WorldWideScience

Sample records for modeling panel volume

  1. Carbon emissions, logistics volume and GDP in China: empirical analysis based on panel data model.

    Science.gov (United States)

    Guo, Xiaopeng; Ren, Dongfang; Shi, Jiaxing

    2016-12-01

    This paper studies the relationship among carbon emissions, GDP, and logistics by using a panel data model and a combination of statistics and econometrics theory. The model is based on the historical data of 10 typical provinces and cities in China during 2005-2014. The model in this paper adds the variability of logistics on the basis of previous studies, and this variable is replaced by the freight turnover of the provinces. Carbon emissions are calculated by using the annual consumption of coal, oil, and natural gas. GDP is the gross domestic product. The results showed that the amount of logistics and GDP have a contribution to carbon emissions and the long-term relationships are different between different cities in China, mainly influenced by the difference among development mode, economic structure, and level of logistic development. After the testing of panel model setting, this paper established a variable coefficient model of the panel. The influence of GDP and logistics on carbon emissions is obtained according to the influence factors among the variables. The paper concludes with main findings and provides recommendations toward rational planning of urban sustainable development and environmental protection for China.

  2. Dynamic panel data models

    NARCIS (Netherlands)

    Bun, M.J.G.; Sarafidis, V.

    2013-01-01

    This Chapter reviews the recent literature on dynamic panel data models with a short time span and a large cross-section. Throughout the discussion we considerlinear models with additional endogenous covariates. First we give a broad overview of available inference methods placing emphasis on GMM.

  3. Seismic hazard analysis. Volume 5. Review panel, Ground Motion Panel, and feedback results

    Energy Technology Data Exchange (ETDEWEB)

    Bernreuter, D. L.

    1981-08-01

    The Site Specific Spectra Project (SSSP) was a multi-year study funded by the US Nuclear Regulatory Commission to provide estimates of the seismic hazards at a number of nuclear power plant sites in the Eastern US. A key element of our approach was the Peer Review Panel, which we formed in order to ensure that our use of expert opinion was reasonable. We discuss the Peer Review Panel results and provide the complete text of each member's report. In order to improve the ground motion model, an Eastern US Ground Motion Model Panel was formed. In Section 4 we tabulate the responses from the panel members to our feedback questionnaire and discuss the implications of changes introduced by them. We conclude that the net difference in seismic hazard values from those presented in Volume 4 is small and does not warrant a reanalysis. 22 figs.

  4. Panel Smooth Transition Regression Models

    DEFF Research Database (Denmark)

    González, Andrés; Terasvirta, Timo; Dijk, Dick van

    models to the panel context. The strategy consists of model specification based on homogeneity tests, parameter estimation, and model evaluation, including tests of parameter constancy and no remaining heterogeneity. The model is applied to describing firms' investment decisions in the presence...

  5. Ray Tracing Modelling of Reflector for Vertical Bifacial Panel

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff

    2016-01-01

    Bifacial solar panels have recently become a new attractive building block for PV systems. In this work we propose a reflector system for a vertical bifacial panel, and use ray tracing modelling to model the performance. Particularly, we investigate the impact of the reflector volume being filled...... with a refractive medium, and shows the refractive medium improves the reflector performance since it directs almost all the light incident on the incoming plane into the PV panel....

  6. Ray Tracing modelling of reflector for vertical bifacial panel

    DEFF Research Database (Denmark)

    Jakobsen, Michael Linde; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff

    2016-01-01

    Bifacial solar panels have recently become a new attractive building block for PV systems. In this work we propose a reflector system for a vertical bifacial panel, and use ray tracing modelling to model the performance. Particularly, we investigate the impact of the reflector volume being filled...... with a refractive medium, and shows the refractive medium improves the reflector performance since it directs almost all the light incident on the incoming plane into the PV panel....

  7. Flat-Panel Detector—Based Volume Computed Tomography: A Novel 3D Imaging Technique to Monitor Osteolytic Bone Lesions in a Mouse Tumor Metastasis Model

    Directory of Open Access Journals (Sweden)

    Jeannine Missbach-Guentner

    2007-09-01

    Full Text Available Skeletal metastasis is an important cause of mortality in patients with breast cancer. Hence, animal models, in combination with various imaging techniques, are in high demand for preclinical assessment of novel therapies. We evaluated the applicability of flat-panel volume computed tomography (fpVCT to noninvasive detection of osteolytic bone metastases that develop in severe immunodeficient mice after intracardial injection of MDA-MB-231 breast cancer cells. A single fpVCT scan at 200-wm isotropic resolution was employed to detect osteolysis within the entire skeleton. Osteolytic lesions identified by fpVCT correlated with Faxitron X-ray analysis and were subsequently confirmed by histopathological examination. Isotropic three-dimensional image data sets obtained by fpVCT were the basis for the precise visualization of the extent of the lesion within the cortical bone and for the measurement of bone loss. Furthermore, fpVCT imaging allows continuous monitoring of growth kinetics for each metastatic site and visualization of lesions in more complex regions of the skeleton, such as the skull. Our findings suggest that fpVCT is a powerful tool that can be used to monitor the occurrence and progression of osteolytic lesions in vivo and can be further developed to monitor responses to antimetastatic therapies over the course of the disease.

  8. PV panel model based on datasheet values

    DEFF Research Database (Denmark)

    Sera, Dezso; Teodorescu, Remus; Rodriguez, Pedro

    2007-01-01

    This work presents the construction of a model for a PV panel using the single-diode five-parameters model, based exclusively on data-sheet parameters. The model takes into account the series and parallel (shunt) resistance of the panel. The equivalent circuit and the basic equations of the PV cell...

  9. Dynamic spatial panels : models, methods, and inferences

    NARCIS (Netherlands)

    Elhorst, J. Paul

    This paper provides a survey of the existing literature on the specification and estimation of dynamic spatial panel data models, a collection of models for spatial panels extended to include one or more of the following variables and/or error terms: a dependent variable lagged in time, a dependent

  10. Behavioral Model of Photovoltaic Panel in Simulink

    Directory of Open Access Journals (Sweden)

    ZAPLATILEK, K.

    2011-11-01

    Full Text Available This article deals with creation and application of a model of photovoltaic panel in the MATLAB and Simulink environments. An original model of the real PV panel is applied using the model based design technique. A so-called physical model is also developed using the SimPowerSystems library. The described PV panel model is applied for maximum power optimization in the one-shot and the continuous modes. A few illustrating examples and source code parts are also presented.

  11. Robust estimation procedure in panel data model

    Energy Technology Data Exchange (ETDEWEB)

    Shariff, Nurul Sima Mohamad [Faculty of Science of Technology, Universiti Sains Islam Malaysia (USIM), 71800, Nilai, Negeri Sembilan (Malaysia); Hamzah, Nor Aishah [Institute of Mathematical Sciences, Universiti Malaya, 50630, Kuala Lumpur (Malaysia)

    2014-06-19

    The panel data modeling has received a great attention in econometric research recently. This is due to the availability of data sources and the interest to study cross sections of individuals observed over time. However, the problems may arise in modeling the panel in the presence of cross sectional dependence and outliers. Even though there are few methods that take into consideration the presence of cross sectional dependence in the panel, the methods may provide inconsistent parameter estimates and inferences when outliers occur in the panel. As such, an alternative method that is robust to outliers and cross sectional dependence is introduced in this paper. The properties and construction of the confidence interval for the parameter estimates are also considered in this paper. The robustness of the procedure is investigated and comparisons are made to the existing method via simulation studies. Our results have shown that robust approach is able to produce an accurate and reliable parameter estimates under the condition considered.

  12. Nearly Unbiased Estimationin Dynamic Panel Data Models

    NARCIS (Netherlands)

    M.A. Carree (Martin)

    2002-01-01

    textabstractThis paper introduces two easy to calculate estimators with desirable properties for the autoregressive parameter in dynamic panel data models. The estimators are (nearly) unbiased and perform satisfactorily even for small samples in either the time-series or cross-section dimension.

  13. Modeling and simulation of photovoltaic solar panel

    International Nuclear Information System (INIS)

    Belarbi, M.; Haddouche, K.; Midoun, A.

    2006-01-01

    In this article, we present a new approach for estimating the model parameters of a photovoltaic solar panel according to the irradiance and temperature. The parameters of the one diode model are given from the knowledge of three operating points: short-circuit, open circuit, and maximum power. In the first step, the adopted approach concerns the resolution of the system of equations constituting the three operating points to write all the model parameters according to series resistance. Secondly, we make an iterative resolution at the optimal operating point by using the Newton-Raphson method to calculate the series resistance value as well as the model parameters. Once the panel model is identified, we consider other equations for taking into account the irradiance and temperature effect. The simulation results show the convergence speed of the model parameters and the possibility of visualizing the electrical behaviour of the panel according to the irradiance and temperature. Let us note that a sensitivity of the algorithm at the optimal operating point was observed owing to the fact that a small variation of the optimal voltage value leads to a very great variation of the identified parameters values. With the identified model, we can develop algorithms of maximum power point tracking, and make simulations of a solar water pumping system.(Author)

  14. Continuous time modeling of panel data by means of SEM

    NARCIS (Netherlands)

    Oud, J.H.L.; Delsing, M.J.M.H.; Montfort, C.A.G.M.; Oud, J.H.L.; Satorra, A.

    2010-01-01

    After a brief history of continuous time modeling and its implementation in panel analysis by means of structural equation modeling (SEM), the problems of discrete time modeling are discussed in detail. This is done by means of the popular cross-lagged panel design. Next, the exact discrete model

  15. Endoscopic Lung Volume Reduction : An Expert Panel Recommendation - Update 2017

    NARCIS (Netherlands)

    Herth, Felix J. F.; Slebos, Dirk-Jan; Criner, Gerard J.; Shah, Pallav L.

    2017-01-01

    Interest in endoscopic lung volume reduction (ELVR) technologies for emphysema is consistently growing. In the last couple of months, several endoscopic options (e.g., endo-or intrabronchial valves, coil implants, and thermal vapor ablation) that have been evaluated in randomized controlled trials

  16. Linearised model for PV panel power output variation with changes ...

    Indian Academy of Sciences (India)

    PALLAVI BHARADWAJ

    2017-10-26

    Oct 26, 2017 ... which can be the PV panel current or the real power. In this work a linearised model is derived to relate the change in system input, namely: irradiance and temperature, with its output, namely: array current and power. The proposed model is experimentally verified with tests run on PV panels, when they are ...

  17. FPGA Implementation of Multilayer Perceptron for Modeling of Photovoltaic panel

    International Nuclear Information System (INIS)

    Mekki, H.; Belhout, K.; Mellit, A.; Salhi, H.

    2008-01-01

    The Number of electronic applications using artificial neural network-based solutions has increased considerably in the last few years. However, their applications in photovoltaic systems are very limited. This paper introduces the preliminary result of the modeling and simulation of photovoltaic panel based on neural network and VHDL-language. In fact, an experimental database of meteorological data (irradiation, temperature) and output electrical generation signals of the PV-panel (current and voltage) has been used in this study. The inputs of the ANN-PV-panel are the daily total irradiation and mean average temperature while the outputs are the current and voltage generated from the panel. Firstly, a dataset of 4x364 have been used for training the network. Subsequently, the neural network (MLP) corresponding to PV-panel is simulated using VHDL language based on the saved weights and bias of the network. Simulation results of the trained MLP-PV panel based on Matlab and VHDL are presented. The proposed PV-panel model based ANN and VHDL permit to evaluate the performance PV-panel using only the environmental factors and involves less computational efforts, and it can be used for predicting the output electrical energy from the PV-panel

  18. Consistent estimation of linear panel data models with measurement error

    NARCIS (Netherlands)

    Meijer, Erik; Spierdijk, Laura; Wansbeek, Thomas

    2017-01-01

    Measurement error causes a bias towards zero when estimating a panel data linear regression model. The panel data context offers various opportunities to derive instrumental variables allowing for consistent estimation. We consider three sources of moment conditions: (i) restrictions on the

  19. Report of the International Ozone Trends Panel 1988, volume 2

    International Nuclear Information System (INIS)

    1989-01-01

    Chapters on the following topics are presented: trends in stratospheric temperature; theory and observations- model simulations of the period 1955-1985; trends in source gases; trends in stratospheric minor constituents; trends in aerosol abundances and distribution; and observations and theories related to antarctic ozone

  20. Model of a photovoltaic panel emulator in MATLAB-Simulink

    OpenAIRE

    CAN, Hayrettin

    2014-01-01

    Being able to behave electrically similar to photovoltaic (PV) panels, PV emulator systems make it possible to perform different PV system tests under various operation conditions. In this paper, a model of a PV panel emulator is presented using the Power System Blockset under MATLAB-Simulink. The simulation of the emulator system is developed for testing a controller prior to a real-time implementation. The model can handle the dependence of all of the parameters in the model with ...

  1. Bayesian interference in heterogeneous dynamic panel data models: three essays.

    OpenAIRE

    Ciccarelli, Matteo

    2001-01-01

    The task of this work is to discuss issues conceming the specification, estimation, inference and forecasting in multivariate dynamic heterogeneous panel data models from a Bayesian perspective. Three essays linked by a few conraion ideas compose the work. Multivariate dynamic models (mainly VARs) based on micro or macro panel data sets have become increasingly popular in macroeconomics, especially to study the transmission of real and monetary shocks across economies. This great use...

  2. A thermal model for photovoltaic panels under varying atmospheric conditions

    International Nuclear Information System (INIS)

    Armstrong, S.; Hurley, W.G.

    2010-01-01

    The response of the photovoltaic (PV) panel temperature is dynamic with respect to the changes in the incoming solar radiation. During periods of rapidly changing conditions, a steady state model of the operating temperature cannot be justified because the response time of the PV panel temperature becomes significant due to its large thermal mass. Therefore, it is of interest to determine the thermal response time of the PV panel. Previous attempts to determine the thermal response time have used indoor measurements, controlling the wind flow over the surface of the panel with fans or conducting the experiments in darkness to avoid radiative heat loss effects. In real operating conditions, the effective PV panel temperature is subjected to randomly varying ambient temperature and fluctuating wind speeds and directions; parameters that are not replicated in controlled, indoor experiments. A new thermal model is proposed that incorporates atmospheric conditions; effects of PV panel material composition and mounting structure. Experimental results are presented which verify the thermal behaviour of a photovoltaic panel for low to strong winds.

  3. Modelling and arrangement of composite panels in modernized freight cars

    Directory of Open Access Journals (Sweden)

    Płaczek Marek

    2017-01-01

    Full Text Available A process of modelling in a CAD system and designing of arrangement of composite panels used for freight cars’ body shell protection against corrosion and for easier unloading of transported cargo in winter conditions is presented in this work. Arrangement of used composite panels was designing in order to fulfil assumed criteria and thus to improve the process of freight cars modernization during periodic repairs.

  4. Modelling and arrangement of composite panels in modernized freight cars

    OpenAIRE

    Płaczek Marek; Wróbel Andrzej; Olesiejuk Maciej

    2017-01-01

    A process of modelling in a CAD system and designing of arrangement of composite panels used for freight cars’ body shell protection against corrosion and for easier unloading of transported cargo in winter conditions is presented in this work. Arrangement of used composite panels was designing in order to fulfil assumed criteria and thus to improve the process of freight cars modernization during periodic repairs.

  5. A Bootstrap Cointegration Rank Test for Panels of VAR Models

    DEFF Research Database (Denmark)

    Callot, Laurent

    functions of the individual Cointegrated VARs (CVAR) models. A bootstrap based procedure is used to compute empirical distributions of the trace test statistics for these individual models. From these empirical distributions two panel trace test statistics are constructed. The satisfying small sample...

  6. The importance of dynamics in panel gravity models of trade

    NARCIS (Netherlands)

    Bun, M.J.G.; Klaassen, F.J.G.M.

    2002-01-01

    Existing gravity models of trade based on panel data are often static, that is, they only allow for contemporaneous effects of regressors on trade. However, there are numerous economic arguments suggesting that trade is a dynamic process. Hence, we extend the static model with lagged regressors

  7. GMM estimation in panel data models with measurement error

    NARCIS (Netherlands)

    Wansbeek, T.J.

    Griliches and Hausman (J. Econom. 32 (1986) 93) have introduced GMM estimation in panel data models with measurement error. We present a simple, systematic approach to derive moment conditions for such models under a variety of assumptions. (C) 2001 Elsevier Science S.A. All rights reserved.

  8. Crash Frequency Modeling Using Real-Time Environmental and Traffic Data and Unbalanced Panel Data Models.

    Science.gov (United States)

    Chen, Feng; Chen, Suren; Ma, Xiaoxiang

    2016-06-18

    Traffic and environmental conditions (e.g., weather conditions), which frequently change with time, have a significant impact on crash occurrence. Traditional crash frequency models with large temporal scales and aggregated variables are not sufficient to capture the time-varying nature of driving environmental factors, causing significant loss of critical information on crash frequency modeling. This paper aims at developing crash frequency models with refined temporal scales for complex driving environments, with such an effort providing more detailed and accurate crash risk information which can allow for more effective and proactive traffic management and law enforcement intervention. Zero-inflated, negative binomial (ZINB) models with site-specific random effects are developed with unbalanced panel data to analyze hourly crash frequency on highway segments. The real-time driving environment information, including traffic, weather and road surface condition data, sourced primarily from the Road Weather Information System, is incorporated into the models along with site-specific road characteristics. The estimation results of unbalanced panel data ZINB models suggest there are a number of factors influencing crash frequency, including time-varying factors (e.g., visibility and hourly traffic volume) and site-varying factors (e.g., speed limit). The study confirms the unique significance of the real-time weather, road surface condition and traffic data to crash frequency modeling.

  9. Micro-economic panel data models for Dutch dairy farming

    NARCIS (Netherlands)

    Ooms, D.L.

    2007-01-01

    Keywords:micro-economic models, panel data, GMM, CAP reform, dairy farmingIn The Netherlands, thedairy sector is the largest agricultural sub-sector based on both gross production value and number of

  10. Inference in High-dimensional Dynamic Panel Data Models

    DEFF Research Database (Denmark)

    Kock, Anders Bredahl; Tang, Haihan

    We establish oracle inequalities for a version of the Lasso in high-dimensional fixed effects dynamic panel data models. The inequalities are valid for the coefficients of the dynamic and exogenous regressors. Separate oracle inequalities are derived for the fixed effects. Next, we show how one can...

  11. Estimation of Nonlinear Dynamic Panel Data Models with Individual Effects

    Directory of Open Access Journals (Sweden)

    Yi Hu

    2014-01-01

    Full Text Available This paper suggests a generalized method of moments (GMM based estimation for dynamic panel data models with individual specific fixed effects and threshold effects simultaneously. We extend Hansen’s (Hansen, 1999 original setup to models including endogenous regressors, specifically, lagged dependent variables. To address the problem of endogeneity of these nonlinear dynamic panel data models, we prove that the orthogonality conditions proposed by Arellano and Bond (1991 are valid. The threshold and slope parameters are estimated by GMM, and asymptotic distribution of the slope parameters is derived. Finite sample performance of the estimation is investigated through Monte Carlo simulations. It shows that the threshold and slope parameter can be estimated accurately and also the finite sample distribution of slope parameters is well approximated by the asymptotic distribution.

  12. Biosocial models of adolescent problem behavior: extension to panel design.

    Science.gov (United States)

    Drigotas, S M; Udry, J R

    1993-01-01

    We extended the biosocial model of problem behavior tested by Udry (1990) to a panel design, following a sample of over one hundred boys in adolescence for three years. We found the expected results for sociological variables, but weaker effects for testosterone than Udry found on cross-sectional data. Using panel models with lagged hormone effects, we identified relationships between Time-1 testosterone and problem behavior one year or more later. The relationship between testosterone and problem behavior was not present for subsequent measures of testosterone, either in cross-section or with time-lagged models. Therefore we cannot interpret the results as showing testosterone effects on problem behavior. Rather it appears that testosterone level in early adolescence is a marker for a more general growth trajectory of early development.

  13. A guide for estimating dynamic panel models: the macroeconomics models specifiness

    International Nuclear Information System (INIS)

    Coletta, Gaetano

    2005-10-01

    The aim of this paper is to review estimators for dynamic panel data models, a topic in which the interest has grown recently. As a consequence 01 this late interest, different estimation techniques have been proposed in the last few years and, given the last development of the subject, there is still a lack 01 a comprehensive guide for panel data applications, and for macroeconomics panel data models in particular. Finally, we also provide some indications about the Stata software commands to estimate dynamic panel data models with the techniques illustrated in the paper [it

  14. Atomic Safety and Licensing Board Panel Biennial Report, Fiscal Years 1993--1994. Volume 6

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    In Fiscal Year 1993, the Atomic Safety and Licensing Board Panel (``the Panel``) handled 30 proceedings. In Fiscal Year 1994, the Panel handled 36 proceedings. The cases addressed issues in the construction, operation, and maintenance of commercial nuclear power reactors and other activities requiring a license form the Nuclear Regulatory Commission. This report sets out the Panel`s caseload during the year and summarizes, highlight, and analyzes how the wide- ranging issues raised in those proceedings were addressed by the Panel`s judges and licensing boards.

  15. A Conditional Approach to Panel Data Models with Common Shocks

    Directory of Open Access Journals (Sweden)

    Giovanni Forchini

    2016-01-01

    Full Text Available This paper studies the effects of common shocks on the OLS estimators of the slopes’ parameters in linear panel data models. The shocks are assumed to affect both the errors and some of the explanatory variables. In contrast to existing approaches, which rely on using results on martingale difference sequences, our method relies on conditional strong laws of large numbers and conditional central limit theorems for conditionally-heterogeneous random variables.

  16. Modelling characteristics of photovoltaic panels with thermal phenomena taken into account

    International Nuclear Information System (INIS)

    Krac, Ewa; Górecki, Krzysztof

    2016-01-01

    In the paper a new form of the electrothermal model of photovoltaic panels is proposed. This model takes into account the optical, electrical and thermal properties of the considered panels, as well as electrical and thermal properties of the protecting circuit and thermal inertia of the considered panels. The form of this model is described and some results of measurements and calculations of mono-crystalline and poly-crystalline panels are presented

  17. Development of circuit model for arcing on solar panels

    International Nuclear Information System (INIS)

    Mehta, Bhoomi K; Deshpande, S P; Mukherjee, S; Gupta, S B; Ranjan, M; Rane, R; Vaghela, N; Acharya, V; Sudhakar, M; Sankaran, M; Suresh, E P

    2010-01-01

    The increased requirements of payload capacity of the satellites have resulted in much higher power requirements of the satellites. In order to minimize the energy loss during power transmission due to cable loss, use of high voltage solar panels becomes necessary. When a satellite encounters space plasma it floats negatively with respect to the surrounding space plasma environment. At high voltage, charging and discharging on solar panels causes the power system breakdown. Once a solar panel surface is charged and potential difference between surface insulator and conductor exceeds certain value, electrostatic discharge (ESD) may occur. This ESD may trigger a secondary arc that can destroy the solar panel circuit. ESD is also called as primary or minor arc and secondary is called major arc. The energy of minor arc is supplied by the charge stored in the coverglass of solar array and is a pulse of typically several 100 ns to several 100 μs duration. The damage caused by minor arc is less compared to major arcs, but it is observed that the minor arc is cause of major arc. Therefore it is important to develop an understanding of minor arc and mitigation techniques. In this paper we present a linear circuit analysis for minor arcs on solar panels. To study arcing event, a ground experimental facility to simulate space plasma environment has been developed at Facilitation Centre for Industrial Plasma Technologies (Institute for Plasma Research) in collaboration with Indian Space Research Organization's ISRO Satellite Technology Centre (ISAC). A linear circuit model has been developed to explain the experimental results by representing the coverglass, solar cell interconnect and wiring by an LCR circuit and the primary arc by an equivalent LR circuit. The aim of the circuit analysis is to predict the arc current which flows through the arc plasma. It is established from the model that the current depends on various parameters like potential difference between insulator

  18. Atomic Safety and Licensing Board Panel Biennial Report, Fiscal Years 1993--1994. Volume 6

    International Nuclear Information System (INIS)

    1995-08-01

    In Fiscal Year 1993, the Atomic Safety and Licensing Board Panel (''the Panel'') handled 30 proceedings. In Fiscal Year 1994, the Panel handled 36 proceedings. The cases addressed issues in the construction, operation, and maintenance of commercial nuclear power reactors and other activities requiring a license form the Nuclear Regulatory Commission. This report sets out the Panel's caseload during the year and summarizes, highlight, and analyzes how the wide- ranging issues raised in those proceedings were addressed by the Panel's judges and licensing boards

  19. Efficient Estimation of Non-Linear Dynamic Panel Data Models with Application to Smooth Transition Models

    DEFF Research Database (Denmark)

    Gørgens, Tue; Skeels, Christopher L.; Wurtz, Allan

    This paper explores estimation of a class of non-linear dynamic panel data models with additive unobserved individual-specific effects. The models are specified by moment restrictions. The class includes the panel data AR(p) model and panel smooth transition models. We derive an efficient set...... of moment restrictions for estimation and apply the results to estimation of panel smooth transition models with fixed effects, where the transition may be determined endogenously. The performance of the GMM estimator, both in terms of estimation precision and forecasting performance, is examined in a Monte...... Carlo experiment. We find that estimation of the parameters in the transition function can be problematic but that there may be significant benefits in terms of forecast performance....

  20. Energy Production and Regional Economic Growth in China: A More Comprehensive Analysis Using a Panel Model

    Directory of Open Access Journals (Sweden)

    Yaobin Liu

    2013-03-01

    Full Text Available China has witnessed a fast economic growth in the recent two decades. However, the heavy energy exploitation seems to show a negative relation to regional economic growth. Thus, the issue is whether the energy production is a curse or blessing for the regional economic growth in China. The present study deploys a comprehensive approach to rigorously prove the validity of a proposed panel data model that includes a second generation panel unit root test and panel cointegration and a spatial panel model. The results from the second generation panel unit root test and panel cointegration allowing for cross-sectional dependences show the differenced series are stationary and there exists a cointegration relationship among these variables for all sub-regions. The results from the spatial panel data model support the conjecture of the spatial dependent and show that there is a “resource curse” only for the Western region and Central region in China.

  1. Panel Data Models of New Firm Formation in New England

    Directory of Open Access Journals (Sweden)

    Jitendra Parajuli

    2017-10-01

    Full Text Available This study examines the impact of the determinants of new firm formation in New England at the county level from 1999 to 2009. Based on the Spatial Durbin panel model that accounts for spillover effects, it is found that population density and human capital positively affect single-unit firm births within a county and its neighbors. Population growth rate also exerts a significant positive impact on new firm formation, but most of the effect is from spatial spillovers. On the contrary, the ratio of large to small firm in terms of employment size and unemployment rate negatively influence single-unit firm births both within counties and among neighbors. However, there is no significant impact of local financial capital and personal income growth on new firm formation.

  2. Final report of the Multiprogram Laboratory Panel Energy Research Advisory Board. Volume II. Support studies

    International Nuclear Information System (INIS)

    Spiewak, I.; Guthrie, M.P.; Nichols, J.P.; Preston, E.L.; West, C.D.; Wilbanks, T.J.; Wilkes, B.Y.; Zerby, A.C.

    1982-09-01

    Volume II - support studies for nine national laboratories include: report of statistical data on the multiprogram laboratories; examples of national laboratory use in foreign countries; domestic models for national laboratory utilization; relationships of laboratories with industry and universities; uses of laboratories for training industrial R and D personnel; legal mandates and constraints on the national laboratories; with appendices on facts about Harwell, CEN-Saclay, TNO, Studsvik, and JAERI-Tokai; the Requirements Boards of the United Kingdom Department of Industry; impact of President's FY 1983 budget; and the PNL experiment

  3. Semi-automatic classification of skeletal morphology in genetically altered mice using flat-panel volume computed tomography.

    Directory of Open Access Journals (Sweden)

    Christian Dullin

    2007-07-01

    Full Text Available Rapid progress in exploring the human and mouse genome has resulted in the generation of a multitude of mouse models to study gene functions in their biological context. However, effective screening methods that allow rapid noninvasive phenotyping of transgenic and knockout mice are still lacking. To identify murine models with bone alterations in vivo, we used flat-panel volume computed tomography (fpVCT for high-resolution 3-D imaging and developed an algorithm with a computational intelligence system. First, we tested the accuracy and reliability of this approach by imaging discoidin domain receptor 2- (DDR2- deficient mice, which display distinct skull abnormalities as shown by comparative landmark-based analysis. High-contrast fpVCT data of the skull with 200 microm isotropic resolution and 8-s scan time allowed segmentation and computation of significant shape features as well as visualization of morphological differences. The application of a trained artificial neuronal network to these datasets permitted a semi-automatic and highly accurate phenotype classification of DDR2-deficient compared to C57BL/6 wild-type mice. Even heterozygous DDR2 mice with only subtle phenotypic alterations were correctly determined by fpVCT imaging and identified as a new class. In addition, we successfully applied the algorithm to classify knockout mice lacking the DDR1 gene with no apparent skull deformities. Thus, this new method seems to be a potential tool to identify novel mouse phenotypes with skull changes from transgenic and knockout mice on the basis of random mutagenesis as well as from genetic models. However for this purpose, new neuronal networks have to be created and trained. In summary, the combination of fpVCT images with artificial neuronal networks provides a reliable, novel method for rapid, cost-effective, and noninvasive primary screening tool to detect skeletal phenotypes in mice.

  4. A Panel Data Model for Subjective Information on Household Income Growth

    NARCIS (Netherlands)

    Das, J.W.M.; van Soest, A.H.O.

    1996-01-01

    Subjective expectations about future income changes are analyzed, using household panel data.The models used are extensions of existing binary choice panel data models to the case of ordered response.We consider both random and fixed individual effects.The random effects model is estimated by

  5. Linearised model for PV panel power output variation with changes ...

    Indian Academy of Sciences (India)

    PALLAVI BHARADWAJ

    This equivalent resistance represents the load seen at the PV panel terminals. It is dependent on the actual power drawn by the system and the interfacing converter between the PV panels and the load. Thus it is a function of the converter duty ratio and load characteristics. Due to the disturbance, output characteristics of ...

  6. A guide for estimating dynamic panel models: the macroeconomics models specifiness; Una guida per la stima dei modelli panel dinamici: le specificita dei modelli macroeconomici

    Energy Technology Data Exchange (ETDEWEB)

    Coletta, Gaetano [ENEA, Centro Ricerche Casaccia, Rome (Italy). Unita di Agenzia per lo Sviluppo Sostenibile Advisor

    2005-10-15

    The aim of this paper is to review estimators for dynamic panel data models, a topic in which the interest has grown recently. As a consequence 01 this late interest, different estimation techniques have been proposed in the last few years and, given the last development of the subject, there is still a lack 01 a comprehensive guide for panel data applications, and for macroeconomics panel data models in particular. Finally, we also provide some indications about the Stata software commands to estimate dynamic panel data models with the techniques illustrated in the paper. [Italian] L'obiettivo del presente lavoro e quello di effettuare una rassegna degli stimatori per modelli panel dinamici, una materia per cui l'interesse e cresciuto di recente. In conseguenza di questo crescente interesse, negli ultimi anni sono stati proposti una serie di differenti tecniche di stima ma, dato il rapido sviluppo della materia, non esiste, infatti, una guida esaustiva per le applicazioni su dati panel, in particolare nel caso di modelli macroeconomici. A conclusione del lavoro sono fornite, infine, alcune indicazioni relative ai comandi del software Stata per stimare i modelli panel dinamici con le tecniche illustrate nel testo.

  7. Numerical modeling of sandwich panel response to ballistic loading - energy balance for varying impactor geometries

    DEFF Research Database (Denmark)

    Kepler, Jørgen Asbøl; Hansen, Michael Rygaard

    2007-01-01

    A sandwich panel is described by an axisymmetric lumped mass- spring model. The panel compliance is simplified, considering only core shear deformation uniformly distributed across the core thickness. Transverse penetrating impact is modeled for impactors of diameters comparable to the panel thic...... between the impactor and the panel during penetration. The force histories are selected from a primary criterion of conservation of linear momentum in the impactor-panel system, and evaluated according to agreement with the total measured energy balance....... thickness but significantly smaller than panel length dimensions. Experimental data for the total loss in impactor kinetic energy and momentum and estimated damage energy are described. For a selection of impactor tip shapes, the numerical model is used to evaluate different simplified force histories...

  8. Bias Correction in the Dynamic Panel Data Model with a Nonscalar Disturbance Covariance Matrix

    NARCIS (Netherlands)

    Bun, M.J.G.

    2003-01-01

    Approximation formulae are developed for the bias of ordinary and generalized Least Squares Dummy Variable (LSDV) estimators in dynamic panel data models. Results from Kiviet [Kiviet, J. F. (1995), on bias, inconsistency, and efficiency of various estimators in dynamic panel data models, J.

  9. Numerical modeling of sandwich panel response to ballistic loading - energy balance for varying impactor geometries

    DEFF Research Database (Denmark)

    Kepler, Jørgen Asbøl; Hansen, Michael Rygaard

    2007-01-01

    thickness but significantly smaller than panel length dimensions. Experimental data for the total loss in impactor kinetic energy and momentum and estimated damage energy are described. For a selection of impactor tip shapes, the numerical model is used to evaluate different simplified force histories...... between the impactor and the panel during penetration. The force histories are selected from a primary criterion of conservation of linear momentum in the impactor-panel system, and evaluated according to agreement with the total measured energy balance....

  10. Coupled thermal model of photovoltaic-thermoelectric hybrid panel for sample cities in Europe

    DEFF Research Database (Denmark)

    Rezaniakolaei, Alireza; Sera, Dezso; Rosendahl, Lasse Aistrup

    2016-01-01

    of the hybrid system under different weather conditions. The model takes into account solar irradiation, wind speed and ambient temperature as well as convective and radiated heat losses from the front and rear surfaces of the panel. The model is developed for three sample cities in Europe with different......In general, modeling of photovoltaic-thermoelectric (PV/TEG) hybrid panels have been mostly simplified and disconnected from the actual ambient conditions and thermal losses from the panel. In this study, a thermally coupled model of PV/TEG panel is established to precisely predict performance...... weather conditions. The results show that radiated heat loss from the front surface and the convective heat loss due to the wind speed are the most critical parameters on performance of the hybrid panel performance. The results also indicate that, with existing thermoelectric materials, the power...

  11. Modeling and Control of the Redundant Parallel Adjustment Mechanism on a Deployable Antenna Panel

    Directory of Open Access Journals (Sweden)

    Lili Tian

    2016-10-01

    Full Text Available With the aim of developing multiple input and multiple output (MIMO coupling systems with a redundant parallel adjustment mechanism on the deployable antenna panel, a structural control integrated design methodology is proposed in this paper. Firstly, the modal information from the finite element model of the structure of the antenna panel is extracted, and then the mathematical model is established with the Hamilton principle; Secondly, the discrete Linear Quadratic Regulator (LQR controller is added to the model in order to control the actuators and adjust the shape of the panel. Finally, the engineering practicality of the modeling and control method based on finite element analysis simulation is verified.

  12. Propulsion and Energetics Panel Working Group 11 on Aircraft Fire Safety. Volume 2. Main Report

    Science.gov (United States)

    1979-11-01

    combs of various densities; laminated epoxy aromatic polyamide honeycombs. 1, 32 The laminated bismaleimide panels which contain the carbon microballons...formed of films of polycarbonate phenolphthalein on laminated bismaleimide - honeycombs aromatic polyamide containing a polyquinoxaline foam give a very...polycarbonates were among the least toxic, PVF and polystyrene had a good ranking. PVC and phenylene oxide rated as less toxic if one referred to the

  13. Different Modelling Approaches to Coupling Wall and Floor Panels within a Dynamic Finite Element Model of a Lightweight Building

    DEFF Research Database (Denmark)

    Kiel, Nikolaj; Andersen, Lars Vabbersgaard; Niu, Bin

    2012-01-01

    , with as many applications as possible, for the least possible computational cost. The coupling method of the structural panels in the above mentioned modular finite element model is in this paper discussed and evaluated. The coupling of the panels are performed using the commercial finite element program...... ABAQUS [2], where the built-in element constraints applications are utilised. The models are setup in scripts, using the Python language, to ensure a fast and consistent model. It is found that the modules, i.e. panels, are easy to couple, if an auxiliary skeleton is introduced in all panel intersections...

  14. Computational Model for Spacecraft/Habitat Volume

    Data.gov (United States)

    National Aeronautics and Space Administration — Please note that funding to Dr. Simon Hsiang, a critical co-investigator for the development of the Spacecraft Optimization Layout and Volume (SOLV) model, was...

  15. Energy Research Advisory Board, Civilian Nuclear Power Panel: Subpanel 3 report, Institutional challenges: Volume IV

    International Nuclear Information System (INIS)

    1986-10-01

    The Institutional Challenges Subpanel of the Energy Research Advisory Board's Civilian Nuclear Power Panel was charged with the task of addressing the institutional issues that affect the future of nuclear power in the United States. Barriers created by non-technical issues are generally considered to be primary obstacles to revitalizing the nuclear fission option as part of a robust supply for future electrical generation. The Subpanel examined the following categories of institutional issues: (1) Administration Policy and Leadership, (2) Licensing Reform, (3) Standardized Designs, (4) Shared Financial Risk, (5) State and Economic Regulation, (6) Waste Disposal, and (7) Public Perception. The Subpanel concluded that the Administration and Congress have the opportunity and responsibility to provide leadership in resolving these difficulties. The main report provides information on the background and current situation for each institutional issue and concludes with the set of recommendations for action

  16. Low velocity impact behaviour of ultra high strength concrete panels

    Indian Academy of Sciences (India)

    oped to simulate the impact behaviour of UHSC panel. The Brittle cracking model is used to simulate the behaviour of UHSC panel under impact loading and to perform parametric studies by varying the volume fraction of steel fibres. Keywords. Ultra high strength concrete; panel; drop weight test; impact analysis;. ABAQUS.

  17. Proceedings of the workshop on program options in intermediate-energy physics. Volume 1. Summary and panel reports

    Energy Technology Data Exchange (ETDEWEB)

    Allred, J.C.; Talley, B. (comps.)

    1980-05-01

    A Workshop on Program Options in Intermediate-Energy Physics sponsored by the US Department of Energy was held at Los Alamos Scientific Laboratory, August 20 to 31, 1979. The scope of the workshop included all laboratories in intermediate-energy physics, worldwide, and all of these sent representatives to the workshop. The workshop addressed itself to the critical questions on nuclear and particle physics and how they can best be investigated by intermediate-energy accelerators. Among the questions that the workshop members considered were: (1) what are the important physics topics which might be understood through research on these accelerators in the next 10 years. These topics include, but are not restricted to, fundamental interactions and symmetries in particle physics, and nuclear modes of motion, structure, and reaction mechanisms; (2) what experiments should be undertaken to carry out the program. What are the kinematical conditions, accuracies, resolutions, and other parameters required to obtain the desired knowledge; (3) which accelerators are best suited for each experiment. What work at other laboratories (low-, intermediate-, or high-energy) could be undertaken to complement and/or supplement the proposed LAMPF program; and (4) what new facility capabilities should be explored for the long-term future. The workshop was divided into small panels in order to promote effective interchange of ideas. After reports to other panels and plenary sessions, the panelists prepared reports stating the results of their deliberations. These reports comprise the principal part of Volume I.

  18. Proceedings of the workshop on program options in intermediate-energy physics. Volume 1. Summary and panel reports

    International Nuclear Information System (INIS)

    Allred, J.C.; Talley, B.

    1980-05-01

    A Workshop on Program Options in Intermediate-Energy Physics sponsored by the US Department of Energy was held at Los Alamos Scientific Laboratory, August 20 to 31, 1979. The scope of the workshop included all laboratories in intermediate-energy physics, worldwide, and all of these sent representatives to the workshop. The workshop addressed itself to the critical questions on nuclear and particle physics and how they can best be investigated by intermediate-energy accelerators. Among the questions that the workshop members considered were: (1) what are the important physics topics which might be understood through research on these accelerators in the next 10 years. These topics include, but are not restricted to, fundamental interactions and symmetries in particle physics, and nuclear modes of motion, structure, and reaction mechanisms; (2) what experiments should be undertaken to carry out the program. What are the kinematical conditions, accuracies, resolutions, and other parameters required to obtain the desired knowledge; (3) which accelerators are best suited for each experiment. What work at other laboratories (low-, intermediate-, or high-energy) could be undertaken to complement and/or supplement the proposed LAMPF program; and (4) what new facility capabilities should be explored for the long-term future. The workshop was divided into small panels in order to promote effective interchange of ideas. After reports to other panels and plenary sessions, the panelists prepared reports stating the results of their deliberations. These reports comprise the principal part of Volume I

  19. Dark radiation in LARGE volume models

    Science.gov (United States)

    Cicoli, Michele; Conlon, Joseph P.; Quevedo, Fernando

    2013-02-01

    We consider reheating driven by volume modulus decays in the LARGE volume scenario. Such reheating always generates nonzero dark radiation through the decays to the axion partner, while the only competitive visible sector decays are Higgs pairs via the Giudice-Masiero term. In the framework of sequestered models where the cosmological moduli problem is absent, the simplest model with a shift-symmetric Higgs sector generates 1.56≤ΔNeff≤1.74. For more general cases, the known experimental bounds on ΔNeff strongly constrain the parameters and matter content of the models.

  20. Ohlson model by panel cointegration with Mexican data

    Directory of Open Access Journals (Sweden)

    Arturo Lorenzo Valdés

    2010-01-01

    Full Text Available En este estudio utilizamos métodos de cointegración para investigar la relación entre las variables del modelo de Ohlson (precio de la acción, ganancia por acción y valor en libros con datos de panel. Las pruebas de cointegración se realizaron de forma individual y a nivel de grupo total y por grupo de sectores. Las empresas estudiadas pertenecen a los sectores económicos de alimentos y bebidas, comercial y construcción, que cotizan en el Mercado Accionario Mexicano. Los datos utilizados fueron trimestrales de 1997 a 2008. Los resultados empíricos, basados en la prueba de Johansen, muestran que existen relaciones individuales de cointegración. Los resultados de las pruebas de cointegración en panel indican que las variables del modelo de Ohlson no están cointegradas para el sector de construcción, pero sí lo están para los sectores comercial y de alimentos y bebidas.

  1. Sensitivity to plant modelling uncertainties in optimal feedback control of sound radiation from a panel

    DEFF Research Database (Denmark)

    Mørkholt, Jakob

    1997-01-01

    Optimal feedback control of broadband sound radiation from a rectangular baffled panel has been investigated through computer simulations. Special emphasis has been put on the sensitivity of the optimal feedback control to uncertainties in the modelling of the system under control.A model...... in terms of a set of radiation filters modelling the radiation dynamics.Linear quadratic feedback control applied to the panel in order to minimise the radiated sound power has then been simulated. The sensitivity of the model based controller to modelling uncertainties when using feedback from actual...

  2. High-resolution dynamic angiography using flat-panel volume CT: feasibility demonstration for neuro and lower limb vascular applications

    Energy Technology Data Exchange (ETDEWEB)

    Mehndiratta, Amit [Massachusetts General Hospital, Department of Radiology, Harvard Medical School, Boston, MA (United States); University of Oxford, Institute of Biomedical Engineering and Keble College, Oxford (United Kingdom); Indian Institute of Technology Delhi and All India Institute of Medical Science, Centre for Biomedical Engineering, New Delhi (India); Rabinov, James D. [Massachusetts General Hospital, Interventional Neuroradiology, Harvard Medical School, Boston, MA (United States); Grasruck, Michael [Siemens Medical Solutions, Forchheim (Germany); Liao, Eric C. [Massachusetts General Hospital, Department of Plastic and Reconstructive Surgery and Center for Regenerative Medicine, Harvard Medical School, Boston, MA (United States); Crandell, David [Spaulding Rehabilitation Hospital, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Charlestown, MA (United States); Gupta, Rajiv [Massachusetts General Hospital, Department of Radiology, Harvard Medical School, Boston, MA (United States)

    2015-07-15

    This paper evaluates a prototype flat-panel volume CT (fpVCT) for dynamic in vivo imaging in a variety of neurovascular and lower limb applications. Dynamic CTA was performed on 12 patients (neuro = 8, lower limb = 4) using an fpVCT with 120 kVp, 50 mA, rotation time varying from 8 to 19 s, and field of view of 25 x 25 x 18 cm{sup 3}. Four-dimensional data sets (i.e. 3D images over time) were reconstructed and reviewed. Dynamic CTA demonstrated sufficient spatio-temporal resolution to elucidate first-pass and recirculation dynamics of contrast bolus through neurovasclar pathologies and phasic blood flow though lower-limb vasculature and grafts. The high spatial resolution of fpVCT resulted in reduced partial volume and metal beam-hardening artefacts. This facilitated assessment of vascular lumen in the presence of calcified plaque and evaluation of fractures, especially in the presence of fixation hardware. Evaluation of arteriovenous malformation using dynamic fpVCT angiography was of limited utility. Dynamic CTA using fpVCT can visualize time-varying phenomena in neuro and lower limb vascular applications and has sufficient diagnostic imaging quality to evaluate a number of pathologies affecting these regions. (orig.)

  3. High-resolution dynamic angiography using flat-panel volume CT: feasibility demonstration for neuro and lower limb vascular applications

    International Nuclear Information System (INIS)

    Mehndiratta, Amit; Rabinov, James D.; Grasruck, Michael; Liao, Eric C.; Crandell, David; Gupta, Rajiv

    2015-01-01

    This paper evaluates a prototype flat-panel volume CT (fpVCT) for dynamic in vivo imaging in a variety of neurovascular and lower limb applications. Dynamic CTA was performed on 12 patients (neuro = 8, lower limb = 4) using an fpVCT with 120 kVp, 50 mA, rotation time varying from 8 to 19 s, and field of view of 25 x 25 x 18 cm 3 . Four-dimensional data sets (i.e. 3D images over time) were reconstructed and reviewed. Dynamic CTA demonstrated sufficient spatio-temporal resolution to elucidate first-pass and recirculation dynamics of contrast bolus through neurovasclar pathologies and phasic blood flow though lower-limb vasculature and grafts. The high spatial resolution of fpVCT resulted in reduced partial volume and metal beam-hardening artefacts. This facilitated assessment of vascular lumen in the presence of calcified plaque and evaluation of fractures, especially in the presence of fixation hardware. Evaluation of arteriovenous malformation using dynamic fpVCT angiography was of limited utility. Dynamic CTA using fpVCT can visualize time-varying phenomena in neuro and lower limb vascular applications and has sufficient diagnostic imaging quality to evaluate a number of pathologies affecting these regions. (orig.)

  4. Dynamic heat transfer modeling and parametric study of thermoelectric radiant cooling and heating panel system

    International Nuclear Information System (INIS)

    Luo, Yongqiang; Zhang, Ling; Liu, Zhongbing; Wang, Yingzi; Wu, Jing; Wang, Xiliang

    2016-01-01

    Highlights: • Dynamic model of thermoelectric radiant panel system is established. • The internal parameters of thermoelectric module are dynamically calculated in simulation. • Both artificial neural networks model and system model are verified through experiment data. • Optimized system structure is obtained through parametric study. - Abstract: Radiant panel system can optimize indoor thermal comfort with lower energy consumption. The thermoelectric radiant panel (TERP) system is a new and effective prototype of radiant system using thermoelectric module (TEM) instead of conventional water pipes, as heat source. The TERP can realize more stable and easier system control as well as lower initial and operative cost. In this study, an improved system dynamic model was established by combining analytical system model and artificial neural networks (ANN) as well as the dynamic calculation functions of internal parameters of TEM. The double integral was used for the calculation of surface average temperature of TERP. The ANN model and system model were in good agreement with experiment data in both cooling and heating mode. In order to optimize the system design structure, parametric study was conducted in terms of the thickness of aluminum panel and insulation, as well as the arrangement of TEMs on the surface of radiant panel. It was found through simulation results that the optimum thickness of aluminum panel and insulation are respectively around 1–2 mm and 40–50 mm. In addition, TEMs should be uniformly installed on the surface of radiant panel and each TEM should stand at the central position of a square-shaped typical region with length around 0.387–0.548 m.

  5. Consistency in Estimation and Model Selection of Dynamic Panel Data Models with Fixed Effects

    Directory of Open Access Journals (Sweden)

    Guangjie Li

    2015-07-01

    Full Text Available We examine the relationship between consistent parameter estimation and model selection for autoregressive panel data models with fixed effects. We find that the transformation of fixed effects proposed by Lancaster (2002 does not necessarily lead to consistent estimation of common parameters when some true exogenous regressors are excluded. We propose a data dependent way to specify the prior of the autoregressive coefficient and argue for comparing different model specifications before parameter estimation. Model selection properties of Bayes factors and Bayesian information criterion (BIC are investigated. When model uncertainty is substantial, we recommend the use of Bayesian Model Averaging to obtain point estimators with lower root mean squared errors (RMSE. We also study the implications of different levels of inclusion probabilities by simulations.

  6. NONPARAMETRIC FIXED EFFECT PANEL DATA MODELS: RELATIONSHIP BETWEEN AIR POLLUTION AND INCOME FOR TURKEY

    Directory of Open Access Journals (Sweden)

    Rabia Ece OMAY

    2013-06-01

    Full Text Available In this study, relationship between gross domestic product (GDP per capita and sulfur dioxide (SO2 and particulate matter (PM10 per capita is modeled for Turkey. Nonparametric fixed effect panel data analysis is used for the modeling. The panel data covers 12 territories, in first level of Nomenclature of Territorial Units for Statistics (NUTS, for period of 1990-2001. Modeling of the relationship between GDP and SO2 and PM10 for Turkey, the non-parametric models have given good results.

  7. EARTHWORK VOLUME CALCULATION FROM DIGITAL TERRAIN MODELS

    Directory of Open Access Journals (Sweden)

    JANIĆ Milorad

    2015-06-01

    Full Text Available Accurate calculation of cut and fill volume has an essential importance in many fields. This article shows a new method, which has no approximation, based on Digital Terrain Models. A relatively new mathematical model is developed for that purpose, which is implemented in the software solution. Both of them has been tested and verified in the praxis on several large opencast mines. This application is developed in AutoLISP programming language and works in AutoCAD environment.

  8. Modeling Unobserved Consideration Sets for Household Panel Data

    NARCIS (Netherlands)

    J.E.M. van Nierop; R. Paap (Richard); B. Bronnenberg; Ph.H.B.F. Franses (Philip Hans)

    2000-01-01

    textabstractWe propose a new method to model consumers' consideration and choice processes. We develop a parsimonious probit type model for consideration and a multinomial probit model for choice, given consideration. Unlike earlier models of consideration ours is not prone to the curse of

  9. Modeling Microalgae Productivity in Industrial-Scale Vertical Flat Panel Photobioreactors.

    Science.gov (United States)

    Endres, Christian Hermann; Roth, Arne; Brück, Thomas Bartholomaeus

    2018-03-29

    Potentially achievable biomass yields are a decisive performance indicator for the economic viability of mass cultivation of microalgae. In this study, a computer model has been developed and applied to estimate the productivity of microalgae for large-scale outdoor cultivation in vertical flat panel photobioreactors. Algae growth is determined based on simulations of the reactor temperature and light distribution. Site-specific weather and irradiation data are used for annual yield estimations in six climate zones. Shading and reflections between opposing panels and between panels and the ground are dynamically computed based on the reactor geometry and the position of the sun. The results indicate that thin panels (≤ 0.05 m) are best suited for the assumed cell density of 2 g L -1 and that reactor panels should face in north-south direction. Panel spacings of 0.4 - 0.75 m appear most suitable for commercial applications. Under these preconditions, yields of around 10 kg m -2 a -1 are possible for most locations in the U.S. Only in hot climates significantly lower yields have to be expected, as extreme reactor temperatures limit overall productivity.

  10. Thermal Modeling of the Mars Reconnaissance Orbiter's Solar Panel and Instruments during Aerobraking

    Science.gov (United States)

    Dec, John A.; Gasbarre, Joseph F.; Amundsen, Ruth M.

    2007-01-01

    The Mars Reconnaissance Orbiter (MRO) launched on August 12, 2005 and started aerobraking at Mars in March 2006. During the spacecraft s design phase, thermal models of the solar panels and instruments were developed to determine which components would be the most limiting thermally during aerobraking. Having determined the most limiting components, thermal limits in terms of heat rate were established. Advanced thermal modeling techniques were developed utilizing Thermal Desktop and Patran Thermal. Heat transfer coefficients were calculated using a Direct Simulation Monte Carlo technique. Analysis established that the solar panels were the most limiting components during the aerobraking phase of the mission.

  11. The irradiance and temperature dependent mathematical model for estimation of photovoltaic panel performances

    International Nuclear Information System (INIS)

    Barukčić, M.; Ćorluka, V.; Miklošević, K.

    2015-01-01

    Highlights: • The temperature and irradiance dependent model for the I–V curve estimation is presented. • The purely mathematical model based on the analysis of the I–V curve shape is presented. • The model includes the Gompertz function with temperature and irradiance dependent parameters. • The input data are extracted from the data sheet I–V curves. - Abstract: The temperature and irradiance dependent mathematical model for photovoltaic panel performances estimation is proposed in the paper. The base of the model is the mathematical function of the photovoltaic panel current–voltage curve. The model of the current–voltage curve is based on the sigmoid function with temperature and irradiance dependent parameters. The temperature and irradiance dependencies of the parameters are proposed in the form of analytic functions. The constant parameters are involved in the analytical functions. The constant parameters need to be estimated to get the temperature and irradiance dependent current–voltage curve. The mathematical model contains 12 constant parameters and they are estimated by using the evolutionary algorithm. The optimization problem is defined for this purpose. The optimization problem objective function is based on estimated and extracted (measured) current and voltage values. The current and voltage values are extracted from current–voltage curves given in datasheet of the photovoltaic panels. The new procedure for estimation of open circuit voltage value at any temperature and irradiance is proposed in the model. The performance of the proposed mathematical model is presented for three different photovoltaic panel technologies. The simulation results indicate that the proposed mathematical model is acceptable for estimation of temperature and irradiance dependent current–voltage curve and photovoltaic panel performances within temperature and irradiance ranges

  12. 1988 DOE model conference proceedings: Volume 4

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    These Proceedings of the October 3-7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics discussed in Volume 4 include site characterization and remediation projects, environmental monitoring and modeling; disposal site selection and facility design, risk assessment, safety and health issues, and site remediation technology.

  13. 1988 DOE model conference proceedings: Volume 4

    International Nuclear Information System (INIS)

    1988-01-01

    These Proceedings of the October 3-7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics discussed in Volume 4 include site characterization and remediation projects, environmental monitoring and modeling; disposal site selection and facility design, risk assessment, safety and health issues, and site remediation technology

  14. Variable-intercept panel model for deformation zoning of a super-high arch dam.

    Science.gov (United States)

    Shi, Zhongwen; Gu, Chongshi; Qin, Dong

    2016-01-01

    This study determines dam deformation similarity indexes based on an analysis of deformation zoning features and panel data clustering theory, with comprehensive consideration to the actual deformation law of super-high arch dams and the spatial-temporal features of dam deformation. Measurement methods of these indexes are studied. Based on the established deformation similarity criteria, the principle used to determine the number of dam deformation zones is constructed through entropy weight method. This study proposes the deformation zoning method for super-high arch dams and the implementation steps, analyzes the effect of special influencing factors of different dam zones on the deformation, introduces dummy variables that represent the special effect of dam deformation, and establishes a variable-intercept panel model for deformation zoning of super-high arch dams. Based on different patterns of the special effect in the variable-intercept panel model, two panel analysis models were established to monitor fixed and random effects of dam deformation. Hausman test method of model selection and model effectiveness assessment method are discussed. Finally, the effectiveness of established models is verified through a case study.

  15. Effects of uncertainty in model predictions of individual tree volume on large area volume estimates

    Science.gov (United States)

    Ronald E. McRoberts; James A. Westfall

    2014-01-01

    Forest inventory estimates of tree volume for large areas are typically calculated by adding model predictions of volumes for individual trees. However, the uncertainty in the model predictions is generally ignored with the result that the precision of the large area volume estimates is overestimated. The primary study objective was to estimate the effects of model...

  16. Modeling non-ignorable attrition and measurement error in panel surveys: an application to travel demand modeling

    OpenAIRE

    Brownstone, David; Golob, Thomas F.; Kazimi, Camilla

    1991-01-01

    Modern panel surveys frequently suffer from high and likely non-ignorable attrition, and transportation surveys suffer from poor travel time estimates. This paper examines new methods for adjusting forecasts and model estimates to account for these problems. The methods we describe are illustrated using a new panel survey of 1500 commuters in San Diego, California. These data are being collected to evaluate a federally-funded “Congestion Pricing†experiment investigating the impacts of all...

  17. Orthogonal model and experimental data for analyzing wood-fiber-based tri-axial ribbed structural panels in bending

    Science.gov (United States)

    Jinghao Li; John F. Hunt; Shaoqin Gong; Zhiyong Cai

    2017-01-01

    This paper presents an analysis of 3-dimensional engineered structural panels (3DESP) made from wood-fiber-based laminated paper composites. Since the existing models for calculating the mechanical behavior of core configurations within sandwich panels are very complex, a new simplified orthogonal model (SOM) using an equivalent element has been developed. This model...

  18. Statistical model based gender prediction for targeted NGS clinical panels

    Directory of Open Access Journals (Sweden)

    Palani Kannan Kandavel

    2017-12-01

    The reference test dataset are being used to test the model. The sensitivity on predicting the gender has been increased from the current “genotype composition in ChrX” based approach. In addition, the prediction score given by the model can be used to evaluate the quality of clinical dataset. The higher prediction score towards its respective gender indicates the higher quality of sequenced data.

  19. Modeling nuclear volume isotope effects in crystals

    Science.gov (United States)

    Schauble, Edwin A.

    2013-01-01

    Mass-independent isotope fractionations driven by differences in volumes and shapes of nuclei (the field shift effect) are known in several elements and are likely to be found in more. All-electron relativistic electronic structure calculations can predict this effect but at present are computationally intensive and limited to modeling small gas phase molecules and clusters. Density functional theory, using the projector augmented wave method (DFT-PAW), has advantages in greater speed and compatibility with a three-dimensional periodic boundary condition while preserving information about the effects of chemistry on electron densities within nuclei. These electron density variations determine the volume component of the field shift effect. In this study, DFT-PAW calculations are calibrated against all-electron, relativistic Dirac–Hartree–Fock, and coupled-cluster with single, double (triple) excitation methods for estimating nuclear volume isotope effects. DFT-PAW calculations accurately reproduce changes in electron densities within nuclei in typical molecules, when PAW datasets constructed with finite nuclei are used. Nuclear volume contributions to vapor–crystal isotope fractionation are calculated for elemental cadmium and mercury, showing good agreement with experiments. The nuclear-volume component of mercury and cadmium isotope fractionations between atomic vapor and montroydite (HgO), cinnabar (HgS), calomel (Hg2Cl2), monteponite (CdO), and the CdS polymorphs hawleyite and greenockite are calculated, indicating preferential incorporation of neutron-rich isotopes in more oxidized, ionically bonded phases. Finally, field shift energies are related to Mössbauer isomer shifts, and equilibrium mass-independent fractionations for several tin-bearing crystals are calculated from 119Sn spectra. Isomer shift data should simplify calculations of mass-independent isotope fractionations in other elements with Mössbauer isotopes, such as platinum and uranium

  20. Analysis of Composite Panel-Stiffener Debonding Using a Shell/3D Modeling Technique

    Science.gov (United States)

    Krueger, Ronald; Ratcliffe, James; Minguet, Pierre J.

    2007-01-01

    Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used successfully primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities, however, requires the successful demonstration of the methodology on the structural level. For this purpose, a panel was selected that is reinforced with stiffeners. Shear loading causes the panel to buckle, and the resulting out-of-plane deformations initiate skin/stiffener separation at the location of an embedded defect. A small section of the stiffener foot, web and noodle as well as the panel skin in the vicinity of the delamination front were modeled with a local 3D solid model. Across the width of the stiffener foot, the mixedmode strain energy release rates were calculated using the virtual crack closure technique. A failure index was calculated by correlating the results with a mixed-mode failure criterion of the graphite/epoxy material. Computed failure indices were compared to corresponding results where the entire web was modeled with shell elements and only a small section of the stiffener foot and panel were modeled locally with solid elements. Including the stiffener web in the local 3D solid model increased the computed failure index. Further including the noodle and transition radius in the local 3D solid model changed the local distribution across the width. The magnitude of the failure index decreased with increasing transition radius and noodle area. For the transition radii modeled, the material properties used for the noodle area had a negligible effect on the results. The results of this study are intended to be used as a guide for conducting finite element and fracture mechanics analyses of delamination and debonding in complex structures such as integrally stiffened panels.

  1. Multi-State Models for Panel Data: The msm Package for R

    Directory of Open Access Journals (Sweden)

    Christopher H. Jackson

    2011-01-01

    Full Text Available Panel data are observations of a continuous-time process at arbitrary times, for example, visits to a hospital to diagnose disease status. Multi-state models for such data are generally based on the Markov assumption. This article reviews the range of Markov models and their extensions which can be fitted to panel-observed data, and their implementation in the msm package for R. Transition intensities may vary between individuals, or with piecewise-constant time-dependent covariates, giving an inhomogeneous Markov model. Hidden Markov models can be used for multi-state processes which are misclassified or observed only through a noisy marker. The package is intended to be straightforward to use, flexible and comprehensively documented. Worked examples are given of the use of msm to model chronic disease progression and screening. Assessment of model fit, and potential future developments of the software, are also discussed.

  2. Testing and thermal modeling of radiant panels systems as commissioning tool

    International Nuclear Information System (INIS)

    Fonseca Diaz, Nestor; Cuevas, Cristian

    2010-01-01

    This paper presents the results of a study performed to develop a thermal modeling of radiant panels systems to be used in situ, as diagnosis tool in commissioning processes to determine the main operating conditions of the system in cooling or heating mode. The model considers the radiant panels as a finned heat exchanger in dry regime. By using as inputs the ceiling and room dimensions, the radiant ceiling material properties and the measurements of air and water mass flow rates and temperatures, the model is able to calculate the radiant ceiling capacity, ceiling surface average temperature, water exhaust temperature and resultant temperature as a comfort indicator. The modeling proposed considers combined convection, perforation effect and a detailed radiative heat exchange method for radiant ceiling systems. An example of each system considered in this study is shown, illustrating the validation of the model. A sensitive analysis of the model is performed.

  3. 1988 DOE model conference proceedings: Volume 2

    International Nuclear Information System (INIS)

    1988-01-01

    These Proceedings of the October 3 - 7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Volume 2 contains information on environmental restoration at federal facilities, waste disposal technology, quality assurance, contingency planning and emergency response, decontamination and decommissioning, environmental restoration, and public involvement in waste management

  4. 1988 DOE model conference proceedings: Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    These Proceedings of the October 3 - 7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics included in Volume 3 include treatment of soils, waste characterization and certification, waste minimization site remediation management plans and programs, and training programs.

  5. 1988 DOE model conference proceedings: Volume 3

    International Nuclear Information System (INIS)

    1988-01-01

    These Proceedings of the October 3 - 7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics included in Volume 3 include treatment of soils, waste characterization and certification, waste minimization site remediation management plans and programs, and training programs

  6. 1988 DOE model conference proceedings: Volume 1

    International Nuclear Information System (INIS)

    1988-01-01

    These Proceedings of the October 3-7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics included in Volume 1 are Environmental Data Management, Site characterization technology, Wastewater treatment, Waste management in foreign countries, Transuranic waste management, and Groundwater characterization and treatment

  7. 1988 DOE model conference proceedings: Volume 5

    International Nuclear Information System (INIS)

    1988-01-01

    These Proceedings of the October 3--7, 1988 DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics discussed in Volume 5 include environmental assessments and program strategies, waste treatment technologies, and regulations and compliance studies

  8. 1988 DOE model conference proceedings: Volume 5

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    These Proceedings of the October 3--7, 1988 DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics discussed in Volume 5 include environmental assessments and program strategies, waste treatment technologies, and regulations and compliance studies.

  9. 1988 DOE model conference proceedings: Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1988-01-01

    These Proceedings of the October 3-7, 1988, DOE Model Conference are a compilation of the papers that were presented in the technical or poster sessions at the conference. Papers and posters not submitted for publication are not included in the Proceedings. The Table of Contents lists the titles of papers as well as the names of the presenters. These individuals are not, in all cases, the primary authors of the papers published. The actual title pages, appearing later with the papers, show the primary author(s) and all co-authors. The papers in all three volumes of the Proceedings appear as they were originally submitted for publication and have not been edited or changed in any way. Topics included in Volume 1 are Environmental Data Management, Site characterization technology, Wastewater treatment, Waste management in foreign countries, Transuranic waste management, and Groundwater characterization and treatment.

  10. Long-Run Effects in Large Heterogeneous Panel Data Models with Cross-Sectionally Correlated Errors

    OpenAIRE

    Chudik, Alexander; Mohaddes, Kamiar; Pesaran, M Hashem; Raissi, Mehdi

    2016-01-01

    This paper develops a cross-sectionally augmented distributed lag (CS-DL) approach to the estimation of long-run effects in large dynamic heterogeneous panel data models with cross-sectionally dependent errors. The asymptotic distribution of the CS-DL estimator is derived under coefficient heterogeneity in the case where the time dimension (T) and the cross-section dimension (N) are both large. The CS-DL approach is compared with more standard panel data estimators that are based on autoregre...

  11. Long-run effects in large heterogenous panel data models with cross-sectionally correlated errors

    OpenAIRE

    Chudik, Alexander; Mohaddes, Kamiar; Pesaran, M. Hashem; Raissi, Mehdi

    2015-01-01

    This paper develops a cross-sectionally augmented distributed lag (CS-DL) approach to the estimation of long-run effects in large dynamic heterogeneous panel data models with cross-sectionally dependent errors. The asymptotic distribution of the CS-DL estimator is derived under coefficient heterogeneity in the case where the time dimension (T) and the cross-section dimension (N) are both large. The CS-DL approach is compared with more standard panel data estimators that are based on autoregre...

  12. Identification and estimation of nonseparable single-index models in panel data with correlated random effects

    NARCIS (Netherlands)

    Cizek, Pavel; Lei, Jinghua

    The identification in a nonseparable single-index models with correlated random effects is considered in panel data with a fixed number of time periods. The identification assumption is based on the correlated random effects structure. Under this assumption, the parameters of interest are identified

  13. Identification and Estimation of Nonseparable Single-Index Models in Panel Data with Correlated Random Effects

    NARCIS (Netherlands)

    Cizek, P.; Lei, J.

    2013-01-01

    Abstract: The identification of parameters in a nonseparable single-index models with correlated random effects is considered in the context of panel data with a fixed number of time periods. The identification assumption is based on the correlated random-effect structure: the distribution of

  14. A PANEL-DATA SWITCHING REGRESSION-MODEL OF MOBILITY AND CAR OWNERSHIP

    NARCIS (Netherlands)

    MEURS, H

    1993-01-01

    The objective of this paper is to present a panel data model of car ownership and mobility. Unobserved heterogeneity is controlled for by including correlated random effects in the equations describing car ownership and mobility. A mass-points approach is adopted to control for unobserved

  15. Panel Stiffener Debonding Analysis using a Shell/3D Modeling Technique

    Science.gov (United States)

    Krueger, Ronald; Ratcliffe, James G.; Minguet, Pierre J.

    2008-01-01

    A shear loaded, stringer reinforced composite panel is analyzed to evaluate the fidelity of computational fracture mechanics analyses of complex structures. Shear loading causes the panel to buckle. The resulting out -of-plane deformations initiate skin/stringer separation at the location of an embedded defect. The panel and surrounding load fixture were modeled with shell elements. A small section of the stringer foot, web and noodle as well as the panel skin near the delamination front were modeled with a local 3D solid model. Across the width of the stringer fo to, the mixed-mode strain energy release rates were calculated using the virtual crack closure technique. A failure index was calculated by correlating the results with a mixed-mode failure criterion of the graphite/epoxy material. The objective was to study the effect of the fidelity of the local 3D finite element model on the computed mixed-mode strain energy release rates and the failure index.

  16. Panel-Stiffener Debonding and Analysis Using a Shell/3D Modeling Technique

    Science.gov (United States)

    Krueger, Ronald; Ratcliffe, James G.; Minguet, Pierre J.

    2007-01-01

    A shear loaded, stringer reinforced composite panel is analyzed to evaluate the fidelity of computational fracture mechanics analyses of complex structures. Shear loading causes the panel to buckle. The resulting out-of-plane deformations initiate skin/stringer separation at the location of an embedded defect. The panel and surrounding load fixture were modeled with shell elements. A small section of the stringer foot, web and noodle as well as the panel skin near the delamination front were modeled with a local 3D solid model. Across the width of the stringer foot, the mixed-mode strain energy release rates were calculated using the virtual crack closure technique. A failure index was calculated by correlating the results with a mixed-mode failure criterion of the graphite/epoxy material. The objective was to study the effect of the fidelity of the local 3D finite element model on the computed mixed-mode strain energy release rates and the failure index.

  17. An efficient model of an equipment loaded panel for active control design studies.

    Science.gov (United States)

    Aglietti, G S; Langley, R S; Rogers, E; Gabriel, S B

    2000-10-01

    An effective investigation of alternative control strategies for the reduction of vibration levels in satellite structures requires realistic, yet efficient, structural models to simulate the dynamics of the system. These models should include the effects of the sources, receivers, supporting structure, sensors, and actuators. In this paper, a modeling technique which meets these requirements is developed and some active control strategies are briefly investigated. The particular subject of investigation is an equipment-loaded panel and the equations of motion are derived using the Lagrange-Rayleigh-Ritz (LRR) approach. The various pieces of equipment on the panel are mounted on active or passive suspensions, and resonators are used to represent the internal dynamics of the mounted equipment. Control of the panel, which transmits vibrations from sources to receivers, is by means of piezoelectric patches and the excitation consists of dynamic loads acting on the equipment enclosures and/or directly on the panel. The control objective is to minimize the displacement at an arbitrary output location. The LRR model developed is verified against one produced by using the finite-element method. Finally, some initial controller design studies are undertaken to investigate and compare the effectiveness of different control strategies (e.g., minimization at the source, along the vibration path, or at the receiver).

  18. Markov models for digraph panel data : Monte Carlo-based derivative estimation

    NARCIS (Netherlands)

    Schweinberger, Michael; Snijders, Tom A. B.

    2007-01-01

    A parametric, continuous-time Markov model for digraph panel data is considered. The parameter is estimated by the method of moments. A convenient method for estimating the variance-covariance matrix of the moment estimator relies on the delta method, requiring the Jacobian matrix-that is, the

  19. Robust estimation and moment selection in dynamic fixed-effects panel data models

    NARCIS (Netherlands)

    Cizek, Pavel; Aquaro, Michele

    Considering linear dynamic panel data models with fixed effects, existing outlier–robust estimators based on the median ratio of two consecutive pairs of first-differenced data are extended to higher-order differencing. The estimation procedure is thus based on many pairwise differences and their

  20. An SEM Approach to Continuous Time Modeling of Panel Data: Relating Authoritarianism and Anomia

    Science.gov (United States)

    Voelkle, Manuel C.; Oud, Johan H. L.; Davidov, Eldad; Schmidt, Peter

    2012-01-01

    Panel studies, in which the same subjects are repeatedly observed at multiple time points, are among the most popular longitudinal designs in psychology. Meanwhile, there exists a wide range of different methods to analyze such data, with autoregressive and cross-lagged models being 2 of the most well known representatives. Unfortunately, in these…

  1. The Accuracy of Inference in Small Samples of Dynamic Panel Data Models

    NARCIS (Netherlands)

    Bun, M.J.G.; Kiviet, J.F.

    2001-01-01

    Through Monte Carlo experiments the small sample behavior is examined of various inference techniques for dynamic panel data models when both the time-series and cross-section dimensions of the data set are small. The LSDV technique and corrected versions of it are compared with IV and GMM

  2. System Estimation of Panel Data Models under Long-Range Dependence

    DEFF Research Database (Denmark)

    Ergemen, Yunus Emre

    using conditional-sum-of-squares criteria based on projected series by which latent characteristics are proxied. Resulting estimates are consistent and asymptotically normal at standard parametric rates. A simulation study provides reliability on the estimation method. The method is then applied......A general dynamic panel data model is considered that incorporates individual and interactive fixed effects allowing for contemporaneous correlation in model innovations. The model accommodates general stationary or nonstationary long-range dependence through interactive fixed effects...

  3. Unsteady panel method for complex configurations including wake modeling

    CSIR Research Space (South Africa)

    Van Zyl, Lourens H

    2008-01-01

    Full Text Available The calculation of unsteady air loads is an essential step in any aeroelastic analysis. The subsonic doublet lattice method (DLM) is used extensively for this purpose due to its simplicity and reliability. The body models available with the popular...

  4. IMPLEMENTASI SINGLE MINUTE EXCHANGE OF DIES (SMED UNTUK OPTIMASI WAKTU CHANGEOVER MODEL PADA PRODUKSI PANEL TELEKOMUNIKASI

    Directory of Open Access Journals (Sweden)

    Ahmad Mulyana

    2017-06-01

    Full Text Available Sebagai salah satu perusahaan pembuat panel telekomunikasi dan panel elektrik, PT. Cometal dihadapkan pada tantangan waktu delivery yang kompetitif.  Permasalahannya perusahaan masih mengalami keterlambatan pengiriman produk ke konsumen akibat lamanya waktu changeover model yang menyebabkan downtime mesin punching pada proses produksi panel telekomunikasi. Untuk mengurangi lead time maka perlu diupayakan minimasi waste pada changeover model di mesin punching.  Tujuan penelitian ini adalah mengidentifikasi faktor penyebab tingginya waktu changeover model pada mesin punching dan melakukan improvement dengan metode SMED (single minute exchange of dies.  Penerapan metode SMED dilakukan dengan mengotimalkan aktifitas eksternal pada produksi panel telekomunikasi melalui koordinasi kegiatan Pengamatan dilakukan selama 30 hari menggunakan studi waktu sebelum dan sesudah implementasi SMED.  Penerapan konsep SMED dilakukan dengan  mengubah 15 aktifitas internal menjadi 5 aktifitas internal dan merekayasa alat bantu gauge tool untuk mengurangi downtime mesin.  Improvement yang diperoleh adalah berkurangnya waktu downtime mesin punching dari 44,90 jam menjadi 10,96 jam atau terjadi penurunan waktu setup sebesar 75, 59 persen.

  5. Atmospheric Renewable Energy Research, Volume 5 (Solar Radiation Flux Model)

    Science.gov (United States)

    2017-09-01

    ARL-TR-8155 ● SEP 2017 US Army Research Laboratory Atmospheric Renewable Energy Research, Volume 5 (Solar Radiation Flux Model... Energy Research, Volume 5 (Solar Radiation Flux Model) by Clayton Walker and Gail Vaucher Computational and Information Sciences Directorate, ARL...2017 June 28 4. TITLE AND SUBTITLE Atmospheric Renewable Energy Research, Volume 5 (Solar Radiation Flux Model) 5a. CONTRACT NUMBER ROTC Internship

  6. The comparison of numerical models of a sandwich panel in the context of the core deformations at the supports

    Science.gov (United States)

    Pozorska, Jolanta; Pozorski, Zbigniew

    2018-01-01

    The paper presents the problem of static structural behavior of sandwich panels at the supports. The panels have a soft core and correspond to typical structures applied in civil engineering. To analyze the problem, five different 3-D numerical models were created. The results were compared in the context of core compression and stress redistribution. The numerical solutions verify methods of evaluating the capacity of the sandwich panel that are known from the literature.

  7. A single-level random-effects cross-lagged panel model for longitudinal mediation analysis.

    Science.gov (United States)

    Wu, Wei; Carroll, Ian A; Chen, Po-Yi

    2017-12-06

    Cross-lagged panel models (CLPMs) are widely used to test mediation with longitudinal panel data. One major limitation of the CLPMs is that the model effects are assumed to be fixed across individuals. This assumption is likely to be violated (i.e., the model effects are random across individuals) in practice. When this happens, the CLPMs can potentially yield biased parameter estimates and misleading statistical inferences. This article proposes a model named a random-effects cross-lagged panel model (RE-CLPM) to account for random effects in CLPMs. Simulation studies show that the RE-CLPM outperforms the CLPM in recovering the mean indirect and direct effects in a longitudinal mediation analysis when random effects exist in the population. The performance of the RE-CLPM is robust to a certain degree, even when the random effects are not normally distributed. In addition, the RE-CLPM does not produce harmful results when the model effects are in fact fixed in the population. Implications of the simulation studies and potential directions for future research are discussed.

  8. Unobserved Heterogeneity in the Binary Logit Model with Cross-Sectional Data and Short Panels

    DEFF Research Database (Denmark)

    Holm, Anders; Jæger, Mads Meier; Pedersen, Morten

    This paper proposes a new approach to dealing with unobserved heterogeneity in applied research using the binary logit model with cross-sectional data and short panels. Unobserved heterogeneity is particularly important in non-linear regression models such as the binary logit model because, unlike...... in linear regression models, estimates of the effects of observed independent variables are biased even when omitted independent variables are uncorrelated with the observed independent variables. We propose an extension of the binary logit model based on a finite mixture approach in which we conceptualize...

  9. Estimation of Dynamic Panel Data Models with Stochastic Volatility Using Particle Filters

    Directory of Open Access Journals (Sweden)

    Wen Xu

    2016-10-01

    Full Text Available Time-varying volatility is common in macroeconomic data and has been incorporated into macroeconomic models in recent work. Dynamic panel data models have become increasingly popular in macroeconomics to study common relationships across countries or regions. This paper estimates dynamic panel data models with stochastic volatility by maximizing an approximate likelihood obtained via Rao-Blackwellized particle filters. Monte Carlo studies reveal the good and stable performance of our particle filter-based estimator. When the volatility of volatility is high, or when regressors are absent but stochastic volatility exists, our approach can be better than the maximum likelihood estimator which neglects stochastic volatility and generalized method of moments (GMM estimators.

  10. Land-use regression panel models of NO2 concentrations in Seoul, Korea

    Science.gov (United States)

    Kim, Youngkook; Guldmann, Jean-Michel

    2015-04-01

    Transportation and land-use activities are major air pollution contributors. Since their shares of emissions vary across space and time, so do air pollution concentrations. Despite these variations, panel data have rarely been used in land-use regression (LUR) modeling of air pollution. In addition, the complex interactions between traffic flows, land uses, and meteorological variables, have not been satisfactorily investigated in LUR models. The purpose of this research is to develop and estimate nitrogen dioxide (NO2) panel models based on the LUR framework with data for Seoul, Korea, accounting for the impacts of these variables, and their interactions with spatial and temporal dummy variables. The panel data vary over several scales: daily (24 h), seasonally (4), and spatially (34 intra-urban measurement locations). To enhance model explanatory power, wind direction and distance decay effects are accounted for. The results show that vehicle-kilometers-traveled (VKT) and solar radiation have statistically strong positive and negative impacts on NO2 concentrations across the four seasonal models. In addition, there are significant interactions with the dummy variables, pointing to VKT and solar radiation effects on NO2 concentrations that vary with time and intra-urban location. The results also show that residential, commercial, and industrial land uses, and wind speed, temperature, and humidity, all impact NO2 concentrations. The R2 vary between 0.95 and 0.98.

  11. Industrial based volume manufacturing of lightweight aluminium alloy panel components with high-strength and complex-shape for car body and chassis structures

    Science.gov (United States)

    Anyasodor, Gerald; Koroschetz, Christian

    2017-09-01

    To achieve the high volume manufacture of lightweight passenger cars at economic cost as required in the automotive industry, low density materials and new process route will be needed. While high strength aluminium alloy grades: AA7075 and AA6082 may provide the alternative material solution, hot stamping process used for high-strength and ultrahigh strength steels such as boron steel 22mnb5 can enable the volume manufacture of panel components with high-strength and complex-shape for car body and chassis structures. These aluminium alloy grades can be used to manufacture panel components with possible yield strengths ≥ 500 MPa. Due to the differences in material behaviors, hot stamping process of 22mnb5 cannot be directly applied to high strength aluminium alloy grades. Despite recorded successes in laboratories, researches and niche hot forming processes of high strength aluminium alloy grades, not much have been achieved for adequate and efficient volume manufacturing system applicable in the automotive industry. Due to lack of such system and based on expert knowledge in hot stamping production-line, AP&T presents in this paper a hot stamping processing route for high strength aluminium alloys been suitable for production-line development and volume manufacturing.

  12. Nonlinear Modeling and Identification of an Aluminum Honeycomb Panel with Multiple Bolts

    Directory of Open Access Journals (Sweden)

    Yongpeng Chu

    2016-01-01

    Full Text Available This paper focuses on the nonlinear dynamics modeling and parameter identification of an Aluminum Honeycomb Panel (AHP with multiple bolted joints. Finite element method using eight-node solid elements is exploited to model the panel and the bolted connection interface as a homogeneous, isotropic plate and as a thin layer of nonlinear elastic-plastic material, respectively. The material properties of a thin layer are defined by a bilinear elastic plastic model, which can describe the energy dissipation and softening phenomena in the bolted joints under nonlinear states. Experimental tests at low and high excitation levels are performed to reveal the dynamic characteristics of the bolted structure. In particular, the linear material parameters of the panel are identified via experimental tests at low excitation levels, whereas the nonlinear material parameters of the thin layer are updated by using the genetic algorithm to minimize the residual error between the measured and the simulation data at a high excitation level. It is demonstrated by comparing the frequency responses of the updated FEM and the experimental system that the thin layer of bilinear elastic-plastic material is very effective for modeling the nonlinear joint interface of the assembled structure with multiple bolts.

  13. Varying Coefficient Panel Data Model in the Presence of Endogenous Selectivity and Fixed Effects

    OpenAIRE

    Malikov, Emir; Kumbhakar, Subal C.; Sun, Yiguo

    2013-01-01

    This paper considers a flexible panel data sample selection model in which (i) the outcome equation is permitted to take a semiparametric, varying coefficient form to capture potential parameter heterogeneity in the relationship of interest, (ii) both the outcome and (parametric) selection equations contain unobserved fixed effects and (iii) selection is generalized to a polychotomous case. We propose a two-stage estimator. Given consistent parameter estimates from the selection equation obta...

  14. Energy Poverty in China: A Dynamic Analysis Based on a Hybrid Panel Data Decision Model

    OpenAIRE

    Bing Wang; Hua-Nan Li; Xiao-Chen Yuan; Zhen-Ming Sun

    2017-01-01

    Renewable energy can help to tackle energy poverty issues of the availability of modern energy services and the sustainability of energy supply. Based on the concept of the Energy Development Index, published by International Energy Agency, this paper builds the clean energy development index and applies the Grey incidence decision method to analyze regional energy poverty issues in China. A model using panel data investigates the influencing factors that are governing energy poverty alleviat...

  15. Oracle Efficient Variable Selection in Random and Fixed Effects Panel Data Models

    DEFF Research Database (Denmark)

    Kock, Anders Bredahl

    This paper generalizes the results for the Bridge estimator of Huang et al. (2008) to linear random and fixed effects panel data models which are allowed to grow in both dimensions. In particular we show that the Bridge estimator is oracle efficient. It can correctly distinguish between relevant...... of Huang et al. (2008). Furthermore, the number of relevant variables is allowed to be larger than the sample size....

  16. Hybrid FEA/SEA Assessment for an Orthogrid Cylindrical Panel Section and Periodic Subsystem Modeling Evaluation

    Science.gov (United States)

    Smith, Andrew M.; LaVerde, Bruce; Teague, David W.

    2010-01-01

    In the lower frequency range, where particular boundary conditions can make a significant difference to panel response characteristics Statistical Energy Analysis (SEA) has never been the analytical tool of choice. In addition to boundary condition effects, SEA is not well suited in frequency bands where no modes or less than a few modes exist. The advent of the Hybrid Module has enabled integration of Finite Element Analysis to expand and enhance the capability for response calculations within VA One into the lower frequency range. Exploration of several additional modeling approaches was completed for the cylindrical orthogrid panel test article that was examined in Reference 1. Comparison of the new analytical response predictions with the measured response data from ground test and the pure SEA results from the reference will be presented. One approach that is considered promising is the periodic subsystem capability. Initially, a detailed FEM of just one region of the test article is defined. After evaluating this small region using symmetric boundary conditions, the FEM may be expanded to determine the properties of the entire system using similar connected regions that map over the entire test article. Another approach is the direct use of a very detailed finite element model of the entire panel, explicitly modeling pocket and rib details of the structure. A third approach is to approximate localized structure geometry details with a smeared property generalization using a PCOMP (NASTRAN card used to define layered composite structures) to define skin layer and ribbed layer for the orthogrid panel. The authors expect to demonstrate that the integrated Hybrid/FEM approach increases confidence in response prediction in the lower frequency range (for example from 20-300 Hz for the test article under consideration). In addition the strength and weakness of each additional approach will be highlighted and compared to those reported with those reported in an

  17. Impact of energy technology patents in China: Evidence from a panel cointegration and error correction model

    International Nuclear Information System (INIS)

    Li, Ke; Lin, Boqiang

    2016-01-01

    Enhancing energy technology innovation performance, which is widely measured by energy technology patents through energy technology research and development (R&D) activities, is a fundamental way to implement energy conservation and emission abatement. This study analyzes the effects of R&D investment activities, economic growth, and energy price on energy technology patents in 30 provinces of China over the period 1999–2013. Several unit root tests indicate that all the above variables are generated by panel unit root processes, and a panel cointegration model is confirmed among the variables. In order to ensure the consistency of the estimators, the Fully-Modified OLS (FMOLS) method is adopted, and the results indicate that R&D investment activities and economic growth have positive effects on energy technology patents while energy price has a negative effect. However, the panel error correction models indicate that the cointegration relationship helps to promote economic growth, but it reduces R&D investment and energy price in the short term. Therefore, market-oriented measures including financial support and technical transformation policies for the development of low-carbon energy technologies, an effective energy price mechanism, especially the targeted fossil-fuel subsidies and their die away mode are vital in promoting China's energy technology innovation. - Highlights: • Energy technology patents in China are analyzed. • Relationship between energy patents and funds for R&D activities are analyzed. • China's energy price system hinders energy technology innovation. • Some important implications for China's energy technology policy are discussed. • A panel cointegration model with FMOLS estimator is used.

  18. Modelling of electric characteristics of 150-watt peak solar panel using Boltzmann sigmoid function under various temperature and irradiance

    Science.gov (United States)

    Sapteka, A. A. N. G.; Narottama, A. A. N. M.; Winarta, A.; Amerta Yasa, K.; Priambodo, P. S.; Putra, N.

    2018-01-01

    Solar energy utilized with solar panel is a renewable energy that needs to be studied further. The site nearest to the equator, it is not surprising, receives the highest solar energy. In this paper, a modelling of electrical characteristics of 150-Watt peak solar panels using Boltzmann sigmoid function under various temperature and irradiance is reported. Current, voltage, temperature and irradiance data in Denpasar, a city located at just south of equator, was collected. Solar power meter is used to measure irradiance level, meanwhile digital thermometer is used to measure temperature of front and back panels. Short circuit current and open circuit voltage data was also collected at different temperature and irradiance level. Statistically, the electrical characteristics of 150-Watt peak solar panel can be modelled using Boltzmann sigmoid function with good fit. Therefore, it can be concluded that Boltzmann sigmoid function might be used to determine current and voltage characteristics of 150-Watt peak solar panel under various temperature and irradiance.

  19. Zero-truncated panel Poisson mixture models: Estimating the impact on tourism benefits in Fukushima Prefecture.

    Science.gov (United States)

    Narukawa, Masaki; Nohara, Katsuhito

    2018-04-01

    This study proposes an estimation approach to panel count data, truncated at zero, in order to apply a contingent behavior travel cost method to revealed and stated preference data collected via a web-based survey. We develop zero-truncated panel Poisson mixture models by focusing on respondents who visited a site. In addition, we introduce an inverse Gaussian distribution to unobserved individual heterogeneity as an alternative to a popular gamma distribution, making it possible to capture effectively the long tail typically observed in trip data. We apply the proposed method to estimate the impact on tourism benefits in Fukushima Prefecture as a result of the Fukushima Nuclear Power Plant No. 1 accident. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Sustainable Education: Analyzing the Determinants of University Student Dropout by Nonlinear Panel Data Models

    Directory of Open Access Journals (Sweden)

    Donggeun Kim

    2018-03-01

    Full Text Available University dropout is a serious problem. It affects not only the individual who drops out but also the university and society. However, most previous studies have focused only on the subjective/individual level. University dropout is a very important issue in South Korea, but it has not received much research attention so far. This study examined the possible causes of university dropout in South Korea at the aggregate level, focusing on four fundamental categories: students, resources, faculty, and university characteristics. Three-year balanced panel data from 2013 to 2015 were constructed and estimated by using nonlinear panel data models. The findings show that cost and burden for students, financial resources, qualitative and quantitative features of faculty, and type/size of the university have significant effects on university dropout.

  1. High-quality 3D correction of ring and radiant artifacts in flat panel detector-based cone beam volume CT imaging

    Science.gov (United States)

    Abu Anas, Emran Mohammad; Kim, Jae Gon; Lee, Soo Yeol; Kamrul Hasan, Md

    2011-10-01

    The use of an x-ray flat panel detector is increasingly becoming popular in 3D cone beam volume CT machines. Due to the deficient semiconductor array manufacturing process, the cone beam projection data are often corrupted by different types of abnormalities, which cause severe ring and radiant artifacts in a cone beam reconstruction image, and as a result, the diagnostic image quality is degraded. In this paper, a novel technique is presented for the correction of error in the 2D cone beam projections due to abnormalities often observed in 2D x-ray flat panel detectors. Template images are derived from the responses of the detector pixels using their statistical properties and then an effective non-causal derivative-based detection algorithm in 2D space is presented for the detection of defective and mis-calibrated detector elements separately. An image inpainting-based 3D correction scheme is proposed for the estimation of responses of defective detector elements, and the responses of the mis-calibrated detector elements are corrected using the normalization technique. For real-time implementation, a simplification of the proposed off-line method is also suggested. Finally, the proposed algorithms are tested using different real cone beam volume CT images and the experimental results demonstrate that the proposed methods can effectively remove ring and radiant artifacts from cone beam volume CT images compared to other reported techniques in the literature.

  2. High-quality 3D correction of ring and radiant artifacts in flat panel detector-based cone beam volume CT imaging

    International Nuclear Information System (INIS)

    Anas, Emran Mohammad Abu; Hasan, Md Kamrul; Kim, Jae Gon; Lee, Soo Yeol

    2011-01-01

    The use of an x-ray flat panel detector is increasingly becoming popular in 3D cone beam volume CT machines. Due to the deficient semiconductor array manufacturing process, the cone beam projection data are often corrupted by different types of abnormalities, which cause severe ring and radiant artifacts in a cone beam reconstruction image, and as a result, the diagnostic image quality is degraded. In this paper, a novel technique is presented for the correction of error in the 2D cone beam projections due to abnormalities often observed in 2D x-ray flat panel detectors. Template images are derived from the responses of the detector pixels using their statistical properties and then an effective non-causal derivative-based detection algorithm in 2D space is presented for the detection of defective and mis-calibrated detector elements separately. An image inpainting-based 3D correction scheme is proposed for the estimation of responses of defective detector elements, and the responses of the mis-calibrated detector elements are corrected using the normalization technique. For real-time implementation, a simplification of the proposed off-line method is also suggested. Finally, the proposed algorithms are tested using different real cone beam volume CT images and the experimental results demonstrate that the proposed methods can effectively remove ring and radiant artifacts from cone beam volume CT images compared to other reported techniques in the literature.

  3. An interactive environmental model for economic growth: evidence from a panel of countries.

    Science.gov (United States)

    Ramakrishnan, Suresh; Hishan, Sanil S; Nabi, Agha Amad; Arshad, Zeeshan; Kanjanapathy, Malini; Zaman, Khalid; Khan, Faisal

    2016-07-01

    This study aims to determine an interactive environmental model for economic growth that would be supported by the "sustainability principles" across the globe. The study examines the relationship between environmental pollutants (i.e., carbon dioxide emission, sulfur dioxide emission, mono-nitrogen oxide, and nitrous oxide emission); population growth; energy use; trade openness; per capita food production; and it's resulting impact on the real per capita GDP and sectoral growth (i.e., share of agriculture, industry, and services in GDP) in a panel of 34 high-income OECD, high-income non-OECD, and Europe and Central Asian countries, for the period of 1995-2014. The results of the panel fixed effect regression show that per capita GDP are influenced by sulfur dioxide emission, population growth, and per capita food production variability, while energy and trade openness significantly increases per capita income of the region. The results of the panel Seemingly Unrelated Regression (SUR) show that carbon dioxide emission significantly decreases the share of agriculture and industry in GDP, while it further supports the share of services sector to GDP. Both the sulfur dioxide and mono-nitrogen oxide emission decreases the share of services in GDP; nitrous oxide decreases the share of industry in GDP; while mono-nitrogen oxide supports the industrial activities. The following key growth-specific results has been obtained from the panel SUR estimation, i.e., (i) Both the food production per capita and trade openness significantly associated with the increasing share of agriculture, (ii) food production and energy use significantly increases the service sectors' productivity; (iii) food production decreases the industrial activities; (iv) trade openness decreases the share of services to GDP while it supports the industrial share to GDP; and finally, (v) energy demand decreases along with the increase agricultural share in the region. The results emphasize the need for

  4. An efficient analytical model for baffled, multi-celled membrane-type acoustic metamaterial panels

    Science.gov (United States)

    Langfeldt, F.; Gleine, W.; von Estorff, O.

    2018-03-01

    A new analytical model for the oblique incidence sound transmission loss prediction of baffled panels with multiple subwavelength sized membrane-type acoustic metamaterial (MAM) unit cells is proposed. The model employs a novel approach via the concept of the effective surface mass density and approximates the unit cell vibrations in the form of piston-like displacements. This yields a coupled system of linear equations that can be solved efficiently using well-known solution procedures. A comparison with results from finite element model simulations for both normal and diffuse field incidence shows that the analytical model delivers accurate results as long as the edge length of the MAM unit cells is smaller than half the acoustic wavelength. The computation times for the analytical calculations are 100 times smaller than for the numerical simulations. In addition to that, the effect of flexible MAM unit cell edges compared to the fixed edges assumed in the analytical model is studied numerically. It is shown that the compliance of the edges has only a small impact on the transmission loss of the panel, except at very low frequencies in the stiffness-controlled regime. The proposed analytical model is applied to investigate the effect of variations of the membrane prestress, added mass, and mass eccentricity on the diffuse transmission loss of a MAM panel with 120 unit cells. Unlike most previous investigations of MAMs, these results provide a better understanding of the acoustic performance of MAMs under more realistic conditions. For example, it is shown that by varying these parameters deliberately in a checkerboard pattern, a new anti-resonance with large transmission loss values can be introduced. A random variation of these parameters, on the other hand, is shown to have only little influence on the diffuse transmission loss, as long as the standard deviation is not too large. For very large random variations, it is shown that the peak transmission loss

  5. A flexible model for correlated medical costs, with application to medical expenditure panel survey data.

    Science.gov (United States)

    Chen, Jinsong; Liu, Lei; Shih, Ya-Chen T; Zhang, Daowen; Severini, Thomas A

    2016-03-15

    We propose a flexible model for correlated medical cost data with several appealing features. First, the mean function is partially linear. Second, the distributional form for the response is not specified. Third, the covariance structure of correlated medical costs has a semiparametric form. We use extended generalized estimating equations to simultaneously estimate all parameters of interest. B-splines are used to estimate unknown functions, and a modification to Akaike information criterion is proposed for selecting knots in spline bases. We apply the model to correlated medical costs in the Medical Expenditure Panel Survey dataset. Simulation studies are conducted to assess the performance of our method. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Estimating a theoretical model of state banking competition using a dynamic panel: the Brazilian case

    Directory of Open Access Journals (Sweden)

    Fábio A. Miessi Sanches

    2009-03-01

    Full Text Available In this paper we set up a model of regional banking competition based on Bresnahan (1982, Lau (1982 and Nakane (2002. The structural model is estimated using data from eight Brazilian states and a dynamic panel. The results show that on average the level of competition in the Brazilian banking system is high, even tough the null of perfect competition can be rejected at the usual significance levels. This result also prevails at the state level: Rio Grande do Sul, São Paulo, Rio de Janeiro, Pernambuco and Minas Gerais have high degree of competition.

  7. APLIKASI REGRESI DATA PANEL DENGAN PENDEKATAN FIXED EFFECT MODEL (STUDI KASUS: PT PLN GIANYAR

    Directory of Open Access Journals (Sweden)

    NI PUTU ANIK MAS RATNASARI

    2014-01-01

    Full Text Available Panel data regression has three approaches. One of these approaches is Fixed Effect Model (FEM. FEM is common estimated using Least Square Dummy Variable. The use of dummy variable in FEM is based on assumption that slope coefficients are constant but intercept varies over individuals. One of application of FEM is to find out motivation of employees at PT PLN Gianyar for non-outsourcing and outsourcing employees based on existence, relatedness, and growth. This research yields the following two models: with 67% motivation non-outsourcing employees represented by existenceand73% motivation non-outsourcing employees represented by existence and growth.

  8. 7th U.S. / Japan Natural Resources (UJNR) Panel on Earthquake Research: Abstract Volume and Technical Program

    Science.gov (United States)

    Detweiler, Shane T.; Ellsworth, William L.

    2008-01-01

    The U.S. / Japan Natural Resources (UJNR) Panel on Earthquake Research promotes advanced study toward a more fundamental understanding of the earthquake process and hazard estimation. The Panel promotes basic and applied research to improve our understanding of the causes and effects of earthquakes and to facilitate the transmission of research results to those who implement hazard reduction measures on both sides of the Pacific and around the world. Meetings are held every other year, and alternate between countries with short presentation on current research and local field trips being the highlights. The 5th Joint Panel meeting was held at Asilomar, California in October, 2004. The technical sessions featured reports on the September 28, 2004 Parkfield, California earthquake, progress on earthquake early warning and rapid post-event assessment technology, probabilistic earthquake forecasting and the newly discovered phenomenon of nonvolcanic tremor. The Panel visited the epicentral region of the M 6.0 Parkfield earthquake and viewed the surface ruptures along the San Andreas Fault. They also visited the San Andreas Fault Observatory at Depth (SAFOD), which had just completed the first phase of drilling into the fault. The 6th Joint Panel meeting was held in Tokushima, Japan in November, 2006. The meeting included very productive exchanges of information on approaches to systematic observation of earthquake processes. Sixty eight technical papers were presented during the meeting on a wide range of subjects, including interplate earthquakes in subduction zones, slow slip and nonvolcanic tremor, crustal deformation, recent earthquake activity and hazard mapping. Through our discussion, we reaffirmed the benefits of working together to achieve our common goal of reducing earthquake hazard, continued cooperation on issues involving densification of observation networks and the open exchange of data among scientific communities. We also reaffirmed the importance of

  9. A dynamic analysis of motorcycle ownership and usage: a panel data modeling approach.

    Science.gov (United States)

    Wen, Chieh-Hua; Chiou, Yu-Chiun; Huang, Wan-Ling

    2012-11-01

    This study aims to develop motorcycle ownership and usage models with consideration of the state dependence and heterogeneity effects based on a large-scale questionnaire panel survey on vehicle owners. To account for the independence among alternatives and heterogeneity among individuals, the modeling structure of motorcycle ownership adopts disaggregate choice models considering the multinomial, nested, and mixed logit formulations. Three types of panel data regression models--ordinary, fixed, and random effects--are developed and compared for motorcycle usage. The estimation results show that motorcycle ownership in the previous year does exercise a significantly positive effect on the number of motorcycles owned by households in the current year, suggesting that the state dependence effect does exist in motorcycle ownership decisions. In addition, the fixed effects model is the preferred specification for modeling motorcycle usage, indicating strong evidence for existence of heterogeneity. Among various management strategies evaluated under different scenarios, increasing gas prices and parking fees will lead to larger reductions in total kilometers traveled. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Low and High Frequency Models of Response Statistics of a Cylindrical Orthogrid Vehicle Panel to Acoustic Excitation

    Science.gov (United States)

    Smith, Andrew; LaVerde, Bruce; Teague, David; Gardner, Bryce; Cotoni, Vincent

    2010-01-01

    This presentation further develops the orthogrid vehicle panel work. Employed Hybrid Module capabilities to assess both low/mid frequency and high frequency models in the VA One simulation environment. The response estimates from three modeling approaches are compared to ground test measurements. Detailed Finite Element Model of the Test Article -Expect to capture both the global panel modes and the local pocket mode response, but at a considerable analysis expense (time & resources). A Composite Layered Construction equivalent global stiffness approximation using SEA -Expect to capture response of the global panel modes only. An SEA approximation using the Periodic Subsystem Formulation. A finite element model of a single periodic cell is used to derive the vibroacoustic properties of the entire periodic structure (modal density, radiation efficiency, etc. Expect to capture response at various locations on the panel (on the skin and on the ribs) with less analysis expense

  11. Mathematical model for the power generation from arbitrarily oriented photovoltaic panel

    Directory of Open Access Journals (Sweden)

    Hassan Qusay

    2017-01-01

    Full Text Available In this paper, a mathematical model for modelling the solar radiation components and photovoltaic arrays power outputs from arbitrarily oriented photovoltaic panel has been presented. Base on the model electrical power prediction of the photovoltaic system in realistic local condition has been presented and compared with experimental measurement. The results show the effectiveness of the proposed model, which provides tools to better understand the performance and reliability as well as decision-making tool in designing of a hybrid renewable energy base power generation system. It has been shown that base on the model prediction, the efficiency and possible failures of the system can be found which are important from the technical and economical point of view.

  12. Energy Research Advisory Board, Civilian Nuclear Power Panel: Subpanel 1 report, Light water reactor utilization and improvement: Volume 2

    International Nuclear Information System (INIS)

    1986-10-01

    The Secretary of Energy requested that the Office of Nuclear Energy prepare a strategic national plan that outlines the Department's role in the future development of civilian nuclear power and that the Energy Research Advisory Board establish an ad hoc panel to review and comment on this plan. The Energy Research Advisory Board formed a panel for this review and three subpanels were formed. One subpanel was formed to address the institutional issues surrounding nuclear power, one on research and development for advanced nuclear power plants and a third subpanel on light water reactor utilization and improvement. The subpanel on light water reactors held two meetings at which representatives of the DOE, the NRC, EPRI, industry and academic groups made presentations. This is the report of the subpanel on light water reactor utilization and improvement. This report presents the subpanel's assessment of initiatives which the Department of Energy should undertake in the national interest, to develop and support light water reactor technologies

  13. Modelling of scintillator based flat-panel detectors with Monte-Carlo simulations

    International Nuclear Information System (INIS)

    Reims, N; Sukowski, F; Uhlmann, N

    2011-01-01

    Scintillator based flat panel detectors are state of the art in the field of industrial X-ray imaging applications. Choosing the proper system and setup parameters for the vast range of different applications can be a time consuming task, especially when developing new detector systems. Since the system behaviour cannot always be foreseen easily, Monte-Carlo (MC) simulations are keys to gain further knowledge of system components and their behaviour for different imaging conditions. In this work we used two Monte-Carlo based models to examine an indirect converting flat panel detector, specifically the Hamamatsu C9312SK. We focused on the signal generation in the scintillation layer and its influence on the spatial resolution of the whole system. The models differ significantly in their level of complexity. The first model gives a global description of the detector based on different parameters characterizing the spatial resolution. With relatively small effort a simulation model can be developed which equates the real detector regarding signal transfer. The second model allows a more detailed insight of the system. It is based on the well established cascade theory, i.e. describing the detector as a cascade of elemental gain and scattering stages, which represent the built in components and their signal transfer behaviour. In comparison to the first model the influence of single components especially the important light spread behaviour in the scintillator can be analysed in a more differentiated way. Although the implementation of the second model is more time consuming both models have in common that a relatively small amount of system manufacturer parameters are needed. The results of both models were in good agreement with the measured parameters of the real system.

  14. A method for mapping tissue volume model onto target volume using volumetric self-organizing deformable model

    Science.gov (United States)

    Miyauchi, Shoko; Morooka, Ken'ichi; Tsuji, Tokuo; Miyagi, Yasushi; Fukuda, Takaichi; Kurazume, Ryo

    2016-03-01

    This paper proposes a new method for mapping volume models of human tissues onto a target volume with simple shapes. The proposed method is based on our modified self-organizing deformable model (mSDM)1, 2 which finds the one-to-one mapping with no foldovers between arbitrary surface model and a target surface. By extending mSDM to apply to volume models, the proposed method, called volumetric SDM (vSDM), establishes the one-to-one correspondence between the tissue volume model and its target volume. At the same time, vSDM can preserve geometrical properties of the original model before and after mapping. This characteristic of vSDM makes it easy to find the correspondence between tissue models.

  15. Which model of truth and reconciliation applies to former Yugoslavia?: Some thoughts on the closing panel discussion

    Directory of Open Access Journals (Sweden)

    Tošić Jelena

    2002-01-01

    Full Text Available This paper represents a reflection on the final panel discussion of the conference "Which Model of Truth and Reconciliation applies to ex-Yugoslavia?". By the means of sequential and hierarchical analysis of the argumentative structure of the discussion, the author «extracts» key dimensions of the expert discourse on truth and reconciliation using the case of the mentioned panel discussion. By identifying the points of consensus the author seeks to describe the notion of truth and reconciliation as it emerged in the closing panel discussion of the conference.

  16. Total tree, merchantable stem and branch volume models for ...

    African Journals Online (AJOL)

    Total tree, merchantable stem and branch volume models for miombo woodlands of Malawi. Daud J Kachamba, Tron Eid. Abstract. The objective of this study was to develop general (multispecies) models for prediction of total tree, merchantable stem and branch volume including options with diameter at breast height (dbh) ...

  17. Modeling the thermal absorption factor of photovoltaic/thermal combi-panels

    International Nuclear Information System (INIS)

    Santbergen, R.; Zolingen, R.J.Ch. van

    2006-01-01

    In a photovoltaic/thermal combi-panel solar cells generate electricity while residual heat is extracted to be used for tap water heating or room heating. In such a panel the entire solar spectrum can be used in principle. Unfortunately long wavelength solar irradiance is poorly absorbed by the semiconductor material in standard solar cells. A computer model was developed to determine the thermal absorption factor of crystalline silicon solar cells. It was found that for a standard untextured solar cell with a silver back contact a relatively large amount of long wavelength irradiance is lost by reflection resulting in an absorption factor of only 74%. The model was then used to investigate ways to increase this absorption factor. One way is absorbing long wavelength irradiance in a second absorber behind a semi-transparent solar cell. According to the model this will increase the total absorption factor to 87%. The second way is to absorb irradiance in the back contact of the solar cell by using rough interfaces in combination with a non-standard metal as back contact. Theoretically the absorption factor can then be increased to 85%

  18. Comparison of actual tidal volume in neonatal lung model volume control ventilation using three ventilators.

    Science.gov (United States)

    Toyama, H; Endo, Y; Ejima, Y; Matsubara, M; Kurosawa, S

    2011-07-01

    In neonates, small changes in tidal volumes (V(T)) may lead to complications. Previous studies have shown a significant difference between ventilator-measured tidal volume and tidal volume delivered (actual V(T)). We evaluated the accuracy of three different ventilators to deliver small V(T) during volume-controlled ventilation. We tested Servo 300, 840 ventilator and Evita 4 Neoflow ventilators with lung models simulating normal and injured neonatal lung compliance models. Gas volume delivered from the ventilator into the test circuit (V(TV)) and actual V(T) to the test lung were measured using Ventrak respiration monitors at set V(T) (30 ml). The gas volume increase of the breathing circuit was then calculated. Tidal volumes of the SV300 and PB840 in both lung models were similar to the set V(T) and the actual tidal volumes in the injured model (20.7 ml and 19.8 ml, respectively) were significantly less than that in the normal model (27.4 ml and 23.4 ml). PB840 with circuit compliance compensation could not improve the actual V(T). V(TV) of the EV4N in the normal and the injured models (37.8 ml and 46.6 ml) were markedly increased compared with set V(T), and actual V(T) were similar to set V(T) in the normal and injured model (30.2 ml and 31.9 ml, respectively). EV4N measuring V(T) close to the lung could match actual V(T) to almost the same value as the set V(T) however the gas volume of the breathing circuit was increased. If an accurate value for the patient's actual V(T) is needed, this V(T) must be measured by a sensor located between the Y-piece and the tracheal tube.

  19. Impacts of subsidized renewable electricity generation on spot market prices in Germany: evidence from a Garch model with panel data

    International Nuclear Information System (INIS)

    Pham, Thao; Lemoine, Killian

    2015-01-01

    Electricity generated by renewable energy sources creates a downward pressure on wholesale prices through - the so-called 'merit order effect'. This effect tends to lower average power prices and average market revenue that renewables producers should have received, making integration costs of renewables very high at large penetration rate. It is therefore crucial to determine the amplitude of this merit order effect particularly in the context of increasing burden of renewable support policies borne by final consumers. Using hourly data for the period 2009-2012 in German electricity wholesale market for GARCH model under panel data framework, we find that wind and solar power generation injected into German electricity network during this period induces a decrease of electricity spot prices and a slight increase of their volatility. The model-based results suggest that the merit-order effect created by renewable production ranges from 3.86 to 8.34 euro/MWh which implies to the annual volume of consumers' surplus from 1.89 to 3.92 billion euros. However this surplus has not been re-distributed equally among different types of electricity consumers. (authors)

  20. Therapeutic Efficacy Assessment of CK6, a Monoclonal KIT Antibody, in a Panel of Gastrointestinal Stromal Tumor Xenograft Models

    Directory of Open Access Journals (Sweden)

    Thomas Van Looy

    2015-04-01

    Full Text Available We evaluated the efficacy of CK6, a KIT monoclonal antibody, in a panel of human gastrointestinal stromal tumor (GIST xenograft models. Nude mice were bilaterally transplanted with human GIST xenografts (four patient derived and two cell line derived, treated for 3 weeks, and grouped as follows: control (untreated; CK6 (40 mg/kg, 3× weekly; imatinib (50 mg/kg, twice daily; sunitinib (40 mg/kg, once daily; imatinib + CK6; sunitinib + CK6 (same doses and schedules as in the single-agent treatments. Tumor volume assessment, Western blot analysis, and histopathology were used for evaluation of efficacy. Statistical analysis was performed using Mann-Whitney U (MWU and Wilcoxon matched-pairs tests. CK6 as a single agent only reduced tumor growth rate in the UZLX-GIST3 model (P = .053, MWU compared to control, while in none of the other GIST models an effect on tumor growth rate was observed. CK6 did not result in significant anti-proliferative or pro-apoptotic effects in any of the GIST models, and moreover, CK6 did not induce a remarkable inhibition of KIT activation. Furthermore, no synergistic effect of combining CK6 with tyrosine kinase inhibitors (TKIs was observed. Conversely, in certain GIST xenografts, anti-tumor effects seemed to be inferior under combination treatment compared to single-agent TKI treatment. In the GIST xenografts tested, the anti-tumor efficacy of CK6 was limited. No synergy was observed on combination of CK6 with TKIs in these GIST models. Our findings highlight the importance of using relevant in vivo human tumor xenograft models in the preclinical assessment of drug combination strategies.

  1. Modeling vehicle operating speed on urban roads in Montreal: a panel mixed ordered probit fractional split model.

    Science.gov (United States)

    Eluru, Naveen; Chakour, Vincent; Chamberlain, Morgan; Miranda-Moreno, Luis F

    2013-10-01

    Vehicle operating speed measured on roadways is a critical component for a host of analysis in the transportation field including transportation safety, traffic flow modeling, roadway geometric design, vehicle emissions modeling, and road user route decisions. The current research effort contributes to the literature on examining vehicle speed on urban roads methodologically and substantively. In terms of methodology, we formulate a new econometric model framework for examining speed profiles. The proposed model is an ordered response formulation of a fractional split model. The ordered nature of the speed variable allows us to propose an ordered variant of the fractional split model in the literature. The proposed formulation allows us to model the proportion of vehicles traveling in each speed interval for the entire segment of roadway. We extend the model to allow the influence of exogenous variables to vary across the population. Further, we develop a panel mixed version of the fractional split model to account for the influence of site-specific unobserved effects. The paper contributes substantively by estimating the proposed model using a unique dataset from Montreal consisting of weekly speed data (collected in hourly intervals) for about 50 local roads and 70 arterial roads. We estimate separate models for local roads and arterial roads. The model estimation exercise considers a whole host of variables including geometric design attributes, roadway attributes, traffic characteristics and environmental factors. The model results highlight the role of various street characteristics including number of lanes, presence of parking, presence of sidewalks, vertical grade, and bicycle route on vehicle speed proportions. The results also highlight the presence of site-specific unobserved effects influencing the speed distribution. The parameters from the modeling exercise are validated using a hold-out sample not considered for model estimation. The results indicate

  2. Limit Theory for Panel Data Models with Cross Sectional Dependence and Sequential Exogeneity.

    Science.gov (United States)

    Kuersteiner, Guido M; Prucha, Ingmar R

    2013-06-01

    The paper derives a general Central Limit Theorem (CLT) and asymptotic distributions for sample moments related to panel data models with large n . The results allow for the data to be cross sectionally dependent, while at the same time allowing the regressors to be only sequentially rather than strictly exogenous. The setup is sufficiently general to accommodate situations where cross sectional dependence stems from spatial interactions and/or from the presence of common factors. The latter leads to the need for random norming. The limit theorem for sample moments is derived by showing that the moment conditions can be recast such that a martingale difference array central limit theorem can be applied. We prove such a central limit theorem by first extending results for stable convergence in Hall and Hedye (1980) to non-nested martingale arrays relevant for our applications. We illustrate our result by establishing a generalized estimation theory for GMM estimators of a fixed effect panel model without imposing i.i.d. or strict exogeneity conditions. We also discuss a class of Maximum Likelihood (ML) estimators that can be analyzed using our CLT.

  3. Fitting and interpreting continuous-time latent Markov models for panel data.

    Science.gov (United States)

    Lange, Jane M; Minin, Vladimir N

    2013-11-20

    Multistate models characterize disease processes within an individual. Clinical studies often observe the disease status of individuals at discrete time points, making exact times of transitions between disease states unknown. Such panel data pose considerable modeling challenges. Assuming the disease process progresses accordingly, a standard continuous-time Markov chain (CTMC) yields tractable likelihoods, but the assumption of exponential sojourn time distributions is typically unrealistic. More flexible semi-Markov models permit generic sojourn distributions yet yield intractable likelihoods for panel data in the presence of reversible transitions. One attractive alternative is to assume that the disease process is characterized by an underlying latent CTMC, with multiple latent states mapping to each disease state. These models retain analytic tractability due to the CTMC framework but allow for flexible, duration-dependent disease state sojourn distributions. We have developed a robust and efficient expectation-maximization algorithm in this context. Our complete data state space consists of the observed data and the underlying latent trajectory, yielding computationally efficient expectation and maximization steps. Our algorithm outperforms alternative methods measured in terms of time to convergence and robustness. We also examine the frequentist performance of latent CTMC point and interval estimates of disease process functionals based on simulated data. The performance of estimates depends on time, functional, and data-generating scenario. Finally, we illustrate the interpretive power of latent CTMC models for describing disease processes on a dataset of lung transplant patients. We hope our work will encourage wider use of these models in the biomedical setting. Copyright © 2013 John Wiley & Sons, Ltd.

  4. Metabolic Panel

    Science.gov (United States)

    A metabolic panel is a group of tests that measures different chemicals in the blood. These tests are usually done on ... and liver. There are two types: basic metabolic panel (BMP) and comprehensive metabolic panel (CMP). The BMP ...

  5. State selection in Markov models for panel data with application to psoriatic arthritis.

    Science.gov (United States)

    Thom, Howard H Z; Jackson, Christopher H; Commenges, Daniel; Sharples, Linda D

    2015-07-20

    Markov multistate models in continuous-time are commonly used to understand the progression over time of disease or the effect of treatments and covariates on patient outcomes. The states in multistate models are related to categorisations of the disease status, but there is often uncertainty about the number of categories to use and how to define them. Many categorisations, and therefore multistate models with different states, may be possible. Different multistate models can show differences in the effects of covariates or in the time to events, such as death, hospitalisation, or disease progression. Furthermore, different categorisations contain different quantities of information, so that the corresponding likelihoods are on different scales, and standard, likelihood-based model comparison is not applicable. We adapt a recently developed modification of Akaike's criterion, and a cross-validatory criterion, to compare the predictive ability of multistate models on the information which they share. All the models we consider are fitted to data consisting of observations of the process at arbitrary times, often called 'panel' data. We develop an implementation of these criteria through Hidden Markov models and apply them to the comparison of multistate models for the Health Assessment Questionnaire score in psoriatic arthritis. This procedure is straightforward to implement in the R package 'msm'. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Alternative approaches for econometric analysis of panel count data using dynamic latent class models (with application to doctor visits data).

    Science.gov (United States)

    Hyppolite, Judex; Trivedi, Pravin

    2012-06-01

    Cross-sectional latent class regression models, also known as switching regressions or hidden Markov models, cannot identify transitions between classes that may occur over time. This limitation can potentially be overcome when panel data are available. For such data, we develop a sequence of models that combine features of the static cross-sectional latent class (finite mixture) models with those of hidden Markov models. We model the probability of movement between categories in terms of a Markovian structure, which links the current state with a previous state, where state may refer to the category of an individual. This article presents a suite of mixture models of varying degree of complexity and flexibility for use in a panel count data setting, beginning with a baseline model which is a two-component mixture of Poisson distribution in which latent classes are fixed and permanent. Sequentially, we extend this framework (i) to allow the mixing proportions to be smoothly varying continuous functions of time-varying covariates, (ii) to add time dependence to the benchmark model by modeling the class-indicator variable as a first-order Markov chain and (iii) to extend item (i) by making it dynamic and introducing covariate dependence in the transition probabilities. We develop and implement estimation algorithms for these models and provide an empirical illustration using 1995-1999 panel data on the number of doctor visits derived from the German Socio-Economic Panel. Copyright © 2012 John Wiley & Sons, Ltd.

  7. Numerical modelling of phase-change material used for PV panels cooling

    Science.gov (United States)

    Sellami, Assia; Elotmani, Rabie; Kandoussi, Khalid; Eljouad, Mohamed; Hajjaji, Abdelowahed; Boutaous, M'Hamed

    2017-12-01

    Passive cooling of a PV solar panel using phase-change material (PCM) may play an important role in increasing efficiency of PV cells. Because it does not need a maintenance and does not release greenhouses gases, PCM seems to be a good way to decrease the among of overheating of PV cell. The aims of this paper describes a detailed multiphysical issue in order to understand the effect of PCM (RT25) in keeping PV cell temperature close to ambient. The study is focused on modeling the heat and mass transfer in a PCM domain by modifying the buoyancy term in momentum equation. Due to a phase-change and free convection, transient incompressible flow is taken into account to explain the dynamic variations of the velocity profile and viscosity distribution. With standard condition of irradiation and heat flux on both sides of the PV panel, a melt front has been tracked by the energy equation, which gives a good argument for the temperature evolution during phase-change.

  8. Finite element modeling of guided wave scattering at delaminations in composite panels

    Science.gov (United States)

    Murat, B. I. S.; Fromme, P.

    2016-04-01

    Carbon fiber laminate composites, consisting of layers of polymer matrix reinforced with high strength carbon fibers, are increasingly employed for aerospace structures. They offer advantages for aerospace applications, e.g., good strength to weight ratio. However, impact during the operation and servicing of the aircraft can lead to barely visible and difficult to detect damage. Depending on the severity of the impact, delaminations can occur, reducing the load carrying capacity of the structure. Efficient structural health monitoring of composite panels can be achieved using guided ultrasonic waves propagating along the structure. The guided ultrasonic wave (A0 Lamb wave mode) scattering at delaminations was modelled using full three-dimensional Finite Element (FE) simulations. The influence of the delamination size was systematically investigated from a parameter study. The angular dependency of the scattered guided wave amplitude was calculated using a baseline subtraction method. A significant influence of the delamination width on the guided wave scattering was found. The sensitivity of guided waves for the detection of barely visible impact damage in composite panels has been predicted.

  9. The Determinants of FDI Flows from the EU‐15 to the Visegrad Group Countries – A Panel Gravity Model Approach

    Directory of Open Access Journals (Sweden)

    Liwiusz Wojciechowski

    2013-03-01

    Full Text Available The objective of this paper is to evaluate determinants of the general FDI flow to Visegrad countries and the effect of participation in EMU and EU. It was decided to investigate how augmented Gravity Model of trade allows identifying and evaluating the significance of pull and push factors of FDI. In an empirical analysis of panel data Hausman‐Taylor estimator was used because of the time‐invariant variables presence. While investment decisions regarding the choice of country are determined by the size of the target market, the distance is still a negative factor in creation of FDI volume. Additionally, it was proven that membership in EMU, differences in taxation, historical background, access to the sea and prices stability have significant impact of FDI stock formation in each country belonging to V4. Is was also noted that Poland became a leader of the V4 as well as EU‐12 FDI market sourcing from the old EU Member States. It is necessary to develop an “FDI attracting mechanism” using existing resources. Business regulations and taxation policy as well as main macroeconomic variables which are responsible for the economy standing are also examined as attracting the FDI flow. The originality of this work lies in studying some aspects of FDI inflow into the group of both similar and different countries in economic measures terms.

  10. 1987 Oak Ridge model conference: Proceedings: Volume 2, Environmental protection

    International Nuclear Information System (INIS)

    1987-01-01

    See the abstract for Volume I for general information on the conference. Topics discussed in Volume II include data management techiques for environmental protection efforts, the use of models in environmental auditing, in emergency plans, chemical accident emergency response, risk assessment, monitoring of waste sites, air and water monitoring of waste sites, and in training programs

  11. Assessing type I error and power of multistate Markov models for panel data-A simulation study.

    Science.gov (United States)

    Cassarly, Christy; Martin, Renee' H; Chimowitz, Marc; Peña, Edsel A; Ramakrishnan, Viswanathan; Palesch, Yuko Y

    2017-01-01

    Ordinal outcomes collected at multiple follow-up visits are common in clinical trials. Sometimes, one visit is chosen for the primary analysis and the scale is dichotomized amounting to loss of information. Multistate Markov models describe how a process moves between states over time. Here, simulation studies are performed to investigate the type I error and power characteristics of multistate Markov models for panel data with limited non-adjacent state transitions. The results suggest that the multistate Markov models preserve the type I error and adequate power is achieved with modest sample sizes for panel data with limited non-adjacent state transitions.

  12. Correlation Results for a Mass Loaded Vehicle Panel Test Article Finite Element Models and Modal Survey Tests

    Science.gov (United States)

    Maasha, Rumaasha; Towner, Robert L.

    2012-01-01

    High-fidelity Finite Element Models (FEMs) were developed to support a recent test program at Marshall Space Flight Center (MSFC). The FEMs correspond to test articles used for a series of acoustic tests. Modal survey tests were used to validate the FEMs for five acoustic tests (a bare panel and four different mass-loaded panel configurations). An additional modal survey test was performed on the empty test fixture (orthogrid panel mounting fixture, between the reverb and anechoic chambers). Modal survey tests were used to test-validate the dynamic characteristics of FEMs used for acoustic test excitation. Modal survey testing and subsequent model correlation has validated the natural frequencies and mode shapes of the FEMs. The modal survey test results provide a basis for the analysis models used for acoustic loading response test and analysis comparisons

  13. Disc volume reduction with percutaneous nucleoplasty in an animal model.

    Directory of Open Access Journals (Sweden)

    Richard Kasch

    Full Text Available STUDY DESIGN: We assessed volume following nucleoplasty disc decompression in lower lumbar spines from cadaveric pigs using 7.1Tesla magnetic resonance imaging (MRI. PURPOSE: To investigate coblation-induced volume reductions as a possible mechanism underlying nucleoplasty. METHODS: We assessed volume following nucleoplastic disc decompression in pig spines using 7.1-Tesla MRI. Volumetry was performed in lumbar discs of 21 postmortem pigs. A preoperative image data set was obtained, volume was determined, and either disc decompression or placebo therapy was performed in a randomized manner. Group 1 (nucleoplasty group was treated according to the usual nucleoplasty protocol with coblation current applied to 6 channels for 10 seconds each in an application field of 360°; in group 2 (placebo group the same procedure was performed but without coblation current. After the procedure, a second data set was generated and volumes calculated and matched with the preoperative measurements in a blinded manner. To analyze the effectiveness of nucleoplasty, volumes between treatment and placebo groups were compared. RESULTS: The average preoperative nucleus volume was 0.994 ml (SD: 0.298 ml. In the nucleoplasty group (n = 21 volume was reduced by an average of 0.087 ml (SD: 0.110 ml or 7.14%. In the placebo group (n = 21 volume was increased by an average of 0.075 ml (SD: 0.075 ml or 8.94%. The average nucleoplasty-induced volume reduction was 0.162 ml (SD: 0.124 ml or 16.08%. Volume reduction in lumbar discs was significant in favor of the nucleoplasty group (p<0.0001. CONCLUSIONS: Our study demonstrates that nucleoplasty has a volume-reducing effect on the lumbar nucleus pulposus in an animal model. Furthermore, we show the volume reduction to be a coblation effect of nucleoplasty in porcine discs.

  14. Fixed site neutralization model programmer's manual. Volume II

    International Nuclear Information System (INIS)

    Engi, D.; Chapman, L.D.; Judnick, W.; Blum, R.; Broegler, L.; Lenz, J.; Weinthraub, A.; Ballard, D.

    1979-12-01

    This report relates to protection of nuclear materials at nuclear facilities. This volume presents the source listings for the Fixed Site Neutralization Model and its supporting modules, the Plex Preprocessor and the Data Preprocessor

  15. Does Climate Change Mitigation Activity Affect Crude Oil Prices? Evidence from Dynamic Panel Model

    Directory of Open Access Journals (Sweden)

    Jude C. Dike

    2014-01-01

    Full Text Available This paper empirically investigates how climate change mitigation affects crude oil prices while using carbon intensity as the indicator for climate change mitigation. The relationship between crude oil prices and carbon intensity is estimated using an Arellano and Bond GMM dynamic panel model. This study undertakes a regional-level analysis because of the geographical similarities among the countries in a region. Regions considered for the study are Africa, Asia and Oceania, Central and South America, the EU, the Middle East, and North America. Results show that there is a positive relationship between crude oil prices and carbon intensity, and a 1% change in carbon intensity is expected to cause about 1.6% change in crude oil prices in the short run and 8.4% change in crude oil prices in the long run while the speed of adjustment is 19%.

  16. Determinants of Oil Demand in OECD Countries: An Application of Panel Data Model

    Directory of Open Access Journals (Sweden)

    Burcu OZCAN

    2015-05-01

    Full Text Available This study aimed to analyze demand for oil in 20 selected OECD countries over the period 1980 to 2011, within the framework of panel data model. The long-run income and price elasticities of oil demand were computed and the Granger causality between variables of interest was tested. The results indicated that oil demand has positive and negative income and price elasticities, respectively. In addition, both income and price were inelastic in the long-run, but price elasticity was lower than income elasticity. Furthermore, a bidirectional causality running from economic growth to oil consumption and vice versa was obtained, providing evidence of feedback hypothesis. Based on these results, some crucial policy implications were suggested

  17. Ovarian volume throughout life: a validated normative model.

    Science.gov (United States)

    Kelsey, Thomas W; Dodwell, Sarah K; Wilkinson, A Graham; Greve, Tine; Andersen, Claus Y; Anderson, Richard A; Wallace, W Hamish B

    2013-01-01

    The measurement of ovarian volume has been shown to be a useful indirect indicator of the ovarian reserve in women of reproductive age, in the diagnosis and management of a number of disorders of puberty and adult reproductive function, and is under investigation as a screening tool for ovarian cancer. To date there is no normative model of ovarian volume throughout life. By searching the published literature for ovarian volume in healthy females, and using our own data from multiple sources (combined n=59,994) we have generated and robustly validated the first model of ovarian volume from conception to 82 years of age. This model shows that 69% of the variation in ovarian volume is due to age alone. We have shown that in the average case ovarian volume rises from 0.7 mL (95% CI 0.4-1.1 mL) at 2 years of age to a peak of 7.7 mL (95% CI 6.5-9.2 mL) at 20 years of age with a subsequent decline to about 2.8 mL (95% CI 2.7-2.9 mL) at the menopause and smaller volumes thereafter. Our model allows us to generate normal values and ranges for ovarian volume throughout life. This is the first validated normative model of ovarian volume from conception to old age; it will be of use in the diagnosis and management of a number of diverse gynaecological and reproductive conditions in females from birth to menopause and beyond.

  18. Characterization of PV panel and global optimization of its model parameters using genetic algorithm

    International Nuclear Information System (INIS)

    Ismail, M.S.; Moghavvemi, M.; Mahlia, T.M.I.

    2013-01-01

    Highlights: • Genetic Algorithm optimization ability had been utilized to extract parameters of PV panel model. • Effect of solar radiation and temperature variations was taken into account in fitness function evaluation. • We used Matlab-Simulink to simulate operation of the PV-panel to validate results. • Different cases were analyzed to ascertain which of them gives more accurate results. • Accuracy and applicability of this approach to be used as a valuable tool for PV modeling were clearly validated. - Abstract: This paper details an improved modeling technique for a photovoltaic (PV) module; utilizing the optimization ability of a genetic algorithm, with different parameters of the PV module being computed via this approach. The accurate modeling of any PV module is incumbent upon the values of these parameters, as it is imperative in the context of any further studies concerning different PV applications. Simulation, optimization and the design of the hybrid systems that include PV are examples of these applications. The global optimization of the parameters and the applicability for the entire range of the solar radiation and a wide range of temperatures are achievable via this approach. The Manufacturer’s Data Sheet information is used as a basis for the purpose of parameter optimization, with an average absolute error fitness function formulated; and a numerical iterative method used to solve the voltage-current relation of the PV module. The results of single-diode and two-diode models are evaluated in order to ascertain which of them are more accurate. Other cases are also analyzed in this paper for the purpose of comparison. The Matlab–Simulink environment is used to simulate the operation of the PV module, depending on the extracted parameters. The results of the simulation are compared with the Data Sheet information, which is obtained via experimentation in order to validate the reliability of the approach. Three types of PV modules

  19. Numerical modeling for longwall pillar design: a case study from a typical longwall panel in China

    Science.gov (United States)

    Zhang, Guangchao; Liang, Saijiang; Tan, Yunliang; Xie, Fuxing; Chen, Shaojie; Jia, Hongguo

    2018-02-01

    This paper presents a new numerical modeling procedure and design principle for longwall pillar design with the assistance of numerical simulation of FLAC3D. A coal mine located in Yanzhou city, Shandong Province, China, was selected for this case study. A meticulously validated numerical model was developed to investigate the stress changes across the longwall pillar with various sizes. In order to improve the reliability of the numerical modeling, a calibration procedure is undertaken to match the Salamon and Munro pillar strength formula for the coal pillar, while a similar calibration procedure is used to estimate the stress-strain response of a gob. The model results demonstrated that when the coal pillar width was 7-8 m, most of the vertical load was carried by the panel rib, whilst the gateroad was overall in a relatively low stress environment and could keep its stability with proper supports. Thus, the rational longwall pillar width was set as 8 m and the field monitoring results confirmed the feasibility of this pillar size. The proposed numerical simulation procedure and design principle presented in this study could be a viable alternative approach for longwall pillar design for other similar projects.

  20. A Parameter Study of Coupling Properties in Finite Element Models of Single-Stud Double-Plate Panels

    DEFF Research Database (Denmark)

    Dickow, Kristoffer Ahrens; Domadiya, Parthkumar Gandalal; Andersen, Lars Vabbersgaard

    2011-01-01

    Lightweight building techniques are currently progressing fast and using such structures for multi-storey multi-family dwellings is becoming part of the industry standard. Partitions in lightweight buildings are often constructed as plates on frame structures made of either wood or steel. In any...... case the low frequency sound transmission is often an issue that needs attention. The present paper utilizes a finite element model of a single-stud double-plate panel structure to investigate how different couplings between the plates and the frame structure affect the direct sound transmission. Four...... and the load acts as a diffuse field on one side of the panel. The obtained results indicate that in order to accurately model sound transmission through a double-plate panel structure, the choice of coupling is an important factor....

  1. Optimized volume models of earthquake-triggered landslides.

    Science.gov (United States)

    Xu, Chong; Xu, Xiwei; Shen, Lingling; Yao, Qi; Tan, Xibin; Kang, Wenjun; Ma, Siyuan; Wu, Xiyan; Cai, Juntao; Gao, Mingxing; Li, Kang

    2016-07-12

    In this study, we proposed three optimized models for calculating the total volume of landslides triggered by the 2008 Wenchuan, China Mw 7.9 earthquake. First, we calculated the volume of each deposit of 1,415 landslides triggered by the quake based on pre- and post-quake DEMs in 20 m resolution. The samples were used to fit the conventional landslide "volume-area" power law relationship and the 3 optimized models we proposed, respectively. Two data fitting methods, i.e. log-transformed-based linear and original data-based nonlinear least square, were employed to the 4 models. Results show that original data-based nonlinear least square combining with an optimized model considering length, width, height, lithology, slope, peak ground acceleration, and slope aspect shows the best performance. This model was subsequently applied to the database of landslides triggered by the quake except for two largest ones with known volumes. It indicates that the total volume of the 196,007 landslides is about 1.2 × 10(10) m(3) in deposit materials and 1 × 10(10) m(3) in source areas, respectively. The result from the relationship of quake magnitude and entire landslide volume related to individual earthquake is much less than that from this study, which reminds us the necessity to update the power-law relationship.

  2. Model documentation Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    International Nuclear Information System (INIS)

    1996-01-01

    The Natural Gas Transmission and Distribution Model (NGTDM) of the National Energy Modeling System is developed and maintained by the Energy Information Administration (EIA), Office of Integrated Analysis and Forecasting. This report documents the archived version of the NGTDM that was used to produce the natural gas forecasts presented in the Annual Energy Outlook 1996, (DOE/EIA-0383(96)). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic approach, and provides detail on the methodology employed. Previously this report represented Volume I of a two-volume set. Volume II reported on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues

  3. Model documentation Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-26

    The Natural Gas Transmission and Distribution Model (NGTDM) of the National Energy Modeling System is developed and maintained by the Energy Information Administration (EIA), Office of Integrated Analysis and Forecasting. This report documents the archived version of the NGTDM that was used to produce the natural gas forecasts presented in the Annual Energy Outlook 1996, (DOE/EIA-0383(96)). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic approach, and provides detail on the methodology employed. Previously this report represented Volume I of a two-volume set. Volume II reported on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues.

  4. The Soil Model Development and Intercomparison Panel (SoilMIP) of the International Soil Modeling Consortium (ISMC)

    Science.gov (United States)

    Vanderborght, Jan; Priesack, Eckart

    2017-04-01

    The Soil Model Development and Intercomparison Panel (SoilMIP) is an initiative of the International Soil Modeling Consortium. Its mission is to foster the further development of soil models that can predict soil functions and their changes (i) due to soil use and land management and (ii) due to external impacts of climate change and pollution. Since soil functions and soil threats are diverse but linked with each other, the overall aim is to develop holistic models that represent the key functions of the soil system and the links between them. These models should be scaled up and integrated in terrestrial system models that describe the feedbacks between processes in the soil and the other terrestrial compartments. We propose and illustrate a few steps that could be taken to achieve these goals. A first step is the development of scenarios that compare simulations by models that predict the same or different soil services. Scenarios can be considered at three different levels of comparisons: scenarios that compare the numerics (accuracy but also speed) of models, scenarios that compare the effect of differences in process descriptions, and scenarios that compare simulations with experimental data. A second step involves the derivation of metrics or summary statistics that effectively compare model simulations and disentangle parameterization from model concept differences. These metrics can be used to evaluate how more complex model simulations can be represented by simpler models using an appropriate parameterization. A third step relates to the parameterization of models. Application of simulation models implies that appropriate model parameters have to be defined for a range of environmental conditions and locations. Spatial modelling approaches are used to derive parameter distributions. Considering that soils and their properties emerge from the interaction between physical, chemical and biological processes, the combination of spatial models with process

  5. On a novel approach for optimizing composite materials panel using surrogate models

    NARCIS (Netherlands)

    De Guido, S.; Akcay-Perdahcioglu, Didem; Geijselaers, Hubertus J.M.; de Boer, Andries; Rolfes, R.; Jansen, E.L.

    2011-01-01

    This paper describes an optimization procedure to design thermoplastic composite panels under axial compressive load conditions. Minimum weight is the goal. The panel design is subject to buckling constraints. The presence of the bending-twisting coupling and of particular boundary conditions does

  6. Catalogue of abrupt shifts in Intergovernmental Panel on Climate Change climate models

    Science.gov (United States)

    Drijfhout, Sybren; Bathiany, Sebastian; Beaulieu, Claudie; Brovkin, Victor; Claussen, Martin; Huntingford, Chris; Scheffer, Marten; Sgubin, Giovanni; Swingedouw, Didier

    2015-10-01

    Abrupt transitions of regional climate in response to the gradual rise in atmospheric greenhouse gas concentrations are notoriously difficult to foresee. However, such events could be particularly challenging in view of the capacity required for society and ecosystems to adapt to them. We present, to our knowledge, the first systematic screening of the massive climate model ensemble informing the recent Intergovernmental Panel on Climate Change report, and reveal evidence of 37 forced regional abrupt changes in the ocean, sea ice, snow cover, permafrost, and terrestrial biosphere that arise after a certain global temperature increase. Eighteen out of 37 events occur for global warming levels of less than 2°, a threshold sometimes presented as a safe limit. Although most models predict one or more such events, any specific occurrence typically appears in only a few models. We find no compelling evidence for a general relation between the overall number of abrupt shifts and the level of global warming. However, we do note that abrupt changes in ocean circulation occur more often for moderate warming (less than 2°), whereas over land they occur more often for warming larger than 2°. Using a basic proportion test, however, we find that the number of abrupt shifts identified in Representative Concentration Pathway (RCP) 8.5 scenarios is significantly larger than in other scenarios of lower radiative forcing. This suggests the potential for a gradual trend of destabilization of the climate with respect to such shifts, due to increasing global mean temperature change.

  7. Testing the Causal Links between School Climate, School Violence, and School Academic Performance: A Cross-Lagged Panel Autoregressive Model

    Science.gov (United States)

    Benbenishty, Rami; Astor, Ron Avi; Roziner, Ilan; Wrabel, Stephani L.

    2016-01-01

    The present study explores the causal link between school climate, school violence, and a school's general academic performance over time using a school-level, cross-lagged panel autoregressive modeling design. We hypothesized that reductions in school violence and climate improvement would lead to schools' overall improved academic performance.…

  8. EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF); Scientific Opinion on Flavouring Group Evaluation 96 (FGE.96): Consideration of 88 flavouring substances considered by EFSA for which EU production volumes / anticipated production volumes have been submitted

    DEFF Research Database (Denmark)

    Larsen, John Christian; Nørby, Karin Kristiane; Beltoft, Vibe Meister

    The Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids of the European Food Safety Authority was requested to consider evaluations of flavouring substances assessed since 2000 by the Joint FAO/WHO Expert Committee on Food Additives (the JECFA), and to decide whether further...... evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The present FGE.96 concerns 88 JECFA-evaluated substances from different FGEs. Common for all the 88 substances was that for none of them European production volumes were available at the time for the first consideration...... have been calculated and based on these MSDI values the substances have been re-considered by the stepwise approach (the Procedure) that integrates information on structure-activity relationships, intake from current uses, toxicological threshold of concern, and available data on metabolism...

  9. Spatial Economics Model Predicting Transport Volume

    Directory of Open Access Journals (Sweden)

    Lu Bo

    2016-10-01

    Full Text Available It is extremely important to predict the logistics requirements in a scientific and rational way. However, in recent years, the improvement effect on the prediction method is not very significant and the traditional statistical prediction method has the defects of low precision and poor interpretation of the prediction model, which cannot only guarantee the generalization ability of the prediction model theoretically, but also cannot explain the models effectively. Therefore, in combination with the theories of the spatial economics, industrial economics, and neo-classical economics, taking city of Zhuanghe as the research object, the study identifies the leading industry that can produce a large number of cargoes, and further predicts the static logistics generation of the Zhuanghe and hinterlands. By integrating various factors that can affect the regional logistics requirements, this study established a logistics requirements potential model from the aspect of spatial economic principles, and expanded the way of logistics requirements prediction from the single statistical principles to an new area of special and regional economics.

  10. Mathematical models for volume rendering and neutron transport

    International Nuclear Information System (INIS)

    Max, N.

    1994-09-01

    This paper reviews several different models for light interaction with volume densities of absorbing, glowing, reflecting, or scattering material. They include absorption only, glow only, glow and absorption combined, single scattering of external illumination, and multiple scattering. The models are derived from differential equations, and illustrated on a data set representing a cloud. They are related to corresponding models in neutron transport. The multiple scattering model uses an efficient method to propagate the radiation which does not suffer from the ray effect

  11. Heterogeneity of growth in the west Balkans and emerging Europe: A dynamic panel data model approach

    Directory of Open Access Journals (Sweden)

    Josifidis Kosta

    2012-01-01

    Full Text Available This paper explores the heterogeneity of growth in the Western Balkan and Emerging European economies. For that purpose, growth determinants are estimated in the period 1997-2009 by dynamic panel data models. The chosen period provides a comparison for the model results with those estimated for the period up to 2007 in order to analyze changes caused by the global instability. According to the main findings of the paper, macroeconomic stabilization and structural reforms still matter in determining economic growth, but foreign direct investments and economic integrations seem to have the most important role in stimulating growth in the observed countries. Moreover, significant positive effects of foreign direct investments and economic integrations produce differences in growth paths between Emerging European and Western Balkan economies. Sharp decrease of foreign inflows in 2008 determined contractions of growth rates firstly in Emerging European economies with subsequent spill-over on the Western Balkan economies during 2009. Consequently, in the period of global instability, differences between two groups of economies become even more obvious.

  12. Socioeconomic inequality in health in the British household panel: Tests of the social causation, health selection and the indirect selection hypothesis using dynamic fixed effects panel models.

    Science.gov (United States)

    Foverskov, Else; Holm, Anders

    2016-02-01

    Despite social inequality in health being well documented, it is still debated which causal mechanism best explains the negative association between socioeconomic position (SEP) and health. This paper is concerned with testing the explanatory power of three widely proposed causal explanations for social inequality in health in adulthood: the social causation hypothesis (SEP determines health), the health selection hypothesis (health determines SEP) and the indirect selection hypothesis (no causal relationship). We employ dynamic data of respondents aged 30 to 60 from the last nine waves of the British Household Panel Survey. Household income and location on the Cambridge Scale is included as measures of different dimensions of SEP and health is measured as a latent factor score. The causal hypotheses are tested using a time-based Granger approach by estimating dynamic fixed effects panel regression models following the method suggested by Anderson and Hsiao. We propose using this method to estimate the associations over time since it allows one to control for all unobserved time-invariant factors and hence lower the chances of biased estimates due to unobserved heterogeneity. The results showed no proof of the social causation hypothesis over a one to five year period and limited support for the health selection hypothesis was seen only for men in relation to HH income. These findings were robust in multiple sensitivity analysis. We conclude that the indirect selection hypothesis may be the most important in explaining social inequality in health in adulthood, indicating that the well-known cross-sectional correlations between health and SEP in adulthood seem not to be driven by a causal relationship, but instead by dynamics and influences in place before the respondents turn 30 years old that affect both their health and SEP onwards. The conclusion is limited in that we do not consider the effect of specific diseases and causal relationships in adulthood may be

  13. Panel Analysis

    DEFF Research Database (Denmark)

    Brænder, Morten; Andersen, Lotte Bøgh

    2014-01-01

    where panel attrition, the practical and ethical challenges of contacting the same respondents at different points of time may affect response rates negatively. In the article, we present some key distinctions regarding panel data and analyses, and in the subsequent exercises we invite readers to apply...... these concepts on a number of recently published panel studies....

  14. Morphological modeling of terrains and volume data

    CERN Document Server

    Comic, Lidija; Magillo, Paola; Iuricich, Federico

    2014-01-01

    This book describes the mathematical background behind discrete approaches to morphological analysis of scalar fields, with a focus on Morse theory and on the discrete theories due to Banchoff and Forman. The algorithms and data structures presented are used for terrain modeling and analysis, molecular shape analysis, and for analysis or visualization of sensor and simulation 3D data sets. It covers a variety of application domains including geography, geology, environmental sciences, medicine and biology. The authors classify the different approaches to morphological analysis which are all ba

  15. Modelling drug-related morbidity in Sweden using an expert panel of physicians.

    Science.gov (United States)

    Hakkarainen, Katja M; Alström, Daniel; Hägg, Staffan; Carlsten, Anders; Gyllensten, Hanna

    2012-09-01

    In modelling studies using pharmacists' opinions, drug-related morbidity (DRM) and preventable DRM have been more common than in observational studies, and the resulting costs are extensive. Modelling studies' estimates may vary depending on informants' profession. The purpose of this modelling study was to estimate the proportion of patients with DRM and preventable DRM and the cost of illness (COI) of DRM in Sweden based on physicians' expert opinions. A conceptual model of DRM was modified from previous studies. Using a modified Delphi technique, a panel of physicians (n = 19) estimated the probabilities of DRM, preventable DRM, and clinical outcomes of DRM separately for outpatients and inpatients. DRM included new medical problems (adverse drug reactions, drug dependence, and intoxications by overdose) and therapeutic failure (insufficient effects of medicines, and morbidity due to untreated indication). A COI analysis included the direct costs of DRM. Physicians estimated that 51 ± 22% [mean ± standard deviation (SD)] of outpatients experience DRM and 12 ± 8% preventable DRM. Of inpatients, 54 ± 17% was estimated to experience DRM and 16 ± 7% preventable DRM. Of outpatients with DRM, 24 ± 11% was estimated to experience preventable DRM, whereas this proportion for inpatients was 31 ± 15%. The estimated COI was 376 euros per outpatient and 838 euros per inpatient. Swedish physicians estimated that every other outpatient and inpatient experiences DRM, which is often preventable and costly. As physicians' estimates on the proportion of patients with DRM were higher than in observational studies in restricted subpopulations, DRM may be more common in the general population than observational studies suggest.

  16. Conditional models accounting for regression to the mean in observational multi-wave panel studies on alcohol consumption.

    Science.gov (United States)

    Ripatti, Samuli; Mäkelä, Pia

    2008-01-01

    To develop statistical methodology needed for studying whether effects of an acute-onset intervention differ by consumption group that accounts correctly for the effect of regression to the mean (RTM) in observational panel studies with three or more measurement waves. A general statistical modelling framework, based on conditional models, is presented for analysing alcohol panel data with three or more measurements, that models the dependence between initial drinking level and change in consumption controlling for RTM. The method is illustrated by panel data from Finland, southern Sweden and Denmark, where the effects of large changes in alcohol taxes and travellers' allowances were studied. The suggested model allows for drawing statistical inference of the parameters of interest and also the identification of non-linear effects of an intervention by initial consumption using standard statistical software modelling tools. There was no evidence in any of the countries of the changes being larger among heavy drinkers, but in southern Sweden there was evidence that light drinkers raised their level of consumption. Conditional models are a versatile modelling framework that offers a flexible tool for modelling and testing changes due to intervention in consumption by initial consumption while controlling simultaneously for RTM.

  17. IMPLEMENTATION OF SEMI-EMPIRICAL MODELS TO ENHANCE THE ACCURACY OF PANEL METHODS FOR DRAG PREDICTION AT SUPERSONIC SPEEDS

    Directory of Open Access Journals (Sweden)

    Abdulkareem Shafiq Mahdi Al-Obaidi

    2011-12-01

    Full Text Available 0 0 1 328 1876 International Islamic University 15 4 2200 14.0 Normal 0 false false false EN-US JA X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Times New Roman";} This paper introduces an attempt to enhance the accuracy of panel methods. A low-order panel method is selected and coupled with semi-empirical methods to enhance the accuracy of drag prediction of flying bodies at supersonic speeds. The semi-empirical methods are used to improve the accuracy of drag prediction by mathematical modelling of viscosity, base drag, and drag due to wing-body interference. Both methods were implemented by a computer program and validated against experimental and analytical results. The comparisons show that a considerable improvement has been achieved for the selected panel method for prediction of drag coefficients. In general, accuracy within an average value of -4.4% was obtained for the enhanced panel method. Such accuracy could be considered acceptable for the preliminary design stages of supersonic flying bodies such as projectiles and missiles. The developed computer program gives satisfactory results as long as the considered configurations are slender and the angles of attack are small (below stall angle.  ABSTRAK: Kertas kerja ini memperkenalkan percubaan untuk  mempertingkatkan ketepatan kaedah panel. Kaedah panel tertib rendah telah dipilih dan digabungkan dengan kaedah separa empirik untuk mempertingkatkan ketepatan ramalan seret objek terbang pada kelajuan supersonik. Kaedah semi empirikal yang digunakan untuk meningkatkan ketepatan jangkaan seret menggunakan model matematik bagi kelikatan, seretan dasar, dan  seretan disebabkan  oleh

  18. Laboratory testing and finite element modeling of precast bridge deck panel transverse connections.

    Science.gov (United States)

    2010-08-06

    Precast bridge deck panels are increasingly used to reduce construction times and associated traffic delays as part of many DOTs push for accelerated bridge construction. They allow a bridge deck to be built or replaced in days instead of months. ...

  19. Panel 5 -- Open Architecture, Open Business Models and Collaboration for Acquisition

    National Research Council Canada - National Science Library

    Johnson, Bill; Guertin, Nick

    2007-01-01

    .... OA delivers increased warfighting capabilities in a shorter time at reduced cost. This panel's presentations discuss the use of a key tool set to make the business part of the Naval Open Architecture equation come to fruition...

  20. Modelling drug-related morbidity in Sweden using an expert panel of pharmacists'.

    Science.gov (United States)

    Gyllensten, Hanna; Hakkarainen, Katja M; Jönsson, Anna K; Andersson Sundell, Karolina; Hägg, Staffan; Rehnberg, Clas; Carlsten, Anders

    2012-08-01

    Drug-related morbidity (DRM) is common and to some extent preventable, and associated with considerable costs in patients attending hospital. In outpatients and in the general public corresponding data are limited, but pharmacists' expert opinion has suggested high rates of DRM also in US ambulatory care. It is unknown if the results are applicable in Sweden today. To estimate the proportions of patients with DRM and preventable DRM and the cost-of-illness (COI) of DRM in Sweden based on pharmacists' expert opinion. Swedish healthcare. The study applied a conceptual model of DRM based on a decision tree. An expert panel of pharmacists determined the probabilities of therapeutic outcomes of medication therapy. The COI analysis included direct costs from the healthcare perspective. Sensitivity analyses were performed for variations in probabilities and pathway costs. DRM included new medical problems (adverse drug reactions, drug dependence and intoxications) and therapeutic failures (insufficient effects of medicines and morbidity due to untreated indication). The expert panel estimated that 61 ± 14 % (mean ± SD) of all patients attending healthcare suffered from DRM, of which 29 ± 8 % suffered from new medical problems, 18 ± 6 % from therapeutic failures, and 15 ± 7 % from a combination of both. The DRM was considered preventable in 45 ± 15 % of the patients with DRM. The estimated COI was EUR 997 per patient attending healthcare, corresponding to an annual cost of EUR 6,600 million to the Swedish healthcare system. The COI ranged from EUR 490 to EUR 1,314 when varying the participants' probabilities of DRM and clinical outcomes from the first to the third quartile. Of the pathway costs, the COI was most sensitive to variation in the cost of prolonged hospital stay (COI range EUR 953-1,306). According to pharmacists' expert opinion, a large proportion of patients in Sweden experience DRM and preventable DRM, and the estimated COI of DRM is extensive. Since

  1. TAX COMPOSITION AND ECONOMIC GROWTH. A PANEL-MODEL APPROACH FOR EASTERN EUROPE

    Directory of Open Access Journals (Sweden)

    MURA PETRU-OVIDIU

    2015-03-01

    Full Text Available In this paper, we investigate the impact of tax composition on economic growth, based on a panel-model approach. The dataset includes six East-European countries and covers the period 1995-2012. Specifically, the study explores the relative impact of different components of tax revenue (direct and indirect tax revenue, as percentage of total tax revenue on economic growth. The paper adds marginally to the empirical literature, showing how the two types of tax revenue influence economic growth in Eastern Europe, under an extended set of economic and sociopolitical control variables. The most important empirical output, for the 6 investigated East-European countries during 1995-2012, suggests that direct taxes are significant and negatively correlated with economic growth, while indirect taxes exert a positive influence on the dependent variable, though insignificant. As for the control variables, it seems that only freedom from corruption and political stability have a significant impact on economic growth. The study suggests that the design of tax systems in Eastern European countries is in accordance with the Commission’s priorities regarding its growth-friendliness. As for policy implications, governments should continue shifting the tax burden away from labour on to tax bases linked to consumption, property, and combating pollution, with potential positive effects both for growth and for fighting against tax evasion.

  2. Modeling and vibro-acoustic analysis of elastically restrained panel backed by irregular sound space

    Science.gov (United States)

    Chen, Yuehua; Jin, G.; Feng, Zhimin; Liu, Zhigang

    2017-11-01

    A general analytical method is developed for the natural features and vibro-acoustic response analysis of an arbitrarily restrained rectangular plate backed by an irregular cavity. The modeling of the structure and the sound space are developed by employing the variational theory based on the sub-structure method. The irregular enclosure is disassembled into sub-cavities and the coupling formulae are deduced. The continuity conditions of both sound pressure and particle velocity at the coupling interface are exactly satisfied. The variational expressions of elastic boundary conditions of the panel are presented and thus the classical boundary conditions can be easily obtained by assigning appropriate elastic coupling coefficients. The vibration and sound pressure solutions are obtained by performing the Rayleigh-Ritz procedure. The accuracy and efficiency of the present method are validated by checking the present results against the finite element method (FEM) results for systems separately with right-angled trapezoidal and concave curved trapezoidal sub-cavity. It is shown that the present method is suitable for a system with an irregular cavity and an elastically restrained plate by exhibiting satisfactory accuracy, fast convergence speed while requiring small computation effort.

  3. Explaining regional variations in health care utilization between Swiss cantons using panel econometric models.

    Science.gov (United States)

    Camenzind, Paul A

    2012-03-13

    In spite of a detailed and nation-wide legislation frame, there exist large cantonal disparities in consumed quantities of health care services in Switzerland. In this study, the most important factors of influence causing these regional disparities are determined. The findings can also be productive for discussing the containment of health care consumption in other countries. Based on the literature, relevant factors that cause geographic disparities of quantities and costs in western health care systems are identified. Using a selected set of these factors, individual panel econometric models are calculated to explain the variation of the utilization in each of the six largest health care service groups (general practitioners, specialist doctors, hospital inpatient, hospital outpatient, medication, and nursing homes) in Swiss mandatory health insurance (MHI). The main data source is 'Datenpool santésuisse', a database of Swiss health insurers. For all six health care service groups, significant factors influencing the utilization frequency over time and across cantons are found. A greater supply of service providers tends to have strong interrelations with per capita consumption of MHI services. On the demand side, older populations and higher population densities represent the clearest driving factors. Strategies to contain consumption and costs in health care should include several elements. In the federalist Swiss system, the structure of regional health care supply seems to generate significant effects. However, the extent of driving factors on the demand side (e.g., social deprivation) or financing instruments (e.g., high deductibles) should also be considered.

  4. Energy Poverty in China: A Dynamic Analysis Based on a Hybrid Panel Data Decision Model

    Directory of Open Access Journals (Sweden)

    Bing Wang

    2017-11-01

    Full Text Available Renewable energy can help to tackle energy poverty issues of the availability of modern energy services and the sustainability of energy supply. Based on the concept of the Energy Development Index, published by International Energy Agency, this paper builds the clean energy development index and applies the Grey incidence decision method to analyze regional energy poverty issues in China. A model using panel data investigates the influencing factors that are governing energy poverty alleviation and the relationship between energy poverty and social development. The improved index system not only considers the access to modern energy services, but also addresses the cleanliness of energy supply and the transition to clean energy consumption for cooking. The results indicate that due to insufficient clean energy development, China’s Northeast and West regions have experienced increasing energy poverty problems, while energy poverty in the Southwest region has improved considerably because of its renewable energy development. Urbanization, affordability, and renewable energy development can increase access to modern energy services, contributing to energy poverty alleviation. However, the role of rural household consumption levels in energy poverty alleviation should be considered in rural energy policy.

  5. A volume element model (VEM) for energy systems engineering

    OpenAIRE

    Dilay, Emerson; Vargas, Jose Viriato Coelho; Souza, Jeferson Avila; Ordonez, Juan Carlos; Yang, Sam; Mariano, André Bellin

    2015-01-01

    This work presents a simplified modeling and simulation approach for energy systems engineering that is capable of providing quick and accurate responses during system design. For that, the laws of conservation are combined with available empirical and theoretical correlations to quantify the diverse types of flows that cross the system and produce a simplified tridimensional mathematical model, namely a volume element model (VEM). The physical domain of interest is discretized in space, thus...

  6. Assessing type I error and power of multistate Markov models for panel data-A simulation study

    OpenAIRE

    Cassarly, Christy; Martin, Renee’ H.; Chimowitz, Marc; Peña, Edsel A.; Ramakrishnan, Viswanathan; Palesch, Yuko Y.

    2016-01-01

    Ordinal outcomes collected at multiple follow-up visits are common in clinical trials. Sometimes, one visit is chosen for the primary analysis and the scale is dichotomized amounting to loss of information. Multistate Markov models describe how a process moves between states over time. Here, simulation studies are performed to investigate the type I error and power characteristics of multistate Markov models for panel data with limited non-adjacent state transitions. The results suggest that ...

  7. Development and Analysis of Volume Multi-Sphere Method Model Generation using Electric Field Fitting

    Science.gov (United States)

    Ingram, G. J.

    Electrostatic modeling of spacecraft has wide-reaching applications such as detumbling space debris in the Geosynchronous Earth Orbit regime before docking, servicing and tugging space debris to graveyard orbits, and Lorentz augmented orbits. The viability of electrostatic actuation control applications relies on faster-than-realtime characterization of the electrostatic interaction. The Volume Multi-Sphere Method (VMSM) seeks the optimal placement and radii of a small number of equipotential spheres to accurately model the electrostatic force and torque on a conducting space object. Current VMSM models tuned using force and torque comparisons with commercially available finite element software are subject to the modeled probe size and numerical errors of the software. This work first investigates fitting of VMSM models to Surface-MSM (SMSM) generated electrical field data, removing modeling dependence on probe geometry while significantly increasing performance and speed. A proposed electric field matching cost function is compared to a force and torque cost function, the inclusion of a self-capacitance constraint is explored and 4 degree-of-freedom VMSM models generated using electric field matching are investigated. The resulting E-field based VMSM development framework is illustrated on a box-shaped hub with a single solar panel, and convergence properties of select models are qualitatively analyzed. Despite the complex non-symmetric spacecraft geometry, elegantly simple 2-sphere VMSM solutions provide force and torque fits within a few percent.

  8. A volume-balance model for flow on porous media

    Science.gov (United States)

    Malaga, Carlos; Mandujano, Francisco; Becerra, Julian

    2015-11-01

    Volume-balance models are used by petroleum engineers for simulating multiphase and multicomponent flow phenomena in porous media and the extraction process in oil reservoirs. In these models, mass conservation equations and Darcy's law are supplemented by a balance condition for the pore and fluid volumes. This provides a pressure equation suitable for simulating a compressible flow within a compressible solid matrix. Here we present an alternative interpretation of the volume-balance condition that includes the advective transport within a consolidated porous media. We obtain a modified equation for the time evolution of the pressure field. Numerical tests for phase separation under gravity are presented for multiphase three dimensional flow in heterogeneous porous media. The authors acknowledge funding from Fondo Sectorial CONACYT-SENER grant number 42536 (DGAJ-SPI-34-170412-217).

  9. Panel data analysis using EViews

    CERN Document Server

    Agung, I Gusti Ngurah

    2013-01-01

    A comprehensive and accessible guide to panel data analysis using EViews software This book explores the use of EViews software in creating panel data analysis using appropriate empirical models and real datasets. Guidance is given on developing alternative descriptive statistical summaries for evaluation and providing policy analysis based on pool panel data. Various alternative models based on panel data are explored, including univariate general linear models, fixed effect models and causal models, and guidance on the advantages and disadvantages of each one is given. Panel Data Analysis

  10. Different effects of meteorological factors on hand, foot and mouth disease in various climates: a spatial panel data model analysis.

    Science.gov (United States)

    Wang, Chao; Cao, Kai; Zhang, Yingjie; Fang, Liqun; Li, Xia; Xu, Qin; Huang, Fangfang; Tao, Lixin; Guo, Jin; Gao, Qi; Guo, Xiuhua

    2016-05-26

    Major outbreaks of hand, foot and mouth disease (HFMD) have been reported in China since 2008, posing a great threat to the health of children. Although many studies have examined the effect of meteorological variables on the incidence of HFMD, the results have been inconsistent. This study aimed to quantify the relationship between meteorological factors and HFMD occurrence in different climates of mainland China using spatial panel data models. All statistical analyses were carried out according to different climate types. We firstly conducted a descriptive analysis to summarize the epidemic characteristics of HFMD from May 2008 to November 2012 and then detected the spatial autocorrelation of HFMD using a global autocorrelation statistic (Moran's I) in each month. Finally, the association between HFMD incidence and meteorological factors was explored by spatial panel data models. The 353 regions were divided into 4 groups according to climate (G1: subtropical monsoon climate; G2: temperate monsoon climate; G3: temperate continental climate; G4: plateau mountain climate). The Moran's I values were significant with high correlations in most months of group G1 and G2 and some months of group G3 and G4. This suggested the existence of a high spatial autocorrelation with HFMD. Spatial panel data models were more appropriate to describe the data than fixed effect models. The results showed that HFMD incidences were significantly associated with average atmospheric pressure (AAP), average temperature (AT), average vapor pressure (AVP), average relative humidity (ARH), monthly precipitation (MP), average wind speed (AWS), monthly total sunshine hours (MSH), mean temperature difference (MTD), rain day (RD) and average temperature distance (ATD), but the effect of meteorological factors might differ in various climate types. Spatial panel data models are useful and effective when longitudinal data are available and spatial autocorrelation exists. Our findings showed that

  11. Control volume based modelling of compressible flow in reciprocating machines

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2004-01-01

    conservation laws for mass, energy, and momentum applied to a staggered mesh consisting of two overlapping strings of control volumes. Loss mechanisms can be included directly in the governing equations of models by including them as terms in the conservation laws. Heat transfer, flow friction......, and multidimensional effects must be calculated using empirical correlations; correlations for steady state flow can be used as an approximation. A transformation that assumes ideal gas is presented for transforming equations for masses and energies in control volumes into the corresponding pressures and temperatures...

  12. Does job promotion affect men's and women's health differently? Dynamic panel models with fixed effects.

    Science.gov (United States)

    Nyberg, Anna; Peristera, Paraskevi; Westerlund, Hugo; Johansson, Gunn; Hanson, Linda L Magnusson

    2017-08-01

    Higher occupational status has consistently been shown to be associated with better health, but few studies have to date examined if an upward change in occupational status is associated with a positive change in health. Furthermore, very little is known about whether this association differs by sex. Data were derived from four waves (2008-14) of the Swedish Longitudinal Occupational Survey of Health (SLOSH), a follow-up study of a nationally representative sample of the Swedish working population. The present study comprises 1410 men and 1926 women. A dynamic panel model with fixed effects was used to analyse the lagged association between job promotion on the one hand and self-rated health (SRH) and symptoms of depression on the other. This method allowed controlling for unobserved time-invariant confounders and determining the direction of causality between the variables. Multigroup comparisons were performed to investigate differences between the sexes. The results showed that job promotion was associated with decreased subsequent SRH and increased symptoms of depression among both men and women. Women reported a larger relative worsening of self-rated health following a job promotion than men and men reported a larger relative worsening of depression symptoms. There was limited evidence that SRH and symptoms of depression were associated with subsequent job promotion. The present study indicates that a job promotion could lead to decreased SRH and increased symptoms of depression in a 2-4-year perspective. Associations appear to differ for women and men. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

  13. Modeling the Dynamics and Spillovers of the Health Labor Market: Evidence from China’s Provincial Panel Data

    Directory of Open Access Journals (Sweden)

    Bin Zhu

    2018-01-01

    Full Text Available Health workforce misdistribution is a major challenge faced by almost all countries. A more profound understanding of the dynamics of the health labor market provides evidence for policy makers to balance health workforce distribution with solid evidence. However, one major deficit of existing theoretical and empirical studies is that they often ignore the intra-regional spillovers of the health labor market. This study builds a theoretical “supply–demand–spillover” model that considers both intra-regional supply and demand-side factors, and inter-regional spillovers, hence providing a theoretical reference point for further in-depth studies. Using spatial econometric panel models, the effect of all determinants and spillovers were empirically measured based on a Chinese panel data set, shedding light on health workforce policies in China.

  14. Modeling of piezoelectric devices with the finite volume method.

    Science.gov (United States)

    Bolborici, Valentin; Dawson, Francis; Pugh, Mary

    2010-07-01

    A partial differential equation (PDE) model for the dynamics of a thin piezoelectric plate in an electric field is presented. This PDE model is discretized via the finite volume method (FVM), resulting in a system of coupled ordinary differential equations. A static analysis and an eigenfrequency analysis are done with results compared with those provided by a commercial finite element (FEM) package. We find that fewer degrees of freedom are needed with the FVM model to reach a specified degree of accuracy. This suggests that the FVM model, which also has the advantage of an intuitive interpretation in terms of electrical circuits, may be a better choice in control situations.

  15. Hybrid Active/Passive Control of Sound Radiation from Panels with Constrained Layer Damping and Model Predictive Feedback Control

    Science.gov (United States)

    Cabell, Randolph H.; Gibbs, Gary P.

    2000-01-01

    There has been considerable interest over the past several years in applying feedback control methods to problems of structural acoustics. One problem of particular interest is the control of sound radiation from aircraft panels excited on one side by a turbulent boundary layer (TBL). TBL excitation appears as many uncorrelated sources acting on the panel, which makes it difficult to find a single reference signal that is coherent with the excitation. Feedback methods have no need for a reference signal, and are thus suited to this problem. Some important considerations for the structural acoustics problem include the fact that the required controller bandwidth can easily extend to several hundred Hertz, so a digital controller would have to operate at a few kilohertz. In addition, aircraft panel structures have a reasonably high modal density over this frequency range. A model based controller must therefore handle the modally dense system, or have some way to reduce the bandwidth of the problem. Further complicating the problem is the fact that the stiffness and dynamic properties of an aircraft panel can vary considerably during flight due to altitude changes resulting in significant resonant frequency shifts. These considerations make the tradeoff between robustness to changes in the system being controlled and controller performance especially important. Recent papers concerning the design and implementation of robust controllers for structural acoustic problems highlight the need to consider both performance and robustness when designing the controller. While robust control methods such as H1 can be used to balance performance and robustness, their implementation is not easy and requires assumptions about the types of uncertainties in the plant being controlled. Achieving a useful controller design may require many tradeoff studies of different types of parametric uncertainties in the system. Another approach to achieving robustness to plant changes is to

  16. Atomistic models of amorphous polybutadienes; 3 -- Static free volume

    Energy Technology Data Exchange (ETDEWEB)

    Misra, S.; Mattice, W.L. [Univ. of Akron, OH (United States). Inst. of Polymer Science

    1993-12-20

    Atomistic models of polybutadiene have been generated using molecular mechanics and molecular dynamics at a bulk density of 0.89 g cm{sup {minus}3}. Four microstructures formed by cis-1,4-polybutadiene, trans-1,4-polybutadiene, 1,2-polybutadiene, and a random copolymer of the three (55% trans, 35% cis, and 10% vinyl) are analyzed for static free volume. The free volume is determined by hard spherical probes that see the atoms as hard spheres of radii which equal 89% of their van der Waals radii. The total free volume, the free volume distribution, and the shape of the voids are analyzed for all four microstructures. The accessible free volume as a function of the probe size is found to be characteristic of voids in disordered packings of hard spheres. The free volume distributions have some common features across the microstructures. In particular, the free volume distributions as probed by a 1-{angstrom} radius probe show void size concentrations around {approximately}7.5 and 15 {angstrom}{sup 3} (with the exception of trans-polybutadiene, which does not display the latter). The shape factors for all four structures decay to the same asymptotic value of 0.67 {+-} 0.1 over the size range of 0--5 {angstrom}{sup 3}. There is a marked difference in the asphericity and the acylindricity of voids in the four microstructures. Analysis of randomly generated shapes suggests that the voids in the polymer microstructures are mostly elongated in comparison with randomly ``grown`` cavities, probably due to the connectivity of the polymer chains.

  17. An SEM approach to continuous time modeling of panel data: Relating authoritarianism and anomia

    NARCIS (Netherlands)

    Voelkle, M.C.; Oud, J.H.L.; Davidov, E.; Schmidt, P.

    2012-01-01

    [Correction Notice: An Erratum for this article was reported in Vol 17(3) of Psychological Methods (see record 2012-24038-005). The supplemental materials link was missing. All versions of this article have been corrected.] Panel studies, in which the same subjects are repeatedly observed at

  18. Dynamic panel data models and causality : Applications to labor supply, health and insurance

    NARCIS (Netherlands)

    Michaud, P.C.

    2005-01-01

    One of the main findings concerns the importance of common persistent factors, or unobserved traits of respondents, in order to study dynamic relationships between two variables of interest using panel data. The ¿hand of the past¿ can reinforce existent causal relationships, or blur their effect,

  19. Model documentation: Natural Gas Transmission and Distribution Model of the National Energy Modeling System; Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-02-24

    The Natural Gas Transmission and Distribution Model (NGTDM) is a component of the National Energy Modeling System (NEMS) used to represent the domestic natural gas transmission and distribution system. NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the Energy Information Administration (EIA) and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. This report documents the archived version of NGTDM that was used to produce the natural gas forecasts used in support of the Annual Energy Outlook 1994, DOE/EIA-0383(94). The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic design, provides detail on the methodology employed, and describes the model inputs, outputs, and key assumptions. It is intended to fulfill the legal obligation of the EIA to provide adequate documentation in support of its models (Public Law 94-385, Section 57.b.2). This report represents Volume 1 of a two-volume set. (Volume 2 will report on model performance, detailing convergence criteria and properties, results of sensitivity testing, comparison of model outputs with the literature and/or other model results, and major unresolved issues.) Subsequent chapters of this report provide: (1) an overview of the NGTDM (Chapter 2); (2) a description of the interface between the National Energy Modeling System (NEMS) and the NGTDM (Chapter 3); (3) an overview of the solution methodology of the NGTDM (Chapter 4); (4) the solution methodology for the Annual Flow Module (Chapter 5); (5) the solution methodology for the Distributor Tariff Module (Chapter 6); (6) the solution methodology for the Capacity Expansion Module (Chapter 7); (7) the solution methodology for the Pipeline Tariff Module (Chapter 8); and (8) a description of model assumptions, inputs, and outputs (Chapter 9).

  20. The spatial impact of neighbouring on the exports activities of COMESA countries by using spatial panel models

    Science.gov (United States)

    Hamzalouh, L.; Ismail, M. T.; Rahman, R. A.

    2017-09-01

    In this paper, spatial panel models were used and the method for selecting the best model amongst the spatial fixed effects model and the spatial random effects model to estimate the fitting model by using the robust Hausman test for analysis of the exports pattern of the Common Market for Eastern and Southern African (COMESA) countries. And examine the effects of the interactions of the economic statistic of explanatory variables on the exports of the COMESA. Results indicated that the spatial Durbin model with fixed effects specification should be tested and considered in most cases of this study. After that, the direct and indirect effects among COMESA regions were assessed, and the role of indirect spatial effects in estimating exports was empirically demonstrated. Regarding originality and research value, and to the best of the authors’ knowledge, this is the first attempt to examine exports between COMESA and its member countries through spatial panel models using XSMLE, which is a new command for spatial analysis using STATA.

  1. MODEL PERUBAHAN VOLUME KERIPIK BUAH SELAMA PROSES PENGGORENGAN SECARA VAKUM [Model for Volume Changes in Fruit Chips during Vacuum Frying

    Directory of Open Access Journals (Sweden)

    Jamaluddin1*

    2011-06-01

    Full Text Available Expansion and puffing are specific characteristics of fried products critical for consumer preferences. To obtain expanded and puffed dried products that fit well with consumer acceptance criteria, it is necessary to pay attention to the process conditions which change the raw material characteristics during frying. The important changes include volume and density ratio of the products during frying. Hypothetically, these changes are due to water vaporization and the decrease dry matter in the products. The objective of this research is to develop a mathematical model of volume and density ratio changes for jack fruit during vacuum frying as a function of water and starch content reductions. Samples were vacuum fried at 70–100OC and pressure of 80-90 kPa for 15–60 min. The parameters observed were volume and density as well as water and starch contents of samples before and after vacuum frying. The results showed that the developed model can be used to predict changes in volume and density ratio of jack fruit during vacuum frying.

  2. Development of a Murine Model for Aerosolized Ebolavirus Infection Using a Panel of Recombinant Inbred Mice

    Directory of Open Access Journals (Sweden)

    Malak Kotb

    2012-12-01

    two of the three strains.  The two BXD strains that exhibited 90–100% mortality, even at a low dose of airborne MA-EBOV will be useful mouse models for testing vaccines and therapies. Additionally, since disease susceptibility is affected by complex genetic traits, a systems genetics approach was used to identify preliminary gene loci modulating disease severity among the panel BXD strains. Preliminary quantitative trait loci (QTLs were identified that are likely to harbor genes involved in modulating differential susceptibility to Ebola infection.

  3. Estimating the Trade and Welfare Effects of Brexit: A Panel Data Structural Gravity Model

    OpenAIRE

    Oberhofer, Harald; Pfaffermayr, Michael

    2018-01-01

    This paper proposes a new panel data structural gravity approach for estimating the trade and welfare effects of Brexit. The suggested Constrained Poisson Pseudo Maximum Likelihood Estimator exhibits some useful properties for trade policy analysis and allows to obtain estimates and confidence intervals which are consistent with structural trade theory. Assuming different counterfactual post-Brexit scenarios, our main findings suggest that UKs (EUs) exports of goods to the EU (UK) are likely...

  4. Estimating the Trade and Welfare Effects of Brexit: A Panel Data Structural Gravity Model

    OpenAIRE

    Oberhofer, Harald; Pfaffermayr, Michael

    2017-01-01

    This paper proposes a new panel data structural gravity approach for estimating the trade and welfare effects of Brexit. The suggested Constrained Poisson Pseudo Maximum Likelihood Estimator exhibits some useful properties for trade policy analysis and allows to obtain estimates and confidence intervals which are consistent with structural trade theory. Assuming different counterfactual post-Brexit scenarios, our main findings suggest that UKs (EUs) exports of goods to the EU (UK) are likely ...

  5. Numerical optimization,modeling and system evaluation of a thermophotovoltaic hybrid panel

    OpenAIRE

    Greppi, Matteo

    2013-01-01

    Photovoltaic (PV) solar panels generally produce electricity in the 6% to 16% efficiency range, the rest being dissipated in thermal losses. To recover this amount, hybrid photovoltaic thermal systems (PVT) have been devised. These are devices that simultaneously convert solar energy into electricity and heat. It is thus interesting to study the PVT system globally from different point of views in order to evaluate advantages and disadvantages of this technology and its possible uses. In p...

  6. Fuzzy rule-based model for optimum orientation of solar panels using satellite image processing

    International Nuclear Information System (INIS)

    Zaher, A; Thiery, F; Grieu, S; Traoré, A; N’goran, Y

    2017-01-01

    In solar energy converting systems, a particular attention is paid to the orientation of solar collectors in order to optimize the overall system efficiency. In this context, the collectors can be fixed or oriented by a continuous solar tracking system. The proposed approach is based on METEOSAT images processing in order to detect the cloud coverage and its duration. These two parameters are treated by a fuzzy inference system deciding the optimal position of the solar panel. In fact, three weather cases can be considered: clear, partly covered or overcast sky. In the first case, the direct sunlight is more important than the diffuse radiation, thus the panel is always pointed towards the sun. In the overcast case, the solar beam is close to zero and the panel is placed horizontally to receive the diffuse radiation. Under partly covered conditions, the fuzzy inference system decides which of the previous positions is more efficient. The proposed approach is implemented using experimental prototype located in Perpignan (France). On a period of 17 months, the results are very satisfactory, with power gains of up to 23 % compared to the collectors oriented by a continuous solar tracking. (paper)

  7. Fuzzy rule-based model for optimum orientation of solar panels using satellite image processing

    Science.gov (United States)

    Zaher, A.; N'goran, Y.; Thiery, F.; Grieu, S.; Traoré, A.

    2017-01-01

    In solar energy converting systems, a particular attention is paid to the orientation of solar collectors in order to optimize the overall system efficiency. In this context, the collectors can be fixed or oriented by a continuous solar tracking system. The proposed approach is based on METEOSAT images processing in order to detect the cloud coverage and its duration. These two parameters are treated by a fuzzy inference system deciding the optimal position of the solar panel. In fact, three weather cases can be considered: clear, partly covered or overcast sky. In the first case, the direct sunlight is more important than the diffuse radiation, thus the panel is always pointed towards the sun. In the overcast case, the solar beam is close to zero and the panel is placed horizontally to receive the diffuse radiation. Under partly covered conditions, the fuzzy inference system decides which of the previous positions is more efficient. The proposed approach is implemented using experimental prototype located in Perpignan (France). On a period of 17 months, the results are very satisfactory, with power gains of up to 23 % compared to the collectors oriented by a continuous solar tracking.

  8. Transportation and socioeconomic impacts of bypasses on communities : an integrated synthesis of panel data, multilevel, and spatial econometric models with case studies.

    Science.gov (United States)

    2011-09-21

    Title: Transportation and Socioeconomic Impacts of Bypasses on Communities: An Integrated Synthesis of Panel Data, Multilevel, and Spatial Econometric Models with Case Studies. The title used at the start of this project was Transportation and Soc...

  9. Modelling and Simulation of Volume Controlled Mechanical Ventilation System

    Directory of Open Access Journals (Sweden)

    Yan Shi

    2014-01-01

    Full Text Available Volume controlled mechanical ventilation system is a typical time-delay system, which is applied to ventilate patients who cannot breathe adequately on their own. To illustrate the influences of key parameters of the ventilator on the dynamics of the ventilated respiratory system, this paper firstly derived a new mathematical model of the ventilation system; secondly, simulation and experimental results are compared to verify the mathematical model; lastly, the influences of key parameters of ventilator on the dynamics of the ventilated respiratory system are carried out. This study can be helpful in the VCV ventilation treatment and respiratory diagnostics.

  10. Development of modelling and forecasting in geology. (Volume 2)

    International Nuclear Information System (INIS)

    Seguin, J.J.; Fourniguet, J.; Peaudecerf, P.

    1990-01-01

    To access the long-term safety of radioactive waste disposal systems, validation of predictive models is essential and large efforts should be given to barriers, particularly geologic barriers. This work appears in the form of four volumes, the subject of the second part is described below. HERODE (calculation of relief altitude under erosion process from 0 to 100000 years) is a weathering and erosion computerized simulation. The model describes materials and rocks transport and also substratum weathering process. FORTRAN 77 is the software language. 31 figs., 6 tabs., 40 refs

  11. An investigation of a new 2D CDM model in predicting failure in HFQing of an automotive panel

    Directory of Open Access Journals (Sweden)

    Mohamed Mohamed

    2015-01-01

    Full Text Available In this paper a comparative analysis of failure prediction when using the solution heat treatment cold die forming and quenching process, known as HFQTM, for forming an aluminium alloy AA6082 automotive panel part (bulkhead panel, is presented. An experimental programme has been designed and a series of tests have been carried out to investigate the effect of process parameters on the success of forming the complex-shaped automotive panel component using the high strength aluminium alloy. A set of unified viscoplastic plane-stress continuum damage mechanics (2D-CDM constitutive equations was calibrated for AA6082 over a temperature range of 450 ∘C–525 ∘C and strain rates of 0.1, 1.0 and 10 s−1, and then was integrated into the commercial finite element code, LS-DYNA, via a user-defined material subroutine, UMAT, for the forming process simulation. The results show that the CDM model can be used to provide accurate formability and failure predictions.

  12. Comparison of Statistically Modeled Contaminated Soil Volume Estimates and Actual Excavation Volumes at the Maywood FUSRAP Site - 13555

    International Nuclear Information System (INIS)

    Moore, James; Hays, David; Quinn, John; Johnson, Robert; Durham, Lisa

    2013-01-01

    As part of the ongoing remediation process at the Maywood Formerly Utilized Sites Remedial Action Program (FUSRAP) properties, Argonne National Laboratory (Argonne) assisted the U.S. Army Corps of Engineers (USACE) New York District by providing contaminated soil volume estimates for the main site area, much of which is fully or partially remediated. As part of the volume estimation process, an initial conceptual site model (ICSM) was prepared for the entire site that captured existing information (with the exception of soil sampling results) pertinent to the possible location of surface and subsurface contamination above cleanup requirements. This ICSM was based on historical anecdotal information, aerial photographs, and the logs from several hundred soil cores that identified the depth of fill material and the depth to bedrock under the site. Specialized geostatistical software developed by Argonne was used to update the ICSM with historical sampling results and down-hole gamma survey information for hundreds of soil core locations. The updating process yielded both a best guess estimate of contamination volumes and a conservative upper bound on the volume estimate that reflected the estimate's uncertainty. Comparison of model results to actual removed soil volumes was conducted on a parcel-by-parcel basis. Where sampling data density was adequate, the actual volume matched the model's average or best guess results. Where contamination was un-characterized and unknown to the model, the actual volume exceeded the model's conservative estimate. Factors affecting volume estimation were identified to assist in planning further excavations. (authors)

  13. Simplified model and performance analysis for top insulated metal ceiling radiant cooling panels with serpentine tube arrangement

    Directory of Open Access Journals (Sweden)

    Guoqing Yu

    2018-03-01

    Full Text Available This paper develops a simplified model for top insulated metal ceiling radiant cooling panels with serpentine tube arrangement (CRCP-s to predict the mean panel temperature, outlet water temperature and cooling capacity. The simplified model needs no complicated calculation and can be conducted with a calculator. Experiment was conducted for two kinds of CRCP-s, comparisons indicate that the model predicted outlet water temperature and cooling capacity agree well with experiment measured results. The differences between model predicted and experiment measured results are acceptable for most engineering purpose, and the thermal performance analysis were conducted by the model. The results show that: (1 The tube spacing has significant effect on the cooling capacity within the applicable range of tube spacing from 0.05m to 0.3 m; (2 The tube thermal conductivity affect the cooling capacity significantly if it is less than 1.0 W/(m K; (3 The plate thickness has significant effect of the cooling capacity, if the plate thickness is less than 0.5 mm; (4 The water flowrate should be large enough to keep the flow in turbulent regime.

  14. Modeling of deformation phenomena in volume label during its operation

    Directory of Open Access Journals (Sweden)

    Svitlana Sheludko

    2017-06-01

    Full Text Available BIt was considered in the article the research of physical and mechanical properties of materials based on PVC film ORACAL and RITRAMA that used in the production of volume labels. In particular, it was shown the changes of dependences between linear deformation of printed and unprinted films and the value of stress with regard to their minimum and maximum values. It was also established that deformation properties of the films are different in the transverse and longitudinal directions, which should be considered when producing labels. It was conducted the modeling of stress-strain state of volume label when gluing it to the surfaces of various shapes. We considered the boundary conditions for displacement and stress of labels layer components with regard to the chemical structure of epoxy resins and their physical and mechanical characteristics.

  15. Panel 3

    OpenAIRE

    Lin, Jizhen; Hafren, Lena; Kerschner, Joseph; Li, Jian-Dong; Brown, Steve; Zheng, Qing Y.; Preciado, Diego; Nakamura, Yoshihisa; Huang, Qiuhong; Zhang, Yan

    2017-01-01

    Objective. The objective is to perform a comprehensive review of the literature up to 2015 on the genetics and precision medicine relevant to otitis media. Data Sources. PubMed database of the National Library of Medicine. Review Methods. Two subpanels were formed comprising experts in the genetics and precision medicine of otitis media. Each of the panels reviewed the literature in their respective fields and wrote draft reviews. The reviews were shared with all panel members, and a merged d...

  16. Panel Session

    DEFF Research Database (Denmark)

    Bertelsen, Olav Wedege

    2004-01-01

    In this panel session, four researchers will discuss the role of a theoretical foundation, in particular AT, in the design of information technology based artefacts. The general discussion will take of from a specific examination of the ActAD approach.......In this panel session, four researchers will discuss the role of a theoretical foundation, in particular AT, in the design of information technology based artefacts. The general discussion will take of from a specific examination of the ActAD approach....

  17. Modelado y simulación de un panel fotovoltaico empleando técnicas de inteligencia artificial; Modeling and simulation of a photovoltaic panel using artificial intelligence techniques

    Directory of Open Access Journals (Sweden)

    Adalberto Ospino Castro

    2015-04-01

    Full Text Available El trabajo presenta la modelación del comportamiento energético y la determinación de los parámetros del circuito equivalente de un panel fotovoltaico con el empleo de técnicas de inteligencia artificial. Para tal efecto, se desarrolló en Matlab un algoritmo genético que permite obtener los parámetros físicos no brindados por los fabricantes para la implementación de funciones matemáticas que se homologuen al comportamiento dinámico de un panel solar. El algoritmo desarrollado en Matlab permite determinar, además, la eficiencia del algoritmo seguidor del punto de máxima potencia del inversor, el cual es un parámetro de no simple obtención o no determinado en condiciones de campo. Finalmente, el algoritmo se probó satisfactoriamente en un panel solar monocristalino de 50W obteniendo adecuados resultados en comparación con el modelo experimental para diferentes niveles de irradiación solar. Los resultados demuestran que el proceso desarrollado constituye una herramienta que puede ser aplicada a paneles fotovoltaicos en condiciones de campo. The paper presents the modeling of the energy behavior and determination of equivalent circuit parameters for a photovoltaic panel using artificial intelligence techniques. For this purpose, it was performed a genetic algorithm in Matlab, which calculates the physical parameters not provided by manufacturers to implement mathematical functions that approve the dynamic behavior of a solar panel. In addition, the algorithm can determine the efficiency of the maximum power point tracking algorithm of the inverter, which is a parameter of not simple obtaining or not determined under field conditions. Finally, the algorithm was successfully tested in a monocrystalline solar 50W panel with excellent results, compared to the experimental model for different levels of solar irradiation. The results demonstrate that the developed process is a tool that can be applied to photovoltaic panels under

  18. Dynamic modeling of the microalgae cultivation phase for energy production in open raceway ponds and flat panel photobioreactors

    Directory of Open Access Journals (Sweden)

    Matteo eMarsullo

    2015-09-01

    Full Text Available A dynamic model of microalgae cultivation phase is presented in this work. Two cultivation technologies are taken into account: the open raceway pond and the flat panel photobioreactor. For each technology, the model is able to evaluate the microalgae areal and volumetric productivity and the energy production and consumption. Differently from the most common existing models in literature, which deal with a specific part of the overall cultivation process, the model presented here includes all physical and chemical quantities that mostly affect microalgae growth: the equation of the specific growth rate for the microalgae is influenced by CO2 and nutrients concentration in the water, light intensity, temperature of the water in the reactor and by the microalgae species being considered. All these input parameters can be tuned to obtain reliable predictions. A comparison with experimental data taken from the literature shows that the predictions are consistent, slightly overestimating the productivity in case of closed photobioreactor. The results obtained by the simulation runs are consistent with those found in literature, being the areal productivity for the open raceway pond between 50 and 70 t/(ha*year in Southern Spain (Sevilla and Brazil (Petrolina and between 250 and 350 t/(ha*year for the flat panel photobioreactor in the same locations.

  19. EPR-based material modelling of soils considering volume changes

    Science.gov (United States)

    Faramarzi, Asaad; Javadi, Akbar A.; Alani, Amir M.

    2012-11-01

    In this paper an approach is presented for developing material models for soils based on evolutionary polynomial regression (EPR), taking into account its volumetric behaviour. EPR is a recently developed hybrid data mining technique that searches for structured mathematical equations (representing the behaviour of a system) using genetic algorithm and the least squares method. Stress-strain data from triaxial test are used to train and develop EPR-based material models for soil. The developed models are compared with some of the well known conventional material models. In particular, the capability of the developed EPR models in predicting volume change behaviour of soils is illustrated. It is also shown that the developed EPR-based material models can be incorporated in finite element (FE) analysis. Two geotechnical examples are presented to verify the developed EPR-based FE model (EPR-FEM). The results of the EPR-FEM are compared with those of a standard FEM where conventional constitutive models are used to describe the material behaviour. The results show that EPR-FEM can be successfully employed to analyse geotechnical engineering problems. The advantages of the proposed EPR models are highlighted.

  20. Analysis of modeling cumulative noise from simultaneous flights volume 1 : analysis at four national parks

    Science.gov (United States)

    2012-12-31

    This is the first of two volumes of the report on modeling cumulative noise from simultaneous flights. This volume includes: an overview of the time compression algorithms used to model simultaneous aircraft; revised summary of a preliminary study (w...

  1. Assessment of the hybrid propagation model, Volume 1: Analysis of noise propagation effects

    Science.gov (United States)

    2012-08-31

    This is the first of two volumes of a report on the Hybrid Propagation Model (HPM), an advanced prediction model for aviation noise propagation. This volume presents the noise level predictions for eleven different sets of propagation conditions, run...

  2. Modeling of Cementitious Representative Volume Element with Additives

    Science.gov (United States)

    Shahzamanian, M. M.; Basirun, W. J.

    CEMHYD3D has been employed to simulate the representative volume element (RVE) of cementitious systems (Type I cement) containing fly ash (Class F) through a voxel-based finite element analysis (FEA) approach. Three-dimensional microstructures composed of voxels are generated for a heterogeneous cementitious material consisting of various constituent phases. The primary focus is to simulate a cementitious RVE containing fly ash and to present the homogenized macromechanical properties obtained from its analysis. Simple kinematic uniform boundary conditions as well as periodic boundary conditions were imposed on the RVE to obtain the principal and shear moduli. Our current work considers the effect of fly ash percentage on the elastic properties based on the mass and volume replacements. RVEs with lengths of 50, 100 and 200μm at different degrees of hydration are generated, and the elastic properties are modeled and simulated. In general, the elastic properties of a cementitious RVE with fly ash replacement for cement based on mass and volume differ from each other. Moreover, the finite element (FE) mesh density effect is studied. Results indicate that mechanical properties decrease with increasing mesh density.

  3. Homogenization in the Modelling of Volume-Controlled Elastic Structures

    International Nuclear Information System (INIS)

    Russell, David L.

    2007-01-01

    The background for this article is the question of modification of the geometric configuration of an elastic structure by means of 'volume'-type actuation. In this actuation mode stresses are applied to the elastic body by injection/extraction of a fluid into, or from, a large number of vacuoles in the elastic 'matrix' material. Previous articles by the author, and others, have examined this process and studied its effectiveness in the context of a 'naive' continuous model. The present paper develops modified models in the two-dimensional case by applying the 'multiple scales' homogenization method to elastic bodies with increasingly small and numerous vacuoles arranged in a rectangularly periodic structure. The process leads to a modification of the naive model potentially useful in future elastic system control research

  4. Volume Dynamics Propulsion System Modeling for Supersonics Vehicle Research

    Science.gov (United States)

    Kopasakis, George; Connolly, Joseph W.; Paxson, Daniel E.; Ma, Peter

    2010-01-01

    Under the NASA Fundamental Aeronautics Program the Supersonics Project is working to overcome the obstacles to supersonic commercial flight. The proposed vehicles are long slim body aircraft with pronounced aero-servo-elastic modes. These modes can potentially couple with propulsion system dynamics; leading to performance challenges such as aircraft ride quality and stability. Other disturbances upstream of the engine generated from atmospheric wind gusts, angle of attack, and yaw can have similar effects. In addition, for optimal propulsion system performance, normal inlet-engine operations are required to be closer to compressor stall and inlet unstart. To study these phenomena an integrated model is needed that includes both airframe structural dynamics as well as the propulsion system dynamics. This paper covers the propulsion system component volume dynamics modeling of a turbojet engine that will be used for an integrated vehicle Aero-Propulso-Servo-Elastic model and for propulsion efficiency studies.

  5. MODELING OF THERMOELASTIC WAVES IN ROTATING CYLINDRICAL PANEL BY USING MATRIX FROBENIUS METHOD

    Directory of Open Access Journals (Sweden)

    HARJIT SINGH

    2015-07-01

    Full Text Available In this paper, free vibrations are investigated in a homogeneous transversely isotropic, rotating cylindrical panel, in context of the linear theory of thermoelasticity. Three displacement potential functions have been introduced in the equations of motion and heat conduction in order to decouple purely shear and longitudinal motions. The purely transverse wave is not affected by thermal field. By using the method of separation of variables, the system of governing partial differential equations is reduced to four second order coupled ordinary differential equations in radial coordinate. The Matrix Frobenius method of extended power series is employed to obtain the solution in radial direction. The secular equations are obtained by using traction free and thermally insulated boundary conditions. In order to illustrate the analytic results, the numerical solution of various relations and equations has been carried out to compute the lowest frequency, phase velocity, frequency shift and damping factor of vibrations in a rotating cylindrical panel of zinc material with MATLAB software programming. The computer simulated results have been presented graphically.

  6. Development of a type 2 diabetes risk model from a panel of serum biomarkers from the Inter99 cohort

    DEFF Research Database (Denmark)

    Kolberg, Janice A; Jørgensen, Torben; Gerwien, Robert W

    2009-01-01

    of approximately 6,600 Danes in a nested case-control design with the primary outcome of 5-year conversion to type 2 diabetes. Nondiabetic subjects, aged >or=39 years, with BMI >or=25 kg/m(2) at baseline were selected. Baseline fasting serum samples from 160 individuals who developed type 2 diabetes and from 472......OBJECTIVE: The purpose of this study was to develop a model for assessing the 5-year risk of developing type 2 diabetes from a panel of 64 circulating candidate biomarkers. RESEARCH DESIGN AND METHODS: Subjects were selected from the Inter99 cohort, a longitudinal population-based study...... model performance was estimated using a validated bootstrap bias-correction procedure. RESULTS: A model using six biomarkers (adiponectin, C-reactive protein, ferritin, interleukin-2 receptor A, glucose, and insulin) was developed for assessing an individual's 5-year risk of developing type 2 diabetes...

  7. FY 2000 report on the results of the model project on facilities for the effective utilization of industrial waste from industrial complex. Separate Volume 3; 2000 nendo Kogyo danchi sangyo haikibutsu yuko riyo setsubi model jigyo. Dai 3 Bunsatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-03-01

    For the purpose of promoting the effective utilization of industrial waste as petroleum substitution energy resource and reducing the consumption of fossil fuels in Thailand, a model project on facilities for the effective utilization of industrial waste from industrial complex was worked on, and the FY 2000 results were reported. In Separate Volume 3, drawings of the following were included: furnace, free board spray nozzle, dispersion air nozzle, secondary burner, sand make-up conveyor, sand discharge gate, boiler, silencer for boiler safety valve, steam header, steam accumulator, gas cooling tower, refuse drainage storage tank, small sized drainage pump, pressure tank, flue gas duct, air damper, incombustible conveyor 2, sand circulation system bag filter, weighing bridge, fan starter panel, control panel, control panel, local switch box, distributed control system, field instrument, flue gas analyzer. (NEDO)

  8. Integrating model of the Project Independence Evaluation System. Volume IV. Model documentation

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M L; Allen, B J; Gale, J E; Lutz, M S; O& #x27; Hara, N E; Wood, R K

    1979-02-01

    This volume is the fourth in a series of seven documenting the PIES Integrating Model. It contains detailed descriptions of the basic assumptions behind each of the components of PIES and how they interact with one another. Chapter II of this volume presents the methodology used to integrate supply and demand. It includes a discussion of both the interface between the Demand Model and the equilibrating mechanism and the various supply models via the equilibrating algorithm used by PIES. Chapters III through IX describe each supply submodel in turn: coal, oil, and natural gas supply, utilities, refineries, advanced technologies, and transportation. Code and data documentation are covered elsewhere in this series (Volumes V and VI respectively). PIES is an evolving system. As this document was being prepared, many parts of the model were being modified. This document describes the PIES Integrating Model as of January 1, 1978.

  9. Development of modelling and forecasting in geology (Volume 4)

    International Nuclear Information System (INIS)

    Courbouleix, S.; Colleau, A.; Defaut, B.; Fourniguet, J.; Peaudecerf, P.

    1990-01-01

    To access the long-term safety of radioactive waste disposal systems, validation of predictive models is essential and large efforts should be given to barriers, particularly geologic barriers. This work appears in the form of four volumes, the subject of the fourth part is described below. The purpose of this study is to find actual climates which can represent past climates in Europe, during Plio-Quaternary Palynology technics is the most adapted to restore ancient climates. A climatic index, Q n is defined as a function of yearly rainfalls, monthly extreme temperatures and aridity. A climatic diagram is built with climatic index Q n along X axis and a function of the yearly mean temperature along Y axis. This original method can ensure vegetation determination from climate and vice versa. Erosion and Weathering values may be determined after model calibration. 23 figs., 21 refs

  10. Fixed site neutralization model programmer's manual. Volume 1

    International Nuclear Information System (INIS)

    Engi, D.; Chapman, L.; Judnick, W.; Blum, R.; Broegler, L.; Lenz, J.; Weinthraub, A.; Ballard, D.

    1979-12-01

    The Fixed Site Neutralization Model (FSNM) is a stochastic, time-stepped simulation of an engagement process whereby an adversary force attempts to steal or sabotage sensitive (e.g., nuclear) materials being guarded by a security force on a fixed site and a response force that is off-site. FSNM will assist regulatory bodies of the US Government in evaluating fixed site physical protection systems at various installations in a variety of scenarios. Most data input to the Fixed Site Neutralization Model are in binary form. The user's data are transformed into binary form by two supporting modules, the Data Preprocessor (DPP) and the Plex Preprocessor (PPP). Both preprocessors and the FSNM itself are written in FORTRAN. This volume of the program maintenance program contains: introduction, logic descriptions, PLEX data structure, PLEX records, dictionaries, and error conditions and comments

  11. Volume conductor model of transcutaneous electrical stimulation with kilohertz signals

    Science.gov (United States)

    Medina, Leonel E.; Grill, Warren M.

    2014-12-01

    Objective. Incorporating high-frequency components in transcutaneous electrical stimulation (TES) waveforms may make it possible to stimulate deeper nerve fibers since the impedance of tissue declines with increasing frequency. However, the mechanisms of high-frequency TES remain largely unexplored. We investigated the properties of TES with frequencies beyond those typically used in neural stimulation. Approach. We implemented a multilayer volume conductor model including dispersion and capacitive effects, coupled to a cable model of a nerve fiber. We simulated voltage- and current-controlled transcutaneous stimulation, and quantified the effects of frequency on the distribution of potentials and fiber excitation. We also quantified the effects of a novel transdermal amplitude modulated signal (TAMS) consisting of a non-zero offset sinusoidal carrier modulated by a square-pulse train. Main results. The model revealed that high-frequency signals generated larger potentials at depth than did low frequencies, but this did not translate into lower stimulation thresholds. Both TAMS and conventional rectangular pulses activated more superficial fibers in addition to the deeper, target fibers, and at no frequency did we observe an inversion of the strength-distance relationship. Current regulated stimulation was more strongly influenced by fiber depth, whereas voltage regulated stimulation was more strongly influenced by skin thickness. Finally, our model reproduced the threshold-frequency relationship of experimentally measured motor thresholds. Significance. The model may be used for prediction of motor thresholds in TES, and contributes to the understanding of high-frequency TES.

  12. Hepatitis Panel

    Science.gov (United States)

    ... others, the virus can cause long-term, chronic liver disease . Hepatitis C is most often spread by contact with infected ... contact with an infected person. Many people with hepatitis C develop chronic liver disease and cirrhosis . A hepatitis panel includes tests for ...

  13. INTRA/Mod3.2. Manual and Code Description. Volume I - Physical Modelling

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Jenny; Edlund, O.; Hermann, J.; Johansson, Lise-Lotte

    1999-01-01

    The INTRA Manual consists of two volumes. Volume I of the manual is a thorough description of the code INTRA, the Physical modelling of INTRA and the ruling numerical methods and volume II, the User`s Manual is an input description. This document, the Physical modelling of INTRA, contains code characteristics, integration methods and applications

  14. Models for estimation of tree volume in the miombo woodlands of ...

    African Journals Online (AJOL)

    Volume of trees is an important parameter in forest management, but only volume models with limited geographical and tree size coverage have previously been developed for Tanzanian miombo woodlands. This study developed models for estimating total, merchantable stem and branches volume applicable for the entire ...

  15. Modified panel data regression model and its applications to the airline industry: Modeling the load factor of Europe North and Europe Mid Atlantic flights

    Directory of Open Access Journals (Sweden)

    Yohannes Yebabe Tesfay

    2016-08-01

    Full Text Available This article conducts a stochastic analysis on the passenger load factor of the airline industry. Used to measure competence and performance of the airline, load factor is the percentage of seats filled by revenue passengers. It is considered a complex metric in the airline industry. Thus, it is affected by several dynamic factors. This paper applies advanced stochastic models to obtain the best fitted trend of load factor for Europe's North Atlantic (NA and Mid Atlantic (MA flights in the Association of European Airlines. The stochastic model's fit helps to forecast the load factor of flights within these geographical regions and evaluate the airline's demand and capacity management. The paper applies spectral density estimation and dynamic time effects panel data regression models on the monthly load factor flights of NA and MA from 1991 to 2013. The results show that the load factor has both periodic and serial correlations. Consequently, the author acknowledges that the use of an ordinal panel data model is inappropriate for a realistic econometric model of load factor. Therefore, to control the periodic correlation structure, the author modified the existing model was modified by introducing dynamic time effects. Moreover, to eradicate serial correlation, the author applied the Prais–Winsten methodology was applied to fit the model. In this econometric analysis, the study finds that AEA airlines have greater demand and capacity management for both NA and MA flights. In conclusion, this study prosperous in finding an effective and efficient dynamic time effects panel data regression model fit, which empowers engineers to forecast the load factor off AEA airlines.

  16. Matlab Software for Spatial Panels

    NARCIS (Netherlands)

    Elhorst, J.Paul

    2014-01-01

    Elhorst provides Matlab routines to estimate spatial panel data models at his website. This article extends these routines to include the bias correction procedure proposed by Lee and Yu if the spatial panel data model contains spatial and/or time-period fixed effects, the direct and indirect

  17. Panel 5: Microbiology and immunology panel.

    Science.gov (United States)

    Murphy, Timothy F; Chonmaitree, Tasnee; Barenkamp, Stephen; Kyd, Jennelle; Nokso-Koivisto, Johanna; Patel, Janak A; Heikkinen, Terho; Yamanaka, Noboru; Ogra, Pearay; Swords, W Edward; Sih, Tania; Pettigrew, Melinda M

    2013-04-01

    The objective is to perform a comprehensive review of the literature from January 2007 through June 2011 on the virology, bacteriology, and immunology related to otitis media. PubMed database of the National Library of Medicine. Three subpanels with co-chairs comprising experts in the virology, bacteriology, and immunology of otitis media were formed. Each of the panels reviewed the literature in their respective fields and wrote draft reviews. The reviews were shared with all panel members, and a second draft was created. The entire panel met at the 10th International Symposium on Recent Advances in Otitis Media in June 2011 and discussed the review and refined the content further. A final draft was created, circulated, and approved by the panel. Excellent progress has been made in the past 4 years in advancing an understanding of the microbiology and immunology of otitis media. Advances include laboratory-based basic studies, cell-based assays, work in animal models, and clinical studies. The advances of the past 4 years formed the basis of a series of short-term and long-term research goals in an effort to guide the field. Accomplishing these goals will provide opportunities for the development of novel interventions, including new ways to better treat and prevent otitis media.

  18. Panel 5: Microbiology and Immunology Panel

    Science.gov (United States)

    Murphy, Timothy F.; Chonmaitree, Tasnee; Barenkamp, Stephen; Kyd, Jennelle; Nokso-Koivisto, Johanna; Patel, Janak A.; Heikkinen, Terho; Yamanaka, Noboru; Ogra, Pearay; Swords, W. Edward; Sih, Tania; Pettigrew, Melinda M.

    2014-01-01

    Objective The objective is to perform a comprehensive review of the literature from January 2007 through June 2011 on the virology, bacteriology, and immunology related to otitis media. Data Sources PubMed database of the National Library of Medicine. Review Methods Three subpanels with co-chairs comprising experts in the virology, bacteriology, and immunology of otitis media were formed. Each of the panels reviewed the literature in their respective fields and wrote draft reviews. The reviews were shared with all panel members, and a second draft was created. The entire panel met at the 10th International Symposium on Recent Advances in Otitis Media in June 2011 and discussed the review and refined the content further. A final draft was created, circulated, and approved by the panel. Conclusion Excellent progress has been made in the past 4 years in advancing an understanding of the microbiology and immunology of otitis media. Advances include laboratory-based basic studies, cell-based assays, work in animal models, and clinical studies. Implications for Practice The advances of the past 4 years formed the basis of a series of short-term and long-term research goals in an effort to guide the field. Accomplishing these goals will provide opportunities for the development of novel interventions, including new ways to better treat and prevent otitis media. PMID:23536533

  19. Development of modelling and forecasting in geology. (Volume 1)

    International Nuclear Information System (INIS)

    Afzali, H.; Fourniguet, J.; Peaudecerf, P.

    1990-01-01

    To assess the long-term safety of radioactive waste disposal systems, validation of predictive models is essential and large efforts should be given to barriers, particularly geologic barriers. This work appears in the form of four volumes, the subject of the first part is described below. Soils and rocks erosion depends upon climate, relief, lithology and human activities (deforesting). In the world, mechanical erosion is evaluated from 5 to 8 cm per 1000 years (mean denudation ratio). Rocks weathering solubilize chemical elements in the running water and rocks fracturation becomes more easily under erosion effects. Alteration front progress is 0.3-3 cm per 1000 years in temperate zones and 4-7 cm per 1000 years in tropical zones. 5 figs., 14 tabs., 80 refs

  20. Ammunition Resupply Model. Volume 2. Programmer’s Manual.

    Science.gov (United States)

    1983-05-01

    database for the ARM model (see volume I for the array definitions): COMMON/LOG/IATP(lO,53), IASP (lO,lIO), IUNIT(75,142), Z ITRUCK(1400,15), ITYPE(9,6), IMIX...from either the ATP or the ASP. C NASP The ASP number from the IASP array. (..6) C NATP The ATP rumber from the IATP array. (1..6) C ND ) The number of...TTLOAD C**Z2 DECREMENT AMMO AVAILABLE SO0 CONTINUE IASP (NASP9NUMAM*37+1B) = IASP (NASPYNUMAMt3+19) - MIX(MIXPNUMAM) IF7IASP(NASPiNUMAHM*3+1S).LT, 0

  1. Alligator Rivers Analogue project. Hydrogeological modelling. Final Report - Volume 6

    Energy Technology Data Exchange (ETDEWEB)

    Townley, L.R.; Trefry, M.G.; Barr, A.D. [CSIRO Div of Water Resources, PO Wembley, WA (Australia); Braumiller, S. [Univ of Arizona, Tucson, AZ (United States). Dept of Hydrology and Water Resources; Kawanishi, M. [Central Research Institute of Electric Power Industry, Abiko-Shi, Chiba-Ken (Japan)] [and others

    1992-12-31

    This volume describes hydrogeological modelling carried out as part of the Alligator Rivers Analogue Project. Hydrogeology has played a key integrating role in the Project, largely because water movement is believed to have controlled the evolution of the Koongarra uranium Orebody and therefore affects field observations of all types at all scales. Aquifer testing described uses the concept of transmissivity in its interpretation of aquifer response to pumping. The concept of an aquifer, a layer transmitting significant quantities of water in a mainly horizontal direction, seems hard to accept in an environment as heterogeneous as that at Koongarra. But modelling of aquifers both in one dimension and two dimensionally in plan has contributed significantly to our understanding of the site. A one-dimensional model with three layers (often described as a quasi two dimensional model) was applied to flow between the Fault and Koongarra Creek. Being a transient model, this model was able to show that reverse flows can indeed occur back towards the Fault, but only if there is distributed recharge over the orebody as well as a mechanism for the Fault, or a region near the Fault, to remove water from the simulated cross-section. The model also showed clearly that the response of the three-layered system, consisting of a highly weathered zone, a fractured transmissive zone and a less conductive lower schist zone, is governed mainly by the transmissivity and storage coefficient of the middle layer. The storage coefficient of the higher layer has little effect. A two-dimensional model in plan used a description of anisotropy to show that reverse flows can also occur even without a conducting Fault. Modelling of a three-dimensional region using discrete fractures showed that it is certainly possible to simulate systems like that observed at Koongarra, but that large amounts of data are probably needed to obtain realistic descriptions of the fracture networks. Inverse modelling

  2. Alligator Rivers Analogue project. Hydrogeological modelling. Final Report - Volume 6

    International Nuclear Information System (INIS)

    Townley, L.R.; Trefry, M.G.; Barr, A.D.; Braumiller, S.

    1992-01-01

    This volume describes hydrogeological modelling carried out as part of the Alligator Rivers Analogue Project. Hydrogeology has played a key integrating role in the Project, largely because water movement is believed to have controlled the evolution of the Koongarra uranium Orebody and therefore affects field observations of all types at all scales. Aquifer testing described uses the concept of transmissivity in its interpretation of aquifer response to pumping. The concept of an aquifer, a layer transmitting significant quantities of water in a mainly horizontal direction, seems hard to accept in an environment as heterogeneous as that at Koongarra. But modelling of aquifers both in one dimension and two dimensionally in plan has contributed significantly to our understanding of the site. A one-dimensional model with three layers (often described as a quasi two dimensional model) was applied to flow between the Fault and Koongarra Creek. Being a transient model, this model was able to show that reverse flows can indeed occur back towards the Fault, but only if there is distributed recharge over the orebody as well as a mechanism for the Fault, or a region near the Fault, to remove water from the simulated cross-section. The model also showed clearly that the response of the three-layered system, consisting of a highly weathered zone, a fractured transmissive zone and a less conductive lower schist zone, is governed mainly by the transmissivity and storage coefficient of the middle layer. The storage coefficient of the higher layer has little effect. A two-dimensional model in plan used a description of anisotropy to show that reverse flows can also occur even without a conducting Fault. Modelling of a three-dimensional region using discrete fractures showed that it is certainly possible to simulate systems like that observed at Koongarra, but that large amounts of data are probably needed to obtain realistic descriptions of the fracture networks. Inverse modelling

  3. Modeled Urea Distribution Volume and Mortality in the HEMO Study

    Science.gov (United States)

    Greene, Tom; Depner, Thomas A.; Levin, Nathan W.; Chertow, Glenn M.

    2011-01-01

    Summary Background and objectives In the Hemodialysis (HEMO) Study, observed small decreases in achieved equilibrated Kt/Vurea were noncausally associated with markedly increased mortality. Here we examine the association of mortality with modeled volume (Vm), the denominator of equilibrated Kt/Vurea. Design, setting, participants, & measurements Parameters derived from modeled urea kinetics (including Vm) and blood pressure (BP) were obtained monthly in 1846 patients. Case mix–adjusted time-dependent Cox regressions were used to relate the relative mortality hazard at each time point to Vm and to the change in Vm over the preceding 6 months. Mixed effects models were used to relate Vm to changes in intradialytic systolic BP and to other factors at each follow-up visit. Results Mortality was associated with Vm and change in Vm over the preceding 6 months. The association between change in Vm and mortality was independent of vascular access complications. In contrast, mortality was inversely associated with V calculated from anthropometric measurements (Vant). In case mix–adjusted analysis using Vm as a time-dependent covariate, the association of mortality with Vm strengthened after statistical adjustment for Vant. After adjustment for Vant, higher Vm was associated with slightly smaller reductions in intradialytic systolic BP and with risk factors for mortality including recent hospitalization and reductions in serum albumin concentration and body weight. Conclusions An increase in Vm is a marker for illness and mortality risk in hemodialysis patients. PMID:21511841

  4. Transportation Sector Model of the National Energy Modeling System. Volume 2 -- Appendices: Part 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This volume contains input data and parameters used in the model of the transportation sector of the National Energy Modeling System. The list of Transportation Sector Model variables includes parameters for the following: Light duty vehicle modules (fuel economy, regional sales, alternative fuel vehicles); Light duty vehicle stock modules; Light duty vehicle fleet module; Air travel module (demand model and fleet efficiency model); Freight transport module; Miscellaneous energy demand module; and Transportation emissions module. Also included in these appendices are: Light duty vehicle market classes; Maximum light duty vehicle market penetration parameters; Aircraft fleet efficiency model adjustment factors; and List of expected aircraft technology improvements.

  5. Modelling drug-related morbidity in Sweden using an expert panel of physicians

    OpenAIRE

    Hakkarainen, Katja M; Alström, Daniel; Hägg, Staffan; Carlsten, Anders; Gyllensten, Hanna

    2012-01-01

    PURPOSE: In modelling studies using pharmacists' opinions, drug-related morbidity (DRM) and preventable DRM have been more common than in observational studies, and the resulting costs are extensive. Modelling studies' estimates may vary depending on informants' profession. The purpose of this modelling study was to estimate the proportion of patients with DRM and preventable DRM and the cost of illness (COI) of DRM in Sweden based on physicians' expert opinions. METHOD: A conceptual model of...

  6. An investigation of a new 2D CDM model in predicting failure in HFQing of an automotive panel

    OpenAIRE

    Mohamed, M; Li, N; Wang, L; El Fakir, O; Lin, J; Dean, T; Dear, J

    2015-01-01

    In this paper a comparative analysis of failure prediction when using the solution heat treatment cold die forming and quenching process, known as HFQTM, for forming an aluminium alloy AA6082 automotive panel part (bulkhead panel), is presented. An experimental programme has been designed and a series of tests have been carried out to investigate the effect of process parameters on the success of forming the complex-shaped automotive panel component using the high strength aluminium alloy. A ...

  7. Theoretical modeling of molar volume and thermal expansion

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiaogang [Department of Materials Science and Engineering, Royal Institute of Technology, 100 44 Stockholm (Sweden)]. E-mail: gang@mse.kth.se; Selleby, Malin [Department of Materials Science and Engineering, Royal Institute of Technology, 100 44 Stockholm (Sweden); Sundman, Bo [Department of Materials Science and Engineering, Royal Institute of Technology, 100 44 Stockholm (Sweden)

    2005-05-15

    The molar volumes and thermal expansions of transition cubic metals were studied by means of the Calphad approach and the Debye-Grueneisen model. Experimental data were collected and assessed using Calphad procedures, and consistent results were obtained which give the best description of all experimental data. In order to put the prediction of the thermodynamic properties of metastable phases on a sound physical basis, the Debye-Grueneisen model was chosen to account for the vibrational contribution and calculate the coefficients of linear thermal expansion (CLEs) of stable cubic metals. Two approximations for Grueneisen parameter {gamma}, i.e. Slater's and Dugdale and MacDonald's expressions were adopted. A modified calculation scheme, first proposed by Wang et al., was derived in a straightforward way and used to evaluate the Debye temperature from ab initio electronic total-energy calculations at T = 0 K. The thermal electronic contribution to CLE was also evaluated from the electronic density of states. The calculated total CLEs were compared with those from the Calphad assessments. A satisfactory agreement is reached.

  8. Theoretical modeling of molar volume and thermal expansion

    International Nuclear Information System (INIS)

    Lu Xiaogang; Selleby, Malin; Sundman, Bo

    2005-01-01

    The molar volumes and thermal expansions of transition cubic metals were studied by means of the Calphad approach and the Debye-Grueneisen model. Experimental data were collected and assessed using Calphad procedures, and consistent results were obtained which give the best description of all experimental data. In order to put the prediction of the thermodynamic properties of metastable phases on a sound physical basis, the Debye-Grueneisen model was chosen to account for the vibrational contribution and calculate the coefficients of linear thermal expansion (CLEs) of stable cubic metals. Two approximations for Grueneisen parameter γ, i.e. Slater's and Dugdale and MacDonald's expressions were adopted. A modified calculation scheme, first proposed by Wang et al., was derived in a straightforward way and used to evaluate the Debye temperature from ab initio electronic total-energy calculations at T = 0 K. The thermal electronic contribution to CLE was also evaluated from the electronic density of states. The calculated total CLEs were compared with those from the Calphad assessments. A satisfactory agreement is reached

  9. The Latent Curve ARMA (P, Q) Panel Model: Longitudinal Data Analysis in Educational Research and Evaluation

    Science.gov (United States)

    Sivo, Stephen; Fan, Xitao

    2008-01-01

    Autocorrelated residuals in longitudinal data are widely reported as common to longitudinal data. Yet few, if any, researchers modeling growth processes evaluate a priori whether their data have this feature. Sivo, Fan, and Witta (2005) found that not modeling autocorrelated residuals present in longitudinal data severely biases latent curve…

  10. A two-dimensional iterative panel method and boundary layer model for bio-inspired multi-body wings

    Science.gov (United States)

    Blower, Christopher J.; Dhruv, Akash; Wickenheiser, Adam M.

    2014-03-01

    The increased use of Unmanned Aerial Vehicles (UAVs) has created a continuous demand for improved flight capabilities and range of use. During the last decade, engineers have turned to bio-inspiration for new and innovative flow control methods for gust alleviation, maneuverability, and stability improvement using morphing aircraft wings. The bio-inspired wing design considered in this study mimics the flow manipulation techniques performed by birds to extend the operating envelope of UAVs through the installation of an array of feather-like panels across the airfoil's upper and lower surfaces while replacing the trailing edge flap. Each flap has the ability to deflect into both the airfoil and the inbound airflow using hinge points with a single degree-of-freedom, situated at 20%, 40%, 60% and 80% of the chord. The installation of the surface flaps offers configurations that enable advantageous maneuvers while alleviating gust disturbances. Due to the number of possible permutations available for the flap configurations, an iterative constant-strength doublet/source panel method has been developed with an integrated boundary layer model to calculate the pressure distribution and viscous drag over the wing's surface. As a result, the lift, drag and moment coefficients for each airfoil configuration can be calculated. The flight coefficients of this numerical method are validated using experimental data from a low speed suction wind tunnel operating at a Reynolds Number 300,000. This method enables the aerodynamic assessment of a morphing wing profile to be performed accurately and efficiently in comparison to Computational Fluid Dynamics methods and experiments as discussed herein.

  11. Panel C report: Standards needed for the use of ISO Open Systems Interconnection - basic reference model

    Science.gov (United States)

    1981-01-01

    The use of an International Standards Organization (ISO) Open Systems Interconnection (OSI) Reference Model and its relevance to interconnecting an Applications Data Service (ADS) pilot program for data sharing is discussed. A top level mapping between the conjectured ADS requirements and identified layers within the OSI Reference Model was performed. It was concluded that the OSI model represents an orderly architecture for the ADS networking planning and that the protocols being developed by the National Bureau of Standards offer the best available implementation approach.

  12. Simple, Inexpensive Model Spirometer for Understanding Ventilation Volumes

    Science.gov (United States)

    Giuliodori, Mauricio J.; DiCarlo, Stephen E.

    2004-01-01

    Spirometers are useful for enhancing students' understanding of normal lung volumes, capacities, and flow rates. Spirometers are also excellent for understanding how lung diseases alter ventilation volumes. However, spirometers are expensive, complex, and not appropriate for programs with limited space and budgets. Therefore, we developed a…

  13. Development and validation of stem volume models for Pinus kesiya ...

    African Journals Online (AJOL)

    Stem volume equations (overbark) were developed, using established volume equation forms, and validated using a subset of the data collected for Pinus kesiya in Benguet province, Philippines. A total of 481 trees from Pinus kesiya stands in Benguet were measured through non-destructive sampling. The data set was ...

  14. Stem biomass and volume models of selected tropical tree species ...

    African Journals Online (AJOL)

    Estimating tree volume and biomass constitutes an essential part of the forest resources assessment and the evaluation of the climate change mitigation potential of forests through biomass accumulation and carbon sequestration. This research article provides stem volume and biomass equations applicable to five tree ...

  15. The dynamic and indirect spatial effects of neighborhood conditions on land value, spatial panel dynamic econometrics model

    Science.gov (United States)

    Fitriani, Rahma; Sumarminingsih, Eni; Astutik, Suci

    2017-05-01

    Land value is the product of past decision of its use leading to its value, as well as the value of the surrounded land. It is also affected by the local characteristic and the spillover development demand of the previous time period. The effect of each factor on land value will have dynamic and spatial virtues. Thus, a spatial panel dynamic model is used to estimate the particular effects. The model will be useful for predicting the future land value or the effect of implemented policy on land value. The objective of this paper is to derive the dynamic and indirect spatial marginal effects of the land characteristic and the spillover development demand on land value. Each effect is the partial derivative of the expected land value based on the spatial dynamic model with respect to each variable, by considering different time period and different location. The results indicate that the instant change of local or neighborhood characteristics on land value affect the local and the immediate neighborhood land value. However, the longer the change take place, the effect will spread further, not only on the immediate neighborhood.

  16. Modeling individual exposures to ambient PM2.5 in the diabetes and the environment panel study (DEPS).

    Science.gov (United States)

    Breen, Michael; Xu, Yadong; Schneider, Alexandra; Williams, Ronald; Devlin, Robert

    2018-06-01

    Air pollution epidemiology studies of ambient fine particulate matter (PM 2.5 ) often use outdoor concentrations as exposure surrogates, which can induce exposure error. The goal of this study was to improve ambient PM 2.5 exposure assessments for a repeated measurements study with 22 diabetic individuals in central North Carolina called the Diabetes and Environment Panel Study (DEPS) by applying the Exposure Model for Individuals (EMI), which predicts five tiers of individual-level exposure metrics for ambient PM 2.5 using outdoor concentrations, questionnaires, weather, and time-location information. Using EMI, we linked a mechanistic air exchange rate (AER) model to a mass-balance PM 2.5 infiltration model to predict residential AER (Tier 1), infiltration factors (F inf_home , Tier 2), indoor concentrations (C in , Tier 3), personal exposure factors (F pex , Tier 4), and personal exposures (E, Tier 5) for ambient PM 2.5 . We applied EMI to predict daily PM 2.5 exposure metrics (Tiers 1-5) for 174 participant-days across the 13 months of DEPS. Individual model predictions were compared to a subset of daily measurements of F pex and E (Tiers 4-5) from the DEPS participants. Model-predicted F pex and E corresponded well to daily measurements with a median difference of 14% and 23%; respectively. Daily model predictions for all 174 days showed considerable temporal and house-to-house variability of AER, F inf_home , and C in (Tiers 1-3), and person-to-person variability of F pex and E (Tiers 4-5). Our study demonstrates the capability of predicting individual-level ambient PM 2.5 exposure metrics for an epidemiological study, in support of improving risk estimation. Copyright © 2018. Published by Elsevier B.V.

  17. Panel 4: Recent advances in otitis media in molecular biology, biochemistry, genetics, and animal models.

    Science.gov (United States)

    Li, Jian-Dong; Hermansson, Ann; Ryan, Allen F; Bakaletz, Lauren O; Brown, Steve D; Cheeseman, Michael T; Juhn, Steven K; Jung, Timothy T K; Lim, David J; Lim, Jae Hyang; Lin, Jizhen; Moon, Sung-Kyun; Post, J Christopher

    2013-04-01

    Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating OM based on full understanding of molecular pathogenesis in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. To provide a state-of-the-art review concerning recent advances in OM in the areas of molecular biology, biochemistry, genetics, and animal model studies and to discuss the future directions of OM studies in these areas. A structured search of the current literature (since June 2007). The authors searched PubMed for published literature in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Over the past 4 years, significant progress has been made in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. These studies brought new insights into our understanding of the molecular and biochemical mechanisms underlying the molecular pathogenesis of OM and helped identify novel therapeutic targets for OM. Our understanding of the molecular pathogenesis of OM has been significantly advanced, particularly in the areas of inflammation, innate immunity, mucus overproduction, mucosal hyperplasia, middle ear and inner ear interaction, genetics, genome sequencing, and animal model studies. Although these studies are still in their experimental stages, they help identify new potential therapeutic targets. Future preclinical and clinical studies will help to translate these exciting experimental research findings into clinical applications.

  18. Grounds of two positions photovoltaic panels

    OpenAIRE

    Castán Fortuño, Fernando

    2008-01-01

    The objective of this Master Thesis is to find the optimum positioning for a two positions photovoltaic panel. Hence, it will be implemented a model in order to optimize the energy of the sun that the photovoltaic panel is receiving by its positioning. Likewise this project will include the comparison with other photovoltaic panel systems as the single position photovoltaics panels. Ultimately, it is also going to be designed a system array for the optimized model of two positions photovoltai...

  19. Panel 4: Report of the Microbiology Panel.

    Science.gov (United States)

    Barenkamp, Stephen J; Chonmaitree, Tasnee; Hakansson, Anders P; Heikkinen, Terho; King, Samantha; Nokso-Koivisto, Johanna; Novotny, Laura A; Patel, Janak A; Pettigrew, Melinda; Swords, W Edward

    2017-04-01

    Objective To perform a comprehensive review of the literature from July 2011 until June 2015 on the virology and bacteriology of otitis media in children. Data Sources PubMed database of the National Library of Medicine. Review Methods Two subpanels comprising experts in the virology and bacteriology of otitis media were created. Each panel reviewed the relevant literature in the fields of virology and bacteriology and generated draft reviews. These initial reviews were distributed to all panel members prior to meeting together at the Post-symposium Research Conference of the 18th International Symposium on Recent Advances in Otitis Media, National Harbor, Maryland, in June 2015. A final draft was created, circulated, and approved by all panel members. Conclusions Excellent progress has been made in the past 4 years in advancing our understanding of the microbiology of otitis media. Numerous advances were made in basic laboratory studies, in animal models of otitis media, in better understanding the epidemiology of disease, and in clinical practice. Implications for Practice (1) Many viruses cause acute otitis media without bacterial coinfection, and such cases do not require antibiotic treatment. (2) When respiratory syncytial virus, metapneumovirus, and influenza virus peak in the community, practitioners can expect to see an increase in clinical otitis media cases. (3) Biomarkers that predict which children with upper respiratory tract infections will develop otitis media may be available in the future. (4) Compounds that target newly identified bacterial virulence determinants may be available as future treatment options for children with otitis media.

  20. An SEM approach to continuous time modeling of panel data: Relating authoritarianism and anomia: Correction to Voelkle, Oud, Davidov, and Schmidt

    NARCIS (Netherlands)

    Voelkle, M.C.; Oud, J.H.L.; Davidov, E.; Schmidt, P.

    2012-01-01

    Reports an error in "An SEM approach to continuous time modeling of panel data: Relating authoritarianism and anomia" by Manuel C. Voelkle, Johan H. L. Oud, Eldad Davidov and Peter Schmidt (Psychological Methods, 2012[Jun], Vol 17[2], 176-192). The supplemental materials link was missing. All

  1. Reciprocal Effects between Intrinsic Reading Motivation and Reading Competence? A Cross-Lagged Panel Model for Academic Track and Nonacademic Track Students

    Science.gov (United States)

    Schaffner, Ellen; Philipp, Maik; Schiefele, Ulrich

    2016-01-01

    Previous research has demonstrated positive relations between intrinsic reading motivation and reading competence. However, the causal direction of these relations and the moderating role of relevant background variables (e.g., students' achievement level) are not well understood. In the present study, a cross-lagged panel model was applied to…

  2. A smoothed maximum score estimator for the binary choice panel data model with individual fixed effects and applications to labour force participation

    NARCIS (Netherlands)

    Charlier, G.W.P.

    1994-01-01

    In a binary choice panel data model with individual effects and two time periods, Manski proposed the maximum score estimator, based on a discontinuous objective function, and proved its consistency under weak distributional assumptions. However, the rate of convergence of this estimator is low (N)

  3. Panel 4: Recent Advances in Otitis Media in Molecular Biology, Biochemistry, Genetics, and Animal Models

    Science.gov (United States)

    Li, Jian-Dong; Hermansson, Ann; Ryan, Allen F.; Bakaletz, Lauren O.; Brown, Steve D.; Cheeseman, Michael T.; Juhn, Steven K.; Jung, Timothy T. K.; Lim, David J.; Lim, Jae Hyang; Lin, Jizhen; Moon, Sung-Kyun; Post, J. Christopher

    2014-01-01

    Background Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating OM based on full understanding of molecular pathogenesis in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Objective To provide a state-of-the-art review concerning recent advances in OM in the areas of molecular biology, biochemistry, genetics, and animal model studies and to discuss the future directions of OM studies in these areas. Data Sources and Review Methods A structured search of the current literature (since June 2007). The authors searched PubMed for published literature in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. Results Over the past 4 years, significant progress has been made in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. These studies brought new insights into our understanding of the molecular and biochemical mechanisms underlying the molecular pathogenesis of OM and helped identify novel therapeutic targets for OM. Conclusions and Implications for Practice Our understanding of the molecular pathogenesis of OM has been significantly advanced, particularly in the areas of inflammation, innate immunity, mucus overproduction, mucosal hyperplasia, middle ear and inner ear interaction, genetics, genome sequencing, and animal model studies. Although these studies are still in their experimental stages, they help identify new potential therapeutic targets. Future preclinical and clinical studies will help to translate these exciting experimental research findings into clinical applications. PMID:23536532

  4. Quantification of landfill methane using modified Intergovernmental Panel on Climate Change's waste model and error function analysis.

    Science.gov (United States)

    Govindan, Siva Shangari; Agamuthu, P

    2014-10-01

    Waste management can be regarded as a cross-cutting environmental 'mega-issue'. Sound waste management practices support the provision of basic needs for general health, such as clean air, clean water and safe supply of food. In addition, climate change mitigation efforts can be achieved through reduction of greenhouse gas emissions from waste management operations, such as landfills. Landfills generate landfill gas, especially methane, as a result of anaerobic degradation of the degradable components of municipal solid waste. Evaluating the mode of generation and collection of landfill gas has posted a challenge over time. Scientifically, landfill gas generation rates are presently estimated using numerical models. In this study the Intergovernmental Panel on Climate Change's Waste Model is used to estimate the methane generated from a Malaysian sanitary landfill. Key parameters of the model, which are the decay rate and degradable organic carbon, are analysed in two different approaches; the bulk waste approach and waste composition approach. The model is later validated using error function analysis and optimum decay rate, and degradable organic carbon for both approaches were also obtained. The best fitting values for the bulk waste approach are a decay rate of 0.08 y(-1) and degradable organic carbon value of 0.12; and for the waste composition approach the decay rate was found to be 0.09 y(-1) and degradable organic carbon value of 0.08. From this validation exercise, the estimated error was reduced by 81% and 69% for the bulk waste and waste composition approach, respectively. In conclusion, this type of modelling could constitute a sensible starting point for landfills to introduce careful planning for efficient gas recovery in individual landfills. © The Author(s) 2014.

  5. Physical activity and fatigue in breast cancer survivors: a panel model examining the role of self-efficacy and depression.

    Science.gov (United States)

    Phillips, Siobhan M; McAuley, Edward

    2013-05-01

    Physical activity is associated with reductions in fatigue in breast cancer survivors. However, mechanisms underlying this relationship are not well-understood. The purpose of this study was to longitudinally test a model examining the role of self-efficacy and depression as potential mediators of the relationship between physical activity and fatigue in a sample of breast cancer survivors using both self-report and objective measures of physical activity. All participants (N = 1,527) completed self-report measures of physical activity, self-efficacy, depression, and fatigue at baseline and 6 months. A subsample was randomly selected to wear an accelerometer at both time points. It was hypothesized that physical activity indirectly influences fatigue via self-efficacy and depression. Relationships among model constructs were examined over the 6-month period using panel analysis within a covariance modeling framework. The hypothesized model provided a good model-data fit (χ(2) = 599.66, df = 105, P ≤ 0.001; CFI = 0.96; SRMR = 0.02) in the full sample when controlling for covariates. At baseline, physical activity indirectly influenced fatigue via self-efficacy and depression. These relationships were also supported across time. In addition, the majority of the hypothesized relationships were supported in the subsample with accelerometer data (χ(2) = 387.48, df = 147, P ≤ 0.001, CFI = 0.94, SRMR = 0.04). This study provides evidence to suggest the relationship between physical activity and fatigue in breast cancer survivors may be mediated by more proximal, modifiable outcomes of physical activity participation. Recommendations are made relative to future applications and research concerning these relationships.

  6. Damping Enhancement of Composite Panels by Inclusion of Shunted Piezoelectric Patches: A Wave-Based Modelling Approach

    Directory of Open Access Journals (Sweden)

    Dimitrios Chronopoulos

    2015-02-01

    Full Text Available The waves propagating within complex smart structures are hereby computed by employing a wave and finite element method. The structures can be of arbitrary layering and of complex geometric characteristics as long as they exhibit two-dimensional periodicity. The piezoelectric coupling phenomena are considered within the finite element formulation. The mass, stiffness and piezoelectric stiffness matrices of the modelled segment can be extracted using a conventional finite element code. The post-processing of these matrices involves the formulation of an eigenproblem whose solutions provide the phase velocities for each wave propagating within the structure and for any chosen direction of propagation. The model is then modified in order to account for a shunted piezoelectric patch connected to the composite structure. The impact of the energy dissipation induced by the shunted circuit on the total damping loss factor of the composite panel is then computed. The influence of the additional mass and stiffness provided by the attached piezoelectric devices on the wave propagation characteristics of the structure is also investigated.

  7. Association between Sleep and Body Weight: A Panel Data Model Based on a Retrospective Longitudinal Cohort of Chinese Infants

    Directory of Open Access Journals (Sweden)

    Tingting Sha

    2017-04-01

    Full Text Available The focus of this article is on sleep duration and sleep problems in infants and their association with body weight. A retrospective birth cohort of 519 infants was enrolled in a community-based study conducted in Changsha, China. Infant weight and other health-related information were collected during regular standard checkups at the Community Health Service Centers when infants were 1, 3, 6, 8, and 12 months old. The sleep duration and sleep problems of infants were assessed by maternal self-reports. Panel data model was used to evaluate the association of sleep duration and sleep problems with infant body weight. Significant relevance between self-reported sleep duration and weight of infants has been reported in the literature tested by the fixed effects model (p < 0.01. However, this study indicated that sleep problems of infants had no effect on their weight (p = 0.151, after adjusting feeding patterns and socioeconomic factors of their families. This paper argues that, as a potentially modifiable risk factor, infant sleep duration deserves more attention from their parents and families in order to prevent and control overweight or obesity in infants as well as reducing the incidence of obesity in adults.

  8. On the Efficacy of PCM to Shave Peak Temperature of Crystalline Photovoltaic Panels: An FDM Model and Field Validation

    Directory of Open Access Journals (Sweden)

    Valerio Lo Brano

    2013-11-01

    Full Text Available The exploitation of renewable energy sources and specifically photovoltaic (PV devices have been showing significant growth; however, for a more effective development of this technology it is essential to have higher energy conversion performances. PV producers often declare a higher efficiency respect to real conditions and this deviation is mainly due to the difference between nominal and real temperature conditions of the PV. In order to improve the solar cell energy conversion efficiency many authors have proposed a methodology to keep the temperature of a PV system lower: a modified crystalline PV system built with a normal PV panel coupled with a Phase Change Material (PCM heat storage device. In this paper a thermal model analysis of the crystalline PV-PCM system based on a theoretical study using finite difference approach is described. The authors developed an algorithm based on an explicit finite difference formulation of energy balance of the crystalline PV-PCM system. Two sets of recursive equations were developed for two types of spatial domains: a boundary domain and an internal domain. The reliability of the developed model is tested by a comparison with data coming from a test facility. The results of numerical simulations are in good agreement with experimental data.

  9. Non-destructive, preclinical evaluation of root canal anatomy of human teeth with flat-panel detector volume CT (FD-VCT); Zerstoerungsfreie praeklinische Evaluation der Wurzelkanalanatomie menschlicher Zaehne mittels Flaechendetektor-Volumen-CT (FD-VCT)

    Energy Technology Data Exchange (ETDEWEB)

    Heidrich, G.; Hassepass, F.; Dullin, C.; Grabbe, E. [Universitaetsklinikum Goettingen, Abt. Diagnostische Radiologie (Germany); Attin, T.; Hannig, C. [Universitaetsklinikum Goettingen, Abt. fuer Zahnerhaltung, Praeventive Zahnheilkunde und Paradontologie (Germany)

    2005-12-15

    Purpose: Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). Materials and methods: 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. Results: The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as dentricles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 {mu}m. Only around 73% of the main root canals detected with FD-VCT and 87% of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. (orig.)

  10. Flutter and Thermal Buckling Analysis for Composite Laminated Panel Embedded with Shape Memory Alloy Wires in Supersonic Flow

    Directory of Open Access Journals (Sweden)

    Chonghui Shao

    2016-01-01

    Full Text Available The flutter and thermal buckling behavior of laminated composite panels embedded with shape memory alloy (SMA wires are studied in this research. The classical plate theory and nonlinear von-Karman strain-displacement relation are employed to investigate the aeroelastic behavior of the smart laminated panel. The thermodynamic behaviors of SMA wires are simulated based on one-dimensional Brinson SMA model. The aerodynamic pressure on the panel is described by the nonlinear piston theory. Nonlinear governing partial differential equations of motion are derived for the panel via the Hamilton principle. The effects of ply angle of the composite panel, SMA layer location and orientation, SMA wires temperature, volume fraction and prestrain on the buckling, flutter boundary, and amplitude of limit cycle oscillation of the panel are analyzed in detail.

  11. Partial molar volume of proteins studied by the three-dimensional reference interaction site model theory.

    Science.gov (United States)

    Imai, Takashi; Kovalenko, Andriy; Hirata, Fumio

    2005-04-14

    The three-dimensional reference interaction site model (3D-RISM) theory is applied to the analysis of hydration effects on the partial molar volume of proteins. For the native structure of some proteins, the partial molar volume is decomposed into geometric and hydration contributions using the 3D-RISM theory combined with the geometric volume calculation. The hydration contributions are correlated with the surface properties of the protein. The thermal volume, which is the volume of voids around the protein induced by the thermal fluctuation of water molecules, is directly proportional to the accessible surface area of the protein. The interaction volume, which is the contribution of electrostatic interactions between the protein and water molecules, is apparently governed by the charged atomic groups on the protein surface. The polar atomic groups do not make any contribution to the interaction volume. The volume differences between low- and high-pressure structures of lysozyme are also analyzed by the present method.

  12. Panel discussion

    Energy Technology Data Exchange (ETDEWEB)

    No Author Given

    1975-01-01

    Panel discussion: summation and future projections. Introductory remarks by panelists followed by questions and comments from the floor. Panelists: Dr. Joseph Barnea (former director of Resources and Transport for the United Nations; energy consultant to the United Nations Institute for Training and Research (UNITAR)); the Honorable Clyde F. Bel, Jr. (member of the Louisiana House of Representatives representing District 90 and New Orleans); Dr. David Lombard (acting chief of the Advanced Systems Branch of the Division of Geothermal Energy Research and Technology, Energy Research and Development Administration (ERDA)); Fred C. Repper (vice-president of Central Power and Light Company in Corpus Christi, Texas); Dr. Hans Suter (environmental consultant in Corpus Christi, Texas; environmental columnist for the Corpus Christi Caller Times). Session chairman: Herbert Woodson.

  13. Considerations on FEM modeling in analyzing buckling and plastic collapse of a detection control; Boto panel no zakutsu sosei hokai kaiseki ni okeru FEM model ka ni kansuru kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Yao, T.; Fujikubo, M.; Yanagihara, D.; Irisawa, M. [Hiroshima University, Hiroshima (Japan). Faculty of Engineering

    1997-10-01

    Buckling and plastic collapse of upper decks and bottom outer plates of a hull results directly in longitudinal bending collapse of the hull. Therefore, discussions were given on analysis for pressure destruction strength of a detection control panel which assumes an upper deck and a bottom outer plate. Pressure destruction behavior of the panting panel is a complex phenomenon accompanying non-linearity and geometrical non-linearity of the materials. Its whole phenomenon may be analyzed by using the finite element method (FEM) as a principle, but the analysis is not efficient. Therefore, considerations were given in relation to modeling when using the FEM. The considerations were given on a panel attached with flat steel panting members with respect to the modeling scope which considers the buckling mode according to the aspect ratio of the panel partitioned by the deflection control members. If the local buckling mode of the panel is an even number wave mode in the longitudinal direction, a triple span model is required. A modeling scope for a case of being subjected to water pressure and in-plane compression was considered on a panel attached with angle-type steel members having non-symmetric cross section. In this case, a triple bay model is more preferable to reproduce the behavior under water pressure loading. 1 ref., 6 figs.

  14. Physical activity, self-efficacy and self-esteem in breast cancer survivors: a panel model.

    Science.gov (United States)

    Awick, Elizabeth A; Phillips, Siobhan M; Lloyd, Gillian R; McAuley, Edward

    2017-10-01

    Physical activity (PA) has been consistently associated with improved self-esteem in breast cancer survivors. However, this relationship is poorly understood. The purpose of this study was to examine whether changes in PA and self-efficacy influenced changes in self-esteem in breast cancer survivors across 6 months. Increases in PA were hypothesized to result in increases in self-efficacy, which were hypothesized to influence increases in physical self-worth (PSW) and global self-esteem. Breast cancer survivors (n = 370; M age  = 56.04) wore accelerometers to measure PA and completed measures of self-efficacy (e.g., exercise and barriers self-efficacy), PSW, and global self-esteem at baseline and 6 months. The hypothesized model provided a good fit to the data (χ 2  = 67.56, df = 26, p self-efficacy. In turn, more efficacious women reported significantly higher PSW (β = 0.26, 0.16). Finally, higher PSW was significantly associated with greater global self-esteem (β = 0.47). Relationships were similar among changes in model constructs over 6 months. After controlling for covariates, the hypothesized model provided an excellent fit to the data (χ 2  = 59.93, df = 33, p = 0.003; comparative fit index = 0.99; standardized root mean residual = 0.03). Our findings provide support for the role played by PA and self-efficacy in positive self-esteem, a key component of well-being. Highlighting successful PA mastery experiences is likely to enhance self-efficacy and improve self-esteem in this population. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Uncertainty modelling and analysis of volume calculations based on a regular grid digital elevation model (DEM)

    Science.gov (United States)

    Li, Chang; Wang, Qing; Shi, Wenzhong; Zhao, Sisi

    2018-05-01

    The accuracy of earthwork calculations that compute terrain volume is critical to digital terrain analysis (DTA). The uncertainties in volume calculations (VCs) based on a DEM are primarily related to three factors: 1) model error (ME), which is caused by an adopted algorithm for a VC model, 2) discrete error (DE), which is usually caused by DEM resolution and terrain complexity, and 3) propagation error (PE), which is caused by the variables' error. Based on these factors, the uncertainty modelling and analysis of VCs based on a regular grid DEM are investigated in this paper. Especially, how to quantify the uncertainty of VCs is proposed by a confidence interval based on truncation error (TE). In the experiments, the trapezoidal double rule (TDR) and Simpson's double rule (SDR) were used to calculate volume, where the TE is the major ME, and six simulated regular grid DEMs with different terrain complexity and resolution (i.e. DE) were generated by a Gauss synthetic surface to easily obtain the theoretical true value and eliminate the interference of data errors. For PE, Monte-Carlo simulation techniques and spatial autocorrelation were used to represent DEM uncertainty. This study can enrich uncertainty modelling and analysis-related theories of geographic information science.

  16. Accurate Finite Element Modelling of Chipboard Single-Stud Floor Panels subjected to Dynamic Loads

    DEFF Research Database (Denmark)

    Sjöström, A.; Flodén, O.; Persson, K.

    2012-01-01

    In multi-storey buildings, the use of lightweight material has many advantages. The low weight, the low energy consumption and the sustainability of the material are some attractive benefits from using lightweight materials. Compared with heavier structures i.e. concrete the challenge...... in constructing a building compliant with building codes vis-a-vis the propagation of sound and vibrations within the structure is a challenge. Focusing on junctions in a multi-storey lightweight buildings, a modular finite element model is developed to be used for analyses of vibration transmission...

  17. Applying ARIMA model for annual volume time series of the Magdalena River

    Directory of Open Access Journals (Sweden)

    Gloria Amaris

    2017-04-01

    Conclusions: The simulated results obtained with the ARIMA model compared to the observed data showed a fairly good adjustment of the minimum and maximum magnitudes. This allows concluding that it is a good tool for estimating minimum and maximum volumes, even though this model is not capable of simulating the exact behaviour of an annual volume time series.

  18. Numerical and Analytical Model of an Electrodynamic Dust Shield for Solar Panels on Mars

    Science.gov (United States)

    Calle, C. I.; Linell, B.; Chen, A.; Meyer, J.; Clements, S.; Mazumder, M. K.

    2006-01-01

    Masuda and collaborators at the University of Tokyo developed a method to confine and transport particles called the electric curtain in which a series of parallel electrodes connected to an AC source generates a traveling wave that acts as a contactless conveyor. The curtain electrodes can be excited by a single-phase or a multi-phase AC voltage. A multi-phase curtain produces a non-uniform traveling wave that provides controlled transport of those particles [1-6]. Multi-phase electric curtains from two to six phases have been developed and studied by several research groups [7-9]. We have developed an Electrodynamic Dust Shield prototype using threephase AC voltage electrodes to remove dust from surfaces. The purpose of the modeling work presented here is to research and to better understand the physics governing the electrodynamic shield, as well as to advance and to support the experimental dust shield research.

  19. Verification and transfer of thermal pollution model. Volume 5: Verification of 2-dimensional numerical model

    Science.gov (United States)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.

    1982-01-01

    The six-volume report: describes the theory of a three dimensional (3-D) mathematical thermal discharge model and a related one dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorate (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth (e.g., natural or man-made inland lakes) because surface elevation has been removed as a parameter. These models allow computation of time dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions.

  20. Modeling Longitudinal Relationships Between Habit and Physical Activity: Two Cross-Lagged Panel Design Studies in Older Adults.

    Science.gov (United States)

    van Bree, Rob J H; Bolman, Catherine; Mudde, Aart N; van Stralen, Maartje M; Peels, Denise A; de Vries, Hein; Lechner, Lilian

    2017-07-01

    These longitudinal studies in older adults targeted mediated relationships between habit and physical activity (PA). In The Netherlands two independent studies were conducted among 1976 (Study 1: Mage = 63.63, SD = 8.66, 30% functional limitations) and 2140 (Study 2: Mage = 62.75, SD = 8.57, 45% functional limitations) adults aged 50 years or older. Cross-lagged panel designs were applied to examine whether habit mediates the relationship between prior and later PA and whether PA simultaneously mediates the relationship between prior and later habit. Data on habit and PA were collected by means of questionnaires at baseline (t0) and at 6 (t1) and 12 (t2) months after baseline measurement. Results of structural equation modeling analyses were not unambiguous. Indications for the existence of both hypothesized mediation effects were found, but no clear, unequivocal pattern appeared. Somewhat more support was found for the PA-habit-PA path than for the habit-PA-habit path. More research is needed to draw more definitive conclusions.

  1. Diagnostic for Photovoltaic panels: models and methods for the "on-line" identification of the PV degradation

    OpenAIRE

    Petrone, Giovanni

    2015-01-01

    In the past the diagnosis of PV panels was mainly devoted to evaluate the performance degradation due to the manufacturing process and to guarantee the 25 years lifetime; these analysis was essentially based on off-line costly laboratory measurement. Recent studies shown that the degradation of photovoltaic (PV) panels is accelerated by various unpredictable and unavoidable phenomena, e.g, the extreme environmental and operating conditions, or by the type of electrical connections thus, in or...

  2. Heat exchanger panel

    Science.gov (United States)

    Warburton, Robert E. (Inventor); Cuva, William J. (Inventor)

    2005-01-01

    The present invention relates to a heat exchanger panel which has broad utility in high temperature environments. The heat exchanger panel has a first panel, a second panel, and at least one fluid containment device positioned intermediate the first and second panels. At least one of the first panel and the second panel have at least one feature on an interior surface to accommodate the at least one fluid containment device. In a preferred embodiment, each of the first and second panels is formed from a high conductivity, high temperature composite material. Also, in a preferred embodiment, the first and second panels are joined together by one or more composite fasteners.

  3. An in vitro model of skeletal muscle volume regulation.

    Science.gov (United States)

    Wibberley, Anna; Staunton, Caroline A; Feetham, Claire H; Vereninov, Alexey A; Barrett-Jolley, Richard

    2015-01-01

    Hypertonic media causes cells to shrink due to water loss through aquaporin channels. After acute shrinkage, cells either regulate their volume or, alternatively, undergo a number of metabolic changes which ultimately lead to cell death. In many cell types, hypertonic shrinkage is followed by apoptosis. Due to the complex 3D morphology of skeletal muscle and the difficulty in obtaining isolated human tissue, we have begun skeletal muscle volume regulation studies using the human skeletal muscle cell line TE671RD. In this study we investigated whether hypertonic challenge of the human skeletal muscle cell line TE671RD triggered cell death or evoked a cell volume recovery response. The cellular volume of TE671RD cells was calculated from the 2D surface area. Cell death was assessed by both the trypan blue live/dead assay and the TUNEL assay. Medium osmolality was increased by addition of up to 200 mM sucrose. Addition of 200 mM sucrose resulted in mean cell shrinkage of 44±1% after 30 mins. At later time points (2 and 4 hrs) two separate cell subpopulations with differing mean cell volume became apparent. The first subpopulation (15±2% of the total cell number) continued to shrink whereas the second subpopulation had an increased cell volume. Cell death was observed in a small proportion of cells (approximately 6-8%). We have established that a substantial proportion of TE671RD cells respond to hypertonic challenge with RVI, but that these cells are resistant to hypertonicity triggered cell death.

  4. An in vitro model of skeletal muscle volume regulation.

    Directory of Open Access Journals (Sweden)

    Anna Wibberley

    Full Text Available Hypertonic media causes cells to shrink due to water loss through aquaporin channels. After acute shrinkage, cells either regulate their volume or, alternatively, undergo a number of metabolic changes which ultimately lead to cell death. In many cell types, hypertonic shrinkage is followed by apoptosis. Due to the complex 3D morphology of skeletal muscle and the difficulty in obtaining isolated human tissue, we have begun skeletal muscle volume regulation studies using the human skeletal muscle cell line TE671RD. In this study we investigated whether hypertonic challenge of the human skeletal muscle cell line TE671RD triggered cell death or evoked a cell volume recovery response.The cellular volume of TE671RD cells was calculated from the 2D surface area. Cell death was assessed by both the trypan blue live/dead assay and the TUNEL assay.Medium osmolality was increased by addition of up to 200 mM sucrose. Addition of 200 mM sucrose resulted in mean cell shrinkage of 44±1% after 30 mins. At later time points (2 and 4 hrs two separate cell subpopulations with differing mean cell volume became apparent. The first subpopulation (15±2% of the total cell number continued to shrink whereas the second subpopulation had an increased cell volume. Cell death was observed in a small proportion of cells (approximately 6-8%.We have established that a substantial proportion of TE671RD cells respond to hypertonic challenge with RVI, but that these cells are resistant to hypertonicity triggered cell death.

  5. Carbon footprint estimator, phase II : volume I - GASCAP model & volume II - technical appendices [technical brief].

    Science.gov (United States)

    2014-03-01

    This study resulted in the development of the GASCAP model (the Greenhouse Gas Assessment : Spreadsheet for Transportation Capital Projects). This spreadsheet model provides a user-friendly interface for determining the greenhouse gas (GHG) emissions...

  6. Verification and transfer of thermal pollution model. Volume 6: User's manual for 1-dimensional numerical model

    Science.gov (United States)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.

    1982-01-01

    The six-volume report: describes the theory of a three dimensional (3-D) mathematical thermal discharge model and a related one dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth (e.g., natural or man-made inland lakes) because surface elevation has been removed as a parameter.

  7. Transportation Sector Model of the National Energy Modeling System. Volume 2 -- Appendices: Part 3

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This Appendix consists of two unpublished reports produced by Energy and Environmental Analysis, Inc., under contract to Oak Ridge National Laboratory. These two reports formed the basis for the subsequent development of the Fuel Economy Model described in Volume 1. They are included in order to document more completely the efforts undertaken to construct a comprehensive model of automobile fuel economy. The supplemental reports are as follows: Supplement 1--Documentation Attributes of Technologies to Improve Automotive Fuel Economy; Supplement 2--Analysis of the Fuel Economy Boundary for 2010 and Comparison to Prototypes.

  8. Diameter structure modeling and the calculation of plantation volume of black poplar clones

    Directory of Open Access Journals (Sweden)

    Andrašev Siniša

    2004-01-01

    Full Text Available A method of diameter structure modeling was applied in the calculation of plantation (stand volume of two black poplar clones in the section Aigeiros (Duby: 618 (Lux and S1-8. Diameter structure modeling by Weibull function makes it possible to calculate the plantation volume by volume line. Based on the comparison of the proposed method with the existing methods, the obtained error of plantation volume was less than 2%. Diameter structure modeling and the calculation of plantation volume by diameter structure model, by the regularity of diameter distribution, enables a better analysis of the production level and assortment structure and it can be used in the construction of yield and increment tables.

  9. A dynamic panel model of the associations of sweetened beverage purchases with dietary quality and food-purchasing patterns.

    Science.gov (United States)

    Piernas, Carmen; Ng, Shu Wen; Mendez, Michelle A; Gordon-Larsen, Penny; Popkin, Barry M

    2015-05-01

    Investigating the association between consumption of sweetened beverages and dietary quality is challenging because issues such as reverse causality and unmeasured confounding might result in biased and inconsistent estimates. Using a dynamic panel model with instrumental variables to address those issues, we examined the independent associations of beverages sweetened with caloric and low-calorie sweeteners with dietary quality and food-purchasing patterns. We analyzed purchase data from the Homescan survey, an ongoing, longitudinal, nationally representative US survey, from 2000 to 2010 (n = 34,294). Our model included lagged measures of dietary quality and beverage purchases (servings/day in the previous year) as exposures to predict the outcomes (macronutrient (kilocalories per capita per day; %), total energy, and food purchases) in the next year after adjustment for other sociodemographic covariates. Despite secular declines in purchases (kilocalories per capita per day) from all sources, each 1-serving/day increase in consumption of either beverage type resulted in higher purchases of total daily kilocalories and kilocalories from food, carbohydrates, total sugar, and total fat. Each 1-serving/day increase in consumption of either beverage was associated with more purchases of caloric-sweetened desserts or sweeteners, which accounted for a substantial proportion of the increase in total kilocalories. We concluded that consumers of both beverages sweetened with low-calorie sweeteners and beverages sweetened with caloric sweeteners had poorer dietary quality, exhibited higher energy from all purchases, sugar, and fat, and purchased more caloric-sweetened desserts/caloric sweeteners compared with nonconsumers. © The Author 2015. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Utilizing flat-panel detector parenchymal blood volume imaging (FD-PBV) for quantitative kidney perfusion analysis during the process of percutaneous transluminal renal angioplasty (PTRA): A case report.

    Science.gov (United States)

    Qiu, Chenyang; Shao, Jiang; Liu, Xiu; Liu, Bao

    2017-11-01

    Traditional digital subtraction angiography (DSA) provides lumen morphology of renal artery as indicators for vascular patency in patients with renal artery stenosis (RAS). It, however, lacks hemodynamic information toward target kidney. To solve this shortcoming, a novel technique, flat-panel detector parenchymal blood volume imaging (FD-PBV), is introduced, which is able to evaluate hemodynamic changes of target kidney intraoperatively. A 77-year-old female presented with hypertension, intermittent dizziness, nausea, and fatigue. Ninety-nine percent stenosis of left RAS was found. Percutaneous transluminal renal angioplasty was performed, along with FD-PBV acquisition protocol. Her symptoms relieved gradually after procedure. Intuitive FD-PBV maps showed her renal perfusion improved remarkably. Quantitative analysis of FD-PBV showed her kidney volume was 47.02 and 75.61 cm with average density of contrast medium (CM) 58.1 HU and 311.5 HU before and after stenting. Follow-up at 6 months showed patency of the stent and stable kidney blood perfusion. FD-PBV technique possesses a remarkable value in quantitatively assessing the changes of kidney blood perfusion and can be a useful auxiliary technique for DSA. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  11. Electric field distribution in a finite-volume head model of deep brain stimulation

    OpenAIRE

    Grant, Peadar F.; Lowery, Madeleine M.

    2009-01-01

    This study presents a whole-head finite element model of deep brain stimulation to examine the effect of electrical grounding, the finite conducting volume of the head, and scalp, skull and cerebrospinal fluid layers. The impedance between the stimulating and reference electrodes in the whole-head model was found to lie within clinically reported values when the reference electrode was incorporated on a localized surface in the model. Incorporation of the finite volume of the head and inclusi...

  12. Transportation Sector Model of the National Energy Modeling System. Volume 2 -- Appendices: Part 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    The attachments contained within this appendix provide additional details about the model development and estimation process which do not easily lend themselves to incorporation in the main body of the model documentation report. The information provided in these attachments is not integral to the understanding of the model`s operation, but provides the reader with opportunity to gain a deeper understanding of some of the model`s underlying assumptions. There will be a slight degree of replication of materials found elsewhere in the documentation, made unavoidable by the dictates of internal consistency. Each attachment is associated with a specific component of the transportation model; the presentation follows the same sequence of modules employed in Volume 1. The following attachments are contained in Appendix F: Fuel Economy Model (FEM)--provides a discussion of the FEM vehicle demand and performance by size class models; Alternative Fuel Vehicle (AFV) Model--describes data input sources and extrapolation methodologies; Light-Duty Vehicle (LDV) Stock Model--discusses the fuel economy gap estimation methodology; Light Duty Vehicle Fleet Model--presents the data development for business, utility, and government fleet vehicles; Light Commercial Truck Model--describes the stratification methodology and data sources employed in estimating the stock and performance of LCT`s; Air Travel Demand Model--presents the derivation of the demographic index, used to modify estimates of personal travel demand; and Airborne Emissions Model--describes the derivation of emissions factors used to associate transportation measures to levels of airborne emissions of several pollutants.

  13. Report of the panel on models of effects of high LET radiation on whole animals and man

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Human data are the most convincing data--even when their applicability may be considerably strained--and the acquisition and interpretation of such data deserves a high priority. This would include currently funded studies on plutonium workers, thorium workers, and uranium diffusion plant workers. It is obvious, however, that there is also need for information totally unavailable from human sources. Appropriate experimental animal studies must provide this information. These studies must be designed to permit the most credible extrapolation to man, and the development of such extrapolation techniques is as important as the conduct of the studies themselves. There was agreement that the results of toxicity experiments are almost never reported in a manner most useful to modelers and that this situation should be rectified by some means short of dictatorial edict: perhaps a manual of recommended practices, perhaps a ''flying squad'' of consulting epidemiologists, perhaps more frequent workshops involving the people who actually gather and report the data. Among the forbidden practices would be the expression of radiation dose in rem and the reporting of tumor incidence without individual animal data on time at risk. In the opinion of the panel, a delay in the implementation of plutonium recycle or the LMFBR increases, rather than decreases, the need for additional experimental data on pluonium toxicity. Without the delay there might be insufficient time for the acquisition and effective application of data from newly initiated research programs. But when the inevitability of plutonium as an energy source is acknowledged--5, 10, or 20 years hence--we will be severely and justifiably criticized if we have not used this period to acquire a better understanding of the health effects of plutonium

  14. Volume CT with a flat-panel detector on a mobile, isocentric C-arm: pre-clinical investigation in guidance of minimally invasive surgery.

    Science.gov (United States)

    Siewerdsen, J H; Moseley, D J; Burch, S; Bisland, S K; Bogaards, A; Wilson, B C; Jaffray, D A

    2005-01-01

    A mobile isocentric C-arm (Siemens PowerMobil) has been modified in our laboratory to include a large area flat-panel detector (in place of the x-ray image intensifier), providing multi-mode fluoroscopy and cone-beam computed tomography (CT) imaging capability. This platform represents a promising technology for minimally invasive, image-guided surgical procedures where precision in the placement of interventional tools with respect to bony and soft-tissue structures is critical. The image quality and performance in surgical guidance was investigated in pre-clinical evaluation in image-guided spinal surgery. The control, acquisition, and reconstruction system are described. The reproducibility of geometric calibration, essential to achieving high three-dimensional (3D) image quality, is tested over extended time scales (7 months) and across a broad range in C-arm angulation (up to 45 degrees), quantifying the effect of improper calibration on spatial resolution, soft-tissue visibility, and image artifacts. Phantom studies were performed to investigate the precision of 3D localization (viz., fiber optic probes within a vertebral body) and effect of lateral projection truncation (limited field of view) on soft-tissue detectability in image reconstructions. Pre-clinical investigation was undertaken in a specific spinal procedure (photodynamic therapy of spinal metastases) in five animal subjects (pigs). In each procedure, placement of fiber optic catheters in two vertebrae (L1 and L2) was guided by fluoroscopy and cone-beam CT. Experience across five procedures is reported, focusing on 3D image quality, the effects of respiratory motion, limited field of view, reconstruction filter, and imaging dose. Overall, the intraoperative cone-beam CT images were sufficient for guidance of needles and catheters with respect to bony anatomy and improved surgical performance and confidence through 3D visualization and verification of transpedicular trajectories and tool placement

  15. Estimating tree bole volume using artificial neural network models for four species in Turkey.

    Science.gov (United States)

    Ozçelik, Ramazan; Diamantopoulou, Maria J; Brooks, John R; Wiant, Harry V

    2010-01-01

    Tree bole volumes of 89 Scots pine (Pinus sylvestris L.), 96 Brutian pine (Pinus brutia Ten.), 107 Cilicica fir (Abies cilicica Carr.) and 67 Cedar of Lebanon (Cedrus libani A. Rich.) trees were estimated using Artificial Neural Network (ANN) models. Neural networks offer a number of advantages including the ability to implicitly detect complex nonlinear relationships between input and output variables, which is very helpful in tree volume modeling. Two different neural network architectures were used and produced the Back propagation (BPANN) and the Cascade Correlation (CCANN) Artificial Neural Network models. In addition, tree bole volume estimates were compared to other established tree bole volume estimation techniques including the centroid method, taper equations, and existing standard volume tables. An overview of the features of ANNs and traditional methods is presented and the advantages and limitations of each one of them are discussed. For validation purposes, actual volumes were determined by aggregating the volumes of measured short sections (average 1 meter) of the tree bole using Smalian's formula. The results reported in this research suggest that the selected cascade correlation artificial neural network (CCANN) models are reliable for estimating the tree bole volume of the four examined tree species since they gave unbiased results and were superior to almost all methods in terms of error (%) expressed as the mean of the percentage errors. 2009 Elsevier Ltd. All rights reserved.

  16. Does amniotic fluid volume affect fetofetal transfusion in monochorionic twin pregnancies? Modelling two possible mechanisms

    NARCIS (Netherlands)

    Umur, Asli; van Gemert, Martin J. C.; Ross, Michael G.

    2002-01-01

    Clinical evidence suggests that increased amniotic fluid volume due to polyhydrarnnios increases placental vascular resistance. We have sought to model the possible effects of an increased amniotic fluid volume oil the net fetofetal transfusion in monochorionic twin pregnancies. We wanted to compare

  17. 1987 Oak Ridge model conference: Proceedings: Volume 3, Health and safety

    International Nuclear Information System (INIS)

    1987-01-01

    See the abstract for Volume I for general information on the conference. Topics discussed in Volume III include the use of models in handling hazardous materials, communication at waste sites, asbestos, regulatory decisions, emergency planning, training programs, occupational hazards, and protection of subcontractors

  18. Research on the influencing factors of financing efficiency of big data industry based on panel data model--Empirical evidence from Guizhou province

    Science.gov (United States)

    Li, Chenggang; Feng, Yujia

    2018-03-01

    This paper mainly studies the influence factors of financing efficiency of Guizhou big data industry, and selects the financial and macro data of 20 Guizhou big data enterprises from 2010 to 2016. Using the DEA model to obtain the financing efficiency of Guizhou big data enterprises. A panel data model is constructed to select the six macro and micro influencing factors for panel data analysis. The results show that the external economic environment, the turnover rate of the total assets of the enterprises, the increase of operating income, the increase of the revenue per share of each share of the business income have positive impact on the financing efficiency of of the big data industry in Guizhou. The key to improve the financing efficiency of Guizhou big data enterprises is to improve.

  19. A Compact Energy Harvesting System for Outdoor Wireless Sensor Nodes Based on a Low-Cost In Situ Photovoltaic Panel Characterization-Modelling Unit.

    Science.gov (United States)

    Antolín, Diego; Medrano, Nicolás; Calvo, Belén; Martínez, Pedro A

    2017-08-04

    This paper presents a low-cost high-efficiency solar energy harvesting system to power outdoor wireless sensor nodes. It is based on a Voltage Open Circuit (VOC) algorithm that estimates the open-circuit voltage by means of a multilayer perceptron neural network model trained using local experimental characterization data, which are acquired through a novel low cost characterization system incorporated into the deployed node. Both units-characterization and modelling-are controlled by the same low-cost microcontroller, providing a complete solution which can be understood as a virtual pilot cell, with identical characteristics to those of the specific small solar cell installed on the sensor node, that besides allows an easy adaptation to changes in the actual environmental conditions, panel aging, etc. Experimental comparison to a classical pilot panel based VOC algorithm show better efficiency under the same tested conditions.

  20. Application of Meta-Heuristic Hybrid Artificial Intelligence Techniques for Modeling of Bonding Strength of Plywood Panels

    Directory of Open Access Journals (Sweden)

    Cenk Demirkır

    2014-04-01

    Full Text Available Plywood, which is one of the most important wood based panels, has many usage areas changing from traffic signs to building constructions in many countries. It is known that the high quality plywood panel manufacturing has been achieved with a good bonding under the optimum pressure conditions depending on adhesive type. This is a study of determining the using possibilities of modern meta-heuristic hybrid artificial intelligence techniques such as IKE and AANN methods for prediction of bonding strength of plywood panels. This study has composed of two main parts as experimental and analytical. Scots pine, maritime pine and European black pine logs were used as wood species. The pine veneers peeled at 32°C and 50°C were dried at 110°C, 140°C and 160°C temperatures. Phenol formaldehyde and melamine urea formaldehyde resins were used as adhesive types. EN 314-1 standard was used to determine the bonding shear strength values of plywood panels in experimental part of this study. Then the intuitive k-nearest neighbor estimator (IKE and adaptive artificial neural network (AANN were used to estimate bonding strength of plywood panels. The best estimation performance was obtained from MA metric for k-value=10. The most effective factor on bonding strength was determined as adhesive type. Error rates were determined less than 5% for both of the IKE and AANN. It may be recommended that proposed methods could be used in applying to estimation of bonding strength values of plywood panels.

  1. Integration of Financial Markets in Post Global Financial Crises and Implications for British Financial Sector: Analysis Based on A Panel VAR Model

    OpenAIRE

    Nasir, M; Du, M

    2017-01-01

    This study analyses the dynamics of integration among global financial markets in the context of Global Financial Crisis (2008) by employing a Panel Vector Autoregressive (VAR) model on the monthly data of nine countries and three markets from Jan 2003 to Oct 2015. It was found that there has been a shift in the association among the global financial markets since Global Financial Crisis (GFC).Moreover, the British financial sectors in Post-GFC world clearly showed a change in the association...

  2. Review of air quality modeling techniques. Volume 8

    International Nuclear Information System (INIS)

    Rosen, L.C.

    1977-01-01

    Air transport and diffusion models which are applicable to the assessment of the environmental effects of nuclear, geothermal, and fossil-fuel electric generation are reviewed. The general classification of models and model inputs are discussed. A detailed examination of the statistical, Gaussian plume, Gaussian puff, one-box and species-conservation-of-mass models is given. Representative models are discussed with attention given to the assumptions, input data requirement, advantages, disadvantages and applicability of each

  3. A general method for assessing the effects of uncertainty in individual-tree volume model predictions on large-area volume estimates with a subtropical forest illustration

    Science.gov (United States)

    Ronald E. McRoberts; Paolo Moser; Laio Zimermann Oliveira; Alexander C. Vibrans

    2015-01-01

    Forest inventory estimates of tree volume for large areas are typically calculated by adding the model predictions of volumes for individual trees at the plot level, calculating the mean over plots, and expressing the result on a per unit area basis. The uncertainty in the model predictions is generally ignored, with the result that the precision of the large-area...

  4. Maryland Panel Proposes Anti-Drug-Abuse Plan, Urges Campus to Be a Model for Other Universities.

    Science.gov (United States)

    Hirschorn, Michael

    1987-01-01

    A University of Maryland panel on drug abuse hopes its report on drug policies, enforcement, and education will become a prototype for other colleges and universities. It uses four approaches to combat substance abuse: education and counseling, discipline, drug testing, and law enforcement. (MSE)

  5. Calculation of search volume on cruise-searching planktivorous fish in foraging model.

    Science.gov (United States)

    Park, Bae Kyung; Lee, Yong Seok; Park, Seok Soon

    2007-07-01

    Search volume of cruising planktivorous fish was calculated based on its detailed behavior Th examine the factors influencing search volume, a series of experiments were conducted by varying ambient conditions, such as structural complexity light intensity and turbidity Pseudorasbora parva were used in experiment as predator and Daphnia pulex was selected as prey The shape of scanning area of P parva showed elliptic and the search volume changed drastically depending on ambient conditions. Compared with the results of previous foraging model, the search volumes of the fish under previous study were larger (1.2 to 2.4 times) than those from our study These results on the changes in feeding rate can be useful in determining microhabitat requirement of P parva and othercyprinids with a similar foraging behavior The calculated search volume is compared with other foraging model andthe effect of zooplankton-planktivore interactions on aquatic ecosystem is discussed.

  6. An enhanced matrix-free edge-based finite volume approach to model structures

    CSIR Research Space (South Africa)

    Suliman, Ridhwaan

    2010-01-01

    Full Text Available This paper presents the formulation, implementation and evaluation of an enhanced matrix free edge-based finite volume approach to model the mechanics of solids undergoing large non-linear deformations. The developed technology is evaluated via...

  7. Fixed site neutralization model programmer's manual. Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Engi, D.; Chapman, L.D.; Judnick, W.; Blum, R.; Broegler, L.; Lenz, J.; Weinthraub, A.; Ballard, D.

    1979-12-01

    This report relates to protection of nuclear materials at nuclear facilities. This volume presents the source listings for the Fixed Site Neutralization Model and its supporting modules, the Plex Preprocessor and the Data Preprocessor. (DLC)

  8. HYDROCARBON SPILL SCREENING MODEL (HSSM) VOLUME 1: USER'S GUIDE

    Science.gov (United States)

    This users guide describes the Hydrocarbon Spill Screening Model (HSSM). The model is intended for simulation of subsurface releases of light nonaqueous phase liquids (LNAPLs). The model consists of separate modules for LNAPL flow through the vadose zone, spreading in the capil...

  9. Statistical Modeling of Ultrawideband Body-Centric Wireless Channels Considering Room Volume

    Directory of Open Access Journals (Sweden)

    Miyuki Hirose

    2012-01-01

    Full Text Available This paper presents the results of a statistical modeling of onbody ultrawideband (UWB radio channels for wireless body area network (WBAN applications. Measurements were conducted in five different rooms. A measured delay profile can be divided into two domains; in the first domain (04 ns has multipath components that are dominant and dependent on room volume. The first domain was modeled with a conventional power decay law model, and the second domain with a modified Saleh-Valenzuela model considering the room volume. Realizations of the impulse responses are presented based on the composite model and compared with the measured average power delay profiles.

  10. Underground Test Area Subproject Phase I Data Analysis Task. Volume VII - Tritium Transport Model Documentation Package

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-12-01

    Volume VII of the documentation for the Phase I Data Analysis Task performed in support of the current Regional Flow Model, Transport Model, and Risk Assessment for the Nevada Test Site Underground Test Area Subproject contains the tritium transport model documentation. Because of the size and complexity of the model area, a considerable quantity of data was collected and analyzed in support of the modeling efforts. The data analysis task was consequently broken into eight subtasks, and descriptions of each subtask's activities are contained in one of the eight volumes that comprise the Phase I Data Analysis Documentation.

  11. Stimulation model for lenticular sands: Volume 2, Users manual

    Energy Technology Data Exchange (ETDEWEB)

    Rybicki, E.F.; Luiskutty, C.T.; Sutrick, J.S.; Palmer, I.D.; Shah, G.H.; Tomutsa, L.

    1987-07-01

    This User's Manual contains information for four fracture/proppant models. TUPROP1 contains a Geertsma and de Klerk type fracture model. The section of the program utilizing the proppant fracture geometry data from the pseudo three-dimensional highly elongated fracture model is called TUPROPC. The analogous proppant section of the program that was modified to accept fracture shape data from SA3DFRAC is called TUPROPS. TUPROPS also includes fracture closure. Finally there is the penny fracture and its proppant model, PENNPROP. In the first three chapters, the proppant sections are based on the same theory for determining the proppant distribution but have modifications to support variable height fractures and modifications to accept fracture geometry from three different fracture models. Thus, information about each proppant model in the User's Manual builds on information supplied in the previous chapter. The exception to the development of combined treatment models is the penny fracture and its proppant model. In this case, a completely new proppant model was developed. A description of how to use the combined treatment model for the penny fracture is contained in Chapter 4. 2 refs.

  12. Predictor model for seasonal variations in skid resistance, volume 1

    Science.gov (United States)

    Henry, J. J.; Saito, K.; Blackburn, R.

    1984-04-01

    Two models, utilizing data collected in 1979 and 1980, were developed to predict variations in skid resistance due to rainfall conditions, temperature effects, and time of the year. A generalized predictor model was developed from purely statistical considerations and a mechanistic model was developed from hypothesized mechanisms. This model may be utilized to estimate the skid resistance at any time in the season from a measurement made during the same season, or to adjust skid-resistance measurement made at any time during the season to the end-of-season level. The mechanistic model requires, in addition to the above inputs, two pavement properties describing the polishing characteristics of the aggregate and an estimate of the percent normalized gradient of the skid resistance. The application of these models is summarized.

  13. Mesorad dose assessment model. Volume 1. Technical basis

    International Nuclear Information System (INIS)

    Scherpelz, R.I.; Bander, T.J.; Athey, G.F.; Ramsdell, J.V.

    1986-03-01

    MESORAD is a dose assessment model for emergency response applications. Using release data for as many as 50 radionuclides, the model calculates: (1) external doses resulting from exposure to radiation emitted by radionuclides contained in elevated or deposited material; (2) internal dose commitment resulting from inhalation; and (3) total whole-body doses. External doses from airborne material are calculated using semi-infinite and finite cloud approximations. At each stage in model execution, the appropriate approximation is selected after considering the cloud dimensions. Atmospheric processes are represented in MESORAD by a combination of Lagrangian puff and Gaussian plume dispersion models, a source depletion (deposition velocity) dry deposition model, and a wet deposition model using washout coefficients based on precipitation rates

  14. A model for vented deflagration of hydrogen in a volume

    International Nuclear Information System (INIS)

    Mulpuru, S.R.; Wilkin, G.B.

    1982-02-01

    A simple model was constructed to predict the property transients resulting from the deflagration of a combustible mixture in a sphere or cylinder with venting of the gas mixture to the environment. A computer program VENT, was written to solve the model equation. The model will be particularly useful for studying hydrogen burning effects in loss-of-coolant plus losss of emergency coolant accidents in CANDU reactors

  15. Panel data specifications in nonparametric kernel regression

    DEFF Research Database (Denmark)

    Czekaj, Tomasz Gerard; Henningsen, Arne

    We discuss nonparametric regression models for panel data. A fully nonparametric panel data specification that uses the time variable and the individual identifier as additional (categorical) explanatory variables is considered to be the most suitable. We use this estimator and conventional...... parametric panel data estimators to analyse the production technology of Polish crop farms. The results of our nonparametric kernel regressions generally differ from the estimates of the parametric models but they only slightly depend on the choice of the kernel functions. Based on economic reasoning, we...... found the estimates of the fully nonparametric panel data model to be more reliable....

  16. A Validated Normative Model for Human Uterine Volume from Birth to Age 40 Years.

    Science.gov (United States)

    Kelsey, Thomas W; Ginbey, Eleanor; Chowdhury, Moti M; Bath, Louise E; Anderson, Richard A; Wallace, W Hamish B

    2016-01-01

    Transabdominal pelvic ultrasound and/or pelvic Magnetic Resonance Imaging are safe, accurate and non-invasive means of determining the size and configuration of the internal female genitalia. The assessment of uterine size and volume is helpful in the assessment of many conditions including disorders of sex development, precocious or delayed puberty, infertility and menstrual disorders. Using our own data from the assessment of MRI scans in healthy young females and data extracted from four studies that assessed uterine volume using transabdominal ultrasound in healthy females we have derived and validated a normative model of uterine volume from birth to age 40 years. This shows that uterine volume increases across childhood, with a faster increase in adolescence reflecting the influence of puberty, followed by a slow but progressive rise during adult life. The model suggests that around 84% of the variation in uterine volumes in the healthy population up to age 40 is due to age alone. The derivation of a validated normative model for uterine volume from birth to age 40 years has important clinical applications by providing age-related reference values for uterine volume.

  17. Mechanistic Fluid Transport Model to Estimate Gastrointestinal Fluid Volume and Its Dynamic Change Over Time.

    Science.gov (United States)

    Yu, Alex; Jackson, Trachette; Tsume, Yasuhiro; Koenigsknecht, Mark; Wysocki, Jeffrey; Marciani, Luca; Amidon, Gordon L; Frances, Ann; Baker, Jason R; Hasler, William; Wen, Bo; Pai, Amit; Sun, Duxin

    2017-11-01

    Gastrointestinal (GI) fluid volume and its dynamic change are integral to study drug disintegration, dissolution, transit, and absorption. However, key questions regarding the local volume and its absorption, secretion, and transit remain unanswered. The dynamic fluid compartment absorption and transit (DFCAT) model is proposed to estimate in vivo GI volume and GI fluid transport based on magnetic resonance imaging (MRI) quantified fluid volume. The model was validated using GI local concentration of phenol red in human GI tract, which was directly measured by human GI intubation study after oral dosing of non-absorbable phenol red. The measured local GI concentration of phenol red ranged from 0.05 to 168 μg/mL (stomach), to 563 μg/mL (duodenum), to 202 μg/mL (proximal jejunum), and to 478 μg/mL (distal jejunum). The DFCAT model characterized observed MRI fluid volume and its dynamic changes from 275 to 46.5 mL in stomach (from 0 to 30 min) with mucus layer volume of 40 mL. The volumes of the 30 small intestine compartments were characterized by a max of 14.98 mL to a min of 0.26 mL (0-120 min) and a mucus layer volume of 5 mL per compartment. Regional fluid volumes over 0 to 120 min ranged from 5.6 to 20.38 mL in the proximal small intestine, 36.4 to 44.08 mL in distal small intestine, and from 42 to 64.46 mL in total small intestine. The DFCAT model can be applied to predict drug dissolution and absorption in the human GI tract with future improvements.

  18. Modelling the drying of three-dimensional pulp moulded structures. Part II, Drying data obtained from flat panels using virgin and recycled paper fibre

    Science.gov (United States)

    John F. Hunt; Margit. Tamasy-Bano; Heike. Nyist

    1999-01-01

    A three-dimensional structural panel, called FPL Spaceboard, was developed at the USDA Forest Products Laboratory. Spaceboard panels have been formed using a variety of fibrous materials using either a wet- or dry-forming process. Geometrically, the panel departs from the traditional two-dimensional flat panel by integrally forming an array of perpendicular ribs and...

  19. Influencing Factors and Development Trend Analysis of China Electric Grid Investment Demand Based on a Panel Co-Integration Model

    OpenAIRE

    Jinchao Li; Lin Chen; Yuwei Xiang; Jinying Li; Dong Peng

    2018-01-01

    Electric grid investment demand analysis is significant to reasonably arranging construction funds for the electric grid and reduce costs. This paper used the panel data of electric grid investment from 23 provinces of China between 2004 and 2016 as samples to analyze the influence between electric grid investment demand and GDP, population scale, social electricity consumption, installed electrical capacity, and peak load based on co-integration tests. We find that GDP and peak load have pos...

  20. A six-component model for assessing procedural fairness in the Intergovernmental Panel on Climate Change (IPCC)

    OpenAIRE

    Okereke, Chuks

    2017-01-01

    This article provides an analysis of the Intergovernmental Panel on Climate Change (IPCC) focusing on procedural justice. I demonstrate how, to what end, and with what effects questions of justice and procedural fairness matter in the IPCC work. Then, with the aim to advance critical research, policy and practice on this important subject, I draw on scholarship from social psychology and legal procedures along with socio-political literature on the IPCC to construct a unique six-component fra...

  1. A hybrid ARIMA and neural network model applied to forecast catch volumes of Selar crumenophthalmus

    Science.gov (United States)

    Aquino, Ronald L.; Alcantara, Nialle Loui Mar T.; Addawe, Rizavel C.

    2017-11-01

    The Selar crumenophthalmus with the English name big-eyed scad fish, locally known as matang-baka, is one of the fishes commonly caught along the waters of La Union, Philippines. The study deals with the forecasting of catch volumes of big-eyed scad fish for commercial consumption. The data used are quarterly caught volumes of big-eyed scad fish from 2002 to first quarter of 2017. This actual data is available from the open stat database published by the Philippine Statistics Authority (PSA)whose task is to collect, compiles, analyzes and publish information concerning different aspects of the Philippine setting. Autoregressive Integrated Moving Average (ARIMA) models, Artificial Neural Network (ANN) model and the Hybrid model consisting of ARIMA and ANN were developed to forecast catch volumes of big-eyed scad fish. Statistical errors such as Mean Absolute Errors (MAE) and Root Mean Square Errors (RMSE) were computed and compared to choose the most suitable model for forecasting the catch volume for the next few quarters. A comparison of the results of each model and corresponding statistical errors reveals that the hybrid model, ARIMA-ANN (2,1,2)(6:3:1), is the most suitable model to forecast the catch volumes of the big-eyed scad fish for the next few quarters.

  2. Measurement and modeling of advanced coal conversion processes, Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G. [and others

    1993-06-01

    A two dimensional, steady-state model for describing a variety of reactive and nonreactive flows, including pulverized coal combustion and gasification, is presented. The model, referred to as 93-PCGC-2 is applicable to cylindrical, axi-symmetric systems. Turbulence is accounted for in both the fluid mechanics equations and the combustion scheme. Radiation from gases, walls, and particles is taken into account using a discrete ordinates method. The particle phase is modeled in a lagrangian framework, such that mean paths of particle groups are followed. A new coal-general devolatilization submodel (FG-DVC) with coal swelling and char reactivity submodels has been added.

  3. Measurement and modeling of advanced coal conversion processes, Volume III

    Energy Technology Data Exchange (ETDEWEB)

    Ghani, M.U.; Hobbs, M.L.; Hamblen, D.G. [and others

    1993-08-01

    A generalized one-dimensional, heterogeneous, steady-state, fixed-bed model for coal gasification and combustion is presented. The model, FBED-1, is a design and analysis tool that can be used to simulate a variety of gasification, devolatilization, and combustion processes. The model considers separate gas and solid temperatures, axially variable solid and gas flow rates, variable bed void fraction, coal drying, devolatilization based on chemical functional group composition, depolymerization, vaporization and crosslinking, oxidation, and gasification of char, and partial equilibrium in the gas phase.

  4. Operational Modelling of the Aerospace Propagation Environment. Volume II

    Science.gov (United States)

    1978-11-01

    radiative transfer models are rarely available in a battlefield environment. tnly secondary ECNET parameters may be available. Hence, current modeling and...adopthe done lee traitements a 6tA de remplacer chaque valeur X4Dar son rang. Clest-h-diro quo Zj eet rermplacO pax Is nombre d’dohant~illons do X. qui...out uslub r -aItistial model relevant to thobe arcac If the Urt chooses a terraln typ- from the lIs- glvtn ,hov, a stetistlcol ’irregulal terr .’n

  5. Volume and aboveground biomass models for dry Miombo woodland in Tanzania

    DEFF Research Database (Denmark)

    Mwakalukwa, Ezekiel Edward; Meilby, Henrik; Treue, Thorsten

    2014-01-01

    Tools to accurately estimate tree volume and biomass are scarce for most forest types in East Africa, including Tanzania. Based on a sample of 142 trees and 57 shrubs from a 6,065 ha area of dry miombo woodland in Iringa rural district in Tanzania, regression models were developed for volume...... and biomass of three important species, Brachystegia spiciformis Benth. (n=40), Combretum molle G. Don (n=41), and Dalbergia arbutifolia Baker (n=37) separately, and for broader samples of trees (28 species, n=72), shrubs (16 species, n=31), and trees and shrubs combined (44 species, n=104). Applied...... of the predictions tended to increase from general to species-specific models. Except for a few volume and biomass models developed for shrubs, all models had R2 values of 96–99%. Thus, the models appear robust and should be applicable to forests with similar site conditions, species, and diameter ranges....

  6. Carbon footprint estimator, phase II : volume I - GASCAP model.

    Science.gov (United States)

    2014-03-01

    The GASCAP model was developed to provide a software tool for analysis of the life-cycle GHG : emissions associated with the construction and maintenance of transportation projects. This phase : of development included techniques for estimating emiss...

  7. Allometric Models for Estimating Tree Volume and Aboveground Biomass in Lowland Forests of Tanzania

    Directory of Open Access Journals (Sweden)

    Wilson Ancelm Mugasha

    2016-01-01

    Full Text Available Models to assist management of lowland forests in Tanzania are in most cases lacking. Using a sample of 60 trees which were destructively harvested from both dry and wet lowland forests of Dindili in Morogoro Region (30 trees and Rondo in Lindi Region (30 trees, respectively, this study developed site specific and general models for estimating total tree volume and aboveground biomass. Specifically the study developed (i height-diameter (ht-dbh models for trees found in the two sites, (ii total, merchantable, and branches volume models, and (iii total and sectional aboveground biomass models of trees found in the two study sites. The findings show that site specific ht-dbh model appears to be suitable in estimating tree height since the tree allometry was found to differ significantly between studied forests. The developed general volume models yielded unbiased mean prediction error and hence can adequately be applied to estimate tree volume in dry and wet lowland forests in Tanzania. General aboveground biomass model appears to yield biased estimates; hence, it is not suitable when accurate results are required. In this case, site specific biomass allometric models are recommended. Biomass allometric models which include basic wood density are highly recommended for improved estimates accuracy when such information is available.

  8. A physical multifield model predicts the development of volume and structure in the human brain

    Science.gov (United States)

    Rooij, Rijk de; Kuhl, Ellen

    2018-03-01

    The prenatal development of the human brain is characterized by a rapid increase in brain volume and a development of a highly folded cortex. At the cellular level, these events are enabled by symmetric and asymmetric cell division in the ventricular regions of the brain followed by an outwards cell migration towards the peripheral regions. The role of mechanics during brain development has been suggested and acknowledged in past decades, but remains insufficiently understood. Here we propose a mechanistic model that couples cell division, cell migration, and brain volume growth to accurately model the developing brain between weeks 10 and 29 of gestation. Our model accurately predicts a 160-fold volume increase from 1.5 cm3 at week 10 to 235 cm3 at week 29 of gestation. In agreement with human brain development, the cortex begins to form around week 22 and accounts for about 30% of the total brain volume at week 29. Our results show that cell division and coupling between cell density and volume growth are essential to accurately model brain volume development, whereas cell migration and diffusion contribute mainly to the development of the cortex. We demonstrate that complex folding patterns, including sinusoidal folds and creases, emerge naturally as the cortex develops, even for low stiffness contrasts between the cortex and subcortex.

  9. Adolescent Idiopathic Scoliosis Thoracic Volume Modeling: The Effect of Surgical Correction.

    Science.gov (United States)

    Wozniczka, Jennifer K; Ledonio, Charles G T; Polly, David W; Rosenstein, Benjamin E; Nuckley, David J

    2017-12-01

    Scoliosis has been shown to have detrimental effects on pulmonary function, traditionally measured by pulmonary function tests, which is theorized to be correlated to the distortion of the spine and thorax. The changes in thoracic volume with surgical correction have not been well quantified. This study seeks to define the effect of surgical correction on thoracic volume in patients with adolescent idiopathic scoliosis. Images were obtained from adolescents with idiopathic scoliosis enrolled in a multicenter database (Prospective Pediatric Scoliosis Study). A convenience sample of patients with Lenke type 1 curves with a complete data set meeting specific parameters was used. Blender v2.63a software was used to construct a 3-dimensional (3D) computational model of the spine from 2-dimensional calibrated radiographs. To accomplish this, the 3D thorax model was deformed to match the calibrated radiographs. The thorax volume was then calculated in cubic centimeters using Mimics v15 software. The results using this computational modeling technique demonstrated that surgical correction resulted in decreased curve measurement as determined by Cobb method, and increased postoperative thoracic volume as expected. Thoracic volume significantly increased by a mean of 567 mm (P3D changes in thoracic volumes using 2-dimensional imaging. This is an assessment of the novel modeling technique, to be used in larger future studies to assess clinical significance. Level 3-retrospective comparison of prospectively collected data.

  10. Developing a stochastic traffic volume prediction model for public-private partnership projects

    Science.gov (United States)

    Phong, Nguyen Thanh; Likhitruangsilp, Veerasak; Onishi, Masamitsu

    2017-11-01

    Transportation projects require an enormous amount of capital investment resulting from their tremendous size, complexity, and risk. Due to the limitation of public finances, the private sector is invited to participate in transportation project development. The private sector can entirely or partially invest in transportation projects in the form of Public-Private Partnership (PPP) scheme, which has been an attractive option for several developing countries, including Vietnam. There are many factors affecting the success of PPP projects. The accurate prediction of traffic volume is considered one of the key success factors of PPP transportation projects. However, only few research works investigated how to predict traffic volume over a long period of time. Moreover, conventional traffic volume forecasting methods are usually based on deterministic models which predict a single value of traffic volume but do not consider risk and uncertainty. This knowledge gap makes it difficult for concessionaires to estimate PPP transportation project revenues accurately. The objective of this paper is to develop a probabilistic traffic volume prediction model. First, traffic volumes were estimated following the Geometric Brownian Motion (GBM) process. Monte Carlo technique is then applied to simulate different scenarios. The results show that this stochastic approach can systematically analyze variations in the traffic volume and yield more reliable estimates for PPP projects.

  11. Finite-volume model for chemical vapor infiltration incorporating radiant heat transfer. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.W.; Starr, T.L. [Georgia Institute of Technology, Atlanta, GA (United States). School of Materials Science and Engineering

    1995-05-01

    Most finite-volume thermal models account for the diffusion and convection of heat and may include volume heating. However, for certain simulation geometries, a large percentage of heat flux is due to thermal radiation. In this paper a finite-volume computational procedure for the simulation of heat transfer by conduction, convection and radiation in three dimensional complex enclosures is developed. The radiant heat transfer is included as a source term in each volume element which is derived by Monte Carlo ray tracing from all possible radiating and absorbing faces. The importance of radiative heat transfer is illustrated in the modeling of chemical vapor infiltration (CVI) of tubes. The temperature profile through the tube preform matches experimental measurements only when radiation is included. An alternative, empirical approach using an {open_quotes}effective{close_quotes} thermal conductivity for the gas space can match the initial temperature profile but does not match temperature changes that occur during preform densification.

  12. Probabilistic Modeling of Aircraft Trajectories for Dynamic Separation Volumes

    Science.gov (United States)

    Lewis, Timothy A.

    2016-01-01

    With a proliferation of new and unconventional vehicles and operations expected in the future, the ab initio airspace design will require new approaches to trajectory prediction for separation assurance and other air traffic management functions. This paper presents an approach to probabilistic modeling of the trajectory of an aircraft when its intent is unknown. The approach uses a set of feature functions to constrain a maximum entropy probability distribution based on a set of observed aircraft trajectories. This model can be used to sample new aircraft trajectories to form an ensemble reflecting the variability in an aircraft's intent. The model learning process ensures that the variability in this ensemble reflects the behavior observed in the original data set. Computational examples are presented.

  13. Recreation of architectural structures using procedural modeling based on volumes

    Directory of Open Access Journals (Sweden)

    Santiago Barroso Juan

    2013-11-01

    Full Text Available While the procedural modeling of buildings and other architectural structures has evolved very significantly in recent years, there is noticeable absence of high-level tools that allow a designer, an artist or an historian, creating important buildings or architectonic structures in a particular city. In this paper we present a tool for creating buildings in a simple and clear, following rules that use the language and methodology of creating their own buildings, and hiding the user the algorithmic details of the creation of the model.

  14. Pharmacodynamic modeling of propofol-induced tidal volume depression in children.

    Science.gov (United States)

    Hahn, Jin-Oh; Khosravi, Sara; Dosani, Maryam; Dumont, Guy A; Mark Ansermino, J

    2011-08-01

    This investigation aimed to develop a pediatric pharmacodynamic model of propofol-induced tidal volume depression towards an ultimate goal of developing a dosing schedule that would preserve spontaneous breathing following a loading dose of propofol. Fifty two ASA 1 and 2 children aged 6-15 year presenting for gastrointestinal endoscopy were enrolled. Subjects were administered a loading dose of 4 mg/kg of propofol intravenously at a constant infusion rate determined by a randomization schedule. Respiratory parameters including tidal volume, respiratory rate, minute volume, and end-tidal CO(2) were recorded at 5 s intervals. Using the predicted plasma concentration, based on the Paedfusor pharmacokinetic model, propofol-induced tidal volume depression was modeled by 3 different approaches (2-stage, pooled, and mixed effects) and results were compared using prediction residual, median percentage errors, median absolute percentage errors, and root-mean-squared normalized errors. The effects of age and body weight as covariates were examined. Respiratory rate and end-tidal CO(2) did not show clear dependence on the predicted plasma concentration. The pharmacodynamic models for tidal volume derived from different modeling approaches were highly consistent. The 2-stage, pooled, and mixed effects approaches yielded k(e0) of 1.06, 1.24, and 0.72 min(-1); γ of 1.10, 0.83, and 0.93; EC50 of 3.18, 3.44, and 3.00 mcg/ml. Including age and body weight as covariates did not significantly improve the predictive performance of the models. A pediatric pharmacodynamic model of propofol-induced tidal volume depression was developed. Models derived from 3 different approaches were shown to be consistent with each other; however, the individual pharmacodynamic parameters exhibited significant inter-individual variability without strong dependence on age and body weight. This would suggest the desirability of adapting the pharmacodynamic model to each subject in real time.

  15. Applying control volume finite element for modelling direct injection boom spraying flow

    OpenAIRE

    El Aissaoui, Abdellah; Lebeau, Frédéric; Destain, Marie-France; Houmy, Karim

    2009-01-01

    Assessment of injection lag transport and uniformity of direct injection boom sprayer is an important issue for successful variable rate spraying technology. To estimate the boom lag transport and pressure loss, a numerical model is formulated on the basis of fluid hydrodynamic conservation equations. The software is implemented in visual basic. To solve the pressure – velocities equations, control volume finite element method (CV) is used to delimit elementary volumes of the boom. Linearizat...

  16. Faster Deterministic Volume Estimation in the Oracle Model via Thin Lattice Coverings

    NARCIS (Netherlands)

    D.N. Dadush (Daniel)

    2015-01-01

    htmlabstractWe give a 2O(n)(1+1/")n time and poly(n)-space deterministic algorithm for computing a (1+")n approximation to the volume of a general convex body K, which comes close to matching the (1+c/")n/2 lower bound for volume estimation in the oracle model by Bárány and Füredi (STOC 1986,

  17. Volume Sculpting: Intuitive, Interactive 3D Shape Modelling

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas

    A system for interactive modelling of 3D shapes on a computer is presented. The system is intuitive and has a flat learning curve. It is especially well suited to the creation of organic shapes and shapes of complex topology. The interaction is simple; the user can either add new shape features...

  18. Modeling Degradation in Solid Oxide Electrolysis Cells - Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Manohar Motwani

    2011-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential,, within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, non-equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  19. Abelian Sandpile Model (ASM) and Infinite Volume Limit

    Indian Academy of Sciences (India)

    Self Organised Criticality (SOC). SOC- dynamics drive a system towards stationary state characterized by power law correlations in space and time. SOC- was proposed by [BTW 87,88] as a mechanism which could explain occurrence of fractal structures in diverse natural phenomena. ASM is a simple model where SOC ...

  20. 3D Modeling and Visualization of Geology Volume based on Geophysical Field Data

    Directory of Open Access Journals (Sweden)

    Min Qi

    2007-10-01

    Full Text Available 3D modeling and visualization of geology volume is very important to interpret accurately and locate subsurface geology volume for mining exploration and deep prospecting. However, it faces a lack of information because the target area is usually unexplored and lacks geological data. This paper presents our experience in applying a 3D model of geology volume based on geophysics. This work has researched and developed a 3D visualization system. It is based on an OO (orientated object approach and modular programming, uses the C++ language and Microsoft .NET platform. This system has built first a high resistivity method and MT database. The system uses irregular tetrahedrons to construct its model and then finally has built the 3D geological model itself.

  1. Modelling and Bayesian adaptive prediction of individual patients’ tumour volume change during radiotherapy

    International Nuclear Information System (INIS)

    Tariq, Imran; Chen, Tao; Kirkby, Norman F; Jena, Rajesh

    2016-01-01

    The aim of this study is to develop a mathematical modelling method that can predict individual patients’ response to radiotherapy, in terms of tumour volume change during the treatment. The main concept is to start from a population-average model, which is subsequently updated from an individual’s tumour volume measurement. The model becomes increasingly personalised and so too does the prediction it produces. This idea of adaptive prediction was realised by using a Bayesian approach for updating the model parameters. The feasibility of the developed method was demonstrated on the data from 25 non-small cell lung cancer patients treated with helical tomotherapy, during which tumour volume was measured from daily imaging as part of the image-guided radiotherapy. The method could provide useful information for adaptive treatment planning and dose scheduling based on the patient’s personalised response. (paper)

  2. Tree Root System Characterization and Volume Estimation by Terrestrial Laser Scanning and Quantitative Structure Modeling

    Directory of Open Access Journals (Sweden)

    Aaron Smith

    2014-12-01

    Full Text Available The accurate characterization of three-dimensional (3D root architecture, volume, and biomass is important for a wide variety of applications in forest ecology and to better understand tree and soil stability. Technological advancements have led to increasingly more digitized and automated procedures, which have been used to more accurately and quickly describe the 3D structure of root systems. Terrestrial laser scanners (TLS have successfully been used to describe aboveground structures of individual trees and stand structure, but have only recently been applied to the 3D characterization of whole root systems. In this study, 13 recently harvested Norway spruce root systems were mechanically pulled from the soil, cleaned, and their volumes were measured by displacement. The root systems were suspended, scanned with TLS from three different angles, and the root surfaces from the co-registered point clouds were modeled with the 3D Quantitative Structure Model to determine root architecture and volume. The modeling procedure facilitated the rapid derivation of root volume, diameters, break point diameters, linear root length, cumulative percentages, and root fraction counts. The modeled root systems underestimated root system volume by 4.4%. The modeling procedure is widely applicable and easily adapted to derive other important topological and volumetric root variables.

  3. ERDYM: Economic Recovery Dynamics Model. Volume 1. Modifications and Simulations.

    Science.gov (United States)

    1984-05-01

    factors of production and demands. The use of input-output structure can improve the realism of the analysis, thus it can aid the formation of policies...follow a neoclassical approach. The second maior *0.1 structural change to ERDYM is the addition of a monetary sector structured so that interest rates...changes, the investment sector 4 * still remains a neoclassical model of optimum capital accumulation rather than -01 the investment sector originally

  4. MARS CODE MANUAL VOLUME V: Models and Correlations

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Bae, Sung Won; Lee, Seung Wook; Yoon, Churl; Hwang, Moon Kyu; Kim, Kyung Doo; Jeong, Jae Jun

    2010-02-01

    Korea Advanced Energy Research Institute (KAERI) conceived and started the development of MARS code with the main objective of producing a state-of-the-art realistic thermal hydraulic systems analysis code with multi-dimensional analysis capability. MARS achieves this objective by very tightly integrating the one dimensional RELAP5/MOD3 with the multi-dimensional COBRA-TF codes. The method of integration of the two codes is based on the dynamic link library techniques, and the system pressure equation matrices of both codes are implicitly integrated and solved simultaneously. In addition, the Equation-Of-State (EOS) for the light water was unified by replacing the EOS of COBRA-TF by that of the RELAP5. This models and correlations manual provides a complete list of detailed information of the thermal-hydraulic models used in MARS, so that this report would be very useful for the code users. The overall structure of the manual is modeled on the structure of the RELAP5 and as such the layout of the manual is very similar to that of the RELAP. This similitude to RELAP5 input is intentional as this input scheme will allow minimum modification between the inputs of RELAP5 and MARS3.1. MARS3.1 development team would like to express its appreciation to the RELAP5 Development Team and the USNRC for making this manual possible

  5. Calibration model of a dual gain flat panel detector for 2D and 3D x-ray imaging

    International Nuclear Information System (INIS)

    Schmidgunst, C.; Ritter, D.; Lang, E.

    2007-01-01

    The continuing research and further development in flat panel detector technology have led to its integration into more and more medical x-ray systems for two-dimensional (2D) and three-dimensional (3D) imaging, such as fixed or mobile C arms. Besides the obvious advantages of flat panel detectors, like the slim design and the resulting optimum accessibility to the patient, their success is primarily a product of the image quality that can be achieved. The benefits in the physical and performance-related features as opposed to conventional image intensifier systems (e.g., distortion-free reproduction of imaging information or almost linear signal response over a large dynamic range) can be fully exploited, however, only if the raw detector images are correctly calibrated and postprocessed. Previous procedures for processing raw data contain idealizations that, in the real world, lead to artifacts or losses in image quality. Thus, for example, temperature dependencies or changes in beam geometry, as can occur with mobile C arm systems, have not been taken into account up to this time. Additionally, adverse characteristics such as image lag or aging effects have to be compensated to attain the best possible image quality. In this article a procedure is presented that takes into account the important dependencies of the individual pixel sensitivity of flat panel detectors used in 2D or 3D imaging and simultaneously minimizes the work required for an extensive recalibration. It is suitable for conventional detectors with only one gain mode as well as for the detectors specially developed for 3D imaging with dual gain read-out technology

  6. REDESIGN OF OUTER HOOD PANEL OF ESEMKA R2 CAR TO IMPROVE PEDESTRIAN PROTECTION USING FINITE ELEMENT MODELING

    Directory of Open Access Journals (Sweden)

    Binyamin Binyamin

    2016-12-01

    Full Text Available Traffic accidents are terrible scourge that occur in many countries, specially for developing countries where transportation affairs like tangled yarn. Besides functioning as an engine compartment cover, the hood of modern compact SUV can also help to manage the impact energy of a pedestrian’s head in a vehicle-pedestrian impact. This paper presents outer hood design of Esemka R2 that has a potential to improve hood’s ability and also to absorb the impact energy of a pedestrian’s head. The developed method for the design of an outer hood configuration aims to provide a robust design and homogeneous of Head Injury Criterion (HIC for impact position at WAD 1000 and three different thicknesses (1.25 mm, 1.35 mm & 1.50 mm of outer hood panel of Esemka R2 compact SUV, taking into consideration the limited space available for deformation. The non-linear Finite Element Analysis (FEA software (Explicit Dynamics was used in this research to simulate the testing procedurs of head impact for child pedestrian. The results show that the average of comparison dimensional of outer hood panel of Esemka R2 was 4.89 mm. The minimum of deformation space meet the requirement for HIC value which required obtaining robust and homogeneous head impact performance. Outer hood thickness and materials were identified as the factors to influence the stress and HIC value of the hood. By comparing all outer hood panels, aluminium alloy as the best selected material which has the lowest value is 32.78% for the pedestrian protection.

  7. Hepatitis virus panel

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003558.htm Hepatitis virus panel To use the sharing features on this page, please enable JavaScript. The hepatitis virus panel is a series of blood tests used ...

  8. Modeling finite-volume effects and chiral symmetry breaking in two-flavor QCD thermodynamics

    Science.gov (United States)

    Klein, Bertram

    2017-11-01

    Finite-volume effects in Quantum Chromodynamics (QCD) have been a subject of much theoretical interest for more than two decades. They are in particular important for the analysis and interpretation of QCD simulations on a finite, discrete space-time lattice. Most of these effects are closely related to the phenomenon of spontaneous breaking of the chiral flavor symmetry and the emergence of pions as light Goldstone bosons. These long-range fluctuations are strongly affected by putting the system into a finite box, and an analysis with different methods can be organized according to the interplay between pion mass and box size. The finite volume also affects critical behavior at the chiral phase transition in QCD. In the present review, I will be mainly concerned with modeling such finite volume effects as they affect the thermodynamics of the chiral phase transition for two quark flavors. I review recent work on the analysis of finite-volume effects which makes use of the quark-meson model for dynamical chiral symmetry breaking. To account for the effects of critical long-range fluctuations close to the phase transition, most of the calculations have been performed using non-perturbative Renormalization Group (RG) methods. I give an overview over the application of these methods to a finite volume. The method, the model and the results are put into the context of related work in random matrix theory for very small volumes, chiral perturbation theory for larger volumes, and related methods and approaches. They are applied towards the analysis of finite-volume effects in lattice QCD simulations and their interpretation, mainly in the context of the chiral phase transition for two quark flavors.

  9. Tactical Target Acquisition Model (TATAC). Volume I. Analysts’ Manual,

    Science.gov (United States)

    1977-12-01

    Cockpit Obstructions C. THE SEARCH TERMo .... ... . . . ..... 0 1-8 D. DISCRIMINABILITY (P3 ) ".. ..-. ... I0-l X. DYNAMICS OF ACQUISITION...amplitude which will be designated the square wave flux response RSF(N(r ]** The mean value of g(x) is: 4S W [rK 1/2 N(r) R *[N(r) - 4"" .(r) K/ ( wr)osN...angles from 20* to 120* off the axis of the flight path using Cassegrain antenna designs . The MARSAM model was modified to account for this variable

  10. COMBINING 3D VOLUME AND MESH MODELS FOR REPRESENTING COMPLICATED HERITAGE BUILDINGS

    Directory of Open Access Journals (Sweden)

    F. Tsai

    2017-08-01

    Full Text Available This study developed a simple but effective strategy to combine 3D volume and mesh models for representing complicated heritage buildings and structures. The idea is to seamlessly integrate 3D parametric or polyhedral models and mesh-based digital surfaces to generate a hybrid 3D model that can take advantages of both modeling methods. The proposed hybrid model generation framework is separated into three phases. Firstly, after acquiring or generating 3D point clouds of the target, these 3D points are partitioned into different groups. Secondly, a parametric or polyhedral model of each group is generated based on plane and surface fitting algorithms to represent the basic structure of that region. A “bare-bones” model of the target can subsequently be constructed by connecting all 3D volume element models. In the third phase, the constructed bare-bones model is used as a mask to remove points enclosed by the bare-bones model from the original point clouds. The remaining points are then connected to form 3D surface mesh patches. The boundary points of each surface patch are identified and these boundary points are projected onto the surfaces of the bare-bones model. Finally, new meshes are created to connect the projected points and original mesh boundaries to integrate the mesh surfaces with the 3D volume model. The proposed method was applied to an open-source point cloud data set and point clouds of a local historical structure. Preliminary results indicated that the reconstructed hybrid models using the proposed method can retain both fundamental 3D volume characteristics and accurate geometric appearance with fine details. The reconstructed hybrid models can also be used to represent targets in different levels of detail according to user and system requirements in different applications.

  11. A simplified permeability model for coalbed methane reservoirs based on matchstick strain and constant volume theory

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Qiang [China University of Mining and Technology, Beijing (China); Harpalani, Satya; Liu, Shimin [Southern Illinois University, Carbondale (United States)

    2011-01-01

    Significant changes occur in the absolute permeability of coalbed methane (CBM) reservoirs during primary depletion or enhanced recovery/CO{sub 2} sequestration operations. In order to project gas production, several analytical models have been developed to predict changes in coal permeability as a function of stress/porosity and sorption. Although these models are more transparent and less complicated than the coupled numerical models, there are differences between the various analytical models and there are several uncertainties. These are discussed briefly in this paper. A new model is then proposed, which is based on the volumetric balance between the bulk coal, and solid grains and pores, using the constant volume theory. It incorporates primarily the changes in grain and cleat volumes and is, therefore, different from the other models that lay heavy emphasis on the pore volume/cleat compressibility values. Finally, in order to demonstrate the simplicity of the proposed model, a history matching exercise is carried out using field data in order to compare the different models. The modeling results suggest that the agreement between the predicted permeability using the existing models and the one proposed here is very good. The merit of the proposed model is its simplicity, and the fact that all input parameters are easily measurable for any coal type with no uncertainties. (author)

  12. Model documentation: Natural gas transmission and distribution model of the National Energy Modeling System. Volume 1

    International Nuclear Information System (INIS)

    1995-01-01

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of integrated Analysis and Forecasting of the Energy information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The methodology employed allows the analysis of impacts of regional capacity constraints in the interstate natural gas pipeline network and the identification of pipeline capacity expansion requirements. There is an explicit representation of core and noncore markets for natural gas transmission and distribution services, and the key components of pipeline tariffs are represented in a pricing algorithm. Natural gas pricing and flow patterns are derived by obtaining a market equilibrium across the three main elements of the natural gas market: the supply element, the demand element, and the transmission and distribution network that links them. The NGTDM consists of four modules: the Annual Flow Module, the Capacity F-expansion Module, the Pipeline Tariff Module, and the Distributor Tariff Module. A model abstract is provided in Appendix A

  13. Model documentation: Natural gas transmission and distribution model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-17

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. NEMS was developed in the Office of integrated Analysis and Forecasting of the Energy information Administration (EIA). NEMS is the third in a series of computer-based, midterm energy modeling systems used since 1974 by the EIA and its predecessor, the Federal Energy Administration, to analyze domestic energy-economy markets and develop projections. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The methodology employed allows the analysis of impacts of regional capacity constraints in the interstate natural gas pipeline network and the identification of pipeline capacity expansion requirements. There is an explicit representation of core and noncore markets for natural gas transmission and distribution services, and the key components of pipeline tariffs are represented in a pricing algorithm. Natural gas pricing and flow patterns are derived by obtaining a market equilibrium across the three main elements of the natural gas market: the supply element, the demand element, and the transmission and distribution network that links them. The NGTDM consists of four modules: the Annual Flow Module, the Capacity F-expansion Module, the Pipeline Tariff Module, and the Distributor Tariff Module. A model abstract is provided in Appendix A.

  14. Volume-Targeted Ventilation in the Neonate: Benchmarking Ventilators on an Active Lung Model.

    Science.gov (United States)

    Krieger, Tobias J; Wald, Martin

    2017-03-01

    Mechanically ventilated neonates have been observed to receive substantially different ventilation after switching ventilator models, despite identical ventilator settings. This study aims at establishing the range of output variability among 10 neonatal ventilators under various breathing conditions. Relative benchmarking test of 10 neonatal ventilators on an active neonatal lung model. Neonatal ICU. Ten current neonatal ventilators. Ventilators were set identically to flow-triggered, synchronized, volume-targeted, pressure-controlled, continuous mandatory ventilation and connected to a neonatal lung model. The latter was configured to simulate three patients (500, 1,500, and 3,500 g) in three breathing modes each (passive breathing, constant active breathing, and variable active breathing). Averaged across all weight conditions, the included ventilators delivered between 86% and 110% of the target tidal volume in the passive mode, between 88% and 126% during constant active breathing, and between 86% and 120% under variable active breathing. The largest relative deviation occurred during the 500 g constant active condition, where the highest output machine produced 147% of the tidal volume of the lowest output machine. All machines deviate significantly in volume output and ventilation regulation. These differences depend on ventilation type, respiratory force, and patient behavior, preventing the creation of a simple conversion table between ventilator models. Universal neonatal tidal volume targets for mechanical ventilation cannot be transferred from one ventilator to another without considering necessary adjustments.

  15. Comprehensive metabolic panel

    Science.gov (United States)

    Metabolic panel - comprehensive; Chem-20; SMA20; Sequential multi-channel analysis with computer-20; SMAC20; Metabolic panel 20 ... Normal values for the panel tests are: Albumin : 3.4 to 5.4 g/dL (34 to 54 g/L) Alkaline phosphatase : 44 to 147 ...

  16. An advective volume-balance model for flow in porous media

    Science.gov (United States)

    Malaga, Carlos; Mandujano, Francisco; Becerra, Julian

    2016-11-01

    Volume-balance models are used by petroleum engineers to simulate multiphase and multicomponent flow phenomena in porous media and the extraction process in oil reservoirs. In these models, mass conservation equations and Darcy's law are supplemented by a balance condition for the pore and fluid volumes. This provides a pressure equation suitable for simulating a compressible flow within a compressible solid matrix. Here we present an alternative interpretation of the volume-balance condition that includes the advective transport within a consolidated porous media. We obtain a modified equation for the time evolution of the pressure field. Preliminary numerical tests of phase separation due to gravity suggest the model reproduces qualitatively the physical phenomena. Fondo Sectorial CONACYT-SENER Grant Number 42536 (DGAJ-SPI-34-170412-217).

  17. Multi-objective optimization of a functionally graded sandwich panel under mechanical loading in the presence of stress constraint

    Science.gov (United States)

    Ashjari, Mohammad; Khoshravan, Mohammad Reza

    2017-12-01

    A method was presented for multi-objective optimization of material distribution of simply supported functionally graded (FG) sandwich panel, and sensitivity analyses of optimal designs were also conducted based on design variables and objective functions. The material composition was assumed to vary only in the thickness direction. Piecewise cubic interpolation of volume fractions was used to calculate volume fractions of constituent material phases at a point; these fractions were defined at a limited number of evenly spaced control points. The effective material properties of the panel were obtained by applying the linear rule of mixtures. The behavior of FG sandwich panel was predicted by Reddy's assumptions of third-order shear deformation theory. Exact solutions for deflections and stresses of simply supported sandwich panel were presented using the Navier-type solution technique. The volume fractions at control points, material, and thickness of the faces which were selected as decision variables were optimized by a multi-objective evolutionary algorithm known as the fast and elitist multi-objective genetic algorithm (NSGA-II). The mass and deflection of the model were considered the objective functions to be minimized with stress constraints. This model was optimized to verify the capability and efficiency of the proposed model under mechanical loading. The framework proposed for designing FG sandwich panel under pure mechanical conditions was furnished by the results.

  18. Glass Transition Temperature of Saccharide Aqueous Solutions Estimated with the Free Volume/Percolation Model.

    Science.gov (United States)

    Constantin, Julian Gelman; Schneider, Matthias; Corti, Horacio R

    2016-06-09

    The glass transition temperature of trehalose, sucrose, glucose, and fructose aqueous solutions has been predicted as a function of the water content by using the free volume/percolation model (FVPM). This model only requires the molar volume of water in the liquid and supercooled regimes, the molar volumes of the hypothetical pure liquid sugars at temperatures below their pure glass transition temperatures, and the molar volumes of the mixtures at the glass transition temperature. The model is simplified by assuming that the excess thermal expansion coefficient is negligible for saccharide-water mixtures, and this ideal FVPM becomes identical to the Gordon-Taylor model. It was found that the behavior of the water molar volume in trehalose-water mixtures at low temperatures can be obtained by assuming that the FVPM holds for this mixture. The temperature dependence of the water molar volume in the supercooled region of interest seems to be compatible with the recent hypothesis on the existence of two structure of liquid water, being the high density liquid water the state of water in the sugar solutions. The idealized FVPM describes the measured glass transition temperature of sucrose, glucose, and fructose aqueous solutions, with much better accuracy than both the Gordon-Taylor model based on an empirical kGT constant dependent on the saccharide glass transition temperature and the Couchman-Karasz model using experimental heat capacity changes of the components at the glass transition temperature. Thus, FVPM seems to be an excellent tool to predict the glass transition temperature of other aqueous saccharides and polyols solutions by resorting to volumetric information easily available.

  19. Precise determination of universal finite volume observables in the Gross-Neveu model

    International Nuclear Information System (INIS)

    Korzec, T.

    2007-01-01

    The Gross-Neveu model is a quantum field theory in two space time dimensions that shares many features with quantum chromo dynamics. In this thesis the continuum model and its discretized versions are reviewed and a finite volume renormalization scheme is introduced and tested. Calculations in the limit of infinitely many fermion flavors as well as perturbative computations are carried out. In extensive Monte-Carlo simulations of the one flavor and the four flavor lattice models with Wilson fermions a set of universal finite volume observables is calculated to a high precision. In the one flavor model which is equivalent to the massless Thirring model the continuum extrapolated Monte-Carlo results are confronted with an exact solution of the model. (orig.)

  20. Integrating Model of the Project Independence Evaluation System. Volume III. User's Guide

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M.L.; Hutzler, M.J.

    1979-03-01

    Volume III of the six-volume series documenting the Integrating Model of PIES provides a potential PIES user with a description of how PIES operates with particular emphasis on the possible variations in assumptions and data that can be made in specifying alternative scenarios. PIES is described as it existed on January 1, 1978. The introductory chapter is followed by Section II, an overview of the structure and components of PIES. Section III discusses each of the PIES components in detail; describes the Demand Model; contains a description of the models, assumptions, and data which provide supply side inputs to the PIES Integrating Model; and concludes with a discussion of those aspects of PIES which extend the scope of the analysis beyond the national energy market. Section IV discusses two reports produced by the PIES Integrating Model: the PIES Integrating Model Report and the Coal Transportation Report. (MCW)

  1. Absorption and scattering coefficient dependence of laser-Doppler flowmetry models for large tissue volumes

    International Nuclear Information System (INIS)

    Binzoni, T; Leung, T S; Ruefenacht, D; Delpy, D T

    2006-01-01

    Based on quasi-elastic scattering theory (and random walk on a lattice approach), a model of laser-Doppler flowmetry (LDF) has been derived which can be applied to measurements in large tissue volumes (e.g. when the interoptode distance is >30 mm). The model holds for a semi-infinite medium and takes into account the transport-corrected scattering coefficient and the absorption coefficient of the tissue, and the scattering coefficient of the red blood cells. The model holds for anisotropic scattering and for multiple scattering of the photons by the moving scatterers of finite size. In particular, it has also been possible to take into account the simultaneous presence of both Brownian and pure translational movements. An analytical and simplified version of the model has also been derived and its validity investigated, for the case of measurements in human skeletal muscle tissue. It is shown that at large optode spacing it is possible to use the simplified model, taking into account only a 'mean' light pathlength, to predict the blood flow related parameters. It is also demonstrated that the 'classical' blood volume parameter, derived from LDF instruments, may not represent the actual blood volume variations when the investigated tissue volume is large. The simplified model does not need knowledge of the tissue optical parameters and thus should allow the development of very simple and cost-effective LDF hardware

  2. Automated modelling of spatially-distributed glacier ice thickness and volume

    Science.gov (United States)

    James, William H. M.; Carrivick, Jonathan L.

    2016-07-01

    Ice thickness distribution and volume are both key parameters for glaciological and hydrological applications. This study presents VOLTA (Volume and Topography Automation), which is a Python script tool for ArcGISTM that requires just a digital elevation model (DEM) and glacier outline(s) to model distributed ice thickness, volume and bed topography. Ice thickness is initially estimated at points along an automatically generated centreline network based on the perfect-plasticity rheology assumption, taking into account a valley side drag component of the force balance equation. Distributed ice thickness is subsequently interpolated using a glaciologically correct algorithm. For five glaciers with independent field-measured bed topography, VOLTA modelled volumes were between 26.5% (underestimate) and 16.6% (overestimate) of that derived from field observations. Greatest differences were where an asymmetric valley cross section shape was present or where significant valley infill had occurred. Compared with other methods of modelling ice thickness and volume, key advantages of VOLTA are: a fully automated approach and a user friendly graphical user interface (GUI), GIS consistent geometry, fully automated centreline generation, inclusion of a side drag component in the force balance equation, estimation of glacier basal shear stress for each individual glacier, fully distributed ice thickness output and the ability to process multiple glaciers rapidly. VOLTA is capable of regional scale ice volume assessment, which is a key parameter for exploring glacier response to climate change. VOLTA also permits subtraction of modelled ice thickness from the input surface elevation to produce an ice-free DEM, which is a key input for reconstruction of former glaciers. VOLTA could assist with prediction of future glacier geometry changes and hence in projection of future meltwater fluxes.

  3. Joint modelling of flood peaks and volumes: A copula application for the Danube River

    Directory of Open Access Journals (Sweden)

    Papaioannou George

    2016-12-01

    Full Text Available Flood frequency analysis is usually performed as a univariate analysis of flood peaks using a suitable theoretical probability distribution of the annual maximum flood peaks or peak over threshold values. However, other flood attributes, such as flood volume and duration, are necessary for the design of hydrotechnical projects, too. In this study, the suitability of various copula families for a bivariate analysis of peak discharges and flood volumes has been tested. Streamflow data from selected gauging stations along the whole Danube River have been used. Kendall’s rank correlation coefficient (tau quantifies the dependence between flood peak discharge and flood volume settings. The methodology is applied to two different data samples: 1 annual maximum flood (AMF peaks combined with annual maximum flow volumes of fixed durations at 5, 10, 15, 20, 25, 30 and 60 days, respectively (which can be regarded as a regime analysis of the dependence between the extremes of both variables in a given year, and 2 annual maximum flood (AMF peaks with corresponding flood volumes (which is a typical choice for engineering studies. The bivariate modelling of the extracted peak discharge - flood volume couples is achieved with the use of the Ali-Mikhail-Haq (AMH, Clayton, Frank, Joe, Gumbel, Hüsler-Reiss, Galambos, Tawn, Normal, Plackett and FGM copula families. Scatterplots of the observed and simulated peak discharge - flood volume pairs and goodness-of-fit tests have been used to assess the overall applicability of the copulas as well as observing any changes in suitable models along the Danube River. The results indicate that for the second data sampling method, almost all of the considered Archimedean class copula families perform better than the other copula families selected for this study, and that for the first method, only the upper-tail-flat copulas excel (except for the AMH copula due to its inability to model stronger relationships.

  4. Solar-Panel Dust Accumulation and Cleanings

    Science.gov (United States)

    2005-01-01

    Air-fall dust accumulates on the solar panels of NASA's Mars Exploration Rovers, reducing the amount of sunlight reaching the solar arrays. Pre-launch models predicted steady dust accumulation. However, the rovers have been blessed with occasional wind events that clear significant amounts of dust from the solar panels. This graph shows the effects of those panel-cleaning events on the amount of electricity generated by Spirit's solar panels. The horizontal scale is the number of Martian days (sols) after Spirit's Jan. 4, 2005, (Universal Time) landing on Mars. The vertical scale indicates output from the rover's solar panels as a fraction of the amount produced when the clean panels first opened. Note that the gradual declines are interrupted by occasional sharp increases, such as a dust-cleaning event on sol 420.

  5. Orbiter radiator panel solar focusing test

    Science.gov (United States)

    Howell, H. R.; Rankin, J. G.

    1983-01-01

    Test data are presented which define the area around the Orbiter radiator panels for which the solar reflections are concentrated to one-sun or more. The concave shape of the panels and their specular silver/Teflon coating causes focusing of the reflected solar energy which could have adverse heating effects on equipment or astronaut extravehicular activity (EVA) in the vicinity of the radiator panels. A room ambient test method was utilized with a one-tenth scale model of the radiator panels.

  6. Performance Prediction Modelling for Flexible Pavement on Low Volume Roads Using Multiple Linear Regression Analysis

    Directory of Open Access Journals (Sweden)

    C. Makendran

    2015-01-01

    Full Text Available Prediction models for low volume village roads in India are developed to evaluate the progression of different types of distress such as roughness, cracking, and potholes. Even though the Government of India is investing huge quantum of money on road construction every year, poor control over the quality of road construction and its subsequent maintenance is leading to the faster road deterioration. In this regard, it is essential that scientific maintenance procedures are to be evolved on the basis of performance of low volume flexible pavements. Considering the above, an attempt has been made in this research endeavor to develop prediction models to understand the progression of roughness, cracking, and potholes in flexible pavements exposed to least or nil routine maintenance. Distress data were collected from the low volume rural roads covering about 173 stretches spread across Tamil Nadu state in India. Based on the above collected data, distress prediction models have been developed using multiple linear regression analysis. Further, the models have been validated using independent field data. It can be concluded that the models developed in this study can serve as useful tools for the practicing engineers maintaining flexible pavements on low volume roads.

  7. Determinants of Economic Growth for EU - 27 Countries and Turkey: An Implem e ntation with Static Panel Model

    Directory of Open Access Journals (Sweden)

    Aynur Pala

    2014-03-01

    Full Text Available The aim of this study is to figure out the determinants that explain the economic growth for EU27 countries and Turkey for the years 2000-2011. The database consists of GDP, population, total local credits to GDP, private sector credits to GDP, foreign trade to GDP, consumer inflation and total savings to GNI. Initially, unit root tests such as LLC and Hadri are implemented. Then, Breusch-Pagan LM, Breusch-Pagan/Cook-Weisberg LM and White tests are run for heterogeneity and Wooldridge (2000 test for autocorrelation. Static panel regression have been used to analysis. As a result of the analysis, economic growth has been explained by human capital, credits providing by banking sector, inflation, financial development and savings.

  8. ATHENA code manual. Volume 1. Code structure, system models, and solution methods

    International Nuclear Information System (INIS)

    Carlson, K.E.; Roth, P.A.; Ransom, V.H.

    1986-09-01

    The ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) code has been developed to perform transient simulation of the thermal hydraulic systems which may be found in fusion reactors, space reactors, and other advanced systems. A generic modeling approach is utilized which permits as much of a particular system to be modeled as necessary. Control system and secondary system components are included to permit modeling of a complete facility. Several working fluids are available to be used in one or more interacting loops. Different loops may have different fluids with thermal connections between loops. The modeling theory and associated numerical schemes are documented in Volume I in order to acquaint the user with the modeling base and thus aid effective use of the code. The second volume contains detailed instructions for input data preparation

  9. Glass Property Data and Models for Estimating High-Level Waste Glass Volume

    International Nuclear Information System (INIS)

    Vienna, John D.; Fluegel, Alexander; Kim, Dong-Sang; Hrma, Pavel R.

    2009-01-01

    This report describes recent efforts to develop glass property models that can be used to help estimate the volume of high-level waste (HLW) glass that will result from vitrification of Hanford tank waste. The compositions of acceptable and processable HLW glasses need to be optimized to minimize the waste-form volume and, hence, to save cost. A database of properties and associated compositions for simulated waste glasses was collected for developing property-composition models. This database, although not comprehensive, represents a large fraction of data on waste-glass compositions and properties that were available at the time of this report. Glass property-composition models were fit to subsets of the database for several key glass properties. These models apply to a significantly broader composition space than those previously publised. These models should be considered for interim use in calculating properties of Hanford waste glasses.

  10. Models for high cell density bioreactors must consider biomass volume fraction: Cell recycle example.

    Science.gov (United States)

    Monbouquette, H G

    1987-06-01

    Intrinsic models, which take into account biomass volume fraction, must be formulated for adequate simulation of high-biomass-density fermentations with cell recycle. Through comparison of corresponding intrinsic and non-intrinsic models in dimensionless form, constraints for non-intrinsic model usage in terms of biokinetic and fermenter operating parameters can be identified a priori. Analysis of a simple product-inhibition model indicates that the non-intrinsic approach is suitable only when the attainable biomass volume fraction in the fermentation broth is less than about 0.10. Inappropriate application of a non-intrinsic model can lead to gross errors in calculated substrate and product concentrations, substrate conversion, and volumetric productivity.

  11. Models for high cell density bioreactors must consider biomass volume fraction: cell recycle example

    Energy Technology Data Exchange (ETDEWEB)

    Monbouquette, H.G.

    1987-06-01

    Intrinsic models, which take into account biomass volume fraction, must be formulated for adequate simulation of high-biomass-density fermentations with cell recycle. Through comparison of corresponding intrinsic and non-intrinsic models in dimensionless form, constraints for non-intrinsic model usage in terms of biokinetic and fermenter operating parameters can be identified a priori. Analysis of a simple product-inhibition model indicates that the non-intrinsic approach is suitable only when the attainable biomass volume fraction in the fermentation broth is less than about 0.10. Inappropriate application of a non-intrinsic model can lead to gross errors in calculated substrate and product concentrations, substrate conversion, and volumetric productivity. (Refs. 14).

  12. Glass Property Data and Models for Estimating High-Level Waste Glass Volume

    Energy Technology Data Exchange (ETDEWEB)

    Vienna, John D.; Fluegel, Alexander; Kim, Dong-Sang; Hrma, Pavel R.

    2009-10-05

    This report describes recent efforts to develop glass property models that can be used to help estimate the volume of high-level waste (HLW) glass that will result from vitrification of Hanford tank waste. The compositions of acceptable and processable HLW glasses need to be optimized to minimize the waste-form volume and, hence, to save cost. A database of properties and associated compositions for simulated waste glasses was collected for developing property-composition models. This database, although not comprehensive, represents a large fraction of data on waste-glass compositions and properties that were available at the time of this report. Glass property-composition models were fit to subsets of the database for several key glass properties. These models apply to a significantly broader composition space than those previously publised. These models should be considered for interim use in calculating properties of Hanford waste glasses.

  13. Continuous modelling study of numerical volumes - Applications to the visualization of anatomical structures

    International Nuclear Information System (INIS)

    Goret, C.

    1990-12-01

    Several technics of imaging (IRM, image scanners, tomoscintigraphy, echography) give numerical informations presented by means of a stack of parallel cross-sectional images. Since many years, 3-D mathematical tools have been developed and allow the 3 D images synthesis of surfaces. In first part, we give the technics of numerical volume exploitation and their medical applications to diagnosis and therapy. The second part is about a continuous modelling of the volume with a tensor product of cubic splines. We study the characteristics of this representation and its clinical validation. Finally, we treat of the problem of surface visualization of objects contained in the volume. The results show the interest of this model and allow to propose specifications for 3-D workstation realization [fr

  14. Assessment of uncertainty in the numerical simulation of solar irradiance over inclined PV panels: New algorithms using measurements and modeling tools

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yu; Sengupta, Manajit; Dooraghi, Mike

    2018-05-01

    Development of accurate transposition models to simulate plane-of-array (POA) irradiance from horizontal measurements or simulations is a complex process mainly because of the anisotropic distribution of diffuse solar radiation in the atmosphere. The limited availability of reliable POA measurements at large temporal and spatial scales leads to difficulties in the comprehensive evaluation of transposition models. This paper proposes new algorithms to assess the uncertainty of transposition models using both surface-based observations and modeling tools. We reviewed the analytical derivation of POA irradiance and the approximation of isotropic diffuse radiation that simplifies the computation. Two transposition models are evaluated against the computation by the rigorous analytical solution. We proposed a new algorithm to evaluate transposition models using the clear-sky measurements at the National Renewable Energy Laboratory's (NREL's) Solar Radiation Research Laboratory (SRRL) and a radiative transfer model that integrates diffuse radiances of various sky-viewing angles. We found that the radiative transfer model and a transposition model based on empirical regressions are superior to the isotropic models when compared to measurements. We further compared the radiative transfer model to the transposition models under an extensive range of idealized conditions. Our results suggest that the empirical transposition model has slightly higher cloudy-sky POA irradiance than the radiative transfer model, but performs better than the isotropic models under clear-sky conditions. Significantly smaller POA irradiances computed by the transposition models are observed when the photovoltaics (PV) panel deviates from the azimuthal direction of the sun. The new algorithms developed in the current study have opened the door to a more comprehensive evaluation of transposition models for various atmospheric conditions and solar and PV orientations.

  15. Clinically useful dilution factors for iodine and gadolinium contrast material: an animal model of pediatric digital subtraction angiography using state-of-the-art flat-panel detectors.

    Science.gov (United States)

    Racadio, John M; Kashinkunti, Soumya R; Nachabe, Rami A; Racadio, Judy M; Johnson, Neil D; Kukreja, Kamlesh U; Patel, Manish N; Privitera, Mary Beth; Hales, Jasmine E; Abruzzo, Todd A

    2013-11-01

    Iodinated and gadolinium contrast agents pose some risk for certain pediatric patients, including allergic-like reactions, contrast-induced nephropathy (CIN) and nephrogenic systemic fibrosis (NSF). Digital flat-panel detectors enhance image quality during angiography and might allow use of more dilute contrast material to decrease risk of complications that might be dose-dependent, such as CIN and NSF. To assess the maximum dilution factors for iodine- and gadolinium-based contrast agents suitable for vascular imaging with fluoroscopy and digital subtraction angiography (DSA) on digital flat-panel detectors in an animal model. We performed selective catheterization of the abdominal aorta, renal artery and common carotid artery on a rabbit. In each vessel we performed fluoroscopy and DSA during contrast material injection using iodinated and gadolinium contrast material at 100%, 80%, 50%, 33% and 20% dilutions. An image quality score (0 to 3) was assigned by each of eight evaluators. Intracorrelation coefficient, paired t-test, one-way repeated analysis of variance, Spearman correlation and receiver operating characteristic curve analysis were applied to the data. Overall the image quality scores correlated linearly with dilution levels. For iodinated contrast material, the optimum cut-off level for DSA when a score of at least 2 is acceptable is above 33%; it is above 50% when a score of 3 is necessary. For gadolinium contrast material, the optimum cut-off for DSA images is above 50% when a score of at least 2 is acceptable and above 80% when a score of 3 is necessary. Knowledge of the relationship between image quality and contrast material dilution might allow a decrease in overall contrast load while maintaining appropriate image quality when using digital flat-panel detectors.

  16. MELSAR: a mesoscale air quality model for complex terrain. Volume 2. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Allwine, K.J.; Whiteman, C.D.

    1985-04-01

    This final report is submitted as part of the Green River Ambient Model Assessment (GRAMA) project conducted at the US Department of Energy's Pacific Northwest Laboratory for the US Environmental Protection Agency. The GRAMA Program has, as its ultimate goal, the development of validated air quality models that can be applied to the complex terrain of the Green River Formation of western Colorado, eastern Utah and southern Wyoming. The Green River Formation is a geologic formation containing large reserves of oil shale, coal, and other natural resources. Development of these resources may lead to a degradation of the air quality of the region. Air quality models are needed immediately for planning and regulatory purposes to assess the magnitude of these regional impacts. This report documents one of the models being developed for this purpose within GRAMA - specifically a model to predict short averaging time (less than or equal to 24 h) pollutant concentrations resulting from the mesoscale transport of pollutant releases from multiple sources. MELSAR has not undergone any rigorous operational testing, sensitivity analyses, or validation studies. Testing and evaluation of the model are needed to gain a measure of confidence in the model's performance. This report consists of two volumes. This volume contains the Appendices, which include listings of the FORTRAN code and Volume 1 contains the model overview, technical description, and user's guide. 13 figs., 10 tabs.

  17. A model to incorporate organ deformation in the evaluation of dose/volume relationship

    International Nuclear Information System (INIS)

    Yan, D.; Jaffray, D.; Wong, J.; Brabbins, D.; Martinez, A. A.

    1997-01-01

    Purpose: Measurements of internal organ motion have demonstrated that daily organ deformation exists during the course of radiation treatment. However, a model to evaluate the resultant dose delivered to a daily deformed organ remains a difficult challenge. Current methods which model such organ deformation as rigid body motion in the dose calculation for treatment planning evaluation are incorrect and misleading. In this study, a new model for treatment planning evaluation is introduced which incorporates patient specific information of daily organ deformation and setup variation. The model was also used to retrospectively analyze the actual treatment data measured using daily CT scans for 5 patients with prostate treatment. Methods and Materials: The model assumes that for each patient, the organ of interest can be measured during the first few treatment days. First, the volume of each organ is delineated from each of the daily measurements and cumulated in a 3D bit-map. A tissue occupancy distribution is then constructed with the 50% isodensity representing the mean, or effective, organ volume. During the course of treatment, each voxel in the effective organ volume is assumed to move inside a local 3D neighborhood with a specific distribution function. The neighborhood and the distribution function are deduced from the positions and shapes of the organ in the first few measurements using the biomechanics model of viscoelastic body. For each voxel, the local distribution function is then convolved with the spatial dose distribution. The latter includes also the variation in dose due to daily setup error. As a result, the cumulative dose to the voxel incorporates the effects of daily setup variation and organ deformation. A ''variation adjusted'' dose volume histogram, aDVH, for the effective organ volume can then be constructed for the purpose of treatment evaluation and optimization. Up to 20 daily CT scans and daily portal images for 5 patients with prostate

  18. On the Use of Generalized Volume Scattering Models for the Improvement of General Polarimetric Model-Based Decomposition

    Directory of Open Access Journals (Sweden)

    Qinghua Xie

    2017-01-01

    Full Text Available Recently, a general polarimetric model-based decomposition framework was proposed by Chen et al., which addresses several well-known limitations in previous decomposition methods and implements a simultaneous full-parameter inversion by using complete polarimetric information. However, it only employs four typical models to characterize the volume scattering component, which limits the parameter inversion performance. To overcome this issue, this paper presents two general polarimetric model-based decomposition methods by incorporating the generalized volume scattering model (GVSM or simplified adaptive volume scattering model, (SAVSM proposed by Antropov et al. and Huang et al., respectively, into the general decomposition framework proposed by Chen et al. By doing so, the final volume coherency matrix structure is selected from a wide range of volume scattering models within a continuous interval according to the data itself without adding unknowns. Moreover, the new approaches rely on one nonlinear optimization stage instead of four as in the previous method proposed by Chen et al. In addition, the parameter inversion procedure adopts the modified algorithm proposed by Xie et al. which leads to higher accuracy and more physically reliable output parameters. A number of Monte Carlo simulations of polarimetric synthetic aperture radar (PolSAR data are carried out and show that the proposed method with GVSM yields an overall improvement in the final accuracy of estimated parameters and outperforms both the version using SAVSM and the original approach. In addition, C-band Radarsat-2 and L-band AIRSAR fully polarimetric images over the San Francisco region are also used for testing purposes. A detailed comparison and analysis of decomposition results over different land-cover types are conducted. According to this study, the use of general decomposition models leads to a more accurate quantitative retrieval of target parameters. However, there

  19. Air loads on solar panels during launch

    NARCIS (Netherlands)

    Beltman, W.M.; van der Hoogt, Peter; Spiering, R.M.E.J.; Tijdeman, H.

    1996-01-01

    The dynamical behaviour of solar panels during launch is significantly affected by the thin layers of air trapped between the panels. For narrow gaps the air manifests itself not only as a considerable added mass, but its viscosity can result in a substantial amount of damping. A model has been

  20. PAN AIR - A Computer Program for Predicting Subsonic or Supersonic Linear Potential Flows about Arbitrary Configurations Using a Higher Order Panel Method. Volume I. Theory Document (Version 1.0)

    Science.gov (United States)

    1980-04-15

    Subsonic and Supersonic Speeds," Journal of Aircraft, Vol. 5, No. 6, Nov.-Dec. 1968, pp. 528-534. 1.2b Woodward, F. A.: "An Improved Method for the...Methods, HSA-MAE-R-FDM-O039, British Nirceaft Corpormbion,’ er, 1978, B.2 Johnson, F. T., Lu, P., Tinoco, E. N., and Epton, M. A.: An Improved Panel Method...subsonic flow except for a jump by 4w across the panel. Thus hJ is continuo ,:s everywhere in subsonic flow except near the panel edge, where Ik - log

  1. Real-time bladder volume monitoring by the application of a new implantable bladder volume sensor for a small animal model

    Directory of Open Access Journals (Sweden)

    Dong Sup Lee

    2011-04-01

    Full Text Available Although real-time monitoring of bladder volume together with intravesical pressure can provide more information for understanding the functional changes of the urinary bladder, it still entails difficulties in the accurate prediction of real-time bladder volume in urodynamic studies with small animal models. We studied a new implantable bladder volume monitoring device with eight rats. During cystometry, microelectrodes prepared by the microelectromechanical systems process were placed symmetrically on both lateral walls of the bladder, and the expanded bladder volume was calculated. Immunohistological study was done after 1 week and after 4 weeks to evaluate the biocompatibility of the microelectrode. From the point that infused saline volume into the bladder was higher than 0.6 mL, estimated bladder volume was statistically correlated with the volume of saline injected (p<0.01. Additionally, the microelectromechanical system microelectrodes used in this study showed reliable biocompatibility. Therefore, the device can be used to evaluate changes in bladder volume in studies with small animals, and it may help to provide more information about functional changes in the bladder in laboratory studies. Furthermore, owing to its biocompatibility, the device could be chronically implanted in conscious ambulating animals, thus allowing a novel longitudinal study to be performed for a specific purpose.

  2. Sensitivity Analysis of Wavelet Neural Network Model for Short-Term Traffic Volume Prediction

    Directory of Open Access Journals (Sweden)

    Jinxing Shen

    2013-01-01

    Full Text Available In order to achieve a more accurate and robust traffic volume prediction model, the sensitivity of wavelet neural network model (WNNM is analyzed in this study. Based on real loop detector data which is provided by traffic police detachment of Maanshan, WNNM is discussed with different numbers of input neurons, different number of hidden neurons, and traffic volume for different time intervals. The test results show that the performance of WNNM depends heavily on network parameters and time interval of traffic volume. In addition, the WNNM with 4 input neurons and 6 hidden neurons is the optimal predictor with more accuracy, stability, and adaptability. At the same time, a much better prediction record will be achieved with the time interval of traffic volume are 15 minutes. In addition, the optimized WNNM is compared with the widely used back-propagation neural network (BPNN. The comparison results indicated that WNNM produce much lower values of MAE, MAPE, and VAPE than BPNN, which proves that WNNM performs better on short-term traffic volume prediction.

  3. Comparison of Moving Boundary and Finite-Volume Heat Exchanger Models in the Modelica Language

    Directory of Open Access Journals (Sweden)

    Adriano Desideri

    2016-05-01

    Full Text Available When modeling low capacity energy systems, such as a small size (5–150 kWel organic Rankine cycle unit, the governing dynamics are mainly concentrated in the heat exchangers. As a consequence, the accuracy and simulation speed of the higher level system model mainly depend on the heat exchanger model formulation. In particular, the modeling of thermo-flow systems characterized by evaporation or condensation requires heat exchanger models capable of handling phase transitions. To this aim, the finite volume (FV and the moving boundary (MB approaches are the most widely used. The two models are developed and included in the open-source ThermoCycle Modelica library. In this contribution, a comparison between the two approaches is presented. An integrity and accuracy test is designed to evaluate the performance of the FV and MB models during transient conditions. In order to analyze how the two modeling approaches perform when integrated at a system level, two organic Rankine cycle (ORC system models are built using the FV and the MB evaporator model, and their responses are compared against experimental data collected on an 11 kWel ORC power unit. Additionally, the effect of the void fraction value in the MB evaporator model and of the number of control volumes (CVs in the FV one is investigated. The results allow drawing general guidelines for the development of heat exchanger dynamic models involving two-phase flows.

  4. Volume and Aboveground Biomass Models for Dry Miombo Woodland in Tanzania

    Directory of Open Access Journals (Sweden)

    Ezekiel Edward Mwakalukwa

    2014-01-01

    Full Text Available Tools to accurately estimate tree volume and biomass are scarce for most forest types in East Africa, including Tanzania. Based on a sample of 142 trees and 57 shrubs from a 6,065 ha area of dry miombo woodland in Iringa rural district in Tanzania, regression models were developed for volume and biomass of three important species, Brachystegia spiciformis Benth. (n = 40, Combretum molle G. Don (n = 41, and Dalbergia arbutifolia Baker (n = 37 separately, and for broader samples of trees (28 species, n = 72, shrubs (16 species, n = 32, and trees and shrubs combined (44 species, n = 104. Applied independent variables were log-transformed diameter, height, and wood basic density, and in each case a range of different models were tested. The general tendency among the final models is that the fit improved when height and wood basic density were included. Also the precision and accuracy of the predictions tended to increase from general to species-specific models. Except for a few volume and biomass models developed for shrubs, all models had R2 values of 96–99%. Thus, the models appear robust and should be applicable to forests with similar site conditions, species, and diameter ranges.

  5. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael

    2010-07-26

    The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, socalled panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects. © 2010 ACM.

  6. Paneling architectural freeform surfaces

    KAUST Repository

    Eigensatz, Michael

    2010-07-25

    The emergence of large-scale freeform shapes in architecture poses big challenges to the fabrication of such structures. A key problem is the approximation of the design surface by a union of patches, so-called panels, that can be manufactured with a selected technology at reasonable cost, while meeting the design intent and achieving the desired aesthetic quality of panel layout and surface smoothness. The production of curved panels is mostly based on molds. Since the cost of mold fabrication often dominates the panel cost, there is strong incentive to use the same mold for multiple panels. We cast the major practical requirements for architectural surface paneling, including mold reuse, into a global optimization framework that interleaves discrete and continuous optimization steps to minimize production cost while meeting user-specified quality constraints. The search space for optimization is mainly generated through controlled deviation from the design surface and tolerances on positional and normal continuity between neighboring panels. A novel 6-dimensional metric space allows us to quickly compute approximate inter-panel distances, which dramatically improves the performance of the optimization and enables the handling of complex arrangements with thousands of panels. The practical relevance of our system is demonstrated by paneling solutions for real, cutting-edge architectural freeform design projects.

  7. RELAP5/MOD3 code manual: Code structure, system models, and solution methods. Volume 1

    International Nuclear Information System (INIS)

    1995-08-01

    The RELAP5 code has been developed for best estimate transient simulation of light water reactor coolant systems during postulated accidents. The code models the coupled behavior of the reactor coolant system and the core for loss-of-coolant accidents, and operational transients, such as anticipated transient without scram, loss of offsite power, loss of feedwater, and loss of flow. A generic modeling, approach is used that permits simulating a variety of thermal hydraulic systems. Control system and secondary system components are included to permit modeling of plant controls, turbines, condensers, and secondary feedwater systems. RELAP5/MOD3 code documentation is divided into seven volumes: Volume I provides modeling theory and associated numerical schemes

  8. Volume Averaging Theory (VAT) based modeling and closure evaluation for fin-and-tube heat exchangers

    Science.gov (United States)

    Zhou, Feng; Catton, Ivan

    2012-10-01

    A fin-and-tube heat exchanger was modeled based on Volume Averaging Theory (VAT) in such a way that the details of the original structure was replaced by their averaged counterparts, so that the VAT based governing equations can be efficiently solved for a wide range of parameters. To complete the VAT based model, proper closure is needed, which is related to a local friction factor and a heat transfer coefficient of a Representative Elementary Volume (REV). The terms in the closure expressions are complex and sometimes relating experimental data to the closure terms is difficult. In this work we use CFD to evaluate the rigorously derived closure terms over one of the selected REVs. The objective is to show how heat exchangers can be modeled as a porous media and how CFD can be used in place of a detailed, often formidable, experimental effort to obtain closure for the model.

  9. Computational Methods for Protein Structure Prediction and Modeling Volume 1: Basic Characterization

    CERN Document Server

    Xu, Ying; Liang, Jie

    2007-01-01

    Volume one of this two volume sequence focuses on the basic characterization of known protein structures as well as structure prediction from protein sequence information. The 11 chapters provide an overview of the field, covering key topics in modeling, force fields, classification, computational methods, and struture prediction. Each chapter is a self contained review designed to cover (1) definition of the problem and an historical perspective, (2) mathematical or computational formulation of the problem, (3) computational methods and algorithms, (4) performance results, (5) existing software packages, and (6) strengths, pitfalls, challenges, and future research directions.

  10. Non-linear panel flutter for temperature-dependent functionally graded material panels

    Science.gov (United States)

    Ibrahim, Hesham Hamed; Tawfik, Mohammad; Al-Ajmi, Mohammed

    2008-01-01

    The non-linear flutter and thermal buckling of an FGM panel under the combined effect of elevated temperature conditions and aerodynamic loading is investigated using a finite element model based on the thin plate theory and von Karman strain-displacement relations to account for moderately large deflection. The aerodynamic pressure is modeled using the quasi-steady first order piston theory. The governing non-linear equations are obtained using the principal of virtual work adopting an approach based on the thermal strain being a cumulative physical quantity to account for temperature dependent material properties. This system of non-linear equations is solved by Newton-Raphson numerical technique. It is found that the temperature increase has an adverse effect on the FGM panel flutter characteristics through decreasing the critical dynamic pressure. Decreasing the volume fraction enhances flutter characteristics but this is limited by structural integrity aspect. The presence of aerodynamic flow results in postponing the buckling temperature and in suppressing the post buckling deflection while the temperature increase gives way for higher limit cycle amplitude.

  11. The Development of a Finite Volume Method for Modeling Sound in Coastal Ocean Environment

    Energy Technology Data Exchange (ETDEWEB)

    Long, Wen; Yang, Zhaoqing; Copping, Andrea E.; Jung, Ki Won; Deng, Zhiqun

    2015-10-28

    : As the rapid growth of marine renewable energy and off-shore wind energy, there have been concerns that the noises generated from construction and operation of the devices may interfere marine animals’ communication. In this research, a underwater sound model is developed to simulate sound prorogation generated by marine-hydrokinetic energy (MHK) devices or offshore wind (OSW) energy platforms. Finite volume and finite difference methods are developed to solve the 3D Helmholtz equation of sound propagation in the coastal environment. For finite volume method, the grid system consists of triangular grids in horizontal plane and sigma-layers in vertical dimension. A 3D sparse matrix solver with complex coefficients is formed for solving the resulting acoustic pressure field. The Complex Shifted Laplacian Preconditioner (CSLP) method is applied to efficiently solve the matrix system iteratively with MPI parallelization using a high performance cluster. The sound model is then coupled with the Finite Volume Community Ocean Model (FVCOM) for simulating sound propagation generated by human activities in a range-dependent setting, such as offshore wind energy platform constructions and tidal stream turbines. As a proof of concept, initial validation of the finite difference solver is presented for two coastal wedge problems. Validation of finite volume method will be reported separately.

  12. Electric field distribution in a finite-volume head model of deep brain stimulation.

    Science.gov (United States)

    Grant, Peadar F; Lowery, Madeleine M

    2009-11-01

    This study presents a whole-head finite element model of deep brain stimulation to examine the effect of electrical grounding, the finite conducting volume of the head, and scalp, skull and cerebrospinal fluid layers. The impedance between the stimulating and reference electrodes in the whole-head model was found to lie within clinically reported values when the reference electrode was incorporated on a localized surface in the model. Incorporation of the finite volume of the head and inclusion of surrounding outer tissue layers reduced the magnitude of the electric field and activating function by approximately 20% in the region surrounding the electrode. Localized distortions of the electric field were also observed when the electrode was placed close to the skull. Under bipolar conditions the effect of the finite conducting volume was shown to be negligible. The results indicate that, for monopolar stimulation, incorporation of the finite volume and outer tissue layers can alter the magnitude of the electric field and activating function when the electrode is deep within the brain, and may further affect the shape if the electrode is close to the skull.

  13. Influencing Factors and Development Trend Analysis of China Electric Grid Investment Demand Based on a Panel Co-Integration Model

    Directory of Open Access Journals (Sweden)

    Jinchao Li

    2018-01-01

    Full Text Available Electric grid investment demand analysis is significant to reasonably arranging construction funds for the electric grid and reduce costs. This paper used the panel data of electric grid investment from 23 provinces of China between 2004 and 2016 as samples to analyze the influence between electric grid investment demand and GDP, population scale, social electricity consumption, installed electrical capacity, and peak load based on co-integration tests. We find that GDP and peak load have positive influences on electric grid investment demand, but the impact of population scale, social electricity consumption, and installed electrical capacity on electric grid investment is not remarkable. We divide different regions in China into the eastern region, central region, and western region to analyze influence factors of electric grid investment, finally obtaining key factors in the eastern, central, and western regions. In the end, according to the analysis of key factors, we make a prediction about China’s electric grid investment for 2020 in different scenarios. The results offer a certain understanding for the development trend of China’s electric grid investment and contribute to the future development of electric grid investment.

  14. Enhanced model of one axis-two positions manual tracking photovoltaic panels for lighting projects in Palestine

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, M.T.; Albarqouni, S.N. [The Islamic University of Gaza, Gaza, Gaza Strip, Palestine (Israel)

    2010-08-13

    Palestine receives good solar radiation throughout the year. The orientation of a solar collector (SC) in space is the primary factor influencing the quantity of absorbed solar radiation energy. By maximizing the optimal angles of a solar collector, the maximum of solar radiant energy will be achieved. This paper discussed a study that presented a new design idea of a one axis two position manual tracking photovoltaic (PV) system and demonstrated the enhancements on the optimum design. The purpose of this study was to provide technical information about tilt angle and orientation of PV panels for architects who are interested in building integrated photovoltaic (BIPV) systems and practitioner engineers who are interested in the utilization of renewable energy to enhance the efficiency of PV systems while reducing costs. The optimum tilt angle was determined mathematically. The optimum tilt angle depends on the geographical position and on the investigation period when the position of a solar collector will be stationary. The paper presented a case study on the lighting Gaza Valley project, which involved the re-design and re-evaluation for orientation and tiling of a previous design. It was concluded that power generation could be increased by 17 percent of the previous design, and can be increased by 3 percent of the optimum design without any additional cost. 12 refs., 3 tabs., 14 figs.

  15. Titanium Honeycomb Panel Testing

    Science.gov (United States)

    Richards, W. Lance; Thompson, Randolph C.

    1996-01-01

    Thermal-mechanical tests were performed on a titanium honeycomb sandwich panel to experimentally validate the hypersonic wing panel concept and compare test data with analysis. Details of the test article, test fixture development, instrumentation, and test results are presented. After extensive testing to 900 deg. F, non-destructive evaluation of the panel has not detected any significant structural degradation caused by the applied thermal-mechanical loads.

  16. Solar reflection panels

    Science.gov (United States)

    Diver, Jr., Richard B.; Grossman, James W [Albuquerque, NM; Reshetnik, Michael [Boulder, CO

    2006-07-18

    A solar collector comprising a glass mirror, and a composite panel, wherein the back of the mirror is affixed to a front surface of the composite panel. The composite panel comprises a front sheet affixed to a surface of a core material, preferably a core material comprising a honeycomb structure, and a back sheet affixed to an opposite surface of the core material. The invention may further comprise a sealing strip, preferably comprising EPDM, positioned between the glass mirror and the front surface of the composite panel. The invention also is of methods of making such solar collectors.

  17. A structural model of age, grey matter volumes, education, and personality traits.

    Science.gov (United States)

    Kitamura, Soichiro; Yasuno, Fumihiko; Yamamoto, Akihide; Kazui, Hiroaki; Kudo, Takashi; Matsuoka, Kiwamu; Kiuchi, Kuniaki; Kosaka, Jun; Nagatsuka, Kazuyuki; Iida, Hidehiro; Kishimoto, Toshifumi

    2016-01-01

    When the relationship between ageing and changes in personality traits is considered, it is important to know how they are influenced by biological and environmental factors. The present study examined the relationships between various factors associated with the effect of ageing on personality traits, including structural changes of the brain and environmental factors such as education. We recruited 41 healthy subjects. We administered the NEO Five-Factor Inventory to assess personality factors. Magnetic resonance imaging was performed, and regional grey matter (GM) volumes were obtained. We identified associations in the correlation analysis of age, cerebral GM volume, years of education, and the personality trait of openness. Path analysis was used to estimate the relationships among these factors. The path analysis model of age, GM volume, years of education, and the personality trait of openness revealed that age has an indirect negative association with openness through GM volume and years of education. Ageing was related to a decrease in GM volume, which was in turn related to a decrease in the openness score. Older subjects generally had fewer years of education, which was related to a lower openness score. Maintaining openness against the effects of ageing is desirable, and our results imply that interventions against age-related cerebral atrophy and the promotion of opportunities for higher education may contribute to the development and stability of a healthy personality during the adult life course. © 2015 The Authors. Psychogeriatrics © 2015 Japanese Psychogeriatric Society.

  18. A Control Volume Model of Solute Transport in a Single Fracture

    Science.gov (United States)

    Kennedy, Christopher A.; Lennox, William C.

    1995-02-01

    A control volume model of solute transport through a single fracture in a porous matrix is developed. Application to problems of contaminant transport through fractured clay demonstrates several strong features of the method. The control volume approach inherently conserves mass and treats dispersivity at interfaces in a physically correct manner. By employing an upstream weighting scheme, based on the exact solution to the one-dimensional steady state advection-dispersion equation, the model proves to be more efficient than previous single-fracture models. The significance of matrix diffusion in the direction parallel to the fracture axis is investigated. For the transport of a nonreactive tracer through a 20-micrometer-wide fracture in clay material, analytical solutions based on one-dimensional matrix diffusion are erroneous for flow velocities of less than 1 m/day. The influence of boundary conditions on two-dimensional matrix diffusion is considered, and the clean-up of a contaminated fracture is simulated.

  19. Simulation model for wind energy storage systems. Volume III. Program descriptions. [SIMWEST CODE

    Energy Technology Data Exchange (ETDEWEB)

    Warren, A.W.; Edsinger, R.W.; Burroughs, J.D.

    1977-08-01

    The effort developed a comprehensive computer program for the modeling of wind energy/storage systems utilizing any combination of five types of storage (pumped hydro, battery, thermal, flywheel and pneumatic). An acronym for the program is SIMWEST (Simulation Model for Wind Energy Storage). The level of detail of SIMWEST is consistent with a role of evaluating the economic feasibility as well as the general performance of wind energy systems. The software package consists of two basic programs and a library of system, environmental, and load components. Volume III, the SIMWEST program description contains program descriptions, flow charts and program listings for the SIMWEST Model Generation Program, the Simulation program, the File Maintenance program and the Printer Plotter program. Volume III generally would not be required by SIMWEST user.

  20. Modeling Accumulated Volume of Landslides Using Remote Sensing and DTM Data

    Directory of Open Access Journals (Sweden)

    Zhengchao Chen

    2014-02-01

    Full Text Available Landslides, like other natural hazards, such as avalanches, floods, and debris flows, may result in a lot of property damage and human casualties. The volume of landslide deposits is a key parameter for landslide studies and disaster relief. Using remote sensing and digital terrain model (DTM data, this paper analyzes errors that can occur in calculating landslide volumes using conventional models. To improve existing models, the mechanisms and laws governing the material deposited by landslides are studied and then the mass balance principle and mass balance line are defined. Based on these ideas, a novel and improved model (Mass Balance Model, MBM is proposed. By using a parameter called the “height adaptor”, MBM translates the volume calculation into an automatic search for the mass balance line within the scope of the landslide. Due to the use of mass balance constraints and the height adaptor, MBM is much more effective and reliable. A test of MBM was carried out for the case of a typical landslide, triggered by the Wenchuan Earthquake of 12 May 2008.

  1. Measurement and modeling of advanced coal conversion processes, Volume I, Part 2. Final report, September 1986--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, P.R.; Serio, M.A.; Hamblen, D.G. [and others

    1995-09-01

    This report describes work pertaining to the development of models for coal gasification and combustion processes. This volume, volume 1, part 2, contains research progress in the areas of large particle oxidation at high temperatures, large particle, thick-bed submodels, sulfur oxide/nitrogen oxides submodels, and comprehensive model development and evaluation.

  2. The Effect of the Volume Flow rate on the Efficiency of a Solar Collector

    DEFF Research Database (Denmark)

    Fan, Jianhua; Shah, Louise Jivan; Furbo, Simon

    rates. Theoretically, a simplified model of the solar collector panel is built by means of the CFD (Computational Fluid Dynamics) code Fluent, where the geometry of the collector panel except the casing is fully modeled. Both lateral and longitudinal heat conduction in the absorber fins, the heat...... transfer from the absorber to the solar collector fluid and the heat loss from the absorber are considered. Flow and temperature distribution in the collector panel are investigated with buoyancy effect. Measurements are carried out with the solar collector panel. Collector efficiencies are measured......The flow distribution inside a collector panel with an area of 12.5 m² and with 16 parallel connected horizontal fins and the effect of the flow nonuniformity on the risk of boiling and on the collector efficiency have been theoretically and experimentally investigated for different volume flow...

  3. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 2: Papers and presentations

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, R.L.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies, or exercises. The conference proceedings consist of three volumes. Volume 1 contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and panels. This volume contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.). Individual papers in this volume were abstracted and indexed for the database.

  4. The history of NATO TNF policy: The role of studies, analysis and exercises conference proceedings. Volume 1, Introduction and summary

    Energy Technology Data Exchange (ETDEWEB)

    Rinne, R.L. [ed.

    1994-02-01

    This conference was organized to study and analyze the role of simulation, analysis, modeling, and exercises in the history of NATO policy. The premise was not that the results of past studies will apply to future policy, but rather that understanding what influenced the decision process -- and how -- would be of value. The structure of the conference was built around discussion panels. The panels were augmented by a series of papers and presentations focusing on particular TNF events, issues, studies or exercise. The conference proceedings consist of three volumes. This volume, Volume 1, contains the conference introduction, agenda, biographical sketches of principal participants, and analytical summary of the presentations and discussion panels. Volume 2 contains a short introduction and the papers and presentations from the conference. Volume 3 contains selected papers by Brig. Gen. Robert C. Richardson III (Ret.).

  5. A Bayesian Model and Stochastic Exposure (Dose) Estimation for Relative Exposure Risk Comparison Involving Asbestos-Containing Dropped Ceiling Panel Installation and Maintenance Tasks.

    Science.gov (United States)

    Boelter, Fred W; Xia, Yulin; Persky, Jacob D

    2017-09-01

    Assessing exposures to hazards in order to characterize risk is at the core of occupational hygiene. Our study examined dropped ceiling systems commonly used in schools and commercial buildings and lay-in ceiling panels that may have contained asbestos prior to the mid to late 1970s. However, most ceiling panels and tiles do not contain asbestos. Since asbestos risk relates to dose, we estimated the distribution of eight-hour TWA concentrations and one-year exposures (a one-year dose equivalent) to asbestos fibers (asbestos f/cc-years) for five groups of workers who may encounter dropped ceilings: specialists, generalists, maintenance workers, nonprofessional do-it-yourself (DIY) persons, and other tradespersons who are bystanders to ceiling work. Concentration data (asbestos f/cc) were obtained through two exposure assessment studies in the field and one chamber study. Bayesian and stochastic models were applied to estimate distributions of eight-hour TWAs and annual exposures (dose). The eight-hour TWAs for all work categories were below current and historic occupational exposure limits (OELs). Exposures to asbestos fibers from dropped ceiling work would be categorized as "highly controlled" for maintenance workers and "well controlled" for remaining work categories, according to the American Industrial Hygiene Association exposure control rating system. Annual exposures (dose) were found to be greatest for specialists, followed by maintenance workers, generalists, bystanders, and DIY. On a comparative basis, modeled dose and thus risk from dropped ceilings for all work categories were orders of magnitude lower than published exposures for other sources of banned friable asbestos-containing building material commonly encountered in construction trades. © 2016 The Authors Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

  6. Models of cognitive behavior in nuclear power plant personnel. A feasibility study: main report. Volume 2

    International Nuclear Information System (INIS)

    Woods, D.D.; Roth, E.M.; Hanes, L.F.

    1986-07-01

    This report contains the results of a feasibility study to determine if the current state of models human cognitive activities can serve as the basis for improved techniques for predicting human error in nuclear power plants emergency operations. Based on the answer to this questions, two subsequent phases of research are planned. Phase II is to develop a model of cognitive activities, and Phase III is to test the model. The feasibility study included an analysis of the cognitive activities that occur in emergency operations and an assessment of the modeling concepts/tools available to capture these cognitive activities. The results indicated that a symbolic processing (or artificial intelligence) model of cognitive activities in nuclear power plants is both desirable and feasible. This cognitive model can be built upon the computational framework provided by an existing artificial intelligence system for medical problem solving called Caduceus. The resulting cognitive model will increase the capability to capture the human contribution to risk in probabilistic risk assessments studies. Volume I summarizes the major findings and conclusions of the study. Volume II provides a complete description of the methods and results, including a synthesis of the cognitive activities that occur during emergency operations, and a literature review on cognitive modeling relevant to nuclear power plants. 112 refs., 10 figs

  7. Verification of Conjugate Heat Transfer Models in a Closed Volume with Radiative Heat Source

    Directory of Open Access Journals (Sweden)

    Maksimov Vyacheslav I.

    2016-01-01

    Full Text Available The results of verification of mathematical model of convective-conductive heat transfer in a closed volume with a thermally conductive enclosing structures are presented. Experiments were carried out to determine the temperature of floor premises in the working conditions of radiant heating systems. Comparison of mathematical modelling of temperature fields and experiments showed their good agreement. It is concluded that the mathematical model of conjugate heat transfers in the air cavity with a heat-conducting and heat-retaining walls correspond to the real process of formation of temperature fields in premises with gas infrared heaters system.

  8. Understanding the growth mechanism of carbon nanotubes via the ``cluster volume to surface area" model

    Science.gov (United States)

    Mandati, Sreekanth; Kunstmann, Jens; Boerrnert, Felix; Schoenfelder, Ronny; Ruemmeli, Mark; Kar, Kamal K.; Cuniberti, Gianaurelio

    2010-03-01

    The influence of mixed catalysts for the high yield production of carbon nanotubes (CNTs) has been studied systematically. Based on extensive experimental data a ``Catalyst Volume to Surface Area'' (CVSA) model was developed to understand the influence of the process parameters on the yield and CNT diameter distribution [1]. In our study, we present a refined version of the CVSA model developed by combining experiments and simulations. We discuss our current understanding of the growth mechanism and how the model might be used to increase CNT yields by using mixed catalysts.[4pt] [1] S. Tetali et al., ACS Nano (2009), DOI: 10.1021/nn9012548.

  9. A Comparison of Sales Response Predictions From Demand Models Applied to Store-Level versus Panel Data

    NARCIS (Netherlands)

    Andrews, Rick L.; Currim, Imran S.; Leeflang, Peter S. H.

    In order to generate sales promotion response predictions, marketing analysts estimate demand models using either disaggregated (consumer-level) or aggregated (store-level) scanner data. Comparison of predictions from these demand models is complicated by the fact that models may accommodate

  10. Statistical modeling of volume of alcohol exposure for epidemiological studies of population health: the US example

    Directory of Open Access Journals (Sweden)

    Gmel Gerrit

    2010-03-01

    Full Text Available Abstract Background Alcohol consumption is a major risk factor in the global burden of disease, with overall volume of exposure as the principal underlying dimension. Two main sources of data on volume of alcohol exposure are available: surveys and per capita consumption derived from routine statistics such as taxation. As both sources have significant problems, this paper presents an approach that triangulates information from both sources into disaggregated estimates in line with the overall level of per capita consumption. Methods A modeling approach was applied to the US using data from a large and representative survey, the National Epidemiologic Survey on Alcohol and Related Conditions. Different distributions (log-normal, gamma, Weibull were used to model consumption among drinkers in subgroups defined by sex, age, and ethnicity. The gamma distribution was used to shift the fitted distributions in line with the overall volume as derived from per capita estimates. Implications for alcohol-attributable fractions were presented, using liver cirrhosis as an example. Results The triangulation of survey data with aggregated per capita consumption data proved feasible and allowed for modeling of alcohol exposure disaggregated by sex, age, and ethnicity. These models can be used in combination with risk relations for burden of disease calculations. Sensitivity analyses showed that the gamma distribution chosen yielded very similar results in terms of fit and alcohol-attributable mortality as the other tested distributions. Conclusions Modeling alcohol consumption via the gamma distribution was feasible. To further refine this approach, research should focus on the main assumptions underlying the approach to explore differences between volume estimates derived from surveys and per capita consumption figures.

  11. Conversion of a Surface Model of a Structure of Interest into a Volume Model for Medical Image Retrieval

    Directory of Open Access Journals (Sweden)

    Sarmad ISTEPHAN

    2015-06-01

    Full Text Available Volumetric medical image datasets contain vital information for noninvasive diagnosis, treatment planning and prognosis. However, direct and unlimited query of such datasets is hindered due to the unstructured nature of the imaging data. This study is a step towards the unlimited query of medical image datasets by focusing on specific Structures of Interest (SOI. A requirement in achieving this objective is having both the surface and volume models of the SOI. However, typically, only the surface model is available. Therefore, this study focuses on creating a fast method to convert a surface model to a volume model. Three methods (1D, 2D and 3D are proposed and evaluated using simulated and real data of Deep Perisylvian Area (DPSA within the human brain. The 1D method takes 80 msec for DPSA model; about 4 times faster than 2D method and 7.4 fold faster than 3D method, with over 97% accuracy. The proposed 1D method is feasible for surface to volume conversion in computer aided diagnosis, treatment planning and prognosis systems containing large amounts of unstructured medical images.

  12. Developing a patient and family research advisory panel to include people with significant disease, multimorbidity and advanced age.

    Science.gov (United States)

    Portalupi, Laura B; Lewis, Carmen L; Miller, Carl D; Whiteman-Jones, Kerry L; Sather, Kay A; Nease, Donald E; Matlock, Daniel D

    2017-06-01

    People who have experienced illness due to significant disease, multimorbidity and/or advanced age are high utilizers of the health care system. Yet this population has had little formal opportunity to participate in guiding the health care research agenda, and few mechanisms exist for researchers to engage this population in an efficient way. We describe the process of developing a standing patient and family advisory panel to incorporate this population's voice into research in the USA. The panel was created at the University of Colorado. Preliminary panel development consisted of a needs assessment, information gathering and participant recruitment. We collected feedback from researchers who consulted with the panel and from panel members in order to better understand the experience from the patient and family member perspective. The patient and family research advisory panel consists of eight advisors who have experience with significant disease, multimorbidity and/or advanced age, two physicians and a program manager. The panel meets every other month for 2 hours with the main purpose of advising diverse researchers on health care studies. People with significant disease, multimorbidity and/or advanced age represent a growing demographic in the USA, and their engagement in research is essential as the model of health care delivery moves from volume to value. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Iterative model reconstruction reduces calcified plaque volume in coronary CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Károlyi, Mihály, E-mail: mihaly.karolyi@cirg.hu [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); Szilveszter, Bálint, E-mail: szilveszter.balint@gmail.com [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); Kolossváry, Márton, E-mail: martonandko@gmail.com [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); Takx, Richard A.P, E-mail: richard.takx@gmail.com [Department of Radiology, University Medical Center Utrecht, 100 Heidelberglaan, 3584, CX Utrecht (Netherlands); Celeng, Csilla, E-mail: celengcsilla@gmail.com [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); Bartykowszki, Andrea, E-mail: bartyandi@gmail.com [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); Jermendy, Ádám L., E-mail: adam.jermendy@gmail.com [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); Panajotu, Alexisz, E-mail: panajotualexisz@gmail.com [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); Karády, Júlia, E-mail: karadyjulia@gmail.com [MTA-SE Cardiovascular Imaging Research Group, Heart and Vascular Center, Semmelweis University, 68. Varosmajor st, 1122, Budapest (Hungary); and others

    2017-02-15

    Objective: To assess the impact of iterative model reconstruction (IMR) on calcified plaque quantification as compared to filtered back projection reconstruction (FBP) and hybrid iterative reconstruction (HIR) in coronary computed tomography angiography (CTA). Methods: Raw image data of 52 patients who underwent 256-slice CTA were reconstructed with IMR, HIR and FBP. We evaluated qualitative, quantitative image quality parameters and quantified calcified and partially calcified plaque volumes using automated software. Results: Overall qualitative image quality significantly improved with HIR as compared to FBP, and further improved with IMR (p < 0.01 all). Contrast-to-noise ratios were improved with IMR, compared to HIR and FBP (51.0 [43.5–59.9], 20.3 [16.2–25.9] and 14.0 [11.2–17.7], respectively, all p < 0.01) Overall plaque volumes were lowest with IMR and highest with FBP (121.7 [79.3–168.4], 138.7 [90.6–191.7], 147.0 [100.7–183.6]). Similarly, calcified volumes (>130 HU) were decreased with IMR as compared to HIR and FBP (105.9 [62.1–144.6], 110.2 [63.8–166.6], 115.9 [81.7–164.2], respectively, p < 0.05 all). High-attenuation non-calcified volumes (90–129 HU) yielded similar values with FBP and HIR (p = 0.81), however it was lower with IMR (p < 0.05 both). Intermediate- (30–89 HU) and low-attenuation (<30 HU) non-calcified volumes showed no significant difference (p = 0.22 and p = 0.67, respectively). Conclusions: IMR improves image quality of coronary CTA and decreases calcified plaque volumes.

  14. Puncture panel optimization

    International Nuclear Information System (INIS)

    Glass, R.E.; Longenbaugh, R.S.

    1986-01-01

    Sandia National Laboratories developed the TRansUranic PACkage Transporter (TRUPACT) to transport defense contact-handled transuranic wastes. The package has been designed to meet the normal and hypothetical accident conditions in 10CFR71 which includes the demonstrated ability to survive a 1-meter drop onto a mild steel pin. The puncture protection is provided by puncture resistant panels. In conjunction with the development of TRUPACT, a series of experiments has been conducted to reduce the weight of the puncture resistant panels. The initial scoping tests resulted in a preliminary design incorporating 30 layers of Kevlar. This design has been shown to meet the regulatory puncture test. To reduce the weight of this panel, subscale tests were conducted on panels utilizing Kevlar yarns with varying mass per unit length (denier) as well as different resins. This paper reviews the testing undertaken in the original panel development and discusses the results obtained from the recent subscale and full-scale optimization tests

  15. Solar panel cleaning robot

    Science.gov (United States)

    Nalladhimmu, Pavan Kumar Reddy; Priyadarshini, S.

    2018-04-01

    As the demand of electricity is increasing, there is need to using the renewable sources to produce the energy at present of power shortage, the use of solar energy could be beneficial to great extent and easy to get the maximum efficiency. There is an urgent in improving the efficiency of solar power generation. Current solar panels setups take a major power loss when unwanted obstructions cover the surface of the panels. To make solar energy more efficiency of solar array systems must be maximized efficiency evaluation of PV panels, that has been discussed with particular attention to the presence of dust on the efficiency of the PV panels have been highlighted. This paper gives the how the solar panel cleaning system works and designing of the cleaning system.

  16. Multiple Site Damage in Flat Panel Testing

    National Research Council Canada - National Science Library

    Shrage, Daniel

    2000-01-01

    This report aimed to experimentally verify analytical models that predict the residual strength of representative aircraft structures, such as wide panels, that are subjected to Multiple Site Damage (MSD...

  17. Codominant scoring of AFLP in association panels

    NARCIS (Netherlands)

    Gort, G.; Eeuwijk, van F.A.

    2010-01-01

    A study on the codominant scoring of AFLP markers in association panels without prior knowledge on genotype probabilities is described. Bands are scored codominantly by fitting normal mixture models to band intensities, illustrating and optimizing existing methodology, which employs the

  18. Integrating model of the Project Independence Evaluation System. Volume VI. Data documentation. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Allen, B J

    1979-02-01

    This documentation describes the PIES Integrating Model as it existed on January 1, 1978. This Volume VI of six volumes is data documentation, containing the standard table data used for the Administrator's Report at the beginning of 1978, along with the primary data sources and the office responsible. It also contains a copy of a PIES Integrating Model Report with a description of its content. Following an overview chapter, Chapter II, Supply and Demand Data Tables and Sources for the Mid-range Scenario for Target Years 1985 and 1990, data on demand, price, and elasticity; coal; imports; oil and gas; refineries; synthetics, shale, and solar/geothermal; transportation; and utilities are presented. The following data on alternate scenarios are discussed: low and high demand; low and high oil and gas supply; refinery and oil and gas data assuming a 5% annual increase in real world oil prices. Chapter IV describes the solution output obtained from an execution of PIES.

  19. 3-D reconstruction and volume modelling of the grain fabric of geological materials

    Science.gov (United States)

    Marschallinger, R.

    This paper describes three-dimensional reconstruction and volume modelling of geological materials at the macroscopic and the microscopic scale. By means of a precision lapping device, samples are eroded in plan-parallel steps, erosion intervals being adapted to the size of minerals and fabric features of interest. For reconstruction of macroscopic features, each newly eroded sample surface is recorded by a high-resolution color flatbed scanner. Supervised image classification applied to the derived images yields color based mineral recognition. At the microscopic scale, scanning is done with a microanalyzer to portray mineral phases and microchemical variation. Minerals and fabric features are three dimensionally reconstructed by stacking and interpolating the acquired raster images of successive erosion levels in a voxel array. The voxel data structure features analyical flexibility, integration of both discrete and continuous spatial variation and versatile 3-D volume model visualization.

  20. Monte Carlo method for critical systems in infinite volume: The planar Ising model.

    Science.gov (United States)

    Herdeiro, Victor; Doyon, Benjamin

    2016-10-01

    In this paper we propose a Monte Carlo method for generating finite-domain marginals of critical distributions of statistical models in infinite volume. The algorithm corrects the problem of the long-range effects of boundaries associated to generating critical distributions on finite lattices. It uses the advantage of scale invariance combined with ideas of the renormalization group in order to construct a type of "holographic" boundary condition that encodes the presence of an infinite volume beyond it. We check the quality of the distribution obtained in the case of the planar Ising model by comparing various observables with their infinite-plane prediction. We accurately reproduce planar two-, three-, and four-point of spin and energy operators. We also define a lattice stress-energy tensor, and numerically obtain the associated conformal Ward identities and the Ising central charge.

  1. Simulation model for wind energy storage systems. Volume II. Operation manual. [SIMWEST code

    Energy Technology Data Exchange (ETDEWEB)

    Warren, A.W.; Edsinger, R.W.; Burroughs, J.D.

    1977-08-01

    The effort developed a comprehensive computer program for the modeling of wind energy/storage systems utilizing any combination of five types of storage (pumped hydro, battery, thermal, flywheel and pneumatic). An acronym for the program is SIMWEST (Simulation Model for Wind Energy Storage). The level of detail of SIMWEST is consistent with a role of evaluating the economic feasibility as well as the general performance of wind energy systems. The software package consists of two basic programs and a library of system, environmental, and load components. Volume II, the SIMWEST operation manual, describes the usage of the SIMWEST program, the design of the library components, and a number of simple example simulations intended to familiarize the user with the program's operation. Volume II also contains a listing of each SIMWEST library subroutine.

  2. Modelling the Hydraulic Behaviour of Growing Media with the Explicit Finite Volume Solution

    Directory of Open Access Journals (Sweden)

    Marco Carbone

    2015-02-01

    Full Text Available The increasing imperviousness of urban areas reduces the infiltration and evapotranspiration capacity of urban catchments and results in increased runoff. In the last few decades, several solutions and techniques have been proposed to prevent such impacts by restoring the hydrological cycle. A limiting factor in spreading the use of such systems is the lack of proper modelling tools for design, especially for the infiltration processes in a growing medium. In this research, a physically-based model, employing the explicit Finite Volume Method (FVM, is proposed for modelling infiltration into growing media. The model solves a modified version of the Richards equation using a formulation which takes into account the main characteristics of green infrastructure substrates. The proposed model was verified against the HYDRUS-1D software and the comparison of results confirmed the suitability of the proposed model for correctly describing the hydraulic behaviour of soil substrates.

  3. Verification and transfer of thermal pollution model. Volume 3: Verification of 3-dimensional rigid-lid model

    Science.gov (United States)

    Lee, S. S.; Sengupta, S.; Nwadike, E. V.; Sinha, S. K.

    1982-01-01

    The six-volume report: describes the theory of a three dimensional (3-D) mathematical thermal discharge model and a related one dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth (e.g., natural or man-made inland lakes) because surface elevation has been removed as a parameter. These models allow computation of time-dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions. The free-surface model also provides surface height variations with time.

  4. AN AUTOMATIC FEATURE BASED MODEL FOR CELL SEGMENTATION FROM CONFOCAL MICROSCOPY VOLUMES

    OpenAIRE

    Delibaltov, Diana; Ghosh, Pratim; Veeman, Michael; Smith, William; Manjunath, B.S.

    2011-01-01

    We present a model for the automated segmentation of cells from confocal microscopy volumes of biological samples. The segmentation task for these images is exceptionally challenging due to weak boundaries and varying intensity during the imaging process. To tackle this, a two step pruning process based on the Fast Marching Method is first applied to obtain an over-segmented image. This is followed by a merging step based on an effective feature representation. The algorithm is applied on two...

  5. Applying Training System Estimation Models to Army Training. Volume 2. An Annotated Bibliography 1970-1990

    Science.gov (United States)

    1994-05-01

    associated with the Educational Technology Assessment Model ( ETAM ). It contains relevant background information and results of prior studies leading to...the finalized ETAM procedures and computerized routines. A comparison of the manual and automated approach is included, and data base structures and... ETAM program flow are described. The second volume (see PA, Vol 59:11358) contains the 344-page appendix. 039Duffy, L.R., Miller, R.B., & Staley, J.D

  6. Control volume based modelling in one space dimension of oscillating, compressible flow in reciprocating machines

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Carlsen, Henrik; Thomsen, Per Grove

    2006-01-01

    We present an approach for modelling unsteady, primarily one-dimensional, compressible flow. The conservation laws for mass, energy, and momentum are applied to a staggered mesh of control volumes and loss mechanisms are included directly as extra terms. Heat transfer, flow friction......, and multidimensional effects are calculated using empirical correlations. Transformations of the conservation equations into new variables, artificial dissipation for dissipating acoustic phenomena, and an asymmetric interpolation method for minimising numerical diffusion and non physical temperature oscillations...

  7. Model-based segmentation in orbital volume measurement with cone beam computed tomography and evaluation against current concepts.

    Science.gov (United States)

    Wagner, Maximilian E H; Gellrich, Nils-Claudius; Friese, Karl-Ingo; Becker, Matthias; Wolter, Franz-Erich; Lichtenstein, Juergen T; Stoetzer, Marcus; Rana, Majeed; Essig, Harald

    2016-01-01

    Objective determination of the orbital volume is important in the diagnostic process and in evaluating the efficacy of medical and/or surgical treatment of orbital diseases. Tools designed to measure orbital volume with computed tomography (CT) often cannot be used with cone beam CT (CBCT) because of inferior tissue representation, although CBCT has the benefit of greater availability and lower patient radiation exposure. Therefore, a model-based segmentation technique is presented as a new method for measuring orbital volume and compared to alternative techniques. Both eyes from thirty subjects with no known orbital pathology who had undergone CBCT as a part of routine care were evaluated (n = 60 eyes). Orbital volume was measured with manual, atlas-based, and model-based segmentation methods. Volume measurements, volume determination time, and usability were compared between the three methods. Differences in means were tested for statistical significance using two-tailed Student's t tests. Neither atlas-based (26.63 ± 3.15 mm(3)) nor model-based (26.87 ± 2.99 mm(3)) measurements were significantly different from manual volume measurements (26.65 ± 4.0 mm(3)). However, the time required to determine orbital volume was significantly longer for manual measurements (10.24 ± 1.21 min) than for atlas-based (6.96 ± 2.62 min, p model-based (5.73 ± 1.12 min, p measurements. All three orbital volume measurement methods examined can accurately measure orbital volume, although atlas-based and model-based methods seem to be more user-friendly and less time-consuming. The new model-based technique achieves fully automated segmentation results, whereas all atlas-based segmentations at least required manipulations to the anterior closing. Additionally, model-based segmentation can provide reliable orbital volume measurements when CT image quality is poor.

  8. Engineered materials characterization report for the Yucca Mountain Site Characterization Project. Volume 3: Corrosion and data modeling

    International Nuclear Information System (INIS)

    Van Konynenburg, R.A.; McCright, R.D.; Roy, A.K.; Jones, D.A.

    1995-08-01

    This three-volume report serves several purposes. The first volume provides an introduction to the engineered materials effort for the Yucca Mountain Site Characterization Project. It defines terms and outlines the history of selection and characterization of these materials. A summary of the recent engineered barrier materials characterization workshop is presented, and the current candidate materials are listed. The second volume tabulates design data for engineered materials, and the third volume is devoted to corrosion data, radiation effects on corrosion, and corrosion modeling. The second and third volumes are intended to be evolving documents, to which new data will be added as they become available from additional studies. The initial version of Volume 3 is devoted to information currently available for environments most similar to those expected in the potential Yucca Mountain repository. This is volume three

  9. Acoustically Tailored Composite Rotorcraft Fuselage Panels

    Science.gov (United States)

    2015-07-02

    structural integrity analysis. Penn State analyzed Bell’s FE model of the baseline panel using NX/ NASTRAN . Unfortunately, the model required over a day...per the data shown in Figure 39. The Poisson’s ratio was set to 0.499. Modes of the panel with free boundary conditions were extracted using NASTRAN ...connected to nodes of solid elements, they will not run properly in NASTRAN SOL 101 (Static Analysis), but they will work in NASTRAN SOL 103 (Real Normal

  10. Productivity Analysis of Volume Fractured Vertical Well Model in Tight Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Jiahang Wang

    2017-01-01

    Full Text Available This paper presents a semianalytical model to simulate the productivity of a volume fractured vertical well in tight oil reservoirs. In the proposed model, the reservoir is a composite system which contains two regions. The inner region is described as formation with finite conductivity hydraulic fracture network and the flow in fracture is assumed to be linear, while the outer region is simulated by the classical Warren-Root model where radial flow is applied. The transient rate is calculated, and flow patterns and characteristic flowing periods caused by volume fractured vertical well are analyzed. Combining the calculated results with actual production data at the decline stage shows a good fitting performance. Finally, the effects of some sensitive parameters on the type curves are also analyzed extensively. The results demonstrate that the effect of fracture length is more obvious than that of fracture conductivity on improving production in tight oil reservoirs. When the length and conductivity of main fracture are constant, the contribution of stimulated reservoir volume (SRV to the cumulative oil production is not obvious. When the SRV is constant, the length of fracture should also be increased so as to improve the fracture penetration and well production.

  11. Efficient panel designs for longitudinal recurrent event studies recording panel counts.

    Science.gov (United States)

    Juarez-Colunga, Elizabeth; Dean, C B; Balshaw, Robert

    2014-04-01

    Many clinical trials are designed to study outcome measures recorded as the number of events occurring during specific intervals, called panel data. In such data, the intervals are specified by a planned set of follow-up times. As the collection of panel data results in a partial loss of information relative to a record of the actual event times, it is important to gain a thorough understanding of the impact of panel study designs on the efficiency of the estimates of treatment effects and covariates. This understanding can then be used as a base from which to formulate appropriate designs by layering in other concerns, e.g. clinical constraints, or other practical considerations. We compare the efficiency of the analysis of panel data with respect to the analysis of data recorded precisely as times of recurrences, and articulate conditions for efficient panel designs where the focus is on estimation of a treatment effect when adjusting for other covariates. We build from the efficiency comparisons to optimize the design of panel follow-up times. We model the recurrent intensity through the common proportional intensity framework, with the treatment effect modeled flexibly as piecewise constant over panels, or groups of panels. We provide some important considerations for the design of efficient panel studies, and illustrate the methods through analysis of designs of studies of adenomas.

  12. Methods to Increase the Robustness of Finite-Volume Flow Models in Thermodynamic Systems

    Directory of Open Access Journals (Sweden)

    Sylvain Quoilin

    2014-03-01

    Full Text Available This paper addresses the issues linked to simulation failures during integration in finite-volume flow models, especially those involving a two-phase state. This kind of model is particularly useful when modeling 1D heat exchangers or piping, e.g., in thermodynamic cycles involving a phase change. Issues, such as chattering or stiff systems, can lead to low simulation speed, instabilities and simulation failures. In the particular case of two-phase flow models, they are usually linked to a discontinuity in the density derivative between the liquid and two-phase zones. In this work, several methods to tackle numerical problems are developed, described, implemented and compared. In addition, methods available in the literature are also implemented and compared to the proposed approaches. Results suggest that the robustness of the models can be significantly increased with these different methods, at the price of a small increase of the error in the mass and energy balances.

  13. Classical and recent free-volume models for polymer solutions: A comparative evaluation

    DEFF Research Database (Denmark)

    Radfarnia, H.R.; Kontogeorgis, Georgios; Ghotbi, C.

    2007-01-01

    In this work, two "classical" (UNIFAC-FV, Entropic-FV) and two "recent" free-volume (FV) models (Kannan-FV, Freed-FV) are comparatively evaluated for polymer-solvent vapor-liquid equilibria including both aqueous and non-aqueous solutions. Moreover, some further developments are presented here...... by the modified Freed-FV model for athermal and non-athermal polymer systems are compared to other "recent" and "classical" FV models, indicating an improvement for the modified Freed-FV model for aqueous polymer solutions. Second, for the original Freed-FV model, new UNIFAC group energy parameters are regressed...... to using the classical UNIFAC parameters, for VLE of aqueous and alcohol polymer systems....

  14. Verification and transfer of thermal pollution model. Volume 2: User's manual for 3-dimensional free-surface model

    Science.gov (United States)

    Lee, S. S.; Sengupta, S.; Tuann, S. Y.; Lee, C. R.

    1982-01-01

    The six-volume report: describes the theory of a three-dimensional (3-D) mathematical thermal discharge model and a related one-dimensional (1-D) model, includes model verification at two sites, and provides a separate user's manual for each model. The 3-D model has two forms: free surface and rigid lid. The former, verified at Anclote Anchorage (FL), allows a free air/water interface and is suited for significant surface wave heights compared to mean water depth; e.g., estuaries and coastal regions. The latter, verified at Lake Keowee (SC), is suited for small surface wave heights compared to depth. These models allow computation of time-dependent velocity and temperature fields for given initial conditions and time-varying boundary conditions.

  15. Effect of stand structure on models for volume and aboveground biomass assessment (Castelfusano pinewood, Roma

    Directory of Open Access Journals (Sweden)

    2009-03-01

    Full Text Available The main purpose of this research was to analyse the effects of stand structure on biomass allocation and on the accurancy of estimation models for volume and aboveground biomass of Italian stone pine (Pinus pinea L.. Although the species is widely distributed on Mediterranean coasts, few studies on forest biomass estimation have focused on pinewoods. The research was carried out in the Castelfusano’s pinewood (Rome and concerned the two most common structural types: (a 50 years-old pinewood originated by broadcast seeding; and (b 62 years-old pinewood originated by partial seeding alternating worked strips to firm strips. Some 83 sample trees were selected for stem volume estimation and a subset of 32 trees used to quantify the total epigeous biomass, the wooden biomass compartment, including stem and big branches (diameter > 3 cm and the photosynthetic biomass, including thin branches (diameter < 3 cm and needles. Collected data were used to elaborate allometric relations for stem volume, total biomass and specific relations for both compartments, based on one (d2 or two (d2h indipendent variables, for both structural types. Furthermore, pinewood specific biomass expansion factors (BEF - indexes used to estimate carbon stocks starting from stem biomass data - were obtained. The achieved estimation models were subjected to both parallelism and coincidence tests, showing significant effects of stand structure on the accurancy of the allometric relations. The effects of stand structure and reliability of tree height curves on the accurancy of estimation models for volume and aboveground biomass and on biomass allocation in different compartments are analysed and discussed.

  16. Integrating model of the Project Independence Evaluation System. Volume VI. Data documentation. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Allen, B J

    1979-02-01

    This documentation describes the PIES Integrating Model as it existed on January 1, 1978. This volume contains two chapters. In Chapter I, Overview, the following subjects are briefly described: supply data, EIA projection series and scenarios, demand data and assumptions, and supply assumptions - oil and gas availabilities. Chapter II contains supply and demand data tables and sources used by the PIES Integrating Model for the mid-range scenario target years 1985 and 1990. Tabulated information is presented for demand, price, and elasticity data; coal data; imports data; oil and gas data; refineries data; synthetics, shale, and solar/geothermal data; transportation data; and utilities data.

  17. Measurements and Modeling of Soot Formation and Radiation in Microgravity Jet Diffusion Flames. Volume 4

    Science.gov (United States)

    Ku, Jerry C.; Tong, Li; Greenberg, Paul S.

    1996-01-01

    This is a computational and experimental study for soot formation and radiative heat transfer in jet diffusion flames under normal gravity (1-g) and microgravity (0-g) conditions. Instantaneous soot volume fraction maps are measured using a full-field imaging absorption technique developed by the authors. A compact, self-contained drop rig is used for microgravity experiments in the 2.2-second drop tower facility at NASA Lewis Research Center. On modeling, we have coupled flame structure and soot formation models with detailed radiation transfer calculations. Favre-averaged boundary layer equations with a k-e-g turbulence model are used to predict the flow field, and a conserved scalar approach with an assumed Beta-pdf are used to predict gaseous species mole fraction. Scalar transport equations are used to describe soot volume fraction and number density distributions, with formation and oxidation terms modeled by one-step rate equations and thermophoretic effects included. An energy equation is included to couple flame structure and radiation analyses through iterations, neglecting turbulence-radiation interactions. The YIX solution for a finite cylindrical enclosure is used for radiative heat transfer calculations. The spectral absorption coefficient for soot aggregates is calculated from the Rayleigh solution using complex refractive index data from a Drude- Lorentz model. The exponential-wide-band model is used to calculate the spectral absorption coefficient for H20 and C02. It is shown that when compared to results from true spectral integration, the Rosseland mean absorption coefficient can provide reasonably accurate predictions for the type of flames studied. The soot formation model proposed by Moss, Syed, and Stewart seems to produce better fits to experimental data and more physically sound than the simpler model by Khan et al. Predicted soot volume fraction and temperature results agree well with published data for a normal gravity co-flow laminar

  18. Make Your Own Solar Panel.

    Science.gov (United States)

    Suzuki, David

    1992-01-01

    Presents an activity in which students make a simulated solar panel to learn about the principles behind energy production using solar panels. Provides information about how solar panels function to produce energy. (MCO)

  19. International Space Station Human Behavior and Performance Competency Model: Volume I

    Science.gov (United States)

    Schmidt, Lacey

    2008-01-01

    This document defines Human Behavior and Performance (HBP) competencies that are recommended to be included as requirements to participate in international long duration missions. They were developed in response to the Multilateral Crew Operations Panel (MMOP) request to develop HBP training requirements for the International Space Station (ISS). The competency model presented here was developed by the ITCB HBPT WG and forms the basis for determining the HBP training curriculum for long duration crewmembers. This document lists specific HBP competencies and behaviors required of astronauts/cosmonauts who participate in ISS expedition and other international longduration missions. Please note that this model does not encompass all competencies required. For example, outside the scope of this document are cognitive skills and abilities, including but not limited to concentration, memorization, perception, imagination, and thinking. It is assumed that these skills, which are crucial in terms of human behavior and performance, are considered during selection phase since such professionally significant qualities of the operator should be taken into consideration in order to ensure sufficient baseline levels that can be further improved during general astronaut training. Also, technical competencies, even though critical for crewmembers, are beyond the scope of this document. It should also be noted that the competencies in this model (and subsequent objectives) are not intended to limit the internal activities or training programs of any international partner.

  20. Rapid Estimation of Aircraft Performance Models using Differential Vortex Panel Method and Extended Kalman Filter, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The problem of estimating the aerodynamic models for flight control of damaged aircraft using an innovative differential vortex lattice method tightly coupled with...

  1. Formulation and Application of a Stochastic Fatigue Damage Accumulation Model for the Response of Buckled Composite Panels

    National Research Council Canada - National Science Library

    Chen, P

    2000-01-01

    ...., excursions from one buckled state to the other. First, a large displacements small strains structural dynamic formulation is developed that accounts for the given temperature effects and relies on a higher-order shear modeling...

  2. Rapid Estimation of Aircraft Performance Models using Differential Vortex Panel Method and Extended Kalman Filter, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Estimation of aerodynamic models for the control of damaged aircraft using an innovative differential vortex lattice method tightly coupled with an extended Kalman...

  3. Long-Term Prediction of Emergency Department Revenue and Visitor Volume Using Autoregressive Integrated Moving Average Model

    Directory of Open Access Journals (Sweden)

    Chieh-Fan Chen

    2011-01-01

    Full Text Available This study analyzed meteorological, clinical and economic factors in terms of their effects on monthly ED revenue and visitor volume. Monthly data from January 1, 2005 to September 30, 2009 were analyzed. Spearman correlation and cross-correlation analyses were performed to identify the correlation between each independent variable, ED revenue, and visitor volume. Autoregressive integrated moving average (ARIMA model was used to quantify the relationship between each independent variable, ED revenue, and visitor volume. The accuracies were evaluated by comparing model forecasts to actual values with mean absolute percentage of error. Sensitivity of prediction errors to model training time was also evaluated. The ARIMA models indicated that mean maximum temperature, relative humidity, rainfall, non-trauma, and trauma visits may correlate positively with ED revenue, but mean minimum temperature may correlate negatively with ED revenue. Moreover, mean minimum temperature and stock market index fluctuation may correlate positively with trauma visitor volume. Mean maximum temperature, relative humidity and stock market index fluctuation may correlate positively with non-trauma visitor volume. Mean maximum temperature and relative humidity may correlate positively with pediatric visitor volume, but mean minimum temperature may correlate negatively with pediatric visitor volume. The model also performed well in forecasting revenue and visitor volume.

  4. Sample selection and spatial models of housing price indexes, and, A disequilibrium analysis of the U.S. gasoline market using panel data

    Science.gov (United States)

    Hu, Haixin

    This dissertation consists of two parts. The first part studies the sample selection and spatial models of housing price index using transaction data on detached single-family houses of two California metropolitan areas from 1990 through 2008. House prices are often spatially correlated due to shared amenities, or when the properties are viewed as close substitutes in a housing submarket. There have been many studies that address spatial correlation in the context of housing markets. However, none has used spatial models to construct housing price indexes at zip code level for the entire time period analyzed in this dissertation to the best of my knowledge. In this paper, I study a first-order autoregressive spatial model with four different weighing matrix schemes. Four sets of housing price indexes are constructed accordingly. Gatzlaff and Haurin (1997, 1998) study the sample selection problem in housing index by using Heckman's two-step method. This method, however, is generally inefficient and can cause multicollinearity problem. Also, it requires data on unsold houses in order to carry out the first-step probit regression. Maximum likelihood (ML) method can be used to estimate a truncated incidental model which allows one to correct for sample selection based on transaction data only. However, convergence problem is very prevalent in practice. In this paper I adopt Lewbel's (2007) sample selection correction method which does not require one to model or estimate the selection model, except for some very general assumptions. I then extend this method to correct for spatial correlation. In the second part, I analyze the U.S. gasoline market with a disequilibrium model that allows lagged-latent variables, endogenous prices, and panel data with fixed effects. Most existing studies (see the survey of Espey, 1998, Energy Economics) of the gasoline market assume equilibrium. In practice, however, prices do not always adjust fast enough to clear the market

  5. Coupling model of aerobic waste degradation considering temperature, initial moisture content and air injection volume.

    Science.gov (United States)

    Ma, Jun; Liu, Lei; Ge, Sai; Xue, Qiang; Li, Jiangshan; Wan, Yong; Hui, Xinminnan

    2018-03-01

    A quantitative description of aerobic waste degradation is important in evaluating landfill waste stability and economic management. This research aimed to develop a coupling model to predict the degree of aerobic waste degradation. On the basis of the first-order kinetic equation and the law of conservation of mass, we first developed the coupling model of aerobic waste degradation that considered temperature, initial moisture content and air injection volume to simulate and predict the chemical oxygen demand in the leachate. Three different laboratory experiments on aerobic waste degradation were simulated to test the model applicability. Parameter sensitivity analyses were conducted to evaluate the reliability of parameters. The coupling model can simulate aerobic waste degradation, and the obtained simulation agreed with the corresponding results of the experiment. Comparison of the experiment and simulation demonstrated that the coupling model is a new approach to predict aerobic waste degradation and can be considered as the basis for selecting the economic air injection volume and appropriate management in the future.

  6. A mathematical model relating cortical oxygenated and deoxygenated hemoglobin flows and volumes to neural activity

    Science.gov (United States)

    Cornelius, Nathan R.; Nishimura, Nozomi; Suh, Minah; Schwartz, Theodore H.; Doerschuk, Peter C.

    2015-08-01

    Objective. To describe a toolkit of components for mathematical models of the relationship between cortical neural activity and space-resolved and time-resolved flows and volumes of oxygenated and deoxygenated hemoglobin motivated by optical intrinsic signal imaging (OISI). Approach. Both blood flow and blood volume and both oxygenated and deoxygenated hemoglobin and their interconversion are accounted for. Flow and volume are described by including analogies to both resistive and capacitive electrical circuit elements. Oxygenated and deoxygenated hemoglobin and their interconversion are described by generalization of Kirchhoff's laws based on well-mixed compartments. Main results. Mathematical models built from this toolkit are able to reproduce experimental single-stimulus OISI results that are described in papers from other research groups and are able to describe the response to multiple-stimuli experiments as a sublinear superposition of responses to the individual stimuli. Significance. The same assembly of tools from the toolkit but with different parameter values is able to describe effects that are considered distinctive, such as the presence or absence of an initial decrease in oxygenated hemoglobin concentration, indicating that the differences might be due to unique parameter values in a subject rather than different fundamental mechanisms.

  7. Radiative Forcing by Well-Mixed Greenhouse Gases: Estimates from Climate Models in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4)

    Science.gov (United States)

    Collins, W. D.; Ramaswamy, V.; Schwarzkopf, M. D.; Sun, Y.; Portmann, R. W.; Fu, Q.; Casanova, S. E. B.; Dufresne, J.-L.; Fillmore, D. W.; Forster, P. M. D.; hide

    2006-01-01

    The radiative effects from increased concentrations of well-mixed greenhouse gases (WMGHGs) represent the most significant and best understood anthropogenic forcing of the climate system. The most comprehensive tools for simulating past and future climates influenced by WMGHGs are fully coupled atmosphere-ocean general circulation models (AOGCMs). Because of the importance of WMGHGs as forcing agents it is essential that AOGCMs compute the radiative forcing by these gases as accurately as possible. We present the results of a radiative transfer model intercomparison between the forcings computed by the radiative parameterizations of AOGCMs and by benchmark line-by-line (LBL) codes. The comparison is focused on forcing by CO2, CH4, N2O, CFC-11, CFC-12, and the increased H2O expected in warmer climates. The models included in the intercomparison include several LBL codes and most of the global models submitted to the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). In general, the LBL models are in excellent agreement with each other. However, in many cases, there are substantial discrepancies among the AOGCMs and between the AOGCMs and LBL codes. In some cases this is because the AOGCMs neglect particular absorbers, in particular the near-infrared effects of CH4 and N2O, while in others it is due to the methods for modeling the radiative processes. The biases in the AOGCM forcings are generally largest at the surface level. We quantify these differences and discuss the implications for interpreting variations in forcing and response across the multimodel ensemble of AOGCM simulations assembled for the IPCC AR4.

  8. Discovery proteomics and nonparametric modeling pipeline in the development of a candidate biomarker panel for dengue hemorrhagic fever.

    Science.gov (United States)

    Brasier, Allan R; Garcia, Josefina; Wiktorowicz, John E; Spratt, Heidi M; Comach, Guillermo; Ju, Hyunsu; Recinos, Adrian; Soman, Kizhake; Forshey, Brett M; Halsey, Eric S; Blair, Patrick J; Rocha, Claudio; Bazan, Isabel; Victor, Sundar S; Wu, Zheng; Stafford, Susan; Watts, Douglas; Morrison, Amy C; Scott, Thomas W; Kochel, Tadeusz J

    2012-02-01

    Secondary dengue viral infection can produce capillary leakage associated with increased mortality known as dengue hemorrhagic fever (DHF). Because the mortality of DHF can be reduced by early detection and intensive support, improved methods for its detection are needed. We applied multidimensional protein profiling to predict outcomes in a prospective dengue surveillance study in South America. Plasma samples taken from initial clinical presentation of acute dengue infection were subjected to proteomics analyses using ELISA and a recently developed biofluid analysis platform. Demographics, clinical laboratory measurements, nine cytokines, and 419 plasma proteins collected at the time of initial presentation were compared between the DF and DHF outcomes. Here, the subject's gender, clinical parameters, two cytokines, and 42 proteins discriminated between the outcomes. These factors were reduced by multivariate adaptive regression splines (MARS) that a highly accurate classification model based on eight discriminant features with an area under the receiver operator curve (AUC) of 0.999. Model analysis indicated that the feature-outcome relationship were nonlinear. Although this DHF risk model will need validation in a larger cohort, we conclude that approaches to develop predictive biomarker models for disease outcome will need to incorporate nonparametric modeling approaches. © 2012 Wiley Periodicals, Inc.

  9. Stochastic modeling of gob gas venthole production performances in active and completed longwall panels of coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Karacan, C. Oezgen [NIOSH, Office of Mine Safety and Health Research, Pittsburgh, PA (United States); Luxbacher, Kray [Virginia Tech, Dept. of Mining and Minerals Engineering, Blacksburg, VA (United States)

    2010-11-01

    Gob gas ventholes (GGVs) are an integral part of longwall coal mining operations, enhancing safety by controlling methane in underground workings. As in many disciplines in earth sciences, uncertainties due to the heterogeneity of geologic formations exist. These uncertainties, and the wide range of mining and venthole operation parameters, lead to performance variability in GGVs. Random variations in parameters affecting GGV performance and influencing parameters that cannot be quantified sufficiently due to lack of information limit deterministic GGV models and even introduce error in severe cases. Therefore, evaluation of GGV performance data and the uncertainty in input parameters is valuable for understanding the variability in GGV production and for designing them accordingly. This paper describes a practical approach for implementing stochastic determination of GGV production performances and for generalizing the prediction capability of deterministic models. Deterministic site-specific models were derived by using the GGV module in the recently developed MCP (Methane Control and Prediction) software suite. These models were generated using multi-parameter regression techniques and were then improved by inclusion of extra input parameters that eliminated the site dependency and improved the predictions. Statistical distributions of input parameters in these models were quantified and tested with the Kolmogorov-Smirnov goodness-of-fit technique. Next, Monte Carlo simulations were performed using these distributions and generalized results for GGV performances were generated. The results of this work indicate that this approach is a promising method of representing the variability in GGV performances and to improve the limited and site-specific character of the deterministic models. (author)

  10. Intention to Purchase Products under Volume Discount Scheme: A Conceptual Model and Research Propositions

    Directory of Open Access Journals (Sweden)

    Mohammad Iranmanesh

    2014-12-01

    Full Text Available Many standard brands sell products under the volume discount scheme (VDS as more and more consumers are fond of purchasing products under this scheme. Despite volume discount being commonly practiced, there is a dearth of research, both conceptual and empirical, focusing on purchase characteristics factors and consumer internal evaluation concerning the purchase of products under VDS. To attempt to fill this void, this article develops a conceptual model on VDS with the intention of delineating the influence of the purchase characteristics factors on the consumer intention to purchase products under VDS and provides an explanation of their effects through consumer internal evaluation. Finally, the authors discuss the managerial implications of their research and offer guidelines for future empirical research.

  11. Inference in Non-Linear Panels with Partially Missing Observations: The Case of the Equilibrium Search Model

    DEFF Research Database (Denmark)

    Christensen, Bent J.; M. Kiefer, Nicholas

    1996-01-01

    A thorough econometric analysis of the pure equilibrium search model is given. Minimal data requirements for estimation are unemployment durations, wages, and employment durations. An assessment of the information contribution of each data element is given. The results define the range of potential...

  12. Documentation for grants equal to tax model: Volume 3, Source code

    International Nuclear Information System (INIS)

    Boryczka, M.K.

    1986-01-01

    The GETT model is capable of forecasting the amount of tax liability associated with all property owned and all activities undertaken by the US Department of Energy (DOE) in site characterization and repository development. The GETT program is a user-friendly, menu-driven model developed using dBASE III/trademark/, a relational data base management system. The data base for GETT consists primarily of eight separate dBASE III/trademark/ files corresponding to each of the eight taxes (real property, personal property, corporate income, franchise, sales, use, severance, and excise) levied by State and local jurisdictions on business property and activity. Additional smaller files help to control model inputs and reporting options. Volume 3 of the GETT model documentation is the source code. The code is arranged primarily by the eight tax types. Other code files include those for JURISDICTION, SIMULATION, VALIDATION, TAXES, CHANGES, REPORTS, GILOT, and GETT. The code has been verified through hand calculations

  13. A reaction-diffusion model for market fluctuations - A relation between price change and traded volumes

    Science.gov (United States)

    Yuvan, Steven; Bier, Martin

    2018-02-01

    Two decades ago Bak et al. (1997) [3] proposed a reaction-diffusion model to describe market fluctuations. In the model buyers and sellers diffuse from opposite ends of a 1D interval that represents a price range. Trades occur when buyers and sellers meet. We show analytically and numerically that the model well reproduces the square-root relation between traded volumes and price changes that is observed in real-life markets. The result is remarkable as this relation has commonly been explained in terms of more elaborate trader strategies. We furthermore explain why the square-root relation is robust under model modifications and we show how real-life bond market data exhibit the square-root relation.

  14. Robust control investigations for equipment loaded panels

    DEFF Research Database (Denmark)

    Aglietti, G.S.; Langley, R.S.; Rogers, E.

    1998-01-01

    This paper develops a modelling technique for equipment load panels which directly produces (adequate) models of the underlying dynamics on which to base robust controller design/evaluations. This technique is based on the use of the Lagrange's equations of motion and the resulting models are ver...... are verified against those produced by a finite Element Method Model...

  15. Blue Ribbon Panel Report

    Science.gov (United States)

    An NCI Cancer Currents blog by the NCI acting director thanking the cancer community for contributing to the Cancer Moonshot Blue Ribbon Panel report, which was presented to the National Cancer Advisory Board on September 7.

  16. Autoimmune liver disease panel

    Science.gov (United States)

    Liver disease test panel - autoimmune ... Autoimmune disorders are a possible cause of liver disease. The most common of these diseases are autoimmune hepatitis and primary biliary cholangitis (formerly called primary biliary cirrhosis). This group of tests ...

  17. Basic metabolic panel

    Science.gov (United States)

    ... Alternative Names SMAC7; Sequential multi-channel analysis with computer-7; SMA7; Metabolic panel 7; CHEM-7 References ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  18. REINFORCED COMPOSITE PANEL

    DEFF Research Database (Denmark)

    2003-01-01

    A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing...... reinforcement being located on or embedded in matrix material adjacent to the front face of the panel, the backing reinforcement being located in a plane or planes substantially parallel to the plane or planes of the facing reinforcement, and being substantially coextensive therewith, and spaced therefrom...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

  19. An Efficient Model for NPD Performance Evaluation Using DEMATEL and Fuzzy ANP—Applied to the TFT-LCD Touch Panel Industry in Taiwan

    Directory of Open Access Journals (Sweden)

    Wen-Chin Chen

    2015-10-01

    Full Text Available As the competitive market nowadays shortens the life cycle of products, new products should be designed to meet the customer’s demand under a dynamic marketing environment so as to efficiently enhance the product strength of new products with maximization of profit. Hence, the key solution for enterprises to succeed will be the precise evaluation of new product development (NPD performance, particularly for those who manage to survive in the intensely competitive market in Taiwan. This study is to identify the thin film transistor-liquid crystal display (TFT-LCD touch panel industry and then establish an integrated model of NPD performance evaluation for enterprises. Firstly, literature review and interviews with experts are conducted to select the four aspects and 15 criteria as the main factors affecting NDP performance evaluation. Secondly, Decision Making Trial and Evaluation Laboratory (DEMATEL is employed to identify the interrelationships among those factors. Finally, a Fuzzy theory is applied to resolve the linguistic hedges and an Analytic Network Process (ANP is adopted to obtain the weights of all factors. A case study is performed to validate the proposed model in a Taiwanese TFT-LCD company. It not only provides the decision maker with a guidance system but also increases the competitive advantages for the TFT-LCD industry to design new products in the future.

  20. Hexagon solar power panel

    Science.gov (United States)

    Rubin, I. (Inventor)

    1978-01-01

    A solar energy panel support is described upon which silicon cells are arrayed. The cells are wafer thin and of two geometrical types, both of the same area and electrical rating, namely hexagon cells and hourglass cells. The hourglass cells are composites of half hexagons. A near perfect nesting relationship of the cells achieves a high density packing whereby optimum energy production per panel area is achieved.

  1. Pop-Art Panels

    Science.gov (United States)

    Alford, Joanna

    2012-01-01

    James Rosenquist's giant Pop-art panels included realistic renderings of well-known contemporary foods and objects, juxtaposed with famous people in the news--largely from the 1960s, '70s and '80s--and really serve as visual time capsules. In this article, eighth-graders focus on the style of James Rosenquist to create their own Pop-art panel that…

  2. Equal Opportunities Advisory Panel

    CERN Multimedia

    HR Department

    2006-01-01

    At its meeting on 7 December 2006, the Standing Concertation Committee took note of the appointment of four new members of the Panel: Wisla Carena, Pierre Charrue, Sue Foffano and Markus Nordberg. The present composition of the Panel (appointed ad personam) is as follows: Tiziano Camporesi (Chairperson), Wisla Carena, Pierre Charrue, Sue Foffano, Josi Schinzel (Equal Opportunities Officer), Markus Nordberg, Christine Petit-Jean-Genaz et Elena Wildner. Human Resources Department Tel. 74480

  3. Hexagon solar power panel

    Science.gov (United States)

    Rubin, Irwin

    1978-01-01

    A solar energy panel comprises a support upon which silicon cells are arrayed. The cells are wafer thin and of two geometrical types, both of the same area and electrical rating, namely hexagon cells and hourglass cells. The hourglass cells are composites of half hexagons. A near perfect nesting relationship of the cells achieves a high density packing whereby optimum energy production per panel area is achieved.

  4. 3D robust Chan-Vese model for industrial computed tomography volume data segmentation

    Science.gov (United States)

    Liu, Linghui; Zeng, Li; Luan, Xiao

    2013-11-01

    Industrial computed tomography (CT) has been widely applied in many areas of non-destructive testing (NDT) and non-destructive evaluation (NDE). In practice, CT volume data to be dealt with may be corrupted by noise. This paper addresses the segmentation of noisy industrial CT volume data. Motivated by the research on the Chan-Vese (CV) model, we present a region-based active contour model that draws upon intensity information in local regions with a controllable scale. In the presence of noise, a local energy is firstly defined according to the intensity difference within a local neighborhood. Then a global energy is defined to integrate local energy with respect to all image points. In a level set formulation, this energy is represented by a variational level set function, where a surface evolution equation is derived for energy minimization. Comparative analysis with the CV model indicates the comparable performance of the 3D robust Chan-Vese (RCV) model. The quantitative evaluation also shows the segmentation accuracy of 3D RCV. In addition, the efficiency of our approach is validated under several types of noise, such as Poisson noise, Gaussian noise, salt-and-pepper noise and speckle noise.

  5. A Gaussian mixture model for definition of lung tumor volumes in positron emission tomography

    International Nuclear Information System (INIS)

    Aristophanous, Michalis; Penney, Bill C.; Martel, Mary K.; Pelizzari, Charles A.

    2007-01-01

    The increased interest in 18 F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in radiation treatment planning in the past five years necessitated the independent and accurate segmentation of gross tumor volume (GTV) from FDG-PET scans. In some studies the radiation oncologist contours the GTV based on a computed tomography scan, while incorporating pertinent data from the PET images. Alternatively, a simple threshold, typically 40% of the maximum intensity, has been employed to differentiate tumor from normal tissue, while other researchers have developed algorithms to aid the PET based GTV definition. None of these methods, however, results in reliable PET tumor segmentation that can be used for more sophisticated treatment plans. For this reason, we developed a Gaussian mixture model (GMM) based segmentation technique on selected PET tumor regions from non-small cell lung cancer patients. The purpose of this study was to investigate the feasibility of using a GMM-based tumor volume definition in a robust, reliable and reproducible way. A GMM relies on the idea that any distribution, in our case a distribution of image intensities, can be expressed as a mixture of Gaussian densities representing different classes. According to our implementation, each class belongs to one of three regions in the image; the background (B), the uncertain (U) and the target (T), and from these regions we can obtain the tumor volume. User interaction in the implementation is required, but is limited to the initialization of the model parameters and the selection of an ''analysis region'' to which the modeling is restricted. The segmentation was developed on three and tested on another four clinical cases to ensure robustness against differences observed in the clinic. It also compared favorably with thresholding at 40% of the maximum intensity and a threshold determination function based on tumor to background image intensities proposed in a recent paper. The parts of the

  6. Solar energy heating panel

    Energy Technology Data Exchange (ETDEWEB)

    McMurtrie, T.

    1984-08-14

    A solar energy collecting and radiating panel for heating a fluid such as air circulating in an enclosure disposed behind the panel. The panel is in the form of a pan made of sheet metal, such as thin aluminum, darkened on its irradiated surface, the blackened or darkened surface being protected by a pane of glass. The panel has a plurality of dome-shaped dimples embossed on and projecting from its irradiated surface such as to present a large surface area to exposure to sun rays and to capture solar energy independently of the sun height or position relative to the horizon. The heat absorbed by the panel is conveyed by its back surface to air circulating by convection or by forced circulation in a thermally insulated enclosure, for heating a building or for any other utilization. A plurality of panels may be disposed side by side to form a solar energy collecting array preferably mounted on an outside wall of a building, in a southerly orientation.

  7. Sound Transmission Loss Through a Corrugated-Core Sandwich Panel with Integrated Acoustic Resonators

    Science.gov (United States)

    Schiller, Noah H.; Allen, Albert R.; Zalewski, Bart F; Beck, Benjamin S.

    2014-01-01

    The goal of this study is to better understand the effect of structurally integrated resonators on the transmission loss of a sandwich panel. The sandwich panel has facesheets over a corrugated core, which creates long aligned chambers that run parallel to the facesheets. When ports are introduced through the facesheet, the long chambers within the core can be used as low-frequency acoustic resonators. By integrating the resonators within the structure they contribute to the static load bearing capability of the panel while also attenuating noise. An analytical model of a panel with embedded resonators is derived and compared with numerical simulations. Predictions show that acoustic resonators can significantly improve the transmission loss of the sandwich panel around the natural frequency of the resonators. In one configuration with 0.813 m long internal chambers, the diffuse field transmission loss is improved by more than 22 dB around 104 Hz. The benefit is achieved with no added mass or volume relative to the baseline structure. The embedded resonators are effective because they radiate sound out-of-phase with the structure. This results in destructive interference, which leads to less transmitted sound power.

  8. Predicting oropharyngeal tumor volume throughout the course of radiation therapy from pretreatment computed tomography data using general linear models

    International Nuclear Information System (INIS)

    Yock, Adam D.; Kudchadker, Rajat J.; Rao, Arvind; Dong, Lei; Beadle, Beth M.; Garden, Adam S.; Court, Laurence E.

    2014-01-01

    Purpose: The purpose of this work was to develop and evaluate the accuracy of several predictive models of variation in tumor volume throughout the course of radiation therapy. Methods: Nineteen patients with oropharyngeal cancers were imaged daily with CT-on-rails for image-guided alignment per an institutional protocol. The daily volumes of 35 tumors in these 19 patients were determined and used to generate (1) a linear model in which tumor volume changed at a constant rate, (2) a general linear model that utilized the power fit relationship between the daily and initial tumor volumes, and (3) a functional general linear model that identified and exploited the primary modes of variation between time series describing the changing tumor volumes. Primary and nodal tumor volumes were examined separately. The accuracy of these models in predicting daily tumor volumes were compared with those of static and linear reference models using leave-one-out cross-validation. Results: In predicting the daily volume of primary tumors, the general linear model and the functional general linear model were more accurate than the static reference model by 9.9% (range: −11.6%–23.8%) and 14.6% (range: −7.3%–27.5%), respectively, and were more accurate than the linear reference model by 14.2% (range: −6.8%–40.3%) and 13.1% (range: −1.5%–52.5%), respectively. In predicting the daily volume of nodal tumors, only the 14.4% (range: −11.1%–20.5%) improvement in accuracy of the functional general linear model compared to the static reference model was statistically significant. Conclusions: A general linear model and a functional general linear model trained on data from a small population of patients can predict the primary tumor volume throughout the course of radiation therapy with greater accuracy than standard reference models. These more accurate models may increase the prognostic value of information about the tumor garnered from pretreatment computed tomography

  9. Panel and planar experimental shear behavior of wood panels ...

    African Journals Online (AJOL)

    Panel and planar experimental shear behavior of wood panels laminated softwood oriented OSB conditioned at different environments. ... to that measured in the case of panel shear for different environments. Keywords : oriented strand board – panel shear strength- planar shear strength - environment – moisture content ...

  10. New model for estimating the relationship between surface area and volume in the human body using skeletal remains.

    Science.gov (United States)

    Kasabova, Boryana E; Holliday, Trenton W

    2015-04-01

    A new model for estimating human body surface area and body volume/mass from standard skeletal metrics is presented. This model is then tested against both 1) "independently estimated" body surface areas and "independently estimated" body volume/mass (both derived from anthropometric data) and 2) the cylindrical model of Ruff. The model is found to be more accurate in estimating both body surface area and body volume/mass than the cylindrical model, but it is more accurate in estimating body surface area than it is for estimating body volume/mass (as reflected by the standard error of the estimate when "independently estimated" surface area or volume/mass is regressed on estimates derived from the present model). Two practical applications of the model are tested. In the first test, the relative contribution of the limbs versus the trunk to the body's volume and surface area is compared between "heat-adapted" and "cold-adapted" populations. As expected, the "cold-adapted" group has significantly more of its body surface area and volume in its trunk than does the "heat-adapted" group. In the second test, we evaluate the effect of variation in bi-iliac breadth, elongated or foreshortened limbs, and differences in crural index on the body's surface area to volume ratio (SA:V). Results indicate that the effects of bi-iliac breadth on SA:V are substantial, while those of limb lengths and (especially) the crural index are minor, which suggests that factors other than surface area relative to volume are driving morphological variation and ecogeographical patterning in limb prorportions. © 2014 Wiley Periodicals, Inc.

  11. The development of a volume element model for energy systems engineering and integrative thermodynamic optimization

    Science.gov (United States)

    Yang, Sam

    The dissertation presents the mathematical formulation, experimental validation, and application of a volume element model (VEM) devised for modeling, simulation, and optimization of energy systems in their early design stages. The proposed model combines existing modeling techniques and experimental adjustment to formulate a reduced-order model, while retaining sufficient accuracy to serve as a practical system-level design analysis and optimization tool. In the VEM, the physical domain under consideration is discretized in space using lumped hexahedral elements (i.e., volume elements), and the governing equations for the variable of interest are applied to each element to quantify diverse types of flows that cross it. Subsequently, a system of algebraic and ordinary differential equations is solved with respect to time and scalar (e.g., temperature, relative humidity, etc.) fields are obtained in both spatial and temporal domains. The VEM is capable of capturing and predicting dynamic physical behaviors in the entire system domain (i.e., at system level), including mutual interactions among system constituents, as well as with their respective surroundings and cooling systems, if any. The VEM is also generalizable; that is, the model can be easily adapted to simulate and optimize diverse systems of different scales and complexity and attain numerical convergence with sufficient accuracy. Both the capability and generalizability of the VEM are demonstrated in the dissertation via thermal modeling and simulation of an Off-Grid Zero Emissions Building, an all-electric ship, and a vapor compression refrigeration (VCR) system. Furthermore, the potential of the VEM as an optimization tool is presented through the integrative thermodynamic optimization of a VCR system, whose results are used to evaluate the trade-offs between various objective functions, namely, coefficient of performance, second law efficiency, pull-down time, and refrigerated space temperature, in

  12. Modeling the Interplay Between Tumor Volume Regression and Oxygenation in Uterine Cervical Cancer During Radiotherapy Treatment.

    Science.gov (United States)

    Belfatto, Antonella; Riboldi, Marco; Ciardo, Delia; Cattani, Federica; Cecconi, Agnese; Lazzari, Roberta; Jereczek-Fossa, Barbara Alicja; Orecchia, Roberto; Baroni, Guido; Cerveri, Pietro

    2016-03-01

    This paper describes a patient-specific mathematical model to predict the evolution of uterine cervical tumors at a macroscopic scale, during fractionated external radiotherapy. The model provides estimates of tumor regrowth and dead-cell reabsorption, incorporating the interplay between tumor regression rate and radiosensitivity, as a function of the tumor oxygenation level. Model parameters were estimated by minimizing the difference between predicted and measured tumor volumes, these latter being obtained from a set of 154 serial cone-beam computed tomography scans acquired on 16 patients along the course of the therapy. The model stratified patients according to two different estimated dynamics of dead-cell removal and to the predicted initial value of the tumor oxygenation. The comparison with a simpler model demonstrated an improvement in fitting properties of this approach (fitting error average value <5%, p < 0.01), especially in case of tumor late responses, which can hardly be handled by models entailing a constant radiosensitivity, failing to model changes from initial severe hypoxia to aerobic conditions during the treatment course. The model predictive capabilities suggest the need of clustering patients accounting for cancer cell line, tumor staging, as well as microenvironment conditions (e.g., oxygenation level).

  13. Final safety analysis report for the Galileo Mission: Volume 2, Book 2: Accident model document: Appendices

    Energy Technology Data Exchange (ETDEWEB)

    1988-12-15

    This section of the Accident Model Document (AMD) presents the appendices which describe the various analyses that have been conducted for use in the Galileo Final Safety Analysis Report II, Volume II. Included in these appendices are the approaches, techniques, conditions and assumptions used in the development of the analytical models plus the detailed results of the analyses. Also included in these appendices are summaries of the accidents and their associated probabilities and environment models taken from the Shuttle Data Book (NSTS-08116), plus summaries of the several segments of the recent GPHS safety test program. The information presented in these appendices is used in Section 3.0 of the AMD to develop the Failure/Abort Sequence Trees (FASTs) and to determine the fuel releases (source terms) resulting from the potential Space Shuttle/IUS accidents throughout the missions.

  14. Modelling of Evaporator in Waste Heat Recovery System using Finite Volume Method and Fuzzy Technique

    Directory of Open Access Journals (Sweden)

    Jahedul Islam Chowdhury

    2015-12-01

    Full Text Available The evaporator is an important component in the Organic Rankine Cycle (ORC-based Waste Heat Recovery (WHR system since the effective heat transfer of this device reflects on the efficiency of the system. When the WHR system operates under supercritical conditions, the heat transfer mechanism in the evaporator is unpredictable due to the change of thermo-physical properties of the fluid with temperature. Although the conventional finite volume model can successfully capture those changes in the evaporator of the WHR process, the computation time for this method is high. To reduce the computation time, this paper develops a new fuzzy based evaporator model and compares its performance with the finite volume method. The results show that the fuzzy technique can be applied to predict the output of the supercritical evaporator in the waste heat recovery system and can significantly reduce the required computation time. The proposed model, therefore, has the potential to be used in real time control applications.

  15. Modeling the spatial distribution of the parameters of the coolant in the reactor volume

    International Nuclear Information System (INIS)

    Nikonov, S.P.

    2011-01-01

    In this paper the approach to the question about the spatial distribution of the parameters of the coolant in-reactor volume. To describe the in-core space is used specially developed preprocessor. When the work of the preprocessor in the first place, is recreated on the basis of available information (mostly-the original drawings) with high accuracy three-dimensional description of the structures of the reactor volume and, secondly, are prepared on this basis blocks input to the nodal system code improved estimate ATHLET, allows to take into account the hydrodynamic interaction between the spatial control volumes. As an example the special case of solutions of international standard problem on the reconstruction of the transition process in the third unit of the Kalinin nuclear power plant, due to the shutdown of one of the four Main Coolant Pumps in operation at the rated capacity (first download). Model-core area consists of approximately 58 000 control volumes and spatial relationships. It shows the influence of certain structural units of the core to the distribution of the mass floe rate of its height. It is detected a strong cross-flow coolant in the area over the baffle. Moreover, we study the distribution of the coolant temperature at the assembly head of WWER-1000 reactor. It is shown that in the region of the top of the assembly head, where we have installation of thermocouples, the flow coolant for internal assemblies core is formed by only from guide channel Reactor control and protected system Control rod flow, or a mixture of the guide channel flow and flow from the area in front of top grid head assembly (the peripheral assemblies). It is shown that the magnitude of the flow guide channels affects not only the position of control rods, but also the presence of a particular type of measuring channels (Self powered neutron detector sensors or Temperature control sensors) in the cassette. (Author)

  16. Front tracking based modeling of the solid grain growth on the adaptive control volume grid

    Science.gov (United States)

    Seredyński, Mirosław; Łapka, Piotr

    2017-07-01

    The paper presents the micro-scale model of unconstrained solidification of the grain immersed in under-cooled liquid, based on the front tracking approach. For this length scale, the interface tracked through the domain is meant as the solid-liquid boundary. To prevent generation of huge meshes the energy transport equation is discretized on the adaptive control volume (c.v.) mesh. The coupling of dynamically changing mesh and moving front position is addressed. Preliminary results of simulation of a test case, the growth of single grain, are presented and discussed.

  17. The Spatial Mechanism and Drive Mechanism Study of Chinese Urban Efficiency - Based on the Spatial Panel Data Model

    Directory of Open Access Journals (Sweden)

    Yuan Xiaoling

    2016-08-01

    Full Text Available In this article, the urban efficiency factors of 285 Chinese prefecture-level cities in the period from 2003 to 2012 are analyzed by using the spatial econometric model. The result shows that the development of urban efficiency between the cities positively correlates with space. And we conclude that the Industrial Structure, Openness and the Infrastructure can promote the development of such urban efficiency. The Urban Agglomeration Scale, Government Control, Fixed Asset Investment and other factors can inhibit the development of urban efficiency to a certain degree. Therefore, we come to a conclusion that, in the new urbanization construction process, the cities need to achieve cross-regional coordination from the perspective of urban agglomerations and metropolitan development. The efficiency of the city together with the scientific and rational flow of the factors should also be improved.

  18. Review of models used for determining consequences of UF6 release: Model evaluation report. Volume 2

    International Nuclear Information System (INIS)

    Nair, S.K.; Chambers, D.B.; Park, S.H.; Radonjic, Z.R.; Coutts, P.T.; Lewis, C.J.; Hammonds, J.S.; Hoffman, F.O.

    1997-11-01

    Three uranium hexafluoride-(UF 6 -) specific models--HGSYSTEM/UF 6 , Science Application International Corporation, and RTM-96; three dense-gas models--DEGADIS, SLAB, and the Chlorine Institute methodology; and one toxic chemical model--AFTOX--are evaluated on their capabilities to simulate the chemical reactions, thermodynamics, and atmospheric dispersion of UF 6 released from accidents at nuclear fuel-cycle facilities, to support Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis. These models are also evaluated for user-friendliness and for quality assurance and quality control features, to ensure the validity and credibility of the results. Model performance evaluations are conducted for the three UF 6 -specific models, using field data on releases of UF 6 and other heavy gases. Predictions from the HGSYSTEM/UF 6 and SAIC models are within an order of magnitude of the field data, but the SAIC model overpredicts beyond an order of magnitude for a few UF 6 -specific data points. The RTM-96 model provides overpredictions within a factor of 3 for all data points beyond 400 m from the source. For one data set, however, the RTM-96 model severely underpredicts the observations within 200 m of the source. Outputs of the models are most sensitive to the meteorological parameters at large distances from the source and to certain source-specific and meteorological parameters at distances close to the source. Specific recommendations are being made to improve the applicability and usefulness of the three models and to choose a specific model to support the intended analyses. Guidance is also provided on the choice of input parameters for initial dilution, building wake effects, and distance to completion of UF 6 reaction with water

  19. Thermo-mechanical interaction effects in foam cored sandwich panels-correlation between High-order models and Finite element analysis results

    DEFF Research Database (Denmark)

    Palleti, Hara Naga Krishna Teja; Santiuste, Carlos; Thomsen, Ole Thybo

    2010-01-01

    Thermo-mechanical interaction effects including thermal material degradation in polymer foam cored sandwich structures is investigated using the commercial Finite Element Analysis (FEA) package ABAQUS/Standard. Sandwich panels with different boundary conditions in the form of simply supported...

  20. Preliminary thermal and thermomechanical modeling for the near surface test facility heater experiments at Hanford. Volume II: Appendix D

    International Nuclear Information System (INIS)

    Chan, T.; Remer, J.S.

    1978-12-01

    Appendix D is a complete set of figures illustrating the detailed calculations necessary for designing the heater experiments at the Near Surface Test Facility (NSTF) at Hanford, Washington. The discussion of the thermal and thermomechanical modeling that yielded these calculations is presented in Volume 1. A summary of the figures and the models they illustrate is given in table D1. The most important figures have also been included in the discussion in Volume 1, and Table D2 lists the figure numbers in this volume that correspond to figure numbers used there

  1. Natural Gas Transmission and Distribution Model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    The Natural Gas Transmission and Distribution Model (NGTDM) is the component of the National Energy Modeling System (NEMS) that is used to represent the domestic natural gas transmission and distribution system. The NGTDM is the model within the NEMS that represents the transmission, distribution, and pricing of natural gas. The model also includes representations of the end-use demand for natural gas, the production of domestic natural gas, and the availability of natural gas traded on the international market based on information received from other NEMS models. The NGTDM determines the flow of natural gas in an aggregate, domestic pipeline network, connecting domestic and foreign supply regions with 12 demand regions. The purpose of this report is to provide a reference document for model analysts, users, and the public that defines the objectives of the model, describes its basic design, provides detail on the methodology employed, and describes the model inputs, outputs, and key assumptions. Subsequent chapters of this report provide: an overview of NGTDM; a description of the interface between the NEMS and NGTDM; an overview of the solution methodology of the NGTDM; the solution methodology for the Annual Flow Module; the solution methodology for the Distributor Tariff Module; the solution methodology for the Capacity Expansion Module; the solution methodology for the Pipeline Tariff Module; and a description of model assumptions, inputs, and outputs.

  2. Documentation for Grants Equal to Tax model: Volume 1, Technical description

    International Nuclear Information System (INIS)

    1986-01-01

    A computerized model, the Grants Equal to Tax (GETT) model, was developed to assist in evaluating the amount of federal grant monies that would go to state and local jurisdictions under the provisions outlined in the Nuclear Waste Policy Act of 1982. The GETT model is capable of forecasting the amount of tax liability associated with all property owned and all activities undertaken by the US Department of Energy (DOE) in site characterization and repository development. The GETT program is a user-friendly, menu-driven model developed using dBASE III/trademark/, a relational data base management system. The data base for GETT consists primarily of eight separate dBASE III/trademark/ files corresponding to each of the eight taxes levied by state and local jurisdictions on business property and activity. Additional smaller files help to control model inputs and reporting options. Volume 1 of the GETT model documentation is a technical description of the program and its capabilities providing (1) descriptions of the data management system and its procedures; (2) formulas for calculating taxes (illustrated with flow charts); (3) descriptions of tax data base variables for the Deaf Smith County, Texas, Richton Dome, Mississippi, and Davis Canyon, Utah, salt sites; and (4) data inputs for the GETT model. 10 refs., 18 figs., 3 tabs

  3. A Volume-Fraction Based Two-Phase Constitutive Model for Blood

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Rui (Carnegie-Mellon Univ.); Massoudi, Mehrdad; Hund, S.J. (Carnegie-Mellon Univ.); •Antaki, J.F. (Carnegie-Mellon Univ.)

    2008-06-01

    Mechanically-induced blood trauma such as hemolysis and thrombosis often occurs at microscopic channels, steps and crevices within cardiovascular devices. A predictive mathematical model based on a broad understanding of hemodynamics at micro scale is needed to mitigate these effects, and is the motivation of this research project. Platelet transport and surface deposition is important in thrombosis. Microfluidic experiments have previously revealed a significant impact of red blood cell (RBC)-plasma phase separation on platelet transport [5], whereby platelet localized concentration can be enhanced due to a non-uniform distribution of RBCs of blood flow in a capillary tube and sudden expansion. However, current platelet deposition models either totally ignored RBCs in the fluid by assuming a zero sample hematocrit or treated them as being evenly distributed. As a result, those models often underestimated platelet advection and deposition to certain areas [2]. The current study aims to develop a two-phase blood constitutive model that can predict phase separation in a RBC-plasma mixture at the micro scale. The model is based on a sophisticated theory known as theory of interacting continua, i.e., mixture theory. The volume fraction is treated as a field variable in this model, which allows the prediction of concentration as well as velocity profiles of both RBC and plasma phases. The results will be used as the input of successive platelet deposition models.

  4. Geometry modeling and grid generation using 3D NURBS control volume

    Science.gov (United States)

    Yu, Tzu-Yi; Soni, Bharat K.; Shih, Ming-Hsin

    1995-01-01

    The algorithms for volume grid generation using NURBS geometric representation are presented. The parameterization algorithm is enhanced to yield a desired physical distribution on the curve, surface and volume. This approach bridges the gap between CAD surface/volume definition and surface/volume grid generation. Computational examples associated with practical configurations have shown the utilization of these algorithms.

  5. Predicting bending stiffness of randomly oriented hybrid panels

    Science.gov (United States)

    Laura Moya; William T.Y. Tze; Jerrold E. Winandy

    2010-01-01

    This study was conducted to develop a simple model to predict the bending modulus of elasticity (MOE) of randomly oriented hybrid panels. The modeling process involved three modules: the behavior of a single layer was computed by applying micromechanics equations, layer properties were adjusted for densification effects, and the entire panel was modeled as a three-...

  6. A Computational Model for the Automatic Diagnosis of Attention Deficit Hyperactivity Disorder Based on Functional Brain Volume

    Directory of Open Access Journals (Sweden)

    Lirong Tan

    2017-09-01

    Full Text Available In this paper, we investigated the problem of computer-aided diagnosis of Attention Deficit Hyperactivity Disorder (ADHD using machine learning techniques. With the ADHD-200 dataset, we developed a Support Vector Machine (SVM model to classify ADHD patients from typically developing controls (TDCs, using the regional brain volumes as predictors. Conventionally, the volume of a brain region was considered to be an anatomical feature and quantified using structural magnetic resonance images. One major contribution of the present study was that we had initially proposed to measure the regional brain volumes using fMRI images. Brain volumes measured from fMRI images were denoted as functional volumes, which quantified the volumes of brain regions that were actually functioning during fMRI imaging. We compared the predictive power of functional volumes with that of regional brain volumes measured from anatomical images, which were denoted as anatomical volumes. The former demonstrated higher discriminative power than the latter for the classification of ADHD patients vs. TDCs. Combined with our two-step feature selection approach which integrated prior knowledge with the recursive feature elimination (RFE algorithm, our SVM classification model combining functional volumes and demographic characteristics achieved a balanced accuracy of 67.7%, which was 16.1% higher than that of a relevant model published previously in the work of Sato et al. Furthermore, our classifier highlighted 10 brain regions that were most discriminative in distinguishing between ADHD patients and TDCs. These 10 regions were mainly located in occipital lobe, cerebellum posterior lobe, parietal lobe, frontal lobe, and temporal lobe. Our present study using functional images will likely provide new perspectives about the brain regions affected by ADHD.

  7. Transportation Sector Model of the National Energy Modeling System. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model. The NEMS Transportation Model comprises a series of semi-independent models which address different aspects of the transportation sector. The primary purpose of this model is to provide mid-term forecasts of transportation energy demand by fuel type including, but not limited to, motor gasoline, distillate, jet fuel, and alternative fuels (such as CNG) not commonly associated with transportation. The current NEMS forecast horizon extends to the year 2010 and uses 1990 as the base year. Forecasts are generated through the separate consideration of energy consumption within the various modes of transport, including: private and fleet light-duty vehicles; aircraft; marine, rail, and truck freight; and various modes with minor overall impacts, such as mass transit and recreational boating. This approach is useful in assessing the impacts of policy initiatives, legislative mandates which affect individual modes of travel, and technological developments. The model also provides forecasts of selected intermediate values which are generated in order to determine energy consumption. These elements include estimates of passenger travel demand by automobile, air, or mass transit; estimates of the efficiency with which that demand is met; projections of vehicle stocks and the penetration of new technologies; and estimates of the demand for freight transport which are linked to forecasts of industrial output. Following the estimation of energy demand, TRAN produces forecasts of vehicular emissions of the following pollutants by source: oxides of sulfur, oxides of nitrogen, total carbon, carbon dioxide, carbon monoxide, and volatile organic compounds.

  8. The CRRES high efficiency solar panel

    International Nuclear Information System (INIS)

    Trumble, T.M.

    1991-01-01

    This paper reports on the High Efficiency Solar Panel (HESP) experiments which is to provide both engineering and scientific information concerning the effects of space radiation on advanced gallium arsenide (GaAs) solar cells. The HESP experiment consists of an ambient panel, and annealing panel and a programmable load. This experiment, in conjunction with the radiation measurement experiments abroad the CREES, provides the first opportunity to simultaneously measure the trapped radiation belts and the results of radiation damage to solar cells. The engineering information will result in a design guide for selecting the optimum solar array characteristics for different orbits and different lifetimes. The scientific information will provide both correlation of laboratory damage effects to space damage effects and a better model for predicting effective solar cell panel lifetimes

  9. Geoscience data base handbook for modeling a nuclear waste repository. Volume 1

    International Nuclear Information System (INIS)

    Isherwood, D.

    1979-12-01

    This handbook contains reference information on parameters that should be considered in analyzing or modeling a proposed nuclear waste repository site. Only those parameters and values that best represent the natural environment are included. Rare extremes are avoided. Where laboratory and field data are inadequate, theoretical treatments and informed engineering judgements are presented. Volume 1 contains a data base on salt as a repository medium. Chapters on the geology of bedded and dome salt, the geomechanics of salt, hydrology, geochemistry, natural and man-made features, and seismology provide compiled data and related information useful for studying a proposed repository in salt. These and other data will be needed to derive generic deep geologic modeling parameters and will also serve as background for the verification of source data that may be presented in licensing applications for nuclear waste repositories. Volume 2 is the result of a scoping study for a data base on the geology, geomechanics, and hydrology of shale, granite, and basalt as alternative repository media. Except for the geomechanics of shale, most of the sections contain relatively complete compilations of the available data, as well as discussions of the properties that are unique to each rock type

  10. Environmental fate model for ultra-low-volume insecticide applications used for adult mosquito management

    Science.gov (United States)

    Schleier, Jerome J.; Peterson, Robert K.D.; Irvine, Kathryn M.; Marshall, Lucy M.; Weaver, David K.; Preftakes, Collin J.

    2012-01-01

    One of the more effective ways of managing high densities of adult mosquitoes that vector human and animal pathogens is ultra-low-volume (ULV) aerosol applications of insecticides. The U.S. Environmental Protection Agency uses models that are not validated for ULV insecticide applications and exposure assumptions to perform their human and ecological risk assessments. Currently, there is no validated model that can accurately predict deposition of insecticides applied using ULV technology for adult mosquito management. In addition, little is known about the deposition and drift of small droplets like those used under conditions encountered during ULV applications. The objective of this study was to perform field studies to measure environmental concentrations of insecticides and to develop a validated model to predict the deposition of ULV insecticides. The final regression model was selected by minimizing the Bayesian Information Criterion and its prediction performance was evaluated using k-fold cross validation. Density of the formulation and the density and CMD interaction coefficients were the largest in the model. The results showed that as density of the formulation decreases, deposition increases. The interaction of density and CMD showed that higher density formulations and larger droplets resulted in greater deposition. These results are supported by the aerosol physics literature. A k-fold cross validation demonstrated that the mean square error of the selected regression model is not biased, and the mean square error and mean square prediction error indicated good predictive ability.

  11. Dose-volume effects in rat thoracolumbar spinal cord: an evaluation of NTCP models.

    Science.gov (United States)

    Philippens, Marielle E P; Pop, Lucas A M; Visser, Andries G; Schellekens, Suzanne A M W; van der Kogel, Albert J

    2004-10-01

    To evaluate models for normal-tissue-complication probability (NTCP) on describing the dose-volume effect in rat thoracolumbar spinal cord. Single-dose irradiation of four field lengths (4, 1.5, 1.0, and 0.5 cm) was evaluated by the endpoints paresis and white-matter necrosis. The resulting dose-response data were used to rank phenomenological and tissue architecture NTCP models. The 0.5-cm field length showed a steep increase in radiation tolerance. Statistical analysis of the model fits, which included evaluation of goodness of fit (GOF) and confidence intervals, resulted in the rejection of all the models considered. Excluding the smallest field length, the Schultheiss (D(50) = 21.5 Gy, k = 26.5), the relative seriality (D(50) = 21.4 Gy, s = 1.6, gamma(50) = 6.3), and the critical element (D(50,FSU) = 26.6 Gy, gamma(50,FSU) = 2.3, n = 1.3) model gave the best fit. A thorough statistical analysis resulted in a serial or critical-element behavior for the field lengths of 1.0 cm and greater. Including the 0.5-cm field length, the radiation response markedly diverged from serial properties, but none of the models applied acceptably described this dose-response relationship. This study suggests that the commonly assumed serial behavior of the spinal cord might be valid for daily use in external- beam irradiation.

  12. Development of temporally refined land-use regression models predicting daily household-level air pollution in a panel study of lung function among asthmatic children.

    Science.gov (United States)

    Johnson, Markey; Macneill, Morgan; Grgicak-Mannion, Alice; Nethery, Elizabeth; Xu, Xiaohong; Dales, Robert; Rasmussen, Pat; Wheeler, Amanda

    2013-01-01

    Regulatory monitoring data and land-use regression (LUR) models have been widely used for estimating individual exposure to ambient air pollution in epidemiologic studies. However, LUR models lack fine-scale temporal resolution for predicting acute exposure and regulatory monitoring provides daily concentrations, but fails to capture spatial variability within urban areas. This study coupled LUR models with continuous regulatory monitoring to predict daily ambient nitrogen dioxide (NO(2)) and particulate matter (PM(2.5)) at 50 homes in Windsor, Ontario. We compared predicted versus measured daily outdoor concentrations for 5 days in winter and 5 days in summer at each home. We also examined the implications of using modeled versus measured daily pollutant concentrations to predict daily lung function among asthmatic children living in those homes. Mixed effect analysis suggested that temporally refined LUR models explained a greater proportion of the spatial and temporal variance in daily household-level outdoor NO(2) measurements compared with daily concentrations based on regulatory monitoring. Temporally refined LUR models captured 40% (summer) and 10% (winter) more of the spatial variance compared with regulatory monitoring data. Ambient PM(2.5) showed little spatial variation; therefore, daily PM(2.5) models were similar to regulatory monitoring data in the proportion of variance explained. Furthermore, effect estimates for forced expiratory volume in 1 s (FEV(1)) and peak expiratory flow (PEF) based on modeled pollutant concentrations were consistent with effects based on household-level measurements for NO(2) and PM(2.5). These results suggest that LUR modeling can be combined with continuous regulatory monitoring data to predict daily household-level exposure to ambient air pollution. Temporally refined LUR models provided a modest improvement in estimating daily household-level NO(2) compared with regulatory monitoring data alone, suggesting that this

  13. Mixed finite element - discontinuous finite volume element discretization of a general class of multicontinuum models

    Science.gov (United States)

    Ruiz-Baier, Ricardo; Lunati, Ivan

    2016-10-01

    We present a novel discretization scheme tailored to a class of multiphase models that regard the physical system as consisting of multiple interacting continua. In the framework of mixture theory, we consider a general mathematical model that entails solving a system of mass and momentum equations for both the mixture and one of the phases. The model results in a strongly coupled and nonlinear system of partial differential equations that are written in terms of phase and mixture (barycentric) velocities, phase pressure, and saturation. We construct an accurate, robust and reliable hybrid method that combines a mixed finite element discretization of the momentum equations with a primal discontinuous finite volume-element discretization of the mass (or transport) equations. The scheme is devised for unstructured meshes and relies on mixed Brezzi-Douglas-Marini approximations of phase and total velocities, on piecewise constant elements for the approximation of phase or total pressures, as well as on a primal formulation that employs discontinuous finite volume elements defined on a dual diamond mesh to approximate scalar fields of interest (such as volume fraction, total density, saturation, etc.). As the discretization scheme is derived for a general formulation of multicontinuum physical systems, it can be readily applied to a large class of simplified multiphase models; on the other, the approach can be seen as a generalization of these models that are commonly encountered in the literature and employed when the latter are not sufficiently accurate. An extensive set of numerical test cases involving two- and three-dimensional porous media are presented to demonstrate the accuracy of the method (displaying an optimal convergence rate), the physics-preserving properties of the mixed-primal scheme, as well as the robustness of the method (which is successfully used to simulate diverse physical phenomena such as density fingering, Terzaghi's consolidation

  14. International Nuclear Model. Volume 3. Program description. Appendix A-H (Part 1)

    International Nuclear Information System (INIS)

    Andress, D.

    1985-01-01

    The International Nuclear Model (INM) is a comprehensive model of the commercial nuclear power industry. It simulates economic decisions for reactor deployment and fuel management decisions based on an input set of technical, economic and scenario parameters. The technical parameters include reactor operating characteristics, fuel cycle timing and mass loss factors, and enrichment tails assays. Economic parameters include fuel cycle costs, financial data, and tax alternatives. INM has a broad range of scenario options covering, for example, process constraints, interregional activities, reprocessing, and fuel management selection. INM reports reactor deployment schedules, electricity generation, and fuel cycle requirements and costs. It also has specialized reports for extended burnup and permanent disposal. This volume contains appendices A through H including a description of subroutines and the Fortran listing of the program

  15. Advanced solar panel designs

    Science.gov (United States)

    Ralph, E. L.; Linder, E.

    1995-01-01

    This paper describes solar cell panel designs that utilize new hgih efficiency solar cells along with lightweight rigid panel technology. The resulting designs push the W/kg and W/sq m parameters to new high levels. These new designs are well suited to meet the demand for higher performance small satellites. This paper reports on progress made on two SBIR Phase 1 contracts. One panel design involved the use of large area (5.5 cm x 6.5 cm) GaAs/Ge solar cells of 19% efficiency combined with a lightweight rigid graphite fiber epoxy isogrid substrate configuration. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power level of 60 W/kg with a potential of reaching 80 W/kg. The second panel design involved the use of newly developed high efficiency (22%) dual junction GaInP2/GaAs/Ge solar cells combined with an advanced lightweight rigid substrate using aluminum honeycomb core with high strength graphite fiber mesh facesheets. A coupon (38 cm x 38 cm) was fabricated and tested which demonstrated an array specific power of 105 W/kg and 230 W/sq m. This paper will address the construction details of the panels and an a analysis of the component weights. A strawman array design suitable for a typical small-sat mission is described for each of the two panel design technologies being studied. Benefits in respect to weight reduction, area reduction, and system cost reduction are analyzed and compared to conventional arrays.

  16. Aerosol Deposition and Solar Panel Performance

    Science.gov (United States)

    Arnott, W. P.; Rollings, A.; Taylor, S. J.; Parks, J.; Barnard, J.; Holmes, H.

    2015-12-01

    Passive and active solar collector farms are often located in relatively dry desert regions where cloudiness impacts are minimized. These farms may be susceptible to reduced performance due to routine or episodic aerosol deposition on collector surfaces. Intense episodes of wind blown dust deposition may negatively impact farm performance, and trigger need to clean collector surfaces. Aerosol deposition rate depends on size, morphology, and local meteorological conditions. We have developed a system for solar panel performance testing under real world conditions. Two identical 0.74 square meter solar panels are deployed, with one kept clean while the other receives various doses of aerosol deposition or other treatments. A variable load is used with automation to record solar panel maximum output power every 10 minutes. A collocated sonic anemometer measures wind at 10 Hz, allowing for both steady and turbulent characterization to establish a link between wind patterns and particle distribution on the cells. Multispectral photoacoustic instruments measure aerosol light scattering and absorption. An MFRSR quantifies incoming solar radiation. Solar panel albedo is measured along with the transmission spectra of particles collected on the panel surface. Key questions are: At what concentration does aerosol deposition become a problem for solar panel performance? What are the meteorological conditions that most strongly favor aerosol deposition, and are these predictable from current models? Is it feasible to use the outflow from an unmanned aerial vehicle hovering over solar panels to adequately clean their surface? Does aerosol deposition from episodes of nearby forest fires impact performance? The outlook of this research is to build a model that describes environmental effects on solar panel performance. Measurements from summer and fall 2015 will be presented along with insights gleaned from them.

  17. Numerical Modeling of Poroelastic-Fluid Systems Using High-Resolution Finite Volume Methods

    Science.gov (United States)

    Lemoine, Grady

    Poroelasticity theory models the mechanics of porous, fluid-saturated, deformable solids. It was originally developed by Maurice Biot to model geophysical problems, such as seismic waves in oil reservoirs, but has also been applied to modeling living bone and other porous media. Poroelastic media often interact with fluids, such as in ocean bottom acoustics or propagation of waves from soft tissue into bone. This thesis describes the development and testing of high-resolution finite volume numerical methods, and simulation codes implementing these methods, for modeling systems of poroelastic media and fluids in two and three dimensions. These methods operate on both rectilinear grids and logically rectangular mapped grids. To allow the use of these methods, Biot's equations of poroelasticity are formulated as a first-order hyperbolic system with a source term; this source term is incorporated using operator splitting. Some modifications are required to the classical high-resolution finite volume method. Obtaining correct solutions at interfaces between poroelastic media and fluids requires a novel transverse propagation scheme and the removal of the classical second-order correction term at the interface, and in three dimensions a new wave limiting algorithm is also needed to correctly limit shear waves. The accuracy and convergence rates of the methods of this thesis are examined for a variety of analytical solutions, including simple plane waves, reflection and transmission of waves at an interface between different media, and scattering of acoustic waves by a poroelastic cylinder. Solutions are also computed for a variety of test problems from the computational poroelasticity literature, as well as some original test problems designed to mimic possible applications for the simulation code.

  18. Mass residuals in implicit finite volume models for overland and groundwater flow

    Science.gov (United States)

    Lal, A. M. Wasantha; Wang, Naming; Moustafa, M. Z.; Brown, M. C.

    2010-04-01

    SummaryA primary advantage in using the finite volume method for simulating groundwater flow and overland flow is the conservation property or the ability to conserve mass. However, when implicit finite volume methods are used with large time steps, small cell areas, or parameters with extreme value ranges, the conservation of mass equation becomes slightly unbalanced with a residual. Problems with large mass residuals can be predicted using the condition number of the solution matrix, and the convergence criterion used in the sparse matrix solver. The amount of practical guidance available on how to manage the magnitude of the mass residual or the matrix condition number is limited. To address this need, the current paper shows the usefulness of the mesh ratio. The mesh ratio is a dimensionless number that is a function of the mesh resolution and the temporal resolution. It is directly related to the condition number of the matrix, which in turn affects the mass residual and the model run time. During the current study, several numerical experiments are carried out to determine how the mesh ratio and the water level are related to the condition number, how the critical mesh ratio is related to the number of cells, how the run time is related to the mesh ratio, and how the mass residual is related to the mesh ratio. The results are useful in creating guidelines for mesh design during large-scale model applications. These guidelines can be applied to reducing the mass residual and the run time. The usefulness of the mesh ratio is illustrated using a Regional Simulation Model (RSM) (Lal, A.M.W., Van Zee, Randy, Belnap, Mark, 2005. Case study: model to simulate regional flow in South Florida. Journal of Hydraulic Engineering 131 (4), 247-258) application in south Florida.

  19. Does amniotic fluid volume affect fetofetal transfusion in monochorionic twin pregnancies? Modelling two possible mechanisms

    Science.gov (United States)

    Umur, Asli; van Gemert, Martin J. C.; Ross, Michael G.

    2002-06-01

    Clinical evidence suggests that increased amniotic fluid volume due to polyhydramnios increases placental vascular resistance. We have sought to model the possible effects of an increased amniotic fluid volume on the net fetofetal transfusion in monochorionic twin pregnancies. We wanted to compare these effects with the results of previous simulations, which aimed to explain why the twin-twin transfusion syndrome (TTTS) placentas more often include bidirectional arteriovenous (AV) rather than AV plus arterioarterial (AA) anastomoses. We extended our mathematical model of TTTS by simulating two different mechanisms that increase the placental vascular resistance as a consequence of polyhydramnios. First, there is an increase in the placental capillary resistance and hence in deep AV and opposite AV (denoted as VA) resistances due to polyhydramnios. Second, there is an increase in the resistance of chorionic veins due to polyhydramnios, assuming that these veins act as Starling resistors. We then simulated the effects of polyhydramnios on different placental anastomotic patterns. The results were as follows. In the first mechanism (polyhydramnios affects AV-VA resistances), an increased amniotic fluid volume hardly affected bidirectional AV, but slightly decreased fetofetal transfusion in AV plus AA anastomoses. However, for these effects to change the natural development of the pregnancy, polyhydramnios needed to persist for approximately 4 weeks, and by comparing the effects of polyhydramnios with the effects of amnioreduction, amnioreduction was more beneficial for normalizing the donor amniotic fluid volume. Therefore, these beneficial effects due to polyhydramnios have no practical clinical significance. In the second mechanism (Starling resistor for chorionic veins), polyhydramnios slightly increased fetofetal transfusion and hence slightly increased TTTS severity in bidirectional AV and AV plus VV, but did not affect AV plus AA anastomoses. In conclusion, we

  20. Panel 3 - characterization

    Energy Technology Data Exchange (ETDEWEB)

    Erck, R.A.; Erdemir, A.; Janghsing Hsieh; Lee, R.H.; Xian Zheng Pan; Deming Shu [Argonne National Lab., IL (United States); Feldman, A. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Glass, J.T. [North Carolina State Univ., Raleigh (United States); Kleimer, R. [Coors Ceramics Co., Golden, CO (United States); Lawton, E.A. [JPL/Caltech, Pasadena, CA (United States); McHargue, C.J. [Univ. of Tennessee, Knoxville (United States)

    1993-01-01

    The task of this panel was to identify and prioritize needs in the area of characterization of diamond and diamond-like-carbon (DLC) films for use in the transportation industry. Until recent advances in production of inexpensive films of diamonds and DLC, it was not feasible that these materials could be mass produced. The Characterization Panel is restricting itself to identifying needs in areas that would be most useful to manufacturers and users in producing and utilizing diamond and DLC coatings in industry. These characterization needs include in-situ monitoring during growth, relation of structure to performance, and standards and definitions.