WorldWideScience

Sample records for weighted model components

  1. Weighted Model Components for Gradient Direction Matching in Overhead Images

    Energy Technology Data Exchange (ETDEWEB)

    Grant, C W; Nikolaev, S; Paglieroni, D W

    2006-03-17

    Gradient direction matching (GDM) is the main target identification algorithm used in the Image Content Engine project at Lawrence Livermore National Laboratory. GDM is a 3D solid model-based edge-matching algorithm which does not require explicit edge extraction from the source image. The GDM algorithm is presented, identifying areas where performance enhancement seems possible. Improving the process of producing model gradient directions from the solid model by assigning different weights to different parts of the model is an extension tested in the current study. Given a simple geometric model, we attempt to determine, without obvious semantic clues, if different weight values produce significantly better matching accuracy, and how those weights should be assigned to produce the best matching accuracy. Two simple candidate strategies for assigning weights are proposed--pixel-weighted and edge-weighted. We adjust the weights of the components in a simple model of a tractor/semi-trailer using relevance feedback to produce an optimal set of weights for this model and a particular test image. The optimal weights are then compared with pixel and edge-weighting strategies to determine which is most suitable and under what circumstances.

  2. Trajectory modeling of gestational weight: A functional principal component analysis approach.

    Directory of Open Access Journals (Sweden)

    Menglu Che

    Full Text Available Suboptimal gestational weight gain (GWG, which is linked to increased risk of adverse outcomes for a pregnant woman and her infant, is prevalent. In the study of a large cohort of Canadian pregnant women, our goals are to estimate the individual weight growth trajectory using sparsely collected bodyweight data, and to identify the factors affecting the weight change during pregnancy, such as prepregnancy body mass index (BMI, dietary intakes and physical activity. The first goal was achieved through functional principal component analysis (FPCA by conditional expectation. For the second goal, we used linear regression with the total weight gain as the response variable. The trajectory modeling through FPCA had a significantly smaller root mean square error (RMSE and improved adaptability than the classic nonlinear mixed-effect models, demonstrating a novel tool that can be used to facilitate real time monitoring and interventions of GWG. Our regression analysis showed that prepregnancy BMI had a high predictive value for the weight changes during pregnancy, which agrees with the published weight gain guideline.

  3. Modelling the Cast Component Weight in Hot Chamber Die Casting using Combined Taguchi and Buckingham's π Approach

    Science.gov (United States)

    Singh, Rupinder

    2017-03-01

    Hot chamber (HC) die casting process is one of the most widely used commercial processes for the casting of low temperature metals and alloys. This process gives near-net shape product with high dimensional accuracy. However in actual field environment the best settings of input parameters is often conflicting as the shape and size of the casting changes and one have to trade off among various output parameters like hardness, dimensional accuracy, casting defects, microstructure etc. So for online inspection of the cast components properties (without affecting the production line) the weight measurement has been established as one of the cost effective method (as the difference in weight of sound and unsound casting reflects the possible casting defects) in field environment. In the present work at first stage the effect of three input process parameters (namely: pressure at 2nd phase in HC die casting; metal pouring temperature and die opening time) has been studied for optimizing the cast component weight `W' as output parameter in form of macro model based upon Taguchi L9 OA. After this Buckingham's π approach has been applied on Taguchi based macro model for the development of micro model. This study highlights the Taguchi-Buckingham based combined approach as a case study (for conversion of macro model into micro model) by identification of optimum levels of input parameters (based on Taguchi approach) and development of mathematical model (based on Buckingham's π approach). Finally developed mathematical model can be used for predicting W in HC die casting process with more flexibility. The results of study highlights second degree polynomial equation for predicting cast component weight in HC die casting and suggest that pressure at 2nd stage is one of the most contributing factors for controlling the casting defect/weight of casting.

  4. Modelling the Cast Component Weight in Hot Chamber Die Casting using Combined Taguchi and Buckingham's π Approach

    Science.gov (United States)

    Singh, Rupinder

    2018-02-01

    Hot chamber (HC) die casting process is one of the most widely used commercial processes for the casting of low temperature metals and alloys. This process gives near-net shape product with high dimensional accuracy. However in actual field environment the best settings of input parameters is often conflicting as the shape and size of the casting changes and one have to trade off among various output parameters like hardness, dimensional accuracy, casting defects, microstructure etc. So for online inspection of the cast components properties (without affecting the production line) the weight measurement has been established as one of the cost effective method (as the difference in weight of sound and unsound casting reflects the possible casting defects) in field environment. In the present work at first stage the effect of three input process parameters (namely: pressure at 2nd phase in HC die casting; metal pouring temperature and die opening time) has been studied for optimizing the cast component weight `W' as output parameter in form of macro model based upon Taguchi L9 OA. After this Buckingham's π approach has been applied on Taguchi based macro model for the development of micro model. This study highlights the Taguchi-Buckingham based combined approach as a case study (for conversion of macro model into micro model) by identification of optimum levels of input parameters (based on Taguchi approach) and development of mathematical model (based on Buckingham's π approach). Finally developed mathematical model can be used for predicting W in HC die casting process with more flexibility. The results of study highlights second degree polynomial equation for predicting cast component weight in HC die casting and suggest that pressure at 2nd stage is one of the most contributing factors for controlling the casting defect/weight of casting.

  5. Identifying Bottom-Up and Top-Down Components of Attentional Weight by Experimental Analysis and Computational Modeling

    DEFF Research Database (Denmark)

    Nordfang, Maria; Dyrholm, Mads; Bundesen, Claus

    2013-01-01

    The attentional weight of a visual object depends on the contrast of the features of the object to its local surroundings (feature contrast) and the relevance of the features to one’s goals (feature relevance). We investigated the dependency in partial report experiments with briefly presented st...

  6. Identifying Bottom-Up and Top-Down Components of Attentional Weight by Experimental Analysis and Computational Modeling

    Science.gov (United States)

    Nordfang, Maria; Dyrholm, Mads; Bundesen, Claus

    2013-01-01

    The attentional weight of a visual object depends on the contrast of the features of the object to its local surroundings (feature contrast) and the relevance of the features to one's goals (feature relevance). We investigated the dependency in partial report experiments with briefly presented stimuli but unspeeded responses. The task was to…

  7. Variance components for body weight in Japanese quails (Coturnix japonica

    Directory of Open Access Journals (Sweden)

    RO Resende

    2005-03-01

    Full Text Available The objective of this study was to estimate the variance components for body weight in Japanese quails by Bayesian procedures. The body weight at hatch (BWH and at 7 (BW07, 14 (BW14, 21 (BW21 and 28 days of age (BW28 of 3,520 quails was recorded from August 2001 to June 2002. A multiple-trait animal model with additive genetic, maternal environment and residual effects was implemented by Gibbs sampling methodology. A single Gibbs sampling with 80,000 rounds was generated by the program MTGSAM (Multiple Trait Gibbs Sampling in Animal Model. Normal and inverted Wishart distributions were used as prior distributions for the random effects and the variance components, respectively. Variance components were estimated based on the 500 samples that were left after elimination of 30,000 rounds in the burn-in period and 100 rounds of each thinning interval. The posterior means of additive genetic variance components were 0.15; 4.18; 14.62; 27.18 and 32.68; the posterior means of maternal environment variance components were 0.23; 1.29; 2.76; 4.12 and 5.16; and the posterior means of residual variance components were 0.084; 6.43; 22.66; 31.21 and 30.85, at hatch, 7, 14, 21 and 28 days old, respectively. The posterior means of heritability were 0.33; 0.35; 0.36; 0.43 and 0.47 at hatch, 7, 14, 21 and 28 days old, respectively. These results indicate that heritability increased with age. On the other hand, after hatch there was a marked reduction in the maternal environment variance proportion of the phenotypic variance, whose estimates were 0.50; 0.11; 0.07; 0.07 and 0.08 for BWH, BW07, BW14, BW21 and BW28, respectively. The genetic correlation between weights at different ages was high, except for those estimates between BWH and weight at other ages. Changes in body weight of quails can be efficiently achieved by selection.

  8. Inorganic nitrite improves components of the metabolic syndrome independent of weight change in a murine model of obesity and insulin resistance.

    Science.gov (United States)

    Singamsetty, Srikanth; Watanabe, Yoshio; Guo, Lanping; Corey, Catherine; Wang, Yinna; Tejero, Jesus; McVerry, Bryan J; Gladwin, Mark T; Shiva, Sruti; O'Donnell, Christopher P

    2015-07-15

    Nitrite acts as an endocrine source of bioactive nitric oxide, impacting vascular reactivity, angiogenesis and cytoprotection. Nitrite has recently been shown to have a metabolic role although its effects and mechanisms of action in the obese insulin-resistant state are unknown. We examined glucose tolerance and insulin secretion using the frequently sampled intravenous glucose tolerance test and insulin sensitivity using the hyperinsulinaemic euglycaemic clamp in obese male ob(lep) mice administered nitrite (100 mg kg(-1) day(-1) ) or saline (control) for 7 days and compared responses to the known insulin-sensitizing effects of rosiglitazone (6 mg kg(-1) day(-1) ). Under weight-matched conditions, nitrite lowered blood pressure relative to saline and rosiglitazone, whereas only rosiglitazone was effective at reducing hepatic glucose output and basal blood glucose. Both nitrite and rosiglitazone produced improvements, relative to saline, in glucose tolerance (12,524 ± 602, 12,811 ± 692 vs.14,428 ± 335 mg (dl min)(-1) , respectively; P insulin sensitivity (8.6 ± 0.7, 7.9 ± 0.3 vs. 6.6 ± 0.5 mg kg(-1) min(-1) , respectively; P insulin secretion. Nitrite exhibited an uncoupling of mitochondrial respiration and a decrease in ATP generation in muscle that was independent of mitochondrial biogenesis or activation of uncoupling proteins. There was no insulin-stimulated phosphorylation of Akt, but nitrite increased the phosphorylation of AMP-activated protein kinase. We conclude that nitrite improves two key components of the metabolic syndrome, blood pressure and insulin sensitivity, independent of weight and with effectiveness comparable to rosiglitazone. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  9. From Reference Model to Component Model

    OpenAIRE

    Albani, Antonia; Zaha, Johannes Maria

    2005-01-01

    Stable component models are an essential prerequisite for developingcustomer-individual business applications. Thereby the information for theidentification and specification of their components is gained from domainmodels. Reference models constitute a potential source for building enterprisespecificdomain models. Based on the analysis of existing reference models,this article shows how information available through reference models can beused for the development of stable component models. ...

  10. Weighted Components of i-Government Enterprise Architecture

    Science.gov (United States)

    Budiardjo, E. K.; Firmansyah, G.; Hasibuan, Z. A.

    2017-01-01

    Lack of government performance, among others due to the lack of coordination and communication among government agencies. Whilst, Enterprise Architecture (EA) in the government can be use as a strategic planning tool to improve productivity, efficiency, and effectivity. However, the existence components of Government Enterprise Architecture (GEA) do not show level of importance, that cause difficulty in implementing good e-government for good governance. This study is to explore the weight of GEA components using Principal Component Analysis (PCA) in order to discovered an inherent structure of e-government. The results show that IT governance component of GEA play a major role in the GEA. The rest of components that consist of e-government system, e-government regulation, e-government management, and application key operational, contributed more or less the same. Beside that GEA from other countries analyzes using comparative base on comon enterprise architecture component. These weighted components use to construct i-Government enterprise architecture. and show the relative importance of component in order to established priorities in developing e-government.

  11. Variance components and genetic parameters for body weight and ...

    African Journals Online (AJOL)

    Variance components resulting from direct additive genetic effects, maternal additive genetic effects, maternal permanent environmental effects, as well as the relationship between direct and maternal genetic effects for several body weight and fleece traits, were estimated by DFREML procedures. Traits analysed included ...

  12. (co) variance components and genetic parameters for live weight ...

    African Journals Online (AJOL)

    admin

    Against this background the present study estimated the (co)variance components as well as the genetic, phenotypic, environmental and maternal correlations for 16-months live weight and objectively measured wool traits in a South African Merino flock. Materials and Methods. The experimental flock is maintained on the ...

  13. The weighted random graph model

    Science.gov (United States)

    Garlaschelli, Diego

    2009-07-01

    We introduce the weighted random graph (WRG) model, which represents the weighted counterpart of the Erdos-Renyi random graph and provides fundamental insights into more complicated weighted networks. We find analytically that the WRG is characterized by a geometric weight distribution, a binomial degree distribution and a negative binomial strength distribution. We also characterize exactly the percolation phase transitions associated with edge removal and with the appearance of weighted subgraphs of any order and intensity. We find that even this completely null model displays a percolation behaviour similar to what is observed in real weighted networks, implying that edge removal cannot be used to detect community structure empirically. By contrast, the analysis of clustering successfully reveals different patterns between the WRG and real networks.

  14. Nonparametric weighted stochastic block models

    Science.gov (United States)

    Peixoto, Tiago P.

    2018-01-01

    We present a Bayesian formulation of weighted stochastic block models that can be used to infer the large-scale modular structure of weighted networks, including their hierarchical organization. Our method is nonparametric, and thus does not require the prior knowledge of the number of groups or other dimensions of the model, which are instead inferred from data. We give a comprehensive treatment of different kinds of edge weights (i.e., continuous or discrete, signed or unsigned, bounded or unbounded), as well as arbitrary weight transformations, and describe an unsupervised model selection approach to choose the best network description. We illustrate the application of our method to a variety of empirical weighted networks, such as global migrations, voting patterns in congress, and neural connections in the human brain.

  15. Modeling Systems of Dependent Components

    Science.gov (United States)

    2014-09-17

    Marked Shocks generated by a Poisson, a Renewal , or a Hawkes Point Process , ( ) . A Generalized Coupon Collecting Model as a Parsimonious Optimal...estimators of the mean, variance, and tail probabilities of the system life when the shock process is a Poisson process , a renewal process , or a...Modeling Systems of Dependent Components New classes of stochastic models for network systems having stochastically dependent components are studied by

  16. The cyclical component factor model

    DEFF Research Database (Denmark)

    Dahl, Christian Møller; Hansen, Henrik; Smidt, John

    Forecasting using factor models based on large data sets have received ample attention due to the models' ability to increase forecast accuracy with respect to a range of key macroeconomic variables in the US and the UK. However, forecasts based on such factor models do not uniformly outperform...... the simple autoregressive model when using data from other countries. In this paper we propose to estimate the factors based on the pure cyclical components of the series entering the large data set. Monte Carlo evidence and an empirical illustration using Danish data shows that this procedure can indeed...

  17. Weighted polynomial models and weighted sampling schemes for finite population

    OpenAIRE

    Chen, Sean X.

    1998-01-01

    This paper outlines a theoretical framework for finite population models with unequal sample probabilities, along with sampling schemes for drawing random samples from these models. We first present four exact weighted sampling schemes that can be used for any finite population model to satisfy such requirements as ordered/ unordered samples, with/without replacement, and fixed/nonfixed sample size. We then introduce a new class of finite population models called weighted po...

  18. Component Composition Using Feature Models

    DEFF Research Database (Denmark)

    Eichberg, Michael; Klose, Karl; Mitschke, Ralf

    2010-01-01

    In general, components provide and require services and two components are bound if the first component provides a service required by the second component. However, certain variability in services - w.r.t. how and which functionality is provided or required - cannot be described using standard i...

  19. Infrared small target and background separation via column-wise weighted robust principal component analysis

    Science.gov (United States)

    Dai, Yimian; Wu, Yiquan; Song, Yu

    2016-07-01

    When facing extremely complex infrared background, due to the defect of l1 norm based sparsity measure, the state-of-the-art infrared patch-image (IPI) model would be in a dilemma where either the dim targets are over-shrinked in the separation or the strong cloud edges remains in the target image. In order to suppress the strong edges while preserving the dim targets, a weighted infrared patch-image (WIPI) model is proposed, incorporating structural prior information into the process of infrared small target and background separation. Instead of adopting a global weight, we allocate adaptive weight to each column of the target patch-image according to its patch structure. Then the proposed WIPI model is converted to a column-wise weighted robust principal component analysis (CWRPCA) problem. In addition, a target unlikelihood coefficient is designed based on the steering kernel, serving as the adaptive weight for each column. Finally, in order to solve the CWPRCA problem, a solution algorithm is developed based on Alternating Direction Method (ADM). Detailed experiment results demonstrate that the proposed method has a significant improvement over the other nine classical or state-of-the-art methods in terms of subjective visual quality, quantitative evaluation indexes and convergence rate.

  20. Modelling body weight, dieting and obesity traps

    Science.gov (United States)

    Barbieri, Paolo Nicola

    2017-02-01

    This paper presents a theoretical investigation into why losing weight is so difficult even in the absence of rational addiction, time-inconsistent preferences or bounded rationality. We add to the existing literature by focusing on the role that individual metabolism has on weight loss. The results from the theoretical model provide multiple steady states and a threshold revealing a situation of "obesity traps" that the individual must surpass in order to successfully lose weight. Any weight-loss efforts that the individual undertakes have to surpass such threshold in order to result in permanent weight loss, otherwise the individual will gradually regain weight and converge to his or her previous body weight.

  1. Dealing with multicollinearity in predicting egg components from egg weight and egg dimension

    Directory of Open Access Journals (Sweden)

    Tarek M. Shafey

    2014-10-01

    Full Text Available Measurements of 174 eggs from meat-type breeder flock (Ross at 36 weeks of age were used to study the problem of multicollinearity (MC instability in the estimation of egg components of yolk weight (YKWT, albumen weight (ALBWT and eggshell weight (SHWT. Egg weight (EGWT, egg shape index (ESI=egg width (EGWD*100/egg length (EGL and their interaction (EGWTESI were used in the context of un-centred vs centred data and principal components regression (PCR models. The pairwise phenotypic correlations, variance inflation factor (VIF, eigenvalues, condition index (CI, and variance proportions were examined. Egg weight had positive correlations with EGWD and EGL (r=0.56 and 0.50, respectively; P<0.0001 and EGL had a negative correlation with ESI (r=-0.79; P<0.0001. The highest correlation was observed between EGWT and ALBWT (r=0.94; P<0.0001, while the lowest was between EGWD and SHWT (r=0.33; P<0.0001. Multicollinearity problems were found in EGWT, ESI and their interaction as shown by VIF (>10, eigenvalues (near zero, CI (>30 and high corresponding proportions of variance of EGWT, ESI and EGWTESI with respect to EGWTESI. Results from this study suggest that mean centring and PCR were appropriate to overcome the MC instability in the estimation of egg components from EGWT and ESI. These methods improved the meaning of intercept values and produced much lower standard error values for regression coefficients than those from un-centred data.

  2. An Architectural Model for Component Groupware

    NARCIS (Netherlands)

    Guareis de farias, Cléver; Goncalves, Carlos E.; Rosatelli, Marta C.; Ferreira Pires, Luis; van Sinderen, Marten J.; Fuks, Hugo; Lukosch, Stephan; Salgado, Ana Carolina

    2005-01-01

    This paper proposes an architectural model to facilitate the design of component-based groupware systems. This architectural model has been defined based on (1) three pre-defined component types, (2) a refinement strategy that relies on these component types, (3) the identification of layers of

  3. Modelling Livestock Component in FSSIM

    NARCIS (Netherlands)

    Thorne, P.J.; Hengsdijk, H.; Janssen, S.J.C.; Louhichi, K.; Keulen, van H.; Thornton, P.K.

    2009-01-01

    This document summarises the development of a ruminant livestock component for the Farm System Simulator (FSSIM). This includes treatments of energy and protein transactions in ruminant livestock that have been used as a basis for the biophysical simulations that will generate the input production

  4. Understanding symmetrical components for power system modeling

    CERN Document Server

    Das, J C

    2017-01-01

    This book utilizes symmetrical components for analyzing unbalanced three-phase electrical systems, by applying single-phase analysis tools. The author covers two approaches for studying symmetrical components; the physical approach, avoiding many mathematical matrix algebra equations, and a mathematical approach, using matrix theory. Divided into seven sections, topics include: symmetrical components using matrix methods, fundamental concepts of symmetrical components, symmetrical components –transmission lines and cables, sequence components of rotating equipment and static load, three-phase models of transformers and conductors, unsymmetrical fault calculations, and some limitations of symmetrical components.

  5. Recovery of a spectrum based on a compressive-sensing algorithm with weighted principal component analysis

    Science.gov (United States)

    Dafu, Shen; Leihong, Zhang; Dong, Liang; Bei, Li; Yi, Kang

    2017-07-01

    The purpose of this study is to improve the reconstruction precision and better copy the color of spectral image surfaces. A new spectral reflectance reconstruction algorithm based on an iterative threshold combined with weighted principal component space is presented in this paper, and the principal component with weighted visual features is the sparse basis. Different numbers of color cards are selected as the training samples, a multispectral image is the testing sample, and the color differences in the reconstructions are compared. The channel response value is obtained by a Mega Vision high-accuracy, multi-channel imaging system. The results show that spectral reconstruction based on weighted principal component space is superior in performance to that based on traditional principal component space. Therefore, the color difference obtained using the compressive-sensing algorithm with weighted principal component analysis is less than that obtained using the algorithm with traditional principal component analysis, and better reconstructed color consistency with human eye vision is achieved.

  6. Variance components and genetic parameters for body weight and ...

    African Journals Online (AJOL)

    ) op l8 maande-ouderdom. Om die mees geskikte model vir elke eienskap te bepaal, is vier verskillende modelle gepas deur maternale genetiese en omgewingsef- fekte te ignoreer of in te sluit. WW en GFW6 is betekenisvol deur maternale ...

  7. Determining Component Weights in a Communications Assessment Using Judgmental Policy Capturing.

    Science.gov (United States)

    Harvill, Leo M; Lang, F Forrest; McCord, Ronald S

    2004-12-01

    Tools are needed for determining appropriate weights for complex performance assessment components in medical education. The feasibility of using judgmental policy capturing (JPC), a procedure to statistically describe the information processing strategies of experts, for this purpose was investigated. Iterative JPC was used to determine appropriate weighting for the six core communication skill scores from a communications objective structured clinical examination (OSCE) for medical students using a panel of four communication skill experts. The mean regression weights from the panel indicated they placed less importance on information management (8.5%), moderate and nearly equal importance on rapport building (15.8%), agenda setting (15.4%), and addressing feelings (14.1%), and greater importance on active listening (20.1%) and reaching common ground with the patient (25.5%). JPC is an effective procedure for determining appropriate weights for complex clinical assessment components. The derived weights may be very different for those assessment components.

  8. Building automation system of payment platform weight component for large spacecraft reflector

    Science.gov (United States)

    Kovalev, I. V.; Badanina, J. O.

    2016-04-01

    Considered Design and the logic of opening large convertible antenna. The necessity of compensation weight component in the assembly and testing of the design. Given the logic of the movement elements of power spokes, concluded that the use of the tracking system to compensate for the weight component. The analysis of the existing equipment and control systems. Produced selection of the manufacturer of automated equipment that meets the stated objectives of management and control. It is concluded that the design component of the weight compensation system based on servo controllers and sensors combined platform automation, controlled by special software. The structure of the platform automation, consistent workflow testing. It defines the principles of interaction between subsystems of the weight compensation component for receiving, processing and monitoring of process parameters testing. It is concluded that the proposed system can be integrated into the automation system and the perspective of process control testing of disclosure of large spacecraft.

  9. Geographically weighted regression model on poverty indicator

    Science.gov (United States)

    Slamet, I.; Nugroho, N. F. T. A.; Muslich

    2017-12-01

    In this research, we applied geographically weighted regression (GWR) for analyzing the poverty in Central Java. We consider Gaussian Kernel as weighted function. The GWR uses the diagonal matrix resulted from calculating kernel Gaussian function as a weighted function in the regression model. The kernel weights is used to handle spatial effects on the data so that a model can be obtained for each location. The purpose of this paper is to model of poverty percentage data in Central Java province using GWR with Gaussian kernel weighted function and to determine the influencing factors in each regency/city in Central Java province. Based on the research, we obtained geographically weighted regression model with Gaussian kernel weighted function on poverty percentage data in Central Java province. We found that percentage of population working as farmers, population growth rate, percentage of households with regular sanitation, and BPJS beneficiaries are the variables that affect the percentage of poverty in Central Java province. In this research, we found the determination coefficient R2 are 68.64%. There are two categories of district which are influenced by different of significance factors.

  10. Determining Component Weights in a Communications Assessment Using Judgmental Policy Capturing

    OpenAIRE

    Harvill, Leo M.; Lang, F. Forrest; McCord, Ronald S.

    2009-01-01

    Objectives: Tools are needed for determining appropriate weights for complex performance assessment components in medical education. The feasibility of using judgmental policy capturing (JPC), a procedure to statistically describe the information processing strategies of experts, for this purpose was investigated. Methods: Iterative JPC was used to determine appropriate weighting for the six core communication skill scores from a communications objective structured clinical examination (OSCE)...

  11. The polysaccharide and low molecular weight components of Opuntia ficus indica cladodes: Structure and skin repairing properties.

    Science.gov (United States)

    Di Lorenzo, Flaviana; Silipo, Alba; Molinaro, Antonio; Parrilli, Michelangelo; Schiraldi, Chiara; D'Agostino, Antonella; Izzo, Elisabetta; Rizza, Luisa; Bonina, Andrea; Bonina, Francesco; Lanzetta, Rosa

    2017-02-10

    The Opuntia ficus-indica multiple properties are reflected in the increasing interest of chemists in the identification of its natural components having pharmaceutical and/or cosmetical applications. Here we report the structural elucidation of Opuntia ficus-indica mucilage that highlighted the presence of components differing for their chemical nature and the molecular weight distribution. The high molecular weight components were identified as a linear galactan polymer and a highly branched xyloarabinan. The low molecular weight components were identified as lactic acid, D-mannitol, piscidic, eucomic and 2-hydroxy-4-(4'-hydroxyphenyl)-butanoic acids. A wound healing assay was performed in order to test the cicatrizing properties of the various components, highlighting the ability of these latter to fasten dermal regeneration using a simplified in vitro cellular model based on a scratched keratinocytes monolayer. The results showed that the whole Opuntia mucilage and the low molecular weight components are active in the wound repair. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A Linguistic Model in Component Oriented Programming

    Science.gov (United States)

    Crăciunean, Daniel Cristian; Crăciunean, Vasile

    2016-12-01

    It is a fact that the component-oriented programming, well organized, can bring a large increase in efficiency in the development of large software systems. This paper proposes a model for building software systems by assembling components that can operate independently of each other. The model is based on a computing environment that runs parallel and distributed applications. This paper introduces concepts as: abstract aggregation scheme and aggregation application. Basically, an aggregation application is an application that is obtained by combining corresponding components. In our model an aggregation application is a word in a language.

  13. Tweaking the Four-Component Model

    Science.gov (United States)

    Curzer, Howard J.

    2014-01-01

    By maintaining that moral functioning depends upon four components (sensitivity, judgment, motivation, and character), the Neo-Kohlbergian account of moral functioning allows for uneven moral development within individuals. However, I argue that the four-component model does not go far enough. I offer a more accurate account of moral functioning…

  14. Improved Reference Speaker Weighting Using Aspect Model

    Science.gov (United States)

    Hahm, Seong-Jun; Ohkawa, Yuichi; Ito, Masashi; Suzuki, Motoyuki; Ito, Akinori; Makino, Shozo

    We propose an improved reference speaker weighting (RSW) and speaker cluster weighting (SCW) approach that uses an aspect model. The concept of the approach is that the adapted model is a linear combination of a few latent reference models obtained from a set of reference speakers. The aspect model has specific latent-space characteristics that differ from orthogonal basis vectors of eigenvoice. The aspect model is a “mixture-of-mixture” model. We first calculate a small number of latent reference models as mixtures of distributions of the reference speaker's models, and then the latent reference models are mixed to obtain the adapted distribution. The mixture weights are calculated based on the expectation maximization (EM) algorithm. We use the obtained mixture weights for interpolating mean parameters of the distributions. Both training and adaptation are performed based on likelihood maximization with respect to the training and adaptation data, respectively. We conduct a continuous speech recognition experiment using a Korean database (KAIST-TRADE). The results are compared to those of a conventional MAP, MLLR, RSW, eigenvoice and SCW. Absolute word accuracy improvement of 2.06 point was achieved using the proposed method, even though we use only 0.3 s of adaptation data.

  15. Time-Weighted Balanced Stochastic Model Reduction

    DEFF Research Database (Denmark)

    Tahavori, Maryamsadat; Shaker, Hamid Reza

    2011-01-01

    A new relative error model reduction technique for linear time invariant (LTI) systems is proposed in this paper. Both continuous and discrete time systems can be reduced within this framework. The proposed model reduction method is mainly based upon time-weighted balanced truncation and a recently...... developed inner-outer factorization technique. Compared to the other analogous counterparts, the proposed method shows to provide more accurate results in terms of time weighted norms, when applied to different practical examples. The results are further illustrated by a numerical example....

  16. Stochastic Modeling Of Wind Turbine Drivetrain Components

    DEFF Research Database (Denmark)

    Rafsanjani, Hesam Mirzaei; Sørensen, John Dalsgaard

    2014-01-01

    are needed for initial defects and damage accumulation. In this paper, stochastic models are formulated considering some of the failure modes observed in these components. The models are based on theoretical considerations, manufacturing uncertainties, size effects of different scales. It is illustrated how...

  17. Independent Component Analysis in Multimedia Modeling

    DEFF Research Database (Denmark)

    Larsen, Jan; Hansen, Lars Kai; Kolenda, Thomas

    2003-01-01

    Modeling of multimedia and multimodal data becomes increasingly important with the digitalization of the world. The objective of this paper is to demonstrate the potential of independent component analysis and blind sources separation methods for modeling and understanding of multimedia data, which...

  18. Independent Component Analysis in Multimedia Modeling

    DEFF Research Database (Denmark)

    Larsen, Jan

    Modeling of multimedia and multimodal data becomes increasingly important with the digitalization of the world. The objective of this paper is to demonstrate the potential of independent component analysis and blind sources separation methods for modeling and understanding of multimedia data, which...

  19. Weighted Kernel Entropy Component Analysis for Fault Diagnosis of Rolling Bearings.

    Science.gov (United States)

    Zhou, Hongdi; Shi, Tielin; Liao, Guanglan; Xuan, Jianping; Duan, Jie; Su, Lei; He, Zhenzhi; Lai, Wuxing

    2017-03-18

    This paper presents a supervised feature extraction method called weighted kernel entropy component analysis (WKECA) for fault diagnosis of rolling bearings. The method is developed based on kernel entropy component analysis (KECA) which attempts to preserve the Renyi entropy of the data set after dimension reduction. It makes full use of the labeled information and introduces a weight strategy in the feature extraction. The class-related weights are introduced to denote differences among the samples from different patterns, and genetic algorithm (GA) is implemented to seek out appropriate weights for optimizing the classification results. The features based on wavelet packet decomposition are derived from the original signals. Then the intrinsic geometric features extracted by WKECA are fed into the support vector machine (SVM) classifier to recognize different operating conditions of bearings, and we obtain the overall accuracy (97%) for the experimental samples. The experimental results demonstrated the feasibility and effectiveness of the proposed method.

  20. Overview of the model component in ECOCLIM

    DEFF Research Database (Denmark)

    Geels, Camilla; Boegh, Eva; Bendtsen, J

    and atmospheric models. We will use the model system to 1) quantify the potential effects of climate change on ecosystem exchange of GHG and 2) estimate the impacts of changes in management practices including land use change and nitrogen (N) loads. Here the various model components will be introduced......As part of the Danish strategic research project ECOCLIM: Ecosystems Surface Exchange of Greenhouse Gases in an Environment of Changing Anthropogenic and Climate forcing a model system will be developed. This model system will be based on both terrestrial and marine ecosystems in order to be able...

  1. Application of variance components estimation to calibrate geoid error models.

    Science.gov (United States)

    Guo, Dong-Mei; Xu, Hou-Ze

    2015-01-01

    The method of using Global Positioning System-leveling data to obtain orthometric heights has been well studied. A simple formulation for the weighted least squares problem has been presented in an earlier work. This formulation allows one directly employing the errors-in-variables models which completely descript the covariance matrices of the observables. However, an important question that what accuracy level can be achieved has not yet to be satisfactorily solved by this traditional formulation. One of the main reasons for this is the incorrectness of the stochastic models in the adjustment, which in turn allows improving the stochastic models of measurement noises. Therefore the issue of determining the stochastic modeling of observables in the combined adjustment with heterogeneous height types will be a main focus point in this paper. Firstly, the well-known method of variance component estimation is employed to calibrate the errors of heterogeneous height data in a combined least square adjustment of ellipsoidal, orthometric and gravimetric geoid. Specifically, the iterative algorithms of minimum norm quadratic unbiased estimation are used to estimate the variance components for each of heterogeneous observations. Secondly, two different statistical models are presented to illustrate the theory. The first method directly uses the errors-in-variables as a priori covariance matrices and the second method analyzes the biases of variance components and then proposes bias-corrected variance component estimators. Several numerical test results show the capability and effectiveness of the variance components estimation procedure in combined adjustment for calibrating geoid error model.

  2. Executive function in weight loss and weight loss maintenance: a conceptual review and novel neuropsychological model of weight control.

    Science.gov (United States)

    Gettens, Katelyn M; Gorin, Amy A

    2017-10-01

    Weight loss maintenance is a complex, multifaceted process that presents a significant challenge for most individuals who lose weight. A growing body of literature indicates a strong relationship between cognitive dysfunction and excessive body weight, and suggests that a subset of high-order cognitive processes known as executive functions (EF) likely play an important role in weight management. Recent reviews cover neuropsychological correlates of weight status yet fail to address the role of executive function in the central dilemma of successful weight loss maintenance. In this paper, we provide an overview of the existing literature examining executive functions as they relate to weight status and initial weight loss. Further, we propose a novel conceptual model of the relationships between EF, initial weight loss, and weight loss maintenance, mapping specific executive functions onto strategies known to be associated with both phases of the weight control process. Implications for the development of more efficacious weight loss maintenance interventions are discussed.

  3. Determining Component Weights in a Communications Assessment Using Judgmental Policy Capturing

    Directory of Open Access Journals (Sweden)

    Leo M. Harvill, PhD

    2004-01-01

    Full Text Available Abstract Objectives: Tools are needed for determining appropriate weights for complex performance assessment components in medical education. The feasibility of using judgmental policy capturing (JPC, a procedure to statistically describe the information processing strategies of experts, for this purpose was investigated. Methods: Iterative JPC was used to determine appropriate weighting for the six core communication skill scores from a communications objective structured clinical examination (OSCE for medical students using a panel of four communication skill experts. Results: The mean regression weights from the panel indicated they placed less importance on information management (8.5%, moderate and nearly equal importance on rapport building (15.8%, agenda setting (15.4%, and addressing feelings (14.1%, and greater importance on active listening (20.1% and reaching common ground with the patient (25.5%. Discussion: JPC is an effective procedure for determining appropriate weights for complex clinical assessment components. The derived weights may be very different for those assessment components

  4. Probabilistic Modeling of Wind Turbine Drivetrain Components

    DEFF Research Database (Denmark)

    Rafsanjani, Hesam Mirzaei

    Wind energy is one of several energy sources in the world and a rapidly growing industry in the energy sector. When placed in offshore or onshore locations, wind turbines are exposed to wave excitations, highly dynamic wind loads and/or the wakes from other wind turbines. Therefore, most components...... in a wind turbine experience highly dynamic and time-varying loads. These components may fail due to wear or fatigue, and this can lead to unplanned shutdown repairs that are very costly. The design by deterministic methods using safety factors is generally unable to account for the many uncertainties. Thus......, a reliability assessment should be based on probabilistic methods where stochastic modeling of failures is performed. This thesis focuses on probabilistic models and the stochastic modeling of the fatigue life of the wind turbine drivetrain. Hence, two approaches are considered for stochastic modeling...

  5. 47 CFR 65.300 - Calculations of the components and weights of the cost of capital.

    Science.gov (United States)

    2010-10-01

    ... the cost of capital. 65.300 Section 65.300 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... METHODOLOGIES Exchange Carriers § 65.300 Calculations of the components and weights of the cost of capital. (a... unreasonable. (b) Excluded from cost of capital calculations made pursuant to § 65.300 shall be those sources...

  6. Modeling accelerator structures and RF components

    Energy Technology Data Exchange (ETDEWEB)

    Ko, K., Ng, C.K.; Herrmannsfeldt, W.B.

    1993-03-01

    Computer modeling has become an integral part of the design and analysis of accelerator structures RF components. Sophisticated 3D codes, powerful workstations and timely theory support all contributed to this development. We will describe our modeling experience with these resources and discuss their impact on ongoing work at SLAC. Specific examples from R&D on a future linear collide and a proposed e{sup +}e{sup {minus}} storage ring will be included.

  7. A principal components model of soundscape perception.

    Science.gov (United States)

    Axelsson, Östen; Nilsson, Mats E; Berglund, Birgitta

    2010-11-01

    There is a need for a model that identifies underlying dimensions of soundscape perception, and which may guide measurement and improvement of soundscape quality. With the purpose to develop such a model, a listening experiment was conducted. One hundred listeners measured 50 excerpts of binaural recordings of urban outdoor soundscapes on 116 attribute scales. The average attribute scale values were subjected to principal components analysis, resulting in three components: Pleasantness, eventfulness, and familiarity, explaining 50, 18 and 6% of the total variance, respectively. The principal-component scores were correlated with physical soundscape properties, including categories of dominant sounds and acoustic variables. Soundscape excerpts dominated by technological sounds were found to be unpleasant, whereas soundscape excerpts dominated by natural sounds were pleasant, and soundscape excerpts dominated by human sounds were eventful. These relationships remained after controlling for the overall soundscape loudness (Zwicker's N(10)), which shows that 'informational' properties are substantial contributors to the perception of soundscape. The proposed principal components model provides a framework for future soundscape research and practice. In particular, it suggests which basic dimensions are necessary to measure, how to measure them by a defined set of attribute scales, and how to promote high-quality soundscapes.

  8. Growth curves for body weight and major component parts, feed consumption, and mortality of male broiler chickens raised to maturity.

    Science.gov (United States)

    Goliomytis, M; Panopoulou, E; Rogdakis, E

    2003-07-01

    Body weight; yield of the major carcass component parts of breast, leg, thigh, drumstick, breast meat, thigh meat, and drumstick meat; feed consumption; feed conversion; and mortality of male broiler chickens from two commercial strains were measured from hatching to 154 d of age. As no differences were observed between the two strains, for any of the traits measured, the statistical analysis was made using pooled data. Growth curves for BW, breast weight, and leg weight were calculated. The Richards function was chosen to fit the data. The type of the curves predicted was typically sigmoid. Asymptotic weights for BW, breast weight, and leg weight were estimated at 6,870.2, 1,744.2, and 851.5 g, respectively. Age at point of inflection, at which maximum growth rate is attained, was predicted at 44.4, 47, and 49.1 d, respectively. The percentage of breast and breast meat increased with age, whereas percentages of leg, thigh, and drumstick remained roughly constant. Weekly feed conversion was determined, and polynomial functions were applied to relate feed consumption and feed conversion to the age of the birds. Cumulative mortality increased with age, especially beyond 70 d of age, rising to 50% by the end of the experiment. Mortality was related to high incidence of leg weakness observed in the same period. The results of the current study provide information on the growth potential of contemporary, genetically improved broiler chickens by means of a mathematical model.

  9. Tribological Performance Optimization of Electroless Ni-P-W Coating Using Weighted Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    S. Roy

    2013-12-01

    Full Text Available The present investigation is an experimental approach to deposit electroless Ni-P-W coating on mild steel substrate and find out the optimum combination of various tribological performances on the basis of minimum friction and wear, using weighted principal component analysis (WPCA. In this study three main tribological parameters are chosen viz. load (A, speed (B and time(C. The responses are coefficient of friction and wear depth. Here Weighted Principal Component Analysis (WPCA method is adopted to convert the multi-responses into single performance index called multiple performance index (MPI and Taguchi L27 orthogonal array is used to design the experiment and to find the optimum combination of tribological parameters for minimum coefficient of friction and wear depth. ANOVA is performed to find the significance of the each tribological process parameters and their interactions. The EDX analysis, SEM and XRD are performed to study the composition and structural aspects.

  10. Pool scrubbing models for iodine components

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, K. [Battelle Ingenieurtechnik GmbH, Eschborn (Germany)

    1996-12-01

    Pool scrubbing is an important mechanism to retain radioactive fission products from being carried into the containment atmosphere or into the secondary piping system. A number of models and computer codes has been developed to predict the retention of aerosols and fission product vapours that are released from the core and injected into water pools of BWR and PWR type reactors during severe accidents. Important codes in this field are BUSCA, SPARC and SUPRA. The present paper summarizes the models for scrubbing of gaseous Iodine components in these codes, discusses the experimental validation, and gives an assessment of the state of knowledge reached and the open questions which persist. The retention of gaseous Iodine components is modelled by the various codes in a very heterogeneous manner. Differences show up in the chemical species considered, the treatment of mass transfer boundary layers on the gaseous and liquid sides, the gas-liquid interface geometry, calculation of equilibrium concentrations and numerical procedures. Especially important is the determination of the pool water pH value. This value is affected by basic aerosols deposited in the water, e.g. Cesium and Rubidium compounds. A consistent model requires a mass balance of these compounds in the pool, thus effectively coupling the pool scrubbing phenomena of aerosols and gaseous Iodine species. Since the water pool conditions are also affected by drainage flow of condensate water from different regions in the containment, and desorption of dissolved gases on the pool surface is determined by the gas concentrations above the pool, some basic limitations of specialized pool scrubbing codes are given. The paper draws conclusions about the necessity of coupling between containment thermal-hydraulics and pool scrubbing models, and proposes ways of further simulation model development in order to improve source term predictions. (author) 2 tabs., refs.

  11. Egg weights, egg component weights, and laying gaps in great tits (Parus major) in relation to ambient temperature.

    NARCIS (Netherlands)

    Lessells, C.M.; Dingemanse, N.J.; Both, C.

    2002-01-01

    We collected 328 freshly laid Great Tit (Parus major) eggs from 38 clutches in 1999 to determine the relationship of whole egg weight, wet yolk weight, wet albumen weight, dry shell weight, and the occurrence of laying gaps with mean ambient temperature in the three days preceding laying, while

  12. Egg weights, egg component weights, and laying gaps in Great Tits (Parus major) in relation to ambient temperature

    NARCIS (Netherlands)

    Lessells, C.M.; Dingemanse, N.J.; Both, C.; Blem, C.

    2002-01-01

    We collected 328 freshly laid Great Tit (Parus major) eggs from 38 clutches in 1999 to determine the relationship of whole egg weight, wet yolk weight, wet albumen weight, dry shell weight, and the occurrence of laying gaps with mean ambient temperature in the three days preceding laying, while

  13. Efficient speaker verification using Gaussian mixture model component clustering.

    Energy Technology Data Exchange (ETDEWEB)

    De Leon, Phillip L. (New Mexico State University, Las Cruces, NM); McClanahan, Richard D.

    2012-04-01

    In speaker verification (SV) systems that employ a support vector machine (SVM) classifier to make decisions on a supervector derived from Gaussian mixture model (GMM) component mean vectors, a significant portion of the computational load is involved in the calculation of the a posteriori probability of the feature vectors of the speaker under test with respect to the individual component densities of the universal background model (UBM). Further, the calculation of the sufficient statistics for the weight, mean, and covariance parameters derived from these same feature vectors also contribute a substantial amount of processing load to the SV system. In this paper, we propose a method that utilizes clusters of GMM-UBM mixture component densities in order to reduce the computational load required. In the adaptation step we score the feature vectors against the clusters and calculate the a posteriori probabilities and update the statistics exclusively for mixture components belonging to appropriate clusters. Each cluster is a grouping of multivariate normal distributions and is modeled by a single multivariate distribution. As such, the set of multivariate normal distributions representing the different clusters also form a GMM. This GMM is referred to as a hash GMM which can be considered to a lower resolution representation of the GMM-UBM. The mapping that associates the components of the hash GMM with components of the original GMM-UBM is referred to as a shortlist. This research investigates various methods of clustering the components of the GMM-UBM and forming hash GMMs. Of five different methods that are presented one method, Gaussian mixture reduction as proposed by Runnall's, easily outperformed the other methods. This method of Gaussian reduction iteratively reduces the size of a GMM by successively merging pairs of component densities. Pairs are selected for merger by using a Kullback-Leibler based metric. Using Runnal's method of reduction, we

  14. A weighted information criterion for multiple minor components and its adaptive extraction algorithms.

    Science.gov (United States)

    Gao, Yingbin; Kong, Xiangyu; Zhang, Huihui; Hou, Li'an

    2017-05-01

    Minor component (MC) plays an important role in signal processing and data analysis, so it is a valuable work to develop MC extraction algorithms. Based on the concepts of weighted subspace and optimum theory, a weighted information criterion is proposed for searching the optimum solution of a linear neural network. This information criterion exhibits a unique global minimum attained if and only if the state matrix is composed of the desired MCs of an autocorrelation matrix of an input signal. By using gradient ascent method and recursive least square (RLS) method, two algorithms are developed for multiple MCs extraction. The global convergences of the proposed algorithms are also analyzed by the Lyapunov method. The proposed algorithms can extract the multiple MCs in parallel and has advantage in dealing with high dimension matrices. Since the weighted matrix does not require an accurate value, it facilitates the system design of the proposed algorithms for practical applications. The speed and computation advantages of the proposed algorithms are verified through simulations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Integration of Simulink Models with Component-based Software Models

    Directory of Open Access Journals (Sweden)

    MARIAN, N.

    2008-06-01

    Full Text Available Model based development aims to facilitate the development of embedded control systems by emphasizing the separation of the design level from the implementation level. Model based design involves the use of multiple models that represent different views of a system, having different semantics of abstract system descriptions. Usually, in mechatronics systems, design proceeds by iterating model construction, model analysis, and model transformation. Constructing a MATLAB/Simulink model, a plant and controller behavior is simulated using graphical blocks to represent mathematical and logical constructs and process flow, then software code is generated. A Simulink model is a representation of the design or implementation of a physical system that satisfies a set of requirements. A software component-based system aims to organize system architecture and behavior as a means of computation, communication and constraints, using computational blocks and aggregates for both discrete and continuous behavior, different interconnection and execution disciplines for event-based and time-based controllers, and so on, to encompass the demands to more functionality, at even lower prices, and with opposite constraints. COMDES (Component-based Design of Software for Distributed Embedded Systems is such a component-based system framework developed by the software engineering group of Mads Clausen Institute for Product Innovation (MCI, University of Southern Denmark. Once specified, the software model has to be analyzed. One way of doing that is to integrate in wrapper files the model back into Simulink S-functions, and use its extensive simulation features, thus allowing an early exploration of the possible design choices over multiple disciplines. The paper describes a safe translation of a restricted set of MATLAB/Simulink blocks to COMDES software components, both for continuous and discrete behavior, and the transformation of the software system into the S

  16. The Effects of Weight Loss Versus Weight Loss Maintenance on Sympathetic Nervous System Activity and Metabolic Syndrome Components

    National Research Council Canada - National Science Library

    Straznicky, Nora E; Grima, Mariee T; Eikelis, Nina; Nestel, Paul J; Dawood, Tye; Schlaich, Markus P; Chopra, Reena; Masuo, Kazuko; Esler, Murray D; Sari, Carolina I; Lambert, Gavin W; Lambert, Elisabeth A

    2011-01-01

    This study demonstrates divergent effects of successful weight loss maintenance on whole body norepinephrine spillover rate and muscle sympathetic nerve activity in obese metabolic syndrome subjects. Context...

  17. Gaining weight and components of metabolic syndrome in the period of menopause

    Directory of Open Access Journals (Sweden)

    Simoncig-Netjasov Aleksandra

    2008-01-01

    Full Text Available INTRODUCTION Menopause induces redistribution of fat mass and development of abdominal obesity, increasing risk for metabolic syndrome (MS by 60%. Related cardiovascular diseases become a leading cause of morbidity and mortality in women after fifty years of age. OBJECTIVE The aim of this study was to investigate the influence of gaining weight on components of MS in the menopause. METHOD The study included 50 obese women, BMI=31.92± 5.83 kg/m2, age 54.40±3.64, time since menopause 5.90±5.46 years, and 37 normal weight women, BMI=23.50±2.13 kg/m2, age 53.92±3.95, time since menopause 5.96±4.92 years. Both groups were divided according to the presence of MS into two subgroups. Anthropometric characteristics and blood pressure were measured. Blood was taken at 8 am for the following: fasting glucose, triglycerides, cholesterol, HDL, LDL, apolipoprotein A (ApoA, apolipoprotein B (ApoB, lipoprotein(a (Lp(a, C-reactive protein (CRP, fibrinogen, FSH, LH, prolactin, oestrogen, progesterone, testosterone and sex hormonebinding globulin (SHBG. RESULTS 66% of obese women had MS compared with 22% normal weight women. Significant differences between groups were found for the following: weight, BMI, waist, hip circumference, waist/hip ratio, diastolic blood pressure, Lp(a, FSH, LH, prolactin (all p<0.01 and fasting glucose (p<0.05. Obese women with and without MS were significantly diverse for the following: waist/hip ratio, systolic blood pressure and fasting glucose (all p<0.01; age, BMI, waist circumference, triglycerides, HDL, Lp(a and SHBG (all p<0.05. Normal weight women with and without MS had significantly different values of waist/hip ratio, systolic, diastolic blood pressure, triglycerides (all p<0.01; HDL and testosterone (p<0.05. Significant differences were found between obese and normal weight women with MS in anthropometric characteristics, ApoA, Lp(a, fibrinogen (all p<0.01 and FSH (p<0.05. CONCLUSION Abdominal obesity significantly

  18. A model for the dynamics of human weight cycling.

    Science.gov (United States)

    Goldbeter, Albert

    2006-03-01

    The resolution to lose weight by cognitive restraint of nutritional intake often leads to repeated bouts of weight loss and regain, a phenomenon known as weight cycling or "yo-yo dieting". A simple mathematical model for weight cycling is presented. The model is based on a feedback of psychological nature by which a subject decides to reduce dietary intake once a threshold weight is exceeded. The analysis of the model indicates that sustained oscillations in body weight occur in a parameter range bounded by critical values. Only outside this range can body weight reach a stable steady state. The model provides a theoretical framework that captures key facets of weight cycling and suggests ways to control the phenomenon. The view that weight cycling represents self-sustained oscillations has indeed specific implications. In dynamical terms, to bring weight cycling to an end, parameter values should change in such a way as to induce the transition of body weight from sustained oscillations around an unstable steady state to a stable steady state. Maintaining weight under a critical value should prevent weight cycling and allow body weight to stabilize below the oscillatory range.

  19. Use of principal component analysis for differentiation of gelatine sources based on polypeptide molecular weights.

    Science.gov (United States)

    Nur Azira, T; Che Man, Y B; Raja Mohd Hafidz, R N; Aina, M A; Amin, I

    2014-05-15

    The study was aimed to differentiate between porcine and bovine gelatines in adulterated samples by utilising sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) combined with principal component analysis (PCA). The distinct polypeptide patterns of 6 porcine type A and 6 bovine type B gelatines at molecular weight ranged from 50 to 220 kDa were studied. Experimental samples of raw gelatine were prepared by adding porcine gelatine in a proportion ranging from 5% to 50% (v/v) to bovine gelatine and vice versa. The method used was able to detect 5% porcine gelatine added to the bovine gelatine. There were no differences in the electrophoretic profiles of the jelly samples when the proteins were extracted with an acetone precipitation method. The simple approach employing SDS-PAGE and PCA reported in this paper may provide a useful tool for food authenticity issues concerning gelatine. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Long-term effects of a weight loss intervention with or without exercise component in postmenopausal women : A randomized trial

    NARCIS (Netherlands)

    de Roon, Martijn; van Gemert, Willemijn A; Peeters, Petra H M; Schuit, Albertine J; Monninkhof, Evelyn M.

    The aim of this study was to determine the long-term effects of a weight loss intervention with or without an exercise component on body weight and physical activity. Women were randomized to diet (n = 97) or exercise (N = 98) for 16 weeks. During the intervention, both groups had achieved the set

  1. Long-term effects of a weight loss intervention with or without exercise component in postmenopausal women : A randomized trial

    NARCIS (Netherlands)

    de Roon, Martijn; van Gemert, Willemijn A.; Peeters, Petra H.; Schuit, Albertine J.; Monninkhof, Evelyn M.

    2017-01-01

    The aim of this study was to determine the long-term effects of a weight loss intervention with or without an exercise component on body weight and physical activity. Women were randomized to diet (n = 97) or exercise (N = 98) for 16 weeks. During the intervention, both groups had achieved the set

  2. A model for the dynamics of human weight cycling

    Indian Academy of Sciences (India)

    The model provides a theoretical framework that captures key facets of weight cycling and suggests ways to control the phenomenon. The view that weight cycling represents self-sustained oscillations has indeed specific implications. In dynamical terms, to bring weight cycling to an end, parameter values should change in ...

  3. Accurate modelling of UV written waveguide components

    DEFF Research Database (Denmark)

    Svalgaard, Mikael

    BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure.......BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure....

  4. Accurate modeling of UV written waveguide components

    DEFF Research Database (Denmark)

    Svalgaard, Mikael

    BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure.......BPM simulation results of UV written waveguide components that are indistinguishable from measurements can be achieved on the basis of trajectory scan data and an equivalent step index profile that is very easy to measure....

  5. Organs and carcass non-integrant components of Holstein calves, slaughtered at different weights, held in different finishing systems

    Directory of Open Access Journals (Sweden)

    Ana Maria Osorio Dias

    2016-04-01

    Full Text Available The objective of this study was to evaluate the weight of the empty body and non-integrant components of Holstein calves carcass, kept in confinement system or pasture, slaughtered at different weights. We used 43 Holstein calves, entire, age and initial body weight of approximately 58 days and 57 kg, distributed entirely at random in confinement or cultivated pasture. In feeding systems, it was pre-stipulated four slaughter weights (SW - 140, 180, 220 and 260 kg of live weight. In confinement, were provided corn silage and concentrate based on corn meal and soybean meal, in the ratio 40:60. The other animals in ryegrass pasture, followed by pearl millet, were fed based in supplementation of corn bran and soybean meal to 1% of live weight. The EBW showed linear growth with increasing slaughter weight (SW, as well as income from hot and cold carcass and there was no effect in relation EBW/ SW. The leather, the scraps, the head, the legs, as well as the sum of external components showed growth in its absolute weight as the weight increased at the slaughter of animals. In relative terms, the hot and cold carcass yields were inversely correlated with the relative weights, as well as external components (- 0.68 and - 0.81, the heart (- 0.35 and -0, 38 lungs (- 0.53 and - 0.53, the sum of the gastrointestinal tract (-0.75 and - 0.77, the sum of vital organs (- 0.71 to - 0.75 respectively in feedlot and pasture. This is due to the different ages that the animals were slaughtered (200; 237; 251 and 263 days of age, due to pre-stipulate weights. The absolute weights of heart, kidney, lungs, liver, spleen, gall bladder, reproductive tract and gastrointestinal tract accompanied the increase in weight at animal’s slaughter. However, when grouped, showed no difference related to the increase in weight at slaughter. The differences presented by the liver, trachea and spleen were sufficient to alter the absolute and relative weights of the set of internal

  6. Features of somatotype and body weight component composition in patients with acne: boys and girls of Podillya region of Ukraine

    Directory of Open Access Journals (Sweden)

    Gunas Igor

    2016-06-01

    Full Text Available The article describes the differences in peculiarities of somatotype and body weight component composition in patients with acne, the study population being boys and girls of the Podillya region of Ukraine. In the study subjects, regardless of sex, body muscle mass, bone mass and the mesomorphic somatotype component of those with acne were significantly greater, while fat body mass indicators and the endomorphic somatotype component was smaller – in comparison to that of non-afflicted subjects of similar gender. Regarding the ectomorphic component of somatotype, between the surveyed groups of those with and without acne, whether male or female, no significant differences were revealed. For all indicators, whether the somatotype components or the component composition of body weight, between groups of boys or girls with different degrees of severity of acne, again no significant differences were established.

  7. A cluster randomised control trial of a multi-component weight management programme for adults with intellectual disabilities and obesity.

    Science.gov (United States)

    Harris, Leanne; Hankey, Catherine; Jones, Nathalie; Pert, Carol; Murray, Heather; Tobin, Janet; Boyle, Susan; Melville, Craig

    2017-08-01

    There have been few published controlled studies of multi-component weight management programmes that include an energy deficit diet (EDD), for adults with intellectual disabilities and obesity. The objective of this study was to conduct a single-blind, cluster randomised controlled trial comparing a multi-component weight management programme to a health education programme. Participants were randomised to either TAKE 5, which included an EDD or Waist Winners Too (WWToo), based on health education principles. Outcomes measured at baseline, 6 months (after a weight loss phase) and 12 months (after a 6-month weight maintenance phase), by a researcher blinded to treatment allocation, included: weight; BMI; waist circumference; physical activity; sedentary behaviour and health-related quality of life. The recruitment strategy was effective with fifty participants successfully recruited. Both programmes were acceptable to adults with intellectual disabilities, evidenced by high retention rates (90 %). Exploratory efficacy analysis revealed that at 12 months there was a trend for more participants in TAKE 5 (50·0 %) to achieve a clinically important weight loss of 5-10 %, in comparison to WWToo (20·8 %) (OR 3·76; 95 % CI 0·92, 15·30; 0·064). This study found that a multi-component weight management programme that included an EDD, is feasible and an acceptable approach to weight loss when tailored to meet the needs of adults with intellectual disabilities and obesity.

  8. Attentional weights in vision as products of spatial and nonspatial components

    DEFF Research Database (Denmark)

    Nordfang, Maria; Staugaard, Camilla; Bundesen, Claus

    2017-01-01

    , but for each of the ten participants, the ratio of the weight of a distractor at a given location to the weight of a target at the same location was approximately constant. The results were accommodated by revising the weight equation of TVA such that the attentional weight of an object equals a product...

  9. Estimates of (covariance components and genetic parameters for body weights and growth efficiency traits in the New Zealand white rabbit

    Directory of Open Access Journals (Sweden)

    M. Sakthivel

    2017-12-01

    Full Text Available The genetic parameters of growth traits in the New Zealand White rabbits kept at Sheep Breeding and Research Station, Sandynallah, The Nilgiris, India were estimated by partitioning the variance and covariance components. The (covariance components of body weights at weaning (W42, post-weaning (W70 and marketing (W135 age and growth efficiency traits viz., average daily gain (ADG, relative growth rate (RGR and Kleiber ratio (KR estimated on a daily basis at different age intervals (42 to 70 d; 70 to 135 d and 42 to 135 d from weaning to marketing were estimated by restricted maximum likelihood, fitting 6 animal models with various combinations of direct and maternal effects. Data were collected over a period of 15 yr (1998 to 2012. A log-likelihood ratio test was used to select the most appropriate univariate model for each trait, which was subsequently used in bivariate analysis. Heritability estimates for W42, W70 and W135 were 0.42±0.07, 0.40±0.08 and 0.27±0.07, respectively. Heritability estimates of growth efficiency traits were moderate to high (0.18 to 0.42. Of the total phenotypic variation, maternal genetic effect contributed 14 to 32% for early body weight traits (W42 and W70 and ADG1. The contribution of maternal permanent environmental effect varied from 6 to 18% for W42 and for all the growth efficiency traits except for KR2. Maternal permanent environmental effect on most of the growth efficiency traits was a carryover effect of maternal care during weaning. Direct maternal genetic correlations, for the traits in which maternal genetic effect was significant, were moderate to high in magnitude and negative in direction. Maternal effect declined as the age of the animal increased. The estimates of total heritability and maternal across year repeatability for growth traits were moderate and an optimum rate of genetic progress seems possible in the herd by mass selection. The genetic and phenotypic correlations among body weights

  10. Integration of Simulink Models with Component-based Software Models

    DEFF Research Database (Denmark)

    Marian, Nicolae; Top, Søren

    2008-01-01

    of abstract system descriptions. Usually, in mechatronics systems, design proceeds by iterating model construction, model analysis, and model transformation. Constructing a MATLAB/Simulink model, a plant and controller behavior is simulated using graphical blocks to represent mathematical and logical......, communication and constraints, using computational blocks and aggregates for both discrete and continuous behaviour, different interconnection and execution disciplines for event-based and time-based controllers, and so on, to encompass the demands to more functionality, at even lower prices, and with opposite...... of MATLAB/Simulink blocks to COMDES software components, both for continuous and discrete behaviour, and the transformation of the software system into the S-functions. The general aim of this work is the improvement of multi-disciplinary development of embedded systems with the focus on the relation...

  11. Asymmetric Gepner models II. Heterotic weight lifting

    Energy Technology Data Exchange (ETDEWEB)

    Gato-Rivera, B. [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); Schellekens, A.N., E-mail: t58@nikhef.n [NIKHEF Theory Group, Kruislaan 409, 1098 SJ Amsterdam (Netherlands); Instituto de Fisica Fundamental, CSIC, Serrano 123, Madrid 28006 (Spain); IMAPP, Radboud Universiteit, Nijmegen (Netherlands)

    2011-05-21

    A systematic study of 'lifted' Gepner models is presented. Lifted Gepner models are obtained from standard Gepner models by replacing one of the N=2 building blocks and the E{sub 8} factor by a modular isomorphic N=0 model on the bosonic side of the heterotic string. The main result is that after this change three family models occur abundantly, in sharp contrast to ordinary Gepner models. In particular, more than 250 new and unrelated moduli spaces of three family models are identified. We discuss the occurrence of fractionally charged particles in these spectra.

  12. Seasonality with trend and cycle interactions in unobserved components models

    NARCIS (Netherlands)

    Koopman, S.J.; Lee, K.M.

    2009-01-01

    Summary. Unobserved components time series models decompose a time series into a trend, a season, a cycle, an irregular disturbance and possibly other components. These models have been successfully applied to many economic time series. The standard assumption of a linear model, which is often

  13. Component-based event composition modeling for CPS

    Science.gov (United States)

    Yin, Zhonghai; Chu, Yanan

    2017-06-01

    In order to combine event-drive model with component-based architecture design, this paper proposes a component-based event composition model to realize CPS’s event processing. Firstly, the formal representations of component and attribute-oriented event are defined. Every component is consisted of subcomponents and the corresponding event sets. The attribute “type” is added to attribute-oriented event definition so as to describe the responsiveness to the component. Secondly, component-based event composition model is constructed. Concept lattice-based event algebra system is built to describe the relations between events, and the rules for drawing Hasse diagram are discussed. Thirdly, as there are redundancies among composite events, two simplification methods are proposed. Finally, the communication-based train control system is simulated to verify the event composition model. Results show that the event composition model we have constructed can be applied to express composite events correctly and effectively.

  14. Option valuation with the simplified component GARCH model

    DEFF Research Database (Denmark)

    Dziubinski, Matt P.

    We introduce the Simplified Component GARCH (SC-GARCH) option pricing model, show and discuss sufficient conditions for non-negativity of the conditional variance, apply it to low-frequency and high-frequency financial data, and consider the option valuation, comparing the model performance...... with similar models from the literature. Two volatility components in our model allow us to model time structure of volatility....

  15. TLR2- and 4-independent immunomodulatory effect of high molecular weight components from Ascaris suum.

    Science.gov (United States)

    Favoretto, Bruna C; Silva, Sandriana R; Jacysyn, Jacqueline F; Câmara, Niels O S; Faquim-Mauro, Eliana L

    2014-03-01

    Components of high molecular-weight (PI) obtained from Ascaris suum extract down-regulate the Th1/Th2-related immune responses induced by ovalbumin (OVA)-immunization in mice. Furthermore, the PI down-modulates the ability of dendritic cells (DCs) to activate T lymphocytes by an IL-10-mediated mechanism. Here, we evaluated the role of toll like receptors 2 and 4 (TLR2 and 4) in the modulatory effect of PI on OVA-specific immune response and the PI interference on DC full activation. An inhibition of OVA-specific cellular and humoral responses were observed in wild type (WT) or in deficient in TLR2 (TLR2(-/-)) or 4 (TLR4(-/-)) mice immunized with OVA plus PI when compared with OVA-immunized mice. Low expression of class II MHC, CD40, CD80 and CD86 molecules was observed in lymph node (LN) cells from WT, TLR2(-/-) or TLR4(-/-) mice immunized with OVA plus PI compared with OVA-primed cells. We also verified that PI was able to modulate the activation of DCs derived from bone marrow of WT, TLR2(-/-) or TLR4(-/-) mice induced in vitro by agonists of TLRs, as observed by a decreased expression of class II MHC and costimulatory molecules and by low secretion of pro-inflammatory cytokines. Its effect was accompanied by IL-10 synthesis. In this sense, the modulatory effect of PI on specific-immune response and DC activation is independent of TLR2 or TLR4. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Nitrogen component in nonpoint source pollution models

    Science.gov (United States)

    Pollutants entering a water body can be very destructive to the health of that system. Best Management Practices (BMPs) and/or conservation practices are used to reduce these pollutants, but understanding the most effective practices is very difficult. Watershed models are an effective tool to aid...

  17. Modeling microstructural evolution of multiple texture components during recrystallization

    DEFF Research Database (Denmark)

    Vandermeer, R.A.; Juul Jensen, D.

    1994-01-01

    Models were formulated in an effort to characterize recrystallization in materials with multiple texture components. The models are based on a microstructural path methodology (MPM). Experimentally the microstructural evolution of conmmercial aluminum during recrystallization was characterized...... using stereological point and lineal measurements of microstructural properties in combination with EBSP analysis for orientation determinations. The potential of the models to describe the observed recrystallization behavior of heavily cold-rolled commercial aluminum was demonstrated. A successful MPM...... model was deduced which, for each texture component-random, rolling and cube orientations, was quantitatively consistent with the measured microstructural properties. Nucleation and growth rates were deduced for each texture component using the model....

  18. Skill and independence weighting for multi-model assessments

    Science.gov (United States)

    Sanderson, Benjamin M.; Wehner, Michael; Knutti, Reto

    2017-06-01

    We present a weighting strategy for use with the CMIP5 multi-model archive in the fourth National Climate Assessment, which considers both skill in the climatological performance of models over North America as well as the inter-dependency of models arising from common parameterizations or tuning practices. The method exploits information relating to the climatological mean state of a number of projection-relevant variables as well as metrics representing long-term statistics of weather extremes. The weights, once computed can be used to simply compute weighted means and significance information from an ensemble containing multiple initial condition members from potentially co-dependent models of varying skill. Two parameters in the algorithm determine the degree to which model climatological skill and model uniqueness are rewarded; these parameters are explored and final values are defended for the assessment. The influence of model weighting on projected temperature and precipitation changes is found to be moderate, partly due to a compensating effect between model skill and uniqueness. However, more aggressive skill weighting and weighting by targeted metrics is found to have a more significant effect on inferred ensemble confidence in future patterns of change for a given projection.

  19. Model-integrating software components engineering flexible software systems

    CERN Document Server

    Derakhshanmanesh, Mahdi

    2015-01-01

    In his study, Mahdi Derakhshanmanesh builds on the state of the art in modeling by proposing to integrate models into running software on the component-level without translating them to code. Such so-called model-integrating software exploits all advantages of models: models implicitly support a good separation of concerns, they are self-documenting and thus improve understandability and maintainability and in contrast to model-driven approaches there is no synchronization problem anymore between the models and the code generated from them. Using model-integrating components, software will be

  20. Modeling regulatory networks with weight matrices

    DEFF Research Database (Denmark)

    Weaver, D.C.; Workman, Christopher; Stormo, Gary D.

    1999-01-01

    Systematic gene expression analyses provide comprehensive information about the transcriptional responseto different environmental and developmental conditions. With enough gene expression data points,computational biologists may eventually generate predictive computer models of transcription...... regulation.Such models will require computational methodologies consistent with the behavior of known biologicalsystems that remain tractable. We represent regulatory relationships between genes as linear coefficients orweights, with the "net" regulation influence on a gene's expression being...... the mathematical summation of theindependent regulatory inputs. Test regulatory networks generated with this approach display stable andcyclically stable gene expression levels, consistent with known biological systems. We include variables tomodel the effect of environmental conditions on transcription regulation...

  1. How many separable sources? Model selection in independent components analysis.

    Science.gov (United States)

    Woods, Roger P; Hansen, Lars Kai; Strother, Stephen

    2015-01-01

    Unlike mixtures consisting solely of non-Gaussian sources, mixtures including two or more Gaussian components cannot be separated using standard independent components analysis methods that are based on higher order statistics and independent observations. The mixed Independent Components Analysis/Principal Components Analysis (mixed ICA/PCA) model described here accommodates one or more Gaussian components in the independent components analysis model and uses principal components analysis to characterize contributions from this inseparable Gaussian subspace. Information theory can then be used to select from among potential model categories with differing numbers of Gaussian components. Based on simulation studies, the assumptions and approximations underlying the Akaike Information Criterion do not hold in this setting, even with a very large number of observations. Cross-validation is a suitable, though computationally intensive alternative for model selection. Application of the algorithm is illustrated using Fisher's iris data set and Howells' craniometric data set. Mixed ICA/PCA is of potential interest in any field of scientific investigation where the authenticity of blindly separated non-Gaussian sources might otherwise be questionable. Failure of the Akaike Information Criterion in model selection also has relevance in traditional independent components analysis where all sources are assumed non-Gaussian.

  2. How Many Separable Sources? Model Selection In Independent Components Analysis

    DEFF Research Database (Denmark)

    Woods, Roger P.; Hansen, Lars Kai; Strother, Stephen

    2015-01-01

    /Principal Components Analysis (mixed ICA/PCA) model described here accommodates one or more Gaussian components in the independent components analysis model and uses principal components analysis to characterize contributions from this inseparable Gaussian subspace. Information theory can then be used to select from...... computationally intensive alternative for model selection. Application of the algorithm is illustrated using Fisher’s iris data set and Howells’ craniometric data set. Mixed ICA/PCA is of potential interest in any field of scientific investigation where the authenticity of blindly separated non-Gaussian sources...... might otherwise be questionable. Failure of the Akaike Information Criterion in model selection also has relevance in traditional independent components analysis where all sources are assumed non-Gaussian....

  3. Low-temperature oxidative degradation of PBX 9501 and its components determined via molecular weight analysis of the poly [ester urethane] binder

    Energy Technology Data Exchange (ETDEWEB)

    Kress, Joel D [Los Alamos National Laboratory

    2008-01-01

    The results of following the oxidative degradation of a plastic-bonded explosive (PBX 9501) are reported. Into over 1100 sealed containers were placed samples of PBX 9501 and combinations of its components and aged at relatively low temperatures to induce oxidative degradation of the samples. One of the components of the explosive is a poly(ester urethane) polymer and the oxidative degradation of the samples were following by measuring the molecular weight change of the polymer by gel permeation chromatography (coupled with both differential refractive index and multiangle laser light scattering detectors). Multiple temperatures between 40 and 64 {sup o}C were used to accelerate the aging of the samples. Interesting induction period behavior, along with both molecular weight increasing (crosslinking) and decreasing (chain scissioning) processes, were found at these relatively mild conditions. The molecular weight growth rates were fit to a random crosslinking model for all the combinations of components. The fit rate coefficients show Arrhenius behavior and activation energies and frequency factors were obtained. The kinetics of molecular weight growth shows a compensatory effect between the Arrhenius prefactors and activation energies, suggesting a common degradation process between PBX 9501 and the various combinations of its constituents. An oxidative chemical mechanism of the polymer is postulated, consistent with previous experimental results, that involves a competition between urethane radical crosslinking and carbonyl formation.

  4. Modeling Philippine Stock Exchange Composite Index Using Weighted Geometric Brownian Motion Forecasts

    Directory of Open Access Journals (Sweden)

    Gayo Willy

    2016-01-01

    Full Text Available Philippine Stock Exchange Composite Index (PSEi is the main stock index of the Philippine Stock Exchange (PSE. PSEi is computed using a weighted mean of the top 30 publicly traded companies in the Philippines, called component stocks. It provides a single value by which the performance of the Philippine stock market is measured. Unfortunately, these weights, which may vary for every trading day, are not disclosed by the PSE. In this paper, we propose a model of forecasting the PSEi by estimating the weights based on historical data and forecasting each component stock using Monte Carlo simulation based on a Geometric Brownian Motion (GBM assumption. The model performance is evaluated and its forecast compared is with the results using a direct GBM forecast of PSEi over different forecast periods. Results showed that the forecasts using WGBM will yield smaller error compared to direct GBM forecast of PSEi.

  5. Modeling and simulation of orlistat to predict weight loss and weight maintenance in obesity patients.

    Science.gov (United States)

    Nakai, Kiyohiko; Wada, Russell; Iida, Satofumi; Kawanishi, Takehiko; Matsumoto, Yoshiaki

    2014-01-01

    Orlistat is used clinically worldwide as anti-obesity drug. It is a chemically synthesized hydrogenated derivative of lipstatin and is an inhibitor of gastric and pancreatic lipases. It has been found to reduce the absorption of dietary fat in the gastrointestinal tract. Modeling and simulation based on pharmacokinetic/pharmacodynamic analysis is becoming increasingly used in the design of clinical trials to assure that the trials are of high quality and are conducted efficiently. We developed a clinical trial simulation model for orlistat based on Phase III clinical study data. This innovative weight loss model includes the relationships between orlistat dose, changes in fecal fat excretion, and weight loss, and also incorporates a dropout function. The model guided the dose-finding strategy and allowed simulation of long-term clinical outcomes of orlistat.

  6. Weighted Quantile Regression for AR model with Infinite Variance Errors.

    Science.gov (United States)

    Chen, Zhao; Li, Runze; Wu, Yaohua

    2012-09-01

    Autoregressive (AR) models with finite variance errors have been well studied. This paper is concerned with AR models with heavy-tailed errors, which is useful in various scientific research areas. Statistical estimation for AR models with infinite variance errors is very different from those for AR models with finite variance errors. In this paper, we consider a weighted quantile regression for AR models to deal with infinite variance errors. We further propose an induced smoothing method to deal with computational challenges in weighted quantile regression. We show that the difference between weighted quantile regression estimate and its smoothed version is negligible. We further propose a test for linear hypothesis on the regression coefficients. We conduct Monte Carlo simulation study to assess the finite sample performance of the proposed procedures. We illustrate the proposed methodology by an empirical analysis of a real-life data set.

  7. Psychological Empowerment: A systemic model with individual and community components

    OpenAIRE

    Banda Castro, Ana Lilia; Morales Zamorano, Miguel Arturo

    2014-01-01

    This study aimed to confirm that social participation may influence empowerment as one ofthe four components explained by the theory. The hypothesis proposes systemic interaction of two components of empowerment: intrapersonal and behavioral. 113 urban residents participated in the study. The hypotheses were tested through the use of structural modeling. An intrapersonal component of empowerment, composed of positive empowerment, negative empowerment and socio-political control was identified...

  8. The effect of weight management interventions that include a diet component on weight-related outcomes in pregnant and postpartum women: a systematic review protocol.

    Science.gov (United States)

    Spencer, Lisa; Rollo, Megan; Hauck, Yvonne; MacDonald-Wicks, Lesley; Wood, Lisa; Hutchesson, Melinda; Giglia, Roslyn; Smith, Roger; Collins, Clare

    2015-01-01

    What are the effects of weight management interventions that include a diet component on weight-related outcomes in pregnant and postpartum women?The primary objective of this systematic review is to evaluate the effectiveness of weight management interventions which include a diet component and are aimed at limiting gestational weight gain and postpartum weight retention in women.The second objective of this systematic review is to investigate included intervention components with respect to effect on weight-related outcomes. This may include, but is not limited to: length of intervention, use of face-to-face counselling, group or individual consultations, use of other interventions components including exercise, use of goals and use of support tools like food diaries, coaching, including email or text message support. Around half of all women of reproductive age are either overweight or obese, with women aged 25-34 years having a greater risk of substantial weight gain compared with men of all ages. Excessive gestational weight gain (GWG) and postpartum weight retention (PPWR) may play a significant role in long term obesity. Having one child doubles the five- and 10-year obesity incidence for women, with many women who gain excessive weight during pregnancy remaining obese permanently. Excessive GWG and/or PPWR can also significantly contribute to short- and long-term adverse health outcomes for mother, baby and future pregnancies.Maternal obesity increases the risk of pregnancy related complications such as pre-eclampsia, gestational diabetes mellitus, stillbirth and the rate of caesarean section. Childhood obesity is a further long term complication of maternal obesity for offspring, which may persist in to adulthood. Excess GWG is also a risk factor for PPWR both in the short and long-term. Nehring et al. conducted a meta-analysis with over 65,000 women showing that, compared to women who gained weight within recommendations during pregnancy, women with GWG

  9. Components in models of learning: Different operationalisations and relations between components

    Directory of Open Access Journals (Sweden)

    Mirkov Snežana

    2013-01-01

    Full Text Available This paper provides the presentation of different operationalisations of components in different models of learning. Special emphasis is on the empirical verifications of relations between components. Starting from the research of congruence between learning motives and strategies, underlying the general model of school learning that comprises different approaches to learning, we have analyzed the empirical verifications of factor structure of instruments containing the scales of motives and learning strategies corresponding to these motives. Considering the problems in the conceptualization of the achievement approach to learning, we have discussed the ways of operational sing the goal orientations and exploring their role in using learning strategies, especially within the model of the regulation of constructive learning processes. This model has served as the basis for researching learning styles that are the combination of a large number of components. Complex relations between the components point to the need for further investigation of the constructs involved in various models. We have discussed the findings and implications of the studies of relations between the components involved in different models, especially between learning motives/goals and learning strategies. We have analyzed the role of regulation in the learning process, whose elaboration, as indicated by empirical findings, can contribute to a more precise operationalisation of certain learning components. [Projekat Ministarstva nauke Republike Srbije, br. 47008: Unapređivanje kvaliteta i dostupnosti obrazovanja u procesima modernizacije Srbije i br. 179034: Od podsticanja inicijative, saradnje i stvaralaštva u obrazovanju do novih uloga i identiteta u društvu

  10. Prediction of gestational weight gain - a biopsychosocial model.

    Science.gov (United States)

    Heery, Emily; Kelleher, Cecily C; Wall, Patrick G; McAuliffe, Fionnuala M

    2015-06-01

    To examine the influence of health behaviours and psychological well-being on gestational weight gain using a biopsychosocial model. A prospective cohort study of pregnant women consecutively recruited at their first antenatal care visit. A self-administered questionnaire was used to collect data on health behaviours and psychological well-being in early pregnancy. Linear regression and logistic regression were used to identify predictors of total weight gain in kilograms and weight gain outside the current Institute of Medicine recommendations, respectively. A maternity hospital in the Republic of Ireland. Data on 799 women were analysed. Pre-pregnant BMI ≥30·0 kg/m2, short stature, parity >0, decreased food intake and absence of health insurance predicted lower absolute gestational weight gain, while foreign nationality, consumption of takeaway meals more than once weekly and increased food intake predicted higher absolute gestational weight gain. Overweight and obesity, foreign nationality, increased food intake and height >170 cm were risk factors for excessive weight gain, while antenatal depression was protective against excessive weight gain. Notably, physical activity measures were not related to the gestational weight gain outcomes. Pre-pregnancy overweight and increased food intake were the strongest predictors of excessive gestational weight gain. None of the psychological well-being measures examined, with the exception of antenatal depression, was associated with any of the weight gain outcomes. The behavioural predictors of gestational weight gain were increased food intake and takeaway consumption. Public health promotions should target pre-pregnancy BMI and pregnancy-associated change in food intake.

  11. Component

    Directory of Open Access Journals (Sweden)

    Tibor Tot

    2011-01-01

    Full Text Available A unique case of metaplastic breast carcinoma with an epithelial component showing tumoral necrosis and neuroectodermal stromal component is described. The tumor grew rapidly and measured 9 cm at the time of diagnosis. No lymph node metastases were present. The disease progressed rapidly and the patient died two years after the diagnosis from a hemorrhage caused by brain metastases. The morphology and phenotype of the tumor are described in detail and the differential diagnostic options are discussed.

  12. A Random Dot Product Model for Weighted Networks

    CERN Document Server

    DeFord, Daryl R

    2016-01-01

    This paper presents a generalization of the random dot product model for networks whose edge weights are drawn from a parametrized probability distribution. We focus on the case of integer weight edges and show that many previously studied models can be recovered as special cases of this generalization. Our model also determines a dimension--reducing embedding process that gives geometric interpretations of community structure and centrality. The dimension of the embedding has consequences for the derived community structure and we exhibit a stress function for determining appropriate dimensions. We use this approach to analyze a coauthorship network and voting data from the U.S. Senate.

  13. Newton-Gauss Algorithm of Robust Weighted Total Least Squares Model

    Directory of Open Access Journals (Sweden)

    WANG Bin

    2015-06-01

    Full Text Available Based on the Newton-Gauss iterative algorithm of weighted total least squares (WTLS, a robust WTLS (RWTLS model is presented. The model utilizes the standardized residuals to construct the weight factor function and the square root of the variance component estimator with robustness is obtained by introducing the median method. Therefore, the robustness in both the observation and structure spaces can be simultaneously achieved. To obtain standardized residuals, the linearly approximate cofactor propagation law is employed to derive the expression of the cofactor matrix of WTLS residuals. The iterative calculation steps for RWTLS are also described. The experiment indicates that the model proposed in this paper exhibits satisfactory robustness for gross errors handling problem of WTLS, the obtained parameters have no significant difference with the results of WTLS without gross errors. Therefore, it is superior to the robust weighted total least squares model directly constructed with residuals.

  14. Automatic bootstrapping of a morphable face model using multiple components

    NARCIS (Netherlands)

    Haar, F.B. ter; Veltkamp, R.C.

    2009-01-01

    We present a new bootstrapping algorithm to automatically enhance a 3D morphable face model with new face data. Our algorithm is based on a morphable model fitting method that uses a set of predefined face components. This fitting method produces accurate model fits to 3D face data with noise and

  15. Data Driven Broiler Weight Forecasting using Dynamic Neural Network Models

    DEFF Research Database (Denmark)

    Johansen, Simon Vestergaard; Bendtsen, Jan Dimon; Riisgaard-Jensen, Martin

    2017-01-01

    In this article, the dynamic influence of environmental broiler house conditions and broiler growth is investigated. Dynamic neural network forecasting models have been trained on farm-scale broiler batch production data from 12 batches from the same house. The model forecasts future broiler weight...

  16. Estimation of Variance Components and Genetic Parameters for Direct and Maternal Effects on Birth Weight in Brown Swiss Cattle

    Directory of Open Access Journals (Sweden)

    Ali Kaygisiz*, Galip Bakir1, Isa Yilmaz2 and Yusuf Vanli3

    2011-01-01

    Full Text Available The purpose of this study was to estimate the variance components and genetic parameters for birth weight in Brown Swiss cattle reared at Malya and Konuklar State Farms, Türkiye. The least square means of birth weight were 39.91±0.005 and 42.26±0.09kg for the calves raised at Malya and Konuklar State Farms, respectively. The effects of calving year, parity and calf sex on birth weight were significant (P<0.05. The effect of calving season on birth weight was highly significant (P<0.01 for Malya State Farm, while it was non-significant for Konuklar State Farm. Direct heritability (h2d, maternal heritability (h2m, total heritability (h2T and the fraction of variance due to maternal permanent environmental effects (c2 were 0.09, 0.04, 0.11 and 0.04, respectively for birth weights of the calves raised at Malya State Farms. The corresponding values of birth weight for calves raised at Konuklar State Farm were 0.39, 0.015, 0.29 and 0.018, respectively.

  17. Sound analysis to model weight of broiler chickens.

    Science.gov (United States)

    Fontana, Ilaria; Tullo, Emanuela; Carpentier, Lenn; Berckmans, Dries; Butterworth, Andy; Vranken, Erik; Norton, Tomas; Berckmans, Daniel; Guarino, Marcella

    2017-09-01

    The pattern of body weight gain during the commercial growing of broiler chickens is important to understand growth and feed conversion ratio of each flock.The application of sound analysis techniques has been widely studied to measure and analyze the amplitude and frequency of animal sounds. Previous studies have shown a significant correlation (P ≤ 0.001) between the frequency of vocalization and the age and weight of broilers. Therefore, the aim of this study was to identify and validate a model that describes the growth rate of broiler chickens based on the peak frequency of their vocalizations and to explore the possibility to develop a tool capable of automatically detecting the growth of the chickens based on the frequency of their vocalizations during the production cycle. It is part of an overall goal to develop a Precision Livestock Farming tool that assists farmers in monitoring the growth of broiler chickens during the production cycle. In the present study, sounds and body weight were continuously recorded in an intensive broiler farm during 5 production cycles. For each cycle the peak frequencies of the chicken vocalizations were used to estimate the weight and then they were compared with the observed weight of the birds automatically measured using on farm automated weighing devices. No significant difference is shown between expected and observed weights along the entire production cycles; this trend was confirmed by the correlation coefficient between expected and observed weights (r = 96%, P value ≤ 0.001).The identified model used to predict the weight as a function of the peak frequency confirmed that bird weight might be predicted by the frequency analysis of the sounds emitted at farm level. Even if the precision of the weighing method based on sounds investigated in this study has to be improved, it gives a reasonable indication regarding the growth of broilers opening a new scenario in monitoring systems in broiler houses. © 2017

  18. Multi-component lattice-Boltzmann model with interparticle interaction

    CERN Document Server

    Shan, X; Shan, Xiaowen; Doolen, Gary

    1995-01-01

    Abstract: A previously proposed [X. Shan and H. Chen, Phys. Rev. E {\\bf 47}, 1815, (1993)] lattice Boltzmann model for simulating fluids with multiple components and interparticle forces is described in detail. Macroscopic equations governing the motion of each component are derived by using Chapman-Enskog method. The mutual diffusivity in a binary mixture is calculated analytically and confirmed by numerical simulation. The diffusivity is generally a function of the concentrations of the two components but independent of the fluid velocity so that the diffusion is Galilean invariant. The analytically calculated shear kinematic viscosity of this model is also confirmed numerically.

  19. Seed weight - seedling size correlation in coastal Douglas-fir: genetic and environmental components.

    Science.gov (United States)

    Frank C. Sorensen; Robert K. Campbell

    1992-01-01

    The effect of seed weight on nursery seedling height was analyzed in two experiments. In expt. 1, 16 seeds per family from 111 families were individually weighed and sown in autumn. In expt. 2, a second group of 16 seeds were individually weighed and stratified and sown in spring. Four-tree noncontiguous family plots were randomly assigned to two densities in two...

  20. The Use of Active Elements to Reduce the Size and Weight of Passive Components in Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan

    . To facilitate the design and analysis of the active damping terms, the effects of the active damping terms on the machine current and the DC-link voltage of the drive system are discussed. A design recommendation for the proposed active damping terms is given. Simulation and experimental results verifying......Adjustable speed drives are considered as workhorse of industry due to various applications in different kind of industries. According to a market survey, low voltage drives are most profitable in the drive industries. The drive consists of a machine and a converter, which processes grid power...... and converts into usable power for the machine. The converter consists of active and passive components. The size, weight, and volume of the drive are decided by the passive components since they typically contribute to 75% of the weight and volume of the drive. Most popular topology for the low voltage drive...

  1. An animal model of antipsychotic-induced weight gain.

    Science.gov (United States)

    Arjona, Anibal A; Zhang, Sandy X; Adamson, Brittany; Wurtman, Richard J

    2004-06-04

    We have established an animal model for olanzapine-induced body weight gain, and used it to explore the relation between this weight gain, excessive food consumption, gross motor activity, and macronutrient choice. Female Sprague-Dawley rats received olanzapine (OLAN) or diluent (1.2mg/kg per day) via gavage for 10 days. Rats receiving OLAN exhibited significant increases in body weight when compared with control rats. Body weight returned to control levels once OLAN treatment was discontinued. Food consumption among the OLAN-treated group was significantly greater than among control rats between 6 and 10 days of treatment. Between 4 and 10 days of treatment, feed efficiency (grams of weight gained/grams of food consumed) was also significantly greater among animals receiving OLAN. In contrast, chronic administration of haloperidol (0.04mg/kg; q.d.; gavage) did not influence body weight or food consumption of treated rats. Gross motor activity was significantly reduced by OLAN between 1 and 10 days of treatment, also returning to control levels when treatment was discontinued. No significant changes were observed in brain DA, DOPAC, HVA or 5-HIAA among animals receiving OLAN daily for 30 days; however, 5-HT levels were significantly elevated. In contrast, acute (1.2mg/kg; 2h; i.p.) administration of OLAN significantly increased brain DOPAC and HVA levels without affecting those of 5-HT or 5-HIAA. OLAN (1.2mg/kg; q.d.; 10 days) administration did not alter macronutrient choice (carbohydrate:protein ratio) of rats. These data show that an animal model of OLAN-induced weight gain is readily generated, and suggest that the weight gain results at least in part from increased food intake, reduced gross motor activity, and enhanced feed efficiency.

  2. Three-Component Dust Models for Interstellar Extinction

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We have used three-component dust models comprising silicate, graphite and very small carbonaceous grains (polycyclic aromatic hydrocarbons) following the grain size distributions introduced by Li & Draine in 2001. It is shown that oxygen, carbon and silicon abundances derived from our models are ...

  3. A Mixture Rasch Model with Item Response Time Components

    Science.gov (United States)

    Meyer, J. Patrick

    2010-01-01

    An examinee faced with a test item will engage in solution behavior or rapid-guessing behavior. These qualitatively different test-taking behaviors bias parameter estimates for item response models that do not control for such behavior. A mixture Rasch model with item response time components was proposed and evaluated through application to real…

  4. A unified treatment of single component replacement models

    NARCIS (Netherlands)

    J.B.G. Frenk (Hans); R. Dekker (Rommert); M.J. Kleijn (Marcel)

    1997-01-01

    textabstractIn this paper we discuss a general framework for single component replacement models. This framework is based on the regenerative structure of these models and by using results from renewal theory a unified presentation of the discounted and average finite and infinite horizon cost

  5. A weighted network model for interpersonal relationship evolution

    Science.gov (United States)

    Hu, Bo; Jiang, Xin-Yu; Ding, Jun-Feng; Xie, Yan-Bo; Wang, Bing-Hong

    2005-08-01

    A simple model is proposed to mimic and study the evolution of interpersonal relationships in a student class. The small social group is simply assumed as an undirected and weighted graph, in which students are represented by vertices, and the depth of favor or disfavor between them are denoted by the corresponding edge weight. In our model, we find that the first impression between people has a crucial influence on the final status of student relations (i.e., the final distribution of edge weights). The system displays a phase transition in the final hostility proportion depending on the initial amity possibility. We can further define the strength of vertices to describe the individual popularity, which exhibits nonlinear evolution. Meanwhile, various nonrandom perturbations to the initial system have been investigated, and simulation results are in accord with common real-life observations.

  6. Modeling laser beam propagation through components with internal multiple reflections

    Science.gov (United States)

    Wang, Zongzhao; Zhang, Site; Wyrowski, Frank

    2015-02-01

    Component, e.g. Fabry-Perot interferometer, with internal multiple reflections plays an important role in laser technology. Its optical functionality is based on multiple reflections inside the component and the interference effect. In this paper, two electromagnetic concepts that allow the modeling of such components for general incident light are proposed. The first one is based on an iterative field tracing approach. With this approach multiple reflections through and inside the component are handled respectively. One typical example is the simulation of Newton's rings effect or the modeling of an Etalon with thickness variation because of fabrication tolerances. The other one is based on the matrix method for stratified media, which is usually used to handle optical layer systems Fabry-Perot interferometer. We present the details, demonstrate various examples and also discuss sampling issues due to the internal multiple reflections.

  7. HealthWorks: results of a multi-component group-randomized worksite environmental intervention trial for weight gain prevention

    Directory of Open Access Journals (Sweden)

    Linde Jennifer A

    2012-02-01

    Full Text Available Abstract Background U.S. adults are at unprecedented risk of becoming overweight or obese, and most scientists believe the primary cause is an obesogenic environment. Worksites provide an opportunity to shape the environments of adults to reduce obesity risk. The goal of this group-randomized trial was to implement a four-component environmental intervention at the worksite level to positively influence weight gain among employees over a two-year period. Environmental components focused on food availability and price, physical activity promotion, scale access, and media enhancements. Methods Six worksites in a U.S. metropolitan area were recruited and randomized in pairs at the worksite level to either a two-year intervention or a no-contact control. Evaluations at baseline and two years included: 1 measured height and weight; 2 online surveys of individual dietary intake and physical activity behaviors; and 3 detailed worksite environment assessment. Results Mean participant age was 42.9 years (range 18-75, 62.6% were women, 68.5% were married or cohabiting, 88.6% were white, 2.1% Hispanic. Mean baseline BMI was 28.5 kg/m2 (range 16.9-61.2 kg/m2. A majority of intervention components were successfully implemented. However, there were no differences between sites in the key outcome of weight change over the two-year study period (p = .36. Conclusions Body mass was not significantly affected by environmental changes implemented for the trial. Results raise questions about whether environmental change at worksites is sufficient for population weight gain prevention. Trial Registration ClinicalTrials.gov: NCT00708461

  8. Weight stigma is stressful. A review of evidence for the Cyclic Obesity/Weight-Based Stigma model.

    Science.gov (United States)

    Tomiyama, A Janet

    2014-11-01

    Weight stigma is highly pervasive, but its consequences are understudied. This review draws from theory in social psychology, health psychology, and neuroendocrinology to construct an original, generative model called the cyclic obesity/weight-based stigma (COBWEBS) model. This model characterizes weight stigma as a "vicious cycle" - a positive feedback loop wherein weight stigma begets weight gain. This happens through increased eating behavior and increased cortisol secretion governed by behavioral, emotional, and physiological mechanisms, which are theorized to ultimately result in weight gain and difficulty of weight loss. The purpose of this review is to evaluate the existing literature for evidence supporting such a model, propose ways in which individuals enter, fight against, and exit the cycle, and conclude by outlining fruitful future directions in this nascent yet important area of research. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. A fuzzy approach to the Weighted Overlap Dominance model

    DEFF Research Database (Denmark)

    Franco de los Rios, Camilo Andres; Hougaard, Jens Leth; Nielsen, Kurt

    2013-01-01

    in an interactive way, where input data can take the form of uniquely-graded or interval-valued information. Here we explore the Weighted Overlap Dominance (WOD) model from a fuzzy perspective and its outranking approach to decision support and multidimensional interval analysis. Firstly, imprecision measures...

  10. Estimation of Genetic Variance Components Including Mutation and Epistasis using Bayesian Approach in a Selection Experiment on Body Weight in Mice

    DEFF Research Database (Denmark)

    Widyas, Nuzul; Jensen, Just; Nielsen, Vivi Hunnicke

    Selection experiment was performed for weight gain in 13 generations of outbred mice. A total of 18 lines were included in the experiment. Nine lines were allotted to each of the two treatment diets (19.3 and 5.1 % protein). Within each diet three lines were selected upwards, three lines were...... selected downwards and three lines were kept as controls. Bayesian statistical methods are used to estimate the genetic variance components. Mixed model analysis is modified including mutation effect following the methods by Wray (1990). DIC was used to compare the model. Models including mutation effect...... have better fit compared to the model with only additive effect. Mutation as direct effect contributes 3.18% of the total phenotypic variance. While in the model with interactions between additive and mutation, it contributes 1.43% as direct effect and 1.36% as interaction effect of the total variance...

  11. A probabilistic model for component-based shape synthesis

    KAUST Repository

    Kalogerakis, Evangelos

    2012-07-01

    We present an approach to synthesizing shapes from complex domains, by identifying new plausible combinations of components from existing shapes. Our primary contribution is a new generative model of component-based shape structure. The model represents probabilistic relationships between properties of shape components, and relates them to learned underlying causes of structural variability within the domain. These causes are treated as latent variables, leading to a compact representation that can be effectively learned without supervision from a set of compatibly segmented shapes. We evaluate the model on a number of shape datasets with complex structural variability and demonstrate its application to amplification of shape databases and to interactive shape synthesis. © 2012 ACM 0730-0301/2012/08-ART55.

  12. Effect of a high-molecular-weight component of cranberry on constituents of dental biofilm.

    Science.gov (United States)

    Steinberg, Doron; Feldman, Mark; Ofek, Itzhak; Weiss, Ervin I

    2004-07-01

    Previous studies have shown that high molecular-weight non-dialysable material derived from cranberry juice (NDM) inhibits co-aggregation of a variety of oral bacteria. In the present study, we examined the effect of NDM on several constituents of the dental biofilm, glucosyltransferase (GTF) and fructosyltransferase (FTF), as well as on the adhesion of Streptococcus sobrinus. The activity of immobilized and soluble GTF and FTF was inhibited by NDM (P > 0.05). NDM also inhibited adhesion of S. sobrinus to hydroxyapatite (P < 0.05). Our results indicate that NDM may affect biofilm formation. One of the proposed mechanisms is via inhibition of extracellular polysaccharide synthesis, which promote the sucrose-dependent adhesion of oral bacteria as S. sobrinus.

  13. The ground stone components of drills in the ancient Near East: Sockets, flywheels, cobble weights, and drill bits

    Directory of Open Access Journals (Sweden)

    David Ilan

    2016-10-01

    Full Text Available Three types of drills are known from antiquity: the bow drill, the pump drill and the crank drill. Each type often included ground stone components - sockets, weights and flywheels. However, these components are inconspicuous; on their own they are almost never associated with drills. The result is that the drill is nearly invisible in many assemblages, particularly those of the proto-historic and historic periods, from the Chalcolithic through to late antiquity. In this article I focus on the identification of the possible ground stone components of each of these drill types. The means by which these components were attached or applied to the drill shaft is examined and the way that they related to the rotary motion of drills is laid out. I briefly discuss the historical development of each type, referencing more detailed studies, where available. This study should be seen as a prelude to a more comprehensive study that will test hypotheses by means of experiment and catalogue more completely and precisely the ground stone components of drills that have been unidentified or misidentified in archaeological contexts.

  14. Dynamic airspace configuration method based on a weighted graph model

    Directory of Open Access Journals (Sweden)

    Chen Yangzhou

    2014-08-01

    Full Text Available This paper proposes a new method for dynamic airspace configuration based on a weighted graph model. The method begins with the construction of an undirected graph for the given airspace, where the vertices represent those key points such as airports, waypoints, and the edges represent those air routes. Those vertices are used as the sites of Voronoi diagram, which divides the airspace into units called as cells. Then, aircraft counts of both each cell and of each air-route are computed. Thus, by assigning both the vertices and the edges with those aircraft counts, a weighted graph model comes into being. Accordingly the airspace configuration problem is described as a weighted graph partitioning problem. Then, the problem is solved by a graph partitioning algorithm, which is a mixture of general weighted graph cuts algorithm, an optimal dynamic load balancing algorithm and a heuristic algorithm. After the cuts algorithm partitions the model into sub-graphs, the load balancing algorithm together with the heuristic algorithm transfers aircraft counts to balance workload among sub-graphs. Lastly, airspace configuration is completed by determining the sector boundaries. The simulation result shows that the designed sectors satisfy not only workload balancing condition, but also the constraints such as convexity, connectivity, as well as minimum distance constraint.

  15. Analytical Formulation for Sizing and Estimating the Dimensions and Weight of Wind Turbine Hub and Drivetrain Components

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Parsons, T. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); King, R. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dykes, K. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Veers, P. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-06-09

    This report summarizes the theory, verification, and validation of a new sizing tool for wind turbine drivetrain components, the Drivetrain Systems Engineering (DriveSE) tool. DriveSE calculates the dimensions and mass properties of the hub, main shaft, main bearing(s), gearbox, bedplate, transformer if up-tower, and yaw system. The level of fi¬ delity for each component varies depending on whether semiempirical parametric or physics-based models are used. The physics-based models have internal iteration schemes based on system constraints and design criteria. Every model is validated against available industry data or finite-element analysis. The verification and validation results show that the models reasonably capture primary drivers for the sizing and design of major drivetrain components.

  16. Towards a Component Based Model for Database Systems

    Directory of Open Access Journals (Sweden)

    Octavian Paul ROTARU

    2004-02-01

    Full Text Available Due to their effectiveness in the design and development of software applications and due to their recognized advantages in terms of reusability, Component-Based Software Engineering (CBSE concepts have been arousing a great deal of interest in recent years. This paper presents and extends a component-based approach to object-oriented database systems (OODB introduced by us in [1] and [2]. Components are proposed as a new abstraction level for database system, logical partitions of the schema. In this context, the scope is introduced as an escalated property for transactions. Components are studied from the integrity, consistency, and concurrency control perspective. The main benefits of our proposed component model for OODB are the reusability of the database design, including the access statistics required for a proper query optimization, and a smooth information exchange. The integration of crosscutting concerns into the component database model using aspect-oriented techniques is also discussed. One of the main goals is to define a method for the assessment of component composition capabilities. These capabilities are restricted by the component’s interface and measured in terms of adaptability, degree of compose-ability and acceptability level. The above-mentioned metrics are extended from database components to generic software components. This paper extends and consolidates into one common view the ideas previously presented by us in [1, 2, 3].[1] Octavian Paul Rotaru, Marian Dobre, Component Aspects in Object Oriented Databases, Proceedings of the International Conference on Software Engineering Research and Practice (SERP’04, Volume II, ISBN 1-932415-29-7, pages 719-725, Las Vegas, NV, USA, June 2004.[2] Octavian Paul Rotaru, Marian Dobre, Mircea Petrescu, Integrity and Consistency Aspects in Component-Oriented Databases, Proceedings of the International Symposium on Innovation in Information and Communication Technology (ISIICT

  17. Frequency weighted model predictive control of wind turbine

    DEFF Research Database (Denmark)

    Klauco, Martin; Poulsen, Niels Kjølstad; Mirzaei, Mahmood

    2013-01-01

    accordingly. In practice is very hard to measure the effective wind speed, this quantity will be estimated using measurements from the turbine itself. For this purpose stationary predictive Kalman filter has been used. Stochastic simulations of the wind turbine behaviour with applied frequency weighted model......This work is focused on applying frequency weighted model predictive control (FMPC) on three blade horizontal axis wind turbine (HAWT). A wind turbine is a very complex, non-linear system influenced by a stochastic wind speed variation. The reduced dynamics considered in this work...... are the rotational degree of freedom of the rotor and the tower for-aft movement. The MPC design is based on a receding horizon policy and a linearised model of the wind turbine. Due to the change of dynamics according to wind speed, several linearisation points must be considered and the control design adjusted...

  18. Weight and the Future of Space Flight Hardware Cost Modeling

    Science.gov (United States)

    Prince, Frank A.

    2003-01-01

    Weight has been used as the primary input variable for cost estimating almost as long as there have been parametric cost models. While there are good reasons for using weight, serious limitations exist. These limitations have been addressed by multi-variable equations and trend analysis in models such as NAFCOM, PRICE, and SEER; however, these models have not be able to address the significant time lags that can occur between the development of similar space flight hardware systems. These time lags make the cost analyst's job difficult because insufficient data exists to perform trend analysis, and the current set of parametric models are not well suited to accommodating process improvements in space flight hardware design, development, build and test. As a result, people of good faith can have serious disagreement over the cost for new systems. To address these shortcomings, new cost modeling approaches are needed. The most promising approach is process based (sometimes called activity) costing. Developing process based models will require a detailed understanding of the functions required to produce space flight hardware combined with innovative approaches to estimating the necessary resources. Particularly challenging will be the lack of data at the process level. One method for developing a model is to combine notional algorithms with a discrete event simulation and model changes to the total cost as perturbations to the program are introduced. Despite these challenges, the potential benefits are such that efforts should be focused on developing process based cost models.

  19. Human growth and body weight dynamics: an integrative systems model.

    Science.gov (United States)

    Rahmandad, Hazhir

    2014-01-01

    Quantifying human weight and height dynamics due to growth, aging, and energy balance can inform clinical practice and policy analysis. This paper presents the first mechanism-based model spanning full individual life and capturing changes in body weight, composition and height. Integrating previous empirical and modeling findings and validated against several additional empirical studies, the model replicates key trends in human growth including A) Changes in energy requirements from birth to old ages. B) Short and long-term dynamics of body weight and composition. C) Stunted growth with chronic malnutrition and potential for catch up growth. From obesity policy analysis to treating malnutrition and tracking growth trajectories, the model can address diverse policy questions. For example I find that even without further rise in obesity, the gap between healthy and actual Body Mass Indexes (BMIs) has embedded, for different population groups, a surplus of 14%-24% in energy intake which will be a source of significant inertia in obesity trends. In another analysis, energy deficit percentage needed to reduce BMI by one unit is found to be relatively constant across ages. Accompanying documented and freely available simulation model facilitates diverse applications customized to different sub-populations.

  20. Maternal Obesity and Excessive Gestational Weight Gain Are Associated with Components of Child Cognition.

    Science.gov (United States)

    Pugh, Sarah J; Richardson, Gale A; Hutcheon, Jennifer A; Himes, Katherine P; Brooks, Maria M; Day, Nancy L; Bodnar, Lisa M

    2015-11-01

    Maternal overweight and obesity affect two-thirds of women of childbearing age and may increase the risk of impaired child cognition. Our objective was to test the hypothesis that high/low gestational weight gain (GWG) and high/low prepregnancy BMI were associated with offspring intelligence quotient (IQ) and executive function at age 10. Mother-infant dyads (n = 763) enrolled in a birth cohort study were followed from early pregnancy to 10 y postpartum. IQ was assessed by trained examiners with the use of the Stanford Binet Intelligence Scale-4th edition. Executive function was assessed by the number of perseverative errors on the Wisconsin Card Sorting Test and time to complete Part B on the Trail Making Test. Self-reported total GWG was converted to gestational-age-standardized GWG z score. Multivariable linear regression and negative binomial regression were used to estimate independent and joint effects of GWG and BMI on outcomes while adjusting for covariates. At enrollment, the majority of women in the Maternal Health Practices and Child Development cohort were unmarried and unemployed, and more than one-half reported their race as black. The mean ± SD GWG z score was -0.5 ± 1.8, and 27% of women had a pregravid BMI ≥ 25. The median (IQR) number of perseverative errors was 23 (17, 29), the mean ± SD time on Part B was 103 ± 42.6 s, and 44% of children had a low average IQ (≤ 89). Maternal obesity was associated with 3.2 lower IQ points (95% CI: -5.6, -0.8) and a slower time to complete the executive function scale Part B (adjusted β: 12.7 s; 95% CI: 2.8, 23 s) compared with offspring of normal-weight mothers. Offspring of mothers whose GWG was >+1 SD, compared with -1 to +1 SD, performed 15 s slower on the executive function task (95% CI: 1.8, 28 s). There was no association between GWG z score and offspring composite IQ score (adjusted β: -0.32; 95% CI: -0.72, 0.10). Prepregnancy BMI did not modify these associations. Although GWG may be important

  1. Polyenergetic known-component reconstruction without prior shape models

    Science.gov (United States)

    Zhang, C.; Zbijewski, W.; Zhang, X.; Xu, S.; Stayman, J. W.

    2017-03-01

    Purpose: Previous work has demonstrated that structural models of surgical tools and implants can be integrated into model-based CT reconstruction to greatly reduce metal artifacts and improve image quality. This work extends a polyenergetic formulation of known-component reconstruction (Poly-KCR) by removing the requirement that a physical model (e.g. CAD drawing) be known a priori, permitting much more widespread application. Methods: We adopt a single-threshold segmentation technique with the help of morphological structuring elements to build a shape model of metal components in a patient scan based on initial filtered-backprojection (FBP) reconstruction. This shape model is used as an input to Poly-KCR, a formulation of known-component reconstruction that does not require a prior knowledge of beam quality or component material composition. An investigation of performance as a function of segmentation thresholds is performed in simulation studies, and qualitative comparisons to Poly-KCR with an a priori shape model are made using physical CBCT data of an implanted cadaver and in patient data from a prototype extremities scanner. Results: We find that model-free Poly-KCR (MF-Poly-KCR) provides much better image quality compared to conventional reconstruction techniques (e.g. FBP). Moreover, the performance closely approximates that of Poly- KCR with an a prior shape model. In simulation studies, we find that imaging performance generally follows segmentation accuracy with slight under- or over-estimation based on the shape of the implant. In both simulation and physical data studies we find that the proposed approach can remove most of the blooming and streak artifacts around the component permitting visualization of the surrounding soft-tissues. Conclusion: This work shows that it is possible to perform known-component reconstruction without prior knowledge of the known component. In conjunction with the Poly-KCR technique that does not require knowledge of

  2. Integration of Simulink Models with Component-based Software Models

    DEFF Research Database (Denmark)

    Marian, Nicolae

    2008-01-01

    , communication and constraints, using computational blocks and aggregates for both discrete and continuous behaviour, different interconnection and execution disciplines for event-based and time-based controllers, and so on, to encompass the demands to more functionality, at even lower prices, and with opposite...... of abstract system descriptions. Usually, in mechatronics systems, design proceeds by iterating model construction, model analysis, and model transformation. Constructing a MATLAB/Simulink model, a plant and controller behavior is simulated using graphical blocks to represent mathematical and logical...... to be analyzed. One way of doing that is to integrate in wrapper files the model back into Simulink S-functions, and use its extensive simulation features, thus allowing an early exploration of the possible design choices over multiple disciplines. The paper describes a safe translation of a restricted set...

  3. Modeling fabrication of nuclear components: An integrative approach

    Energy Technology Data Exchange (ETDEWEB)

    Hench, K.W.

    1996-08-01

    Reduction of the nuclear weapons stockpile and the general downsizing of the nuclear weapons complex has presented challenges for Los Alamos. One is to design an optimized fabrication facility to manufacture nuclear weapon primary components in an environment of intense regulation and shrinking budgets. This dissertation presents an integrative two-stage approach to modeling the casting operation for fabrication of nuclear weapon primary components. The first stage optimizes personnel radiation exposure for the casting operation layout by modeling the operation as a facility layout problem formulated as a quadratic assignment problem. The solution procedure uses an evolutionary heuristic technique. The best solutions to the layout problem are used as input to the second stage - a simulation model that assesses the impact of competing layouts on operational performance. The focus of the simulation model is to determine the layout that minimizes personnel radiation exposures and nuclear material movement, and maximizes the utilization of capacity for finished units.

  4. Virtual Models Linked with Physical Components in Construction

    DEFF Research Database (Denmark)

    Sørensen, Kristian Birch

    virtual models that thoroughly mirror the performance of the final facility and its construction process. However, the potential of the virtual models in construction has not yet been fully utilised. One way to take more advantage of the virtual models is by digitally linking them with the physical...... components in the construction process and thereby improving the information handling. The present PhD project has examined the potential of establishing such a digital link between virtual models and physical components in construction. This is done by integrating knowledge of civil engineering, software......) project progress management, and 3) in operation and maintenance. Experiments and implementations in real life projects showed that mobile technology and passive RFID technology delineate an efficient and practically implementable ways to establish the digital links in construction and are ready for use...

  5. Models for describing the thermal characteristics of building components

    DEFF Research Database (Denmark)

    Jimenez, M.J.; Madsen, Henrik

    2008-01-01

    Outdoor testing of buildings and building components under real weather conditions provides useful information about their dynamic performance. Such knowledge is needed to properly characterize the heat transfer dynamics and provides useful information for implementing energy saving strategies...... of these approaches may therefore be very useful for selecting a suitable approach for each particular case. This paper presents an overview of models that can be applied for modelling the thermal characteristics of buildings and building components using data from outdoor testing. The choice of approach depends......, for example. For the analysis of these tests, dynamic analysis models and methods are required. However, a wide variety of models and methods exists, and the problem of choosing the most appropriate approach for each particular case is a non-trivial and interdisciplinary task. Knowledge of a large family...

  6. Development of self-image and its components during a one-year follow-up in non-referred adolescents with excess and normal weight.

    Science.gov (United States)

    Mäkinen, Mauno; Marttunen, Mauri; Komulainen, Erkki; Terevnikov, Viacheslav; Puukko-Viertomies, Leena-Riitta; Aalberg, Veikko; Lindberg, Nina

    2015-01-01

    The proportion of overweight and obese youths is high. The present study aimed to investigate the development of self-image and its components during a one-year follow-up among non-referred adolescents with excess and normal weight. Furthermore, we separately analyzed the data for girls and boys. Altogether 86 8(th) grades (41 girls and 45 boys) with a relative weight of 26% or more above the median and 91 controls (43 girls and 48 boys) with normal weight participated the follow-up. The Offer Self-Image Questionnaire, Revised (OSIQ-R) was used to assess self-image at baseline and on follow-up. In the OSIQ-R, a low total raw score implies positive adjustment, while a high raw score implies poor adjustment and a negative self-image. The study design was doubly correlated (pairs and time), and a linear mixed model was used in the statistical analysis. In OSIQ-R total scores, a comparative improvement was observed in girls with normal weight. Among these girls, significant change scores compared to zero were seen in impulse control, social functioning, vocational attitudes, self-confidence, self-reliance, body image, sexuality, and ethical values. In girls with excess weight, none of the change scores compared to zero were statistically significant. When the girls with normal and excess weight were compared, the difference in change scores was largest in sexuality and vocational attitudes. Change scores compared to zero were significant in sexuality and idealism for boys with excess weight, and in impulse control, mental health, self-reliance, and sexuality for normal weight boys. When the boys with excess and normal weight were compared, no statistically significant differences emerged in change scores. In mid-adolescent girls, the influence of overweight and obesity on the development of self-image is substantial. Weight management programs directed at overweight adolescent girls should include psychological interventions aiming to diminish self-image distress

  7. Modeling of magnetic components for power electronic converters

    Science.gov (United States)

    Hranov, Tsveti; Hinov, Nikolay

    2017-12-01

    The paper presents the modelling of magnetic components, used in the power electronic devices. Non-linear inductor and transformer are presented. During the design stage are taken into account that the converters are operated with non-sinusoidal currents and voltages. The models are realized in the MATLAB environment and their verification is done using computer simulations. The advantages of these models against the existing models are that relations between the parameters are formalized and this way the computational procedure is significantly faster. This is important in the cases when the quasi-steady-state regime in devices comes significantly slower and the investigations are requiring long simulation times.

  8. A channel-based coordination model for component composition

    NARCIS (Netherlands)

    F. Arbab (Farhad)

    2002-01-01

    textabstractIn this paper, we present $P epsilon omega$, a paradigm for composition of software components based on the notion of mobile channels. $P repsilon omega$ is a channel-based exogenous coordination model wherein complex coordinators, called {em connectors are compositionally built out of

  9. Do Knowledge-Component Models Need to Incorporate Representational Competencies?

    Science.gov (United States)

    Rau, Martina Angela

    2017-01-01

    Traditional knowledge-component models describe students' content knowledge (e.g., their ability to carry out problem-solving procedures or their ability to reason about a concept). In many STEM domains, instruction uses multiple visual representations such as graphs, figures, and diagrams. The use of visual representations implies a…

  10. Hybrid time/frequency domain modeling of nonlinear components

    DEFF Research Database (Denmark)

    Wiechowski, Wojciech Tomasz; Lykkegaard, Jan; Bak, Claus Leth

    2007-01-01

    This paper presents a novel, three-phase hybrid time/frequency methodology for modelling of nonlinear components. The algorithm has been implemented in the DIgSILENT PowerFactory software using the DIgSILENT Programming Language (DPL), as a part of the work described in [1]. Modified HVDC benchmark...

  11. Incremental principal component pursuit for video background modeling

    Science.gov (United States)

    Rodriquez-Valderrama, Paul A.; Wohlberg, Brendt

    2017-03-14

    An incremental Principal Component Pursuit (PCP) algorithm for video background modeling that is able to process one frame at a time while adapting to changes in background, with a computational complexity that allows for real-time processing, having a low memory footprint and is robust to translational and rotational jitter.

  12. A New Software Quality Model for Evaluating COTS Components

    OpenAIRE

    Adnan Rawashdeh; Bassem Matalkah

    2006-01-01

    Studies show that COTS-based (Commercial off the shelf) systems that are being built recently are exceeding 40% of the total developed software systems. Therefore, a model that ensures quality characteristics of such systems becomes a necessity. Among the most critical processes in COTS-based systems are the evaluation and selection of the COTS components. There are several existing quality models used to evaluate software systems in general; however, none of them is dedicated to COTS-based s...

  13. A new weighted mean temperature model in China

    Science.gov (United States)

    Liu, Jinghong; Yao, Yibin; Sang, Jizhang

    2018-01-01

    The Global Positioning System (GPS) has been applied in meteorology to monitor the change of Precipitable Water Vapor (PWV) in atmosphere, transformed from Zenith Wet Delay (ZWD). A key factor in converting the ZWD into the PWV is the weighted mean temperature (Tm), which has a direct impact on the accuracy of the transformation. A number of Bevis-type models, like Tm -Ts and Tm -Ts,Ps type models, have been developed by statistics approaches, and are not able to clearly depict the relationship between Tm and the surface temperature, Ts . A new model for Tm , called weighted mean temperature norm model (abbreviated as norm model), is derived as a function of Ts , the lapse rate of temperature, δ, the tropopause height, htrop , and the radiosonde station height, hs . It is found that Tm is better related to Ts through an intermediate temperature. The small effects of lapse rate can be ignored and the tropopause height be obtained from an empirical model. Then the norm model is reduced to a simplified form, which causes fewer loss of accuracy and needs two inputs, Ts and hs . In site-specific fittings, the norm model performs much better, with RMS values reduced averagely by 0.45 K and the Mean of Absolute Differences (MAD) values by 0.2 K. The norm model is also found more appropriate than the linear models to fit Tm in a large area, not only with the RMS value reduced from 4.3 K to 3.80 K, correlation coefficient R2 increased from 0.84 to 0.88, and MAD decreased from 3.24 K to 2.90 K, but also with the distribution of simplified model values to be more reasonable. The RMS and MAD values of the differences between reference and computed PWVs are reduced by on average 16.3% and 14.27%, respectively, when using the new norm models instead of the linear model.

  14. Modeling of daily body weights and body weight changes of Nordic Red cows.

    Science.gov (United States)

    Mäntysaari, P; Mäntysaari, E A

    2015-10-01

    Increased availability of automated weighing systems have made it possible to record massive amounts of body weight (BW) data in a short time. If the BW measurement is unbiased, the changes in BW reflect the energy status of the cow and can be used for management or breeding purposes. The usefulness of the BW data depends on the reliability of the measures. The noise in BW measurements can be smoothed by fitting a parametric or time series model into the BW measurements. This study examined the accuracy of different models to predict BW of the cows based on daily BW measurements and investigated the usefulness of modeling in increasing the value of BW measurements as management and breeding tools. Data included daily BW measurements, production, and intake from 230 Nordic Red dairy cows. The BW of the cows was recorded twice a day on their return from milking. In total, the data included 50,594 daily observations with 98,418 BW measurements. A clear diurnal change was present in the BW of the cows even if they had feed available 24 h. The daily average BW were used in the modeling. Five different models were tested: (1) a cow-wise fixed second-order polynomial regression model (FiX) including the exponential Wilmink term, (2) a random regression model with fixed and random animal lactation stage functions (MiX), (3) MiX with 13 periods of weighing added (PER), (4) natural cubic smoothing splines with 8 equally spaced knots (SPk8), and (5) spline model with no restriction on knots but a smoothing parameter corresponding to a fit of 5 degrees of freedom (SPdf5). In the original measured BW data, the within-animal variation was 6.4% of the total variance. Modeling decreased the within animal variation to levels of 2.9 to 5.1%. The smallest day-to-day variation and thereafter highest day-to-day repeatabilities were with PER and MiX models. The usability of modeled BW as energy balance (EB) indicator were evaluated by estimating relationships between EB, or EB

  15. Dynamic energy-balance model predicting gestational weight gain123

    Science.gov (United States)

    Thomas, Diana M; Navarro-Barrientos, Jesus E; Rivera, Daniel E; Heymsfield, Steven B; Bredlau, Carl; Redman, Leanne M; Martin, Corby K; Lederman, Sally A; M Collins, Linda; Butte, Nancy F

    2012-01-01

    Background: Gestational weight gains (GWGs) that exceed the 2009 Institute of Medicine recommended ranges increase risk of long-term postpartum weight retention; conversely, GWGs within the recommended ranges are more likely to result in positive maternal and fetal outcomes. Despite this evidence, recent epidemiologic studies have shown that the majority of pregnant women gain outside the target GWG ranges. A mathematical model that predicts GWG and energy intake could provide a clinical tool for setting precise goals during early pregnancy and continuous objective feedback throughout pregnancy. Objective: The purpose of this study was to develop and validate a differential equation model for energy balance during pregnancy that predicts GWG that results from changes in energy intakes. Design: A set of prepregnancy BMI–dependent mathematical models that predict GWG were developed by using data from a longitudinal study that measured gestational-changes in fat-free mass, fat mass, total body water, and total energy expenditure in 63 subjects. Results: Mathematical models developed for women with low, normal, and high prepregnancy BMI were shown to fit the original data. In 2 independent studies used for validation, model predictions of fat-free mass, fat mass, and total body water matched actual measurements within 1 kg. Conclusions: Our energy-balance model provides plausible predictions of GWG that results from changes in energy intakes. Because the model was implemented as a Web-based applet, it can be widely used by pregnant women and their health care providers. PMID:22170365

  16. DMC Based on Weighting Correction of Predictive Model Errors

    OpenAIRE

    Liu Yumin; Sun Yonghe; XU Fengming; Wang Tao

    2013-01-01

    Ordinary dynamic matrix predictive control (DMC) correct predictive value only using current error, so the correction is not enough. This paper proposes an algorithm. In error correction, it introduces predictive model error and predictive value are weighting corrected to improve the capability of resisting disturbance and regulating speed of the control system. By theoretical analysis and simulation, it has been proven that the algorithm is effective.

  17. Modeling cellular networks in fading environments with dominant specular components

    KAUST Repository

    AlAmmouri, Ahmad

    2016-07-26

    Stochastic geometry (SG) has been widely accepted as a fundamental tool for modeling and analyzing cellular networks. However, the fading models used with SG analysis are mainly confined to the simplistic Rayleigh fading, which is extended to the Nakagami-m fading in some special cases. However, neither the Rayleigh nor the Nakagami-m accounts for dominant specular components (DSCs) which may appear in realistic fading channels. In this paper, we present a tractable model for cellular networks with generalized two-ray (GTR) fading channel. The GTR fading explicitly accounts for two DSCs in addition to the diffuse components and offers high flexibility to capture diverse fading channels that appear in realistic outdoor/indoor wireless communication scenarios. It also encompasses the famous Rayleigh and Rician fading as special cases. To this end, the prominent effect of DSCs is highlighted in terms of average spectral efficiency. © 2016 IEEE.

  18. Snow water equivalent modeling components in NewAge-JGrass

    Science.gov (United States)

    Formetta, G.; Kampf, S. K.; David, O.; Rigon, R.

    2014-05-01

    This paper presents a package of modified temperature-index-based snow water equivalent models as part of the hydrological modeling system NewAge-JGrass. Three temperature-based snow models are integrated into the NewAge-JGrass modeling system and use many of its components such as those for radiation balance (short wave radiation balance, SWRB), kriging (KRIGING), automatic calibration algorithms (particle swarm optimization) and tests of goodness of fit (NewAge-V), to build suitable modeling solutions (MS). Similarly to all the NewAge-JGrass components, the models can be executed both in raster and in vector mode. The simulation time step can be daily, hourly or sub-hourly, depending on user needs and availability of input data. The MS are applied on the Cache la Poudre River basin (CO, USA) using three test applications. First, daily snow water equivalent is simulated for three different measurement stations for two snow model formulations. Second, hourly snow water equivalent is simulated using all the three different snow model formulae. Finally, a raster mode application is performed to compute snow water equivalent maps for the whole Cache la Poudre Basin.

  19. Chemical kinetic modeling of component mixtures relevant to gasoline

    Energy Technology Data Exchange (ETDEWEB)

    Mehl, M; Curran, H J; Pitz, W J; Dooley, S; Westbrook, C K

    2008-05-29

    Detailed kinetic models of pyrolysis and combustion of hydrocarbon fuels are nowadays widely used in the design of internal combustion engines and these models are effectively applied to help meet the increasingly stringent environmental and energetic standards. In previous studies by the combustion community, such models not only contributed to the understanding of pure component combustion, but also provided a deeper insight into the combustion behavior of complex mixtures. One of the major challenges in this field is now the definition and the development of appropriate surrogate models able to mimic the actual features of real fuels. Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. Their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. Aside the most commonly used surrogates containing iso-octane and n-heptane only, the so called Primary Reference Fuels (PRF), new mixtures have recently been suggested to extend the reference components in surrogate mixtures to also include alkenes and aromatics. It is generally agreed that, including representative species for all the main classes of hydrocarbons which can be found in real fuels, it is possible to reproduce very effectively in a wide range of operating conditions not just the auto-ignition propensity of gasoline or Diesel fuels, but also their physical properties and their combustion residuals [1]. In this work, the combustion behavior of several components relevant to gasoline surrogate formulation is computationally examined. The attention is focused on the autoignition of iso-octane, hexene and their mixtures. Some important issues relevant to the experimental and modeling investigation of such fuels are discussed with the help of rapid compression machine data and calculations. Following the model validation, the behavior of mixtures is discussed on the

  20. A model of the soft tissue artefact rigid component.

    Science.gov (United States)

    Camomilla, V; Bonci, T; Dumas, R; Chèze, L; Cappozzo, A

    2015-07-16

    When using stereophotogrammetry and skin-markers, the reconstruction of skeletal movement is affected by soft-tissue artefact (STA). This may be described by considering a marker-cluster as a deformable shape undergoing a geometric transformation formed by a non-rigid (change in size and shape) and a rigid component (translation and rotation displacements). A modal decomposition of the STA, relative to an appropriately identified basis, allows the separation of these components. This study proposes a mathematical model of the STA that embeds only its rigid component and estimates the relevant six mode amplitudes as linear functions of selected proximal and distal joint rotations during the analysed task. This model was successfully calibrated for thigh and shank using simultaneously recorded pin- and skin-marker data of running volunteers. The root mean square difference between measured and model-estimated STA rigid component was 1.1(0.8)mm (median (inter-quartile range) over 3 subjects × 5 trials × 33 markers coordinates), and it was mostly due to the wobbling not included in the model. Knee joint kinematics was estimated using reference pin-marker data and skin-marker data, both raw and compensated with the model-estimated STA. STA compensation decreased inaccuracy on average from 6% to 1% for flexion/extension, from 43% to 18% for the other two rotations, and from 69% to 25% for the linear displacements. Thus, the proposed mathematical model provides an STA estimate which can be effectively used within optimal bone pose and joint kinematics estimators for artefact compensation, and for simulations aimed at their comparative assessments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Cognitive components underpinning the development of model-based learning.

    Science.gov (United States)

    Potter, Tracey C S; Bryce, Nessa V; Hartley, Catherine A

    2017-06-01

    Reinforcement learning theory distinguishes "model-free" learning, which fosters reflexive repetition of previously rewarded actions, from "model-based" learning, which recruits a mental model of the environment to flexibly select goal-directed actions. Whereas model-free learning is evident across development, recruitment of model-based learning appears to increase with age. However, the cognitive processes underlying the development of model-based learning remain poorly characterized. Here, we examined whether age-related differences in cognitive processes underlying the construction and flexible recruitment of mental models predict developmental increases in model-based choice. In a cohort of participants aged 9-25, we examined whether the abilities to infer sequential regularities in the environment ("statistical learning"), maintain information in an active state ("working memory") and integrate distant concepts to solve problems ("fluid reasoning") predicted age-related improvements in model-based choice. We found that age-related improvements in statistical learning performance did not mediate the relationship between age and model-based choice. Ceiling performance on our working memory assay prevented examination of its contribution to model-based learning. However, age-related improvements in fluid reasoning statistically mediated the developmental increase in the recruitment of a model-based strategy. These findings suggest that gradual development of fluid reasoning may be a critical component process underlying the emergence of model-based learning. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Model selection for high b-value diffusion-weighted MRI of the prostate.

    Science.gov (United States)

    Mazaheri, Yousef; Hötker, Andreas M; Shukla-Dave, Amita; Akin, Oguz; Hricak, Hedvig

    2018-02-01

    To assess the abilities of the standard mono-exponential (ME), bi-exponential (BE), diffusion kurtosis (DK) and stretched exponential (SE) models to characterize diffusion signal in malignant and prostatic tissues and determine which of the four models best characterizes these tissues on a per-voxel basis. This institutional-review-board-approved, HIPAA-compliant, retrospective study included 55 patients (median age, 61years; range, 42-77years) with untreated, biopsy-proven PCa who underwent endorectal coil MRI at 3-Tesla, diffusion-weighted MRI acquired at eight b-values from 0 to 2000s/mm2. Estimated parameters were apparent diffusion coefficent (ME model); diffusion coefficients for the fast (Dfast) and slow (Dslow) components and fraction of fast component, ffast (BE model); diffusion coefficient D, and kurtosis K (DK model); distributed diffusion coefficient DDC and α for (SE model). For one region-of-interest (ROI) in PZ and another in PCa in each patient, the corrected Akaike information criterion (AICc) and the Akaike weight (w) were calculated for each voxel. Based on AICc and w, all non-monoexponential models outperformed the ME model in PZ and PCa. The DK model in PZ and SE model in PCa ROIs best fit the greatest average percentages of voxels (39% and 43%, respectively) and had the highest mean w (35±16×10-2 and 41±22×10-2, respectively). DK and SE models best fit DWI data in PZ and PCa, and non-ME models consistently outperformed the ME model. Voxel-wise mapping of the preferential model demonstrated that the vast majority of voxels in either tissue type were best fit with one of the non-monoexponential models. At the given SNR levels, the maximum b-value of 2000s/mm2 is not sufficiently high to identify the preferred non-monoexponential model. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Robustness of Component Models in Energy System Simulators

    DEFF Research Database (Denmark)

    Elmegaard, Brian

    2003-01-01

    ). Others have to do with the interaction between models of the nature of the substances in an energy system (e.g., fuels, air, flue gas), models of the components in a system (e.g., heat exchangers, turbines, pumps), and the solver for the system of equations. This paper proposes that the interaction...... or less difficult depending on the mathematical expressions creating the exceptions. The proposed idea suggests that the solvers may be helped by exception handling leading it back on the right track. The original equation of the model is substituted by an algorithm, so the original equation is only...

  4. Formal Model-Driven Engineering: Generating Data and Behavioural Components

    Directory of Open Access Journals (Sweden)

    Chen-Wei Wang

    2012-12-01

    Full Text Available Model-driven engineering is the automatic production of software artefacts from abstract models of structure and functionality. By targeting a specific class of system, it is possible to automate aspects of the development process, using model transformations and code generators that encode domain knowledge and implementation strategies. Using this approach, questions of correctness for a complex, software system may be answered through analysis of abstract models of lower complexity, under the assumption that the transformations and generators employed are themselves correct. This paper shows how formal techniques can be used to establish the correctness of model transformations used in the generation of software components from precise object models. The source language is based upon existing, formal techniques; the target language is the widely-used SQL notation for database programming. Correctness is established by giving comparable, relational semantics to both languages, and checking that the transformations are semantics-preserving.

  5. Four-component united-atom model of bitumen

    DEFF Research Database (Denmark)

    Hansen, Jesper Schmidt; Lemarchand, Claire; Nielsen, Erik

    2013-01-01

    We propose a four-component united-atom molecular model of bitumen. The model includes realistic chemical constituents and introduces a coarse graining level that suppresses the highest frequency modes. Molecular dynamics simulations of the model are carried out using graphic-processor-units based...... software in time spans in order of microseconds, which enables the study of slow relaxation processes characterizing bitumen. This paper also presents results of the model dynamics as expressed through the mean-square displacement, the stress autocorrelation function, and rotational relaxation...... the stress autocorrelation function, the shear viscosity and shear modulus are evaluated, showing a viscous response at frequencies below 100 MHz. The model predictions of viscosity and diffusivities are compared to experimental data, giving reasonable agreement. The model shows that the asphaltene, resin...

  6. Identification of Multimodel LPV Models with Asymmetric Gaussian Weighting Function

    Directory of Open Access Journals (Sweden)

    Jie You

    2013-01-01

    Full Text Available This paper is concerned with the identification of linear parameter varying (LPV systems by utilizing a multimodel structure. To improve the approximation capability of the LPV model, asymmetric Gaussian weighting functions are introduced and compared with commonly used symmetric Gaussian functions. By this mean, locations of operating points can be selected freely. It has been demonstrated through simulations with a high purity distillation column that the identified models provide more satisfactory approximation. Moreover, an experiment is performed on real HVAC (heating, ventilation, and air-conditioning to further validate the effectiveness of the proposed approach.

  7. Feedforward model based arm weight compensation with the rehabilitation robot ARMin.

    Science.gov (United States)

    Just, Fabian; Ozen, Ozhan; Tortora, Stefano; Riener, Robert; Rauter, Georg

    2017-07-01

    Highly impaired stroke patients at early stages of recovery are unable to generate enough muscle force to lift the weight of their own arm. Accordingly, task-related training is strongly limited or even impossible. However, as soon as partial or full arm weight support is provided, patients are enabled to perform arm rehabilitation training again throughout an increased workspace. In the literature, the current solutions for providing arm weight support are mostly mechanical. These systems have components that restrict the freedom of movement or entail additional disturbances. A scalable weight compensation for upper and lower arm that is online adjustable as well as generalizable to any robotic system is necessary. In this paper, a model-based feedforward weight compensation of upper and lower arm fulfilling these requirements is introduced. The proposed method is tested with the upper extremity rehabilitation robot ARMin V, but can be applied in any other actuated exoskeleton system. Experimental results were verified using EMG measurements. These results revealed that the proposed weight compensation reduces the effort of the subjects to 26% on average and more importantly throughout the entire workspace of the robot.

  8. Longitudinal functional principal component modelling via Stochastic Approximation Monte Carlo

    KAUST Repository

    Martinez, Josue G.

    2010-06-01

    The authors consider the analysis of hierarchical longitudinal functional data based upon a functional principal components approach. In contrast to standard frequentist approaches to selecting the number of principal components, the authors do model averaging using a Bayesian formulation. A relatively straightforward reversible jump Markov Chain Monte Carlo formulation has poor mixing properties and in simulated data often becomes trapped at the wrong number of principal components. In order to overcome this, the authors show how to apply Stochastic Approximation Monte Carlo (SAMC) to this problem, a method that has the potential to explore the entire space and does not become trapped in local extrema. The combination of reversible jump methods and SAMC in hierarchical longitudinal functional data is simplified by a polar coordinate representation of the principal components. The approach is easy to implement and does well in simulated data in determining the distribution of the number of principal components, and in terms of its frequentist estimation properties. Empirical applications are also presented.

  9. Mathematical and computer modeling of component surface shaping

    Science.gov (United States)

    Lyashkov, A.

    2016-04-01

    The process of shaping technical surfaces is an interaction of a tool (a shape element) and a component (a formable element or a workpiece) in their relative movements. It was established that the main objects of formation are: 1) a discriminant of a surfaces family, formed by the movement of the shape element relatively the workpiece; 2) an enveloping model of the real component surface obtained after machining, including transition curves and undercut lines; 3) The model of cut-off layers obtained in the process of shaping. When modeling shaping objects there are a lot of insufficiently solved or unsolved issues that make up a single scientific problem - a problem of qualitative shaping of the surface of the tool and then the component surface produced by this tool. The improvement of known metal-cutting tools, intensive development of systems of their computer-aided design requires further improvement of the methods of shaping the mating surfaces. In this regard, an important role is played by the study of the processes of shaping of technical surfaces with the use of the positive aspects of analytical and numerical mathematical methods and techniques associated with the use of mathematical and computer modeling. The author of the paper has posed and has solved the problem of development of mathematical, geometric and algorithmic support of computer-aided design of cutting tools based on computer simulation of the shaping process of surfaces.

  10. Components of the metabolic syndrome are negative predictors of weight loss in obese children with lifestyle intervention.

    Science.gov (United States)

    Uysal, Yvonne; Wolters, Barbara; Knop, Caroline; Reinehr, Thomas

    2014-08-01

    Insulin resistance has been proposed to be associated with weight gain in obesity. Therefore, we analyzed the impact of insulin resistance and its associated cardiovascular risk factors (CRFs) summarized in the Metabolic Syndrome (MetS) on change of weight status in obese children. We analyzed 484 obese children who had participated in a lifestyle intervention and 533 obese children without lifestyle intervention. The changes of BMI-SDS in the time period of 1-year were related to baseline fasting insulin resistance index HOMA, blood pressure, waist circumference, waist-to-height ratio, lipids, uric acid, and HbA1c. In contrast to obese children without lifestyle intervention, BMI-SDS decreased and the majority of CRFs improved significantly in obese children with lifestyle intervention. Age, BMI, waist circumference, waist-to-height ratio, blood pressure, uric acid, triglycerides, and HOMA were negatively significantly related to reduction of BMI-SDS in children with lifestyle intervention. In multiple linear regression analysis adjusted for gender, pubertal stage, and treatment center (R² = 0.26), waist circumference (r = -0.016 [confidence interval -0.019 up to -0.013], p children with lifestyle intervention. In children without lifestyle intervention, we did not find significant relationships between change of BMI-SDS and CRFs including insulin resistance in multiple regression analysis. Insulin resistance and components of the MetS were associated negatively with weight loss in lifestyle intervention. Waist circumference at baseline was the strongest negative predictor of weight loss suggesting that obese children with abdominal fat distribution need more intensive interventions. This study is registered at clinicaltrials.gov (NCT00435734). Copyright © 2013 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  11. Heartbeat Model for Component Failure in Simulation of Plant Behavior

    Energy Technology Data Exchange (ETDEWEB)

    R. W. Youngblood; R. R. Nourgaliev; D. L. Kelly; C. L. Smith; T-N. Dinh

    2011-03-01

    As part of the Department of Energy’s “Light Water Reactor Sustainability Program” (LWRSP), tools and methodology for risk-informed characterization of safety margin are being developed for use in supporting decision-making on plant life extension after the first license renewal. Beginning with the traditional discussion of “margin” in terms of a “load” (a physical challenge to system or component function) and a “capacity” (the capability of that system or component to accommodate the challenge), we are developing the capability to characterize realistic probabilistic load and capacity spectra, reflecting both aleatory and epistemic uncertainty in system behavior. This way of thinking about margin comports with work done in the last 10 years. However, current capabilities to model in this way are limited: it is currently possible, but difficult, to validly simulate enough time histories to support quantification in realistic problems, and the treatment of environmental influences on reliability is relatively artificial in many existing applications. The INL is working on a next-generation safety analysis capability (widely referred to as “R7”) that will enable a much better integration of reliability-related and phenomenology-related aspects of margin. In this paper, we show how to implement cumulative damage (“heartbeat”) models for component reliability that lend themselves naturally to being included as part of the phenomenology simulation. Implementation of this modeling approach relies on the way in which the phenomenology simulation implements its dynamic time step management. Within this approach, component failures influence the phenomenology, and the phenomenology influences the component failures.

  12. Orbital component extraction by time-variant sinusoidal modeling.

    Science.gov (United States)

    Sinnesael, Matthias; Zivanovic, Miroslav; De Vleeschouwer, David; Claeys, Philippe; Schoukens, Johan

    2016-04-01

    Accurately deciphering periodic variations in paleoclimate proxy signals is essential for cyclostratigraphy. Classical spectral analysis often relies on methods based on the (Fast) Fourier Transformation. This technique has no unique solution separating variations in amplitude and frequency. This characteristic makes it difficult to correctly interpret a proxy's power spectrum or to accurately evaluate simultaneous changes in amplitude and frequency in evolutionary analyses. Here, we circumvent this drawback by using a polynomial approach to estimate instantaneous amplitude and frequency in orbital components. This approach has been proven useful to characterize audio signals (music and speech), which are non-stationary in nature (Zivanovic and Schoukens, 2010, 2012). Paleoclimate proxy signals and audio signals have in nature similar dynamics; the only difference is the frequency relationship between the different components. A harmonic frequency relationship exists in audio signals, whereas this relation is non-harmonic in paleoclimate signals. However, the latter difference is irrelevant for the problem at hand. Using a sliding window approach, the model captures time variations of an orbital component by modulating a stationary sinusoid centered at its mean frequency, with a single polynomial. Hence, the parameters that determine the model are the mean frequency of the orbital component and the polynomial coefficients. The first parameter depends on geologic interpretation, whereas the latter are estimated by means of linear least-squares. As an output, the model provides the orbital component waveform, either in the depth or time domain. Furthermore, it allows for a unique decomposition of the signal into its instantaneous amplitude and frequency. Frequency modulation patterns can be used to reconstruct changes in accumulation rate, whereas amplitude modulation can be used to reconstruct e.g. eccentricity-modulated precession. The time-variant sinusoidal model

  13. LFLM (Local Fitting of Linear Models / Locally weighted Fitting of Linear Models)

    DEFF Research Database (Denmark)

    1997-01-01

    LFLM (Local Fitting of Linear Models / Locally weighted Fitting of Linear Models) is an S-PLUS / R library for estimation in conditional parametric models. This class of models can briefly be described as linear models in which the parameters are replaced by smooth functions....

  14. Sparse Principal Component Analysis in Medical Shape Modeling

    DEFF Research Database (Denmark)

    Sjöstrand, Karl; Stegmann, Mikkel Bille; Larsen, Rasmus

    2006-01-01

    Principal component analysis (PCA) is a widely used tool in medical image analysis for data reduction, model building, and data understanding and exploration. While PCA is a holistic approach where each new variable is a linear combination of all original variables, sparse PCA (SPCA) aims...... at producing easily interpreted models through sparse loadings, i.e. each new variable is a linear combination of a subset of the original variables. One of the aims of using SPCA is the possible separation of the results into isolated and easily identifiable effects. This article introduces SPCA for shape...

  15. Modelling raster-based monthly water balance components for Europe

    Energy Technology Data Exchange (ETDEWEB)

    Ulmen, C.

    2000-11-01

    The terrestrial runoff component is a comparatively small but sensitive and thus significant quantity in the global energy and water cycle at the interface between landmass and atmosphere. As opposed to soil moisture and evapotranspiration which critically determine water vapour fluxes and thus water and energy transport, it can be measured as an integrated quantity over a large area, i.e. the river basin. This peculiarity makes terrestrial runoff ideally suited for the calibration, verification and validation of general circulation models (GCMs). Gauging stations are not homogeneously distributed in space. Moreover, time series are not necessarily continuously measured nor do they in general have overlapping time periods. To overcome this problems with regard to regular grid spacing used in GCMs, different methods can be applied to transform irregular data to regular so called gridded runoff fields. The present work aims to directly compute the gridded components of the monthly water balance (including gridded runoff fields) for Europe by application of the well-established raster-based macro-scale water balance model WABIMON used at the Federal Institute of Hydrology, Germany. Model calibration and validation is performed by separated examination of 29 representative European catchments. Results indicate a general applicability of the model delivering reliable overall patterns and integrated quantities on a monthly basis. For time steps less then too weeks further research and structural improvements of the model are suggested. (orig.)

  16. Comparative study of five growth models applied to weight data from congolese infants between birth and 13 months of age.

    Science.gov (United States)

    Simondon, Kirsten B; Simondon, Francois; Delpeuch, Francis; Cornu, Andre

    1992-01-01

    Five growth models are compared using weight data from 95 rural Congolese infants between birth and 13 months of age. The objective is to find the best model in terms of goodness of fit and distribution of parameter estimates. The Infancy component of the Karlberg model, the Count model, and the Kouchi model, which are all three-parameter models, are tested together with the four- and five-parameter versions of the Reed model. The closest fits are obtained using the Reed models, followed by the Karlberg model, while the Count and Kouchi models provide poor fits. The five-parameter Reed model is not superior to the four-parameter version. Examination of mean residuals by age shows a systematic bias in neonatal weight estimation with the three-parameter models. Mean within- and between-individual correlations are especially high for the Kouchi and Reed models. Extreme skewness is observed for some parameters of the Kouchi model and of the five-parameter Reed model. Despite its high degree of collinearity, the four-parameter linear Reed model should be preferred on weight data between birth and 1 year. The I-component of the Karlberg model could be used between ages 2 and 12 months. © 1992 Wiley-Liss, Inc. Copyright © 1992 Wiley-Liss, Inc., A Wiley Company.

  17. Two-component mixture cure rate model with spline estimated nonparametric components.

    Science.gov (United States)

    Wang, Lu; Du, Pang; Liang, Hua

    2012-09-01

    In some survival analysis of medical studies, there are often long-term survivors who can be considered as permanently cured. The goals in these studies are to estimate the noncured probability of the whole population and the hazard rate of the susceptible subpopulation. When covariates are present as often happens in practice, to understand covariate effects on the noncured probability and hazard rate is of equal importance. The existing methods are limited to parametric and semiparametric models. We propose a two-component mixture cure rate model with nonparametric forms for both the cure probability and the hazard rate function. Identifiability of the model is guaranteed by an additive assumption that allows no time-covariate interactions in the logarithm of hazard rate. Estimation is carried out by an expectation-maximization algorithm on maximizing a penalized likelihood. For inferential purpose, we apply the Louis formula to obtain point-wise confidence intervals for noncured probability and hazard rate. Asymptotic convergence rates of our function estimates are established. We then evaluate the proposed method by extensive simulations. We analyze the survival data from a melanoma study and find interesting patterns for this study. © 2011, The International Biometric Society.

  18. Geographically Weighted Logistic Regression Applied to Credit Scoring Models

    Directory of Open Access Journals (Sweden)

    Pedro Henrique Melo Albuquerque

    Full Text Available Abstract This study used real data from a Brazilian financial institution on transactions involving Consumer Direct Credit (CDC, granted to clients residing in the Distrito Federal (DF, to construct credit scoring models via Logistic Regression and Geographically Weighted Logistic Regression (GWLR techniques. The aims were: to verify whether the factors that influence credit risk differ according to the borrower’s geographic location; to compare the set of models estimated via GWLR with the global model estimated via Logistic Regression, in terms of predictive power and financial losses for the institution; and to verify the viability of using the GWLR technique to develop credit scoring models. The metrics used to compare the models developed via the two techniques were the AICc informational criterion, the accuracy of the models, the percentage of false positives, the sum of the value of false positive debt, and the expected monetary value of portfolio default compared with the monetary value of defaults observed. The models estimated for each region in the DF were distinct in their variables and coefficients (parameters, with it being concluded that credit risk was influenced differently in each region in the study. The Logistic Regression and GWLR methodologies presented very close results, in terms of predictive power and financial losses for the institution, and the study demonstrated viability in using the GWLR technique to develop credit scoring models for the target population in the study.

  19. The Situation Awareness Weighted Network (SAWN) model and method: Theory and application.

    Science.gov (United States)

    Kalloniatis, Alexander; Ali, Irena; Neville, Timothy; La, Phuong; Macleod, Iain; Zuparic, Mathew; Kohn, Elizabeth

    2017-05-01

    We introduce a novel model and associated data collection method to examine how a distributed organisation of military staff who feed a Common Operating Picture (COP) generates Situation Awareness (SA), a critical component in organisational performance. The proposed empirically derived Situation Awareness Weighted Network (SAWN) model draws on two scientific models of SA, by Endsley involving perception, comprehension and projection, and by Stanton et al. positing that SA exists across a social and semantic network of people and information objects in activities connected across a set of tasks. The output of SAWN is a representation as a weighted semi-bipartite network of the interaction between people ('human nodes') and information artefacts such as documents and system displays ('product nodes'); link weights represent the Endsley levels of SA that individuals acquire from or provide to information objects and other individuals. The SAWN method is illustrated with aggregated empirical data from a case study of Australian military staff undertaking their work during two very different scenarios, during steady-state operations and in a crisis threat context. A key outcome of analysis of the weighted networks is that we are able to quantify flow of SA through an organisation as staff seek to "value-add" in the conduct of their work. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  20. Estimação de componentes de co-variância para pesos corporais do nascimento aos 365 dias de idade de bovinos Guzerá empregando-se modelos de regressão aleatória Estimates of covariance components for body weights from birth to 365 days of age in Guzera cattle, using random regression models

    Directory of Open Access Journals (Sweden)

    Luciele Cristina Pelicioni

    2009-01-01

    permanent environmental effects, using random regression models. The random effects included were modeled by regression on Legendre Polynomials with orders ranging from linear to quartic. The models were compared through the likelihood ratio test, Akaike's information criterion and the Schwarz's Bayesian information criterion. The model with 18 heterogeneous classes was the one that best fitted the residual variances, according to the statistical tests; however, the model with variance function of 5th order also showed to be appropriate. The direct heritability estimates were higher than those found in literature, ranging from 0.04 to 0.53, showing similar trends when compared to those estimated using univariate models. Selection on body weight in any age should improve the body weight in all ages in the studied interval.

  1. A Quaternion Weighted Fourier Linear Combiner for Modeling Physiological Tremor.

    Science.gov (United States)

    Adhikari, Kabita; Tatinati, Sivanagaraja; Ang, Wei Tech; Veluvolu, Kalyana C; Nazarpour, Kianoush

    2016-11-01

    This paper offers a new approach to model physiological tremor aiming at attenuating undesired vibrations of the tip of microsurgical instruments. Several tremor modeling algorithms, such as the weighted Fourier linear combiner (wFLC), have proved effective. They, however, treat the three-dimensional (3-D) tremor signal as three independent 1-D signals in the x-, y-, and z-axes. In addition, the force f by which a surgeon holds the instrument has never been taken into account in modeling. Hence, conventional algorithms are inherently blind to any potential multidimensional couplings. We first show that there exists statistically significant subject- and task-dependent coherence between data in the x-, y-, z -, and f-axes. We hypothesize that a filter that models the tremor in 4-D ( x , y, z, and f ) yields a more accurate model of tremor. We, therefore, developed a quaternion version of the wFLC algorithm and termed it QwFLC. We tested the proposed QwFLC algorithm with real physiological tremor data that were recorded from five novice subjects and four experienced microsurgeons. Although compared to wFLC, QwFLC requires six times larger computational resources, we showed that QwFLC can improve the modeling by up to 67% and that the improvement is proportional to the total coherence between the tremor in xyz and the force signal. By taking into account interactions of the 3-D tremor and the force data, the tremor modeling performance enhances significantly.

  2. Searching for functional gene modules with interaction component models

    Directory of Open Access Journals (Sweden)

    Kaski Samuel

    2010-01-01

    Full Text Available Abstract Background Functional gene modules and protein complexes are being sought from combinations of gene expression and protein-protein interaction data with various clustering-type methods. Central features missing from most of these methods are handling of uncertainty in both protein interaction and gene expression measurements, and in particular capability of modeling overlapping clusters. It would make sense to assume that proteins may play different roles in different functional modules, and the roles are evidenced in their interactions. Results We formulate a generative probabilistic model for protein-protein interaction links and introduce two ways for including gene expression data into the model. The model finds interaction components, which can be interpreted as overlapping clusters or functional modules. We demonstrate the performance on two data sets of yeast Saccharomyces cerevisiae. Our methods outperform a representative set of earlier models in the task of finding biologically relevant modules having enriched functional classes. Conclusions Combining protein interaction and gene expression data with a probabilistic generative model improves discovery of modules compared to approaches based on either data source alone. With a fairly simple model we can find biologically relevant modules better than with alternative methods, and in addition the modules may be inherently overlapping in the sense that different interactions may belong to different modules.

  3. Independent component model for cognitive functions of multiple subjects using [15O]H2O PET images.

    Science.gov (United States)

    Park, Hae-Jeong; Kim, Jae-Jin; Youn, Tak; Lee, Dong Soo; Lee, Myung Chul; Kwon, Jun Soo

    2003-04-01

    An independent component model of multiple subjects' positron emission tomography (PET) images is proposed to explore the overall functional components involved in a task and to explain subject specific variations of metabolic activities under altered experimental conditions utilizing the Independent component analysis (ICA) concept. As PET images represent time-compressed activities of several cognitive components, we derived a mathematical model to decompose functional components from cross-sectional images based on two fundamental hypotheses: (1) all subjects share basic functional components that are common to subjects and spatially independent of each other in relation to the given experimental task, and (2) all subjects share common functional components throughout tasks which are also spatially independent. The variations of hemodynamic activities according to subjects or tasks can be explained by the variations in the usage weight of the functional components. We investigated the plausibility of the model using serial cognitive experiments of simple object perception, object recognition, two-back working memory, and divided attention of a syntactic process. We found that the independent component model satisfactorily explained the functional components involved in the task and discuss here the application of ICA in multiple subjects' PET images to explore the functional association of brain activations. Copyright 2003 Wiley-Liss, Inc.

  4. Geographical Weighted Regression Model for Poverty Analysis in Jambi Province

    Directory of Open Access Journals (Sweden)

    Inti Pertiwi Nashwari

    2017-07-01

    Full Text Available Agriculture sector has an important contribution to food security in Indonesia, but it also huge contribution to the number of poverty, especially in rural area. Studies using a global model might not be sufficient to pinpoint the factors having most impact on poverty due to spatial differences. Therefore, a Geographically Weighted Regression (GWR was used to analyze the factors influencing the poverty among food crops famers. Jambi Province is selected because have high number of poverty in rural area and the lowest farmer exchange term in Indonesia. The GWR was better than the global model, based on high value of R2, lowers AIC and MSE and Leung test. Location in upland area and road system had more influence to the poverty in the western-southern. Rainfall was significantly influence in eastern. The effect of each factor, however, was not generic, since the parameter estimate might have a positive or negative value.

  5. The Generalized Trajectory Simulation System. Volume 5. Weight Estimation Models for Sizing Applications

    Science.gov (United States)

    1975-11-21

    component. WINX WINX (WIN - WIN) (16) Expended (thrust producing) internal insulation weight component. X IN T KWINX’I WINX Expended (non-thrust producing...computation; N.D. I KWINNX KWINNx Coefficient for WINNX computation; N.D.1 KWINX KWINX Coefficient for WINX computation; N.D. 1 KWINXT K Coefficient for...weight exi.,,nent; lb Eq. 15 %rIlR WIN Weight of residual internal insulation;- lb Eq. 13 WINX WIN Total expended internal insulation weight X component

  6. Characterizing fundamental frequency in Mandarin: a functional principal component approach utilizing mixed effect models.

    Science.gov (United States)

    Hadjipantelis, Pantelis Z; Aston, John A D; Evans, Jonathan P

    2012-06-01

    A model for fundamental frequency (F0, or commonly pitch) employing a functional principal component (FPC) analysis framework is presented. The model is applied to Mandarin Chinese; this Sino-Tibetan language is rich in pitch-related information as the relative pitch curve is specified for most syllables in the lexicon. The approach yields a quantification of the influence carried by each identified component in relation to original tonal content, without formulating any assumptions on the shape of the tonal components. The original five speaker corpus is preprocessed using a locally weighted least squares smoother to produce F0 curves. These smoothed curves are then utilized as input for the computation of FPC scores and their corresponding eigenfunctions. These scores are analyzed in a series of penalized mixed effect models, through which meaningful categorical prototypes are built. The prototypes appear to confirm known tonal characteristics of the language, as well as suggest the presence of a sinusoid tonal component that is previously undocumented.

  7. Modelling safety of multistate systems with ageing components

    Science.gov (United States)

    Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna

    2016-06-01

    An innovative approach to safety analysis of multistate ageing systems is presented. Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics of the consecutive "m out of n: F" is presented as well.

  8. Improving Stiffness-to-weight Ratio of Spot-welded Structures based upon Nonlinear Finite Element Modelling

    Science.gov (United States)

    Zhang, Shengyong

    2017-07-01

    Spot welding has been widely used for vehicle body construction due to its advantages of high speed and adaptability for automation. An effort to increase the stiffness-to-weight ratio of spot-welded structures is investigated based upon nonlinear finite element analysis. Topology optimization is conducted for reducing weight in the overlapping regions by choosing an appropriate topology. Three spot-welded models (lap, doubt-hat and T-shape) that approximate “typical” vehicle body components are studied for validating and illustrating the proposed method. It is concluded that removing underutilized material from overlapping regions can result in a significant increase in structural stiffness-to-weight ratio.

  9. A multi-component evaporation model for beam melting processes

    Science.gov (United States)

    Klassen, Alexander; Forster, Vera E.; Körner, Carolin

    2017-02-01

    In additive manufacturing using laser or electron beam melting technologies, evaporation losses and changes in chemical composition are known issues when processing alloys with volatile elements. In this paper, a recently described numerical model based on a two-dimensional free surface lattice Boltzmann method is further developed to incorporate the effects of multi-component evaporation. The model takes into account the local melt pool composition during heating and fusion of metal powder. For validation, the titanium alloy Ti-6Al-4V is melted by selective electron beam melting and analysed using mass loss measurements and high-resolution microprobe imaging. Numerically determined evaporation losses and spatial distributions of aluminium compare well with experimental data. Predictions of the melt pool formation in bulk samples provide insight into the competition between the loss of volatile alloying elements from the irradiated surface and their advective redistribution within the molten region.

  10. Reference Models for Structural Technology Assessment and Weight Estimation

    Science.gov (United States)

    Cerro, Jeff; Martinovic, Zoran; Eldred, Lloyd

    2005-01-01

    Previously the Exploration Concepts Branch of NASA Langley Research Center has developed techniques for automating the preliminary design level of launch vehicle airframe structural analysis for purposes of enhancing historical regression based mass estimating relationships. This past work was useful and greatly reduced design time, however its application area was very narrow in terms of being able to handle a large variety in structural and vehicle general arrangement alternatives. Implementation of the analysis approach presented herein also incorporates some newly developed computer programs. Loft is a program developed to create analysis meshes and simultaneously define structural element design regions. A simple component defining ASCII file is read by Loft to begin the design process. HSLoad is a Visual Basic implementation of the HyperSizer Application Programming Interface, which automates the structural element design process. Details of these two programs and their use are explained in this paper. A feature which falls naturally out of the above analysis paradigm is the concept of "reference models". The flexibility of the FEA based JAVA processing procedures and associated process control classes coupled with the general utility of Loft and HSLoad make it possible to create generic program template files for analysis of components ranging from something as simple as a stiffened flat panel, to curved panels, fuselage and cryogenic tank components, flight control surfaces, wings, through full air and space vehicle general arrangements.

  11. A novel multilayer MV imager computational model for component optimization.

    Science.gov (United States)

    Myronakis, Marios; Star-Lack, Josh; Baturin, Paul; Rottmann, Joerg; Morf, Daniel; Wang, Adam; Hu, Yue-Houng; Shedlock, Daniel; Berbeco, Ross I

    2017-08-01

    A novel Megavoltage (MV) multilayer imager (MLI) design featuring higher detective quantum efficiency and lower noise than current conventional MV imagers in clinical use has been recently reported. Optimization of the MLI design for multiple applications including tumor tracking, MV-CBCT and portal dosimetry requires a computational model that will provide insight into the physics processes that affect the overall and individual components' performance. The purpose of the current work was to develop and validate a comprehensive computational model that can be used for MLI optimization. The MLI model was built using the Geant4 Application for Tomographic Emission (GATE) application. The model includes x-ray and charged-particle interactions as well as the optical transfer within the phosphor. A first prototype MLI device featuring a stack of four detection layers was used for model validation. Each layer of the prototype contains a copper buildup plate, a phosphor screen and photodiode array. The model was validated against measured data of Modulation Transfer Function (MTF), Noise-Power Spectrum (NPS), and Detective Quantum Efficiency (DQE). MTF was computed using a slanted slit with 2.3(°) angle and 0.1 mm width. NPS was obtained using the autocorrelation function technique. DQE was calculated from MTF and NPS data. The comparison metrics between simulated and measured data were the Pearson's correlation coefficient (r) and the normalized root-mean-square error (NRMSE). Good agreement between measured and simulated MTF and NPS values was observed. Pearson's correlation coefficient for the combined signal from all layers of the MLI was equal to 0.9991 for MTF and 0.9992 for NPS; NRMSE was 0.0121 for MTF and 0.0194 for NPS. Similarly, the DQE correlation coefficient for the combined signal was 0.9888 and the NRMSE was 0.0686. A comprehensive model of the novel MLI design was developed using the GATE toolkit and validated against measured MTF, NPS, and DQE data

  12. Spatial modelling of population concentration using geographically weighted regression method

    Directory of Open Access Journals (Sweden)

    Bajat Branislav

    2011-01-01

    Full Text Available This paper presents possibilities of applying the geographically weighted regression method in mapping population change index. During the last decade, this contemporary spatial modeling method has been increasingly used in geographical analyses. On the example of the researched region of Timočka Krajina (defined for the needs of elaborating the Regional Spatial Plan, the possibilities for applying this method in disaggregation of traditional models of population density, which are created using the choropleth maps at the level of statistical spatial units, are shown. The applied method is based on the use of ancillary spatial predictors which are in correlation with a targeted variable, the population change index. For this purpose, spatial databases have been used such as digital terrain model, distances from the network of I and II category state roads, as well as soil sealing databases. Spatial model has been developed in the GIS software environment using commercial GIS applications, as well as open source GIS software. Population change indexes for the period 1961-2002 have been mapped based on population census data, while the data on planned population forecast have been used for the period 2002-2027.

  13. Hybrid Model Predictive Control for Optimizing Gestational Weight Gain Behavioral Interventions.

    Science.gov (United States)

    Dong, Yuwen; Rivera, Daniel E; Downs, Danielle S; Savage, Jennifer S; Thomas, Diana M; Collins, Linda M

    2013-01-01

    Excessive gestational weight gain (GWG) represents a major public health issue. In this paper, we pursue a control engineering approach to the problem by applying model predictive control (MPC) algorithms to act as decision policies in the intervention for assigning optimal intervention dosages. The intervention components consist of education, behavioral modification and active learning. The categorical nature of the intervention dosage assignment problem dictates the need for hybrid model predictive control (HMPC) schemes, ultimately leading to improved outcomes. The goal is to design a controller that generates an intervention dosage sequence which improves a participant's healthy eating behavior and physical activity to better control GWG. An improved formulation of self-regulation is also presented through the use of Internal Model Control (IMC), allowing greater flexibility in describing self-regulatory behavior. Simulation results illustrate the basic workings of the model and demonstrate the benefits of hybrid predictive control for optimized GWG adaptive interventions.

  14. Understanding science teacher enhancement programs: Essential components and a model

    Science.gov (United States)

    Spiegel, Samuel Albert

    Researchers and practioners alike recognize that "the national goal that every child in the United States has access to high-quality school education in science and mathematics cannot be realized without the availability of effective professional development of teachers" (Hewson, 1997, p. 16). Further, there is a plethora of reports calling for the improvement of professional development efforts (Guskey & Huberman, 1995; Kyle, 1995; Loucks-Horsley, Hewson, Love, & Stiles, 1997). In this study I analyze a successful 3-year teacher enhancement program, one form of professional development, to: (1) identify essential components of an effective teacher enhancement program; and (2) create a model to identify and articulate the critical issues in designing, implementing, and evaluating teacher enhancement programs. Five primary sources of information were converted into data: (1) exit questionnaires, (2) exit surveys, (3) exit interview transcripts, (4) focus group transcripts, and (5) other artifacts. Additionally, a focus group was used to conduct member checks. Data were analyzed in an iterative process which led to the development of the list of essential components. The Components are categorized by three organizers: Structure (e.g., science research experience, a mediator throughout the program), Context (e.g., intensity, collaboration), and Participant Interpretation (e.g., perceived to be "safe" to examine personal beliefs and practices, actively engaged). The model is based on: (1) a 4-year study of a successful teacher enhancement program; (2) an analysis of professional development efforts reported in the literature; and (3) reflective discussions with implementors, evaluators, and participants of professional development programs. The model consists of three perspectives, cognitive, symbolic interaction, and organizational, representing different viewpoints from which to consider issues relevant to the success of a teacher enhancement program. These

  15. Analysis of Groundwater Nitrate Contamination in the Central Valley: Comparison of the Geodetector Method, Principal Component Analysis and Geographically Weighted Regression

    Directory of Open Access Journals (Sweden)

    Anil Shrestha

    2017-09-01

    Full Text Available Groundwater nitrate contamination in the Central Valley (CV aquifer of California is a ubiquitous groundwater problem found in various parts of the valley. Heavy irrigation and application of fertilizer over the last several decades have caused groundwater nitrate contamination in several domestic, public and monitoring wells in the CV above EPA’s Maximum Contamination level of 10 mg/L. Source variables, aquifer susceptibility and geochemical variables could affect the contamination rate and groundwater quality in the aquifer. A comparative study was conducted using Geodetector (GED, Principal Component Analysis (PCA and Geographically Weighted Regression (GWR to observe which method is most effective at revealing environmental variables that control groundwater nitrate concentration. The GED method detected precipitation, fertilizer, elevation, manure and clay as statistically significant variables. Watersheds with percent of wells above 5 mg/L of nitrate were higher in San Joaquin and Tulare Basin compared to Sacramento Valley. PCA grouped cropland, fertilizer, manure and precipitation as a first principal component, suggesting similar construct of these variables and existence of data redundancy. The GWR model performed better than the OLS model, with lower corrected Akaike Information Criterion (AIC values, and captured the spatial heterogeneity of fertilizer, precipitation and elevation for the percent of wells above 5 mg/L in the CV. Overall, the GED method was more effective than the PCA and GWR methods in determining the influence of explanatory variables on groundwater nitrate contamination.

  16. Blood components and OCT reflectivity evaluated in animal model.

    Science.gov (United States)

    Sonoda, Shozo; Sakamoto, Taiji; Shirasawa, Makoto; Yamashita, Takehiro; Uchino, Eisuke; Terasaki, Hiroto

    2014-12-01

    To see the relationship between blood components and optical coherence tomography (OCT) reflectivity using an animal model in which the aqueous humor was substituted by different experimental solutions without changing the integrity of the retina. The aqueous humor of an enucleated swine eye was replaced with plasma obtained from healthy volunteers. The OCT reflectivity of the anterior chamber filled with each plasma was calculated from individual OCT images, and was expressed by an arbitrary unit (AU). The concentration of blood components such as cholesterol, hemoglobin (Hb) and bilirubin of each individual was measured, and the correlation between each of them and the OCT reflectivity of aqueous humor in an enucleated swine eye was analyzed. Using the same model, the effects of the single plasma component on OCT reflectivity were examined. Blood samples were obtained from 24 individuals. OCT reflectivity was 30.68 ± 14.8 AU (average ± SD), ranging from 11.11 to 60.31 AU. OCT reflectivity correlated significantly with the concentration of triglycerides (R = 0.634, p = 0.001) and total cholesterol (R = 0.488, p = 0.015) using Spearman's rank correlation coefficient. While a partial correlation analysis showed that it correlated significantly with triglyceride (R = 0.60, p = 0.003), but not total cholesterol. OCT reflectivity was highest in a balanced salt solution (BSS) with Hb (average 42.05 AU), followed by fibrinogen (8.08 AU), bilirubin (6.12 AU) and γ-globulin (2.85 AU). Albumin did not increase the reflectivity of the BSS with a normal concentration (1.11 AU) compared to the control BSS alone (0.73 AU). OCT reflectivity was most strongly affected by the presence of triglycerides among the blood components. Some molecules such as Hb and fibrinogen significantly increase the OCT reflectivity. This information should be helpful for interpreting the OCT findings correctly.

  17. A weight restricted DEA model for FMEA risk prioritization

    Directory of Open Access Journals (Sweden)

    Pauli Adriano de Almada Garcia

    2012-01-01

    Full Text Available In this paper we present a linear programming (LP approach to risk prioritization in failure mode and effects analysis (FMEA. The LP is a data envelopment analysis (DEA-based model considering weight restriction. In a FMEA, we commonly consider three criteria to prioritize the failure modes, occurrence, severity and detectability. These criteria are in an ordinal scale commonly varying from 1 to 10, higher the figure worse the result. Considering the values established for each criteria, in traditional FMEA one adopts a Risk Priority Number, calculated considering the product of criteria, which has been very criticized due to its shortcoming. Through the proposed approach a frontier is established considering the less critical failure modes. Considering this frontier, one can establish how much each failure mode must be improved to become relatively acceptable. A simplified case concerning an AFWS of a two loops PWR power plant is presented to shows the applicability of the proposed approach.

  18. Modeling Organic Contaminant Desorption from Municipal Solid Waste Components

    Science.gov (United States)

    Knappe, D. R.; Wu, B.; Barlaz, M. A.

    2002-12-01

    Approximately 25% of the sites on the National Priority List (NPL) of Superfund are municipal landfills that accepted hazardous waste. Unlined landfills typically result in groundwater contamination, and priority pollutants such as alkylbenzenes are often present. To select cost-effective risk management alternatives, better information on factors controlling the fate of hydrophobic organic contaminants (HOCs) in landfills is required. The objectives of this study were (1) to investigate the effects of HOC aging time, anaerobic sorbent decomposition, and leachate composition on HOC desorption rates, and (2) to simulate HOC desorption rates from polymers and biopolymer composites with suitable diffusion models. Experiments were conducted with individual components of municipal solid waste (MSW) including polyvinyl chloride (PVC), high-density polyethylene (HDPE), newsprint, office paper, and model food and yard waste (rabbit food). Each of the biopolymer composites (office paper, newsprint, rabbit food) was tested in both fresh and anaerobically decomposed form. To determine the effects of aging on alkylbenzene desorption rates, batch desorption tests were performed after sorbents were exposed to toluene for 30 and 250 days in flame-sealed ampules. Desorption tests showed that alkylbenzene desorption rates varied greatly among MSW components (PVC slowest, fresh rabbit food and newsprint fastest). Furthermore, desorption rates decreased as aging time increased. A single-parameter polymer diffusion model successfully described PVC and HDPE desorption data, but it failed to simulate desorption rate data for biopolymer composites. For biopolymer composites, a three-parameter biphasic polymer diffusion model was employed, which successfully simulated both the initial rapid and the subsequent slow desorption of toluene. Toluene desorption rates from MSW mixtures were predicted for typical MSW compositions in the years 1960 and 1997. For the older MSW mixture, which had a

  19. Language Model Combination and Adaptation Using Weighted Finite State Transducers

    Science.gov (United States)

    Liu, X.; Gales, M. J. F.; Hieronymus, J. L.; Woodland, P. C.

    2010-01-01

    In speech recognition systems language model (LMs) are often constructed by training and combining multiple n-gram models. They can be either used to represent different genres or tasks found in diverse text sources, or capture stochastic properties of different linguistic symbol sequences, for example, syllables and words. Unsupervised LM adaption may also be used to further improve robustness to varying styles or tasks. When using these techniques, extensive software changes are often required. In this paper an alternative and more general approach based on weighted finite state transducers (WFSTs) is investigated for LM combination and adaptation. As it is entirely based on well-defined WFST operations, minimum change to decoding tools is needed. A wide range of LM combination configurations can be flexibly supported. An efficient on-the-fly WFST decoding algorithm is also proposed. Significant error rate gains of 7.3% relative were obtained on a state-of-the-art broadcast audio recognition task using a history dependently adapted multi-level LM modelling both syllable and word sequences

  20. Impact of body composition during weight change on resting energy expenditure and homeostasis model assessment index in overweight nonsmoking adults.

    Science.gov (United States)

    Pourhassan, Maryam; Bosy-Westphal, Anja; Schautz, Britta; Braun, Wiebke; Glüer, Claus-C; Müller, Manfred J

    2014-04-01

    Weight change affects resting energy expenditure (REE) and metabolic risk factors. The impact of changes in individual body components on metabolism is unclear. We investigated changes in detailed body composition to assess their impacts on REE and insulin resistance. Eighty-three healthy subjects [body mass index (BMI; in kg/m²) range: 20.2-46.8; 50% obese] were investigated at 2 occasions with weight changes between -11.2 and +6.5 kg (follow-up periods between 23.5 and 43.5 mo). Detailed body composition was measured by using the 4-component model and whole-body magnetic resonance imaging. REE, plasma thyroid hormone concentrations, and insulin resistance were measured by using standard methods. Weight loss was associated with decreases in fat mass (FM) and fat-free mass (FFM) by 72.0% and 28.0%, respectively. A total of 87.9% of weight gain was attributed to FM. With weight loss, sizes of skeletal muscle, kidneys, heart, and all fat depots decreased. With weight gain, skeletal muscle, liver, kidney masses, and several adipose tissue depots increased except for visceral adipose tissue (VAT). After adjustments for FM and FFM, REE decreased with weight loss (by 0.22 MJ/d) and increased with weight gain (by 0.11 MJ/d). In a multiple stepwise regression analysis, changes in skeletal muscle, plasma triiodothyronine, and kidney masses explained 34.9%, 5.3%, and 4.5%, respectively, of the variance in changes in REE. A reduction in subcutaneous adipose tissue rather than VAT was associated with the improvement of insulin sensitivity with weight loss. Weight gain had no effect on insulin resistance. Beyond a 2-compartment model, detailed changes in organ and tissue masses further add to explain changes in REE and insulin resistance.

  1. On the brain structure heterogeneity of autism: Parsing out acquisition site effects with significance‐weighted principal component analysis

    Science.gov (United States)

    Martinez‐Murcia, Francisco Jesús; Lai, Meng‐Chuan; Ramírez, Javier; Young, Adam M. H.; Deoni, Sean C. L.; Ecker, Christine; Lombardo, Michael V.; Baron‐Cohen, Simon; Murphy, Declan G. M.; Bullmore, Edward T.; Suckling, John

    2016-01-01

    Abstract Neuroimaging studies have reported structural and physiological differences that could help understand the causes and development of Autism Spectrum Disorder (ASD). Many of them rely on multisite designs, with the recruitment of larger samples increasing statistical power. However, recent large‐scale studies have put some findings into question, considering the results to be strongly dependent on the database used, and demonstrating the substantial heterogeneity within this clinically defined category. One major source of variance may be the acquisition of the data in multiple centres. In this work we analysed the differences found in the multisite, multi‐modal neuroimaging database from the UK Medical Research Council Autism Imaging Multicentre Study (MRC AIMS) in terms of both diagnosis and acquisition sites. Since the dissimilarities between sites were higher than between diagnostic groups, we developed a technique called Significance Weighted Principal Component Analysis (SWPCA) to reduce the undesired intensity variance due to acquisition site and to increase the statistical power in detecting group differences. After eliminating site‐related variance, statistically significant group differences were found, including Broca's area and the temporo‐parietal junction. However, discriminative power was not sufficient to classify diagnostic groups, yielding accuracies results close to random. Our work supports recent claims that ASD is a highly heterogeneous condition that is difficult to globally characterize by neuroimaging, and therefore different (and more homogenous) subgroups should be defined to obtain a deeper understanding of ASD. Hum Brain Mapp 38:1208–1223, 2017. © 2016 Wiley Periodicals, Inc. PMID:27774713

  2. A Batch-Incremental Video Background Estimation Model using Weighted Low-Rank Approximation of Matrices

    KAUST Repository

    Dutta, Aritra

    2017-07-02

    Principal component pursuit (PCP) is a state-of-the-art approach for background estimation problems. Due to their higher computational cost, PCP algorithms, such as robust principal component analysis (RPCA) and its variants, are not feasible in processing high definition videos. To avoid the curse of dimensionality in those algorithms, several methods have been proposed to solve the background estimation problem in an incremental manner. We propose a batch-incremental background estimation model using a special weighted low-rank approximation of matrices. Through experiments with real and synthetic video sequences, we demonstrate that our method is superior to the state-of-the-art background estimation algorithms such as GRASTA, ReProCS, incPCP, and GFL.

  3. Modelling safety of multistate systems with ageing components

    Energy Technology Data Exchange (ETDEWEB)

    Kołowrocki, Krzysztof; Soszyńska-Budny, Joanna [Gdynia Maritime University, Department of Mathematics ul. Morska 81-87, Gdynia 81-225 Poland (Poland)

    2016-06-08

    An innovative approach to safety analysis of multistate ageing systems is presented. Basic notions of the ageing multistate systems safety analysis are introduced. The system components and the system multistate safety functions are defined. The mean values and variances of the multistate systems lifetimes in the safety state subsets and the mean values of their lifetimes in the particular safety states are defined. The multi-state system risk function and the moment of exceeding by the system the critical safety state are introduced. Applications of the proposed multistate system safety models to the evaluation and prediction of the safty characteristics of the consecutive “m out of n: F” is presented as well.

  4. Frequency Weighted Model Order Reduction Technique and Error Bounds for Discrete Time Systems

    Directory of Open Access Journals (Sweden)

    Muhammad Imran

    2014-01-01

    for whole frequency range. However, certain applications (like controller reduction require frequency weighted approximation, which introduce the concept of using frequency weights in model reduction techniques. Limitations of some existing frequency weighted model reduction techniques include lack of stability of reduced order models (for two sided weighting case and frequency response error bounds. A new frequency weighted technique for balanced model reduction for discrete time systems is proposed. The proposed technique guarantees stable reduced order models even for the case when two sided weightings are present. Efficient technique for frequency weighted Gramians is also proposed. Results are compared with other existing frequency weighted model reduction techniques for discrete time systems. Moreover, the proposed technique yields frequency response error bounds.

  5. Modeling of Strain Effects in Multi-component Semiconductors

    Science.gov (United States)

    Arjmand, Mehrdad

    Strain affects the properties of crystalline material by changing the atomic symmetry. Controlling the strain in semiconductors helps to tune properties of material and design new material. For instance, strained semiconductor heterostructures have improved the efficiency of traditional solar cells remarkably. Another example of strain application is in electronic devices. Strained heterostructure nanowires provide a better control on electronic properties of gates used in transistors. Gate-all-around nanowires are promising candidates to power microprocessors in future. Strain is also used to make quantum dot structures from semiconductors. These quantum dots are used in quantum computing, diode lasers and sensors. Once the stored strain in a structure reaches a critical limit, it relaxes by triggering different phenomena in the structure. For instance, strain causes morphology change, plastic deformation, phase separation and intermixing, fracture, buckling, bulging and peeling. In order to use these strained structures for design purposes, it is critical to understand these different relaxation phenomena and be able to control them. Modeling provides a powerful framework to understand different relaxation mechanisms and provide guidance to control these strain induced phenomena. In this thesis, I have developed a continuum based model called "phase field" to study morphology change, plastic deformation and phase separation in multi-component semiconductors during growth and annealing processes. The advantage of phase field approach compared to some other modeling techniques is that it includes the effects of both thermodynamics and kinetics. Also, I have developed a continuum based elasto-plasticity model to study the effects of plastic relaxation in semiconductor nanowires. This model can particularly be useful for piezoelectric and surface stability analysis of nanowires.

  6. Long-term effects of a weight loss intervention with or without exercise component in postmenopausal women: A randomized trial

    Directory of Open Access Journals (Sweden)

    Martijn de Roon

    2017-03-01

    This study shows largely sustained weight loss one year after completing a weight loss program with and without exercise in overweight postmenopausal women. Although the mainly exercise group maintained more physically active compared to the diet group, maintenance of weight loss did not differ between groups.

  7. Stochastic Models of Defects in Wind Turbine Drivetrain Components

    DEFF Research Database (Denmark)

    Rafsanjani, Hesam Mirzaei; Sørensen, John Dalsgaard

    2013-01-01

    The drivetrain in a wind turbine nacelle typically consists of a variety of heavily loaded components, like the main shaft, bearings, gearbox and generator. The variations in environmental load challenge the performance of all the components of the drivetrain. Failure of each of these components...

  8. Characterization of the Organic Component of Low-Molecular-Weight Chromium-Binding Substance and Its Binding of Chromium123

    Science.gov (United States)

    Chen, Yuan; Watson, Heather M.; Gao, Junjie; Sinha, Sarmistha Halder; Cassady, Carolyn J.; Vincent, John B.

    2011-01-01

    Chromium was proposed to be an essential element over 50 y ago and was shown to have therapeutic potential in treating the symptoms of type 2 diabetes; however, its mechanism of action at a molecular level is unknown. One chromium-binding biomolecule, low-molecular weight chromium-binding substance (LMWCr or chromodulin), has been found to be biologically active in in vitro assays and proposed as a potential candidate for the in vivo biologically active form of chromium. Characterization of the organic component of LMWCr has proven difficult. Treating bovine LMWCr with trifluoroacetic acid followed by purification on a graphite powder micro-column generates a heptapeptide fragment of LMWCr. The peptide sequence of the fragment was analyzed by MS and tandem MS (MS/MS and MS/MS/MS) using collision-induced dissociation and post-source decay. Two candidate sequences, pEEEEGDD and pEEEGEDD (where pE is pyroglutamate), were identified from the MS/MS experiments; additional tandem MS suggests the sequence is pEEEEGDD. The N-terminal glutamate residues explain the inability to sequence LMWCr by the Edman method. Langmuir isotherms and Hill plots were used to analyze the binding constants of chromic ions to synthetic peptides similar in composition to apoLMWCr. The sequence pEEEEGDD was found to bind 4 chromic ions per peptide with nearly identical cooperativity and binding constants to those of apoLMWCr. This work should lead to further studies elucidating or eliminating a potential role for LMWCr in treating the symptoms of type 2 diabetes and other conditions resulting from improper carbohydrate and lipid metabolism. PMID:21593351

  9. System model network for adipose tissue signatures related to weight changes in response to calorie restriction and subsequent weight maintenance.

    Science.gov (United States)

    Montastier, Emilie; Villa-Vialaneix, Nathalie; Caspar-Bauguil, Sylvie; Hlavaty, Petr; Tvrzicka, Eva; Gonzalez, Ignacio; Saris, Wim H M; Langin, Dominique; Kunesova, Marie; Viguerie, Nathalie

    2015-01-01

    Nutrigenomics investigates relationships between nutrients and all genome-encoded molecular entities. This holistic approach requires systems biology to scrutinize the effects of diet on tissue biology. To decipher the adipose tissue (AT) response to diet induced weight changes we focused on key molecular (lipids and transcripts) AT species during a longitudinal dietary intervention. To obtain a systems model, a network approach was used to combine all sets of variables (bio-clinical, fatty acids and mRNA levels) and get an overview of their interactions. AT fatty acids and mRNA levels were quantified in 135 obese women at baseline, after an 8-week low calorie diet (LCD) and after 6 months of ad libitum weight maintenance diet (WMD). After LCD, individuals were stratified a posteriori according to weight change during WMD. A 3 steps approach was used to infer a global model involving the 3 sets of variables. It consisted in inferring intra-omic networks with sparse partial correlations and inter-omic networks with regularized canonical correlation analysis and finally combining the obtained omic-specific network in a single global model. The resulting networks were analyzed using node clustering, systematic important node extraction and cluster comparisons. Overall, AT showed both constant and phase-specific biological signatures in response to dietary intervention. AT from women regaining weight displayed growth factors, angiogenesis and proliferation signaling signatures, suggesting unfavorable tissue hyperplasia. By contrast, after LCD a strong positive relationship between AT myristoleic acid (a fatty acid with low AT level) content and de novo lipogenesis mRNAs was found. This relationship was also observed, after WMD, in the group of women that continued to lose weight. This original system biology approach provides novel insight in the AT response to weight control by highlighting the central role of myristoleic acid that may account for the beneficial

  10. System model network for adipose tissue signatures related to weight changes in response to calorie restriction and subsequent weight maintenance.

    Directory of Open Access Journals (Sweden)

    Emilie Montastier

    2015-01-01

    Full Text Available Nutrigenomics investigates relationships between nutrients and all genome-encoded molecular entities. This holistic approach requires systems biology to scrutinize the effects of diet on tissue biology. To decipher the adipose tissue (AT response to diet induced weight changes we focused on key molecular (lipids and transcripts AT species during a longitudinal dietary intervention. To obtain a systems model, a network approach was used to combine all sets of variables (bio-clinical, fatty acids and mRNA levels and get an overview of their interactions. AT fatty acids and mRNA levels were quantified in 135 obese women at baseline, after an 8-week low calorie diet (LCD and after 6 months of ad libitum weight maintenance diet (WMD. After LCD, individuals were stratified a posteriori according to weight change during WMD. A 3 steps approach was used to infer a global model involving the 3 sets of variables. It consisted in inferring intra-omic networks with sparse partial correlations and inter-omic networks with regularized canonical correlation analysis and finally combining the obtained omic-specific network in a single global model. The resulting networks were analyzed using node clustering, systematic important node extraction and cluster comparisons. Overall, AT showed both constant and phase-specific biological signatures in response to dietary intervention. AT from women regaining weight displayed growth factors, angiogenesis and proliferation signaling signatures, suggesting unfavorable tissue hyperplasia. By contrast, after LCD a strong positive relationship between AT myristoleic acid (a fatty acid with low AT level content and de novo lipogenesis mRNAs was found. This relationship was also observed, after WMD, in the group of women that continued to lose weight. This original system biology approach provides novel insight in the AT response to weight control by highlighting the central role of myristoleic acid that may account for the

  11. System Model Network for Adipose Tissue Signatures Related to Weight Changes in Response to Calorie Restriction and Subsequent Weight Maintenance

    Science.gov (United States)

    Montastier, Emilie; Villa-Vialaneix, Nathalie; Caspar-Bauguil, Sylvie; Hlavaty, Petr; Tvrzicka, Eva; Gonzalez, Ignacio; Saris, Wim H. M.; Langin, Dominique; Kunesova, Marie; Viguerie, Nathalie

    2015-01-01

    Nutrigenomics investigates relationships between nutrients and all genome-encoded molecular entities. This holistic approach requires systems biology to scrutinize the effects of diet on tissue biology. To decipher the adipose tissue (AT) response to diet induced weight changes we focused on key molecular (lipids and transcripts) AT species during a longitudinal dietary intervention. To obtain a systems model, a network approach was used to combine all sets of variables (bio-clinical, fatty acids and mRNA levels) and get an overview of their interactions. AT fatty acids and mRNA levels were quantified in 135 obese women at baseline, after an 8-week low calorie diet (LCD) and after 6 months of ad libitum weight maintenance diet (WMD). After LCD, individuals were stratified a posteriori according to weight change during WMD. A 3 steps approach was used to infer a global model involving the 3 sets of variables. It consisted in inferring intra-omic networks with sparse partial correlations and inter-omic networks with regularized canonical correlation analysis and finally combining the obtained omic-specific network in a single global model. The resulting networks were analyzed using node clustering, systematic important node extraction and cluster comparisons. Overall, AT showed both constant and phase-specific biological signatures in response to dietary intervention. AT from women regaining weight displayed growth factors, angiogenesis and proliferation signaling signatures, suggesting unfavorable tissue hyperplasia. By contrast, after LCD a strong positive relationship between AT myristoleic acid (a fatty acid with low AT level) content and de novo lipogenesis mRNAs was found. This relationship was also observed, after WMD, in the group of women that continued to lose weight. This original system biology approach provides novel insight in the AT response to weight control by highlighting the central role of myristoleic acid that may account for the beneficial

  12. Estimation models of variance components for farrowing interval in swine

    Directory of Open Access Journals (Sweden)

    Aderbal Cavalcante Neto

    2009-02-01

    Full Text Available The main objective of this study was to evaluate the importance of including maternal genetic, common litter environmental and permanent environmental effects in estimation models of variance components for the farrowing interval trait in swine. Data consisting of 1,013 farrowing intervals of Dalland (C-40 sows recorded in two herds were analyzed. Variance components were obtained by the derivative-free restricted maximum likelihood method. Eight models were tested which contained the fixed effects(contemporary group and covariables and the direct genetic additive and residual effects, and varied regarding the inclusion of the maternal genetic, common litter environmental, and/or permanent environmental random effects. The likelihood-ratio test indicated that the inclusion of these effects in the model was unnecessary, but the inclusion of the permanent environmental effect caused changes in the estimates of heritability, which varied from 0.00 to 0.03. In conclusion, the heritability values obtained indicated that this trait appears to present no genetic gain as response to selection. The common litter environmental and the maternal genetic effects did not present any influence on this trait. The permanent environmental effect, however, should be considered in the genetic models for this trait in swine, because its presence caused changes in the additive genetic variance estimates.Este trabalho teve como objetivo principal avaliar a importância da inclusão dos efeitos genético materno, comum de leitegada e de ambiente permanente no modelo de estimação de componentes de variância para a característica intervalo de parto em fêmeas suínas. Foram utilizados dados que consistiam de 1.013 observações de fêmeas Dalland (C-40, registradas em dois rebanhos. As estimativas dos componentes de variância foram realizadas pelo método da máxima verossimilhança restrita livre de derivadas. Foram testados oito modelos, que continham os efeitos

  13. Evaluation of weighted regression and sample size in developing a taper model for loblolly pine

    Science.gov (United States)

    Kenneth L. Cormier; Robin M. Reich; Raymond L. Czaplewski; William A. Bechtold

    1992-01-01

    A stem profile model, fit using pseudo-likelihood weighted regression, was used to estimate merchantable volume of loblolly pine (Pinus taeda L.) in the southeast. The weighted regression increased model fit marginally, but did not substantially increase model performance. In all cases, the unweighted regression models performed as well as the...

  14. Weight loss programs for urban-based, postpartum African-American women: perceived barriers and preferred components.

    Science.gov (United States)

    Setse, Rosanna; Grogan, Ruby; Cooper, Lisa A; Strobino, Donna; Powe, Neil R; Nicholson, Wanda

    2008-01-01

    There are currently 1.85 million reproductive-aged women in the United States with diabetes or glucose intolerance. While it is known that postpartum weight retention can lead to obesity and diabetes, particularly among African-American women, little is known about African-American women's preferences for postpartum weight loss programs. Our objective was to explore urban-based African-American women's attitudes toward weight gain, perceived barriers to postpartum weight loss, and preferences for weight intervention strategies. Focus groups of pregnant African-American women (n = 22) were conducted by a race-concordant moderator. Open-ended questions were posed to stimulate discussions which were audio taped and transcribed verbatim. Transcriptions were independently reviewed by two investigators who extracted quotations and coded each statement to identify major themes. The median age of participants was 26 years. Median pre-pregnancy or first trimester body-mass index was 31 kg/m(2). Fifty-seven percent of the women were multiparous and 68% were Medicaid recipients. We identified 16 themes with the majority of participant comments focused on: (1) effect of postpartum depression on motivation to lose weight; (2) strong desire to lose weight; (3) knowledge of adverse effects of obesity; (4) costs of weight loss programs; (5) negative impact of media coverage of successful celebrity postpartum weight loss; (6) limitations of childcare on ability to exercise; and (7) family-centered lifestyle behaviors that promote unhealthy eating. Weight loss interventions for African-American women with postpartum obesity should address psychological effects of childbearing, affordability, and perceptions of body image. Interventions should incorporate family-centered approaches and weight loss maintenance strategies.

  15. Modeling the relationship between body weight and energy intake: a molecular diffusion-based approach.

    Science.gov (United States)

    Gong, Zhejun; Gong, Zhefeng

    2012-06-29

    Body weight is at least partly controlled by the choices made by a human in response to external stimuli. Changes in body weight are mainly caused by energy intake. By analyzing the mechanisms involved in food intake, we considered that molecular diffusion plays an important role in body weight changes. We propose a model based on Fick's second law of diffusion to simulate the relationship between energy intake and body weight. This model was applied to food intake and body weight data recorded in humans; the model showed a good fit to the experimental data. This model was also effective in predicting future body weight. In conclusion, this model based on molecular diffusion provides a new insight into the body weight mechanisms. This article was reviewed by Dr. Cabral Balreira (nominated by Dr. Peter Olofsson), Prof. Yang Kuang and Dr. Chao Chen.

  16. To Compare Time-Weighted Graphs to Evaluate the Inclination of the Acetabular Component of Patients Who Had Total Hip Replacement Surgery

    Directory of Open Access Journals (Sweden)

    Leman Tomak

    2015-01-01

    Full Text Available Time-weighted graphs are used to detect small shifts in statistical process control. The aim of this study is to evaluate the inclination of the acetabular component with CUmulative SUM (CUSUM chart, Moving Average (MA chart, and Exponentially Weighted Moving Average (EWMA chart. The data were obtained directly from thirty patients who had undergone total hip replacement surgery at Ondokuz Mayis University, Faculty of Medicine. The inclination of the acetabular component of these people, after total hip replacement, was evaluated. CUSUM chart, Moving Average chart, and Exponentially Weighted Moving Average were used to evaluate the quality control process of acetabular component inclination. MINITAB Statistical Software 15.0 was used to generate these control charts. The assessment done with time-weighted charts revealed that the acetabular inclination angles were settled within control limits and the process was under control. It was determined that the change within the control limits had a random pattern. As a result of this study it has been obtained that time-weighted quality control charts which are used mostly in the field of industry can also be used in the field of medicine. It has provided us with a faster visual decision.

  17. Component-based handprint segmentation using adaptive writing style model

    Science.gov (United States)

    Garris, Michael D.

    1997-04-01

    Building upon the utility of connected components, NIST has designed a new character segmentor based on statistically modeling the style of a person's handwriting. Simple spatial features capture the characteristics of a particular writer's style of handprint, enabling the new method to maintain a traditional character-level segmentation philosophy without the integration of recognition or the use of oversegmentation and linguistic postprocessing. Estimates for stroke width and character height are used to compute aspect ratio and standard stroke count features that adapt to the writer's style at the field level. The new method has been developed with a predetermined set of fuzzy rules making the segmentor much less fragile and much more adaptive, and the new method successfully reconstructs fragmented characters as well as splits touching characters. The new segmentor was integrated into the NIST public domain form-based handprint recognition systems and then tested on a set of 490 handwriting sample forms found in NIST special database 19. When compared to a simple component-based segmentor, the new adaptable method improved the overall recognition of handprinted digits by 3.4 percent and field level recognition by 6.9 percent, while effectively reducing deletion errors by 82 percent. The same program code and set of parameters successfully segments sequences of uppercase and lowercase characters without any context-based tuning. While not as dramatic as digits, the recognition of uppercase and lowercase characters improved by 1.7 percent and 1.3 percent respectively. The segmentor maintains a relatively straight-forward and logical process flow avoiding convolutions of encoded exceptions as is common in expert systems. As a result, the new segmentor operates very efficiently, and throughput as high as 362 characters per second can be achieved. Letters and numbers are constructed from a predetermined configuration of a relatively small number of strokes. Results

  18. Component Model of Reading Comprehension for Adult Education Participants

    Science.gov (United States)

    Mellard, Daryl F.; Fall, Emily

    2012-01-01

    The following insights into the reading skills of 312 participants in adult basic and secondary education programs are based on a principal components analysis of reading components' contributions to variance in reading comprehension. Overall, 75% of variance was explained by four composite variables representing word skills, language…

  19. Prenatal centrifugation: A model for fetal programming of adult weight?

    Science.gov (United States)

    Baer, Lisa A.; Rushing, Linda; Wade, Charles E.; Ronca, April E.

    2005-08-01

    'Fetal programming' is a newly emerging field that is revealing astounding insights into the prenatal origins of adult disease, including metabolic, endocrine, and cardiovascular pathophysiology. In the present study, we tested the hypothesis that rat pups conceived, gestated and born at 2-g have significantly reduced birth weights and increased adult body weights as compared to 1-g controls. Offspring were produced by mating young adult male and female rats that were adapted to 2-g centrifugation. Female rats underwent conception, pregnancy and birth at 2-g. Newborn pups in the 2-g condition were removed from the centrifuge and fostered to non-manipulated, newly parturient dams maintained at 1-g. Comparisons were made with 1-g stationary controls, also cross- fostered at birth. As compared to 1-g controls, birth weights of pups gestated and born at 2-g were significantly reduced. Pup body weights were significantly reduced until Postnatal day (P)12. Beginning on P63, body weights of 2-g-gestated offspring exceeded those of 1-g controls by 7-10%. Thus, prenatal rearing at 2-g restricts neonatal growth and increases adult body weight. Collectively, these data support the hypothesis that 2-g centrifugation alters the intrauterine milieu, thereby inducing persistent changes in adult phenotype.

  20. A three-component cognitive behavioural lifestyle program for preconceptional weight-loss in women with polycystic ovary syndrome (PCOS): a protocol for a randomized controlled trial.

    Science.gov (United States)

    Jiskoot, G; Benneheij, S H; Beerthuizen, A; de Niet, J E; de Klerk, C; Timman, R; Busschbach, J J; Laven, J S E

    2017-03-06

    Obesity in women with polycystic ovary syndrome (PCOS) negatively affects all clinical features, and a 5 to 10% weight loss has shown promising results on reproductive, metabolic and psychological level. Incorporating a healthy diet, increasing physical activity and changing dysfunctional thought patterns in women with PCOS are key points in losing weight. The biggest challenge in weight management programs is to achieve a reasonable and sustainable weight loss. The aim of this study is to explore whether Cognitive Behavioural Therapy (CBT) by a mental health professional, working in a multidisciplinary team with a dietician and a physical therapist (a three-component intervention), is more effective for weight loss in the long term, within 12 months. We will also explore whether mobile phone applications are effective in supporting behavioural change and sustainable weight loss. The present study is a longitudinal randomized controlled trial (RCT) to study the effectiveness of a three-component 1-year cognitive-behavioural lifestyle intervention in overweight/obese women with PCOS. A total of 210 participants are randomly assigned to three groups: 1) CBT provided by the multidisciplinary team or; 2) CBT provided by the multidisciplinary team and Short Message Service (SMS) or; 3) usual care: encourage weight loss through publicly available services (control group). The primary aim of the 12-month intervention is to explore whether a three-component 1-year cognitive-behavioural lifestyle intervention is effective to decrease weight, when compared to usual care. Secondary outcomes include: the effect of the intervention on the PCOS phenotype, waist circumference, waist to hip ratio, ovulation rates, total testosterone, SHBG, free androgen index (FAI), AMH, hirsutism, acne, fasting glucose, blood pressure and all psychological parameters. Additionally, we assessed time to pregnancy, ongoing pregnancies, clinical pregnancies, miscarriages and birth weight. All

  1. Models of energy homeostasis in response to maintenance of reduced body weight.

    Science.gov (United States)

    Rosenbaum, Michael; Leibel, Rudolph L

    2016-08-01

    To test three proposed models for adaptive thermogenesis in compartments of energy expenditure following different degrees of weight loss. Specifically, (1) there is no adaptive thermogenesis [constant relationship of energy expenditure (EE) to metabolic mass]. (2) There is a fixed degree of adaptive thermogenesis once fat stores are below a "threshold." (3) The degree of adaptive thermogenesis is proportional to weight loss. The relationship between weight loss and EE was examined in 17 inpatient subjects with stable weight and obesity studied at usual weight and again following a 10% and a 20% weight loss. Following initial weight loss (10%), resting (REE) and non-resting (NREE) EE were significantly below those predicted on the basis of the amount and composition of weight lost. Further reductions below predicted values of NREE but not REE occurred following an additional 10% weight loss. Changes in body weight, composition, and/or energy stores were significantly correlated with changes in EE. All models are applicable to the decline in EE following weight loss. The disproportionate decline in REE is consistent with a threshold model (no change with further weight loss) while the disproportionate decline in NREE is largely reflective of the degree of weight loss. © 2016 The Obesity Society.

  2. Expression-robust 3D face recognition via weighted sparse representation of multi-scale and multi-component local normal patterns

    KAUST Repository

    Li, Huibin

    2014-06-01

    In the theory of differential geometry, surface normal, as a first order surface differential quantity, determines the orientation of a surface at each point and contains informative local surface shape information. To fully exploit this kind of information for 3D face recognition (FR), this paper proposes a novel highly discriminative facial shape descriptor, namely multi-scale and multi-component local normal patterns (MSMC-LNP). Given a normalized facial range image, three components of normal vectors are first estimated, leading to three normal component images. Then, each normal component image is encoded locally to local normal patterns (LNP) on different scales. To utilize spatial information of facial shape, each normal component image is divided into several patches, and their LNP histograms are computed and concatenated according to the facial configuration. Finally, each original facial surface is represented by a set of LNP histograms including both global and local cues. Moreover, to make the proposed solution robust to the variations of facial expressions, we propose to learn the weight of each local patch on a given encoding scale and normal component image. Based on the learned weights and the weighted LNP histograms, we formulate a weighted sparse representation-based classifier (W-SRC). In contrast to the overwhelming majority of 3D FR approaches which were only benchmarked on the FRGC v2.0 database, we carried out extensive experiments on the FRGC v2.0, Bosphorus, BU-3DFE and 3D-TEC databases, thus including 3D face data captured in different scenarios through various sensors and depicting in particular different challenges with respect to facial expressions. The experimental results show that the proposed approach consistently achieves competitive rank-one recognition rates on these databases despite their heterogeneous nature, and thereby demonstrates its effectiveness and its generalizability. © 2014 Elsevier B.V.

  3. On the Efficiency of Score Tests for Homogeneity in Two-Component Parametric Models for Discrete Data

    Science.gov (United States)

    Todem, David; Hsu, Wei-Wen; Kim, Kyung Mann

    2013-01-01

    Summary In many applications of two-component mixture models for discrete data such as zero-inflated models, it is often of interest to conduct inferences for the mixing weights. Score tests derived from the marginal model that allows for negative mixing weights have been particularly useful for this purpose. But the existing testing procedures often rely on restrictive assumptions such as the constancy of the mixing weights and typically ignore the structural constraints of the marginal model. In this article, we develop a score test of homogeneity that overcomes the limitations of existing procedures. The technique is based on a decomposition of the mixing weights into terms that have an obvious statistical interpretation. We exploit this decomposition to lay the foundation of the test. Simulation results show that the proposed covariate-adjusted test statistic can greatly improve the efficiency over test statistics based on constant mixing weights. A real-life example in dental caries research is used to illustrate the methodology. PMID:22348298

  4. The quest for conditional independence in prospectivity modeling: weights-of-evidence, boost weights-of-evidence, and logistic regression

    Science.gov (United States)

    Schaeben, Helmut; Semmler, Georg

    2016-09-01

    The objective of prospectivity modeling is prediction of the conditional probability of the presence T = 1 or absence T = 0 of a target T given favorable or prohibitive predictors B, or construction of a two classes 0,1 classification of T. A special case of logistic regression called weights-of-evidence (WofE) is geologists' favorite method of prospectivity modeling due to its apparent simplicity. However, the numerical simplicity is deceiving as it is implied by the severe mathematical modeling assumption of joint conditional independence of all predictors given the target. General weights of evidence are explicitly introduced which are as simple to estimate as conventional weights, i.e., by counting, but do not require conditional independence. Complementary to the regression view is the classification view on prospectivity modeling. Boosting is the construction of a strong classifier from a set of weak classifiers. From the regression point of view it is closely related to logistic regression. Boost weights-of-evidence (BoostWofE) was introduced into prospectivity modeling to counterbalance violations of the assumption of conditional independence even though relaxation of modeling assumptions with respect to weak classifiers was not the (initial) purpose of boosting. In the original publication of BoostWofE a fabricated dataset was used to "validate" this approach. Using the same fabricated dataset it is shown that BoostWofE cannot generally compensate lacking conditional independence whatever the consecutively processing order of predictors. Thus the alleged features of BoostWofE are disproved by way of counterexamples, while theoretical findings are confirmed that logistic regression including interaction terms can exactly compensate violations of joint conditional independence if the predictors are indicators.

  5. Short- and Long-Term Effects of Weight Loss on the Complement Component C3 After Laparoscopic Gastric Bypass in Obese Patients.

    Science.gov (United States)

    Gómez-Abril, Segundo Á; Morillas-Ariño, Carlos; Ponce-Marco, Jose L; Torres-Sánchez, Teresa; Delgado-Gomis, Fernando; Hernández-Mijares, Antonio; Rocha, Milagros

    2016-11-01

    The C3 complement component (C3c) is increasingly recognized as a cardiometabolic risk factor, but how it is affected after weight loss through gastric bypass is a question yet to be answered. A total of 66 obese patients underwent laparoscopic gastric bypass. Anthropometric parameters, total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), glucose, insulin, HOMA-IR, liver enzymes, high-sensitivity C-reactive protein (hsCRP), and C3c levels were evaluated at baseline and at 1 and 5 years post-surgery. All anthropometric and biochemical parameters improved significantly after surgery, although a deterioration was detected with respect to the percentage of excess of weight loss, insulin, TC, LDLc, and lactate dehydrogenase 5 years post-surgery. Despite this, a remission rate of 84 % was observed in the presence of metabolic syndrome after 5 years follow-up. hsCRP and C3c were reduced significantly after surgery and maintained throughout the experimental period. In addition, C3c was correlated with BMI and insulin at all time points. The multivariate regression model, in which C3c was a dependent variable, revealed that aspartate aminotransferase and BMI were independent variables at baseline, alkaline phosphatase and insulin were independent at 1 year post-surgery, and insulin, BMI, and TC were independent at 5 years post-surgery. C3c may be a marker of the chronic inflammatory process underlying insulin resistance. Its association with BMI and liver enzymes supports a major role in metabolic activity, although future research is needed to clarify the nature of the molecular mechanisms involved and the physiological significance of these findings.

  6. Predicting successful long-term weight loss from short-term weight-loss outcomes: new insights from a dynamic energy balance model (the POUNDS Lost study).

    Science.gov (United States)

    Thomas, Diana M; Ivanescu, Andrada E; Martin, Corby K; Heymsfield, Steven B; Marshall, Kaitlyn; Bodrato, Victoria E; Williamson, Donald A; Anton, Stephen D; Sacks, Frank M; Ryan, Donna; Bray, George A

    2015-03-01

    Currently, early weight-loss predictions of long-term weight-loss success rely on fixed percent-weight-loss thresholds. The objective was to develop thresholds during the first 3 mo of intervention that include the influence of age, sex, baseline weight, percent weight loss, and deviations from expected weight to predict whether a participant is likely to lose 5% or more body weight by year 1. Data consisting of month 1, 2, 3, and 12 treatment weights were obtained from the 2-y Preventing Obesity Using Novel Dietary Strategies (POUNDS Lost) intervention. Logistic regression models that included covariates of age, height, sex, baseline weight, target energy intake, percent weight loss, and deviation of actual weight from expected were developed for months 1, 2, and 3 that predicted the probability of losing treatment approaches during early intervention. © 2015 American Society for Nutrition.

  7. Estimating the weight of Douglas-fir tree boles and logs with an iterative computer model.

    Science.gov (United States)

    Dale R. Waddell; Dale L Weyermann; Michael B. Lambert

    1987-01-01

    A computer model that estimates the green weights of standing trees was developed and validated for old-growth Douglas-fir. The model calculates the green weight for the entire bole, for the bole to any merchantable top, and for any log length within the bole. The model was validated by estimating the bias and accuracy of an independent subsample selected from the...

  8. Estimating a DIF decomposition model using a random-weights linear logistic test model approach.

    Science.gov (United States)

    Paek, Insu; Fukuhara, Hirotaka

    2015-09-01

    A differential item functioning (DIF) decomposition model separates a testlet item DIF into two sources: item-specific differential functioning and testlet-specific differential functioning. This article provides an alternative model-building framework and estimation approach for a DIF decomposition model that was proposed by Beretvas and Walker (2012). Although their model is formulated under multilevel modeling with the restricted pseudolikelihood estimation method, our approach illustrates DIF decomposition modeling that is directly built upon the random-weights linear logistic test model framework with the marginal maximum likelihood estimation method. In addition to demonstrating our approach's performance, we provide detailed information on how to implement this new DIF decomposition model using an item response theory software program; using DIF decomposition may be challenging for practitioners, yet practical information on how to implement it has previously been unavailable in the measurement literature.

  9. Frequency Weighted Model Order Reduction Technique and Error Bounds for Discrete Time Systems

    OpenAIRE

    Muhammad Imran; Abdul Ghafoor; Victor Sreeram

    2014-01-01

    Model reduction is a process of approximating higher order original models by comparatively lower order models with reasonable accuracy in order to provide ease in design, modeling and simulation for large complex systems. Generally, model reduction techniques approximate the higher order systems for whole frequency range. However, certain applications (like controller reduction) require frequency weighted approximation, which introduce the concept of using frequency weights in model reductio...

  10. A biobehavioral model of weight loss associated with meditative movement practice among breast cancer survivors

    Directory of Open Access Journals (Sweden)

    Linda K Larkey

    2014-12-01

    Full Text Available Women with breast cancer often experience weight gain during and after treatment, significantly increasing risk for recurrence as well as all-cause mortality. Based on a growing body of evidence, meditative movement practices may be effective for weight management. First, we describe the effects of stress on factors associated with weight gain for breast cancer survivors. Then, a model is proposed that utilizes existing evidence to suggest how meditative movement supports behavioral, psychological, and neurohormonal changes that may explain weight loss. Application of the model suggests how a novel “mindful-body-wisdom” approach may work to help reduce weight for this at-risk group.

  11. Weighted low-rank sparse model via nuclear norm minimization for bearing fault detection

    Science.gov (United States)

    Du, Zhaohui; Chen, Xuefeng; Zhang, Han; Yang, Boyuan; Zhai, Zhi; Yan, Ruqiang

    2017-07-01

    It is a fundamental task in the machine fault diagnosis community to detect impulsive signatures generated by the localized faults of bearings. The main goal of this paper is to exploit the low-rank physical structure of periodic impulsive features and further establish a weighted low-rank sparse model for bearing fault detection. The proposed model mainly consists of three basic components: an adaptive partition window, a nuclear norm regularization and a weighted sequence. Firstly, due to the periodic repetition mechanism of impulsive feature, an adaptive partition window could be designed to transform the impulsive feature into a data matrix. The highlight of partition window is to accumulate all local feature information and align them. Then, all columns of the data matrix share similar waveforms and a core physical phenomenon arises, i.e., these singular values of the data matrix demonstrates a sparse distribution pattern. Therefore, a nuclear norm regularization is enforced to capture that sparse prior. However, the nuclear norm regularization treats all singular values equally and thus ignores one basic fact that larger singular values have more information volume of impulsive features and should be preserved as much as possible. Therefore, a weighted sequence with adaptively tuning weights inversely proportional to singular amplitude is adopted to guarantee the distribution consistence of large singular values. On the other hand, the proposed model is difficult to solve due to its non-convexity and thus a new algorithm is developed to search one satisfying stationary solution through alternatively implementing one proximal operator operation and least-square fitting. Moreover, the sensitivity analysis and selection principles of algorithmic parameters are comprehensively investigated through a set of numerical experiments, which shows that the proposed method is robust and only has a few adjustable parameters. Lastly, the proposed model is applied to the

  12. A Physics Model for Weight Loss by Dieting

    Science.gov (United States)

    2012-09-01

    body, weight change, diet, energy loss. Resumen El peso promedio de una persona está determinado por el equilibrio entre su ingesta de calorías...through by 2x to get 2 1 1dx X dt T x X        , (2) where the two constants a and b have been re-expressed in terms of two new... constants /X a b and 22 /T a b . Their physical significance is that 2W X is the person’s equilibrium weight and T is a time constant characterizing

  13. Probability Weighting Functions Derived from Hyperbolic Time Discounting: Psychophysical Models and Their Individual Level Testing.

    Science.gov (United States)

    Takemura, Kazuhisa; Murakami, Hajime

    2016-01-01

    A probability weighting function (w(p)) is considered to be a nonlinear function of probability (p) in behavioral decision theory. This study proposes a psychophysical model of probability weighting functions derived from a hyperbolic time discounting model and a geometric distribution. The aim of the study is to show probability weighting functions from the point of view of waiting time for a decision maker. Since the expected value of a geometrically distributed random variable X is 1/p, we formulized the probability weighting function of the expected value model for hyperbolic time discounting as w(p) = (1 - k log p)(-1). Moreover, the probability weighting function is derived from Loewenstein and Prelec's (1992) generalized hyperbolic time discounting model. The latter model is proved to be equivalent to the hyperbolic-logarithmic weighting function considered by Prelec (1998) and Luce (2001). In this study, we derive a model from the generalized hyperbolic time discounting model assuming Fechner's (1860) psychophysical law of time and a geometric distribution of trials. In addition, we develop median models of hyperbolic time discounting and generalized hyperbolic time discounting. To illustrate the fitness of each model, a psychological experiment was conducted to assess the probability weighting and value functions at the level of the individual participant. The participants were 50 university students. The results of individual analysis indicated that the expected value model of generalized hyperbolic discounting fitted better than previous probability weighting decision-making models. The theoretical implications of this finding are discussed.

  14. Effectiveness of a Smartphone Application for the Management of Metabolic Syndrome Components Focusing on Weight Loss: A Preliminary Study.

    Science.gov (United States)

    Toro-Ramos, Tatiana; Lee, Dong-Hwa; Kim, Youngin; Michaelides, Andreas; Oh, Tae Jung; Kim, Kyoung Min; Jang, Hak Chul; Lim, Soo

    2017-11-01

    There are inconsistent results for the effectiveness of using smartphone applications (apps) or websites on weight loss. We investigated the efficacy of a smartphone intervention using a designated app that utilizes a lifestyle intervention-focused approach, including a human coaching element, toward weight loss in overweight or obese Korean adults. One hundred four adults aged 20-60 years with a body mass index ≥23 kg/m2, who signed up for a smartphone program for weight loss (using the Noom app), were recruited. Participants received an in-person orientation about the study and app use, and a baseline blood sample was obtained. The in-app intervention with daily behavior and nutrition education content and coaching lasted 15 weeks. The primary endpoint of the study was a change in weight. The secondary endpoints were changes in metabolic risk factors such as blood pressure, waist circumference, and glucose and lipid profiles. Body composition changes were also assessed, and body weight at 52 weeks was measured to ascertain long-term effects. Participants showed a clinically significant weight loss effect of -7.5% at the end of the 15-week program (P loss effect of -5.2% was maintained. At 15 weeks, percent body fat and visceral fat decreased by -6.0 ± 5.4% and -3.4 ± 2.7 kg, respectively (both P loss. This advanced smartphone app was a useful tool to maintain weight loss in overweight or obese people.

  15. A Core Journal Decision Model Based on Weighted Page Rank

    Science.gov (United States)

    Wang, Hei-Chia; Chou, Ya-lin; Guo, Jiunn-Liang

    2011-01-01

    Purpose: The paper's aim is to propose a core journal decision method, called the local impact factor (LIF), which can evaluate the requirements of the local user community by combining both the access rate and the weighted impact factor, and by tracking citation information on the local users' articles. Design/methodology/approach: Many…

  16. Modelling olanzapine-induced weight gain in rats

    NARCIS (Netherlands)

    van der Zwaal, E. M.; Janhunen, S. K.; La Fleur, S. E.; Adan, R. A. H.

    2014-01-01

    The second-generation antipsychotic drug olanzapine has become a widely prescribed drug in the treatment of schizophrenia and bipolar disorder. Unfortunately, its therapeutic benefits are partly outweighed by significant weight gain and other metabolic side effects, which increase the risk for

  17. A Bayesian posterior predictive framework for weighting ensemble regional climate models

    Directory of Open Access Journals (Sweden)

    Y. Fan

    2017-06-01

    Full Text Available We present a novel Bayesian statistical approach to computing model weights in climate change projection ensembles in order to create probabilistic projections. The weight of each climate model is obtained by weighting the current day observed data under the posterior distribution admitted under competing climate models. We use a linear model to describe the model output and observations. The approach accounts for uncertainty in model bias, trend and internal variability, including error in the observations used. Our framework is general, requires very little problem-specific input, and works well with default priors. We carry out cross-validation checks that confirm that the method produces the correct coverage.

  18. Ecological, psychological, and cognitive components of reading difficulties: testing the component model of reading in fourth graders across 38 countries.

    Science.gov (United States)

    Chiu, Ming Ming; McBride-Chang, Catherine; Lin, Dan

    2012-01-01

    The authors tested the component model of reading (CMR) among 186,725 fourth grade students from 38 countries (45 regions) on five continents by analyzing the 2006 Progress in International Reading Literacy Study data using measures of ecological (country, family, school, teacher), psychological, and cognitive components. More than 91% of the differences in student difficulty occurred at the country (61%) and classroom (30%) levels (ecological), with less than 9% at the student level (cognitive and psychological). All three components were negatively associated with reading difficulties: cognitive (student's early literacy skills), ecological (family characteristics [socioeconomic status, number of books at home, and attitudes about reading], school characteristics [school climate and resources]), and psychological (students' attitudes about reading, reading self-concept, and being a girl). These results extend the CMR by demonstrating the importance of multiple levels of factors for reading deficits across diverse cultures.

  19. New approaches to the modelling of multi-component fuel droplet heating and evaporation

    KAUST Repository

    Sazhin, Sergei S

    2015-02-25

    The previously suggested quasi-discrete model for heating and evaporation of complex multi-component hydrocarbon fuel droplets is described. The dependence of density, viscosity, heat capacity and thermal conductivity of liquid components on carbon numbers n and temperatures is taken into account. The effects of temperature gradient and quasi-component diffusion inside droplets are taken into account. The analysis is based on the Effective Thermal Conductivity/Effective Diffusivity (ETC/ED) model. This model is applied to the analysis of Diesel and gasoline fuel droplet heating and evaporation. The components with relatively close n are replaced by quasi-components with properties calculated as average properties of the a priori defined groups of actual components. Thus the analysis of the heating and evaporation of droplets consisting of many components is replaced with the analysis of the heating and evaporation of droplets consisting of relatively few quasi-components. It is demonstrated that for Diesel and gasoline fuel droplets the predictions of the model based on five quasi-components are almost indistinguishable from the predictions of the model based on twenty quasi-components for Diesel fuel droplets and are very close to the predictions of the model based on thirteen quasi-components for gasoline fuel droplets. It is recommended that in the cases of both Diesel and gasoline spray combustion modelling, the analysis of droplet heating and evaporation is based on as little as five quasi-components.

  20. Building Component Library: An Online Repository to Facilitate Building Energy Model Creation; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Fleming, K.; Long, N.; Swindler, A.

    2012-05-01

    This paper describes the Building Component Library (BCL), the U.S. Department of Energy's (DOE) online repository of building components that can be directly used to create energy models. This comprehensive, searchable library consists of components and measures as well as the metadata which describes them. The library is also designed to allow contributors to easily add new components, providing a continuously growing, standardized list of components for users to draw upon.

  1. Conceptual Model of Weight Management in Overweight and Obese African-American Females.

    Science.gov (United States)

    Sutton, Suzanne M; Magwood, Gayenell S; Nemeth, Lynne S; Jenkins, Carolyn M

    2017-04-01

    Weight management of overweight and obese (OWO) African-American females (AAFs) is a poorly defined concept, leading to ineffective treatment of overweight and obesity, prevention of health sequelae, and risk reduction. A conceptual model of the phenomenon of weight management in OWO AAFs was developed through dimensional analysis of the literature. Constructs were identified and sorted into the dimensions of perspective, context, conditions, process, and consequences and integrated into an explanatory matrix. Through dimensional analysis, weight management in OWO AAFs was characterized as a multidimensional concept, defined from the perspective of weight loss in community-dwelling AAFs. Behaviors associated with weight management are strongly influenced by intrinsic factors and extrinsic conditions, which influence engagement in the processes and consequences of weight management. The resulting conceptual model of weight management in OWO AAFs provides a framework for research interventions applicable in a variety of settings. © 2016 Wiley Periodicals, Inc.

  2. Impacts of weighting climate models for hydro-meteorological climate change studies

    Science.gov (United States)

    Chen, Jie; Brissette, François P.; Lucas-Picher, Philippe; Caya, Daniel

    2017-06-01

    Weighting climate models is controversial in climate change impact studies using an ensemble of climate simulations from different climate models. In climate science, there is a general consensus that all climate models should be considered as having equal performance or in other words that all projections are equiprobable. On the other hand, in the impacts and adaptation community, many believe that climate models should be weighted based on their ability to better represent various metrics over a reference period. The debate appears to be partly philosophical in nature as few studies have investigated the impact of using weights in projecting future climate changes. The present study focuses on the impact of assigning weights to climate models for hydrological climate change studies. Five methods are used to determine weights on an ensemble of 28 global climate models (GCMs) adapted from the Coupled Model Intercomparison Project Phase 5 (CMIP5) database. Using a hydrological model, streamflows are computed over a reference (1961-1990) and future (2061-2090) periods, with and without post-processing climate model outputs. The impacts of using different weighting schemes for GCM simulations are then analyzed in terms of ensemble mean and uncertainty. The results show that weighting GCMs has a limited impact on both projected future climate in term of precipitation and temperature changes and hydrology in terms of nine different streamflow criteria. These results apply to both raw and post-processed GCM model outputs, thus supporting the view that climate models should be considered equiprobable.

  3. Weight information labels on media models reduce body dissatisfaction in adolescent girls

    NARCIS (Netherlands)

    Veldhuis, Jolanda; Konijn, Elly A; Seidell, Jacob C

    2012-01-01

    PURPOSE: To examine how weight information labels on variously sized media models affect (pre)adolescent girls' body perceptions and how they compare themselves with media models. METHODS: We used a three (body shape: extremely thin vs. thin vs. normal weight) × three (information label: 6-kg

  4. Virtual enterprise model for the electronic components business in the Nuclear Weapons Complex

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, T.J.; Long, K.S.; Sayre, J.A. [Sandia National Labs., Albuquerque, NM (United States); Hull, A.L. [Sandia National Labs., Livermore, CA (United States); Carey, D.A.; Sim, J.R.; Smith, M.G. [Allied-Signal Aerospace Co., Kansas City, MO (United States). Kansas City Div.

    1994-08-01

    The electronic components business within the Nuclear Weapons Complex spans organizational and Department of Energy contractor boundaries. An assessment of the current processes indicates a need for fundamentally changing the way electronic components are developed, procured, and manufactured. A model is provided based on a virtual enterprise that recognizes distinctive competencies within the Nuclear Weapons Complex and at the vendors. The model incorporates changes that reduce component delivery cycle time and improve cost effectiveness while delivering components of the appropriate quality.

  5. Renormalization group flows of the N -component Abelian Higgs model

    Science.gov (United States)

    Fejős, G.; Hatsuda, T.

    2017-09-01

    Flows of the couplings of a theory of an N -component (complex) scalar field coupled to electrodynamics are investigated using the functional renormalization group formalism in d dimensions in covariant gauges. We find charged fixed points for any number of components in d =3 , in accordance with the findings of [G. Fejos and T. Hatsuda, Phys. Rev. D 93, 121701 (2016), 10.1103/PhysRevD.93.121701] for N =1 . It is argued that the appropriate choice of the regulator matrix is indispensable to obtain such a result. Ward-Takahashi identities are analyzed in the presence of the regulator, and their compatibility with the flow equation is investigated in detail.

  6. Modeling Hydraulic Components for Automated FMEA of a Braking System

    Science.gov (United States)

    2014-12-23

    to be reusable and, on the other hand, powerful enough to deliver the predictions relevant to FMEA of braking systems. In this paper, we present...context-independent,  analyze how a stimulus in terms of a local pressure change (e.g. pushing a brake pedal ) propagates through the system...mechanical components and the electronic control unit (ECU) and its software. It contains a tandem pedal actuation unit (with two pistons and two

  7. Scalable Power-Component Models for Concept Testing

    Science.gov (United States)

    2011-08-17

    motor speed can be either positive or negative dependent upon the propelling or regenerative braking scenario. The simulation provides three...the machine during generation or regenerative braking . To use the model, the user modifies the motor model criteria parameters by double-clicking... SYSTEMS ENGINEERING AND TECHNOLOGY SYMPOSIUM MODELING & SIMULATION, TESTING AND VALIDATION (MSTV) MINI-SYMPOSIUM AUGUST 9-11 DEARBORN, MICHIGAN

  8. Exploring component-based approaches in forest landscape modeling

    Science.gov (United States)

    H. S. He; D. R. Larsen; D. J. Mladenoff

    2002-01-01

    Forest management issues are increasingly required to be addressed in a spatial context, which has led to the development of spatially explicit forest landscape models. The numerous processes, complex spatial interactions, and diverse applications in spatial modeling make the development of forest landscape models difficult for any single research group. New...

  9. Model for predicting phosphorus removal in relation to weight of iron ...

    African Journals Online (AJOL)

    Model for predicting phosphorus removal in relation to weight of iron oxide ore and ph during leaching with oxalic acid. ... Model for predicting the concentration of phosphorus removed during leaching of iron oxide ore ... from 32 Countries:.

  10. Group-Based Yogic Weight Loss with Ayurveda-Inspired Components: A Pilot Investigation of Female Yoga Practitioners and Novices.

    Science.gov (United States)

    Braun, Tosca D; Park, Crystal L; Gorin, Amy A; Garivaltis, Hilary; Noggle, Jessica J; Conboy, Lisa A

    2016-09-01

    Overweight/obesity is a pressing international health concern and conventional treatments demonstrate poor long-term efficacy. Preliminary evidence suggests yoga and Ayurveda may be promising approaches, although recent NHIS estimates indicate rare utilization of Ayurveda in the US. Group-based curricula that integrate yoga and Ayurveda-inspired principles to attenuate overweight and obesity across individuals may prove a feasible, disseminable clinical adjunct to facilitate psychosocial health and weight loss and/or maintenance. Determine feasibility and preliminary effectiveness of a ten-week yoga-based, Ayurveda-inspired weight management curriculum (YWL) piloted in female yoga practitioners (Study 1) then refined and tailored for yoga naïves (Study 2), on self-reported psychosocial process variables and % of self-reported total body weight loss (%TBWL). Study 1 enrolled 22 yoga-experienced women (48.2 ± 14.3 years, BMI 30.8 ± 4.2 kg/m2) in a 10-week yoga-based program (YWL-YE). Study 2 enrolled 21 yoga- naïve women (49.4 ± 10.7 years, BMI 35.5 ± 6.8 kg/m2) in a revised 10-week program (YWL-YN). Self-reported weight and self-ratings of mindful eating behavior, body image disturbance, weight loss self-efficacy, body awareness, and self-compassion were collected at baseline, post-treatment (T2), and 3-month follow- up (T3). YWL curricula was feasible in both studies. While attrition rates for both studies favorably compared to other weight management studies, attrition was higher for YWL-YN (28.6%) than YWL-YE (18.2%). In both studies, self-reported process variables and self-reported % TBWL changed in hypothesized directions at T2 and evidenced greater improvement at T3; effect sizes across all process variables were medium (-0.4) to large (-1.8). % TBWL reached clinical significance (>5%) only at T3 for the YWL-YE group. The YWL curricula employed here appear to improve psychosocial health among both overweight/obese yoga-experienced and yoga-naïve women

  11. Parameters Estimation of Geographically Weighted Ordinal Logistic Regression (GWOLR) Model

    Science.gov (United States)

    Zuhdi, Shaifudin; Retno Sari Saputro, Dewi; Widyaningsih, Purnami

    2017-06-01

    A regression model is the representation of relationship between independent variable and dependent variable. The dependent variable has categories used in the logistic regression model to calculate odds on. The logistic regression model for dependent variable has levels in the logistics regression model is ordinal. GWOLR model is an ordinal logistic regression model influenced the geographical location of the observation site. Parameters estimation in the model needed to determine the value of a population based on sample. The purpose of this research is to parameters estimation of GWOLR model using R software. Parameter estimation uses the data amount of dengue fever patients in Semarang City. Observation units used are 144 villages in Semarang City. The results of research get GWOLR model locally for each village and to know probability of number dengue fever patient categories.

  12. Using Avatars to Model Weight Loss Behaviors: Participant Attitudes and Technology Development

    Science.gov (United States)

    Napolitano, Melissa A.; Hayes, Sharon; Russo, Giuseppe; Muresu, Debora; Giordano, Antonio; Foster, Gary D.

    2013-01-01

    Background: Virtual reality and other avatar-based technologies are potential methods for demonstrating and modeling weight loss behaviors. This study examined avatar-based technology as a tool for modeling weight loss behaviors. Methods: This study consisted of two phases: (1) an online survey to obtain feedback about using avatars for modeling weight loss behaviors and (2) technology development and usability testing to create an avatar-based technology program for modeling weight loss behaviors. Results: Results of phase 1 (n = 128) revealed that interest was high, with 88.3% stating that they would participate in a program that used an avatar to help practice weight loss skills in a virtual environment. In phase 2, avatars and modules to model weight loss skills were developed. Eight women were recruited to participate in a 4-week usability test, with 100% reporting they would recommend the program and that it influenced their diet/exercise behavior. Most women (87.5%) indicated that the virtual models were helpful. After 4 weeks, average weight loss was 1.6 kg (standard deviation = 1.7). Conclusion: This investigation revealed a high level of interest in an avatar-based program, with formative work indicating promise. Given the high costs associated with in vivo exposure and practice, this study demonstrates the potential use of avatar-based technology as a tool for modeling weight loss behaviors. PMID:23911189

  13. Modeling social influence through network autocorrelation : constructing the weight matrix

    NARCIS (Netherlands)

    Leenders, Roger Th. A. J.

    Many physical and social phenomena are embedded within networks of interdependencies, the so-called 'context' of these phenomena. In network analysis, this type of process is typically modeled as a network autocorrelation model. Parameter estimates and inferences based on autocorrelation models,

  14. Modeling urban expansion by using variable weights logistic cellular automata

    NARCIS (Netherlands)

    Shu, Bangrong; Bakker, Martha M.; Zhang, Honghui; Li, Yongle; Qin, Wei; Carsjens, Gerrit J.

    2017-01-01

    Simulation models based on cellular automata (CA) are widely used for understanding and simulating complex urban expansion process. Among these models, logistic CA (LCA) is commonly adopted. However, the performance of LCA models is often limited because the fixed coefficients obtained from binary

  15. Obesity and internalized weight stigma: a formulation model for an emerging psychological problem.

    Science.gov (United States)

    Ratcliffe, Denise; Ellison, Nell

    2015-03-01

    Obese individuals frequently experience weight stigma and this is associated with psychological distress and difficulties. The process of external devaluation can lead to negative self-perception and evaluation and some obese individuals develop "internalized weight stigma". The prevalence of weight stigma is well established but there is a lack of information about the interplay between external and internal weight stigma. To synthesize the literature on the psychological effects of weight stigma into a formulation model that addresses the maintenance of internalized weight stigma. Current research on the psychological impact of weight stigma was reviewed. We identify cognitive, behavioural and attentional processes that maintain psychological conditions where self-evaluation plays a central role. A model was developed based on clinical utility. The model focuses on identifying factors that influence and maintain internalized weight stigma. We highlight the impact of negative societal and interpersonal experiences of weight stigma on how individuals view themselves as an obese person. Processing the self as a stigmatized individual is at the core of the model. Maintenance factors include negative self-judgements about the meaning of being an obese individual, attentional and mood shifts, and avoidance and safety behaviours. In addition, eating and weight management behaviours become deregulated and maintain both obesity and weight stigma. As obesity increases, weight stigma and the associated psychological effects are likely to increase. We provide a framework for formulating and intervening with internalized weight stigma as well as making therapists aware of the applicability and transferability of strategies that they may already use with other presenting problems.

  16. Protein and lipid accretion in body components of growing pigs : effects of body weight and nutrient intake

    NARCIS (Netherlands)

    Bikker, P.

    1994-01-01

    In pig production, optimization of the conversion of animal feeding-stuffs into body components, especially lean meat, requires knowledge of the response relationships between nutrient intake and animal performance. In this study, the separate effects of protein and energy intake on rate

  17. Relationship of C-reactive protein with components of the metabolic syndrome in normal-weight and overweight elderly

    NARCIS (Netherlands)

    Hoekstra, T.; Geleijnse, J.M.; Schouten, E.G.; Kluft, C.; Kok, F.J.

    2005-01-01

    C-reactive protein (CRP) is known to be elevated in the metabolic syndrome. We aimed to explore in more detail the relationship between CRP and other components of the metabolic syndrome in a general population of 605 Dutch elderly individuals aged 65¿84 years. Methods and results Data were

  18. PyCatch: Component based hydrological catchment modelling

    NARCIS (Netherlands)

    Lana-Renault, N.|info:eu-repo/dai/nl/337170177; Karssenberg, D.J.|info:eu-repo/dai/nl/241557119

    2013-01-01

    Dynamic numerical models are powerful tools for representing and studying environmental processes through time. Usually they are constructed with environmental modelling languages, which are high-level programming languages that operate at the level of thinking of the scientists. In this paper we

  19. A New Global Regression Analysis Method for the Prediction of Wind Tunnel Model Weight Corrections

    Science.gov (United States)

    Ulbrich, Norbert Manfred; Bridge, Thomas M.; Amaya, Max A.

    2014-01-01

    A new global regression analysis method is discussed that predicts wind tunnel model weight corrections for strain-gage balance loads during a wind tunnel test. The method determines corrections by combining "wind-on" model attitude measurements with least squares estimates of the model weight and center of gravity coordinates that are obtained from "wind-off" data points. The method treats the least squares fit of the model weight separate from the fit of the center of gravity coordinates. Therefore, it performs two fits of "wind- off" data points and uses the least squares estimator of the model weight as an input for the fit of the center of gravity coordinates. Explicit equations for the least squares estimators of the weight and center of gravity coordinates are derived that simplify the implementation of the method in the data system software of a wind tunnel. In addition, recommendations for sets of "wind-off" data points are made that take typical model support system constraints into account. Explicit equations of the confidence intervals on the model weight and center of gravity coordinates and two different error analyses of the model weight prediction are also discussed in the appendices of the paper.

  20. Disentangling density-dependent dynamics using full annual cycle models and Bayesian model weight updating

    Science.gov (United States)

    Robinson, Orin J.; McGowan, Conor P.; Devers, Patrick K.

    2017-01-01

    Density dependence regulates populations of many species across all taxonomic groups. Understanding density dependence is vital for predicting the effects of climate, habitat loss and/or management actions on wild populations. Migratory species likely experience seasonal changes in the relative influence of density dependence on population processes such as survival and recruitment throughout the annual cycle. These effects must be accounted for when characterizing migratory populations via population models.To evaluate effects of density on seasonal survival and recruitment of a migratory species, we used an existing full annual cycle model framework for American black ducks Anas rubripes, and tested different density effects (including no effects) on survival and recruitment. We then used a Bayesian model weight updating routine to determine which population model best fit observed breeding population survey data between 1990 and 2014.The models that best fit the survey data suggested that survival and recruitment were affected by density dependence and that density effects were stronger on adult survival during the breeding season than during the non-breeding season.Analysis also suggests that regulation of survival and recruitment by density varied over time. Our results showed that different characterizations of density regulations changed every 8–12 years (three times in the 25-year period) for our population.Synthesis and applications. Using a full annual cycle, modelling framework and model weighting routine will be helpful in evaluating density dependence for migratory species in both the short and long term. We used this method to disentangle the seasonal effects of density on the continental American black duck population which will allow managers to better evaluate the effects of habitat loss and potential habitat management actions throughout the annual cycle. The method here may allow researchers to hone in on the proper form and/or strength of

  1. Multivariable frequency weighted model order reduction for control synthesis

    Science.gov (United States)

    Schmidt, David K.

    1989-01-01

    Quantitative criteria are presented for model simplification, or order reduction, such that the reduced order model may be used to synthesize and evaluate a control law, and the stability robustness obtained using the reduced order model will be preserved when controlling the full-order system. The error introduced due to model simplification is treated as modeling uncertainty, and some of the results from multivariate robustness theory are brought to bear on the model simplification problem. A numerical procedure developed previously is shown to lead to results that meet the necessary criteria. The procedure is applied to reduce the model of a flexible aircraft. Also, the importance of the control law itself, in meeting the modeling criteria, is underscored. An example is included that demonstrates that an apparently robust control law actually amplifies modest modeling errors in the critical frequency region, and leads to undesirable results. The cause of this problem is associated with the canceling of lightly damped transmission zeroes in the plant. An attempt is made to expand on some of the earlier results and to further clarify the theoretical basis behind the proposed methodology.

  2. Comprehensive FDTD modelling of photonic crystal waveguide components

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Borel, Peter Ingo; Frandsen, Lars Hagedorn

    2004-01-01

    Planar photonic crystal waveguide structures have been modelled using the finite-difference-time-domain method and perfectly matched layers have been employed as boundary conditions. Comprehensive numerical calculations have been performed and compared to experimentally obtained transmission spec...

  3. Scalable Power-Component Models for Concept Testing

    Science.gov (United States)

    2011-08-16

    Technology: Permanent Magnet Brushless DC machine • Model: Self-generating torque-speed-efficiency map • Future improvements: Induction machine ...system to the standard driveline – Example: BAS System – 3 kW system ISG Block, Rev. 2.0 Revision 2.0 • Four quadrant • PM Brushless Machine • Speed...and systems engineering. • Scope: Scalable, generic MATLAB/Simulink models in three areas: – Electromechanical machines (Integrated Starter

  4. Coating Weight Model for the Continuous Hot-Dip Galvanizing Process

    Science.gov (United States)

    Elsaadawy, E. A.; Hanumanth, G. S.; Balthazaar, A. K. S.; McDermid, J. R.; Hrymak, A. N.; Forbes, J. F.

    2007-06-01

    A coating weight model was developed to describe the pressure and wall shear stress distributions as functions of slot gap ( d) and impingement distance ( Z), for the air knife wiping of the liquid zinc coatings in continuous hot dip galvanizing at ratios of Z/ d ≤ 8. This model was then used in validation studies in order to predict the coating weight as a function of the process parameters. The model was based on improved correlations for pressure and shear stress developed by a combination of experimental and computation techniques, which has resulted in more accurate predictions of coating weight validated using industrial coil average coating weight data, particularly for coating weights of up to 75 g/m2. For this region, the maximum deviation between the predicted and measured coating weights was 8 pct. The coating weight model was further developed by incorporating a lumped heat-transfer analysis to predict the solidification “dry line” of the coating. For a typical continuous galvanizing process, the model predicts an 80 pct coating solid fraction for a coating weight of 130 g/m2 to occur at 15 m from the air knives, which agrees qualitatively with visual observations in continuous galvanizing lines.

  5. Fuzzy Multiple Criteria Decision Making Model with Fuzzy Time Weight Scheme

    OpenAIRE

    Chin-Yao Low; Sung-Nung Lin

    2013-01-01

    In this study, we purpose a common fuzzy multiple criteria decision making model. A brand new concept - fuzzy time weighted scheme is adopted for considering in the model to establish a fuzzy multiple criteria decision making with time weight (FMCDMTW) model. A real case of fuzzy multiple criteria decision making (FMCDM) problems to be considering in this study. The performance evaluation of auction websites based on all criteria proposed in related literature. Obviously, the problem under in...

  6. Component-Based Model for Single-Plate Shear Connections with Pretension and Pinched Hysteresis.

    Science.gov (United States)

    Weigand, Jonathan M

    2017-02-01

    Component-based connection models provide a natural framework for modeling the complex behaviors of connections under extreme loads by capturing both the individual behaviors of the connection components, such as the bolt, shear plate, and beam web, and the complex interactions between those components. Component-based models also provide automatic coupling between the in-plane flexural and axial connection behaviors, a feature that is essential for modeling the behavior of connections under column removal. This paper presents a new component-based model for single-plate shear connections that includes the effects of pre-tension in the bolts and provides the capability to model standard and slotted holes. The component-based models are exercised under component-level deformations calculated from the connection demands via a practical rigid-body displacement model, so that the results of the presented modeling approach remains hand-calculable. Validation cases are presented for connections subjected to both seismic and column removal loading. These validation cases show that the component-based model is capable of predicting the response of single-plate shear connections for both seismic and column removal loads.

  7. Modelling plexcitons of periodic gold nanorod arrays with molecular components

    Science.gov (United States)

    Liu, B.; Yan, H.; Stosch, R.; Wolfram, B.; Bröring, M.; Bakin, A.; Schilling, M.; Lemmens, P.

    2017-05-01

    Plasmonic or exciton/plasmon (plexcitonic) systems are presently described based on electromagnetic models, ignoring the need for an improved microscopic understanding. This is based on the fact that a full quantum mechanical approach on a micrometer scale still represents a considerable challenge. In this paper we report on the experimental observation of plexcitons in 2D gold nanorod array systems coupled to dye molecules and we provide a description of the experimental data using a quantum model. We show that treating the collective behavior in the array as being represented by a single quasiparticle is a suitable approximation that offers the opportunity to avoid the complicated calculation of long-distance interactions between the individual nanoparticles of the plexcitonic, periodic system. This enables us to model the optical response of plasmons in nanostructured arrays in contact with quantum emitters and to derive microscopic informations. Our work provides a potential tool for the design of plexcitonic devices, which rely on periodic metallic nanostructures.

  8. Process evaluation of TXT2BFiT: a multi-component mHealth randomised controlled trial to prevent weight gain in young adults.

    Science.gov (United States)

    Partridge, Stephanie R; Allman-Farinelli, Margaret; McGeechan, Kevin; Balestracci, Kate; Wong, Annette T Y; Hebden, Lana; Harris, Mark F; Bauman, Adrian; Phongsavan, Philayrath

    2016-01-19

    TXT2BFiT was one of the first few innovative mHealth programs designed for young adults (18-35 years) with demonstrated efficacy in weight management. However, research is lacking to understand intervention effectiveness, especially in complex, multi-component mHealth programs. This paper investigates participant perceptions of and engagement with the mHealth program components in the TXT2BFiT to understand program effects. Process evaluation data were collected continuously for the study duration. The TXT2BFiT program was a multi-component lifestyle program delivered intensively for 3-month followed by a 6-month maintenance phase. Program components included personalised coaching calls, text messages, emails, smartphone apps and website access. Process evaluation measures included frequency of use of components and frequency for number of components used (online survey data); dose delivered and engagement with program components (researcher logs and web platform reports); frequency, timing and difficulties experienced with program components (online survey data) and overall perceptions of program components (online survey data and semi-structured telephone interviews). Qualitative data analysis was performed using NVivo10. Over 80% of participants completed post-intervention (3-months, intervention, n = 110, control n = 104) and follow-up surveys (9-months, intervention, n = 96, control n = 104). Thirty intervention participants completed semi-structured telephone interviews. Participants reported high use of coaching calls, text messages and emails and no issues in content delivery from these components. These components were described as helping them to achieve their goals. Website and app use and engagement was low for the duration of the program. Participants would prefer incorporation of the self-monitoring apps and website resources into one smartphone application that can be individualised by entry of their personal data. Our process

  9. Rare earth-doped integrated glass components: modeling and optimization

    DEFF Research Database (Denmark)

    Lumholt, Ole; Bjarklev, Anders Overgaard; Rasmussen, Thomas

    1995-01-01

    For the integrated optic erbium-doped phosphate silica-amplifier, a comprehensive model is presented which includes high-concentration dissipative ion-ion interactions. Based on actual waveguide parameters, the model is seen to reproduce measured gains closely. A rigorous design optimization...... is performed, and the influence of variations in the launched pump power, the core cross section, the waveguide length, the erbium concentration, and the background losses are evaluated. Optimal design proposals are given, and the process reproducibility of the proposed optimal design is examined. Requirements...

  10. Weight Control of Sports Training Chaos Predicting Model

    National Research Council Canada - National Science Library

    Yanping Tang; Guanghui Li

    2014-01-01

    As the sports training predicting model based on chaos local predicting method still has the low predicting accuracy and the slow function speed problems, this paper proposes a sports training chaos...

  11. Confidence intervals for intraclass correlation coefficients in variance components models

    NARCIS (Netherlands)

    Demetrashvili, Nino; Wit, Ernst C.; van den Heuvel, Edwin R.

    2016-01-01

    Confidence intervals for intraclass correlation coefficients in agreement studies with continuous outcomes are model-specific and no generic approach exists. This paper provides two generic approaches for intraclass correlation coefficients of the form Sigma q=1 2). The first approach uses

  12. Physiological comparisons of two soybean cultivars differing in canopy photosynthesis. II. Variation in specific leaf weight, nitrogen, and protein components.

    Science.gov (United States)

    Wells, R; Ashley, D A; Boerma, H R; Reger, B J

    1986-01-01

    Cultivar differences in canopy apparent photosynthesis (CAP) have been observed in soybean (Glycine max (L.) Merr.) but little is known about the physiological mechanisms which are responsible for such differences. This study was initiated to determine if variation in ribulose 1,5-bisphosphate carboxylase (RuBPCase) and soluble protein exists among cultivars which differ in CAP during reproductive growth. In addition, the relationship between specific leaf weight (SLW) and leaf protein was examined. Two Maturity Group VI cultivars, 'Tracy' (high CAP) and 'Davis' (low CAP), were grown in the field during 1979, 1980, and 1981 and in a greenhouse experiment. Leaves located at two canopy positions (topmost, fully expanded leaf and eighth node from the top) in 1979 and three canopy positions (those mentioned, plus the fourth node from the top) in 1980 and 1981 were sampled. Leaves at the two upper canopy positions exhibited greater SLW, RuBPCase m(-2), and soluble protein m(-2) than found at the eighth node down. Photosynthetic capacity of leaves at inner canopy regions was therefore affected by both light penetration into the canopy and leaf protein status. Over the three year period, the SLW was 23 percent and the soluble protein m(-2) leaf 21 percent greater in Tracy than in Davis. Although the trend in RuBPCase m(-2) leaf was not significant, it was consistently greater in Tracy in the field and greenhouse. No cultivar differences were observed when the proteins were expressed on a unit of leaf dry weight. The quantity of RuBPCase per unit leaf area was positively correlated with SLW with significant partial correlation coefficients of 0.62, 0.67, 0.35, and 0.82 for 1979, 1980, 1981, and the greenhouse study, respectively. Since these cultivars have similar leaf area indices during September, the greater SLW of Tracy is translated into more photosynthetic proteins per unit ground area and higher CAP rate.

  13. Monitor-Based Statistical Model Checking for Weighted Metric Temporal Logic

    DEFF Research Database (Denmark)

    Bulychev, Petr; David, Alexandre; Larsen, Kim Guldstrand

    2012-01-01

    We present a novel approach and implementation for ana- lysing weighted timed automata (WTA) with respect to the weighted metric temporal logic (WMTL≤ ). Based on a stochastic semantics of WTAs, we apply statistical model checking (SMC) to estimate and test probabilities of satisfaction...

  14. Optimization of medium components for high-molecular-weight hyaluronic acid production by Streptococcus sp. ID9102 via a statistical approach.

    Science.gov (United States)

    Im, Jong-Hyuk; Song, Jung-Min; Kang, Jae-Hoon; Kang, Dae-Jung

    2009-11-01

    Hyaluronic acid (HA), linear high-molecular-weight glycosaminoglycan produced from Streptococcus sp., has raised interest in the medical and cosmetics industries because of the various biological functions of HA. In this paper, we report on the optimization of medium components for HA production in Streptococcus sp. ID9102 (KCTC 11935BP) by two-step optimization (one-factor-at-a-time and taguchi orthogonal array design). In the first step, medium components, such as carbon, nitrogen, phosphate, and mineral sources, were selected for HA production in Streptococcus sp. ID9102 (KCTC 11935BP) using the one-factor-at-a-time method. In the second step, the concentration of the selected medium components was optimized using taguchi orthogonal array design. The design for medium optimization was developed and analyzed using MINITAB 14 software. In addition, the effect of amino acid and organic acid, such as glutamine, glutamate, and oxalic acid, was studied for HA production in Streptococcus sp. ID9102 (KCTC 11935BP). Through these processes, the optimum medium comprising 4% glucose, 0.75% yeast extract, 1.0% casein peptone, 0.25% K(2)HPO(4), 0.05% MgCl(2), 0.5% NaCl, 0.04% glutamine, 0.06% glutamate, and 0.02% oxalic acid was determined. We were able to produce HA with a molecular weight of 5.9 x 10(6) at a productivity of 6.94 g/l on pilot scale fermentation.

  15. A QUADTREE ORGANIZATION CONSTRUCTION AND SCHEDULING METHOD FOR URBAN 3D MODEL BASED ON WEIGHT

    Directory of Open Access Journals (Sweden)

    C. Yao

    2017-09-01

    Full Text Available The increasement of Urban 3D model precision and data quantity puts forward higher requirements for real-time rendering of digital city model. Improving the organization, management and scheduling of 3D model data in 3D digital city can improve the rendering effect and efficiency. This paper takes the complexity of urban models into account, proposes a Quadtree construction and scheduling rendering method for Urban 3D model based on weight. Divide Urban 3D model into different rendering weights according to certain rules, perform Quadtree construction and schedule rendering according to different rendering weights. Also proposed an algorithm for extracting bounding box extraction based on model drawing primitives to generate LOD model automatically. Using the algorithm proposed in this paper, developed a 3D urban planning&management software, the practice has showed the algorithm is efficient and feasible, the render frame rate of big scene and small scene are both stable at around 25 frames.

  16. a Quadtree Organization Construction and Scheduling Method for Urban 3d Model Based on Weight

    Science.gov (United States)

    Yao, C.; Peng, G.; Song, Y.; Duan, M.

    2017-09-01

    The increasement of Urban 3D model precision and data quantity puts forward higher requirements for real-time rendering of digital city model. Improving the organization, management and scheduling of 3D model data in 3D digital city can improve the rendering effect and efficiency. This paper takes the complexity of urban models into account, proposes a Quadtree construction and scheduling rendering method for Urban 3D model based on weight. Divide Urban 3D model into different rendering weights according to certain rules, perform Quadtree construction and schedule rendering according to different rendering weights. Also proposed an algorithm for extracting bounding box extraction based on model drawing primitives to generate LOD model automatically. Using the algorithm proposed in this paper, developed a 3D urban planning&management software, the practice has showed the algorithm is efficient and feasible, the render frame rate of big scene and small scene are both stable at around 25 frames.

  17. Economic weights for feed intake in the growing pig derived from a growth model and an economic model

    NARCIS (Netherlands)

    Hermesch, S.; Kanis, E.; Eissen, J.J.

    2003-01-01

    Economic weights are obtained for feed intake using a growth model and an economic model. The underlying concept of the growth model is the linear plateau model. Parameters of this model are the marginal ratio (MR) of extra fat and extra protein deposition with increasing feed intake (FI) and the

  18. Measuring and Modeling Component and Whole-System Carbon Exchange

    Energy Technology Data Exchange (ETDEWEB)

    Paul Bolstad

    2006-11-01

    We measured ecosystem/atmospheric carbon exchange through a range of methods covering a range of scales. We measured carbon (C) pool and flux for a number of previously poorly quantified ecosystems, developed measurement and modeling methods, and applied these to substantially increase the accuracy and reduce uncertainty in ecosystem/atmospheric C exchange at a range of scales. It appears most upland forests are weak to strong carbon sinks, and status depends largely on disturbance history and age. Net flux from wetland ecosystems appears to be from weak sinks to moderate sources of C to the atmosphere. We found limited evidence for a positive feedback of warming/drying to increased ecosystem C emissions. We further developed multi-source integration and modeling methods, including multiple towers, to scale estimates to landscapes and larger regions.

  19. Modelling the Epistemic Uncertainty in the Vulnerability Assessment Component of an Earthquake Loss Model

    Science.gov (United States)

    Crowley, H.; Modica, A.

    2009-04-01

    Loss estimates have been shown in various studies to be highly sensitive to the methodology employed, the seismicity and ground-motion models, the vulnerability functions, and assumed replacement costs (e.g. Crowley et al., 2005; Molina and Lindholm, 2005; Grossi, 2000). It is clear that future loss models should explicitly account for these epistemic uncertainties. Indeed, a cause of frequent concern in the insurance and reinsurance industries is precisely the fact that for certain regions and perils, available commercial catastrophe models often yield significantly different loss estimates. Of equal relevance to many users is the fact that updates of the models sometimes lead to very significant changes in the losses compared to the previous version of the software. In order to model the epistemic uncertainties that are inherent in loss models, a number of different approaches for the hazard, vulnerability, exposure and loss components should be clearly and transparently applied, with the shortcomings and benefits of each method clearly exposed by the developers, such that the end-users can begin to compare the results and the uncertainty in these results from different models. This paper looks at an application of a logic-tree type methodology to model the epistemic uncertainty in the vulnerability component of a loss model for Tunisia. Unlike other countries which have been subjected to damaging earthquakes, there has not been a significant effort to undertake vulnerability studies for the building stock in Tunisia. Hence, when presented with the need to produce a loss model for a country like Tunisia, a number of different approaches can and should be applied to model the vulnerability. These include empirical procedures which utilise observed damage data, and mechanics-based methods where both the structural characteristics and response of the buildings are analytically modelled. Some preliminary applications of the methodology are presented and discussed

  20. The effect of a multi-component camp-based weight-loss program on children's motor skills and physical fitness

    DEFF Research Database (Denmark)

    Larsen, Kristian Traberg; Huang, Tao; Larsen, Lisbeth Runge

    2016-01-01

    BACKGROUND: Many weight-loss programs in children are performed without specific foci on training both physical fitness and motor skills. The aim of this study was to describe the effect of a one-year weight-loss program on children's motor skills and physical fitness. METHODS: Participants...... included 115 overweight fifth-grade children (12.0 years) randomized into either a Day-Camp Intervention Arm (DCIA), with a subsequent family-based support program or a low-intense Standard Intervention Arm (SIA). Physical fitness was assessed by vertical jump, hand grip strength, and a progressive cardio...... the DCIA compared to the SIA. Contrary to the expected, children from the SIA improved aiming and catching skills relative to the DCIA children. Overall z-scores of the physical fitness components and cardio-respiratory fitness improved more in children from the DCIA compared to children from the SIA...

  1. Forecasting Daily Time Series using Periodic Unobserved Components Time Series Models

    NARCIS (Netherlands)

    Koopman, Siem Jan; Ooms, Marius

    2004-01-01

    We explore a periodic analysis in the context of unobserved components time series models that decompose time series into components of interest such as trend and seasonal. Periodic time series models allow dynamic characteristics to depend on the period of the year, month, week or day. In the

  2. Weight information labels on media models reduce body dissatisfaction in adolescent girls.

    Science.gov (United States)

    Veldhuis, Jolanda; Konijn, Elly A; Seidell, Jacob C

    2012-06-01

    To examine how weight information labels on variously sized media models affect (pre)adolescent girls' body perceptions and how they compare themselves with media models. We used a three (body shape: extremely thin vs. thin vs. normal weight) × three (information label: 6-kg underweight vs. 3-kg underweight vs. normal weight) experimental design in three age-groups (9-10 years, 12-13 years, and 15-16 years; n = 184). The girls completed questionnaires after exposure to media models. Weight information labels affected girls' body dissatisfaction, social comparison with media figures, and objectified body consciousness. Respondents exposed to an extremely thin body shape labeled to be of "normal weight" were most dissatisfied with their own bodies and showed highest levels of objectified body consciousness and comparison with media figures. An extremely thin body shape combined with a corresponding label (i.e., 6-kg underweight), however, induced less body dissatisfaction and less comparison with the media model. Age differences were also found to affect body perceptions: adolescent girls showed more negative body perceptions than preadolescents. Weight information labels may counteract the generally media-induced thin-body ideal. That is, when the weight labels appropriately informed the respondents about the actual thinness of the media model's body shape, girls were less affected. Weight information labels also instigated a normalization effect when a "normal-weight" label was attached to underweight-sized media models. Presenting underweight as a normal body shape, clearly increased body dissatisfaction in girls. Results also suggest age between preadolescence and adolescence as a critical criterion in responding to media models' body shape. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  3. Time-series modeling of long-term weight self-monitoring data.

    Science.gov (United States)

    Helander, Elina; Pavel, Misha; Jimison, Holly; Korhonen, Ilkka

    2015-08-01

    Long-term self-monitoring of weight is beneficial for weight maintenance, especially after weight loss. Connected weight scales accumulate time series information over long term and hence enable time series analysis of the data. The analysis can reveal individual patterns, provide more sensitive detection of significant weight trends, and enable more accurate and timely prediction of weight outcomes. However, long term self-weighing data has several challenges which complicate the analysis. Especially, irregular sampling, missing data, and existence of periodic (e.g. diurnal and weekly) patterns are common. In this study, we apply time series modeling approach on daily weight time series from two individuals and describe information that can be extracted from this kind of data. We study the properties of weight time series data, missing data and its link to individuals behavior, periodic patterns and weight series segmentation. Being able to understand behavior through weight data and give relevant feedback is desired to lead to positive intervention on health behaviors.

  4. Estimation of genotype X environment interactions, in a grassbased system, for milk yield, body condition score,and body weight using random regression models

    NARCIS (Netherlands)

    Berry, D.P.; Buckley, F.; Dillon, P.; Evans, R.D.; Rath, M.; Veerkamp, R.F.

    2003-01-01

    (Co)variance components for milk yield, body condition score (BCS), body weight (BW), BCS change and BW change over different herd-year mean milk yields (HMY) and nutritional environments (concentrate feeding level, grazing severity and silage quality) were estimated using a random regression model.

  5. Three Fundamental Components of the Autopoiesic Leadership Model

    Directory of Open Access Journals (Sweden)

    Mateja Kalan

    2017-06-01

    Full Text Available Research Question (RQ: What type of leadership could be developed upon transformational leadership? Purpose: The purpose of the research was to create a new leadership style. Its variables can be further developed upon transformational leadership variables. Namely, this leadership style is known as a successful leadership style in successful organisations. Method: In the research of published papers from scientific databases, we relied on the triangulation of theories. To clarify the research question, we have researched different authors, who based their research papers on different hypotheses. In some articles, hypotheses were even contradictory. Results: Through the research, we have concluded that authors often changed certain variables when researching the topic of transformational leadership. We have correlated these variables and developed a new model, naming it autopoiesic leadership. Its main variables are (1 goal orientation, (2 emotional sensitivity, and (3 manager’s flexibility in organisations. Organisation: Our research can have a positive effect on managers in terms of recognising the importance of selected variables. Practical application of autopoiesic leadership can imply more efficiency in business processes of a company, increasing its financial performance. Society: Autopoiesic leadership is a leadership style that largely influences the use of the individual’s internal resources. Thus, she or he becomes internally motivated, and this is the basis for quality work. This strengthens employees’ social aspect which consequently also has a positive effect on their life outside the organisational system, i.e. their family and broader living environment. Originality: In the worldwide literature, we have noticed the concept autopoiesis in papers about management subjects, but the autopoiesic leadership model has not been developed so far. Limitations / Future Research: We based our research on the triangulation of theories

  6. Genetic and Modeling Approaches Reveal Distinct Components of Impulsive Behavior.

    Science.gov (United States)

    Nautiyal, Katherine M; Wall, Melanie M; Wang, Shuai; Magalong, Valerie M; Ahmari, Susanne E; Balsam, Peter D; Blanco, Carlos; Hen, René

    2017-05-01

    Impulsivity is an endophenotype found in many psychiatric disorders including substance use disorders, pathological gambling, and attention deficit hyperactivity disorder. Two behavioral features often considered in impulsive behavior are behavioral inhibition (impulsive action) and delayed gratification (impulsive choice). However, the extent to which these behavioral constructs represent distinct facets of behavior with discrete biological bases is unclear. To test the hypothesis that impulsive action and impulsive choice represent statistically independent behavioral constructs in mice, we collected behavioral measures of impulsivity in a single cohort of mice using well-validated operant behavioral paradigms. Mice with manipulation of serotonin 1B receptor (5-HT1BR) expression were included as a model of disordered impulsivity. A factor analysis was used to characterize correlations between the measures of impulsivity and to identify covariates. Using two approaches, we dissociated impulsive action from impulsive choice. First, the absence of 5-HT1BRs caused increased impulsive action, but not impulsive choice. Second, based on an exploratory factor analysis, a two-factor model described the data well, with measures of impulsive action and choice separating into two independent factors. A multiple-indicator multiple-causes analysis showed that 5-HT1BR expression and sex were significant covariates of impulsivity. Males displayed increased impulsivity in both dimensions, whereas 5-HT1BR expression was a predictor of increased impulsive action only. These data support the conclusion that impulsive action and impulsive choice are distinct behavioral phenotypes with dissociable biological influences that can be modeled in mice. Our work may help inform better classification, diagnosis, and treatment of psychiatric disorders, which present with disordered impulsivity.

  7. Effects of error covariance structure on estimation of model averaging weights and predictive performance

    Science.gov (United States)

    Lu, Dan; Ye, Ming; Meyer, Philip D.; Curtis, Gary P.; Shi, Xiaoqing; Niu, Xu-Feng; Yabusaki, Steve B.

    2013-01-01

    When conducting model averaging for assessing groundwater conceptual model uncertainty, the averaging weights are often evaluated using model selection criteria such as AIC, AICc, BIC, and KIC (Akaike Information Criterion, Corrected Akaike Information Criterion, Bayesian Information Criterion, and Kashyap Information Criterion, respectively). However, this method often leads to an unrealistic situation in which the best model receives overwhelmingly large averaging weight (close to 100%), which cannot be justified by available data and knowledge. It was found in this study that this problem was caused by using the covariance matrix, CE, of measurement errors for estimating the negative log likelihood function common to all the model selection criteria. This problem can be resolved by using the covariance matrix, Cek, of total errors (including model errors and measurement errors) to account for the correlation between the total errors. An iterative two-stage method was developed in the context of maximum likelihood inverse modeling to iteratively infer the unknown Cek from the residuals during model calibration. The inferred Cek was then used in the evaluation of model selection criteria and model averaging weights. While this method was limited to serial data using time series techniques in this study, it can be extended to spatial data using geostatistical techniques. The method was first evaluated in a synthetic study and then applied to an experimental study, in which alternative surface complexation models were developed to simulate column experiments of uranium reactive transport. It was found that the total errors of the alternative models were temporally correlated due to the model errors. The iterative two-stage method using Cekresolved the problem that the best model receives 100% model averaging weight, and the resulting model averaging weights were supported by the calibration results and physical understanding of the alternative models. Using Cek

  8. Weight information labels on media models reduce body dissatisfaction in adolescent girls

    National Research Council Canada - National Science Library

    Veldhuis, Jolanda; Konijn, Elly A; Seidell, Jacob C

    2012-01-01

    ...)adolescent girls' body perceptions and how they compare themselves with media models. METHODS: We used a three (body shape: extremely thin vs. thin vs. normal weight) × three (information label: 6-kg underweight vs...

  9. A Multi-Component Day-Camp Weight-Loss Program Is Effective in Reducing BMI in Children after One Year

    DEFF Research Database (Denmark)

    Larsen, Kristian Traberg; Huang, Tao; Ried-Larsen, Mathias

    2016-01-01

    The objective of the present study was to evaluate the effectiveness of a one-year multi-component immersive day-camp weight-loss intervention for children with overweight and obesity. The study design was a parallel-group randomized controlled trial. One hundred fifteen 11-13-year-old children...... with overweight and obesity were randomized into either: A six-week day-camp intervention arm focusing on increased physical activity, and healthy diet followed by a subsequent one-year family-based intervention, or a standard intervention arm consisting of one weekly exercise session for six weeks. Body mass...

  10. Postmortem heart weight modelled using piecewise linear regression in 27,645 medicolegal autopsy cases.

    Science.gov (United States)

    Wingren, Carl Johan; Ottosson, Anders

    2015-07-01

    The interpretation of postmortem heart weight is often difficult, and references for normal heart weight are important. However, to assess the cause of death at a medicolegal autopsy it is also important to have references based on an unselected population of medicolegal autopsy cases with non-natural causes of death (not due directly to disease). We aimed at studying and deriving references for adult heart weight by considering sex, age and body size in cases with an external cause of death. We identified all medicolegal autopsies in Sweden from 1999 to 2013 (n=79,778) and included 27,645 cases. We applied multivariate piecewise linear regression models in three strata of body mass-underweight, normal-/overweight and obesity. We observed that approximately 50% of the variation in heart weight was explained by age, sex and body size. These variables were slightly less important in explaining the variation in heart weight in the underweight and obese compared to in those normal or overweight. Based on the linear regression models we present equations to calculate the predicted heart weight with reference intervals using age, sex, body weight and height. We provide an online heart weight calculator (http://lundforensicmedicine.com) based on these equations. In the forensic interpretation of postmortem heart weights, we suggest that heart weight references derived in cases with an external cause of death is an important complement to references solely based on healthy and normal hearts. Furthermore, the heart weight references presented are derived from a large population, with sufficient numbers for separate models in underweight, normal-/overweight and obese populations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Six Different Models for Estimation of Genetic Parameters and Breeding Values for Pre-weaning and Post-weaning Weights in Suckler Cattle

    OpenAIRE

    Ulutaş, Zafer

    2001-01-01

    Estimates of (co)variance components and breeding values for pre-weaning (100-day) and post-weaning (300-day) weights were obtained for a commercial herd of Welsh Black cattle recorded from 1976 to 1996. Estimates were obtained from six animal models ranging from a model with only an additive direct effect to a model that also included an additive maternal effect, a maternal permanent environmental effect and a covariance between additive direct and additive maternal effects. The most appropr...

  12. A weighted network evolving model with capacity constraints

    Science.gov (United States)

    Wu, XiaoHuan; Zhu, JinFu; Wu, WeiWei; Ge, Wei

    2013-09-01

    Most of existing works on complex network assumed that the nodes and edges were uncapacitated during the evolving process, and displayed "rich club" phenomenon. Here we will show that the "rich club" could be changed to "common rich" if we consider the node capacity. In this paper, we define the node and edge attractive index with node capacity, and propose a new evolving model on the base of BBV model, with evolving simulations of the networks. In the new model, an entering node is linked with an existing node according to the preferential attachment mechanism defined with the attractive index of the existing node. We give the theoretical approximation and simulation solutions. If node capacity is finite, the rich node may not be richer further when the node strength approaches or gets to the node capacity. This is confirmed by analyzing the passenger traffic and routes of Chinese main airports. Due to node strength being function of time t, we can use the theoretical approximation solution to forecast how node strength changes and the time when node strength reaches its maximum value.

  13. Validity of Weight Estimation Models in Pigs Reared under Different Management Conditions

    Directory of Open Access Journals (Sweden)

    Marvelous Sungirai

    2014-01-01

    Full Text Available A study was carried out to determine the relationship between linear body measurements and live weight in Landrace and Large White pigs reared under different management conditions in Zimbabwe. Data was collected for body length, heart girth, and live weight in 358 pigs reared under intensive commercial conditions. The stepwise multiple linear regression method was done to develop a model using a random selection of 202 records of pigs. The model showed that age, body length, and heart girth were useful predictors of live weight in these pigs with significantly high positive correlations observed. The model was internally validated using records of the remaining 156 pigs and there was a significantly high positive correlation between the actual and predicted weights. The model was then externally validated using 40 market age pigs reared under communal conditions and there was a significantly low positive correlation between the actual and predicted weights. The results of the study show that while linear measurements can be useful in predicting pig weights the appropriateness of the model is also influenced by the management of the pigs. Models can only be applicable to pigs reared under similar conditions of management.

  14. Total ankle replacement in obese patients: component stability, weight change, and functional outcome in 118 consecutive patients.

    Science.gov (United States)

    Barg, Alexej; Knupp, Markus; Anderson, Andrew E; Hintermann, Beat

    2011-10-01

    Obesity is a growing problem in Europe and the United States. While obesity has been linked to poor outcomes after total knee or hip replacement, there are no data addressing outcomes in obese patients who underwent total ankle replacement (TAR). This retrospective chart review included 118 patients (123 ankles) with a minimum body mass index (BMI) of 30 kg/m2 who underwent TAR between May 2000 and June 2008. There were 61 male (51.7%) and 57 female (48.3%) patients with a mean age of 59.8 +/- 11.6 years (range, 25.4 to 85.0). All patients were evaluated pre- and postoperatively (mean followup 67.7 +/- 27.0 months; range, 29 to 126). Radiological outcomes were assessed using standardized weightbearing radiographs. Clinical outcomes were assessed using the visual analogue scale (VAS) and American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scale. There were nine intraoperative complications. All patients experienced significant pain relief (VAS change from 7.0 +/- 1.7 to 1.4 +/- 1.1, p sports activity. Revision surgery was performed in six patients, resulting in a 6-year survivorship of 93%. Our findings confirm that TAR gives significant pain relief and functional improvement. In this study, the survivorship of the prosthesis components was comparable to the results obtained in non-obese patients.

  15. Strontium-doped calcium polyphosphate/ultrahigh molecular weight polyethylene composites: A new class of artificial joint components with enhanced biological efficacy to aseptic loosening

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Zhipeng [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu 610041 (China); Huang, Bingxue; Li, Yiwen [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Tian, Meng [Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu 610041 (China); Li, Li [Department of Oncology, the 452 Hospital of Chinese PLA, Chengdu 610021 (China); Yu, Xixun, E-mail: yuxixun@163.com [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China)

    2016-04-01

    To enhance implant stability and prolong the service life of artificial joint component, a new approach was proposed to improve the wear resistance of artificial joint component and endow artificial joint component with the biological efficacy of resistance to aseptic loosening. Strontium calcium polyphosphate (SCPP) were interfused in ultrahigh molecular weight polyethylene (UHMWPE) by a combination of liquid nitrogen ball-milling and flat-panel curing process to prepare the SCPP/UHMWPE composites. The micro-structure, mechanical characterization, tribological characterization and bioactivities of various SCPP/UHMWPE composites were investigated. The results suggested that this method could statistically improve the wear resistance of UHMWPE resulting from a good SCPP particle dispersion. Moreover, it is also observed that the SCPP/UHMWPE composites-wear particles could promote the production of OPG by osteoblasts and decrease the production of RANKL by osteoblasts, and then increase the OPG/RANKL ratio. This indicated that the SCPP/UHMWPE composites had potential efficacy to prevent and treat aseptic loosening. Above all, the SCPP/UHMWPE composites with a suitable SCPP content would be the promising materials for fabricating artificial joint component with ability to resist aseptic loosening. - Highlights: • SCPP/UHMWPE composites could enhance biological efficacy of resistance to aseptic loosening. • SCPP would improve biological efficacy with a few sacrifice of wear resistance. • The results might provide a promising wear-resistant material for fabricating acetabular cup.

  16. Genetic parameters for various random regression models to describe the weight data of pigs

    NARCIS (Netherlands)

    Huisman, A.E.; Veerkamp, R.F.; Arendonk, van J.A.M.

    2002-01-01

    Various random regression models have been advocated for the fitting of covariance structures. It was suggested that a spline model would fit better to weight data than a random regression model that utilizes orthogonal polynomials. The objective of this study was to investigate which kind of random

  17. Genetic parameters for different random regression models to describe weight data of pigs

    NARCIS (Netherlands)

    Huisman, A.E.; Veerkamp, R.F.; Arendonk, van J.A.M.

    2001-01-01

    Various random regression models have been advocated for the fitting of covariance structures. It was suggested that a spline model would fit better to weight data than a random regression model that utilizes orthogonal polynomials. The objective of this study was to investigate which kind of random

  18. A review of typical thermal fatigue failure models for solder joints of electronic components

    Science.gov (United States)

    Li, Xiaoyan; Sun, Ruifeng; Wang, Yongdong

    2017-09-01

    For electronic components, cyclic plastic strain makes it easier to accumulate fatigue damage than elastic strain. When the solder joints undertake thermal expansion or cold contraction, different thermal strain of the electronic component and its corresponding substrate is caused by the different coefficient of thermal expansion of the electronic component and its corresponding substrate, leading to the phenomenon of stress concentration. So repeatedly, cracks began to sprout and gradually extend [1]. In this paper, the typical thermal fatigue failure models of solder joints of electronic components are classified and the methods of obtaining the parameters in the model are summarized based on domestic and foreign literature research.

  19. The freshman weight gain: a model for the study of the epidemic of obesity.

    Science.gov (United States)

    Levitsky, D A; Halbmaier, C A; Mrdjenovic, G

    2004-11-01

    The objective of this study was to quantify the weight gain of freshmen during their first 12 weeks at Cornell University. In addition, students completed questionnaires that revealed particular behaviors and activities that were associated with weight gain. Serial, correlational study. A total of 68 freshmen from Cornell University. A total of 60 students were weighed during the first week of the semester, then again 12 weeks later. They were also given a questionnaire to complete concerning their behavior during the previous 12 weeks. After adjusting for clothing weights, the mean weight gain of the freshmen was 1.9+/-2.4 kg, a value significantly different from 0. Two regression models generated from the questionnaire were fitted to the weight gain. The first linear regression model (Model 1) accounted for 58% of the variance and indicated that eating in the 'all-you-can-eat' dining halls accounted for 20% of the variance in weight gain. Snacking and eating high-fat 'junk food' accounted for anther 20%. When initial weight was used as a covariate (Model 2), the consumption of junk foods, meal frequency and number of snacks accounted for 47% of the variance. The study clearly demonstrated that significant weight gain during first semester college is a real phenomenon and can be attributed to tangible environmental stimuli. The weight gain is considerably greater than that observed in the population and may be useful as a model to test various techniques that may reduce or reverse the 'epidemic' of obesity observed in the general population.

  20. 2-Port Modeling Technique for Surface-Mount Passive Components Using Partial Inductance Concept

    Science.gov (United States)

    Yamanaga, Koh; Sato, Takashi; Masu, Kazuya

    Electrical modeling for surface-mount passive components is proposed. In order to accurately capture parasitic inductance, the proposed 2-port model accounts for surrounding ground layer configurations of the print circuit board (PCB) on which the component is mounted. Our model retains conventional modeling paradigm in which component suppliers provide their customers with simulation models characterized independently of the customers' PCB. We also present necessary corrections that compensate magnetic coupling between the separated models. Impedance and its anti-resonant frequency of two power distribution networks are experimentally analyzed being non-separated modeling as the reference. The proposed model achieved very good match with the reference result reducing 7-34% error of the conventional model to about 2%.

  1. Adopting epidemic model to optimize medication and surgical intervention of excess weight

    Science.gov (United States)

    Sun, Ruoyan

    2017-01-01

    We combined an epidemic model with an objective function to minimize the weighted sum of people with excess weight and the cost of a medication and surgical intervention in the population. The epidemic model is consisted of ordinary differential equations to describe three subpopulation groups based on weight. We introduced an intervention using medication and surgery to deal with excess weight. An objective function is constructed taking into consideration the cost of the intervention as well as the weight distribution of the population. Using empirical data, we show that fixed participation rate reduces the size of obese population but increases the size for overweight. An optimal participation rate exists and decreases with respect to time. Both theoretical analysis and empirical example confirm the existence of an optimal participation rate, u*. Under u*, the weighted sum of overweight (S) and obese (O) population as well as the cost of the program is minimized. This article highlights the existence of an optimal participation rate that minimizes the number of people with excess weight and the cost of the intervention. The time-varying optimal participation rate could contribute to designing future public health interventions of excess weight.

  2. A Dynamical Systems Model for Understanding Behavioral Interventions for Weight Loss

    Science.gov (United States)

    Navarro-Barrientos, J.-Emeterio; Rivera, Daniel E.; Collins, Linda M.

    We propose a dynamical systems model that captures the daily fluctuations of human weight change, incorporating both physiological and psychological factors. The model consists of an energy balance integrated with a mechanistic behavioral model inspired by the Theory of Planned Behavior (TPB); the latter describes how important variables in a behavioral intervention can influence healthy eating habits and increased physical activity over time. The model can be used to inform behavioral scientists in the design of optimized interventions for weight loss and body composition change.

  3. Adolescent weight control: an intervention targeting parent communication and modeling compared with minimal parental involvement.

    Science.gov (United States)

    Jelalian, Elissa; Hadley, Wendy; Sato, Amy; Kuhl, Elizabeth; Rancourt, Diana; Oster, Danielle; Lloyd-Richardson, Elizabeth

    2015-03-01

    Adolescent weight control interventions demonstrate variable findings, with inconsistent data regarding the appropriate role for parents. The current study examined the efficacy of a standard adolescent behavioral weight control (BWC) intervention that also targeted parent-adolescent communication and parental modeling of healthy behaviors (Standard Behavioral Treatment + Enhanced Parenting; SBT + EP) compared with a standard BWC intervention (SBT). 49 obese adolescents (M age = 15.10; SD = 1.33; 76% female; 67.3% non-Hispanic White) and a caregiver were randomly assigned to SBT or SBT + EP. Adolescent and caregiver weight and height, parental modeling, and weight-related communication were obtained at baseline and end of the 16-week intervention. Significant decreases in adolescent weight and increases in parental self-monitoring were observed across both conditions. Analyses of covariance revealed a trend for greater reduction in weight and negative maternal commentary among SBT condition participants. Contrary to hypotheses, targeting parent-adolescent communication and parental modeling did not lead to better outcomes in adolescent weight control. © The Author 2014. Published by Oxford University Press on behalf of the Society of Pediatric Psychology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Interpreting lateral dynamic weight shifts using a simple inverted pendulum model.

    Science.gov (United States)

    Kennedy, Michael W; Bretl, Timothy; Schmiedeler, James P

    2014-01-01

    Seventy-five young, healthy adults completed a lateral weight-shifting activity in which each shifted his/her center of pressure (CoP) to visually displayed target locations with the aid of visual CoP feedback. Each subject's CoP data were modeled using a single-link inverted pendulum system with a spring-damper at the joint. This extends the simple inverted pendulum model of static balance in the sagittal plane to lateral weight-shifting balance. The model controlled pendulum angle using PD control and a ramp setpoint trajectory, and weight-shifting was characterized by both shift speed and a non-minimum phase (NMP) behavior metric. This NMP behavior metric examines the force magnitude at shift initiation and provides weight-shifting balance performance information that parallels the examination of peak ground reaction forces in gait analysis. Control parameters were optimized on a subject-by-subject basis to match balance metrics for modeled results to metric values calculated from experimental data. Overall, the model matches experimental data well (average percent error of 0.35% for shifting speed and 0.05% for NMP behavior). These results suggest that the single-link inverted pendulum model can be used effectively to capture lateral weight-shifting balance, as it has been shown to model static balance. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Modeling weight loss and chlorogenic acids content in coffee during roasting.

    Science.gov (United States)

    Perrone, Daniel; Donangelo, Raul; Donangelo, Carmen M; Farah, Adriana

    2010-12-08

    Roasting is a key step in the production of a high-quality coffee. Roasting degree is directly related to coffee chemical composition and may be determined objectively by weight loss after roasting. Chlorogenic acids (CGA) are thermally labile phenolic compounds that play an important role in the final cup quality and health benefits of coffee. Considering the interest in finding a reliable method to predict weight loss and CGA content in coffee, models have been developed to estimate these parameters during roasting. Weight loss was successfully modeled (r = 0.99) independent of the instant temperature. CGA degradation followed first-order Arrhenius-compliant kinetic models with good predictability (r = 0.98), especially for light to moderately dark samples. In both cases distinct models for Coffea arabica and Coffea canephora were calculated, because of differences in chemical composition and cell wall structure between these species. The proposed models may become important predictive tools in the coffee industry.

  6. Analysis of litter size and average litter weight in pigs using a recursive model

    DEFF Research Database (Denmark)

    Varona, Luis; Sorensen, Daniel; Thompson, Robin

    2007-01-01

    An analysis of litter size and average piglet weight at birth in Landrace and Yorkshire using a standard two-trait mixed model (SMM) and a recursive mixed model (RMM) is presented. The RMM establishes a one-way link from litter size to average piglet weight. It is shown that there is a one......-to-one correspondence between the parameters of SMM and RMM and that they generate equivalent likelihoods. As parameterized in this work, the RMM tests for the presence of a recursive relationship between additive genetic values, permanent environmental effects, and specific environmental effects of litter size......, on average piglet weight. The equivalent standard mixed model tests whether or not the covariance matrices of the random effects have a diagonal structure. In Landrace, posterior predictive model checking supports a model without any form of recursion or, alternatively, a SMM with diagonal covariance...

  7. Component-based Hydrologic and Landscape Evolution Models: Interoperability, Standards, and New Algorithms

    Science.gov (United States)

    Peckham, S. D.

    2010-12-01

    The Community Surface Dynamics Modeling System (CSDMS) has an ever-growing collection of reusable, plug-and-play components for earth surface process modeling and this includes numerous components for spatial hydrologic and landscape evolution modeling. While components may represent any level of granularity from a simple function to a complete hydrologic model, the optimum level appears to be that of a particular physical process, such as infiltration, evaporation or snowmelt. It is at this level of complexity that researchers are most often interested in "swapping out" one method of modeling a process for another that differs in terms of required input, complexity, accuracy, or computational efficiency. CSDMS model components are designed for maximum reusability and strict adherence to this simple-sounding goal has proven to be a powerful decider when it comes to chosing between a number of different design choices. For example, it determines key aspects of a component's interface, and the need for each component to have or manage its own state variables, input files, output files and help files. As a result, each component can be used either as a stand-alone "submodel" or as a component in some larger model. Components do not, however, need to be written in the same language because the CSDMS project employs a powerful language-interoperability tool called Babel. The purpose of this talk is to share a few lessons learned from the CSDMS project, to provide an overview of the many components that are currently available, and to briefly present performance results from a new fluvial landscape evolution algorithm.

  8. Association of the components of the metabolic syndrome with non- alcoholic fatty liver disease among normal-weight, overweight and obese children and adolescents

    Directory of Open Access Journals (Sweden)

    Kelishadi Roya

    2009-12-01

    Full Text Available Abstract Objectives This study aimed to determine the prevalence of the metabolic syndrome, abnormalities of liver enzymes and sonographic fatty liver, as well as the inter-related associations in normal weight, overweight and obese children and adolescents. Methods This cross-sectional study was conducted among a sample of 1107 students (56.1% girls, aged 6-18 years in Isfahan, Iran. In addition to physical examination, fasting blood glucose, serum lipid profile and liver enzymes were determined. Liver sonography was performed among 931 participants. These variables were compared among participants with different body mass index (BMI categories. Results From lower to higher BMI category, alanine aminotransferase (ALT, total cholesterol, LDL-cholesterol, triglycerides and systolic blood pressure increased, and HDL-cholesterol decreased significantly. Elevated ALT, aspartate aminotransferase (AST and alkaline phosphatase (ALP were documented in respectively 4.1%, 6.6% and 9.8% of normal weight group. The corresponding figure was 9.5%, 9.8% and 9.1% in overweight group, and 16.9%, 14.9% and 10.8% in obese group, respectively. In all BMI categories, ALT increased significantly by increasing the number of the components of the metabolic syndrome. Odds ratio for elevated liver enzymes and sonographic fatty liver increased significantly with higher number of the components of the metabolic syndrome and higher BMI categories before and after adjustment for age. Conclusions Because of the interrelationship of biochemical and sonographic indexes of fatty liver with the components of the metabolic syndrome, and with increase in their number, it is suggested to determine the clinical impact of such association in future longitudinal studies.

  9. Towards system-level modeling and characterization of components for intravenous therapy

    NARCIS (Netherlands)

    Alveringh, Dennis; Wiegerink, Remco J.; Lötters, Joost Conrad

    2014-01-01

    Problems occur regularly with intravenous therapy, especially with the flow behavior. A mechanical model can predict which components of intravenous therapy systems introduce non-ideal effects in the flow. This study concentrates on gaining quantitative information of each separate component for

  10. The Three-Component Model of Shyness: Conceptual, Correlational, and Treatment Considerations.

    Science.gov (United States)

    Weyer, Christina Y.; Carducci, Bernardo J.

    The purpose of this study was to examine the three-component model of shyness as assessed by the Cheek-Buss Shyness Scale (CBSS). Eighty-four introductory psychology students completed the twenty-item CBSS and three single-item measures assessing the physiological, behavioral, and cognitive components of shyness. The results indicated a consistent…

  11. An integrative affect regulation process model of internalized weight bias and intuitive eating in college women.

    Science.gov (United States)

    Webb, Jennifer B; Hardin, Abigail S

    2016-07-01

    The present study extended the weight stigma and well-being process model (Tylka et al., 2014) by examining three affect regulation pathways that may help simultaneously explain the predicted inverse association between internalized weight bias and intuitive eating. A weight-diverse sample of 333 college women completed an online survey assessing internalized weight stigma, intuitive eating, body shame, body image flexibility, and self-compassion. Self-reported height and weight were used to calculate body mass index (BMI). Non-parametric bootstrap resampling procedures were computed to ascertain the presence of the indirect effects of internalized weight bias on intuitive eating via the three hypothesized mediators controlling for BMI in a combined model. Results demonstrated that body image flexibility significantly and self-compassion marginally contributed unique variance in accounting for this relationship. Our preliminary cross-sectional findings contribute to a nascent body of scholarship seeking to provide a theoretically-driven understanding of how negative and positive forms of experiencing and relating to the body may co-occur within individuals. Results also point to potential target variables to consider incorporating in later-stage efforts to promote more adaptive ways of eating amidst internalized weight stigma. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. A fuzzy MCDM model with objective and subjective weights for evaluating service quality in hotel industries

    Science.gov (United States)

    Zoraghi, Nima; Amiri, Maghsoud; Talebi, Golnaz; Zowghi, Mahdi

    2013-12-01

    This paper presents a fuzzy multi-criteria decision-making (FMCDM) model by integrating both subjective and objective weights for ranking and evaluating the service quality in hotels. The objective method selects weights of criteria through mathematical calculation, while the subjective method uses judgments of decision makers. In this paper, we use a combination of weights obtained by both approaches in evaluating service quality in hotel industries. A real case study that considered ranking five hotels is illustrated. Examples are shown to indicate capabilities of the proposed method.

  13. REMOVAL OF IMPULSIVE NOISE USING WEIGHTED FUZZY MEAN FILTER BASED ON CLOUD MODEL

    Directory of Open Access Journals (Sweden)

    K. Kannan

    2013-08-01

    Full Text Available This paper proposes a weighted fuzzy mean filter based on cloud model and reports its performance in removing the impulsive noise from the digital image. In addition, the performance of the proposed weighted fuzzy mean filter is compared with already existing variants of median and switching filters using root mean square error, peak signal to noise ratio and quality index. Even though the image is corrupted by 90%, this weighted fuzzy mean filter is capable of recovering the original image with good detail preservation.

  14. FE Simulation Models for Hot Stamping an Automobile Component with Tailor-Welded High-Strength Steels

    Science.gov (United States)

    Tang, Bingtao; Wang, Qiaoling; Wei, Zhaohui; Meng, Xianju; Yuan, Zhengjun

    2016-05-01

    Ultra-high-strength in sheet metal parts can be achieved with hot stamping process. To improve the crash performance and save vehicle weight, it is necessary to produce components with tailored properties. The use of tailor-welded high-strength steel is a relatively new hot stamping process for saving weight and obtaining desired local stiffness and crash performance. The simulation of hot stamping boron steel, especially tailor-welded blanks (TWBs) stamping, is more complex and challenging. Information about thermal/mechanical properties of tools and sheet materials, heat transfer, and friction between the deforming material and the tools is required in detail. In this study, the boron-manganese steel B1500HS and high-strength low-alloy steel B340LA are tailor welded and hot stamped. In order to precisely simulate the hot stamping process, modeling and simulation of hot stamping tailor-welded high-strength steels, including phase transformation modeling, thermal modeling, and thermal-mechanical modeling, is investigated. Meanwhile, the welding zone of tailor-welded blanks should be sufficiently accurate to describe thermal, mechanical, and metallurgical parameters. FE simulation model using TWBs with the thickness combination of 1.6 mm boron steel and 1.2 mm low-alloy steel is established. In order to evaluate the mechanical properties of the hot stamped automotive component (mini b-pillar), hardness and microstructure at each region are investigated. The comparisons between simulated results and experimental observations show the reliability of thermo-mechanical and metallurgical modeling strategies of TWBs hot stamping process.

  15. Quantifying functional connectivity in multi-subject fMRI data using component models.

    Science.gov (United States)

    Madsen, Kristoffer H; Churchill, Nathan W; Mørup, Morten

    2017-02-01

    Functional magnetic resonance imaging (fMRI) is increasingly used to characterize functional connectivity between brain regions. Given the vast number of between-voxel interactions in high-dimensional fMRI data, it is an ongoing challenge to detect stable and generalizable functional connectivity in the brain among groups of subjects. Component models can be used to define subspace representations of functional connectivity that are more interpretable. It is, however, unclear which component model provides the optimal representation of functional networks for multi-subject fMRI datasets. A flexible cross-validation approach that assesses the ability of the models to predict voxel-wise covariance in new data, using three different measures of generalization was proposed. This framework is used to compare a range of component models with varying degrees of flexibility in their representation of functional connectivity, evaluated on both simulated and experimental resting-state fMRI data. It was demonstrated that highly flexible subject-specific component subspaces, as well as very constrained average models, are poor predictors of whole-brain functional connectivity, whereas the best-generalizing models account for subject variability within a common spatial subspace. Within this set of models, spatial Independent Component Analysis (sICA) on concatenated data provides more interpretable brain patterns, whereas a consistent-covariance model that accounts for subject-specific network scaling (PARAFAC2) provides greater stability in functional connectivity relationships between components and their spatial representations. The proposed evaluation framework is a promising quantitative approach to evaluating component models, and reveals important differences between subspace models in terms of predictability, robustness, characterization of subject variability, and interpretability of the model parameters. Hum Brain Mapp 38:882-899, 2017. © 2016 Wiley Periodicals, Inc

  16. Model-Checking of Component-Based Event-Driven Real-Time Embedded Software

    National Research Council Canada - National Science Library

    Gu, Zonghua; Shin, Kang G

    2005-01-01

    .... We discuss application of model-checking to verify system-level concurrency properties of component-based real-time embedded software based on CORBA Event Service, using Avionics Mission Computing...

  17. Model-Based Design Tools for Extending COTS Components To Extreme Environments Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation in this project is model-based design (MBD) tools for predicting the performance and useful life of commercial-off-the-shelf (COTS) components and...

  18. Detailed finite element method modeling of evaporating multi-component droplets

    Energy Technology Data Exchange (ETDEWEB)

    Diddens, Christian, E-mail: C.Diddens@tue.nl

    2017-07-01

    The evaporation of sessile multi-component droplets is modeled with an axisymmetic finite element method. The model comprises the coupled processes of mixture evaporation, multi-component flow with composition-dependent fluid properties and thermal effects. Based on representative examples of water–glycerol and water–ethanol droplets, regular and chaotic examples of solutal Marangoni flows are discussed. Furthermore, the relevance of the substrate thickness for the evaporative cooling of volatile binary mixture droplets is pointed out. It is shown how the evaporation of the more volatile component can drastically decrease the interface temperature, so that ambient vapor of the less volatile component condenses on the droplet. Finally, results of this model are compared with corresponding results of a lubrication theory model, showing that the application of lubrication theory can cause considerable errors even for moderate contact angles of 40°. - Graphical abstract:.

  19. A proposed centralised distribution model for the South African automotive component industry

    Directory of Open Access Journals (Sweden)

    Micheline J. Naude

    2009-12-01

    Full Text Available Purpose: This article explores the possibility of developing a distribution model, similar to the model developed and implemented by the South African pharmaceutical industry, which could be implemented by automotive component manufacturers for supply to independent retailers. Problem Investigated: The South African automotive components distribution chain is extensive with a number of players of varying sizes, from the larger spares distribution groups to a number of independent retailers. Distributing to the smaller independent retailers is costly for the automotive component manufacturers. Methodology: This study is based on a preliminary study of an explorative nature. Interviews were conducted with a senior staff member from a leading automotive component manufacturer in KwaZulu Natal and nine participants at a senior management level at five of their main customers (aftermarket retailers. Findings: The findings from the empirical study suggest that the aftermarket component industry is mature with the role players well established. The distribution chain to the independent retailer is expensive in terms of transaction and distribution costs for the automotive component manufacturer. A proposed centralised distribution model for supply to independent retailers has been developed which should reduce distribution costs for the automotive component manufacturer in terms of (1 the lowest possible freight rate; (2 timely and controlled delivery; and (3 reduced congestion at the customer's receiving dock. Originality: This research is original in that it explores the possibility of implementing a centralised distribution model for independent retailers in the automotive component industry. Furthermore, there is a dearth of published research on the South African automotive component industry particularly addressing distribution issues. Conclusion: The distribution model as suggested is a practical one and should deliver added value to automotive

  20. Modeling time-varying exposure using inverse probability of treatment weights

    NARCIS (Netherlands)

    Grafféo, Nathalie; Latouche, Aurélien; Geskus, Ronald B.; Chevret, Sylvie

    2017-01-01

    For estimating the causal effect of treatment exposure on the occurrence of adverse events, inverse probability weights (IPW) can be used in marginal structural models to correct for time-dependent confounding. The R package ipw allows IPW estimation by modeling the relationship between the exposure

  1. Stability equation and two-component Eigenmode for domain walls in scalar potential model

    Energy Technology Data Exchange (ETDEWEB)

    Dias, G.S.; Graca, E.L.; Rodrigues, R. de Lima [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: dias@cbpf.br; rafaelr@cbpf.br

    2002-08-01

    Supersymmetric quantum mechanics involving a two-component representation and two-component eigenfunctions is applied to obtain the stability equation associated to a potential model formulated in terms of two coupled real scalar fields. We investigate the question of stability by introducing an operator technique for the Bogomol'nyi-Prasad-Sommerfield (BPS) and non-BPS states on two domain walls in a scalar potential model with minimal N 1-supersymmetry. (author)

  2. Seismic assessment and performance of nonstructural components affected by structural modeling

    Energy Technology Data Exchange (ETDEWEB)

    Hur, Jieun; Althoff, Eric; Sezen, Halil; Denning, Richard; Aldemir, Tunc [Ohio State University, Columbus (United States)

    2017-03-15

    Seismic probabilistic risk assessment (SPRA) requires a large number of simulations to evaluate the seismic vulnerability of structural and nonstructural components in nuclear power plants. The effect of structural modeling and analysis assumptions on dynamic analysis of 3D and simplified 2D stick models of auxiliary buildings and the attached nonstructural components is investigated. Dynamic characteristics and seismic performance of building models are also evaluated, as well as the computational accuracy of the models. The presented results provide a better understanding of the dynamic behavior and seismic performance of auxiliary buildings. The results also help to quantify the impact of uncertainties associated with modeling and analysis of simplified numerical models of structural and nonstructural components subjected to seismic shaking on the predicted seismic failure probabilities of these systems.

  3. Seismic Assessment and Performance of Nonstructural Components Affected by Structural Modeling

    Directory of Open Access Journals (Sweden)

    Jieun Hur

    2017-03-01

    Full Text Available Seismic probabilistic risk assessment (SPRA requires a large number of simulations to evaluate the seismic vulnerability of structural and nonstructural components in nuclear power plants. The effect of structural modeling and analysis assumptions on dynamic analysis of 3D and simplified 2D stick models of auxiliary buildings and the attached nonstructural components is investigated. Dynamic characteristics and seismic performance of building models are also evaluated, as well as the computational accuracy of the models. The presented results provide a better understanding of the dynamic behavior and seismic performance of auxiliary buildings. The results also help to quantify the impact of uncertainties associated with modeling and analysis of simplified numerical models of structural and nonstructural components subjected to seismic shaking on the predicted seismic failure probabilities of these systems.

  4. Characterizing long-term patterns of weight change in China using latent class trajectory modeling.

    Directory of Open Access Journals (Sweden)

    Lauren Paynter

    Full Text Available Over the past three decades, obesity-related diseases have increased tremendously in China, and are now the leading causes of morbidity and mortality. Patterns of weight change can be used to predict risk of obesity-related diseases, increase understanding of etiology of disease risk, identify groups at particularly high risk, and shape prevention strategies.Latent class trajectory modeling was used to compute weight change trajectories for adults aged 18 to 66 using the China Health and Nutrition Survey (CHNS data (n = 12,611. Weight change trajectories were computed separately for males and females by age group at baseline due to differential age-related patterns of weight gain in China with urbanization. Generalized linear mixed effects models examined the association between weight change trajectories and baseline characteristics including urbanicity, BMI category, age, and year of study entry.Trajectory classes were identified for each of six age-sex subgroups corresponding to various degrees of weight loss, maintenance and weight gain. Baseline BMI status was a significant predictor of trajectory membership for all age-sex subgroups. Baseline overweight/obesity increased odds of following 'initial loss with maintenance' trajectories. We found no significant association between baseline urbanization and trajectory membership after controlling for other covariates.Trajectory analysis identified patterns of weight change for age by gender groups. Lack of association between baseline urbanization status and trajectory membership suggests that living in a rural environment at baseline was not protective. Analyses identified age-specific nuances in weight change patterns, pointing to the importance of subgroup analyses in future research.

  5. Automatic Detection of Repetitive Components in 3D Mechanical Engineering Models

    Directory of Open Access Journals (Sweden)

    Laixiang Wen

    2013-01-01

    Full Text Available We present an intelligent method to automatically detect repetitive components in 3D mechanical engineering models. In our work, a new Voxel-based Shape Descriptor (VSD is proposed for effective matching, based on which a similarity function is defined. It uses the voxels intersecting with 3D outline of mechanical components as the feature descriptor. Because each mechanical component may have different poses, the alignment before the matching is needed. For the alignment, we adopt the genetic algorithm to search for optimal solution where the maximum global similarity is the objective. Two components are the same if the maximum global similarity is over a certain threshold. Note that the voxelization of component during feature extraction and the genetic algorithm for searching maximum global similarity are entirely implemented on GPU; the efficiency is improved significantly than with CPU. Experimental results show that our method is more effective and efficient than that existing methods for repetitive components detection.

  6. Coupling Multi-Component Models with MPH on Distributed MemoryComputer Architectures

    Energy Technology Data Exchange (ETDEWEB)

    He, Yun; Ding, Chris

    2005-03-24

    A growing trend in developing large and complex applications on today's Teraflop scale computers is to integrate stand-alone and/or semi-independent program components into a comprehensive simulation package. One example is the Community Climate System Model which consists of atmosphere, ocean, land-surface and sea-ice components. Each component is semi-independent and has been developed at a different institution. We study how this multi-component, multi-executable application can run effectively on distributed memory architectures. For the first time, we clearly identify five effective execution modes and develop the MPH library to support application development utilizing these modes. MPH performs component-name registration, resource allocation and initial component handshaking in a flexible way.

  7. The effect of non-linear human visual system components on linear model observers

    Science.gov (United States)

    Zhang, Yani; Pham, Binh T.; Eckstein, Miguel P.

    2004-05-01

    Linear model observers have been used successfully to predict human performance in clinically relevant visual tasks for a variety of backgrounds. On the other hand, there has been another family of models used to predict human visual detection of signals superimposed on one of two identical backgrounds (masks). These masking models usually include a number of non-linear components in the channels that reflect properties of the firing of cells in the primary visual cortex (V1). The relationship between these two traditions of models has not been extensively investigated in the context of detection in noise. In this paper, we evaluated the effect of including some of these non-linear components into a linear channelized Hotelling observer (CHO), and the associated practical implications for medical image quality evaluation. In particular, we evaluate whether the rank order evaluation of two compression algorithms (JPEG vs. JPEG 2000) is changed by inclusion of the non-linear components. The results show: a) First that the simpler linear CHO model observer outperforms CHO model with the nonlinear components investigated. b) The rank order of model observer performance for the compression algorithms did not vary when the non-linear components were included. For the present task, the results suggest that the addition of the physiologically based channel non-linearities to a channelized Hotelling might add complexity to the model observers without great impact on medical image quality evaluation.

  8. Mixed-level optical-system simulation incorporating component-level modeling of interface elements

    Science.gov (United States)

    Mena, Pablo V.; Stone, Bryan; Heller, Evan; Herrmann, Dan; Ghillino, Enrico; Scarmozzino, Rob

    2014-03-01

    While system-level simulation can allow designers to assess optical system performance via measures such as signal waveforms, spectra, eye diagrams, and BER calculations, component-level modeling can provide a more accurate description of coupling into and out of individual devices, as well as their detailed signal propagation characteristics. In particular, the system-level simulation of interface components used in optical systems, including splitters, combiners, grating couplers, waveguides, spot-size converters, and lens assemblies, can benefit from more detailed component-level modeling. Depending upon the nature of the device and the scale of the problem, simulation of optical transmission through these components can be carried out using either electromagnetic device-level simulation, such as the beampropagation method, or ray-based approaches. In either case, system-level simulation can interface to such componentlevel modeling via a suitable exchange of optical signal data. This paper presents the use of a mixed-level simulation flow in which both electromagnetic device-level and ray-based tools are integrated with a system-level simulation environment in order to model the use of various interface components in optical systems for a range of purposes, including, for example, coupling to and from optical transmission media such as single- and multimode optical fiber. This approach enables case studies on the impact of physical and geometric component variations on system performance, and the sensitivity of system behavior to misalignment between components.

  9. Reliability Assessment of IGBT Modules Modeled as Systems with Correlated Components

    DEFF Research Database (Denmark)

    Kostandyan, Erik; Sørensen, John Dalsgaard

    2013-01-01

    System modeling of electrical components for Wind Turbine (WT) applications is an important part for the overall WT reliability assessment. The presented approach is an approximate method for Insulated Gate Bipolar Transistor (IGBT) reliability estimation, modeled based on the parallel system...... the components in the reliability estimation though limit state functions and mechanical (failure-effect) correlations. The model is based on a physics of failure approach and a linear accumulated damage rule. To account model parameter variabilities, the First Order Reliability Method (FORM) technique...

  10. Local Model Checking of Weighted CTL with Upper-Bound Constraints

    DEFF Research Database (Denmark)

    Jensen, Jonas Finnemann; Larsen, Kim Guldstrand; Srba, Jiri

    2013-01-01

    We present a symbolic extension of dependency graphs by Liu and Smolka in order to model-check weighted Kripke structures against the logic CTL with upper-bound weight constraints. Our extension introduces a new type of edges into dependency graphs and lifts the computation of fixed-points from...... boolean domain to nonnegative integers in order to cope with the weights. We present both global and local algorithms for the fixed-point computation on symbolic dependency graphs and argue for the advantages of our approach compared to the direct encoding of the model checking problem into dependency...... graphs. We implement all algorithms in a publicly available tool prototype and evaluate them on several experiments. The principal conclusion is that our local algorithm is the most efficient one with an order of magnitude improvement for model checking problems with a high number of “witnesses”....

  11. The performance evaluation model of mining project founded on the weight optimization entropy value method

    Science.gov (United States)

    Mao, Chao; Chen, Shou

    2017-01-01

    According to the traditional entropy value method still have low evaluation accuracy when evaluating the performance of mining projects, a performance evaluation model of mineral project founded on improved entropy is proposed. First establish a new weight assignment model founded on compatible matrix analysis of analytic hierarchy process (AHP) and entropy value method, when the compatibility matrix analysis to achieve consistency requirements, if it has differences between subjective weights and objective weights, moderately adjust both proportions, then on this basis, the fuzzy evaluation matrix for performance evaluation. The simulation experiments show that, compared with traditional entropy and compatible matrix analysis method, the proposed performance evaluation model of mining project based on improved entropy value method has higher accuracy assessment.

  12. Five-Factor Model Personality Traits and the Objective and Subjective Experience of Body Weight.

    Science.gov (United States)

    Sutin, Angelina R; Terracciano, Antonio

    2016-02-01

    Research on personality and adiposity has focused primarily on middle-aged and older adults. The present research sought to (a) replicate these associations in a young adult sample, (b) examine whether sex, race, or ethnicity moderate these associations, and (c) test whether personality is associated with the subjective experience of body weight and discrepancies between perceived and actual weight. Participants (N = 15,669; M(age) = 29; 53% female; ∼40% ethnic/racial minority) from Wave 4 of the National Longitudinal Study of Adolescent Health completed a Five-Factor Model personality measure and reported their weight, height, and perception of weight category (e.g., overweight); trained staff measured participants' height, weight, and waist circumference. Conscientiousness was associated with healthier weight, with a nearly 5 kg difference between the top and bottom quartiles. Neuroticism among women and Extraversion among men were associated with higher adiposity. Neuroticism was also associated with misperceived heavier weight, whereas Extraversion was associated with misperceived taller and leaner. The associations were similar across race/ethnic groups. Personality is associated with objective and subjective adiposity in young adulthood. Although modest, the effects are consistent with life span theories of personality, and the misperceptions are consistent with the conceptual worldviews associated with the traits. © 2014 Wiley Periodicals, Inc.

  13. Evaluating the effect of neighbourhood weight matrices on smoothing properties of Conditional Autoregressive (CAR models

    Directory of Open Access Journals (Sweden)

    Ryan Louise

    2007-11-01

    Full Text Available Abstract Background The Conditional Autoregressive (CAR model is widely used in many small-area ecological studies to analyse outcomes measured at an areal level. There has been little evaluation of the influence of different neighbourhood weight matrix structures on the amount of smoothing performed by the CAR model. We examined this issue in detail. Methods We created several neighbourhood weight matrices and applied them to a large dataset of births and birth defects in New South Wales (NSW, Australia within 198 Statistical Local Areas. Between the years 1995–2003, there were 17,595 geocoded birth defects and 770,638 geocoded birth records with available data. Spatio-temporal models were developed with data from 1995–2000 and their fit evaluated within the following time period: 2001–2003. Results We were able to create four adjacency-based weight matrices, seven distance-based weight matrices and one matrix based on similarity in terms of a key covariate (i.e. maternal age. In terms of agreement between observed and predicted relative risks, categorised in epidemiologically relevant groups, generally the distance-based matrices performed better than the adjacency-based neighbourhoods. In terms of recovering the underlying risk structure, the weight-7 model (smoothing by maternal-age 'Covariate model' was able to correctly classify 35/47 high-risk areas (sensitivity 74% with a specificity of 47%, and the 'Gravity' model had sensitivity and specificity values of 74% and 39% respectively. Conclusion We found considerable differences in the smoothing properties of the CAR model, depending on the type of neighbours specified. This in turn had an effect on the models' ability to recover the observed risk in an area. Prior to risk mapping or ecological modelling, an exploratory analysis of the neighbourhood weight matrix to guide the choice of a suitable weight matrix is recommended. Alternatively, the weight matrix can be chosen a priori

  14. Parameter estimation and statistical test of geographically weighted bivariate Poisson inverse Gaussian regression models

    Science.gov (United States)

    Amalia, Junita; Purhadi, Otok, Bambang Widjanarko

    2017-11-01

    Poisson distribution is a discrete distribution with count data as the random variables and it has one parameter defines both mean and variance. Poisson regression assumes mean and variance should be same (equidispersion). Nonetheless, some case of the count data unsatisfied this assumption because variance exceeds mean (over-dispersion). The ignorance of over-dispersion causes underestimates in standard error. Furthermore, it causes incorrect decision in the statistical test. Previously, paired count data has a correlation and it has bivariate Poisson distribution. If there is over-dispersion, modeling paired count data is not sufficient with simple bivariate Poisson regression. Bivariate Poisson Inverse Gaussian Regression (BPIGR) model is mix Poisson regression for modeling paired count data within over-dispersion. BPIGR model produces a global model for all locations. In another hand, each location has different geographic conditions, social, cultural and economic so that Geographically Weighted Regression (GWR) is needed. The weighting function of each location in GWR generates a different local model. Geographically Weighted Bivariate Poisson Inverse Gaussian Regression (GWBPIGR) model is used to solve over-dispersion and to generate local models. Parameter estimation of GWBPIGR model obtained by Maximum Likelihood Estimation (MLE) method. Meanwhile, hypothesis testing of GWBPIGR model acquired by Maximum Likelihood Ratio Test (MLRT) method.

  15. Principal components and generalized linear modeling in the correlation between hospital admissions and air pollution

    Science.gov (United States)

    de Souza, Juliana Bottoni; Reisen, Valdério Anselmo; Santos, Jane Méri; Franco, Glaura Conceição

    2014-01-01

    OBJECTIVE To analyze the association between concentrations of air pollutants and admissions for respiratory causes in children. METHODS Ecological time series study. Daily figures for hospital admissions of children aged < 6, and daily concentrations of air pollutants (PM10, SO2, NO2, O3 and CO) were analyzed in the Região da Grande Vitória, ES, Southeastern Brazil, from January 2005 to December 2010. For statistical analysis, two techniques were combined: Poisson regression with generalized additive models and principal model component analysis. Those analysis techniques complemented each other and provided more significant estimates in the estimation of relative risk. The models were adjusted for temporal trend, seasonality, day of the week, meteorological factors and autocorrelation. In the final adjustment of the model, it was necessary to include models of the Autoregressive Moving Average Models (p, q) type in the residuals in order to eliminate the autocorrelation structures present in the components. RESULTS For every 10:49 μg/m3 increase (interquartile range) in levels of the pollutant PM10 there was a 3.0% increase in the relative risk estimated using the generalized additive model analysis of main components-seasonal autoregressive – while in the usual generalized additive model, the estimate was 2.0%. CONCLUSIONS Compared to the usual generalized additive model, in general, the proposed aspect of generalized additive model − principal component analysis, showed better results in estimating relative risk and quality of fit. PMID:25119940

  16. Principal components and generalized linear modeling in the correlation between hospital admissions and air pollution.

    Science.gov (United States)

    Souza, Juliana Bottoni de; Reisen, Valdério Anselmo; Santos, Jane Méri; Franco, Glaura Conceição

    2014-06-01

    OBJECTIVE To analyze the association between concentrations of air pollutants and admissions for respiratory causes in children. METHODS Ecological time series study. Daily figures for hospital admissions of children aged PM10, SO2, NO2, O3 and CO) were analyzed in the Região da Grande Vitória, ES, Southeastern Brazil, from January 2005 to December 2010. For statistical analysis, two techniques were combined: Poisson regression with generalized additive models and principal model component analysis. Those analysis techniques complemented each other and provided more significant estimates in the estimation of relative risk. The models were adjusted for temporal trend, seasonality, day of the week, meteorological factors and autocorrelation. In the final adjustment of the model, it was necessary to include models of the Autoregressive Moving Average Models (p, q) type in the residuals in order to eliminate the autocorrelation structures present in the components. RESULTS For every 10:49 μg/m3 increase (interquartile range) in levels of the pollutant PM10 there was a 3.0% increase in the relative risk estimated using the generalized additive model analysis of main components-seasonal autoregressive - while in the usual generalized additive model, the estimate was 2.0%. CONCLUSIONS Compared to the usual generalized additive model, in general, the proposed aspect of generalized additive model - principal component analysis, showed better results in estimating relative risk and quality of fit.

  17. Principal components and generalized linear modeling in the correlation between hospital admissions and air pollution

    Directory of Open Access Journals (Sweden)

    Juliana Bottoni de Souza

    2014-06-01

    Full Text Available OBJECTIVE To analyze the association between concentrations of air pollutants and admissions for respiratory causes in children. METHODS Ecological time series study. Daily figures for hospital admissions of children aged < 6, and daily concentrations of air pollutants (PM10, SO2, NO2, O3 and CO were analyzed in the Região da Grande Vitória, ES, Southeastern Brazil, from January 2005 to December 2010. For statistical analysis, two techniques were combined: Poisson regression with generalized additive models and principal model component analysis. Those analysis techniques complemented each other and provided more significant estimates in the estimation of relative risk. The models were adjusted for temporal trend, seasonality, day of the week, meteorological factors and autocorrelation. In the final adjustment of the model, it was necessary to include models of the Autoregressive Moving Average Models (p, q type in the residuals in order to eliminate the autocorrelation structures present in the components. RESULTS For every 10:49 μg/m3 increase (interquartile range in levels of the pollutant PM10 there was a 3.0% increase in the relative risk estimated using the generalized additive model analysis of main components-seasonal autoregressive – while in the usual generalized additive model, the estimate was 2.0%. CONCLUSIONS Compared to the usual generalized additive model, in general, the proposed aspect of generalized additive model − principal component analysis, showed better results in estimating relative risk and quality of fit.

  18. Breast Radiotherapy with Mixed Energy Photons; a Model for Optimal Beam Weighting.

    Science.gov (United States)

    Birgani, Mohammadjavad Tahmasebi; Fatahiasl, Jafar; Hosseini, Seyed Mohammad; Bagheri, Ali; Behrooz, Mohammad Ali; Zabiehzadeh, Mansour; Meskani, Reza; Gomari, Maryam Talaei

    2015-01-01

    Utilization of high energy photons (>10 MV) with an optimal weight using a mixed energy technique is a practical way to generate a homogenous dose distribution while maintaining adequate target coverage in intact breast radiotherapy. This study represents a model for estimation of this optimal weight for day to day clinical usage. For this purpose, treatment planning computed tomography scans of thirty-three consecutive early stage breast cancer patients following breast conservation surgery were analyzed. After delineation of the breast clinical target volume (CTV) and placing opposed wedge paired isocenteric tangential portals, dosimeteric calculations were conducted and dose volume histograms (DVHs) were generated, first with pure 6 MV photons and then these calculations were repeated ten times with incorporating 18 MV photons (ten percent increase in weight per step) in each individual patient. For each calculation two indexes including maximum dose in the breast CTV (Dmax) and the volume of CTV which covered with 95% Isodose line (VCTV, 95%IDL) were measured according to the DVH data and then normalized values were plotted in a graph. The optimal weight of 18 MV photons was defined as the intersection point of Dmax and VCTV, 95%IDL graphs. For creating a model to predict this optimal weight multiple linear regression analysis was used based on some of the breast and tangential field parameters. The best fitting model for prediction of 18 MV photons optimal weight in breast radiotherapy using mixed energy technique, incorporated chest wall separation plus central lung distance (Adjusted R2=0.776). In conclusion, this study represents a model for the estimation of optimal beam weighting in breast radiotherapy using mixed photon energy technique for routine day to day clinical usage.

  19. Two component WIMP-FImP dark matter model with singlet fermion, scalar and pseudo scalar

    Energy Technology Data Exchange (ETDEWEB)

    Dutta Banik, Amit; Pandey, Madhurima; Majumdar, Debasish [Saha Institute of Nuclear Physics, HBNI, Astroparticle Physics and Cosmology Division, Kolkata (India); Biswas, Anirban [Harish Chandra Research Institute, Allahabad (India)

    2017-10-15

    We explore a two component dark matter model with a fermion and a scalar. In this scenario the Standard Model (SM) is extended by a fermion, a scalar and an additional pseudo scalar. The fermionic component is assumed to have a global U(1){sub DM} and interacts with the pseudo scalar via Yukawa interaction while a Z{sub 2} symmetry is imposed on the other component - the scalar. These ensure the stability of both dark matter components. Although the Lagrangian of the present model is CP conserving, the CP symmetry breaks spontaneously when the pseudo scalar acquires a vacuum expectation value (VEV). The scalar component of the dark matter in the present model also develops a VEV on spontaneous breaking of the Z{sub 2} symmetry. Thus the various interactions of the dark sector and the SM sector occur through the mixing of the SM like Higgs boson, the pseudo scalar Higgs like boson and the singlet scalar boson. We show that the observed gamma ray excess from the Galactic Centre as well as the 3.55 keV X-ray line from Perseus, Andromeda etc. can be simultaneously explained in the present two component dark matter model and the dark matter self interaction is found to be an order of magnitude smaller than the upper limit estimated from the observational results. (orig.)

  20. Penalising Model Component Complexity: A Principled, Practical Approach to Constructing Priors

    KAUST Repository

    Simpson, Daniel

    2017-04-06

    In this paper, we introduce a new concept for constructing prior distributions. We exploit the natural nested structure inherent to many model components, which defines the model component to be a flexible extension of a base model. Proper priors are defined to penalise the complexity induced by deviating from the simpler base model and are formulated after the input of a user-defined scaling parameter for that model component, both in the univariate and the multivariate case. These priors are invariant to repa-rameterisations, have a natural connection to Jeffreys\\' priors, are designed to support Occam\\'s razor and seem to have excellent robustness properties, all which are highly desirable and allow us to use this approach to define default prior distributions. Through examples and theoretical results, we demonstrate the appropriateness of this approach and how it can be applied in various situations.

  1. The Peculiarities of Identifying the Components of a Business Model of Restaurant Industry Enterprise

    Directory of Open Access Journals (Sweden)

    Grosul Victoria A.

    2017-06-01

    Full Text Available The article substantiates the need for elaborating an efficient business model, implementation of which would enable enterprises of restaurant industry to create sustainable competitive advantages and would contribute to successful development in the long term. The basic scientific approaches to defining the business model components have been allocated. The main emphases and standard elements of a business model of enterprise in terms of each of the scientific approaches have been defined. The basic components of a business model of restaurant industry enterprise have been identified, taking into account the pivotal interrelated management processes: production, sales, consumption organization. The characteristics of each component of the business model of enterprise of restaurant industry have been provided in accordance with objectives of its activity in the context of efficient strategical decisions.

  2. A globally applicable, season-specific model for estimating the weighted mean temperature of the atmosphere

    Science.gov (United States)

    Yao, YiBin; Zhu, Shuang; Yue, ShunQiang

    2012-12-01

    In GPS meteorology, the weighted mean temperature is usually obtained by using a linear function of the surface temperature T s. However, not every GPS station can measure the surface temperature. The current study explores the characteristics of surface temperature and weighted mean temperature based on the global pressure and temperature model (GPT) and the Bevis T m- T s relationship ( T m = a + bT s). A new global weighted mean temperature (GWMT) model has been built which directly uses three-dimensional coordinates and day of the year to calculate the weighted mean temperature. The data of year 2005-2009 from 135 radiosonde stations provided by the Integrated Global Radiosonde Archive were used to calculate the model coefficients, which have been validated through examples. The result shows that the GWMT model is generally better than the existing liner models in most areas according to the statistic indexes (namely, mean absolute error and root mean square). Then we calculated precipitable water vapor, and the result shows that GWMT model can also yield high precision PWV.

  3. Understanding weight management perceptions in first-year college students using the health belief model.

    Science.gov (United States)

    Das, Bhibha M; Evans, Ellen M

    2014-01-01

    To examine weight management barriers, using the Health Belief Model, in first-year college students. First-year college students (n = 45), with data collected in April, May, and November 2013. Nominal group technique sessions (n = 8) were conducted. First-year students recognize benefits to weight management beyond physical attractiveness to quality-of-life domains, including social (eg, bonding opportunities and energy to socially engage) and mental health (eg, stress management). Men believe that weight management is important for career/financial reasons, whereas women voiced that it will allow them to live a full, independent life with a high level of multitasking. Men believed that their barriers were external (eg, campus resources/programs), whereas females perceived their barriers to be internal (eg, poor time management). College students are challenged by weight management and want the institution to provide resources, including curriculum, to help them manage their physical activity and nutrition behaviors.

  4. An experimental test of two mathematical models applied to the size-weight illusion.

    Science.gov (United States)

    Sarris, V; Heineken, E

    1976-05-01

    Two quantitative models, which make different quantitative predictions for the amount of the size-weight illusion, were tested according to the psychophysical methods employed by the respective authors (magnitude estimation versus category ratings). Both models with their corresponding method were supported. This causes uncertainty over Anderson's chaim that the validity of both a model and the applied scale used is sufficiently test by the socalled joint testing procedure.

  5. LAND COVER CLASSIFICATION OF MULTI-SENSOR IMAGES BY DECISION FUSION USING WEIGHTS OF EVIDENCE MODEL

    Directory of Open Access Journals (Sweden)

    P. Li

    2012-07-01

    Full Text Available This paper proposed a novel method of decision fusion based on weights of evidence model (WOE. The probability rules from classification results from each separate dataset were fused using WOE to produce the posterior probability for each class. The final classification was obtained by maximum probability. The proposed method was evaluated in land cover classification using two examples. The results showed that the proposed method effectively combined multisensor data in land cover classification and obtained higher classification accuracy than the use of single source data. The weights of evidence model provides an effective decision fusion method for improved land cover classification using multi-sensor data.

  6. Bayesian Analyses of Multiple Epistatic QTL Models for Body Weight and Body Composition in Mice

    OpenAIRE

    Yi, Nengjun; Zinniel, Denise K.; Kim, Kyoungmi; Eisen, Eugene J.; Bartolucci, Alfred; Allison, David B.; Pomp, Daniel

    2006-01-01

    To comprehensively investigate the genetic architecture of growth and obesity, we performed Bayesian analyses of multiple epistatic quantitative trait locus (QTL) models for body weights at five ages (12 days, 3, 6, 9 and 12 weeks) and body composition traits (weights of two fat pads and five organs) in mice produced from a cross of the F1 between M16i (selected for rapid growth rate) and CAST/Ei (wild-derived strain of small and lean mice) back to M16i. Bayesian model selection revealed a te...

  7. Kurtosis based weighted sparse model with convex optimization technique for bearing fault diagnosis

    Science.gov (United States)

    Zhang, Han; Chen, Xuefeng; Du, Zhaohui; Yan, Ruqiang

    2016-12-01

    The bearing failure, generating harmful vibrations, is one of the most frequent reasons for machine breakdowns. Thus, performing bearing fault diagnosis is an essential procedure to improve the reliability of the mechanical system and reduce its operating expenses. Most of the previous studies focused on rolling bearing fault diagnosis could be categorized into two main families, kurtosis-based filter method and wavelet-based shrinkage method. Although tremendous progresses have been made, their effectiveness suffers from three potential drawbacks: firstly, fault information is often decomposed into proximal frequency bands and results in impulsive feature frequency band splitting (IFFBS) phenomenon, which significantly degrades the performance of capturing the optimal information band; secondly, noise energy spreads throughout all frequency bins and contaminates fault information in the information band, especially under the heavy noisy circumstance; thirdly, wavelet coefficients are shrunk equally to satisfy the sparsity constraints and most of the feature information energy are thus eliminated unreasonably. Therefore, exploiting two pieces of prior information (i.e., one is that the coefficient sequences of fault information in the wavelet basis is sparse, and the other is that the kurtosis of the envelope spectrum could evaluate accurately the information capacity of rolling bearing faults), a novel weighted sparse model and its corresponding framework for bearing fault diagnosis is proposed in this paper, coined KurWSD. KurWSD formulates the prior information into weighted sparse regularization terms and then obtains a nonsmooth convex optimization problem. The alternating direction method of multipliers (ADMM) is sequentially employed to solve this problem and the fault information is extracted through the estimated wavelet coefficients. Compared with state-of-the-art methods, KurWSD overcomes the three drawbacks and utilizes the advantages of both family

  8. Development of a sleeve gastrectomy weight-loss model in obese Zucker rats

    Science.gov (United States)

    Lopez, Peter P.; Nicholson, Susannah E.; Burkhardt, Gabriel E.; Johnson, Robert A.; Johnson, Fruzsina K.

    2009-01-01

    Background: Obesity promotes the development of diabetes and cardiovascular disease. The most effective weight-loss treatment is bariatric surgery, but results greatly vary depending on the procedure. Sleeve gastrectomy (SG) has recently emerged as a reduced risk weight-loss procedure for super obese patients. However, the mechanism of weight-loss from SG and its effects on obesity-induced complications are yet to be determined. Our goal was to develop an experimental model of SG in genetically obese rats. Materials and Methods: Male obese Zucker rats (400-500g, leptin-insensitive) were anesthetized with isoflurane. After a midline laparotomy, the stomach was clamped, the greater curvature was excised and a triple suture line was used to close the gastric remnant. Sham rats underwent laparotomy only. Metabolic parameters were followed for 14 days after surgery. Results: Caloric intake and body weight decreased in SG rats over 14 days by 98±10kcal/day and 74±14g, respectively. Blood total cholesterol levels were lower in rats that lost weight. Furthermore, blood glucose levels were lower in rats that lost weight. Active ghrelin levels were unchanged in SG rats 14 days after surgery. Conclusions: These results show that SG promotes weight-loss in obese Zucker rats. Furthermore, SG-induced weight-loss is accompanied by improved plasma cholesterol and glucose profile. However, SG does not promote a prolonged decrease in ghrelin levels. These results suggest that SG is an effective weight-loss procedure in leptin-insensitivity to improve the lipid profile and decrease insulin resistance and these effects might be independent of changes in ghrelin levels. PMID:19394650

  9. Components of functional information model of city environment reorganization in interactive mode

    Directory of Open Access Journals (Sweden)

    Kuzina Olga

    2016-01-01

    Full Text Available The article contents the description of reorganization complementary information model provided for the lifecycle stage of facility management. The main components or assets of that model are functional, constructive, and organization-technological level of a declination from the project perfect model. There are also three-level model of building reorganization type definition. It represents an operation-automated algorithm for updating the technical specification of building reorganization.

  10. High molecular weight components containing N-linked oligosaccharides of Ascaris suum extract inhibit the dendritic cells activation through DC-SIGN and MR.

    Science.gov (United States)

    Favoretto, Bruna C; Casabuono, Adriana A C; Portes-Junior, José A; Jacysyn, Jacqueline F; Couto, Alicia S; Faquim-Mauro, Eliana L

    2017-07-01

    Helminths, as well as their secretory/excretory products, induce a tolerogenic immune microenvironment. High molecular weight components (PI) from Ascaris suum extract down-modulate the immune response against ovalbumin (OVA). The PI exerts direct effect on dendritic cells (DCs) independent of TLR 2, 4 and MyD88 molecule and, thus, decreases the T lymphocytes response. Here, we studied the glycoconjugates in PI and the role of C-type lectin receptors (CLRs), DC-SIGN and MR, in the modulation of DCs activity. Our data showed the presence of glycoconjugates with high mannose- and complex-type N-linked oligosaccharide chains and phosphorylcholine residues on PI. In addition, these N-linked glycoconjugates inhibited the DCs maturation induced by LPS. The binding and internalization of PI-Alexa were decreased on DCs previously incubated with mannan, anti-DC-SIGN and/or anti-MR antibodies. In agreement with this, the incubation of DCs with mannan, anti-DC-SIGN and/or anti-MR antibodies abolished the down-modulatory effect of PI on these cells. It was also observed that the blockage of CLRs, DC-SIGN and MR on DCs reverted the inhibitory effect of PI in in vitro T cells proliferation. Therefore, our data show the involvement of DC-SIGN and MR in the recognition and consequent modulatory effect of N-glycosylated components of PI on DCs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Spatial downscaling of soil prediction models based on weighted generalized additive models in smallholder farm settings.

    Science.gov (United States)

    Xu, Yiming; Smith, Scot E; Grunwald, Sabine; Abd-Elrahman, Amr; Wani, Suhas P; Nair, Vimala D

    2017-09-11

    Digital soil mapping (DSM) is gaining momentum as a technique to help smallholder farmers secure soil security and food security in developing regions. However, communications of the digital soil mapping information between diverse audiences become problematic due to the inconsistent scale of DSM information. Spatial downscaling can make use of accessible soil information at relatively coarse spatial resolution to provide valuable soil information at relatively fine spatial resolution. The objective of this research was to disaggregate the coarse spatial resolution soil exchangeable potassium (Kex) and soil total nitrogen (TN) base map into fine spatial resolution soil downscaled map using weighted generalized additive models (GAMs) in two smallholder villages in South India. By incorporating fine spatial resolution spectral indices in the downscaling process, the soil downscaled maps not only conserve the spatial information of coarse spatial resolution soil maps but also depict the spatial details of soil properties at fine spatial resolution. The results of this study demonstrated difference between the fine spatial resolution downscaled maps and fine spatial resolution base maps is smaller than the difference between coarse spatial resolution base maps and fine spatial resolution base maps. The appropriate and economical strategy to promote the DSM technique in smallholder farms is to develop the relatively coarse spatial resolution soil prediction maps or utilize available coarse spatial resolution soil maps at the regional scale and to disaggregate these maps to the fine spatial resolution downscaled soil maps at farm scale.

  12. Softened food reduces weight loss in the streptozotocin-induced male mouse model of diabetic nephropathy.

    Science.gov (United States)

    Nørgaard, Sisse A; Sand, Fredrik W; Sørensen, Dorte B; Abelson, Klas Sp; Søndergaard, Henrik

    2018-01-01

    The streptozotocin (STZ)-induced diabetic mouse is a widely used model of diabetes and diabetic nephropathy (DN). However, it is a well-known issue that this model is challenged by high weight loss, which despite supportive measures often results in high euthanization rates. To overcome these issues, we hypothesized that supplementing STZ-induced diabetic mice with water-softened chow in addition to normal chow would reduce weight loss, lower the need for supportive treatment, and reduce the number of mice reaching the humane endpoint of 20% weight loss. In a 15 week STZ-induced DN study we demonstrated that diabetic male mice receiving softened chow had reduced acute weight loss following STZ treatment ( p = 0.045) and additionally fewer mice were euthanized due to weight loss. By supplementing the diabetic mice with softened chow, no mice reached 20% weight loss whereas 37.5% of the mice without this supplement reached this humane endpoint ( p = 0.0027). Excretion of corticosterone metabolites in faeces was reduced in diabetic mice on softened chow ( p = 0.0007), suggesting lower levels of general stress. Finally, it was demonstrated that the water-softened chow supplement did not significantly affect the induction of key disease parameters, i.e. %HbA1C and albuminuria nor result in abnormal teeth wear. In conclusion, supplementation of softened food is refining the STZ-induced diabetic mouse model significantly by reducing stress, weight loss and the number of animals sacrificed due to humane endpoints, while maintaining the key phenotypes of diabetes and nephropathy.

  13. A mesoscopic reaction rate model for shock initiation of multi-component PBX explosives.

    Science.gov (United States)

    Liu, Y R; Duan, Z P; Zhang, Z Y; Ou, Z C; Huang, F L

    2016-11-05

    The primary goal of this research is to develop a three-term mesoscopic reaction rate model that consists of a hot-spot ignition, a low-pressure slow burning and a high-pressure fast reaction terms for shock initiation of multi-component Plastic Bonded Explosives (PBX). Thereinto, based on the DZK hot-spot model for a single-component PBX explosive, the hot-spot ignition term as well as its reaction rate is obtained through a "mixing rule" of the explosive components; new expressions for both the low-pressure slow burning term and the high-pressure fast reaction term are also obtained by establishing the relationships between the reaction rate of the multi-component PBX explosive and that of its explosive components, based on the low-pressure slow burning term and the high-pressure fast reaction term of a mesoscopic reaction rate model. Furthermore, for verification, the new reaction rate model is incorporated into the DYNA2D code to simulate numerically the shock initiation process of the PBXC03 and the PBXC10 multi-component PBX explosives, and the numerical results of the pressure histories at different Lagrange locations in explosive are found to be in good agreements with previous experimental data. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. The association of lesion eccentricity with plaque morphology and components in the superficial femoral artery: a high-spatial-resolution, multi-contrast weighted CMR study

    Directory of Open Access Journals (Sweden)

    Zhao Xihai

    2010-07-01

    Full Text Available Abstract Background Atherosclerotic plaque morphology and components are predictors of subsequent cardiovascular events. However, associations of plaque eccentricity with plaque morphology and plaque composition are unclear. This study investigated associations of plaque eccentricity with plaque components and morphology in the proximal superficial femoral artery using cardiovascular magnetic resonance (CMR. Methods Twenty-eight subjects with an ankle-brachial index less than 1.00 were examined with 1.5T high-spatial-resolution, multi-contrast weighted CMR. One hundred and eighty diseased locations of the proximal superficial femoral artery (about 40 mm were analyzed. The eccentric lesion was defined as [(Maximum wall thickness- Minimum wall thickness/Maximum wall thickness] ≥ 0.5. The arterial morphology and plaque components were measured using semi-automatic image analysis software. Results One hundred and fifteen locations were identified as eccentric lesions and sixty-five as concentric lesions. The eccentric lesions had larger wall but similar lumen areas, larger mean and maximum wall thicknesses, and more calcification and lipid rich necrotic core, compared to concentric lesions. For lesions with the same lumen area, the degree of eccentricity was associated with an increased wall area. Eccentricity (dichotomous as eccentric or concentric was independently correlated with the prevalence of calcification (odds ratio 3.78, 95% CI 1.47-9.70 after adjustment for atherosclerotic risk factors and wall area. Conclusions Plaque eccentricity is associated with preserved lumen size and advanced plaque features such as larger plaque burden, more lipid content, and increased calcification in the superficial femoral artery.

  15. Diffusion weighted imaging in patients with rectal cancer: Comparison between Gaussian and non-Gaussian models.

    Science.gov (United States)

    Manikis, Georgios C; Marias, Kostas; Lambregts, Doenja M J; Nikiforaki, Katerina; van Heeswijk, Miriam M; Bakers, Frans C H; Beets-Tan, Regina G H; Papanikolaou, Nikolaos

    2017-01-01

    The purpose of this study was to compare the performance of four diffusion models, including mono and bi-exponential both Gaussian and non-Gaussian models, in diffusion weighted imaging of rectal cancer. Nineteen patients with rectal adenocarcinoma underwent MRI examination of the rectum before chemoradiation therapy including a 7 b-value diffusion sequence (0, 25, 50, 100, 500, 1000 and 2000 s/mm2) at a 1.5T scanner. Four different diffusion models including mono- and bi-exponential Gaussian (MG and BG) and non-Gaussian (MNG and BNG) were applied on whole tumor volumes of interest. Two different statistical criteria were recruited to assess their fitting performance, including the adjusted-R2 and Root Mean Square Error (RMSE). To decide which model better characterizes rectal cancer, model selection was relied on Akaike Information Criteria (AIC) and F-ratio. All candidate models achieved a good fitting performance with the two most complex models, the BG and the BNG, exhibiting the best fitting performance. However, both criteria for model selection indicated that the MG model performed better than any other model. In particular, using AIC Weights and F-ratio, the pixel-based analysis demonstrated that tumor areas better described by the simplest MG model in an average area of 53% and 33%, respectively. Non-Gaussian behavior was illustrated in an average area of 37% according to the F-ratio, and 7% using AIC Weights. However, the distributions of the pixels best fitted by each of the four models suggest that MG failed to perform better than any other model in all patients, and the overall tumor area. No single diffusion model evaluated herein could accurately describe rectal tumours. These findings probably can be explained on the basis of increased tumour heterogeneity, where areas with high vascularity could be fitted better with bi-exponential models, and areas with necrosis would mostly follow mono-exponential behavior.

  16. A comparative study of the proposed models for the components of the national health information system.

    Science.gov (United States)

    Ahmadi, Maryam; Damanabi, Shahla; Sadoughi, Farahnaz

    2014-04-01

    National Health Information System plays an important role in ensuring timely and reliable access to Health information, which is essential for strategic and operational decisions that improve health, quality and effectiveness of health care. In other words, using the National Health information system you can improve the quality of health data, information and knowledge used to support decision making at all levels and areas of the health sector. Since full identification of the components of this system - for better planning and management influential factors of performanceseems necessary, therefore, in this study different attitudes towards components of this system are explored comparatively. This is a descriptive and comparative kind of study. The society includes printed and electronic documents containing components of the national health information system in three parts: input, process and output. In this context, search for information using library resources and internet search were conducted, and data analysis was expressed using comparative tables and qualitative data. The findings showed that there are three different perspectives presenting the components of national health information system Lippeveld and Sauerborn and Bodart model in 2000, Health Metrics Network (HMN) model from World Health Organization in 2008, and Gattini's 2009 model. All three models outlined above in the input (resources and structure) require components of management and leadership, planning and design programs, supply of staff, software and hardware facilities and equipment. Plus, in the "process" section from three models, we pointed up the actions ensuring the quality of health information system, and in output section, except for Lippeveld Model, two other models consider information products and use and distribution of information as components of the national health information system. the results showed that all the three models have had a brief discussion about the

  17. Modelling and Recognition of the Linguistic Components in American Sign Language.

    Science.gov (United States)

    Ding, Liya; Martinez, Aleix M

    2009-11-01

    The manual signs in sign languages are generated and interpreted using three basic building blocks: handshape, motion, and place of articulation. When combined, these three components (together with palm orientation) uniquely determine the meaning of the manual sign. This means that the use of pattern recognition techniques that only employ a subset of these components is inappropriate for interpreting the sign or to build automatic recognizers of the language. In this paper, we define an algorithm to model these three basic components form a single video sequence of two-dimensional pictures of a sign. Recognition of these three components are then combined to determine the class of the signs in the videos. Experiments are performed on a database of (isolated) American Sign Language (ASL) signs. The results demonstrate that, using semi-automatic detection, all three components can be reliably recovered from two-dimensional video sequences, allowing for an accurate representation and recognition of the signs.

  18. Can the Components of a Cognitive Model Predict the Severity of Generalized Anxiety Disorder?

    Science.gov (United States)

    Dugas, Michel J.; Savard, Pierre; Gaudet, Adrienne; Turcotte, Julie; Laugesen, Nina; Robichaud, Melisa; Francis, Kylie; Koerner, Naomi

    2007-01-01

    Over the past decade, a number of well-controlled studies have supported the validity of a cognitive model of generalized anxiety disorder (GAD) that has four main components: intolerance of uncertainty, positive beliefs about worry, negative problem orientation, and cognitive avoidance. Although these studies have shown that the model components…

  19. A mathematical model for the dissolution of particles in multi-component alloys

    NARCIS (Netherlands)

    F.J. Vermolen; C. Vuik

    1998-01-01

    textabstractDissolution of stoichiometric multi-component particles is an important process ocurring during the heat treatment of as-cast aluminium alloys prior to hot extrusion. A mathematical model is proposed to describe such a process. In this model equations are given to determine the position

  20. Facilitating Performance Optimization of RF PCB Designs by using Parametric Finite-Element Component Models

    DEFF Research Database (Denmark)

    Rohde, John; Toftegaard, Thomas Skjødeberg

    2012-01-01

    Novel parametric finite-element models are provided for discrete SMD capacitors and inductors in the frequency range 100 MHz to 4 GHz. The aim of the models is to facilitate performance optimization and analysis of RF PCB designs integrating these SMD components with layout geometries such as ant...

  1. Refinement and verification in component-based model-driven design

    DEFF Research Database (Denmark)

    Chen, Zhenbang; Liu, Zhiming; Ravn, Anders Peter

    2009-01-01

    Modern software development is complex as it has to deal with many different and yet related aspects of applications. In practical software engineering this is now handled by a UML-like modelling approach in which different aspects are modelled by different notations. Component-based and object...

  2. Forecasting daily time series using periodic unobserved components time series models

    NARCIS (Netherlands)

    Ooms, M.; Koopman, S.J.

    2006-01-01

    A periodic time series analysis is explored in the context of unobserved components time series models that include stochastic time functions for trend, seasonal and irregular effects. Periodic time series models allow dynamic characteristics (autocovariances) to depend on the period of the year,

  3. Mathematical Model for Multicomponent Adsorption Equilibria Using Only Pure Component Data

    DEFF Research Database (Denmark)

    Marcussen, Lis

    2000-01-01

    A mathematical model for nonideal adsorption equilibria in multicomponent mixtures is developed. It is applied with good results for pure substances and for prediction of strongly nonideal multicomponent equilibria using only pure component data. The model accounts for adsorbent-adsorbate and ads...

  4. Abstract behavior types : a foundation model for components and their composition

    NARCIS (Netherlands)

    F. Arbab (Farhad)

    2003-01-01

    textabstractThe notion of Abstract Data Type (ADT) has served as a foundation model for structured and object oriented programming for some thirty years. The current trend in software engineering toward component based systems requires a foundation model as well. The most basic inherent property of

  5. Modelling Earth's surface topography: decomposition of the static and dynamic components

    DEFF Research Database (Denmark)

    Guerri, Mattia; Cammarano, Fabio; Tackley, Paul J.

    2016-01-01

    Contrasting results on the magnitude of the dynamic component of topography motivate us to analyse the sources of uncertainties affecting long wavelength topography modelling. We obtain a range of mantle density structures from thermo-chemical interpretation of available seismic tomography models...

  6. An AeroCom initial assessment – optical properties in aerosol component modules of global models

    NARCIS (Netherlands)

    Kinne, S.; Schulz, M.; Textor, C.; Guibert, S.; Balkanski, Y.; Bauer, S.; Berntsen, E.; Berglen, T.F.; Boucher, O.; Chin, M.; Collins, W.; Dentener, F.; Diehl, T.; Easter, R.; Feichter, J.; Fillmore, D.; Ghan, S.; Ginoux, P.; Gong, S.; Grini, A.; Hendricks, J.; Herzog, M.; Horowitz, L.; Isaksen, I.; Iversen, T.; Kirkevåg, A.; Kloster, S.; Koch, D.; Kristjansson, J.E.; Krol, M.C.; Lauer, A.; Lamarque, J.F.; Lesins, G.; Liu, X.; Lohmann, U.; Montanaro, V.; Myhre, G.; Penner, J.; Pitari, G.; Reddy, S.; Seland, O.; Stier, P.; Takemura, T.; Tie, X.

    2006-01-01

    The AeroCom exercise diagnoses multi-component aerosol modules in global modeling. In an initial assessment simulated global distributions for mass and mid-visible aerosol optical thickness (aot) were compared among 20 different modules. Model diversity was also explored in the context of previous

  7. A Co-modeling Method Based on Component Features for Mechatronic Devices in Aero-engines

    Science.gov (United States)

    Wang, Bin; Zhao, Haocen; Ye, Zhifeng

    2017-08-01

    Data-fused and user-friendly design of aero-engine accessories is required because of their structural complexity and stringent reliability. This paper gives an overview of a typical aero-engine control system and the development process of key mechatronic devices used. Several essential aspects of modeling and simulation in the process are investigated. Considering the limitations of a single theoretic model, feature-based co-modeling methodology is suggested to satisfy the design requirements and compensate for diversity of component sub-models for these devices. As an example, a stepper motor controlled Fuel Metering Unit (FMU) is modeled in view of the component physical features using two different software tools. An interface is suggested to integrate the single discipline models into the synthesized one. Performance simulation of this device using the co-model and parameter optimization for its key components are discussed. Comparison between delivery testing and the simulation shows that the co-model for the FMU has a high accuracy and the absolute superiority over a single model. Together with its compatible interface with the engine mathematical model, the feature-based co-modeling methodology is proven to be an effective technical measure in the development process of the device.

  8. MODELING THERMAL DUST EMISSION WITH TWO COMPONENTS: APPLICATION TO THE PLANCK HIGH FREQUENCY INSTRUMENT MAPS

    Energy Technology Data Exchange (ETDEWEB)

    Meisner, Aaron M.; Finkbeiner, Douglas P., E-mail: ameisner@fas.harvard.edu, E-mail: dfinkbeiner@cfa.harvard.edu [Department of Physics, Harvard University, 17 Oxford Street, Cambridge, MA 02138 (United States)

    2015-01-10

    We apply the Finkbeiner et al. two-component thermal dust emission model to the Planck High Frequency Instrument maps. This parameterization of the far-infrared dust spectrum as the sum of two modified blackbodies (MBBs) serves as an important alternative to the commonly adopted single-MBB dust emission model. Analyzing the joint Planck/DIRBE dust spectrum, we show that two-component models provide a better fit to the 100-3000 GHz emission than do single-MBB models, though by a lesser margin than found by Finkbeiner et al. based on FIRAS and DIRBE. We also derive full-sky 6.'1 resolution maps of dust optical depth and temperature by fitting the two-component model to Planck 217-857 GHz along with DIRBE/IRAS 100 μm data. Because our two-component model matches the dust spectrum near its peak, accounts for the spectrum's flattening at millimeter wavelengths, and specifies dust temperature at 6.'1 FWHM, our model provides reliable, high-resolution thermal dust emission foreground predictions from 100 to 3000 GHz. We find that, in diffuse sky regions, our two-component 100-217 GHz predictions are on average accurate to within 2.2%, while extrapolating the Planck Collaboration et al. single-MBB model systematically underpredicts emission by 18.8% at 100 GHz, 12.6% at 143 GHz, and 7.9% at 217 GHz. We calibrate our two-component optical depth to reddening, and compare with reddening estimates based on stellar spectra. We find the dominant systematic problems in our temperature/reddening maps to be zodiacal light on large angular scales and the cosmic infrared background anisotropy on small angular scales.

  9. Chronic clozapine treatment in female rats does not induce weight gain or metabolic abnormalities but enhances adiposity: implications for animal models of antipsychotic-induced weight gain.

    Science.gov (United States)

    Cooper, G D; Harrold, J A; Halford, J C G; Goudie, A J

    2008-02-15

    -571.]. These and other findings which show that the results of studies of antipsychotic treatment in animals do not always mimic clinical findings have important implications for the use of animal models of antipsychotic-induced weight gain. With regard to weight gain the results obtained appear to depend critically on the experimental procedures used and the specific drugs studied. Thus such models are not without limitations. However, they do consistently demonstrate the ability of various antipsychotics to enhance adiposity.

  10. Two-Variance-Component Model Improves Genetic Prediction in Family Datasets.

    Science.gov (United States)

    Tucker, George; Loh, Po-Ru; MacLeod, Iona M; Hayes, Ben J; Goddard, Michael E; Berger, Bonnie; Price, Alkes L

    2015-11-05

    Genetic prediction based on either identity by state (IBS) sharing or pedigree information has been investigated extensively with best linear unbiased prediction (BLUP) methods. Such methods were pioneered in plant and animal-breeding literature and have since been applied to predict human traits, with the aim of eventual clinical utility. However, methods to combine IBS sharing and pedigree information for genetic prediction in humans have not been explored. We introduce a two-variance-component model for genetic prediction: one component for IBS sharing and one for approximate pedigree structure, both estimated with genetic markers. In simulations using real genotypes from the Candidate-gene Association Resource (CARe) and Framingham Heart Study (FHS) family cohorts, we demonstrate that the two-variance-component model achieves gains in prediction r(2) over standard BLUP at current sample sizes, and we project, based on simulations, that these gains will continue to hold at larger sample sizes. Accordingly, in analyses of four quantitative phenotypes from CARe and two quantitative phenotypes from FHS, the two-variance-component model significantly improves prediction r(2) in each case, with up to a 20% relative improvement. We also find that standard mixed-model association tests can produce inflated test statistics in datasets with related individuals, whereas the two-variance-component model corrects for inflation. Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  11. Four-component model of body composition in children: density and hydration of fat-free mass and comparison with simpler models.

    Science.gov (United States)

    Wells, J C; Fuller, N J; Dewit, O; Fewtrell, M S; Elia, M; Cole, T J

    1999-05-01

    Body composition in children is generally measured by 2-component (2C) models, which are subject to error arising from variation in fat-free mass (FFM) composition. The 4-component (4C) model, which divides body weight into fat, water, mineral, and protein, can overcome these limitations. The aims of our study were to 1) describe 4C model data for children aged 8-12 y; 2) evaluate interindividual variability in the hydration, bone mineral content, and density of FFM; 3) evaluate the success with which 2C models and bedside techniques measure body composition in this age group with use of the 4C model as a reference. Dual-energy X-ray absorptiometry, underwater weighing, deuterium dilution, bioelectrical impedance analysis, and anthropometry were used to determine body composition in 30 children. The contribution of methodologic error to the observed variability in the hydration and density of FFM was evaluated by using propagation of error. Mean (+/-SD) FFM density and hydration were 1.0864+/-0.0074 kg/L and 75.3+/-2.2%, respectively, and were significantly different from adult values (P fatness, whereas underwater weighing underestimated fatness (P Fatness determined by using skinfold-thickness and bioelectrical impedance analysis measurements along with published equations showed poor agreement with 4C model data. Biological variability and methodologic error contribute equally to the variability of FFM composition. Our findings have major implications for bedside prediction methods used for children, traditionally developed in relation to underwater weighing.

  12. A Modified Obesity Proneness Model Predicts Adolescent Weight Concerns and Inability to Self-Regulate Eating

    Science.gov (United States)

    Nickelson, Jen; Bryant, Carol A.; McDermott, Robert J.; Buhi, Eric R.; DeBate, Rita D.

    2012-01-01

    Background: The prevalence of obesity among high school students has risen in recent decades. Many high school students report trying to lose weight and some engage in disordered eating to do so. The obesity proneness model suggests that parents may influence their offspring's development of disordered eating. This study examined the viability of…

  13. On the Relationships between Jeffreys Modal and Weighted Likelihood Estimation of Ability under Logistic IRT Models

    Science.gov (United States)

    Magis, David; Raiche, Gilles

    2012-01-01

    This paper focuses on two estimators of ability with logistic item response theory models: the Bayesian modal (BM) estimator and the weighted likelihood (WL) estimator. For the BM estimator, Jeffreys' prior distribution is considered, and the corresponding estimator is referred to as the Jeffreys modal (JM) estimator. It is established that under…

  14. A mediation model linking body weight, cognition, and sleep-disordered breathing.

    Science.gov (United States)

    Spruyt, Karen; Gozal, David

    2012-01-15

    Academic success involves the ability to use cognitive skills in a school environment. Poor academic performance has been linked to disrupted sleep associated with sleep-disordered breathing (SDB). In parallel, poor sleep is associated with increased risk for obesity, and weight management problems have been linked to executive dysfunction, suggesting that interactions may be operational between SDB and obesity to adversely affect neurocognitive outcomes. To test whether mediator relationships exist between body weight, SDB, and cognition. Structural equation modeling was conducted on data from 351 children in a community-based cohort assessed with the core subtests of the Differential Abilities Scales after an overnight polysomnogram. Body mass index, apnea-hypopnea index, and cognitive abilities were modeled as latent constructs. In a sample of predominantly white children 6 to 10 years of age, SDB amplified the adverse cognitive and weight outcomes by 0.55- to 0.46-fold, respectively. Weight amplified the risk by 0.39- to 0.40-fold for SDB and cognitive outcomes, respectively. Poor ability to perform complex mental processing functions increased the risk of adverse weight and SDB outcomes by 2.9- and 7.9-fold, respectively. Cognitive functioning in children is adversely affected by frequent health-related problems, such as obesity and SDB. Furthermore, poorer integrative mental processing may place a child at a bigger risk for adverse health outcomes.

  15. A Mediation Model Linking Body Weight, Cognition, and Sleep-Disordered Breathing

    Science.gov (United States)

    Gozal, David

    2012-01-01

    Rationale: Academic success involves the ability to use cognitive skills in a school environment. Poor academic performance has been linked to disrupted sleep associated with sleep-disordered breathing (SDB). In parallel, poor sleep is associated with increased risk for obesity, and weight management problems have been linked to executive dysfunction, suggesting that interactions may be operational between SDB and obesity to adversely affect neurocognitive outcomes. Objectives: To test whether mediator relationships exist between body weight, SDB, and cognition. Methods: Structural equation modeling was conducted on data from 351 children in a community-based cohort assessed with the core subtests of the Differential Abilities Scales after an overnight polysomnogram. Body mass index, apnea–hypopnea index, and cognitive abilities were modeled as latent constructs. Measurements and Main Results: In a sample of predominantly white children 6 to 10 years of age, SDB amplified the adverse cognitive and weight outcomes by 0.55- to 0.46-fold, respectively. Weight amplified the risk by 0.39- to 0.40-fold for SDB and cognitive outcomes, respectively. Poor ability to perform complex mental processing functions increased the risk of adverse weight and SDB outcomes by 2.9- and 7.9-fold, respectively. Conclusions: Cognitive functioning in children is adversely affected by frequent health-related problems, such as obesity and SDB. Furthermore, poorer integrative mental processing may place a child at a bigger risk for adverse health outcomes. PMID:22071385

  16. Bayesian analyses of multiple epistatic QTL models for body weight and body composition in mice.

    Science.gov (United States)

    Yi, Nengjun; Zinniel, Denise K; Kim, Kyoungmi; Eisen, Eugene J; Bartolucci, Alfred; Allison, David B; Pomp, Daniel

    2006-02-01

    To comprehensively investigate the genetic architecture of growth and obesity, we performed Bayesian analyses of multiple epistatic quantitative trait locus (QTL) models for body weights at five ages (12 days, 3, 6, 9 and 12 weeks) and body composition traits (weights of two fat pads and five organs) in mice produced from a cross of the F1 between M16i (selected for rapid growth rate) and CAST/Ei (wild-derived strain of small and lean mice) back to M16i. Bayesian model selection revealed a temporally regulated network of multiple QTL for body weight, involving both strong main effects and epistatic effects. No QTL had strong support for both early and late growth, although overlapping combinations of main and epistatic effects were observed at adjacent ages. Most main effects and epistatic interactions had an opposite effect on early and late growth. The contribution of epistasis was more pronounced for body weights at older ages. Body composition traits were also influenced by an interacting network of multiple QTLs. Several main and epistatic effects were shared by the body composition and body weight traits, suggesting that pleiotropy plays an important role in growth and obesity.

  17. Development of a stochastic dynamical model for hermetic compressor's components with experimental investigation

    Science.gov (United States)

    Fontanela, F.; Silva, O. M.; Lenzi, A.; Ritto, T. G.

    2016-08-01

    The analysis of household compressor's components is typically evaluated by using mathematical-mechanical models, and many decisions are taken based on simulations. However, such an investigation is usually performed in a deterministic framework, which cannot consider manufacturing variabilities and epistemic uncertainties. In this paper, a stochastic structural model that considers data and model uncertainties is developed for a discharge pipe connected to a hermetic compressor's shell. An experimental test rig is constructed to test each part separately, and an identification strategy is proposed to fit the stochastic model to experimental results. Finally, the impact of the uncertainties in each structural component on the dynamical responses of the whole system is investigated. It turns out that: (1) the proposed stochastic dynamical model presented very good results when compared to the experimental responses, and (2) uncertainties in the discharge pipe model play an important role in the coupled system dynamics.

  18. A simplified model predicting the weight of the load carrying beam in a wind turbine blade

    DEFF Research Database (Denmark)

    Mikkelsen, Lars Pilgaard

    2016-01-01

    Based on a simplified beam model, the loads, stresses and deflections experienced by a wind turbine blade of a given length is estimated. Due to the simplicity of the model used, the model is well suited for work investigating scaling effects of wind turbine blades. Presently, the model is used...... to predict the weight of the load carrying beam when using glassfibre reinforced polymers, carbon fibre reinforced polymers or an aluminium alloy as the construction material. Thereby, it is found that the weight of a glass fibre wind turbine blade is increased from 0.5 to 33 tons when the blade length grows...... from 20 to 90 m. In addition, it can be seen that for a blade using glass fibre reinforced polymers, the design is controlled by the deflection and thereby the material stiffness in order to avoid the blade to hit the tower. On the other hand if using aluminium, the design will be controlled...

  19. Focused information criterion and model averaging based on weighted composite quantile regression

    KAUST Repository

    Xu, Ganggang

    2013-08-13

    We study the focused information criterion and frequentist model averaging and their application to post-model-selection inference for weighted composite quantile regression (WCQR) in the context of the additive partial linear models. With the non-parametric functions approximated by polynomial splines, we show that, under certain conditions, the asymptotic distribution of the frequentist model averaging WCQR-estimator of a focused parameter is a non-linear mixture of normal distributions. This asymptotic distribution is used to construct confidence intervals that achieve the nominal coverage probability. With properly chosen weights, the focused information criterion based WCQR estimators are not only robust to outliers and non-normal residuals but also can achieve efficiency close to the maximum likelihood estimator, without assuming the true error distribution. Simulation studies and a real data analysis are used to illustrate the effectiveness of the proposed procedure. © 2013 Board of the Foundation of the Scandinavian Journal of Statistics..

  20. The Peculiarities of Identifying the Components of a Business Model of Restaurant Industry Enterprise

    OpenAIRE

    Grosul Victoria A.; Ivanova Tatyana P.

    2017-01-01

    The article substantiates the need for elaborating an efficient business model, implementation of which would enable enterprises of restaurant industry to create sustainable competitive advantages and would contribute to successful development in the long term. The basic scientific approaches to defining the business model components have been allocated. The main emphases and standard elements of a business model of enterprise in terms of each of the scientific approaches have been defined. T...

  1. Revisiting the ‘Low BirthWeight paradox’ using a model-based definition

    OpenAIRE

    Juárez, Sol; Ploubidis, George B.; Clarke, Lynda

    2014-01-01

    Introduction: Immigrant mothers in Spain have a lower risk of delivering Low BirthWeight (LBW) babies in comparison to Spaniards (LBW paradox). This study aimed at revisiting this finding by applying a model-based threshold as an alternative to the conventional definition of LBW. Methods: Vital information data from Madrid was used (2005–2006). LBW was defined in two ways (less than 2500 g and Wilcox's proposal). Logistic and linear regression models were run. Results: According to comm...

  2. Quantifying functional connectivity in multi-subject fMRI data using component models

    DEFF Research Database (Denmark)

    Madsen, Kristoffer Hougaard; Churchill, Nathan William; Mørup, Morten

    2017-01-01

    Functional magnetic resonance imaging (fMRI) is increasingly used to characterize functional connectivity between brain regions. Given the vast number of between-voxel interactions in high-dimensional fMRI data, it is an ongoing challenge to detect stable and generalizable functional connectivity...... in the brain among groups of subjects. Component models can be used to define subspace representations of functional connectivity that are more interpretable. It is, however, unclear which component model provides the optimal representation of functional networks for multi-subject fMRI datasets. A flexible...... of functional connectivity, evaluated on both simulated and experimental resting-state fMRI data. It was demonstrated that highly flexible subject-specific component subspaces, as well as very constrained average models, are poor predictors of whole-brain functional connectivity, whereas the best...

  3. Discriminant models to estimate the body weight loss after a six-month long diet and exercise-based intervention.

    Science.gov (United States)

    Rojo-Tirado, Miguel A; Benito, Pedro J; Peinado, Ana B; Zapico, Augusto G; Calderón, Franciso J

    2016-01-01

    The main concern of the people who follow a weight loss program is the body weight loss, independently of the body composition. The aim of this study was to create a mathematical model able to discriminate the body weight change based on initial body composition variables. The study included 239 overweight and obese participants (18-50 years; Body Mass Index (BMI)>25 and weight loss, during twenty-four weeks while having 25-30% caloric restriction. Two multivariate discriminant models were performed taking into account the groups below and above the mean body weight change. The discriminant models obtained could discriminate the body weight change with a 65-70% of correct classification. BW, fat-free mass (FFM), and fat mass (FM) were shown to be the most discriminant variables for the discriminant models. People having higher FM and FFM at the beginning of an intervention will lose a greater amount of weight until the end of it.

  4. Ensemble learning of inverse probability weights for marginal structural modeling in large observational datasets.

    Science.gov (United States)

    Gruber, Susan; Logan, Roger W; Jarrín, Inmaculada; Monge, Susana; Hernán, Miguel A

    2015-01-15

    Inverse probability weights used to fit marginal structural models are typically estimated using logistic regression. However, a data-adaptive procedure may be able to better exploit information available in measured covariates. By combining predictions from multiple algorithms, ensemble learning offers an alternative to logistic regression modeling to further reduce bias in estimated marginal structural model parameters. We describe the application of two ensemble learning approaches to estimating stabilized weights: super learning (SL), an ensemble machine learning approach that relies on V-fold cross validation, and an ensemble learner (EL) that creates a single partition of the data into training and validation sets. Longitudinal data from two multicenter cohort studies in Spain (CoRIS and CoRIS-MD) were analyzed to estimate the mortality hazard ratio for initiation versus no initiation of combined antiretroviral therapy among HIV positive subjects. Both ensemble approaches produced hazard ratio estimates further away from the null, and with tighter confidence intervals, than logistic regression modeling. Computation time for EL was less than half that of SL. We conclude that ensemble learning using a library of diverse candidate algorithms offers an alternative to parametric modeling of inverse probability weights when fitting marginal structural models. With large datasets, EL provides a rich search over the solution space in less time than SL with comparable results. Copyright © 2014 John Wiley & Sons, Ltd.

  5. Probabilistic Inference: Task Dependency and Individual Differences of Probability Weighting Revealed by Hierarchical Bayesian Modeling.

    Science.gov (United States)

    Boos, Moritz; Seer, Caroline; Lange, Florian; Kopp, Bruno

    2016-01-01

    Cognitive determinants of probabilistic inference were examined using hierarchical Bayesian modeling techniques. A classic urn-ball paradigm served as experimental strategy, involving a factorial two (prior probabilities) by two (likelihoods) design. Five computational models of cognitive processes were compared with the observed behavior. Parameter-free Bayesian posterior probabilities and parameter-free base rate neglect provided inadequate models of probabilistic inference. The introduction of distorted subjective probabilities yielded more robust and generalizable results. A general class of (inverted) S-shaped probability weighting functions had been proposed; however, the possibility of large differences in probability distortions not only across experimental conditions, but also across individuals, seems critical for the model's success. It also seems advantageous to consider individual differences in parameters of probability weighting as being sampled from weakly informative prior distributions of individual parameter values. Thus, the results from hierarchical Bayesian modeling converge with previous results in revealing that probability weighting parameters show considerable task dependency and individual differences. Methodologically, this work exemplifies the usefulness of hierarchical Bayesian modeling techniques for cognitive psychology. Theoretically, human probabilistic inference might be best described as the application of individualized strategic policies for Bayesian belief revision.

  6. Three-Dimensional Modeling of Aircraft High-Lift Components with Vehicle Sketch Pad

    Science.gov (United States)

    Olson, Erik D.

    2016-01-01

    Vehicle Sketch Pad (OpenVSP) is a parametric geometry modeler that has been used extensively for conceptual design studies of aircraft, including studies using higher-order analysis. OpenVSP can model flap and slat surfaces using simple shearing of the airfoil coordinates, which is an appropriate level of complexity for lower-order aerodynamic analysis methods. For three-dimensional analysis, however, there is not a built-in method for defining the high-lift components in OpenVSP in a realistic manner, or for controlling their complex motions in a parametric manner that is intuitive to the designer. This paper seeks instead to utilize OpenVSP's existing capabilities, and establish a set of best practices for modeling high-lift components at a level of complexity suitable for higher-order analysis methods. Techniques are described for modeling the flap and slat components as separate three-dimensional surfaces, and for controlling their motion using simple parameters defined in the local hinge-axis frame of reference. To demonstrate the methodology, an OpenVSP model for the Energy-Efficient Transport (EET) AR12 wind-tunnel model has been created, taking advantage of OpenVSP's Advanced Parameter Linking capability to translate the motions of the high-lift components from the hinge-axis coordinate system to a set of transformations in OpenVSP's frame of reference.

  7. Electricity Price Forecast Using Combined Models with Adaptive Weights Selected and Errors Calibrated by Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    Da Liu

    2013-01-01

    Full Text Available A combined forecast with weights adaptively selected and errors calibrated by Hidden Markov model (HMM is proposed to model the day-ahead electricity price. Firstly several single models were built to forecast the electricity price separately. Then the validation errors from every individual model were transformed into two discrete sequences: an emission sequence and a state sequence to build the HMM, obtaining a transmission matrix and an emission matrix, representing the forecasting ability state of the individual models. The combining weights of the individual models were decided by the state transmission matrixes in HMM and the best predict sample ratio of each individual among all the models in the validation set. The individual forecasts were averaged to get the combining forecast with the weights obtained above. The residuals of combining forecast were calibrated by the possible error calculated by the emission matrix of HMM. A case study of day-ahead electricity market of Pennsylvania-New Jersey-Maryland (PJM, USA, suggests that the proposed method outperforms individual techniques of price forecasting, such as support vector machine (SVM, generalized regression neural networks (GRNN, day-ahead modeling, and self-organized map (SOM similar days modeling.

  8. Comprehensive Weighted Clique Degree Ranking Algorithms and Evolutionary Model of Complex Network

    Directory of Open Access Journals (Sweden)

    Xu Jie

    2016-01-01

    Full Text Available This paper analyses the degree ranking (DR algorithm, and proposes a new comprehensive weighted clique degree ranking (CWCDR algorithms for ranking importance of nodes in complex network. Simulation results show that CWCDR algorithms not only can overcome the limitation of degree ranking algorithm, but also can find important nodes in complex networks more precisely and effectively. To the shortage of small-world model and BA model, this paper proposes an evolutionary model of complex network based on CWCDR algorithms, named CWCDR model. Simulation results show that the CWCDR model accords with power-law distribution. And compare with the BA model, this model has better average shortest path length, and clustering coefficient. Therefore, the CWCDR model is more consistent with the real network.

  9. A Collaborative Approach to Component-Based Community Models and Tools

    Science.gov (United States)

    Leavesley, G. H.; David, O.

    2008-12-01

    The advantages of community, component-based models are well recognized. Getting a community to participate in such a development involves a variety of technical, as well as related social, issues. A key technical issue is the choice of an existing, or design of a new, modeling framework. A wide variety of modeling system frameworks and tools are reported in the literature. Differences among these systems typically are related to the science concepts, problem objectives and institutional guidelines that were used in the design and development of the system. While alternative designs have limited the ability to share components and tools among systems, they have enabled the evaluation of the strengths and limitations of different approaches to system development. Building on this previous experience and knowledge, more recent systems enable the use of multiple programming languages, different computational platforms, and distributed cluster computations. One of these systems is the U.S. Department of Agriculture (USDA) Object Modeling System (OMS). OMS is a modular modeling framework that uses an open source software approach to enable all members of the scientific community to collaboratively address the many complex issues associated with the design, development, and application of distributed hydrological and environmental models. OMS will be used as an example to compare and contrast alternative modeling framework concepts and opportunities for component sharing among frameworks. An important feature in the OMS design is scalability of component applications. That is, components can be developed and tested on a laptop with a multi-core processor, but are fully compatible for execution on a cluster or a computing cloud. Collaborative multi-disciplinary and multi-institutional model and tool development in OMS is supported by the USDA internet-based Collaborative Software Development Laboratory (CoLab). Providing a common development environment addresses a number

  10. Weight Gain, Schizophrenia and Antipsychotics: New Findings from Animal Model and Pharmacogenomic Studies

    Directory of Open Access Journals (Sweden)

    Fabio Panariello

    2011-01-01

    Full Text Available Excess body weight is one of the most common physical health problems among patients with schizophrenia that increases the risk for many medical problems, including type 2 diabetes mellitus, coronary heart disease, osteoarthritis, and hypertension, and accounts in part for 20% shorter life expectancy than in general population. Among patients with severe mental illness, obesity can be attributed to an unhealthy lifestyle, personal genetic profile, as well as the effects of psychotropic medications, above all antipsychotic drugs. Novel “atypical” antipsychotic drugs represent a substantial improvement on older “typical” drugs. However, clinical experience has shown that some, but not all, of these drugs can induce substantial weight gain. Animal models of antipsychotic-related weight gain and animal transgenic models of knockout or overexpressed genes of antipsychotic receptors have been largely evaluated by scientific community for changes in obesity-related gene expression or phenotypes. Moreover, pharmacogenomic approaches have allowed to detect more than 300 possible candidate genes for antipsychotics-induced body weight gain. In this paper, we summarize current thinking on: (1 the role of polymorphisms in several candidate genes, (2 the possible roles of various neurotransmitters and neuropeptides in this adverse drug reaction, and (3 the state of development of animal models in this matter. We also outline major areas for future research.

  11. Domain Walls and Textured Vortices in a Two-Component Ginzburg-Landau Model

    DEFF Research Database (Denmark)

    Madsen, Søren Peder; Gaididei, Yu. B.; Christiansen, Peter Leth

    2005-01-01

    We look for domain wall and textured vortex solutions in a two-component Ginzburg-Landau model inspired by two-band superconductivity. The two-dimensional two-component model, with equal coherence lengths and no magnetic field, shows some interesting properties. In the absence of a Josephson type...... coupling between the two order parameters a ''textured vortex'' is found by analytical and numerical solution of the Ginzburg-Landau equations. With a Josephson type coupling between the two order parameters we find the system to split up in two domains separated by a domain wall, where the order parameter...

  12. Towards a Complete Model for Software Component Deployment on Heterogeneous Platform

    Directory of Open Access Journals (Sweden)

    Švogor Ivan

    2014-12-01

    Full Text Available This report briefly describes an ongoing research related to optimization of allocating software components to heterogeneous computing platform (which includes CPU, GPU and FPGA. Research goal is also presented, along with current hot topics of the research area, related research teams, and finally results and contribution of my research. It involves mathematical modelling which results in goal function, optimization method which finds a suboptimal solution to the goal function and a software modeling tool which enables graphical representation of the problem at hand and help developers determine component placement in the system design phase.

  13. Research on Modeling Method of Power System Key Components for E-REV

    OpenAIRE

    Niu Jigao; Shi Xiaoli; Xu Chunhua; Li Chenxu

    2017-01-01

    Aiming at the modeling problem of power system key components for an Extended-Range Electric Vehicle (E-REV), the co-simulation platform based on AVL-Cruise and Matlab/Simulink software is introduced, and the modeling methods of E-REV engine, driving motor and battery are studies by the method of mixing the theoretical modeling with the experimental modeling. Off-line simulation results with chosen driving cycles indicate that the proposed vehicle model has better simulation precision and can...

  14. A Dynamic Multinode Model for Component-Oriented Thermal Analysis of Flat-Plate Solar Collectors

    Directory of Open Access Journals (Sweden)

    Christoph N. Reiter

    2015-01-01

    Full Text Available A mathematical model of a flat-plate solar collector was developed on the basis of the physical principles of optics and heat transfer in order to determine collector’s component temperatures as well as collector efficiency. In contrast to many available models, the targeted use of this dynamic model is the detailed, theoretical investigation of the thermal behaviour of newly developed or adjusted collector designs on component level, for example, absorber, casing, or transparent cover. The defined model is based on a multinode network (absorber, fluid, glazing, and backside insulation containing the relevant physical equations to transfer the energy. The heat transfer network covers heat conduction, convection, and radiation. Furthermore, the collector optics is defined for the plane glazing and the absorber surface and also considers interactions between them. The model enables the variation of physical properties considering the geometric parameters and materials. Finally, the model was validated using measurement data and existing efficiency curve models. Both comparisons proved high accuracy of the developed model with deviation of up to 3% in collector efficiency and 1 K in component temperatures.

  15. Modelling bivariate astronomical data with multiple components and non-linear relationships

    Science.gov (United States)

    Koen, C.; Bere, A.

    2017-11-01

    A common approach towards modelling bivariate scatterplots is decomposition into Gaussian components, I.e. Gaussian mixture modelling. This implicitly assumes linear relationships between the variables within each of the components in the mixture. An alternative, namely dependence modelling by mixtures of copulas, is advocated in this paper. This approach allows separate modelling of the univariate marginal distributions and the dependence which can possibly be non-linear and/or asymmetric. It also accommodates the use of a variety of parametric families for modelling each component and for each variable. The variety of dependence structures can be extended by introducing rotated versions of the copulas. Gaussian mixture modelling on the one hand, and separate modelling of univariate marginal distributions and dependence on the other hand, are illustrated by application to pulsar period - period-derivative observations. Parameter estimation for mixtures of copulas is performed using the method of maximum likelihood and selected copula models are subjected to non-parametric goodness-of-fit testing.

  16. A Bayesian destructive weighted Poisson cure rate model and an application to a cutaneous melanoma data.

    Science.gov (United States)

    Rodrigues, Josemar; Cancho, Vicente G; de Castro, Mário; Balakrishnan, N

    2012-12-01

    In this article, we propose a new Bayesian flexible cure rate survival model, which generalises the stochastic model of Klebanov et al. [Klebanov LB, Rachev ST and Yakovlev AY. A stochastic-model of radiation carcinogenesis--latent time distributions and their properties. Math Biosci 1993; 113: 51-75], and has much in common with the destructive model formulated by Rodrigues et al. [Rodrigues J, de Castro M, Balakrishnan N and Cancho VG. Destructive weighted Poisson cure rate models. Technical Report, Universidade Federal de São Carlos, São Carlos-SP. Brazil, 2009 (accepted in Lifetime Data Analysis)]. In our approach, the accumulated number of lesions or altered cells follows a compound weighted Poisson distribution. This model is more flexible than the promotion time cure model in terms of dispersion. Moreover, it possesses an interesting and realistic interpretation of the biological mechanism of the occurrence of the event of interest as it includes a destructive process of tumour cells after an initial treatment or the capacity of an individual exposed to irradiation to repair altered cells that results in cancer induction. In other words, what is recorded is only the damaged portion of the original number of altered cells not eliminated by the treatment or repaired by the repair system of an individual. Markov Chain Monte Carlo (MCMC) methods are then used to develop Bayesian inference for the proposed model. Also, some discussions on the model selection and an illustration with a cutaneous melanoma data set analysed by Rodrigues et al. [Rodrigues J, de Castro M, Balakrishnan N and Cancho VG. Destructive weighted Poisson cure rate models. Technical Report, Universidade Federal de São Carlos, São Carlos-SP. Brazil, 2009 (accepted in Lifetime Data Analysis)] are presented.

  17. Probabilistic inference: Task dependency and individual differences of probability weighting revealed by hierarchical Bayesian modelling

    Directory of Open Access Journals (Sweden)

    Moritz eBoos

    2016-05-01

    Full Text Available Cognitive determinants of probabilistic inference were examined using hierarchical Bayesian modelling techniques. A classic urn-ball paradigm served as experimental strategy, involving a factorial two (prior probabilities by two (likelihoods design. Five computational models of cognitive processes were compared with the observed behaviour. Parameter-free Bayesian posterior probabilities and parameter-free base rate neglect provided inadequate models of probabilistic inference. The introduction of distorted subjective probabilities yielded more robust and generalizable results. A general class of (inverted S-shaped probability weighting functions had been proposed; however, the possibility of large differences in probability distortions not only across experimental conditions, but also across individuals, seems critical for the model’s success. It also seems advantageous to consider individual differences in parameters of probability weighting as being sampled from weakly informative prior distributions of individual parameter values. Thus, the results from hierarchical Bayesian modelling converge with previous results in revealing that probability weighting parameters show considerable task dependency and individual differences. Methodologically, this work exemplifies the usefulness of hierarchical Bayesian modelling techniques for cognitive psychology. Theoretically, human probabilistic inference might be best described as the application of individualized strategic policies for Bayesian belief revision.

  18. A mouse model of weight-drop closed head injury: emphasis on cognitive and neurological deficiency

    Directory of Open Access Journals (Sweden)

    Igor Khalin

    2016-01-01

    Full Text Available Traumatic brain injury (TBI is a leading cause of death and disability in individuals worldwide. Producing a clinically relevant TBI model in small-sized animals remains fairly challenging. For good screening of potential therapeutics, which are effective in the treatment of TBI, animal models of TBI should be established and standardized. In this study, we established mouse models of closed head injury using the Shohami weight-drop method with some modifications concerning cognitive deficiency assessment and provided a detailed description of the severe TBI animal model. We found that 250 g falling weight from 2 cm height produced severe closed head injury in C57BL/6 male mice. Cognitive disorders in mice with severe closed head injury could be detected using passive avoidance test on day 7 after injury. Findings from this study indicate that weight-drop injury animal models are suitable for further screening of brain neuroprotectants and potentially are similar to those seen in human TBI.

  19. Consequences of Transfusing Blood Components in Patients With Trauma: A Conceptual Model.

    Science.gov (United States)

    Jones, Allison R; Frazier, Susan K

    2017-04-01

    Transfusion of blood components is often required in resuscitation of patients with major trauma. Packed red blood cells and platelets break down and undergo chemical changes during storage (known as the storage lesion) that lead to an inflammatory response once the blood components are transfused to patients. Although some evidence supports a detrimental association between transfusion and a patient's outcome, the mechanisms connecting transfusion of stored components to outcomes remain unclear. The purpose of this review is to provide critical care nurses with a conceptual model to facilitate understanding of the relationship between the storage lesion and patients' outcomes after trauma; outcomes related to trauma, hemorrhage, and blood component transfusion are grouped according to those occurring in the short-term (≤30 days) and the long-term (>30 days). Complete understanding of these clinical implications is critical for practitioners in evaluating and treating patients given transfusions after traumatic injury. ©2017 American Association of Critical-Care Nurses.

  20. Common and Critical Components Among Community Health Assessment and Community Health Improvement Planning Models.

    Science.gov (United States)

    Pennel, Cara L; Burdine, James N; Prochaska, John D; McLeroy, Kenneth R

    Community health assessment and community health improvement planning are continuous, systematic processes for assessing and addressing health needs in a community. Since there are different models to guide assessment and planning, as well as a variety of organizations and agencies that carry out these activities, there may be confusion in choosing among approaches. By examining the various components of the different assessment and planning models, we are able to identify areas for coordination, ways to maximize collaboration, and strategies to further improve community health. We identified 11 common assessment and planning components across 18 models and requirements, with a particular focus on health department, health system, and hospital models and requirements. These common components included preplanning; developing partnerships; developing vision and scope; collecting, analyzing, and interpreting data; identifying community assets; identifying priorities; developing and implementing an intervention plan; developing and implementing an evaluation plan; communicating and receiving feedback on the assessment findings and/or the plan; planning for sustainability; and celebrating success. Within several of these components, we discuss characteristics that are critical to improving community health. Practice implications include better understanding of different models and requirements by health departments, hospitals, and others involved in assessment and planning to improve cross-sector collaboration, collective impact, and community health. In addition, federal and state policy and accreditation requirements may be revised or implemented to better facilitate assessment and planning collaboration between health departments, hospitals, and others for the purpose of improving community health.

  1. Characterization of protein quality control components via dual reporter-containing misfolded cytosolic model substrates.

    Science.gov (United States)

    Amm, Ingo; Kawan, Mona; Wolf, Dieter H

    2016-12-15

    Protein misfolding and protein aggregation are causes of severe diseases as neurodegenerative disorders, diabetes and cancer. Therefore, the cell has to constantly monitor the folding status of its proteome. Chaperones and components of the ubiquitin-proteasome system are key players in the cellular protein quality control process. In order to characterize components of the protein quality control system in a well-established model eukaryote - the yeast Saccharomyces cerevisiae - we established new cytosolic model substrates based on firefly luciferase and β-isopropylmalate dehydrogenase (Leu2). The use of these two different enzymes arranged in tandem as reporters enabled us to analyse the folding status and the degradation propensity of these new model substrates in yeast cells mutated in components of the cellular protein quality control system. The Hsp70 chaperone system known to be essential in the cellular protein quality control was chosen as a model for showing the high value of the luciferase-based model substrates in the characterization of components of the cytosolic protein quality control system in yeast. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Evaluation of Radiation Components in a Global Freshwater Model with Station-Based Observations

    Directory of Open Access Journals (Sweden)

    Hannes Müller Schmied

    2016-10-01

    Full Text Available In many hydrological models, the amount of evapotranspired water is calculated using the potential evapotranspiration (PET approach. The main driver of several PET approaches is net radiation, whose downward components are usually obtained from meteorological input data, whereas the upward components are calculated by the model itself. Thus, uncertainties can be large due to both the input data and model assumptions. In this study, we compare the radiation components of the WaterGAP Global Hydrology Model, driven by two meteorological input datasets and two radiation setups from ERA-Interim reanalysis. We assess the performance with respect to monthly observations provided by the Baseline Surface Radiation Network (BSRN and the Global Energy Balance Archive (GEBA. The assessment is done for the global land area and specifically for energy/water limited regions. The results indicate that there is no optimal radiation input throughout the model variants, but standard meteorological input datasets perform better than those directly obtained by ERA-Interim reanalysis for the key variable net radiation. The low number of observations for some radiation components, as well as the scale mismatch between station observations and 0.5° × 0.5° grid cell size, limits the assessment.

  3. A weighting lysimeter for a laboratory experiment on water and energy fluxes measurements and hydrological models verification

    Science.gov (United States)

    Corbari, Chiara; paleari, roberto; mantovani, federico; tarro, stefano; mancini, marco

    2017-04-01

    Weighting lysimeters allow a direct measurement of water loss from the soil, determining the soil water balance, and thus providing an interesting tool to validate hydrological models. Lysimeters, which world originates from the greek words "lysis" (movement) and "metron" (to measure) have been used to measure percolation of water through the soils for over 300 years. The aim of this study is twofold: 1) to perform water and energy flux measurements under different meteorological conditions, irrigation practice (surface flood, drip and groundwater capillary rise), and soil coverage (bare soil and basil crop), 2) to verify hydrological model FEST-EWB parameterization at the lysimeter scale. A weighting lysimeter has been constructed in the Hydraulic Laboratory of Politecnico di Milano. It consists of a steel box of 1.5 x 1.5 x 1 m containing reconstructed soil. The box is mounted on a scale with four load cells with a nominal weight of 6000 kg and a precision of 0,5 kg. The lysimeter is fully instrumented to measure all the main components of the hydrological cycle. Profiles of soil moisture and temperature are provided by 7 probes; ground heat flux is measured by a heat flux plate and two thermocouples; the drainage flux is measured by a tipping bucket rain gauge; the four components of radiation are provided by a net radiometer; air temperature and humidity are measured by a thermo-hygrometer. Data are collected every 10 minutes on a datalogger. A thermal camera is also installed to provide accurate maps of land surface temperature. The different instruments have been subjected to a rigorous calibration process. A low cost station is also installed based on an Arduino micro-controller measuring soil moisture and temperature, air humidity and temperature and solar radiation. The idea is to understand whether low cost instruments can be used to monitor the fundamental hydrological variables. The measured fluxes (e.g. evapotranspiration, soil moisture, land surface

  4. Failure Predictions for VHTR Core Components using a Probabilistic Contiuum Damage Mechanics Model

    Energy Technology Data Exchange (ETDEWEB)

    Fok, Alex

    2013-10-30

    The proposed work addresses the key research need for the development of constitutive models and overall failure models for graphite and high temperature structural materials, with the long-term goal being to maximize the design life of the Next Generation Nuclear Plant (NGNP). To this end, the capability of a Continuum Damage Mechanics (CDM) model, which has been used successfully for modeling fracture of virgin graphite, will be extended as a predictive and design tool for the core components of the very high- temperature reactor (VHTR). Specifically, irradiation and environmental effects pertinent to the VHTR will be incorporated into the model to allow fracture of graphite and ceramic components under in-reactor conditions to be modeled explicitly using the finite element method. The model uses a combined stress-based and fracture mechanics-based failure criterion, so it can simulate both the initiation and propagation of cracks. Modern imaging techniques, such as x-ray computed tomography and digital image correlation, will be used during material testing to help define the baseline material damage parameters. Monte Carlo analysis will be performed to address inherent variations in material properties, the aim being to reduce the arbitrariness and uncertainties associated with the current statistical approach. The results can potentially contribute to the current development of American Society of Mechanical Engineers (ASME) codes for the design and construction of VHTR core components.

  5. A Dynamical Systems Model for Improving Gestational Weight Gain Behavioral Interventions

    Science.gov (United States)

    Dong, Yuwen; Rivera, Daniel E.; Thomas, Diana M.; Navarro-Barrientos, Jesús E.; Downs, Danielle S.; Savage, Jennifer S.; Collins, Linda M.

    2013-01-01

    Excessive gestational weight gain (GWG) represents a major public health concern. In this paper, we present a dynamical systems model that describes how a behavioral intervention can influence weight gain during pregnancy. The model relies on the integration of a mechanistic energy balance with a dynamical behavioral model. The behavioral model incorporates some well-accepted concepts from psychology: the Theory of Planned Behavior (TPB) and the principle of self-regulation which describes how internal processes within the individual can serve to reinforce the positive outcomes of an intervention. A hypothetical case study is presented to illustrate the basic workings of the model and demonstrate how the proper design of the intervention can counteract natural trends towards declines in healthy eating and reduced physical activity during the course of pregnancy. The model can be used by behavioral scientists to evaluate decision rules for adaptive time-varying behavioral interventions, or as the open-loop model for hybrid model predictive control algorithms acting as decision frameworks for such interventions. PMID:24309837

  6. A Case Study on a Combination NDVI Forecasting Model Based on the Entropy Weight Method

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Shengzhi; Ming, Bo; Huang, Qiang; Leng, Guoyong; Hou, Beibei

    2017-05-05

    It is critically meaningful to accurately predict NDVI (Normalized Difference Vegetation Index), which helps guide regional ecological remediation and environmental managements. In this study, a combination forecasting model (CFM) was proposed to improve the performance of NDVI predictions in the Yellow River Basin (YRB) based on three individual forecasting models, i.e., the Multiple Linear Regression (MLR), Artificial Neural Network (ANN), and Support Vector Machine (SVM) models. The entropy weight method was employed to determine the weight coefficient for each individual model depending on its predictive performance. Results showed that: (1) ANN exhibits the highest fitting capability among the four orecasting models in the calibration period, whilst its generalization ability becomes weak in the validation period; MLR has a poor performance in both calibration and validation periods; the predicted results of CFM in the calibration period have the highest stability; (2) CFM generally outperforms all individual models in the validation period, and can improve the reliability and stability of predicted results through combining the strengths while reducing the weaknesses of individual models; (3) the performances of all forecasting models are better in dense vegetation areas than in sparse vegetation areas.

  7. A new enhanced index tracking model in portfolio optimization with sum weighted approach

    Science.gov (United States)

    Siew, Lam Weng; Jaaman, Saiful Hafizah; Hoe, Lam Weng

    2017-04-01

    Index tracking is a portfolio management which aims to construct the optimal portfolio to achieve similar return with the benchmark index return at minimum tracking error without purchasing all the stocks that make up the index. Enhanced index tracking is an improved portfolio management which aims to generate higher portfolio return than the benchmark index return besides minimizing the tracking error. The objective of this paper is to propose a new enhanced index tracking model with sum weighted approach to improve the existing index tracking model for tracking the benchmark Technology Index in Malaysia. The optimal portfolio composition and performance of both models are determined and compared in terms of portfolio mean return, tracking error and information ratio. The results of this study show that the optimal portfolio of the proposed model is able to generate higher mean return than the benchmark index at minimum tracking error. Besides that, the proposed model is able to outperform the existing model in tracking the benchmark index. The significance of this study is to propose a new enhanced index tracking model with sum weighted apporach which contributes 67% improvement on the portfolio mean return as compared to the existing model.

  8. Credit Risk Assessment Model Based Using Principal component Analysis And Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Hamdy Abeer

    2016-01-01

    Full Text Available Credit risk assessment for bank customers has gained increasing attention in recent years. Several models for credit scoring have been proposed in the literature for this purpose. The accuracy of the model is crucial for any financial institution’s profitability. This paper provided a high accuracy credit scoring model that could be utilized with small and large datasets utilizing a principal component analysis (PCA based breakdown to the significance of the attributes commonly used in the credit scoring models. The proposed credit scoring model applied PCA to acquire the main attributes of the credit scoring data then an ANN classifier to determine the credit worthiness of an individual applicant. The performance of the proposed model was compared to other models in terms of accuracy and training time. Results, based on German dataset showed that the proposed model is superior to others and computationally cheaper. Thus it can be a potential candidate for future credit scoring systems.

  9. Effect of dietary adherence on the body weight plateau: a mathematical model incorporating intermittent compliance with energy intake prescription.

    Science.gov (United States)

    Thomas, Diana M; Martin, Corby K; Redman, Leanne M; Heymsfield, Steven B; Lettieri, Steven; Levine, James A; Bouchard, Claude; Schoeller, Dale A

    2014-09-01

    Clinical weight loss in individuals typically stabilizes at 6 mo. However, validated models of dynamic energy balance have consistently shown weight plateaus between 1 and 2 y. The cause for this discrepancy is unclear. We developed 2 mathematical models on the basis of the first law of thermodynamics to investigate plausible explanations for reaching an early weight plateau at 6 mo. The first model was an energy-expenditure adaptation model and was applied to determine the degree of metabolic adaptation required to generate this plateau. The second model was an intermittent lack-of-adherence model formulated by using a randomly fluctuating energy intake term accounting for intermittent noncompliance in dietary intake to reach this plateau. To set model variables, validate models, and compare free-living weight-loss patterns to in-residence supervised programs, we applied the following 4 different studies: The US NHANES 1999-2004, Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) weight-loss study, the Bouchard Twin overfeeding study, and the Minnesota Starvation Experiment. The metabolic adaptation model increased final weight but did not affect the predicted plateau time point. The intermittent lack-of-adherence model generated oscillating weight graphs that have been frequently observed in weight-loss studies. The model showed that a 6-mo weight-loss plateau can be attained despite what can be considered as high diet adherence. The model was programmed as a downloadable application. An intermittent lack of diet adherence, not metabolic adaptation, is a major contributor to the frequently observed early weight-loss plateau. The new weight-loss prediction software, which incorporates an intermittent lack of adherence, can be used to guide and inform patients on realistic levels of adherence on the basis of patient lifestyle. © 2014 American Society for Nutrition.

  10. Quantitative phase-field model for phase transformations in multi-component alloys

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Abhik Narayan

    2013-08-01

    Phase-field modeling has spread to a variety of applications involving phase transformations. While the method has wide applicability, derivation of quantitative predictions requires deeper understanding of the coupling between the system and model parameters. The present work highlights a novel phase-field model based on a grand-potential formalism allowing for an elegant and efficient solution to the problems in phase transformations. In particular, applications involving single and multi-phase, multi-component solidification have been investigated and a thorough study into the quantitative modeling of these problems have been examined.

  11. Abrupt Strategy Change Underlies Gradual Performance Change: Bayesian Hierarchical Models of Component and Aggregate Strategy Use

    Science.gov (United States)

    Wynton, Sarah K. A.; Anglim, Jeromy

    2017-01-01

    While researchers have often sought to understand the learning curve in terms of multiple component processes, few studies have measured and mathematically modeled these processes on a complex task. In particular, there remains a need to reconcile how abrupt changes in strategy use can co-occur with gradual changes in task completion time. Thus,…

  12. Detailed measurements and modelling of thermo active components using a room size test facility

    DEFF Research Database (Denmark)

    Weitzmann, Peter; Svendsen, Svend

    2005-01-01

    measurements in an office sized test facility with thermo active ceiling and floor as well as modelling of similar conditions in a computer program designed for analysis of building integrated heating and cooling systems. A method for characterizing the cooling capacity of thermo active components is described...

  13. A review of multi-component maintenance models with economic dependence

    NARCIS (Netherlands)

    R. Dekker (Rommert); R.E. Wildeman (Ralph); F.A. van der Duyn Schouten (Frank)

    1997-01-01

    textabstractIn this paper we review the literature on multi-component maintenance models with economic dependence. The emphasis is on papers that appeared after 1991, but there is an overlap with Section 2 of the most recent review paper by Cho and Parlar (1991). We distinguish between stationary

  14. An Exploratory Analysis of the .Net Component Model and Uniframe Paradigm Using a Collaborative Approach

    Science.gov (United States)

    2004-08-01

    Architecture [SIR01]..................................................................... 87 Figure 5.2 Communication between HH, AR and DSM in .NET URDS...Shelf DCOM Distributed Component Object Model DCS Distributed Computing System DM Discovery Manager DSM Domain Security Manager EAI Enterprise...service descriptions with little or no human administrative intervention. Service Location Protocol ( SLP ) [GUT99a], JINI [SUN01a], Ninja project

  15. Ontologies to Support RFID-Based Link between Virtual Models and Construction Components

    DEFF Research Database (Denmark)

    Sørensen, Kristian Birch; Christiansson, Per; Svidt, Kjeld

    2010-01-01

    the virtual models and the physical components in the construction process can improve the information handling and sharing in construction and building operation management. Such a link can be created by means of Radio Frequency Identification (RFID) technology. Ontologies play an important role...

  16. An Examination of Motivation Model Components in Face-to-Face and Online Instruction

    Science.gov (United States)

    Jones, Brett D.

    2010-01-01

    Introduction: The MUSIC Model of Academic Motivation consists of psychological components (i.e., empowerment, usefulness, success, interest, and caring) that have been derived from research and theory as ones that are critical to student engagement in academic settings. The purpose of this study was to: (1) determine whether men and women rate…

  17. Forecasting outdoor recreation participation: a cohort-component projection model for Illinois residents

    Science.gov (United States)

    John F. Dwyer

    1995-01-01

    Population projections for Illinois predicts lower growth, an older population, and increased racial diversity. If percent of the population participating in outdoor recreation activities by age and race remains at present levels, cohort-component projection models suggest that with projected changes in the population between 1990 and 2025, the number of Illinois...

  18. Specification and Generation of Environment for Model Checking of Software Components

    Czech Academy of Sciences Publication Activity Database

    Pařízek, P.; Plášil, František

    2007-01-01

    Roč. 176, - (2007), s. 143-154 ISSN 1571-0661 R&D Projects: GA AV ČR 1ET400300504 Institutional research plan: CEZ:AV0Z10300504 Keywords : software components * behavior protocols * model checking * automated generation of environment Subject RIV: JC - Computer Hardware ; Software

  19. A model for determining condition-based maintenance policies for deteriorating multi-component systems

    NARCIS (Netherlands)

    Hontelez, J.A.M.; Wijnmalen, D.J.D.

    1993-01-01

    We discuss a method to determine strategies for preventive maintenance of systems consisting of gradually deteriorating components. A model has been developed to compute not only the range of conditions inducing a repair action, but also inspection moments based on the last known condition value so

  20. Helpful Components Involved in the Cognitive-Experiential Model of Dream Work

    Science.gov (United States)

    Tien, Hsiu-Lan Shelley; Chen, Shuh-Chi; Lin, Chia-Huei

    2009-01-01

    The purpose of the study was to examine the helpful components involved in the Hill's cognitive-experiential dream work model. Participants were 27 volunteer clients from colleges and universities in northern and central parts of Taiwan. Each of the clients received 1-2 sessions of dream interpretations. The cognitive-experiential dream work model…

  1. Particle Markov Chain Monte Carlo Techniques of Unobserved Component Time Series Models Using Ox

    DEFF Research Database (Denmark)

    Nonejad, Nima

    This paper details Particle Markov chain Monte Carlo techniques for analysis of unobserved component time series models using several economic data sets. PMCMC combines the particle filter with the Metropolis-Hastings algorithm. Overall PMCMC provides a very compelling, computationally fast and e...

  2. Swelling in light water reactor internal components: Insights from computational modeling

    Energy Technology Data Exchange (ETDEWEB)

    Stoller, Roger E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Barashev, Alexander V. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Golubov, Stanislav I. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    A modern cluster dynamics model has been used to investigate the materials and irradiation parameters that control microstructural evolution under the relatively low-temperature exposure conditions that are representative of the operating environment for in-core light water reactor components. The focus is on components fabricated from austenitic stainless steel. The model accounts for the synergistic interaction between radiation-produced vacancies and the helium that is produced by nuclear transmutation reactions. Cavity nucleation rates are shown to be relatively high in this temperature regime (275 to 325°C), but are sensitive to assumptions about the fine scale microstructure produced under low-temperature irradiation. The cavity nucleation rates observed run counter to the expectation that void swelling would not occur under these conditions. This expectation was based on previous research on void swelling in austenitic steels in fast reactors. This misleading impression arose primarily from an absence of relevant data. The results of the computational modeling are generally consistent with recent data obtained by examining ex-service components. However, it has been shown that the sensitivity of the model s predictions of low-temperature swelling behavior to assumptions about the primary damage source term and specification of the mean-field sink strengths is somewhat greater that that observed at higher temperatures. Further assessment of the mathematical model is underway to meet the long-term objective of this research, which is to provide a predictive model of void swelling at relevant lifetime exposures to support extended reactor operations.

  3. Principal Component-Based Radiative Transfer Model (PCRTM) for Hyperspectral Sensors. Part I; Theoretical Concept

    Science.gov (United States)

    Liu, Xu; Smith, William L.; Zhou, Daniel K.; Larar, Allen

    2005-01-01

    Modern infrared satellite sensors such as Atmospheric Infrared Sounder (AIRS), Cosmic Ray Isotope Spectrometer (CrIS), Thermal Emission Spectrometer (TES), Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) and Infrared Atmospheric Sounding Interferometer (IASI) are capable of providing high spatial and spectral resolution infrared spectra. To fully exploit the vast amount of spectral information from these instruments, super fast radiative transfer models are needed. This paper presents a novel radiative transfer model based on principal component analysis. Instead of predicting channel radiance or transmittance spectra directly, the Principal Component-based Radiative Transfer Model (PCRTM) predicts the Principal Component (PC) scores of these quantities. This prediction ability leads to significant savings in computational time. The parameterization of the PCRTM model is derived from properties of PC scores and instrument line shape functions. The PCRTM is very accurate and flexible. Due to its high speed and compressed spectral information format, it has great potential for super fast one-dimensional physical retrievals and for Numerical Weather Prediction (NWP) large volume radiance data assimilation applications. The model has been successfully developed for the National Polar-orbiting Operational Environmental Satellite System Airborne Sounder Testbed - Interferometer (NAST-I) and AIRS instruments. The PCRTM model performs monochromatic radiative transfer calculations and is able to include multiple scattering calculations to account for clouds and aerosols.

  4. Mean-Variance-CvaR Model of Multiportfolio Optimization via Linear Weighted Sum Method

    Directory of Open Access Journals (Sweden)

    Younes Elahi

    2014-01-01

    Full Text Available We propose a new approach to optimizing portfolios to mean-variance-CVaR (MVC model. Although of several researches have studied the optimal MVC model of portfolio, the linear weighted sum method (LWSM was not implemented in the area. The aim of this paper is to investigate the optimal portfolio model based on MVC via LWSM. With this method, the solution of the MVC model of portfolio as the multiobjective problem is presented. In data analysis section, this approach in investing on two assets is investigated. An MVC model of the multiportfolio was implemented in MATLAB and tested on the presented problem. It is shown that, by using three objective functions, it helps the investors to manage their portfolio better and thereby minimize the risk and maximize the return of the portfolio. The main goal of this study is to modify the current models and simplify it by using LWSM to obtain better results.

  5. Extending a Consensus-based Fuzzy Ordered Weighting Average (FOWA Model in New Water Quality Indices

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Baghapour

    2017-07-01

    Full Text Available In developing a specific WQI (Water Quality Index, many quality parameters are involved with different levels of importance. The impact of experts’ different opinions and viewpoints, current risks affecting their opinions, and plurality of the involved parameters double the significance of the issue. Hence, the current study tries to apply a consensus-based FOWA (Fuzzy Ordered Weighting Average model as one of the most powerful and well-known Multi-Criteria Decision- Making (MCDM techniques to determine the importance of the used parameters in the development of such WQIs which is shown with an example. This operator has provided the capability of modeling the risks in decision-making through applying the optimistic degree of stakeholders and their power coupled with the use of fuzzy numbers. Totally, 22 water quality parameters for drinking purposes were considered in this study. To determine the weight of each parameter, the viewpoints of 4 decision-making groups of experts were taken into account. After determining the final weights, to validate the use of each parameter in a potential WQI, consensus degrees of both the decision makers and the parameters are calculated. The highest and the lowest weight values, 0.999 and 0.073 respectively, were related to Hg and temperature. Regarding the type of consumption that was drinking, the parameters’ weights and ranks were consistent with their health impacts. Moreover, the decision makers’ highest and lowest consensus degrees were 0.9905 and 0.9669, respectively. Among the water quality parameters, temperature (with consensus degree of 0.9972 and Pb (with consensus degree of 0.9665, received the highest and lowest agreement with the decision-making group. This study indicated that the weight of parameters in determining water quality largely depends on the experts’ opinions and approaches. Moreover, using the FOWA model provides results accurate and closer- to-reality on the significance of

  6. Abrupt strategy change underlies gradual performance change: Bayesian hierarchical models of component and aggregate strategy use.

    Science.gov (United States)

    Wynton, Sarah K A; Anglim, Jeromy

    2017-10-01

    While researchers have often sought to understand the learning curve in terms of multiple component processes, few studies have measured and mathematically modeled these processes on a complex task. In particular, there remains a need to reconcile how abrupt changes in strategy use can co-occur with gradual changes in task completion time. Thus, the current study aimed to assess the degree to which strategy change was abrupt or gradual, and whether strategy aggregation could partially explain gradual performance change. It also aimed to show how Bayesian methods could be used to model the effect of practice on strategy use. To achieve these aims, 162 participants completed 15 blocks of practice on a complex computer-based task-the Wynton-Anglim booking (WAB) task. The task allowed for multiple component strategies (i.e., memory retrieval, information reduction, and insight) that could also be aggregated to a global measure of strategy use. Bayesian hierarchical models were used to compare abrupt and gradual functions of component and aggregate strategy use. Task completion time was well-modeled by a power function, and global strategy use explained substantial variance in performance. Change in component strategy use tended to be abrupt, whereas change in global strategy use was gradual and well-modeled by a power function. Thus, differential timing of component strategy shifts leads to gradual changes in overall strategy efficiency, and this provides one reason for why smooth learning curves can co-occur with abrupt changes in strategy use. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Component- and Alloy-Specific Modeling for Evaluating Aluminum Recycling Strategies for Vehicles

    Science.gov (United States)

    Modaresi, Roja; Løvik, Amund N.; Müller, Daniel B.

    2014-11-01

    Previous studies indicated that the availability of mixed shredded aluminum scrap from end-of-life vehicles (ELV) is likely to surpass the capacity of secondary castings to absorb this type of scrap, which could lead to a scrap surplus unless suitable interventions can be identified and implemented. However, there is a lack of studies analyzing potential solutions to this problem, among others, because of a lack of component- and alloy-specific information in the models. In this study, we developed a dynamic model of aluminum in the global vehicle stock (distinguishing 5 car segments, 14 components, and 7 alloy groups). The forecasts made up to the year 2050 for the demand for vehicle components and alloy groups, for the scrap supply from discarded vehicles, and for the effects of different ELV management options. Furthermore, we used a source-sink diagram to identify alloys that could potentially serve as alternative sinks for the growing scrap supply. Dismantling the relevant components could remove up to two-thirds of the aluminum from the ELV stream. However, the use of these components for alloy-specific recycling is currently limited because of the complex composition of components (mixed material design and applied joining techniques), as well as provisions that practically prevent the production of safety-relevant cast parts from scrap. In addition, dismantling is more difficult for components that are currently penetrating rapidly. Therefore, advanced alloy sorting seems to be a crucial step that needs to be developed over the coming years to avoid a future scrap surplus and prevent negative energy use and emission consequences.

  8. The Tripartite Model of Risk Perception (TRIRISK): Distinguishing Deliberative, Affective, and Experiential Components of Perceived Risk.

    Science.gov (United States)

    Ferrer, Rebecca A; Klein, William M P; Persoskie, Alexander; Avishai-Yitshak, Aya; Sheeran, Paschal

    2016-10-01

    Although risk perception is a key predictor in health behavior theories, current conceptions of risk comprise only one (deliberative) or two (deliberative vs. affective/experiential) dimensions. This research tested a tripartite model that distinguishes among deliberative, affective, and experiential components of risk perception. In two studies, and in relation to three common diseases (cancer, heart disease, diabetes), we used confirmatory factor analyses to examine the factor structure of the tripartite risk perception (TRIRISK) model and compared the fit of the TRIRISK model to dual-factor and single-factor models. In a third study, we assessed concurrent validity by examining the impact of cancer diagnosis on (a) levels of deliberative, affective, and experiential risk perception, and (b) the strength of relations among risk components, and tested predictive validity by assessing relations with behavioral intentions to prevent cancer. The tripartite factor structure was supported, producing better model fit across diseases (studies 1 and 2). Inter-correlations among the components were significantly smaller among participants who had been diagnosed with cancer, suggesting that affected populations make finer-grained distinctions among risk perceptions (study 3). Moreover, all three risk perception components predicted unique variance in intentions to engage in preventive behavior (study 3). The TRIRISK model offers both a novel conceptualization of health-related risk perceptions, and new measures that enhance predictive validity beyond that engendered by unidimensional and bidimensional models. The present findings have implications for the ways in which risk perceptions are targeted in health behavior change interventions, health communications, and decision aids.

  9. Modeling of Body Weight Metrics for Effective and Cost-Efficient Conventional Factor VIII Dosing in Hemophilia A Prophylaxis

    Directory of Open Access Journals (Sweden)

    Alanna McEneny-King

    2017-10-01

    Full Text Available The total body weight-based dosing strategy currently used in the prophylactic treatment of hemophilia A may not be appropriate for all populations. The assumptions that guide weight-based dosing are not valid in overweight and obese populations, resulting in overdosing and ineffective resource utilization. We explored different weight metrics including lean body weight, ideal body weight, and adjusted body weight to determine an alternative dosing strategy that is both safe and resource-efficient in normal and overweight/obese adult patients. Using a validated population pharmacokinetic model, we simulated a variety of dosing regimens using different doses, weight metrics, and frequencies; we also investigated the implications of assuming various levels of endogenous factor production. Ideal body weight performed the best across all of the regimens explored, maintaining safety while moderating resource consumption for overweight and obese patients.

  10. Verification of the component accuracy prediction obtained by physical modelling and the elastic simulation of the die/component interaction

    DEFF Research Database (Denmark)

    Ravn, Bjarne Gottlieb; Andersen, Claus Bo; Wanheim, Tarras

    2001-01-01

    There are three demands on a component that must undergo a die-cavity elasticity analysis. The demands to the product are specified as: (i) to be able to measure the loading profile which results in elestic die-cavity deflections; (ii) to be able to compute the elestic deflections using FE; (iii......) compensating the elestic deflection must lead to closer product tolerances and thus a higher-value product....

  11. Evaluation of the Component Chemical Potentials in Analytical Models for Ordered Alloy Phases

    Directory of Open Access Journals (Sweden)

    W. A. Oates

    2011-01-01

    Full Text Available The component chemical potentials in models of solution phases with a fixed number of sites can be evaluated easily when the Helmholtz energy is known as an analytical function of composition. In the case of ordered phases, however, the situation is less straightforward, because the Helmholtz energy is a functional involving internal order parameters. Because of this, the chemical potentials are usually obtained numerically from the calculated integral Helmholtz energy. In this paper, we show how the component chemical potentials can be obtained analytically in ordered phases via the use of virtual cluster chemical potentials. Some examples are given which illustrate the simplicity of the method.

  12. [The influence of dietary factors on weight change estimated by the use of multivariate graphical models].

    Science.gov (United States)

    Jørgensen, L M; Sørensen, T I; Schroll, M; Larsen, S

    1997-03-03

    The aim of the present study was to analyse the influence of dietary factors on weight change in a multifactorial context by use of graphical models. A random sample of 2304 Danish men and women, aged 30, 40, 50, and 60 years, living in Copenhagen County underwent a general health examination, and their BMI was calculated. They all completed questionnaires regarding education, life conditions, life habits, and dietary intake at entry. At follow-up five years later BMI was also calculated. BMI at entry depended on family predisposition to obesity, and for women, on cohabitation as well. At follow-up five years later BMI in the male group was only related to former BMI, whereas in the female group it was influenced by parity as well: No association was found between total energy intake, percentage of energy from fat or from alcohol and weight changes. No influence of other putative determining factors was found for either gender. We conclude, that although the graphical model detected several relations between diet, habits, and social factors, no influence of dietary factors on weight changes were found by use of multifactorial graphical models.

  13. The Influence of Internal Structures in Fused Deposition Modeling Method on Dimensional Accuracy of Components

    Directory of Open Access Journals (Sweden)

    Milde Ján

    2016-09-01

    Full Text Available The paper investigates the influence of infill (internal structures of components in the Fused Deposition Modeling (FDM method on dimensional and geometrical accuracy of components. The components in this case were real models of human mandible, which were obtained by Computed Tomography (CT mostly used in medical applications. In the production phase, the device used for manufacturing, was a 3D printer Zortrax M200 based on the FDM technology. In the second phase, the mandibles made by the printer, were digitized using optical scanning device of GOM ATOS Triple Scan II. They were subsequently evaluated in the final phase. The practical part of this article describes the procedure of jaw model modification, the production of components using a 3D printer, the procedure of digitization of printed parts by optical scanning device and the procedure of comparison. The outcome of this article is a comparative analysis of individual printed parts, containing tables with mean deviations for individual printed parts, as well as tables for groups of printed parts with the same infill parameter.

  14. Mixed geographically weighted regression (MGWR) model with weighted adaptive bi-square for case of dengue hemorrhagic fever (DHF) in Surakarta

    Science.gov (United States)

    Astuti, H. N.; Saputro, D. R. S.; Susanti, Y.

    2017-06-01

    MGWR model is combination of linear regression model and geographically weighted regression (GWR) model, therefore, MGWR model could produce parameter estimation that had global parameter estimation, and other parameter that had local parameter in accordance with its observation location. The linkage between locations of the observations expressed in specific weighting that is adaptive bi-square. In this research, we applied MGWR model with weighted adaptive bi-square for case of DHF in Surakarta based on 10 factors (variables) that is supposed to influence the number of people with DHF. The observation unit in the research is 51 urban villages and the variables are number of inhabitants, number of houses, house index, many public places, number of healthy homes, number of Posyandu, area width, level population density, welfare of the family, and high-region. Based on this research, we obtained 51 MGWR models. The MGWR model were divided into 4 groups with significant variable is house index as a global variable, an area width as a local variable and the remaining variables vary in each. Global variables are variables that significantly affect all locations, while local variables are variables that significantly affect a specific location.

  15. Data-Driven Robust RVFLNs Modeling of a Blast Furnace Iron-Making Process Using Cauchy Distribution Weighted M-Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Ping; Lv, Youbin; Wang, Hong; Chai, Tianyou

    2017-09-01

    Optimal operation of a practical blast furnace (BF) ironmaking process depends largely on a good measurement of molten iron quality (MIQ) indices. However, measuring the MIQ online is not feasible using the available techniques. In this paper, a novel data-driven robust modeling is proposed for online estimation of MIQ using improved random vector functional-link networks (RVFLNs). Since the output weights of traditional RVFLNs are obtained by the least squares approach, a robustness problem may occur when the training dataset is contaminated with outliers. This affects the modeling accuracy of RVFLNs. To solve this problem, a Cauchy distribution weighted M-estimation based robust RFVLNs is proposed. Since the weights of different outlier data are properly determined by the Cauchy distribution, their corresponding contribution on modeling can be properly distinguished. Thus robust and better modeling results can be achieved. Moreover, given that the BF is a complex nonlinear system with numerous coupling variables, the data-driven canonical correlation analysis is employed to identify the most influential components from multitudinous factors that affect the MIQ indices to reduce the model dimension. Finally, experiments using industrial data and comparative studies have demonstrated that the obtained model produces a better modeling and estimating accuracy and stronger robustness than other modeling methods.

  16. Modelling Creativity: Identifying Key Components through a Corpus-Based Approach.

    Science.gov (United States)

    Jordanous, Anna; Keller, Bill

    2016-01-01

    Creativity is a complex, multi-faceted concept encompassing a variety of related aspects, abilities, properties and behaviours. If we wish to study creativity scientifically, then a tractable and well-articulated model of creativity is required. Such a model would be of great value to researchers investigating the nature of creativity and in particular, those concerned with the evaluation of creative practice. This paper describes a unique approach to developing a suitable model of how creative behaviour emerges that is based on the words people use to describe the concept. Using techniques from the field of statistical natural language processing, we identify a collection of fourteen key components of creativity through an analysis of a corpus of academic papers on the topic. Words are identified which appear significantly often in connection with discussions of the concept. Using a measure of lexical similarity to help cluster these words, a number of distinct themes emerge, which collectively contribute to a comprehensive and multi-perspective model of creativity. The components provide an ontology of creativity: a set of building blocks which can be used to model creative practice in a variety of domains. The components have been employed in two case studies to evaluate the creativity of computational systems and have proven useful in articulating achievements of this work and directions for further research.

  17. Generalized Two-Component Model of Solar Wind Turbulence: Coupled Large and Small Scales

    Science.gov (United States)

    Oughton, S.; Wiengarten, T.; Engelbrecht, N. E.; Fichtner, H.; Kleimann, J.; Scherer, K.

    2016-12-01

    We extend a two-component model for the evolution of (small-scale) fluctuations in the solar windplasma so that it is fully three-dimensional (3D) and also coupled self-consistently to dynamicallarge-scale magnetohydrodynamic (MHD) equations describing the background solar wind. The two classes of fluctuations considered are a high-frequency parallel-propagating wave-like pieceand a low-frequency quasi-two-dimensional component. For both components, the nonlinear dynamics is dominanted by quasi-perpendicular spectral cascades of energy. Support for driving of the fluctuations is included, for example, by velocity shear and pickup ions. Numerical solutions to the new model are obtained using the CRONOS [1] framework, and these are validated against previous simpler models. Comparing results from the new model with spacecraft measurements, we find improved agreement relative to earlier models that employ prescribed background solar wind fields. We also employ the new results for the wave-like and quasi-two-dimensional fluctuations to calculate ab initio diffusion mean free paths and drift lengthscales for the transport of cosmic rays in the turbulent solar wind. [1] Wiengarten et al. ApJ, vol 805, 155, doi: 10.1088/0004-637X/805/2/155 (2015)

  18. Advanced parametrical modelling of 24 GHz radar sensor IC packaging components

    Science.gov (United States)

    Kazemzadeh, R.; John, W.; Wellmann, J.; Bala, U. B.; Thiede, A.

    2011-08-01

    This paper deals with the development of an advanced parametrical modelling concept for packaging components of a 24 GHz radar sensor IC used in automotive driver assistance systems. For fast and efficient design of packages for system-in-package modules (SiP), a simplified model for the description of parasitic electromagnetic effects within the package is desirable, as 3-D field computation becomes inefficient due to the high density of conductive elements of the various signal paths in the package. By using lumped element models for the characterization of the conductive components, a fast indication of the design's signal-quality can be gained, but so far does not offer enough flexibility to cover the whole range of geometric arrangements of signal paths in a contemporary package. This work pursues to meet the challenge of developing a flexible and fast package modelling concept by defining parametric lumped-element models for all basic signal path components, e.g. bond wires, vias, strip lines, bumps and balls.

  19. An AeroCom initial assessment – optical properties in aerosol component modules of global models

    Directory of Open Access Journals (Sweden)

    S. Kinne

    2006-01-01

    Full Text Available The AeroCom exercise diagnoses multi-component aerosol modules in global modeling. In an initial assessment simulated global distributions for mass and mid-visible aerosol optical thickness (aot were compared among 20 different modules. Model diversity was also explored in the context of previous comparisons. For the component combined aot general agreement has improved for the annual global mean. At 0.11 to 0.14, simulated aot values are at the lower end of global averages suggested by remote sensing from ground (AERONET ca. 0.135 and space (satellite composite ca. 0.15. More detailed comparisons, however, reveal that larger differences in regional distribution and significant differences in compositional mixture remain. Of particular concern are large model diversities for contributions by dust and carbonaceous aerosol, because they lead to significant uncertainty in aerosol absorption (aab. Since aot and aab, both, influence the aerosol impact on the radiative energy-balance, the aerosol (direct forcing uncertainty in modeling is larger than differences in aot might suggest. New diagnostic approaches are proposed to trace model differences in terms of aerosol processing and transport: These include the prescription of common input (e.g. amount, size and injection of aerosol component emissions and the use of observational capabilities from ground (e.g. measurements networks or space (e.g. correlations between aerosol and clouds.

  20. Three-Component Power Decomposition for Polarimetric SAR Data Based on Adaptive Volume Scatter Modeling

    Directory of Open Access Journals (Sweden)

    Sang-Eun Park

    2012-05-01

    Full Text Available In this paper, the three-component power decomposition for polarimetric SAR (PolSAR data with an adaptive volume scattering model is proposed. The volume scattering model is assumed to be reflection-symmetric but parameterized. For each image pixel, the decomposition first starts with determining the adaptive parameter based on matrix similarity metric. Then, a respective scattering power component is retrieved with the established procedure. It has been shown that the proposed method leads to complete elimination of negative powers as the result of the adaptive volume scattering model. Experiments with the PolSAR data from both the NASA/JPL (National Aeronautics and Space Administration/Jet Propulsion Laboratory Airborne SAR (AIRSAR and the JAXA (Japan Aerospace Exploration Agency ALOS-PALSAR also demonstrate that the proposed method not only obtains similar/better results in vegetated areas as compared to the existing Freeman-Durden decomposition but helps to improve discrimination of the urban regions.

  1. Analysis of Dynamic Interactions between Different Drivetrain Components with a Detailed Wind Turbine Model

    Science.gov (United States)

    Bartschat, A.; Morisse, M.; Mertens, A.; Wenske, J.

    2016-09-01

    The presented work describes a detailed analysis of the dynamic interactions among mechanical and electrical drivetrain components of a modern wind turbine under the influence of parameter variations, different control mechanisms and transient excitations. For this study, a detailed model of a 2MW wind turbine with a gearbox, a permanent magnet synchronous generator and a full power converter has been developed which considers all relevant characteristics of the mechanical and electrical subsystems. This model includes an accurate representation of the aerodynamics and the mechanical properties of the rotor and the complete mechanical drivetrain. Furthermore, a detailed electrical modelling of the generator, the full scale power converter with discrete switching devices, its filters, the transformer and the grid as well as the control structure is considered. The analysis shows that, considering control measures based on active torsional damping, interactions between mechanical and electrical subsystems can significantly affect the loads and thus the individual lifetime of the components.

  2. Modeling time-varying exposure using inverse probability of treatment weights.

    Science.gov (United States)

    Grafféo, Nathalie; Latouche, Aurélien; Geskus, Ronald B; Chevret, Sylvie

    2017-12-27

    For estimating the causal effect of treatment exposure on the occurrence of adverse events, inverse probability weights (IPW) can be used in marginal structural models to correct for time-dependent confounding. The R package ipw allows IPW estimation by modeling the relationship between the exposure and confounders via several regression models, among which is the Cox model. For right-censored data and time-dependent exposures such as treatment switches, the ipw package allows a single switch, assuming that patients are treated once and for all. However, to accommodate multiple switches, we extend this package by implementing a function that allows for multiple and intermittent exposure status in the estimation of IPW using a survival model. This extension allows for the whole exposure treatment trajectory in the estimation of IPW. The impact of the estimated weights on the estimated causal effect, with both methods, is assessed in a simulation study. Then, the function is illustrated on a real dataset from a nationwide prospective observational cohort including patients with inflammatory bowel disease. In this study, patients received one or multiple medications (thiopurines, methotrexate, and anti-TNF) over time. We used a Cox marginal structural model to assess the effect of thiopurines exposure on the cause-specific hazard for cancer incidence considering other treatments as confounding factors. To this end, we used our extended function which is available online in the Supporting Information. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Weighted Exponential Region Energy Model for River Segmentation of SAR Images

    Directory of Open Access Journals (Sweden)

    HAN Bin

    2017-09-01

    Full Text Available The traditional active contour models can hardly achieve the accurate river segmentation of SAR images. To solve this problem, a novel active contour model with weighted exponential region energy is proposed, which can extract rivers in SAR images accurately. The exponential region energy is incorporated into the energy functional of the Chan-Vese model, which can measure the difference between the segmented image and the original image, resulting in the improvement of segmentation accuracy of the model. In addition, the maximum absolute differences of the pixel grayscale values inside the object and background regions are utilized to replace the original constant region energy weights, which can adaptively adjust the ratios of the object and background region energies and accelerate the motion of the curve towards the boundaries of the object region, resulting in the higher segmentation efficiency. The experiments are performed on real SAR images of rivers and results demonstrate that compared with the traditional active contour models, the proposed model can segment rivers in SAR images more rapidly and accurately and has some advantages in terms of both segmentation performance and segmentation efficiency.

  4. Hidden semi-Markov Model based earthquake classification system using Weighted Finite-State Transducers

    Directory of Open Access Journals (Sweden)

    M. Beyreuther

    2011-02-01

    Full Text Available Automatic earthquake detection and classification is required for efficient analysis of large seismic datasets. Such techniques are particularly important now because access to measures of ground motion is nearly unlimited and the target waveforms (earthquakes are often hard to detect and classify. Here, we propose to use models from speech synthesis which extend the double stochastic models from speech recognition by integrating a more realistic duration of the target waveforms. The method, which has general applicability, is applied to earthquake detection and classification. First, we generate characteristic functions from the time-series. The Hidden semi-Markov Models are estimated from the characteristic functions and Weighted Finite-State Transducers are constructed for the classification. We test our scheme on one month of continuous seismic data, which corresponds to 370 151 classifications, showing that incorporating the time dependency explicitly in the models significantly improves the results compared to Hidden Markov Models.

  5. Hidden semi-Markov Model based earthquake classification system using Weighted Finite-State Transducers

    Science.gov (United States)

    Beyreuther, M.; Wassermann, J.

    2011-02-01

    Automatic earthquake detection and classification is required for efficient analysis of large seismic datasets. Such techniques are particularly important now because access to measures of ground motion is nearly unlimited and the target waveforms (earthquakes) are often hard to detect and classify. Here, we propose to use models from speech synthesis which extend the double stochastic models from speech recognition by integrating a more realistic duration of the target waveforms. The method, which has general applicability, is applied to earthquake detection and classification. First, we generate characteristic functions from the time-series. The Hidden semi-Markov Models are estimated from the characteristic functions and Weighted Finite-State Transducers are constructed for the classification. We test our scheme on one month of continuous seismic data, which corresponds to 370 151 classifications, showing that incorporating the time dependency explicitly in the models significantly improves the results compared to Hidden Markov Models.

  6. Hybrid Wing-Body (HWB) Pressurized Fuselage Modeling, Analysis, and Design for Weight Reduction

    Science.gov (United States)

    Mukhopadhyay, Vivek

    2012-01-01

    This paper describes the interim progress for an in-house study that is directed toward innovative structural analysis and design of next-generation advanced aircraft concepts, such as the Hybrid Wing-Body (HWB) and the Advanced Mobility Concept-X flight vehicles, for structural weight reduction and associated performance enhancement. Unlike the conventional, skin-stringer-frame construction for a cylindrical fuselage, the box-type pressurized fuselage panels in the HWB undergo significant deformation of the outer aerodynamic surfaces, which must be minimized without significant structural weight penalty. Simple beam and orthotropic plate theory is first considered for sizing, analytical verification, and possible equivalent-plate analysis with appropriate simplification. By designing advanced composite stiffened-shell configurations, significant weight reduction may be possible compared with the sandwich and ribbed-shell structural concepts that have been studied previously. The study involves independent analysis of the advanced composite structural concepts that are presently being developed by The Boeing Company for pressurized HWB flight vehicles. High-fidelity parametric finite-element models of test coupons, panels, and multibay fuselage sections, were developed for conducting design studies and identifying critical areas of potential failure. Interim results are discussed to assess the overall weight/strength advantages.

  7. Steady-state plant model to predict hydrogen levels in power plant components

    Science.gov (United States)

    Glatzmaier, Greg C.; Cable, Robert; Newmarker, Marc

    2017-06-01

    The National Renewable Energy Laboratory (NREL) and Acciona Energy North America developed a full-plant steady-state computational model that estimates levels of hydrogen in parabolic trough power plant components. The model estimated dissolved hydrogen concentrations in the circulating heat transfer fluid (HTF), and corresponding partial pressures within each component. Additionally for collector field receivers, the model estimated hydrogen pressure in the receiver annuli. The model was developed to estimate long-term equilibrium hydrogen levels in power plant components, and to predict the benefit of hydrogen mitigation strategies for commercial power plants. Specifically, the model predicted reductions in hydrogen levels within the circulating HTF that result from purging hydrogen from the power plant expansion tanks at a specified target rate. Our model predicted hydrogen partial pressures from 8.3 mbar to 9.6 mbar in the power plant components when no mitigation treatment was employed at the expansion tanks. Hydrogen pressures in the receiver annuli were 8.3 to 8.4 mbar. When hydrogen partial pressure was reduced to 0.001 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.001 mbar to 0.02 mbar. When hydrogen partial pressure was reduced to 0.3 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.25 mbar to 0.28 mbar. Our results show that controlling hydrogen partial pressure in the expansion tanks allows us to reduce and maintain hydrogen pressures in the receiver annuli to any practical level.

  8. Steady-State Plant Model to Predict Hydroden Levels in Power Plant Components

    Energy Technology Data Exchange (ETDEWEB)

    Glatzmaier, Greg C.; Cable, Robert; Newmarker, Marc

    2017-06-27

    The National Renewable Energy Laboratory (NREL) and Acciona Energy North America developed a full-plant steady-state computational model that estimates levels of hydrogen in parabolic trough power plant components. The model estimated dissolved hydrogen concentrations in the circulating heat transfer fluid (HTF), and corresponding partial pressures within each component. Additionally for collector field receivers, the model estimated hydrogen pressure in the receiver annuli. The model was developed to estimate long-term equilibrium hydrogen levels in power plant components, and to predict the benefit of hydrogen mitigation strategies for commercial power plants. Specifically, the model predicted reductions in hydrogen levels within the circulating HTF that result from purging hydrogen from the power plant expansion tanks at a specified target rate. Our model predicted hydrogen partial pressures from 8.3 mbar to 9.6 mbar in the power plant components when no mitigation treatment was employed at the expansion tanks. Hydrogen pressures in the receiver annuli were 8.3 to 8.4 mbar. When hydrogen partial pressure was reduced to 0.001 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.001 mbar to 0.02 mbar. When hydrogen partial pressure was reduced to 0.3 mbar in the expansion tanks, hydrogen pressures in the receiver annuli fell to a range of 0.25 mbar to 0.28 mbar. Our results show that controlling hydrogen partial pressure in the expansion tanks allows us to reduce and maintain hydrogen pressures in the receiver annuli to any practical level.

  9. Fitting a Bivariate Measurement Error Model for Episodically Consumed Dietary Components

    KAUST Repository

    Zhang, Saijuan

    2011-01-06

    There has been great public health interest in estimating usual, i.e., long-term average, intake of episodically consumed dietary components that are not consumed daily by everyone, e.g., fish, red meat and whole grains. Short-term measurements of episodically consumed dietary components have zero-inflated skewed distributions. So-called two-part models have been developed for such data in order to correct for measurement error due to within-person variation and to estimate the distribution of usual intake of the dietary component in the univariate case. However, there is arguably much greater public health interest in the usual intake of an episodically consumed dietary component adjusted for energy (caloric) intake, e.g., ounces of whole grains per 1000 kilo-calories, which reflects usual dietary composition and adjusts for different total amounts of caloric intake. Because of this public health interest, it is important to have models to fit such data, and it is important that the model-fitting methods can be applied to all episodically consumed dietary components.We have recently developed a nonlinear mixed effects model (Kipnis, et al., 2010), and have fit it by maximum likelihood using nonlinear mixed effects programs and methodology (the SAS NLMIXED procedure). Maximum likelihood fitting of such a nonlinear mixed model is generally slow because of 3-dimensional adaptive Gaussian quadrature, and there are times when the programs either fail to converge or converge to models with a singular covariance matrix. For these reasons, we develop a Monte-Carlo (MCMC) computation of fitting this model, which allows for both frequentist and Bayesian inference. There are technical challenges to developing this solution because one of the covariance matrices in the model is patterned. Our main application is to the National Institutes of Health (NIH)-AARP Diet and Health Study, where we illustrate our methods for modeling the energy-adjusted usual intake of fish and whole

  10. Mapping the Two-Component Atomic Fermi Gas to the Nuclear Shell-Model

    DEFF Research Database (Denmark)

    Özen, C.; Zinner, Nikolaj Thomas

    2014-01-01

    of the external potential becomes important. A system of two-species fermionic cold atoms with an attractive zero-range interaction is analogous to a simple model of nucleus in which neutrons and protons interact only through a residual pairing interaction. In this article, we discuss how the problem of a two......-component atomic fermi gas in a tight external trap can be mapped to the nuclear shell model so that readily available many-body techniques in nuclear physics, such as the Shell Model Monte Carlo (SMMC) method, can be directly applied to the study of these systems. We demonstrate an application of the SMMC method...

  11. Development of pure component property models for chemical product-process design and analysis

    DEFF Research Database (Denmark)

    Hukkerikar, Amol Shivajirao

    the CAPEC database, the US Environmental Protection Agency (EPA) database, and the USEtox database are used. In total, 21 thermo-physical properties and 22 environmental-related properties of pure components which include normal boiling point, critical constants, standard enthalpy of formation, liquid......Property prediction models based on the group-contribution+ (GC+) approach have been developed to provide reliable predictions of pure component properties together with uncertainties of predicted property values which is much needed information in performing chemical product and process design...... statistical information about the quality of parameter estimation, such as the parameter covariance, the standard errors in predicted properties, and the confidence intervals. For parameter estimation, large data sets of experimentally measured property values of a wide range of pure components taken from...

  12. Markov Modeling of Component Fault Growth over a Derived Domain of Feasible Output Control Effort Modifications

    Science.gov (United States)

    Bole, Brian; Goebel, Kai; Vachtsevanos, George

    2012-01-01

    This paper introduces a novel Markov process formulation of stochastic fault growth modeling, in order to facilitate the development and analysis of prognostics-based control adaptation. A metric representing the relative deviation between the nominal output of a system and the net output that is actually enacted by an implemented prognostics-based control routine, will be used to define the action space of the formulated Markov process. The state space of the Markov process will be defined in terms of an abstracted metric representing the relative health remaining in each of the system s components. The proposed formulation of component fault dynamics will conveniently relate feasible system output performance modifications to predictions of future component health deterioration.

  13. SU-F-BRD-01: A Logistic Regression Model to Predict Objective Function Weights in Prostate Cancer IMRT

    Energy Technology Data Exchange (ETDEWEB)

    Boutilier, J; Chan, T; Lee, T [University of Toronto, Toronto, Ontario (Canada); Craig, T; Sharpe, M [University of Toronto, Toronto, Ontario (Canada); The Princess Margaret Cancer Centre - UHN, Toronto, ON (Canada)

    2014-06-15

    Purpose: To develop a statistical model that predicts optimization objective function weights from patient geometry for intensity-modulation radiotherapy (IMRT) of prostate cancer. Methods: A previously developed inverse optimization method (IOM) is applied retrospectively to determine optimal weights for 51 treated patients. We use an overlap volume ratio (OVR) of bladder and rectum for different PTV expansions in order to quantify patient geometry in explanatory variables. Using the optimal weights as ground truth, we develop and train a logistic regression (LR) model to predict the rectum weight and thus the bladder weight. Post hoc, we fix the weights of the left femoral head, right femoral head, and an artificial structure that encourages conformity to the population average while normalizing the bladder and rectum weights accordingly. The population average of objective function weights is used for comparison. Results: The OVR at 0.7cm was found to be the most predictive of the rectum weights. The LR model performance is statistically significant when compared to the population average over a range of clinical metrics including bladder/rectum V53Gy, bladder/rectum V70Gy, and mean voxel dose to the bladder, rectum, CTV, and PTV. On average, the LR model predicted bladder and rectum weights that are both 63% closer to the optimal weights compared to the population average. The treatment plans resulting from the LR weights have, on average, a rectum V70Gy that is 35% closer to the clinical plan and a bladder V70Gy that is 43% closer. Similar results are seen for bladder V54Gy and rectum V54Gy. Conclusion: Statistical modelling from patient anatomy can be used to determine objective function weights in IMRT for prostate cancer. Our method allows the treatment planners to begin the personalization process from an informed starting point, which may lead to more consistent clinical plans and reduce overall planning time.

  14. Hydrodynamic Cucker-Smale model with normalized communication weights and time delay

    KAUST Repository

    Choi, Young-Pil

    2017-07-17

    We study a hydrodynamic Cucker-Smale-type model with time delay in communication and information processing, in which agents interact with each other through normalized communication weights. The model consists of a pressureless Euler system with time delayed non-local alignment forces. We resort to its Lagrangian formulation and prove the existence of its global in time classical solutions. Moreover, we derive a sufficient condition for the asymptotic flocking behavior of the solutions. Finally, we show the presence of a critical phenomenon for the Eulerian system posed in the spatially one-dimensional setting.

  15. Atomic Weights Confirm Bipolar Model of Oscillations in a Chain System

    Directory of Open Access Journals (Sweden)

    Ries A.

    2013-10-01

    Full Text Available We apply the bipolar model of oscillations in a chain system to the data set of standard atomic weights. 90% of these masses could be reproduced by this model and were expressed in continued fraction form, where all numerators are Euler’s number and the sum of the free link and all partial denominators yields zero. All outliers were either radioactive or polynuclidic elements whose isotopic compositions as found in samples on Earth might not be fully representative for the mean values when considering samples from all parts of the universe.

  16. Building a Nomogram for Survey-Weighted Cox Models Using R

    Directory of Open Access Journals (Sweden)

    Marinela Capanu

    2015-03-01

    Full Text Available Nomograms have become very useful tools among clinicians as they provide individualized predictions based on the characteristics of the patient. For complex design survey data with survival outcome, Binder (1992 proposed methods for fitting survey-weighted Cox models, but to the best of our knowledge there is no available software to build a nomogram based on such models. This paper introduces an R package, SvyNom, to accomplish this goal and illustrates its use on a gastric cancer dataset. Validation and calibration routines are also included.

  17. Mechanical properties of multifunctional structure with viscoelastic components based on FVE model

    Science.gov (United States)

    Hao, Dong; Zhang, Lin; Yu, Jing; Mao, Daiyong

    2018-02-01

    Based on the models of Lion and Kardelky (2004) and Hofer and Lion (2009), a finite viscoelastic (FVE) constitutive model, considering the predeformation-, frequency- and amplitude-dependent properties, has been proposed in our earlier paper [1]. FVE model is applied to investigating the dynamic characteristics of the multifunctional structure with the viscoelastic components. Combing FVE model with the finite element theory, the dynamic model of the multifunctional structure could be obtained. Additionally, the parametric identification and the experimental verification are also given via the frequency-sweep tests. The results show that the computational data agree well with the experimental data. FVE model has made a success of expressing the dynamic characteristics of the viscoelastic materials utilized in the multifunctional structure. The multifunctional structure technology has been verified by in-orbit experiments.

  18. Deformable known component model-based reconstruction for coronary CT angiography

    Science.gov (United States)

    Zhang, X.; Tilley, S.; Xu, S.; Mathews, A.; McVeigh, E. R.; Stayman, J. W.

    2017-03-01

    Purpose: Atherosclerosis detection remains challenging in coronary CT angiography for patients with cardiac implants. Pacing electrodes of a pacemaker or lead components of a defibrillator can create substantial blooming and streak artifacts in the heart region, severely hindering the visualization of a plaque of interest. We present a novel reconstruction method that incorporates a deformable model for metal leads to eliminate metal artifacts and improve anatomy visualization even near the boundary of the component. Methods: The proposed reconstruction method, referred as STF-dKCR, includes a novel parameterization of the component that integrates deformation, a 3D-2D preregistration process that estimates component shape and position, and a polyenergetic forward model for x-ray propagation through the component where the spectral properties are jointly estimated. The methodology was tested on physical data of a cardiac phantom acquired on a CBCT testbench. The phantom included a simulated vessel, a metal wire emulating a pacing lead, and a small Teflon sphere attached to the vessel wall, mimicking a calcified plaque. The proposed method was also compared to the traditional FBP reconstruction and an interpolation-based metal correction method (FBP-MAR). Results: Metal artifacts presented in standard FBP reconstruction were significantly reduced in both FBP-MAR and STF- dKCR, yet only the STF-dKCR approach significantly improved the visibility of the small Teflon target (within 2 mm of the metal wire). The attenuation of the Teflon bead improved to 0.0481 mm-1 with STF-dKCR from 0.0166 mm-1 with FBP and from 0.0301 mm-1 with FBP-MAR - much closer to the expected 0.0414 mm-1. Conclusion: The proposed method has the potential to improve plaque visualization in coronary CT angiography in the presence of wire-shaped metal components.

  19. Disentangling community functional components in a litter-macrodetritivore model system reveals the predominance of the mass ratio hypothesis.

    Science.gov (United States)

    Bílá, Karolína; Moretti, Marco; Bello, Francesco; Dias, André Tc; Pezzatti, Gianni B; Van Oosten, Arend Raoul; Berg, Matty P

    2014-02-01

    RECENT INVESTIGATIONS HAVE SHOWN THAT TWO COMPONENTS OF COMMUNITY TRAIT COMPOSITION ARE IMPORTANT FOR KEY ECOSYSTEM PROCESSES: (i) the community-weighted mean trait value (CWM), related to the mass ratio hypothesis and dominant trait values in the community, and (ii) functional diversity (FD), related to the complementarity hypothesis and the divergence of trait values. However, no experiments controlling for the inherent dependence between CWM and FD have been conducted so far. We used a novel experimental framework to disentangle the unique and shared effects of CWM and FD in a leaf litter-macrodetritivore model system. We manipulated isopod assemblages varying in species number, CWM and FD of litter consumption rate to test the relative contribution of these community parameters in the decomposition process. We showed that CWM, but also the combination of CWM and FD, is a main factor controlling litter decomposition. When we tested individual biodiversity components separately, CWM of litter consumption rate showed a significant effect on decomposition, while FD and species richness alone did not. Our study demonstrated that (i) trait composition rather than species diversity drives litter decomposition, (ii) dominant trait values in the community (CWM) play a chief role in driving ecosystem processes, corroborating the mass ratio hypothesis, and (iii) trait dissimilarity can contribute in modulating the overall biodiversity effects. Future challenge is to assess whether the generality of our finding, that is, that dominant trait values (CWM) predominate over trait dissimilarity (FD), holds for other ecosystem processes, environmental conditions and different spatial and temporal scales.

  20. Astronomical component estimation (ACE v.1) by time-variant sinusoidal modeling

    Science.gov (United States)

    Sinnesael, Matthias; Zivanovic, Miroslav; De Vleeschouwer, David; Claeys, Philippe; Schoukens, Johan

    2016-09-01

    Accurately deciphering periodic variations in paleoclimate proxy signals is essential for cyclostratigraphy. Classical spectral analysis often relies on methods based on (fast) Fourier transformation. This technique has no unique solution separating variations in amplitude and frequency. This characteristic can make it difficult to correctly interpret a proxy's power spectrum or to accurately evaluate simultaneous changes in amplitude and frequency in evolutionary analyses. This drawback is circumvented by using a polynomial approach to estimate instantaneous amplitude and frequency in orbital components. This approach was proven useful to characterize audio signals (music and speech), which are non-stationary in nature. Paleoclimate proxy signals and audio signals share similar dynamics; the only difference is the frequency relationship between the different components. A harmonic-frequency relationship exists in audio signals, whereas this relation is non-harmonic in paleoclimate signals. However, this difference is irrelevant for the problem of separating simultaneous changes in amplitude and frequency. Using an approach with overlapping analysis frames, the model (Astronomical Component Estimation, version 1: ACE v.1) captures time variations of an orbital component by modulating a stationary sinusoid centered at its mean frequency, with a single polynomial. Hence, the parameters that determine the model are the mean frequency of the orbital component and the polynomial coefficients. The first parameter depends on geologic interpretations, whereas the latter are estimated by means of linear least-squares. As output, the model provides the orbital component waveform, either in the depth or time domain. Uncertainty analyses of the model estimates are performed using Monte Carlo simulations. Furthermore, it allows for a unique decomposition of the signal into its instantaneous amplitude and frequency. Frequency modulation patterns reconstruct changes in

  1. The ORC method. Effective modelling of thermal performance of multilayer building components

    Energy Technology Data Exchange (ETDEWEB)

    Akander, Jan

    2000-02-01

    The ORC Method (Optimised RC-networks) provides a means of modelling one- or multidimensional heat transfer in building components, in this context within building simulation environments. The methodology is shown, primarily applied to heat transfer in multilayer building components. For multilayer building components, the analytical thermal performance is known, given layer thickness and material properties. The aim of the ORC Method is to optimise the values of the thermal resistances and heat capacities of an RC-model such as to give model performance a good agreement with the analytical performance, for a wide range of frequencies. The optimisation procedure is made in the frequency domain, where the over-all deviation between model and analytical frequency response, in terms of admittance and dynamic transmittance, is minimised. It is shown that ORC's are effective in terms of accuracy and computational time in comparison to finite difference models when used in building simulations, in this case with IDA/ICE. An ORC configuration of five mass nodes has been found to model building components in Nordic countries well, within the application of thermal comfort and energy requirement simulations. Simple RC-networks, such as the surface heat capacity and the simple R-C-configuration are not appropriate for detailed building simulation. However, these can be used as basis for defining the effective heat capacity of a building component. An approximate method is suggested on how to determine the effective heat capacity without the use of complex numbers. This entity can be calculated on basis of layer thickness and material properties with the help of two time constants. The approximate method can give inaccuracies corresponding to 20%. In-situ measurements have been carried out in an experimental building with the purpose of establishing the effective heat capacity of external building components that are subjected to normal thermal conditions. The auxiliary

  2. Blind Separation of Acoustic Signals Combining SIMO-Model-Based Independent Component Analysis and Binary Masking

    Directory of Open Access Journals (Sweden)

    Hiekata Takashi

    2006-01-01

    Full Text Available A new two-stage blind source separation (BSS method for convolutive mixtures of speech is proposed, in which a single-input multiple-output (SIMO-model-based independent component analysis (ICA and a new SIMO-model-based binary masking are combined. SIMO-model-based ICA enables us to separate the mixed signals, not into monaural source signals but into SIMO-model-based signals from independent sources in their original form at the microphones. Thus, the separated signals of SIMO-model-based ICA can maintain the spatial qualities of each sound source. Owing to this attractive property, our novel SIMO-model-based binary masking can be applied to efficiently remove the residual interference components after SIMO-model-based ICA. The experimental results reveal that the separation performance can be considerably improved by the proposed method compared with that achieved by conventional BSS methods. In addition, the real-time implementation of the proposed BSS is illustrated.

  3. Machine learning of frustrated classical spin models. I. Principal component analysis

    Science.gov (United States)

    Wang, Ce; Zhai, Hui

    2017-10-01

    This work aims at determining whether artificial intelligence can recognize a phase transition without prior human knowledge. If this were successful, it could be applied to, for instance, analyzing data from the quantum simulation of unsolved physical models. Toward this goal, we first need to apply the machine learning algorithm to well-understood models and see whether the outputs are consistent with our prior knowledge, which serves as the benchmark for this approach. In this work, we feed the computer data generated by the classical Monte Carlo simulation for the X Y model in frustrated triangular and union jack lattices, which has two order parameters and exhibits two phase transitions. We show that the outputs of the principal component analysis agree very well with our understanding of different orders in different phases, and the temperature dependences of the major components detect the nature and the locations of the phase transitions. Our work offers promise for using machine learning techniques to study sophisticated statistical models, and our results can be further improved by using principal component analysis with kernel tricks and the neural network method.

  4. Sensitivity analysis of key components in large-scale hydroeconomic models

    Science.gov (United States)

    Medellin-Azuara, J.; Connell, C. R.; Lund, J. R.; Howitt, R. E.

    2008-12-01

    This paper explores the likely impact of different estimation methods in key components of hydro-economic models such as hydrology and economic costs or benefits, using the CALVIN hydro-economic optimization for water supply in California. In perform our analysis using two climate scenarios: historical and warm-dry. The components compared were perturbed hydrology using six versus eighteen basins, highly-elastic urban water demands, and different valuation of agricultural water scarcity. Results indicate that large scale hydroeconomic hydro-economic models are often rather robust to a variety of estimation methods of ancillary models and components. Increasing the level of detail in the hydrologic representation of this system might not greatly affect overall estimates of climate and its effects and adaptations for California's water supply. More price responsive urban water demands will have a limited role in allocating water optimally among competing uses. Different estimation methods for the economic value of water and scarcity in agriculture may influence economically optimal water allocation; however land conversion patterns may have a stronger influence in this allocation. Overall optimization results of large-scale hydro-economic models remain useful for a wide range of assumptions in eliciting promising water management alternatives.

  5. The multi-component model of working memory: explorations in experimental cognitive psychology.

    Science.gov (United States)

    Repovs, G; Baddeley, A

    2006-04-28

    There are a number of ways one can hope to describe and explain cognitive abilities, each of them contributing a unique and valuable perspective. Cognitive psychology tries to develop and test functional accounts of cognitive systems that explain the capacities and properties of cognitive abilities as revealed by empirical data gathered by a range of behavioral experimental paradigms. Much of the research in the cognitive psychology of working memory has been strongly influenced by the multi-component model of working memory [Baddeley AD, Hitch GJ (1974) Working memory. In: Recent advances in learning and motivation, Vol. 8 (Bower GA, ed), pp 47-90. New York: Academic Press; Baddeley AD (1986) Working memory. Oxford, UK: Clarendon Press; Baddeley A. Working memory: Thought and action. Oxford: Oxford University Press, in press]. By expanding the notion of a passive short-term memory to an active system that provides the basis for complex cognitive abilities, the model has opened up numerous questions and new lines of research. In this paper we present the current revision of the multi-component model that encompasses a central executive, two unimodal storage systems: a phonological loop and a visuospatial sketchpad, and a further component, a multimodal store capable of integrating information into unitary episodic representations, termed episodic buffer. We review recent empirical data within experimental cognitive psychology that has shaped the development of the multicomponent model and the understanding of the capacities and properties of working memory. Research based largely on dual-task experimental designs and on neuropsychological evidence has yielded valuable information about the fractionation of working memory into independent stores and processes, the nature of representations in individual stores, the mechanisms of their maintenance and manipulation, the way the components of working memory relate to each other, and the role they play in other

  6. User's guide to the weather model: a component of the western spruce budworm modeling system.

    Science.gov (United States)

    W. P. Kemp; N. L. Crookston; P. W. Thomas

    1989-01-01

    A stochastic model useful in simulating daily maximum and minimum temperature and precipitation developed by Bruhn and others has been adapted for use in the western spruce budworm modeling system. This document describes how to use the weather model and illustrates some aspects of its behavior.

  7. Large-scale Models Reveal the Two-component Mechanics of Striated Muscle

    Directory of Open Access Journals (Sweden)

    Robert Jarosch

    2008-12-01

    Full Text Available This paper provides a comprehensive explanation of striated muscle mechanics and contraction on the basis of filament rotations. Helical proteins, particularly the coiled-coils of tropomyosin, myosin and α-actinin, shorten their H-bonds cooperatively and produce torque and filament rotations when the Coulombic net-charge repulsion of their highly charged side-chains is diminished by interaction with ions. The classical “two-component model” of active muscle differentiated a “contractile component” which stretches the “series elastic component” during force production. The contractile components are the helically shaped thin filaments of muscle that shorten the sarcomeres by clockwise drilling into the myosin cross-bridges with torque decrease (= force-deficit. Muscle stretch means drawing out the thin filament helices off the cross-bridges under passive counterclockwise rotation with torque increase (= stretch activation. Since each thin filament is anchored by four elastic α-actinin Z-filaments (provided with forceregulating sites for Ca2+ binding, the thin filament rotations change the torsional twist of the four Z-filaments as the “series elastic components”. Large scale models simulate the changes of structure and force in the Z-band by the different Z-filament twisting stages A, B, C, D, E, F and G. Stage D corresponds to the isometric state. The basic phenomena of muscle physiology, i. e. latency relaxation, Fenn-effect, the force-velocity relation, the length-tension relation, unexplained energy, shortening heat, the Huxley-Simmons phases, etc. are explained and interpreted with the help of the model experiments.

  8. Androgenic influences on behavior, body weight, and body composition in a model of chronic social stress.

    Science.gov (United States)

    Nguyen, Mary M N; Tamashiro, Kellie L K; Melhorn, Susan J; Ma, Li Y; Gardner, Stacy R; Sakai, Randall R

    2007-12-01

    The visible burrow system (VBS) is a model used to study chronic social stress in colony-housed rats. A hierarchy develops among the males resulting in dominant (DOM) and subordinate (SUB) animals. Hierarchy-associated changes in body weight, body composition, behavior, and neuroendocrine measures have been observed. After 14 d of VBS housing, SUB animals have decreased body weight, elevated corticosterone, and decreased testosterone (T), compared with DOM animals and controls, placing SUB animals in an ideal endocrine state to regain lost body weight as adipose tissue. It is hypothesized that maintaining constant androgen concentrations in SUB males during stress will prevent body weight loss by maintaining more lean body mass. To test this, animals were gonadectomized and implanted with SILASTIC implants containing T, 5alpha-dihydrotestosterone (DHT), or cholesterol. Implants maintained constant physiological levels of T. Standard intact, T, and DHT implant colonies formed hierarchies, whereas cholesterol colonies did not. Androgen manipulations significantly altered offensive and defensive behaviors only on the first day of VBS housing. After VBS stress, intact, T, and DHT SUB animals weighed less and lost more adipose and lean tissue than DOM and control males, whereas DOM animals primarily lost adipose tissue. However, on recovery, DHT SUB animals maintained more lean tissue than intact SUB animals. Oral glucose tolerance tests revealed that glucose clears faster in stressed T-implanted males that have increased adipose tissue. Overall, these data suggest that constant androgen concentrations in SUB animals do not prevent weight loss and changes in body composition during stress but do so during recovery.

  9. A Modeling Framework to Investigate the Radial Component of the Pushrim Force in Manual Wheelchair Propulsion

    Directory of Open Access Journals (Sweden)

    Ackermann Marko

    2015-01-01

    Full Text Available The ratio of tangential to total pushrim force, the so-called Fraction Effective Force (FEF, has been used to evaluate wheelchair propulsion efficiency based on the fact that only the tangential component of the force on the pushrim contributes to actual wheelchair propulsion. Experimental studies, however, consistently show low FEF values and recent experimental as well as modelling investigations have conclusively shown that a more tangential pushrim force direction can lead to a decrease and not increase in propulsion efficiency. This study aims at quantifying the contributions of active, inertial and gravitational forces to the normal pushrim component. In order to achieve this goal, an inverse dynamics-based framework is proposed to estimate individual contributions to the pushrim forces using a model of the wheelchair-user system. The results show that the radial pushrim force component arise to a great extent due to purely mechanical effects, including inertial and gravitational forces. These results corroborate previous findings according to which radial pushrim force components are not necessarily a result of inefficient propulsion strategies or hand-rim friction requirements. This study proposes a novel framework to quantify the individual contributions of active, inertial and gravitational forces to pushrim forces during wheelchair propulsion.

  10. Interacting Components

    NARCIS (Netherlands)

    Orlic, B.; Broenink, Johannes F.; Welch, Peter; Kerridge, Jon; Barnes, Fred

    2006-01-01

    SystemCSP is a graphical modeling language based on both CSP and concepts of component-based software development. The component framework of SystemCSP enables specification of both interaction scenarios and relative execution ordering among components. Specification and implementation of

  11. Roadmap for Lean implementation in Indian automotive component manufacturing industry: comparative study of UNIDO Model and ISM Model

    Science.gov (United States)

    Jadhav, J. R.; Mantha, S. S.; Rane, S. B.

    2014-07-01

    The demands for automobiles increased drastically in last two and half decades in India. Many global automobile manufacturers and Tier-1 suppliers have already set up research, development and manufacturing facilities in India. The Indian automotive component industry started implementing Lean practices to fulfill the demand of these customers. United Nations Industrial Development Organization (UNIDO) has taken proactive approach in association with Automotive Component Manufacturers Association of India (ACMA) and the Government of India to assist Indian SMEs in various clusters since 1999 to make them globally competitive. The primary objectives of this research are to study the UNIDO-ACMA Model as well as ISM Model of Lean implementation and validate the ISM Model by comparing with UNIDO-ACMA Model. It also aims at presenting a roadmap for Lean implementation in Indian automotive component industry. This paper is based on secondary data which include the research articles, web articles, doctoral thesis, survey reports and books on automotive industry in the field of Lean, JIT and ISM. ISM Model for Lean practice bundles was developed by authors in consultation with Lean practitioners. The UNIDO-ACMA Model has six stages whereas ISM Model has eight phases for Lean implementation. The ISM-based Lean implementation model is validated through high degree of similarity with UNIDO-ACMA Model. The major contribution of this paper is the proposed ISM Model for sustainable Lean implementation. The ISM-based Lean implementation framework presents greater insight of implementation process at more microlevel as compared to UNIDO-ACMA Model.

  12. Sea Surface Temperature Modeling using Radial Basis Function Networks With a Dynamically Weighted Particle Filter

    KAUST Repository

    Ryu, Duchwan

    2013-03-01

    The sea surface temperature (SST) is an important factor of the earth climate system. A deep understanding of SST is essential for climate monitoring and prediction. In general, SST follows a nonlinear pattern in both time and location and can be modeled by a dynamic system which changes with time and location. In this article, we propose a radial basis function network-based dynamic model which is able to catch the nonlinearity of the data and propose to use the dynamically weighted particle filter to estimate the parameters of the dynamic model. We analyze the SST observed in the Caribbean Islands area after a hurricane using the proposed dynamic model. Comparing to the traditional grid-based approach that requires a supercomputer due to its high computational demand, our approach requires much less CPU time and makes real-time forecasting of SST doable on a personal computer. Supplementary materials for this article are available online. © 2013 American Statistical Association.

  13. NCWin — A Component Object Model (COM) for processing and visualizing NetCDF data

    Science.gov (United States)

    Liu, Jinxun; Chen, J.M.; Price, D.T.; Liu, S.

    2005-01-01

    NetCDF (Network Common Data Form) is a data sharing protocol and library that is commonly used in large-scale atmospheric and environmental data archiving and modeling. The NetCDF tool described here, named NCWin and coded with Borland C + + Builder, was built as a standard executable as well as a COM (component object model) for the Microsoft Windows environment. COM is a powerful technology that enhances the reuse of applications (as components). Environmental model developers from different modeling environments, such as Python, JAVA, VISUAL FORTRAN, VISUAL BASIC, VISUAL C + +, and DELPHI, can reuse NCWin in their models to read, write and visualize NetCDF data. Some Windows applications, such as ArcGIS and Microsoft PowerPoint, can also call NCWin within the application. NCWin has three major components: 1) The data conversion part is designed to convert binary raw data to and from NetCDF data. It can process six data types (unsigned char, signed char, short, int, float, double) and three spatial data formats (BIP, BIL, BSQ); 2) The visualization part is designed for displaying grid map series (playing forward or backward) with simple map legend, and displaying temporal trend curves for data on individual map pixels; and 3) The modeling interface is designed for environmental model development by which a set of integrated NetCDF functions is provided for processing NetCDF data. To demonstrate that the NCWin can easily extend the functions of some current GIS software and the Office applications, examples of calling NCWin within ArcGIS and MS PowerPoint for showing NetCDF map animations are given.

  14. Health Belief Model Offers Opportunities for Designing Weight Management Interventions for College Students.

    Science.gov (United States)

    McArthur, Laura H; Riggs, Alysse; Uribe, Franchesca; Spaulding, Trent J

    2017-10-30

    Identify weight-related beliefs of college students and test the predictive power of the Health Belief Model for body mass index (BMI). Cross-sectional online survey with beliefs measured on 5-point scales. University in North Carolina. Undergraduates (n = 516; 91.9%), females (n = 399; 71.3%), white non-Hispanic students (n = 507; 86.2%), and 20.3% of overweight or obese status. Perceived severity, susceptibility, barriers, benefits, and internal and external cues to action. One-way ANOVA and regression. Significance was P external cues, barriers, and benefits predicted BMI. Several beliefs were identified that could serve as the basis for weight-related interventions addressing specific concerns, needs, and goals of college students. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  15. A Model of Yeast Cell-Cycle Regulation Based on a Standard Component Modeling Strategy for Protein Regulatory Networks.

    Science.gov (United States)

    Laomettachit, Teeraphan; Chen, Katherine C; Baumann, William T; Tyson, John J

    2016-01-01

    To understand the molecular mechanisms that regulate cell cycle progression in eukaryotes, a variety of mathematical modeling approaches have been employed, ranging from Boolean networks and differential equations to stochastic simulations. Each approach has its own characteristic strengths and weaknesses. In this paper, we propose a "standard component" modeling strategy that combines advantageous features of Boolean networks, differential equations and stochastic simulations in a framework that acknowledges the typical sorts of reactions found in protein regulatory networks. Applying this strategy to a comprehensive mechanism of the budding yeast cell cycle, we illustrate the potential value of standard component modeling. The deterministic version of our model reproduces the phenotypic properties of wild-type cells and of 125 mutant strains. The stochastic version of our model reproduces the cell-to-cell variability of wild-type cells and the partial viability of the CLB2-dbΔ clb5Δ mutant strain. Our simulations show that mathematical modeling with "standard components" can capture in quantitative detail many essential properties of cell cycle control in budding yeast.

  16. A Model of Yeast Cell-Cycle Regulation Based on a Standard Component Modeling Strategy for Protein Regulatory Networks.

    Directory of Open Access Journals (Sweden)

    Teeraphan Laomettachit

    Full Text Available To understand the molecular mechanisms that regulate cell cycle progression in eukaryotes, a variety of mathematical modeling approaches have been employed, ranging from Boolean networks and differential equations to stochastic simulations. Each approach has its own characteristic strengths and weaknesses. In this paper, we propose a "standard component" modeling strategy that combines advantageous features of Boolean networks, differential equations and stochastic simulations in a framework that acknowledges the typical sorts of reactions found in protein regulatory networks. Applying this strategy to a comprehensive mechanism of the budding yeast cell cycle, we illustrate the potential value of standard component modeling. The deterministic version of our model reproduces the phenotypic properties of wild-type cells and of 125 mutant strains. The stochastic version of our model reproduces the cell-to-cell variability of wild-type cells and the partial viability of the CLB2-dbΔ clb5Δ mutant strain. Our simulations show that mathematical modeling with "standard components" can capture in quantitative detail many essential properties of cell cycle control in budding yeast.

  17. Analytical probabilistic modeling of RBE-weighted dose for ion therapy

    Science.gov (United States)

    Wieser, H. P.; Hennig, P.; Wahl, N.; Bangert, M.

    2017-12-01

    Particle therapy is especially prone to uncertainties. This issue is usually addressed with uncertainty quantification and minimization techniques based on scenario sampling. For proton therapy, however, it was recently shown that it is also possible to use closed-form computations based on analytical probabilistic modeling (APM) for this purpose. APM yields unique features compared to sampling-based approaches, motivating further research in this context. This paper demonstrates the application of APM for intensity-modulated carbon ion therapy to quantify the influence of setup and range uncertainties on the RBE-weighted dose. In particular, we derive analytical forms for the nonlinear computations of the expectation value and variance of the RBE-weighted dose by propagating linearly correlated Gaussian input uncertainties through a pencil beam dose calculation algorithm. Both exact and approximation formulas are presented for the expectation value and variance of the RBE-weighted dose and are subsequently studied in-depth for a one-dimensional carbon ion spread-out Bragg peak. With V and B being the number of voxels and pencil beams, respectively, the proposed approximations induce only a marginal loss of accuracy while lowering the computational complexity from order O(V × B^2) to O(V × B) for the expectation value and from O(V × B^4) to O(V × B^2) for the variance of the RBE-weighted dose. Moreover, we evaluated the approximated calculation of the expectation value and standard deviation of the RBE-weighted dose in combination with a probabilistic effect-based optimization on three patient cases considering carbon ions as radiation modality against sampled references. The resulting global γ-pass rates (2 mm,2%) are > 99.15% for the expectation value and > 94.95% for the standard deviation of the RBE-weighted dose, respectively. We applied the derived analytical model to carbon ion treatment planning, although the concept is in general applicable to other

  18. Composition-Based Prediction of Temperature-Dependent Thermophysical Food Properties: Reevaluating Component Groups and Prediction Models.

    Science.gov (United States)

    Phinney, David Martin; Frelka, John C; Heldman, Dennis Ray

    2017-01-01

    Prediction of temperature-dependent thermophysical properties (thermal conductivity, density, specific heat, and thermal diffusivity) is an important component of process design for food manufacturing. Current models for prediction of thermophysical properties of foods are based on the composition, specifically, fat, carbohydrate, protein, fiber, water, and ash contents, all of which change with temperature. The objectives of this investigation were to reevaluate and improve the prediction expressions for thermophysical properties. Previously published data were analyzed over the temperature range from 10 to 150 °C. These data were analyzed to create a series of relationships between the thermophysical properties and temperature for each food component, as well as to identify the dependence of the thermophysical properties on more specific structural properties of the fats, carbohydrates, and proteins. Results from this investigation revealed that the relationships between the thermophysical properties of the major constituents of foods and temperature can be statistically described by linear expressions, in contrast to the current polynomial models. Links between variability in thermophysical properties and structural properties were observed. Relationships for several thermophysical properties based on more specific constituents have been identified. Distinctions between simple sugars (fructose, glucose, and lactose) and complex carbohydrates (starch, pectin, and cellulose) have been proposed. The relationships between the thermophysical properties and proteins revealed a potential correlation with the molecular weight of the protein. The significance of relating variability in constituent thermophysical properties with structural properties--such as molecular mass--could significantly improve composition-based prediction models and, consequently, the effectiveness of process design. © 2016 Institute of Food Technologists®.

  19. A two-component Frenkel-Kontorowa model for surface alloy formation

    CERN Document Server

    Daruka, I

    2003-01-01

    It has been shown by recent experiments that bulk immiscible metals (e.g. Ag/Cu, Ag/Co and Au/Ni) can form binary alloys on certain surfaces where the substrate mediates the elastic misfits between the two components, thus relieving the elastic strain in the overlayer. These novel surface alloys exhibit a rich phase structure. We formulate a two-component Frenkel-Kontorova model in one dimension to study surface alloy formation. This model can naturally incorporate dislocation formation that plays a crucial role in determining the actual structure of the system. Using energy minimization calculations we provide a phase diagram in terms of average alloy composition and the energy of mixing. Monte Carlo simulations were also performed to study the structure and interaction of the emerging dislocations.

  20. Pinning Properties of Commercial Nb-Ti Wires Described by a 2-Components Model

    CERN Document Server

    Muzzi, L; Zignani, Chiarasole Fiamozzi; De Marzi, Gianluca; Muzzi, Luigi; Dominguez, Cesar Octavio; Bottura, Luca; Napolitano, Mathieu; Viola, Rosario; Affinito, Luigi; della Corte, Antonio; Le Naour, Sandrine

    2010-01-01

    We report on the magnetic and transport characterization of different NbTi commercial strands, carried out at variable temperature and magnetic field. From the critical current densities extracted from transport measurements and magnetization cycles we were able to calculate the normalized bulk pinning forces. The curves show good temperature scaling throughout the explored temperature range, and the reduced pinning force can be described by a simple two-components model system. The extension of the 2-components description of the pinning force to an expression for the critical current density gives a very good agreement with experimental measurements over the whole explored B, T range. The model works for all investigated samples, which are different in size, Cu:nonCu ratios, filament diameters and layouts. These results suggest that pinning mechanisms in conventional NbTi strands should be revised, since Nb-Ti composition gradients and grain boundaries seems to play a not negligible role.

  1. Structural assessment of aerospace components using image processing algorithms and Finite Element models

    DEFF Research Database (Denmark)

    Stamatelos, Dimtrios; Kappatos, Vassilios

    2017-01-01

    Purpose – This paper presents the development of an advanced structural assessment approach for aerospace components (metallic and composites). This work focuses on developing an automatic image processing methodology based on Non Destructive Testing (NDT) data and numerical models, for predicting...... of the damaged plates showed that strength reduction occurs compare to reference plates. This methodology is a promising method for structural assessment of aerospace components, since conclusions regarding their functionality can be drawn. Research limitations/implications – The investigated structural...... in a tough economic area. Originality/value – As far as it is known, this is the first time that an aerospace structural assessment combines image processing algorithms and FE models....

  2. Improving the accuracy: volatility modeling and forecasting using high-frequency data and the variational component

    Directory of Open Access Journals (Sweden)

    Manish Kumar

    2010-06-01

    Full Text Available In this study, we predict the daily volatility of the S&P CNX NIFTY market index of India using the basic ‘heterogeneous autoregressive’ (HAR and its variant. In doing so, we estimated several HAR and Log form of HAR models using different regressor. The different regressors were obtained by extracting the jump and continuous component and the threshold jump and continuous component from the realized volatility. We also tried to investigate whether dividing volatility into simple and threshold jumps and continuous variation yields a substantial improvement in volatility forecasting or not. The results provide the evidence that inclusion of realized bipower variance in the HAR models helps in predicting future volatility.

  3. The Research and Analysis on Failure Distribution Model of Diesel Engine Component Parts

    Directory of Open Access Journals (Sweden)

    Wang Shaokun

    2016-01-01

    Full Text Available Reliability research not only provides the direction of quality improvement for new product research and development, but also helps to get the product failure distribution model, so as to ensure the logistics organization to improve the service level. According to the reliability data from the database of research group, we analyzed the rule of failure distribution of high frequency fault component (fuel injection pump and built a Weibull model. The parameters of the model are estimated and solved by using the uniform linear method and the least square method. After solving the model, the density function curves and the failure rate curves are drawn, and then the model of the demand forecasting of spare parts based on the failure distribution is obtained.

  4. Capable of Suicide: A Functional Model of the Acquired Capability Component of the Interpersonal-Psychological Theory of Suicide

    Science.gov (United States)

    Smith, Phillip N.; Cukrowicz, Kelly C.

    2010-01-01

    A functional model of the acquired capability for suicide, a component of Joiner's (2005) Interpersonal-Psychological Theory of Suicide, is presented. A component of Joiner's (2005) Interpersonal-Psychological Theory of Suicide a functional model of the acquired capability for suicide is presented. The model integrates the points discussed by…

  5. Function-weighted frequency response function sensitivity method for analytical model updating

    Science.gov (United States)

    Lin, R. M.

    2017-09-01

    Since the frequency response function (FRF) sensitivity method was first proposed [26], it has since become a most powerful and practical method for analytical model updating. Nevertheless, the original formulation of the FRF sensitivity method does suffer the limitation that the initial analytical model to be updated should be reasonably close to the final updated model to be sought, due the assumed mathematical first order approximation implicit to most sensitivity based methods. Convergence to correct model is not guaranteed when large modelling errors exist and blind application often leads to optimal solutions which are truly sought. This paper seeks to examine all the important numerical characteristics of the original FRF sensitivity method including frequency data selection, numerical balance and convergence performance. To further improve the applicability of the method to cases of large modelling errors, a new novel function-weighted sensitivity method is developed. The new method has shown much superior performance on convergence even in the presence of large modelling errors. Extensive numerical case studies based on a mass-spring system and a GARTEUR structure have been conducted and very encouraging results have been achieved. Effect of measurement noise has been examined and the method works reasonably well in the presence of measurement uncertainties. The new method removes the restriction of modelling error magnitude being of second order in Euclidean norm as compared with that of system matrices, thereby making it a truly general method applicable to most practical model updating problems.

  6. Agile Modeling of Component Connections for Simulation and Design of Complex Vehicle Structures (Slides)

    Science.gov (United States)

    2009-04-01

    1996) • Optimal design of spot-weld and adhesive bond patterns for static compliance Chickermane and Gea (1997) • Multi-component structural...Shifted Lagrangian in OC MMA (Method of Moving Asymptotes) – K. Svanberg (’87) Convex Linearization with Asymptotes of Objective and Constraints Joining...Applicability both dynamic and static problems Design domain modeling SIMP (Solid Isotropic Material with Penalization) MMA (Method of Moving Asymptote

  7. Evaluation of low dose ionizing radiation effect on some blood components in animal model

    OpenAIRE

    H. El-Shanshoury; G. El-Shanshoury; A. Abaza

    2016-01-01

    Exposure to ionizing radiation is known to have lethal effects in blood cells. It is predicted that an individual may spend days, weeks or even months in a radiation field without becoming alarmed. The study aimed to discuss the evaluation of low dose ionizing radiation (IR) effect on some blood components in animal model. Hematological parameters were determined for 110 animal rats (divided into 8 groups) pre- and post-irradiation. An attempt to explain the blood changes resulting from both ...

  8. Model Components of Mangrove Resources Management Based on Blue Economy Concept

    OpenAIRE

    Bidayani, Endang; Soemarno, Soemarno; Harahab, Nuddin; Rudianto, Rudianto

    2016-01-01

    This study was aimed at analyzing variables affecting mangrove resource conservation based on blue economy concept. The model component analysis applied Spearman Rank Correlation test. Result showed that Z-calc.was bigger than Z-tab. (1.64) at 95% confidence level, and therefore, Ho was rejected. This study concluded that resource efficiency, without wastes, social awareness, cyclic system of production, innovation and adaptation, and institution were blue economy concept-based variables. In ...

  9. Conservative modelling of the moisture and heat transfer in building components under atmospheric excitation

    DEFF Research Database (Denmark)

    Janssen, Hans; Blocken, Bert; Carmeliet, Jan

    2007-01-01

    While the transfer equations for moisture and heat in building components are currently undergoing standardisation, atmospheric boundary conditions, conservative modelling and numerical efficiency are not addressed. In a first part, this paper adds a comprehensive description of those boundary...... conditions, emphasising wind-driven rain and vapour exchange, the main moisture supply and removal mechanism, respectively. In the second part the numerical implementation is tackled, with specific attention to the monotony of the spatial discretisation, and to the mass and energy conservation...

  10. Numerical Modelling of Multi-Phase Multi-Component Reactive Transport in the Earth's interior

    Science.gov (United States)

    Oliveira, Beñat; Afonso, Juan Carlos; Zlotnik, Sergio; Tilhac, Romain

    2017-04-01

    We present a conceptual and numerical approach to model processes in the Earth's interior that involve multiple phases that simultaneously interact thermally, mechanically and chemically. The approach is truly multiphase in the sense that each dynamic phase is explicitly modelled with an individual set of mass, momentum, energy and chemical mass balance equations coupled via interfacial interaction terms. It is also truly multi-component in the sense that the compositions of the system and its constituent thermodynamic phases are expressed by a full set of fundamental chemical components (e.g. SiO_2, Al_2O_3, MgO, etc) rather than proxies. In contrast to previous approaches these chemical components evolve, react with, and partition into, different phases with different physical properties according to an internally-consistent thermodynamic model. This enables a thermodynamically-consistent coupling of the governing set of balance equations. Interfacial processes such as surface tensions and/or surface energy contributions to the dynamics and energetics of the system are also taken into account. The model presented here describes the evolution of systems governed by Multi-Phase Multi-Component Reactive Transport (MPMCRT) based on Ensemble Averaging and Classical Irreversible Thermodynamics principles. This novel approach provides a flexible platform to study the dynamics and non-linear feedbacks occurring within various natural systems at different scales. This notably includes major- and trace-element transport, diffusion-controlled trace-element re-equilibration or rheological changes associated with melt generation and migration in the Earth's mantle.

  11. Technical Description of Urban Microscale Modeling System: Component 1 of CRTI Project 02-0093RD

    Science.gov (United States)

    2007-03-01

    for the Urban Environment" involved a collaborative model development effort by Defence R&D Canada - Suffield and Enviroment Canada. The primary...0093RD. The memory management scheme used in urbanSTREAM, urbanEU, and urbanAEU is full dynamic array allocation which allows the maximum array dimensions...sequentially and iterated to convergence, defined by reference to Ll-residual norms for the mass and momentum components. Here, the Ll-residual norm is

  12. High Cost/High Risk Components to Chalcogenide Molded Lens Model: Molding Preforms and Mold Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bernacki, Bruce E.

    2012-10-05

    This brief report contains a critique of two key components of FiveFocal's cost model for glass compression molding of chalcogenide lenses for infrared applications. Molding preforms and mold technology have the greatest influence on the ultimate cost of the product and help determine the volumes needed to select glass molding over conventional single-point diamond turning or grinding and polishing. This brief report highlights key areas of both technologies with recommendations for further study.

  13. Genetic heterogeneity of residual variance - estimation of variance components using double hierarchical generalized linear models

    Directory of Open Access Journals (Sweden)

    Fikse Freddy

    2010-03-01

    Full Text Available Abstract Background The sensitivity to microenvironmental changes varies among animals and may be under genetic control. It is essential to take this element into account when aiming at breeding robust farm animals. Here, linear mixed models with genetic effects in the residual variance part of the model can be used. Such models have previously been fitted using EM and MCMC algorithms. Results We propose the use of double hierarchical generalized linear models (DHGLM, where the squared residuals are assumed to be gamma distributed and the residual variance is fitted using a generalized linear model. The algorithm iterates between two sets of mixed model equations, one on the level of observations and one on the level of variances. The method was validated using simulations and also by re-analyzing a data set on pig litter size that was previously analyzed using a Bayesian approach. The pig litter size data contained 10,060 records from 4,149 sows. The DHGLM was implemented using the ASReml software and the algorithm converged within three minutes on a Linux server. The estimates were similar to those previously obtained using Bayesian methodology, especially the variance components in the residual variance part of the model. Conclusions We have shown that variance components in the residual variance part of a linear mixed model can be estimated using a DHGLM approach. The method enables analyses of animal models with large numbers of observations. An important future development of the DHGLM methodology is to include the genetic correlation between the random effects in the mean and residual variance parts of the model as a parameter of the DHGLM.

  14. The Development of Nursing Care Services Model for Low Birth Weight Infants

    Directory of Open Access Journals (Sweden)

    Dessie Wanda

    2017-01-01

    Full Text Available Introduction: Low birth weight (LBW infants deal with various problems during transitional period from intra-uterine and extra-uterine because of immature organs’ functions. This leads to LBW as the second death cause in Indonesia, particularly in the fi rst seventh days of infants’ lifes. The problem continues to occur at home when the infants have discharged. This research was aimed to develop the nursing care services model for LBW infants and to test the model. Method: The research design was an action research using quantitative and qualitative approach. This design was chosen as it facilitated improvement in health care system, which was involving nurses and other health providers. Results: Nursing care services provided by the nursing team are hindered by several factors, such as various level of nurses’ knowledge, not optimal health education activities, incomplete standard operational procedure, ethical dilemma, paramedic functions, and documentation system. This model was developed based on conservation and becoming a mother/maternal role attainment theory, family-centered care principles, and input from the experts through focus group discussion. Discussion: The result of this research is going to increase the quality of nursing care for LBW infants by achieving nurses’ and parents’ satisfaction in giving care for their infants which can lead to lower infant death rate.Key words: Model, Low birth weight infant, Nursing services, Action research

  15. A Canine Non-Weight-Bearing Model with Radial Neurectomy for Rotator Cuff Repair.

    Directory of Open Access Journals (Sweden)

    Xiaoxi Ji

    Full Text Available The major concern of using a large animal model to study rotator cuff repair is the high rate of repair retears. The purpose of this study was to test a non-weight-bearing (NWB canine model for rotator cuff repair research.First, in the in vitro study, 18 shoulders were randomized to 3 groups. 1 Full-width transections repaired with modified Mason-Allen sutures using 3-0 polyglactin suture, 2 Group 1 repaired using number 2 (#2 polyester braid and long-chain polyethylene suture, and 3 Partial-width transections leaving the superior 2 mm infraspinatus tendon intact without repair. In the in vivo study of 6 dogs, the infraspinatus tendon was partially transected as the same as the in vitro group 3. A radial neurectomy was performed to prevent weight bearing. The operated limb was slung in a custom-made jacket for 6 weeks.In the in vitro study, mean ultimate tensile load and stiffness in Group 2 were significantly higher than Group 1 and 3 (p<0.05. In the in vivo study, gross inspection and histology showed that the preserved superior 2-mm portion of the infraspinatus tendon remained intact with normal structure.Based on the biomechanical and histological findings, this canine NWB model may be an appropriate and useful model for studies of rotator cuff repair.

  16. Potential of weight of evidence modelling for gully erosion hazard assessment in Mbire District - Zimbabwe

    Science.gov (United States)

    Dube, F.; Nhapi, I.; Murwira, A.; Gumindoga, W.; Goldin, J.; Mashauri, D. A.

    Gully erosion is an environmental concern particularly in areas where landcover has been modified by human activities. This study assessed the extent to which the potential of gully erosion could be successfully modelled as a function of seven environmental factors (landcover, soil type, distance from river, distance from road, Sediment Transport Index (STI), Stream Power Index (SPI) and Wetness Index (WI) using a GIS-based Weight of Evidence Modelling (WEM) in the Mbire District of Zimbabwe. Results show that out of the studied seven factors affecting gully erosion, five were significantly correlated (p road were not significantly correlated to gully occurrence (p > 0.05). A gully erosion hazard map showed that 78% of the very high hazard class area is within a distance of 250 m from rivers. Model validation indicated that 70% of the validation set of gullies were in the high hazard and very high hazard class. The resulting map of areas susceptible to gully erosion has a prediction accuracy of 67.8%. The predictive capability of the weight of evidence model in this study suggests that landcover, soil type, distance from river, STI and SPI are useful in creating a gully erosion hazard map but may not be sufficient to produce a valid map of gully erosion hazard.

  17. A Computational Model of Torque Generation: Neural, Contractile, Metabolic and Musculoskeletal Components

    Science.gov (United States)

    Callahan, Damien M.; Umberger, Brian R.; Kent-Braun, Jane A.

    2013-01-01

    The pathway of voluntary joint torque production includes motor neuron recruitment and rate-coding, sarcolemmal depolarization and calcium release by the sarcoplasmic reticulum, force generation by motor proteins within skeletal muscle, and force transmission by tendon across the joint. The direct source of energetic support for this process is ATP hydrolysis. It is possible to examine portions of this physiologic pathway using various in vivo and in vitro techniques, but an integrated view of the multiple processes that ultimately impact joint torque remains elusive. To address this gap, we present a comprehensive computational model of the combined neuromuscular and musculoskeletal systems that includes novel components related to intracellular bioenergetics function. Components representing excitatory drive, muscle activation, force generation, metabolic perturbations, and torque production during voluntary human ankle dorsiflexion were constructed, using a combination of experimentally-derived data and literature values. Simulation results were validated by comparison with torque and metabolic data obtained in vivo. The model successfully predicted peak and submaximal voluntary and electrically-elicited torque output, and accurately simulated the metabolic perturbations associated with voluntary contractions. This novel, comprehensive model could be used to better understand impact of global effectors such as age and disease on various components of the neuromuscular system, and ultimately, voluntary torque output. PMID:23405245

  18. Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, Stephen [Cleveland State Univ., Cleveland, OH (United States)

    2013-09-09

    This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

  19. Models and Frameworks: A Synergistic Association for Developing Component-Based Applications

    Science.gov (United States)

    Sánchez-Ledesma, Francisco; Sánchez, Pedro; Pastor, Juan A.; Álvarez, Bárbara

    2014-01-01

    The use of frameworks and components has been shown to be effective in improving software productivity and quality. However, the results in terms of reuse and standardization show a dearth of portability either of designs or of component-based implementations. This paper, which is based on the model driven software development paradigm, presents an approach that separates the description of component-based applications from their possible implementations for different platforms. This separation is supported by automatic integration of the code obtained from the input models into frameworks implemented using object-oriented technology. Thus, the approach combines the benefits of modeling applications from a higher level of abstraction than objects, with the higher levels of code reuse provided by frameworks. In order to illustrate the benefits of the proposed approach, two representative case studies that use both an existing framework and an ad hoc framework, are described. Finally, our approach is compared with other alternatives in terms of the cost of software development. PMID:25147858

  20. Complex relation among Health Belief Model components in TB prevention and care.

    Science.gov (United States)

    Li, Z T; Yang, S S; Zhang, X X; Fisher, E B; Tian, B C; Sun, X Y

    2015-07-01

    This study aims to explore the relationships among components of the Health Belief Model, tuberculosis (TB) preventive behavior, and intention of seeking TB care. Cross section study. Using convenience sampling, 1154 rural-to-urban migrant workers were selected between the ages of 18-50 years in six urban areas of three provinces in China. The survey was conducted by individual, face-to-face interviews with a standardized questionnaire. Lisrel 8.7 was used to conduct path analysis. The knowledge and benefits components of the Health Belief Model predicted preventive behaviors: cover nose/mouth when coughing or sneezing (β = 0.24, 0.33 respectively), evade others' coughs (β = 0.13, 0.25) and also predicted seeking TB care (β = 0.27, 0.19). Susceptibility and severity also predicted seeking TB care (β = 0.12, 0.16). There were also important relationships among model components. Knowledge of TB predicted both susceptibility (β = 0.32-0.60) and severity (β = 0.41-0.45). Further, each of susceptibility (β = 0.30) and severity (β = 0.41) predicted perceived benefits of preventive care. Thus, a path from knowledge, through severity and susceptibility, and then through benefits predicted prevention and TB care seeking behaviors. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  1. Analysis of landfill components in estimating the percolated leachate to groundwater using the HELP model.

    Science.gov (United States)

    Alslaibi, Tamer M; Mogheir, Yunes K; Afifi, Samir

    2010-01-01

    Landfills are one of the groundwater pollution sources in Gaza Strip. This study focuses on two landfills operating in Gaza Strip; the first is Dear Al Balah landfill which has a lining system and the second landfill is Gaza landfill which does not have a lining system. The main objective of the present study is to assess the effect of landfill components on percolated leachate to groundwater aquifer using the Hydrologic Evaluation of Landfill Performance (HELP) model. A comprehensive analysis of landfill components affecting the generated leachate was conducted. The results showed that the landfill components were ordered in priority according to their effects on percolated leachate through clay layer as follows: (1) existing of lining system enhances the percolation reduction up to 87%, (2) 30% reduction of rainfall level enhances the percolation reduction up to 50%, (3) 50% reduction of existing landfill area enhances the percolation reduction up to 50%, and (4) the absent of recirculation system slight enhances the percolation reduction up to 2.5% more than with the availability of recirculation system. The waste depth has no significant effect on the quantity of percolated leachate. Analysis suggested that changes in lining system type, rainfall level, landfill area, and recirculation ratio have the most significant impact on model outputs indicating that these parameters should be carefully selected when similar modeling studies are performed.

  2. Geographically weighted negative binomial regression applied to zonal level safety performance models.

    Science.gov (United States)

    Gomes, Marcos José Timbó Lima; Cunto, Flávio; da Silva, Alan Ricardo

    2017-09-01

    Generalized Linear Models (GLM) with negative binomial distribution for errors, have been widely used to estimate safety at the level of transportation planning. The limited ability of this technique to take spatial effects into account can be overcome through the use of local models from spatial regression techniques, such as Geographically Weighted Poisson Regression (GWPR). Although GWPR is a system that deals with spatial dependency and heterogeneity and has already been used in some road safety studies at the planning level, it fails to account for the possible overdispersion that can be found in the observations on road-traffic crashes. Two approaches were adopted for the Geographically Weighted Negative Binomial Regression (GWNBR) model to allow discrete data to be modeled in a non-stationary form and to take note of the overdispersion of the data: the first examines the constant overdispersion for all the traffic zones and the second includes the variable for each spatial unit. This research conducts a comparative analysis between non-spatial global crash prediction models and spatial local GWPR and GWNBR at the level of traffic zones in Fortaleza/Brazil. A geographic database of 126 traffic zones was compiled from the available data on exposure, network characteristics, socioeconomic factors and land use. The models were calibrated by using the frequency of injury crashes as a dependent variable and the results showed that GWPR and GWNBR achieved a better performance than GLM for the average residuals and likelihood as well as reducing the spatial autocorrelation of the residuals, and the GWNBR model was more able to capture the spatial heterogeneity of the crash frequency. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Predicting adenocarcinoma recurrence using computational texture models of nodule components in lung CT.

    Science.gov (United States)

    Depeursinge, Adrien; Yanagawa, Masahiro; Leung, Ann N; Rubin, Daniel L

    2015-04-01

    To investigate the importance of presurgical computed tomography (CT) intensity and texture information from ground-glass opacities (GGO) and solid nodule components for the prediction of adenocarcinoma recurrence. For this study, 101 patients with surgically resected stage I adenocarcinoma were selected. During the follow-up period, 17 patients had disease recurrence with six associated cancer-related deaths. GGO and solid tumor components were delineated on presurgical CT scans by a radiologist. Computational texture models of GGO and solid regions were built using linear combinations of steerable Riesz wavelets learned with linear support vector machines (SVMs). Unlike other traditional texture attributes, the proposed texture models are designed to encode local image scales and directions that are specific to GGO and solid tissue. The responses of the locally steered models were used as texture attributes and compared to the responses of unaligned Riesz wavelets. The texture attributes were combined with CT intensities to predict tumor recurrence and patient hazard according to disease-free survival (DFS) time. Two families of predictive models were compared: LASSO and SVMs, and their survival counterparts: Cox-LASSO and survival SVMs. The best-performing predictive model of patient hazard was associated with a concordance index (C-index) of 0.81 ± 0.02 and was based on the combination of the steered models and CT intensities with survival SVMs. The same feature group and the LASSO model yielded the highest area under the receiver operating characteristic curve (AUC) of 0.8 ± 0.01 for predicting tumor recurrence, although no statistically significant difference was found when compared to using intensity features solely. For all models, the performance was found to be significantly higher when image attributes were based on the solid components solely versus using the entire tumors (p adenocarcinoma aggressiveness is related to the intensity and morphological

  4. Predicting adenocarcinoma recurrence using computational texture models of nodule components in lung CT

    Energy Technology Data Exchange (ETDEWEB)

    Depeursinge, Adrien, E-mail: adrien.depeursinge@hevs.ch [Department of Radiology, Stanford University School of Medicine, Stanford, California 94305 and Business Information Systems, University of Applied Sciences Western Switzerland (HES-SO), Sierre 3960 (Switzerland); Yanagawa, Masahiro [Department of Radiology, Stanford University School of Medicine, Stanford, California 94305 and Department of Radiology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871 (Japan); Leung, Ann N.; Rubin, Daniel L. [Department of Radiology, Stanford University School of Medicine, Stanford, California 94305 (United States)

    2015-04-15

    Purpose: To investigate the importance of presurgical computed tomography (CT) intensity and texture information from ground-glass opacities (GGO) and solid nodule components for the prediction of adenocarcinoma recurrence. Methods: For this study, 101 patients with surgically resected stage I adenocarcinoma were selected. During the follow-up period, 17 patients had disease recurrence with six associated cancer-related deaths. GGO and solid tumor components were delineated on presurgical CT scans by a radiologist. Computational texture models of GGO and solid regions were built using linear combinations of steerable Riesz wavelets learned with linear support vector machines (SVMs). Unlike other traditional texture attributes, the proposed texture models are designed to encode local image scales and directions that are specific to GGO and solid tissue. The responses of the locally steered models were used as texture attributes and compared to the responses of unaligned Riesz wavelets. The texture attributes were combined with CT intensities to predict tumor recurrence and patient hazard according to disease-free survival (DFS) time. Two families of predictive models were compared: LASSO and SVMs, and their survival counterparts: Cox-LASSO and survival SVMs. Results: The best-performing predictive model of patient hazard was associated with a concordance index (C-index) of 0.81 ± 0.02 and was based on the combination of the steered models and CT intensities with survival SVMs. The same feature group and the LASSO model yielded the highest area under the receiver operating characteristic curve (AUC) of 0.8 ± 0.01 for predicting tumor recurrence, although no statistically significant difference was found when compared to using intensity features solely. For all models, the performance was found to be significantly higher when image attributes were based on the solid components solely versus using the entire tumors (p < 3.08 × 10{sup −5}). Conclusions: This study

  5. Observation Data Model Core Components, its Implementation in the Table Access Protocol Version 1.1

    Science.gov (United States)

    Louys, Mireille; Tody, Doug; Dowler, Patrick; Durand, Daniel; Michel, Laurent; Bonnarel, Francos; Micol, Alberto; IVOA DataModel Working Group; Louys, Mireille; Tody, Doug; Dowler, Patrick; Durand, Daniel

    2017-05-01

    This document defines the core components of the Observation data model that are necessary to perform data discovery when querying data centers for astronomical observations of interest. It exposes use-cases to be carried out, explains the model and provides guidelines for its implementation as a data access service based on the Table Access Protocol (TAP). It aims at providing a simple model easy to understand and to implement by data providers that wish to publish their data into the Virtual Observatory. This interface integrates data modeling and data access aspects in a single service and is named ObsTAP. It will be referenced as such in the IVOA registries. In this document, the Observation Data Model Core Components (ObsCoreDM) defines the core components of queryable metadata required for global discovery of observational data. It is meant to allow a single query to be posed to TAP services at multiple sites to perform global data discovery without having to understand the details of the services present at each site. It defines a minimal set of basic metadata and thus allows for a reasonable cost of implementation by data providers. The combination of the ObsCoreDM with TAP is referred to as an ObsTAP service. As with most of the VO Data Models, ObsCoreDM makes use of STC, Utypes, Units and UCDs. The ObsCoreDM can be serialized as a VOTable. ObsCoreDM can make reference to more complete data models such as Characterisation DM, Spectrum DM or Simple Spectral Line Data Model (SSLDM). ObsCore shares a large set of common concepts with DataSet Metadata Data Model (Cresitello-Dittmar et al. 2016) which binds together most of the data model concepts from the above models in a comprehensive and more general frame work. This current specification on the contrary provides guidelines for implementing these concepts using the TAP protocol and answering ADQL queries. It is dedicated to global discovery.

  6. Modelling malaria incidence by an autoregressive distributed lag model with spatial component.

    Science.gov (United States)

    Laguna, Francisco; Grillet, María Eugenia; León, José R; Ludeña, Carenne

    2017-08-01

    The influence of climatic variables on the dynamics of human malaria has been widely highlighted. Also, it is known that this mosquito-borne infection varies in space and time. However, when the data is spatially incomplete most popular spatio-temporal methods of analysis cannot be applied directly. In this paper, we develop a two step methodology to model the spatio-temporal dependence of malaria incidence on local rainfall, temperature, and humidity as well as the regional sea surface temperatures (SST) in the northern coast of Venezuela. First, we fit an autoregressive distributed lag model (ARDL) to the weekly data, and then, we adjust a linear separable spacial vectorial autoregressive model (VAR) to the residuals of the ARDL. Finally, the model parameters are tuned using a Markov Chain Monte Carlo (MCMC) procedure derived from the Metropolis-Hastings algorithm. Our results show that the best model to account for the variations of malaria incidence from 2001 to 2008 in 10 endemic Municipalities in North-Eastern Venezuela is a logit model that included the accumulated local precipitation in combination with the local maximum temperature of the preceding month as positive regressors. Additionally, we show that although malaria dynamics is highly heterogeneous in space, a detailed analysis of the estimated spatial parameters in our model yield important insights regarding the joint behavior of the disease incidence across the different counties in our study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. A Spatial Disaster Assessment Model of Social Resilience Based on Geographically Weighted Regression

    Directory of Open Access Journals (Sweden)

    Hwikyung Chun

    2017-12-01

    Full Text Available Since avoiding the occurrence of natural disasters is difficult, building ‘resilient cities’ is gaining more attention as a common objective within urban communities. By enhancing community resilience, it is possible to minimize the direct and indirect losses from disasters. However, current studies have focused more on physical aspects, despite the fact that social aspects may have a closer relation to the inhabitants. The objective of this paper is to develop an assessment model for social resilience by measuring the heterogeneity of local indicators that are related to disaster risk. Firstly, variables were selected by investigating previous assessment models with statistical verification. Secondly, spatial heterogeneity was analyzed using the Geographically Weighted Regression (GWR method. A case study was then undertaken on a flood-prone area in the metropolitan city, Seoul, South Korea. Based on the findings, the paper proposes a new spatial disaster assessment model that can be used for disaster management at the local levels.

  8. Use of a Bayesian hierarchical model to study the allometric scaling of the fetoplacental weight ratio

    Directory of Open Access Journals (Sweden)

    Fidel Ernesto Castro Morales

    2016-03-01

    Full Text Available Abstract Objectives: to propose the use of a Bayesian hierarchical model to study the allometric scaling of the fetoplacental weight ratio, including possible confounders. Methods: data from 26 singleton pregnancies with gestational age at birth between 37 and 42 weeks were analyzed. The placentas were collected immediately after delivery and stored under refrigeration until the time of analysis, which occurred within up to 12 hours. Maternal data were collected from medical records. A Bayesian hierarchical model was proposed and Markov chain Monte Carlo simulation methods were used to obtain samples from distribution a posteriori. Results: the model developed showed a reasonable fit, even allowing for the incorporation of variables and a priori information on the parameters used. Conclusions: new variables can be added to the modelfrom the available code, allowing many possibilities for data analysis and indicating the potential for use in research on the subject.

  9. Potential for monitoring soil erosion features and soil erosion modeling components from remotely sensed data

    Science.gov (United States)

    Langran, K. J.

    1983-01-01

    Accurate estimates of soil erosion and its effects on soil productivity are essential in agricultural decision making and planning from the field scale to the national level. Erosion models have been primarily developed for designing erosion control systems, predicting sediment yield for reservoir design, predicting sediment transport, and simulating water quality. New models proposed are more comprehensive in that the necessary components (hydrology, erosion-sedimentation, nutrient cycling, tillage, etc.) are linked in a model appropriate for studying the erosion-productivity problem. Recent developments in remote sensing systems, such as Landsat Thematic Mapper, Shuttle Imaging Radar (SIR-B), etc., can contribute significantly to the future development and operational use of these models.

  10. Weight loss and brown adipose tissue reduction in rat model of sleep apnea

    Directory of Open Access Journals (Sweden)

    de Oliveira Patricia G

    2008-07-01

    Full Text Available Abstract Background - Obesity is related to obstructive sleep apnea-hypopnea syndrome (OSAHS, but its roles in OSAHS as cause or consequence are not fully clarified. Isocapnic intermittent hypoxia (IIH is a model of OSAHS. We verified the effect of IIH on body weight and brown adipose tissue (BAT of Wistar rats. Methods Nine-month-old male breeders Wistar rats of two groups were studied: 8 rats submitted to IIH and 5 control rats submitted to sham IIH. The rats were weighed at the baseline and at the end of three weeks, after being placed in the IIH apparatus seven days per week, eight hours a day, in the lights on period, simulating an apnea index of 30/hour. After experimental period, the animals were weighed and measured as well as the BAT, abdominal, perirenal, and epididymal fat, the heart, and the gastrocnemius muscle. Results Body weight of the hypoxia group decreased 17 ± 7 grams, significantly different from the variation observed in the control group (p = 0,001. The BAT was 15% lighter in the hypoxia group and reached marginally the alpha error probability (p = 0.054. Conclusion Our preliminary results justify a larger study for a longer time in order to confirm the effect of isocapnic intermittent hypoxia on body weight and BAT.

  11. T2 weighted MRI for assessing renal lesions in transgenic mouse models of tuberous sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Kalogerou, Maria; Zhang, Yadan; Yang, Jian; Garrahan, Nigel [Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN (United Kingdom); Paisey, Stephen; Tokarczuk, Paweł; Stewart, Andrew [School of Bioscience, Cardiff University, Museum Avenue, Cardiff CF10 3AX (United Kingdom); Gallacher, John [Department of Primary Care and Public Health, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4YS (United Kingdom); Sampson, Julian R. [Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN (United Kingdom); Shen, Ming Hong, E-mail: shenmh@cf.ac.uk [Institute of Medical Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN (United Kingdom)

    2012-09-15

    Objective: Transgenic mouse models of tuberous sclerosis (TSC) develop renal cysts, cystadenomas, solid adenomas and carcinomas. Identification and characterisation of these lesions in vivo may help in TSC pre-clinical trials. This study was to evaluate T2 weighted MRI for assessment of renal lesions in two Tsc mouse models. Materials and Methods: Tsc1{sup +/−}, Tsc2{sup +/−} and wild type mice were subjected to a first MRI scan at 12 months of age and a second scan 2 months later. One Tsc2{sup +/−} mouse was treated with rapamycin for two months after the initial scan. Immediately following the second scan, mice were sacrificed and MRI images were compared to renal histological findings. Results: MRI identified all types of Tsc-associated renal lesions in both Tsc1{sup +/−} and Tsc2{sup +/−} mice. The smallest detectable lesions were <0.1 mm{sup 3}. Eighty three percent of all renal lesions detected in the first scan were re-identified in the second scan. By MRI, these lesions demonstrated significant growth in the 9 untreated Tsc1{sup +/−} and Tsc2{sup +/−} mice but shrinkage in the rapamycin treated Tsc2{sup +/−} mouse. Between the two scans, MRI also revealed significant increase in both the total number and volume of lesions in untreated mice and decrease in the rapamycin treated mouse, respectively. In comparison to histological analysis MRI detected most cysts and cystadenomas (66%) but only a minority of solid tumours (29%). Conclusion: These results suggest that T2 weighted MRI may be a useful tool for assessing some renal lesions in pre-clinical studies using Tsc mouse models. However, improved sensitivity for T2 weighted MRI is required, particularly for solid renal lesions.

  12. Helping young weight controllers develop healthy obsessions: preliminary test of the Healthy Obsession Model.

    Science.gov (United States)

    Byrne, S; Kirschenbaum, D S

    2011-04-01

    The Healthy Obsession Model posits that successful weight controllers must develop a preoccupation with the planning and execution of target behaviours, including eating on programme, consistent activity and self-monitoring. When barriers emerge, committed weight controllers are expected to feel distressed (e.g. anxious or frustrated), which should motivate them to reinstate these behaviours. This study investigated the effects on moods of sudden withdrawal of self-monitoring among obese adolescents within an immersion treatment programme. Fifty-five (55% female) adolescents participated in a weight loss camp and received four weekly cognitive-behaviour therapy sessions focused on maximizing commitment to programme behaviours. During the fourth week, campers and staff completed daily mood ratings using the Positive and Negative Affect Schedule. After 3 d of ratings, campers' self-monitoring journals were removed without warning for 1 d. As expected, journal removal resulted in decreased positive affect for the campers, according to staff ratings. Also in accord with hypotheses, campers who demonstrated heightened commitment to the programme based on higher levels of activity and more writing in their journals reacted more negatively to the withdrawal of the opportunity to self-monitor. Mood ratings by campers did not show the effects hypothesized by the Healthy Obsession Model. These results provide preliminary support for the Healthy Obsession Model by showing some of the anticipated negative reactions to the removal of access to self-monitoring, especially among those who demonstrated strong commitments to the process. © 2011 The Authors. Clinical Obesity © 2011 International Association for the Study of Obesity.

  13. The Effect of Multidimensional Motivation Interventions on Cognitive and Behavioral Components of Motivation: Testing Martin's Model.

    Science.gov (United States)

    Pooragha Roodbarde, Fatemeh; Talepasand, Siavash; Rahimian Boogar, Issac

    2017-04-01

    Objective: The present study aimed at examining the effect of multidimensional motivation interventions based on Martin's model on cognitive and behavioral components of motivation. Method: The research design was prospective with pretest, posttest, and follow-up, and 2 experimental groups. In this study, 90 students (45 participants in the experimental group and 45 in the control group) constituted the sample of the study, and they were selected by available sampling method. Motivation interventions were implemented for fifteen 60-minute sessions 3 times a week, which lasted for about 2 months. Data were analyzed using repeated measures multivariate variance analysis test. Results: The findings revealed that multidimensional motivation interventions resulted in a significant increase in the scores of cognitive components such as self-efficacy, mastery goal, test anxiety, and feeling of lack of control, and behavioral components such as task management. The results of one-month follow-up indicated the stability of the created changes in test anxiety and cognitive strategies; however, no significant difference was found between the 2 groups at the follow-up in self-efficacy, mastery goals, source of control, and motivation. Conclusion: The research evidence indicated that academic motivation is a multidimensional component and is affected by cognitive and behavioral factors; therefore, researchers, teachers, and other authorities should attend to these factors to increase academic motivation.

  14. The Effect of Multidimensional Motivation Interventions on Cognitive and Behavioral Components of Motivation: Testing Martin's Model

    Directory of Open Access Journals (Sweden)

    Fatemeh PooraghaRoodbarde

    2017-04-01

    Full Text Available Objective: The present study aimed at examining the effect of multidimensional motivation interventions based on Martin's model on cognitive and behavioral components of motivation.Methods: The research design was prospective with pretest, posttest, and follow-up, and 2 experimental groups. In this study, 90 students (45 participants in the experimental group and 45 in the control group constituted the sample of the study, and they were selected by available sampling method. Motivation interventions were implemented for fifteen 60-minute sessions 3 times a week, which lasted for about 2 months. Data were analyzed using repeated measures multivariate variance analysis test.Results: The findings revealed that multidimensional motivation interventions resulted in a significant increase in the scores of cognitive components such as self-efficacy, mastery goal, test anxiety, and feeling of lack of control, and behavioral components such as task management. The results of one-month follow-up indicated the stability of the created changes in test anxiety and cognitive strategies; however, no significant difference was found between the 2 groups at the follow-up in self-efficacy, mastery goals, source of control, and motivation.Conclusions: The research evidence indicated that academic motivation is a multidimensional component and is affected by cognitive and behavioral factors; therefore, researchers, teachers, and other authorities should attend to these factors to increase academic motivation.

  15. A Four–Component Model of Age–Related Memory Change

    Science.gov (United States)

    Healey, M. Karl; Kahana, Michael J.

    2015-01-01

    We develop a novel, computationally explicit, theory of age–related memory change within the framework of the context maintenance and retrieval (CMR2) model of memory search. We introduce a set of benchmark findings from the free recall and recognition tasks that includes aspects of memory performance that show both age-related stability and decline. We test aging theories by lesioning the corresponding mechanisms in a model fit to younger adult free recall data. When effects are considered in isolation, many theories provide an adequate account, but when all effects are considered simultaneously, the existing theories fail. We develop a novel theory by fitting the full model (i.e., allowing all parameters to vary) to individual participants and comparing the distributions of parameter values for older and younger adults. This theory implicates four components: 1) the ability to sustain attention across an encoding episode, 2) the ability to retrieve contextual representations for use as retrieval cues, 3) the ability to monitor retrievals and reject intrusions, and 4) the level of noise in retrieval competitions. We extend CMR2 to simulate a recognition memory task using the same mechanisms the free recall model uses to reject intrusions. Without fitting any additional parameters, the four–component theory that accounts for age differences in free recall predicts the magnitude of age differences in recognition memory accuracy. Confirming a prediction of the model, free recall intrusion rates correlate positively with recognition false alarm rates. Thus we provide a four–component theory of a complex pattern of age differences across two key laboratory tasks. PMID:26501233

  16. Spatially-constrained probability distribution model of incoherent motion (SPIM) for abdominal diffusion-weighted MRI.

    Science.gov (United States)

    Kurugol, Sila; Freiman, Moti; Afacan, Onur; Perez-Rossello, Jeannette M; Callahan, Michael J; Warfield, Simon K

    2016-08-01

    Quantitative diffusion-weighted MR imaging (DW-MRI) of the body enables characterization of the tissue microenvironment by measuring variations in the mobility of water molecules. The diffusion signal decay model parameters are increasingly used to evaluate various diseases of abdominal organs such as the liver and spleen. However, previous signal decay models (i.e., mono-exponential, bi-exponential intra-voxel incoherent motion (IVIM) and stretched exponential models) only provide insight into the average of the distribution of the signal decay rather than explicitly describe the entire range of diffusion scales. In this work, we propose a probability distribution model of incoherent motion that uses a mixture of Gamma distributions to fully characterize the multi-scale nature of diffusion within a voxel. Further, we improve the robustness of the distribution parameter estimates by integrating spatial homogeneity prior into the probability distribution model of incoherent motion (SPIM) and by using the fusion bootstrap solver (FBM) to estimate the model parameters. We evaluated the improvement in quantitative DW-MRI analysis achieved with the SPIM model in terms of accuracy, precision and reproducibility of parameter estimation in both simulated data and in 68 abdominal in-vivo DW-MRIs. Our results show that the SPIM model not only substantially reduced parameter estimation errors by up to 26%; it also significantly improved the robustness of the parameter estimates (paired Student's t-test, p < 0.0001) by reducing the coefficient of variation (CV) of estimated parameters compared to those produced by previous models. In addition, the SPIM model improves the parameter estimates reproducibility for both intra- (up to 47%) and inter-session (up to 30%) estimates compared to those generated by previous models. Thus, the SPIM model has the potential to improve accuracy, precision and robustness of quantitative abdominal DW-MRI analysis for clinical applications

  17. Weight evaluation of Tabapuã cattle raised in northeastern Brazil using random-regression models

    Directory of Open Access Journals (Sweden)

    M.R. Oliveira

    Full Text Available ABSTRACT The objective of this study is to compare random-regression models used to describe changes in evaluation parameters for growth in Tabapuã bovine raised in the Northeast of Brazilian. The M4532-5 random-regression model was found to be best for estimating the variation and heritability of growth characteristics in the animals evaluated. Estimates of direct additive genetic variance increased with age, while the maternal additive genetic variance demonstrated growth from birth to up to nearly 420 days of age. The genetic correlations between the first four characteristics were positive with moderate to large ranges. The greatest genetic correlation was observed between birth weight and at 240 days of age (0.82. The phenotypic correlation between birth weight and other characteristics was low. The M4532-5 random-regression model with 39 parameters was found to be best for describing the growth curve of the animals evaluated providing improved selection for heavier animals when performed after weaning. The interpretation of genetic parameters to predict the growth curve of cattle may allow the selection of animals to accelerate slaughter procedures.

  18. Application of a weighted spatial probability model in GIS to analyse landslides in Penang Island, Malaysia

    Directory of Open Access Journals (Sweden)

    Samy Ismail Elmahdy

    2016-01-01

    Full Text Available In the current study, Penang Island, which is one of the several mountainous areas in Malaysia that is often subjected to landslide hazard, was chosen for further investigation. A multi-criteria Evaluation and the spatial probability weighted approach and model builder was applied to map and analyse landslides in Penang Island. A set of automated algorithms was used to construct new essential geological and morphometric thematic maps from remote sensing data. The maps were ranked using the weighted probability spatial model based on their contribution to the landslide hazard. Results obtained showed that sites at an elevation of 100–300 m, with steep slopes of 10°–37° and slope direction (aspect in the E and SE directions were areas of very high and high probability for the landslide occurrence; the total areas were 21.393 km2 (11.84% and 58.690 km2 (32.48%, respectively. The obtained map was verified by comparing variogram models of the mapped and the occurred landslide locations and showed a strong correlation with the locations of occurred landslides, indicating that the proposed method can successfully predict the unpredictable landslide hazard. The method is time and cost effective and can be used as a reference for geological and geotechnical engineers.

  19. Disentangling community functional components in a litter-macrodetritivore model system revels the predominance of the mass ratio hypothesis

    NARCIS (Netherlands)

    Bila, K.; Moretti, M.; de Bello, F.; Dias, A.T.C.; Pezzatti, G.B.; van Oosten, A.R.; Berg, M.P.

    2014-01-01

    Recent investigations have shown that two components of community trait composition are important for key ecosystem processes: (i) the community-weighted mean trait value (CWM), related to the mass ratio hypothesis and dominant trait values in the community, and (ii) functional diversity (FD),

  20. Managing Colllinearity in Modeling the Effect of Age in the Prediction of Egg Components of Laying Hens Using Stepwise and Ridge Regression Analysis

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    TM Shafey

    2015-12-01

    Full Text Available ABSTRACT The relationships between egg measurements [egg weight (EGWT, egg width (EGWD, egg shape index (EGSI, egg volume (EGV and egg density (EGD], and egg components [eggshell (SWT, yolk (YWT and albumen (AWT] were investigated in laying hens with 32, 45, and 59 weeks of age with an objective of managing multicollinearity (MC, using stepwise regression (SR and ridge regression (RR analyses. There were significant correlations among egg traits that led to MC problems in all eggs. Hen age influenced egg characteristics and the magnitude of the correlations among egg characteristics. Eggs produced at older age had significantly (p<0.01 higher EGWT, EGWD, EGV, YWT and AWT than those produced at younger age. The SR model alleviated MC problem in eggs produced at 32 weeks, with condition index greater than 30, and one predictor, EGWT had a model fit predicted egg components with R2 ranged from 60 to 99%. The SR model of eggs produced at 45 and 59 weeks indicated MC problem with variance inflation factors (VIF values greater than 10, and 4 predictors; EGWT, EGWD, EGV and EGD had a model fit that significantly predicted egg components with R2 % ranged from 76 to 99 %. The RR analysis provided lower VIF values than 10 and eliminated the MC problem for eggs produced at any age group. It is concluded that the RR analysis provided an ideal solution for managing the MC problem and successfully predicting egg components of laying hens from egg measurements.