Goldstein, Seth D; Hayashi, Masanori; Albert, Catherine M; Jackson, Kyle W; Loeb, David M
2015-10-01
Overall survival rates for pediatric high-grade sarcoma have improved greatly in the past few decades, but prevention and treatment of distant metastasis remain the most compelling problems facing these patients. Traditional preclinical mouse models have not proven adequate to study the biology and treatment of spontaneous distant sarcoma metastasis. To address this deficit, we developed an orthotopic implantation/amputation model in which patient-derived sarcoma xenografts are surgically implanted into mouse hindlimbs, allowed to grow, then subsequently amputated and the animals observed for development of metastases. NOD/SCID/IL-2Rγ-null mice were implanted with either histologically intact high grade sarcoma patient-derived xenografts or cell lines in the pretibial space and affected limbs were amputated after tumor growth. In contrast to subcutaneous flank tumors, we were able to consistently detect spontaneous distant spread of the tumors using our model. Metastases were seen in 27-90 % of animals, depending on the xenograft, and were repeatable and predictable. We also demonstrate the utility of this model for studying the biology of metastasis and present preliminary new insights suggesting the role of arginine metabolism and macrophage phenotype polarization in creating a tumor microenvironment that facilitates metastasis. Subcutaneous tumors express more arginase than inducible nitric oxide synthase and demonstrate significant macrophage infiltration, whereas orthotopic tumors express similar amounts of inducible nitric oxide synthase and arginase and have only a scant macrophage infiltrate. Thus, we present a model of spontaneous distant sarcoma metastasis that mimics the clinical situation and is amenable to studying the biology of the entire metastatic cascade.
Tango, Toshiro
2017-02-13
Tango (Biostatistics 2016) proposed a new repeated measures design called the S:T repeated measures design, combined with generalized linear mixed-effects models and sample size calculations for a test of the average treatment effect that depend not only on the number of subjects but on the number of repeated measures before and after randomization per subject used for analysis. The main advantages of the proposed design combined with the generalized linear mixed-effects models are (1) it can easily handle missing data by applying the likelihood-based ignorable analyses under the missing at random assumption and (2) it may lead to a reduction in sample size compared with the simple pre-post design. In this article, we present formulas for calculating power and sample sizes for a test of the average treatment effect allowing for missing data within the framework of the S:T repeated measures design with a continuous response variable combined with a linear mixed-effects model. Examples are provided to illustrate the use of these formulas.
Isaev, S. A.; Baranov, P. A.; Sudakov, A. G.; Ermakov, A. M.
2015-01-01
The Reynolds equations closed using the Menter shear-stress-transfer model modified with allowance for the curvature of flow lines have been numerically solved using multiblock computational technologies. The obtained solution has been used to analyze subsonic flow past a thick (37.5% chord) airfoil with slot suction in circular vortex cells intended for the Ecology and Progress (Ekologiya i Progress, EKIP) aircraft project in comparison to a distributed (from the central body surface) suction at fixed values of the total volume flow rate (0.02121) and Reynolds number (105) in a range of Mach numbers from 0 to 0.4. This analysis revealed a significant (up to tenfold) decrease in the bow drag (determined with allowance for the energy losses) and a large (by an order of magnitude) increase in the aerodynamic efficiency of the thick airfoil containing vortex cells with slot suction, which reached up to 160.
Directory of Open Access Journals (Sweden)
Garrick Dorian J
2010-06-01
Full Text Available Abstract Background The distribution of residual effects in linear mixed models in animal breeding applications is typically assumed normal, which makes inferences vulnerable to outlier observations. In order to mute the impact of outliers, one option is to fit models with residuals having a heavy-tailed distribution. Here, a Student's-t model was considered for the distribution of the residuals with the degrees of freedom treated as unknown. Bayesian inference was used to investigate a bivariate Student's-t (BSt model using Markov chain Monte Carlo methods in a simulation study and analysing field data for gestation length and birth weight permitted to study the practical implications of fitting heavy-tailed distributions for residuals in linear mixed models. Methods In the simulation study, bivariate residuals were generated using Student's-t distribution with 4 or 12 degrees of freedom, or a normal distribution. Sire models with bivariate Student's-t or normal residuals were fitted to each simulated dataset using a hierarchical Bayesian approach. For the field data, consisting of gestation length and birth weight records on 7,883 Italian Piemontese cattle, a sire-maternal grandsire model including fixed effects of sex-age of dam and uncorrelated random herd-year-season effects were fitted using a hierarchical Bayesian approach. Residuals were defined to follow bivariate normal or Student's-t distributions with unknown degrees of freedom. Results Posterior mean estimates of degrees of freedom parameters seemed to be accurate and unbiased in the simulation study. Estimates of sire and herd variances were similar, if not identical, across fitted models. In the field data, there was strong support based on predictive log-likelihood values for the Student's-t error model. Most of the posterior density for degrees of freedom was below 4. Posterior means of direct and maternal heritabilities for birth weight were smaller in the Student's-t model
Charvat, Hadrien; Remontet, Laurent; Bossard, Nadine; Roche, Laurent; Dejardin, Olivier; Rachet, Bernard; Launoy, Guy; Belot, Aurélien
2016-08-15
The excess hazard regression model is an approach developed for the analysis of cancer registry data to estimate net survival, that is, the survival of cancer patients that would be observed if cancer was the only cause of death. Cancer registry data typically possess a hierarchical structure: individuals from the same geographical unit share common characteristics such as proximity to a large hospital that may influence access to and quality of health care, so that their survival times might be correlated. As a consequence, correct statistical inference regarding the estimation of net survival and the effect of covariates should take this hierarchical structure into account. It becomes particularly important as many studies in cancer epidemiology aim at studying the effect on the excess mortality hazard of variables, such as deprivation indexes, often available only at the ecological level rather than at the individual level. We developed here an approach to fit a flexible excess hazard model including a random effect to describe the unobserved heterogeneity existing between different clusters of individuals, and with the possibility to estimate non-linear and time-dependent effects of covariates. We demonstrated the overall good performance of the proposed approach in a simulation study that assessed the impact on parameter estimates of the number of clusters, their size and their level of unbalance. We then used this multilevel model to describe the effect of a deprivation index defined at the geographical level on the excess mortality hazard of patients diagnosed with cancer of the oral cavity. Copyright © 2016 John Wiley & Sons, Ltd.
Spatial capture-recapture models allowing Markovian transience or dispersal
Royle, J. Andrew; Fuller, Angela K.; Sutherland, Chris
2016-01-01
Spatial capture–recapture (SCR) models are a relatively recent development in quantitative ecology, and they are becoming widely used to model density in studies of animal populations using camera traps, DNA sampling and other methods which produce spatially explicit individual encounter information. One of the core assumptions of SCR models is that individuals possess home ranges that are spatially stationary during the sampling period. For many species, this assumption is unlikely to be met and, even for species that are typically territorial, individuals may disperse or exhibit transience at some life stages. In this paper we first conduct a simulation study to evaluate the robustness of estimators of density under ordinary SCR models when dispersal or transience is present in the population. Then, using both simulated and real data, we demonstrate that such models can easily be described in the BUGS language providing a practical framework for their analysis, which allows us to evaluate movement dynamics of species using capture–recapture data. We find that while estimators of density are extremely robust, even to pathological levels of movement (e.g., complete transience), the estimator of the spatial scale parameter of the encounter probability model is confounded with the dispersal/transience scale parameter. Thus, use of ordinary SCR models to make inferences about density is feasible, but interpretation of SCR model parameters in relation to movement should be avoided. Instead, when movement dynamics are of interest, such dynamics should be parameterized explicitly in the model.
Can extra dimensional effects allow wormholes without exotic matter?
Energy Technology Data Exchange (ETDEWEB)
Kar, Sayan, E-mail: sayan@iitkgp.ac.in [Department of Physics and Center for Theoretical Studies, Indian Institute of Technology, Kharagpur, 721 302 (India); Lahiri, Sayantani, E-mail: sayantani.lahiri@gmail.com [Institute for Physics, University Oldenburg, D-26111 Oldenburg (Germany); ZARM, University of Bremen, Am Fallturm, 28359 Bremen (Germany); SenGupta, Soumitra, E-mail: tpssg@iacs.res.in [Department of Theoretical Physics, Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mallick Road, Jadavpur, Kolkata 700 032 (India)
2015-11-12
We explore the existence of Lorentzian wormholes in the context of an effective on-brane, scalar-tensor theory of gravity. In such theories, the timelike convergence condition, which is always violated for wormholes, has contributions, via the field equations, from on-brane matter as well as from an effective geometric stress energy generated by a bulk-induced radion field. It is shown that, for a class of wormholes, the required on-brane matter, as seen by an on-brane observer in the Jordan frame, is not exotic and does not violate the Weak Energy Condition. The presence of the effective geometric stress energy in addition to on-brane matter is largely responsible for creating this intriguing possibility. Thus, if such wormholes are ever found to exist in the Universe, they would clearly provide pointers towards the existence of a warped extra dimension as proposed in the two-brane model of Randall and Sundrum.
Meyer, Daniel R.; And Others
1991-01-01
Argues that a children's allowance could be instituted in this country that would decrease poverty and welfare participation while not costing the federal government any additional resources. Discusses microsimulation model that shows effects of three levels of children's allowances on government revenues, family incomes, welfare use, and labor…
Allowed Parameter Regions for a Tree-Level Inflation Model
Institute of Scientific and Technical Information of China (English)
MENG Xin-He
2001-01-01
The early universe inflation is well known as a promising theory to explain the origin of large-scale structure of universe and to solve the early universe pressing problems. For a reasonable inflation model, the potential during inflation must be very flat, at least, in the direction of the inflaton. To construct the inflaton potential all the known related astrophysics observations should be included. For a general tree-level hybrid inflation potential, which is notdiscussed fully so far, the parameters in it are shown how to be constrained via the astrophysics data observed and to be obtained to the expected accuracy, and to be consistent with cosmology requirements.``
Can extra dimensional effects allow wormholes without exotic matter?
Directory of Open Access Journals (Sweden)
Sayan Kar
2015-11-01
Full Text Available We explore the existence of Lorentzian wormholes in the context of an effective on-brane, scalar-tensor theory of gravity. In such theories, the timelike convergence condition, which is always violated for wormholes, has contributions, via the field equations, from on-brane matter as well as from an effective geometric stress energy generated by a bulk-induced radion field. It is shown that, for a class of wormholes, the required on-brane matter, as seen by an on-brane observer in the Jordan frame, is not exotic and does not violate the Weak Energy Condition. The presence of the effective geometric stress energy in addition to on-brane matter is largely responsible for creating this intriguing possibility. Thus, if such wormholes are ever found to exist in the Universe, they would clearly provide pointers towards the existence of a warped extra dimension as proposed in the two-brane model of Randall and Sundrum.
Allowing for crystalline structure effects in Geant4
Bagli, Enrico; Asai, Makoto; Dotti, Andrea; Pandola, Luciano; Verderi, Marc
2017-07-01
In recent years, the Geant4 toolkit for the Monte Carlo simulation of radiation with matter has seen large growth in its divers user community. A fundamental aspect of a successful physics experiment is the availability of a reliable and precise simulation code. Geant4 currently does not allow for the simulation of particle interactions with anything other than amorphous matter. To overcome this limitation, the GECO (GEant4 Crystal Objects) project developed a general framework for managing solid-state structures in the Geant4 kernel and validate it against experimental data. Accounting for detailed geometrical structures allows, for example, simulation of diffraction from crystal planes or the channeling of charged particle.
Manufacturing Methods for Process Effects on Aluminum Casting Allowables
1985-03-01
aluminum alloy A356 ingots were melted in a silicon Scarbide crucible and held at 1350F. Flux was added, and the oxides were Sskim~med off the...1REFERENCES 1. Lemon, R.C., and Hunsicker, H.Y., "New Aluminum Permanent Mold Casting Alloys C355 and A356 ," Aluminum Company of America, May 1956. 2... A356 ," Aluminum Company of America, May 1956. Lipson, S., "Effect of Section Thickness on the Tensile Properties of Thin- Section Aluminum Alloy Sand
Nyerges, Ákos; Csörgő, Bálint; Nagy, István; Bálint, Balázs; Bihari, Péter; Lázár, Viktória; Apjok, Gábor; Umenhoffer, Kinga; Bogos, Balázs; Pósfai, György; Pál, Csaba
2016-03-01
Currently available tools for multiplex bacterial genome engineering are optimized for a few laboratory model strains, demand extensive prior modification of the host strain, and lead to the accumulation of numerous off-target modifications. Building on prior development of multiplex automated genome engineering (MAGE), our work addresses these problems in a single framework. Using a dominant-negative mutant protein of the methyl-directed mismatch repair (MMR) system, we achieved a transient suppression of DNA repair in Escherichia coli, which is necessary for efficient oligonucleotide integration. By integrating all necessary components into a broad-host vector, we developed a new workflow we term pORTMAGE. It allows efficient modification of multiple loci, without any observable off-target mutagenesis and prior modification of the host genome. Because of the conserved nature of the bacterial MMR system, pORTMAGE simultaneously allows genome editing and mutant library generation in other biotechnologically and clinically relevant bacterial species. Finally, we applied pORTMAGE to study a set of antibiotic resistance-conferring mutations in Salmonella enterica and E. coli. Despite over 100 million y of divergence between the two species, mutational effects remained generally conserved. In sum, a single transformation of a pORTMAGE plasmid allows bacterial species of interest to become an efficient host for genome engineering. These advances pave the way toward biotechnological and therapeutic applications. Finally, pORTMAGE allows systematic comparison of mutational effects and epistasis across a wide range of bacterial species.
Directory of Open Access Journals (Sweden)
Jaggi Chandra K.
2016-01-01
Full Text Available This study develops an inventory model to determine ordering policy for deteriorating items with constant demand rate under inflationary condition over a fixed planning horizon. Shortages are allowed and are partially backlogged. In today’s wobbling economy, especially for long term investment, the effects of inflation cannot be disregarded as uncertainty about future inflation may influence the ordering policy. Therefore, in this paper a fuzzy model is developed that fuzzify the inflation rate, discount rate, deterioration rate, and backlogging parameter by using triangular fuzzy numbers to represent the uncertainty. For Defuzzification, the well known signed distance method is employed to find the total profit over the planning horizon. The objective of the study is to derive the optimal number of cycles and their optimal length so to maximize the net present value of the total profit over a fixed planning horizon. The necessary and sufficient conditions for an optimal solution are characterized. An algorithm is proposed to find the optimal solution. Finally, the proposed model has been validated with numerical example. Sensitivity analysis has been performed to study the impact of various parameters on the optimal solution, and some important managerial implications are presented.
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
In this paper,a new model with a total amount control target of allowable water withdrawal based on initial water right is built for the implementation of initial water right allocation scheme as well as unified allocation for allowable water withdrawal and sewage discharge.The model couples the water allocation simulation model and the computational model of permissible pol-lution bearing capacity.In view of the model complexity,a new technology which synthesizes system simulation,iterative reservoir turns and intelligent computation is proposed to improve the operability of allocation scheme and computational efficiency.Taking the Beijiang River Basin in the Pearl River Basin as an example,the study explains the model establishment,solution and application,and draws an optimized operation graph of large-scale reservoirs.The study also obtains a long-term operation strategy of river basin water resources system,the allocation schemes of allowable water withdrawal and sewage discharge in a typical year and the flow hydrographs of trans-boundary sections.The validity of the model and the allocation rationality are analyzed as well.
Modeling the price dynamics of CO{sub 2} emission allowances
Energy Technology Data Exchange (ETDEWEB)
Benz, Eva [Bonn Graduate School of Economics (Germany); Trueck, Stefan [Macquarie University Sydney (Australia)
2009-01-15
In this paper we analyze the short-term spot price behavior of carbon dioxide (CO{sub 2}) emission allowances of the new EU-wide CO{sub 2} emissions trading system (EU ETS). After reviewing the stylized facts of this new class of assets we investigate several approaches for modeling the returns of emission allowances. Due to different phases of price and volatility behavior in the returns, we suggest the use of Markov switching and AR-GARCH models for stochastic modeling. We examine the approaches by conducting an in-sample and out-of-sample forecasting analysis and by comparing the results to alternative approaches. Our findings strongly support the adequacy of the models capturing characteristics like skewness, excess kurtosis and in particular different phases of volatility behavior in the returns. (author)
MODELLING THE POSITION OF CELL PROFILES ALLOWING FOR BOTH INHOMOGENEITY AND INTERACTION
Directory of Open Access Journals (Sweden)
Linda Stougaard Nielsen
2011-05-01
Full Text Available It is of interest to consider models for point processes that allow for interaction between the points as well as for inhomogeneity in the intensity of the points. Markov point process models are very useful to describe point interaction and can also be used to describe inhomogeneity. A particular type of inhomogeneous Markov point processes obtained by transforming a homogeneous Markov point process will be considered. The position of cell proles in a 2D section of the mucous membrane in the stomach of a rat will be examined using this model.
DEFF Research Database (Denmark)
Teodorescu, Remus; Ruiz, Alberto Parera; Cirstea, Marcian
2008-01-01
The paper describes a new holistic approach to the modeling of integrated renewable energy systems. The method is using the DK5 modeling/design environment from Celoxica and is based on the new Handel-C programming language. The goal of the work carried out was to achieve a combined model...... of a photovoltaic energy system and a wind power system, which would allow an optimized holistic digital control system design, followed by rapid prototyping of the controller into a single Field Programmable Gate Array (FPGA). Initially, the system was simulated using Matlab / Simulink, to create a reference...
Allowing for model error in strong constraint 4D-Var
Howes, Katherine; Lawless, Amos; Fowler, Alison
2016-04-01
Four dimensional variational data assimilation (4D-Var) can be used to obtain the best estimate of the initial conditions of an environmental forecasting model, namely the analysis. In practice, when the forecasting model contains errors, the analysis from the 4D-Var algorithm will be degraded to allow for errors later in the forecast window. This work focusses on improving the analysis at the initial time by allowing for the fact that the model contains error, within the context of strong constraint 4D-Var. The 4D-Var method developed acknowledges the presence of random error in the model at each time step by replacing the observation error covariance matrix with an error covariance matrix that includes both observation error and model error statistics. It is shown that this new matrix represents the correct error statistics of the innovations in the presence of model error. A method for estimating this matrix using innovation statistics, without requiring prior knowledge of the model error statistics, is presented. The method is demonstrated numerically using a non-linear chaotic system with erroneous parameter values. We show that that the new method works to reduce the analysis error covariance when compared with a standard strong constraint 4D-Var scheme. We discuss the fact that an improved analysis will not necessarily provide a better forecast.
McGurk, B. J.; Painter, T. H.
2014-12-01
Deterministic snow accumulation and ablation simulation models are widely used by runoff managers throughout the world to predict runoff quantities and timing. Model fitting is typically based on matching modeled runoff volumes and timing with observed flow time series at a few points in the basin. In recent decades, sparse networks of point measurements of the mountain snowpacks have been available to compare with modeled snowpack, but the comparability of results from a snow sensor or course to model polygons of 5 to 50 sq. km is suspect. However, snowpack extent, depth, and derived snow water equivalent have been produced by the NASA/JPL Airborne Snow Observatory (ASO) mission for spring of 20013 and 2014 in the Tuolumne River basin above Hetch Hetchy Reservoir. These high-resolution snowpack data have exposed the weakness in a model calibration based on runoff alone. The U.S. Geological Survey's Precipitation Runoff Modeling System (PRMS) calibration that was based on 30-years of inflow to Hetch Hetchy produces reasonable inflow results, but modeled spatial snowpack location and water quantity diverged significantly from the weekly measurements made by ASO during the two ablation seasons. The reason is that the PRMS model has many flow paths, storages, and water transfer equations, and a calibrated outflow time series can be right for many wrong reasons. The addition of a detailed knowledge of snow extent and water content constrains the model so that it is a better representation of the actual watershed hydrology. The mechanics of recalibrating PRMS to the ASO measurements will be described, and comparisons in observed versus modeled flow for both a small subbasin and the entire Hetch Hetchy basin will be shown. The recalibrated model provided a bitter fit to the snowmelt recession, a key factor for water managers as they balance declining inflows with demand for power generation and ecosystem releases during the final months of snow melt runoff.
Examination of Modeling Languages to Allow Quantitative Analysis for Model-Based Systems Engineering
2014-06-01
model of the system (Friendenthal, Moore and Steiner 2008, 17). The premise is that maintaining a logical and consistent model can be accomplished...Standard for Exchange of Product data (STEP) subgroup of ISO, and defines a standard data format for certain types of SE information ( Johnson 2006...search.credoreference.com/content/entry/encyccs/formal_languages/0. Friedenthal, Sanford, Alan Moore, and Rick Steiner . 2008. A Practical Guide to SysML
A New Item Response Theory Model for Open-Ended Online Homework with Multiple Allowed Attempts
Gönülateş, Emre
2015-01-01
Item Response Theory (IRT) was originally developed in traditional exam settings, and it has been shown that the model does not readily transfer to formative assessment in the form of online homework. We investigate if this is mostly due to learner traits that do not become apparent in exam settings, namely random guessing due to lack of diligence or dedication, and copying work from other students or resources. Both of these traits mask the true ability of the learner, which is the only trait considered in most mainstream unidimensional IRT models. We find that indeed the introduction of these traits allows to better assess the true ability of the learners, as well as to better gauge the quality of assessment items. Correspondence of the model traits to self-reported behavior is investigated and confirmed. We find that of these two traits, copying answers has a larger influence on initial homework attempts than random guessing.
Haxton, Thomas K; Zuckermann, Ronald N; Whitelam, Stephen
2014-01-01
Certain sequences of peptoid polymers (synthetic analogs of peptides) assemble into bilayer nanosheets via a nonequilibrium assembly pathway of adsorption, compression, and collapse at an air-water interface. As with other large-scale dynamic processes in biology and materials science, understanding the details of this supramolecular assembly process requires a modeling approach that captures behavior on a wide range of length and time scales, from those on which individual sidechains fluctuate to those on which assemblies of polymers evolve. Here we demonstrate that a new coarse-grained modeling approach is accurate and computationally efficient enough to do so. Our approach uses only a minimal number of coarse-grained sites, but retains independently fluctuating orientational degrees of freedom for each site. These orientational degrees of freedom allow us to accurately parameterize both bonded and nonbonded interactions, and to generate all-atom configurations with sufficient accuracy to perform atomic sca...
Directory of Open Access Journals (Sweden)
Gizzatkulov Nail M
2010-08-01
Full Text Available Abstract Background Systems biology research and applications require creation, validation, extensive usage of mathematical models and visualization of simulation results by end-users. Our goal is to develop novel method for visualization of simulation results and implement it in simulation software package equipped with the sophisticated mathematical and computational techniques for model development, verification and parameter fitting. Results We present mathematical simulation workbench DBSolve Optimum which is significantly improved and extended successor of well known simulation software DBSolve5. Concept of "dynamic visualization" of simulation results has been developed and implemented in DBSolve Optimum. In framework of the concept graphical objects representing metabolite concentrations and reactions change their volume and shape in accordance to simulation results. This technique is applied to visualize both kinetic response of the model and dependence of its steady state on parameter. The use of the dynamic visualization is illustrated with kinetic model of the Krebs cycle. Conclusion DBSolve Optimum is a user friendly simulation software package that enables to simplify the construction, verification, analysis and visualization of kinetic models. Dynamic visualization tool implemented in the software allows user to animate simulation results and, thereby, present them in more comprehensible mode. DBSolve Optimum and built-in dynamic visualization module is free for both academic and commercial use. It can be downloaded directly from http://www.insysbio.ru.
Effect of Forging Allowance Value on the Power Consumption of Machining Process
Directory of Open Access Journals (Sweden)
L. D. Mal'kova
2015-01-01
Full Text Available The paper aim is to develop and study possible energy-efficiency measures for machined forgings drawing on analysis of the impact of the allowance for machining and its scatter.The most sophisticated option to take into consideration the effect of the cut depth is the work-piece machining in which the forging allowance value results from the blank production.Research of power consumption was conducted for turning the cylindrical surface of 144 mm length and 1,5 33 0,5 diameter on forgings of the work-pieces "screw of steering control" made from steel 60PP. A radial dimension allowance at said cylindrical surface at six points of the five sections was sized to assess the allowance value dispersion. The size of the sample measurements at the control points was n = 600. Statistic processing has shown normal law of distribution and sample homogeneity.To analyze the results of experiments was calculated a range of allowances for this workpiece. Calculated minimum and maximum allowance per one side for rough lathing were, respectively, 0.905 mm and 1.905mm. It was found that 77% points under control lie in calculated range of allowance values. And there are no points out of the range on lesser side that proves a lack of rejects; but there are points out of the range on the bigger side, that will require additional costs for machining the specified surface, including the cost of electricity.There were three power consumption calculations based on factory- recommended duty: for processing the entire sample of forgings with an average allowance, for machining forgings allowances of which are within the recommended design range of allowance, and for processing the entire sample of forgings with a minimum value of allowance.It was found that elimination of allowance values which are outside the recommended range enables to reduce the power consumption, at least, by 6%, and the overall power consumption for processing the measured forgings
Allowance for the tunnel effect in the entrance channel of fusion-fission reactions
Litnevsky, V. L.; Kosenko, G. I.; Ivanyuk, F. A.
2016-05-01
A two-stage model is developed in order to describe fusion-fission reactions. The process in the course of which colliding ions approach each other is simulated at the first stage, the deformations and relative orientations of the ions being taken into account. The first stage of the calculation is completed as soon as colliding nuclei touch each other. A continuous nuclear system (monosystem) is formed at this instant. The emerging distributions of the angular momenta of this system and of its potential and internal energies at the point of touching are used as input data that are necessary for triggering the second stage of the calculation. The evolution of collective coordinates that describe the shape of the monosystem is calculated at the second stage. The description of this evolution is terminated either at the instant of its fission or upon the release of a major part of its excess energy via particle and photon emission. In the latter case, the probability for the fission of the monosystem or a further decrease in its excitation energy becomes extremely small. The ion-collision process and the evolution of the monosystem formed after primary nuclei come into contact are simulated on the basis of stochastic Langevin equations. The quantities appearing in them (which include the potential energy and inertial and friction parameters) are determined with allowance for the shell structure of nuclei. The tunneling of colliding nuclei through the Coulomb barrier is taken into account, and the effect of this phenomenon on model predictions is studied.
Thielecke, Lars; Glauche, Ingmar
2016-01-01
The availability of several methods to unambiguously mark individual cells has strongly fostered the understanding of clonal developments in hematopoiesis and other stem cell driven regenerative tissues. While cellular barcoding is the method of choice for experimental studies, patients that underwent gene therapy carry a unique insertional mark within the transplanted cells originating from the integration of the retroviral vector. Close monitoring of such patients allows accessing their clonal dynamics, however, the early detection of events that predict monoclonal conversion and potentially the onset of leukemia are beneficial for treatment. We developed a simple mathematical model of a self-stabilizing hematopoietic stem cell population to generate a wide range of possible clonal developments, reproducing typical, experimentally and clinically observed scenarios. We use the resulting model scenarios to suggest and test a set of statistical measures that should allow for an interpretation and classification of relevant clonal dynamics. Apart from the assessment of several established diversity indices we suggest a measure that quantifies the extension to which the increase in the size of one clone is attributed to the total loss in the size of all other clones. By evaluating the change in relative clone sizes between consecutive measurements, the suggested measure, referred to as maximum relative clonal expansion (mRCE), proves to be highly sensitive in the detection of rapidly expanding cell clones prior to their dominant manifestation. This predictive potential places the mRCE as a suitable means for the early recognition of leukemogenesis especially in gene therapy patients that are closely monitored. Our model based approach illustrates how simulation studies can actively support the design and evaluation of preclinical strategies for the analysis and risk evaluation of clonal developments. PMID:27764218
Multi-scale finite element modeling allows the mechanics of amphibian neurulation to be elucidated
Chen, Xiaoguang; Brodland, G. Wayne
2008-03-01
The novel multi-scale computational approach introduced here makes possible a new means for testing hypotheses about the forces that drive specific morphogenetic movements. A 3D model based on this approach is used to investigate neurulation in the axolotl (Ambystoma mexicanum), a type of amphibian. The model is based on geometric data from 3D surface reconstructions of live embryos and from serial sections. Tissue properties are described by a system of cell-based constitutive equations, and parameters in the equations are determined from physical tests. The model includes the effects of Shroom-activated neural ridge reshaping and lamellipodium-driven convergent extension. A typical whole-embryo model consists of 10 239 elements and to run its 100 incremental time steps requires 2 days. The model shows that a normal phenotype does not result if lamellipodium forces are uniform across the width of the neural plate; but it can result if the lamellipodium forces decrease from a maximum value at the mid-sagittal plane to zero at the plate edge. Even the seemingly simple motions of neurulation are found to contain important features that would remain hidden, they were not studied using an advanced computational model. The present model operates in a setting where data are extremely sparse and an important outcome of the study is a better understanding of the role of computational models in such environments.
A Mediated Definite Delegation Model allowing for Certified Grid Job Submission
Schreiner, Steffen; Grigoras, Costin; Litmaath, Maarten
2012-01-01
Grid computing infrastructures need to provide traceability and accounting of their users" activity and protection against misuse and privilege escalation. A central aspect of multi-user Grid job environments is the necessary delegation of privileges in the course of a job submission. With respect to these generic requirements this document describes an improved handling of multi-user Grid jobs in the ALICE ("A Large Ion Collider Experiment") Grid Services. A security analysis of the ALICE Grid job model is presented with derived security objectives, followed by a discussion of existing approaches of unrestricted delegation based on X.509 proxy certificates and the Grid middleware gLExec. Unrestricted delegation has severe security consequences and limitations, most importantly allowing for identity theft and forgery of delegated assignments. These limitations are discussed and formulated, both in general and with respect to an adoption in line with multi-user Grid jobs. Based on the architecture of the ALICE...
Wybo, Willem A M; Boccalini, Daniele; Torben-Nielsen, Benjamin; Gewaltig, Marc-Oliver
2015-12-01
We prove that when a class of partial differential equations, generalized from the cable equation, is defined on tree graphs and the inputs are restricted to a spatially discrete, well chosen set of points, the Green's function (GF) formalism can be rewritten to scale as O(n) with the number n of inputs locations, contrary to the previously reported O(n(2)) scaling. We show that the linear scaling can be combined with an expansion of the remaining kernels as sums of exponentials to allow efficient simulations of equations from the aforementioned class. We furthermore validate this simulation paradigm on models of nerve cells and explore its relation with more traditional finite difference approaches. Situations in which a gain in computational performance is expected are discussed.
Role of Probabilistic Micromechanics Modeling in Establishing Design Allowables in Composites
Mital, Subodh K.; Keith, Theo G., Jr.; Murthy, Pappu L. N.; Brewer, David N.
2005-01-01
One of the major challenges in designing with any new material, and particularly with advanced composite materials, is the fidelity of material design allowables. In the case of composite materials, the concern arises from the inherent nature of these materials, i.e., their heterogeneous make-up and the various factors that affect their properties in a specific design environment. Composites have various scales - micro, macro, laminate and structural, as well as numerous other fabrication related parameters. Many advanced composites in aerospace applications involve complex two- and three-dimensional fiber architectures and requires high-temperature processing. Since there are uncertainties associated with each of these, the observed behavior of composite materials shows scatter. Evaluating the effect of each of these variables on the observed scatter in composite properties solely by teSting is cost and time prohibitive. One alternative is to evaluate these effects by computational simulation. The authors have developed probabilistic composite micromechanics techniques by combining woven composite micromechanics and Fast Probability Integration (FPI) techniques to address these issues. In this paper these techniques will be described and demonstrated through selected examples. Results in the form of cumulative distribution functions (CDF) of the composite properties of a MI (melt-infiltrated) SiC/SiC (silicon carbide fiber in a silicon carbide matrix) Composite will be presented. A CDF is a relationship defined by the value of the property (the response variable) with respect to the cumulative probability of occurrence. Furthermore, input variables causing scatter are identified and ranked based upon their sensitivity magnitude. Sensitivity information is very valuable in quality control. How these results can be utilized to develop design allowables so that these materials may be used by structural analysts/designers will also be discussed.
Directory of Open Access Journals (Sweden)
Reto Eggenschwiler
2011-01-01
Full Text Available Direct reprogramming of somatic cells into pluripotent cells by retrovirus-mediated expression of OCT4, SOX2, KLF4, and C-MYC is a promising approach to derive disease-specific induced pluripotent stem cells (iPSCs. In this study, we focused on three murine models for metabolic liver disorders: the copper storage disorder Wilson's disease (toxic-milk mice, tyrosinemia type 1 (fumarylacetoacetate-hydrolase deficiency, FAH−/− mice, and alpha1-antitrypsin deficiency (PiZ mice. Colonies of iPSCs emerged 2-3 weeks after transduction of fibroblasts, prepared from each mouse strain, and were maintained as individual iPSC lines. RT-PCR and immunofluorescence analyses demonstrated the expression of endogenous pluripotency markers. Hepatic precursor cells could be derived from these disease-specific iPSCs applying an in vitro differentiation protocol and could be visualized after transduction of a lentiviral albumin-GFP reporter construct. Functional characterization of these cells allowed the recapitulation of the disease phenotype for further studies of underlying molecular mechanisms of the respective disease.
Adverse Effects Associated with Protein Intake above the Recommended Dietary Allowance for Adults
Delimaris, Ioannis
2013-01-01
Background. While high-protein consumption—above the current recommended dietary allowance for adults (RDA: 0.8 g protein/kg body weight/day)—is increasing in popularity, there is a lack of data on its potential adverse effects. Objective. To determine the potential disease risks due to high protein/high meat intake obtained from diet and/or nutritional supplements in humans. Design. Review. Subjects. Healthy adult male and female subjects. Method. In order to identify relevant studies, the e...
Single Field Inflation models allowed and ruled out by the three years WMAP data
De Vega, H J
2006-01-01
We study the single field slow-roll inflation models that better fit the available CMB and LSS data including the three years WMAP data: new inflation and hybrid inflation. We study them as effective field theories in the Ginsburg-Landau context: a trinomial potential turns out to be a simple and well motivated model. The compute the spectral index n_s of the adiabatic fluctuations, the ratio r of tensor to scalar fluctuations and the running index d n_s/dln k, derive explicit formulae and provide relevant plots. In new inflation, and for the three years WMAP central value n_s = 0.95, we predict 0.031. Hybrid inflation for mu_0^2>Lambda_0 M_{Pl}^2/192 can fullfill all the present CMB+LSS data. Even if chaotic inflation predicts n_s values compatible with the data, chaotic inflation is disfavoured since it predicts a too high value for the ratio r=0.27. The model which best fits the current data and which best prepares the way to the expected data r < 0.1, is the trinomial potential with negative mass term:...
CEA-targeted nanoparticles allow specific in vivo fluorescent imaging of colorectal cancer models.
Tiernan, James P; Ingram, Nicola; Marston, Gemma; Perry, Sarah L; Rushworth, Jo V; Coletta, P Louise; Millner, Paul A; Jayne, David G; Hughes, Thomas A
2015-01-01
Fluorescent imaging of colorectal tumor cells would improve tumor localization and allow intra-operative staging, facilitating stratification of surgical resections thereby improving patient outcomes. We aimed to develop and test fluorescent nanoparticles capable of allowing this in vivo. Dye-doped silica nanoparticles were synthesized. Anti-CEA (carcinoembryonic antigen) or control IgGs were conjugated to nanoparticles using various chemical strategies. Binding of CEA-targeted or control nanoparticles to colorectal cancer cells was quantified in vitro, and in vivo after systemic-delivery to murine xenografts. CEA-targeted, polyamidoamine dendrimer-conjugated, nanoparticles, but not control nanoparticles, allowed strong tumor-specific imaging. We are the first to demonstrate live, specific, in vivo imaging of colorectal cancer cells using antibody-targeted fluorescent nanoparticles. These nanoparticles have potential to allow intra-operative fluorescent visualization of tumor cells.
Human Resources Division
2001-01-01
HR Division wishes to clarify to members of the personnel that the allowance for a dependent child continues to be paid during all training courses ('stages'), apprenticeships, 'contrats de qualification', sandwich courses or other courses of similar nature. Any payment received for these training courses, including apprenticeships, is however deducted from the amount reimbursable as school fees. HR Division would also like to draw the attention of members of the personnel to the fact that any contract of employment will lead to the suppression of the child allowance and of the right to reimbursement of school fees.
The effect of a southward interplanetary magnetic field on St\\"ormer's allowed regions
Lemaire, Joseph F
2012-01-01
The motion of a charged particle in a magnetic dipole has first been studied by Stormer. The different applications of Stormer's theory to aurorae, cosmic rays and Van Allen radiation belt particles are recalled in an historical perspective. In this paper, we expand the Stormer theory in order to take into account the effects produced by an additional uniform and stationary interplanetary magnetic field (IMF) whose orientation is parallel or antiparallel to the magnetic moment of the dipole. A new expression is derived for the Stormer potential taking into account the additional IMF component. It is shown how Stormer's allowed and forbidden zones are influenced by the implementation of a northward or a southward IMF, and how a southward turning of the IMF orientation makes it easier for Solar Energetic Particle and Galactic Cosmic Rays to enter into the inner part of the geomagnetic field along interconnected magnetic field lines.
Sorrentino, Sajoscha A; Kielstein, Jan T; Lukasz, Alexander; Sorrentino, Janine-Nicole; Gohrbandt, Bernhard; Haller, Hermann; Schmidt, Bernhard M W
2011-01-01
The objective of this study was to test the ability of myoglobin removal of a novel, high-permeability polysulphone dialyzer in acute kidney injury as a result of rhabdomyolysis. Intensive care unit of a tertiary care hospital. Six patients (one female; aged 24, 36, 41, 55, 63, and 65 yrs) with oligoanuric acute kidney injury resulting from rhabdomyolysis. Extended dialysis was performed using a single-pass batch dialysis system and a novel polysulphone high-flux dialyzer (effective surface area 1.8 m; inner lumen 220 μm; wall thickness 35 μm; allowing elimination of substances with a molecular weight of up to 30 kDa). Samples were collected at prefilter and postfilter sites as well as from the collected spent dialysate. The dialyzer clearance was calculated from concentrations before and directly after the dialysis membrane, the blood flow, and the ultrafiltration rate. The total amount of the myoglobin removed was measured directly as the whole dialysate was preserved. A median myoglobin clearance of 90.5 mL/min (range, 52.4-126.3 mL/min) was achieved, resulting in a median myoglobin removal per treatment hour of 0.54 g (range, 0.15-2.21 g). Extended dialysis with a high-flux, high-permeability membrane allowed effective elimination of myoglobin with a clearance of myoglobin that surpassed all previously reported dialysis techniques. This membrane may be advantageous in preventing acute kidney injury or avoiding complete loss of kidney function in patients with rhabdomyolysis. Further studies are needed to determine whether improving renal recovery or mortality in patients with acute kidney injury resulting from rhabdomyolysis is possible.
Institute of Scientific and Technical Information of China (English)
Andrea J. McKinney; Sheri L. Holmen
2011-01-01
The increasing incidence and mortality associated with advanced stages of melanoma are cause for concern. Few treatment options are available for advanced melanoma and the 5-year survival rate is less than 15％. Targeted therapies may revolutionize melanoma treatment by providing less toxic and more effective strategies. However, maximizing effectiveness requires further understanding of the molecular alterations that drive tumor formation, progression, and maintenance, as well as elucidating the mechanisms of resistance. Several different genetic alterations identified in human melanoma have been recapitulated in mice. This review outlines recent progress made in the development of mouse models of melanoma and summarizes what these findings reveal about the human disease. We begin with a discussion of traditional models and conclude with the recently developed RCAS/TVA somatic cell gene delivery mouse model of melanoma.
Cherkas, S L
2015-01-01
It is shown, that initial conditions in the quasi-Heisenberg quantization scheme can be set at an initial cosmological singularity per se. This possibility is provided by finiteness of some quantities, namely momentums of the dynamical variables, at a singularity, in spite of infinity of the dynamical variables themselves. The uncertainty principle allows avoiding a necessity to set values of the dynamical variables at singularity, as a wave packet can be expressed through the finite momentums. The issue of a vacuum energy, arising during evolution when the gravitational waves appear, is addressed as well. It is shown that, in the certain gauge, the equations of motion contain a difference of kinetic and potential energies of the field oscillators. Thus, in this gauge, the leading divergent parts of the vacuum energy in the equations of motion cancel each other. It is conjectured that the UV cut-off allows physical interpretation of the weakly divergent part of the vacuum energy.
Allowed rare pion and muon decays as tests of the Standard Model
Pocanic, Dinko
2016-01-01
Simple dynamics, few available decay channels, and extremely well controlled radiative and loop corrections, make pion and muon decays a sensitive means for testing the underlying symmetries, the universality of weak fermion couplings, as well as for study of pion structure and chiral dynamics. We review the current state of experimental study of the allowed rare decays of charged pions: (a) electronic, $\\pi^+ \\to e^+\
Probability Criterion for a Dynamic Financial Model with Short-Selling Allowed
Institute of Scientific and Technical Information of China (English)
韩其恒; 唐万生; 李光泉
2003-01-01
Probability criterion has its practical significance, and its investment decision-making is determined by the expected discounted wealth. In a complete, standard financial market with short-selling allowed, this paper probes into the investment decision-making with probability criterion. The upper limit of criterion function is obtained. The corresponding discounted wealth process and hedging portfolio process are provided. Finally, an illustrative example of one-dimensional constant-coefficient financial market is given.
Adverse Effects Associated with Protein Intake above the Recommended Dietary Allowance for Adults.
Delimaris, Ioannis
2013-01-01
Background. While high-protein consumption-above the current recommended dietary allowance for adults (RDA: 0.8 g protein/kg body weight/day)-is increasing in popularity, there is a lack of data on its potential adverse effects. Objective. To determine the potential disease risks due to high protein/high meat intake obtained from diet and/or nutritional supplements in humans. Design. Review. Subjects. Healthy adult male and female subjects. Method. In order to identify relevant studies, the electronic databases, Medline and Google Scholar, were searched using the terms:"high protein diet," "protein overconsumption," "protein overuse," and "high meat diet." Papers not in English were excluded. Further studies were identified by citations in retrieved papers. Results. 32 studies (21 experimental human studies and 11 reviews) were identified. The adverse effects associated with long-term high protein/high meat intake in humans were (a) disorders of bone and calcium homeostasis, (b) disorders of renal function, (c) increased cancer risk, (d) disorders of liver function, and (e) precipitated progression of coronary artery disease. Conclusions. The findings of the present study suggest that there is currently no reasonable scientific basis in the literature to recommend protein consumption above the current RDA (high protein diet) for healthy adults due to its potential disease risks. Further research needs to be carried out in this area, including large randomized controlled trials.
DEFF Research Database (Denmark)
Wesolowska, Agata; Dalgaard, M. D.; Borst, L.;
2011-01-01
a model disease for exploring the impact of genetic variation due to well-characterized cytogenetics, drug response pathways and precise monitoring of minimal residual disease. Here, we have selected clinically relevant genes and SNPs through literature screening, and on the basis of associations with key...... designed a cost-effective, high-throughput capture assay of â¼25â000 clinically relevant SNPs, and demonstrated that multiple samples can be tagged and pooled before genome capture in targeted enrichment with a sufficient sequencing depth for genotyping. This multiplexed, targeted sequencing method allows...
Mechanical characterization and modelling of the heavy tungsten allow IT180
Scapin, M
2015-01-01
In this work, the mechanical characterization and the consequent material modeling of the tungsten alloy INERMET® IT180 were performed. The material is actually used in the collimation system of the Large Hadron Collider at CERN and several studies are currently under development in order to be able to numerically predict the material damage in case of energy beamimpact, but to do this, a confident strength model has to be obtained. This is the basis of this work, in which a test campaign in compression and tension at different strain-rates and tempe...
Coupled model of composite synthesis allowing the melting of one of the components
Chumakov, Yurii A.; Knyazeva, Anna G.
2016-11-01
A model of initiation of the reaction in the flat layer under external heating and various loading was proposed and numerically investigated. Different types of mechanical loading such as uniaxial loading, compression and pure shear were considered. The estimation of stressed-deformed state of reaction system with consumable component and reaction product is based on the model of Maxwell's viscoelastic body. The influence of the coupling between thermal and mechanical processes on temperature, stress and strain fields was investigated. The phenomenon of thermal explosion caused by the acceleration of the reaction by additional thermal flux due to viscous dissipation was discovered.
Jung, Insung; Seongyoun, Hong
2014-01-01
Research indicates that distance education (DE) students regard learner support systems as the key element in quality provision. This study sought to identify the key concerns of Asian DE students regarding support provision in different types of DE and dual-mode providers and formulate a student support model which took account of gender issues.…
A three-dimensional laboratory steam injection model allowing in situ saturation measurements
Energy Technology Data Exchange (ETDEWEB)
Demiral, B.M.R.; Pettit, P.A.; Castanier, L.M.; Brigham, W.E.
1992-08-01
The CT imaging technique together with temperature and pressure measurements were used to follow the steam propagation during steam and steam foam injection experiments in a three dimensional laboratory steam injection model. The advantages and disadvantages of different geometries were examined to find out which could best represent radial and gravity override flows and also fit the dimensions of the scanning field of the CT scanner. During experiments, steam was injected continuously at a constant rate into the water saturated model and CT scans were taken at six different cross sections of the model. Pressure and temperature data were collected with time at three different levels in the model. During steam injection experiments, the saturations obtained by CT matched well with the temperature data. That is, the steam override as observed by temperature data was also clearly seen on the CT pictures. During the runs where foam was present, the saturation distributions obtained from CT pictures showed a piston like displacement. However, the temperature distributions were different depending on the type of steam foam process used. The results clearly show that the pressure/temperature data alone are not sufficient to study steam foam in the presence of non-condensible gas.
Functional Connectivity under Optogenetic Control Allows Modeling of Human Neuromuscular Disease.
Steinbeck, Julius A; Jaiswal, Manoj K; Calder, Elizabeth L; Kishinevsky, Sarah; Weishaupt, Andreas; Toyka, Klaus V; Goldstein, Peter A; Studer, Lorenz
2016-01-07
Capturing the full potential of human pluripotent stem cell (PSC)-derived neurons in disease modeling and regenerative medicine requires analysis in complex functional systems. Here we establish optogenetic control in human PSC-derived spinal motorneurons and show that co-culture of these cells with human myoblast-derived skeletal muscle builds a functional all-human neuromuscular junction that can be triggered to twitch upon light stimulation. To model neuromuscular disease we incubated these co-cultures with IgG from myasthenia gravis patients and active complement. Myasthenia gravis is an autoimmune disorder that selectively targets neuromuscular junctions. We saw a reversible reduction in the amplitude of muscle contractions, representing a surrogate marker for the characteristic loss of muscle strength seen in this disease. The ability to recapitulate key aspects of disease pathology and its symptomatic treatment suggests that this neuromuscular junction assay has significant potential for modeling of neuromuscular disease and regeneration. Copyright © 2016 Elsevier Inc. All rights reserved.
ESTIMATION MODEL OF RESIDUAL LIFE-TIME OF LOCOMOTIVE FRAME BOGIE WITH ALLOWANCE FOR CREEP
Directory of Open Access Journals (Sweden)
V. R. Skalskyi
2014-12-01
Full Text Available Purpose. The problem of determining the residual life of frame bogie elements of locomotives is a great importance for predicting their work safely and avoidance potential failures on the track. This especially concern cases when such elements have creep-fatigue cracks which grow under action of cyclic loading with excerpts T1 in the cycle and reach their critical size. Here the question of the propagation of such defects (cracks arises, their kinetics and about the period of subcritical cracks growth. The aim is to develop a calculation model for determination the period of subcritical creep-fatigue cracks growth in the bogies frames of electric locomotive. The model takes into account the basic parameters of load, geometry of the construction element and cracks. Methodology. The calculation model for determination the period of subcritical creep-fatigue cracks growth in structural elements of frame under conditions of variable load time has been formulated. It is based on the first law of thermodynamics concerning to mechanics of solids slow fracture at low temperature creep and variable loadings. It is assumed that the period of unsteady creep dominates here (the first section of the creep curve. Low-temperature creep is creep of materials at temperatures T0 < 0,5Tmp, where Tmp − the melting point of the material. Findings. The analytical formula for the determination of the stress intensity factor of truck bolster with technological hole has been obtained. It is shown that by experimentally established constants of the material using the proposed analytical relations can easily determine residual resource of the bogie frame elements. Originality. The new mathematical model for describing the kinetics of creep-fatigue cracks growth in the frames bogies of electric locomotive under variable in time loadings with various time excerpts and on this base the period determination of subcritical crack growth has been proposed. Practical value
A model that allows teachers to reflect on their ict approaches
DEFF Research Database (Denmark)
Kjeldsen, Lars Peter Bech; Kjærgaard, Hanne Wacher
2016-01-01
The increased global availability of technology and its entry onto the educational stage of Higher Education (HE) requires changes in the way we think of education and learning. This article will briefly describe and shed light on the new conditions for learning that are challenging our traditional...... to these elements. The model has been developed through a three-year action-research project, and this article will show the results of an intervention study carried out by the research team in collaboration with eight teachers and their students across a variety of educational programs in the fall of 2016. Against...
A solid-fluid mixture model allowing for solid dilatation under external pressure
Sciarra, Giulio; Hutter, Kolumban
2010-01-01
A sponge subjected to an increase of the outside fluid pressure expands its volume but nearly mantains its true density and thus gives way to an increase of the interstitial volume. This behaviour, not yet properly described by solid-fluid mixture theories, is studied here by using the Principle of Virtual Power with the most simple dependence of the free energy as a function of the partial apparent densities of the solid and the fluid. The model is capable of accounting for the above mentioned dilatational behaviour, but in order to isolate its essential features more clearly we compromise on the other aspects of deformation.
Ebadzadeh, M; Tondu, B; Darlot, C
2005-01-01
The command and control of limb movements by the cerebellar and reflex pathways are modeled by means of a circuit whose structure is deduced from functional constraints. One constraint is that fast limb movements must be accurate although they cannot be continuously controlled in closed loop by use of sensory signals. Thus, the pathways which process the motor orders must contain approximate inverse functions of the bio-mechanical functions of the limb and of the muscles. This can be achieved by means of parallel feedback loops, whose pattern turns out to be comparable to the anatomy of the cerebellar pathways. They contain neural networks able to anticipate the motor consequences of the motor orders, modeled by artificial neural networks whose connectivity is similar to that of the cerebellar cortex. These networks learn the direct biomechanical functions of the limbs and muscles by means of a supervised learning process. Teaching signals calculated from motor errors are sent to the learning sites, as, in the cerebellum, complex spikes issued from the inferior olive are conveyed to the Purkinje cells by climbing fibers. Learning rules are deduced by a differential calculation, as classical gradient rules, and they account for the long term depression which takes place in the dendritic arborizations of the Purkinje cells. Another constraint is that reflexes must not impede voluntary movements while remaining at any instant ready to oppose perturbations. Therefore, efferent copies of the motor orders are sent to the interneurones of the reflexes, where they cancel the sensory-motor consequences of the voluntary movements. After learning, the model is able to drive accurately, both in velocity and position, angular movements of a rod actuated by two pneumatic McKibben muscles. Reflexes comparable to the myotatic and tendinous reflexes, and stabilizing reactions comparable to the cerebellar sensory-motor reactions, reduce efficiently the effects of perturbing torques
Feedback models allowing estimation of thresholds for self-promoting body weight gain
DEFF Research Database (Denmark)
Christiansen, Edmund; Swann, Andrew; Sørensen, Thorkild I. A.
2008-01-01
. The difference between the two situations is typically an energy imbalance of about 1% over a long period of time. THEORY: Weight gain increases basal metabolic rate. Weight gain is often associated with a decrease in physical activity, although not to such an extent that it prevents an increase in total energy...... expenditure and energy intake. Dependent on the precise balance between these effects of weight gain, they may make the body weight unstable and tend to further promote weight gain. With the aim of identifying the thresholds beyond which such self-promoting weight gain may take place, we develop a simple...... cases do they take values that make weight gain self-promoting. RESULTS: We determine the quantitative conditions under which body weight gain becomes self-promoting. We find that these conditions can easily be met, and that they are so small that they are not observable with currently available...
DEFF Research Database (Denmark)
Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.;
2015-01-01
A model is proposed capable of accounting for the local electric field increase in front of the lightning stepped leader up to magnitudes allowing front electrons to overcome the runaway energy threshold and thus to initiate relativistic runaway electron avalanches capable of generating X...
Cos, Oriol; Ramon, Ramon; Montesinos, José Luis; Valero, Francisco
2006-09-05
A predictive control algorithm coupled with a PI feedback controller has been satisfactorily implemented in the heterologous Rhizopus oryzae lipase production by Pichia pastoris methanol utilization slow (Mut(s)) phenotype. This control algorithm has allowed the study of the effect of methanol concentration, ranging from 0.5 to 1.75 g/L, on heterologous protein production. The maximal lipolytic activity (490 UA/mL), specific yield (11,236 UA/g(biomass)), productivity (4,901 UA/L . h), and specific productivity (112 UA/g(biomass)h were reached for a methanol concentration of 1 g/L. These parameters are almost double than those obtained with a manual control at a similar methanol set-point. The study of the specific growth, consumption, and production rates showed different patterns for these rates depending on the methanol concentration set-point. Results obtained have shown the need of implementing a robust control scheme when reproducible quality and productivity are sought. It has been demonstrated that the model-based control proposed here is a very efficient, robust, and easy-to-implement strategy from an industrial application point of view.
Ludwig, C; Grimmer, S; Seyfarth, A; Maus, H-M
2012-09-21
The spring-loaded inverted pendulum (SLIP) model is a well established model for describing bouncy gaits like human running. The notion of spring-like leg behavior has led many researchers to compute the corresponding parameters, predominantly stiffness, in various experimental setups and in various ways. However, different methods yield different results, making the comparison between studies difficult. Further, a model simulation with experimentally obtained leg parameters typically results in comparatively large differences between model and experimental center of mass trajectories. Here, we pursue the opposite approach which is calculating model parameters that allow reproduction of an experimental sequence of steps. In addition, to capture energy fluctuations, an extension of the SLIP (ESLIP) is required and presented. The excellent match of the models with the experiment validates the description of human running by the SLIP with the obtained parameters which we hence call dynamical leg parameters.
Tan, Yikun; Rivera, Jimmy G Lafontaine; Contador, Carolina A; Asenjo, Juan A; Liao, James C
2011-01-01
Dynamic models of metabolism are instrumental for gaining insight and predicting possible outcomes of perturbations. Current approaches start from the selection of lumped enzyme kinetics and determine the parameters within a large parametric space. However, kinetic parameters are often unknown and obtaining these parameters requires detailed characterization of enzyme kinetics. In many cases, only steady-state fluxes are measured or estimated, but these data have not been utilized to construct dynamic models. Here, we extend the previously developed Ensemble Modeling methodology by allowing various kinetic rate expressions and employing a more efficient solution method for steady states. We show that anchoring the dynamic models to the same flux reduces the allowable parameter space significantly such that sampling of high dimensional kinetic parameters becomes meaningful. The methodology enables examination of the properties of the model's structure, including multiple steady states. Screening of models based on limited steady-state fluxes or metabolite profiles reduces the parameter space further and the remaining models become increasingly predictive. We use both succinate overproduction and central carbon metabolism in Escherichia coli as examples to demonstrate these results. Published by Elsevier Inc.
Effects of nursery floor space allowance on growth, physiology, and immunology of replacement gilts
Callahan, Stuart Russell
2013-01-01
In U.S. swine herds, sow removal rates due to death and voluntary and involuntary culling exceed 50% annually. This loss poses an economic problem for producers because the cost of acquiring replacement females is great. Although research has shown that crowding in the nursery has negative impacts on growth, research describing effects of crowding on subsequent reproductive performance and longevity in sows is lacking. This experiment was conducted to determine the impacts of crowding during ...
DEFF Research Database (Denmark)
Jensen, Margit Bak; Studnitz, Merete; Pedersen, Lene Juul
2010-01-01
The experiment aimed to investigate the effect of type of rooting material and space allowance on explorative and abnormal behaviour in growing pigs. Thirty-six pens with partly slatted concrete floor were allocated to one of four treatments: (1) low space allowance and maize silage as rooting...... material, (2) high space allowance and maize silage as rooting material, (3) low space allowance and straw as rooting material, and (4) high space allowance and straw as rooting material. Pens with low space allowance had 17 pigs (0.64m2/pig), while pens with high space allowance had 11 pigs (1.0m2/pig......). Behaviour was recorded by instantaneous sampling during 1 h before and 1 h after the daily allocation of rooting material at 10.00 h, as well as during 1 h in the afternoon starting at 13.00 h. Observations were conducted at 13 and 20 weeks of age. Pigs offered maize silage manipulated rooting material more...
Kim, K H; Kim, K S; Kim, J E; Kim, D W; Seol, K H; Lee, S H; Chae, B J; Kim, Y H
2017-03-01
This study was conducted to determine the optimal space allowance for maximizing the growth performance of pigs at each of the following five growth stages (based on BW ranges): stage 1, 11 to 25 kg BW; stage 2, 25 to 45 kg BW; stage 3, 45 to 65 kg BW; stage 4, 65 to 85 kg BW; and stage 5, 85 to 110 kg BW. A total of 1590 crossbred (Landrace×Yorkshire×Duroc) pigs were assigned to one of four treatments at each growth stage, with three replicates each. Pen areas at each growth stage were 6, 11, 16, 19.5 and 20 m2 for stages 1 to 5, respectively. Space allowances for the four treatments at each growth stage were modified by varying the number of pigs per pen (22, 25, 28 and 31 pigs in T1, T2, T3 and T4, respectively). Blood samples were collected on the final day of each growth stage. The average daily gain (ADG) decreased significantly with decreased space allowances at all growth stages, except at stage 2. Average daily feed intake (ADFI) was not significantly affected by space allowances at stages 1 to 4; however, at stage 5, there was a linear effect of space allowance on ADFI. Thus, the feed conversion ratio showed results similar to those for ADG. Serum cortisol concentrations, indicating the level of stress response, increased as space allowances decreased. The highest serum cortisol concentrations were observed in T3 at stages 2 to 5. Serum tumor necrosis factor-α levels were significantly higher in association with a small space allowance than with at large space allowance at stages 2, 4 and 5. Serum interleukin-1β levels also increased in a significant linear manner at every growth stage in pigs reared at a low space allowance, except at stage 4 (P=0.068). This study found that limited space allowance decreases the growth performance of pigs and induces stress and inflammatory responses. We confirmed that no significant effect of space allowance on growth performance and serum cortisol concentrations are observed between T1 and T2 across all growth
DEFF Research Database (Denmark)
Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.;
2015-01-01
A model is proposed capable of accounting for the local electric field increase in front of the lightning stepped leader up to magnitudes allowing front electrons to overcome the runaway energy threshold and thus to initiate relativistic runaway electron avalanches capable of generating X......-ray and ray bursts observed in negative lightning leader. The model is based on an idea that an ionization wave, propagating in a preionized channel, is being focused, such that its front remains narrow and the front electric field is being enhanced. It is proposed that when a space leader segment, formed...... ahead of a negative lightning leader, connects to the leader, the electric potential of the leader is transferred through the space leader in an ionizing wave that continues into the partly ionized channels of preexisting streamers of the space leader. It is shown with numerical simulations...
DEFF Research Database (Denmark)
Duve, Linda Rosager; Weary, D.M.; Halekoh, Ulrich
2012-01-01
responses to restraint and increased play and competitive success. The high milk allowance increased play but reduced competitive success after grouping. Lower responses to restraint indicated less responsiveness to stress. Play is considered an indicator of positive welfare, and competitive success helps......The aim of this study was to investigate the effects of social contact and milk allowance on social behavior, play behavior, and responses to handling in dairy calves. Forty test calves and 16 companion calves were allocated to 1 of 5 treatments from birth to 4 wk of age: (1) housed singly and fed...... with the dam, and pair-housed calves struggled at an intermediate level. Play behavior was recorded for 20 min/wk after the provision of fresh straw; calves housed singly and fed a low milk allowance spent less time playing than did calves in all other treatments. Three days after grouping, calves were...
Kiyan, I N; Vorozhtsov, S B
2002-01-01
The Cyclotron Analytic Model Program (CAMP) written in C++ with the use of Visual C++ is described. The program is intended for the mean magnetic field calculation of the isochronous cyclotron with allowance for flutter. The program algorithm was developed on the basis of the paper 'Calculation of Isochronous Fields for Sector-Focused Cyclotrons', by M.M.Gordon (Particle Accelerators. 1983. V.13). The accuracy of the calculations, performed with this program, was tested with the use of maps of isochronous magnetic fields of different cyclotrons with the azimuthally varying fields - AVF cyclotrons, in which the ion beams were produced. The calculation by CAMP showed that the isochronous mean magnetic field curve for the measured magnetic field, in which the ion beam was produced, exactly corresponded to the curve of the isochronous mean magnetic field, calculated with the allowance for flutter for all the AVF cyclotrons that were considered. As is evident from the calculations, this program can be used for cal...
Eze, Valentine C; Phan, Anh N; Harvey, Adam P
2014-03-01
A more robust kinetic model of base-catalysed transesterification than the conventional reaction scheme has been developed. All the relevant reactions in the base-catalysed transesterification of rapeseed oil (RSO) to fatty acid methyl ester (FAME) were investigated experimentally, and validated numerically in a model implemented using MATLAB. It was found that including the saponification of RSO and FAME side reactions and hydroxide-methoxide equilibrium data explained various effects that are not captured by simpler conventional models. Both the experiment and modelling showed that the "biodiesel reaction" can reach the desired level of conversion (>95%) in less than 2min. Given the right set of conditions, the transesterification can reach over 95% conversion, before the saponification losses become significant. This means that the reaction must be performed in a reactor exhibiting good mixing and good control of residence time, and the reaction mixture must be quenched rapidly as it leaves the reactor.
Directory of Open Access Journals (Sweden)
Zhao Yang
2015-01-01
Full Text Available By using optical microscope (OM, scanning electron microscope (SEM, transmission electron microscope (TEM, X-ray diffraction (XRD, electron back scattered diffraction (EBSD and tensile test, the effect of annealing temperature on microstructure and mechanical properties of a high Al-low Si TRIP steel was investigated. The results show that TRIP effect can be obtained when annealing temperature is above Ac3 due to the existence of δ-ferrite in this high Al-low Si TRIP steel. That is to say, the microstructure consisting of ferrite, bainite and retained austenite can be obtained when annealing temperature is above Ac3. Furthermore, the tensile strength and the product of strength and elongation decrease with increasing annealing temperature when annealing temperature is above Ac3.
Free-access stalls allow sows to choose the protection of a stall or use of a shared group space. This study investigated the effect of group space width: 0.91 (SS), 2.13 (IS), and 3.05 (LS) m on the health, production, behavior, and welfare of gestating sows. At gestational day (GD) 35.4 ± 2.3, 21 ...
Directory of Open Access Journals (Sweden)
Arnau Benet
2015-01-01
Full Text Available Aim. To evaluate the feasibility of implanting 3D-printed brain aneurysm model in human cadavers and to assess their utility in neurosurgical research, complex case management/planning, and operative training. Methods. Two 3D-printed aneurysm models, basilar apex and middle cerebral artery, were generated and implanted in four cadaveric specimens. The aneurysms were implanted at the same anatomical region as the modeled patient. Pterional and orbitozygomatic approaches were done on each specimen. The aneurysm implant, manipulation capabilities, and surgical clipping were evaluated. Results. The 3D aneurysm models were successfully implanted to the cadaveric specimens’ arterial circulation in all cases. The features of the neck in terms of flexibility and its relationship with other arterial branches allowed for the practice of surgical maneuvering characteristic to aneurysm clipping. Furthermore, the relationship of the aneurysm dome with the surrounding structures allowed for better understanding of the aneurysmal local mass effect. Noticeably, all of these observations were done in a realistic environment provided by our customized embalming model for neurosurgical simulation. Conclusion. 3D aneurysms models implanted in cadaveric specimens may represent an untapped training method for replicating clip technique; for practicing certain approaches to aneurysms specific to a particular patient; and for improving neurosurgical research.
Keane, M P; McGee, M; O'Riordan, E G; Kelly, A K; Earley, B
2017-06-21
Accommodating cattle indoors during the winter is widely practiced throughout Europe. There is currently no legislation surrounding the space allowance and floor type that should be provided to cattle during this time, however, concerns have been raised regarding the type of housing systems currently in use. The objective of the study was to investigate the effect of space allowance and floor type on performance and welfare of finishing beef heifers. Continental crossbred heifers (n=240: mean initial live; weight, 504 (SD 35.8) kg) were blocked by breed, weight and age and randomly assigned to one of four treatments; (i) 3.0 m2, (ii) 4.5 m2 and (iii) 6.0 m2 space allowance per animal on a fully slatted concrete floor and (iv) 6.0 m2 space allowance per animal on a straw-bedded floor, for 105 days. Heifers were offered a total mixed ration ad libitum. Dry matter intake was recorded on a pen basis and refusals were weighed back twice weekly. Heifers were weighed, dirt scored and blood sampled every 3 weeks. Whole blood was analysed for complete cell counts and serum samples were assayed for metabolite concentrations. Behaviour was recorded continuously using IR cameras from days 70 to 87. Heifers' hooves were inspected for lesions at the start of the study and again after slaughter. Post-slaughter, carcass weight, conformation and fat scores and hide weight were recorded. Heifers housed at 4.5 m2 had a greater average daily live weight gain (ADG) than those on both of the other concrete slat treatments; however, space allowance had no effect on carcass weight. Heifers accommodated on straw had a greater ADG (0.15 kg) (Pfloor type had no effect on the number of hoof lesions gained or on any of the haematological or metabolic variables measured. It was concluded that increasing space allowance above 3.0 m2/animal on concrete slats was of no benefit to animal performance but it did improve animal cleanliness. Housing heifers on straw instead of concrete slats improved
Thomson, Kyle E; White, H Steve
2014-12-30
Nonadherence to a physician-prescribed therapeutic intervention is a costly, dangerous, and sometimes fatal concern in healthcare. To date, the study of nonadherence has been constrained to clinical studies. The novel approach described herein allows for the preclinical study of nonadherence in etiologically relevant disease animal model systems. The method herein describes a novel computer-automated pellet delivery system which allows for the study of nonadherence in animals. This system described herein allows for tight experimenter control of treatment using a drug-in-food protocol. Food-restricted animals receive either medicated or unmedicated pellets, designed to mimic either "taking" or "missing" a drug. The system described permits the distribution of medicated or unmedicated food pellets on an experimenter-defined feeding schedule. The flexibility of this system permits the delivery of drug according to the known pharmacokinetics of investigational drugs. Current clinical adherence research relies on medication-event monitoring system (MEMS) tracking caps, which allows clinicians to directly monitor patient adherence. However, correlating the effects of nonadherence to efficacy still relies on the accuracy of patient journals. This system allows for the design of studies to address the impact of nonadherence in an etiologically relevant animal model. Given methodological and ethical concerns of designing clinical studies of nonadherence, animal studies are critical to better understand medication adherence. While the system described was designed to measure the impact of nonadherence on seizure control, it is clear that the utility of this system extends beyond epilepsy to include other disease states. Copyright © 2014 Elsevier B.V. All rights reserved.
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Esfandiar, Habib; KoraYem, Moharam Habibnejad [Islamic Azad University, Tehran (Iran, Islamic Republic of)
2015-09-15
In this study, the researchers try to examine nonlinear dynamic analysis and determine Dynamic load carrying capacity (DLCC) in flexible manipulators. Manipulator modeling is based on Timoshenko beam theory (TBT) considering the effects of shear and rotational inertia. To get rid of the risk of shear locking, a new procedure is presented based on mixed finite element formulation. In the method proposed, shear deformation is free from the risk of shear locking and independent of the number of integration points along the element axis. Dynamic modeling of manipulators will be done by taking into account small and large deformation models and using extended Hamilton method. System motion equations are obtained by using nonlinear relationship between displacements-strain and 2nd PiolaKirchoff stress tensor. In addition, a comprehensive formulation will be developed to calculate DLCC of the flexible manipulators during the path determined considering the constraints end effector accuracy, maximum torque in motors and maximum stress in manipulators. Simulation studies are conducted to evaluate the efficiency of the method proposed taking two-link flexible and fixed base manipulators for linear and circular paths into consideration. Experimental results are also provided to validate the theoretical model. The findings represent the efficiency and appropriate performance of the method proposed.
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Geraldine M Clarke
Full Text Available Multiple rare variants either within or across genes have been hypothesised to collectively influence complex human traits. The increasing availability of high throughput sequencing technologies offers the opportunity to study the effect of rare variants on these traits. However, appropriate and computationally efficient analytical methods are required to account for collections of rare variants that display a combination of protective, deleterious and null effects on the trait. We have developed a novel method for the analysis of rare genetic variation in a gene, region or pathway that, by simply aggregating summary statistics at each variant, can: (i test for the presence of a mixture of effects on a trait; (ii be applied to both binary and quantitative traits in population-based and family-based data; (iii adjust for covariates to allow for non-genetic risk factors and; (iv incorporate imputed genetic variation. In addition, for preliminary identification of promising genes, the method can be applied to association summary statistics, available from meta-analysis of published data, for example, without the need for individual level genotype data. Through simulation, we show that our method is immune to the presence of bi-directional effects, with no apparent loss in power across a range of different mixtures, and can achieve greater power than existing approaches as long as summary statistics at each variant are robust. We apply our method to investigate association of type-1 diabetes with imputed rare variants within genes in the major histocompatibility complex using genotype data from the Wellcome Trust Case Control Consortium.
Yaghini, N.; Iedema, P.D.
2015-01-01
Modeling of the mol. wt. distribution (MWD) of low-d. Polyethylene (ldPE) has been carried out for a tubular reactor under realistic non-isothermal conditions and for a series of CSTR's. The model allows for the existence of multiradicals and the occurrence of gelation. The deterministic model is
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Loreen eHertäg
2012-09-01
Full Text Available For large-scale network simulations, it is often desirable to have computationally tractable, yet in a defined sense still physiologically valid neuron models. In particular, these models should be able to reproduce physiological measurements, ideally in a predictive sense, and under different input regimes in which neurons may operate in vivo. Here we present an approach to parameter estimation for a simple spiking neuron model mainly based on standard f-I curves obtained from in vitro recordings. Such recordings are routinely obtained in standard protocols and assess a neuron's response under a wide range of mean input currents. Our fitting procedure makes use of closed-form expressions for the firing rate derived from an approximation to the adaptive exponential integrate-and-fire (AdEx model. The resulting fitting process is simple and about two orders of magnitude faster compared to methods based on numerical integration of the differential equations. We probe this method on different cell types recorded from rodent prefrontal cortex. After fitting to the f-I current-clamp data, the model cells are tested on completely different sets of recordings obtained by fluctuating ('in-vivo-like' input currents. For a wide range of different input regimes, cell types, and cortical layers, the model could predict spike times on these test traces quite accurately within the bounds of physiological reliability, although no information from these distinct test sets was used for model fitting. Further analyses delineated some of the empirical factors constraining model fitting and the model's generalization performance. An even simpler adaptive LIF neuron was also examined in this context. Hence, we have developed a 'high-throughput' model fitting procedure which is simple and fast, with good prediction performance, and which relies only on firing rate information and standard physiological data widely and easily available.
Effect of Floor Space Allowance on Pig Productivity across Stages of Growth: A Field-scale Analysis.
Lee, Joon H; Choi, Hong L; Heo, Yong J; Chung, Yoon P
2016-05-01
A total of 152 pig farms were randomly selected from the five provinces in South Korea. During the experiment, the average temperature and relative humidity was 24.7°C and 74% in summer and 2.4°C and 53% in winter, respectively. The correlation between floor space allowance (FSA) and productivity index was analyzed, including non-productive sow days (NPD), number of weaners (NOW), survival rate (SR), appearance rate of A-grade pork (ARA), and days at a slaughter weight of 110 kg (d-SW) at different growth stages. The objectives of the present study were i) to determine the effect of FSA on the pig productivity index and ii) to suggest the minimum FSA for pigs based on scientific baseline data. For the pregnant sow, NPD could be decreased if pregnant sows were raised with a medium level (M) of FSA (3.10 to 3.67 m(2)/head) while also keeping the pig house clean which improves hygiene, and operating the ventilation system properly. For the farrowing sows, the NOW tended to decrease as the FSA increased. Similarly, a high level of FSA (H) is significantly negative with weaner SR of farrowing sows (p-value = 0.017), indicating this FSA tends to depress SR. Therefore, a FSA of 2.30 to 6.40 m(2)/head (very low) could be appropriate for weaners because a limited space can provide a sense of security and protection from external interruptions. The opposite trend was observed that an increase in floor space (>1.12 m(2)/head) leads to increase the SR of growing pigs. For the fattening pigs, H level of FSA was negatively correlated with SR, but M level of FSA was positively correlated with SR, indicating that SR tended to increase with the FSA of 1.10 to 1.27 m(2)/head. In contrast, ARA of male fattening pigs showed opposite results. H level of FSA (1.27 to 1.47 m(2)/head) was suggested to increase productivity because ARA was most affected by H level of space allowance with positive correlation (R(2) = 0.523). The relationship between the FSA and d-SW of fattening pigs was
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Marius Enachescu
2013-09-01
Full Text Available Model membrane approaches have attracted much attention in biomedical sciences to investigate and simulate biological processes. The application of model membrane systems for biosensor measurements is partly restricted by the fact that the integrity of membranes critically depends on the maintenance of an aqueous surrounding, while various biosensors require a preconditioning of dry sensors. This is for example true for the well-established surface acoustic wave (SAW biosensor SAM®5 blue. Here, a simple drying procedure of sensor-supported model membranes is introduced using the protective disaccharide trehalose. Highly reproducible model membranes were prepared by the Langmuir-Blodgett technique, transferred to SAW sensors and supplemented with a trehalose solution. Membrane rehydration after dry incorporation into the SAW device becomes immediately evident by phase changes. Reconstituted model membranes maintain their full functionality, as indicated by biotin/avidin binding experiments. Atomic force microscopy confirmed the morphological invariability of dried and rehydrated membranes. Approximating to more physiological recognition phenomena, the site-directed immobilization of the integrin VLA-4 into the reconstituted model membrane and subsequent VCAM-1 ligand binding with nanomolar affinity were illustrated. This simple drying procedure is a novel way to combine the model membrane generation by Langmuir-Blodgett technique with SAW biosensor measurements, which extends the applicability of SAM®5 blue in biomedical sciences.
Amundsen, David Skålid; Thøgersen, Kjetil; Trømborg, Jørgen; Malthe-Sørenssen, Anders
2011-01-01
We study the dynamic behaviour of 1D spring-block models of friction when the external loading is applied from a side, and not on all blocks like in the classical Burridge-Knopoff-like models. Such a change in the loading yields specific difficulties, both from numerical and physical viewpoints. To address some of these difficulties and clarify the precise role of a series of model parameters, we start with the minimalistic model by Maegawa et al. (Tribol. Lett. 38, 313, 2010) which was proposed to reproduce their experiments about precursors to frictional sliding in the stick-slip regime. By successively adding (i) an internal viscosity, (ii) an interfacial stiffness and (iii) an initial tangential force distribution at the interface, we manage to (i) avoid the model's unphysical stress fluctuations, (ii) avoid its unphysical dependence on the spatial resolution and (iii) improve its agreement with the experimental results, respectively. Based on the behaviour of this improved 1D model, we develop an analyti...
Jeong, Won Joong; Park, Youn-Il; Suh, KyeHong; Raven, John A; Yoo, Ook Joon; Liu, Jang Ryol
2002-05-01
We generated transgenic tobacco (Nicotiana tabacum cv Xanthi) plants that contained only one to three enlarged chloroplasts per leaf mesophyll cell by introducing NtFtsZ1-2, a cDNA for plastid division. These plants were used to investigate the advantages of having a large population of small chloroplasts rather than a few enlarged chloroplasts in a leaf mesophyll cell. Despite the similarities in photosynthetic components and ultrastructure of photosynthetic machinery between wild-type and transgenic plants, the overall growth of transgenic plants under low- and high-light conditions was retarded. In wild-type plants, the chloroplasts moved toward the face position under low light and toward the profile position under high-light conditions. However, chloroplast rearrangement in transgenic plants in response to light conditions was not evident. In addition, transgenic plant leaves showed greatly diminished changes in leaf transmittance values under both light conditions, indicating that chloroplast rearrangement was severely retarded. Therefore, under low-light conditions the incomplete face position of the enlarged chloroplasts results in decreased absorbance of light energy. This, in turn, reduces plant growth. Under high-light conditions, the amount of absorbed light exceeds the photosynthetic utilization capacity due to the incomplete profile position of the enlarged chloroplasts, resulting in photodamage to the photosynthetic machinery, and decreased growth. The presence of a large number of small and/or rapidly moving chloroplasts in the cells of higher land plants permits more effective chloroplast phototaxis and, hence, allows more efficient utilization of low-incident photon flux densities. The photosynthetic apparatus is, consequently, protected from damage under high-incident photon flux densities.
Yaghini, N.; Iedema, P.D.
2015-01-01
Modeling of the mol. wt. distribution (MWD) under circumstances of low-d. polyethylene (ldPE) has been carried out for a tubular reactor under realistic non-isothermal conditions and for a series of CSTR's (Yaghini and Iedema, in press). The model allows for the existence of multiradicals and the
Zaccagnini, Germana; Palmisano, Anna; Canu, Tamara; Maimone, Biagina; Lo Russo, Francesco M; Ambrogi, Federico; Gaetano, Carlo; De Cobelli, Francesco; Del Maschio, Alessandro; Esposito, Antonio; Martelli, Fabio
2015-01-01
Magnetic resonance imaging (MRI) provides non-invasive, repetitive measures in the same individual, allowing the study of a physio-pathological event over time. In this study, we tested the performance of 7 Tesla multi-parametric MRI to monitor the dynamic changes of mouse skeletal muscle injury and regeneration upon acute ischemia induced by femoral artery dissection. T2-mapping (T2 relaxation time), diffusion-tensor imaging (Fractional Anisotropy) and perfusion by Dynamic Contrast-Enhanced MRI (K-trans) were measured and imaging results were correlated with histological morphometric analysis in both Gastrocnemius and Tibialis anterior muscles. We found that tissue damage positively correlated with T2-relaxation time, while myofiber regeneration and capillary density positively correlated with Fractional Anisotropy. Interestingly, K-trans positively correlated with capillary density. Accordingly, repeated MRI measurements between day 1 and day 28 after surgery in ischemic muscles showed that: 1) T2-relaxation time rapidly increased upon ischemia and then gradually declined, returning almost to basal level in the last phases of the regeneration process; 2) Fractional Anisotropy dropped upon ischemic damage induction and then recovered along with muscle regeneration and neoangiogenesis; 3) K-trans reached a minimum upon ischemia, then progressively recovered. Overall, Gastrocnemius and Tibialis anterior muscles displayed similar patterns of MRI parameters dynamic, with more marked responses and less variability in Tibialis anterior. We conclude that MRI provides quantitative information about both tissue damage after ischemia and the subsequent vascular and muscle regeneration, accounting for the differences between subjects and, within the same individual, between different muscles.
Scheit, Katrin; Bauer, Georg
2015-03-01
Salicylic acid and anthocyanidins are known as plant-derived antioxidants, but also can provoke paradoxically seeming prooxidant effects in vitro. These prooxidant effects are connected to the potential of salicylic acid and anthocyanidins to induce apoptosis selectively in tumor cells in vitro and to inhibit tumor growth in animal models. Several epidemiological studies have shown that salicylic acid and its prodrug acetylsalicylic acid are tumor-preventive for humans. The mechanism of salicylic acid- and anthocyanidin-dependent antitumor effects has remained enigmatic so far. Extracellular apoptosis-inducing reactive oxygen species signaling through the NO/peroxynitrite and the HOCl signaling pathway specifically induces apoptosis in transformed cells. Tumor cells have acquired resistance against intercellular reactive oxygen species signaling through expression of membrane-associated catalase. Here, we show that salicylic acid and anthocyanidins inactivate tumor cell protective catalase and thus reactive apoptosis-inducing intercellular reactive oxygen species signaling of tumor cells and the mitochondrial pathway of apoptosis Salicylic acid inhibits catalase directly through its potential to transform compound I of catalase into the inactive compound II. In contrast, anthocyanidins provoke a complex mechanism for catalase inactivation that is initiated by anthocyanidin-mediated inhibition of NO dioxygenase. This allows the formation of extracellular singlet oxygen through the reaction between H(2)O(2) and peroxynitrite, amplification through a caspase8-dependent step and subsequent singlet oxygen-mediated inactivation of catalase. The combination of salicylic acid and anthocyanidins allows for a remarkable synergistic effect in apoptosis induction. This effect may be potentially useful to elaborate novel therapeutic approaches and crucial for the interpretation of epidemiological results related to the antitumor effects of secondary plant compounds.
Hohwieler, Meike; Illing, Anett; Hermann, Patrick C; Mayer, Tobias; Stockmann, Marianne; Perkhofer, Lukas; Eiseler, Tim; Antony, Justin S; Müller, Martin; Renz, Susanne; Kuo, Chao-Chung; Lin, Qiong; Sendler, Matthias; Breunig, Markus; Kleiderman, Susanne M; Lechel, André; Zenker, Martin; Leichsenring, Michael; Rosendahl, Jonas; Zenke, Martin; Sainz, Bruno; Mayerle, Julia; Costa, Ivan G; Seufferlein, Thomas; Kormann, Michael; Wagner, Martin; Liebau, Stefan; Kleger, Alexander
2017-03-01
The generation of acinar and ductal cells from human pluripotent stem cells (PSCs) is a poorly studied process, although various diseases arise from this compartment. We designed a straightforward approach to direct human PSCs towards pancreatic organoids resembling acinar and ductal progeny. Extensive phenotyping of the organoids not only shows the appropriate marker profile but also ultrastructural, global gene expression and functional hallmarks of the human pancreas in the dish. Upon orthotopic transplantation into immunodeficient mice, these organoids form normal pancreatic ducts and acinar tissue resembling fetal human pancreas without evidence of tumour formation or transformation. Finally, we implemented this unique phenotyping tool as a model to study the pancreatic facets of cystic fibrosis (CF). For the first time, we provide evidence that in vitro, but also in our xenograft transplantation assay, pancreatic commitment occurs generally unhindered in CF. Importantly, cystic fibrosis transmembrane conductance regulator (CFTR) activation in mutated pancreatic organoids not only mirrors the CF phenotype in functional assays but also at a global expression level. We also conducted a scalable proof-of-concept screen in CF pancreatic organoids using a set of CFTR correctors and activators, and established an mRNA-mediated gene therapy approach in CF organoids. Taken together, our platform provides novel opportunities to model pancreatic disease and development, screen for disease-rescuing agents and to test therapeutic procedures. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Energy Technology Data Exchange (ETDEWEB)
Dobranich, D.
1987-08-01
Calculations were performed to determine the mass of a space-based platform as a function of the maximum-allowed operating temperature of the electrical equipment within the platform payload. Two computer programs were used in conjunction to perform these calculations. The first program was used to determine the mass of the platform reactor, shield, and power conversion system. The second program was used to determine the mass of the main and secondary radiators of the platform. The main radiator removes the waste heat associated with the power conversion system and the secondary radiator removes the waste heat associated with the platform payload. These calculations were performed for both Brayton and Rankine cycle platforms with two different types of payload cooling systems: a pumped-loop system (a heat exchanger with a liquid coolant) and a refrigerator system. The results indicate that increases in the maximum-allowed payload temperature offer significant platform mass savings for both the Brayton and Rankine cycle platforms with either the pumped-loop or refrigerator payload cooling systems. Therefore, with respect to platform mass, the development of high temperature electrical equipment would be advantageous. 3 refs., 24 figs., 7 tabs.
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Cozar, A.; Rodriguez, A.I.; Garijo, P.; Calvo, L.; Vergara, H.
2016-11-01
A total of 72 male lambs of Merina breed were sampled in a 3×2 factorial design, testing three different space allowances treatment (SA) during transport [0.16 m2/animal (SAL; n=24); 0.20 m2/animal (SAM; n=24) and 0.30 m2/animal (SAH; n=24)] and two lairage treatments (TL) during 18 h previous slaughter [fasting (FAST; n=36) vs feeding (FEED; n=36)] on welfare physiological indicators. After transport, glucose and lactate dehydrogenase (LDH) were highest in SAM group and lowest in SAH one (p<0.05). SAL showed intermediate values for both parameters. SA did not affect the rest of the blood parameters studied. TL-FAST treatment decreased glucose values (p<0.001) while increased LDH (p<0.001). Fasting caused an increase (p<0.05) of Red Blood Cell Count values in SAM group. Feed deprivation did not affect cortisol or adrenaline values. Noradrenaline value was higher (p<0.001) in TL-FAST groups than in TL-FEED. In conclusion, under the conditions of this study, a range of space allowance during transport between 0.16 and 0.30 m2/lamb could be recommended without showing major changes on welfare physiological indicators; and feeding could be more appropriate than fasting during lairage. (Author)
Volkov, I. A.; Egunov, V. V.; Igumnov, L. A.; Kazakov, D. A.; Korotkikh, Yu. G.; Mitenkov, F. M.
2015-11-01
A mathematical model is developed within the framework of equations of damaged medium mechanics to describe the processes of viscoplastic straining and damage accumulation in structural steels with allowance for fatigue and creep of the material. A model of damage summation due to interaction of low-cycle fatigue and creep of the material is proposed. Material parameters and scalar functions of equations of mechanics of damaged media are determined. Viscoplastic straining and fatigue-induced damage accumulation in 08Kh18N10T and 12Kh18N9 are studied numerically, and the data obtained are compared with available results of physical experiments.
Shen, Yao An; Shyu, Ing Luen; Lu, Maggie; He, Chun Lin; Hsu, Yen Mei; Liang, Hsiang Fa; Liu, Chih Peng; Liu, Ren Shyan; Shen, Biing Jiun; Wei, Yau Huei; Chuang, Chi Mu
2015-01-01
The current enhanced permeability and retention (EPR)-based approved nanomedicines have had little impact in terms of prolongation of overall survival in patients with cancer. For example, the two Phase III trials comparing Doxil(®), the first nanomedicine approved by the US Food and Drug Administration, with free doxorubicin did not find an actual translation of the EPR effect into a statistically significant increase in overall survival but did show less cardiotoxicity. In the current work, we used a two-factor factorial experimental design with intraperitoneal versus intravenous delivery and nanomedicine versus free drug as factors to test our hypothesis that regional (intraperitoneal) delivery of nanomedicine may better increase survival when compared with systemic delivery. In this study, we demonstrate that bypassing, rather than exploiting, the EPR effect via intraperitoneal delivery of nanomedicine harboring a sustained-release function demonstrates dual pharmacokinetic advantages, producing more efficient tumor control and suppressing the expression of stemness markers, epithelial-mesenchymal transition, angiogenesis signals, and multidrug resistance in the tumor microenvironment. Metastases to vital organs (eg, lung, liver, and lymphatic system) are also better controlled by intraperitoneal delivery of nanomedicine than by standard systemic delivery of the corresponding free drug. Moreover, the intraperitoneal delivery of nanomedicine has the potential to replace hyperthermic intraperitoneal chemotherapy because it shows equal efficacy and lower toxicity. In terms of efficacy, exploiting the EPR effect may not be the best approach for developing a nanomedicine. Because intraperitoneal chemotherapy is a type of regional chemotherapy, the pharmaceutical industry might consider the regional delivery of nanomedicine as a valid alternative pathway to develop their nanomedicine(s) with the goal of better tumor control in the future.
Ried, Karin; Eng, Peter; Sali, Avni
2017-08-27
Background: Circulating-Tumour-Cells (CTC) provide a blood biomarker for early carcinogenesis, cancer progression and treatment effectiveness. An increase in CTCs is associated with cancer progression, a CTC decrease with cancer containment or remission. Several technologies have been developed to identify CTC, including the validated Isolation-by-Size-of-Epithelial-Tumour (ISET, Rarecells) technology, combining blood filtration and microscopy using standard histo-pathological criteria. Methods: This observational study compared CTC count to cancer status and cancer risk, by monitoring treatment effectiveness in cancer patients and by screening for CTC in asymptomatic patients with risk factors, including family history of cancer. Results: Between Sept-2014 and Dec-2016 we undertook 600 CTC tests (542 patients), including 50% screening requests of patients without cancer diagnosis but with risk factors. CTC were detected in all cancer patients (n=277, 100%), and in half of the asymptomatic patients screened (50%, 132 out-of 265 patients). Follow-up tests including scans, scheduled within 1-10 months of positive CTC tests, found early cancerous lesions in 20% of screened patients. In 50% of male patients with CTC and normal PSA (prostate-specific-antigen) levels, PSMA-PET scans revealed increased uptake in the prostate, indicative of early prostate cancer. Other types of cancers detected by CTC screening and subsequent scans included early breast, ovarian, lung, or renal cancer. Patients with CTC were advised on integrative approaches including immune-stimulating and anti-carcinogenic nutritional therapies. CTC repeat tests were available in 10% of patients with detected CTC (40 outof 409 patients, n=98 CTC tests) to assess treatment effectiveness, suggesting nutritional therapies to be beneficial in reducing CTC count. Conclusions: CTC screening provided a highly sensitive biomarker for the early detection of cancer, with higher CTC counts being associated with
Vetrov, S. Ya.; Pankin, P. S.; Timofeev, I. V.
2015-07-01
The spectral properties of a one-dimensional photonic crystal (PC) with a structure defect (a layer of isotropic nanocomposite inserted between two multilayer dielectric mirrors) have been investigated. The nanocomposite consists of spherical gold nanoparticles dispersed in a transparent matrix; it is characterized by effective resonant permittivity. The dependence of the transmission and absorption spectra on the size and concentration of nanoparticles is analyzed. It is shown that the transmission spectrum contains, along with the band gap caused by Bragg diffraction of light, an additional nontransmission band due to the nanocomposite absorption near the resonant frequency.
Directory of Open Access Journals (Sweden)
Leslie P Kozak
Full Text Available Interscapular brown adipose tissue (iBAT is formed during fetal development and stable for the life span of the mouse. In addition, brown adipocytes also appear in white fat depots (wBAT between 10 and 21 days of age in mice maintained at a room temperature of 23 °C. However, this expression is transient. By 60 days of age the brown adipocytes have disappeared, but they can re-emerge if the adult mouse is exposed to the cold (5 °C or treated with β3-adrenergic agonists. Since the number of brown adipocytes that can be induced in white fat influences the capacity of the mouse to resist the obese state, we determined the effects of the nutritional conditions on post-natal development (birth to 21 days of wBAT and its long-term effects on diet-induced obesity (DIO. Under-nutrition caused essentially complete suppression of wBAT in inguinal fat at 21 days of age, as indicated by expression of Ucp1 and genes of mitochondrial structure and function based upon microarray and qRT-PCR analysis, whereas over-nutrition had no discernible effects on wBAT induction. Surprisingly, the suppression of wBAT at 21 days of age did not affect DIO in adult mice maintained at 23 °C, nor did it affect the reduction in obesity or cold tolerance when DIO mice were exposed to the cold at 5 °C for one week. Gene expression analysis indicated that mice raised under conditions that suppressed wBAT at 21 days of age were able to normally induce wBAT as adults. Therefore, neither severe hypoleptinemia nor hypoinsulinemia during suckling permanently impaired brown adipogenesis in white fat. In addition, energy balance studies of DIO mice exposed to cold indicates that mice with reduced adipose stores preferentially increased food intake, whereas those with larger adipose tissue depots preferred to utilize energy from their adipose stores.
Lyons, S E; Shaeffer, A D; Drewnoski, M E; Poore, M H; Poole, D H
2016-04-01
Stockpiled tall fescue can provide adequate winter forage for beef cattle, although unsupplemented replacement heifers may display marginal performance before breeding. The objective of this study was to determine if protein supplementation and/or additional forage improves growth and reproductive performance of replacement heifers grazing stockpiled fescue. Cattle averaging 272 ± 1.59 kg were stratified by BW and then randomly assigned to 1 of 4 plots within a pasture replication. Treatment combinations were assigned in a 2 × 2 factorial arrangement and included 1) a conservative forage allocation ("normal," targeting 85% forage use) and mineral supplement (normal forage allocation with mineral supplement [FM]), 2) normal forage allocation with protein tub (FT), 3) more liberal forage allocation ("extra," targeting 70% forage use) and mineral supplement (extra forage allocation with mineral supplement [EM]), and 4) "extra forage allocation with protein tub (ET). Treatments were administered for 8 wk from early November to early January. Heifers were fed fescue hay for 1 wk before breeding in late January. Heifers were synchronized with the 7-d CO-Synch + controlled internal drug release device protocol and inseminated in late January. Heifers were checked for pregnancy by ultrasonography at 35 and 90 d after AI. Main and interaction effects between the 2 treatments were determined. Total supplement intake was greater for protein tub than mineral supplement (0.36 vs. 0.11 kg·heifer·d, respectively; Reproductive tract scores, pelvic area, and AI pregnancy rates were not different between treatments ( > 0.05). Overall, feeding a protein supplement or providing extra forage increased gain and interacted to increase BCS but did not have an effect on reproductive performance. Supplementing with protein and providing extra forage are strategies that can increase gain in heifers, which could aid heifers in reaching puberty before estrous synchronization.
Callahan, S R; Cross, A J; DeDecker, A E; Lindemann, M D; Estienne, M J
2017-01-01
The objective was to determine effects of nursery group-size-floor space allowance on growth, physiology, and hematology of replacement gilts. A 3 × 3 factorial arrangement of treatments was used wherein gilts classified as large, medium, or small ( = 2537; BW = 5.6 ± 0.6 kg) from 13 groups of weaned pigs were placed in pens of 14, 11, or 8 pigs resulting in floor space allowances of 0.15, 0.19, or 0.27 m/pig, respectively. Pigs were weighed on d 0 (weaning) and d 46 (exit from nursery). The ADG was affected by group-size-floor space allowance × pig size ( = 0.04). Large- and medium-size gilts allowed the most floor space had greater ( floor space but for small size gilts there was no effect ( > 0.05) of group size-floor space allowance. Mortality in the nursery was not affected ( > 0.05) by treatment, size, or treatment × size and overall was approximately 2.1%. Complete blood counts and blood chemistry analyses were performed on samples collected at d 6 and 43 from a subsample of gilts ( = 18/group-size-floor space allowance) within a single group. The concentration ( blood cell distribution width the greatest ( floor space (effects of treatment). Blood calcium was affected by treatment ( = 0.02) and concentrations for gilts allowed the greatest and intermediate amounts of floor space were greater ( floor space. Serum concentrations of cortisol were not affected by treatment × day ( = 0.27). Cortisol concentrations increased from d 6 to d 43 in all groups and were affected by day ( blood parameters and resulted in large- and medium-size replacement gilts displaying increased ADG. Further study will determine if these effects influence lifetime reproductive capacity and sow longevity.
Downey, Todd R.; Meriaudeau, Fabrice; Passian, Ali; Wig, Andrew; Ferrell, Thomas L.
1999-11-01
The effect of variation of core and cladding index difference, Δ n= ncore- ncladding, on allowable values for the guided mode transverse magnetic propagation constants within a step-index, multi-mode optical fiber is investigated. We use a iterative computational technique to calculate the propagation constants for modes inside and outside the core that satisfy the boundary conditions contained within the characteristic eigen-equation for the TM field components. Evidence of a strong dependence of the allowable propagation constants on changes of Δ n is shown.
Directory of Open Access Journals (Sweden)
Nicholas Joseph Matzke
2013-12-01
Full Text Available Historical biogeography has been characterized by a large diversity of methods and unresolved debates about which processes, such as dispersal or vicariance, are most important for explaining distributions. A new R package, BioGeoBEARS, implements many models in a common likelihood framework, so that standard statistical model selection procedures can be applied to let the data choose the best model. Available models include a likelihood version of DIVA (“DIVALIKE”, LAGRANGE’s DEC model, and BAYAREA, as well as “+J” versions of these models which include founder-event speciation, an important process left out of most inference methods. I use BioGeoBEARS on a large sample of island and non-island clades (including two fossil clades to show that founder-event speciation is a crucial process in almost every clade, and that most published datasets reject the non-J models currently in widespread use. BioGeoBEARS is open-source and freely available for installation at the Comprehensive R Archive Network at http://CRAN.R-project.org/package=BioGeoBEARS. A step-by-step tutorial is available at http://phylo.wikidot.com/biogeobears.
Dittrich, Birger; Wandtke, Claudia M; Meents, Alke; Pröpper, Kevin; Mondal, Kartik Chandra; Samuel, Prinson P; Amin Sk, Nurul; Singh, Amit Pratap; Roesky, Herbert W; Sidhu, Navdeep
2015-02-02
Single-crystal X-ray diffraction (XRD) is often considered the gold standard in analytical chemistry, as it allows element identification as well as determination of atom connectivity and the solid-state structure of completely unknown samples. Element assignment is based on the number of electrons of an atom, so that a distinction of neighboring heavier elements in the periodic table by XRD is often difficult. A computationally efficient procedure for aspherical-atom least-squares refinement of conventional diffraction data of organometallic compounds is proposed. The iterative procedure is conceptually similar to Hirshfeld-atom refinement (Acta Crystallogr. Sect. A- 2008, 64, 383-393; IUCrJ. 2014, 1,61-79), but it relies on tabulated invariom scattering factors (Acta Crystallogr. Sect. B- 2013, 69, 91-104) and the Hansen/Coppens multipole model; disordered structures can be handled as well. Five linear-coordinate 3d metal complexes, for which the wrong element is found if standard independent-atom model scattering factors are relied upon, are studied, and it is shown that only aspherical-atom scattering factors allow a reliable assignment. The influence of anomalous dispersion in identifying the correct element is investigated and discussed.
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Alexandre Menezes Dias
2016-09-01
Full Text Available This study aimed to evaluate the effect of three herbage allowances (5, 10, and 15 kg dry matter [DM] 100-1 of body weight [BW] for Brachiaria brizantha cv. Marandu pastures in a continuous grazing system on the morphological and nutritional characteristics of forage, animal performance, and economic viability in Nellore heifers. The total experimental area was 60 ha, divided into 12 paddocks of 5 ha each, with 4 paddocks per treatment. The experimental animals were Nellore heifers (260 in total, with average BW of 301.16 ± 9.12 kg, receiving 0.4 % BW in multiple supplements. We evaluated the production, structural characteristics, and nutritional value of the forage, productive performance, carcass characteristics, and economic viability of each allowance. There were significant effects for the production, st uctural characteristics, and nutritional value of the forage treatment. The proportions of leaves were 42.40, 38.20, and 30.88 % and the leaf:stem ratios were 1.22, 1.03, and 0.83 for the 5, 10, and 15 kg DM 100-1 BW herbage allowances, respectively. The average daily weight gain (mean 0.42, 0.75, and 0.63 kg daily-1 and stocking rate (3.35, 1.87, and 1.26 animal unit ha-1 had a significant effect for the 5, 10, and 15 kg DM 100-1 BW forage allowance, respectively. The herbage allowances were evaluated as being economically viable with a profit margin of 10.37, 23.65, and 14.43 % for the 5, 10, and 15 kg DM 100-1 BW allowances, respectively. The greatest pasture response was found in the 5 kg DM 100-1 BW allowance and was related to better nutritional values and morphological characteristics of the pasture and greater stoking rate and weight gain per area. The herbage allowance of 10 kg DM 100-1 BW be applied to obtain higher animal performance and better economic viability of heifers in B. brizantha cv. Marandu pastures in a continuous grazing method that are receiving protein-energy supplementation.
Chiang, Po-Chang; Kishore, Nandini N; Thompson, David C
2010-03-01
NF-kappaB activation is clearly linked to the pathogenesis of multiple inflammatory diseases including arthritis. The prominent role of IkappaB kinase-2 (IKK-2) in regulating NF-kappaB signaling in response to proinflammatory stimuli has made IKK-2 a primary anti-inflammation therapeutic target. PHA-408, a potent and selective IKK-2 inhibitor, was identified internally and used for our studies to assess this target. In early in vivo studies, PHA-408 demonstrated efficacy at high doses; however, the correlation between PHA-408 exposure and efficacy could not be established using standard dosing paradigms for the rat disease models. Similar concerns arose from early in vivo safety studies where appropriate NOAEL margins were not achieved. Following a full investigation of the physicochemical properties of the molecule and pharmacokinetic modeling, an oral steady-state delivery strategy was designed to administer PHA-408 to the rat for both efficacy and safety studies. Using this steady-state delivery, a clear dose-response relationship was established between plasma concentrations of PHA-408 and efficacy in the rat arthritis model. The same steady-state delivery approach was used to demonstrate the target safety. In summary, a combination of pharmacokinetic modeling with a steady-state delivery approach allowed us to establish confidence in both the mechanism and safety of the target.
Maillot, Matthieu; Drewnowski, Adam
2011-02-01
The 2010 Dietary Guidelines Advisory Committee has recommended that no more than 5-15% of total dietary energy should be derived from solid fats and added sugars (SoFAS). The guideline was based on USDA food pattern modeling analyses that met the Dietary Reference Intake recommendations and Dietary Guidelines and followed typical American eating habits. This study recreated food intake patterns for 6 of the same gender-age groups by using USDA data sources and a mathematical optimization technique known as linear programming. The analytic process identified food consumption patterns based on 128 food categories that met the nutritional goals for 9 vitamins, 9 minerals, 8 macronutrients, and dietary fiber and minimized deviation from typical American eating habits. Linear programming Model 1 created gender- and age-specific food patterns that corresponded to energy needs for each group. Model 2 created food patterns that were iso-caloric with diets observed for that group in the 2001-2002 NHANES. The optimized food patterns were evaluated with respect to MyPyramid servings goals, energy density [kcal/g (1 kcal = 4.18 kJ)], and energy cost (US$/2000 kcal). The optimized food patterns had more servings of vegetables and fruit, lower energy density, and higher cost compared with the observed diets. All nutrient goals were met. In contrast to the much lower USDA estimates, the 2 models placed SoFAS allowances at between 17 and 33% of total energy, depending on energy needs.
Leung, Kawai; Mohammadi, Aylia; Ryu, William; Nemenman, Ilya
In animals, we must infer the pain level from experimental characterization of behavior. This is not trivial since behaviors are very complex and multidimensional. To establish C.elegans as a model for pain research, we propose for the first time a quantitative model that allows inference of a thermal nociceptive stimulus level from the behavior of an individual worm. We apply controlled levels of pain by locally heating worms with an infrared laser and capturing the subsequent behavior. We discover that the behavioral response is a product of stereotypical behavior and a nonlinear function of the strength of stimulus. The same stereotypical behavior is observed in normal, anesthetized and mutated worms. From this result we build a Bayesian model to infer the strength of laser stimulus from the behavior. This model allows us to measure the efficacy of anaesthetization and mutation by comparing the inferred strength of stimulus. Based on the measured nociceptive escape of over 200 worms, our model is able to significantly differentiate normal, anaesthetized and mutated worms with 40 worm samples. This work was partially supported by NSF Grant No. IOS/1208126 and HFSP Grant No. RGY0084/.
Burkman, Ernest; Brezin, Michael; Griffin, Patrick
The simultaneous effects of teaching method (self-directed, group directed, and teacher directed), allowed time for study, and two student variables (academic ability and assessment of treatment implementation) are described for student achievement in a high school biology course (ISIS). The variable student assessment of treatment implementation was viewed as a particularly important variable for two reasons: (1) in research by Stayrook, Corno, and Winne (1978) it has accounted for as much variance in achievement as the assigned treatment; and (2) it provides a means for controlling the range of implementation of teaching methods. A between-student analysis resulted in a description of effects complicated by interactions among all the variables. While the interactions were particularly strong in the student-directed method, it may generally be concluded that as time allowed for study decreased, students who perceived the treatment as being well implemented tended to have higher achievement. Also, it was found that the main effect of ability was quite strong. The results confirmed the importance of student assessment of treatment implementation as a descriptive variable. Additionally, the results suggest a qualification in the conclusion of Cronbach and Snow (1971) that individualized instruction tends to favor high-ability students; that conclusion may need to be modified to situations in which students fully perceive their autonomy.
Allowable Generalized Quantum Gates
Institute of Scientific and Technical Information of China (English)
LONG Gui-Lu; LIU Yang; WANG Chuan
2009-01-01
In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulated perfectly with an ordinary quantum computer with n qubits and one auxiliary qudit. Using this model, we give the most general form of duality gates which is of the form Σ(d-1)(i=0)piUi, and the Pi's are complex numbers with module less or equal to I and constrained by |Σipi|≤1.
Silvent, Jérémie; Nassif, Nadine; Helary, Christophe; Azaïs, Thierry; Sire, Jean-Yves; Guille, Marie Madeleine Giraud
2013-01-01
Among persisting questions on bone calcification, a major one is the link between protein expression and mineral deposition. A cell culture system is here proposed opening new integrative studies on biomineralization, improving our knowledge on the role played by non-collagenous proteins in bone. This experimental in vitro model consisted in human primary osteoblasts cultured for 60 days at the surface of a 3D collagen scaffold mimicking an osteoid matrix. Various techniques were used to analyze the results at the cellular and molecular level (adhesion and viability tests, histology and electron microscopy, RT- and qPCR) and to characterize the mineral phase (histological staining, EDX, ATG, SAED and RMN). On long term cultures human bone cells seeded on the osteoid-like matrix displayed a clear osteoblast phenotype as revealed by the osteoblast-like morphology, expression of specific protein such as alkaline phosphatase and expression of eight genes classically considered as osteoblast markers, including BGLAP, COL1A1, and BMP2. Von Kossa and alizarine red allowed us to identify divalent calcium ions at the surface of the matrix, EDX revealed the correct Ca/P ratio, and SAED showed the apatite crystal diffraction pattern. In addition RMN led to the conclusion that contaminant phases were absent and that the hydration state of the mineral was similar to fresh bone. A temporal correlation was established between quantified gene expression of DMP1 and IBSP, and the presence of hydroxyapatite, confirming the contribution of these proteins to the mineralization process. In parallel a difference was observed in the expression pattern of SPP1 and BGLAP, which questioned their attributed role in the literature. The present model opens new experimental possibilities to study spatio-temporal relations between bone cells, dense collagen scaffolds, NCPs and hydroxyapatite mineral deposition. It also emphasizes the importance of high collagen density environment in bone cell
Energy Technology Data Exchange (ETDEWEB)
Berge, P.; Buisine, D. [Electricite de France (EDF), 92 - Clamart (France); Gelpi, A. [FRAMATOME, 92 - Paris-La-Defence (France)
1997-12-31
When a 600 alloy component is significantly deformed during installation, by welding, rolling, bending, its stress corrosion cracking in Pressurized Water Nuclear Reactor`s primary coolant, is significantly changed by the initial surface treatment. Therefore, the crack initiated time may be reduced by several orders of magnitude for certain surfaces preparations. Allowing for cold working of the surface, for which modelling is proposed, depends less on the degree of cold work then on the depths of the hardened layers. Honing hardens the metal over depths of about one micron for vessel head penetrations, for example, and has little influence on subsequent behaviour after the part deforms. On the other hand, coarser turning treatment produces cold worked layers which can reach several tens of microns and can very significantly reduce the initiation time compared to fine honing. So evaluation after depths of hardening is vital on test pieces for interpreting laboratory results as well as on service components for estimating their service life. Suppression by mechanical or chemical treatment of these layers, after deformation, seems to be the most appropriate solution for reducing over-stressing connected with surface treatment carried out before deformation. (author). 14 refs.
Institute of Scientific and Technical Information of China (English)
周任军; 刘阳升; 成天乐; 潘志; 肖国骏
2013-01-01
Considering carbon emission allowance investment cost under the cap-and-trade carbon emission trading scheme,a carbon emission allowance trading model is established based on generation cost model.According to profitability loss result from energy consumption of carbon capture system,the power selling loss is defined and the carbon capture level optimization model is further proposed.The different resources installed with carbon capture system are used as reference to calculate the changes in carbon capture level with net power under different carbon emission allowance prices.The sensitive internals of carbon emission allowance that boost GenCos anticipating in carbon capturing under both carbon trading model and carbon capture level optimization model are acquired.Comparison analysis on spot and future price of carbon emission allowance under European Union Emissions Trading System shows the proposed carbon capture level optimization model is reasonable,feasible and effective.%在总量控制与排放贸易的碳排放权交易市场机制下,以发电成本模型为基础,考虑碳排放权购买成本,建立了碳排放权交易模型.由于碳捕集系统消耗捕集能耗,造成电厂利润损失,因此定义了售电损失成本,进而建立了考虑售电损失成本的碳捕集水平优化模型.以具有碳捕集系统的不同费用特性的机组为参照,分别计算不同碳排放权价格和净输出功率下的碳捕集水平,得出碳排放权交易模型和碳捕集水平优化模型下能有效刺激发电商参与碳捕集的碳排放权价格敏感区间,对照分析欧盟碳排放交易体系下碳排放权期货价格和现货价格变化特点,反映了碳捕集水平优化模型的合理、可行和有效.
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Bin eLi
2016-02-01
Full Text Available This study examined the possibility that there is a curvilinear relationship between income and subjective well-being in China. This study also investigated whether this curvilinear relationship is moderated by social class and mediated by respondents’ material affluence. The study was conducted in China, and the sample consisted of 900 blue-collar workers and 546 white-collar workers. The results for emotional well-being showed that income significantly predicted negative affect but not positive affect. This finding indicates that in China, high incomes may not make people happier but might allow them to worry less, which we call the money buffer effect. The results also showed that material affluence mediates the interaction effect between income and social class on subjective well-being. The implications of these results for future research and practice are discussed.
Li, Bin; Li, Aimei; Wang, Xiaotian; Hou, Yunsong
2016-01-01
This study examined the possibility that there is a curvilinear relationship between income and subjective well-being in China. This study also investigated whether this curvilinear relationship is moderated by social class and mediated by respondents' material affluence. The study was conducted in China, and the sample consisted of 900 blue-collar workers and 546 white-collar workers. The results for emotional well-being showed that income significantly predicted negative affect but not positive affect. This finding indicates that in China, high incomes may not make people happier but might allow them to worry less, which we call the "money buffer effect." The results also showed that material affluence mediates the interaction effect between income and social class on subjective well-being. The implications of these results for future research and practice are discussed.
Ecotoxicological effects extrapolation models
Energy Technology Data Exchange (ETDEWEB)
Suter, G.W. II
1996-09-01
One of the central problems of ecological risk assessment is modeling the relationship between test endpoints (numerical summaries of the results of toxicity tests) and assessment endpoints (formal expressions of the properties of the environment that are to be protected). For example, one may wish to estimate the reduction in species richness of fishes in a stream reach exposed to an effluent and have only a fathead minnow 96 hr LC50 as an effects metric. The problem is to extrapolate from what is known (the fathead minnow LC50) to what matters to the decision maker, the loss of fish species. Models used for this purpose may be termed Effects Extrapolation Models (EEMs) or Activity-Activity Relationships (AARs), by analogy to Structure-Activity Relationships (SARs). These models have been previously reviewed in Ch. 7 and 9 of and by an OECD workshop. This paper updates those reviews and attempts to further clarify the issues involved in the development and use of EEMs. Although there is some overlap, this paper does not repeat those reviews and the reader is referred to the previous reviews for a more complete historical perspective, and for treatment of additional extrapolation issues.
Organizational effectiveness of coalition operations' headquarters : A theoretical model
Vogler-Bisig, E.; Blais, A.R.; Hof, T.; Tresch, T.S.; Seiler, S.; Yanakiev, Y.
2012-01-01
Purpose - This article describes a theoretical model that allows understanding, explaining, and measuring the perceived organizational effectiveness of multinational coalition operations' headquarters. Design/methodology/approach - The proposed model is based on subject matter experts' opinions and
Factors affecting the carbon allowance market in the US
Energy Technology Data Exchange (ETDEWEB)
Kim, Hyun Seok; Koo, Won W. [Center for Agricultural Policy and Trade Studies, Department of Agribusiness and Applied Economics, North Dakota State University, Dept 7610, P.O. Box 6050, Fargo, ND 58103-6050 (United States)
2010-04-15
The US carbon allowance market has different characteristic and price determination process from the EU ETS market, since emitting installations voluntarily participate in emission trading scheme. This paper examines factors affecting the US carbon allowance market. An autoregressive distributed lag model is used to examine the short- and long-run relationships between the US carbon allowance market and its determinant factors. In the long-run, the price of coal is a main factor in the determination of carbon allowance trading. In the short-run, on the other hand, the changes in crude oil and natural gas prices as well as coal price have significant effects on carbon allowance market. (author)
Lefebvre, P; Brouillette, L; Felteau, C
1994-12-01
"We suppose that women (couples), who are less than 40 years old, are faced with three types of sequential decisions: the fertility decision, the decision relative to the number of children to have and the decision concerning labour force participation.... We use a nested polychotomous discrete choice model to estimate the responsiveness of the behaviour of 'married' women in Quebec to variations in the expected flow of revenue resulting from changes in the parameters of the personal income tax and in the level of public monetary transfers conditional on the number of children. The model is estimated with micro-data from 9 repeated cross-sections for the years 1975 to 1987 with a full information maximum likelihood method.... This empirical setting is used to simulate the effects of changes made to the fiscal and transfer policies in favor of families with dependent children on fertility, [women's] labor force participation and the importance of spending costs for the two levels of government." (SUMMARY IN ENG)
Little, Philip; Kvist, Ola; Grankvist, Rikard; Jonsson, Stefan; Damberg, Peter; Söderman, Michael; Arnberg, Fabian; Holmin, Staffan
2017-01-01
Interventional treatment regimens have increased the demand for accurate understanding of the progression of injury in acute ischemic stroke. However, conventional animal models severely inhibit collateral blood flow and mimic the malignant infarction profile not suitable for treatment. The aim of this study was to provide a clinically relevant profile of the emergence and course of ischemic injury in cases suitable for acute intervention, and was achieved by employing a M2 occlusion model (M2CAO) that more accurately simulates middle cerebral artery (MCA) occlusion in humans. Twenty-five Sprague-Dawley rats were subjected to Short (90 min), Intermediate (180 min) or Extended (600 min) transient M2CAO and examined longitudinally with interleaved diffusion-, T2- and arterial spin labeling perfusion-weighted magnetic resonance imaging before and after reperfusion. We identified a rapid emergence of cytotoxic edema within tissue regions undergoing infarction, progressing in several distinct phases in the form of subsequent moderation and then reversal at 230 min (p < 0.0001). We identified also the early emergence of vasogenic edema, which increased consistently before and after reperfusion (p < 0.0001). The perfusion of the penumbra correlated more strongly to the perfusion of adjacent tissue regions than did the perfusion of regions undergoing infarction (p = 0.0088). This was interpreted as an effect of preserved collateral blood flow during M2CAO. Accordingly, we observed only limited recruitment of penumbra regions to the infarction core. However, a gradual increase in infarction size was still occurring as late as 10 hours after M2CAO. Our results indicate that patients suffering MCA branch occlusion stand to benefit from interventional therapy for an extended time period after the emergence of ischemic injury. PMID:28068417
Directory of Open Access Journals (Sweden)
Knols Bart GJ
2002-06-01
Full Text Available Abstract Background Based on sensitivity analysis of the MacDonald-Ross model, it has long been argued that the best way to reduce malaria transmission is to target adult female mosquitoes with insecticides that can reduce the longevity and human-feeding frequency of vectors. However, these analyses have ignored a fundamental biological difference between mosquito adults and the immature stages that precede them: adults are highly mobile flying insects that can readily detect and avoid many intervention measures whereas mosquito eggs, larvae and pupae are confined within relatively small aquatic habitats and cannot readily escape control measures. Presentation of the hypothesis We hypothesize that the control of adult but not immature mosquitoes is compromised by their ability to avoid interventions such as excito-repellant insecticides. Testing the hypothesis We apply a simple model of intervention avoidance by mosquitoes and demonstrate that this can substantially reduce effective coverage, in terms of the proportion of the vector population that is covered, and overall impact on malaria transmission. We review historical evidence that larval control of African malaria vectors can be effective and conclude that the only limitations to the effective coverage of larval control are practical rather than fundamental. Implications of the hypothesis Larval control strategies against the vectors of malaria in sub-Saharan Africa could be highly effective, complementary to adult control interventions, and should be prioritized for further development, evaluation and implementation as an integral part of Rolling Back Malaria.
Jang, J C; Jin, X H; Hong, J S; Kim, Y Y
2017-06-26
This experiment was conducted to evaluate the optimal space allowance on growth performance, blood profile and pork quality of growing-finishing pigs. A total of ninety crossbred pigs ([Yorkshire x Landrace] x Duroc, 30.25 ± 1.13 kg) were allocated into three treatments (0.96: four pigs / pen, 0.96 m2/pig; 0.80: five pigs / pen, 0.80 m2/pig; 0.69: six pigs / pen, 0.69 m2/pig) in a randomized complete block (RCB) design. Pigs were housed in balanced sex and had free access to feed in all phases for 14 weeks (growing phase I, growing phase II, finishing phase I and finishing phase II). There was no statistical difference in growing phase, but a linear decrease was observed on average daily gain (ADG, pfinishing phase. On the other hand, a quadratic effect was observed on gain to feed ratio in early finishing phase (pfinish production system is more than 0.80 m2/pig for maximizing growth performance and production efficiency.
Andreyeva, Tatiana; Luedicke, Joerg; Henderson, Kathryn E; Schwartz, Marlene B
2014-04-01
In 2009, the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) implemented revisions to the WIC food packages. Milk and cheese allowances were reduced, and whole milk was disallowed for participants older than 23 months. Using a pre-post research design and scanner data from a New England supermarket chain on purchases of WIC households, this article assesses how the new WIC packages affected milk and cheese purchases and saturated fat intake among WIC households in Connecticut and Massachusetts. Milk and cheese volume purchased by 515 WIC households in Connecticut was compared before and after the WIC revisions (2009-2010) using generalized estimating equation models. Analysis for Massachusetts was descriptive. After implementation of the new WIC packages in Connecticut, whole-milk share declined from about 60% to 25% in WIC milk purchases, but remained flat at about 50% for purchases with non-WIC funds. Total milk volume fell by 14.2% (P<0.001), whole milk by half (P<0.001), and WIC-eligible cheese by 37.2% (P<0.001). Restrictions on whole milk shifted WIC purchases to reduced-fat milk in Connecticut and low-fat milk in Massachusetts, where reduced-fat milk is not permitted by WIC. The amounts of saturated fat from purchased milk and cheese declined by 85 g/month per WIC household in Connecticut and 107 g/month in Massachusetts. The 2009 WIC revisions led to a substantial decrease in purchases of whole milk and cheese among WIC families in New England. The related reduction in saturated fat intake could have important public health implications.
Better models are more effectively connected models
Nunes, João Pedro; Bielders, Charles; Darboux, Frederic; Fiener, Peter; Finger, David; Turnbull-Lloyd, Laura; Wainwright, John
2016-04-01
can be represented in models: either by allowing it to emerge from model behaviour or by parameterizing it inside model structures; and on the appropriate scale at which processes should be represented explicitly or implicitly. It will also explore how modellers themselves approach connectivity through the results of a community survey. Finally, it will present the outline of an international modelling exercise aimed at assessing how different modelling concepts can capture connectivity in real catchments.
Directory of Open Access Journals (Sweden)
Dario de Biase
Full Text Available Selection of lung cancer patients for therapy with tyrosine kinase inhibitors directed at EGFR requires the identification of specific EGFR mutations. In most patients with advanced, inoperable lung carcinoma limited tumor samples often represent the only material available for both histologic typing and molecular analysis. We defined a next generation sequencing protocol targeted to EGFR exons 18-21 suitable for the routine diagnosis of such clinical samples. The protocol was validated in an unselected series of 80 small biopsies (n=14 and cytology (n=66 specimens representative of the material ordinarily submitted for diagnostic evaluation to three referral medical centers in Italy. Specimens were systematically evaluated for tumor cell number and proportion relative to non-neoplastic cells. They were analyzed in batches of 100-150 amplicons per run, reaching an analytical sensitivity of 1% and obtaining an adequate number of reads, to cover all exons on all samples analyzed. Next generation sequencing was compared with Sanger sequencing. The latter identified 15 EGFR mutations in 14/80 cases (17.5% but did not detected mutations when the proportion of neoplastic cells was below 40%. Next generation sequencing identified 31 EGFR mutations in 24/80 cases (30.0%. Mutations were detected with a proportion of neoplastic cells as low as 5%. All mutations identified by the Sanger method were confirmed. In 6 cases next generation sequencing identified exon 19 deletions or the L858R mutation not seen after Sanger sequencing, allowing the patient to be treated with tyrosine kinase inhibitors. In one additional case the R831H mutation associated with treatment resistance was identified in an EGFR wild type tumor after Sanger sequencing. Next generation sequencing is robust, cost-effective and greatly improves the detection of EGFR mutations. Its use should be promoted for the clinical diagnosis of mutations in specimens with unfavorable tumor cell
Yaghini, N.; Iedema, P.
2014-01-01
A population balance model for the prediction of molecular weight distribution (MWD) in a continuous stirred tank reactor (CSTR) has been developed accounting for multiradicals and gel formation in the framework of Galerkin-FEM. In the absence of recombination, gel does not form, but accounting for
2010-07-01
... years. See § 1039.101 for exhaust emission standards that apply to later model years. See 40 CFR 89.112... 40 CFR part 89. However, except as specified by paragraph (a)(1) of this section, the transient PM...+NMHC credits from any Tier 2 engine at or above 37 kW certified under 40 CFR part 89 to meet the...
Energy Technology Data Exchange (ETDEWEB)
Demiral, B.M.R.; Pettit, P.A.; Castanier, L.M.; Brigham, W.E.
1992-08-01
The CT imaging technique together with temperature and pressure measurements were used to follow the steam propagation during steam and steam foam injection experiments in a three dimensional laboratory steam injection model. The advantages and disadvantages of different geometries were examined to find out which could best represent radial and gravity override flows and also fit the dimensions of the scanning field of the CT scanner. During experiments, steam was injected continuously at a constant rate into the water saturated model and CT scans were taken at six different cross sections of the model. Pressure and temperature data were collected with time at three different levels in the model. During steam injection experiments, the saturations obtained by CT matched well with the temperature data. That is, the steam override as observed by temperature data was also clearly seen on the CT pictures. During the runs where foam was present, the saturation distributions obtained from CT pictures showed a piston like displacement. However, the temperature distributions were different depending on the type of steam foam process used. The results clearly show that the pressure/temperature data alone are not sufficient to study steam foam in the presence of non-condensible gas.
Energy Technology Data Exchange (ETDEWEB)
Verdonk, M.; Vollebergh, H.
2012-11-15
A set-aside of CO2 allowances would reduce the current oversupply in the European Emissions Trading System (ETS). This would result in temporary higher CO2 prices. However, a literature study has shown that the impact of the European Commission's proposal on CO2 prices is likely to be limited, because the total amount of allowances up to 2020 would remain unchanged. However, the proposal sends out a signal to investors that the functioning of the ETS is a priority for politicians, and increases the likelihood of further reforms. Any negative impact of back loading on ETS companies in the Netherlands is likely to be limited.
Directory of Open Access Journals (Sweden)
Kundu Antara
2013-01-01
Full Text Available The present paper deals with an economic order quantity (EOQ model of an inventory problem with alternating demand rate: (i For a certain period, the demand rate is a non linear function of the instantaneous inventory level. (ii For the rest of the cycle, the demand rate is time dependent. The time at which demand rate changes, may be deterministic or uncertain. The deterioration rate of the item is time dependent. The holding cost and shortage cost are taken as a linear function of time. The total cost function per unit time is obtained. Finally, the model is solved using a gradient based non-linear optimization technique (LINGO and is illustrated by a numerical example.
Ferrari, Ulisse
2016-08-01
Maximum entropy models provide the least constrained probability distributions that reproduce statistical properties of experimental datasets. In this work we characterize the learning dynamics that maximizes the log-likelihood in the case of large but finite datasets. We first show how the steepest descent dynamics is not optimal as it is slowed down by the inhomogeneous curvature of the model parameters' space. We then provide a way for rectifying this space which relies only on dataset properties and does not require large computational efforts. We conclude by solving the long-time limit of the parameters' dynamics including the randomness generated by the systematic use of Gibbs sampling. In this stochastic framework, rather than converging to a fixed point, the dynamics reaches a stationary distribution, which for the rectified dynamics reproduces the posterior distribution of the parameters. We sum up all these insights in a "rectified" data-driven algorithm that is fast and by sampling from the parameters' posterior avoids both under- and overfitting along all the directions of the parameters' space. Through the learning of pairwise Ising models from the recording of a large population of retina neurons, we show how our algorithm outperforms the steepest descent method.
40 CFR 35.2025 - Allowance and advance of allowance.
2010-07-01
... facilities planning and design of the project and Step 7 agreements will include an allowance for facility planning in accordance with appendix B of this subpart. (b) Advance of allowance to potential grant... grant applicants for facilities planning and project design. (2) The State may request that the right to...
Modeling and Simulating Environmental Effects
Guest, Peter S.; Murphree, Tom; Frederickson, Paul A.; Guest, Arlene A.
2012-01-01
MOVES Research & Education Systems Seminar: Presentation; Session 4: Collaborative NWDC/NPS M&S Research; Moderator: Curtis Blais; Modeling and Simulating Environmental Effects; speakers: Peter Guest, Paul Frederickson & Tom Murphree Environmental Effects Group
Modeling dynamic effects of promotion on interpurchase times
D. Fok (Dennis); R. Paap (Richard); Ph.H.B.F. Franses (Philip Hans)
2002-01-01
textabstractIn this paper we put forward a duration model to analyze the dynamic effects of marketing-mix variables on interpurchase times. We extend the accelerated failure-time model with an autoregressive structure. An important feature of our model is that it allows for different long-run and
Modeling dynamic effects of promotion on interpurchase times
D. Fok (Dennis); R. Paap (Richard); Ph.H.B.F. Franses (Philip Hans)
2002-01-01
textabstractIn this paper we put forward a duration model to analyze the dynamic effects of marketing-mix variables on interpurchase times. We extend the accelerated failure-time model with an autoregressive structure. An important feature of our model is that it allows for different long-run and
Directory of Open Access Journals (Sweden)
Glayce Junqueira Quintanilha
2013-07-01
Full Text Available The municipality of Goytacazes is established in areas previously bathed by extensive water bodies. Several areas of this municipality are as a result of major human interventions for drainage of low lands in the region aiming mainly to expand agricultural areas. However, due to bad management of drainage network, the region still suffers from floods, mainly because of the nature of geomorphological land, home flooded. The zoning of areas subject to flooding in this sense, it is presented as an extremely valuable tool for organizing and planning the use and occupation of a region, especially those where these flood events are recurring, as is the case of Goytacazes. This instrument is able to identify critical areas and direct the use of land according to its characteristics. The objective of this work was to offer from a Digital Terrain Model, a tool to perform the Zoning Areas Susceptible to Flooding of a representative area of Baixada Camper, using as a tool to support an Information System (GIS in the case this study, we used the ArcGIS software, version 9.3. Results show the lower areas of the region studied, comparing the information found in data preservation areas and occupation of the area, which indicates the current study as a support tool for planning and environmental policies in order to rationalize the use of land in the Baixada Camper.
Modeling of the magnetic Barkhausen effect
Clatterbuck, D. M.; Garcia, V. J.; Johnson, M. J.; Jiles, D. C.
2000-05-01
The magnetic Barkhausen effect has been found particularly useful for the nondestructive evaluation of ferromagnetic alloys. It has been shown to be sensitive to both the microstructure and the stress state of a material. In order to improve interpretation of the Barkhausen signals, models are needed which are able to directly relate the Barkhausen signals to material properties such as grain size. In this paper, the advantages and disadvantages of two existing magnetic Barkhausen models are studied with a view to their suitability for use in the field of nondestructive evaluation. The model of Alessandro, Beatrice, Bertotti, and Montorsi describes the pinning field which interacts with a domain wall in terms of a Wiener-Levy stochastic process. The domain wall velocity is then assumed to depend linearly on the difference between the local magnetic field and this pinning field. The assumptions of this model limit its use to experiments where the permeability and rate-of-change of applied field are constant. The model of Jiles, Sipahi, and Williams assumes that the Barkhausen activity in a given time interval is proportional to the rate-of-change of the magnetization which can be calculated from the hysteresis model of Jiles and Atherton. The model uses Poisson statistics to describe the stochastic nature of the Barkhausen events. A new model which incorporates ideas from both of these older models is introduced. The new model allows for changes in permeability with applied field and can accurately reproduce the frequency response of experimental Barkhausen signals. In order to validate the model, experiments were performed by measuring the magnetic flux produced when a sample was magnetized in a solenoid. The high-frequency components of the flux signal represent Barkhausen events and were separated from the main signal using a high-pass filter. This approach allowed quantitative comparisons to be made between the experiments and the model.—This work was
Brookes, Emre; Demeler, Borries; Rosano, Camillo; Rocco, Mattia
2010-02-01
The interpretation of solution hydrodynamic data in terms of macromolecular structural parameters is not a straightforward task. Over the years, several approaches have been developed to cope with this problem, the most widely used being bead modeling in various flavors. We report here the implementation of the SOMO (SOlution MOdeller; Rai et al. in Structure 13:723-734, 2005) bead modeling suite within one of the most widely used analytical ultracentrifugation data analysis software packages, UltraScan (Demeler in Modern analytical ultracentrifugation: techniques and methods, Royal Society of Chemistry, UK, 2005). The US-SOMO version is now under complete graphical interface control, and has been freed from several constraints present in the original implementation. In the direct beads-per-atoms method, virtually any kind of residue as defined in the Protein Data Bank (e.g., proteins, nucleic acids, carbohydrates, prosthetic groups, detergents, etc.) can be now represented with beads whose number, size and position are all defined in user-editable tables. For large structures, a cubic grid method based on the original AtoB program (Byron in Biophys J 72:408-415, 1997) can be applied either directly on the atomic structure, or on a previously generated bead model. The hydrodynamic parameters are then computed in the rigid-body approximation. An extensive set of tests was conducted to further validate the method, and the results are presented here. Owing to its accuracy, speed, and versatility, US-SOMO should allow to fully take advantage of the potential of solution hydrodynamics as a complement to higher resolution techniques in biomacromolecular modeling.
Słupski, Jacek; Gębczyński, Piotr; Korus, Anna; Lisiewska, Zofia
2014-06-01
The aim of this work was to evaluate calcium retention in 14 species of vegetable (from four usable groups). The material investigated consisted of raw and boiled fresh vegetables and two types of frozen product prepared for consumption after 12-month storage: one traditionally produced; the other obtained using the modified method (convenience food). The highest calcium content was found in leafy vegetables, followed (in descending order) by leguminous, root and brassica vegetables. The proportion by weight of Ca to P was highest in leafy vegetables and decreased with calcium retention despite the fact that levels of phosphorus were highest in leguminous and lowest in leafy vegetables. The nutrient density (ND%) of calcium for adults exceeded 100 for each individual vegetable species. The recommended daily allowance (RDA) percentage value varied between 23.04 (kale) and 1.46 (white cauliflower). Of the three types of product, ND and RDA values were generally greater in the frozen convenience products.
Knols Bart GJ; Fillinger Ulrike; Killeen Gerry F
2002-01-01
Abstract Background Based on sensitivity analysis of the MacDonald-Ross model, it has long been argued that the best way to reduce malaria transmission is to target adult female mosquitoes with insecticides that can reduce the longevity and human-feeding frequency of vectors. However, these analyses have ignored a fundamental biological difference between mosquito adults and the immature stages that precede them: adults are highly mobile flying insects that can readily detect and avoid many i...
Kriging with mixed effects models
Directory of Open Access Journals (Sweden)
Alessio Pollice
2007-10-01
Full Text Available In this paper the effectiveness of the use of mixed effects models for estimation and prediction purposes in spatial statistics for continuous data is reviewed in the classical and Bayesian frameworks. A case study on agricultural data is also provided.
Size Effect in Continuum Modeling
Energy Technology Data Exchange (ETDEWEB)
Lu, Wei-Yang [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials; Foulk, James W. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials; Huestis, Edwin M. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials; Connelly, Kevin [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials; Song, Bo [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Mechanics of Materials; Yang, Nancy Y. C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States). Engineered Materials
2008-09-01
The mechanical properties of some materials (Cu, Ni, Ag, etc.) have been shown to develop strong dependence on the geometric dimensions, resulting in a size effect. Several theories have been proposed to model size effects, but have been based on very few experiments conducted at appropriate scales. Some experimental results implied that size effects are caused by increasing strain gradients and have been used to confirm many strain gradient theories. On the other hand, some recent experiments show that a size effect exists in the absence of strain gradients. This report describes a brief analytical and experimental study trying to clarify the material and experimental issues surrounding the most influential size-effect experiments by Fleck et al (1994). This effort is to understand size effects intended to further develop predictive models.
On the Methods for Calculating Annual Allowable Cut
Directory of Open Access Journals (Sweden)
V. А. Sokolov
2014-10-01
Full Text Available Crisis in supplying regions and the country related to available forest resources and low profitability of forest sector, as a whole, is an indicator of failure of the existing model of forest management and forest use organization in Russia at the present time. Many Russian regions, which are traditionally considered as forest industrial territories, face the challenge of lack of economically accessible forests. The forests are decreasing against a background of under exploitation of the annual allowable cut. This situation occurs in Siberia as well. In many cases, using calculated allowable cut will result in unsustainable harvest levels and a future decrease of accessible forest resources. Thus, the statement that «a volume of wood resource utilization is determined by allowable cut represented the scientifically grounded norm of sustainable forest use» is considered as no more than the declarative proposition. Modeling the normal forest, and using a formula of allowable cut calculation estimated for some decades based on the modeling, is totally unreliable and unreal. The long-term forecast should use analog methods, but it will hardly be sufficiently accurate and adequate to set norms. In order to estimate ecological and economic accessibility of forest resources, an algorithm was made, and a method and model were developed. This model is based on GIS-database and makes it possible to estimate accessibility of forest resources and to map it as well. The conclusion on necessity to determine annual allowable cut in two varieties was drawn following the procedures for calculating annual allowable cut. The first variety is silvicultural (according the currently used methods and the other one is economically accessible allowable cut, which could provide economic effective use of tradable mature wood, taking in to account ecological and economic accessibility of forest resources.
DEFF Research Database (Denmark)
Knudsen, Ib; Poulsen, Morten
2007-01-01
high dose level and a dietary design based upon compositional data on the GM food and toxicity data on the gene product is sensitive and specific enough to verify the presence/absence of the biological/nutritional/toxicological effects of the novel gene insert and further by the use of spiking able......This article discusses the wider experiences regarding the usefulness of the 90-day rat feeding study for the testing of whole foods from genetically modified (GM) plant based on data from a recent EU-project [Poulsen, M., Schroder, M., Wilcks, A., Kroghsbo, S., Lindecrona, R.H., Miller, A......., Frenzel, T., Danier, J., Rychlik, M., Shu, Q., Emami, K., Taylor, M., Gatehouse, A., Engel, K.-H., Knudsen, I., 2007a. Safety testing of GM-rice expressing PHA-E lectin using a new animal test design. Food Chem. Toxicol. 45, 364-377; Poulsen, M., Kroghsbo, S., Schroder, M., Wilcks, A., Jacobsen, H...
Knudsen, Ib; Poulsen, Morten
2007-10-01
This article discusses the wider experiences regarding the usefulness of the 90-day rat feeding study for the testing of whole foods from genetically modified (GM) plant based on data from a recent EU-project [Poulsen, M., Schrøder, M., Wilcks, A., Kroghsbo, S., Lindecrona, R.H., Miller, A., Frenzel, T., Danier, J., Rychlik, M., Shu, Q., Emami, K., Taylor, M., Gatehouse, A., Engel, K.-H., Knudsen, I., 2007a. Safety testing of GM-rice expressing PHA-E lectin using a new animal test design. Food Chem. Toxicol. 45, 364-377; Poulsen, M., Kroghsbo, S., Schrøder, M., Wilcks, A., Jacobsen, H., Miller, A., Frenzel, T., Danier, J., Rychlik, M., Shu, Q., Emami, K., Sudhakar, D., Gatehouse, A., Engel, K.-H., Knudsen, I., 2007b. A 90-day safety in Wistar rats fed genetically modified rice expressing snowdrop lectin Galanthus nivalis (GNA). Food Chem. Toxicol. 45, 350-363; Schrøder, M., Poulsen, M., Wilcks, A., Kroghsbo, S., Miller, A., Frenzel, T., Danier, J., Rychlik, M., Emami, K., Gatehouse, A., Shu, Q., Engel, K.-H., Knudsen, I., 2007. A 90-day safety study of genetically modified rice expressing Cry1Ab protein (Bacillus thuringiensis toxin) in Wistar rats. Food Chem. Toxicol. 45, 339-349]. The overall objective of the project has been to develop and validate the scientific methodology necessary for assessing the safety of foods from genetically modified plants in accordance with the present EU regulation. The safety assessment in the project is combining the results of the 90-day rat feeding study on the GM food with and without spiking with the pure novel gene product, with the knowledge about the identity of the genetic change, the compositional data of the GM food, the results from in-vitro/ex-vivo studies as well as the results from the preceding 28-day toxicity study with the novel gene product, before the hazard characterisation is concluded. The results demonstrated the ability of the 90-day rat feeding study to detect the biological/toxicological effects of the
Exotic properties of neutrinos using effective Lagrangians and specific models
Aparici, Alberto
2013-01-01
This doctoral dissertation presents several works on nonstandard properties of neutrinos exploiting the synergies between effective field theory and models. The phenomena are first analysed by means of effective operators, which allow to discuss their phenomenological consequences and to derive estimations about the mass scale of the heavy particles needed to induce the new interactions. In a second phase we propose models that realise the effective operators, allowing us to check the conclusions of effective field theory as well as to extract new phenomenological features of the scenarios considered. The text is divided into two parts: in the first one we apply these ideas to an effective interaction that generates magnetic dipole moments for right-handed neutrinos, and in the second one we discuss a family of operators that violate lepton number without quarks, and which can allow for large rates of neutrinoless double $\\beta$ decay and small neutrino masses. The right-handed neutrino magnetic moments have ...
Tokunaga, Jin; Takamura, Norito; Kourogi, Yasuyuki; Imada, Misato; Kozasa, Ayaka; Komori, Kanako; Ono, Chisa; Nishimura, Akie; Ogata, Kenji; Setoguchi, Nao; Matsuoka, Toshikazu; Kai, Mitsuhiro; Sato, Keizo; Arimori, Kazuhiko
2016-01-01
We utilized the information and communication technology to develop the physical assessment (PA) learning materials in the virtual experience type. This learning material consists of two parts which include case learning and basic learning. We created example scenarios about various conditions that a pharmacist may experience in medical scenes such as in a hospital ward, community pharmacy, home, and drugstore. Illustrations of a virtual patient's avatar before and after taking the medicines were incorporated in the learning materials. The virtual training includes a stethoscope that was used in examining sounds (heart, pulmonary and bowel sounds) that served as evidences in the confirmation of drug efficacy and its possible adverse effects. In addition, we included the images of each body part, the 24 format question items, the palpation (rate and rhythm) of the radial artery, brachial artery and pedal artery, the clinical data obtained from several medical equipment, the pupillary reflex, and the urine dipstick test. This way, learners are able to experience PA with reference to the subjective and objective data from patient reception and questions. The virtual patient's avatar displayed on the monitor features auscultatory sounds on the stethoscope. It also features clinical data obtained from other medical equipment that can give the learners an interactive way of learning about various medical conditions. For evaluation, we gave out questionnaires on the virtual PA to pharmacy students. As a result, a high evaluation was reflected in terms of the degree of usefulness for both case learning and basic learning.
Richly parameterized linear models additive, time series, and spatial models using random effects
Hodges, James S
2013-01-01
A First Step toward a Unified Theory of Richly Parameterized Linear ModelsUsing mixed linear models to analyze data often leads to results that are mysterious, inconvenient, or wrong. Further compounding the problem, statisticians lack a cohesive resource to acquire a systematic, theory-based understanding of models with random effects.Richly Parameterized Linear Models: Additive, Time Series, and Spatial Models Using Random Effects takes a first step in developing a full theory of richly parameterized models, which would allow statisticians to better understand their analysis results. The aut
Behavioral effects in room evacuation models
Dossetti, V.; Bouzat, S.; Kuperman, M. N.
2017-08-01
In this work we study a model for the evacuation of pedestrians from an enclosure considering a continuous space substrate and discrete time. We analyze the influence of behavioral features that affect the use of the empty space, that can be linked to the attitudes or characters of the pedestrians. We study how the interaction of different behavioral profiles affects the needed time to evacuate completely a room and the occurrence of clogging. We find that neither fully egotistic nor fully cooperative attitudes are optimal from the point of view of the crowd. In contrast, intermediate behaviors provide lower evacuation times. This leads us to identify some phenomena closely analogous to the faster-is-slower effect. The proposed model allows for distinguishing between the role of the attitudes in the search for empty space and the attitudes in the conflicts.
An antenna model for the Purcell effect.
Krasnok, Alexander E; Slobozhanyuk, Alexey P; Simovski, Constantin R; Tretyakov, Sergei A; Poddubny, Alexander N; Miroshnichenko, Andrey E; Kivshar, Yuri S; Belov, Pavel A
2015-08-10
The Purcell effect is defined as a modification of the spontaneous emission rate of a quantum emitter at the presence of a resonant cavity. However, a change of the emission rate of an emitter caused by an environment has a classical counterpart. Any small antenna tuned to a resonance can be described as an oscillator with radiative losses, and the effect of the environment on its radiation can be modeled and measured in terms of the antenna radiation resistance, similar to a quantum emitter. We exploit this analogue behavior to develop a general approach for calculating the Purcell factors of different systems and various frequency ranges including both electric and magnetic Purcell factors. Our approach is illustrated by a general equivalent scheme, and it allows resenting the Purcell factor through the continuous radiation of a small antenna at the presence of an electromagnetic environment.
Speciation Effect in the Penna Aging Model
Łaszkiewicz, A.; Szymczak, Sz.; Cebrat, S.
We have simulated the evolution of diploid, sexually reproducing populations using the Penna model of aging. We have noted that diminishing the recombination frequency during the gamete production generates a specific diversity of genomes in the populations. When two populations independently evolving for some time were mixed in one environmental niche of the limited size and crossbreeding between them was allowed, the average lifespan of hybrids was significantly shorter than the lifespan of the individuals of parental lines. Another effect of higher hybrid mortality is the faster elimination of one parental line from the shared environment. The two populations living in one environment co-exist much longer if they are genetically separated — they compete as two species instead of crossbreeding. This effect can be considered as the first step to speciation — any barrier eliminating crossbreeding between these populations, leading to speciation, would favor the populations.
2011-03-24
... http://www.gsa.gov/relocationpolicy . Dated: March 21, 2011. Janet Dobbs, Director, Office of Travel... ADMINISTRATION Federal Travel Regulation (FTR); Relocation Allowances-- Relocation Income Tax Allowance (RITA... effective March 24, 2011. FOR FURTHER INFORMATION CONTACT: Mr. Ed Davis, Office of Governmentwide Policy...
Mixed Effects Models for Complex Data
Wu, Lang
2009-01-01
Presenting effective approaches to address missing data, measurement errors, censoring, and outliers in longitudinal data, this book covers linear, nonlinear, generalized linear, nonparametric, and semiparametric mixed effects models. It links each mixed effects model with the corresponding class of regression model for cross-sectional data and discusses computational strategies for likelihood estimations of mixed effects models. The author briefly describes generalized estimating equations methods and Bayesian mixed effects models and explains how to implement standard models using R and S-Pl
Vietnam recommended dietary allowances 2007.
Khan, Nguyen Cong; Hoan, Pham Van
2008-01-01
It has been well acknowledged that Vietnam is undergoing a nutrition transition. With a rapid change in the country's reform and economic growth, food supply at the macronutrient level has improved. Changes of the Vietnamese diet include significantly more foods of animal origin, and an increase of fat/oils, and ripe fruits. Consequently, nutritional problems in Vietnam now include not only malnutrition but also overweight/obesity, metabolic syndrome and other chronic diseases related to nutrition and lifestyles. The recognition of these shifts, which is also associated with morbidity and mortality, was a major factor in the need to review and update the Recommended Dietary Allowances (RDA) for the Vietnamese population. This revised RDA established an important science-based tool for evaluation of nutrition adequacy, for teaching, and for scientific communications within Vietnam. It is expected that the 2007 Vietnam RDA and its conversion to food-based dietary guidelines will facilitate education to the public, as well as the policy implementation of programs for prevention of non-communicable chronic diseases and addressing the double burden of both under and over nutrition.
Toy models for wrapping effects
Penedones, João; Vieira, Pedro
2008-08-01
The anomalous dimensions of local single trace gauge invariant operators in Script N = 4 supersymmetric Yang-Mills theory can be computed by diagonalizing a long range integrable Hamiltonian by means of a perturbative asymptotic Bethe ansatz. This formalism breaks down when the number of fields of the composite operator is smaller than the range of the Hamiltonian which coincides with the order in perturbation theory at study. We analyze two spin chain toy models which might shed some light on the physics behind these wrapping effects. One of them, the Hubbard model, is known to be closely related to Script N = 4 SYM. In this example, we find that the knowledge of the effective spin chain description is insufficient to reconstruct the finite size effects of the underlying electron theory. We compute the wrapping corrections for generic states and relate them to a Luscher like approach. The second toy models are long range integrable Hamiltonians built from the standard algebraic Bethe ansatz formalism. This construction is valid for any symmetry group. In particular, for non-compact groups it exhibits an interesting relation between wrapping interactions and transcendentality.
Entanglement effects in model polymer networks
Everaers, R.; Kremer, K.
The influence of topological constraints on the local dynamics in cross-linked polymer melts and their contribution to the elastic properties of rubber elastic systems are a long standing problem in statistical mechanics. Polymer networks with diamond lattice connectivity (Everaers and Kremer 1995, Everaers and Kremer 1996a) are idealized model systems which isolate the effect of topology conservation from other sources of quenched disorder. We study their behavior in molecular dynamics simulations under elongational strain. In our analysis we compare the measured, purely entropic shear moduli G to the predictions of statistical mechanical models of rubber elasticity, making extensive use of the microscopic structural and topological information available in computer simulations. We find (Everaers and Kremer 1995) that the classical models of rubber elasticity underestimate the true change in entropy in a deformed network significantly, because they neglect the tension along the contour of the strands which cannot relax due to entanglements (Everaers and Kremer (in preparation)). This contribution and the fluctuations in strained systems seem to be well described by the constrained mode model (Everaers 1998) which allows to treat the crossover from classical rubber elasticity to the tube model for polymer networks with increasing strand length within one transparant formalism. While this is important for the description of the effects we try to do a first quantitative step towards their explanation by topological considerations. We show (Everaers and Kremer 1996a) that for the comparatively short strand lengths of our diamond networks the topology contribution to the shear modulus is proportional to the density of entangled mesh pairs with non-zero Gauss linking number. Moreover, the prefactor can be estimated consistently within a rather simple model developed by Vologodskii et al. and by Graessley and Pearson, which is based on the definition of an entropic
Nonproductive Factor Allowance. (Pilot Study).
1980-03-31
a separate factor for each size of facility, i.e., MEDCEN, Large MEDDAC, and Small MEDDAC. f. In a GAO audit report, "Development and Use of Military...measurement in determining and Justifying staffing requirements. g. Another GAO audit report, "Uniform Accounting and Workload Measurement Systems Needed for...Effective Writing, AFIT, Survival, TDY, Technical Training, IDEA High School, CDC and Survey Taking. Also taking tests such as PFE , SKT, AF Sup Exam, CLEP
Yniguez, A.T.; McManus, J.W.; DeAngelis, D.L.
2008-01-01
The growth patterns of macroalgae in three-dimensional space can provide important information regarding the environments in which they live, and insights into changes that may occur when those environments change due to anthropogenic and/or natural causes. To decipher these patterns and their attendant mechanisms and influencing factors, a spatially explicit model has been developed. The model SPREAD (SPatially-explicit Reef Algae Dynamics), which incorporates the key morphogenetic characteristics of clonality and morphological plasticity, is used to investigate the influences of light, temperature, nutrients and disturbance on the growth and spatial occupancy of dominant macroalgae in the Florida Reef Tract. The model species, Halimeda and Dictyota spp., are modular organisms, with an 'individual' being made up of repeating structures. These species can also propagate asexually through clonal fragmentation. These traits lead to potentially indefinite growth and plastic morphology that can respond to environmental conditions in various ways. The growth of an individual is modeled as the iteration of discrete macroalgal modules whose dynamics are affected by the light, temperature, and nutrient regimes. Fragmentation is included as a source of asexual reproduction and/or mortality. Model outputs are the same metrics that are obtained in the field, thus allowing for easy comparison. The performance of SPREAD was tested through sensitivity analysis and comparison with independent field data from four study sites in the Florida Reef Tract. Halimeda tuna was selected for initial model comparisons because the relatively untangled growth form permits detailed characterization in the field. Differences in the growth patterns of H. tuna were observed among these reefs. SPREAD was able to closely reproduce these variations, and indicate the potential importance of light and nutrient variations in producing these patterns. ?? 2008 Elsevier B.V.
Mechanical effects in cookoff modeling
Energy Technology Data Exchange (ETDEWEB)
Gross, R.J.; Baer, M.R.; Hobbs, M.L.
1994-07-01
Complete cookoff modeling of energetic material in confined geometries must couple thermal, chemical and mechanical effects. In the past, modeling has focused on the prediction of the onset of combustion behavior based only on thermal-chemistry effects with little or no regard to the mechanical behavior of the energetic material. In this paper, an analysis tool is outlined which couples thermal, chemical, and mechanical behavior for one-dimensional Geometries comprised of multi-materials. A reactive heat flow code, XCHEM, and a quasistatic mechanics code, SANTOS, have been completely coupled using, a reactive, elastic-plastic constitutive model describing pressurization of the energetic material. This new Thermally Reactive Elastic-plastic explosive code, TREX, was developed to assess the coupling, of mechanics with thermal chemistry making multidimensional cookoff analysis possible. In this study, TREX is applied to confined and unconfined systems. The confined systems simulate One-Dimensional Time to explosion (ODTX) experiments in both spherical and cylindrical configurations. The spherical ODTX system is a 1.27 cm diameter sphere of TATB confined by aluminum exposed to a constant external temperature. The cylindrical ODTX system is an aluminum tube filled with HMX, NC, and inert exposed to a constant temperature bath. Finally. an unconfined system consisting of a hollow steel cylinder filled with a propellant composed of Al, RMX, and NC, representative of a rocket motor, is considered. This model system is subjected to transient internal and external radiative/convective boundary conditions representative of 5 minutes exposure to a fire. The confined systems show significant pressure prior to ignition, and the unconfined system shows extrusion of the propellent suggesting that the energetic material becomes more shock sensitive.
Analysis of electric vehicle's trip cost allowing late arrival
Leng, Jun-Qiang; Liu, Wei-Yi; Zhao, Lin
2017-05-01
In this paper, we use a car-following model to study each electric vehicle's trip cost and the total trip cost allowing late arrival. The numerical result show that the electricity cost has great effects on each commuter's trip cost and the total trip costs and that these effects are dependent on each commuter's time headway at the origin, but the electricity cost has no prominent impacts on the minimum value of total trip cost under each commuter's different time headway at the origin.
Random Effect and Latent Variable Model Selection
Dunson, David B
2008-01-01
Presents various methods for accommodating model uncertainty in random effects and latent variable models. This book focuses on frequentist likelihood ratio and score tests for zero variance components. It also focuses on Bayesian methods for random effects selection in linear mixed effects and generalized linear mixed models
Nuclear EMC effect in non-extensive statistical model
Trevisan, Luis A.; Mirez, Carlos
2013-05-01
In the present work, we attempt to describe the nuclear EMC effect by using the proton structure functions obtained from the non-extensive statistical quark model. We record that such model has three fundamental variables, the temperature T, the radius, and the Tsallis parameter q. By combining different small changes, a good agreement with the experimental data may be obtained. Another interesting point of the model is to allow phenomenological interpretation, for instance, with q constant and changing the radius and the temperature or changing the radius and q and keeping the temperature.
46 CFR 154.421 - Allowable stress.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.421 Section 154.421 Shipping COAST... § 154.421 Allowable stress. The allowable stress for the integral tank structure must meet the American Bureau of Shipping's allowable stress for the vessel's hull published in “Rules for Building and Classing...
46 CFR 154.440 - Allowable stress.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.440 Section 154.440 Shipping COAST... Tank Type A § 154.440 Allowable stress. (a) The allowable stresses for an independent tank type A must... Commandant (CG-522). (b) A greater allowable stress than required in paragraph (a)(1) of this section may be...
A Departmental Cost-Effectiveness Model.
Holleman, Thomas, Jr.
In establishing a departmental cost-effectiveness model, the traditional cost-effectiveness model was discussed and equipped with a distant and deflation equation for both benefits and costs. Next, the economics of costing was examined and program costing procedures developed. Then, the model construct was described as it was structured around the…
Model instruments of effective segmentation of the fast food market
Directory of Open Access Journals (Sweden)
Mityaeva Tetyana L.
2013-03-01
Full Text Available The article presents results of optimisation step-type calculations of economic effectiveness of promotion of fast food with consideration of key parameters of assessment of efficiency of the marketing strategy of segmentation. The article justifies development of a mathematical model on the bases of 3D-presentations and three-dimensional system of management variables. The modern applied mathematical packages allow formation not only of one-dimensional and two-dimensional arrays and analyse links of variables, but also of three-dimensional, besides, the more links and parameters are taken into account, the more adequate and adaptive are results of modelling and, as a result, more informative and strategically valuable. The article shows modelling possibilities that allow taking into account strategies and reactions on formation of the marketing strategy under conditions of entering the fast food market segments.
The differential susceptibility to media effects model
Valkenburg, P.M.; Peter, J.
2013-01-01
In this theoretical article, we introduce the Differential Susceptibility to Media Effects Model (DSMM), a new, integrative model to improve our understanding of media effects. The DSMM organizes, integrates, and extends the insights developed in earlier microlevel media-effects theories. It
The differential susceptibility to media effects model
Valkenburg, P.M.; Peter, J.
2013-01-01
In this theoretical article, we introduce the Differential Susceptibility to Media Effects Model (DSMM), a new, integrative model to improve our understanding of media effects. The DSMM organizes, integrates, and extends the insights developed in earlier microlevel media-effects theories. It disting
The differential susceptibility to media effects model
Valkenburg, P.M.; Peter, J.
2013-01-01
In this theoretical article, we introduce the Differential Susceptibility to Media Effects Model (DSMM), a new, integrative model to improve our understanding of media effects. The DSMM organizes, integrates, and extends the insights developed in earlier microlevel media-effects theories. It disting
Institute of Scientific and Technical Information of China (English)
覃朝晖; 张训保; 姚元虎; 卓朗; 谷玉明
2011-01-01
[Objective] To evaluate the effectiveness on psychological health intervention among the urban residents living on minimum subsistence allowances, and search for a suitable strategy of psychological health intervention. [Methods] 445 people living; on minimum subsistence allowances in Xuzhou were selected by the method of systematic and cluster sampling and were matched with 445 controls who were not living on minimum subsistence allowances. The people living on minimum subsistence allowances were divided into intervention group and control group. A general intervention based on community involved psycholgical health and care lecture, psychodrama treatment and psychological consultancy was made on the intervention group. SCL-90 was used to evaluate the paychological health status and the effecbveness of psychological health intervention.[Resutts] People living on minimum subsistence allowances had higher score in SCL-90 compared with other residents and psychological health of them was serious. After the psychological health intervention, the score of SCL-90 of intervention group on interpersonal relationship sensitiveness. anxiety, hostility and other factor was lower than the control group (P＜ 0.05) and the score of SCL-90 of the control group on interpersonal relationship sensitiveness, anxiety. hostility and other factor was higher than before the intervention (P＜ 0.05). [Conclusion] The objects ' p8ychological health was improved by general intervention based on community and more positive measure of psychological health intervention should be enforced in order to improve their psychological health%[目的]评价低保人员心理干预措施的效果,以期找到对该人群进行心理干预的方法.[方法]采用系统和整群抽样的方法抽取徐州市低保人员445人为调查对象,并选取455名非低保人员进行1:1配对.将低保人员分为干预组和对照组,对干预组实施以社区为基础的综合心理干预.干预方法主
Clean Air Markets - Allowances Query Wizard
U.S. Environmental Protection Agency — The Allowances Query Wizard is part of a suite of Clean Air Markets-related tools that are accessible at http://camddataandmaps.epa.gov/gdm/index.cfm. The Allowances...
Allowance Holdings and Transfers Data Inventory
U.S. Environmental Protection Agency — The Allowance Holdings and Transfers Data Inventory contains measured data on holdings and transactions of allowances under the NOx Budget Trading Program (NBP), a...
Allowable carbon emissions for medium-to-high mitigation scenarios
Energy Technology Data Exchange (ETDEWEB)
Tachiiri, Kaoru; Hargreaves, Julia C.; Annan, James D.; Kawamiya, Michio [Research Inst. for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, (Japan)], e-mail: tachiiri@jamstec.go.jp; Huntingford, Chris [Centre for Ecology and Hydrology, Wallingford (United Kingdom)
2013-11-15
Using an ensemble of simulations with an intermediate complexity climate model and in a probabilistic framework, we estimate future ranges of carbon dioxide (CO{sub 2}) emissions in order to follow three medium-high mitigation concentration pathways: RCP2.6, RCP4.5 and SCP4.5 to 2.6. Uncertainty is first estimated by allowing modelled equilibrium climate sensitivity, aerosol forcing and intrinsic physical and biogeochemical processes to vary within widely accepted ranges. Results are then constrained by comparison against contemporary measurements. For both constrained and unconstrained projections, our calculated allowable emissions are close to the standard (harmonised) emission scenarios associated with these pathways. For RCP4.5, which is the most moderate scenario considered in terms of required emission abatement, then after year 2100 very low net emissions are needed to maintain prescribed year 2100 CO{sub 2} concentrations. As expected, RCP2.6 and SCP4.5 to 2.6 require more strict emission reductions. The implication of this is that direct sequestration of carbon dioxide is likely to be required for RCP4.5 or higher mitigation scenarios, to offset any minimum emissions for society to function (the 'emissions floor'). Despite large uncertainties in the physical and biogeochemical processes, constraints from model-observational comparisons support a high degree of confidence in predicting the allowable emissions consistent with a particular concentration pathway. In contrast the uncertainty in the resulting temperature range remains large. For many parameter sets, and especially for RCP2.6, the land will turn into a carbon source within the twenty first century, but the ocean will remain as a carbon sink. For land carbon storage and our modelling framework, major reductions are seen in northern high latitudes and the Amazon basin even after atmospheric CO{sub 2} is stabilised, while for ocean carbon uptake, the tropical ocean regions will be a
An Effective ARMA Modeling Method.
1981-04-01
directed towards spectral analysis, power spectral density function the preponderance of effort has been directed to- wards two special cases of the...domain spectral density function than from pole model, and, the general ARMA model is seen to its equivalent time domain autocorrelation sequence. be...n-k) (11) prediction. Assuming this prediction behavior, it k-I then follows from relationship (11) that the spectral density function of the time
The Hawking effect in dielectric media and the Hopfield model
Belgiorno, F; Piazza, F Dalla
2014-01-01
We consider the so-called Hopfield model for the electromagnetic field in a dielectric dispersive medium in a framework in which one allows a space-time dependence of microscopic parameters, aimed to a phenomenological description of a space-time varying dielectric perturbation induced by means of the Kerr effect. We discuss the analogue Hawking effect, by first analyzing the geometrical optics for the Hopfield model, and then by introducing a simplified model which has the bonus to avoid many difficulties which are involved in the full Hopfield model, still keeping the same dispersion relation. Amplitude calculations are indicated, and generalized Manley-Rowe identities are derived in a quantum scattering theory framework. Our main result is an analytical calculation of the spontaneous thermal emission in the single-branch case, which is provided non perturbatively for the first time in the framework of dielectric black holes. An universal mechanism for thermality between optical black holes and acoustic bla...
46 CFR 154.428 - Allowable stress.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.428 Section 154.428 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.428 Allowable stress. The membrane tank and the supporting insulation must have allowable stresses...
46 CFR 154.447 - Allowable stress.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Allowable stress. 154.447 Section 154.447 Shipping COAST... Tank Type B § 154.447 Allowable stress. (a) An independent tank type B designed from bodies of revolution must have allowable stresses 3 determined by the following formulae: 3 See Appendix B for stress...
Contact Interactions Probe Effective Dark Matter Models at the LHC
Dreiner, Herbi; Tattersall, Jamie
2013-01-01
Effective field theories provide a simple framework for probing possible dark matter (DM) models by reparametrising full interactions into a reduced number of operators with smaller dimensionality in parameter space. In many cases these models have four particle vertices, e.g. qqXX, leading to the pair production of dark matter particles, X, at a hadron collider from initial state quarks, q. In this analysis we show that for many fundamental DM models with s-channel DM couplings to qq-pairs, these effective vertices must also produce quark contact interactions (CI) of the form qqqq. The respective effective couplings are related by the common underlying theory which allows one to translate the upper limits from one coupling to the other. We show that at the LHC, the experimental limits on quark contact interactions give stronger translated limits on the DM coupling than the experimental searches for dark matter pair production.
Allowing for heterogeneity in monetary subjective well-being valuations.
Mentzakis, Emmanouil
2011-03-01
Recent research on 'happiness' regression equations has shown how monetary values can be put on the well-being effects of many life events (like health problems, marriage or the death of a spouse). Potentially, such work has practical implications for policy-makers and the courts. However, this article argues that we need to be careful in such work to use the appropriate statistical method. It goes beyond previous research and allows for heterogeneity in the subjective well-being scales. Using less restrictive models than the current literature, the article argues that standard linear or ordered response models seem consistently to overstate valuations. With data from the UK, it provides new monetary estimates of the well-being consequences of a number of health problems, social capital indicators, marital status changes and social relationships.
Modeling the effects of labeling
DEFF Research Database (Denmark)
Juhl, Hans Jørn; Fjord, Thomas Ahle; Poulsen, Carsten Stig
A new approach to evaluate the consequences of labeling is presented and applied to test the potential effect of a label on fresh fish. Labeling effects on quality perceptions and overall quality are studied. The empirical study is based on an experimental design and nearly 500 respondents...
Effective Charge on Polymer Colloids Obtained Using a Renormalization Model.
Quesada-Pérez; Callejas-Fernández; Hidalgo-Álvarez
1998-10-01
Static light scattering has been used to study the electrostatic interaction between colloidal particles. Experiments were carried out using a latex with a very small diameter, allowing structure determination at high particle concentration. The obtained effective charge characterizing this interaction is found to be smaller than the bare charge determined from titration. A renormalization model connecting both values has been used. The agreement between the renormalized charge and that obtained from scattering data seems to point out that this model operates well. Copyright 1998 Academic Press.
"Home Made" Model to Study the Greenhouse Effect and Global Warming
Onorato, P.; Mascheretti, P.; DeAmbrosis, A.
2011-01-01
In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of…
"Home Made" Model to Study the Greenhouse Effect and Global Warming
Onorato, P.; Mascheretti, P.; DeAmbrosis, A.
2011-01-01
In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of…
Modeling of Pressure Effects in HVDC Cables
DEFF Research Database (Denmark)
Szabo, Peter; Hassager, Ole; Strøbech, Esben
1999-01-01
A model is developed for the prediction of pressure effects in HVDC mass impregnatedcables as a result of temperature changes.To test the model assumptions, experiments were performed in cable like geometries.It is concluded that the model may predict the formation of gas cavities....
A Model for Measuring Puffery Effects.
Vanden Bergh, Bruce G.; Reid, Leonard N.
The purpose of this paper is to describe and discuss a conceptual model for experimentally investigating the effects of advertising puffery. The various sections contain a discussion of puffery as a legal concept, a description and discussion of the proposed model, research support for the model, and implications for future research on puffery.…
Analytical modelling of temperature effects on synapses
Kufel, Dominik S
2016-01-01
It was previously reported, that temperature may significantly influence neural dynamics on different levels of brain modelling. Due to this fact, while creating the model in computational neuroscience we would like to make it scalable for wide-range of various brain temperatures. However currently, because of a lack of experimental data and an absence of analytical model describing temperature influence on synapses, it is not possible to include temperature effects on multi-neuron modelling level. In this paper, we propose first step to deal with this problem: new analytical model of AMPA-type synaptic conductance, which is able to include temperature effects in low-frequency stimulations. It was constructed on basis of Markov model description of AMPA receptor kinetics and few simplifications motivated both experimentally and from Monte Carlo simulation of synaptic transmission. The model may be used for efficient and accurate implementation of temperature effects on AMPA receptor conductance in large scale...
Circuit models and SPICE macro-models for quantum Hall effect devices
Ortolano, Massimo
2015-01-01
Quantum Hall effect (QHE) devices are a pillar of modern quantum electrical metrology. Electrical networks including one or more QHE elements can be used as quantum resistance and impedance standards. The analysis of these networks allows metrologists to evaluate the effect of the inevitable parasitic parameters on their performance as standards. This paper presents a systematic analysis of the various circuit models for QHE elements proposed in the literature, and the development of a new model. This last model is particularly suited to be employed with the analogue electronic circuit simulator SPICE. The SPICE macro-model and examples of SPICE simulations, validated by comparison with the corresponding analytical solution and/or experimental data, are provided.
Modelling of Size Effect with Regularised Continua
Directory of Open Access Journals (Sweden)
H. Askes
2004-01-01
Full Text Available A nonlocal damage continuum and a viscoplastic damage continuum are used to model size effects. Three-point bending specimens are analysed, whereby a distinction is made between unnotched specimens, specimens with a constant notch and specimens with a proportionally scaled notch. Numerical finite element simulations have been performed for specimen sizes in a range of 1:64. Size effects are established in terms of nominal strength and compared to existing size effect models from the literature.
Nanoindentation shape effect: experiments, simulations and modelling
Energy Technology Data Exchange (ETDEWEB)
Calabri, L [CNR-INFM-National Research Center on nanoStructures and bioSystems at Surfaces (S3), Via Campi 213/a, 41100 Modena (Italy); Pugno, N [Department of Structural Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy); Rota, A [CNR-INFM-National Research Center on nanoStructures and bioSystems at Surfaces (S3), Via Campi 213/a, 41100 Modena (Italy); Marchetto, D [CNR-INFM-National Research Center on nanoStructures and bioSystems at Surfaces (S3), Via Campi 213/a, 41100 Modena (Italy); Valeri, S [CNR-INFM-National Research Center on nanoStructures and bioSystems at Surfaces (S3), Via Campi 213/a, 41100 Modena (Italy)
2007-10-03
AFM nanoindentation is nowadays commonly used for the study of mechanical properties of materials at the nanoscale. The investigation of surface hardness of a material using AFM means that the probe has to be able to indent the surface, but also to image it. Usually standard indenters are not sharp enough to obtain high-resolution images, but on the other hand measuring the hardness behaviour of a material with a non-standard sharp indenter gives only comparative results affected by a significant deviation from the commonly used hardness scales. In this paper we try to understand how the shape of the indenter affects the hardness measurement, in order to find a relationship between the measured hardness of a material and the corner angle of a pyramidal indenter. To achieve this we performed a full experimental campaign, indenting the same material with three focused ion beam (FIB) nanofabricated probes with a highly altered corner angle. We then compared the results obtained experimentally with those obtained by numerical simulations, using the finite element method (FEM), and by theoretical models, using a general scaling law for nanoindentation available for indenters with a variable size and shape. The comparison between these three approaches (experimental, numerical and theoretical approaches) reveals a good agreement and allowed us to find a theoretical relationship which links the measured hardness value with the shape of the indenter. The same theoretical approach has also been used to fit the hardness experimental results considering the indentation size effect. In this case we compare the measured data, changing the applied load.
Nonextensive critical effects in the Nambu--Jona-Lasinio model
Rozynek, Jacek
2009-01-01
The critical phenomena in strongly interaction matter are generally investigated using the mean-field model and are characterized by well defined critical exponents. However, such models provide only average properties of the corresponding order parameters and neglect altogether their possible fluctuations. Also the possible long range effect are neglected in the mean field approach. Here we investigate the critical behavior in the nonextensive version of the Nambu Jona-Lasinio model (NJL). It allows to account for such effects in a phenomenological way by means of a single parameter $q$, the nonextensivity parameter. In particular, we show how the nonextensive statistics influence the region of the critical temperature and chemical potential in the NJL mean field approach.
Multivariate parametric random effect regression models for fecundability studies.
Ecochard, R; Clayton, D G
2000-12-01
Delay until conception is generally described by a mixture of geometric distributions. Weinberg and Gladen (1986, Biometrics 42, 547-560) proposed a regression generalization of the beta-geometric mixture model where covariates effects were expressed in terms of contrasts of marginal hazards. Scheike and Jensen (1997, Biometrics 53, 318-329) developed a frailty model for discrete event times data based on discrete-time analogues of Hougaard's results (1984, Biometrika 71, 75-83). This paper is on a generalization to a three-parameter family distribution and an extension to multivariate cases. The model allows the introduction of explanatory variables, including time-dependent variables at the subject-specific level, together with a choice from a flexible family of random effect distributions. This makes it possible, in the context of medically assisted conception, to include data sources with multiple pregnancies (or attempts at pregnancy) per couple.
Effective Elliptic Models for Efficient Wavefield Extrapolation in Anisotropic Media
Waheed, Umair bin
2014-05-01
Wavefield extrapolation operator for elliptically anisotropic media offers significant cost reduction compared to that of transversely isotropic media (TI), especially when the medium exhibits tilt in the symmetry axis (TTI). However, elliptical anisotropy does not provide accurate focusing for TI media. Therefore, we develop effective elliptically anisotropic models that correctly capture the kinematic behavior of the TTI wavefield. Specifically, we use an iterative elliptically anisotropic eikonal solver that provides the accurate traveltimes for a TI model. The resultant coefficients of the elliptical eikonal provide the effective models. These effective models allow us to use the cheaper wavefield extrapolation operator for elliptic media to obtain approximate wavefield solutions for TTI media. Despite the fact that the effective elliptic models are obtained by kinematic matching using high-frequency asymptotic, the resulting wavefield contains most of the critical wavefield components, including the frequency dependency and caustics, if present, with reasonable accuracy. The methodology developed here offers a much better cost versus accuracy tradeoff for wavefield computations in TTI media, considering the cost prohibitive nature of the problem. We demonstrate the applicability of the proposed approach on the BP TTI model.
Institute of Scientific and Technical Information of China (English)
覃朝晖; 刘苏; 姚元虎; 张训保; 谷玉明; 卓朗; 杜鹃; 梁格; 邹青青; 衡娟
2010-01-01
目的 评价老年低保人员心理干预措施的效果,以期找到对该人群进行心理干预的方法.方法 采用分层整群抽样的方法抽取徐州市老年低保人员112人为调查对象,并选取112名非低保人员进行1∶1配对.将低保人员分为干预组和对照组,对干预组实施心理干预.干预方法主要有心理健康讲座、心理咨询和心理剧治疗等.使用SCL-90量表进行心理卫生状况调查并评价心理干预效果.结果 SCL-90量表评分显示老年低保人员9个因子分均高于非低保人员,心理卫生状况较差.实施心理干预后,干预组的人际关系敏感[(1.13±0.39)与(1.26±0.26),t=2.12,P=0.04]、忧郁[(1.23±0.66)与(1.43±0.24),t=2.08,P=0.04]、焦虑[(1.18±0.50)与(1.38±0.34),t=2.17,P=0.03]、敌对[(1.24±0.49)与(1.40±0.28),t=2.03,P=0.04]和其他项目[(1.31±0.56)与(1.49±0.31),t=2.04,P=0.04]5个因子分及总得分[(115.89±17.21)与(122.64±10.41),t=2.42,P=0.02]均低于对照组.结论 通过实施社区综合心理干预,老年低保人员心理卫生问题得到一定程度的改善.%Objective To evaluate the effectiveness of psychological health intervention in the elderly urban residents living on minimum subsistence allowances, and to search for a suitable psychological health intervention strategy. Methods The 112 elderly persons living on minimum subsistence allowances in Xuzhou were selected by stratified cluster sampling, and they were matched with 112 controls. The elderly persons living on minimum subsistence allowances were divided into intervention group and control group. A general intervention based on community involved psychological health and care lecture, psychodrama treatment and psychological consultancy was made on the intervention. The SCL-90 was used to evaluate the psychological health status and effectiveness of psychological health intervention. Results The elderly persons living on minimum subsistence allowances had higher SCL-90 scores
A sonic boom propagation model including mean flow atmospheric effects
Salamone, Joe; Sparrow, Victor W.
2012-09-01
This paper presents a time domain formulation of nonlinear lossy propagation in onedimension that also includes the effects of non-collinear mean flow in the acoustic medium. The model equation utilized is an augmented Burgers equation that includes the effects of nonlinearity, geometric spreading, atmospheric stratification, and also absorption and dispersion due to thermoviscous and molecular relaxation effects. All elements of the propagation are implemented in the time domain and the effects of non-collinear mean flow are accounted for in each term of the model equation. Previous authors have presented methods limited to showing the effects of wind on ray tracing and/or using an effective speed of sound in their model equation. The present work includes the effects of mean flow for all terms included in the augmented Burgers equation with all of the calculations performed in the time-domain. The capability to include the effects of mean flow in the acoustic medium allows one to make predictions more representative of real-world atmospheric conditions. Examples are presented for nonlinear propagation of N-waves and shaped sonic booms. [Work supported by Gulfstream Aerospace Corporation.
45 CFR 74.27 - Allowable costs.
2010-10-01
... 45 Public Welfare 1 2010-10-01 2010-10-01 false Allowable costs. 74.27 Section 74.27 Public..., AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 74.27 Allowable costs. (a) For each kind of recipient, there is a particular set of Federal principles...
28 CFR 100.11 - Allowable costs.
2010-07-01
... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Allowable costs. 100.11 Section 100.11 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) COST RECOVERY REGULATIONS, COMMUNICATIONS ASSISTANCE FOR LAW ENFORCEMENT ACT OF 1994 § 100.11 Allowable costs. (a) Costs that are eligible...
20 CFR 633.303 - Allowable costs.
2010-04-01
... occupation trained for and at not less than the wage specified in the agreement. (g) Travel costs. (1) The... to the overall administrative cost ceiling. (i) Allowances and reimbursements for board and advisory... grantee per quarter. (2) Allowances and loss of wages. Any individual or family member who is a member of...
75 FR 4098 - Utility Allowance Adjustments
2010-01-26
... URBAN DEVELOPMENT Utility Allowance Adjustments AGENCY: Office of the Chief Information Officer, HUD... are required to advise the Secretary of the need for and request of a new utility allowance for... whether the information will have practical utility; (2) Evaluate the accuracy of the agency's estimate...
44 CFR 13.22 - Allowable costs.
2010-10-01
... uniform cost accounting standards that comply with cost principles acceptable to the Federal agency. ... STATE AND LOCAL GOVERNMENTS Post-Award Requirements Financial Administration § 13.22 Allowable costs. (a... increment above allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each...
32 CFR 33.22 - Allowable costs.
2010-07-01
... accounting standards that comply with cost principles acceptable to the Federal agency. ... Post-Award Requirements Financial Administration § 33.22 Allowable costs. (a) Limitation on use of... allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each kind of...
36 CFR 1207.22 - Allowable costs.
2010-07-01
... uniform cost accounting standards that comply with cost principles acceptable to the Federal agency. ... GOVERNMENTS Post-Award Requirements Financial Administration § 1207.22 Allowable costs. (a) Limitation on use... increment above allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each...
34 CFR 74.27 - Allowable costs.
2010-07-01
... Procedures or uniform cost accounting standards that comply with cost principles acceptable to ED. (b) The... OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial... principles for determining allowable costs. Allowability of costs are determined in accordance with the...
5 CFR 180.104 - Allowable claims.
2010-01-01
... mobile homes may be allowed only in cases of collision, theft, or vandalism. (5) Money. Claims for money... claimant's supervisor. (4) Mobile homes. Claims may be allowed for damage to or loss of mobile homes and their contents under the provisions of § 180.104(c)(2). Claims for structural damage to mobile...
38 CFR 49.27 - Allowable costs.
2010-07-01
... ADMINISTRATIVE REQUIREMENTS FOR GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 49.27 Allowable...-Profit Organizations.” The allowability of costs incurred by institutions of higher education...
20 CFR 435.27 - Allowable costs.
2010-04-01
... AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, OTHER NON-PROFIT ORGANIZATIONS, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 435.27 Allowable costs. For each kind... Organizations.” (c) Allowability of costs incurred by institutions of higher education is determined...
28 CFR 70.27 - Allowable costs.
2010-07-01
... AND AGREEMENTS (INCLUDING SUBAWARDS) WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 70.27 Allowable costs. (a... Organizations.” The allowability of costs incurred by institutions of higher education is determined...
15 CFR 14.27 - Allowable costs.
2010-01-01
... GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, OTHER NON-PROFIT, AND COMMERCIAL ORGANIZATIONS Post-Award Requirements Financial and Program Management § 14.27 Allowable costs. For each kind of... Organizations.” The allowability of costs incurred by institutions of higher education is determined...
24 CFR 17.43 - Allowable claims.
2010-04-01
... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Allowable claims. 17.43 Section 17.43 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development..., superior authority. (6) Clothing and accessories. Claims may be allowed for damage to, or loss of, clothing...
29 CFR 1470.22 - Allowable costs.
2010-07-01
... to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set of Federal principles for determining allowable costs. Allowable costs will be determined in accordance...
45 CFR 2541.220 - Allowable costs.
2010-10-01
... accounting standards that comply with cost principles acceptable to the Federal agency. ... the grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set of Federal principles for determining allowable costs. Allowable costs will be determined...
Comparative assessment of PV plant performance models considering climate effects
DEFF Research Database (Denmark)
Tina, Giuseppe; Ventura, Cristina; Sera, Dezso
2017-01-01
The paper investigates the effect of climate conditions on the accuracy of PV system performance models (physical and interpolation methods) which are used within a monitoring system as a reference for the power produced by a PV system to detect inefficient or faulty operating conditions....... The methodological approach is based on comparative tests of the analyzed models applied to two PV plants installed respectively in north of Denmark (Aalborg) and in the south of Italy (Agrigento). The different ambient, operating and installation conditions allow to understand how these factors impact the precision...... and effectiveness of such approaches, among these factors it is worth mentioning the different percentage of diffuse component of the yearly solar radiation on the global one. The experimental results show the effectiveness of the proposed approach. In order to have the possibility to analyze and compare...
Chan, Jennifer S K
2016-05-01
Dropouts are common in longitudinal study. If the dropout probability depends on the missing observations at or after dropout, this type of dropout is called informative (or nonignorable) dropout (ID). Failure to accommodate such dropout mechanism into the model will bias the parameter estimates. We propose a conditional autoregressive model for longitudinal binary data with an ID model such that the probabilities of positive outcomes as well as the drop-out indicator in each occasion are logit linear in some covariates and outcomes. This model adopting a marginal model for outcomes and a conditional model for dropouts is called a selection model. To allow for the heterogeneity and clustering effects, the outcome model is extended to incorporate mixture and random effects. Lastly, the model is further extended to a novel model that models the outcome and dropout jointly such that their dependency is formulated through an odds ratio function. Parameters are estimated by a Bayesian approach implemented using the user-friendly Bayesian software WinBUGS. A methadone clinic dataset is analyzed to illustrate the proposed models. Result shows that the treatment time effect is still significant but weaker after allowing for an ID process in the data. Finally the effect of drop-out on parameter estimates is evaluated through simulation studies.
Assessing allowable take of migratory birds
Runge, M.C.; Sauer, J.R.; Avery, M.L.; Blackwell, B.F.; Koneff, M.D.
2009-01-01
Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520?212,100) in 2006. Using a simple population model and available estimates of life-history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7?14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 x rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was <3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long-term, that is, sustained harvest rate should be
Keynes, family allowances and Keynesian economic policy
Pressman, Steven
2014-01-01
This paper provides a short history of family allowances and documents the fact that Keynes supported family allowances as early as the 1920s, continuing through the 1930s and early 1940s. Keynes saw this policy as a way to help households raise their children and also as a way to increase consumption without reducing business investment. The paper goes on to argue that a policy of family allowances is consistent with Keynesian economics. Finally, the paper uses the Luxembourg Income Study to...
Little Higgs model effects in →
Indian Academy of Sciences (India)
S Rai Choudhury; Ashok Goyal; A S Cornell; Naveen Gaur
2007-11-01
Though the predictions of the standard model (SM) are in excellent agreement with experiments, there are still several theoretical problems associated with the Higgs sector of the SM, where it is widely believed that some new physics will take over at the TeV scale. One beyond the SM theory which resolves these problems is the Little Higgs (LH) model. In this work we have investigated the effects of the LH model on → scattering [1].
Instructional Models Effective in Distance Education.
Jackman, Diane H.; Swan, Michael K.
The purpose of this study was to identify which instructional models based on the framework of Joyce, Weil, and Showers, could be used effectively in distance education over the Interactive Video Network (IVN) system in North Dakota. Instructional models have been organized into families such as Information Processing, Social, Personal, and…
Modelling of Deterioration Effects on Concrete Structures
Directory of Open Access Journals (Sweden)
B. Teplý
2002-01-01
Full Text Available In order to predict the service life of concrete structures models for deterioration effects are needed. This paper has the form of a survey, listing and describing such analytical models, namely carbonation of concrete, ingress of chlorides, corrosion of reinforcing steel and prestressing tendons. The probabilistic approach is applied.
Sign Patterns That Allow the Given Matrix
Institute of Scientific and Technical Information of China (English)
邵燕灵; 孙良
2003-01-01
Let P be a property referring to a real matrix. For a sign pattern A, if there exists a real matrix B in the qualitative class of A such that B has property P, then we say A allows P. Three cases that A allows an M-matrix, an inverse M-matrix and a P0-matrix are considered. The complete characterizations are obtained.
Regulatory treatment of allowances and compliance costs
Energy Technology Data Exchange (ETDEWEB)
Rose, K. [National Regulatory Research Institute, Columbus, OH (United States)
1993-07-01
The Clean Air Act Amendments of 1990 (CAAA) established a national emission allowance trading system, a market-based form of environmental regulation designed to reduce and limit sulfur dioxide emissions. However, the allowance trading system is being applied primarily to an economically regulated electric utility industry. The combining of the new form of environmental regulation and economic regulation of electric utilities has raised a number of questions including what the role should be of the federal and state utility regulating commissions and how those actions will affect the decision making process of the utilities and the allowance market. There are several dimensions to the regulatory problems that commissions face. Allowances and utility compliance expenditures have implications for least-cost/IPR (integrated resource planning), prudence review procedures, holding company and multistate utility regulation and ratemaking treatment. The focus of this paper is on the ratemaking treatment. The following topics are covered: ratemaking treatment of allowances and compliance costs; Traditional cost-recovery mechanisms; limitations to the traditional approach; traditional approach and the allowance trading market; market-based cost recovery mechanisms; methods of determining the benchmark; determining the split between ratepayers and the utility; other regulatory approaches; limitations of incentive mechanisms.
Maximum Allowable Dynamic Load of Mobile Manipulators with Stability Consideration
Directory of Open Access Journals (Sweden)
Heidary H. R.
2015-09-01
Full Text Available High payload to mass ratio is one of the advantages of mobile robot manipulators. In this paper, a general formula for finding the maximum allowable dynamic load (MADL of wheeled mobile robot is presented. Mobile manipulators operating in field environments will be required to manipulate large loads, and to perform such tasks on uneven terrain, which may cause the system to reach dangerous tip-over instability. Therefore, the method is expanded for finding the MADL of mobile manipulators with stability consideration. Moment-Height Stability (MHS criterion is used as an index for the system stability. Full dynamic model of wheeled mobile base and mounted manipulator is considered with respect to the dynamic of non-holonomic constraint. Then, a method for determination of the maximum allowable loads is described, subject to actuator constraints and by imposing the stability limitation as a new constraint. The actuator torque constraint is applied by using a speed-torque characteristics curve of a typical DC motor. In order to verify the effectiveness of the presented algorithm, several simulation studies considering a two-link planar manipulator, mounted on a mobile base are presented and the results are discussed.
Reaching Consensus by Allowing Moments of Indecision
Svenkeson, A.; Swami, A.
2015-10-01
Group decision-making processes often turn into a drawn out and costly battle between two opposing subgroups. Using analytical arguments based on a master equation description of the opinion dynamics occurring in a three-state model of cooperatively interacting units, we show how the capability of a social group to reach consensus can be enhanced when there is an intermediate state for indecisive individuals to pass through. The time spent in the intermediate state must be relatively short compared to that of the two polar states in order to create the beneficial effect. Furthermore, the cooperation between individuals must not be too low, as the benefit to consensus is possible only when the cooperation level exceeds a specific threshold. We also discuss how zealots, agents that remain in one state forever, can affect the consensus among the rest of the population by counteracting the benefit of the intermediate state or making it virtually impossible for an opposition to form.
Modelling synergistic effects of appetite regulating hormones
DEFF Research Database (Denmark)
Schmidt, Julie Berg; Ritz, Christian
2016-01-01
We briefly reviewed one definition of dose addition, which is applicable within the framework of generalized linear models. We established how this definition of dose addition corresponds to effect addition in case only two doses per compound are considered for evaluating synergistic effects. The....... The link between definitions was exemplified for an appetite study where two appetite hormones were studied....
A Test of the Combined Effects Model.
Kimsey, William D.; And Others
Two waves of telephone interviews with a sample of 141 voters were used in a study of political communication effects during the 1974 congressional election in the Illinois 24th Congressional District. Seven variables specified by the combined-effects model were derived from the interviews and factor analyzed. Two factors were found and…
Applying learning theories and instructional design models for effective instruction.
Khalil, Mohammed K; Elkhider, Ihsan A
2016-06-01
Faculty members in higher education are involved in many instructional design activities without formal training in learning theories and the science of instruction. Learning theories provide the foundation for the selection of instructional strategies and allow for reliable prediction of their effectiveness. To achieve effective learning outcomes, the science of instruction and instructional design models are used to guide the development of instructional design strategies that elicit appropriate cognitive processes. Here, the major learning theories are discussed and selected examples of instructional design models are explained. The main objective of this article is to present the science of learning and instruction as theoretical evidence for the design and delivery of instructional materials. In addition, this article provides a practical framework for implementing those theories in the classroom and laboratory. Copyright © 2016 The American Physiological Society.
Optical Hall effect-model description: tutorial.
Schubert, Mathias; Kühne, Philipp; Darakchieva, Vanya; Hofmann, Tino
2016-08-01
The optical Hall effect is a physical phenomenon that describes the occurrence of magnetic-field-induced dielectric displacement at optical wavelengths, transverse and longitudinal to the incident electric field, and analogous to the static electrical Hall effect. The electrical Hall effect and certain cases of the optical Hall effect observations can be explained by extensions of the classic Drude model for the transport of electrons in metals. The optical Hall effect is most useful for characterization of electrical properties in semiconductors. Among many advantages, while the optical Hall effect dispenses with the need of electrical contacts, electrical material properties such as effective mass and mobility parameters, including their anisotropy as well as carrier type and density, can be determined from the optical Hall effect. Measurement of the optical Hall effect can be performed within the concept of generalized ellipsometry at an oblique angle of incidence. In this paper, we review and discuss physical model equations, which can be used to calculate the optical Hall effect in single- and multiple-layered structures of semiconductor materials. We define the optical Hall effect dielectric function tensor, demonstrate diagonalization approaches, and show requirements for the optical Hall effect tensor from energy conservation. We discuss both continuum and quantum approaches, and we provide a brief description of the generalized ellipsometry concept, the Mueller matrix calculus, and a 4×4 matrix algebra to calculate data accessible by experiment. In a follow-up paper, we will discuss strategies and approaches for experimental data acquisition and analysis.
A periodic pricing model considering reference effect
Directory of Open Access Journals (Sweden)
Yang Hui
2016-01-01
Full Text Available The purpose of this paper is to investigate the optimal pricing strategies with reference effects in revenue management settings. We firstly propose a static pricing model with the properties of stochastic demand, finite horizon and fixed capacity, and prove the existence and uniqueness of the solution. Secondly, we extend the fixed pricing model to a periodic pricing model and incorporate a memory-based reference price in the demand function to investigate how the reference effect impacts on traditional revenue management decisions. We present numerical examples in both low demand situations and high demand situations for different levels of reference effects and different updating frequencies. The results show that the dynamic pricing strategies are superior to a static one even when reference effects are taken into consideration. We also provide some manage-rial insights including pricing directions, pricing dispersion and the optimal updating frequency for both demand situations.
The media effect in Axelrod's model explained
Peres, Lucas R
2011-01-01
We revisit the problem of introducing an external global field -- the mass media -- in Axelrod's model of social dynamics, where in addition to their nearest neighbors, the agents can interact with a virtual neighbor whose cultural features are fixed from the outset. The finding that this apparently homogenizing field actually increases the cultural diversity has been considered a puzzle since the phenomenon was first reported more than a decade ago. Here we offer a simple explanation for it, which is based on the pedestrian observation that Axelrod's model exhibits more cultural diversity, i.e., more distinct cultural domains, when the agents are allowed to interact solely with the media field than when they can interact with their neighbors as well. In this perspective, it is the local homogenizing interactions that work towards making the absorbing configurations less fragmented as compared with the extreme situation in which the agents interact with the media only.
Epidemiological data suggest that a sedentary lifestyle may contribute to increased suseptibility to environmental pollutants. Furthermore, the association between a sedentary pattern and development of obesity may exacerbate susceptibility. To study the effects of ACT vs. SED l...
Epidemiological data suggest that a sedentary lifestyle may contribute to increased suseptibility to environmental pollutants. Furthermore, the association between a sedentary pattern and development of obesity may exacerbate susceptibility. To study the effects of ACT vs. SED l...
Effective ellipsoidal models for wavefield extrapolation in tilted orthorhombic media
Waheed, Umair Bin
2016-04-22
Wavefield computations using the ellipsoidally anisotropic extrapolation operator offer significant cost reduction compared to that for the orthorhombic case, especially when the symmetry planes are tilted and/or rotated. However, ellipsoidal anisotropy does not provide accurate wavefield representation or imaging for media of orthorhombic symmetry. Therefore, we propose the use of ‘effective ellipsoidally anisotropic’ models that correctly capture the kinematic behaviour of wavefields for tilted orthorhombic (TOR) media. We compute effective velocities for the ellipsoidally anisotropic medium using kinematic high-frequency representation of the TOR wavefield, obtained by solving the TOR eikonal equation. The effective model allows us to use the cheaper ellipsoidally anisotropic wave extrapolation operators. Although the effective models are obtained by kinematic matching using high-frequency asymptotic, the resulting wavefield contains most of the critical wavefield components, including frequency dependency and caustics, if present, with reasonable accuracy. The proposed methodology offers a much better cost versus accuracy trade-off for wavefield computations in TOR media, particularly for media of low to moderate anisotropic strength. Furthermore, the computed wavefield solution is free from shear-wave artefacts as opposed to the conventional finite-difference based TOR wave extrapolation scheme. We demonstrate applicability and usefulness of our formulation through numerical tests on synthetic TOR models. © 2016 Institute of Geophysics of the ASCR, v.v.i
A Hierarchical Bayes Error Correction Model to Explain Dynamic Effects of Price Changes
D. Fok (Dennis); R. Paap (Richard); C. Horváth (Csilla); Ph.H.B.F. Franses (Philip Hans)
2005-01-01
textabstractThe authors put forward a sales response model to explain the differences in immediate and dynamic effects of promotional prices and regular prices on sales. The model consists of a vector autoregression rewritten in error-correction format which allows to disentangle the immediate
The dynamic macroeconomic effects of tax policy in an overlapping generations model
Heijdra, BJ; Ligthart, JE
2000-01-01
The paper studies the dynamic allocation effects of tax policy within the context of an overlapping-generations model of the Blanchard-Yaari type. The model is extended to allow for endogenous labour supply and three tax instruments, viz. a capital tax, labour income tax, and consumption tax. Both a
A Second-Order Conditionally Linear Mixed Effects Model with Observed and Latent Variable Covariates
Harring, Jeffrey R.; Kohli, Nidhi; Silverman, Rebecca D.; Speece, Deborah L.
2012-01-01
A conditionally linear mixed effects model is an appropriate framework for investigating nonlinear change in a continuous latent variable that is repeatedly measured over time. The efficacy of the model is that it allows parameters that enter the specified nonlinear time-response function to be stochastic, whereas those parameters that enter in a…
A Hierarchical Bayes Error Correction Model to Explain Dynamic Effects of Price Changes
D. Fok (Dennis); R. Paap (Richard); C. Horváth (Csilla); Ph.H.B.F. Franses (Philip Hans)
2005-01-01
textabstractThe authors put forward a sales response model to explain the differences in immediate and dynamic effects of promotional prices and regular prices on sales. The model consists of a vector autoregression rewritten in error-correction format which allows to disentangle the immediate effec
Mental Models about Seismic Effects: Students' Profile Based Comparative Analysis
Moutinho, Sara; Moura, Rui; Vasconcelos, Clara
2016-01-01
Nowadays, meaningful learning takes a central role in science education and is based in mental models that allow the representation of the real world by individuals. Thus, it is essential to analyse the student's mental models by promoting an easier reconstruction of scientific knowledge, by allowing them to become consistent with the curricular…
Quantum theory allows for absolute maximal contextuality
Amaral, Barbara; Cunha, Marcelo Terra; Cabello, Adán
2015-12-01
Contextuality is a fundamental feature of quantum theory and a necessary resource for quantum computation and communication. It is therefore important to investigate how large contextuality can be in quantum theory. Linear contextuality witnesses can be expressed as a sum S of n probabilities, and the independence number α and the Tsirelson-like number ϑ of the corresponding exclusivity graph are, respectively, the maximum of S for noncontextual theories and for the theory under consideration. A theory allows for absolute maximal contextuality if it has scenarios in which ϑ /α approaches n . Here we show that quantum theory allows for absolute maximal contextuality despite what is suggested by the examination of the quantum violations of Bell and noncontextuality inequalities considered in the past. Our proof is not constructive and does not single out explicit scenarios. Nevertheless, we identify scenarios in which quantum theory allows for almost-absolute-maximal contextuality.
2010-04-01
... factor. Each Value at Risk model shall meet the applicable qualitative and quantitative requirements set... historical data to support a Value at Risk model, the measure obtained by computing the allowance for market... investment bank holding company or member of the affiliate group can demand payment after any payment is...
Dynamical effects of overparametrization in nonlinear models
Aguirre, Luis Antonio; Billings, S. A.
1995-01-01
This paper is concemed with dynamical reconstruction for nonlinear systems. The effects of the driving function and of the complexity of a given representation on the bifurcation patter are investigated. It is shown that the use of different driving functions to excite the system may yield models with different bifurcation patterns. The complexity of the reconstructions considered is quantified by the embedding dimension and the number of estimated parameters. In this respect it appears that models which reproduce the original bifurcation behaviour are of limited complexity and that excessively complex models tend to induce ghost bifurcations and spurious dynamical regimes. Moreover, some results suggest that the effects of overparametrization on the global dynamical behaviour of a nonlinear model may be more deleterious than the presence of moderate noise levels. In order to precisely quantify the complexity of the reconstructions, global polynomials are used although the results are believed to apply to a much wider class of representations including neural networks.
45 CFR 34.4 - Allowable claims.
2010-10-01
... government-owned or operated parking lot or garage incident to employment. This subsection does not include... amount allowed is the value of the vehicle at the time of loss as determined by the National Automobile.... Damage or loss of personal property, including baggage and household items, while being transported by...
45 CFR 2543.27 - Allowable costs.
2010-10-01
... Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL AND COMMUNITY SERVICE GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT... Organizations.” The allowability of costs incurred by institutions of higher education is determined in...
34 CFR 80.22 - Allowable costs.
2010-07-01
... CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting standards that comply... COOPERATIVE AGREEMENTS TO STATE AND LOCAL GOVERNMENTS Post-Award Requirements Financial Administration § 80.22... kind of organization, there is a set of Federal principles for determining allowable costs. For...
13 CFR 143.22 - Allowable costs.
2010-01-01
... to that circular 48 CFR part 31. Contract Cost Principles and Procedures, or uniform cost accounting... Financial Administration § 143.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set...
38 CFR 43.22 - Allowable costs.
2010-07-01
... accounting standards that comply with cost principles acceptable to the Federal agency. ... Requirements Financial Administration § 43.22 Allowable costs. (a) Limitation on use of funds. Grant funds may... the grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is...
22 CFR 135.22 - Allowable costs.
2010-04-01
... Procedures, or uniform cost accounting standards that comply with cost principles acceptable to the Federal... AGREEMENTS TO STATE AND LOCAL GOVERNMENTS Post-Award Requirements Financial Administration § 135.22 Allowable... principles. For each kind of organization, there is a set of Federal principles for determining...
40 CFR 31.22 - Allowable costs.
2010-07-01
... accounting standards that comply with cost principles acceptable to the Federal agency. ... Requirements Financial Administration § 31.22 Allowable costs. (a) Limitation on use of funds. Grant funds may... the grantee or sub-grantee. (b) Applicable cost principles. For each kind of organization, there is...
45 CFR 92.22 - Allowable costs.
2010-10-01
... to that circular 48 CFR Part 31. Contract Cost Principles and Procedures, or uniform cost accounting... Financial Administration § 92.22 Allowable costs. (a) Limitation on use of funds. Grant funds may be used... grantee or subgrantee. (b) Applicable cost principles. For each kind of organization, there is a set...
7 CFR 550.25 - Allowable costs.
2010-01-01
... Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF... Financial Management § 550.25 Allowable costs. For each kind of Cooperator, there is a set of Federal... Acquisition Regulation (FAR) at 48 CFR part 31. Program Management ...
22 CFR 145.27 - Allowable costs.
2010-04-01
... Relations DEPARTMENT OF STATE CIVIL RIGHTS GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 145...-Profit Organizations.” The allowability of costs incurred by institutions of higher education...
22 CFR 518.27 - Allowable costs.
2010-04-01
... INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 518.27 Allowable costs. For each kind of recipient, there is a set of... by institutions of higher education is determined in accordance with the provisions of OMB Circular...
36 CFR 1210.27 - Allowable costs.
2010-07-01
... RULES UNIFORM ADMINISTRATIVE REQUIREMENTS FOR GRANTS AND AGREEMENTS WITH INSTITUTIONS OF HIGHER EDUCATION, HOSPITALS, AND OTHER NON-PROFIT ORGANIZATIONS Post-Award Requirements Financial and Program Management § 1210.27 Allowable costs. For each kind of recipient, there is a set of Federal principles...
Making It Personal: Per Capita Carbon Allowances
DEFF Research Database (Denmark)
Fawcett, Tina; Hvelplund, Frede; Meyer, Niels I
2009-01-01
The Chapter highligts the importance of introducing new, efficient schemes for mitigation of global warming. One such scheme is Personal Carbon Allowances (PCA), whereby individuals are allotted a tradable ration of CO2 emission per year.This chapter reviews the fundamentals of PCA and analyzes its...
Judicial Deference Allows European Consensus to Emerge
DEFF Research Database (Denmark)
Dothan, Shai
2017-01-01
conceived as competing doctrines: the more there is of one, the less there is of another. This paper suggests a novel rationale for the emerging consensus doctrine: the doctrine can allow the ECHR to make good policies by drawing on the independent decision-making of many similar countries. In light of that...
77 FR 34218 - Clothing Allowance; Correction
2012-06-11
... construed to impose a restriction that VA did not intend. This document corrects that error. DATES: This... Service, Veterans Benefits Administration, Department of Veterans Affairs, 810 Vermont Avenue NW... medication would be eligible for a clothing allowance for each such appliance or medication if each...
49 CFR 266.11 - Allowable costs.
2010-10-01
... Management Circular 74-4; and costs of projects eligible under § 266.7 of this part. All allowable costs shall be authorized by a fully executed grant agreement. A State may incur costs prior to the execution... need to incur costs prior to the execution of a grant agreement, has authorized the costs in writing...
33 CFR 136.211 - Compensation allowable.
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.211 Section 136.211 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.211...
33 CFR 136.205 - Compensation allowable.
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.205 Section 136.205 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.205...
33 CFR 136.241 - Compensation allowable.
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.241 Section 136.241 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.241...
33 CFR 136.223 - Compensation allowable.
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.223 Section 136.223 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.223...
33 CFR 136.217 - Compensation allowable.
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.217 Section 136.217 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.217...
33 CFR 136.235 - Compensation allowable.
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.235 Section 136.235 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.235...
33 CFR 136.229 - Compensation allowable.
2010-07-01
... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Compensation allowable. 136.229 Section 136.229 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... PROCEDURES; DESIGNATION OF SOURCE; AND ADVERTISEMENT Procedures for Particular Claims § 136.229...
50 CFR 80.15 - Allowable costs.
2010-10-01
...) FINANCIAL ASSISTANCE-WILDLIFE SPORT FISH RESTORATION PROGRAM ADMINISTRATIVE REQUIREMENTS, PITTMAN-ROBERTSON WILDLIFE RESTORATION AND DINGELL-JOHNSON SPORT FISH RESTORATION ACTS § 80.15 Allowable costs. (a) What are... designed to include purposes other than those eligible under either the Dingell-Johnson Sport Fish...
43 CFR 12.62 - Allowable costs.
2010-10-01
... Public Lands: Interior Office of the Secretary of the Interior ADMINISTRATIVE AND AUDIT REQUIREMENTS AND COST PRINCIPLES FOR ASSISTANCE PROGRAMS Uniform Administrative Requirements for Grants and Cooperative... increment above allowable costs) to the grantee or subgrantee. (b) Applicable cost principles. For each...
Modelling Nuclear Effects in Neutrino Scattering
Leitner, T; Mosel, U
2006-01-01
We have developed a model to describe the interactions of neutrinos with nucleons and nuclei via charged and neutral currents, focusing on the region of the quasielastic and Delta(1232) peaks. For neutrino nucleon collisions a fully relativistic formalism is used. The extension to finite nuclei has been done in the framework of a coupled-channel BUU transport model where we have studied exclusive channels taking into account in-medium effects and final state interactions.
Modeling socioeconomic status effects on language development.
Thomas, Michael S C; Forrester, Neil A; Ronald, Angelica
2013-12-01
Socioeconomic status (SES) is an important environmental predictor of language and cognitive development, but the causal pathways by which it operates are unclear. We used a computational model of development to explore the adequacy of manipulations of environmental information to simulate SES effects in English past-tense acquisition, in a data set provided by Bishop (2005). To our knowledge, this is the first application of computational models of development to SES. The simulations addressed 3 new challenges: (a) to combine models of development and individual differences in a single framework, (b) to expand modeling to the population level, and (c) to implement both environmental and genetic/intrinsic sources of individual differences. The model succeeded in capturing the qualitative patterns of regularity effects in both population performance and the predictive power of SES that were observed in the empirical data. The model suggested that the empirical data are best captured by relatively wider variation in learning abilities and relatively narrow variation in (and good quality of) environmental information. There were shortcomings in the model's quantitative fit, which are discussed. The model made several novel predictions, with respect to the influence of SES on delay versus giftedness, the change of SES effects over development, and the influence of SES on children of different ability levels (gene-environment interactions). The first of these predictions was that SES should reliably predict gifted performance in children but not delayed performance, and the prediction was supported by the Bishop data set. Finally, the model demonstrated limits on the inferences that can be drawn about developmental mechanisms on the basis of data from individual differences. PsycINFO Database Record (c) 2013 APA, all rights reserved.
Dynamic hysteresis modeling including skin effect using diffusion equation model
Hamada, Souad; Louai, Fatima Zohra; Nait-Said, Nasreddine; Benabou, Abdelkader
2016-07-01
An improved dynamic hysteresis model is proposed for the prediction of hysteresis loop of electrical steel up to mean frequencies, taking into account the skin effect. In previous works, the analytical solution of the diffusion equation for low frequency (DELF) was coupled with the inverse static Jiles-Atherton (JA) model in order to represent the hysteresis behavior for a lamination. In the present paper, this approach is improved to ensure the reproducibility of measured hysteresis loops at mean frequency. The results of simulation are compared with the experimental ones. The selected results for frequencies 50 Hz, 100 Hz, 200 Hz and 400 Hz are presented and discussed.
Dynamic hysteresis modeling including skin effect using diffusion equation model
Energy Technology Data Exchange (ETDEWEB)
Hamada, Souad, E-mail: souadhamada@yahoo.fr [LSP-IE: Research Laboratory, Electrical Engineering Department, University of Batna, 05000 Batna (Algeria); Louai, Fatima Zohra, E-mail: fz_louai@yahoo.com [LSP-IE: Research Laboratory, Electrical Engineering Department, University of Batna, 05000 Batna (Algeria); Nait-Said, Nasreddine, E-mail: n_naitsaid@yahoo.com [LSP-IE: Research Laboratory, Electrical Engineering Department, University of Batna, 05000 Batna (Algeria); Benabou, Abdelkader, E-mail: Abdelkader.Benabou@univ-lille1.fr [L2EP, Université de Lille1, 59655 Villeneuve d’Ascq (France)
2016-07-15
An improved dynamic hysteresis model is proposed for the prediction of hysteresis loop of electrical steel up to mean frequencies, taking into account the skin effect. In previous works, the analytical solution of the diffusion equation for low frequency (DELF) was coupled with the inverse static Jiles-Atherton (JA) model in order to represent the hysteresis behavior for a lamination. In the present paper, this approach is improved to ensure the reproducibility of measured hysteresis loops at mean frequency. The results of simulation are compared with the experimental ones. The selected results for frequencies 50 Hz, 100 Hz, 200 Hz and 400 Hz are presented and discussed.
Modelling the effect of shear strength on isentropic compression experiments
Thomson, Stuart; Howell, Peter; Ockendon, John; Ockendon, Hilary
2017-01-01
Isentropic compression experiments (ICE) are a way of obtaining equation of state information for metals undergoing violent plastic deformation. In a typical experiment, millimetre thick metal samples are subjected to pressures on the order of 10 - 102 GPa, while the yield strength of the material can be as low as 10-2 GPa. The analysis of such experiments has so far neglected the effect of shear strength, instead treating the highly plasticised metal as an inviscid compressible fluid. However making this approximation belies the basic elastic nature of a solid object. A more accurate method should strive to incorporate the small but measurable effects of shear strength. Here we present a one-dimensional mathematical model for elastoplasticity at high stress which allows for both compressibility and the shear strength of the material. In the limit of zero yield stress this model reproduces the hydrodynamic models currently used to analyse ICEs. Numerical solutions of the governing equations will then be presented for problems relevant to ICEs in order to investigate the effects of shear strength compared with a model based purely on hydrodynamics.
Event models and the fan effect.
Radvansky, G A; O'Rear, Andrea E; Fisher, Jerry S
2017-08-01
The current study explored the persistence of event model organizations and how this influences the experience of interference during retrieval. People in this study memorized lists of sentences about objects in locations, such as "The potted palm is in the hotel." Previous work has shown that such information can either be stored in separate event models, thereby producing retrieval interference, or integrated into common event models, thereby eliminating retrieval interference. Unlike prior studies, the current work explored the impact of forgetting up to 2 weeks later on this pattern of performance. We explored three possible outcomes across the various retention intervals. First, consistent with research showing that longer delays reduce proactive and retroactive interference, any retrieval interference effects of competing event models could be reduced over time. Second, the binding of information into events models may weaken over time, causing interference effects to emerge when they had previously been absent. Third, and finally, the organization of information into event models could remain stable over long periods of time. The results reported here are most consistent with the last outcome. While there were some minor variations across the various retention intervals, the basic pattern of event model organization remained preserved over the two-week retention period.
Mesomechanical modeling of shape memory effect
Vokoun, David; Kafka, Vratislav
1999-06-01
Shape memory alloys (SMA) are well known materials. There is a lot of technical applications making use of their unique properties. Most of the significant applications are based on use of the thermomechancial properties. Growing number of those applications causes a need for an universal mathematical model with ability to describe all thermomechancial properties of SMA by relatively simple final set of constitutive equations that could be helpful for development of further sophisticated shape memory applications. Unfortunately, a lot of attention has been paid to metallurgical research of shape memory alloys in a few last decades and less attention was dedicated to shape memory modeling. Our model does not claim to be a universal model, but only one contribution to modeling of shape memory effect for binary SMA. The model is adapted for the most applied SMA -- nitinol and is based on the hypothesis that in the course of shape memory effect the distances of first atomic neighbors (Ni-Ti) remain nearly unchanged, whereas the distances of second neighbors (Ti-Ti and Ni-Ni) change substantially. Consequently, we consider some mechanical properties of Ni-substructure and Ti- substructure separately. The mechanical behavior of Ti- substructure is modeled as elastic whereas that of Ni- substructure as elasto-plastic. The resulting relatively simple differential constitutive equations express relationship among internal stress tensors, macroscopic stress tensors, macroscopic strain tensors and temperature.
Antenna model of the Purcell effect
Krasnok, Alexander E; Simovski, Constantin R; Tretyakov, Sergei A; Poddubny, Alexander N; Miroshnichenko, Andrey E; Kivshar, Yuri S; Belov, Pavel A
2015-01-01
The Purcell effect - the modification of the spontaneous emission rate in presence of resonant cavities or other resonant objects - is a fundamental effect of quantum electrodynamics. However, a change of the emission rate caused by environment different from free space has a classical counterpart. Not only quantum emitters, but any small antenna tuned to the resonance is an oscillator with radiative losses, and the influence of the environment on its radiation can be understood and measured in terms of the antenna radiation resistance. We present a general approach which is applicable to measurements of the Purcell factor for radio antennas and to calculations of these factors for quantum emitters. Our methodology is suitable for calculation and measurement of both electric and magnetic Purcell factors, it is versatile and applies to various frequency ranges. The approach is illustrated by a general equivalent scheme and allows the Purcell factor to be expressed through the continious radiation of a small an...
Directory of Open Access Journals (Sweden)
Hao Xu
2014-04-01
Full Text Available Tree height and diameter at breast height are two important forest factors. The best model from 23 height-diameter equations was selected as the basic model to fit the height-diameter relationships of Chinese fir with one level (sites or plots effects and nested two levels (nested effects of sites and plots Nonlinear Mixed Effects (NLME models. The best model was chosen by smaller Bias, RMSE and larger Radj2. Then the best random-effects combinations for the NLME models were determined by AIC, BIC and -2LL. The results showed that the basic model with three random effects parameters &Phi &Phi &Phi1 &Phi2 and &Phi3 was considered the best mixed model. The nested two levels NLME model considering heteroscedasticity structure (power function possessed with higher predictable accuracy and significantly improved model performance (LRT = 469.43, p<0.0001. The NLME model would be allowed for estimating accuracy the height-diameter relationships of Chinese fir and provided better height predictions than the models using only fixed-effects parameters.
Energy Technology Data Exchange (ETDEWEB)
Evans, J.S.; Moeller, D.W.; Cooper, D.W.
1985-07-01
Analysis of the radiological health effects of nuclear power plant accidents requires models for predicting early health effects, cancers and benign thyroid nodules, and genetic effects. Since the publication of the Reactor Safety Study, additional information on radiological health effects has become available. This report summarizes the efforts of a program designed to provide revised health effects models for nuclear power plant accident consequence modeling. The new models for early effects address four causes of mortality and nine categories of morbidity. The models for early effects are based upon two parameter Weibull functions. They permit evaluation of the influence of dose protraction and address the issue of variation in radiosensitivity among the population. The piecewise-linear dose-response models used in the Reactor Safety Study to predict cancers and thyroid nodules have been replaced by linear and linear-quadratic models. The new models reflect the most recently reported results of the follow-up of the survivors of the bombings of Hiroshima and Nagasaki and permit analysis of both morbidity and mortality. The new models for genetic effects allow prediction of genetic risks in each of the first five generations after an accident and include information on the relative severity of various classes of genetic effects. The uncertainty in modeloling radiological health risks is addressed by providing central, upper, and lower estimates of risks. An approach is outlined for summarizing the health consequences of nuclear power plant accidents. 298 refs., 9 figs., 49 tabs.
Realization of allowable qeneralized quantum gates
Institute of Scientific and Technical Information of China (English)
无
2010-01-01
The most general duality gates were introduced by Long,Liu and Wang and named allowable generalized quantum gates (AGQGs,for short).By definition,an allowable generalized quantum gate has the form of U=YfkjsckUK,where Uk’s are unitary operators on a Hilbert space H and the coefficients ck’s are complex numbers with |Yfijo ck\\ ∧ 1 an d 1ck| <1 for all k=0,1,...,d-1.In this paper,we prove that an AGQG U=YfkZo ck∧k is realizable,i.e.there are two d by d unitary matrices W and V such that ck=W0kVk0 (0
Making It Personal: Per Capita Carbon Allowances
DEFF Research Database (Denmark)
Fawcett, Tina; Hvelplund, Frede; Meyer, Niels I
2009-01-01
The Chapter highligts the importance of introducing new, efficient schemes for mitigation of global warming. One such scheme is Personal Carbon Allowances (PCA), whereby individuals are allotted a tradable ration of CO2 emission per year.This chapter reviews the fundamentals of PCA and analyzes its...... merits and problems. The United Kingdom and Denmark have been chosen as case studies because the energy situation and the institutional setup are quite different between the two countries....
Determination of effective loss factors in reduced SEA models
Chimeno Manguán, M.; Fernández de las Heras, M. J.; Roibás Millán, E.; Simón Hidalgo, F.
2017-01-01
The definition of Statistical Energy Analysis (SEA) models for large complex structures is highly conditioned by the classification of the structure elements into a set of coupled subsystems and the subsequent determination of the loss factors representing both the internal damping and the coupling between subsystems. The accurate definition of the complete system can lead to excessively large models as the size and complexity increases. This fact can also rise practical issues for the experimental determination of the loss factors. This work presents a formulation of reduced SEA models for incomplete systems defined by a set of effective loss factors. This reduced SEA model provides a feasible number of subsystems for the application of the Power Injection Method (PIM). For structures of high complexity, their components accessibility can be restricted, for instance internal equipments or panels. For these cases the use of PIM to carry out an experimental SEA analysis is not possible. New methods are presented for this case in combination with the reduced SEA models. These methods allow defining some of the model loss factors that could not be obtained through PIM. The methods are validated with a numerical analysis case and they are also applied to an actual spacecraft structure with accessibility restrictions: a solar wing in folded configuration.
Hypersurface-deformation algebroids and effective space-time models
Bojowald, Martin; Buyukcam, Umut; D'Ambrosio, Fabio
2016-01-01
In canonical gravity, covariance is implemented by brackets of hypersurface-deformation generators forming a Lie algebroid. Lie algebroid morphisms therefore allow one to relate different versions of the brackets that correspond to the same space-time structure. An application to examples of modified brackets found mainly in models of loop quantum gravity can in some cases map the space-time structure back to the classical Riemannian form after a field redefinition. For one type of quantum corrections (holonomies), signature change appears to be a generic feature of effective space-time, and is shown here to be a new quantum space-time phenomenon which cannot be mapped to an equivalent classical structure. In low-curvature regimes, our constructions prove the existence of classical space-time structures assumed elsewhere in models of loop quantum cosmology, but also shows the existence of additional quantum corrections that have not always been included.
Modelling vocal anatomy's significant effect on speech
de Boer, B.
2010-01-01
This paper investigates the effect of larynx position on the articulatory abilities of a humanlike vocal tract. Previous work has investigated models that were built to resemble the anatomy of existing species or fossil ancestors. This has led to conflicting conclusions about the relation between
Anomalous effective lagrangians and vector resonance models
Pallante, E.; Petronzio, R.
1993-01-01
Chiral lagrangians including vector resonances have been shown to saturate the finite part of some of the counterterms needed to regularize ordinary one-loop effective lagrangians of pseudoscalar interactions with external currents. The equivalence between different models has been discussed in the
Random effect selection in generalised linear models
DEFF Research Database (Denmark)
Denwood, Matt; Houe, Hans; Forkman, Björn;
We analysed abattoir recordings of meat inspection codes with possible relevance to onfarm animal welfare in cattle. Random effects logistic regression models were used to describe individual-level data obtained from 461,406 cattle slaughtered in Denmark. Our results demonstrate that the largest...
Effective models for excitons in carbon nanotubes
DEFF Research Database (Denmark)
Cornean, Horia; Duclos, Pierre; Ricaud, Benjamin
We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with a Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum is well described by a one-dimensional effective Hamiltonian...
Projecting Policy Effects with Statistical Models Projecting Policy Effects with Statistical Models
Directory of Open Access Journals (Sweden)
Christopher Sims
1988-03-01
Full Text Available This paper attempts to briefly discus the current frontiers in quantitative modeling for forecastina and policy analvsis. It does so by summarizing some recent developmenrs in three areas: reduced form forecasting models; theoretical models including elements of stochastic optimization; and identification. In the process, the paper tries to provide some remarks on the direction we seem to be headed. Projecting Policy Effects with Statistical Models
Radiative Effects in the Standard Model Extension
Zhukovskii, V C; Murchikova, E M
2006-01-01
The possibility of radiative effects induced by the Lorentz and CPT non-invariant interaction term for fermions in the Standard Model Extension is investigated. In particular, electron-positron photo-production and photon emission by electrons and positrons were studied. The rates of these processes were calculated in the Furry picture. It was demonstrated that the rates obtained in the framework of the model adopted strongly depend on the polarization states of the particles involved. Indeed, ultra-relativistic particles should occupy states with a preferred spin orientation, i.e., photons have the sign of polarization opposite to the sign of the effective potential, while charged particle are preferably in the state with the helicity coinciding with the sign of the effective potential. This leads to evident spatial asymmetries which may have certain consequences observable in astrophysical and cosmological studies.
Multiphysics Modelling of the Mandel- Cryer Effect
Directory of Open Access Journals (Sweden)
E Holzbecher
2016-03-01
Full Text Available In porous medium studies the Mandel-Cryer effect is known, describing non-monotonic pore-water pressure evolution in response to loading or to changed stress conditions. In a 2D poro-elastic model we couple the pore water hydraulics with mechanics (HM. The Mandel-Cryer effect is identified in parts of the model region that are far from the drainage boundary. At parts of the loaded boundary an even more complex pressure evolution is revealed. Variations of the Biot-parameter as the coupling parameter clearly indicate the relevance of the two-way coupling between the involved physical regimes. Hence the Mandel-Cryer effect is a typical result of multi-physical coupling.
High-resolution DEM Effects on Geophysical Flow Models
Williams, M. R.; Bursik, M. I.; Stefanescu, R. E. R.; Patra, A. K.
2014-12-01
Geophysical mass flow models are numerical models that approximate pyroclastic flow events and can be used to assess the volcanic hazards certain areas may face. One such model, TITAN2D, approximates granular-flow physics based on a depth-averaged analytical model using inputs of basal and internal friction, material volume at a coordinate point, and a GIS in the form of a digital elevation model (DEM). The volume of modeled material propagates over the DEM in a way that is governed by the slope and curvature of the DEM surface and the basal and internal friction angles. Results from TITAN2D are highly dependent upon the inputs to the model. Here we focus on a single input: the DEM, which can vary in resolution. High resolution DEMs are advantageous in that they contain more surface details than lower-resolution models, presumably allowing modeled flows to propagate in a way more true to the real surface. However, very high resolution DEMs can create undesirable artifacts in the slope and curvature that corrupt flow calculations. With high-resolution DEMs becoming more widely available and preferable for use, determining the point at which high resolution data is less advantageous compared to lower resolution data becomes important. We find that in cases of high resolution, integer-valued DEMs, very high-resolution is detrimental to good model outputs when moderate-to-low (<10-15°) slope angles are involved. At these slope angles, multiple adjacent DEM cell elevation values are equal due to the need for the DEM to approximate the low slope with a limited set of integer values for elevation. The first derivative of the elevation surface thus becomes zero. In these cases, flow propagation is inhibited by these spurious zero-slope conditions. Here we present evidence for this "terracing effect" from 1) a mathematically defined simulated elevation model, to demonstrate the terracing effects of integer valued data, and 2) a real-world DEM where terracing must be
Biologically based multistage modeling of radiation effects
Energy Technology Data Exchange (ETDEWEB)
William Hazelton; Suresh Moolgavkar; E. Georg Luebeck
2005-08-30
This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of
Relativistic effects in model calculations of double parton distribution function
Rinaldi, Matteo
2016-01-01
In this paper we consider double parton distribution functions (dPDFs) which are the main non perturbative ingredients appearing in the double parton scattering cross section formula in hadronic collisions. By using recent calculation of dPDFs by means of constituent quark models within the so called Light-Front approach, we investigate the role of relativistic effects on dPDFs. We find, in particular, that the so called Melosh operators, which allow to properly convert the LF spin into the canonical one and incorporate a proper treatment of boosts, produce sizeable effects on dPDFs. We discuss specific partonic correlations induced by these operators in transverse plane which are relevant to the proton structure and study under which conditions these results are stable against variations in the choice of the proton wave function.
Modeling the Effects of Knots in Structural Timber
DEFF Research Database (Denmark)
Foley, Christina
was established, which describes variations of radial growth direction and fiber orientation related to knots in timber. The adaptability of the paradigm allows practically any softwood knot and its effect on surrounding wood material to be modeled with an accuracy that is limited only by input data. The knot......The main purpose of the pursued research presented in this thesis is to increase knowledge of the effects of knots in structural timber so that characteristics of weaker timber may be determined and applied to improve current grading techniques. In the process, a three-dimensional fiber paradigm...... are given to Shigo's knot formation theory, and thus predicts two separate patterns of fiber direction within annual growth layers related to live knots. In order to determine the possibility to practically and non destructively predict local material directions in structural timber with the three...
DsixTools: the standard model effective field theory toolkit
Energy Technology Data Exchange (ETDEWEB)
Celis, Alejandro [Ludwig-Maximilians-Universitaet Muenchen, Fakultaet fuer Physik, Arnold Sommerfeld Center for Theoretical Physics, Munich (Germany); Fuentes-Martin, Javier; Vicente, Avelino [Universitat de Valencia-CSIC, Instituto de Fisica Corpuscular, Valencia (Spain); Virto, Javier [University of Bern, Albert Einstein Center for Fundamental Physics, Institute for Theoretical Physics, Bern (Switzerland)
2017-06-15
We present DsixTools, a Mathematica package for the handling of the dimension-six standard model effective field theory. Among other features, DsixTools allows the user to perform the full one-loop renormalization group evolution of the Wilson coefficients in the Warsaw basis. This is achieved thanks to the SMEFTrunner module, which implements the full one-loop anomalous dimension matrix previously derived in the literature. In addition, DsixTools also contains modules devoted to the matching to the ΔB = ΔS = 1, 2 and ΔB = ΔC = 1 operators of the Weak Effective Theory at the electroweak scale, and their QCD and QED Renormalization group evolution below the electroweak scale. (orig.)
Directory of Open Access Journals (Sweden)
Irani Lauer Lellis
2012-06-01
Full Text Available The practice of giving allowance is used by several parents in different parts of the world and can contribute to the economic education of children. This study aimed to investigate the purposes of the allowance with 32 parents of varying incomes. We used the focus group technique and Alceste software to analyze the data. The results involved two classes related to the process of using the allowance. These classes have covered aspects of the role of socialization and education allowance, serving as an instrument of reward, but sometimes encouraging bad habits in children. The justification of the fathers concerning the amount of money to be given to the children and when to stop giving allowance were also highlighted. Keywords: allowance; economic socialization; parenting practices.
Caselle, Michele; Panero, Marco
2007-01-01
We provide accurate Monte Carlo results for the free energy of interfaces with periodic boundary conditions in the 3D Ising model. We study a large range of inverse temperatures, allowing to control corrections to scaling. In addition to square interfaces, we study rectangular interfaces for a large range of aspect ratios u=L_1/L_2. Our numerical results are compared with predictions of effective interface models. This comparison verifies clearly the effective Nambu-Goto model up to two-loop order. Our data also allow us to obtain the estimates T_c sigma^-1/2=1.235(2), m_0++ sigma^-1/2=3.037(16) and R_+=f_+ sigma_0^2 =0.387(2), which are more precise than previous ones.
Effective orthorhombic anisotropic models for wavefield extrapolation
Ibanez-Jacome, W.
2014-07-18
Wavefield extrapolation in orthorhombic anisotropic media incorporates complicated but realistic models to reproduce wave propagation phenomena in the Earth\\'s subsurface. Compared with the representations used for simpler symmetries, such as transversely isotropic or isotropic, orthorhombic models require an extended and more elaborated formulation that also involves more expensive computational processes. The acoustic assumption yields more efficient description of the orthorhombic wave equation that also provides a simplified representation for the orthorhombic dispersion relation. However, such representation is hampered by the sixth-order nature of the acoustic wave equation, as it also encompasses the contribution of shear waves. To reduce the computational cost of wavefield extrapolation in such media, we generate effective isotropic inhomogeneous models that are capable of reproducing the firstarrival kinematic aspects of the orthorhombic wavefield. First, in order to compute traveltimes in vertical orthorhombic media, we develop a stable, efficient and accurate algorithm based on the fast marching method. The derived orthorhombic acoustic dispersion relation, unlike the isotropic or transversely isotropic ones, is represented by a sixth order polynomial equation with the fastest solution corresponding to outgoing P waves in acoustic media. The effective velocity models are then computed by evaluating the traveltime gradients of the orthorhombic traveltime solution, and using them to explicitly evaluate the corresponding inhomogeneous isotropic velocity field. The inverted effective velocity fields are source dependent and produce equivalent first-arrival kinematic descriptions of wave propagation in orthorhombic media. We extrapolate wavefields in these isotropic effective velocity models using the more efficient isotropic operator, and the results compare well, especially kinematically, with those obtained from the more expensive anisotropic extrapolator.
Hysteresis modeling in graphene field effect transistors
Energy Technology Data Exchange (ETDEWEB)
Winters, M.; Rorsman, N. [Department of Microtechnology and Nanoscience, Chalmers University of Technology, 412-96 Göteborg (Sweden); Sveinbjörnsson, E. Ö. [Science Institute, University of Iceland, IS-107 Reykjavik (Iceland)
2015-02-21
Graphene field effect transistors with an Al{sub 2}O{sub 3} gate dielectric are fabricated on H-intercalated bilayer graphene grown on semi-insulating 4H-SiC by chemical vapour deposition. DC measurements of the gate voltage v{sub g} versus the drain current i{sub d} reveal a severe hysteresis of clockwise orientation. A capacitive model is used to derive the relationship between the applied gate voltage and the Fermi energy. The electron transport equations are then used to calculate the drain current for a given applied gate voltage. The hysteresis in measured data is then modeled via a modified Preisach kernel.
SOME THEORETICAL MODELS EXPLAINING ADVERTISING EFFECTS
Directory of Open Access Journals (Sweden)
Vasilica Magdalena SOMEŞFĂLEAN
2014-06-01
Full Text Available Persuade clients is still the main focus of the companies, using a set of methods and techniques designed to influence their behavior, in order to obtain better results (profits over a longer period of time. Since the late nineteenth - early twentieth century, the american E.St.Elmo Lewis, considered a pioneer in advertising and sales, developed the first theory, AIDA model, later used by marketers and advertisers to develop a marketing communications strategy. Later studies have developed other models that are the main subject of this research, which explains how and why persuasive communication works, to understand why some approaches are effective and others are not.
Effect on Prediction when Modeling Covariates in Bayesian Nonparametric Models.
Cruz-Marcelo, Alejandro; Rosner, Gary L; Müller, Peter; Stewart, Clinton F
2013-04-01
In biomedical research, it is often of interest to characterize biologic processes giving rise to observations and to make predictions of future observations. Bayesian nonparametric methods provide a means for carrying out Bayesian inference making as few assumptions about restrictive parametric models as possible. There are several proposals in the literature for extending Bayesian nonparametric models to include dependence on covariates. Limited attention, however, has been directed to the following two aspects. In this article, we examine the effect on fitting and predictive performance of incorporating covariates in a class of Bayesian nonparametric models by one of two primary ways: either in the weights or in the locations of a discrete random probability measure. We show that different strategies for incorporating continuous covariates in Bayesian nonparametric models can result in big differences when used for prediction, even though they lead to otherwise similar posterior inferences. When one needs the predictive density, as in optimal design, and this density is a mixture, it is better to make the weights depend on the covariates. We demonstrate these points via a simulated data example and in an application in which one wants to determine the optimal dose of an anticancer drug used in pediatric oncology.
Energy Technology Data Exchange (ETDEWEB)
Bhardwaj, S [University of Chicago; Mkhitaryan, V V [Ames Laboratory; Gruzberg, I A [Ohio State University
2014-06-01
We consider a recently proposed network model of the integer quantum Hall (IQH) effect in a weak magnetic field. Using a supersymmetry approach, we reformulate the network model in terms of a superspin ladder. A subsequent analysis of the superspin ladder and the corresponding supersymmetric nonlinear sigma model allows us to establish the phase diagram of the network model, and the form of the critical line of the weak-field IQH transition. Our results confirm the universality of the IQH transition, which is described by the same sigma model in strong and weak magnetic fields. We apply the suspersymmetry method to several related network models that were introduced in the literature to describe the quantum Hall effect in graphene, the spin-degenerate Landau levels, and localization of electrons in a random magnetic field.
2011-06-06
... Duty (TDY) Travel Allowances (Taxes); Relocation Allowances (Taxes) AGENCY: Office of Governmentwide... extended temporary duty (TDY) benefits to correct errors and to align that process with the proposed... incurred by employees as a result of relocation and to reimburse ``all'' of the taxes imposed on any...
Modelling of rate effects at multiple scales
DEFF Research Database (Denmark)
Pedersen, R.R.; Simone, A.; Sluys, L. J.
2008-01-01
At the macro- and meso-scales a rate dependent constitutive model is used in which visco-elasticity is coupled to visco-plasticity and damage. A viscous length scale effect is introduced to control the size of the fracture process zone. By comparison of the widths of the fracture process zone......, the length scale in the meso-model and the macro-model can be coupled. In this fashion, a bridging of length scales can be established. A computational analysis of a Split Hopkinson bar test at medium and high impact load is carried out at macro-scale and meso-scale including information from the micro-scale....
Estimation in Dirichlet random effects models
Kyung, Minjung; Casella, George; 10.1214/09-AOS731
2010-01-01
We develop a new Gibbs sampler for a linear mixed model with a Dirichlet process random effect term, which is easily extended to a generalized linear mixed model with a probit link function. Our Gibbs sampler exploits the properties of the multinomial and Dirichlet distributions, and is shown to be an improvement, in terms of operator norm and efficiency, over other commonly used MCMC algorithms. We also investigate methods for the estimation of the precision parameter of the Dirichlet process, finding that maximum likelihood may not be desirable, but a posterior mode is a reasonable approach. Examples are given to show how these models perform on real data. Our results complement both the theoretical basis of the Dirichlet process nonparametric prior and the computational work that has been done to date.
Energy Technology Data Exchange (ETDEWEB)
Duty, Chad E [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Groh, Bill [Radio Systems Corporation, Knoxville, TN (United States)
2014-10-31
ORNL collaborated with Radio Systems Corporation to investigate additive manufacturing (AM) of mold plates for plastic injection molding by direct metal deposition. The team s modelling effort identified a 100% improvement in heat transfer through use of conformal cooling lines that could be built into the mold using a revolutionary design enabled by additive manufacturing. Using the newly installed laser deposition system at the ORNL Manufacturing Demonstration Facility (MDF) a stainless steel mold core was printed.
20 CFR 617.47 - Moving allowance.
2010-04-01
... Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TRADE ADJUSTMENT ASSISTANCE... goods and personal effects of an individual and family, if any, shall not exceed the maximum number of... include the cost of insuring such goods and effects for their actual value or $10,000, whichever is...
ACOUSTIC EFFECTS ON BINARY AEROELASTICITY MODEL
Directory of Open Access Journals (Sweden)
Kok Hwa Yu
2011-10-01
Full Text Available Acoustics is the science concerned with the study of sound. The effects of sound on structures attract overwhelm interests and numerous studies were carried out in this particular area. Many of the preliminary investigations show that acoustic pressure produces significant influences on structures such as thin plate, membrane and also high-impedance medium like water (and other similar fluids. Thus, it is useful to investigate the structure response with the presence of acoustics on aircraft, especially on aircraft wings, tails and control surfaces which are vulnerable to flutter phenomena. The present paper describes the modeling of structural-acoustic interactions to simulate the external acoustic effect on binary flutter model. Here, the binary flutter model which illustrated as a rectangular wing is constructed using strip theory with simplified unsteady aerodynamics involving flap and pitch degree of freedom terms. The external acoustic excitation, on the other hand, is modeled using four-node quadrilateral isoparametric element via finite element approach. Both equations then carefully coupled and solved using eigenvalue solution. The mentioned approach is implemented in MATLAB and the outcome of the simulated result are later described, analyzed and illustrated in this paper.
Energy Technology Data Exchange (ETDEWEB)
Schleich, J.; Cremer, C.
2007-07-01
Basing allocation of allowances for existing installations under the EU Emissions Trading Scheme on specific emission values (benchmarks) rather than on historic emissions may have several advantages. Benchmarking may recognize early ac-tion, provide higher incentives for replacing old installations and result in fewer distortions in case of updating, facilitate EU-wide harmonization of allocation rules or allow for simplified and more efficient closure rules. Applying an optimization model for the German power sector, we analyze the distributional effects of vari-ous allocation regimes across and within different generation technologies. Re-sults illustrate that regimes with a single uniform benchmark for all fuels or with a single benchmark for coal- and lignite-fired plants imply substantial distributional effects. In particular, lignite- and old coal-fired plants would be made worse off. Under a regime with fuel-specific benchmarks for gas, coal, and lignite 50 % of the gas-fired plants and 4 % of the lignite and coal-fired plants would face an allow-ance deficit of at least 10 %, while primarily modern lignite-fired plants would benefit. Capping the surplus and shortage of allowances would further moderate the distributional effects, but may tarnish incentives for efficiency improvements and recognition of early action. (orig.)
Directory of Open Access Journals (Sweden)
Mei Guangyi
Full Text Available A systematic evaluation of nonlinear mixed-effect taper models for volume prediction was performed. Of 21 taper equations with fewer than 5 parameters each, the best 4-parameter fixed-effect model according to fitting statistics was then modified by comparing its values for the parameters total height (H, diameter at breast height (DBH, and aboveground height (h to modeling data. Seven alternative prediction strategies were compared using the best new equation in the absence of calibration data, which is often unavailable in forestry practice. The results of this study suggest that because calibration may sometimes be a realistic option, though it is rarely used in practical applications, one of the best strategies for improving the accuracy of volume prediction is the strategy with 7 calculated total heights of 3, 6 and 9 trees in the largest, smallest and medium-size categories, respectively. We cannot use the average trees or dominant trees for calculating the random parameter for further predictions. The method described here will allow the user to make the best choices of taper type and the best random-effect calculated strategy for each practical application and situation at tree level.
Guangyi, Mei; Yujun, Sun; Hao, Xu; de-Miguel, Sergio
2015-01-01
A systematic evaluation of nonlinear mixed-effect taper models for volume prediction was performed. Of 21 taper equations with fewer than 5 parameters each, the best 4-parameter fixed-effect model according to fitting statistics was then modified by comparing its values for the parameters total height (H), diameter at breast height (DBH), and aboveground height (h) to modeling data. Seven alternative prediction strategies were compared using the best new equation in the absence of calibration data, which is often unavailable in forestry practice. The results of this study suggest that because calibration may sometimes be a realistic option, though it is rarely used in practical applications, one of the best strategies for improving the accuracy of volume prediction is the strategy with 7 calculated total heights of 3, 6 and 9 trees in the largest, smallest and medium-size categories, respectively. We cannot use the average trees or dominant trees for calculating the random parameter for further predictions. The method described here will allow the user to make the best choices of taper type and the best random-effect calculated strategy for each practical application and situation at tree level.
CO2 Allowance and Electricity Price Interaction
Energy Technology Data Exchange (ETDEWEB)
NONE
2007-07-01
With the introduction of CO2 emission constraints on power generators in the European Union, climate policy is starting to have notable effects on energy markets. This paper sheds light on the links between CO2 prices, electricity prices, and electricity costs to industry. It is based on a series of interviews with industrial and electricity stakeholders, as well as a rich literature seeking to estimate the exact effect of CO2 prices on electricity prices.
A single-step genomic model with direct estimation of marker effects.
Liu, Z; Goddard, M E; Reinhardt, F; Reents, R
2014-09-01
Compared with the currently widely used multi-step genomic models for genomic evaluation, single-step genomic models can provide more accurate genomic evaluation by jointly analyzing phenotypes and genotypes of all animals and can properly correct for the effect of genomic preselection on genetic evaluations. The objectives of this study were to introduce a single-step genomic model, allowing a direct estimation of single nucleotide polymorphism (SNP) effects, and to develop efficient computing algorithms for solving equations of the single-step SNP model. We proposed an alternative to the current single-step genomic model based on the genomic relationship matrix by including an additional step for estimating the effects of SNP markers. Our single-step SNP model allowed flexible modeling of SNP effects in terms of the number and variance of SNP markers. Moreover, our single-step SNP model included a residual polygenic effect with trait-specific variance for reducing inflation in genomic prediction. A kernel calculation of the SNP model involved repeated multiplications of the inverse of the pedigree relationship matrix of genotyped animals with a vector, for which numerical methods such as preconditioned conjugate gradients can be used. For estimating SNP effects, a special updating algorithm was proposed to separate residual polygenic effects from the SNP effects. We extended our single-step SNP model to general multiple-trait cases. By taking advantage of a block-diagonal (co)variance matrix of SNP effects, we showed how to estimate multivariate SNP effects in an efficient way. A general prediction formula was derived for candidates without phenotypes, which can be used for frequent, interim genomic evaluations without running the whole genomic evaluation process. We discussed various issues related to implementation of the single-step SNP model in Holstein populations with an across-country genomic reference population.
Magnetic field screening effect in electroweak model
Bakry, A; Zhang, P M; Zou, L P
2014-01-01
It is shown that in the Weinberg-Salam model a magnetic field screening effect for static magnetic solutions takes place. The origin of that phenomenon is conditioned by features of the electro-weak interaction, namely, there is mutual cancellation of Abelian magnetic fields created by the SU(2) gauge fields and Higgs boson. The effect implies monopole charge screening in finite energy system of monopoles and antimonopoles. We consider another manifestation of the screening effect which leads to an essential energy decrease of magnetic solutions. Applying variational method we have found a magnetic field configuration with a topological azimuthal magnetic flux which minimizes the energy functional and possesses a total energy of order 1 TeV. We suppose that corresponding magnetic bound state exists in the electroweak theory and can be detected in experiment.
Yang, Pan; Pang, Min; Li, Ming; Shen, Wei; He, Rongxing
2015-12-05
Geometrical optimizations of the ground and first excited states of benzimidazole and indene were performed using the density functional theory (DFT) and its time-dependent extension methods (TD-DFT), respectively. Their vibrationally resolved (1)Lb ((1)A')↔S0 ((1)A') absorption and fluorescence spectra were simulated within the Franck-Condon approximation including the Herzberg-Teller (HT) and Duschinsky effects. Calculated results revealed that, with the HT and Duschinsky effects getting involved, the simulated weak (1)Lb ((1)A')↔S0 ((1)A') electronic spectra of the two molecules excellently reproduce the experimental findings. Based on the experimental data and other theoretical results, we tentatively assigned most of the vibrational normal modes which emerged in the experimental spectra of the two molecules. The present theoretical insights are expected to help us understand the nature of electronic transitions in the vibrationally resolved absorption and fluorescence spectra of benzimidazole and its analogues.
Modeling the Orbital Sampling Effect of Extrasolar Moons
Heller, René; Jackson, Brian
2016-01-01
The orbital sampling effect (OSE) appears in phase-folded transit light curves of extrasolar planets with moons. Analytical OSE models have hitherto neglected stellar limb darkening and non-zero transit impact parameters and assumed that the moon is on a circular, co-planar orbit around the planet. Here, we present an analytical OSE model for eccentric moon orbits, which we implement in a numerical simulator with stellar limb darkening that allows for arbitrary transit impact parameters. We also describe and publicly release a fully numerical OSE simulator (PyOSE) that can model arbitrary inclinations of the transiting moon orbit. Both our analytical solution for the OSE and PyOSE can be used to search for exomoons in long-term stellar light curves such as those by Kepler and the upcoming PLATO mission. Our updated OSE model offers an independent method for the verification of possible future exomoon claims via transit timing variations and transit duration variations. Photometrically quiet K and M dwarf star...
Directory of Open Access Journals (Sweden)
Lihui Guo
2015-01-01
Full Text Available With the increasing penetration of wind power, the randomness and volatility of wind power output would have a greater impact on safety and steady operation of power system. In allusion to the uncertainty of wind speed and load demand, this paper applied box set robust optimization theory in determining the maximum allowable installed capacity of wind farm, while constraints of node voltage and line capacity are considered. Optimized duality theory is used to simplify the model and convert uncertainty quantities in constraints into certainty quantities. Under the condition of multi wind farms, a bilevel optimization model to calculate penetration capacity is proposed. The result of IEEE 30-bus system shows that the robust optimization model proposed in the paper is correct and effective and indicates that the fluctuation range of wind speed and load and the importance degree of grid connection point of wind farm and load point have impact on the allowable capacity of wind farm.
Stochastic volatility of the futures prices of emission allowances: A Bayesian approach
Kim, Jungmu; Park, Yuen Jung; Ryu, Doojin
2017-01-01
Understanding the stochastic nature of the spot volatility of emission allowances is crucial for risk management in emissions markets. In this study, by adopting a stochastic volatility model with or without jumps to represent the dynamics of European Union Allowances (EUA) futures prices, we estimate the daily volatilities and model parameters by using the Markov Chain Monte Carlo method for stochastic volatility (SV), stochastic volatility with return jumps (SVJ) and stochastic volatility with correlated jumps (SVCJ) models. Our empirical results reveal three important features of emissions markets. First, the data presented herein suggest that EUA futures prices exhibit significant stochastic volatility. Second, the leverage effect is noticeable regardless of whether or not jumps are included. Third, the inclusion of jumps has a significant impact on the estimation of the volatility dynamics. Finally, the market becomes very volatile and large jumps occur at the beginning of a new phase. These findings are important for policy makers and regulators.
Carcinogenic effects in a phenylketonuria mouse model.
Directory of Open Access Journals (Sweden)
Neil Sidell
Full Text Available Phenylketonuria (PKU is a metabolic disorder caused by impaired phenylalanine hydroxylase (PAH. This condition results in hyperphenylalaninemia and elevated levels of abnormal phenylalanine metabolites, among which is phenylacetic acid/phenylacetate (PA. In recent years, PA and its analogs were found to have anticancer activity against a variety of malignancies suggesting the possibility that PKU may offer protection against cancer through chronically elevated levels of PA. We tested this hypothesis in a genetic mouse model of PKU (PAH(enu2 which has a biochemical profile that closely resembles that of human PKU. Plasma levels of phenylalanine in homozygous (HMZ PAH(enu2 mice were >12-fold those of heterozygous (HTZ littermates while tyrosine levels were reduced. Phenylketones, including PA, were also markedly elevated to the range seen in the human disease. Mice were subjected to 7,12 dimethylbenz[a]anthracene (DMBA carcinogenesis, a model which is sensitive to the anticancer effects of the PA derivative 4-chlorophenylacetate (4-CPA. Tumor induction by DMBA was not significantly different between the HTZ and HMZ mice, either in total tumor development or in the type of cancers that arose. HMZ mice were then treated with 4-CPA as positive controls for the anticancer effects of PA and to evaluate its possible effects on phenylalanine metabolism in PKU mice. 4-CPA had no effect on the plasma concentrations of phenylalanine, phenylketones, or tyrosine. Surprisingly, the HMZ mice treated with 4-CPA developed an unexplained neuromuscular syndrome which precluded its use in these animals as an anticancer agent. Together, these studies support the use of PAH(enu2 mice as a model for studying human PKU. Chronically elevated levels of PA in the PAH(enu2 mice were not protective against cancer.
The true-change model with individual method effects : Reliability issues
Vautier, Stephane; Steyer, Rolf; Boomsma, Anne
2008-01-01
The true intra-individual change model is generalized by defining individual method effects. This allows the analysis of non-congeneric test-retest variables assumed to measure a common, possibly (temporally) transient, attribute. Temporal change in the attribute between different times of measureme
Factor Analysis of Drawings: Application to College Student Models of the Greenhouse Effect
Libarkin, Julie C.; Thomas, Stephen R.; Ording, Gabriel
2015-01-01
Exploratory factor analysis was used to identify models underlying drawings of the greenhouse effect made by over 200 entering university freshmen. Initial content analysis allowed deconstruction of drawings into salient features, with grouping of these features via factor analysis. A resulting 4-factor solution explains 62% of the data variance,…
Dual coupling effective band model for polarons
Marchand, Dominic J. J.; Stamp, Philip C. E.; Berciu, Mona
2017-01-01
Nondiagonal couplings to a bosonic bath completely change polaronic dynamics, from the usual diagonally coupled paradigm of smoothly varying properties. We study, using analytic and numerical methods, a model having both diagonal Holstein and nondiagonal Su-Schrieffer-Heeger (SSH) couplings. The critical coupling found previously in the pure SSH model, at which the k =0 effective mass diverges, now becomes a transition line in the coupling constant plane—the form of the line depends on the adiabaticity parameter. Detailed results are given for the quasiparticle and ground-state properties, over a wide range of couplings and adiabaticity ratios. The new paradigm involves a destabilization, at the transition line, of the simple Holstein polaron to one with a finite ground-state momentum, but with everywhere a continuously evolving band shape. No "self-trapping transition" exists in any of these models. The physics may be understood entirely in terms of competition between different hopping terms in a simple renormalized effective band theory. The possibility of further transitions is suggested by the results.
Brandl, M; Grosse-Hovest, L; Holler, E; Kolb, H J; Jung, G
1999-08-01
Bispecific antibodies directed against tumor-associated target antigens and to surface receptors mediating T-cell activation, such as the TCR/CD3 complex and the costimulatory receptor CD28, are capable of mediating T-cell activation resulting in tumor cell killing. In this study, we used the B-cell-associated antigens CD19 and CD20 as target structures on human leukemic cells. We found that a combination of bispecific antibody fragments (bsFab2) with target x CD3 and target x CD28 specificity induces vigorous autologous T-cell activation and killing of malignant cells in peripheral blood and bone marrow cultures from patients with chronic lymphocytic leukemia and follicular lymphoma. The bsFab2 targeting CD20 were considerably more effective than those binding to CD19. The colony-forming capacity of treated bone marrow was impaired due to large amounts of tumor necrosis factor alpha produced during bsFab2-induced T-cell activation. Neutralizing tumor necrosis factor alpha antibodies were found to reverse this negative effect without affecting T-cell activation and tumor cell killing. CD20 x CD28 bsFab2, when used alone rather than in combination, markedly improved the recognition of leukemic cells by allogeneic T cells. Therefore, these reagents may be capable of enhancing the immunogenicity of leukemic cells in general and, in particular, of increasing the antileukemic activity of allogeneic donor buffy coat cells in relapsed bone marrow transplanted patients.
Effects of verbenalin on prostatitis mouse model
Miao, Mingsan; Guo, Lin; Yan, Xiaoli; Wang, Tan; Li, Zuming
2015-01-01
The aim of this study was to observe the treatment characteristics of verbenalin on a prostatitis mouse model. Give Xiaozhiling injection in the prostate locally to make a prostatitis mouse model. High, medium and low doses of verbenalin were each given to different mouse groups. The amount of water was determined in 14th, 28th. The number of white cells and lecithin corpuscle density in prostatic fluid were determined. Morphological changes in the prostate, testis, epididymis and kidney were detected. Compared with the model control group, the mice treated with high, medium and low doses of verbenalin had significantly increased amounts of water, and prostate white blood cell count and prostate volume density (Vv) were decreased significantly, the density of lecithin corpuscle score increased, and pathologic prostatitis changes were significantly reduced. Pathological change in the testis was significantly reduced and the change in the epididymis was obviously reduced. The thymic cortex thickness and the number of lymphocytes increased significantly and could reduce the renal pathological changes in potential. Verbenalin has a good therapeutic effect on the prostatitis mouse model. PMID:26858560
AN EFFECTIVE HUMAN LEG MODELING METHOD
Institute of Scientific and Technical Information of China (English)
无
2000-01-01
Digital medicine is a new concept in medical field, and the need for digital human body is increasing these years. This paper used Free Form Deformation (FFD) to model the motion of human leg. It presented the motion equations of knee joint on the basis of anatomic structure and motion characters, then transmitted the deformation to the mesh of leg through a simplified FFD that only used two-order B-spline basis function. The experiments prove that this method can simulate the bend of leg and the deformation of muscles fairly well. Compared with the method of curved patches, this method is more convenient and effective. Further more, those equations can be easily applied to other joint models of human body.
Lee, Duncan; Rushworth, Alastair; Sahu, Sujit K
2014-06-01
Estimation of the long-term health effects of air pollution is a challenging task, especially when modeling spatial small-area disease incidence data in an ecological study design. The challenge comes from the unobserved underlying spatial autocorrelation structure in these data, which is accounted for using random effects modeled by a globally smooth conditional autoregressive model. These smooth random effects confound the effects of air pollution, which are also globally smooth. To avoid this collinearity a Bayesian localized conditional autoregressive model is developed for the random effects. This localized model is flexible spatially, in the sense that it is not only able to model areas of spatial smoothness, but also it is able to capture step changes in the random effects surface. This methodological development allows us to improve the estimation performance of the covariate effects, compared to using traditional conditional auto-regressive models. These results are established using a simulation study, and are then illustrated with our motivating study on air pollution and respiratory ill health in Greater Glasgow, Scotland in 2011. The model shows substantial health effects of particulate matter air pollution and nitrogen dioxide, whose effects have been consistently attenuated by the currently available globally smooth models.
1994-01-01
This model of the Boeing A/FX (Advanced Attack/Fighter) Aircraft was photographed between test runs in NASA Langley Research Center's 16-Foot Transonic Tunnel. Testing was conducted to determine the effects of the jet exhaust on the aerodynamic characteristics of the aircraft afterbody. The A/FX program was a Navy effort to obtain a next-generation replacement for the A-6 and F/A-18. The A/FX program evolved into the current multi-service JSF (Joint Strike Fighter) program.
Modelling heating effects in cryocooled protein crystals
Nicholson, J; Fayz, K; Fell, B; Garman, E
2001-01-01
With the application of intense X-ray beams from third generation synchrotron sources, damage to cryocooled macromolecular crystals is being observed more commonly . In order to fully utilize synchrotron facilities now available for studying biological crystals, it is essential to understand the processes involved in radiation damage and beam heating so that, if possible, action can be taken to slow the rate of damage. Finite Element Analysis (FEA) has been applied to model the heating effects of X-rays on cryocooled protein crystals, and to compare the relative cooling efficiencies of nitrogen and helium.
Blutke, Andreas; Schneider, Marlon R; Wolf, Eckhard; Wanke, Rüdiger
2016-03-01
Growth hormone (GH)-transgenic mice with permanently elevated systemic levels of GH and insulin-like growth factor 1 (IGF1) reproducibly develop renal and glomerular hypertrophy and subsequent progressive glomerulosclerosis, finally leading to terminal renal failure. To dissociate IGF1-dependent and -independent effects of GH excess on renal growth and lesion development in vivo, the kidneys of 75 days old IGF1-deficient (I(-/-)) and of IGF1-deficient GH-transgenic mice (I(-/-)/G), as well as of GH-transgenic (G) and nontransgenic wild-type control mice (I(+/+)) were examined by quantitative stereological and functional analyses. Both G and I(-/-)/G mice developed glomerular hypertrophy, hyperplasia of glomerular mesangial and endothelial cells, podocyte hypertrophy and foot process effacement, albuminuria, and glomerulosclerosis. However, I(-/-)/G mice exhibited less severe glomerular alterations, as compared to G mice. Compared to I(+/+) mice, G mice exhibited renal hypertrophy with a significant increase in the number without a change in the size of proximal tubular epithelial (PTE) cells. In contrast, I(-/-)/G mice did not display significant PTE cell hyperplasia, as compared to I(-/-) mice. These findings indicate that GH excess stimulates glomerular growth and induces lesions progressing to glomerulosclerosis in the absence of IGF1. In contrast, IGF1 represents an important mediator of GH-dependent proximal tubular growth in GH-transgenic mice.
ACCOUNTING FOR GREENHOUSE GASES EMISSIONS ALLOWANCES IN ROMANIA
Directory of Open Access Journals (Sweden)
Marius Deac
2013-02-01
Full Text Available The present paper tries to analyze the accounting challenges that the implementation of EU Emissions Trading Scheme has risen. On 2 December 2004, IASB has issued an interpretation regarding the accounting of the GHG emissions allowances (IFRIC 3 „Emission Rights”. This interpretation should have been effective for annual periods beginning after 1 March 2005, the first year of the EU Emission Trading Scheme implementation. Less than a year after it was issued, IFRIC has withdrawn IFRIC 3. In December 2007, IASB has started a new project in order to provide guidance on accounting for carbon allowances called Emissions Trading Schemes Project. In the absence of an accounting standard regarding the accounting of these emissions allowances a diversity of accounting practices have been identified. Nowadays, there are three main accounting practices for the recognition of the emissions allowances and the GHG emissions liabilities: IFRIC 3 approach, the government grants approach and the net liability or off balance sheet approach. The accounting treatment of greenhouse gas emissions allowances by Romanian companies resembles the net liability or off balance sheet approach. Finance Ministry Order no. 1118/2012 states that GHG emission certificates should be recognized as fixed assets (if the entity is expecting a profit in the long term or in the category of short term investments (if the entity is expecting a profit in the short term. The accounting of the greenhouse gas emissions allowances described above is applicable mainly to traders of such certificates and not for the installations in the scope of the EU ETS directive, which should recognize GHG emissions off balance sheet, at their nominal value (nil if received for free. The shortfall or excess of allowances will be recognized in the profit or loss as they are bought or sold by the entity (the accounting treatment imposed by Finance Ministry Order no. 3055/2009.
'Home made' model to study the greenhouse effect and global warming
Energy Technology Data Exchange (ETDEWEB)
Onorato, P; Mascheretti, P; DeAmbrosis, A, E-mail: pasquale.onorato@unipv.it, E-mail: anna.deambrosisvigna@unipv.it [Department of Physics ' A. Volta' , University of Pavia, Via Bassi 6, I-27100 Pavia (Italy)
2011-03-15
In this paper a simplified two-parameter model of the greenhouse effect on the Earth is developed, starting from the well known two-layer model. It allows both the analysis of the temperatures of the inner planets, by focusing on the role of the greenhouse effect, and a comparison between the temperatures the planets should have in the absence of greenhouse effect and their actual ones. It may also be used to predict the average temperature of the Earth surface in the future, depending on the variations of the concentration of greenhouse gases in the atmosphere due to human activities. This model can promote an elementary understanding of global warming since it allows a simple formalization of the energy balance for the Earth in the stationary condition, in the presence of greenhouse gases. For these reasons it can be introduced in courses for undergraduate physics students and for teacher preparation.
Just do it: action-dependent learning allows sensory prediction.
Directory of Open Access Journals (Sweden)
Itai Novick
Full Text Available Sensory-motor learning is commonly considered as a mapping process, whereby sensory information is transformed into the motor commands that drive actions. However, this directional mapping, from inputs to outputs, is part of a loop; sensory stimuli cause actions and vice versa. Here, we explore whether actions affect the understanding of the sensory input that they cause. Using a visuo-motor task in humans, we demonstrate two types of learning-related behavioral effects. Stimulus-dependent effects reflect stimulus-response learning, while action-dependent effects reflect a distinct learning component, allowing the brain to predict the forthcoming sensory outcome of actions. Together, the stimulus-dependent and the action-dependent learning components allow the brain to construct a complete internal representation of the sensory-motor loop.
The Ranque-Hilsch effect: CFD modeling
Energy Technology Data Exchange (ETDEWEB)
Bezprozvannykh, V.; Mottl, H. [DYCOR Technologies, Edmonton, Alberta (Canada)]. E-mail: vlad.bez@dycor.com; hank.mottl@dycor.com
2003-07-01
The phenomenon of noticeable temperature distribution in confined steady rotating gas flows is referred as Ranque-Hilsch effect. The simple counter-flow Ranque-Hilsch tube consists of a long hollow cylinder with tangential nozzles at one end for injecting compressed gas. Rotating gas escapes the tube through two outlets - a central orifice diaphragm placed near the injection nozzle plane (cold stream) and a ring-shaped peripheral outlet placed at the opposite end of the tube (hot stream). The flow is essentially three-dimensional, turbulent, compressible, and spinning such that any theoretical simplifications are questionable, if at all possible. Fluent suite of software was applied at Dycor Technologies, Canada to the task of numerical simulation of the Ranque-Hilsch effect that is part of Dycor's program of fundamental and applied research. The behavior of two types of fluids in the Ranque-Hilsch tube was investigated - air and water. Three-dimensional continuity, momentum, and energy equations were solved for incompressible and compressible flows for water and air cases correspondingly. The Reynolds stress turbulence model was originally applied to close the Reynolds-averaged Navier-Stokes equations. The visualization of the velocity and temperature fields inside the vortex tube helped to understand the details of fluid flow. It was shown that CFD approach is applicable for simulating Ranque-Hilsch effect. It was found that various levels of complexity in turbulence modeling are suitable for vortex tube analysis. No vortex effect was observed for incompressible flow. The dependence of vortex tube cooling ability on initial gas pressure was investigated. Numerical simulation data are consistent with available experimental results. (author)
The Effective Kahler Potential, Metastable Vacua and R-Symmetry Breaking in O'Raifeartaigh Models
Benjamin, Shermane; Kain, Ben
2010-01-01
Much has been learned about metastable vacua and R-symmetry breaking in O'Raifeartaigh models. Such work has largely been done from the perspective of the superpotential and by including Coleman-Weinberg corrections to the scalar potential. Instead, we consider these ideas from the perspective of the one loop effective Kahler potential. We translate known ideas to this framework and construct convenient formulas for computing individual terms in the expanded effective Kahler potential. We do so for arbitrary R-charge assignments and allow for small R-symmetry violating terms so that both spontaneous and explicit R-symmetry breaking is allowed in our analysis.
Mixed-Effects State Space Models for Analysis of Longitudinal Dynamic Systems
Liu, Dacheng; Lu, Tao; Niu, Xu-Feng; Wu, Hulin
2010-01-01
The rapid development of new biotechnologies allows us to deeply understand biomedical dynamic systems in more detail and at a cellular level. Many of the subject-specific biomedical systems can be described by a set of differential or difference equations which are similar to engineering dynamic systems. In this paper, motivated by HIV dynamic studies, we propose a class of mixed-effects state space models based on the longitudinal feature of dynamic systems. State space models with mixed-ef...
Modeling terahertz heating effects on water
DEFF Research Database (Denmark)
Kristensen, Torben T.L.; Withayachumnankul, Withawat; Jepsen, Peter Uhd;
2010-01-01
We apply Kirchhoff’s heat equation to model the influence of a CW terahertz beam on a sample of water, which is assumed to be static. We develop a generalized model, which easily can be applied to other liquids and solids by changing the material constants. If the terahertz light source is focused...... down to a spot with a diameter of 0.5 mm, we find that the steadystate temperature increase per milliwatt of transmitted power is 1.8◦C/mW. A quantum cascade laser can produce a CW beam in the order of several milliwatts and this motivates the need to estimate the effect of beam power on the sample...... temperature. For THz time domain systems, we indicate how to use our model as a worst-case approximation based on the beam average power. It turns out that THz pulses created from photoconductive antennas give a negligible increase in temperature. As biotissue contains a high water content, this leads...
Matsumoto, Shigeki; Tsai, Yue-Lin Sming
2016-01-01
We enumerate the set of simplified models which match onto the complete set of gauge invariant effective operators up to dimension six describing interactions of a singlet-like Majorana fermion dark matter with the standard model. Tree level matching conditions for each case are worked out in the large mediator mass limit, defining a one to one correspondence between the effective operator coefficients and the simplified model parameters for weakly interacting models. Utilizing such a mapping, we compute the dark matter annihilation rate in the early universe, as well as other low-energy observables like nuclear recoil rates using the effective operators, while the simplified models are used to compute the dark matter production rates at high energy colliders like LEP, LHC and future lepton colliders. Combining all relevant constraints with a profile likelihood analysis, we then discuss the currently allowed parameter regions and prospects for future searches in terms of the effective operator parameters, red...
Predicting Cumulative Watershed Effects using Spatially Explicit Models
MacDonald, L. H.; Litschert, S.
2004-12-01
Cumulative watershed effects /(CWEs/) result from the combined effects of land disturbances distributed over both space and time. They are of concern because changes in flow and sediment yields can adversely affect aquatic habitat, channel morphology, water yields, and water quality. The assessment procedures currently used by agencies such as the U.S. Forest Service generally rely on a lumped approach to quantify disturbance, despite the widespread recognition that site conditions and location do matter! The overall goal of our work is to develop spatially-explicit models to quantify changes in flow and sediment yields. Key objectives include: use of readily available GIS data; ease of use for resource managers with minimal GIS experience; modularity so that models can be added or updated; and allowing users to select the models and values for key parameters. The DeltaQ model calculates changes in peak, median, and low flows due to forest management activities and fires. Inputs include GIS data with disturbance polygons, an initial change in flow rate, and the time to recovery. Data from paired watershed studies are provided to help guide the user. The initial version of FORest Erosion Simulation Tools /(FOREST/) calculates sediment production from forest harvest, fires, and unpaved roads. Additional modules are being developed to deliver this sediment to the stream channel and route it to downstream locations. In accordance with our objectives, the user can predict sediment production rates using different empirical equations, assign an initial sediment production rate and a specified linear recovery period, or develop a look-up table based on local knowledge, published values, or data from other models such as WEPP. The required GIS layers vary according to the model/(s/) selected, but generally include past disturbances /(e.g., fires and timber harvest/), roads, and elevation. Outputs include GIS layers and text files that can be subjected to additional
Pelloux-Prayer, J.; Cassé, M.; Triozon, F.; Barraud, S.; Niquet, Y.-M.; Rouvière, J.-L.; Faynot, O.; Reimbold, G.
2016-11-01
The effect of strain on carrier mobility in triple gate Fully Depleted Silicon On Insulator (FDSOI) nanowires (NWs) is experimentally investigated through piezoresistance measurements. The piezoresitive coefficients have been extracted and analyzed for rectangular cross-section with varying aspect ratio (width vs. height). We propose an empirical model based on mobility separation between top and sidewall conduction surfaces of the NWs, and on the carrier density calculation in the cross-section of the NWs. The model allows fitting the piezoresistive coefficients and the carrier mobility for the different device geometries. We highlight an enhanced strain effect for Trigate nanowires with channel thickness below 11 nm.
Simple model of the slingshot effect
Directory of Open Access Journals (Sweden)
Gaetano Fiore
2016-07-01
Full Text Available We present a detailed quantitative description of the recently proposed “slingshot effect.” Namely, we determine a broad range of conditions under which the impact of a very short and intense laser pulse normally onto a low-density plasma (or matter locally completely ionized into a plasma by the pulse causes the expulsion of a bunch of surface electrons in the direction opposite to the one of propagation of the pulse, and the detailed, ready-for-experiments features of the expelled electrons (energy spectrum, collimation, etc. The effect is due to the combined actions of the ponderomotive force and the huge longitudinal field arising from charge separation. Our predictions are based on estimating 3D corrections to a simple, yet powerful plane 2-fluid magnetohydrodynamic (MHD model where the equations to be solved are reduced to a system of Hamilton equations in one dimension (or a collection of which become autonomous after the pulse has overcome the electrons. Experimental tests seem to be at hand. If confirmed by the latter, the effect would provide a new extraction and acceleration mechanism for electrons, alternative to traditional radio-frequency-based or Laser-Wake-Field ones.
Mantovanelli, Ivana C. C.; Rivera, Elmer Ccopa; da Costa, Aline C.; Filho, Rubens Maciel
In this work a procedure for the development of a robust mathematical model for an industrial alcoholic fermentation process was evaluated. The proposed model is a hybrid neural model, which combines mass and energy balance equations with functional link networks to describe the kinetics. These networks have been shown to have a good nonlinear approximation capability, although the estimation of its weights is linear. The proposed model considers the effect of temperature on the kinetics and has the neural network weights reestimated always so that a change in operational conditions occurs. This allow to follow the system behavior when changes in operating conditions occur.
Gaurier, Benoît; Cébron, David
2010-01-01
A model using wake oscillators is developed to predict the 2D motion in a transverse plan of two rigid cylinders in tandem arrangement. This model of the wake dynamics is validated with experimental data from previous trials which took place at the Ifremer flume tank in Boulogne-sur-Mer, France. The agreement between the model and the experimental results allows using this model as a simple computational tool in the prediction of 2D Vortex-Induced Vibrations (VIV) and, after some futher developments, Wake-Induced Oscillations (WIO) effects.
Beta-beating in the effective model of the LHC using PTC
Alabau Pons, C; Schmidt, F; Tomas, R
2011-01-01
An effective model of the LHC optics has been developed based on measurements of magnetic field, alignment errors and closed orbit. This model utilizes the Polymorphic Tracking Code, with MAD-X as a front-end, to allow the inclusion of harmonics to arbitrary order in thick lattice elements. Beta-beating calculations have been performed with this model at injection optics and at 3.5 TeV with squeezed optics (Beta=3.5 m at the interaction point) The model predictions are in good agreement with the measurements performed in the 2010 LHC commissioning run.
β-beating in the effective model of the LHC using PTC
Alabau Pons, M C; Schmidt, F; Tomas, R
2011-01-01
An effective model of the LHC optics has been developed based on measurements of magnetic field, alignment errors and closed orbit. This model utilizes the Polymorphic Tracking Code, with MAD-X as a front-end, to allow the inclusion of harmonics to arbitrary order in thick lattice elements. β-beating calculations have been performed with this model at injection optics and at 3.5 TeV squeezed to 3.5 m β-function at the interaction point. The model predictions are in remarkable agreement with the measurements performed in the 2010 LHC commissioning run.
Extending the Standard Model Effective Field Theory with the Complete Set of Dimension-7 Operators
Lehman, Landon
2014-01-01
We present a complete list of the independent dimension-7 operators that are constructed using the Standard Model degrees of freedom and are invariant under the Standard Model gauge group. This list contains only 20 independent operators; far fewer than the 63 operators available at dimension 6. All of these dimension-7 operators contain fermions and violate lepton number, and 7 of the 20 violate baryon number as well. This result extends the Standard Model Effective Field Theory (SMEFT) and allows a more detailed exploration of the structure and properties of possible deformations from the Standard Model Lagrangian.
Extending the standard model effective field theory with the complete set of dimension-7 operators
Lehman, Landon
2014-12-01
We present a complete list of the independent dimension-7 operators that are constructed using the standard model degrees of freedom and are invariant under the standard model gauge group. This list contains only 20 independent operators, far fewer than the 63 operators available at dimension 6. All of these dimension-7 operators contain fermions and violate lepton number, and 7 of the 20 violate baryon number as well. This result extends the standard model effective field theory and allows a more detailed exploration of the structure and properties of possible deformations from the standard model Lagrangian.
Measurement and modelling of enhanced absorption Hanle effect resonances in {sup 85}Rb
Energy Technology Data Exchange (ETDEWEB)
Vilardi, Andrea; Tabarelli, Davide; Botti, Laura; Bertoldi, Andrea; Ricci, Leonardo [Dipartimento di Fisica, Universita di Trento, I-38100 Trento-Povo (Italy)], E-mail: andrea.bertoldi@institutoptique.fr
2009-03-14
We report on a detailed measurement of the enhanced absorption Hanle effect resonances in {sup 85}Rb. The effect was analysed with an experimental setup allowing for the control of each magnetic field component within 1 mG. The characterization deals with the dependence of resonances, observed under different magnetic field conditions, on the frequency, intensity and polarization of the exciting radiation field. An analytic model that precisely describes the resonance behaviour is discussed.
Transfer effects between moral dilemmas: a causal model theory.
Wiegmann, Alex; Waldmann, Michael R
2014-04-01
Evaluations of analogous situations are an important source for our moral intuitions. A puzzling recent set of findings in experiments exploring transfer effects between intuitions about moral dilemmas has demonstrated a striking asymmetry. Transfer often occurred with a specific ordering of moral dilemmas, but not when the sequence was reversed. In this article we present a new theory of transfer between moral intuitions that focuses on two components of moral dilemmas, namely their causal structure and their default evaluations. According to this theory, transfer effects are expected when the causal models underlying the considered dilemmas allow for a mapping of the highlighted aspect of the first scenario onto the causal structure of the second dilemma, and when the default evaluations of the two dilemmas substantially differ. The theory's key predictions for the occurrence and the direction of transfer effects between two moral dilemmas are tested in five experiments with various variants of moral dilemmas from different domains. A sixth experiment tests the predictions of the theory for how the target action in the moral dilemmas is represented.
Modeling Instruction: An Effective Model for Science Education
Jackson, Jane; Dukerich, Larry; Hestenes, David
2008-01-01
The authors describe a Modeling Instruction program that places an emphasis on the construction and application of conceptual models of physical phenomena as a central aspect of learning and doing science. (Contains 1 table.)
40 CFR 73.21 - Phase II repowering allowances.
2010-07-01
... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Phase II repowering allowances. 73.21... (CONTINUED) SULFUR DIOXIDE ALLOWANCE SYSTEM Allowance Allocations § 73.21 Phase II repowering allowances. (a) Repowering allowances. In addition to allowances allocated under § 73.10(b), the Administrator will...
[Effect evaluation of three cell culture models].
Wang, Aiguo; Xia, Tao; Yuan, Jing; Chen, Xuemin
2003-11-01
Primary rat hepatocytes were cultured using three kinds of models in vitro and the enzyme leakage, albumin secretion, and cytochrome P450 1A (CYP 1A) activity were observed. The results showed that the level of LDH in the medium decreased over time in the period of culture. However, on 5 days, LDH showed a significant increase in monolayer culture (MC) while after 8 days LDH was not detected in sandwich culture (SC). The levels of AST and ALT in the medium did not change significantly over the investigated time. The basic CYP 1A activity gradually decreased with time in MC and SC. The decline of CYP 1A in rat hepatocytes was faster in MC than that in SC. This effect was partially reversed by using cytochrome P450 (CYP450) inducers such as omeprazol and 3-methylcholanthrene (3-MC) and the CYP 1A induction was always higher in MC than that in SC. Basic CYP 1A activity in bioreactor was keeped over 2 weeks and the highest albumin production was observed in bioreactor, and next were SC and MC. In conclusion, our results clearly indicated that there have some advantages and disadvantages in each of models in which can address different questions in metabolism of toxicants and drugs.
Effectiveness of Peer Education Involving the use of Theoretical Models
2008-01-01
The effectiveness of health education among university students who received peer-support training was investigated using four theoretical models : the health belief model, the self-efficacy model, social support and the transtheoretical model of health behavior change. Results suggested that the four theoretical models were useful in evaluating the effect of peer education as an alternative assessment tool. In light of this, it is suggested that the use of the theoretical models may facilita...
A simple model of the slingshot effect
Fiore, Gaetano
2015-01-01
We present a detailed quantitative description of the recently proposed "slingshot effect" [Fiore, Fedele, De angelis 2014]. Namely, we determine a broad range of conditions under which the impact of a very short and intense laser pulse normally onto a plasma (or matter to be locally completely ionized into a plasma by the pulse) causes the expulsion of a bunch of surface electrons in the direction opposite to the one of propagation of the pulse, and the detailed, ready-for-experiments features of the expelled electrons (energy spectrum, collimation, etc). The effect is due to the combined actions of the ponderomotive force and the huge longitudinal field arising from charge separation. Our predictions are based on estimating 3D corrections to a simple, yet powerful plane magnetofluidodynamic model where the equations to be solved are reduced to a system of Hamilton equations in one dimension (or a collection of) which become autonomous after the pulse has overcome the electrons. Experimental tests seem to be...
Murphy, Daniel L.; Beretvas, S. Natasha
2015-01-01
This study examines the use of cross-classified random effects models (CCrem) and cross-classified multiple membership random effects models (CCMMrem) to model rater bias and estimate teacher effectiveness. Effect estimates are compared using CTT versus item response theory (IRT) scaling methods and three models (i.e., conventional multilevel…
Wake effects and wind farm modelling
Energy Technology Data Exchange (ETDEWEB)
Crespo, A.; Gomez-Elvira, R. [Univ. Politecnica de Madrid, Dept. of Energy and Fluid Mechanic (Spain)
1999-07-01
A model has been developed to treat simultaneously the changes in wind characteristics due to the transition from land to sea, and the wake effects in offshore wind farms. There are beneficial effects both in an increase of power production and in a reduction of turbulence loads when the distance from the farm to the land coast is increased, however, particularly for the turbulence loads, this effect reaches a limit beyond a certain distance of the order of 1 to 2 km. A method has been proposed to estimate the performance of offshore wind farms, that has been applied to places of interest to the project. As it was observed in the project East Coast of the UK, wake effects are important and significant increases can be obtained in power production by increasing the distance between machines and a better disposition of them, i.e. alternating positions in contiguous rows normal to the prevailing wind direction. The most efficient wind farms from the point of view of wake interference are Gedser and Omo with an efficiency of 89% and 86% respectively. A large wind farm like Rodsand has lower efficiency because of the cumulative effect of the wakes of many turbines. The calculated value of the capacity factor of the three Danish wind farms is larger than 36%. The value of the added turbulence intensity, averaged over rows normal to the incident wind, increases suddenly in the first rows and then reaches an almost constant value in the downstream rows, that is of the order of 10%. A method to calculate the performance of very large wind farms, such that they can change the planetary boundary layer is presented. This method has been applied to the wind farms of interest in the project, and small reductions of the order of 5% or less in power production may occur. However, for very large wind farms (with a of the order of 100 km), that may perturb the whole planetary boundary layer, much more drastic reductions, of the order of 50%, may appear, particularly in the
[Effect of astaxanthin on preeclampsia rat model].
Xuan Rong-rong; Gao Xin; Wu, Wei; Chen, Hai-min
2014-10-01
The effect of astaxanthin on N(Ω)-nitro-L-arginine methyl ester (L-NAME) induced preeclampsia disease rats was investigated. Thirty pregnant Sprague-Dawley rats were randomly divided into three groups (n = 10): blank group, L-NAME group and astaxanthin group. From day 5 to 20, astaxanthin group rats were treated with astaxanthin (25 mg x kg(-1) x d(-1) x bw(-1)) from pregnancy (day 5). To establish the preeclamptic rat model, L-NAME group and astaxanthin group rats were injected with L-NAME (125 mg x kg(-1) x d(-1) x bw(-1)) from days 10-20 of pregnancy. The blood pressure and urine protein were recorded. Serum of each group was collected and malondialdehyde (MDA), superoxide dismutase (SOD) and nitric oxide synthase (NOS) activities were analyzed. Pathological changes were observed with HE stain. The expression of NF-κB (nuclear factor kappa B), ROCK II (Rho-associated protein kinase II), HO-1 (heme oxygenase-1) and Caspase 3 were analyzed with immunohistochemistry. L-NAME induced typical preeclampsia symptoms, such as the increased blood pressure, urinary protein, the content of MDA, etc. Astaxanthin significantly reduced the blood pressure (P astaxanthin, the thickness of basilal membrane was improved and the content of trophoblast cells and spiral arteries was reduced. Immunohistochemistry results revealed that the expressions of NF-κB, ROCK II and Caspase 3 in placenta tissue were effectively decreased, and HO-1 was increased. Results indicated that astaxanthin can improve the preeclampsia symptoms by effectively reducing the oxidative stress and inflammatory damages of preeclampsia. It revealed that astaxanthin may be benefit for prevention and treatment of preeclampsia disease.
Diversity and noise effects in a model of homeostatic regulation of the sleep-wake cycle
Patriarca, Marco; Braun, Hans A; Hernández-García, Emilio; Toral, Raúl; 10.1371/journal.pcbi.1002650
2012-01-01
Recent advances in sleep neurobiology have allowed development of physiologically based mathematical models of sleep regulation that account for the neuronal dynamics responsible for the regulation of sleep-wake cycles and allow detailed examination of the underlying mechanisms. Neuronal systems in general, and those involved in sleep regulation in particular, are noisy and heterogeneous by their nature. It has been shown in various systems that certain levels of noise and diversity can significantly improve signal encoding. However, these phenomena, especially the effects of diversity, are rarely considered in the models of sleep regulation. The present paper is focused on a neuron-based physiologically motivated model of sleep-wake cycles that proposes a novel mechanism of the homeostatic regulation of sleep based on the dynamics of a wake-promoting neuropeptide orexin. Here this model is generalized by the introduction of intrinsic diversity and noise in the orexin-producing neurons in order to study the e...
Vector spin modeling for magnetic tunnel junctions with voltage dependent effects
Energy Technology Data Exchange (ETDEWEB)
Manipatruni, Sasikanth, E-mail: sasikanth.manipatruni@intel.com; Nikonov, Dmitri E.; Young, Ian A. [Exploratory Integrated Circuits, Components Research, Intel Corp., Hillsboro, Oregon 97124 (United States)
2014-05-07
Integration and co-design of CMOS and spin transfer devices requires accurate vector spin conduction modeling of magnetic tunnel junction (MTJ) devices. A physically realistic model of the MTJ should comprehend the spin torque dynamics of nanomagnet interacting with an injected vector spin current and the voltage dependent spin torque. Vector spin modeling allows for calculation of 3 component spin currents and potentials along with the charge currents/potentials in non-collinear magnetic systems. Here, we show 4-component vector spin conduction modeling of magnetic tunnel junction devices coupled with spin transfer torque in the nanomagnet. Nanomagnet dynamics, voltage dependent spin transport, and thermal noise are comprehended in a self-consistent fashion. We show comparison of the model with experimental magnetoresistance (MR) of MTJs and voltage degradation of MR with voltage. Proposed model enables MTJ circuit design that comprehends voltage dependent spin torque effects, switching error rates, spin degradation, and back hopping effects.
Assessing NARCCAP climate model effects using spatial confidence regions
French, Joshua P.; McGinnis, Seth; Schwartzman, Armin
2017-07-01
We assess similarities and differences between model effects for the North American Regional Climate Change Assessment Program (NARCCAP) climate models using varying classes of linear regression models. Specifically, we consider how the average temperature effect differs for the various global and regional climate model combinations, including assessment of possible interaction between the effects of global and regional climate models. We use both pointwise and simultaneous inference procedures to identify regions where global and regional climate model effects differ. We also show conclusively that results from pointwise inference are misleading, and that accounting for multiple comparisons is important for making proper inference.
Assessing NARCCAP climate model effects using spatial confidence regions
Directory of Open Access Journals (Sweden)
J. P. French
2017-07-01
Full Text Available We assess similarities and differences between model effects for the North American Regional Climate Change Assessment Program (NARCCAP climate models using varying classes of linear regression models. Specifically, we consider how the average temperature effect differs for the various global and regional climate model combinations, including assessment of possible interaction between the effects of global and regional climate models. We use both pointwise and simultaneous inference procedures to identify regions where global and regional climate model effects differ. We also show conclusively that results from pointwise inference are misleading, and that accounting for multiple comparisons is important for making proper inference.
Matsumoto, Shigeki; Mukhopadhyay, Satyanarayan; Tsai, Yue-Lin Sming
2016-09-01
We enumerate the set of simplified models which match onto the complete set of gauge invariant effective operators up to dimension six describing interactions of a singlet-like Majorana fermion dark matter with the standard model. Tree-level matching conditions for each case are worked out in the large mediator mass limit, defining a one-to-one correspondence between the effective operator coefficients and the simplified model parameters for weakly interacting models. Utilizing such a mapping, we compute the dark matter annihilation rate in the early universe, as well as other low-energy observables like nuclear recoil rates using the effective operators, while the simplified models are used to compute the dark matter production rates at high-energy colliders like LEP, LHC and future lepton colliders. Combining all relevant constraints with a profile-likelihood analysis, we then discuss the currently allowed parameter regions and prospects for future searches in terms of the effective operator parameters, reducing the model dependence to a minimal level. In the parameter region where such a model-independent analysis is applicable, and leaving aside the special dark matter mass regions where the annihilation proceeds through an s -channel Z or Higgs boson pole, the current constraints allow effective operator suppression scales (Λ ) of the order of a few hundred GeV for dark matter masses mχ>20 GeV at 95% C.L., while the maximum allowed scale is around 3 TeV for mχ˜O (1 TeV ) . An estimate of the future reach of ton-scale direct detection experiments and planned electron-positron colliders show that most of the remaining regions can be probed, apart from dark matter masses near half of the Z -boson mass (with 500 GeV <Λ <2 TeV ) and those beyond the kinematic reach of the future lepton colliders.
Radiative data for allowed transitions in Ni XXV
Energy Technology Data Exchange (ETDEWEB)
Tully, John A [Departement Cassiopee, Observatoire de la Cote d' Azur, BP 4229, 06304 Nice Cedex 4 (France); Chidichimo, Marita C [Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)
2004-02-14
Using Hibbert's configuration interaction program CIV3, which allows for relativistic effects by means of the Breit-Pauli approximation, we have computed radiative data for the 272 optically allowed transitions between levels i = 2l{sub 1} 2l{sub 2} S'L'J' and j = 2l{sub 3} n{sub 4}l{sub 4} SLJ with n{sub 4} = 2, 3, 4 in Be-like Ni XXV. Oscillator strengths f, transition probabilities A, line wavelengths {lambda} and energies E{sub ij} in cm{sup -1} are tabulated. We make detailed comparisons with related work done by other authors during the period 1977 to 2000.
A random effects epidemic-type aftershock sequence model.
Lin, Feng-Chang
2011-04-01
We consider an extension of the temporal epidemic-type aftershock sequence (ETAS) model with random effects as a special case of a well-known doubly stochastic self-exciting point process. The new model arises from a deterministic function that is randomly scaled by a nonnegative random variable, which is unobservable but assumed to follow either positive stable or one-parameter gamma distribution with unit mean. Both random effects models are of interest although the one-parameter gamma random effects model is more popular when modeling associated survival times. Our estimation is based on the maximum likelihood approach with marginalized intensity. The methods are shown to perform well in simulation experiments. When applied to an earthquake sequence on the east coast of Taiwan, the extended model with positive stable random effects provides a better model fit, compared to the original ETAS model and the extended model with one-parameter gamma random effects.
Directory of Open Access Journals (Sweden)
Christopher Heine
2014-08-01
Full Text Available A detailed description of the rubber parts’ properties is gaining in importance in the current simulation models of multi-body simulation. One application example is a multi-body simulation of the washing machine movement. Inside the washing machine, there are different force transmission elements, which consist completely or partly of rubber. Rubber parts or, generally, elastomers usually have amplitude-dependant and frequency-dependent force transmission properties. Rheological models are used to describe these properties. A method for characterization of the amplitude and frequency dependence of such a rheological model is presented within this paper. Within this method, the used rheological model can be reduced or expanded in order to illustrate various non-linear effects. An original result is given with the automated parameter identification. It is fully implemented in Matlab. Such identified rheological models are intended for subsequent implementation in a multi-body model. This allows a significant enhancement of the overall model quality.
45 CFR 2522.245 - How are living allowances disbursed?
2010-10-01
..., Requirements, and Benefits § 2522.245 How are living allowances disbursed? A living allowance is not a wage and programs may not pay living allowances on an hourly basis. Programs must distribute the living allowance at... 45 Public Welfare 4 2010-10-01 2010-10-01 false How are living allowances disbursed? 2522.245...
49 CFR 230.24 - Maximum allowable stress.
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...
Comparison of three artificial models of the magnetohydrodynamic effect on the electrocardiogram.
Oster, Julien; Llinares, Raul; Payne, Stephen; Tse, Zion Tsz Ho; Schmidt, Ehud Jeruham; Clifford, Gari D
2015-01-01
The electrocardiogram (ECG) is often acquired during magnetic resonance imaging (MRI), but its analysis is restricted by the presence of a strong artefact, called magnetohydrodynamic (MHD) effect. MHD effect is induced by the flow of electrically charged particles in the blood perpendicular to the static magnetic field, which creates a potential of the order of magnitude of the ECG and temporally coincident with the repolarisation period. In this study, a new MHD model is proposed by using MRI-based 4D blood flow measurements made across the aortic arch. The model is extended to several cardiac cycles to allow the simulation of a realistic ECG acquisition during MRI examination and the quality assessment of MHD suppression techniques. A comparison of two existing models, based, respectively, on an analytical solution and on a numerical method-based solution of the fluids dynamics problem, is made with the proposed model and with an estimate of the MHD voltage observed during a real MRI scan. Results indicate a moderate agreement between the proposed model and the estimated MHD model for most leads, with an average correlation factor of 0.47. However, the results demonstrate that the proposed model provides a closer approximation to the observed MHD effects and a better depiction of the complexity of the MHD effect compared with the previously published models, with an improved correlation (+5%), coefficient of determination (+22%) and fraction of energy (+1%) compared with the best previous model. The source code will be made freely available under an open source licence to facilitate collaboration and allow more rapid development of more accurate models of the MHD effect.
Effective stimuli for constructing reliable neuron models.
Directory of Open Access Journals (Sweden)
Shaul Druckmann
2011-08-01
Full Text Available The rich dynamical nature of neurons poses major conceptual and technical challenges for unraveling their nonlinear membrane properties. Traditionally, various current waveforms have been injected at the soma to probe neuron dynamics, but the rationale for selecting specific stimuli has never been rigorously justified. The present experimental and theoretical study proposes a novel framework, inspired by learning theory, for objectively selecting the stimuli that best unravel the neuron's dynamics. The efficacy of stimuli is assessed in terms of their ability to constrain the parameter space of biophysically detailed conductance-based models that faithfully replicate the neuron's dynamics as attested by their ability to generalize well to the neuron's response to novel experimental stimuli. We used this framework to evaluate a variety of stimuli in different types of cortical neurons, ages and animals. Despite their simplicity, a set of stimuli consisting of step and ramp current pulses outperforms synaptic-like noisy stimuli in revealing the dynamics of these neurons. The general framework that we propose paves a new way for defining, evaluating and standardizing effective electrical probing of neurons and will thus lay the foundation for a much deeper understanding of the electrical nature of these highly sophisticated and non-linear devices and of the neuronal networks that they compose.
Effective and efficient model clone detection
DEFF Research Database (Denmark)
Störrle, Harald
2015-01-01
Code clones are a major source of software defects. Thus, it is likely that model clones (i.e., duplicate fragments of models) have a significant negative impact on model quality, and thus, on any software created based on those models, irrespective of whether the software is generated fully...... automatically (“MDD-style”) or hand-crafted following the blueprint defined by the model (“MBSD-style”). Unfortunately, however, model clones are much less well studied than code clones. In this paper, we present a clone detection algorithm for UML domain models. Our approach covers a much greater variety...... of model types than existing approaches while providing high clone detection rates at high speed....
Cheung, Mike W.-L.; Cheung, Shu Fai
2016-01-01
Meta-analytic structural equation modeling (MASEM) combines the techniques of meta-analysis and structural equation modeling for the purpose of synthesizing correlation or covariance matrices and fitting structural equation models on the pooled correlation or covariance matrix. Both fixed-effects and random-effects models can be defined in MASEM.…
Mixed effects in stochastic differential equation models
DEFF Research Database (Denmark)
Ditlevsen, Susanne; De Gaetano, Andrea
2005-01-01
maximum likelihood; pharmacokinetics; population estimates; random effects; repeated measurements; stochastic processes......maximum likelihood; pharmacokinetics; population estimates; random effects; repeated measurements; stochastic processes...
Directory of Open Access Journals (Sweden)
Miguel Marques Gontijo Neto
2006-02-01
allowance (HA (kg of leaf blade /100 kg animal live weight/day, % were: 6.1 ± 0.59; 11.1 ± 0.77; 18.0 ± 1.24 and 23.9 ± 1.15%. Eight Nelore animals averaging 229.0 and 249.5 kg grazed each paddock in the first and second sampling periods, respectively. A completely randomized block design was used. Grazing time, leaf dry matter availability, leaf:stem ratio and canopy height were highly correlated with forage intake and can be used to develop prediction models of forage intake and performance of the grazing animal. Studies on intake and grazing animal performance in relation to forage allowances should consider the pasture structural traits for data interpretation and comparison. Tanzaniagrass forage allowances induced changes in the pasture structural characteristics and had quadratic effect on the daily grazing time and on the forage intake by Nelore steers. Shortest grazing time and highest forage intake were observed on pasture with herbage allowance of about 22.5 kg leaf blade/100 kg BW, which corresponded to a post-grazing mass of 4323.2 kg/ha dry matter, 2887.6 kg/ha dry green matter and average canopy height of 64 cm.
Simulation modeling of outcomes and cost effectiveness.
Ramsey, S D; McIntosh, M; Etzioni, R; Urban, N
2000-08-01
Modeling will continue to be used to address important issues in clinical practice and health policy issues that have not been adequately studied with high-quality clinical trials. The apparent ad hoc nature of models belies the methodologic rigor that is applied to create the best models in cancer prevention and care. Models have progressed from simple decision trees to extremely complex microsimulation analyses, yet all are built using a logical process based on objective evaluation of the path between intervention and outcome. The best modelers take great care to justify both the structure and content of the model and then test their assumptions using a comprehensive process of sensitivity analysis and model validation. Like clinical trials, models sometimes produce results that are later found to be invalid as other data become available. When weighing the value of models in health care decision making, it is reasonable to consider the alternatives. In the absence of data, clinical policy decisions are often based on the recommendations of expert opinion panels or on poorly defined notions of the standard of care or medical necessity. Because such decision making rarely entails the rigorous process of data collection, synthesis, and testing that is the core of well-conducted modeling, it is usually not possible for external audiences to examine the assumptions and data that were used to derive the decisions. One of the modeler's most challenging tasks is to make the structure and content of the model transparent to the intended audience. The purpose of this article is to clarify the process of modeling, so that readers of models are more knowledgeable about their uses, strengths, and limitations.
Nonlinear Mixed-Effects Models for Repairable Systems Reliability
Institute of Scientific and Technical Information of China (English)
TAN Fu-rong; JIANG Zhi-bin; KUO Way; Suk Joo BAE
2007-01-01
Mixed-effects models, also called random-effects models, are a regression type of analysis which enables the analyst to not only describe the trend over time within each subject, but also to describe the variation among different subjects. Nonlinear mixed-effects models provide a powerful and flexible tool for handling the unbalanced count data. In this paper, nonlinear mixed-effects models are used to analyze the failure data from a repairable system with multiple copies. By using this type of models, statistical inferences about the population and all copies can be made when accounting for copy-to-copy variance. Results of fitting nonlinear mixed-effects models to nine failure-data sets show that the nonlinear mixed-effects models provide a useful tool for analyzing the failure data from multi-copy repairable systems.
A DNA double-strand break kinetic rejoining model based on the local effect model.
Tommasino, F; Friedrich, T; Scholz, U; Taucher-Scholz, G; Durante, M; Scholz, M
2013-11-01
We report here on a DNA double-strand break (DSB) kinetic rejoining model applicable to a wide range of radiation qualities based on the DNA damage pattern predicted by the local effect model (LEM). In the LEM this pattern is derived from the SSB and DSB yields after photon irradiation in combination with an amorphous track structure approach. Together with the assumption of a giant-loop organization to describe the higher order chromatin structure this allows the definition of two different classes of DSB. These classes are defined by the level of clustering on a micrometer scale, i.e., "isolated DSB" (iDSB) are characterized by a single DSB in a giant loop and "clustered DSB" (cDSB) by two or more DSB in a loop. Clustered DSB are assumed to represent a more difficult challenge for the cell repair machinery compared to isolated DSB, and we thus hypothesize here that the fraction of isolated DSB can be identified with the fast component of rejoining, whereas clustered DSB are identified with the slow component of rejoining. The resulting predicted bi-exponential decay functions nicely reproduce the experimental curves of DSB rejoining over time obtained by means of gel electrophoresis elution techniques as reported by different labs, involving different cell types and a wide spectrum of radiation qualities. New experimental data are also presented aimed at investigating the effects of the same ion species accelerated at different energies. The results presented here further support the relevance of the proposed two classes of DSB as a basis for understanding cell response to ion irradiation. Importantly the density of DSB within DNA giant loops of around 2 Mbp size, i.e., on a micrometer scale, is identified as a key parameter for the description of radiation effectiveness.
Receiver Prejudice and Model Ethnicity: Impact on Advertising Effectiveness.
Lai, Hsiu-Chen Sandra; And Others
1990-01-01
Assesses the effect of model ethnicity on prejudiced respondents, and thus on advertising effectiveness. Finds that, for the most part, use of Asian models does not cause prejudiced respondents to evaluate a product or advertisement more negatively than when White models are used. (SR)
Receiver Prejudice and Model Ethnicity: Impact on Advertising Effectiveness.
Lai, Hsiu-Chen Sandra; And Others
1990-01-01
Assesses the effect of model ethnicity on prejudiced respondents, and thus on advertising effectiveness. Finds that, for the most part, use of Asian models does not cause prejudiced respondents to evaluate a product or advertisement more negatively than when White models are used. (SR)
Bends in nanotubes allow electric spin control and coupling
DEFF Research Database (Denmark)
Flensberg, Karsten; Marcus, Charles Masamed
2010-01-01
We investigate combined effects of spin-orbit coupling and magnetic field in carbon nanotubes containing one or more bends along their length. We show how bends can be used to provide electrical control of confined spins, while spins confined in straight segments remain insensitive to electric...... fields. Device geometries that allow general rotation of single spins are presented and analyzed. In addition, capacitive coupling along bends provides coherent spin-spin interaction, including between otherwise disconnected nanotubes, completing a universal set of one- and two-qubit gates....
Numerical modeling of 3-D terrain effect on MT field
Institute of Scientific and Technical Information of China (English)
徐世浙; 阮百尧; 周辉; 陈乐寿; 徐师文
1997-01-01
Using the boundary element method, the numerical modeling problem of three-dimensional terrain effect on magnetotelluric (MT) field is solved. This modeling technique can be run on PC in the case of adopting special net division. The result of modeling test for 2-D terrain by this modeling technique is basically coincident with that by 2-D modeling technique, but there is a great difference between the results of 3-D and 2-D modeling for 3-D terrain.
A Bayesian based functional mixed-effects model for analysis of LC-MS data.
Befekadu, Getachew K; Tadesse, Mahlet G; Ressom, Habtom W
2009-01-01
A Bayesian multilevel functional mixed-effects model with group specific random-effects is presented for analysis of liquid chromatography-mass spectrometry (LC-MS) data. The proposed framework allows alignment of LC-MS spectra with respect to both retention time (RT) and mass-to-charge ratio (m/z). Affine transformations are incorporated within the model to account for any variability along the RT and m/z dimensions. Simultaneous posterior inference of all unknown parameters is accomplished via Markov chain Monte Carlo method using the Gibbs sampling algorithm. The proposed approach is computationally tractable and allows incorporating prior knowledge in the inference process. We demonstrate the applicability of our approach for alignment of LC-MS spectra based on total ion count profiles derived from two LC-MS datasets.
Integrating Fire Effects into an Ecohydrologic Model for Simulating Fire Regimes
Bart, R. R.; Tague, C.; Kennedy, M. C.; McKenzie, D.
2016-12-01
Ecohydrologic models are used to dynamically simulate vegetation growth/ mortality and their interaction with water and nutrient fluxes. Although disturbances such as wildfire are a natural part of the landscape in environments such as the Western US, wildfire is generally included only as an exogenous variable in ecohydrologic models. An alternative approach is to integrate wildfire directly into ecohydrologic models so that wildfire ignition, spread and effects are driven by simulated landscape conditions within the model. This approach allows for the simulation of natural fire regimes and may provide more robust estimates of long-term ecological variables such as forest health, carbon sequestration and water use. For this study, we detail a fire-effects model that has been developed to couple a fire-spread model, WMFire, with an ecohydrologic model, RHESSys. The fire-effects model is designed for use with a simple two-stratum representation of canopy structure and computes losses following fire spread to a given landscape patch. Losses to a modeled litter layer, coarse woody debris layer and understory vegetation layer are determined based on a patch-level integrated measure of fuel loads, moisture levels, wind speed, and topography. Losses to an overstory vegetation layer are based on understory biomass consumed by the wildfire. The fire effects model was found to replicate the expected impacts of wildfire on vegetation and litter. Further, the fully coupled RHESSys-WMFire model was tested in four Western US watersheds with different vegetation/climate/fire characteristics and preliminary results indicated that the model was able to reproduce the disparate fire regimes. We highlight remaining challenges with simulating fire effects in ecohydrologic models using simplified representations of canopy structures and litter fuels. This study demonstrates the potential for integrating fire into ecohydrologic models for simulating future fire regimes.
Mixed-effects state-space models for analysis of longitudinal dynamic systems.
Liu, Dacheng; Lu, Tao; Niu, Xu-Feng; Wu, Hulin
2011-06-01
The rapid development of new biotechnologies allows us to deeply understand biomedical dynamic systems in more detail and at a cellular level. Many of the subject-specific biomedical systems can be described by a set of differential or difference equations that are similar to engineering dynamic systems. In this article, motivated by HIV dynamic studies, we propose a class of mixed-effects state-space models based on the longitudinal feature of dynamic systems. State-space models with mixed-effects components are very flexible in modeling the serial correlation of within-subject observations and between-subject variations. The Bayesian approach and the maximum likelihood method for standard mixed-effects models and state-space models are modified and investigated for estimating unknown parameters in the proposed models. In the Bayesian approach, full conditional distributions are derived and the Gibbs sampler is constructed to explore the posterior distributions. For the maximum likelihood method, we develop a Monte Carlo EM algorithm with a Gibbs sampler step to approximate the conditional expectations in the E-step. Simulation studies are conducted to compare the two proposed methods. We apply the mixed-effects state-space model to a data set from an AIDS clinical trial to illustrate the proposed methodologies. The proposed models and methods may also have potential applications in other biomedical system analyses such as tumor dynamics in cancer research and genetic regulatory network modeling. © 2010, The International Biometric Society.
A Computational Model of Self-Efficacy's Various Effects on Performance: Moving the Debate Forward.
Vancouver, Jeffrey B; Purl, Justin D
2016-12-19
Self-efficacy, which is one's belief in one's capacity, has been found to both positively and negatively influence effort and performance. The reasons for these different effects have been a major topic of debate among social-cognitive and perceptual control theorists. In particular, the findings of various self-efficacy effects has been motivated by a perceptual control theory view of self-regulation that social-cognitive theorists' question. To provide more clarity to the theoretical arguments, a computational model of the multiple processes presumed to create the positive, negative, and null effects for self-efficacy is presented. Building on an existing computational model of goal choice that produces a positive effect for self-efficacy, the current article adds a symbolic processing structure used during goal striving that explains the negative self-efficacy effect observed in recent studies. Moreover, the multiple processes, operating together, allow the model to recreate the various effects found in a published study of feedback ambiguity's moderating role on the self-efficacy to performance relationship (Schmidt & DeShon, 2010). Discussion focuses on the implications of the model for the self-efficacy debate, alternative computational models, the overlap between control theory and social-cognitive theory explanations, the value of using computational models for resolving theoretical disputes, and future research and directions the model inspires. (PsycINFO Database Record
Multivariate Term Structure Models with Level and Heteroskedasticity Effects
DEFF Research Database (Denmark)
Christiansen, Charlotte
2005-01-01
The paper introduces and estimates a multivariate level-GARCH model for the long rate and the term-structure spread where the conditional volatility is proportional to the ãth power of the variable itself (level effects) and the conditional covariance matrix evolves according to a multivariate...... GARCH process (heteroskedasticity effects). The long-rate variance exhibits heteroskedasticity effects and level effects in accordance with the square-root model. The spread variance exhibits heteroskedasticity effects but no level effects. The level-GARCH model is preferred above the GARCH model...... and the level model. GARCH effects are more important than level effects. The results are robust to the maturity of the interest rates. Udgivelsesdato: MAY...
Modeling Potentially Time-Varying Effects of Promotions on Sales
Ph.H.B.F. Franses (Philip Hans); R. Paap (Richard); Ph.A. Sijthoff
2001-01-01
textabstractA commonly applied modeling tool for the analysis of promotional effects on weekly sales data is a linear regression model. Usually, such a model includes 0/1 dummy variables for promotions, where weeks with a promotion get a value of 1. When these variables are included in a model with
Ashraf, Giti; Kadir, Suhaida bte Abd
2012-01-01
Organizational effectiveness is the main concern of all higher education institutes. Over the years there have been many different models of effectiveness along with the criteria for measuring organizational effectiveness. In this paper, four main models of organizational effectiveness namely the goal approach, the system resource approach, the…
Nature of size effects in compact models of field effect transistors
Energy Technology Data Exchange (ETDEWEB)
Torkhov, N. A., E-mail: trkf@mail.ru [Tomsk State University, Tomsk 634050 (Russian Federation); Scientific-Research Institute of Semiconductor Devices, Tomsk 634050 (Russian Federation); Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Babak, L. I.; Kokolov, A. A.; Salnikov, A. S.; Dobush, I. M. [Tomsk State University of Control Systems and Radioelectronics, Tomsk 634050 (Russian Federation); Novikov, V. A., E-mail: novikovvadim@mail.ru; Ivonin, I. V. [Tomsk State University, Tomsk 634050 (Russian Federation)
2016-03-07
Investigations have shown that in the local approximation (for sizes L < 100 μm), AlGaN/GaN high electron mobility transistor (HEMT) structures satisfy to all properties of chaotic systems and can be described in the language of fractal geometry of fractional dimensions. For such objects, values of their electrophysical characteristics depend on the linear sizes of the examined regions, which explain the presence of the so-called size effects—dependences of the electrophysical and instrumental characteristics on the linear sizes of the active elements of semiconductor devices. In the present work, a relationship has been established for the linear model parameters of the equivalent circuit elements of internal transistors with fractal geometry of the heteroepitaxial structure manifested through a dependence of its relative electrophysical characteristics on the linear sizes of the examined surface areas. For the HEMTs, this implies dependences of their relative static (A/mm, mA/V/mm, Ω/mm, etc.) and microwave characteristics (W/mm) on the width d of the sink-source channel and on the number of sections n that leads to a nonlinear dependence of the retrieved parameter values of equivalent circuit elements of linear internal transistor models on n and d. Thus, it has been demonstrated that the size effects in semiconductors determined by the fractal geometry must be taken into account when investigating the properties of semiconductor objects on the levels less than the local approximation limit and designing and manufacturing field effect transistors. In general, the suggested approach allows a complex of problems to be solved on designing, optimizing, and retrieving the parameters of equivalent circuits of linear and nonlinear models of not only field effect transistors but also any arbitrary semiconductor devices with nonlinear instrumental characteristics.
Nature of size effects in compact models of field effect transistors
Torkhov, N. A.; Babak, L. I.; Kokolov, A. A.; Salnikov, A. S.; Dobush, I. M.; Novikov, V. A.; Ivonin, I. V.
2016-03-01
Investigations have shown that in the local approximation (for sizes L GaN high electron mobility transistor (HEMT) structures satisfy to all properties of chaotic systems and can be described in the language of fractal geometry of fractional dimensions. For such objects, values of their electrophysical characteristics depend on the linear sizes of the examined regions, which explain the presence of the so-called size effects—dependences of the electrophysical and instrumental characteristics on the linear sizes of the active elements of semiconductor devices. In the present work, a relationship has been established for the linear model parameters of the equivalent circuit elements of internal transistors with fractal geometry of the heteroepitaxial structure manifested through a dependence of its relative electrophysical characteristics on the linear sizes of the examined surface areas. For the HEMTs, this implies dependences of their relative static (A/mm, mA/V/mm, Ω/mm, etc.) and microwave characteristics (W/mm) on the width d of the sink-source channel and on the number of sections n that leads to a nonlinear dependence of the retrieved parameter values of equivalent circuit elements of linear internal transistor models on n and d. Thus, it has been demonstrated that the size effects in semiconductors determined by the fractal geometry must be taken into account when investigating the properties of semiconductor objects on the levels less than the local approximation limit and designing and manufacturing field effect transistors. In general, the suggested approach allows a complex of problems to be solved on designing, optimizing, and retrieving the parameters of equivalent circuits of linear and nonlinear models of not only field effect transistors but also any arbitrary semiconductor devices with nonlinear instrumental characteristics.
Klim, Søren; Mortensen, Stig Bousgaard; Kristensen, Niels Rode; Overgaard, Rune Viig; Madsen, Henrik
2009-06-01
The extension from ordinary to stochastic differential equations (SDEs) in pharmacokinetic and pharmacodynamic (PK/PD) modelling is an emerging field and has been motivated in a number of articles [N.R. Kristensen, H. Madsen, S.H. Ingwersen, Using stochastic differential equations for PK/PD model development, J. Pharmacokinet. Pharmacodyn. 32 (February(1)) (2005) 109-141; C.W. Tornøe, R.V. Overgaard, H. Agersø, H.A. Nielsen, H. Madsen, E.N. Jonsson, Stochastic differential equations in NONMEM: implementation, application, and comparison with ordinary differential equations, Pharm. Res. 22 (August(8)) (2005) 1247-1258; R.V. Overgaard, N. Jonsson, C.W. Tornøe, H. Madsen, Non-linear mixed-effects models with stochastic differential equations: implementation of an estimation algorithm, J. Pharmacokinet. Pharmacodyn. 32 (February(1)) (2005) 85-107; U. Picchini, S. Ditlevsen, A. De Gaetano, Maximum likelihood estimation of a time-inhomogeneous stochastic differential model of glucose dynamics, Math. Med. Biol. 25 (June(2)) (2008) 141-155]. PK/PD models are traditionally based ordinary differential equations (ODEs) with an observation link that incorporates noise. This state-space formulation only allows for observation noise and not for system noise. Extending to SDEs allows for a Wiener noise component in the system equations. This additional noise component enables handling of autocorrelated residuals originating from natural variation or systematic model error. Autocorrelated residuals are often partly ignored in PK/PD modelling although violating the hypothesis for many standard statistical tests. This article presents a package for the statistical program R that is able to handle SDEs in a mixed-effects setting. The estimation method implemented is the FOCE(1) approximation to the population likelihood which is generated from the individual likelihoods that are approximated using the Extended Kalman Filter's one-step predictions.
Smith, P.; Beven, K.; Blazkova, S.; Merta, L.
2003-04-01
This poster outlines a methodology for the estimation of parameters in an Aggregated Dead Zone (ADZ) model of pollutant transport, by use of an example reach of the River Elbe. Both tracer and continuous water quality measurements are analysed to investigate the relationship between discharge and advective time delay. This includes a study of the effects of different error distributions being applied to the measurement of both variables using Monte-Carlo Markov Chain (MCMC) techniques. The derived relationships between discharge and advective time delay can then be incorporated into the formulation of the ADZ model to allow prediction of pollutant transport given uncertainty in the parameter values. The calibration is demonstrated in a hierarchical framework, giving the potential for the selection of appropriate model structures for the change in transport characteristics with discharge in the river. The value of different types and numbers of measurements are assessed within this framework.
Urbanization effects on the microclimate of Manaus: A modeling study
Souza, Diego Oliveira de; Alvalá, Regina Célia dos Santos; Nascimento, Marília Guedes do
2016-01-01
Activities associated with land use and land cover changes and urbanization induce local impacts, such as changes in atmospheric composition in water and energy balances and changes in the ecosystem. Therefore, more studies are needed to evaluate the possible relationship between urban growth and local and regional changes. In the last 30 years, the population of Manaus grew by over 500%, with approximately 1.9 million inhabitants in 2010. Trying to understand the effects of the urban growth of the city of Manaus on its microclimate and atmospheric processes, the present study aims to evaluate the possible physical mechanisms related to the urbanization process observed through a study of atmospheric modeling. The results allowed to assess that the presence of the urban area significantly modifies the surface energy balance (SEB), generating a thermal gradient between the city and the surrounding regions, favoring the formation and intensification of local atmospheric circulations. The results indicated that with urban growth there is an increase in temperature, decrease in the atmospheric water content and significant changes in the flow at low levels, mainly in the breeze circulations, with significant changes observed in the structure and characteristic of the planetary boundary layer (PBL) over the study area. A positive correlation between the increase of the urban area and increased rainfall was also observed. From the results, it was possible to observe that there is a direct relationship between urban growth and changes in the local microclimate in Manaus.
Effect of swim cap model on passive drag.
Gatta, Giorgio; Zamparo, Paola; Cortesi, Matteo
2013-10-01
Hydrodynamics plays an important role in swimming because even small decreases in a swimmer's drag can lead to performance improvements. During the gliding phases of a race, the head of a swimmer is an important point of impact with the fluid, and the swim cap, even if it covers only a small portion of the swimmer's body, can have an influence on drag. The purpose of this study was to investigate the effects on passive drag (Dp) of wearing 3 different types of swim caps (LSC: a lycra cap; CSC: a silicone cap; HSC: a silicone helmet cap without seams). Sixteen swimmers were tested at 3 velocities (1.5, 1.7, 1.9 m·s), and the Dp measurements were repeated at each condition 5 times. A statistical analysis revealed significant differences in drag (p swim cap is the most rigid, the most adherent to the swimmer's head, and does not allow the formation of wrinkles compared with the other 2 investigated swim caps. Therefore, the following conclusions can be made: (a) swimmers should take care when selecting their swim cap if they want to improve the fluid dynamics at the "leading edge" of their body and (b) because Dp is affected by the swim cap model, care should be taken when comparing data from different studies, especially at faster investigated speeds.
Effect of GPS errors on Emission model
DEFF Research Database (Denmark)
Lehmann, Anders; Gross, Allan
n this paper we will show how Global Positioning Services (GPS) data obtained from smartphones can be used to model air quality in urban settings. The paper examines the uncertainty of smartphone location utilising GPS, and ties this location uncertainty to air quality models. The results presented...
Model-based experimental design for assessing effects of mixtures of chemicals
Energy Technology Data Exchange (ETDEWEB)
Baas, Jan, E-mail: jan.baas@falw.vu.n [Vrije Universiteit of Amsterdam, Dept of Theoretical Biology, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Stefanowicz, Anna M., E-mail: anna.stefanowicz@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Klimek, Beata, E-mail: beata.klimek@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Laskowski, Ryszard, E-mail: ryszard.laskowski@uj.edu.p [Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387 Krakow (Poland); Kooijman, Sebastiaan A.L.M., E-mail: bas@bio.vu.n [Vrije Universiteit of Amsterdam, Dept of Theoretical Biology, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)
2010-01-15
We exposed flour beetles (Tribolium castaneum) to a mixture of four poly aromatic hydrocarbons (PAHs). The experimental setup was chosen such that the emphasis was on assessing partial effects. We interpreted the effects of the mixture by a process-based model, with a threshold concentration for effects on survival. The behavior of the threshold concentration was one of the key features of this research. We showed that the threshold concentration is shared by toxicants with the same mode of action, which gives a mechanistic explanation for the observation that toxic effects in mixtures may occur in concentration ranges where the individual components do not show effects. Our approach gives reliable predictions of partial effects on survival and allows for a reduction of experimental effort in assessing effects of mixtures, extrapolations to other mixtures, other points in time, or in a wider perspective to other organisms. - We show a mechanistic approach to assess effects of mixtures in low concentrations.
Incorporating Context Effects into a Choice Model
Rooderkerk, Robert P.; Van Heerde, Harald J.; Bijmolt, Tammo H. A.
The behavioral literature provides ample evidence that consumer preferences are partly driven by the context provided by the set of alternatives. Three important context effects are the compromise, attraction, and similarity effects. Because these context effects affect choices in a systematic and
Incorporating Context Effects into a Choice Model
Rooderkerk, Robert P.; Van Heerde, Harald J.; Bijmolt, Tammo H. A.
2011-01-01
The behavioral literature provides ample evidence that consumer preferences are partly driven by the context provided by the set of alternatives. Three important context effects are the compromise, attraction, and similarity effects. Because these context effects affect choices in a systematic and p
7 CFR 3560.202 - Establishing rents and utility allowances.
2010-01-01
... 7 Agriculture 15 2010-01-01 2010-01-01 false Establishing rents and utility allowances. 3560.202... Establishing rents and utility allowances. (a) General. Rents and utility allowances for rental units in Agency... Agency. (b) Agency approval. All rents and utility allowances set by borrowers are subject to...
The Effects of Spatial Resolution and Dimensionality on Modeling Braided River Hydraulics
Altenau, E. H.; Pavelsky, T.; Bates, P. D.
2015-12-01
Braided rivers are challenging features to quantify due to their dynamic morphology and dominance in remote locations. Advances in hydrodynamic modeling and remote sensing over the past few decades offer opportunities to explore braided river processes at finer resolutions with increased efficiency. These methods allow us to address questions such as: What model structure is necessary to accurately reproduce inundation extent and water surface elevations in a braided river? What effects do the smaller channels within a braided river have on simulating wave propagation and slope? How much accuracy is lost as model resolution and dimension are decreased? Here, we use the raster-based hydrodynamic model LISFLOOD-FP to simulate water surface elevations, inundation extent, and slope at various resolutions and dimensions over a ~90 km reach of the Tanana River, Alaska. Model input and validation data were collected during two field campaigns in the summers of 2013 and 2015. Field data included water surface elevation, discharge, velocity, slope, and bathymetric measurements. Six models are run to simulate flood waves across the study reach over a two-month timespan. The model structures vary in complexity from a full 2D model at 10 m resolution to a coupled 1D/2D model at 100 m resolution where the channel is represented in 1D by an effective centerline within a 2D floodplain grid. Results from the different models are compared to assess the effects on inundation extent, wave celerity, water elevations and slope. Digital elevation model (DEM) quality and resolution have major effects on inundation extent and water surface elevations, while model dimensionality has a larger effect on wave celerity and slope. Future work will compare model outputs with AirSWOT data, an airborne analog for the Surface Water and Ocean Topography (SWOT) mission, which aims to provide high-resolution measurements of terrestrial and ocean water surface elevations globally.
Integrating teacher education effectiveness research into educational effectiveness models
Scheerens, Jaap; Blömeke, Sigrid
2016-01-01
The purpose of this article is to review and to connect research about teacher education effectiveness and school effectiveness to arrive at an integrative conceptualization that has the potential of improving empirical research in both fields. Teacher education effectiveness addresses effects of te
Integrating teacher education effectiveness research into educational effectiveness models
Scheerens, Jaap; Blömeke, Sigrid
2016-01-01
The purpose of this article is to review and to connect research about teacher education effectiveness and school effectiveness to arrive at an integrative conceptualization that has the potential of improving empirical research in both fields. Teacher education effectiveness addresses effects of
Utility regulators and the market for emission allowances
Energy Technology Data Exchange (ETDEWEB)
Bohi, D.R.
1993-07-01
When it comes to emission trading under the Clean Air Act, a major concern of most people in the electric utilities industry is the effect of this new form of environmental regulation on the industry and the way it is regulated. This paper focuses on a different concern: the effect of the industry and the way it is regulated on the emission trading program. Emission trading must prove to be successful in lowering the cost of reducing sulfur dioxide emissions if this approach to environmental regulation is to be regarded as a viable substitute for traditional command-and-control regulation. In addition, whether or not utilities will buy and sell allowances as intended depends on the actions of the public utility regulators. This paper covers both setting the cost recovery rules and the incentive to sell and the capital gain.
Review of health effects models for Level 3 PSA
Energy Technology Data Exchange (ETDEWEB)
Lee, Seung Hee; Kim, Ju Youl [FNC Technology Co., Yongin (Korea, Republic of); Han, Seok Jung [KAERI, Daejeon (Korea, Republic of)
2016-05-15
Many international organizations have developed health risk models. Especially, as radiation-induced cancer is an important part among health effects, development has been focused on cancer risk model. This paper reviewed the cancer risk models of international agencies; United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), National Academy of Sciences (NAS) and International Commission on Radiological Protection (ICRP). Moreover, as pre-research for improving the health risk model in Korea, this paper analyzed the three methodologies and specific details in modeling. International agencies have developed radiation-induced cancer risk model reflecting the recent A-bomb survivor LSS data. This paper reviewed the recent cancer risk model of UNSCEAR, NAS and ICRP. All three models were based on ERR and EAR model in the form of a multiplication of dose-response model and modification function. Lifetime risk was calculated as a function of exposure age and gender.
State-space modelling for heater induced thermal effects on LISA Pathfinder's Test Masses
Gibert, Ferran; Diaz-Aguiló, Marc; Lobo, Alberto; Karnesis, Nikolaos; Mateos, Ignacio; Sanjuán, Josep; Lloro, Ivan; Gesa, Lluís; Martín, Víctor; 10.1088/1742-6596/363/1/012044
2012-01-01
The OSE (Offline Simulations Environment) simulator of the LPF (LISA Pathfinder) mission is intended to simulate the different experiments to be carried out in flight. Amongst these, the thermal diagnostics experiments are intended to relate thermal disturbances and interferometer readouts, thereby allowing the subtraction of thermally induced interferences from the interferometer channels. In this paper we report on the modelling of these simulated experiments, including the parametrisation of different thermal effects (radiation pressure effect, radiometer effect) that will appear in the Inertial Sensor environment of the LTP (LISA Technology Package). We report as well how these experiments are going to be implemented in the LTPDA toolbox, which is a dedicated tool for LPF data analysis that will allow full traceability and reproducibility of the analysis thanks to complete recording of the processes.
Effective quantum Monte Carlo algorithm for modeling strongly correlated systems
Kashurnikov, V. A.; Krasavin, A. V.
2007-01-01
A new effective Monte Carlo algorithm based on principles of continuous time is presented. It allows calculating, in an arbitrary discrete basis, thermodynamic quantities and linear response of mixed boson-fermion, spin-boson, and other strongly correlated systems which admit no analytic description
Advertising effects in Sznajd marketing model
Christian Schulze
2002-01-01
The traditional Sznajd model, as well as its Ochrombel simplification for opinion spreading, are applied to marketing with the help of advertising. The larger the lattice is the smaller is the amount of advertising needed to convince the whole market
Tsai, Chia-Ching; Chang, Chih-Hsiang
2007-01-01
This study investigates the effect of advertising with physically attractive models on male and female adolescents. The findings suggest that highly attractive models are less effective than those who are normally attractive. Implications of social comparison are discussed.
Tsai, Chia-Ching; Chang, Chih-Hsiang
2007-01-01
This study investigates the effect of advertising with physically attractive models on male and female adolescents. The findings suggest that highly attractive models are less effective than those who are normally attractive. Implications of social comparison are discussed.
A design-by-treatment interaction model for network meta-analysis with random inconsistency effects.
Jackson, Dan; Barrett, Jessica K; Rice, Stephen; White, Ian R; Higgins, Julian P T
2014-09-20
Network meta-analysis is becoming more popular as a way to analyse multiple treatments simultaneously and, in the right circumstances, rank treatments. A difficulty in practice is the possibility of 'inconsistency' or 'incoherence', where direct evidence and indirect evidence are not in agreement. Here, we develop a random-effects implementation of the recently proposed design-by-treatment interaction model, using these random effects to model inconsistency and estimate the parameters of primary interest. Our proposal is a generalisation of the model proposed by Lumley and allows trials with three or more arms to be included in the analysis. Our methods also facilitate the ranking of treatments under inconsistency. We derive R and I(2) statistics to quantify the impact of the between-study heterogeneity and the inconsistency. We apply our model to two examples.
Credit financing for deteriorating imperfect quality items with allowable shortages
Directory of Open Access Journals (Sweden)
Aditi Khanna
2016-01-01
Full Text Available The outset of new technologies, systems and applications in manufacturing sector has no doubt lighten up our workload, yet the chance causes of variation in production system cannot be eliminated completely. Every produced/ordered lot may have some fraction of defectives which may vary from process to process. In addition the situation is more susceptible when the items are deteriorating in nature. However, the defective items can be secluded from the good quality lot through a careful inspection process. Thus, a screening process is obligatory in today’s technology driven industry which has the customer satisfaction as its only motto. Moreover, in order to survive in the current global markets, credit financing has been proven a very influential promotional tool to attract new customers and a good inducement policy for the retailers. Keeping this scenario in mind, the present paper investigates an inventory model for a retailer dealing with imperfect quality deteriorating items under permissible delay in payments. Shortages are allowed and fully backlogged. This model jointly optimizes the order quantity and shortages by maximizing the expected total profit. A mathematical model is developed to depict this scenario. Results have been validated with the help of numerical example. Comprehensive sensitivity analysis has also been presented.
Effect of mobility models on infrastructure based wireless networks ...
African Journals Online (AJOL)
Effect of mobility models on infrastructure based wireless networks. ... In this paper, the effect of handoff procedure on the performance of random mobile nodes in wireless networks was investigated. Mobility of node is defined ... Article Metrics.
Modelling Effectiveness of Machine Gun Fire
Dutta, D.; S. Sabhanval
2002-01-01
Machine gun is an effective infantry weapon which can cause heavy damage to enemy targets, if sited in a tactically favourable position. It can be engaged effectively against both static and moving targets. The paper deals with the determination of target vulnerability under effective machine gun fire considering relevant tactical parameters, eg, target aiming point, trajectory of fire, sweep angle, target frontage, posture, direction of attack, etc.
Modelling Effectiveness of Machine Gun Fire
Directory of Open Access Journals (Sweden)
D. Dutta
2002-04-01
Full Text Available Machine gun is an effective infantry weapon which can cause heavy damage to enemy targets, if sited in a tactically favourable position. It can be engaged effectively against both static and moving targets. The paper deals with the determination of target vulnerability under effective machine gun fire considering relevant tactical parameters, eg, target aiming point, trajectory of fire, sweep angle, target frontage, posture, direction of attack, etc.
Jougnot, D
2013-01-01
Self-potential (SP) data are of interest to vadose zone hydrology because of their direct sensitivity to water flow and ionic transport. There is unfortunately little consensus in the literature about how to best model SP data under partially saturated conditions and different approaches (often supported by one laboratory data set alone) have been proposed. We argue herein that this lack of agreement can largely be traced to electrode effects that have not been properly taken into account. A series of drainage and imbibition experiments are considered, in which we find that previously proposed approaches to remove electrode effects are unlikely to provide adequate corrections. Instead, we explicitly model the electrode effects together with classical SP contributions using a flow and transport model. The simulated data agree overall with the observed SP signals and allow decomposing the different signal contributions to analyze them separately. By reviewing other published experimental data, we suggest that m...
Allowable levels of take for the trade in Nearctic songbirds
Johnson, Fred A.; Walters, Matthew A.H.; Boomer, G. Scott
2012-01-01
The take of Nearctic songbirds for the caged-bird trade is an important cultural and economic activity in Mexico, but its sustainability has been questioned. We relied on the theta-logistic population model to explore options for setting allowable levels of take for 11 species of passerines that were subject to legal take in Mexico in 2010. Because estimates of population size necessary for making periodic adjustments to levels of take are not routinely available, we examined the conditions under which a constant level of take might contribute to population depletion (i.e., a population below its level of maximum net productivity). The chance of depleting a population is highest when levels of take are based on population sizes that happen to be much lower or higher than the level of maximum net productivity, when environmental variation is relatively high and serially correlated, and when the interval between estimation of population size is relatively long (≥5 years). To estimate demographic rates of songbirds involved in the Mexican trade we relied on published information and allometric relationships to develop probability distributions for key rates, and then sampled from those distributions to characterize the uncertainty in potential levels of take. Estimates of the intrinsic rate of growth (r) were highly variable, but median estimates were consistent with those expected for relatively short-lived, highly fecund species. Allowing for the possibility of nonlinear density dependence generally resulted in allowable levels of take that were lower than would have been the case under an assumption of linearity. Levels of take authorized by the Mexican government in 2010 for the 11 species we examined were small in comparison to relatively conservative allowable levels of take (i.e., those intended to achieve 50% of maximum sustainable yield). However, the actual levels of take in Mexico are unknown and almost certainly exceed the authorized take. Also, the take
Multilevel Modeling of Item Position Effects
Albano, Anthony D.
2013-01-01
In many testing programs it is assumed that the context or position in which an item is administered does not have a differential effect on examinee responses to the item. Violations of this assumption may bias item response theory estimates of item and person parameters. This study examines the potentially biasing effects of item position. A…
Model for Effective Contraceptive Counseling on Campus.
Bachmann, Gloria A.
1981-01-01
A study compared the effective v ineffective use of contraceptives at a major university by comparing college women who had experienced birth control failure with those who had not. Factors related to a woman's use of a contraceptive device include: satisfaction with its aesthetic properties; trust in its effectiveness; a feeling of comfort…
Hoogerheide, Vincent; van Wermeskerken, Margot; Loyens, Sofie M M; van Gog, Tamara
2016-01-01
Learning from (video) modeling examples in which a model demonstrates how to perform a task is an effective instructional strategy. The model-observer similarity (MOS) hypothesis postulates that (perceived) similarity between learners and the model in terms of age or expertise moderates the effectiv
Choosing components in the additive main effect and multiplicative interaction (AMMI models
Directory of Open Access Journals (Sweden)
Dias Carlos Tadeu dos Santos
2006-01-01
Full Text Available The additive main effect and multiplicative interaction (AMMI models allows analysts to detect interactions between rows and columns in a two-way table. However, there are many methods proposed in the literature to determine the number of multiplicative components to include in the AMMI model. These methods typically give different results for any particular data set, so the user needs some guidance as to which methods to use. In this paper we compare four commonly used methods using simulated data based on real experiments, and provide some general recommendations.
Effect of Manure vs. Fertilizer Inputs on Productivity of Forage Crop Models
Directory of Open Access Journals (Sweden)
Pasquale Martiniello
2011-06-01
Full Text Available Manure produced by livestock activity is a dangerous product capable of causing serious environmental pollution. Agronomic management practices on the use of manure may transform the target from a waste to a resource product. Experiments performed on comparison of manure with standard chemical fertilizers (CF were studied under a double cropping per year regime (alfalfa, model I; Italian ryegrass-corn, model II; barley-seed sorghum, model III; and horse-bean-silage sorghum, model IV. The total amount of manure applied in the annual forage crops of the model II, III and IV was 158, 140 and 80 m3 ha−1, respectively. The manure applied to soil by broadcast and injection procedure provides an amount of nitrogen equal to that supplied by CF. The effect of manure applications on animal feeding production and biochemical soil characteristics was related to the models. The weather condition and manures and CF showed small interaction among treatments. The number of MFU ha−1 of biomass crop gross product produced in autumn and spring sowing models under manure applications was 11,769, 20,525, 11,342, 21,397 in models I through IV, respectively. The reduction of MFU ha−1 under CF ranges from 10.7% to 13.2% those of the manure models. The effect of manure on organic carbon and total nitrogen of topsoil, compared to model I, stressed the parameters as CF whose amount was higher in models II and III than model IV. In term of percentage the organic carbon and total nitrogen of model I and treatment with manure was reduced by about 18.5 and 21.9% in model II and model III and 8.8 and 6.3% in model IV, respectively. Manure management may substitute CF without reducing gross production and sustainability of cropping systems, thus allowing the opportunity to recycle the waste product for animal forage feeding.
Effect of manure vs. fertilizer inputs on productivity of forage crop models.
Annicchiarico, Giovanni; Caternolo, Giovanni; Rossi, Emanuela; Martiniello, Pasquale
2011-06-01
Manure produced by livestock activity is a dangerous product capable of causing serious environmental pollution. Agronomic management practices on the use of manure may transform the target from a waste to a resource product. Experiments performed on comparison of manure with standard chemical fertilizers (CF) were studied under a double cropping per year regime (alfalfa, model I; Italian ryegrass-corn, model II; barley-seed sorghum, model III; and horse-bean-silage sorghum, model IV). The total amount of manure applied in the annual forage crops of the model II, III and IV was 158, 140 and 80 m3 ha(-1), respectively. The manure applied to soil by broadcast and injection procedure provides an amount of nitrogen equal to that supplied by CF. The effect of manure applications on animal feeding production and biochemical soil characteristics was related to the models. The weather condition and manures and CF showed small interaction among treatments. The number of MFU ha(-1) of biomass crop gross product produced in autumn and spring sowing models under manure applications was 11,769, 20,525, 11,342, 21,397 in models I through IV, respectively. The reduction of MFU ha(-1) under CF ranges from 10.7% to 13.2% those of the manure models. The effect of manure on organic carbon and total nitrogen of topsoil, compared to model I, stressed the parameters as CF whose amount was higher in models II and III than model IV. In term of percentage the organic carbon and total nitrogen of model I and treatment with manure was reduced by about 18.5 and 21.9% in model II and model III and 8.8 and 6.3% in model IV, respectively. Manure management may substitute CF without reducing gross production and sustainability of cropping systems, thus allowing the opportunity to recycle the waste product for animal forage feeding.
Enhanced battery model including temperature effects
Rosca, B.; Wilkins, S.
2013-01-01
Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a dy
A Mixed Effects Randomized Item Response Model
Fox, J.-P.; Wyrick, Cheryl
2008-01-01
The randomized response technique ensures that individual item responses, denoted as true item responses, are randomized before observing them and so-called randomized item responses are observed. A relationship is specified between randomized item response data and true item response data. True item response data are modeled with a (non)linear…
Modelling irradiation effects in fusion materials
DEFF Research Database (Denmark)
Victoria, M.; Dudarev, S.; Boutard, J.L.;
2007-01-01
We review the current status of the European fusion materials modelling programme. We describe recent findings and outline potential areas for future development. Large-scale density functional theory (DFT) calculations reveal the structure of the point defects in α-Fe, and highlight the crucial...
Effective models for excitons in carbon nanotubes
DEFF Research Database (Denmark)
Cornean, Horia; Duclos, Pierre; Ricaud, Benjamin
2007-01-01
We analyse the low lying spectrum of a model of excitons in carbon nanotubes. Consider two particles with opposite charges and a Coulomb self-interaction, placed on an infinitely long cylinder. If the cylinder radius becomes small, the low lying spectrum of their relative motion is well described...
Enhanced battery model including temperature effects
Rosca, B.; Wilkins, S.
2013-01-01
Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a dy
Systems modelling for effective mine water management
Energy Technology Data Exchange (ETDEWEB)
Cote, C.M.; Moran, C.J.; Hedemann, C.J.; Koch, C. [University of Queensland, Brisbane, Qld. (Australia)
2010-12-15
Concerns about the difficulties in securing water have led the Australian coal mining industry to seek innovative ways to improve its water management and to adopt novel strategies that will lead to less water being used and more water being reused. Simulation tools are essential to assess current water management performance and to predict the efficiency of potential strategies. As water systems on coal mines are complex and consist of various inter-connected elements, a systems approach was selected, which views mine site water management as a system that obtains water from various sources (surface, groundwater), provides sufficient water of suitable quality to the mining tasks (coal beneficiation, dust suppression, underground operations) and maintains environmental performance. In this paper, the model is described and its calibration is illustrated. The results of applying the model for the comparison of the water balances of 7 coal mines in the northern Bowen Basin (Queensland, Australia) are presented. The model is used to assess the impact of applying specific water management strategies. Results show that a simple systems model is an appropriate tool for assessing site performance, for providing guidance to improve performance through strategic planning, and for guiding adoption of site objectives.
Enhanced battery model including temperature effects
Rosca, B.; Wilkins, S.
2013-01-01
Within electric and hybrid vehicles, batteries are used to provide/buffer the energy required for driving. However, battery performance varies throughout the temperature range specific to automotive applications, and as such, models that describe this behaviour are required. This paper presents a
Lin, Cheng-Jhe; Wu, Changxu
2012-01-01
Numerical typing is an important perceptual-motor task whose performance may vary with different pacing, finger strategies and urgency of situations. Queuing network-model human processor (QN-MHP), a computational architecture, allows performance of perceptual-motor tasks to be modelled mathematically. The current study enhanced QN-MHP with a top-down control mechanism, a close-loop movement control and a finger-related motor control mechanism to account for task interference, endpoint reduction, and force deficit, respectively. The model also incorporated neuromotor noise theory to quantify endpoint variability in typing. The model predictions of typing speed and accuracy were validated with Lin and Wu's (2011) experimental results. The resultant root-mean-squared errors were 3.68% with a correlation of 95.55% for response time, and 35.10% with a correlation of 96.52% for typing accuracy. The model can be applied to provide optimal speech rates for voice synthesis and keyboard designs in different numerical typing situations. An enhanced QN-MHP model was proposed in the study to mathematically account for the effects of pacing, finger strategies and internalised urgency on numerical typing performance. The model can be used to provide optimal pacing for voice synthesise systems and suggested optimal numerical keyboard designs under urgency.
Coriolis effects and motion sickness modelling.
Bles, W
1998-11-15
Coriolis effects are notorious in relation to disorientation and motion sickness in aircrew. A review is provided of experimental data on these Coriolis effects, including the modulatory effects of adding visual or somatosensory rotatory motion information. A vector analysis of the consequences of head movements during somatosensory, visual and/or vestibular rotatory motion stimulation revealed that the more the sensed angular velocity vector after the head movements is aligned with the gravitoinertial force vector, the less nauseating effects are experienced. It is demonstrated that this is a special case of the subjective vertical conflict theory on motion sickness that assumes that motion sickness may be provoked if a discrepancy is detected between the subjective vertical and the sensed vertical as determined on the basis of incoming sensory information.
Neural Networks for Electrohydrodynamic Effect Modelling
Directory of Open Access Journals (Sweden)
Jolanta Gancarz
2004-01-01
Full Text Available This paper presents currently achieved results concerning methods of electrohydrodynamic effect used in geophysics simulated with feedforward networks trained with backpropagation algorithm, radial basis function networks and generalized regression networks.
Wei, Jiawei
2011-07-01
We consider the problem of testing for a constant nonparametric effect in a general semi-parametric regression model when there is the potential for interaction between the parametrically and nonparametrically modeled variables. The work was originally motivated by a unique testing problem in genetic epidemiology (Chatterjee, et al., 2006) that involved a typical generalized linear model but with an additional term reminiscent of the Tukey one-degree-of-freedom formulation, and their interest was in testing for main effects of the genetic variables, while gaining statistical power by allowing for a possible interaction between genes and the environment. Later work (Maity, et al., 2009) involved the possibility of modeling the environmental variable nonparametrically, but they focused on whether there was a parametric main effect for the genetic variables. In this paper, we consider the complementary problem, where the interest is in testing for the main effect of the nonparametrically modeled environmental variable. We derive a generalized likelihood ratio test for this hypothesis, show how to implement it, and provide evidence that our method can improve statistical power when compared to standard partially linear models with main effects only. We use the method for the primary purpose of analyzing data from a case-control study of colorectal adenoma.
Wei, Jiawei; Carroll, Raymond J; Maity, Arnab
2011-07-01
We consider the problem of testing for a constant nonparametric effect in a general semi-parametric regression model when there is the potential for interaction between the parametrically and nonparametrically modeled variables. The work was originally motivated by a unique testing problem in genetic epidemiology (Chatterjee, et al., 2006) that involved a typical generalized linear model but with an additional term reminiscent of the Tukey one-degree-of-freedom formulation, and their interest was in testing for main effects of the genetic variables, while gaining statistical power by allowing for a possible interaction between genes and the environment. Later work (Maity, et al., 2009) involved the possibility of modeling the environmental variable nonparametrically, but they focused on whether there was a parametric main effect for the genetic variables. In this paper, we consider the complementary problem, where the interest is in testing for the main effect of the nonparametrically modeled environmental variable. We derive a generalized likelihood ratio test for this hypothesis, show how to implement it, and provide evidence that our method can improve statistical power when compared to standard partially linear models with main effects only. We use the method for the primary purpose of analyzing data from a case-control study of colorectal adenoma.
A random effects generalized linear model for reliability compositive evaluation
Institute of Scientific and Technical Information of China (English)
无
2009-01-01
This paper first proposes a random effects generalized linear model to evaluate the storage life of one kind of high reliable and small sample-sized products by combining multi-sources information of products coming from the same population but stored at different environments. The relevant algorithms are also provided. Simulation results manifest the soundness and effectiveness of the proposed model.
Evaluating Differential Effects Using Regression Interactions and Regression Mixture Models
Van Horn, M. Lee; Jaki, Thomas; Masyn, Katherine; Howe, George; Feaster, Daniel J.; Lamont, Andrea E.; George, Melissa R. W.; Kim, Minjung
2015-01-01
Research increasingly emphasizes understanding differential effects. This article focuses on understanding regression mixture models, which are relatively new statistical methods for assessing differential effects by comparing results to using an interactive term in linear regression. The research questions which each model answers, their…
Modeling the effects of study abroad programs on college students
Alvin H. Yu; Garry E. Chick; Duarte B. Morais; Chung-Hsien Lin
2009-01-01
This study explored the possibility of modeling the effects of a study abroad program on students from a university in the northeastern United States. A program effect model was proposed after conducting an extensive literature review and empirically examining a sample of 265 participants in 2005. Exploratory factor analysis (EFA), confirmatory factor analysis (CFA),...
A random effects generalized linear model for reliability compositive evaluation
Institute of Scientific and Technical Information of China (English)
ZHAO Hui; YU Dan
2009-01-01
This paper first proposes a random effects generalized linear model to evaluate the storage life of one kind of high reliable and small sample-sized products by combining multi-sources information of products coming from the same population but stored at different environments.The relevant algorithms are also provided.Simulation results manifest the soundness and effectiveness of the proposed model.
Medical Surveillance System & Medical Effect Modeling Thrust Areas
2007-06-01
Equations ( PFE ) developed for this project model physiological systems in biological organisms as 1D liquid or gas flows. Special attention is given...in the model to capturing 2D viscous effects and branching effects. Multiple PFE representations of physiological systems (e.g. the respiratory and
A fiber-bridging model with stress gradient effects
Yi, Sun; Tao, Li
2000-05-01
A fiber-bridging model with stress gradient effects is proposed for unidirectional fiber-reinforced composites. The stress gradient terms are introduced by solving a micromechanical model under a non-uniform stress loading. It is shown that the stress gradient effect is significant on both the fiber-bridging stress distribution and the value of the critical load of fiber failure.
Effective Reading and Writing Instruction: A Focus on Modeling
Regan, Kelley; Berkeley, Sheri
2012-01-01
When providing effective reading and writing instruction, teachers need to provide explicit modeling. Modeling is particularly important when teaching students to use cognitive learning strategies. Examples of how teachers can provide specific, explicit, and flexible instructional modeling is presented in the context of two evidence-based…
Effects of Modeling and Reinforcement on Adult Chronic Schizophrenics
Olson, R. Paul
1971-01-01
This study confirmed two general predictions: (1) the model contributes to new learning; and (2) neither the model nor reinforcement of the model adds significantly to motivation, beyond the effect that can be attributed to reinforcement of the subject himself. (Author/CG)
Seventh Grade Students' Mental Models of the Greenhouse Effect
Shepardson, Daniel P.; Choi, Soyoung; Niyogi, Dev; Charusombat, Umarporn
2011-01-01
This constructivist study investigates 225 student drawings and explanations from three different schools in the midwest in the US, to identify seventh grade students' mental models of the greenhouse effect. Five distinct mental models were derived from an inductive analysis of the content of the students' drawings and explanations: Model 1, a…
A Gompertzian model with random effects to cervical cancer growth
Energy Technology Data Exchange (ETDEWEB)
Mazlan, Mazma Syahidatul Ayuni; Rosli, Norhayati [Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Pahang (Malaysia)
2015-05-15
In this paper, a Gompertzian model with random effects is introduced to describe the cervical cancer growth. The parameters values of the mathematical model are estimated via maximum likehood estimation. We apply 4-stage Runge-Kutta (SRK4) for solving the stochastic model numerically. The efficiency of mathematical model is measured by comparing the simulated result and the clinical data of the cervical cancer growth. Low values of root mean-square error (RMSE) of Gompertzian model with random effect indicate good fits.
Environmental Radiation Effects on Mammals A Dynamical Modeling Approach
Smirnova, Olga A
2010-01-01
This text is devoted to the theoretical studies of radiation effects on mammals. It uses the framework of developed deterministic mathematical models to investigate the effects of both acute and chronic irradiation in a wide range of doses and dose rates on vital body systems including hematopoiesis, small intestine and humoral immunity, as well as on the development of autoimmune diseases. Thus, these models can contribute to the development of the system and quantitative approaches in radiation biology and ecology. This text is also of practical use. Its modeling studies of the dynamics of granulocytopoiesis and thrombocytopoiesis in humans testify to the efficiency of employment of the developed models in the investigation and prediction of radiation effects on these hematopoietic lines. These models, as well as the properly identified models of other vital body systems, could provide a better understanding of the radiation risks to health. The modeling predictions will enable the implementation of more ef...
27 CFR 20.24 - Allowance of claims.
2010-04-01
... OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF DENATURED ALCOHOL AND RUM Administrative Provisions Authorities § 20.24 Allowance of claims. The appropriate TTB officer is authorized to allow claims for...
27 CFR 22.23 - Allowance of claims.
2010-04-01
... OF THE TREASURY LIQUORS DISTRIBUTION AND USE OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.23 Allowance of claims. The appropriate TTB officer is authorized to allow claims for...
Sensitivity analysis of the relative biological effectiveness predicted by the local effect model.
Friedrich, T; Grün, R; Scholz, U; Elsässer, T; Durante, M; Scholz, M
2013-10-07
The relative biological effectiveness (RBE) is a central quantity in particle radiobiology and depends on many physical and biological factors. The local effect model (LEM) allows one to predict the RBE for radiobiologic experiments and particle therapy. In this work the sensitivity of the RBE on its determining factors is elucidated based on monitoring the RBE dependence on the input parameters of the LEM. The relevance and meaning of all parameters are discussed within the formalism of the LEM. While most of the parameters are fixed by experimental constraints, one parameter, the threshold dose Dt, may remain free and is then regarded as a fit parameter to the high LET dose response curve. The influence of each parameter on the RBE is understood in terms of theoretic considerations. The sensitivity analysis has been systematically carried out for fictitious in vitro cell lines or tissues with α/β = 2 Gy and 10 Gy, either irradiated under track segment conditions with a monoenergetic beam or within a spread out Bragg peak. For both irradiation conditions, a change of each of the parameters typically causes an approximately equal or smaller relative change of the predicted RBE values. These results may be used for the assessment of treatment plans and for general uncertainty estimations of the RBE.
Singlet model interference effects with high scale UV physics
Dawson, S.; Lewis, I. M.
2017-01-01
One of the simplest extensions of the Standard Model (SM) is the addition of a scalar gauge singlet, S . If S is not forbidden by a symmetry from mixing with the Standard Model Higgs boson, the mixing will generate non-SM rates for Higgs production and decays. In general, there could also be unknown high energy physics that generates additional effective low energy interactions. We show that interference effects between the scalar resonance of the singlet model and the effective field theory (EFT) operators can have significant effects in the Higgs sector. We examine a non-Z2 symmetric scalar singlet model and demonstrate that a fit to the 125 GeV Higgs boson couplings and to limits on high mass resonances, S , exhibit an interesting structure and possible large cancellations of effects between the resonance contribution and the new EFT interactions, that invalidate conclusions based on the renormalizable singlet model alone.
Quasi-Newton Method for Optimal Blank Allowance Balancing
Institute of Scientific and Technical Information of China (English)
CHEN Manyi
2006-01-01
A balancing technique for casting or forging parts to be machined is presented in this paper. It allows an optimal part setup to make sure that no shortage of material (undercut) will occur during machining. Particularly in the heavy part industry, where the resulting casting size and shape may deviate from expectations, the balancing process discovers whether or not the design model is totally enclosed in the actual part to be machined. The alignment is an iterative process involving nonlinear constrained optimization, which forces data points to lie outside the nominal model under a specific order of priority. Newton methods for non-linear numerical minimization are rarely applied to this problem because of the high cost of computing. In this paper, Newton methods are applied to the balancing of blank part. The aforesaid algorithm is demonstrated in term of a marine propeller blade, and result shows that The Newton methods are more efficient and accurate than those implemented in past research and have distinct advantages compared to the registration methods widely used today.
SOME THEORETICAL MODELS EXPLAINING ADVERTISING EFFECTS
Vasilica Magdalena SOMEŞFĂLEAN
2014-01-01
Persuade clients is still the main focus of the companies, using a set of methods and techniques designed to influence their behavior, in order to obtain better results (profits) over a longer period of time. Since the late nineteenth - early twentieth century, the american E.St.Elmo Lewis, considered a pioneer in advertising and sales, developed the first theory, AIDA model, later used by marketers and advertisers to develop a marketing communications strategy. Later studies have developed o...
Life course models: improving interpretation by consideration of total effects.
Green, Michael J; Popham, Frank
2016-12-28
Life course epidemiology has used models of accumulation and critical or sensitive periods to examine the importance of exposure timing in disease aetiology. These models are usually used to describe the direct effects of exposures over the life course. In comparison with consideration of direct effects only, we show how consideration of total effects improves interpretation of these models, giving clearer notions of when it will be most effective to intervene. We show how life course variation in the total effects depends on the magnitude of the direct effects and the stability of the exposure. We discuss interpretation in terms of total, direct and indirect effects and highlight the causal assumptions required for conclusions as to the most effective timing of interventions.
50 CFR 665.127 - Allowable gear and gear restrictions.
2010-10-01
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun;...
50 CFR 665.427 - Allowable gear and gear restrictions.
2010-10-01
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3)...
50 CFR 665.227 - Allowable gear and gear restrictions.
2010-10-01
... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun;...
14 CFR 151.125 - Allowable advance planning costs.
2010-01-01
... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Allowable advance planning costs. 151.125... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Rules and Procedures for Advance Planning and Engineering Proposals § 151.125 Allowable advance planning costs. (a) The United States' share of the allowable costs of...
24 CFR 891.785 - Adjustment of utility allowances.
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Handicapped Families and Individuals-Section 162 Assistance § 891.785 Adjustment of utility allowances. In... adjustment of utility allowances provided in § 891.440 apply....
24 CFR 891.440 - Adjustment of utility allowances.
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Project Management § 891.440 Adjustment of utility allowances. This section shall apply to projects funded... submit an analysis of any utility allowances applicable. Such data as changes in utility rates and...
24 CFR 886.326 - Adjustment of utility allowances.
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... utility allowances. When the owner requests HUD approval of an adjustment in Contract Rents under § 886.312, an analysis of the project's Utility Allowances must be included. Such data as changes in...
24 CFR 880.610 - Adjustment of utility allowances.
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Management § 880.610 Adjustment of utility allowances. In connection with annual and special adjustments of contract rents, the owner must submit an analysis of the project's Utility Allowances. Such data as...
24 CFR 886.126 - Adjustment of utility allowances.
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... utility allowances. When the owner requests HUD approval of adjustment in Contract Rents under § 886.112, an analysis of the project's Utility Allowances must be included. Such data as changes in...
24 CFR 884.220 - Adjustment of utility allowances.
2010-04-01
... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Adjustment of utility allowances... Adjustment of utility allowances. In connection with annual and special adjustments of contract rents, the owner must submit an analysis of the project's Utility Allowances. Such data as changes in utility...
45 CFR 1801.43 - Allowance for books.
2010-10-01
... 45 Public Welfare 4 2010-10-01 2010-10-01 false Allowance for books. 1801.43 Section 1801.43... HARRY S. TRUMAN SCHOLARSHIP PROGRAM Payments to Finalists and Scholars § 1801.43 Allowance for books. The cost allowance for a Scholar's books is $1000 per year, or such higher amount published on...
42 CFR 50.504 - Allowable cost of drugs.
2010-10-01
... 42 Public Health 1 2010-10-01 2010-10-01 false Allowable cost of drugs. 50.504 Section 50.504... APPLICABILITY Maximum Allowable Cost for Drugs § 50.504 Allowable cost of drugs. (a) The maximum amount which may be expended from program funds for the acquisition of any drug shall be the lowest of (1)...
20 CFR 606.2 - Total credits allowable.
2010-04-01
... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Total credits allowable. 606.2 Section 606.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TAX CREDITS UNDER THE... credits allowable. The total credits allowed to an employer subject to the tax imposed by section 3301 of...
46 CFR 154.412 - Cargo tank corrosion allowance.
2010-10-01
... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo tank corrosion allowance. 154.412 Section 154.412... Containment Systems § 154.412 Cargo tank corrosion allowance. A cargo tank must be designed with a corrosion...) carries a cargo that corrodes the tank material. Note: Corrosion allowance for independent tank type C...
46 CFR 54.25-5 - Corrosion allowance.
2010-10-01
... Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-5 Corrosion allowance. The corrosion allowance must be as required in 46 CFR 54.01-35. ... 46 Shipping 2 2010-10-01 2010-10-01 false Corrosion allowance. 54.25-5 Section 54.25-5...
32 CFR 842.35 - Depreciation and maximum allowances.
2010-07-01
... 32 National Defense 6 2010-07-01 2010-07-01 false Depreciation and maximum allowances. 842.35... LITIGATION ADMINISTRATIVE CLAIMS Personnel Claims (31 U.S.C. 3701, 3721) § 842.35 Depreciation and maximum allowances. The military services have jointly established the “Allowance List-Depreciation Guide”...
Inverse modeling of dynamic nonequilibrium in water flow with an effective approach
Diamantopoulos, E.; Iden, S. C.; Durner, W.
2012-03-01
Observations of water flow in unsaturated soils often show "dynamic effects," indicated by nonequilibrium between water contents and water potential, a phenomenon that cannot be modeled with the Richards equation. The objective of this article is to formulate an effective process description of dynamic nonequilibrium flow in variably saturated soil which is both flexible enough to match experimental observations and as parsimonious as possible to allow unique parameter estimation by inverse modeling. In the conceptual model, water content is partitioned into two fractions. Water in one fraction is in equilibrium with the pressure head, whereas water in the second fraction is in nonequilibrium, described by the kinetic equilibration approach of Ross and Smettem (2000). Between the two fractions an instantaneous equilibration of the pressure head is assumed. The new model, termed the dual-fraction nonequilibrium model, requires only one additional parameter compared to the nonequilibrium approach of Ross and Smettem. We tested the model with experimental data from multistep outflow experiments conducted on two soils and compared it to the Richards equation, the nonequilibrium model of Ross and Smettem, and the dual-porosity model of Philip (1968). The experimental data were evaluated by inverse modeling using a robust Markov chain Monte Carlo sampler. The results show that the proposed model is superior to the Richards equation and the Ross and Smettem model in describing dynamic nonequilibrium effects occurring in multistep outflow experiments. The three popular model selection criteria (Akaike information criterion, Bayesian information criterion, and deviance information criterion) all favored the new model because of its smaller number of parameters.
Effects of modeling means on properties of monitoring models of spot welding quality
Institute of Scientific and Technical Information of China (English)
张忠典; 李冬青; 赵洪运; 于燕
2002-01-01
Analyzing and modeling the relation between monitoring information during welding and quality information of the joints is the foundation of monitoring resistance spot welding quality. According to the means of modeling, the known models can be divided into three large categories: single linear regression models, multiple linear regression models and multiple non-linear models. By modeling the relations between dynamic resistance information and welding quality parameters with different means, this paper analyzes effects of modeling means on performances of monitoring models of resistance spot welding quality. From the test results, the following conclusions can be drawn: By comparison with two other kinds of models, artificial neural network (ANN) model can describe non-linear and high coupling relationship between monitoring information and quality information more reasonably, improve performance of monitoring model remarkably, and make the estimated values of welding quality parameters more accurate and reliable.
Finite line-source model for borehole heat exchangers. Effect of vertical temperature variations
Energy Technology Data Exchange (ETDEWEB)
Bandos, Tatyana V.; Fernandez, Esther; Santander, Juan Luis G.; Isidro, Jose Maria; Perez, Jezabel; Cordoba, Pedro J. Fernandez de [Instituto Universitario de Matematica Pura y Aplicada, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Montero, Alvaro; Urchueguia, Javier F. [Instituto de Ingenieria Energetica, Universidad Politecnica de Valencia, Camino de Vera s/n, 46022 Valencia (Spain)
2009-06-15
A solution to the three-dimensional finite line-source (FLS) model for borehole heat exchangers (BHEs) that takes into account the prevailing geothermal gradient and allows arbitrary ground surface temperature changes is presented. Analytical expressions for the average ground temperature are derived by integrating the exact solution over the line-source depth. A self-consistent procedure to evaluate the in situ thermal response test (TRT) data is outlined. The effective thermal conductivity and the effective borehole thermal resistance can be determined by fitting the TRT data to the time-series expansion obtained for the average temperature. (author)
Jeong, Jinwoo; Kim, Hyoungbum; Chae, Dong-hyun; Kim, Eunjeong
2014-01-01
The purpose of this study is to investigate the effects of the case-based reasoning instructional model on learning about climate change unit. Results suggest that students showed interest because it allowed them to find the solution to the problem and solve the problem for themselves by analogy from other cases such as crossword puzzles in an…
The Standard Model Effective Field Theory and Next to Leading Order
Passarino, Giampiero
2016-01-01
We review the status of calculations in the Standard Model Effective Field Theory (SMEFT) beyond leading order (LO). Improving the SMEFT beyond LO allows theoretical errors to be characterized and reduced when considering SMEFT interpretations of the data, which is essential considering the improving experimental precision at LHC. Next to leading order results also allow a more consistent analysis of measurements with different effective scales in the SMEFT. Going beyond LO is clearly important in the event that deviations from the SM are large enough that experimental indications of physics beyond the SM emerge. We discuss a consistent and well defined approach to LO in the SMEFT, so that the improvement to NLO is straightforward. We discuss the basic issues involved in improving calculations to NLO in the SMEFT, and review the advances in this direction that have been achieved to date.
Towards effective food chains : models and applications
Trienekens, J.H.; Top, J.L.; Vorst, van der J.G.A.J.; Beulens, A.J.M.
2010-01-01
Food chain management research can help in the analysis and redesign of value creation and the product flow throughout the chain from primary producer down to the consumer. The aim is to meet consumer and societal requirements effectively at minimal cost. In the Wageningen UR strategic research prog
Modeling the effects of pharmaceutical marketing
Leeflang, P.S.H.; Wieringa, J.E.
Successful innovation of prescription drugs requires a substantial amount of marketing support. There is, however, much concern about the effects of marketing expenditures on the demand of pharmaceutical products (Manchanda et al., Market Lett 16(3/4):293-308, 2005). For example, excessive marketing
Modeling the effects of pharmaceutical marketing
Leeflang, P.S.H.; Wieringa, J.E.
2010-01-01
Successful innovation of prescription drugs requires a substantial amount of marketing support. There is, however, much concern about the effects of marketing expenditures on the demand of pharmaceutical products (Manchanda et al., Market Lett 16(3/4):293-308, 2005). For example, excessive marketing
Multivariate Term Structure Models with Level and Heteroskedasticity Effects
DEFF Research Database (Denmark)
Christiansen, Charlotte
2005-01-01
The paper introduces and estimates a multivariate level-GARCH model for the long rate and the term-structure spread where the conditional volatility is proportional to the ãth power of the variable itself (level effects) and the conditional covariance matrix evolves according to a multivariate GA...... and the level model. GARCH effects are more important than level effects. The results are robust to the maturity of the interest rates. Udgivelsesdato: MAY...
Modeling the effects of physician emigration on human development.
2011-01-01
We analyzed the effects of physician emigration on human development indicators in developing countries. First, the geographical distribution of physician brain drain was documented for the period 1991–2004. Second, random and fixed effects models were employed to investigate the effects of physicians in the home countries and abroad on child mortality and vaccination rates. Third, models were estimated to investigate migration-induced incentives in the medical sector that would increase the ...
Model Equations of Shape Memory Effect - Nitinol
Directory of Open Access Journals (Sweden)
Ion Vela
2010-01-01
Full Text Available Even it has been already confirmed that SMA’s have high potential for robotic actuators, actuators included in space robotics, underwater robotics, robotics for logistics, safety, as well as “green robotics” (robotics for the environment, energy conservation, sustainable development or agriculture, the number of applications of SMA-based actuators is still quite small, especially in applications in which their large strains, high specific work output and structural integration potential are useful,. The paper presents a formulated mathematical model calculated for binary SMA (Ni-Ti, helpful to estimate the stress distribution along with the transformation ratio of a SMA active element.
Directory of Open Access Journals (Sweden)
Erik J M Toonen
Full Text Available Prednisolone and other glucocorticoids (GCs are potent anti-inflammatory drugs, but chronic use is hampered by metabolic side effects. Therefore, there is an urgent medical need for improved GCs that are as effective as classical GCs but have a better safety profile. A well-established model to assess anti-inflammatory efficacy is the chronic collagen-induced arthritis (CIA model in mice, a model with features resembling rheumatoid arthritis. Models to quantify undesired effects of glucocorticoids on glucose kinetics are less well-established. Recently, we have described a model to quantify basal blood glucose kinetics using stably-labeled glucose. In the present study, we have integrated this blood glucose kinetic model in the CIA model to enable quantification of both efficacy and adverse effects in one animal model. Arthritis scores were decreased after treatment with prednisolone, confirming the anti-inflammatory properties of GCs. Both inflammation and prednisolone induced insulin resistance as insulin secretion was strongly increased whereas blood glucose concentrations and hepatic glucose production were only slightly decreased. This insulin resistance did not directly resulted in hyperglycemia, indicating a highly adaptive compensatory mechanism in these mice. In conclusion, this 'all-in-one' model allows for studying effects of (novel GC compounds on the development of arthritis and glucose kinetics in a single animal. This integrative model provides a valuable tool for investigating (drug-induced metabolic dysregulation in an inflammatory setting.
Clustering Effects Within the Dinuclear Model
Adamian, Gurgen; Antonenko, Nikolai; Scheid, Werner
The clustering of two nuclei in a nuclear system creates configurations denoted in literature as nuclear molecular structures. A nuclear molecule or a dinuclear system (DNS) as named by Volkov consists of two touching nuclei (clusters) which keep their individuality. Such a system has two main degrees of freedom of collective motions which govern its dynamics: (i) the relative motion between the clusters leading to molecular resonances in the internuclear potential and to the decay of the dinuclear system (separation of the clusters) which is called quasifission since no compound system like in fission is first formed. (ii) the transfer of nucleons or light constituents between the two clusters of the dinuclear system leading to a special dynamics of the mass and charge asymmetries between the clusters in fusion and fission reactions. In this article we discuss the essential aspects of the diabatic internuclear potential used by the di-nuclear system concept and present applications to nuclear structure and reactions. We show applications of the dinuclear model to superdeformed and hyperdeformed bands. An extended discussion is given to the problems of fusion dynamics in the production of superheavy nuclei, to the quasifission process and to multi-nucleon transfer between nuclei. Also the binary and ternary fission processes are discussed within the scission-point model and the dinuclear system concept.
Waheed, Umair bin
2014-08-01
The wavefield extrapolation operator for ellipsoidally anisotropic (EA) media offers significant cost reduction compared to that for the orthorhombic case, especially when the symmetry planes are tilted and/or rotated. However, ellipsoidal anisotropy does not provide accurate focusing for media of orthorhombic anisotropy. Therefore, we develop effective EA models that correctly capture the kinematic behavior of the wavefield for tilted orthorhombic (TOR) media. Specifically, we compute effective source-dependent velocities for the EA model using kinematic high-frequency representation of the TOR wavefield. The effective model allows us to use the cheaper EA wavefield extrapolation operator to obtain approximate wavefield solutions for a TOR model. Despite the fact that the effective EA models are obtained by kinematic matching using high-frequency asymptotic, the resulting wavefield contains most of the critical wavefield components, including the frequency dependency and caustics, if present, with reasonable accuracy. The methodology developed here offers a much better cost versus accuracy tradeoff for wavefield computations in TOR media, particularly for media of low to moderate complexity. We demonstrate applicability of the proposed approach on a layered TOR model.
Modeling the ocean effect of geomagnetic storms
DEFF Research Database (Denmark)
Olsen, Nils; Kuvshinov, A.
2004-01-01
At coastal sites, geomagnetic variations for periods shorter than a few days are strongly distorted by the conductivity of the nearby sea-water. This phenomena, known as the ocean (or coast) effect, is strongest in the magnetic vertical component. We demonstrate the ability to predict the ocean...... if the oceans are considered. Our analysis also indicates a significant local time asymmetry (i.e., contributions from spherical harmonics other than P-I(0)), especially during the main phase of the storm....
Effective models for interacting quarks from QCD
Energy Technology Data Exchange (ETDEWEB)
Braghin, Fabio L. [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Inst. de Fisica
2012-07-01
Full text: In this work the Quantum Chromodynamics ( QCD ) path integral is considered with the introduction of auxiliary variables for composite gluon fields. One of these variables eventually leads to the gluon condensates of order 2 and another one corresponds to an anti - symmetric composite gluon configuration. Gluon degrees of freedom, and part of the quark degrees of freedom, are integrated out and two different limits of the resulting effective quark interactions are analysed. (author)
An effective model for dynamic finite difference calculations
Energy Technology Data Exchange (ETDEWEB)
Dey, T.N.
1996-01-01
An effective stress model, which simulates the mechanical effects of pore fluids on deformation and strength of porous materials, is described. The model can directly use SESAME table equations-of-state (EOSs) for the solid and fluid components. the model assumes that undrained (no fluid flow) conditions occur. Elastic and crushing behavior of the pore space can be specified from the results of simple laboratory tests. The model fully couples deviatoric and volumetric behavior in the sense that deviatoric and tensile failure depend on the effective pressure, while volumetric changes caused by deviatoric failure are coupled back to the volumetric behavior of the material. Strain hardening and softening of the yield surface, together with a number of flow rules, can be modeled. This model has been implemented into the SMC123 and CTH codes.
Effective UV radiation from model calculations and measurements
Feister, Uwe; Grewe, Rolf
1994-01-01
Model calculations have been made to simulate the effect of atmospheric ozone and geographical as well as meteorological parameters on solar UV radiation reaching the ground. Total ozone values as measured by Dobson spectrophotometer and Brewer spectrometer as well as turbidity were used as input to the model calculation. The performance of the model was tested by spectroradiometric measurements of solar global UV radiation at Potsdam. There are small differences that can be explained by the uncertainty of the measurements, by the uncertainty of input data to the model and by the uncertainty of the radiative transfer algorithms of the model itself. Some effects of solar radiation to the biosphere and to air chemistry are discussed. Model calculations and spectroradiometric measurements can be used to study variations of the effective radiation in space in space time. The comparability of action spectra and their uncertainties are also addressed.
Two-dimensional effects in nonlinear Kronig-Penney models
DEFF Research Database (Denmark)
Gaididei, Yuri Borisovich; Christiansen, Peter Leth; Rasmussen, Kim
1997-01-01
An analysis of two-dimensional (2D) effects in the nonlinear Kronig-Penney model is presented. We establish an effective one-dimensional description of the 2D effects, resulting in a set of pseudodifferential equations. The stationary states of the 2D system and their stability is studied...
Cellular automaton model considering headway-distance effect
Institute of Scientific and Technical Information of China (English)
Hu Shou-Xin; Gao Kun; Wang Bing-Hong; Lu Yu-Feng
2008-01-01
This paper presents a cellular automaton model for single-lane traffic flow.On the basis of the Nagel-Schreckenberg (NS) model,it further considers the effect of headway-distance between two successive cars on the randomization of the latter one.In numerical simulations,this model shows the following characteristics.(1) With a simple structure,this model succeeds in reproducing the hysteresis effect,which is absent in the NS model.(2) Compared with the slow-tostart models,this model exhibits a local fundamental diagram which is more consistent to empirical observations.(3)This model has much higher efficiency in dissolving congestions compared with the so-called NS model with velocitydependent randomization (VDR model).(4) This model is more robust when facing traffic obstructions.It can resist much longer shock times and has much shorter relaxation times on the other hand.To summarize,compared with the existing models,this model is quite simple in structure,but has good characteristics.
Opinion dynamics: models, extensions and external effects
Sîrbu, Alina; Servedio, Vito D P; Tria, Francesca
2016-01-01
Recently, social phenomena have received a lot of attention not only from social scientists, but also from physicists, mathematicians and computer scientists, in the emerging interdisciplinary field of complex system science. Opinion dynamics is one of the processes studied, since opinions are the drivers of human behaviour, and play a crucial role in many global challenges that our complex world and societies are facing: global financial crises, global pandemics, growth of cities, urbanisation and migration patterns, and last but not least important, climate change and environmental sustainability and protection. Opinion formation is a complex process affected by the interplay of different elements, including the individual predisposition, the influence of positive and negative peer interaction (social networks playing a crucial role in this respect), the information each individual is exposed to, and many others. Several models inspired from those in use in physics have been developed to encompass many of t...
Modeling of Dissolution Effects on Waterflooding
DEFF Research Database (Denmark)
Alexeev, Artem; Shapiro, Alexander; Thomsen, Kaj
2015-01-01
Physico-chemical interactions between the fluid and reservoir rock due to the presence of active components in the injected brine produce changes within the reservoir and can significantly impact the fluid flow. We have developed a 1D numerical model for waterflooding accounting for dissolution...... and precipitation of the components. Extending previous studies, we consider an arbitrary chemical non-equilibrium reaction-induced dissolution. We account for different individual volumes that a component has when precipitated or dissolved. This volume non-additivity also affects the pressure and the flow rate...... reaction rates) may exhibit rapid increase of porosity and permeability near the inlet probably indicating a formation of high permeable channels (wormholes). Water saturation in the zone of dissolution increases due to an increase in the bulk volume accessible for the injected fluid. Volumetric non...
Modeling Temporal Behavior of Awards Effect on Viewership of Movies
Altaf, Basmah
2017-04-22
The “rich get richer” effect is well-known in recommendation system. Popular items are recommended more, then purchased more, resulting in becoming even more popular over time. For example, we observe in Netflix data that awarded movies are more popular than non-awarded movies. Unlike other work focusing on making fair/neutralized recommendation, in this paper, we target on modeling the effect of awards on the viewership of movies. The main challenge of building such a model is that the effect on popularity changes over time with different intensity from movie to movie. Our proposed approach explicitly models the award effects for each movie and enables the recommendation system to provide a better ranked list of recommended movies. The results of an extensive empirical validation on Netflix and MovieLens data demonstrate the effectiveness of our model.
A thermodynamically consistent phase-field model for two-phase flows with thermocapillary effects
Guo, Zhenlin
2014-01-01
In this paper, we develop a phase-field model for binary incompressible fluid with thermocapillary effects, which allows the different properties (densities, viscosities and heat conductivities) for each component and meanwhile maintains the thermodynamic consistency. The governing equations of the model including the Navier-Stokes equations, Cahn-Hilliard equations and energy balance equation are derived together within a thermodynamic framework based on the entropy generation, which guarantees the thermodynamic consistency. The sharp-interface limit analysis is carried out to show that the interfacial conditions of the classical sharp-interface models can be recovered from our phase-field model. Moreover, some numerical examples including thermocapillary migration of a bubble and thermocapillary convections in a two- layer fluid system are computed by using a continuous finite element method. The results are compared to the existing analytical solutions and theoretical predictions as validations for our mod...
Transpiration and CO2 fluxes of a pine forest: modelling the undergrowth effect
Directory of Open Access Journals (Sweden)
A. Granier
2005-02-01
Full Text Available A modelling study is performed in order to quantify the relative effect of allowing for the physiological properties of an undergrowth grass sward on total canopy water and carbon fluxes of the Le-Bray forest (Les-Landes, South-western France. The Le-Bray forest consists of maritime pine and an herbaceous undergrowth (purple moor-grass, which is characterised by a low stomatal control of transpiration, in contrast to maritime pine. A CO2-responsive land surface model is used that includes responses of woody and herbaceous species to water stress. An attempt is made to represent the properties of the undergrowth vegetation in the land surface model Interactions between Soil, Biosphere, and Atmosphere, CO2-responsive, ISBA-A-gs. The new adjustment allows for a fairly different environmental response between the forest canopy and the understory in a simple manner. The model's simulations are compared with long term (1997 and 1998 micro-meteorological measurements over the Le-Bray site. The fluxes of energy, water and CO2, are simulated with and without the improved representation of the undergrowth vegetation, and the two simulations are compared with the observations. Accounting for the undergrowth permits one to improve the model's scores. A simple sensitivity experiment shows the behaviour of the model in response to climate change conditions, and the understory effect on the water balance and carbon storage of the forest. Accounting for the distinct characteristics of the undergrowth has a substantial and positive effect on the model accuracy and leads to a different response to climate change scenarios.
A Normative Model of Work Team Effectiveness
1983-11-01
contexts--an emphasis also seen in man’.’ state-of-the-art action projects invo)ving ,ork teams in orc~anizataons (e.g., Foza & Varkus, 1%O) The Role ...1976. Belbin , R. M. Manage’-ent teams : Wh’y the," suzceed or fail. London Hene! ann, 193’. Bertcher, H. J. & Maple, F. F. Creating orcups. Beverly...J. j. The role of team development in organizational effectiveness: A critical review. Psychological Bulletin, 1930, 88, 166-186. Zander, A
Crime Modeling with Truncated Levy Flights and Effects of Police Patrol
Pan, Chaohao; Zhang, Yuqi; Geldner, Nathan; Wang, Chuntian; Wang, Li; Bertozzi, Andrea
2016-01-01
In this paper, we developed a truncated Levy flight model to study the crime dynamics. In the discrete case, our model allows criminals to perform long jumps in between committing crimes with a speed light. This is a more realistic extension of a pioneering random walk model by Short et. al and a Levy flight model thereafter in Chaturapruek, et al. We also derive a continuum limit and perform a stability analysis to study the formation of crime hotspots. Our model is more realistic than the Levy Flight Model, and provides an alternative to the Random Walk Model when the criminals can perform long jumps in between committing crimes. In the next step, we introduce patrolling police officers to our new model following that in. We examine the effects of police patrol when the police choose to adopt different strategies, including unbiased random walk, biased random walk, and truncated Levy flight. We evaluate the effectiveness of the police patrol with the number of crime events in a given time frame. With spatia...
Directory of Open Access Journals (Sweden)
Eleftherios Giovanis
2014-12-01
Full Text Available The current study examines the turn of the month effect on stock returns in 20 countries. This will allow us to explore whether the seasonal patterns usually found in global data; America, Australia, Europe and Asia. Ordinary Least Squares (OLS is problematic as it leads to unreliable estimations; because of the autocorrelation and Autoregressive Conditional Heteroskedasticity (ARCH effects existence. For this reason Generalized GARCH models are estimated. Two approaches are followed. The first is the symmetric Generalized ARCH (1,1 model. However, previous studies found that volatility tends to increase more when the stock market index decreases than when the stock market index increases by the same amount. In addition there is higher seasonality in volatility rather on average returns. For this reason the Periodic-GARCH (1,1 is estimated. The findings support the persistence of the specific calendar effect in 19 out of 20 countries examined.
Meander migration modeling accounting for the effect of riparian vegetation
Eke, E.; Parker, G.
2010-12-01
A numerical model is proposed to study the development of meandering rivers so as to reproduce patterns of both migration and spatial/temporal width variation pattern observed in nature. The model comprises of: a) a depth-averaged channel hydrodynamic/morphodynamic model developed using a two-parameter perturbation expansion technique that considers perturbations induced by curvature and spatial channel width variation and b) a bank migration model which separately considers bank erosional and depositional processes. Unlike most previous meandering river models where channel migration is characterized only in terms of bank erosion, channel dynamics are here defined at channel banks which are allowed to migrate independently via deposition/erosion based on the local flow field and bank characteristics. A bank erodes (deposits) if the near bank Shields stress computed from the flow field is greater (less) than a specified threshold. This threshold Shields number is equivalent to the formative Shields stress characterizing bankfull flow. Excessive bank erosion is controlled by means of natural armoring provided by cohesive/rooted slump blocks produced when a stream erodes into the lower non-cohesive part of a composite bank. Bank deposition is largely due to sediment trapping by vegetation; resultant channel narrowing is related to both a natural rate of vegetal encroachment and flow characteristics. This new model allows the channel freedom to vary in width both spatially and in time as it migrates, so accounting for the bi-directional coupling between vegetation and flow dynamics and reproducing more realistic planform geometries. Preliminary results based on the model are presented.
Hartwigsen, Gesa; Bergmann, Til Ole; Herz, Damian Marc; Angstmann, Steffen; Karabanov, Anke; Raffin, Estelle; Thielscher, Axel; Siebner, Hartwig Roman
2015-01-01
Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how these approaches advance the scientific potential of NTBS as an interventional tool in cognitive neuroscience. (i) Leveraging the anatomical information provided by structural imaging, the electric field distribution in the brain can be modeled and simulated. Biophysical modeling approaches generate testable predictions regarding the impact of interindividual variations in cortical anatomy on the injected electric fields or the influence of the orientation of current flow on the physiological stimulation effects. (ii) Functional brain mapping of the spatiotemporal neural dynamics during cognitive tasks can be used to construct causal network models. These models can identify spatiotemporal changes in effective connectivity during distinct cognitive states and allow for examining how effective connectivity is shaped by NTBS. (iii) Modeling the NTBS effects based on neuroimaging can be complemented by behavior-based cognitive models that exploit variations in task performance. For instance, NTBS-induced changes in response speed and accuracy can be explicitly modeled in a cognitive framework accounting for the speed-accuracy trade-off. This enables to dissociate between behavioral NTBS effects that emerge in the context of rapid automatic responses or in the context of slow deliberate responses. We argue that these complementary modeling approaches facilitate the use of NTBS as a means of dissecting the causal architecture of cognitive systems of the human brain.
Development of a mathematical model to study the radiation-induced bystander effect
Energy Technology Data Exchange (ETDEWEB)
Meireles, Sincler P. de; Santos, Adriano M.; Grynberg, Suely Epsztein, E-mail: spm@cdtn.b, E-mail: amsantos@cdtn.b, E-mail: seg@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Nunes, Maria Eugenia S., E-mail: mariaeugenia@iceb.ufop.b [Universidade Federal de Ouro Preto (UFOP), MG (Brazil)
2011-07-01
Living organisms are composed of millions of cells that together perform tasks of great complexity. Although every cell has an internal structure that obeys the laws of chemistry and biochemistry, it is the interactions between cells that generate a range of different phenomena. Until the 1990s it was believed that the DNA was the single molecule affected by radiation, the so-called theory of the single target. But some observations began to challenge this theory; in 1992 the bystander effect was described by Nagasawa and Little. This effect is responsible for a series of responses such as death, chromosomal instability or other abnormalities that occur in non-irradiated cells that came into contact with irradiated cells or medium from irradiated cells. Understanding the bystander effect may have important consequences for therapy and studies of low-dose risk. In this work, we have developed a computational model to study the bystander effect. This computational model is a two-dimensional cellular automata, consisting of two overlapping networks, where the first represents the cell culture, and the second one, the medium in which cells are embedded. The computational model allows the establishment of curves to describe the behavior of the effect for different levels of signals released in the irradiated medium by the irradiated cells or by the bystander cells when a second order effect is considered. The percentage of cell survival obtained from the mathematical model showed to be in good agreement with experimental data available in the literature. (author)
The multilevel p2 model : A random effects model for the analysis of multiple social networks
Zijlstra, B.J.H.; van Duijn, M.A.J.; Snijders, T.A.B.
2006-01-01
The p2 model is a random effects model with covariates for the analysis of binary directed social network data coming from a single observation of a social network. Here, a multilevel variant of the p2 model is proposed for the case of multiple observations of social networks, for example, in a samp
Fan, Xitao; Wang, Lin; Thompson, Bruce
1999-01-01
A Monte Carlo simulation study investigated the effects on 10 structural equation modeling fit indexes of sample size, estimation method, and model specification. Some fit indexes did not appear to be comparable, and it was apparent that estimation method strongly influenced almost all fit indexes examined, especially for misspecified models. (SLD)
The effective Kaehler potential, metastable vacua and R-symmetry breaking in O'Raifeartaigh models
Energy Technology Data Exchange (ETDEWEB)
Benjamin, Shermane; Freund, Christopher [Department of Physics and Astronomy, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028 (United States); Kain, Ben, E-mail: kain@rowan.ed [Department of Physics and Astronomy, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08028 (United States)
2011-01-21
Much has been learned about metastable vacua and R-symmetry breaking in O'Raifeartaigh models. Such work has largely been done from the perspective of the superpotential and by including Coleman-Weinberg corrections to the scalar potential. Instead, we consider these ideas from the perspective of the one loop effective Kaehler potential. We translate known ideas to this framework and construct convenient formulas for computing individual terms in the expanded effective Kaehler potential. We do so for arbitrary R-charge assignments and allow for small R-symmetry violating terms so that both spontaneous and explicit R-symmetry breaking is allowed in our analysis.
Redhu, Poonam; Gupta, Arvind Kumar
2015-03-01
A new lattice hydrodynamic model is proposed by considering the interruption probability effect on traffic flow with passing and analyzed both theoretically and numerically. From linear and non-linear stability analysis, the effect of interruption probability on the phase diagram is investigated and the condition of existence for kink-antikink soliton solution of mKdV equation is derived. The stable region is enhanced with interruption probability and the jamming transition occurs from uniform flow to kink flow through chaotic flow for higher and intermediate values of non-interruption effect of passing. It is also observed that there exists conventional jamming transition between uniform flow and kink flow for lower values of non-interruption effect of passing. Numerical simulations are carried out and found in accordance with the theoretical findings which confirm that the effect of interruption probability plays an important role in stabilizing traffic flow when passing is allowed.
Bayesian Semi- and Non-Parametric Models for Longitudinal Data with Multiple Membership Effects in R
Directory of Open Access Journals (Sweden)
Terrance Savitsky
2014-03-01
Full Text Available We introduce growcurves for R that performs analysis of repeated measures multiple membership (MM data. This data structure arises in studies under which an intervention is delivered to each subject through the subjects participation in a set of multiple elements that characterize the intervention. In our motivating study design under which subjects receive a group cognitive behavioral therapy (CBT treatment, an element is a group CBT session and each subject attends multiple sessions that, together, comprise the treatment. The sets of elements, or group CBT sessions, attended by subjects will partly overlap with some of those from other subjects to induce a dependence in their responses. The growcurves package offers two alternative sets of hierarchical models: 1. Separate terms are specified for multivariate subject and MM element random effects, where the subject effects are modeled under a Dirichlet process prior to produce a semi-parametric construction; 2. A single term is employed to model joint subject-by-MM effects. A fully non-parametric dependent Dirichlet process formulation allows exploration of differences in subject responses across different MM elements. This model allows for borrowing information among subjects who express similar longitudinal trajectories for flexible estimation. growcurves deploys estimation functions to perform posterior sampling under a suite of prior options. An accompanying set of plot functions allows the user to readily extract by-subject growth curves. The design approach intends to anticipate inferential goals with tools that fully extract information from repeated measures data. Computational efficiency is achieved by performing the sampling for estimation functions using compiled C++ code.
Modeling individual effects in the Cormack-Jolly-Seber Model: A state-space formulation
Royle, J. Andrew
2008-01-01
In population and evolutionary biology, there exists considerable interest in individual heterogeneity in parameters of demographic models for open populations. However, flexible and practical solutions to the development of such models have proven to be elusive. In this article, I provide a state-space formulation of open population capture-recapture models with individual effects. The state-space formulation provides a generic and flexible framework for modeling and inference in models with individual effects, and it yields a practical means of estimation in these complex problems via contemporary methods of Markov chain Monte Carlo. A straightforward implementation can be achieved in the software package WinBUGS. I provide an analysis of a simple model with constant parameter detection and survival probability parameters. A second example is based on data from a 7-year study of European dippers, in which a model with year and individual effects is fitted.
Buzzá, Hilde H.; Pires, Layla; Bagnato, Vanderlei S.; Kurachi, Cristina
2014-03-01
Photodynamic Therapy (PDT) is a type of cancer treatment that is based on the interaction of light (with specific wavelength), a photosensitizing agent and molecular oxygen. The photosensitizer (PS) is activated by light and reacts with oxygen resulting in the production of singlet oxygen that is highly reactive and responsible for the cell death. The Chick Chorioallantoic Membrane (CAM) model is a transparent membrane that allows visualization and evaluation of blood vessels and structural changes, where a tumor model was developed. Two induction tumor models were investigated: tumor biopsy or cell culture. It was used a murine melanoma cell B16F10 in culture and a biopsy from a xenograft tumor in hairless mouse. Two PS were tested: Photodithazine® and Photogem®, a chlorine and porphyrin compounds, respectively. Using intravenous administration, the light-drug interval was of 30 minutes, 1 and 3 hours. Illumination was performed at 630 nm and 660 nm, and the vascular and tumor response was monitored and analyzed. The PS distribution was checked with confocal microscopy. This model can be useful to study several parameters of PDT and the effect of this therapy in the cancer treatment since it allows direct visualization of its effects.
The Development of Hierarchy of Effects Model in Advertising
Directory of Open Access Journals (Sweden)
Bambang Sukma Wijaya
2012-04-01
Full Text Available This paper aims to review the hierarchy of effects models in adverti-sing, especially the well-known model, AIDA (Attention, Interest, De-sire, and Action. Since its introduction by Lewis (1900 and generally attributed in the marketing and advertising literature by Strong (1925, the concept of AIDA’s hierarchy of effects model has been used by many researchers, both academicians and practitioners. The model is used to measure the effect of an advertisement. However, the deve-lopment of information technology has radically changed the way of how people communicate and socialize; as well as a paradigm shift from product-oriented marketing to consumer-oriented marketing or people-oriented marketing. Therefore, the variables in the hierarchy of effects model needs to be updated in respond to the latest develop-ments in the notice of public power as consumer audience. Based on deep literature review and reflective method, this paper introduces a new developed concept of hierarchy of effects model that was adop-ted from AIDA’s hierarchy of effects model, namely: AISDALSLove (At-tention, Interest, Search, Desire, Action, Like/dislike, Share, and Love/hate.
Efficient anisotropic wavefield extrapolation using effective isotropic models
Alkhalifah, Tariq Ali
2013-06-10
Isotropic wavefield extrapolation is more efficient than anisotropic extrapolation, and this is especially true when the anisotropy of the medium is tilted (from the vertical). We use the kinematics of the wavefield, appropriately represented in the high-frequency asymptotic approximation by the eikonal equation, to develop effective isotropic models, which are used to efficiently and approximately extrapolate anisotropic wavefields using the isotropic, relatively cheaper, operators. These effective velocity models are source dependent and tend to embed the anisotropy in the inhomogeneity. Though this isotropically generated wavefield theoretically shares the same kinematic behavior as that of the first arrival anisotropic wavefield, it also has the ability to include all the arrivals resulting from a complex wavefield propagation. In fact, the effective models reduce to the original isotropic model in the limit of isotropy, and thus, the difference between the effective model and, for example, the vertical velocity depends on the strength of anisotropy. For reverse time migration (RTM), effective models are developed for the source and receiver fields by computing the traveltime for a plane wave source stretching along our source and receiver lines in a delayed shot migration implementation. Applications to the BP TTI model demonstrates the effectiveness of the approach.
Modeling the effects of annual influenza vaccination
Energy Technology Data Exchange (ETDEWEB)
Smith, D.J.; Ackley, D.H.; Forrest, S. [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Computer Science; Perelson, A.S. [Los Alamos National Lab., NM (United States). Theoretical Div.
1998-12-31
Although influenza vaccine efficacy is 70--90% in young healthy first-time vaccinees, the efficacy in repeat vaccinees has varied considerably. In some studies, vaccine efficacy in repeat vaccinees was higher than in first-time vaccinees, whereas in other studies vaccine efficacy in repeat vaccinees was significantly lower than in first-time vaccinees and sometimes no higher than in unvaccinated controls. It is known that the closeness of the antigenic match between the vaccine strain and the epidemic virus is important for vaccine effectiveness. In this study the authors show that the antigenic differences between a first vaccine strain and a second vaccine strain, and between the first vaccine strain and the epidemic strain, might account for the observed variation in attack rate among two-time vaccinees.
Gompertzian stochastic model with delay effect to cervical cancer growth
Energy Technology Data Exchange (ETDEWEB)
Mazlan, Mazma Syahidatul Ayuni binti; Rosli, Norhayati binti [Faculty of Industrial Sciences and Technology, Universiti Malaysia Pahang, Lebuhraya Tun Razak, 26300 Gambang, Pahang (Malaysia); Bahar, Arifah [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor and UTM Centre for Industrial and Applied Mathematics (UTM-CIAM), Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia)
2015-02-03
In this paper, a Gompertzian stochastic model with time delay is introduced to describe the cervical cancer growth. The parameters values of the mathematical model are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic model numerically. The efficiency of mathematical model is measured by comparing the simulated result and the clinical data of cervical cancer growth. Low values of Mean-Square Error (MSE) of Gompertzian stochastic model with delay effect indicate good fits.
Gompertzian stochastic model with delay effect to cervical cancer growth
Mazlan, Mazma Syahidatul Ayuni binti; Rosli, Norhayati binti; Bahar, Arifah
2015-02-01
In this paper, a Gompertzian stochastic model with time delay is introduced to describe the cervical cancer growth. The parameters values of the mathematical model are estimated via Levenberg-Marquardt optimization method of non-linear least squares. We apply Milstein scheme for solving the stochastic model numerically. The efficiency of mathematical model is measured by comparing the simulated result and the clinical data of cervical cancer growth. Low values of Mean-Square Error (MSE) of Gompertzian stochastic model with delay effect indicate good fits.
Modeling heart rate variability including the effect of sleep stages
Soliński, Mateusz; Gierałtowski, Jan; Żebrowski, Jan
2016-02-01
We propose a model for heart rate variability (HRV) of a healthy individual during sleep with the assumption that the heart rate variability is predominantly a random process. Autonomic nervous system activity has different properties during different sleep stages, and this affects many physiological systems including the cardiovascular system. Different properties of HRV can be observed during each particular sleep stage. We believe that taking into account the sleep architecture is crucial for modeling the human nighttime HRV. The stochastic model of HRV introduced by Kantelhardt et al. was used as the initial starting point. We studied the statistical properties of sleep in healthy adults, analyzing 30 polysomnographic recordings, which provided realistic information about sleep architecture. Next, we generated synthetic hypnograms and included them in the modeling of nighttime RR interval series. The results of standard HRV linear analysis and of nonlinear analysis (Shannon entropy, Poincaré plots, and multiscale multifractal analysis) show that—in comparison with real data—the HRV signals obtained from our model have very similar properties, in particular including the multifractal characteristics at different time scales. The model described in this paper is discussed in the context of normal sleep. However, its construction is such that it should allow to model heart rate variability in sleep disorders. This possibility is briefly discussed.
Modeling and Simulating Blast Effects on Electric Substations
Energy Technology Data Exchange (ETDEWEB)
Lyle G. Roybal; Robert F. Jeffers; Kent E. McGillivary; Tony D. Paul; Ryan Jacobson
2009-05-01
A software simulation tool was developed at the Idaho National Laboratory to estimate the fragility of electric substation components subject to an explosive blast. Damage caused by explosively driven fragments on a generic electric substation was estimated by using a ray-tracing technique to track and tabulate fragment impacts and penetrations of substation components. This technique is based on methods used for assessing vulnerability of military aircraft and ground vehicles to explosive blasts. An open-source rendering and ray-trace engine was used for geometric modeling and interactions between fragments and substation components. Semi-empirical material interactions models were used to calculate blast parameters and simulate high-velocity material interactions between explosively driven fragments and substation components. Finally, a Monte Carlo simulation was added to model the random nature of fragment generation allowing a skilled analyst to predict failure probabilities of substation components.
Stabilizing effect of cannibalism in a two stages population model.
Rault, Jonathan; Benoît, Eric; Gouzé, Jean-Luc
2013-03-01
In this paper we build a prey-predator model with discrete weight structure for the predator. This model will conserve the number of individuals and the biomass and both growth and reproduction of the predator will depend on the food ingested. Moreover the model allows cannibalism which means that the predator can eat the prey but also other predators. We will focus on a simple version with two weight classes or stage (larvae and adults) and present some general mathematical results. In the last part, we will assume that the dynamics of the prey is fast compared to the predator's one to go further in the results and eventually conclude that under some conditions, cannibalism can stabilize the system: more precisely, an unstable equilibrium without cannibalism will become almost globally stable with some cannibalism. Some numerical simulations are done to illustrate this result.
Picogna, Giovanni
2014-01-01
Stellar flybys in star clusters are suspected to affect the orbital architecture of planetary systems causing eccentricity excitation and orbital misalignment between the planet orbit and the equatorial plane of the star. We explore whether the impulsive changes in the orbital elements of planets, caused by an hyperbolic stellar flyby, can be fully damped by the circumstellar disk surrounding the star. The time required to disperse stellar clusters is in fact comparable to circumstellar disk's lifetime. We have modelled in 3D a system made of a solar type star surrounded by a low density disk with a giant planet embedded in it approached on a hyperbolic encounter trajectory by a second star, of similar mass and with its own disk. We focus on extreme configurations where a very deep stellar flyby perturbs a Jovian planet on an external orbit. This allows to test in full the ability of the disk to erase the effects of the stellar encounter. We find that the amount of mass lost by the disk during the stellar fly...
Modeling the isotope effect in Walden inversion reactions
Schechter, Israel
1991-05-01
A simple model to explain the isotope effect in the Walden exchange reaction is suggested. It is developed in the spirit of the line-of-centers models, and considers a hard-sphere collision that transfers energy from the relative translation to the desired vibrational mode, as well as geometrical properties and steric requirements. This model reproduces the recently measured cross sections for the reactions of hydrogen with isotopic silanes and older measurements of the substitution reactions of tritium atoms with isotopic methanes. Unlike previously given explanations, this model explains the effect of the attacking atom as well as of the other participating atoms. The model provides also qualitative explanation of the measured relative yields and thresholds of CH 3T and CH 2TF from the reaction T + CH 3F. Predictions for isotope effects and cross sections of some unmeasured reactions are given.
29 CFR 778.600 - Veterans' subsistence allow- ances.
2010-07-01
... OF GENERAL POLICY OR INTERPRETATION NOT DIRECTLY RELATED TO REGULATIONS OVERTIME COMPENSATION... subsistence allowances provided by Public Law 346 for payment to veterans are not paid as compensation...
Bayesian nonparametric centered random effects models with variable selection.
Yang, Mingan
2013-03-01
In a linear mixed effects model, it is common practice to assume that the random effects follow a parametric distribution such as a normal distribution with mean zero. However, in the case of variable selection, substantial violation of the normality assumption can potentially impact the subset selection and result in poor interpretation and even incorrect results. In nonparametric random effects models, the random effects generally have a nonzero mean, which causes an identifiability problem for the fixed effects that are paired with the random effects. In this article, we focus on a Bayesian method for variable selection. We characterize the subject-specific random effects nonparametrically with a Dirichlet process and resolve the bias simultaneously. In particular, we propose flexible modeling of the conditional distribution of the random effects with changes across the predictor space. The approach is implemented using a stochastic search Gibbs sampler to identify subsets of fixed effects and random effects to be included in the model. Simulations are provided to evaluate and compare the performance of our approach to the existing ones. We then apply the new approach to a real data example, cross-country and interlaboratory rodent uterotrophic bioassay.