handling protocols in caring for this unique population. PMID:27052984

  11. Exergames: neuroplastic hypothesis about cognitive improvement and biological effects on physical function of institutionalized older persons

    PubMed Central

    Monteiro-Junior, Renato Sobral; Vaghetti, César Augusto Otero; Nascimento, Osvaldo José M.; Laks, Jerson; Deslandes, Andrea Camaz

    2016-01-01

    Exergames can be considered a dual task because the games are performed by a man-videogame interface, requiring cognitive and motor functions simultaneously. Although the literature has shown improvements of cognitive and physical functions due to exergames, the intrinsic mechanisms involved in these functional changes have still not been elucidated. The aims of the present study were (1) to demonstrate the known biological mechanisms of physical exercise regarding muscle adaptation and establish a relationship with exergames; and (2) to present a neurobiological hypothesis about the neuroplastic effects of exergames on the cognitive function of institutionalized older persons. These hypotheses are discussed. PMID:27073355

  12. Evaluating performances of simplified physically based landslide susceptibility models.

    NASA Astrophysics Data System (ADS)

    Capparelli, Giovanna; Formetta, Giuseppe; Versace, Pasquale

    2015-04-01

    Rainfall induced shallow landslides cause significant damages involving loss of life and properties. Prediction of shallow landslides susceptible locations is a complex task that involves many disciplines: hydrology, geotechnical science, geomorphology, and statistics. Usually to accomplish this task two main approaches are used: statistical or physically based model. This paper presents a package of GIS based models for landslide susceptibility analysis. It was integrated in the NewAge-JGrass hydrological model using the Object Modeling System (OMS) modeling framework. The package includes three simplified physically based models for landslides susceptibility analysis (M1, M2, and M3) and a component for models verifications. It computes eight goodness of fit indices (GOF) by comparing pixel-by-pixel model results and measurements data. Moreover, the package integration in NewAge-JGrass allows the use of other components such as geographic information system tools to manage inputs-output processes, and automatic calibration algorithms to estimate model parameters. The system offers the possibility to investigate and fairly compare the quality and the robustness of models and models parameters, according a procedure that includes: i) model parameters estimation by optimizing each of the GOF index separately, ii) models evaluation in the ROC plane by using each of the optimal parameter set, and iii) GOF robustness evaluation by assessing their sensitivity to the input parameter variation. This procedure was repeated for all three models. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia municipality. The analysis provided that among all the optimized indices and all the three models, Average Index (AI) optimization coupled with model M3 is the best modeling solution for our test case. This research was funded by PON Project No. 01_01503 "Integrated Systems for Hydrogeological Risk

  13. Improvements of physical, mechanical and biodegradation properties of polybutadiene rubber insulators by chitosan and silica nanoparticles.

    PubMed

    Saboktakin, Amin; Saboktakin, Mohammadreza

    2016-10-01

    1,4-cis-Polybutadiene rubber(1,4-cis pBR) as an insulation material is developing that will provide superior thermal insulation properties, flexibility, toughness by natural polymers such as chitosan(CS) and silica nanoparticles. This material is widely used in the insulation industries specially architecture. This research concerns physical, mechanical properties and also biodegradation of 1,4-cis pBR, which to be composed with the natural polymers such as CS. Silica nanoparticles were used as filler to improve the physical and mechanical properties of 1,4-cis pBR. To evaluating its physical and mechanical properties, stretching and bending and impact tests were used and the results show some improvement in these properties. Our observations show that temperature plays an important role as main factor in order to improve the mechanical properties of nanocomposites. Similar improvements in tensile modulus and strength have been observed for 1,4-cis pBR/CS-silica nanoparticles. PMID:27353394

  14. Coarse-grained, foldable, physical model of the polypeptide chain

    PubMed Central

    Chakraborty, Promita; Zuckermann, Ronald N.

    2013-01-01

    Although nonflexible, scaled molecular models like Pauling–Corey’s and its descendants have made significant contributions in structural biology research and pedagogy, recent technical advances in 3D printing and electronics make it possible to go one step further in designing physical models of biomacromolecules: to make them conformationally dynamic. We report here the design, construction, and validation of a flexible, scaled, physical model of the polypeptide chain, which accurately reproduces the bond rotational degrees of freedom in the peptide backbone. The coarse-grained backbone model consists of repeating amide and α-carbon units, connected by mechanical bonds (corresponding to φ and ψ) that include realistic barriers to rotation that closely approximate those found at the molecular scale. Longer-range hydrogen-bonding interactions are also incorporated, allowing the chain to readily fold into stable secondary structures. The model is easily constructed with readily obtainable parts and promises to be a tremendous educational aid to the intuitive understanding of chain folding as the basis for macromolecular structure. Furthermore, this physical model can serve as the basis for linking tangible biomacromolecular models directly to the vast array of existing computational tools to provide an enhanced and interactive human–computer interface. PMID:23898168

  15. A Pilot Physical Activity Initiative to Improve Mental Health Status amongst Iranian Institutionalized Older People

    PubMed Central

    Matlabi, Hossein; Shaghaghi, Abdolreza; Amiri, Shahriar

    2014-01-01

    Background: Sufficient level of physical activity may promote overall and mental health of old people. This study was carried out to investigate the practi­cability of a physical activity promotion initiative amongst institutionalized older people in Tabriz, Iran. Methods: Purposive sampling method was used in this semi-experimental study to recruit 31 older people living in a selected residential care in Tabriz. Moderate-intensity aerobic and mus­cle-strengthening activity was planned for those who had not severe baseline cognitive impairment or were not too frail to undertake the survey. The General Health Questionnaire (GHQ-28) was used to measure mental health status be­fore and after intervention through a face-to-face interview. Descriptive statistics, Wilkcoxon rank-sum, Mann-Whitney U and Chi-Square tests were employed to analyses the data. Results: The applied intervention was significantly improved status of physical health, anxiety and insomnia, social dysfunction and severe depression. Conclusion: Incorporation of physical activity promotion programs into routines of older people residential care homes in Iran is feasible but may need training of physical activity specialists to work with older people based on their physical endurance and limitations. PMID:25097839

  16. Numerical modelling of Glacial Lake Outburst Floods using physically based dam-breach models

    NASA Astrophysics Data System (ADS)

    Westoby, M. J.; Brasington, J.; Glasser, N. F.; Hambrey, M. J.; Reynolds, J. M.; Hassan, M. A. A. M.

    2014-06-01

    The rapid development and instability of moraine-dammed proglacial lakes is increasing the potential for the occurrence of catastrophic Glacial Lake Outburst Floods (GLOFs) in high-mountain regions. Advanced, physically-based numerical dam-breach models represent an improvement over existing methods for the derivation of breach outflow hydrographs. However, significant uncertainty surrounds the initial parameterisation of such models, and remains largely unexplored. We use a unique combination of numerical dam-breach and two-dimensional hydrodynamic modelling, employed with a Generalised Likelihood Uncertainty Estimation (GLUE) framework to quantify the degree of equifinality in dam-breach model output for the reconstruction of the failure of Dig Tsho, Nepal. Monte Carlo analysis was used to sample the model parameter space, and morphological descriptors of the moraine breach were used to evaluate model performance. Equifinal breach morphologies were produced by parameter ensembles associated with differing breach initiation mechanisms, including overtopping waves and mechanical failure of the dam face. The material roughness coefficient was discovered to exert a dominant influence over model performance. Percentile breach hydrographs derived from cumulative distribution function hydrograph data under- or overestimated total hydrograph volume and were deemed to be inappropriate for input to hydrodynamic modelling. Our results support the use of a Total Variation Diminishing solver for outburst flood modelling, which was found to be largely free of numerical instability and flow oscillation. Routing of scenario-specific optimal breach hydrographs revealed prominent differences in the timing and extent of inundation. A GLUE-based method for constructing likelihood-weighted maps of GLOF inundation extent, flow depth, and hazard is presented, and represents an effective tool for communicating uncertainty and equifinality in GLOF hazard assessment. However, future

  17. Beyond the Standard Model Physics with Lattice Simulations

    NASA Astrophysics Data System (ADS)

    Rinaldi, Enrico

    2016-03-01

    Lattice simulations of gauge theories are a powerful tool to investigate strongly interacting systems like Quantum ChromoDynamics (QCD). In recent years, the expertise gathered from lattice QCD studies has been used to explore new extensions of the Standard Model of particle physics that include strong dynamics. This change of gear in lattice field theories is related to the growing experimental search for new physics, from accelerator facilites like the Large Hadron Collider (LHC) to dark matter detectors like LUX or ADMX. In my presentation I will explore different plausible scenarios for physics beyond the standard model where strong dynamics play a dominant role and can be tackled by numerical lattice simulations. The importance of lattice field theories is highlighted in the context of dark matter searches and the search for new resonances at the LHC. Acknowledge the support of the DOE under Contract DE-AC52-07NA27344 (LLNL).

  18. Filamentous Phages As a Model System in Soft Matter Physics.

    PubMed

    Dogic, Zvonimir

    2016-01-01

    Filamentous phages have unique physical properties, such as uniform particle lengths, that are not found in other model systems of rod-like colloidal particles. Consequently, suspensions of such phages provided powerful model systems that have advanced our understanding of soft matter physics in general and liquid crystals in particular. We described some of these advances. In particular we briefly summarize how suspensions of filamentous phages have provided valuable insight into the field of colloidal liquid crystals. We also describe recent experiments on filamentous phages that have elucidated a robust pathway for assembly of 2D membrane-like materials. Finally, we outline unique structural properties of filamentous phages that have so far remained largely unexplored yet have the potential to further advance soft matter physics and material science. PMID:27446051

  19. Filamentous Phages As a Model System in Soft Matter Physics

    PubMed Central

    Dogic, Zvonimir

    2016-01-01

    Filamentous phages have unique physical properties, such as uniform particle lengths, that are not found in other model systems of rod-like colloidal particles. Consequently, suspensions of such phages provided powerful model systems that have advanced our understanding of soft matter physics in general and liquid crystals in particular. We described some of these advances. In particular we briefly summarize how suspensions of filamentous phages have provided valuable insight into the field of colloidal liquid crystals. We also describe recent experiments on filamentous phages that have elucidated a robust pathway for assembly of 2D membrane-like materials. Finally, we outline unique structural properties of filamentous phages that have so far remained largely unexplored yet have the potential to further advance soft matter physics and material science. PMID:27446051

  20. Scratch as a computational modelling tool for teaching physics

    NASA Astrophysics Data System (ADS)

    Lopez, Victor; Hernandez, Maria Isabel

    2015-05-01

    The Scratch online authoring tool, which features a simple programming language that has been adapted to primary and secondary students, is being used more and more in schools as it offers students and teachers the opportunity to use a tool to build scientific models and evaluate their behaviour, just as can be done with computational modelling programs. In this article, we briefly discuss why Scratch could be a useful tool for computational modelling in the primary or secondary physics classroom, and we present practical examples of how it can be used to build a model.

  1. The Coupled Chemical and Physical Dynamics Model of MALDI.

    PubMed

    Knochenmuss, Richard

    2016-06-12

    The coupled physical and chemical dynamics model of ultraviolet matrix-assisted laser desorption/ionization (MALDI) has reproduced and explained a wide variety of MALDI phenomena. The rationale behind and elements of the model are reviewed, including the photophysics, kinetics, and thermodynamics of primary and secondary reaction steps. Experimental results are compared with model predictions to illustrate the foundations of the model, coupling of ablation and ionization, differences between and commonalities of matrices, secondary charge transfer reactions, ionization in both polarities, fluence and concentration dependencies, and suppression and enhancement effects. PMID:27070182

  2. Structure and physical properties of biomembranes and model membranes

    NASA Astrophysics Data System (ADS)

    Hianik, T.

    2006-12-01

    Biomembranes belong to the most important structures of the cell and the cell organels. They play not only structural role of the barrier separating the external and internal part of the membrane but contain also various functional molecules, like receptors, ionic channels, carriers and enzymes. The cell membrane also preserves non-equillibrium state in a cell which is crucial for maintaining its excitability and other signaling functions. The growing interest to the biomembranes is also due to their unique physical properties. From physical point of view the biomembranes, that are composed of lipid bilayer into which are incorporated integral proteins and on their surface are anchored peripheral proteins and polysaccharides, represent liquid scrystal of smectic type. The biomembranes are characterized by anisotropy of structural and physical properties. The complex structure of biomembranes makes the study of their physical properties rather difficult. Therefore several model systems that mimic the structure of biomembranes were developed. Among them the lipid monolayers at an air-water interphase, bilayer lipid membranes (BLM), supported bilayer lipid membranes (sBLM) and liposomes are most known. This work is focused on the introduction into the "physical word" of the biomembranes and their models. After introduction to the membrane structure and the history of its establishment, the physical properties of the biomembranes and their models areare stepwise presented. The most focus is on the properties of lipid monolayers, BLM, sBLM and liposomes that were most detailed studied. This contribution has tutorial character that may be usefull for undergraduate and graduate students in the area of biophysics, biochemistry, molecular biology and bioengineering, however it contains also original work of the author and his co-worker and PhD students, that may be usefull also for specialists working in the field of biomembranes and model membranes.

  3. TOWARD EFFICIENT RIPARIAN RESTORATION: INTEGRATING ECONOMIC, PHYSICAL, AND BIOLOGICAL MODELS

    EPA Science Inventory

    This paper integrates economic, biological, and physical models to explore the efficient combination and spatial allocation of conservation efforts to protect water quality and increase salmonid populations in the Grande Ronde basin, Oregon. We focus on the effects of shade on wa...

  4. Problem Solving: Physics Modeling-Based Interactive Engagement

    ERIC Educational Resources Information Center

    Ornek, Funda

    2009-01-01

    The purpose of this study was to investigate how modeling-based instruction combined with an interactive-engagement teaching approach promotes students' problem solving abilities. I focused on students in a calculus-based introductory physics course, based on the matter and interactions curriculum of Chabay & Sherwood (2002) at a large state…

  5. Advanced Ground Systems Maintenance Physics Models for Diagnostics Project

    NASA Technical Reports Server (NTRS)

    Harp, Janicce Leshay

    2014-01-01

    The project will use high-fidelity physics models and simulations to simulate real-time operations of cryogenic and systems and calculate the status/health of the systems. The project enables the delivery of system health advisories to ground system operators. The capability will also be used to conduct planning and analysis of cryogenic system operations.

  6. Evaluation of an Interdisciplinary, Physically Active Lifestyle Course Model

    ERIC Educational Resources Information Center

    Fede, Marybeth H.

    2009-01-01

    The purpose of this study was to evaluate a fit for life program at a university and to use the findings from an extensive literature review, consultations with formative and summative committees, and data collection to develop an interdisciplinary, physically active lifestyle (IPAL) course model. To address the 5 research questions examined in…

  7. Project Physics Tests 5, Models of the Atom.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    Test items relating to Project Physics Unit 5 are presented in this booklet. Included are 70 multiple-choice and 23 problem-and-essay questions. Concepts of atomic model are examined on aspects of relativistic corrections, electron emission, photoelectric effects, Compton effect, quantum theories, electrolysis experiments, atomic number and mass,…

  8. Speedminton: Using the Tactical Games Model in Secondary Physical Education

    ERIC Educational Resources Information Center

    Oh, Hyun-Ju; Bullard, Susan; Hovatter, Rhonda

    2011-01-01

    Teaching and learning of sport and sports-related games dominates the curriculum in most secondary physical education programs in America. For many secondary school students, playing games can be exciting and lead to a lifetime of participation in sport-related activities. Using the Tactical Games Model (TGM) (Mitchell et al., 2006) to teach the…

  9. PHYSICAL AND NUMERICAL MODELING OF ASD EXHAUST DISPERSION AROUND HOUSES

    EPA Science Inventory

    The report discusses the use of a wind tunnel to physically model the dispersion of exhaust plumes from active soil depressurization (ASD) radon mitigation systems in houses. he testing studied the effects of exhaust location (grade level vs. above the eave), as house height, roo...

  10. Simplified physically based model of earthen embankment breaching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simplified physically based model has been developed to simulate the breaching processes of homogenous and composite earthen embankments owing to overtopping and piping. The breach caused by overtopping flow is approximated as a flat broad-crested weir with a trapezoidal cross section, downstream ...

  11. Aspects of the Cognitive Model of Physics Problem Solving.

    ERIC Educational Resources Information Center

    Brekke, Stewart E.

    Various aspects of the cognitive model of physics problem solving are discussed in detail including relevant cues, encoding, memory, and input stimuli. The learning process involved in the recognition of familiar and non-familiar sensory stimuli is highlighted. Its four components include selection, acquisition, construction, and integration. The…

  12. Project Physics Text 5, Models of the Atom.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    Basic atomic theories are presented in this fifth unit of the Project Physics text for use by senior high students. Chemical basis of atomic models in the early years of the 18th Century is discussed n connection with Dalton's theory, atomic properties, and periodic tables. The discovery of electrons is described by using cathode rays, Millikan's…

  13. Linear Sigma Model Toolshed for D-brane Physics

    SciTech Connect

    Hellerman, Simeon

    2001-08-23

    Building on earlier work, we construct linear sigma models for strings on curved spaces in the presence of branes. Our models include an extremely general class of brane-worldvolume gauge field configurations. We explain in an accessible manner the mathematical ideas which suggest appropriate worldsheet interactions for generating a given open string background. This construction provides an explanation for the appearance of the derived category in D-brane physic complementary to that of recent work of Douglas.

  14. Two-fluid model for heavy electron physics

    NASA Astrophysics Data System (ADS)

    Yang, Yi-feng

    2016-07-01

    The two-fluid model is a phenomenological description of the gradual change of the itinerant and local characters of f-electrons with temperature and other tuning parameters and has been quite successful in explaining many unusual and puzzling experimental observations in heavy electron materials. We review some of these results and discuss possible implications of the two-fluid model in understanding the microscopic origin of heavy electron physics.

  15. Toward efficient riparian restoration: integrating economic, physical, and biological models.

    PubMed

    Watanabe, Michio; Adams, Richard M; Wu, Junjie; Bolte, John P; Cox, Matt M; Johnson, Sherri L; Liss, William J; Boggess, William G; Ebersole, Joseph L

    2005-04-01

    This paper integrates economic, biological, and physical models to explore the efficient combination and spatial allocation of conservation efforts to protect water quality and increase salmonid populations in the Grande Ronde basin, Oregon. We focus on the effects of shade on water temperatures and the subsequent impacts on endangered juvenile salmonid populations. The integrated modeling system consists of a physical model that links riparian conditions and hydrological characteristics to water temperature; a biological model that links water temperature and riparian conditions to salmonid abundance, and an economic model that incorporates both physical and biological models to estimate minimum cost allocations of conservation efforts. Our findings indicate that conservation alternatives such as passive and active riparian restoration, the width of riparian restoration zones, and the types of vegetation used in restoration activities should be selected based on the spatial distribution of riparian characteristics in the basin. The relative effectiveness of passive and active restoration plays an important role in determining the efficient allocations of conservation efforts. The time frame considered in the restoration efforts and the magnitude of desired temperature reductions also affect the efficient combinations of restoration activities. If the objective of conservation efforts is to maximize fish populations, then fishery benefits should be directly targeted. Targeting other criterion such as water temperatures would result in different allocations of conservation efforts, and therefore are not generally efficient. PMID:15763152

  16. Physical-Socio-Economic Modeling of Climate Change

    NASA Astrophysics Data System (ADS)

    Chamberlain, R. G.; Vatan, F.

    2008-12-01

    Because of the global nature of climate change, any assessment of the effects of plans, policies, and response to climate change demands a model that encompasses the entire Earth System, including socio- economic factors. Physics-based climate models of the factors that drive global temperatures, rainfall patterns, and sea level are necessary but not sufficient to guide decision making. Actions taken by farmers, industrialists, environmentalists, politicians, and other policy makers may result in large changes to economic factors, international relations, food production, disease vectors, and beyond. These consequences will not be felt uniformly around the globe or even across a given region. Policy models must comprehend all of these considerations. Combining physics-based models of the Earth's climate and biosphere with societal models of population dynamics, economics, and politics is a grand challenge with high stakes. We propose to leverage our recent advances in modeling and simulation of military stability and reconstruction operations to models that address all these areas of concern. Following over twenty years' experience of successful combat simulation, JPL has started developing Minerva, which will add demographic, economic, political, and media/information models to capabilities that already exist. With these new models, for which we have design concepts, it will be possible to address a very wide range of potential national and international problems that were previously inaccessible. Our climate change model builds on Minerva and expands the geographical horizon from playboxes containing regions and neighborhoods to the entire globe. This system consists of a collection of interacting simulation models that specialize in different aspects of the global situation. They will each contribute to and draw from a pool of shared data. The basic models are: the physical model; the demographic model; the political model; the economic model; and the media

  17. Evaluating performances of simplified physically based models for landslide susceptibility

    NASA Astrophysics Data System (ADS)

    Formetta, G.; Capparelli, G.; Versace, P.

    2015-12-01

    Rainfall induced shallow landslides cause loss of life and significant damages involving private and public properties, transportation system, etc. Prediction of shallow landslides susceptible locations is a complex task that involves many disciplines: hydrology, geotechnical science, geomorphology, and statistics. Usually to accomplish this task two main approaches are used: statistical or physically based model. Reliable models' applications involve: automatic parameters calibration, objective quantification of the quality of susceptibility maps, model sensitivity analysis. This paper presents a methodology to systemically and objectively calibrate, verify and compare different models and different models performances indicators in order to individuate and eventually select the models whose behaviors are more reliable for a certain case study. The procedure was implemented in package of models for landslide susceptibility analysis and integrated in the NewAge-JGrass hydrological model. The package includes three simplified physically based models for landslides susceptibility analysis (M1, M2, and M3) and a component for models verifications. It computes eight goodness of fit indices by comparing pixel-by-pixel model results and measurements data. Moreover, the package integration in NewAge-JGrass allows the use of other components such as geographic information system tools to manage inputs-output processes, and automatic calibration algorithms to estimate model parameters. The system was applied for a case study in Calabria (Italy) along the Salerno-Reggio Calabria highway, between Cosenza and Altilia municipality. The analysis provided that among all the optimized indices and all the three models, the optimization of the index distance to perfect classification in the receiver operating characteristic plane (D2PC) coupled with model M3 is the best modeling solution for our test case.

  18. Analyzing Students' Understanding of Models and Modeling Referring to the Disciplines Biology, Chemistry, and Physics

    NASA Astrophysics Data System (ADS)

    Krell, Moritz; Reinisch, Bianca; Krüger, Dirk

    2014-08-01

    In this study, secondary school students' (N = 617; grades 7 to 10) understanding of models and modeling was assessed using tasks which explicitly refer to the scientific disciplines of biology, chemistry, and physics and, as a control, to no scientific discipline. The students' responses are interpreted as their biology-, chemistry-, and physics-related or general understanding of models and modeling. A subpopulation (N = 115; one class per grade) was subsequently asked which models they had in mind when answering the tasks referring to biology, chemistry, and physics (open-ended questions). The findings show significant differences between students' biology-, chemistry-, and physics-related understandings of models and modeling. Based on a theoretical framework, the biology-related understanding can be seen as less elaborated than the physics- and chemistry-related understandings. The students' general understanding of models and modeling is located between the biology- and the physics-related understandings. Answers to the open-ended questions indicate that students primarily think about scale and functional models in the context of biology tasks. In contrast, more abstract models (e.g., analogical models, diagrams) were mentioned in relation to chemistry and physics tasks. In sum, the findings suggest that models may be used in a rather descriptive way in biology classes but in a predictive way in chemistry and physics classes. This may explain discipline-specific understandings of models and modeling. Only small differences were found in students' understanding of models and modeling between the different grade levels 7/8 and 9/10.

  19. Analyzing Students' Understanding of Models and Modeling Referring to the Disciplines Biology, Chemistry, and Physics

    NASA Astrophysics Data System (ADS)

    Krell, Moritz; Reinisch, Bianca; Krüger, Dirk

    2015-06-01

    In this study, secondary school students' ( N = 617; grades 7 to 10) understanding of models and modeling was assessed using tasks which explicitly refer to the scientific disciplines of biology, chemistry, and physics and, as a control, to no scientific discipline. The students' responses are interpreted as their biology-, chemistry-, and physics-related or general understanding of models and modeling. A subpopulation ( N = 115; one class per grade) was subsequently asked which models they had in mind when answering the tasks referring to biology, chemistry, and physics (open-ended questions). The findings show significant differences between students' biology-, chemistry-, and physics-related understandings of models and modeling. Based on a theoretical framework, the biology-related understanding can be seen as less elaborated than the physics- and chemistry-related understandings. The students' general understanding of models and modeling is located between the biology- and the physics-related understandings. Answers to the open-ended questions indicate that students primarily think about scale and functional models in the context of biology tasks. In contrast, more abstract models (e.g., analogical models, diagrams) were mentioned in relation to chemistry and physics tasks. In sum, the findings suggest that models may be used in a rather descriptive way in biology classes but in a predictive way in chemistry and physics classes. This may explain discipline-specific understandings of models and modeling. Only small differences were found in students' understanding of models and modeling between the different grade levels 7/8 and 9/10.

  20. Childhood physical abuse and midlife physical health: Testing a multi-pathway life course model

    PubMed Central

    Springer, K. W.

    2009-01-01

    Although prior research has established that childhood abuse adversely affects midlife physical health outcomes, it is unclear how abuse continues to harm health decades after the abuse has ended. In this project, I assess four life course pathways (behavioral, emotional, cognitive, and social relations) that plausibly link childhood physical abuse to three midlife physical health outcomes (bronchitis diagnosis, ulcer diagnosis, and general physical health). These three outcomes are etiologically distinct, leading to unique testable hypotheses. Multivariate models controlling for childhood background and early adversity were estimated using data from over 3,000 respondents in the Wisconsin Longitudinal Study, USA. The results indicate that midlife social relations and cognition do not function as pathways for any outcome. However, smoking is a crucial pathway connecting childhood abuse with bronchitis; mental health is important for ulcers; and BMI, smoking, and mental health are paramount for general physical health. These findings suggest that abuse survivors’ coping mechanisms can lead to an array of midlife health problems. Furthermore, the results validate the use of etiologically distinct outcomes for understanding plausible causal pathways when using cross-sectional data. PMID:19446943

  1. Maintaining physical activity during refeeding improves body composition, intestinal hyperpermeability and behavior in anorectic mice

    PubMed Central

    Achamrah, Najate; Nobis, Séverine; Breton, Jonathan; Jésus, Pierre; Belmonte, Liliana; Maurer, Brigitte; Legrand, Romain; Bôle-Feysot, Christine; Rego, Jean Luc do; Goichon, Alexis; Rego, Jean Claude do; Déchelotte, Pierre; Fetissov, Sergueï O; Claeyssens, Sophie; Coëffier, Moïse

    2016-01-01

    A role of gut-brain axis emerges in the pathophysiology of anorexia nervosa and maintaining adapted physical activity during refeeding remains discussed. We aimed to assess gastrointestinal protein metabolism and investigate the contribution of physical activity during refeeding in C57BL/6 mice with activity-based anorexia (ABA). ABA mice exhibited lower body weight and food intake with increase of lean mass/fat mass ratio and fat oxidation. Colonic permeability was increased in ABA. Ad libitum food access was then restored and ABA group was divided into two subgroups, with access to running wheel (ABA-PA) or not (ABA-NPA). After refeeding, fat free mass was completely restored only in ABA-PA. Colonic permeability was enhanced in ABA-NPA. Finally, muscle kynurenine conversion into kynurenic acid was lower in ABA-NPA who also exhibited altered behavior. Maintaining physical activity during refeeding may thus limit colonic hyperpermeability and improve behavior in anorectic mice. PMID:26906060

  2. Maintaining physical activity during refeeding improves body composition, intestinal hyperpermeability and behavior in anorectic mice.

    PubMed

    Achamrah, Najate; Nobis, Séverine; Breton, Jonathan; Jésus, Pierre; Belmonte, Liliana; Maurer, Brigitte; Legrand, Romain; Bôle-Feysot, Christine; do Rego, Jean Luc; Goichon, Alexis; Rego, Jean Claude do; Déchelotte, Pierre; Fetissov, Sergueï O; Claeyssens, Sophie; Coëffier, Moïse

    2016-01-01

    A role of gut-brain axis emerges in the pathophysiology of anorexia nervosa and maintaining adapted physical activity during refeeding remains discussed. We aimed to assess gastrointestinal protein metabolism and investigate the contribution of physical activity during refeeding in C57BL/6 mice with activity-based anorexia (ABA). ABA mice exhibited lower body weight and food intake with increase of lean mass/fat mass ratio and fat oxidation. Colonic permeability was increased in ABA. Ad libitum food access was then restored and ABA group was divided into two subgroups, with access to running wheel (ABA-PA) or not (ABA-NPA). After refeeding, fat free mass was completely restored only in ABA-PA. Colonic permeability was enhanced in ABA-NPA. Finally, muscle kynurenine conversion into kynurenic acid was lower in ABA-NPA who also exhibited altered behavior. Maintaining physical activity during refeeding may thus limit colonic hyperpermeability and improve behavior in anorectic mice. PMID:26906060

  3. Improving the quantum mechanics content knowledge and pedagogical content knowledge of physics graduate students

    NASA Astrophysics Data System (ADS)

    Marshman, Emily Megan

    Many physics graduate students face the unique challenge of being both students and teachers concurrently. To succeed in these roles, they must develop both physics content knowledge and pedagogical content knowledge. My research focuses on improving both the content knowledge and pedagogical content knowledge of first year graduate students. To improve their content knowledge, I have focused on improving graduate students' conceptual understanding of quantum mechanics covered in upper-level undergraduate courses since our earlier investigations suggest that many graduate students struggle in developing a conceptual understanding of quantum mechanics. Learning tools, such as the Quantum Interactive Learning Tutorials (QuILTs) that I have developed, have been successful in helping graduate students improve their understanding of Dirac notation and single photon behavior in the context of a Mach-Zehnder Interferometer. In addition, I have been involved in enhancing our semester long course professional development course for teaching assistants (TAs) by including research-based activities. In particular, I have been researching the implications of graduate TAs' reflections on the connections between their grading practices and student learning, i.e., the development of introductory physics students' content knowledge and problem-solving, reasoning, and metacognitive skills. This research involves having graduate students grade sample student solutions to introductory physics problems. Afterward, the graduate TAs discuss with each other the pros and cons of different grading rubrics on student learning and formulate a joint grading rubric to grade the problem. The graduate TAs are individually asked to reformulate a rubric and grade problems using the rubric several months after the group activity to assess the impact of the intervention on graduate TAs. In addition to the intervention focusing on grading sample student solutions, graduate TAs are also asked to answer

  4. News Teaching: The epiSTEMe project: KS3 maths and science improvement Field trip: Pupils learn physics in a stately home Conference: ShowPhysics welcomes fun in Europe Student numbers: Physics numbers increase in UK Tournament: Physics tournament travels to Singapore Particle physics: Hadron Collider sets new record Astronomy: Take your classroom into space Forthcoming Events

    NASA Astrophysics Data System (ADS)

    2010-05-01

    Teaching: The epiSTEMe project: KS3 maths and science improvement Field trip: Pupils learn physics in a stately home Conference: ShowPhysics welcomes fun in Europe Student numbers: Physics numbers increase in UK Tournament: Physics tournament travels to Singapore Particle physics: Hadron Collider sets new record Astronomy: Take your classroom into space Forthcoming Events

  5. ARSENIC MODEL DEVELOPMENT FOR IMPROVED RISK ASSESSMENT

    EPA Science Inventory

    This project integrates research on the kinetic behavior and metabolism of arsenic at both the cellular and whole organism levels using a physiologically based pharmacokinetic (PBPK) modeling approach. The ultimate goal is development of a robust human PBPK model for arsenic met...

  6. Rock Physics Models of Biofilm Growth in Porous Media

    NASA Astrophysics Data System (ADS)

    Jaiswal, P.; alhadhrami, F. M.; Atekwana, E. A.

    2013-12-01

    Recent studies suggest the potential to use acoustic techniques to image biofilm growth in porous media. Nonetheless the interpretation of the seismic response to biofilm growth and development remains speculative because of the lack of quantitative petrophysical models that can relate changes in biofilm saturation to changes in seismic attributes. Here, we report our efforts in developing quantitative rock physics models to biofilm saturation with increasing and decreasing P-wave velocity (VP) and amplitudes recorded in the Davis et al. [2010] physical scale experiment. We adapted rock physics models developed for modeling gas hydrates in unconsolidated sediments. Two distinct growth models, which appear to be a function of pore throat size, are needed to explain the experimental data. First, introduction of biofilm as an additional mineral grain in the sediment matrix (load-bearing mode) is needed to explain the increasing time-lapse VP. Second, introduction of biofilm as part of the pore fluid (pore-filling mode) is required to explain the decreasing time-lapse VP. To explain the time-lapse VP, up to 15% of the pore volume was required to be saturated with biofilm. The recorded seismic amplitudes, which can be expressed as a function of porosity, permeability and grain size, showed a monotonic time-lapse decay except on Day 3 at a few selected locations, where it increased. Since porosity changes are constrained by VP, amplitude increase could be modeled by increasing hydraulic conductivity. Time lapse VP at locations with increasing amplitudes suggest that these locations have a load-bearing growth style. We conclude that permeability can increase by up to 10% at low (~2%) biofilm saturation in load-bearing growth style due to the development of channels within the biofilm structure. Developing a rock physics model for the biofilm growth in general may help create a field guide for interpreting porosity and permeability changes in bioremediation, MEOR and

  7. Improving Performance through Motivation: Teaching Biology Pre-Med Students Physics

    NASA Astrophysics Data System (ADS)

    Gregg, Elena

    2013-03-01

    Several major factors which affect students' learning are assessed (curricula, different teaching approaches, assessment methods, engagement, and motivation). Direct connection between motivation, attitudes, self-confidence and achievement was established. It was demonstrated that improvement of motivation and self-confidence among students (particularly females, minorities and low achievers) is essential. Effectiveness of different instructional methods and motivational approaches was analyzed and evaluated in algebra-based Physics course for Biology pre-med undergraduate students.

  8. Pre-Service Physics Teachers' Knowledge of Models and Perceptions of Modelling

    ERIC Educational Resources Information Center

    Ogan-Bekiroglu, Feral

    2006-01-01

    One of the purposes of this study was to examine the differences between knowledge of pre-service physics teachers who experienced model-based teaching in pre-service education and those who did not. Moreover, it was aimed to determine pre-service physics teachers' perceptions of modelling. Posttest-only control group experimental design was used…

  9. Integrating 3D geological information with a national physically-based hydrological modelling system

    NASA Astrophysics Data System (ADS)

    Lewis, Elizabeth; Parkin, Geoff; Kessler, Holger; Whiteman, Mark

    2016-04-01

    Robust numerical models are an essential tool for informing flood and water management and policy around the world. Physically-based hydrological models have traditionally not been used for such applications due to prohibitively large data, time and computational resource requirements. Given recent advances in computing power and data availability, a robust, physically-based hydrological modelling system for Great Britain using the SHETRAN model and national datasets has been created. Such a model has several advantages over less complex systems. Firstly, compared with conceptual models, a national physically-based model is more readily applicable to ungauged catchments, in which hydrological predictions are also required. Secondly, the results of a physically-based system may be more robust under changing conditions such as climate and land cover, as physical processes and relationships are explicitly accounted for. Finally, a fully integrated surface and subsurface model such as SHETRAN offers a wider range of applications compared with simpler schemes, such as assessments of groundwater resources, sediment and nutrient transport and flooding from multiple sources. As such, SHETRAN provides a robust means of simulating numerous terrestrial system processes which will add physical realism when coupled to the JULES land surface model. 306 catchments spanning Great Britain have been modelled using this system. The standard configuration of this system performs satisfactorily (NSE > 0.5) for 72% of catchments and well (NSE > 0.7) for 48%. Many of the remaining 28% of catchments that performed relatively poorly (NSE < 0.5) are located in the chalk in the south east of England. As such, the British Geological Survey 3D geology model for Great Britain (GB3D) has been incorporated, for the first time in any hydrological model, to pave the way for improvements to be made to simulations of catchments with important groundwater regimes. This coupling has involved

  10. The ESA Meteoroid Model 2010: Enhanced Physical Model

    NASA Astrophysics Data System (ADS)

    Dikarev, Valeri; Mints, Alexey; Drolshagen, Gerhard

    The orbital distributions of meteoroids in interplanetary space are revised in the ESA meteoroid model. In the present update, the chemical composition of the meteoroids is simulated in more detail than in the previous meteoroid models. Silicate and carbonaceous fractions are introduced for all meteoroid populations, and in addition to asteroids and Jupiter-crossing comets, comet 2P/Encke is added as a source. The orbital evolution under planetary gravity, Poynting-Robertson effect and mutual collisions is simulated using analytical approximations. Infrared observations of the zodiacal cloud by the COBE DIRBE instrument, in situ flux measurements by the dust detectors on board Galileo, Ulysses, Pioneer 11 and Helios-1 spacecraft, and the crater size distributions on lunar rock samples retrieved by the Apollo missions are incorporated in the model.

  11. A real-time infrared imaging simulation method with physical effects modeling of infrared sensors

    NASA Astrophysics Data System (ADS)

    Li, Ni; Huai, Wenqing; Wang, Shaodan; Ren, Lei

    2016-09-01

    Infrared imaging simulation technology can provide infrared data sources for the development, improvement and evaluation of infrared imaging systems under different environment, status and weather conditions, which is reusable and more economic than physical experiments. A real-time infrared imaging simulation process is established to reproduce a complete physical imaging process. Our emphasis is put on the modeling of infrared sensors, involving physical effects of both spatial domain and frequency domain. An improved image convolution method is proposed based on GPU parallel processing to enhance the real-time simulation ability with ensuring its simulation accuracy at the same time. Finally the effectiveness of the above methods is validated by simulation analysis and result comparison.

  12. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing.

    1993-01-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  13. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing

    1993-04-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  14. Model Independent Search For New Physics At The Tevatron

    SciTech Connect

    Choudalakis, Georgios

    2008-04-01

    The Standard Model of elementary particles can not be the final theory. There are theoretical reasons to expect the appearance of new physics, possibly at the energy scale of few TeV. Several possible theories of new physics have been proposed, each with unknown probability to be confirmed. Instead of arbitrarily choosing to examine one of those theories, this thesis is about searching for any sign of new physics in a model-independent way. This search is performed at the Collider Detector at Fermilab (CDF). The Standard Model prediction is implemented in all final states simultaneously, and an array of statistical probes is employed to search for significant discrepancies between data and prediction. The probes are sensitive to overall population discrepancies, shape disagreements in distributions of kinematic quantities of final particles, excesses of events of large total transverse momentum, and local excesses of data expected from resonances due to new massive particles. The result of this search, first in 1 fb-1 and then in 2 fb-1, is null, namely no considerable evidence of new physics was found.

  15. Precision Higgs Boson Physics and Implications for Beyond the Standard Model Physics Theories

    SciTech Connect

    Wells, James

    2015-06-10

    The discovery of the Higgs boson is one of science's most impressive recent achievements. We have taken a leap forward in understanding what is at the heart of elementary particle mass generation. We now have a significant opportunity to develop even deeper understanding of how the fundamental laws of nature are constructed. As such, we need intense focus from the scientific community to put this discovery in its proper context, to realign and narrow our understanding of viable theory based on this positive discovery, and to detail the implications the discovery has for theories that attempt to answer questions beyond what the Standard Model can explain. This project's first main object is to develop a state-of-the-art analysis of precision Higgs boson physics. This is to be done in the tradition of the electroweak precision measurements of the LEP/SLC era. Indeed, the electroweak precision studies of the past are necessary inputs to the full precision Higgs program. Calculations will be presented to the community of Higgs boson observables that detail just how well various couplings of the Higgs boson can be measured, and more. These will be carried out using state-of-the-art theory computations coupled with the new experimental results coming in from the LHC. The project's second main objective is to utilize the results obtained from LHC Higgs boson experiments and the precision analysis, along with the direct search studies at LHC, and discern viable theories of physics beyond the Standard Model that unify physics to a deeper level. Studies will be performed on supersymmetric theories, theories of extra spatial dimensions (and related theories, such as compositeness), and theories that contain hidden sector states uniquely accessible to the Higgs boson. In addition, if data becomes incompatible with the Standard Model's low-energy effective lagrangian, new physics theories will be developed that explain the anomaly and put it into a more unified framework beyond

  16. Physical Dust Models in the Light of Planck

    NASA Astrophysics Data System (ADS)

    Draine, Bruce T.

    2015-08-01

    The Spitzer, Herschel, and Planck missions have provided observational data that challenge existing models of interstellar dust, and will guide us in the development of a new generation of dust models. The spectacular data from Planck now enable us to characterize the intensity of dust emission at wavelengths from 350um to 3mm, with invaluable measurements of polarized dust emission from 850um to 4mm. Models for interstellar dust are constrained by these new data, and also by many other observational constraints, such as infrared emission at shorter wavelengths, wavelength-dependent extinction and polarization of starlight, scattering of starlight, scattering and extinction of X-rays by dust, and ground-based studies of anomalous microwave emission.A physical dust model consists of dust grains with specified compositions, geometries, and sizes. The assumed physical properties of the dust should be consistent with the laws of physics, our understanding of candidate materials, and interstellar abundance constraints. I will review some contemporary dust models, and discuss how they fare when confronted with available data.

  17. A physically based model for stress sensing using magnetostrictive composites

    NASA Astrophysics Data System (ADS)

    Yoffe, Alexander; Weber, Yarden; Shilo, Doron

    2015-12-01

    Magnetostrictive composites are of considerable interest for real-time remote force sensing and structural health monitoring. In this paper, we introduce a new procedure for modeling the magnetic field induced by an external load applied on an epoxy-based composite material filled with Terfenol-D particles. This model is based on an assumed sequence of physical processes that occur at the microscopic scale, and it includes both domain switching and magnetization rotation. The modeling procedure is demonstrated on a problem relevant for load sensing applications in which the magnetostrictive composite is subjected to a uniaxial compression. Comparison of the calculated and experimental results strengthens the validity of the assumed sequence of physical processes and provides valuable insights important for application developments.

  18. Unifying wildfire models from ecology and statistical physics.

    PubMed

    Zinck, Richard D; Grimm, Volker

    2009-11-01

    Understanding the dynamics of wildfire regimes is crucial for both regional forest management and predicting global interactions between fire regimes and climate. Accordingly, spatially explicit modeling of forest fire ecosystems is a very active field of research, including both generic and highly specific models. There is, however, a second field in which wildfire has served as a metaphor for more than 20 years: statistical physics. So far, there has been only limited interaction between these two fields of wildfire modeling. Here we show that two typical generic wildfire models from ecology are structurally equivalent to the most commonly used model from statistical physics. All three models can be unified to a single model in which they appear as special cases of regrowth-dependent flammability. This local "ecological memory" of former fire events is key to self-organization in wildfire ecosystems. The unified model is able to reproduce three different patterns observed in real boreal forests: fire size distributions, fire shapes, and a hump-shaped relationship between disturbance intensity (average annual area burned) and diversity of succession stages. The unification enables us to bring together insights from both disciplines in a novel way and to identify limitations that provide starting points for further research. PMID:19799499

  19. Naturalness of unknown physics: Theoretical models and experimental signatures

    NASA Astrophysics Data System (ADS)

    Kilic, Can

    In the last few decades collider experiments have not only spectacularly confirmed the predictions of the Standard Model but also have not revealed any direct evidence for new physics beyond the SM, which has led theorists to devise numerous models where the new physics couples weakly to the SM or is simply beyond the reach of past experiments. While phenomenologically viable, many such models appear finely tuned, even contrived. This work illustrates three attempts at coming up with explanations to fine-tunings we observe in the world around us, such as the gauge hierarchy problem or the cosmological constant problem, emphasizing both the theoretical aspects of model building as well as possible experimental signatures. First we investigate the "Little Higgs" mechanism and work on a specifical model, the "Minimal Moose" to highlight its impact on precision observables in the SM, and illustrate that it does not require implausible fine-tuning. Next we build a supersymmetric model, the "Fat Higgs", with an extended gauge structure which becomes confining. This model, aside from naturally preserving the unification of the SM gauge couplings at high energies, also makes it possible to evade the bounds on the lightest Higgs boson mass which are quite restrictive in minimal SUSY scenarios. Lastly we take a look at a possible resolution of the cosmological constant problem through the mechanism of "Ghost Condensation" and dwell on astrophysical observables from the Lorentz Violating sector in this model. We use current experimental data to constrain the coupling of this sector to the SM.

  20. Physically-based modeling and simulation of extraocular muscles.

    PubMed

    Wei, Qi; Sueda, Shinjiro; Pai, Dinesh K

    2010-12-01

    Dynamic simulation of human eye movements, with realistic physical models of extraocular muscles (EOMs), may greatly advance our understanding of the complexities of the oculomotor system and aid in treatment of visuomotor disorders. In this paper we describe the first three dimensional (3D) biomechanical model which can simulate the dynamics of ocular motility at interactive rates. We represent EOMs using "strands", which are physical primitives that can model an EOM's complex nonlinear anatomical and physiological properties. Contact between the EOMs, the globe, and orbital structures can be explicitly modeled. Several studies were performed to assess the validity and utility of the model. EOM deformation during smooth pursuit was simulated and compared with published experimental data; the model reproduces qualitative features of the observed nonuniformity. The model is able to reproduce realistic saccadic trajectories when the lateral rectus muscle was driven by published measurements of abducens neuron discharge. Finally, acute superior oblique palsy, a pathological condition, was simulated to further evaluate the system behavior; the predicted deviation patterns agree qualitatively with experimental observations. This example also demonstrates potential clinical applications of such a model. PMID:20868704