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Sample records for models rarely account

  1. Modelling in Accounting. Theoretical and Practical Dimensions

    Directory of Open Access Journals (Sweden)

    Teresa Szot-Gabryś

    2010-10-01

    Full Text Available Accounting in the theoretical approach is a scientific discipline based on specific paradigms. In the practical aspect, accounting manifests itself through the introduction of a system for measurement of economic quantities which operates in a particular business entity. A characteristic of accounting is its flexibility and ability of adaptation to information needs of information recipients. One of the main currents in the development of accounting theory and practice is to cover by economic measurements areas which have not been hitherto covered by any accounting system (it applies, for example, to small businesses, agricultural farms, human capital, which requires the development of an appropriate theoretical and practical model. The article illustrates the issue of modelling in accounting based on the example of an accounting model developed for small businesses, i.e. economic entities which are not obliged by law to keep accounting records.

  2. Implementing a trustworthy cost-accounting model.

    Science.gov (United States)

    Spence, Jay; Seargeant, Dan

    2015-03-01

    Hospitals and health systems can develop an effective cost-accounting model and maximize the effectiveness of their cost-accounting teams by focusing on six key areas: Implementing an enhanced data model. Reconciling data efficiently. Accommodating multiple cost-modeling techniques. Improving transparency of cost allocations. Securing department manager participation. Providing essential education and training to staff members and stakeholders.

  3. Modeling in Accounting, an Imperative Process?

    Directory of Open Access Journals (Sweden)

    Robu Sorin-Adrian

    2014-08-01

    Full Text Available The approach of this topic suggested to us by the fact that currently, it persists a controversy regarding the elements that influence decisively the qualitative characteristics of useful financial information. From these elements, we remark accounting models and concepts of capital maintenance in terms of the accounting result, which can be under the influence of factors such as subjectivity or even lack of neutrality. Therefore, in formulating the response to the question that is the title of the paper, we will start from the fact that the financial statements prepared by the accounting systems must be the result of processing after appropriate models, which ultimately can respond as good as possible to external user’s requirements and internal, in particular the knowledge of the financial position and performance of economic entities.

  4. Modeling habitat dynamics accounting for possible misclassification

    Science.gov (United States)

    Veran, Sophie; Kleiner, Kevin J.; Choquet, Remi; Collazo, Jaime; Nichols, James D.

    2012-01-01

    Land cover data are widely used in ecology as land cover change is a major component of changes affecting ecological systems. Landscape change estimates are characterized by classification errors. Researchers have used error matrices to adjust estimates of areal extent, but estimation of land cover change is more difficult and more challenging, with error in classification being confused with change. We modeled land cover dynamics for a discrete set of habitat states. The approach accounts for state uncertainty to produce unbiased estimates of habitat transition probabilities using ground information to inform error rates. We consider the case when true and observed habitat states are available for the same geographic unit (pixel) and when true and observed states are obtained at one level of resolution, but transition probabilities estimated at a different level of resolution (aggregations of pixels). Simulation results showed a strong bias when estimating transition probabilities if misclassification was not accounted for. Scaling-up does not necessarily decrease the bias and can even increase it. Analyses of land cover data in the Southeast region of the USA showed that land change patterns appeared distorted if misclassification was not accounted for: rate of habitat turnover was artificially increased and habitat composition appeared more homogeneous. Not properly accounting for land cover misclassification can produce misleading inferences about habitat state and dynamics and also misleading predictions about species distributions based on habitat. Our models that explicitly account for state uncertainty should be useful in obtaining more accurate inferences about change from data that include errors.

  5. Media Accountability Systems: Models, proposals and outlooks

    Directory of Open Access Journals (Sweden)

    Luiz Martins da Silva

    2007-06-01

    Full Text Available This paper analyzes one of the basic actions of SOS-Imprensa, the mechanism to assure Media Accountability with the goal of proposing a synthesis of models for the Brazilian reality. The article aims to address the possibilities of creating and improving mechanisms to stimulate the democratic press process and to mark out and assure freedom of speech and personal rights with respect to the media. Based on the Press Social Responsibility Theory, the hypothesis is that the experiences analyzed (Communication Council, Press Council, Ombudsman and Readers Council are alternatives for accountability, mediation and arbitration, seeking visibility, trust and public support in favor of fairer media.

  6. Potential Models for Radiative Rare B Decays

    CERN Document Server

    Ahmad, S

    2002-01-01

    We compute the branching ratios for the radiative rare decays of B into K-Meson states and compare them to the experimentally determined branching ratio for inclusive decay b -> s gamma using non relativistic quark model, and form factor definitions consistent with HQET covariant trace formalism. Such calculations necessarily involve a potential model. In order to test the sensitivity of calculations to potential models we have used three different potentials, namely linear potential, screening confining potential and heavy quark potential as it stands in QCD.We find the branching ratios relative to the inclusive b ->s gamma decay to be (16.07\\pm 5.2)% for B -> K^* (892)gamma and (7.25\\pm 3.2)% for B -> K_2^* (1430)gamma for linear potential. In the case of the screening confining potential these values are (19.75\\pm 5.3)% and (4.74\\pm 1.2)% while those for the heavy quark potential are (11.18\\pm 4.6)% and (5.09\\pm 2.7)% respectively. All these values are consistent with the corresponding present CLEO experim...

  7. Fusion of expertise among accounting accounting faculty. Towards an expertise model for academia in accounting.

    NARCIS (Netherlands)

    Njoku, Jonathan C.; van der Heijden, Beatrice; Inanga, Eno L.

    2010-01-01

    This paper aims to portray an accounting faculty expert. It is argued that neither the academic nor the professional orientation alone appears adequate in developing accounting faculty expertise. The accounting faculty expert is supposed to develop into a so-called ‘flexpert’ (Van der Heijden, 2003)

  8. MODEL OF MANAGEMENT ACCOUNTING FOR MERCHANDISES SECTOR COMPANIES

    Directory of Open Access Journals (Sweden)

    Glăvan Elena Mariana

    2013-04-01

    Full Text Available Changes in Romanian accounting system have been articulated with priority to financial accounting, without leaving aside management accounting. Changes in management accounting covered a few general indicative directions giving to managers enhanced skills regarding the organisation and function of this branch of the accounting system. Roumanian regulations offered solutions[16] regarding the accounts and records in managerial accounting, but all these elements are recommendations. In the Roumanian chart of accounts there is a specific class of accounts, class number 9-accounts for management accounting, but this class of accounts is an optional one. In fact there are a lot of models applied by companies, but all are based on the accounts that are mentioned in class 9. After an analysis of Romanian accounting literature, we realized that an important part of studies focuses on management accounting models applied to manufacturing companies. As a result, we conceived a model for management accounting specific for marchendises companies. In our model there are two groups of accounts: one from chart of accounts (class 9 and another group composed by accounts proposed by authors. We think that our model could provide more information about each cost object, regarding sales, acquisition cost of sales, distribution cost, administration cost, total cost of sales, contribution margin and profitability. Our model was exemplified by a case study applied to a wholesales company.

  9. DMFCA Model as a Possible Way to Detect Creative Accounting and Accounting Fraud in an Enterprise

    Directory of Open Access Journals (Sweden)

    Jindřiška Kouřilová

    2013-05-01

    Full Text Available The quality of reported accounting data as well as the quality and behaviour of their users influence the efficiency of an enterprise’s management. Its assessment could therefore be changed as well. To identify creative accounting and fraud, several methods and tools were used. In this paper we would like to present our proposal of the DMFCA (Detection model Material Flow Cost Accounting balance model based on environmental accounting and the MFCA (Material Flow Cost Accounting as its method. The following balance areas are included: material, financial and legislative. Using the analysis of strengths and weaknesses of the model, its possible use within a production and business company were assessed. Its possible usage to the detection of some creative accounting techniques was also assessed. The Model is developed in details for practical use and describing theoretical aspects.

  10. Display of the information model accounting system

    Directory of Open Access Journals (Sweden)

    Matija Varga

    2011-12-01

    Full Text Available This paper presents the accounting information system in public companies, business technology matrix and data flow diagram. The paper describes the purpose and goals of the accounting process, matrix sub-process and data class. Data flow in the accounting process and the so-called general ledger module are described in detail. Activities of the financial statements and determining the financial statements of the companies are mentioned as well. It is stated how the general ledger module should function and what characteristics it must have. Line graphs will depict indicators of the company’s business success, indebtedness and company’s efficiency coefficients based on financial balance reports, and profit and loss report.

  11. COMPARATIVE STUDY ON ACCOUNTING MODELS "CASH" AND "ACCRUAL"

    OpenAIRE

    Tatiana Danescu; Luminita Rus

    2013-01-01

    Accounting, as a source of information, can recognize the economic transactionstaking into account the time of payment or receipt thereof, as soon as they occur. There are twobasic models of accounting: accrual basis and cash basis. In the cash accounting method thetransactions are recorded only when cash is received or paid, shall not make the difference betweenthe purchase of an asset and the payment of expenditure - both of which are considered"payments". Accrual accounting achieves this d...

  12. Accountability: a missing construct in models of adherence behavior and in clinical practice.

    Science.gov (United States)

    Oussedik, Elias; Foy, Capri G; Masicampo, E J; Kammrath, Lara K; Anderson, Robert E; Feldman, Steven R

    2017-01-01

    Piano lessons, weekly laboratory meetings, and visits to health care providers have in common an accountability that encourages people to follow a specified course of action. The accountability inherent in the social interaction between a patient and a health care provider affects patients' motivation to adhere to treatment. Nevertheless, accountability is a concept not found in adherence models, and is rarely employed in typical medical practice, where patients may be prescribed a treatment and not seen again until a return appointment 8-12 weeks later. The purpose of this paper is to describe the concept of accountability and to incorporate accountability into an existing adherence model framework. Based on the Self-Determination Theory, accountability can be considered in a spectrum from a paternalistic use of duress to comply with instructions (controlled accountability) to patients' autonomous internal desire to please a respected health care provider (autonomous accountability), the latter expected to best enhance long-term adherence behavior. Existing adherence models were reviewed with a panel of experts, and an accountability construct was incorporated into a modified version of Bandura's Social Cognitive Theory. Defining accountability and incorporating it into an adherence model will facilitate the development of measures of accountability as well as the testing and refinement of adherence interventions that make use of this critical determinant of human behavior.

  13. A holistic model for Islamic accountants and its value added

    OpenAIRE

    El-Halaby, Sherif; Hussainey, Khaled

    2015-01-01

    Purpose – The core objective for this study is introduce the holistic model for Islamic accountants through exploring the perspectives of Muslim scholars; Islamic sharia and AAOIFI ethical standards. The study also contributes to existing literature by exploring the main added value of Muslim accountant towards stakeholders through investigates the main roles of an Islamic accountants. Design/methodology/approach – The paper critically reviews historical debates about Islamic accounting and t...

  14. Accountancy Modeling on Intangible Fixed Assets in Terms of the Main Provisions of International Accounting Standards

    Directory of Open Access Journals (Sweden)

    Riana Iren RADU

    2014-12-01

    Full Text Available Intangible fixed assets are of great importance in terms of progress of economic units. In recent years new approaches have been developed, additions to old standards so that intangible assets have gained a reputation both in the economic environment and in academia. We intend to develop a practical study on the main accounting approaches of the accounting modeling of the intangibles that impact on a company's brand development research PRORESEARCH SRL.

  15. The financial accounting model from a system dynamics' perspective

    NARCIS (Netherlands)

    Melse, E.

    2006-01-01

    This paper explores the foundation of the financial accounting model. We examine the properties of the accounting equation as the principal algorithm for the design and the development of a System Dynamics model. Key to the perspective is the foundational requirement that resolves the temporal

  16. The financial accounting model from a system dynamics' perspective

    NARCIS (Netherlands)

    Melse, E.

    2006-01-01

    This paper explores the foundation of the financial accounting model. We examine the properties of the accounting equation as the principal algorithm for the design and the development of a System Dynamics model. Key to the perspective is the foundational requirement that resolves the temporal confl

  17. The financial accounting model from a system dynamics' perspective

    NARCIS (Netherlands)

    Melse, E.

    2006-01-01

    This paper explores the foundation of the financial accounting model. We examine the properties of the accounting equation as the principal algorithm for the design and the development of a System Dynamics model. Key to the perspective is the foundational requirement that resolves the temporal confl

  18. Modeling Rare Baseball Events--Are They Memoryless?

    Science.gov (United States)

    Huber, Michael; Glen, Andrew

    2007-01-01

    Three sets of rare baseball events--pitching a no-hit game, hitting for the cycle, and turning a triple play--offer excellent examples of events whose occurrence may be modeled as Poisson processes. That is, the time of occurrence of one of these events doesn't affect when we see the next occurrence of such. We modeled occurrences of these three…

  19. Rare B decays as tests of the Standard Model

    Science.gov (United States)

    Blake, Thomas; Lanfranchi, Gaia; Straub, David M.

    2017-01-01

    One of the most interesting puzzles in particle physics today is that new physics is expected at the TeV energy scale to solve the hierarchy problem, and stabilises the Higgs mass, but so far no unambiguous signal of new physics has been found. Strong constraints on the energy scale of new physics can be derived from precision tests of the electroweak theory and from flavour-changing or CP-violating processes in strange, charm and beauty hadron decays. Decays that proceed via flavour-changing-neutral-current processes are forbidden at the lowest perturbative order in the Standard Model and are, therefore, rare. Rare b hadron decays are playing a central role in the understanding of the underlying patterns of Standard Model physics and in setting up new directions in model building for new physics contributions. In this article the status and prospects of this field are reviewed.

  20. Rare $B$ Decays as Tests of the Standard Model

    CERN Document Server

    Blake, Thomas; Straub, David M

    2016-01-01

    One of the most interesting puzzles in particle physics today is that new physics is expected at the TeV energy scale to solve the hierarchy problem, and stabilise the Higgs mass, but so far no unambiguous signal of new physics has been found. Strong constraints on the energy scale of new physics can be derived from precision tests of the electroweak theory and from flavour-changing or CP-violating processes in strange, charm and beauty hadron decays. Decays that proceed via flavour-changing-neutral-current processes are forbidden at the lowest perturbative order in the Standard Model and are, therefore, rare. Rare $b$ hadron decays are playing a central role in the understanding of the underlying patterns of Standard Model physics and in setting up new directions in model building for new physics contributions. In this article the status and prospects of this field are reviewed.

  1. A simple model for /f-->d transitions of rare-earth ions in crystals

    Science.gov (United States)

    Duan, C. K.; Reid, M. F.

    2003-02-01

    Theoretical simulation and interpretation of f→ d transitions of rare earth ions in crystals are more difficult than for f→ f transitions, because f→ d transitions involve many more energy levels and are further complicated by strong vibronic transitions, so the experimental spectra contain many fewer resolvable peaks. In order to better understand the structure of the spectra, a simple model is developed to take into account the main interactions in the fN-1 d configuration. This model leads to quantum numbers characterizing the states and the associated transition selection rules. Relative transition intensities can be quantitatively estimated. The model is applied to Eu 2+ and Sm 3+ ions in crystals.

  2. Models and Rules of Evaluation in International Accounting

    Directory of Open Access Journals (Sweden)

    Liliana Feleaga

    2006-06-01

    Full Text Available The accounting procedures cannot be analyzed without a previous evaluation. Value is in general a very subjective issue, usually the result of a monetary evaluation made to a specific asset, group of assets or entities, or to some rendered services. Within the economic sciences, value comes from its very own deep history. In accounting, the concept of value had a late and fragile start. The term of value must not be misinterpreted as being the same thing with cost, even though value is frequently measured through costs. At the origin of the international accounting standards lays the framework for preparing, presenting and disclosing the financial statements. The framework stays as a reference matrix, as a standard of standards, as a constitution of financial accounting. According to the international framework, the financial statements use different evaluation basis: the hystorical cost, the current cost, the realisable (settlement value, the present value (the present value of cash flows. Choosing the evaluation basis and the capital maintenance concept will eventually determine the accounting evaluation model used in preparing the financial statements of a company. The multitude of accounting evaluation models differentiate themselves one from another through various relevance and reliable degrees of accounting information and therefore, accountants (the prepares of financial statements must try to equilibrate these two main qualitative characteristics of financial information.

  3. Models and Rules of Evaluation in International Accounting

    Directory of Open Access Journals (Sweden)

    Niculae Feleaga

    2006-04-01

    Full Text Available The accounting procedures cannot be analyzed without a previous evaluation. Value is in general a very subjective issue, usually the result of a monetary evaluation made to a specific asset, group of assets or entities, or to some rendered services. Within the economic sciences, value comes from its very own deep history. In accounting, the concept of value had a late and fragile start. The term of value must not be misinterpreted as being the same thing with cost, even though value is frequently measured through costs. At the origin of the international accounting standards lays the framework for preparing, presenting and disclosing the financial statements. The framework stays as a reference matrix, as a standard of standards, as a constitution of financial accounting. According to the international framework, the financial statements use different evaluation basis: the hystorical cost, the current cost, the realisable (settlement value, the present value (the present value of cash flows. Choosing the evaluation basis and the capital maintenance concept will eventually determine the accounting evaluation model used in preparing the financial statements of a company. The multitude of accounting evaluation models differentiate themselves one from another through various relevance and reliable degrees of accounting information and therefore, accountants (the prepares of financial statements must try to equilibrate these two main qualitative characteristics of financial information.

  4. Discovering rare behaviours in stochastic differential equations using decision procedures: applications to a minimal cell cycle model.

    Science.gov (United States)

    Ghosh, Arup Kumar; Hussain, Faraz; Jha, Susmit; Langmead, Christopher J; Jha, Sumit Kumar

    2014-01-01

    Stochastic Differential Equation (SDE) models are used to describe the dynamics of complex systems with inherent randomness. The primary purpose of these models is to study rare but interesting or important behaviours, such as the formation of a tumour. Stochastic simulations are the most common means for estimating (or bounding) the probability of rare behaviours, but the cost of simulations increases with the rarity of events. To address this problem, we introduce a new algorithm specifically designed to quantify the likelihood of rare behaviours in SDE models. Our approach relies on temporal logics for specifying rare behaviours of interest, and on the ability of bit-vector decision procedures to reason exhaustively about fixed-precision arithmetic. We apply our algorithm to a minimal parameterised model of the cell cycle, and take Brownian noise into account while investigating the likelihood of irregularities in cell size and time between cell divisions.

  5. Markov State Models for Rare Events in Molecular Dynamics

    Directory of Open Access Journals (Sweden)

    Marco Sarich

    2013-12-01

    Full Text Available Rare, but important, transition events between long-lived states are a key feature of many molecular systems. In many cases, the computation of rare event statistics by direct molecular dynamics (MD simulations is infeasible, even on the most powerful computers, because of the immensely long simulation timescales needed. Recently, a technique for spatial discretization of the molecular state space designed to help overcome such problems, so-called Markov State Models (MSMs, has attracted a lot of attention. We review the theoretical background and algorithmic realization of MSMs and illustrate their use by some numerical examples. Furthermore, we introduce a novel approach to using MSMs for the efficient solution of optimal control problems that appear in applications where one desires to optimize molecular properties by means of external controls.

  6. Accountability: a missing construct in models of adherence behavior and in clinical practice

    Directory of Open Access Journals (Sweden)

    Oussedik E

    2017-07-01

    Full Text Available Elias Oussedik,1 Capri G Foy,2 E J Masicampo,3 Lara K Kammrath,3 Robert E Anderson,1 Steven R Feldman1,4,5 1Center for Dermatology Research, Department of Dermatology, Wake Forest School of Medicine, Winston-Salem, NC, USA; 2Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, NC, USA; 3Department of Psychology, Wake Forest University, Winston-Salem, NC, USA; 4Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, USA; 5Department of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA Abstract: Piano lessons, weekly laboratory meetings, and visits to health care providers have in common an accountability that encourages people to follow a specified course of action. The accountability inherent in the social interaction between a patient and a health care provider affects patients’ motivation to adhere to treatment. Nevertheless, accountability is a concept not found in adherence models, and is rarely employed in typical medical practice, where patients may be prescribed a treatment and not seen again until a return appointment 8–12 weeks later. The purpose of this paper is to describe the concept of accountability and to incorporate accountability into an existing adherence model framework. Based on the Self-Determination Theory, accountability can be considered in a spectrum from a paternalistic use of duress to comply with instructions (controlled accountability to patients’ autonomous internal desire to please a respected health care provider (autonomous accountability, the latter expected to best enhance long-term adherence behavior. Existing adherence models were reviewed with a panel of experts, and an accountability construct was incorporated into a modified version of Bandura’s Social Cognitive Theory. Defining accountability and incorporating it into an adherence model will facilitate the development of measures of accountability as well

  7. Stochastic models in risk theory and management accounting

    NARCIS (Netherlands)

    Brekelmans, R.C.M.

    2000-01-01

    This thesis deals with stochastic models in two fields: risk theory and management accounting. Firstly, two extensions of the classical risk process are analyzed. A method is developed that computes bounds of the probability of ruin for the classical risk rocess extended with a constant interest

  8. Stochastic models in risk theory and management accounting

    NARCIS (Netherlands)

    Brekelmans, R.C.M.

    2000-01-01

    This thesis deals with stochastic models in two fields: risk theory and management accounting. Firstly, two extensions of the classical risk process are analyzed. A method is developed that computes bounds of the probability of ruin for the classical risk rocess extended with a constant interest for

  9. Accountability Analysis of Electronic Commerce Protocols by Finite Automaton Model

    Institute of Scientific and Technical Information of China (English)

    Xie Xiao-yao; Zhang Huan-guo

    2004-01-01

    The accountability of electronic commerce protocols is an important aspect to insures security of electronic transaction. This paper proposes to use Finite Automaton (FA) model as a new kind of framework to analyze the trans action protocols in the application of electronic commerce.

  10. Stochastic models in risk theory and management accounting

    NARCIS (Netherlands)

    Brekelmans, R.C.M.

    2000-01-01

    This thesis deals with stochastic models in two fields: risk theory and management accounting. Firstly, two extensions of the classical risk process are analyzed. A method is developed that computes bounds of the probability of ruin for the classical risk rocess extended with a constant interest for

  11. The Two-Step Student Teaching Model: Training for Accountability.

    Science.gov (United States)

    Corlett, Donna

    This model of student teaching preparation was developed in collaboration with public schools to focus on systematic experience in teaching and training for accountability in the classroom. In the two-semester plan, students begin with teacher orientation and planning days, serve as teacher aides, attend various methods courses, teach several…

  12. Driving Strategic Risk Planning With Predictive Modelling For Managerial Accounting

    DEFF Research Database (Denmark)

    Nielsen, Steen; Pontoppidan, Iens Christian

    for managerial accounting and shows how it can be used to determine the impact of different types of risk assessment input parameters on the variability of important outcome measures. The purpose is to: (i) point out the theoretical necessity of a stochastic risk framework; (ii) present a stochastic framework......Currently, risk management in management/managerial accounting is treated as deterministic. Although it is well-known that risk estimates are necessarily uncertain or stochastic, until recently the methodology required to handle stochastic risk-based elements appear to be impractical and too...... mathematical. The ultimate purpose of this paper is to “make the risk concept procedural and analytical” and to argue that accountants should now include stochastic risk management as a standard tool. Drawing on mathematical modelling and statistics, this paper methodically develops risk analysis approach...

  13. Quantum-like models cannot account for the conjunction fallacy

    CERN Document Server

    Boyer-Kassem, Thomas; Guerci, Eric

    2016-01-01

    Human agents happen to judge that a conjunction of two terms is more probable than one of the terms, in contradiction with the rules of classical probabilities---this is the conjunction fallacy. One of the most discussed accounts of this fallacy is currently the quantum-like explanation, which relies on models exploiting the mathematics of quantum mechanics. The aim of this paper is to investigate the empirical adequacy of major such quantum-like models. We first argue that they can be tested in three different ways, in a question order effect configuration which is different from the traditional conjunction fallacy experiment. We then carry out our proposed experiment, with varied methodologies from experimental economics. The experimental results we get are at odds with the predictions of the quantum-like models. This strongly suggests that the quantum-like account of the conjunction fallacy fails. Future possible research paths are discussed.

  14. Application of a predictive Bayesian model to environmental accounting.

    Science.gov (United States)

    Anex, R P; Englehardt, J D

    2001-03-30

    Environmental accounting techniques are intended to capture important environmental costs and benefits that are often overlooked in standard accounting practices. Environmental accounting methods themselves often ignore or inadequately represent large but highly uncertain environmental costs and costs conditioned by specific prior events. Use of a predictive Bayesian model is demonstrated for the assessment of such highly uncertain environmental and contingent costs. The predictive Bayesian approach presented generates probability distributions for the quantity of interest (rather than parameters thereof). A spreadsheet implementation of a previously proposed predictive Bayesian model, extended to represent contingent costs, is described and used to evaluate whether a firm should undertake an accelerated phase-out of its PCB containing transformers. Variability and uncertainty (due to lack of information) in transformer accident frequency and severity are assessed simultaneously using a combination of historical accident data, engineering model-based cost estimates, and subjective judgement. Model results are compared using several different risk measures. Use of the model for incorporation of environmental risk management into a company's overall risk management strategy is discussed.

  15. Coupled-channel optical model potential for rare earth nuclei

    CERN Document Server

    Herman, M; Palumbo, A; Dietrich, F S; Brown, D; Hoblit, S

    2013-01-01

    Inspired by the recent work by Dietrich et al., substantiating validity of the adiabatic assumption in coupled-channel calculations, we explore the possibility of generalizing a global spherical optical model potential (OMP) to make it usable in coupled-channel calculations on statically deformed nuclei. The generalization consists in adding the coupling of the ground state rotational band, deforming the potential by introducing appropriate quadrupole and hexadecupole deformation and correcting the OMP radius to preserve volume integral of the spherical OMP. We choose isotopes of three rare-earth elements (W, Ho, Gd), which are known to be nearly perfect rotors, to perform a consistent test of our conjecture on integrated cross sections as well as on angular distributions for elastic and inelastic neutron scattering. When doing this we employ the well-established Koning-Delaroche global spherical potential and experimentally determined deformations without any adjustments. We observe a dramatically improved a...

  16. Rare B decays in the flip SU(5) Model

    CERN Document Server

    Li, Tianjun; Wang, Wenyu; Wang, Xiao-Chuan; Xiong, Zhao-Hua

    2012-01-01

    In the testable Flipped $SU(5)\\times U(1)_X$ model with TeV-scale vector-like particles from F-theory model building dubbed as the flip SU(5) model, we study the vector-like quark contributions to B physics processes, including the quark mass spectra, Feynman rules, new operators and Wilson coefficients, etc. We focus on the implications of the vector-like quark mass scale on B physics. We find that there exists the $\\bar{s}bZ$ interaction at tree level, and the Yukawa interactions are changed. Interestingly, different from many previous models, the effects of vector-like quarks on rare B decays such as $B\\to X_s\\gamma$ and $B\\to X_s\\ell^+\\ell^-$ do not decouple in some viable parameter space, especially when the vector-like quark masses are comparable to the charged Higgs boson mass. Under the constraints from $B\\to X_s\\gamma$ and $\\ B\\to X_s\\ell^+\\ell^-$, the latest measurement for $B_s\\to \\mu^+\\mu^-$ can be explained naturally, and the branching ratio of $B_s\\to \\ell^+\\ell^-\\gamma$ can be up to $(4\\sim5)\\t...

  17. Accounting for Business Models: Increasing the Visibility of Stakeholders

    Directory of Open Access Journals (Sweden)

    Colin Haslam

    2015-01-01

    Full Text Available Purpose: This paper conceptualises a firm’s business model employing stakeholder theory as a central organising element to help inform the purpose and objective(s of business model financial reporting and disclosure. Framework: Firms interact with a complex network of primary and secondary stakeholders to secure the value proposition of a firm’s business model. This value proposition is itself a complex amalgam of value creating, value capturing and value manipulating arrangements with stakeholders. From a financial accounting perspective the purpose of the value proposition for a firm’s business model is to sustain liquidity and solvency as a going concern. Findings: This article argues that stakeholder relations impact upon the financial viability of a firm’s business model value proposition. However current financial reporting by function of expenses and the central organising objectives of the accounting conceptual framework conceal firm-stakeholder relations and their impact on reported financials. Practical implications: The practical implication of our paper is that ‘Business Model’ financial reporting would require a reorientation in the accounting conceptual framework that defines the objectives and purpose of financial reporting. This reorientation would involve reporting about stakeholder relations and their impact on a firms financials not simply reporting financial information to ‘investors’. Social Implications: Business model financial reporting has the potential to be stakeholder inclusive because the numbers and narratives reported by firms in their annual financial statements will increase the visibility of stakeholder relations and how these are being managed. What is original/value of paper: This paper’s original perspective is that it argues that a firm’s business model is structured out of stakeholder relations. It presents the firm’s value proposition as the product of value creating, capturing and

  18. Optimal control design that accounts for model mismatch errors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T.J. [Sandia National Labs., Albuquerque, NM (United States); Hull, D.G. [Texas Univ., Austin, TX (United States). Dept. of Aerospace Engineering and Engineering Mechanics

    1995-02-01

    A new technique is presented in this paper that reduces the complexity of state differential equations while accounting for modeling assumptions. The mismatch controls are defined as the differences between the model equations and the true state equations. The performance index of the optimal control problem is formulated with a set of tuning parameters that are user-selected to tune the control solution in order to achieve the best results. Computer simulations demonstrate that the tuned control law outperforms the untuned controller and produces results that are comparable to a numerically-determined, piecewise-linear optimal controller.

  19. Accounting for microbial habitats in modeling soil organic matter dynamics

    Science.gov (United States)

    Chenu, Claire; Garnier, Patricia; Nunan, Naoise; Pot, Valérie; Raynaud, Xavier; Vieublé, Laure; Otten, Wilfred; Falconer, Ruth; Monga, Olivier

    2017-04-01

    The extreme heterogeneity of soils constituents, architecture and inhabitants at the microscopic scale is increasingly recognized. Microbial communities exist and are active in a complex 3-D physical framework of mineral and organic particles defining pores of various sizes, more or less inter-connected. This results in a frequent spatial disconnection between soil carbon, energy sources and the decomposer organisms and a variety of microhabitats that are more or less suitable for microbial growth and activity. However, current biogeochemical models account for C dynamics at the macroscale (cm, m) and consider time- and spatially averaged relationships between microbial activity and soil characteristics. Different modelling approaches have intended to account for this microscale heterogeneity, based either on considering aggregates as surrogates for microbial habitats, or pores. Innovative modelling approaches are based on an explicit representation of soil structure at the fine scale, i.e. at µm to mm scales: pore architecture and their saturation with water, localization of organic resources and of microorganisms. Three recent models are presented here, that describe the heterotrophic activity of either bacteria or fungi and are based upon different strategies to represent the complex soil pore system (Mosaic, LBios and µFun). These models allow to hierarchize factors of microbial activity in soil's heterogeneous architecture. Present limits of these approaches and challenges are presented, regarding the extensive information required on soils at the microscale and to up-scale microbial functioning from the pore to the core scale.

  20. Accommodating environmental variation in population models: metaphysiological biomass loss accounting.

    Science.gov (United States)

    Owen-Smith, Norman

    2011-07-01

    1. There is a pressing need for population models that can reliably predict responses to changing environmental conditions and diagnose the causes of variation in abundance in space as well as through time. In this 'how to' article, it is outlined how standard population models can be modified to accommodate environmental variation in a heuristically conducive way. This approach is based on metaphysiological modelling concepts linking populations within food web contexts and underlying behaviour governing resource selection. Using population biomass as the currency, population changes can be considered at fine temporal scales taking into account seasonal variation. Density feedbacks are generated through the seasonal depression of resources even in the absence of interference competition. 2. Examples described include (i) metaphysiological modifications of Lotka-Volterra equations for coupled consumer-resource dynamics, accommodating seasonal variation in resource quality as well as availability, resource-dependent mortality and additive predation, (ii) spatial variation in habitat suitability evident from the population abundance attained, taking into account resource heterogeneity and consumer choice using empirical data, (iii) accommodating population structure through the variable sensitivity of life-history stages to resource deficiencies, affecting susceptibility to oscillatory dynamics and (iv) expansion of density-dependent equations to accommodate various biomass losses reducing population growth rate below its potential, including reductions in reproductive outputs. Supporting computational code and parameter values are provided. 3. The essential features of metaphysiological population models include (i) the biomass currency enabling within-year dynamics to be represented appropriately, (ii) distinguishing various processes reducing population growth below its potential, (iii) structural consistency in the representation of interacting populations and

  1. Discrete Model of Ideological Struggle Accounting for Migration

    CERN Document Server

    Vitanov, Nikolay K; Rotundo, Giulia

    2012-01-01

    A discrete in time model of ideological competition is formulated taking into account population migration. The model is based on interactions between global populations of non-believers and followers of different ideologies. The complex dynamics of the attracting manifolds is investigated. Conversion from one ideology to another by means of (i) mass media influence and (ii) interpersonal relations is considered. Moreover a different birth rate is assumed for different ideologies, the rate being assumed to be positive for the reference population, made of initially non-believers. Ideological competition can happen in one or several regions in space. In the latter case, migration of non-believers and adepts is allowed; this leads to an enrichment of the ideological dynamics. Finally, the current ideological situation in the Arab countries and China is commented upon from the point of view of the presently developed mathematical model. The massive forced conversion by Ottoman Turks in the Balkans is briefly dis...

  2. Accounting models and devolution in the Italian public sector

    Directory of Open Access Journals (Sweden)

    Aldo Pavan

    2006-06-01

    Full Text Available In the 1990s Italy started a public sector administrative reform process consistent, in general terms, with the New Public Management movement. In particular, changes have been introduced in the budgeting and accounting systems of the State, municipalities, health care bodies, etc. In the same years an institutional reform also started and a strong power devolution process began to be realised; a shift to a federal form of the State seems to be the goal. Stating form the challenges coming from the devolution process, the article questions 1 if it is possible to find some shared features in theh reformed accounting systems of the different public sector organisation categories, and to shape in this way on or more accounting Italian models, and 2 if these models have an information capacity adequate to sustain the information needs- in terms of accountability, government co-ordination and decision making- emerging from the devolution process. The information needs in a devolved environment are recognised; eleven budgeting and accounting systems are analysed and compared. The issue of the consistency level existing between accountign and institutional reforms is also discussed.En la Italia de los años 90, se inició un proceso de reforma administrativa del sector público en consonancia, en términos generales, con el movimineto New Public Management. En concreto, se han introducido modificaciones en los sistemas contables y presupuestarios del Estado, de las corporaciones locales y de las instituciones sanitarias. Durante el mismo periodo se empreendió una reforma de carácter constitucional cuyo objetivo último parecía ser la constitución de un estado federal. A partir de los desafíos que supone todo proceso de descentralización, el artículo abre dos interrogantes: 1 la posibilidad de encontrar rasgos comunes en los sitemas contables reformados de los distintos niveles organizativos del sector público, con el fin de confirmar uno o

  3. Accounting for Trust: A Conceptual Model for the Determinants of Trust in the Australian Public Accountant – SME Client Relationship

    Directory of Open Access Journals (Sweden)

    Michael Cherry

    2016-06-01

    Full Text Available This paper investigates trust as it relates to the relationship between Australia’s public accountants and their SME clients. It describes the contribution of the accountancy profession to the SME market, as well as the key challenges faced by accountants and their SME clients. Following the review of prior scholarly studies, a working definition of trust as it relates to this important relationship is also developed and presented. A further consequence of prior academic work is the development of a comprehensive conceptual model to describe the determinants of trust in the Australian public accountant – SME client relationship, which requires testing via empirical studies.

  4. Modelling of Rare Earth Elements Complexation With Humic Acid

    Science.gov (United States)

    Pourret, O.; Davranche, M.; Gruau, G.; Dia, A.

    2006-12-01

    The binding of rare earth elements (REE) to humic acid (HA) was studied by combining Ultrafiltration and ICP- MS techniques. REE-HA complexation experiments were performed at various pH conditions (ranging from 2 to 10.5) using a standard batch equilibration method. Results show that the amount of REE bound to HA strongly increase with increasing pH. Moreover, a Middle REE (MREE) downward concavity is evidenced by REE distribution patterns at acidic pH. Modelling of the experimental data using Humic Ion Binding Model VI provided a set of log KMA values (i.e. the REE-HA complexation constants specific to Model VI) for the entire REE series. The log KMA pattern obtained displays a MREE downward concavity. Log KMA values range from 2.42 to 2.79. These binding constants are in good agreement with the few existing datasets quantifying the binding of REE with humic substances except a recently published study which evidence a lanthanide contraction effect (i.e. continuous increase of the constant from La to Lu). The MREE downward concavity displayed by REE-HA complexation pattern determined in this study compares well with results from REE-fulvic acid (FA) and REE-acetic acid complexation studies. This similarity in the REE complexation pattern shapes suggests that carboxylic groups are the main binding sites of REE in HA. This conclusion is further supported by a detailed review of published studies for natural, organic-rich, river- and ground-waters which show no evidence of a lanthanide contraction effect in REE pattern shape. Finally, application of Model VI using the new, experimentally determined log KMA values to World Average River Water confirms earlier suggestions that REE occur predominantly as organic complexes (> 60 %) in the pH range between 5-5.5 and 7-8.5 (i.e. in circumneutral pH waters). The only significant difference as compared to earlier model predictions made using estimated log KMA values is that the experimentally determined log KMA values

  5. Relations between Balance Sheet Policy and Accounting Policy in the Context of Different Accounting Models

    Directory of Open Access Journals (Sweden)

    Rafał Grabowski

    2010-12-01

    Full Text Available In Polish professional literature the terms balance sheet policy (in German: bilanzpolitik and accounting policy are commonly used. The problem raised by the author is defined by the fact that there exist at least a few perspectives of their meaning and their relations with each other. In some opinions balance sheet policy and accounting policy represent the same issues. In other opinions there appear differences between the two, however, there is no consensus as to the nature of the differences. The lack of clarity with regard to the explanation methods of balance sheet policy and accounting policy and their relations represents a research problem for theory and practice. The theory is required to codify the academic debate and systematize the terminology while in practice it is the management board that holds responsibility for a financial statement which is determined by accounting policy adopted by the entity. In this working paper the author has tried to point out the substance of balance sheet policy and accounting policy as well as to provide explanation of existing differences between them. Although the topic has already been discussed in professional literature, there have been no attempts to explain the substance of the two policies and their relations by making reference to their origin, ie. accounting approaches from which they evolved.

  6. Meander migration modeling accounting for the effect of riparian vegetation

    Science.gov (United States)

    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.

  7. Generalized Stefan models accounting for a discontinuous temperature field

    Science.gov (United States)

    Danescu, A.

    We construct a class of generalized Stefan models able to account for a discontinuous temperature field across a nonmaterial interface. The resulting theory introduces a constitutive scalar interfacial field, denoted by /lineθ and called the equivalent temperature of the interface. A classical procedure, based on the interfacial dissipation inequality, relates the interfacial energy release to the interfacial mass flux and restricts the equivalent temperature of the interface. We show that previously proposed theories are obtained as particular cases when /lineθ = ⪉θ > or /lineθ = ⪉(1)/(θ )>-1 or, more generally, when /lineθ = ⪉θ r ⪉ 1/θ1-r-1 for 0<= r<= 1. We study in a particular constitutive framework the solidification of an under-cooled liquid and we are able to give a sufficient condition for the existence of travelling wave solutions.

  8. Natural Resource Accounting Systems and Environmental Policy Modeling

    OpenAIRE

    Richard Cabe; Johnson, Stanley R

    1990-01-01

    Natural Resource Accounting (RCA) combines national income and product accounting concepts with analysis of natural resource and environmental issues. This paper considers this approach for the RCA Appraisal required by the Soil and Water Resources Conservation Act. Recent natural resource accounting literature is examined in light of requirements of the RCA Appraisal. The paper provides a critique of the economic content of the Second RCA Appraisal and develops a natural resource accounting ...

  9. Accounting for Water Insecurity in Modeling Domestic Water Demand

    Science.gov (United States)

    Galaitsis, S. E.; Huber-lee, A. T.; Vogel, R. M.; Naumova, E.

    2013-12-01

    Water demand management uses price elasticity estimates to predict consumer demand in relation to water pricing changes, but studies have shown that many additional factors effect water consumption. Development scholars document the need for water security, however, much of the water security literature focuses on broad policies which can influence water demand. Previous domestic water demand studies have not considered how water security can affect a population's consumption behavior. This study is the first to model the influence of water insecurity on water demand. A subjective indicator scale measuring water insecurity among consumers in the Palestinian West Bank is developed and included as a variable to explore how perceptions of control, or lack thereof, impact consumption behavior and resulting estimates of price elasticity. A multivariate regression model demonstrates the significance of a water insecurity variable for data sets encompassing disparate water access. When accounting for insecurity, the R-squaed value improves and the marginal price a household is willing to pay becomes a significant predictor for the household quantity consumption. The model denotes that, with all other variables held equal, a household will buy more water when the users are more water insecure. Though the reasons behind this trend require further study, the findings suggest broad policy implications by demonstrating that water distribution practices in scarcity conditions can promote consumer welfare and efficient water use.

  10. Capture-recapture survival models taking account of transients

    Science.gov (United States)

    Pradel, R.; Hines, J.E.; Lebreton, J.D.; Nichols, J.D.

    1997-01-01

    The presence of transient animals, common enough in natural populations, invalidates the estimation of survival by traditional capture- recapture (CR) models designed for the study of residents only. Also, the study of transit is interesting in itself. We thus develop here a class of CR models to describe the presence of transients. In order to assess the merits of this approach we examme the bias of the traditional survival estimators in the presence of transients in relation to the power of different tests for detecting transients. We also compare the relative efficiency of an ad hoc approach to dealing with transients that leaves out the first observation of each animal. We then study a real example using lazuli bunting (Passerina amoena) and, in conclusion, discuss the design of an experiment aiming at the estimation of transience. In practice, the presence of transients is easily detected whenever the risk of bias is high. The ad hoc approach, which yields unbiased estimates for residents only, is satisfactory in a time-dependent context but poorly efficient when parameters are constant. The example shows that intermediate situations between strict 'residence' and strict 'transience' may exist in certain studies. Yet, most of the time, if the study design takes into account the expected length of stay of a transient, it should be possible to efficiently separate the two categories of animals.

  11. Islamic Theoretical Intertemporal Model of the Current Account

    Directory of Open Access Journals (Sweden)

    Hassan Belkacem Ghassan

    2016-06-01

    Full Text Available This paper aims to develop an Islamic intertemporal model of the current account based on the prevailing theoretical and empirical literature of PVMCA (Obstfeld and Rogoff, 1996, Cerrato et al., 2014. The proposed model is based on the budget constraint of the present and future consumption, which depends on the obligatory Zakat from the income and assets, the return rate on the owned assets, the inheritance linking previous to subsequent generation. Using logarithmic utility function, featured by a unitary elasticity of intertemporal substitution and a unitary coefficient of relative risk aversion, we show through Euler equation of consumption that there is an inverse relationship between consumption growth from the last age to the first one and the Zakat rate on assets. The outcomes of this result are that the Zakat on assets disciplines the consumer to have more rationality in consumption, and allows additional marginal assets for future generations. By assuming a unitary subjective discount rate, we indicate that the more the return rate on assets is high, the more the consumption growth between today and tomorrow will be fast. Through the budget constraint, if Zakat rate on the Zakatable assets is greater than Zakat rate on income, this leads to a relative expansion in private consumption of the wealthy group. Besides, we point out that an increase in return rate on assets, can drive to increasing or decreasing current consumption, because the substitution and income effects work in opposite ways.

  12. Expert System Models in the Companies' Financial and Accounting Domain

    CERN Document Server

    Mates, D; Bostan, I; Grosu, V

    2010-01-01

    The present paper is based on studying, analyzing and implementing the expert systems in the financial and accounting domain of the companies, describing the use method of the informational systems that can be used in the multi-national companies, public interest institutions, and medium and small dimension economical entities, in order to optimize the managerial decisions and render efficient the financial-accounting functionality. The purpose of this paper is aimed to identifying the economical exigencies of the entities, based on the already used accounting instruments and the management software that could consent the control of the economical processes and patrimonial assets.

  13. Micromapping of very rare anemias: the model of CDA

    Directory of Open Access Journals (Sweden)

    Hermann Heimpel

    2013-03-01

    Full Text Available The congenital dyserythropoietic anemias, first described in 1966 and classified into four distinct types in 1968, are still very rare. However, many cases were described in recent years, mainly in European Countries. The detection of mutations of the CDAN1-gene (Tamary et al. from Israel in all cases of CDA I and of the SEC23B-gene in almost all cases of CDA II (Schwarz, Iolascon, Heimpel et al. from Germany and Italy, Zanella, Bianchi et al. from Italy stimulated greater awarness of the CDAs and resulted in many recent reports from all continents. Period prevalance of the the last 50 years in the European countries collated in the German Registry on CDAs were calculated in 2009 and published in 2010. The cumulated incidence of both types combined variedwidely between European regions, with minimal values of 0.08 cases⁄million in Scandinavia and 2.60 cases⁄million in Italy...

  14. Photo darkening in Rare earth doped silica: Model and Experiment

    DEFF Research Database (Denmark)

    Mattsson, Kent Erik

    2011-01-01

    A model for photo darkening based on chemical bond formation is presented. The formation process, color center spectral response and bleaching is discussed and model predictions is found to follow high power fiber laser operation......A model for photo darkening based on chemical bond formation is presented. The formation process, color center spectral response and bleaching is discussed and model predictions is found to follow high power fiber laser operation...

  15. Carbonatite and alkaline intrusion-related rare earth element deposits–A deposit model

    Science.gov (United States)

    Verplanck, Philip L.; Van Gosen, Bradley S.

    2011-01-01

    The rare earth elements are not as rare in nature as their name implies, but economic deposits with these elements are not common and few deposits have been large producers. In the past 25 years, demand for rare earth elements has increased dramatically because of their wide and diverse use in high-technology applications. Yet, presently the global production and supply of rare earth elements come from only a few sources. China produces more than 95 percent of the world's supply of rare earth elements. Because of China's decision to restrict exports of these elements, the price of rare earth elements has increased and industrial countries are concerned about supply shortages. As a result, understanding the distribution and origin of rare earth elements deposits, and identifying and quantifying our nation's rare earth elements resources have become priorities. Carbonatite and alkaline intrusive complexes, as well as their weathering products, are the primary sources of rare earth elements. The general mineral deposit model summarized here is part of an effort by the U.S. Geological Survey's Mineral Resources Program to update existing models and develop new descriptive mineral deposit models to supplement previously published models for use in mineral-resource and mineral-environmental assessments. Carbonatite and alkaline intrusion-related REE deposits are discussed together because of their spatial association, common enrichment in incompatible elements, and similarities in genesis. A wide variety of commodities have been exploited from carbonatites and alkaline igneous rocks, such as rare earth elements, niobium, phosphate, titanium, vermiculite, barite, fluorite, copper, calcite, and zirconium. Other enrichments include manganese, strontium, tantalum, thorium, vanadium, and uranium.

  16. Models and Rules of Evaluation in International Accounting

    OpenAIRE

    Liliana Feleaga; Niculae Feleaga

    2006-01-01

    The accounting procedures cannot be analyzed without a previous evaluation. Value is in general a very subjective issue, usually the result of a monetary evaluation made to a specific asset, group of assets or entities, or to some rendered services. Within the economic sciences, value comes from its very own deep history. In accounting, the concept of value had a late and fragile start. The term of value must not be misinterpreted as being the same thing with cost, even though value is freque...

  17. Large animal models of rare genetic disorders: sheep as phenotypically relevant models of human genetic disease.

    Science.gov (United States)

    Pinnapureddy, Ashish R; Stayner, Cherie; McEwan, John; Baddeley, Olivia; Forman, John; Eccles, Michael R

    2015-09-02

    Animals that accurately model human disease are invaluable in medical research, allowing a critical understanding of disease mechanisms, and the opportunity to evaluate the effect of therapeutic compounds in pre-clinical studies. Many types of animal models are used world-wide, with the most common being small laboratory animals, such as mice. However, rodents often do not faithfully replicate human disease, despite their predominant use in research. This discordancy is due in part to physiological differences, such as body size and longevity. In contrast, large animal models, including sheep, provide an alternative to mice for biomedical research due to their greater physiological parallels with humans. Completion of the full genome sequences of many species, and the advent of Next Generation Sequencing (NGS) technologies, means it is now feasible to screen large populations of domesticated animals for genetic variants that resemble human genetic diseases, and generate models that more accurately model rare human pathologies. In this review, we discuss the notion of using sheep as large animal models, and their advantages in modelling human genetic disease. We exemplify several existing naturally occurring ovine variants in genes that are orthologous to human disease genes, such as the Cln6 sheep model for Batten disease. These, and other sheep models, have contributed significantly to our understanding of the relevant human disease process, in addition to providing opportunities to trial new therapies in animals with similar body and organ size to humans. Therefore sheep are a significant species with respect to the modelling of rare genetic human disease, which we summarize in this review.

  18. MODELING OF A STRUCTURED PLAN OF ACCOUNTS IN PROCEDURES OF INSOLVENCY AND BANKRUPTCY

    Directory of Open Access Journals (Sweden)

    Chalenko R. V.

    2014-02-01

    Full Text Available The article details the problems of constructing a structured plan of accounts in bankruptcy and insolvency proceedings. The proposed model is based on two principal positions, first structured chart of accounts has its own dimension, and secondly, it is built on the principles of architectonics. Architectonics constructing structured chart of accounts allows you to integrate managerial, strategic, transactional accounting and making accounting transparent and efficient

  19. Accounting for heterogeneity of public lands in hedonic property models

    Science.gov (United States)

    Charlotte Ham; Patricia A. Champ; John B. Loomis; Robin M. Reich

    2012-01-01

    Open space lands, national forests in particular, are usually treated as homogeneous entities in hedonic price studies. Failure to account for the heterogeneous nature of public open spaces may result in inappropriate inferences about the benefits of proximate location to such lands. In this study the hedonic price method is used to estimate the marginal values for...

  20. Accounting for Recoil Effects in Geochronometers: A New Model Approach

    Science.gov (United States)

    Lee, V. E.; Huber, C.

    2012-12-01

    dated grain is a major control on the magnitude of recoil loss, the first feature is the ability to calculate recoil effects on isotopic compositions for realistic, complex grain shapes and surface roughnesses. This is useful because natural grains may have irregular shapes that do not conform to simple geometric descriptions. Perhaps more importantly, the surface area over which recoiled nuclides are lost can be significantly underestimated when grain surface roughness is not accounted for, since the recoil distances can be of similar characteristic lengthscales to surface roughness features. The second key feature is the ability to incorporate dynamical geologic processes affecting grain surfaces in natural settings, such as dissolution and crystallization. We describe the model and its main components, and point out implications for the geologically-relevant chronometers mentioned above.

  1. Accounting for choice of measurement scale in extreme value modeling

    OpenAIRE

    Wadsworth, J. L.; Tawn, J. A.; Jonathan, P.

    2010-01-01

    We investigate the effect that the choice of measurement scale has upon inference and extrapolation in extreme value analysis. Separate analyses of variables from a single process on scales which are linked by a nonlinear transformation may lead to discrepant conclusions concerning the tail behavior of the process. We propose the use of a Box--Cox power transformation incorporated as part of the inference procedure to account parametrically for the uncertainty surrounding the scale of extrapo...

  2. Metal loading effect on rare earth element binding to humic acid: Experimental and modelling evidence

    Science.gov (United States)

    Marsac, Rémi; Davranche, Mélanie; Gruau, Gérard; Dia, Aline

    2010-03-01

    The effect of metal loading on the binding of rare earth elements (REE) to humic acid (HA) was studied by combining ultrafiltration and Inductively Coupled Plasma Mass Spectrometry techniques. REE-HA complexation experiments were performed at pH 3 for REE/C molar ratios ranging from ca 4 × 10 -4 to 2.7 × 10 -2. Results show that the relative amount of REE bound to HA strongly increases with decreasing REE/C. A middle-REE (MREE) downward concavity is shown by patterns at high metal loading, whereas patterns at low metal loading display a regular increase from La to Lu. Humic Ion Model VI modelling are close to the experimental data variations, provided that (i) the ΔLK 2 parameter (i.e. the Model VI parameter taken into account the presence of strong but low density binding sites) is allowed to increase regularly from La to Lu (from 1.1 to 2.1) and (ii) the published log KMA values (i.e. the REE-HA binding constants specific to Model VI) are slightly modified, in particular with respect to heavy REE. Modelling approach provided evidence that logKdREE patterns with varying REE/C likely arises because REE binding to HA occurs through two types of binding sites in different density: (i) a few strong sites that preferentially complex the heavy REE and thus control the logKdREE atterns at low REE/C; (ii) a larger amount of weaker binding sites that preferentially complex the middle-REE and thus control the logKdREE pattern at high REE/C. Hence, metal loading exerts a major effect on HA-mediated REE binding, which could explain the diversity of published conditional constants for REE binding with HA. A literature survey suggests that the few strong sites activated at low REE/C could be multidentate carboxylic sites, or perhaps N-, or P-functional groups. Finally, an examination of the literature field data proposed that the described loading effect could account for much of the variation in REE patterns observed in natural organic-rich waters (DOC > 5 mg L -1 and 4

  3. Rare B-decays in the standard model

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Greub, C. [Zurich Univ. (Switzerland); Mannel, T. [Technische Hochschule Darmstadt (Germany)

    1993-02-01

    We review theoretical work done in studies of the Flavour Changing Neutral Current (FCNC) B-decays in the context of the Standard Model. Making use of the QCD-improved effective Hamiltonian describing the so-called vertical stroke {Delta}Bvertical stroke =1 and vertical stroke {Delta}Bvertical stroke =2, vertical stroke {Delta}Qvertical stroke =0 transitions, we calculate the rates and differential distributions in a large number of B-decays. The FCNC processes discussed here include the radiative decays B {yields} X{sub s} + {gamma}, B {yields} X{sub d} + {gamma}, and the semileptonic decays B {yields} X{sub s} l{sup +}l{sup -}, B {yields} X{sub d}l{sup +}l{sup -}, B {yields} X{sub s} {nu}{sub l} anti {nu}{sub l}, and B {yields} X{sub d} {nu}{sub l} anti {nu}{sub l}. We also discuss the inclusive photon energy spectrum calculated from the Charged Current (CC) decays B {yields} X{sub c} + {gamma} and B {yields} X{sub u} + {gamma} and the mentioned FCNC radiative decays. The importance of carrying out measurements of the inclusive photon energy spectrum in B-decays is emphasized. Using phenomenological potential models and the Heavy Quark Effective Theory (HQET) we estimate decay branching ratios in a number of exclusive FCNC B-decays. Purely leptonic and photonic decays (B{sub d}, B{sub s}) {yields} l{sup +}l{sup -} and (B{sub d}, B{sub s}) {yields} {gamma}{gamma} are also estimated. The principal interest in the studies of FCNC B-decays lies in their use in determining the parameters of the standard Model, in particular the CKM matrix elements and the top quark mass. The parametric dependence of these and other QCD-specific parameters on the rates and distributions is worked out numerically. (orig.)

  4. 76 FR 29249 - Medicare Program; Pioneer Accountable Care Organization Model: Request for Applications

    Science.gov (United States)

    2011-05-20

    ... participate in the Pioneer Accountable Care Organization Model for a period beginning in 2011 and ending...://innovations.cms.gov/areas-of-focus/seamless-and-coordinated-care-models/pioneer-aco . Application Submission... Accountable Care Organization Model or the application process. SUPPLEMENTARY INFORMATION: I. Background...

  5. 76 FR 34712 - Medicare Program; Pioneer Accountable Care Organization Model; Extension of the Submission...

    Science.gov (United States)

    2011-06-14

    ...: This notice extends the deadlines for the submission of the Pioneer Accountable Care Organization Model...-coordinated-care-models/pioneer-aco . Application Submission Deadline: Applications must be postmarked on or before August 19, 2011. The Pioneer Accountable Care Organization Model ] Application is available...

  6. MODELLING THE LESOTHO ECONOMY: A SOCIAL ACCOUNTING MATRIX APPROACH

    Directory of Open Access Journals (Sweden)

    Yonas Tesfamariam Bahta

    2013-07-01

    Full Text Available Using a 2000 Social Accounting Matrix (SAM for Lesotho, this paper investigates the key features of the Lesotho economy and the role played by the agricultural sector. A novel feature of the SAM is the elaborate disaggregation of the agricultural sector into finer subcategories. The fundamental importance of agriculture development emerges clearly from a descriptive review and from SAM multiplier analysis. It is dominant with respect to income generation and value of production. It contributes 23 percent of gross domestic product and 12 percent of the total value of production. It employs 26 percent of labour and 24 percent of capital. The construction sector has the highest open SAM output multiplier (1,588 and SAM output multiplier (1.767. The household multipliers indicate that in the rural and urban areas, agriculture and mining respectively generate most household income. Agriculture has the highest employment coefficient. Agriculture and mining sectors also have the largest employment multipliers in Lesotho.

  7. Resource Allocation Models and Accountability: A Jamaican Case Study

    Science.gov (United States)

    Nkrumah-Young, Kofi K.; Powell, Philip

    2008-01-01

    Higher education institutions (HEIs) may be funded privately, by the state or by a mixture of the two. Nevertheless, any state financing of HE necessitates a mechanism to determine the level of support and the channels through which it is to be directed; that is, a resource allocation model. Public funding, through resource allocation models,…

  8. Identifying Opportunities to Reduce Uncertainty in a National-Scale Forest Carbon Accounting Model

    Science.gov (United States)

    Shaw, C. H.; Metsaranta, J. M.; Kurz, W.; Hilger, A.

    2013-12-01

    Assessing the quality of forest carbon budget models used for national and international reporting of greenhouse gas emissions is essential, but model evaluations are rarely conducted mainly because of lack of appropriate, independent ground plot data sets. Ecosystem carbon stocks for all major pools estimated from data collected for 696 ground plots from Canada's new National Forest Inventory (NFI) were used to assess plot-level carbon stocks predicted by the Carbon Budget Model of the Canadian Forest Sector 3 (CBM-CFS3) -- a model compliant with the most complex (Tier-3) approach in the reporting guidelines of the Intergovernmental Panel on Climate Change. The model is the core of Canada's National Forest Carbon Monitoring, Accounting, and Reporting System. At the landscape scale, a major portion of total uncertainty in both C stock and flux estimation is associated with biomass productivity, turnover, and soil and dead organic matter modelling parameters, which can best be further evaluated using plot-level data. Because the data collected for the ground plots were comprehensive we were able to compare carbon stock estimates for 13 pools also estimated by the CBM-CFS3 (all modelled pools excepting coarse and fine root biomass) using the classical comparison statistics of mean difference and correlation. Using a Monte Carlo approach we were able to determine the contribution of aboveground biomass, deadwood and soil pool error to modeled ecosystem total error, as well as the contribution of pools that are summed to estimate aboveground biomass, deadwood and soil, to the error of these three subtotal pools. We were also able to assess potential sources of error propagation in the computational sequence of the CBM-CFS3. Analysis of the data grouped by the 16 dominant tree species allowed us to isolate the leading species where further research would lead to the greatest reductions in uncertainty for modeling of carbon stocks using the CBM-CFS3. This analysis

  9. Modeling Rare and Unique Documents: Using FRBR[subscript OO]/CIDOC CRM

    Science.gov (United States)

    Le Boeuf, Patrick

    2012-01-01

    Both the library and the museum communities have developed conceptual models for the information they produce about the collections they hold: FRBR (Functional Requirements for Bibliographic Records) and CIDOC CRM (Conceptual Reference Model). But neither proves perfectly adequate when it comes to some specific types of rare and unique materials:…

  10. Rare events analysis of temperature chaos in the Sherrington-Kirkpatrick model

    Science.gov (United States)

    Billoire, Alain

    2014-04-01

    We investigate the question of temperature chaos in the Sherrington-Kirkpatrick spin glass model, applying a recently proposed rare events based data analysis method to existing Monte Carlo data. Thanks to this new method, temperature chaos is now observable for this model, even with the limited size systems that can currently be simulated.

  11. Nonlinear model accounting for minor hysteresis of embedded SMA actuators

    Institute of Scientific and Technical Information of China (English)

    YANG Kai; GU Chenglin

    2007-01-01

    A quantitative index martensite fraction was used to describe the phase transformation degree of shape memory alloy (SMA).On the basis of the martensite fraction,a nonlinear analysis model for major and minor hysteresis loops was developed.The model adopted two exponential equations to calculate the martensite fractions for cooling and heating,respectively.The martensite fractions were derived as the relative parameters were adjusted timely according to continuous,common initial and common limit constraints.By use of the linear relationship between the curvature of embedded SMA actuator and SMA's martensite fraction,the curvature was determined.The results of the simulations and experiments prove the validity and veracity of the model.

  12. Modeling tools to Account for Ethanol Impacts on BTEX Plumes

    Science.gov (United States)

    Widespread usage of ethanol in gasoline leads to impacts at leak sites which differ from those of non-ethanol gasolines. The presentation reviews current research results on the distribution of gasoline and ethanol, biodegradation, phase separation and cosolvancy. Model results f...

  13. A Historical Account of the Hypodermic Model in Mass Communication.

    Science.gov (United States)

    Bineham, Jeffery L.

    1988-01-01

    Critiques different historical conceptions of mass communication research. Argues that the different conceptions of the history of mass communication research, and of the hypodermic model (viewing the media as an all-powerful and direct influence on society), influence the theoretical and methodological choices made by mass media scholars. (MM)

  14. Applying the International Medical Graduate Program Model to Alleviate the Supply Shortage of Accounting Doctoral Faculty

    Science.gov (United States)

    HassabElnaby, Hassan R.; Dobrzykowski, David D.; Tran, Oanh Thikie

    2012-01-01

    Accounting has been faced with a severe shortage in the supply of qualified doctoral faculty. Drawing upon the international mobility of foreign scholars and the spirit of the international medical graduate program, this article suggests a model to fill the demand in accounting doctoral faculty. The underlying assumption of the suggested model is…

  15. 76 FR 33306 - Medicare Program; Pioneer Accountable Care Organization Model, Request for Applications; Correction

    Science.gov (United States)

    2011-06-08

    ... Care Organization Model: Request for Applications.'' FOR FURTHER INFORMATION CONTACT: Maria Alexander... http://innovations.cms.gov/areas-of-focus/seamless-and-coordinated-care-models/pioneer-aco... HUMAN SERVICES Centers for Medicare & Medicaid Services Medicare Program; Pioneer Accountable...

  16. Towards accounting for dissolved iron speciation in global ocean models

    Directory of Open Access Journals (Sweden)

    A. Tagliabue

    2011-10-01

    Full Text Available The trace metal iron (Fe is now routinely included in state-of-the-art ocean general circulation and biogeochemistry models (OGCBMs because of its key role as a limiting nutrient in regions of the world ocean important for carbon cycling and air-sea CO2 exchange. However, the complexities of the seawater Fe cycle, which impact its speciation and bioavailability, are simplified in such OGCBMs due to gaps in understanding and to avoid high computational costs. In a similar fashion to inorganic carbon speciation, we outline a means by which the complex speciation of Fe can be included in global OGCBMs in a reasonably cost-effective manner. We construct an Fe speciation model based on hypothesised relationships between rate constants and environmental variables (temperature, light, oxygen, pH, salinity and assumptions regarding the binding strengths of Fe complexing organic ligands and test hypotheses regarding their distributions. As a result, we find that the global distribution of different Fe species is tightly controlled by spatio-temporal environmental variability and the distribution of Fe binding ligands. Impacts on bioavailable Fe are highly sensitive to assumptions regarding which Fe species are bioavailable and how those species vary in space and time. When forced by representations of future ocean circulation and climate we find large changes to the speciation of Fe governed by pH mediated changes to redox kinetics. We speculate that these changes may exert selective pressure on phytoplankton Fe uptake strategies in the future ocean. In future work, more information on the sources and sinks of ocean Fe ligands, their bioavailability, the cycling of colloidal Fe species and kinetics of Fe-surface coordination reactions would be invaluable. We hope our modeling approach can provide a means by which new observations of Fe speciation can be tested against hypotheses of the processes present in governing the ocean Fe cycle in an

  17. Superposition-model analysis of rare-earth doped BaY2F8

    Science.gov (United States)

    Magnani, N.; Amoretti, G.; Baraldi, A.; Capelletti, R.

    The energy level schemes of four rare-earth dopants (Ce3+ , Nd3+ , Dy3+ , and Er3+) in BaY2 F-8 , as determined by optical absorption spectra, were fitted with a single-ion Hamiltonian and analysed within Newman's Superposition Model for the crystal field. A unified picture for the four dopants was obtained, by assuming a distortion of the F- ligand cage around the RE site; within the framework of the Superposition Model, this distortion is found to have a marked anisotropic behaviour for heavy rare earths, while it turns into an isotropic expansion of the nearest-neighbours polyhedron for light rare earths. It is also inferred that the substituting ion may occupy an off-center position with respect to the original Y3+ site in the crystal.

  18. Towards accounting for dissolved iron speciation in global ocean models

    Directory of Open Access Journals (Sweden)

    A. Tagliabue

    2011-03-01

    Full Text Available The trace metal iron (Fe is now routinely included in state-of-the-art ocean general circulation and biogeochemistry models (OGCBMs because of its key role as a limiting nutrient in regions of the world ocean important for carbon cycling and air-sea CO2 exchange. However, the complexities of the seawater Fe cycle, which impact its speciation and bioavailability, are highly simplified in such OGCBMs to avoid high computational costs. In a similar fashion to inorganic carbon speciation, we outline a means by which the complex speciation of Fe can be included in global OGCBMs in a reasonably cost-effective manner. We use our Fe speciation to suggest the global distribution of different Fe species is tightly controlled by environmental variability (temperature, light, oxygen and pH and the assumptions regarding Fe binding ligands. Impacts on bioavailable Fe are highly sensitive to assumptions regarding which Fe species are bioavailable. When forced by representations of future ocean circulation and climate we find large changes to the speciation of Fe governed by pH mediated changes to redox kinetics. We speculate that these changes may exert selective pressure on phytoplankton Fe uptake strategies in the future ocean. We hope our modeling approach can also be used as a ''test bed'' for exploring our understanding of Fe speciation at the global scale.

  19. A mathematical model of sentimental dynamics accounting for marital dissolution.

    Directory of Open Access Journals (Sweden)

    José-Manuel Rey

    Full Text Available BACKGROUND: Marital dissolution is ubiquitous in western societies. It poses major scientific and sociological problems both in theoretical and therapeutic terms. Scholars and therapists agree on the existence of a sort of second law of thermodynamics for sentimental relationships. Effort is required to sustain them. Love is not enough. METHODOLOGY/PRINCIPAL FINDINGS: Building on a simple version of the second law we use optimal control theory as a novel approach to model sentimental dynamics. Our analysis is consistent with sociological data. We show that, when both partners have similar emotional attributes, there is an optimal effort policy yielding a durable happy union. This policy is prey to structural destabilization resulting from a combination of two factors: there is an effort gap because the optimal policy always entails discomfort and there is a tendency to lower effort to non-sustaining levels due to the instability of the dynamics. CONCLUSIONS/SIGNIFICANCE: These mathematical facts implied by the model unveil an underlying mechanism that may explain couple disruption in real scenarios. Within this framework the apparent paradox that a union consistently planned to last forever will probably break up is explained as a mechanistic consequence of the second law.

  20. Exclusive Rare B ( s, c) Decays in Light-Front Quark Model

    Science.gov (United States)

    Choi, Ho-Meoyng

    2013-03-01

    We investigate the exclusive rare {B_sto (K,η^{(')})(ν_{ell}bar{ν_{ell}}, ell^+ell^-)} and {B_cto D_{(s)}(ν_{ell}bar{ν_{ell}}, ell^+ell^-)} ( ℓ = e, μ, τ) decays within the standard model and the light-front quark model constrained by the variational principle for the QCD motivated effective Hamiltonian. The branching ratios and the longitudinal lepton polarization asymmetries are calculated and compared with other theoretical model predictions.

  1. MODEL OF ACCOUNTING ENGINEERING IN VIEW OF EARNINGS MANAGEMENT IN POLAND

    Directory of Open Access Journals (Sweden)

    Leszek Michalczyk

    2012-10-01

    Full Text Available The article introduces the theoretical foundations of the author’s original concept of accounting engineering. We assume a theoretical premise whereby accounting engineering is understood as a system of accounting practice utilising differences in economic events resultant from the use of divergent accounting methods. Unlike, for instance, creative or praxeological accounting, accounting engineering is composed only, and under all circumstances, of lawful activities and adheres to the current regulations of the balance sheet law. The aim of the article is to construct a model of accounting engineering exploiting taking into account differences inherently present in variant accounting. These differences result in disparate financial results of identical economic events. Given the fact that regardless of which variant is used in accounting, all settlements are eventually equal to one another, a new class of differences emerges - the accounting engineering potential. It is transferred to subsequent reporting (balance sheet periods. In the end, the profit “made” in a given period reduces the financial result of future periods. This effect is due to the “transfer” of costs from one period to another. Such actions may have sundry consequences and are especially dangerous whenever many individuals are concerned with the profit of a given company, e.g. on a stock exchange. The reverse may be observed when a company is privatised and its value is being intentionally reduced by a controlled recording of accounting provisions, depending on the degree to which they are justified. The reduction of a company’s goodwill in Balcerowicz’s model of no-tender privatisation allows to justify the low value of the purchased company. These are only some of many manifestations of variant accounting which accounting engineering employs. A theoretical model of the latter is presented in this article.

  2. A Case Study of the Accounting Models for the Participants in an Emissions Trading Scheme

    Directory of Open Access Journals (Sweden)

    Marius Deac

    2013-10-01

    Full Text Available As emissions trading schemes are becoming more popular across the world, accounting has to keep up with these new economic developments. The absence of guidance regarding the accounting for greenhouse gases (GHGs emissions generated by the withdrawal of IFRIC 3- Emission Rights - is the main reason why there is a diversity of accounting practices. This diversity of accounting methods makes the financial statements of companies that are taking part in emissions trading schemes like EU ETS, difficult to compare. The present paper uses a case study that assumes the existence of three entities that have chosen three different accounting methods: the IFRIC 3 cost model, the IFRIC 3 revaluation model and the “off balance sheet” approach. This illustrates how the choice of an accounting method regarding GHGs emissions influences their interim and annual reports through the chances in the companies’ balance sheet and financial results.

  3. Urine-derived induced pluripotent stem cells as a modeling tool to study rare human diseases.

    Science.gov (United States)

    Shi, Liang; Cui, Yazhou; Luan, Jing; Zhou, Xiaoyan; Han, Jinxiang

    2016-08-01

    Rare diseases with a low prevalence are a key public health issue because the causes of those diseases are difficult to determine and those diseases lack a clearly established or curative treatment. Thus, investigating the molecular mechanisms that underlie the pathology of rare diseases and facilitating the development of novel therapies using disease models is crucial. Human induced pluripotent stem cells (iPSCs) are well suited to modeling rare diseases since they have the capacity for self-renewal and pluripotency. In addition, iPSC technology provides a valuable tool to generate patient-specific iPSCs. These cells can be differentiated into cell types that have been affected by a disease. These cells would circumvent ethical concerns and avoid immunological rejection, so they could be used in cell replacement therapy or regenerative medicine. To date, human iPSCs could have been generated from multiple donor sources, such as skin, adipose tissue, and peripheral blood. However, these cells are obtained via invasive procedures. In contrast, several groups of researchers have found that urine may be a better source for producing iPSCs from normal individuals or patients. This review discusses urinary iPSC (UiPSC) as a candidate for modeling rare diseases. Cells obtained from urine have overwhelming advantages compared to other donor sources since they are safely, affordably, and frequently obtained and they are readily obtained from patients. The use of iPSC-based models is also discussed. UiPSCs may prove to be a key means of modeling rare diseases and they may facilitate the treatment of those diseases in the future.

  4. Dynamic model of production enterprises based on accounting registers and its identification

    Science.gov (United States)

    Sirazetdinov, R. T.; Samodurov, A. V.; Yenikeev, I. A.; Markov, D. S.

    2016-06-01

    The report focuses on the mathematical modeling of economic entities based on accounting registers. Developed the dynamic model of financial and economic activity of the enterprise as a system of differential equations. Created algorithms for identification of parameters of the dynamic model. Constructed and identified the model of Russian machine-building enterprises.

  5. A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

    DEFF Research Database (Denmark)

    Jensen, Ninna Reitzel; Schomacker, Kristian Juul

    2015-01-01

    and unit-linked insurance. By use of a two-account model, we are able to illustrate general concepts without making the model too abstract. To allow for complicated financial markets without dramatically increasing the mathematical complexity, we focus on economic scenarios. We illustrate the use of our......Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death...... product types. This enables comparison of participating life insurance products and unit-linked insurance products, thus building a bridge between the two different ways of formalizing life insurance products. Finally, our model distinguishes itself from the existing literature by taking into account...

  6. An Integrative Model of the Strategic Management Accounting at the Enterprises of Chemical Industry

    Directory of Open Access Journals (Sweden)

    Aleksandra Vasilyevna Glushchenko

    2016-06-01

    Full Text Available Currently, the issues of information and analytical support of strategic management enabling to take timely and high-quality management decisions, are extremely relevant. Conflicting and poor information, haphazard collected in the practice of large companies from unreliable sources, affects the effective implementation of their development strategies and carries the threat of risk, by the increasing instability of the external environment. Thus chemical industry is one of the central places in the industry of Russia and, of course, has its specificity in the formation of the informationsupport system. Such an information system suitable for the development and implementation of strategic directions, changes in recognized competitive advantages of strategic management accounting. The issues of the lack of requirements for strategic accounting information, its inconsistency in the result of simultaneous accumulation in different parts and using different methods of calculation and assessment of indicators is impossible without a well-constructed model of organization of strategic management accounting. The purpose of this study is to develop such a model, the implementation of which will allow realizing the possibility of achieving strategic goals by harmonizing information from the individual objects of the strategic account to increase the functional effectiveness of management decisions with a focus on strategy. Case study was based on dialectical logic and methods of system analysis, and identifying causal relationships in building a model of strategic management accounting that contributes to the forecasts of its development. The study proposed to implement an integrative model of organization of strategic management accounting. The purpose of a phased implementation of this model defines the objects and tools of strategic management accounting. Moreover, it is determined that from the point of view of increasing the usefulness of management

  7. Modelling the winter distribution of a rare and endangered migrant, the Aquatic Warbler Acrocephalus paludicola

    DEFF Research Database (Denmark)

    Walther, Bruno A; Schäffer, Norbert; van Niekerk, Adriaan

    2007-01-01

    . Such model predictions may be useful guidelines to focus further field research on the Aquatic Warbler. Given the excellent model predictions in this study, this novel technique may prove useful to model the distribution of other rare and endangered species, thus providing a means to guide future survey......The Aquatic Warbler Acrocephalus paludicola is one of the most threatened Western Palearctic passerine species, classified as globally Vulnerable. With its breeding grounds relatively secure, a clear need remains for the monitoring and protection of the migration and wintering grounds of this rare...... and endangered migrant. Recent research has shown that the Aquatic Warbler migrates through northwest Africa in autumn and spring. The wintering grounds are apparently limited to wetlands of sub-Saharan West Africa, with records from only about 20 localities in Mauritania, Mali, Senegal and Ghana. Given the lack...

  8. Modeling the Hellenic karst catchments with the Sacramento Soil Moisture Accounting model

    Science.gov (United States)

    Katsanou, K.; Lambrakis, N.

    2017-01-01

    Karst aquifers are very complex due to the presence of dual porosity. Rain-runoff hydrological models are frequently used to characterize these aquifers and assist in their management. The calibration of such models requires knowledge of many parameters, whose quality can be directly related to the quality of the simulation results. The Sacramento Soil Moisture Accounting (SAC-SMA) model includes a number of physically based parameters that permit accurate simulations and predictions of the rain-runoff relationships. Due to common physical characteristics of mature karst structures, expressed by sharp recession limbs of the runoff hydrographs, the calibration of the model becomes relatively simple, and the values of the parameters range within narrow bands. The most sensitive parameters are those related to groundwater storage regulated by the zone of the epikarst. The SAC-SMA model was calibrated for data from the mountainous part of the Louros basin, north-western Greece, which is considered to be representative of such geological formations. Visual assessment of the hydrographs as statistical outcomes revealed that the SAC-SMA model simulated the timing and magnitude of the peak flow and the shape of recession curves well.

  9. Modeling the Hellenic karst catchments with the Sacramento Soil Moisture Accounting model

    Science.gov (United States)

    Katsanou, K.; Lambrakis, N.

    2017-05-01

    Karst aquifers are very complex due to the presence of dual porosity. Rain-runoff hydrological models are frequently used to characterize these aquifers and assist in their management. The calibration of such models requires knowledge of many parameters, whose quality can be directly related to the quality of the simulation results. The Sacramento Soil Moisture Accounting (SAC-SMA) model includes a number of physically based parameters that permit accurate simulations and predictions of the rain-runoff relationships. Due to common physical characteristics of mature karst structures, expressed by sharp recession limbs of the runoff hydrographs, the calibration of the model becomes relatively simple, and the values of the parameters range within narrow bands. The most sensitive parameters are those related to groundwater storage regulated by the zone of the epikarst. The SAC-SMA model was calibrated for data from the mountainous part of the Louros basin, north-western Greece, which is considered to be representative of such geological formations. Visual assessment of the hydrographs as statistical outcomes revealed that the SAC-SMA model simulated the timing and magnitude of the peak flow and the shape of recession curves well.

  10. Rare Baryonic Decays Λb → Λl+l- in the TTM Model

    Science.gov (United States)

    Wen, Yan-Li; Yue, Chong-Xing; Zhang, Jiao

    2013-07-01

    In the framework of the top triangle moose model, we analyze the rare decays Λb → Λl+l-(l = e, μ, τ) by using the form factors calculated in full QCD. We calculate the contributions of the new particles predicted by this model to observables, such as the branching ratios, forward-backward asymmetry (AFB) and polarizations related these decay processes. We find that, in wide range of the parameter space, the values of the branching ratios are enhanced by one order of magnitude comparing to the standard model predictions. This model can also produce significant corrections to AFB, normal polarization PN and transversal polarization PT.

  11. Extension of the hard-sphere particle-wall collision model to account for particle deposition.

    Science.gov (United States)

    Kosinski, Pawel; Hoffmann, Alex C

    2009-06-01

    Numerical simulations of flows of fluids with granular materials using the Eulerian-Lagrangian approach involve the problem of modeling of collisions: both between the particles and particles with walls. One of the most popular techniques is the hard-sphere model. This model, however, has a major drawback in that it does not take into account cohesive or adhesive forces. In this paper we develop an extension to a well-known hard-sphere model for modeling particle-wall interactions, making it possible to account for adhesion. The model is able to account for virtually any physical interaction, such as van der Waals forces or liquid bridging. In this paper we focus on the derivation of the new model and we show some computational results.

  12. An overview of methods for developing bioenergetic and life history models for rare and endangered species

    Science.gov (United States)

    Petersen, J.H.; DeAngelis, D.L.; Paukert, C.P.

    2008-01-01

    Many fish species are at risk to some degree, and conservation efforts are planned or underway to preserve sensitive populations. For many imperiled species, models could serve as useful tools for researchers and managers as they seek to understand individual growth, quantify predator-prey dynamics, and identify critical sources of mortality. Development and application of models for rare species however, has been constrained by small population sizes, difficulty in obtaining sampling permits, limited opportunities for funding, and regulations on how endangered species can be used in laboratory studies. Bioenergetic and life history models should help with endangered species-recovery planning since these types of models have been used successfully in the last 25 years to address management problems for many commercially and recreationally important fish species. In this paper we discuss five approaches to developing models and parameters for rare species. Borrowing model functions and parameters from related species is simple, but uncorroborated results can be misleading. Directly estimating parameters with laboratory studies may be possible for rare species that have locally abundant populations. Monte Carlo filtering can be used to estimate several parameters by means of performing simple laboratory growth experiments to first determine test criteria. Pattern-oriented modeling (POM) is a new and developing field of research that uses field-observed patterns to build, test, and parameterize models. Models developed using the POM approach are closely linked to field data, produce testable hypotheses, and require a close working relationship between modelers and empiricists. Artificial evolution in individual-based models can be used to gain insight into adaptive behaviors for poorly understood species and thus can fill in knowledge gaps. ?? Copyright by the American Fisheries Society 2008.

  13. Mutual Calculations in Creating Accounting Models: A Demonstration of the Power of Matrix Mathematics in Accounting Education

    Science.gov (United States)

    Vysotskaya, Anna; Kolvakh, Oleg; Stoner, Greg

    2016-01-01

    The aim of this paper is to describe the innovative teaching approach used in the Southern Federal University, Russia, to teach accounting via a form of matrix mathematics. It thereby contributes to disseminating the technique of teaching to solve accounting cases using mutual calculations to a worldwide audience. The approach taken in this course…

  14. Mutual Calculations in Creating Accounting Models: A Demonstration of the Power of Matrix Mathematics in Accounting Education

    Science.gov (United States)

    Vysotskaya, Anna; Kolvakh, Oleg; Stoner, Greg

    2016-01-01

    The aim of this paper is to describe the innovative teaching approach used in the Southern Federal University, Russia, to teach accounting via a form of matrix mathematics. It thereby contributes to disseminating the technique of teaching to solve accounting cases using mutual calculations to a worldwide audience. The approach taken in this course…

  15. Accounting for false-positive acoustic detections of bats using occupancy models

    Science.gov (United States)

    Clement, Matthew J.; Rodhouse, Thomas J.; Ormsbee, Patricia C.; Szewczak, Joseph M.; Nichols, James D.

    2014-01-01

    1. Acoustic surveys have become a common survey method for bats and other vocal taxa. Previous work shows that bat echolocation may be misidentified, but common analytic methods, such as occupancy models, assume that misidentifications do not occur. Unless rare, such misidentifications could lead to incorrect inferences with significant management implications.

  16. A Teacher Accountability Model for Overcoming Self-Exclusion of Pupils

    Science.gov (United States)

    Jamal, Abu-Hussain; Tilchin, Oleg; Essawi, Mohammad

    2015-01-01

    Self-exclusion of pupils is one of the prominent challenges of education. In this paper we propose the TERA model, which shapes the process of creating formative accountability of teachers to overcome the self-exclusion of pupils. Development of the model includes elaboration and integration of interconnected model components. The TERA model…

  17. Accounting for the influence of vegetation and landscape improves model transferability in a tropical savannah region

    Science.gov (United States)

    Gao, Hongkai; Hrachowitz, Markus; Sriwongsitanon, Nutchanart; Fenicia, Fabrizio; Gharari, Shervan; Savenije, Hubert H. G.

    2016-10-01

    Understanding which catchment characteristics dominate hydrologic response and how to take them into account remains a challenge in hydrological modeling, particularly in ungauged basins. This is even more so in nontemperate and nonhumid catchments, where—due to the combination of seasonality and the occurrence of dry spells—threshold processes are more prominent in rainfall runoff behavior. An example is the tropical savannah, the second largest climatic zone, characterized by pronounced dry and wet seasons and high evaporative demand. In this study, we investigated the importance of landscape variability on the spatial variability of stream flow in tropical savannah basins. We applied a stepwise modeling approach to 23 subcatchments of the Upper Ping River in Thailand, where gradually more information on landscape was incorporated. The benchmark is represented by a classical lumped model (FLEXL), which does not account for spatial variability. We then tested the effect of accounting for vegetation information within the lumped model (FLEXLM), and subsequently two semidistributed models: one accounting for the spatial variability of topography-based landscape features alone (FLEXT), and another accounting for both topographic features and vegetation (FLEXTM). In cross validation, each model was calibrated on one catchment, and then transferred with its fitted parameters to the remaining catchments. We found that when transferring model parameters in space, the semidistributed models accounting for vegetation and topographic heterogeneity clearly outperformed the lumped model. This suggests that landscape controls a considerable part of the hydrological function and explicit consideration of its heterogeneity can be highly beneficial for prediction in ungauged basins in tropical savannah.

  18. Matrix Representation of the Kaliningrad Regional Accounts System: Experimental Development and Modelling Prospects

    Directory of Open Access Journals (Sweden)

    Soldatova S.

    2015-12-01

    Full Text Available This article addresses the task of creating a regional Social Accounting Matrix (SAM in the Kaliningrad region. Analyzing the behavior of economic systems of national and sub-national levels in the changing environment is one of the main objectives of macroeconomic research. Matrices are used in examining the flow of financial resources, which makes it possible to conduct a comprehensive analysis of commodity and cash flows at the regional level. The study identifies key data sources for matrix development and presents its main results: the data sources for the accounts development and filling the social accounting matrix are identified, regional accounts consolidated, the structure of regional matrix devised, and the multiplier of the regional social accounting matrix calculated. An important aspect of this approach is the set target, which determines the composition of matrix accounts representing different aspects of regional performance. The calculated multiplier suggests the possibility of modelling of a socioeconomic system for the region using a social accounting matrix. The regional modelling approach ensures the matrix compliance with the methodological requirements of the national system.

  19. Matrix Representation of the Kaliningrad Regional Accounts System: Experimental Development and Modelling Prospects

    Directory of Open Access Journals (Sweden)

    Soldatova S.

    2015-08-01

    Full Text Available This article addresses the task of creating a regional Social Accounting Matrix (SAM in the Kaliningrad region. Analyzing the behavior of economic systems of national and sub-national levels in the changing environment is one of the main objectives of macroeconomic research. Matrices are used in examining the flow of financial resources, which makes it possible to conduct a comprehensive analysis of commodity and cash flows at the regional level. The study identifies key data sources for matrix development and presents its main results: the data sources for the accounts development and filling the social accounting matrix are identified, regional accounts consolidated, the structure of regional matrix devised, and the multiplier of the regional social accounting matrix calculated. An important aspect of this approach is the set target, which determines the composition of matrix accounts representing different aspects of regional performance. The calculated multiplier suggests the possibility of modelling of a socioeconomic system for the region using a social accounting matrix. The regional modelling approach ensures the matrix compliance with the methodological requirements of the national system

  20. Matrix Representation of the Kaliningrad Regional Accounts System: Experimental Development and Modelling Prospects

    Directory of Open Access Journals (Sweden)

    Soldatova Svetlana

    2015-09-01

    Full Text Available This article addresses the task of creating a regional Social Accounting Matrix (SAM in the Kaliningrad region. Analyzing the behavior of economic systems of national and sub-national levels in the changing environment is one of the main objectives of macroeconomic research. Matrices are used in examining the flow of financial resources, which makes it possible to conduct a comprehensive analysis of commodity and cash flows at the regional level. The study identifies key data sources for matrix development and presents its main results: the data sources for the accounts development and filling the social accounting matrix are identified, regional accounts consolidated, the structure of regional matrix devised, and the multiplier of the regional social accounting matrix calculated. An important aspect of this approach is the set target, which determines the composition of matrix accounts representing different aspects of regional performance. The calculated multiplier suggests the possibility of modelling of a socioeconomic system for the region using a social accounting matrix. The regional modelling approach ensures the matrix compliance with the methodological requirements of the national system

  1. Development and application of a large scale river system model for National Water Accounting in Australia

    Science.gov (United States)

    Dutta, Dushmanta; Vaze, Jai; Kim, Shaun; Hughes, Justin; Yang, Ang; Teng, Jin; Lerat, Julien

    2017-04-01

    Existing global and continental scale river models, mainly designed for integrating with global climate models, are of very coarse spatial resolutions and lack many important hydrological processes, such as overbank flow, irrigation diversion, groundwater seepage/recharge, which operate at a much finer resolution. Thus, these models are not suitable for producing water accounts, which have become increasingly important for water resources planning and management at regional and national scales. A continental scale river system model called Australian Water Resource Assessment River System model (AWRA-R) has been developed and implemented for national water accounting in Australia using a node-link architecture. The model includes major hydrological processes, anthropogenic water utilisation and storage routing that influence the streamflow in both regulated and unregulated river systems. Two key components of the model are an irrigation model to compute water diversion for irrigation use and associated fluxes and stores and a storage-based floodplain inundation model to compute overbank flow from river to floodplain and associated floodplain fluxes and stores. The results in the Murray-Darling Basin shows highly satisfactory performance of the model with median daily Nash-Sutcliffe Efficiency (NSE) of 0.64 and median annual bias of less than 1% for the period of calibration (1970-1991) and median daily NSE of 0.69 and median annual bias of 12% for validation period (1992-2014). The results have demonstrated that the performance of the model is less satisfactory when the key processes such as overbank flow, groundwater seepage and irrigation diversion are switched off. The AWRA-R model, which has been operationalised by the Australian Bureau of Meteorology for continental scale water accounting, has contributed to improvements in the national water account by substantially reducing accounted different volume (gain/loss).

  2. A simulation model of hospital management based on cost accounting analysis according to disease.

    Science.gov (United States)

    Tanaka, Koji; Sato, Junzo; Guo, Jinqiu; Takada, Akira; Yoshihara, Hiroyuki

    2004-12-01

    Since a little before 2000, hospital cost accounting has been increasingly performed at Japanese national university hospitals. At Kumamoto University Hospital, for instance, departmental costs have been analyzed since 2000. And, since 2003, the cost balance has been obtained according to certain diseases for the preparation of Diagnosis-Related Groups and Prospective Payment System. On the basis of these experiences, we have constructed a simulation model of hospital management. This program has worked correctly at repeated trials and with satisfactory speed. Although there has been room for improvement of detailed accounts and cost accounting engine, the basic model has proved satisfactory. We have constructed a hospital management model based on the financial data of an existing hospital. We will later improve this program from the viewpoint of construction and using more various data of hospital management. A prospective outlook may be obtained for the practical application of this hospital management model.

  3. Rare regions of the susceptible-infected-susceptible model on Barabási-Albert networks.

    Science.gov (United States)

    Ódor, Géza

    2013-04-01

    I extend a previous work to susceptible-infected-susceptible (SIS) models on weighted Barabási-Albert scale-free networks. Numerical evidence is provided that phases with slow, power-law dynamics emerge as the consequence of quenched disorder and tree topologies studied previously with the contact process. I compare simulation results with spectral analysis of the networks and show that the quenched mean-field (QMF) approximation provides a reliable, relatively fast method to explore activity clustering. This suggests that QMF can be used for describing rare-region effects due to network inhomogeneities. Finite-size study of the QMF shows the expected disappearance of the epidemic threshold λ(c) in the thermodynamic limit and an inverse participation ratio ~0.25, meaning localization in case of disassortative weight scheme. Contrarily, for the multiplicative weights and the unweighted trees, this value vanishes in the thermodynamic limit, suggesting only weak rare-region effects in agreement with the dynamical simulations. Strong corrections to the mean-field behavior in case of disassortative weights explains the concave shape of the order parameter ρ(λ) at the transition point. Application of this method to other models may reveal interesting rare-region effects, Griffiths phases as the consequence of quenched topological heterogeneities.

  4. Towards ecosystem accounting: a comprehensive approach to modelling multiple hydrological ecosystem services

    Science.gov (United States)

    Duku, C.; Rathjens, H.; Zwart, S. J.; Hein, L.

    2015-10-01

    Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. One of the specific features of ecosystem accounting is the distinction between the capacity and the flow of ecosystem services. Ecohydrological modelling to support ecosystem accounting requires considering among others physical and mathematical representation of ecohydrological processes, spatial heterogeneity of the ecosystem, temporal resolution, and required model accuracy. This study examines how a spatially explicit ecohydrological model can be used to analyse multiple hydrological ecosystem services in line with the ecosystem accounting framework. We use the Upper Ouémé watershed in Benin as a test case to demonstrate our approach. The Soil Water and Assessment Tool (SWAT), which has been configured with a grid-based landscape discretization and further enhanced to simulate water flow across the discretized landscape units, is used to simulate the ecohydrology of the Upper Ouémé watershed. Indicators consistent with the ecosystem accounting framework are used to map and quantify the capacities and the flows of multiple hydrological ecosystem services based on the model outputs. Biophysical ecosystem accounts are subsequently set up based on the spatial estimates of hydrological ecosystem services. In addition, we conduct trend analysis statistical tests on biophysical ecosystem accounts to identify trends in changes in the capacity of the watershed ecosystems to provide service flows. We show that the integration of hydrological ecosystem services into an ecosystem accounting framework provides relevant information on ecosystems and hydrological ecosystem services at appropriate scales suitable for decision-making.

  5. School Board Improvement Plans in Relation to the AIP Model of Educational Accountability: A Content Analysis

    Science.gov (United States)

    van Barneveld, Christina; Stienstra, Wendy; Stewart, Sandra

    2006-01-01

    For this study we analyzed the content of school board improvement plans in relation to the Achievement-Indicators-Policy (AIP) model of educational accountability (Nagy, Demeris, & van Barneveld, 2000). We identified areas of congruence and incongruence between the plans and the model. Results suggested that the content of the improvement…

  6. Predicting habitat suitability for rare plants at local spatial scales using a species distribution model.

    Science.gov (United States)

    Gogol-Prokurat, Melanie

    2011-01-01

    If species distribution models (SDMs) can rank habitat suitability at a local scale, they may be a valuable conservation planning tool for rare, patchily distributed species. This study assessed the ability of Maxent, an SDM reported to be appropriate for modeling rare species, to rank habitat suitability at a local scale for four edaphic endemic rare plants of gabbroic soils in El Dorado County, California, and examined the effects of grain size, spatial extent, and fine-grain environmental predictors on local-scale model accuracy. Models were developed using species occurrence data mapped on public lands and were evaluated using an independent data set of presence and absence locations on surrounding lands, mimicking a typical conservation-planning scenario that prioritizes potential habitat on unsurveyed lands surrounding known occurrences. Maxent produced models that were successful at discriminating between suitable and unsuitable habitat at the local scale for all four species, and predicted habitat suitability values were proportional to likelihood of occurrence or population abundance for three of four species. Unfortunately, models with the best discrimination (i.e., AUC) were not always the most useful for ranking habitat suitability. The use of independent test data showed metrics that were valuable for evaluating which variables and model choices (e.g., grain, extent) to use in guiding habitat prioritization for conservation of these species. A goodness-of-fit test was used to determine whether habitat suitability values ranked habitat suitability on a continuous scale. If they did not, a minimum acceptable error predicted area criterion was used to determine the threshold for classifying habitat as suitable or unsuitable. I found a trade-off between model extent and the use of fine-grain environmental variables: goodness of fit was improved at larger extents, and fine-grain environmental variables improved local-scale accuracy, but fine-grain variables

  7. Accounting for imperfect forward modeling in geophysical inverse problems — Exemplified for crosshole tomography

    DEFF Research Database (Denmark)

    Hansen, Thomas Mejer; Cordua, Knud Skou; Holm Jacobsen, Bo

    2014-01-01

    forward models, can be more than an order of magnitude larger than the measurement uncertainty. We also found that the modeling error is strongly linked to the spatial variability of the assumed velocity field, i.e., the a priori velocity model.We discovered some general tools by which the modeling error...... synthetic ground-penetrating radar crosshole tomographic inverse problems. Ignoring the modeling error can lead to severe artifacts, which erroneously appear to be well resolved in the solution of the inverse problem. Accounting for the modeling error leads to a solution of the inverse problem consistent...

  8. Accounting for uncertainty in ecological analysis: the strengths and limitations of hierarchical statistical modeling.

    Science.gov (United States)

    Cressie, Noel; Calder, Catherine A; Clark, James S; Ver Hoef, Jay M; Wikle, Christopher K

    2009-04-01

    Analyses of ecological data should account for the uncertainty in the process(es) that generated the data. However, accounting for these uncertainties is a difficult task, since ecology is known for its complexity. Measurement and/or process errors are often the only sources of uncertainty modeled when addressing complex ecological problems, yet analyses should also account for uncertainty in sampling design, in model specification, in parameters governing the specified model, and in initial and boundary conditions. Only then can we be confident in the scientific inferences and forecasts made from an analysis. Probability and statistics provide a framework that accounts for multiple sources of uncertainty. Given the complexities of ecological studies, the hierarchical statistical model is an invaluable tool. This approach is not new in ecology, and there are many examples (both Bayesian and non-Bayesian) in the literature illustrating the benefits of this approach. In this article, we provide a baseline for concepts, notation, and methods, from which discussion on hierarchical statistical modeling in ecology can proceed. We have also planted some seeds for discussion and tried to show where the practical difficulties lie. Our thesis is that hierarchical statistical modeling is a powerful way of approaching ecological analysis in the presence of inevitable but quantifiable uncertainties, even if practical issues sometimes require pragmatic compromises.

  9. Optimization of Actuarial Model for Individual Account of Rural Social Pension Insurance

    Institute of Scientific and Technical Information of China (English)

    Wenxian; CAO

    2013-01-01

    This paper firstly analyzes different payment methods of individual account and the pension replacement rate under the pension payment method.Results show that it will be more scientific and reasonable for the individual account of new rural social pension insurance to adopt the actuarial model of payment according to proportion of income and periodic prestation at variable amount.The Guiding Opinions on New Rural Social Pension Insurance sets forth individual account should be paid at fixed amount,and the insured voluntarily selects payment level as per criteria set by the State.The monthly calculation and distribution amount of pension is the total amount of individual account divided by139.Therefore,it should start from continuation of policies and make adjustment of payment level in accordance with growth of per capita net income of rural residents.When condition permits,it is expected to realize transition to payment as per income proportion and periodic prestation at variable amount.

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

    Science.gov (United States)

    Krac, Ewa; Górecki, Krzysztof

    2016-01-01

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

  11. Shadow Segmentation and Augmentation Using á-overlay Models that Account for Penumbra

    DEFF Research Database (Denmark)

    Nielsen, Michael; Madsen, Claus B.

    2006-01-01

    that an augmented virtual object can cast an exact shadow. The penumbras (half-shadows) must be taken into account so that we can model the soft shadows.We hope to achieve this by modelling the shadow regions (umbra and penumbra alike) with a transparent overlay. This paper reviews the state-of-the-art shadow...... theories and presents two overlay models. These are analyzed analytically in relation to color theory and tangibility....

  12. A Neuronal Model of Predictive Coding Accounting for the Mismatch Negativity

    OpenAIRE

    Wacongne, Catherine; Changeux, Jean-Pierre; Dehaene, Stanislas

    2012-01-01

    International audience; The mismatch negativity (MMN) is thought to index the activation of specialized neural networks for active prediction and deviance detection. However, a detailed neuronal model of the neurobiological mechanisms underlying the MMN is still lacking, and its computational foundations remain debated. We propose here a detailed neuronal model of auditory cortex, based on predictive coding, that accounts for the critical features of MMN. The model is entirely composed of spi...

  13. A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

    DEFF Research Database (Denmark)

    Jensen, Ninna Reitzel; Schomacker, Kristian Juul

    2015-01-01

    Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death......, disability, etc. In our treatment of participating life insurance, we have special focus on the bonus schemes “consolidation” and “additional benefits”, and one goal is to formalize how these work and interact. Another goal is to describe similarities and differences between participating life insurance...... model by conducting scenario analysis based on Monte Carlo simulation, but the model applies to scenarios in general and to worst-case and best-estimate scenarios in particular. In addition to easy computations, our model offers a common framework for the valuation of life insurance payments across...

  14. The Anachronism of the Local Public Accountancy Determinate by the Accrual European Model

    Directory of Open Access Journals (Sweden)

    Riana Iren RADU

    2009-01-01

    Full Text Available Placing the European accrual model upon cash accountancy model,presently used in Romania, at the level of the local communities, makespossible that the anachronism of the model to manifest itself on the discussion’sconcentration at the nominalization about the model’s inclusion in everydaypublic practice. The basis of the accrual model were first defined in the lawregarding the commercial societies adopted in Great Britain in 1985, when theydetermined that all income and taxes referring to the financial year “will betaken into consideration without any boundary to the reception or paymentdate.”1 The accrual model in accountancy needs the recording of the non-casheffects in transactions or financial events for their appearance periods and not inany generated cash, received or paid. The business development was the basisfor “sophistication” of the recordings of the transactions and financial events,being prerequisite for recording the debtors’ or creditors’ sums.

  15. Excited state absorption in glasses activated with rare earth ions: Experiment and modeling

    Science.gov (United States)

    Piatkowski, Dawid; Mackowski, Sebastian

    2012-10-01

    We present semiempirical approach based on the Judd-Ofelt theory and apply it for modeling the spectral properties of fluoride glasses activated with the rare earth (RE) ions. This method provide a powerful tool for simulating both ground state absorption (GSA) and excited state absorption (ESA) spectra of RE ions, e.g. Nd3+, Ho3+, Er3+ and Tm3+ in the ZBLAN glass matrix. The results of theoretical calculations correspond to the experimentally measured data. We also demonstrate that the spectra obtained using the presented approach are applicable in the analysis of up-conversion excitation schemes in these optoelectronically relevant materials.

  16. Dynamics of domain walls with lines in rare-earth orthoferrites in magnetic and electric fields with exchange relaxation processes taken into account

    Science.gov (United States)

    Ekomasov, E. G.

    2003-08-01

    The influence of exchange relaxation on the dynamics of domain walls with a "fine structure" in rare-earth orthoferrites in the presence of external magnetic and electric fields is investigated. A system of differential equations is obtained which describe the dynamics of a domain wall with a solitary line. The dependence of the steady-state velocity of the domain wall and line on the values of the relaxation parameters and on the components of the magnetic and electric fields is found. The results are compared with the known experimental results.

  17. A model for genetic and epigenetic regulatory networks identifies rare pathways for transcription factor induced pluripotency

    Science.gov (United States)

    Artyomov, Maxim; Meissner, Alex; Chakraborty, Arup

    2010-03-01

    Most cells in an organism have the same DNA. Yet, different cell types express different proteins and carry out different functions. This is because of epigenetic differences; i.e., DNA in different cell types is packaged distinctly, making it hard to express certain genes while facilitating the expression of others. During development, upon receipt of appropriate cues, pluripotent embryonic stem cells differentiate into diverse cell types that make up the organism (e.g., a human). There has long been an effort to make this process go backward -- i.e., reprogram a differentiated cell (e.g., a skin cell) to pluripotent status. Recently, this has been achieved by transfecting certain transcription factors into differentiated cells. This method does not use embryonic material and promises the development of patient-specific regenerative medicine, but it is inefficient. The mechanisms that make reprogramming rare, or even possible, are poorly understood. We have developed the first computational model of transcription factor-induced reprogramming. Results obtained from the model are consistent with diverse observations, and identify the rare pathways that allow reprogramming to occur. If validated, our model could be further developed to design optimal strategies for reprogramming and shed light on basic questions in biology.

  18. Model Application of Accounting Information Systems of Spare Parts Sales and Purchase on Car Service Company

    Directory of Open Access Journals (Sweden)

    Lianawati Christian

    2015-12-01

    Full Text Available The purpose of this research is to analyze accounting information systems of sales and purchases of spare parts in general car service companies and to identify the problems encountered and the needs of necessary information. This research used literature study to collect data, field study with observation, and design using UML (Unified Modeling Language with activity diagrams, class diagrams, use case diagrams, database design, form design, display design, draft reports. The result achieved is an application model of accounting information systems of sales and purchases of spare parts in general car service companies. As a conclusion, the accounting information systems of sales and purchases provides ease for management to obtain information quickly and easily as well as the presentation of reports quickly and accurately.

  19. Extension of the gurson model accounting for the void size effect

    Institute of Scientific and Technical Information of China (English)

    Jie Wen; Keh-Chih Hwang; Yonggang Huang

    2005-01-01

    A continuum model of solids with cylindrical microvoids is proposed based on the Taylor dislocation model.The model is an extension of Gurson model in the sense that the void size effect is accounted for. Beside the void volume fraction f, the intrinsic material length l becomes a parameter representing voids since the void size comes into play in the Gurson model. Approximate yield functions in analytic forms are suggested for both solids with cylindrical microvoids and with spherical microvoids. The application to uniaxial tension curves shows a precise agreement between the approximate analytic yield function and the "exact" parametric form of integrals.

  20. Rare baryonic decays $\\Lambda_b \\to \\Lambda l^+ l^-$ in the TTM model

    CERN Document Server

    Wen, Yan-Li; Zhang, Jiao

    2013-01-01

    In the framework of the top triangle moose $(TTM)$ model, we analyze the rare decays $\\Lambda_{b}\\rightarrow \\Lambda l^{+}l^{-} (l=e,\\mu,\\tau)$ by using the form factors calculated in full $QCD$. We calculate the contributions of the new particles predicted by this model to observables, such as the branching ratios, forward-backward asymmetry ($A_{FB}$) and polarizations related these decay processes. We find that, in wide range of the parameter space, the values of the branching ratios are enhanced by one order of magnitude comparing to the $SM$ predictions. This model can also produce significant corrections to $A_{FB}$, normal polarization $P_N$ and transversal polarization $P_T$.

  1. A Two-Account Life Insurance Model for Scenario-Based Valuation Including Event Risk

    Directory of Open Access Journals (Sweden)

    Ninna Reitzel Jensen

    2015-06-01

    Full Text Available Using a two-account model with event risk, we model life insurance contracts taking into account both guaranteed and non-guaranteed payments in participating life insurance as well as in unit-linked insurance. Here, event risk is used as a generic term for life insurance events, such as death, disability, etc. In our treatment of participating life insurance, we have special focus on the bonus schemes “consolidation” and “additional benefits”, and one goal is to formalize how these work and interact. Another goal is to describe similarities and differences between participating life insurance and unit-linked insurance. By use of a two-account model, we are able to illustrate general concepts without making the model too abstract. To allow for complicated financial markets without dramatically increasing the mathematical complexity, we focus on economic scenarios. We illustrate the use of our model by conducting scenario analysis based on Monte Carlo simulation, but the model applies to scenarios in general and to worst-case and best-estimate scenarios in particular. In addition to easy computations, our model offers a common framework for the valuation of life insurance payments across product types. This enables comparison of participating life insurance products and unit-linked insurance products, thus building a bridge between the two different ways of formalizing life insurance products. Finally, our model distinguishes itself from the existing literature by taking into account the Markov model for the state of the policyholder and, hereby, facilitating event risk.

  2. Accounting for environmental variability, modeling errors, and parameter estimation uncertainties in structural identification

    Science.gov (United States)

    Behmanesh, Iman; Moaveni, Babak

    2016-07-01

    This paper presents a Hierarchical Bayesian model updating framework to account for the effects of ambient temperature and excitation amplitude. The proposed approach is applied for model calibration, response prediction and damage identification of a footbridge under changing environmental/ambient conditions. The concrete Young's modulus of the footbridge deck is the considered updating structural parameter with its mean and variance modeled as functions of temperature and excitation amplitude. The identified modal parameters over 27 months of continuous monitoring of the footbridge are used to calibrate the updating parameters. One of the objectives of this study is to show that by increasing the levels of information in the updating process, the posterior variation of the updating structural parameter (concrete Young's modulus) is reduced. To this end, the calibration is performed at three information levels using (1) the identified modal parameters, (2) modal parameters and ambient temperatures, and (3) modal parameters, ambient temperatures, and excitation amplitudes. The calibrated model is then validated by comparing the model-predicted natural frequencies and those identified from measured data after deliberate change to the structural mass. It is shown that accounting for modeling error uncertainties is crucial for reliable response prediction, and accounting only the estimated variability of the updating structural parameter is not sufficient for accurate response predictions. Finally, the calibrated model is used for damage identification of the footbridge.

  3. Business Models, Accounting and Billing Concepts in Grid-Aware Networks

    Science.gov (United States)

    Kotrotsos, Serafim; Racz, Peter; Morariu, Cristian; Iskioupi, Katerina; Hausheer, David; Stiller, Burkhard

    The emerging Grid Economy, shall set new challenges for the network. More and more literature underlines the significance of network - awareness for efficient and effective grid services. Following this path to Grid evolution, this paper identifies some key challenges in the areas of business modeling, accounting and billing and proposes an architecture that addresses them.

  4. Hybrid Markov-mass action law model for cell activation by rare binding events: Application to calcium induced vesicular release at neuronal synapses

    Science.gov (United States)

    Guerrier, Claire; Holcman, David

    2016-10-01

    Binding of molecules, ions or proteins to small target sites is a generic step of cell activation. This process relies on rare stochastic events where a particle located in a large bulk has to find small and often hidden targets. We present here a hybrid discrete-continuum model that takes into account a stochastic regime governed by rare events and a continuous regime in the bulk. The rare discrete binding events are modeled by a Markov chain for the encounter of small targets by few Brownian particles, for which the arrival time is Poissonian. The large ensemble of particles is described by mass action laws. We use this novel model to predict the time distribution of vesicular release at neuronal synapses. Vesicular release is triggered by the binding of few calcium ions that can originate either from the synaptic bulk or from the entry through calcium channels. We report here that the distribution of release time is bimodal although it is triggered by a single fast action potential. While the first peak follows a stimulation, the second corresponds to the random arrival over much longer time of ions located in the synaptic terminal to small binding vesicular targets. To conclude, the present multiscale stochastic modeling approach allows studying cellular events based on integrating discrete molecular events over several time scales.

  5. An analytical model for particulate reinforced composites (PRCs) taking account of particle debonding and matrix cracking

    Science.gov (United States)

    Jiang, Yunpeng

    2016-10-01

    In this work, a simple micromechanics-based model was developed to describe the overall stress-strain relations of particulate reinforced composites (PRCs), taking into account both particle debonding and matrix cracking damage. Based on the secant homogenization frame, the effective compliance tensor could be firstly given for the perfect composites without any damage. The progressive interface debonding damage is controlled by a Weibull probability function, and then the volume fraction of detached particles is involved in the equivalent compliance tensor to account for the impact of particle debonding. The matrix cracking was introduced in the present model to embody the stress softening stage in the deformation of PRCs. The analytical model was firstly verified by comparing with the corresponding experiment, and then parameter analyses were conducted. This modeling will shed some light on optimizing the microstructures in effectively improving the mechanical behaviors of PRCs.

  6. Bayesian hierarchical model used to analyze regression between fish body size and scale size: application to rare fish species Zingel asper

    Directory of Open Access Journals (Sweden)

    Fontez B.

    2014-04-01

    Full Text Available Back-calculation allows to increase available data on fish growth. The accuracy of back-calculation models is of paramount importance for growth analysis. Frequentist and Bayesian hierarchical approaches were used for regression between fish body size and scale size for the rare fish species Zingel asper. The Bayesian approach permits more reliable estimation of back-calculated size, taking into account biological information and cohort variability. This method greatly improves estimation of back-calculated length when sampling is uneven and/or small.

  7. A WEAKLY NONLINEAR WATER WAVE MODEL TAKING INTO ACCOUNT DISPERSION OF WAVE PHASE VELOCITY

    Institute of Scientific and Technical Information of China (English)

    李瑞杰; 李东永

    2002-01-01

    This paper presents a weakly nonlinear water wave model using a mild slope equation and a new explicit formulation which takes into account dispersion of wave phase velocity, approximates Hedges' (1987) nonlinear dispersion relationship, and accords well with the original empirical formula. Comparison of the calculating results with those obtained from the experimental data and those obtained from linear wave theory showed that the present water wave model considering the dispersion of phase velocity is rational and in good agreement with experiment data.

  8. Modeling Spatial Distribution of a Rare and Endangered Plant Species (Brainea insignis) in Central Taiwan

    Science.gov (United States)

    Wang, W.-C.; Lo, N.-J.; Chang, W.-I.; Huang, K.-Y.

    2012-07-01

    With an increase in the rate of species extinction, we should choose right methods that are sustainable on the basis of appropriate science and human needs to conserve ecosystems and rare species. Species distribution modeling (SDM) uses 3S technology and statistics and becomes increasingly important in ecology. Brainea insignis (cycad-fern, CF) has been categorized a rare, endangered plant species, and thus was chosen as a target for the study. Five sampling schemes were created with different combinations of CF samples collected from three sites in Huisun forest station and one site, 10 km farther north from Huisun. Four models, MAXENT, GARP, generalized linear models (GLM), and discriminant analysis (DA), were developed based on topographic variables, and were evaluated by five sampling schemes. The accuracy of MAXENT was the highest, followed by GLM and GARP, and DA was the lowest. More importantly, they can identify the potential habitat less than 10% of the study area in the first round of SDM, thereby prioritizing either the field-survey area where microclimatic, edaphic or biotic data can be collected for refining predictions of potential habitat in the later rounds of SDM or search areas for new population discovery. However, it was shown unlikely to extend spatial patterns of CFs from one area to another with a big separation or to a larger area by predictive models merely based on topographic variables. Follow-up studies will attempt to incorporate proxy indicators that can be extracted from hyperspectral images or LIDAR DEM and substitute for direct parameters to make predictive models applicable on a broader scale.

  9. Accounting for model error due to unresolved scales within ensemble Kalman filtering

    CERN Document Server

    Mitchell, Lewis

    2014-01-01

    We propose a method to account for model error due to unresolved scales in the context of the ensemble transform Kalman filter (ETKF). The approach extends to this class of algorithms the deterministic model error formulation recently explored for variational schemes and extended Kalman filter. The model error statistic required in the analysis update is estimated using historical reanalysis increments and a suitable model error evolution law. Two different versions of the method are described; a time-constant model error treatment where the same model error statistical description is time-invariant, and a time-varying treatment where the assumed model error statistics is randomly sampled at each analysis step. We compare both methods with the standard method of dealing with model error through inflation and localization, and illustrate our results with numerical simulations on a low order nonlinear system exhibiting chaotic dynamics. The results show that the filter skill is significantly improved through th...

  10. Accounting for covariate measurement error in a Cox model analysis of recurrence of depression.

    Science.gov (United States)

    Liu, K; Mazumdar, S; Stone, R A; Dew, M A; Houck, P R; Reynolds, C F

    2001-01-01

    When a covariate measured with error is used as a predictor in a survival analysis using the Cox model, the parameter estimate is usually biased. In clinical research, covariates measured without error such as treatment procedure or sex are often used in conjunction with a covariate measured with error. In a randomized clinical trial of two types of treatments, we account for the measurement error in the covariate, log-transformed total rapid eye movement (REM) activity counts, in a Cox model analysis of the time to recurrence of major depression in an elderly population. Regression calibration and two variants of a likelihood-based approach are used to account for measurement error. The likelihood-based approach is extended to account for the correlation between replicate measures of the covariate. Using the replicate data decreases the standard error of the parameter estimate for log(total REM) counts while maintaining the bias reduction of the estimate. We conclude that covariate measurement error and the correlation between replicates can affect results in a Cox model analysis and should be accounted for. In the depression data, these methods render comparable results that have less bias than the results when measurement error is ignored.

  11. Review of searches for rare processes and physics beyond the Standard Model at HERA

    Energy Technology Data Exchange (ETDEWEB)

    South, David M. [Deutsches Elektronen Synchrotron, Hamburg (Germany); Turcato, Monica [Hamburg University, Institute of Experimental Physics, Hamburg (Germany); European X-ray Free-Electron Laser Facility GmbH, Hamburg (Germany)

    2016-06-15

    The electron-proton collisions collected by the H1 and ZEUS experiments at HERA comprise a unique particle physics data set, and a comprehensive range of measurements has been performed to provide new insight into the structure of the proton. The high centre of mass energy at HERA has also allowed rare processes to be studied, including the production of W and Z{sup 0} bosons and events with multiple leptons in the final state. The data have also opened up a new domain to searches for physics beyond the Standard Model including contact interactions, leptoquarks, excited fermions and a number of supersymmetric models. This review presents a summary of such results, where the analyses reported correspond to an integrated luminosity of up to 1 fb{sup -1}, representing the complete data set recorded by the H1 and ZEUS experiments. (orig.)

  12. Review of searches for rare processes and physics beyond the Standard Model at HERA

    Science.gov (United States)

    South, David M.; Turcato, Monica

    2016-06-01

    The electron-proton collisions collected by the H1 and ZEUS experiments at HERA comprise a unique particle physics data set, and a comprehensive range of measurements has been performed to provide new insight into the structure of the proton. The high centre of mass energy at HERA has also allowed rare processes to be studied, including the production of W and Z0 bosons and events with multiple leptons in the final state. The data have also opened up a new domain to searches for physics beyond the Standard Model including contact interactions, leptoquarks, excited fermions and a number of supersymmetric models. This review presents a summary of such results, where the analyses reported correspond to an integrated luminosity of up to 1 fb^{-1}, representing the complete data set recorded by the H1 and ZEUS experiments.

  13. Review of Searches for Rare Processes and Physics Beyond the Standard Model at HERA

    CERN Document Server

    South, David M

    2016-01-01

    The electron-proton collisions collected by the H1 and ZEUS experiments at HERA comprise a unique particle physics data set, and a comprehensive range of measurements has been performed to provide new insight into the structure of the proton. The high centre of mass energy at HERA has also allowed rare processes to be studied, including the production of W and Z bosons and events with multiple leptons in the final state. The data have also opened up a new domain to searches for physics beyond the Standard Model including contact interactions, leptoquarks, excited fermions and a number of supersymmetric models. This review presents a summary of such results, where the analyses reported correspond to an integrated luminosity of up to 1 fb^-1, representing the complete data set recorded by the H1 and ZEUS experiments.

  14. Predictive distribution modeling for rare Himalayan medicinal plant Berberis aristata DC.

    Science.gov (United States)

    Ray, Rajasri; Gururaja, K V; Ramchandra, T V

    2011-11-01

    Predictive distribution modelling of Berberis aristata DC, a rare threatened plant with high medicinal values has been done with an aim to understand its potential distribution zones in Indian Himalayan region. Bioclimatic and topographic variables were used to develop the distribution model with the help of three different algorithms viz. Genetic Algorithm for Rule-set Production (GARP), Bioclim and Maximum entropy (MaxEnt). Maximum entropy has predicted wider potential distribution (10.36%) compared to GARP (4.63%) and Bioclim (2.44%). Validation confirms that these outputs are comparable to the present distribution pattern of the B. aristata. This exercise highlights that this species favours Western Himalaya. However, GARP and MaxEnt's prediction of Eastern Himalayan states (i. e. Arunachal Pradesh, Nagaland and Manipur) are also identified as potential occurrence places require further exploration.

  15. Cost accounting models used for price-setting of health services: an international review.

    Science.gov (United States)

    Raulinajtys-Grzybek, Monika

    2014-12-01

    The aim of the article was to present and compare cost accounting models which are used in the area of healthcare for pricing purposes in different countries. Cost information generated by hospitals is further used by regulatory bodies for setting or updating prices of public health services. The article presents a set of examples from different countries of the European Union, Australia and the United States and concentrates on DRG-based payment systems as they primarily use cost information for pricing. Differences between countries concern the methodology used, as well as the data collection process and the scope of the regulations on cost accounting. The article indicates that the accuracy of the calculation is only one of the factors that determine the choice of the cost accounting methodology. Important aspects are also the selection of the reference hospitals, precise and detailed regulations and the existence of complex healthcare information systems in hospitals.

  16. THE ROLE OF TECHNICAL CONSUMPTION CALCULATION MODELS ON ACCOUNTING INFORMATION SYSTEMS OF PUBLIC UTILITIES SERVICES OPERATORS

    Directory of Open Access Journals (Sweden)

    GHEORGHE CLAUDIU FEIES

    2012-05-01

    Full Text Available After studying how the operators’ management works, an influence of the specific activities of public utilities on their financial accounting system can be noticed. The asymmetry of these systems is also present, resulting from organization and specific services, which implies a close link between the financial accounting system and the specialized technical department. The research methodology consists in observing specific activities of public utility operators and their influence on information system and analysis views presented in the context of published work in some journals. It analyses the impact of technical computing models used by public utility community services on the financial statements and therefore the information provided by accounting information system stakeholders.

  17. Modeling of Accounting Doctoral Thesis with Emphasis on Solution for Financial Problems

    Directory of Open Access Journals (Sweden)

    F. Mansoori

    2015-02-01

    Full Text Available By passing the instruction period and increase of graduate students and also research budget, knowledge of accounting in Iran entered to the field of research in a way that number of accounting projects has been implemented in the real world. Because of that different experience in implementing the accounting standards were achieved. So, it was expected the mentioned experiences help to solve the financial problems in country, in spite of lots of efforts which were done for researching; we still have many financial and accounting problems in our country. PHD projects could be considered as one of the important solutions to improve the University subjects including accounting. PHD projects are considered as team work job and it will be legitimate by supervisor teams in universities.It is obvious that applied projects should solve part of the problems in accounting field but unfortunately it is not working in the real world. The question which came in to our mind is how come that the out put of the applied and knowledge base projects could not make the darkness of the mentioned problems clear and also why politicians in difficult situations prefer to use their own previous experiences in important decision makings instead of using the consultant’s knowledge base suggestions.In this research I’m going to study, the reasons behind that prevent the applied PHD projects from success in real world which relates to the point of view that consider the political suggestions which are out put of knowledge base projects are not qualified enough for implementation. For this purpose, the indicators of an applied PHD project were considered and 110 vise people were categorized the mentioned indicators and then in a comprehensive study other applied PHD accounting projects were compared to each other.As result, in this study problems of the studied researches were identified and a proper and applied model for creating applied research was developed.

  18. A selection model for accounting for publication bias in a full network meta-analysis.

    Science.gov (United States)

    Mavridis, Dimitris; Welton, Nicky J; Sutton, Alex; Salanti, Georgia

    2014-12-30

    Copas and Shi suggested a selection model to explore the potential impact of publication bias via sensitivity analysis based on assumptions for the probability of publication of trials conditional on the precision of their results. Chootrakool et al. extended this model to three-arm trials but did not fully account for the implications of the consistency assumption, and their model is difficult to generalize for complex network structures with more than three treatments. Fitting these selection models within a frequentist setting requires maximization of a complex likelihood function, and identification problems are common. We have previously presented a Bayesian implementation of the selection model when multiple treatments are compared with a common reference treatment. We now present a general model suitable for complex, full network meta-analysis that accounts for consistency when adjusting results for publication bias. We developed a design-by-treatment selection model to describe the mechanism by which studies with different designs (sets of treatments compared in a trial) and precision may be selected for publication. We fit the model in a Bayesian setting because it avoids the numerical problems encountered in the frequentist setting, it is generalizable with respect to the number of treatments and study arms, and it provides a flexible framework for sensitivity analysis using external knowledge. Our model accounts for the additional uncertainty arising from publication bias more successfully compared to the standard Copas model or its previous extensions. We illustrate the methodology using a published triangular network for the failure of vascular graft or arterial patency.

  19. Modeling of vapor intrusion from hydrocarbon-contaminated sources accounting for aerobic and anaerobic biodegradation

    Science.gov (United States)

    Verginelli, Iason; Baciocchi, Renato

    2011-11-01

    A one-dimensional steady state vapor intrusion model including both anaerobic and oxygen-limited aerobic biodegradation was developed. The aerobic and anaerobic layer thickness are calculated by stoichiometrically coupling the reactive transport of vapors with oxygen transport and consumption. The model accounts for the different oxygen demand in the subsurface required to sustain the aerobic biodegradation of the compound(s) of concern and for the baseline soil oxygen respiration. In the case of anaerobic reaction under methanogenic conditions, the model accounts for the generation of methane which leads to a further oxygen demand, due to methane oxidation, in the aerobic zone. The model was solved analytically and applied, using representative parameter ranges and values, to identify under which site conditions the attenuation of hydrocarbons migrating into indoor environments is likely to be significant. Simulations were performed assuming a soil contaminated by toluene only, by a BTEX mixture, by Fresh Gasoline and by Weathered Gasoline. The obtained results have shown that for several site conditions oxygen concentration below the building is sufficient to sustain aerobic biodegradation. For these scenarios the aerobic biodegradation is the primary mechanism of attenuation, i.e. anaerobic contribution is negligible and a model accounting just for aerobic biodegradation can be used. On the contrary, in all cases where oxygen is not sufficient to sustain aerobic biodegradation alone (e.g. highly contaminated sources), anaerobic biodegradation can significantly contribute to the overall attenuation depending on the site specific conditions.

  20. Modeling of vapor intrusion from hydrocarbon-contaminated sources accounting for aerobic and anaerobic biodegradation.

    Science.gov (United States)

    Verginelli, Iason; Baciocchi, Renato

    2011-11-01

    A one-dimensional steady state vapor intrusion model including both anaerobic and oxygen-limited aerobic biodegradation was developed. The aerobic and anaerobic layer thickness are calculated by stoichiometrically coupling the reactive transport of vapors with oxygen transport and consumption. The model accounts for the different oxygen demand in the subsurface required to sustain the aerobic biodegradation of the compound(s) of concern and for the baseline soil oxygen respiration. In the case of anaerobic reaction under methanogenic conditions, the model accounts for the generation of methane which leads to a further oxygen demand, due to methane oxidation, in the aerobic zone. The model was solved analytically and applied, using representative parameter ranges and values, to identify under which site conditions the attenuation of hydrocarbons migrating into indoor environments is likely to be significant. Simulations were performed assuming a soil contaminated by toluene only, by a BTEX mixture, by Fresh Gasoline and by Weathered Gasoline. The obtained results have shown that for several site conditions oxygen concentration below the building is sufficient to sustain aerobic biodegradation. For these scenarios the aerobic biodegradation is the primary mechanism of attenuation, i.e. anaerobic contribution is negligible and a model accounting just for aerobic biodegradation can be used. On the contrary, in all cases where oxygen is not sufficient to sustain aerobic biodegradation alone (e.g. highly contaminated sources), anaerobic biodegradation can significantly contribute to the overall attenuation depending on the site specific conditions.

  1. The self-consistent field model for Fermi systems with account of three-body interactions

    Directory of Open Access Journals (Sweden)

    Yu.M. Poluektov

    2015-12-01

    Full Text Available On the basis of a microscopic model of self-consistent field, the thermodynamics of the many-particle Fermi system at finite temperatures with account of three-body interactions is built and the quasiparticle equations of motion are obtained. It is shown that the delta-like three-body interaction gives no contribution into the self-consistent field, and the description of three-body forces requires their nonlocality to be taken into account. The spatially uniform system is considered in detail, and on the basis of the developed microscopic approach general formulas are derived for the fermion's effective mass and the system's equation of state with account of contribution from three-body forces. The effective mass and pressure are numerically calculated for the potential of "semi-transparent sphere" type at zero temperature. Expansions of the effective mass and pressure in powers of density are obtained. It is shown that, with account of only pair forces, the interaction of repulsive character reduces the quasiparticle effective mass relative to the mass of a free particle, and the attractive interaction raises the effective mass. The question of thermodynamic stability of the Fermi system is considered and the three-body repulsive interaction is shown to extend the region of stability of the system with the interparticle pair attraction. The quasiparticle energy spectrum is calculated with account of three-body forces.

  2. Modeling the interaction of electric current and tissue: importance of accounting for time varying electric properties.

    Science.gov (United States)

    Evans, Daniel J; Manwaring, Mark L

    2007-01-01

    Time varying computer models of the interaction of electric current and tissue are very valuable in helping to understand the complexity of the human body and biological tissue. The electrical properties of tissue, permittivity and conductivity, are vital to accurately modeling the interaction of the human tissue with electric current. Past models have represented the electric properties of the tissue as constant or temperature dependent. This paper presents time dependent electric properties that change as a result of tissue damage, temperature, blood flow, blood vessels, and tissue property. Six models are compared to emphasize the importance of accounting for these different tissue properties in the computer model. In particular, incorporating the time varying nature of the electric properties of human tissue into the model leads to a significant increase in tissue damage. An important feature of the model is the feedback loop created between the electric properties, tissue damage, and temperature.

  3. A Rapid Pipeline to Model Rare Neurodevelopmental Disorders with Simultaneous CRISPR/Cas9 Gene Editing.

    Science.gov (United States)

    Bell, Scott; Peng, Huashan; Crapper, Liam; Kolobova, Ilaria; Maussion, Gilles; Vasuta, Cristina; Yerko, Volodymyr; Wong, Tak Pan; Ernst, Carl

    2017-03-01

    The development of targeted therapeutics for rare neurodevelopmental disorders (NDDs) faces significant challenges due to the scarcity of subjects and the difficulty of obtaining human neural cells. Here, we illustrate a rapid, simple protocol by which patient derived cells can be reprogrammed to induced pluripotent stem cells (iPSCs) using an episomal vector and differentiated into neurons. Using this platform enables patient somatic cells to be converted to physiologically active neurons in less than two months with minimal labor. This platform includes a method to combine somatic cell reprogramming with CRISPR/Cas9 gene editing at single cell resolution, which enables the concurrent development of clonal knockout or knock-in models that can be used as isogenic control lines. This platform reduces the logistical barrier for using iPSC technology, allows for the development of appropriate control lines for use in rare neurodevelopmental disease research, and establishes a fundamental component to targeted therapeutics and precision medicine. Stem Cells Translational Medicine 2017;6:886-896.

  4. Multiscale models and stochastic simulation methods for computing rare but key binding events in cell biology

    Energy Technology Data Exchange (ETDEWEB)

    Guerrier, C. [Applied Mathematics and Computational Biology, IBENS, Ecole Normale Supérieure, 46 rue d' Ulm, 75005 Paris (France); Holcman, D., E-mail: david.holcman@ens.fr [Applied Mathematics and Computational Biology, IBENS, Ecole Normale Supérieure, 46 rue d' Ulm, 75005 Paris (France); Mathematical Institute, Oxford OX2 6GG, Newton Institute (United Kingdom)

    2017-07-01

    The main difficulty in simulating diffusion processes at a molecular level in cell microdomains is due to the multiple scales involving nano- to micrometers. Few to many particles have to be simulated and simultaneously tracked while there are exploring a large portion of the space for binding small targets, such as buffers or active sites. Bridging the small and large spatial scales is achieved by rare events representing Brownian particles finding small targets and characterized by long-time distribution. These rare events are the bottleneck of numerical simulations. A naive stochastic simulation requires running many Brownian particles together, which is computationally greedy and inefficient. Solving the associated partial differential equations is also difficult due to the time dependent boundary conditions, narrow passages and mixed boundary conditions at small windows. We present here two reduced modeling approaches for a fast computation of diffusing fluxes in microdomains. The first approach is based on a Markov mass-action law equations coupled to a Markov chain. The second is a Gillespie's method based on the narrow escape theory for coarse-graining the geometry of the domain into Poissonian rates. The main application concerns diffusion in cellular biology, where we compute as an example the distribution of arrival times of calcium ions to small hidden targets to trigger vesicular release.

  5. Multiscale models and stochastic simulation methods for computing rare but key binding events in cell biology

    Science.gov (United States)

    Guerrier, C.; Holcman, D.

    2017-07-01

    The main difficulty in simulating diffusion processes at a molecular level in cell microdomains is due to the multiple scales involving nano- to micrometers. Few to many particles have to be simulated and simultaneously tracked while there are exploring a large portion of the space for binding small targets, such as buffers or active sites. Bridging the small and large spatial scales is achieved by rare events representing Brownian particles finding small targets and characterized by long-time distribution. These rare events are the bottleneck of numerical simulations. A naive stochastic simulation requires running many Brownian particles together, which is computationally greedy and inefficient. Solving the associated partial differential equations is also difficult due to the time dependent boundary conditions, narrow passages and mixed boundary conditions at small windows. We present here two reduced modeling approaches for a fast computation of diffusing fluxes in microdomains. The first approach is based on a Markov mass-action law equations coupled to a Markov chain. The second is a Gillespie's method based on the narrow escape theory for coarse-graining the geometry of the domain into Poissonian rates. The main application concerns diffusion in cellular biology, where we compute as an example the distribution of arrival times of calcium ions to small hidden targets to trigger vesicular release.

  6. Precision tests of the Standard Model using key observables of $CP$ violation and rare decays

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00346274; Albrecht, Johannes

    In this thesis advanced statistical methods are used for precision studies in the flavour sector of the Standard Model of particle physics. The necessary tools are developed and applied to two key measurements of the LHCb experiment: the determination of the CKM angle $\\gamma$ and the search for rare $B^{0} _{s} \\to \\mu^+ \\mu^-$ and $B^0 \\to \\mu^+ \\mu^-$ decays. The CKM angle $\\gamma$ is, for the first time, measured from $B^0 _s \\to D^\\mp _s K^\\pm$ decays using a dataset corresponding to $1\\,\\mathrm{fb}^{-1}$ of $pp$ interactions at a centre-of-mass energy of $\\sqrt{s} = 7\\mathrm{TeV}$. The result of $\\gamma = (115^{+27}_{-43})^{\\circ}$ is then combined with a set of $\\gamma$ measurements in ${B} \\to Dh$ decays resulting in a precision on $\\gamma$ of $<8^{\\circ}$. This result improves the legacy results from the $B$-factories by more than a factor of two. The rare decays $B^{0} _{s} \\to \\mu^+ \\mu^-$ and $B^0 \\to \\mu^+ \\mu^-$ are analysed on a dataset corresponding to $3\\,\\mathrm{fb}^{-1}$ of $pp$ interac...

  7. Meta-analysis of diagnostic tests accounting for disease prevalence: a new model using trivariate copulas.

    Science.gov (United States)

    Hoyer, A; Kuss, O

    2015-05-20

    In real life and somewhat contrary to biostatistical textbook knowledge, sensitivity and specificity (and not only predictive values) of diagnostic tests can vary with the underlying prevalence of disease. In meta-analysis of diagnostic studies, accounting for this fact naturally leads to a trivariate expansion of the traditional bivariate logistic regression model with random study effects. In this paper, a new model is proposed using trivariate copulas and beta-binomial marginal distributions for sensitivity, specificity, and prevalence as an expansion of the bivariate model. Two different copulas are used, the trivariate Gaussian copula and a trivariate vine copula based on the bivariate Plackett copula. This model has a closed-form likelihood, so standard software (e.g., SAS PROC NLMIXED) can be used. The results of a simulation study have shown that the copula models perform at least as good but frequently better than the standard model. The methods are illustrated by two examples.

  8. Efficient modeling of sun/shade canopy radiation dynamics explicitly accounting for scattering

    Directory of Open Access Journals (Sweden)

    P. Bodin

    2011-08-01

    Full Text Available The separation of global radiation (Rg into its direct (Rb and diffuse constituents (Rd is important when modeling plant photosynthesis because a high Rd:Rg ratio has been shown to enhance Gross Primary Production (GPP. To include this effect in vegetation models, the plant canopy must be separated into sunlit and shaded leaves, for example using an explicit 3-dimensional ray tracing model. However, because such models are often too intractable and computationally expensive for theoretical or large scale studies simpler sun-shade approaches are often preferred. A widely used and computationally efficient sun-shade model is a model originally developed by Goudriaan (1977 (GOU, which however does not explicitly account for radiation scattering.

    Here we present a new model based on the GOU model, but which in contrast explicitly simulates radiation scattering by sunlit leaves and the absorption of this radiation by the canopy layers above and below (2-stream approach. Compared to the GOU model our model predicts significantly different profiles of scattered radiation that are in better agreement with measured profiles of downwelling diffuse radiation. With respect to these data our model's performance is equal to a more complex and much slower iterative radiation model while maintaining the simplicity and computational efficiency of the GOU model.

  9. The importance of data quality for generating reliable distribution models for rare, elusive, and cryptic species.

    Science.gov (United States)

    Aubry, Keith B; Raley, Catherine M; McKelvey, Kevin S

    2017-01-01

    The availability of spatially referenced environmental data and species occurrence records in online databases enable practitioners to easily generate species distribution models (SDMs) for a broad array of taxa. Such databases often include occurrence records of unknown reliability, yet little information is available on the influence of data quality on SDMs generated for rare, elusive, and cryptic species that are prone to misidentification in the field. We investigated this question for the fisher (Pekania pennanti), a forest carnivore of conservation concern in the Pacific States that is often confused with the more common Pacific marten (Martes caurina). Fisher occurrence records supported by physical evidence (verifiable records) were available from a limited area, whereas occurrence records of unknown quality (unscreened records) were available from throughout the fisher's historical range. We reserved 20% of the verifiable records to use as a test sample for both models and generated SDMs with each dataset using Maxent. The verifiable model performed substantially better than the unscreened model based on multiple metrics including AUCtest values (0.78 and 0.62, respectively), evaluation of training and test gains, and statistical tests of how well each model predicted test localities. In addition, the verifiable model was consistent with our knowledge of the fisher's habitat relations and potential distribution, whereas the unscreened model indicated a much broader area of high-quality habitat (indices > 0.5) that included large expanses of high-elevation habitat that fishers do not occupy. Because Pacific martens remain relatively common in upper elevation habitats in the Cascade Range and Sierra Nevada, the SDM based on unscreened records likely reflects primarily a conflation of marten and fisher habitat. Consequently, accurate identifications are far more important than the spatial extent of occurrence records for generating reliable SDMs for the

  10. Predictive model for ionic liquid extraction solvents for rare earth elements

    Science.gov (United States)

    Grabda, Mariusz; Oleszek, Sylwia; Panigrahi, Mrutyunjay; Kozak, Dmytro; Eckert, Franck; Shibata, Etsuro; Nakamura, Takashi

    2015-12-01

    The purpose of our study was to select the most effective ionic liquid extraction solvents for dysprosium (III) fluoride using a theoretical approach. Conductor-like Screening Model for Real Solvents (COSMO-RS), based on quantum chemistry and the statistical thermodynamics of predefined DyF3-ionic liquid systems, was applied to reach the target. Chemical potentials of the salt were predicted in 4,400 different ionic liquids. On the base of these predictions set of ionic liquids' ions, manifesting significant decrease of the chemical potentials, were selected. Considering the calculated physicochemical properties (hydrophobicity, viscosity) of the ionic liquids containing these specific ions, the most effective extraction solvents for liquid-liquid extraction of DyF3 were proposed. The obtained results indicate that the COSMO-RS approach can be applied to quickly screen the affinity of any rare earth element for a large number of ionic liquid systems, before extensive experimental tests.

  11. Predictive model for ionic liquid extraction solvents for rare earth elements

    Energy Technology Data Exchange (ETDEWEB)

    Grabda, Mariusz; Oleszek, Sylwia [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2,1-Katahira, 2-Chome, 980-8577 Sendai (Japan); Institute of Environmental Engineering of the Polish Academy of Sciences, ul. M. Sklodowskiej-Curie 34, 41-819, Zabrze (Poland); Panigrahi, Mrutyunjay; Kozak, Dmytro; Shibata, Etsuro; Nakamura, Takashi [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 2,1-Katahira, 2-Chome, 980-8577 Sendai (Japan); Eckert, Franck [COSMOlogic GmbH & Co KG, Imbacher Weg 46, 50379 Leverkusen (Germany)

    2015-12-31

    The purpose of our study was to select the most effective ionic liquid extraction solvents for dysprosium (III) fluoride using a theoretical approach. Conductor-like Screening Model for Real Solvents (COSMO-RS), based on quantum chemistry and the statistical thermodynamics of predefined DyF{sub 3}-ionic liquid systems, was applied to reach the target. Chemical potentials of the salt were predicted in 4,400 different ionic liquids. On the base of these predictions set of ionic liquids’ ions, manifesting significant decrease of the chemical potentials, were selected. Considering the calculated physicochemical properties (hydrophobicity, viscosity) of the ionic liquids containing these specific ions, the most effective extraction solvents for liquid-liquid extraction of DyF{sub 3} were proposed. The obtained results indicate that the COSMO-RS approach can be applied to quickly screen the affinity of any rare earth element for a large number of ionic liquid systems, before extensive experimental tests.

  12. Fractionations of rare earth elements in plants and their conceptive model

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Fractionations of rare earth elements (REEs) and their mechanisms in soybean were studied through application of exogenous mixed REEs under hydroponic conditions. Significant enrichment of middle REEs (MREEs) and heavy REEs (HREEs) was observed in plant roots and leaves respectively, with slight fractionation between light REEs (LREEs) and HREEs in stems. Moreover, the tetrad effect was observed in these organs. Investigations into REE speciation in roots and in the xylem sap using X-ray absorption spectroscopy (XAS) and nanometer-sized TiO2 adsorption techniques, associated with other controlled experiments, demonstrated that REE fractionations should be dominated by fixation mechanism in roots caused by cell wall absorption and phosphate precipitation, and by the combined effects of fixation mechanism and transport mechanism in aboveground parts caused by solution complexation by intrinsic organic ligands. A conceptive model was established for REE fractionations in plants based on the above studies.

  13. Long-range magnetic order in models for rare-earth quasicrystals

    Science.gov (United States)

    Thiem, Stefanie; Chalker, J. T.

    2015-12-01

    We take a two-step theoretical approach to study magnetism of rare-earth quasicrystals by considering Ising spins on quasiperiodic tilings, coupled via Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions. First, we compute RKKY interactions from a tight-binding Hamiltonian defined on the two-dimensional quasiperiodic tilings. We find that the magnetic interactions are frustrated and strongly dependent on the local environment. This results in the formation of clusters with strong bonds at certain patterns of the tilings that repeat quasiperiodically. Second, we examine the statistical mechanics of Ising spins with these RKKY interactions, using extensive Monte Carlo simulations. Although models that have frustrated interactions and lack translational invariance might be expected to display spin-glass behavior, we show that the spin system has a phase transition to low-temperature states with long-range quasiperiodic magnetic order. Additionally, we find that in some of the systems spin clusters can fluctuate much below the ordering temperature.

  14. Drift diffusion model of reward and punishment learning in rare alpha-synuclein gene carriers.

    Science.gov (United States)

    Moustafa, Ahmed A; Kéri, Szabolcs; Polner, Bertalan; White, Corey

    2017-03-20

    To understand the cognitive effects of alpha-synuclein polymorphism, we employed a drift diffusion model (DDM) to analyze reward- and punishment-guided probabilistic learning task data of participants with the rare alpha-synuclein gene duplication and age- and education-matched controls. Overall, the DDM analysis showed that, relative to controls, asymptomatic alpha-synuclein gene duplication carriers had significantly increased learning from negative feedback, while they tended to show impaired learning from positive feedback. No significant differences were found in response caution, response bias, or motor/encoding time. We here discuss the implications of these computational findings to the understanding of the neural mechanism of alpha-synuclein gene duplication.

  15. Rare events and their impact on velocity diffusion in a stochastic Fermi-Ulam model.

    Science.gov (United States)

    Karlis, A K; Diakonos, F K; Constantoudis, V; Schmelcher, P

    2008-10-01

    A simplified version of the stochastic Fermi-Ulam model is investigated in order to elucidate the effect of a class of rare low-velocity events on the velocity diffusion process and consequently Fermi acceleration. The relative fraction of these events, for sufficiently large times, decreases monotonically with increasing variance of the magnitude of the particle velocity. However, a treatment of the diffusion problem which totally neglects these events, gives rise to a glaring inconsistency associated with the mean value of the magnitude of the velocity in the ensemble. We propose a general scheme for treating the diffusion process in velocity space, which succeeds in capturing the effect of the low-velocity events on the diffusion, providing a consistent description of the acceleration process. The present study exemplifies the influence of low-probability events on the transport properties of time-dependent billiards.

  16. Evaluating the predictive abilities of community occupancy models using AUC while accounting for imperfect detection

    Science.gov (United States)

    Zipkin, Elise F.; Grant, Evan H. Campbell; Fagan, William F.

    2012-01-01

    The ability to accurately predict patterns of species' occurrences is fundamental to the successful management of animal communities. To determine optimal management strategies, it is essential to understand species-habitat relationships and how species habitat use is related to natural or human-induced environmental changes. Using five years of monitoring data in the Chesapeake and Ohio Canal National Historical Park, Maryland, USA, we developed four multi-species hierarchical models for estimating amphibian wetland use that account for imperfect detection during sampling. The models were designed to determine which factors (wetland habitat characteristics, annual trend effects, spring/summer precipitation, and previous wetland occupancy) were most important for predicting future habitat use. We used the models to make predictions of species occurrences in sampled and unsampled wetlands and evaluated model projections using additional data. Using a Bayesian approach, we calculated a posterior distribution of receiver operating characteristic area under the curve (ROC AUC) values, which allowed us to explicitly quantify the uncertainty in the quality of our predictions and to account for false negatives in the evaluation dataset. We found that wetland hydroperiod (the length of time that a wetland holds water) as well as the occurrence state in the prior year were generally the most important factors in determining occupancy. The model with only habitat covariates predicted species occurrences well; however, knowledge of wetland use in the previous year significantly improved predictive ability at the community level and for two of 12 species/species complexes. Our results demonstrate the utility of multi-species models for understanding which factors affect species habitat use of an entire community (of species) and provide an improved methodology using AUC that is helpful for quantifying the uncertainty in model predictions while explicitly accounting for

  17. Accounting Models of the Human Factor and its Architecture in Scheduling and Acceptance of Administrative Solutions

    Science.gov (United States)

    2010-10-01

    terrorism or fighting, as for example in Bhopal, Goiânia, Chernobyl , Novosibirsk. General global trend is an extension of the tasks from military... animals . Accounting Models of the Human Factor and its Architecture in Scheduling and Acceptance of Administrative Solutions RTO-MP-HFM-202 P14 - 5...endemic infections, dangerous insects and animals . Vector equipment and protective equipment (Eq) describes the physiological and hygienic

  18. An enhanced temperature index model for debris-covered glaciers accounting for thickness effect.

    Science.gov (United States)

    Carenzo, M; Pellicciotti, F; Mabillard, J; Reid, T; Brock, B W

    2016-08-01

    Debris-covered glaciers are increasingly studied because it is assumed that debris cover extent and thickness could increase in a warming climate, with more regular rockfalls from the surrounding slopes and more englacial melt-out material. Debris energy-balance models have been developed to account for the melt rate enhancement/reduction due to a thin/thick debris layer, respectively. However, such models require a large amount of input data that are not often available, especially in remote mountain areas such as the Himalaya, and can be difficult to extrapolate. Due to their lower data requirements, empirical models have been used extensively in clean glacier melt modelling. For debris-covered glaciers, however, they generally simplify the debris effect by using a single melt-reduction factor which does not account for the influence of varying debris thickness on melt and prescribe a constant reduction for the entire melt across a glacier. In this paper, we present a new temperature-index model that accounts for debris thickness in the computation of melt rates at the debris-ice interface. The model empirical parameters are optimized at the point scale for varying debris thicknesses against melt rates simulated by a physically-based debris energy balance model. The latter is validated against ablation stake readings and surface temperature measurements. Each parameter is then related to a plausible set of debris thickness values to provide a general and transferable parameterization. We develop the model on Miage Glacier, Italy, and then test its transferability on Haut Glacier d'Arolla, Switzerland. The performance of the new debris temperature-index (DETI) model in simulating the glacier melt rate at the point scale is comparable to the one of the physically based approach, and the definition of model parameters as a function of debris thickness allows the simulation of the nonlinear relationship of melt rate to debris thickness, summarised by the

  19. An enhanced temperature index model for debris-covered glaciers accounting for thickness effect

    Science.gov (United States)

    Carenzo, M.; Pellicciotti, F.; Mabillard, J.; Reid, T.; Brock, B. W.

    2016-08-01

    Debris-covered glaciers are increasingly studied because it is assumed that debris cover extent and thickness could increase in a warming climate, with more regular rockfalls from the surrounding slopes and more englacial melt-out material. Debris energy-balance models have been developed to account for the melt rate enhancement/reduction due to a thin/thick debris layer, respectively. However, such models require a large amount of input data that are not often available, especially in remote mountain areas such as the Himalaya, and can be difficult to extrapolate. Due to their lower data requirements, empirical models have been used extensively in clean glacier melt modelling. For debris-covered glaciers, however, they generally simplify the debris effect by using a single melt-reduction factor which does not account for the influence of varying debris thickness on melt and prescribe a constant reduction for the entire melt across a glacier. In this paper, we present a new temperature-index model that accounts for debris thickness in the computation of melt rates at the debris-ice interface. The model empirical parameters are optimized at the point scale for varying debris thicknesses against melt rates simulated by a physically-based debris energy balance model. The latter is validated against ablation stake readings and surface temperature measurements. Each parameter is then related to a plausible set of debris thickness values to provide a general and transferable parameterization. We develop the model on Miage Glacier, Italy, and then test its transferability on Haut Glacier d'Arolla, Switzerland. The performance of the new debris temperature-index (DETI) model in simulating the glacier melt rate at the point scale is comparable to the one of the physically based approach, and the definition of model parameters as a function of debris thickness allows the simulation of the nonlinear relationship of melt rate to debris thickness, summarised by the

  20. Magnetic Properties of a Rare-Earth Antiferromagnetic Nanoparticle Investigated with a Quantum Simulation Model

    Institute of Scientific and Technical Information of China (English)

    LIU Zhao-Sen; Sechovsk(y) Vladimir; Divi(s) Martin

    2011-01-01

    @@ A Usov-type quantum model based on a mean-field approximation is utilized to simulate the magnetic structure of an assumed rare-earth nanoparticle consisting of an antiferromagnetic core and a paramagnetic outer shell.We study the magnetic properties in the presence and absence of an external magnetic field.Our simulation results show that the magnetic moments in the core region orientate antiferromagnetically in zero external magnetic field; an applied magnetic field rotates all of the magnetic moments in the paramagnetic shell completely to the field direction, and turns those in the core (which tries to maintain its original antiferromagnetic structure) towards the orientation in some degree; and the paramagnetic shell does not have a strong influence on the magnetic configuration of the core.%A Usov-type quantum model based on a mean-field approximation is utilized to simulate the magnetic structure of an assumed rare-earth nanoparticle consisting of an antiferromagnetic core and a paramagnetic outer shell. We study the magnetic properties in the presence and absence of an external magnetic field. Our simulation results show that the magnetic moments in the core region orientate antiferromagnetically in zero external magnetic field; an applied magnetic field rotates all of the magnetic moments in the paramagnetic shell completely to the Geld direction, and turns those in the core (which tries to maintain its original antiferromagnetic structure) towards the orientation in some degree; and the paramagnetic shell does not have a strong influence on the magnetic configuration of the core.

  1. Bayesian model accounting for within-class biological variability in Serial Analysis of Gene Expression (SAGE

    Directory of Open Access Journals (Sweden)

    Brentani Helena

    2004-08-01

    Full Text Available Abstract Background An important challenge for transcript counting methods such as Serial Analysis of Gene Expression (SAGE, "Digital Northern" or Massively Parallel Signature Sequencing (MPSS, is to carry out statistical analyses that account for the within-class variability, i.e., variability due to the intrinsic biological differences among sampled individuals of the same class, and not only variability due to technical sampling error. Results We introduce a Bayesian model that accounts for the within-class variability by means of mixture distribution. We show that the previously available approaches of aggregation in pools ("pseudo-libraries" and the Beta-Binomial model, are particular cases of the mixture model. We illustrate our method with a brain tumor vs. normal comparison using SAGE data from public databases. We show examples of tags regarded as differentially expressed with high significance if the within-class variability is ignored, but clearly not so significant if one accounts for it. Conclusion Using available information about biological replicates, one can transform a list of candidate transcripts showing differential expression to a more reliable one. Our method is freely available, under GPL/GNU copyleft, through a user friendly web-based on-line tool or as R language scripts at supplemental web-site.

  2. The importance of accounting for the uncertainty of published prognostic model estimates.

    Science.gov (United States)

    Young, Tracey A; Thompson, Simon

    2004-01-01

    Reported is the importance of properly reflecting uncertainty associated with prognostic model estimates when calculating the survival benefit of a treatment or technology, using liver transplantation as an example. Monte Carlo simulation techniques were used to account for the uncertainty of prognostic model estimates using the standard errors of the regression coefficients and their correlations. These methods were applied to patients with primary biliary cirrhosis undergoing liver transplantation using a prognostic model from a historic cohort who did not undergo transplantation. The survival gain over 4 years from transplantation was estimated. Ignoring the uncertainty in the prognostic model, the estimated survival benefit of liver transplantation was 16.7 months (95 percent confidence interval [CI], 13.5 to 20.1), and was statistically significant (p important that the precision of regression coefficients is available for users of published prognostic models. Ignoring this additional information substantially underestimates uncertainty, which can then impact misleadingly on policy decisions.

  3. Accounting for crop rotations in acreage choice modeling: a tractable modeling framework

    OpenAIRE

    Carpentier, Alain; Gohin, Alexandre

    2014-01-01

    Crop rotation effects and constraints are major determinants of farmers’ crop choices. Crop rotations are also keystone elements of most environmentally friendly cropping systems. The aim of this paper is twofold. First, it proposes simple tools for investigating optimal dynamic crop acreage choices accounting for crop rotation effects and constraints in an uncertain context. Second, it illustrates the impacts of crop rotation effects and constraints on farmers’ acreage choices through simple...

  4. Current Account Imbalances and Economic Growth: a two-country model with real-financial linkages

    OpenAIRE

    Laura Barbosa de Carvalho

    2012-01-01

    This paper builds a two-country stock-flow consistent model by com- bining a debt-led economy that emits the international reserve currency with an export-led economy. The model has two major implications. First, an initial trade deficit in the debt-led country leads to a perma- nent imbalance in the current account, even when the exchange rate is at parity. Second, different re-balancing mechanisms, namely a currency depreciation or the reduction of the propensity to import in the debt-led c...

  5. Model of inventory replenishment in periodic review accounting for the occurrence of shortages

    Directory of Open Access Journals (Sweden)

    Stanisław Krzyżaniak

    2014-03-01

    Full Text Available Background: Despite the development of alternative concepts of goods flow management, the inventory management under conditions of random variations of demand is still an important issue, both from the point of view of inventory keeping and replenishment costs and the service level measured as the level of inventory availability. There is a number of inventory replenishment systems used in these conditions, but they are mostly developments of two basic systems: reorder point-based and periodic review-based. The paper deals with the latter system. Numerous researches indicate the need to improve the classical models describing that system, the reason being mainly the necessity to adapt the model better to the actual conditions. This allows a correct selection of parameters that control the used inventory replenishment system and - as a result - to obtain expected economic effects. Methods: This research aimed at building a model of the periodic review system to reflect the relations (observed during simulation tests between the volume of inventory shortages and the degree of accounting for so-called deferred demand, and the service level expressed as the probability of satisfying the demand in the review and the inventory replenishment cycle. The following model building and testing method has been applied: numerical simulation of inventory replenishment - detailed analysis of simulation results - construction of the model taking into account the regularities observed during the simulations - determination of principles of solving the system of relations creating the model - verification of the results obtained from the model using the results from simulation. Results: Presented are selected results of calculations based on classical formulas and using the developed model, which describe the relations between the service level and the parameters controlling the discussed inventory replenishment system. The results are compared to the simulation

  6. Generation of SEEAW asset accounts based on water resources management models

    Science.gov (United States)

    Pedro-Monzonís, María; Solera, Abel; Andreu, Joaquín

    2015-04-01

    One of the main challenges in the XXI century is related with the sustainable use of water. This is due to the fact that water is an essential element for the life of all who inhabit our planet. In many cases, the lack of economic valuation of water resources causes an inefficient water use. In this regard, society expects of policymakers and stakeholders maximise the profit produced per unit of natural resources. Water planning and the Integrated Water Resources Management (IWRM) represent the best way to achieve this goal. The System of Environmental-Economic Accounting for Water (SEEAW) is displayed as a tool for water allocation which enables the building of water balances in a river basin. The main concern of the SEEAW is to provide a standard approach which allows the policymakers to compare results between different territories. But building water accounts is a complex task due to the difficulty of the collection of the required data. Due to the difficulty of gauging the components of the hydrological cycle, the use of simulation models has become an essential tool extensively employed in last decades. The target of this paper is to present the building up of a database that enables the combined use of hydrological models and water resources models developed with AQUATOOL DSSS to fill in the SEEAW tables. This research is framed within the Water Accounting in a Multi-Catchment District (WAMCD) project, financed by the European Union. Its main goal is the development of water accounts in the Mediterranean Andalusian River Basin District, in Spain. This research pretends to contribute to the objectives of the "Blueprint to safeguard Europe's water resources". It is noteworthy that, in Spain, a large part of these methodological decisions are included in the Spanish Guideline of Water Planning with normative status guaranteeing consistency and comparability of the results.

  7. ABOUT CREATION OF MODELS OF NATURAL PLANT COMMUNITIES, INCLUDING RARE SPECIES, IN THE BOTANICAL GARDENS OF KRASNODAR

    Directory of Open Access Journals (Sweden)

    Bakalov A. N.

    2013-10-01

    Full Text Available One of the ways to save rare species of plants is to create models of natural communities on the grounds of the botanical gardens. In the Botanical Garden of Kuban State University we have created the model of forest communities with the participation of rare and endangered species, and we are still working on creating models of herbaceous communities. We have introduced 18 species of plants of the flora of the Krasnodar region in the forest community and more than 30 species in herbaceous community

  8. Accounting for anatomical noise in search-capable model observers for planar nuclear imaging.

    Science.gov (United States)

    Sen, Anando; Gifford, Howard C

    2016-01-01

    Model observers intended to predict the diagnostic performance of human observers should account for the effects of both quantum and anatomical noise. We compared the abilities of several visual-search (VS) and scanning Hotelling-type models to account for anatomical noise in a localization receiver operating characteristic (LROC) study involving simulated nuclear medicine images. Our VS observer invoked a two-stage process of search and analysis. The images featured lesions in the prostate and pelvic lymph nodes. Lesion contrast and the geometric resolution and sensitivity of the imaging collimator were the study variables. A set of anthropomorphic mathematical phantoms was imaged with an analytic projector based on eight parallel-hole collimators with different sensitivity and resolution properties. The LROC study was conducted with human observers and the channelized nonprewhitening, channelized Hotelling (CH) and VS model observers. The CH observer was applied in a "background-known-statistically" protocol while the VS observer performed a quasi-background-known-exactly task. Both of these models were applied with and without internal noise in the decision variables. A perceptual search threshold was also tested with the VS observer. The model observers without inefficiencies failed to mimic the average performance trend for the humans. The CH and VS observers with internal noise matched the humans primarily at low collimator sensitivities. With both internal noise and the search threshold, the VS observer attained quantitative agreement with the human observers. Computational efficiency is an important advantage of the VS observer.

  9. A Buffer Model Account of Behavioral and ERP Patterns in the Von Restorff Paradigm

    Directory of Open Access Journals (Sweden)

    Siri-Maria Kamp

    2016-06-01

    Full Text Available We combined a mechanistic model of episodic encoding with theories on the functional significance of two event-related potential (ERP components to develop an integrated account for the Von Restorff effect, which refers to the enhanced recall probability for an item that deviates in some feature from other items in its study list. The buffer model of Lehman and Malmberg (2009, 2013 can account for this effect such that items encountered during encoding enter an episodic buffer where they are actively rehearsed. When a deviant item is encountered, in order to re-allocate encoding resources towards this item the buffer is emptied from its prior content, a process labeled “compartmentalization”. Based on theories on their functional significance, the P300 component of the ERP may co-occur with this hypothesized compartmentalization process, while the frontal slow wave may index rehearsal. We derived predictions from this integrated model for output patterns in free recall, systematic variance in ERP components, as well as associations between the two types of measures in a dataset of 45 participants who studied and freely recalled lists of the Von Restorff type. Our major predictions were confirmed and the behavioral and physiological results were consistent with the predictions derived from the model. These findings demonstrate that constraining mechanistic models of episodic memory with brain activity patterns and generating predictions for relationships between brain activity and behavior can lead to novel insights into the relationship between the brain, the mind, and behavior.

  10. Regional Balance Model of Financial Flows through Sectoral Approaches System of National Accounts

    Directory of Open Access Journals (Sweden)

    Ekaterina Aleksandrovna Zaharchuk

    2017-03-01

    Full Text Available The main purpose of the study, the results of which are reflected in this article, is the theoretical and methodological substantiation of possibilities to build a regional balance model of financial flows consistent with the principles of the construction of the System of National Accounts (SNA. The paper summarizes the international experience of building regional accounts in the SNA as well as reflects the advantages and disadvantages of the existing techniques for constructing Social Accounting Matrix. The authors have proposed an approach to build the regional balance model of financial flows, which is based on the disaggregated tables of the formation, distribution and use of the added value of territory in the framework of institutional sectors of SNA (corporations, public administration, households. Within the problem resolution of the transition of value added from industries to sectors, the authors have offered an approach to the accounting of development, distribution and use of value added within the institutional sectors of the territories. The methods of calculation are based on the publicly available information base of statistics agencies and federal services. The authors provide the scheme of the interrelations of the indicators of the regional balance model of financial flows. It allows to coordinate mutually the movement of regional resources by the sectors of «corporation», «public administration» and «households» among themselves, and cash flows of the region — by the sectors and directions of use. As a result, they form a single account of the formation and distribution of territorial financial resources, which is a regional balance model of financial flows. This matrix shows the distribution of financial resources by income sources and sectors, where the components of the formation (compensation, taxes and gross profit, distribution (transfers and payments and use (final consumption, accumulation of value added are

  11. A comparison of Graham and Piotroski investment models using accounting information and efficacy measurement

    Directory of Open Access Journals (Sweden)

    Nusrat Jahan

    2016-03-01

    Full Text Available We examine the investment models of Benjamin Graham and Joseph Piotroski and compare the efficacy of these two models by running backtest, using screening rules and ranking systems built in Portfolio 123. Using different combinations of screening rules and ranking systems, we also examine the performance of Piotroski and Graham investment models. We find that the combination of Piotroski and Graham investment models performs better than S&P 500. We also find that the Piotroski screening with Graham ranking generates the highest average annualized return among different combinations of screening rules and ranking systems analyzed in this paper. Overall, our results show a profound impact of accounting information on investor’s decision making.

  12. Improved Mathematical Model of PMSM Taking Into Account Cogging Torque Oscillations

    Directory of Open Access Journals (Sweden)

    TUDORACHE, T.

    2012-08-01

    Full Text Available This paper presents an improved mathematical model of Permanent Magnet Synchronous Machine (PMSM that takes into account the Cogging Torque (CT oscillations that appear due to the mutual attraction between the Permanent Magnets (PMs and the anisotropic stator armature. The electromagnetic torque formula in the proposed model contains an analytical expression of the CT calibrated by Finite Element (FE analysis. The numerical calibration is carried out using a data fitting procedure based on the Simplex Downhill optimization algorithm. The proposed model is characterized by good accuracy and reduced computation effort, its performance being verified by comparison with the classical d-q model of the machine using Matlab/Simulink environment.

  13. A statistical RCL interconnect delay model taking account of process variations

    Institute of Scientific and Technical Information of China (English)

    Zhu Zhang-Ming; wan Da-Jing; Yang Yin-Tang; En Yun-Fei

    2011-01-01

    As the feature size of the CMOS integrated circuit continues to shrink, process variations have become a key factor affecting the interconnect performance. Based on the equivalent Elmore model and the use of the polynomial chaos theory and the Galerkin method, we propose a linear statistical RCL interconnect delay model, taking into account process variations by successive application of the linear approximation method. Based on a variety of nano-CMOS process parameters, HSPICE simulation results show that the maximum error of the proposed model is less than 3.5%.The proposed model is simple, of high precision, and can be used in the analysis and design of nanometer integrated circuit interconnect systems.

  14. Hierarchical modeling for rare event detection and cell subset alignment across flow cytometry samples.

    Directory of Open Access Journals (Sweden)

    Andrew Cron

    Full Text Available Flow cytometry is the prototypical assay for multi-parameter single cell analysis, and is essential in vaccine and biomarker research for the enumeration of antigen-specific lymphocytes that are often found in extremely low frequencies (0.1% or less. Standard analysis of flow cytometry data relies on visual identification of cell subsets by experts, a process that is subjective and often difficult to reproduce. An alternative and more objective approach is the use of statistical models to identify cell subsets of interest in an automated fashion. Two specific challenges for automated analysis are to detect extremely low frequency event subsets without biasing the estimate by pre-processing enrichment, and the ability to align cell subsets across multiple data samples for comparative analysis. In this manuscript, we develop hierarchical modeling extensions to the Dirichlet Process Gaussian Mixture Model (DPGMM approach we have previously described for cell subset identification, and show that the hierarchical DPGMM (HDPGMM naturally generates an aligned data model that captures both commonalities and variations across multiple samples. HDPGMM also increases the sensitivity to extremely low frequency events by sharing information across multiple samples analyzed simultaneously. We validate the accuracy and reproducibility of HDPGMM estimates of antigen-specific T cells on clinically relevant reference peripheral blood mononuclear cell (PBMC samples with known frequencies of antigen-specific T cells. These cell samples take advantage of retrovirally TCR-transduced T cells spiked into autologous PBMC samples to give a defined number of antigen-specific T cells detectable by HLA-peptide multimer binding. We provide open source software that can take advantage of both multiple processors and GPU-acceleration to perform the numerically-demanding computations. We show that hierarchical modeling is a useful probabilistic approach that can provide a

  15. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  16. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  17. Statistical model of rough surface contact accounting for size-dependent plasticity and asperity interaction

    Science.gov (United States)

    Song, H.; Vakis, A. I.; Liu, X.; Van der Giessen, E.

    2017-09-01

    The work by Greenwood and Williamson (GW) has initiated a simple but effective method of contact mechanics: statistical modeling based on the mechanical response of a single asperity. Two main assumptions of the original GW model are that the asperity response is purely elastic and that there is no interaction between asperities. However, as asperities lie on a continuous substrate, the deformation of one asperity will change the height of all other asperities through deformation of the substrate and will thus influence subsequent contact evolution. Moreover, a high asperity contact pressure will result in plasticity, which below tens of microns is size dependent, with smaller being harder. In this paper, the asperity interaction effect is taken into account through substrate deformation, while a size-dependent plasticity model is adopted for individual asperities. The intrinsic length in the strain gradient plasticity (SGP) theory is obtained by fitting to two-dimensional discrete dislocation plasticity simulations of the flattening of a single asperity. By utilizing the single asperity response in three dimensions and taking asperity interaction into account, a statistical calculation of rough surface contact is performed. The effectiveness of the statistical model is addressed by comparison with full-detail finite element simulations of rough surface contact using SGP. Throughout the paper, our focus is on the difference of contact predictions based on size-dependent plasticity as compared to conventional size-independent plasticity.

  18. Organic complexation of rare earth elements in natural waters: Evaluating model calculations from ultrafiltration data

    Science.gov (United States)

    Pourret, Olivier; Davranche, Mélanie; Gruau, Gérard; Dia, Aline

    2007-06-01

    The Stockholm Humic Model (SHM) and Humic Ion-Binding Models V and VI were compared for their ability to predict the role of dissolved organic matter (DOM) in the speciation of rare earth elements (REE) in natural waters. Unlike Models V and VI, SHM is part of a speciation code that also allows us to consider dissolution/precipitation, sorption/desorption and oxidation/reduction reactions. In this context, it is particularly interesting to test the performance of SHM. The REE specific equilibrium constants required by the speciation models were estimated using linear free-energy relationships (LFER) between the first hydrolysis constants and the stability constants for REE complexation with lactic and acetic acid. Three datasets were used for the purpose of comparison: (i) World Average River Water (Dissolved Organic Carbon (DOC) = 5 mg L -1), previously investigated using Model V, was reinvestigated using SHM and Model VI; (ii) two natural organic-rich waters (DOC = 18-24 mg L -1), whose REE speciation has already been determined with both Model V and ultrafiltration studies, were also reinvestigated using SHM and Model VI; finally, (iii) new ultrafiltration experiments were carried out on samples of circumneutral-pH (pH 6.2-7.1), organic-rich (DOC = 7-20 mg L -1) groundwaters from the Kervidy-Naizin and Petit-Hermitage catchments, western France. The results were then compared with speciation predictions provided by Model VI and SHM, successively. When applied to World Average River Water, both Model VI and SHM yield comparable results, confirming the earlier finding that a large fraction of the dissolved REE in rivers occurs as organic complexes This implies that the two models are equally valid for calculating REE speciation in low-DOC waters at circumneutral-pH. The two models also successfully reproduced ultrafiltration results obtained for DOC-rich acidic groundwaters and river waters. By contrast, the two models yielded different results when compared to

  19. Precision tests of the Standard Model: Rare B-meson decays

    Science.gov (United States)

    Ali, Ahmed

    2017-03-01

    The charge given to me by the organisers of the memorial meeting for Prof. Abdus Salam’s 90th birthday is to recall my personal impressions of him and review an aspect of the standard model (SM) physics related to my work. Salam was, first and foremost, a brilliant theoretical physicist whose work is still very much en vogue, currently being tested precisely by the experiments at the Large Hadron Collider (LHC). Salam was, however, equally effective as a scientific advisor to many institutions, such as IAEA and CERN, but also to the government of Pakistan as the chief scientific strategist. He was also an untiring advocate of scientific research and higher education in developing countries, which took a concrete form in the International Centre for Theoretical Physics (ICTP) in Trieste. I discuss these aspects of his scientific life seen from my perspective in the first part. In the second part of my talk, which may appear as a disjoint piece to the first, I summarise some selected topics in rare B-decays — the current flavour physics frontier. Experiments carried out over several decades are largely in agreement with the SM, thanks also to dedicated theoretical effort in their interpretation. However, this field is undergoing an anomalous phase in a number of key measurements, in particular reported by LHCb, triggering a very lively debate and model building. These anomalies, which I review here, are too numerous to be ignored, but none is individually significant enough to announce a breakdown of the SM.

  20. Modelling representative and coherent Danish farm types based on farm accountancy data for use in environmental assessments

    DEFF Research Database (Denmark)

    Dalgaard, Randi; Halberg, Niels; Kristensen, Ib Sillebak

    2006-01-01

    -oriented environmental assessment (e.g. greenhouse gas emissions per kg pork). The objective of this study was to establish a national agricultural model for estimating data on resource use, production and environmentally important emissions for a set of representative farm types. Every year a sample of farm accounts...... is established in order to report Danish agro-economical data to the ‘Farm Accountancy Data Network’ (FADN), and to produce ‘The annual Danish account statistics for agriculture’. The farm accounts are selected and weighted to be representative for the Danish agricultural sector, and similar samples of farm...... accounts are collected in most of the European countries. Based on a sample of 2138 farm accounts from year 1999 a national agricultural model, consisting of 31 farm types, was constructed. The farm accounts were grouped according to the major soil types, the number of working hours, the most important...

  1. Rare decays of the Z and the standard model, 4th generation, and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Weiler, T.J.

    1989-01-01

    Several issues in rare decays of the Z are addressed. The rate for flavor-changing Z decay grows as the fourth power of the fermion masses internal to the quantum loop, and so offers a window to the existence of ultraheavy (m > M{sub W}) fermions. In the standard model, with three generations, BR(Z {yields} bs) < 10{sup -7} and BR(Z{yields}tc)<10{sup -13}. With four generations, BR(Z {yields} bb{sub 4}) may be as large as 10{sup -5} if m{sub b4} < M{sub Z}; and similarly for BR(Z {yields} N{sub 4}v), where N{sub 4} is the possibly heavy fourth generation neutrino. In supersymmetric and other two Higgs doublet models, BR(Z {yields} tc) may be as large as 5 {times} 10{sup -6} in the three generation scheme. With minimal supersymmetry, the reaction Z {yields} H{gamma} is guaranteed to go, with a parameter-dependent branching ratio of 10{sup -6 {plus minus} 3}. With mirror fermions or exotic E{sub 6} fermions, the branching ratios for Z {yields} ct (70 GeV), Z {yields} {mu}{tau}, and Z {yields} bb{sub 4} (70 GeV) are typically 10{sup -4}, 10{sup -4}, and 10{sup -3} respectively, clearly measurable at LEP. Depending on unknown quark masses, the Z may mix with vector (b{sub 4}{bar b}{sub 4}) and the W may mix with vector (t{bar b}) or (t{bar s}). CP violating asymmetries in flavor-changing Z decay are immeasurably small in the standard model, but may be large in supersymmetric and other nonstandard models. 28 refs.

  2. The importance of data quality for generating reliable distribution models for rare, elusive, and cryptic species

    Science.gov (United States)

    Aubry, Keith B.; Raley, Catherine M.; McKelvey, Kevin S.

    2017-01-01

    The availability of spatially referenced environmental data and species occurrence records in online databases enable practitioners to easily generate species distribution models (SDMs) for a broad array of taxa. Such databases often include occurrence records of unknown reliability, yet little information is available on the influence of data quality on SDMs generated for rare, elusive, and cryptic species that are prone to misidentification in the field. We investigated this question for the fisher (Pekania pennanti), a forest carnivore of conservation concern in the Pacific States that is often confused with the more common Pacific marten (Martes caurina). Fisher occurrence records supported by physical evidence (verifiable records) were available from a limited area, whereas occurrence records of unknown quality (unscreened records) were available from throughout the fisher’s historical range. We reserved 20% of the verifiable records to use as a test sample for both models and generated SDMs with each dataset using Maxent. The verifiable model performed substantially better than the unscreened model based on multiple metrics including AUCtest values (0.78 and 0.62, respectively), evaluation of training and test gains, and statistical tests of how well each model predicted test localities. In addition, the verifiable model was consistent with our knowledge of the fisher’s habitat relations and potential distribution, whereas the unscreened model indicated a much broader area of high-quality habitat (indices > 0.5) that included large expanses of high-elevation habitat that fishers do not occupy. Because Pacific martens remain relatively common in upper elevation habitats in the Cascade Range and Sierra Nevada, the SDM based on unscreened records likely reflects primarily a conflation of marten and fisher habitat. Consequently, accurate identifications are far more important than the spatial extent of occurrence records for generating reliable SDMs for the

  3. Green accounts for sulphur and nitrogen deposition in Sweden. Implementation of a theoretical model in practice

    Energy Technology Data Exchange (ETDEWEB)

    Ahlroth, S.

    2001-01-01

    This licentiate thesis tries to bridge the gap between the theoretical and the practical studies in the field of environmental accounting. In the paper, 1 develop an optimal control theory model for adjusting NDP for the effects Of SO{sub 2} and NO{sub x} emissions, and subsequently insert empirically estimated values. The model includes correction entries for the effects on welfare, real capital, health and the quality and quantity of renewable natural resources. In the empirical valuation study, production losses were estimated with dose-response functions. Recreational and other welfare values were estimated by the contingent valuation (CV) method. Effects on capital depreciation are also included. For comparison, abatement costs and environmental protection expenditures for reducing sulfur and nitrogen emissions were estimated. The theoretical model was then utilized to calculate the adjustment to NDP in a consistent manner.

  4. A simple model for predicting sprint-race times accounting for energy loss on the curve

    Science.gov (United States)

    Mureika, J. R.

    1997-11-01

    The mathematical model of J. Keller for predicting World Record race times, based on a simple differential equation of motion, predicted quite well the records of the day. One of its shortcoming is that it neglects to account for a sprinter's energy loss around a curve, a most important consideration particularly in the 200m--400m. An extension to Keller's work is considered, modeling the aforementioned energy loss as a simple function of the centrifugal force acting on the runner around the curve. Theoretical World Record performances for indoor and outdoor 200m are discussed, and the use of the model at 300m is investigated. Some predictions are made for possible 200m outdoor and indoor times as run by Canadian 100m WR holder Donovan Bailey, based on his 100m final performance at the 1996 Olympic Games in Atlanta.

  5. A Simple Model for Predicting Sprint Race Times Accounting for Energy Loss on the Curve

    CERN Document Server

    Mureika, J R

    1997-01-01

    The mathematical model of J. Keller for predicting World Record race times, based on a simple differential equation of motion, predicted quite well the records of the day. One of its shortcoming is that it neglects to account for a sprinter's energy loss around a curve, a most important consideration particularly in the 200m--400m. An extension to Keller's work is considered, modeling the aforementioned energy loss as a simple function of the centrifugal force acting on the runner around the curve. Theoretical World Record performances for indoor and outdoor 200m are discussed, and the use of the model at 300m is investigated. Some predictions are made for possible 200m outdoor and indoor times as run by Canadian 100m WR holder Donovan Bailey, based on his 100m final performance at the 1996 Olympic Games in Atlanta.

  6. Accounting for Epistemic Uncertainty in PSHA: Logic Tree and Ensemble Model

    Science.gov (United States)

    Taroni, M.; Marzocchi, W.; Selva, J.

    2014-12-01

    The logic tree scheme is the probabilistic framework that has been widely used in the last decades to take into account epistemic uncertainties in probabilistic seismic hazard analysis (PSHA). Notwithstanding the vital importance for PSHA to incorporate properly the epistemic uncertainties, we argue that the use of the logic tree in a PSHA context has conceptual and practical drawbacks. Despite some of these drawbacks have been reported in the past, a careful evaluation of their impact on PSHA is still lacking. This is the goal of the present work. In brief, we show that i) PSHA practice does not meet the assumptions that stand behind the logic tree scheme; ii) the output of a logic tree is often misinterpreted and/or misleading, e.g., the use of percentiles (median included) in a logic tree scheme raises theoretical difficulties from a probabilistic point of view; iii) in case the assumptions that stand behind a logic tree are actually met, this leads to several problems in testing any PSHA model. We suggest a different strategy - based on ensemble modeling - to account for epistemic uncertainties in a more proper probabilistic framework. Finally, we show that in many PSHA practical applications, the logic tree is de facto loosely applied to build sound ensemble models.

  7. Climate projections of future extreme events accounting for modelling uncertainties and historical simulation biases

    Science.gov (United States)

    Brown, Simon J.; Murphy, James M.; Sexton, David M. H.; Harris, Glen R.

    2014-11-01

    A methodology is presented for providing projections of absolute future values of extreme weather events that takes into account key uncertainties in predicting future climate. This is achieved by characterising both observed and modelled extremes with a single form of non-stationary extreme value (EV) distribution that depends on global mean temperature and which includes terms that account for model bias. Such a distribution allows the prediction of future "observed" extremes for any period in the twenty-first century. Uncertainty in modelling future climate, arising from a wide range of atmospheric, oceanic, sulphur cycle and carbon cycle processes, is accounted for by using probabilistic distributions of future global temperature and EV parameters. These distributions are generated by Bayesian sampling of emulators with samples weighted by their likelihood with respect to a set of observational constraints. The emulators are trained on a large perturbed parameter ensemble of global simulations of the recent past, and the equilibrium response to doubled CO2. Emulated global EV parameters are converted to the relevant regional scale through downscaling relationships derived from a smaller perturbed parameter regional climate model ensemble. The simultaneous fitting of the EV model to regional model data and observations allows the characterisation of how observed extremes may change in the future irrespective of biases that may be present in the regional models simulation of the recent past climate. The clearest impact of a parameter perturbation in this ensemble was found to be the depth to which plants can access water. Members with shallow soils tend to be biased hot and dry in summer for the observational period. These biases also appear to have an impact on the potential future response for summer temperatures with some members with shallow soils having increases for extremes that reduce with extreme severity. We apply this methodology for London, using the

  8. FORMATION OF CONSUMER ACCOMMODATION MODELS WITH DUE ACCOUNT OF POPULATION INVESTMENT POTENTIAL

    Directory of Open Access Journals (Sweden)

    I. Shaniukevich

    2013-01-01

    Full Text Available The paper considers a theme of typological urban housing diversity  which is relevant for a modern residential real estate market. Analyzed Quantitative and qualitative characteristics of the existing urban residential accommodation, new  house building have been analyzed in the paper. The paper presents author’s calculations of differentiation extent and changes in economic opportunities of the population. Differentiation of  potential consumer accommodation models with specific standardized characteristics has been made in terms of the population economic prosperity.  The paper substantiates proposals on accountability and implementation of typological differences in the government housing policy.

  9. A simple bioclogging model that accounts for spatial spreading of bacteria

    Directory of Open Access Journals (Sweden)

    Laurent Demaret

    2009-04-01

    Full Text Available An extension of biobarrier formation and bioclogging models is presented that accounts for spatial expansion of the bacterial population in the soil. The bacteria move into neighboring sites if locally almost all of the available pore space is occupied and the environmental conditions are such that further growth of the bacterial population is sustained. This is described by a density-dependent, double degenerate diffusion-equation that is coupled with the Darcy equations and a transport-reaction equation for growth limiting substrates. We conduct computational simulations of the governing differential equation system.

  10. A parametric ribcage geometry model accounting for variations among the adult population.

    Science.gov (United States)

    Wang, Yulong; Cao, Libo; Bai, Zhonghao; Reed, Matthew P; Rupp, Jonathan D; Hoff, Carrie N; Hu, Jingwen

    2016-09-06

    The objective of this study is to develop a parametric ribcage model that can account for morphological variations among the adult population. Ribcage geometries, including 12 pair of ribs, sternum, and thoracic spine, were collected from CT scans of 101 adult subjects through image segmentation, landmark identification (1016 for each subject), symmetry adjustment, and template mesh mapping (26,180 elements for each subject). Generalized procrustes analysis (GPA), principal component analysis (PCA), and regression analysis were used to develop a parametric ribcage model, which can predict nodal locations of the template mesh according to age, sex, height, and body mass index (BMI). Two regression models, a quadratic model for estimating the ribcage size and a linear model for estimating the ribcage shape, were developed. The results showed that the ribcage size was dominated by the height (p=0.000) and age-sex-interaction (p=0.007) and the ribcage shape was significantly affected by the age (p=0.0005), sex (p=0.0002), height (p=0.0064) and BMI (p=0.0000). Along with proper assignment of cortical bone thickness, material properties and failure properties, this parametric ribcage model can directly serve as the mesh of finite element ribcage models for quantifying effects of human characteristics on thoracic injury risks.

  11. Improvement of the integration of Soil Moisture Accounting into the NRCS-CN model

    Science.gov (United States)

    Durán-Barroso, Pablo; González, Javier; Valdés, Juan B.

    2016-11-01

    Rainfall-runoff quantification is one of the most important tasks in both engineering and watershed management as it allows the identification, forecast and explanation of the watershed response. This non-linear process depends on the watershed antecedent conditions, which are commonly related to the initial soil moisture content. Although several studies have highlighted the relevance of soil moisture measures to improve flood modelling, the discussion is still open in the literature about the approach to use in lumped model. The integration of these previous conditions in the widely used rainfall-runoff models NRCS-CN (e.g. National Resources Conservation Service - Curve Number model) could be handled in two ways: using the Antecedent Precipitation Index (API) concept to modify the model parameter; or alternatively, using a Soil Moisture Accounting (SMA) procedure into the NRCS-CN, being the soil moisture a state variable. For this second option, the state variable does not have a direct physical representation. This make difficult the estimation of the initial soil moisture store level. This paper presents a new formulation that overcomes such issue, the rainfall-runoff model called RSSa. Its suitability is evaluated by comparing the RSSa model with the original NRCS-CN model and alternatives SMA procedures in 12 watersheds located in six different countries, with different climatic conditions, from Mediterranean to Semi-arid regions. The analysis shows that the new model, RSSa, performs better when compared with previously proposed CN-based models. Finally, an assessment is made of the influence of the soil moisture parameter for each watershed and the relative weight of scale effects over model parameterization.

  12. Advances in stream shade modelling. Accounting for canopy overhang and off-centre view

    Science.gov (United States)

    Davies-Colley, R.; Meleason, M. A.; Rutherford, K.

    2005-05-01

    Riparian shade controls the stream thermal regime and light for photosynthesis of stream plants. The quantity difn (diffuse non-interceptance), defined as the proportion of incident lighting received under a sky of uniform brightness, is useful for general specification of stream light exposure, having the virtue that it can be measured directly with common light sensors of appropriate spatial and spectral character. A simple model (implemented in EXCEL-VBA) (Davies-Colley & Rutherford Ecol. Engrg in press) successfully reproduces the broad empirical trend of decreasing difn at the channel centre with increasing ratio of canopy height to stream width. We have now refined this model to account for (a) foliage overhanging the channel (for trees of different canopy form), and (b) off-centre view of the shade (rather than just the channel centre view). We use two extreme geometries bounding real (meandering) streams: the `canyon' model simulates an infinite straight canal, whereas the `cylinder' model simulates a stream meandering so tightly that its geometry collapses into an isolated pool in the forest. The model has been validated using a physical `rooftop' model of the cylinder case, with which it is possible to measure shade with different geometries.

  13. Accountability and pediatric physician-researchers: are theoretical models compatible with Canadian lived experience?

    Directory of Open Access Journals (Sweden)

    Czoli Christine

    2011-10-01

    Full Text Available Abstract Physician-researchers are bound by professional obligations stemming from both the role of the physician and the role of the researcher. Currently, the dominant models for understanding the relationship between physician-researchers' clinical duties and research duties fit into three categories: the similarity position, the difference position and the middle ground. The law may be said to offer a fourth "model" that is independent from these three categories. These models frame the expectations placed upon physician-researchers by colleagues, regulators, patients and research participants. This paper examines the extent to which the data from semi-structured interviews with 30 physician-researchers at three major pediatric hospitals in Canada reflect these traditional models. It seeks to determine the extent to which existing models align with the described lived experience of the pediatric physician-researchers interviewed. Ultimately, we find that although some physician-researchers make references to something like the weak version of the similarity position, the pediatric-researchers interviewed in this study did not describe their dual roles in a way that tightly mirrors any of the existing theoretical frameworks. We thus conclude that either physician-researchers are in need of better training regarding the nature of the accountability relationships that flow from their dual roles or that models setting out these roles and relationships must be altered to better reflect what we can reasonably expect of physician-researchers in a real-world environment.

  14. Radiative transfer modeling through terrestrial atmosphere and ocean accounting for inelastic processes: Software package SCIATRAN

    Science.gov (United States)

    Rozanov, V. V.; Dinter, T.; Rozanov, A. V.; Wolanin, A.; Bracher, A.; Burrows, J. P.

    2017-06-01

    SCIATRAN is a comprehensive software package which is designed to model radiative transfer processes in the terrestrial atmosphere and ocean in the spectral range from the ultraviolet to the thermal infrared (0.18-40 μm). It accounts for multiple scattering processes, polarization, thermal emission and ocean-atmosphere coupling. The main goal of this paper is to present a recently developed version of SCIATRAN which takes into account accurately inelastic radiative processes in both the atmosphere and the ocean. In the scalar version of the coupled ocean-atmosphere radiative transfer solver presented by Rozanov et al. [61] we have implemented the simulation of the rotational Raman scattering, vibrational Raman scattering, chlorophyll and colored dissolved organic matter fluorescence. In this paper we discuss and explain the numerical methods used in SCIATRAN to solve the scalar radiative transfer equation including trans-spectral processes, and demonstrate how some selected radiative transfer problems are solved using the SCIATRAN package. In addition we present selected comparisons of SCIATRAN simulations with those published benchmark results, independent radiative transfer models, and various measurements from satellite, ground-based, and ship-borne instruments. The extended SCIATRAN software package along with a detailed User's Guide is made available for scientists and students, who are undertaking their own research typically at universities, via the web page of the Institute of Environmental Physics (IUP), University of Bremen: http://www.iup.physik.uni-bremen.de.

  15. Implementation of a cost-accounting model in a biobank: practical implications.

    Science.gov (United States)

    Gonzalez-Sanchez, Maria Beatriz; Lopez-Valeiras, Ernesto; García-Montero, Andres C

    2014-01-01

    Given the state of global economy, cost measurement and control have become increasingly relevant over the past years. The scarcity of resources and the need to use these resources more efficiently is making cost information essential in management, even in non-profit public institutions. Biobanks are no exception. However, no empirical experiences on the implementation of cost accounting in biobanks have been published to date. The aim of this paper is to present a step-by-step implementation of a cost-accounting tool for the main production and distribution activities of a real/active biobank, including a comprehensive explanation on how to perform the calculations carried out in this model. Two mathematical models for the analysis of (1) production costs and (2) request costs (order management and sample distribution) have stemmed from the analysis of the results of this implementation, and different theoretical scenarios have been prepared. Global analysis and discussion provides valuable information for internal biobank management and even for strategic decisions at the research and development governmental policies level.

  16. An extended car-following model accounting for the average headway effect in intelligent transportation system

    Science.gov (United States)

    Kuang, Hua; Xu, Zhi-Peng; Li, Xing-Li; Lo, Siu-Ming

    2017-04-01

    In this paper, an extended car-following model is proposed to simulate traffic flow by considering average headway of preceding vehicles group in intelligent transportation systems environment. The stability condition of this model is obtained by using the linear stability analysis. The phase diagram can be divided into three regions classified as the stable, the metastable and the unstable ones. The theoretical result shows that the average headway plays an important role in improving the stabilization of traffic system. The mKdV equation near the critical point is derived to describe the evolution properties of traffic density waves by applying the reductive perturbation method. Furthermore, through the simulation of space-time evolution of the vehicle headway, it is shown that the traffic jam can be suppressed efficiently with taking into account the average headway effect, and the analytical result is consistent with the simulation one.

  17. Accounting for the kinetics in order parameter analysis: lessons from theoretical models and a disordered peptide

    CERN Document Server

    Berezovska, Ganna; Mostarda, Stefano; Rao, Francesco

    2012-01-01

    Molecular simulations as well as single molecule experiments have been widely analyzed in terms order parameters, the latter representing candidate probes for the relevant degrees of freedom. Notwithstanding this approach is very intuitive, mounting evidence showed that such description is not accurate, leading to ambiguous definitions of states and wrong kinetics. To overcome these limitations a framework making use of order parameter fluctuations in conjunction with complex network analysis is investigated. Derived from recent advances in the analysis of single molecule time traces, this approach takes into account of the fluctuations around each time point to distinguish between states that have similar values of the order parameter but different dynamics. Snapshots with similar fluctuations are used as nodes of a transition network, the clusterization of which into states provides accurate Markov-State-Models of the system under study. Application of the methodology to theoretical models with a noisy orde...

  18. Water accounting for stressed river basins based on water resources management models.

    Science.gov (United States)

    Pedro-Monzonís, María; Solera, Abel; Ferrer, Javier; Andreu, Joaquín; Estrela, Teodoro

    2016-09-15

    Water planning and the Integrated Water Resources Management (IWRM) represent the best way to help decision makers to identify and choose the most adequate alternatives among other possible ones. The System of Environmental-Economic Accounting for Water (SEEA-W) is displayed as a tool for the building of water balances in a river basin, providing a standard approach to achieve comparability of the results between different territories. The target of this paper is to present the building up of a tool that enables the combined use of hydrological models and water resources models to fill in the SEEA-W tables. At every step of the modelling chain, we are capable to build the asset accounts and the physical water supply and use tables according to SEEA-W approach along with an estimation of the water services costs. The case study is the Jucar River Basin District (RBD), located in the eastern part of the Iberian Peninsula in Spain which as in other many Mediterranean basins is currently water-stressed. To guide this work we have used PATRICAL model in combination with AQUATOOL Decision Support System (DSS). The results indicate that for the average year the total use of water in the district amounts to 15,143hm(3)/year, being the Total Water Renewable Water Resources 3909hm(3)/year. On the other hand, the water service costs in Jucar RBD amounts to 1634 million € per year at constant 2012 prices. It is noteworthy that 9% of these costs correspond to non-conventional resources, such as desalinated water, reused water and water transferred from other regions.

  19. A Model for Urban Environment and Resource Planning Based on Green GDP Accounting System

    Directory of Open Access Journals (Sweden)

    Linyu Xu

    2013-01-01

    Full Text Available The urban environment and resources are currently on course that is unsustainable in the long run due to excessive human pursuit of economic goals. Thus, it is very important to develop a model to analyse the relationship between urban economic development and environmental resource protection during the process of rapid urbanisation. This paper proposed a model to identify the key factors in urban environment and resource regulation based on a green GDP accounting system, which consisted of four parts: economy, society, resource, and environment. In this model, the analytic hierarchy process (AHP method and a modified Pearl curve model were combined to allow for dynamic evaluation, with higher green GDP value as the planning target. The model was applied to the environmental and resource planning problem of Wuyishan City, and the results showed that energy use was a key factor that influenced the urban environment and resource development. Biodiversity and air quality were the most sensitive factors that influenced the value of green GDP in the city. According to the analysis, the urban environment and resource planning could be improved for promoting sustainable development in Wuyishan City.

  20. A model proposal concerning balance scorecard application integrated with resource consumption accounting in enterprise performance management

    Directory of Open Access Journals (Sweden)

    ORHAN ELMACI

    2014-06-01

    Full Text Available The present study intended to investigate the “Balance Scorecard (BSC model integrated with Resource Consumption Accounting (RCA” which helps to evaluate the enterprise as matrix structure in its all parts. It aims to measure how much tangible and intangible values (assets of enterprises contribute to the enterprises. In other words, it measures how effectively, actively, and efficiently these values (assets are used. In short, it aims to measure sustainable competency of enterprises. As expressing the effect of tangible and intangible values (assets of the enterprise on the performance in mathematical and statistical methods is insufficient, it is targeted that RCA Method integrated with BSC model is based on matrix structure and control models. The effects of all complex factors in the enterprise on the performance (productivity and efficiency estimated algorithmically with cause and effect diagram. The contributions of matrix structures for reaching the management functional targets of the enterprises that operate in market competitive environment increasing day to day, is discussed. So in the context of modern management theories, as a contribution to BSC approach which is in the foreground in today’s administrative science of enterprises in matrix organizational structures, multidimensional performance evaluation model -RCA integrated with BSC Model proposal- is presented as strategic planning and strategic evaluation instrument.

  1. Pointing, looking at, and pressing keys: A diffusion model account of response modality.

    Science.gov (United States)

    Gomez, Pablo; Ratcliff, Roger; Childers, Russ

    2015-12-01

    Accumulation of evidence models of perceptual decision making have been able to account for data from a wide range of domains at an impressive level of precision. In particular, Ratcliff's (1978) diffusion model has been used across many different 2-choice tasks in which the response is executed via a key-press. In this article, we present 2 experiments in which we used a letter-discrimination task exploring 3 central aspects of a 2-choice task: the discriminability of the stimulus, the modality of the response execution (eye movement, key pressing, and pointing on a touchscreen), and the mapping of the response areas for the eye movement and the touchscreen conditions (consistent vs. inconsistent). We fitted the diffusion model to the data from these experiments and examined the behavior of the model's parameters. Fits of the model were consistent with the hypothesis that the same decision mechanism is used in the task with 3 different response methods. Drift rates are affected by the duration of the presentation of the stimulus while the response execution time changed as a function of the response modality.

  2. A kinetic model for type I and II IP3R accounting for mode changes.

    Science.gov (United States)

    Siekmann, Ivo; Wagner, Larry E; Yule, David; Crampin, Edmund J; Sneyd, James

    2012-08-22

    Based upon an extensive single-channel data set, a Markov model for types I and II inositol trisphosphate receptors (IP(3)R) is developed. The model aims to represent accurately the kinetics of both receptor types of IP(3)R depending on the concentrations of inositol trisphosphate (IP(3)), adenosine trisphosphate (ATP), and intracellular calcium (Ca(2+)). In particular, the model takes into account that for some combinations of ligands the IP(3)R switches between extended periods of inactivity alternating with intervals of bursting activity (mode changes). In a first step, the inactive and active modes are modeled separately. It is found that, within modes, both receptor types are ligand-independent. In a second step, the submodels are connected by transition rates. Ligand-dependent regulation of the channel activity is achieved by modulating these transitions between active and inactive modes. As a result, a compact representation of the IP(3)R is obtained that accurately captures stochastic single-channel dynamics including mode changes in a model with six states and 10 rate constants, only two of which are ligand-dependent.

  3. Modeling and Visualizing the Particle Beam in the Rare Isotope Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, Christopher [Argonne National Lab., IL (United States); Erdelyi, Bela [Argonne National Lab., IL (United States); Northern Illinois Univ. (United States)

    2006-01-01

    Argonne National Laboratory is actively pursuing research and design for a Rare Isotope Accelerator (RIA) facility that will aid basic research in nuclear physics by creating beams of unstable isotopes. Such a facility has been labeled as a high priority by the joint Department of Energy and National Science Foundation Nuclear Science Advisory Committee because it will allow more study on the nature of nucleonic matter, the origin of the elements, the Standard Model, and nuclear medicine. An important part of this research is computer simulations that model the behavior of the particle beam, specifically in the Fragment Separator. The Fragment Separator selects isotopes based on their trajectory in electromagnetic fields and then uses absorbers to separate particles with a certain mass and charge from the rest of the beam. This project focused on the development of a multivariate, correlated Gaussian distribution to model the distribution of particles in the beam as well as visualizations and analysis to view how this distribution changed when passing through an absorber. The distribution was developed in the COSY INFINITY programming language. The user inputs a covariance matrix and a vector of means for the six phase space variables, and the program outputs a vector of correlated, Gaussian random variables. A variety of random test cases were conducted in two, three and six variables. In each case, the expectation values, variances and covariances were calculated and they converged to the input values. The output of the absorber code is a large data set that stores all of the variables for each particle in the distribution. It is impossible to analyze such a large data set by hand, so visualizations and summary statistics had to be developed. The first visualization is a three-dimensional graph that shows the number of each isotope present after each slice of the absorber. A second graph plots any of the six phase space variables against any of the others to see

  4. An agent-based simulation model to study accountable care organizations.

    Science.gov (United States)

    Liu, Pai; Wu, Shinyi

    2016-03-01

    Creating accountable care organizations (ACOs) has been widely discussed as a strategy to control rapidly rising healthcare costs and improve quality of care; however, building an effective ACO is a complex process involving multiple stakeholders (payers, providers, patients) with their own interests. Also, implementation of an ACO is costly in terms of time and money. Immature design could cause safety hazards. Therefore, there is a need for analytical model-based decision-support tools that can predict the outcomes of different strategies to facilitate ACO design and implementation. In this study, an agent-based simulation model was developed to study ACOs that considers payers, healthcare providers, and patients as agents under the shared saving payment model of care for congestive heart failure (CHF), one of the most expensive causes of sometimes preventable hospitalizations. The agent-based simulation model has identified the critical determinants for the payment model design that can motivate provider behavior changes to achieve maximum financial and quality outcomes of an ACO. The results show nonlinear provider behavior change patterns corresponding to changes in payment model designs. The outcomes vary by providers with different quality or financial priorities, and are most sensitive to the cost-effectiveness of CHF interventions that an ACO implements. This study demonstrates an increasingly important method to construct a healthcare system analytics model that can help inform health policy and healthcare management decisions. The study also points out that the likely success of an ACO is interdependent with payment model design, provider characteristics, and cost and effectiveness of healthcare interventions.

  5. Rare semileptonic $B \\to K(\\pi)l_i^- l_j^+$ decay in vector leptoquark model

    CERN Document Server

    Duraisamy, Murugeswaran; Mohanta, Rukmani

    2016-01-01

    We investigate the consequence of vector leptoquarks on the rare semileptonic lepton flavour violating decays of $B$ meson which are more promising and effective channels to probe the new physics signal. We constrain the resulting new leptoquark parameter space by using the branching fractions of $B_{s, d} \\to l^+ l^-$ processes from LHCb and CMS experiments. We estimate the branching ratios of rare lepton flavour violating $B \\to K(\\pi)l_i^- l_j^+$ processes using the constrained leptoquark couplings. We also compute the forward-backward asymmetries and the lepton non-universality parameters of the LFV decays in the vector leptoquark model.

  6. Air quality modeling for accountability research: Operational, dynamic, and diagnostic evaluation

    Science.gov (United States)

    Henneman, Lucas R. F.; Liu, Cong; Hu, Yongtao; Mulholland, James A.; Russell, Armistead G.

    2017-10-01

    Photochemical grid models play a central role in air quality regulatory frameworks, including in air pollution accountability research, which seeks to demonstrate the extent to which regulations causally impacted emissions, air quality, and public health. There is a need, however, to develop and demonstrate appropriate practices for model application and evaluation in an accountability framework. We employ a combination of traditional and novel evaluation techniques to assess four years (2001-02, 2011-12) of simulated pollutant concentrations across a decade of major emissions reductions using the Community Multiscale Air Quality (CMAQ) model. We have grouped our assessments in three categories: Operational evaluation investigates how well CMAQ captures absolute concentrations; dynamic evaluation investigates how well CMAQ captures changes in concentrations across the decade of changing emissions; diagnostic evaluation investigates how CMAQ attributes variability in concentrations and sensitivities to emissions between meteorology and emissions, and how well this attribution compares to empirical statistical models. In this application, CMAQ captures O3 and PM2.5 concentrations and change over the decade in the Eastern United States similarly to past CMAQ applications and in line with model evaluation guidance; however, some PM2.5 species-EC, OC, and sulfate in particular-exhibit high biases in various months. CMAQ-simulated PM2.5 has a high bias in winter months and low bias in the summer, mainly due to a high bias in OC during the cold months and low bias in OC and sulfate during the summer. Simulated O3 and PM2.5 changes across the decade have normalized mean bias of less than 2.5% and 17%, respectively. Detailed comparisons suggest biased EC emissions, negative wintertime SO42- sensitivities to mobile source emissions, and incomplete capture of OC chemistry in the summer and winter. Photochemical grid model-simulated O3 and PM2.5 responses to emissions and

  7. Enterprise marketing potential modeling taking into account optimizing and dynamic essence of the potential

    Directory of Open Access Journals (Sweden)

    Potrashkova Lyudmyla Vladimirovna

    2014-12-01

    consequent enumeration. At the same time, the constituent part of the models system is constrained optimization block. Conclusions and directions of further researches. The suggested simulation and optimization models system of b2b-enterprise marketing potential result-based estimation has the following advantages: it corresponds optimizing essence of potential, takes into account marketing resources dynamics and allows to get estimation in the view of enterprise potential hierarchic levels. The suggested models system is the instrument for estimation and analysis of the future enterprise sales and marketing abilities, comparison of which with producing and financial abilities will allow to define narrow places in the analyzed enterprise activity and increase its general potential. The given models system is a part of mathematical providing to manage future enterprise abilities. The further investigations on research area have to be oriented to build models of the enterprise marketing potential estimation in integral system concerning enterprise integral potential estimation.

  8. Integrative analysis of functional genomic annotations and sequencing data to identify rare causal variants via hierarchical modeling

    Directory of Open Access Journals (Sweden)

    Marinela eCapanu

    2015-05-01

    Full Text Available Identifying the small number of rare causal variants contributing to disease has beena major focus of investigation in recent years, but represents a formidable statisticalchallenge due to the rare frequencies with which these variants are observed. In thiscommentary we draw attention to a formal statistical framework, namely hierarchicalmodeling, to combine functional genomic annotations with sequencing data with theobjective of enhancing our ability to identify rare causal variants. Using simulations weshow that in all configurations studied, the hierarchical modeling approach has superiordiscriminatory ability compared to a recently proposed aggregate measure of deleteriousness,the Combined Annotation-Dependent Depletion (CADD score, supportingour premise that aggregate functional genomic measures can more accurately identifycausal variants when used in conjunction with sequencing data through a hierarchicalmodeling approach

  9. A Unifying Modeling of Plant Shoot Gravitropism With an Explicit Account of the Effects of Growth

    Directory of Open Access Journals (Sweden)

    Renaud eBastien

    2014-04-01

    Full Text Available Gravitropism, the slow reorientation of plant growth in response to gravity, is a major determinant of the form and posture of land plants. Recently a universal model of shoot gravitropism, the AC model, has been presented, in which the dynamics of the tropic movement is only determined by the contradictory controls of i graviception, that tends to curve the plants towards the vertical, and ii proprioception, that tends to keep the stem straights. This model was found valid over a large range of species and over two order of magnitude in organ size. However the motor of the movement, the elongation, has been neglected in the AC model. Taking into account explicit growth effects, however, requires consideration of the material derivative, i.e. the rate of change of curvature bound to an expanding and convected organ elements. Here we show that it is possible to rewrite the material equation of curvature in a compact simplified form that express directly the curvature variation as a function of the median elongation andof the distribution of the differential growth. Through this extended model, called the ACE model, two main destabilizing effects of growth on the tropic movement are identified : i the passive orientation drift, which occurs when a curved element elongates without differential growth and ii the fixed curvature which occurs when a element leaves the elongation zone and is no longer able to change its curvature actively. By comparing the AC and ACE models to experiments, these two effects were however found negligible, revealing a probable selection for rapid convergence to the steady state shape during the tropic movement so as to escape the growth destabilizing effects, involving in particular a selection over proprioceptive sensitivity. Then the simplified AC mode can be used to analyze gravitropism and posture control in actively elongating plant organs without significant information loss.

  10. Adjusting particle-size distributions to account for aggregation in tephra-deposit model forecasts

    Science.gov (United States)

    Mastin, Larry G.; Van Eaton, Alexa; Durant, A.J.

    2016-01-01

    Volcanic ash transport and dispersion (VATD) models are used to forecast tephra deposition during volcanic eruptions. Model accuracy is limited by the fact that fine-ash aggregates (clumps into clusters), thus altering patterns of deposition. In most models this is accounted for by ad hoc changes to model input, representing fine ash as aggregates with density ρagg, and a log-normal size distribution with median μagg and standard deviation σagg. Optimal values may vary between eruptions. To test the variance, we used the Ash3d tephra model to simulate four deposits: 18 May 1980 Mount St. Helens; 16–17 September 1992 Crater Peak (Mount Spurr); 17 June 1996 Ruapehu; and 23 March 2009 Mount Redoubt. In 192 simulations, we systematically varied μagg and σagg, holding ρagg constant at 600 kg m−3. We evaluated the fit using three indices that compare modeled versus measured (1) mass load at sample locations; (2) mass load versus distance along the dispersal axis; and (3) isomass area. For all deposits, under these inputs, the best-fit value of μagg ranged narrowly between  ∼  2.3 and 2.7φ (0.20–0.15 mm), despite large variations in erupted mass (0.25–50 Tg), plume height (8.5–25 km), mass fraction of fine ( operational model forecasts. Further research may indicate whether this narrow range also reflects physical constraints on processes in the evolving cloud.

  11. Adjusting particle-size distributions to account for aggregation in tephra-deposit model forecasts

    Science.gov (United States)

    Mastin, Larry G.; Van Eaton, Alexa R.; Durant, Adam J.

    2016-07-01

    Volcanic ash transport and dispersion (VATD) models are used to forecast tephra deposition during volcanic eruptions. Model accuracy is limited by the fact that fine-ash aggregates (clumps into clusters), thus altering patterns of deposition. In most models this is accounted for by ad hoc changes to model input, representing fine ash as aggregates with density ρagg, and a log-normal size distribution with median μagg and standard deviation σagg. Optimal values may vary between eruptions. To test the variance, we used the Ash3d tephra model to simulate four deposits: 18 May 1980 Mount St. Helens; 16-17 September 1992 Crater Peak (Mount Spurr); 17 June 1996 Ruapehu; and 23 March 2009 Mount Redoubt. In 192 simulations, we systematically varied μagg and σagg, holding ρagg constant at 600 kg m-3. We evaluated the fit using three indices that compare modeled versus measured (1) mass load at sample locations; (2) mass load versus distance along the dispersal axis; and (3) isomass area. For all deposits, under these inputs, the best-fit value of μagg ranged narrowly between ˜ 2.3 and 2.7φ (0.20-0.15 mm), despite large variations in erupted mass (0.25-50 Tg), plume height (8.5-25 km), mass fraction of fine ( water content between these eruptions. This close agreement suggests that aggregation may be treated as a discrete process that is insensitive to eruptive style or magnitude. This result offers the potential for a simple, computationally efficient parameterization scheme for use in operational model forecasts. Further research may indicate whether this narrow range also reflects physical constraints on processes in the evolving cloud.

  12. Material Protection, Accounting, and Control Technologies (MPACT): Modeling and Simulation Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Cipiti, Benjamin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dunn, Timothy [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Durbin, Samual [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Durkee, Joe W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); England, Jeff [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Ketusky, Edward [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Li, Shelly [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lindgren, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Meier, David [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Miller, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Osburn, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pereira, Candido [Argonne National Lab. (ANL), Argonne, IL (United States); Rauch, Eric Benton [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scaglione, John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Scherer, Carolynn P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sprinkle, James K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Yoo, Tae-Sic [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-05

    The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal. This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling. To aid in framing its long-term goal, during FY16, a modeling and simulation roadmap is being developed for three major areas of investigation: (1) radiation transport and sensors, (2) process and chemical models, and (3) shock physics and assessments. For each area, current modeling approaches are described, and gaps and needs are identified.

  13. Accounting for exhaust gas transport dynamics in instantaneous emission models via smooth transition regression.

    Science.gov (United States)

    Kamarianakis, Yiannis; Gao, H Oliver

    2010-02-15

    Collecting and analyzing high frequency emission measurements has become very usual during the past decade as significantly more information with respect to formation conditions can be collected than from regulated bag measurements. A challenging issue for researchers is the accurate time-alignment between tailpipe measurements and engine operating variables. An alignment procedure should take into account both the reaction time of the analyzers and the dynamics of gas transport in the exhaust and measurement systems. This paper discusses a statistical modeling framework that compensates for variable exhaust transport delay while relating tailpipe measurements with engine operating covariates. Specifically it is shown that some variants of the smooth transition regression model allow for transport delays that vary smoothly as functions of the exhaust flow rate. These functions are characterized by a pair of coefficients that can be estimated via a least-squares procedure. The proposed models can be adapted to encompass inherent nonlinearities that were implicit in previous instantaneous emissions modeling efforts. This article describes the methodology and presents an illustrative application which uses data collected from a diesel bus under real-world driving conditions.

  14. Can the forward-shock model account for the multiwavelength emission of GRB afterglow 090510 ?

    CERN Document Server

    Neamus, Ano

    2010-01-01

    GRB 090510 is the first burst whose afterglow emission above 100 MeV was measured by Fermi over two decades in time. Owing to its power-law temporal decay and power-law spectrum, it seems likely that the high-energy emission is from the forward-shock energizing the ambient medium (the standard blast-wave model for GRB afterglows), the GeV flux and its decay rate being consistent with that model's expectations. However, the synchrotron emission from a collimated outflow (the standard jet model) has difficulties in accounting for the lower-energy afterglow emission, where a simultaneous break occurs in the optical and X-ray light-curves at 2 ks, but with the optical flux decay (before and after the break) being much slower than in the X-rays (at same time). The measured X-ray and GeV fluxes are incompatible with the higher-energy afterglow emission being from same spectral component as the lower-energy afterglow emission, which suggests a synchrotron self-Compton model for this afterglow. Cessation of energy in...

  15. Integrated Approach Model of Risk, Control and Auditing of Accounting Information Systems

    Directory of Open Access Journals (Sweden)

    Claudiu BRANDAS

    2013-01-01

    Full Text Available The use of IT in the financial and accounting processes is growing fast and this leads to an increase in the research and professional concerns about the risks, control and audit of Ac-counting Information Systems (AIS. In this context, the risk and control of AIS approach is a central component of processes for IT audit, financial audit and IT Governance. Recent studies in the literature on the concepts of risk, control and auditing of AIS outline two approaches: (1 a professional approach in which we can fit ISA, COBIT, IT Risk, COSO and SOX, and (2 a research oriented approach in which we emphasize research on continuous auditing and fraud using information technology. Starting from the limits of existing approaches, our study is aimed to developing and testing an Integrated Approach Model of Risk, Control and Auditing of AIS on three cycles of business processes: purchases cycle, sales cycle and cash cycle in order to improve the efficiency of IT Governance, as well as ensuring integrity, reality, accuracy and availability of financial statements.

  16. Statistical approaches to account for missing values in accelerometer data: Applications to modeling physical activity.

    Science.gov (United States)

    Xu, Selene Yue; Nelson, Sandahl; Kerr, Jacqueline; Godbole, Suneeta; Patterson, Ruth; Merchant, Gina; Abramson, Ian; Staudenmayer, John; Natarajan, Loki

    2016-07-10

    Physical inactivity is a recognized risk factor for many chronic diseases. Accelerometers are increasingly used as an objective means to measure daily physical activity. One challenge in using these devices is missing data due to device nonwear. We used a well-characterized cohort of 333 overweight postmenopausal breast cancer survivors to examine missing data patterns of accelerometer outputs over the day. Based on these observed missingness patterns, we created psuedo-simulated datasets with realistic missing data patterns. We developed statistical methods to design imputation and variance weighting algorithms to account for missing data effects when fitting regression models. Bias and precision of each method were evaluated and compared. Our results indicated that not accounting for missing data in the analysis yielded unstable estimates in the regression analysis. Incorporating variance weights and/or subject-level imputation improved precision by >50%, compared to ignoring missing data. We recommend that these simple easy-to-implement statistical tools be used to improve analysis of accelerometer data.

  17. ACCOUNTING HARMONIZATION AND HISTORICAL COST ACCOUNTING

    Directory of Open Access Journals (Sweden)

    Valentin Gabriel CRISTEA

    2017-05-01

    Full Text Available There is a huge interest in accounting harmonization and historical costs accounting, in what they offer us. In this article, different valuation models are discussed. Although one notices the movement from historical cost accounting to fair value accounting, each one has its advantages.

  18. REGRESSION MODEL FOR RISK REPORTING IN FINANCIAL STATEMENTS OF ACCOUNTING SERVICES ENTITIES

    Directory of Open Access Journals (Sweden)

    Mirela NICHITA

    2015-06-01

    Full Text Available The purpose of financial reports is to provide useful information to users; the utility of information is defined through the qualitative characteristics (fundamental and enhancing. The financial crisis emphasized the limits of financial reporting which has been unable to prevent investors about the risks they were facing. Due to the current changes in business environment, managers have been highly motivated to rethink and improve the risk governance philosophy, processes and methodologies. The lack of quality, timely data and adequate systems to capture, report and measure the right information across the organization is a fundamental challenge for implementing and sustaining all aspects of effective risk management. Starting with the 80s, the investors are more interested in narratives (Notes to financial statements, than in primary reports (financial position and performance. The research will apply a regression model for assessment of risk reporting by the professional (accounting and taxation services for major companies from Romania during the period 2009 – 2013.

  19. A Thermodamage Strength Theoretical Model of Ceramic Materials Taking into Account the Effect of Residual Stress

    Directory of Open Access Journals (Sweden)

    Weiguo Li

    2012-01-01

    Full Text Available A thermodamage strength theoretical model taking into account the effect of residual stress was established and applied to each temperature phase based on the study of effects of various physical mechanisms on the fracture strength of ultrahigh-temperature ceramics. The effects of SiC particle size, crack size, and SiC particle volume fraction on strength corresponding to different temperatures were studied in detail. This study showed that when flaw size is not large, the bigger SiC particle size results in the greater effect of tensile residual stress in the matrix grains on strength reduction, and this prediction coincides with experimental results; and the residual stress and the combined effort of particle size and crack size play important roles in controlling material strength.

  20. Taking individual scaling differences into account by analyzing profile data with the Mixed Assessor Model

    DEFF Research Database (Denmark)

    Brockhoff, Per Bruun; Schlich, Pascal; Skovgaard, Ib

    2015-01-01

    are deduced that include scaling difference in the error term to the proper extent. A meta study of 8619 sensory attributes from 369 sensory profile data sets from SensoBase (www.sensobase.fr) is conducted. In 45.3% of all attributes scaling heterogeneity is present (P-value ...) that properly takes this into account by a simple inclusion of the product averages as a covariate in the modeling and allowing the covariate regression coefficients to depend on the assessor. This gives a more powerful analysis by removing the scaling difference from the error term and proper confidence limits.......9% of the attributes having a product difference P-value in an intermediate range by the traditional approach, the new approach resulted in a clearly more significant result for 42.3% of these cases. Overall, the new approach claimed significant product difference (P-value

  1. REGRESSION MODEL FOR RISK REPORTING IN FINANCIAL STATEMENTS OF ACCOUNTING SERVICES ENTITIES

    Directory of Open Access Journals (Sweden)

    Mirela NICHITA

    2015-06-01

    Full Text Available The purpose of financial reports is to provide useful information to users; the utility of information is defined through the qualitative characteristics (fundamental and enhancing. The financial crisis emphasized the limits of financial reporting which has been unable to prevent investors about the risks they were facing. Due to the current changes in business environment, managers have been highly motivated to rethink and improve the risk governance philosophy, processes and methodologies. The lack of quality, timely data and adequate systems to capture, report and measure the right information across the organization is a fundamental challenge for implementing and sustaining all aspects of effective risk management. Starting with the 80s, the investors are more interested in narratives (Notes to financial statements, than in primary reports (financial position and performance. The research will apply a regression model for assessment of risk reporting by the professional (accounting and taxation services for major companies from Romania during the period 2009 – 2013.

  2. Accounting for detectability in fish distribution models: an approach based on time-to-first-detection

    Directory of Open Access Journals (Sweden)

    Mário Ferreira

    2015-12-01

    Full Text Available Imperfect detection (i.e., failure to detect a species when the species is present is increasingly recognized as an important source of uncertainty and bias in species distribution modeling. Although methods have been developed to solve this problem by explicitly incorporating variation in detectability in the modeling procedure, their use in freshwater systems remains limited. This is probably because most methods imply repeated sampling (≥ 2 of each location within a short time frame, which may be impractical or too expensive in most studies. Here we explore a novel approach to control for detectability based on the time-to-first-detection, which requires only a single sampling occasion and so may find more general applicability in freshwaters. The approach uses a Bayesian framework to combine conventional occupancy modeling with techniques borrowed from parametric survival analysis, jointly modeling factors affecting the probability of occupancy and the time required to detect a species. To illustrate the method, we modeled large scale factors (elevation, stream order and precipitation affecting the distribution of six fish species in a catchment located in north-eastern Portugal, while accounting for factors potentially affecting detectability at sampling points (stream depth and width. Species detectability was most influenced by depth and to lesser extent by stream width and tended to increase over time for most species. Occupancy was consistently affected by stream order, elevation and annual precipitation. These species presented a widespread distribution with higher uncertainty in tributaries and upper stream reaches. This approach can be used to estimate sampling efficiency and provide a practical framework to incorporate variations in the detection rate in fish distribution models.

  3. A "pivot" Model to set up Large Scale Rare Diseases Information Systems: Application to the Fibromuscular Dysplasia Registry.

    Science.gov (United States)

    Toubiana, Laurent; Ugon, Adrien; Giavarini, Alessandra; Riquier, Jérémie; Charlet, Jean; Jeunemaitre, Xavier; Plouin, Pierre-François; Jaulent, Marie-Christine

    2015-01-01

    The SIR-FMD project is a partnership between the Department of Genetics and Reference Centre for Rare Vascular Diseases at the Georges Pompidou European Hospital in Paris and the Medical Informatics and Knowledge Engineering Laboratory of Inserm. Its aim is to use an ontological approach to implement an information system for the French Fibromuscular Dysplasia Registry. The existing data was dispersed in numerous databases, which had been created independently. These databases have different structures and contain data of diverse quality. The project aims to provide generic solutions for the management of the communication of medical data. The secondary objective is to demonstrate the applicability of these generic solutions in the field of rare diseases (RD) in an operational context. The construction of the French FMD registry was a multistep process. A secure platform has been available since the beginning of November 2013. The medical records of 471 patients from the initial dataset provided by the HEGP-Paris, France have been included, and are accessible from a secure user account. Users are organized into a collaborative group, and can access patient groups. Each electronic patient record contains more than 2,200 items. The problem of semantic interoperability has become one of the major challenges for the development of applications requiring the sharing and reuse of data. The information system component of the SIR-FMD project has a direct impact on the standardisation of coding of rare diseases and thereby contributes to the development of e-Health.

  4. Model calculation of the static magnetic susceptibility in light rare earth metallic systems

    Science.gov (United States)

    Hammoud, Y.; Parlebas, J. C.

    1991-05-01

    Using the impurity Anderson model in the large N_f approximation, where N_f is the orbital and spin degeneracy of the f level, we calculate the zero temperature static paramagnetic susceptibility of light rare earth metallic systems. The calculation is performed for large values of the Coulomb U_ff electron-electron interactions with respect of the V hybridization of f1 and f2 configurations with the conduction states (i.e. f0 configuration) : we only keep the leading terms in a development in successive powers of 1/U_ff and V. Our numerical results on the magnetic susceptibility start from a simple analytic expression and are discussed in terms of the f level position, the hybridization V, the shape and filling of the conduction band and also the finite U_ff effects. Finally we present calculated curves for the susceptibility versus V in connection with the αγ transition of cerium and utilizing the same parameters as those used previously to obtain core level LIII absorption spectra : also in the case of the susceptibility, the hybridization appears to be an important parameter to describe the phase change from γ to α cerium. Nous utilisons le modèle d'Anderson à une impureté dans l'approximation des grands N_f où N_f est la dégénérescence d'orbitale et de spin du niveau f et nous calculons alors la susceptibilité paramagnétique statique (à température nulle) dans les systèmes métalliques de terres rares légères. Nous effectuons notre calcul pour des valeurs de l'interaction de Coulomb U_ff grandes par rapport à l'hybridation V des configurations f1 et f2 avec les états de conduction (c.-à-d. la configuration f0): nous ne retenons que les termes les plus imporatnts dans un développement en puissances successives de 1/U_ff et V. Ensuite nous discutons nos résultats numériques à partir d'une forme analytique simple obtenue pour la susceptibilité magnétique en fonction de la position du niveau f, de l'hybridation V, de la forme et du

  5. Accounting comparability and the accuracy of peer-based valuation models

    NARCIS (Netherlands)

    Young, S.; Zeng, Y.

    2015-01-01

    We examine the link between enhanced accounting comparability and the valuation performance of pricing multiples. Using the warranted multiple method proposed by Bhojraj and Lee (2002, Journal of Accounting Research), we demonstrate how enhanced accounting comparability leads to better peer-based va

  6. Accounting comparability and the accuracy of peer-based valuation models

    NARCIS (Netherlands)

    Young, S.; Zeng, Y.

    2015-01-01

    We examine the link between enhanced accounting comparability and the valuation performance of pricing multiples. Using the warranted multiple method proposed by Bhojraj and Lee (2002, Journal of Accounting Research), we demonstrate how enhanced accounting comparability leads to better peer-based va

  7. Modeling Lung Carcinogenesis in Radon-Exposed Miner Cohorts: Accounting for Missing Information on Smoking.

    Science.gov (United States)

    van Dillen, Teun; Dekkers, Fieke; Bijwaard, Harmen; Brüske, Irene; Wichmann, H-Erich; Kreuzer, Michaela; Grosche, Bernd

    2016-05-01

    Epidemiological miner cohort data used to estimate lung cancer risks related to occupational radon exposure often lack cohort-wide information on exposure to tobacco smoke, a potential confounder and important effect modifier. We have developed a method to project data on smoking habits from a case-control study onto an entire cohort by means of a Monte Carlo resampling technique. As a proof of principle, this method is tested on a subcohort of 35,084 former uranium miners employed at the WISMUT company (Germany), with 461 lung cancer deaths in the follow-up period 1955-1998. After applying the proposed imputation technique, a biologically-based carcinogenesis model is employed to analyze the cohort's lung cancer mortality data. A sensitivity analysis based on a set of 200 independent projections with subsequent model analyses yields narrow distributions of the free model parameters, indicating that parameter values are relatively stable and independent of individual projections. This technique thus offers a possibility to account for unknown smoking habits, enabling us to unravel risks related to radon, to smoking, and to the combination of both.

  8. The Iquique earthquake sequence of April 2014: Bayesian modeling accounting for prediction uncertainty

    Science.gov (United States)

    Duputel, Zacharie; Jiang, Junle; Jolivet, Romain; Simons, Mark; Rivera, Luis; Ampuero, Jean-Paul; Riel, Bryan; Owen, Susan E; Moore, Angelyn W; Samsonov, Sergey V; Ortega Culaciati, Francisco; Minson, Sarah E.

    2016-01-01

    The subduction zone in northern Chile is a well-identified seismic gap that last ruptured in 1877. On 1 April 2014, this region was struck by a large earthquake following a two week long series of foreshocks. This study combines a wide range of observations, including geodetic, tsunami, and seismic data, to produce a reliable kinematic slip model of the Mw=8.1 main shock and a static slip model of the Mw=7.7 aftershock. We use a novel Bayesian modeling approach that accounts for uncertainty in the Green's functions, both static and dynamic, while avoiding nonphysical regularization. The results reveal a sharp slip zone, more compact than previously thought, located downdip of the foreshock sequence and updip of high-frequency sources inferred by back-projection analysis. Both the main shock and the Mw=7.7 aftershock did not rupture to the trench and left most of the seismic gap unbroken, leaving the possibility of a future large earthquake in the region.

  9. A common signal detection model accounts for both perception and discrimination of the watercolor effect.

    Science.gov (United States)

    Devinck, Frédéric; Knoblauch, Kenneth

    2012-03-21

    Establishing the relation between perception and discrimination is a fundamental objective in psychophysics, with the goal of characterizing the neural mechanisms mediating perception. Here, we show that a procedure for estimating a perceptual scale based on a signal detection model also predicts discrimination performance. We use a recently developed procedure, Maximum Likelihood Difference Scaling (MLDS), to measure the perceptual strength of a long-range, color, filling-in phenomenon, the Watercolor Effect (WCE), as a function of the luminance ratio between the two components of its generating contour. MLDS is based on an equal-variance, gaussian, signal detection model and yields a perceptual scale with interval properties. The strength of the fill-in percept increased 10-15 times the estimate of the internal noise level for a 3-fold increase in the luminance ratio. Each observer's estimated scale predicted discrimination performance in a subsequent paired-comparison task. A common signal detection model accounts for both the appearance and discrimination data. Since signal detection theory provides a common metric for relating discrimination performance and neural response, the results have implications for comparing perceptual and neural response functions.

  10. Influential factors of red-light running at signalized intersection and prediction using a rare events logistic regression model.

    Science.gov (United States)

    Ren, Yilong; Wang, Yunpeng; Wu, Xinkai; Yu, Guizhen; Ding, Chuan

    2016-10-01

    Red light running (RLR) has become a major safety concern at signalized intersection. To prevent RLR related crashes, it is critical to identify the factors that significantly impact the drivers' behaviors of RLR, and to predict potential RLR in real time. In this research, 9-month's RLR events extracted from high-resolution traffic data collected by loop detectors from three signalized intersections were applied to identify the factors that significantly affect RLR behaviors. The data analysis indicated that occupancy time, time gap, used yellow time, time left to yellow start, whether the preceding vehicle runs through the intersection during yellow, and whether there is a vehicle passing through the intersection on the adjacent lane were significantly factors for RLR behaviors. Furthermore, due to the rare events nature of RLR, a modified rare events logistic regression model was developed for RLR prediction. The rare events logistic regression method has been applied in many fields for rare events studies and shows impressive performance, but so far none of previous research has applied this method to study RLR. The results showed that the rare events logistic regression model performed significantly better than the standard logistic regression model. More importantly, the proposed RLR prediction method is purely based on loop detector data collected from a single advance loop detector located 400 feet away from stop-bar. This brings great potential for future field applications of the proposed method since loops have been widely implemented in many intersections and can collect data in real time. This research is expected to contribute to the improvement of intersection safety significantly.

  11. A Modified Model of Ecological Footprint Accounting and Its Application to Cropland in Jiangsu,China

    Institute of Scientific and Technical Information of China (English)

    LIU Qin-Pu; LIN Zhen-Shan; FENG Nian-Hua; LIU Yong-Mei

    2008-01-01

    Based on the theory of emergy analysis,a modified model of ecological footprint accounting,termed emergetic ecological footprint (EMEF) in contrast to the conventional ecological footprint (EF) model,is formulated and applied to a case study of Jiangsu cropland,China.Comparisons between the EF and the EMEF with respect to grain,cotton,and food oil were outlined.Per capita EF and EMEF of cropland were also presented to depict the resources consumption level by comparing the biocapacity (BC) or emergetic biocapacity (EMBC,a new BC calculation by emergy analysis)of the same area.In the meanwhile,the ecological sustainability index (ESI),a new concept initiated by the authors,was established in the modified model to indicate and compare the sustainability of cropland use at different levels and between different regions.The results from conventional EF showed that per capita EF of the cropland has exceeded its per capita BC in Jiangsu since 1986.In contrast,based on the EMBC,the per capita EMEF exceeded the per capita EMBC 5 years earlier.The ESIs of Jiangsu cropland use were between 0.7 and 0.4 by the conventional method,while the numbers were between 0.7 and 0.3 by the modified one.The fact that the results of the two methods were similar showed that the modified model was reasonable and feasible,although some principles of the EF and EMEF were quite different.Also,according to the realities of Jiangsu'cropland use,the results from the modified model were more acceptable.

  12. Accounting for selection bias in species distribution models: An econometric approach on forested trees based on structural modeling

    Science.gov (United States)

    Ay, Jean-Sauveur; Guillemot, Joannès; Martin-StPaul, Nicolas K.; Doyen, Luc; Leadley, Paul

    2015-04-01

    Species distribution models (SDMs) are widely used to study and predict the outcome of global change on species. In human dominated ecosystems the presence of a given species is the result of both its ecological suitability and human footprint on nature such as land use choices. Land use choices may thus be responsible for a selection bias in the presence/absence data used in SDM calibration. We present a structural modelling approach (i.e. based on structural equation modelling) that accounts for this selection bias. The new structural species distribution model (SSDM) estimates simultaneously land use choices and species responses to bioclimatic variables. A land use equation based on an econometric model of landowner choices was joined to an equation of species response to bioclimatic variables. SSDM allows the residuals of both equations to be dependent, taking into account the possibility of shared omitted variables and measurement errors. We provide a general description of the statistical theory and a set of application on forested trees over France using databases of climate and forest inventory at different spatial resolution (from 2km to 8 km). We also compared the output of the SSDM with outputs of a classical SDM in term of bioclimatic response curves and potential distribution under current climate. According to the species and the spatial resolution of the calibration dataset, shapes of bioclimatic response curves the modelled species distribution maps differed markedly between the SSDM and classical SDMs. The magnitude and directions of these differences were dependent on the correlations between the errors from both equations and were highest for higher spatial resolutions. A first conclusion is that the use of classical SDMs can potentially lead to strong miss-estimation of the actual and future probability of presence modelled. Beyond this selection bias, the SSDM we propose represents a crucial step to account for economic constraints on tree

  13. Carbon accounting of forest bioenergy: from model calibrations to policy options (Invited)

    Science.gov (United States)

    Lamers, P.

    2013-12-01

    knowledge in the field by comparing different state-of-the-art temporal forest carbon modeling efforts, and discusses whether or to what extent a deterministic ';carbon debt' accounting is possible and appropriate. It concludes upon the possible scientific and eventually political choices in temporal carbon accounting for regulatory frameworks including alternative options to address unintentional carbon losses within forest ecosystems/bioenergy systems.

  14. Standard model of the rare earths analyzed from the Hubbard I approximation

    Science.gov (United States)

    Locht, I. L. M.; Kvashnin, Y. O.; Rodrigues, D. C. M.; Pereiro, M.; Bergman, A.; Bergqvist, L.; Lichtenstein, A. I.; Katsnelson, M. I.; Delin, A.; Klautau, A. B.; Johansson, B.; Di Marco, I.; Eriksson, O.

    2016-08-01

    In this work we examine critically the electronic structure of the rare-earth elements by use of the so-called Hubbard I approximation. From the theoretical side all measured features of both occupied and unoccupied states are reproduced, without significant deviations between observations and theory. We also examine cohesive properties like the equilibrium volume and bulk modulus, where we find, in general, a good agreement between theory and measurements. In addition, we have reproduced the spin and orbital moments of these elements as they are reflected from measurements of the saturation moment. We have also employed the Hubbard I approximation to extract the interatomic exchange parameters of an effective spin Hamiltonian for the heavy rare earths. We show that the Hubbard I approximation gives results which are consistent with calculations where 4 f electrons are treated as core states for Gd. The latter approach was also used to address the series of the heavy/late rare earths. Via Monte Carlo simulations we obtained ordering temperatures which reproduce measurements within about 20 % . We have further illustrated the accuracy of these exchange parameters by comparing measured and calculated magnetic configurations for the heavy rare earths and the magnon dispersion for Gd. The Hubbard I approximation is compared to other theories of the electronic structure, and we argue that it is superior. We discuss the relevance of our results in general and how this makes it possible to treat the electronic structure of materials containing rare-earth elements, such as permanent magnets, magnetostrictive compounds, photovoltaics, optical fibers, topological insulators, and molecular magnets.

  15. Modelling the range expansion of the Tiger mosquito in a Mediterranean Island accounting for imperfect detection.

    Science.gov (United States)

    Tavecchia, Giacomo; Miranda, Miguel-Angel; Borrás, David; Bengoa, Mikel; Barceló, Carlos; Paredes-Esquivel, Claudia; Schwarz, Carl

    2017-01-01

    Aedes albopictus (Diptera; Culicidae) is a highly invasive mosquito species and a competent vector of several arboviral diseases that have spread rapidly throughout the world. Prevalence and patterns of dispersal of the mosquito are of central importance for an effective control of the species. We used site-occupancy models accounting for false negative detections to estimate the prevalence, the turnover, the movement pattern and the growth rate in the number of sites occupied by the mosquito in 17 localities throughout Mallorca Island. Site-occupancy probability increased from 0.35 in the 2012, year of first reported observation of the species, to 0.89 in 2015. Despite a steady increase in mosquito presence, the extinction probability was generally high indicating a high turnover in the occupied sites. We considered two site-dependent covariates, namely the distance from the point of first observation and the estimated yearly occupancy rate in the neighborhood, as predicted by diffusion models. Results suggested that mosquito distribution during the first year was consistent with what predicted by simple diffusion models, but was not consistent with the diffusion model in subsequent years when it was similar to those expected from leapfrog dispersal events. Assuming a single initial colonization event, the spread of Ae. albopictus in Mallorca followed two distinct phases, an early one consistent with diffusion movements and a second consistent with long distance, 'leapfrog', movements. The colonization of the island was fast, with ~90% of the sites estimated to be occupied 3 years after the colonization. The fast spread was likely to have occurred through vectors related to human mobility such as cars or other vehicles. Surveillance and management actions near the introduction point would only be effective during the early steps of the colonization.

  16. Long-term fiscal implications of funding assisted reproduction: a generational accounting model for Spain

    Directory of Open Access Journals (Sweden)

    R. Matorras

    2015-12-01

    Full Text Available The aim of this study was to assess the lifetime economic benefits of assisted reproduction in Spain by calculating the return on this investment. We developed a generational accounting model that simulates the flow of taxes paid by the individual, minus direct government transfers received over the individual’s lifetime. The difference between discounted transfers and taxes minus the cost of either IVF or artificial insemination (AI equals the net fiscal contribution (NFC of a child conceived through assisted reproduction. We conducted sensitivity analysis to test the robustness of our results under various macroeconomic scenarios. A child conceived through assisted reproduction would contribute €370,482 in net taxes to the Spanish Treasury and would receive €275,972 in transfers over their lifetime. Taking into account that only 75% of assisted reproduction pregnancies are successful, the NFC was estimated at €66,709 for IVF-conceived children and €67,253 for AI-conceived children. The return on investment for each euro invested was €15.98 for IVF and €18.53 for AI. The long-term NFC of a child conceived through assisted reproduction could range from €466,379 to €-9,529 (IVF and from €466,923 to €-8,985 (AI. The return on investment would vary between €-2.28 and €111.75 (IVF, and €-2.48 and €128.66 (AI for each euro invested. The break-even point at which the financial position would begin to favour the Spanish Treasury ranges between 29 and 41 years of age. Investment in assisted reproductive techniques may lead to positive discounted future fiscal revenue, notwithstanding its beneficial psychological effect for infertile couples in Spain.

  17. A performance weighting procedure for GCMs based on explicit probabilistic models and accounting for observation uncertainty

    Science.gov (United States)

    Renard, Benjamin; Vidal, Jean-Philippe

    2016-04-01

    In recent years, the climate modeling community has put a lot of effort into releasing the outputs of multimodel experiments for use by the wider scientific community. In such experiments, several structurally distinct GCMs are run using the same observed forcings (for the historical period) or the same projected forcings (for the future period). In addition, several members are produced for a single given model structure, by running each GCM with slightly different initial conditions. This multiplicity of GCM outputs offers many opportunities in terms of uncertainty quantification or GCM comparisons. In this presentation, we propose a new procedure to weight GCMs according to their ability to reproduce the observed climate. Such weights can be used to combine the outputs of several models in a way that rewards good-performing models and discards poorly-performing ones. The proposed procedure has the following main properties: 1. It is based on explicit probabilistic models describing the time series produced by the GCMs and the corresponding historical observations, 2. It can use several members whenever available, 3. It accounts for the uncertainty in observations, 4. It assigns a weight to each GCM (all weights summing up to one), 5. It can also assign a weight to the "H0 hypothesis" that all GCMs in the multimodel ensemble are not compatible with observations. The application of the weighting procedure is illustrated with several case studies including synthetic experiments, simple cases where the target GCM output is a simple univariate variable and more realistic cases where the target GCM output is a multivariate and/or a spatial variable. These case studies illustrate the generality of the procedure which can be applied in a wide range of situations, as long as the analyst is prepared to make an explicit probabilistic assumption on the target variable. Moreover, these case studies highlight several interesting properties of the weighting procedure. In

  18. S-SCAM, a rare copy number variation gene, induces schizophrenia-related endophenotypes in transgenic mouse model.

    Science.gov (United States)

    Zhang, Nanyan; Zhong, Peng; Shin, Seung Min; Metallo, Jacob; Danielson, Eric; Olsen, Christopher M; Liu, Qing-song; Lee, Sang H

    2015-02-01

    Accumulating genetic evidence suggests that schizophrenia (SZ) is associated with individually rare copy number variations (CNVs) of diverse genes, often specific to single cases. However, the causality of these rare mutations remains unknown. One of the rare CNVs found in SZ cohorts is the duplication of Synaptic Scaffolding Molecule (S-SCAM, also called MAGI-2), which encodes a postsynaptic scaffolding protein controlling synaptic AMPA receptor levels, and thus the strength of excitatory synaptic transmission. Here we report that, in a transgenic mouse model simulating the duplication conditions, elevation of S-SCAM levels in excitatory neurons of the forebrain was sufficient to induce multiple SZ-related endophenotypes. S-SCAM transgenic mice showed an increased number of lateral ventricles and a reduced number of parvalbumin-stained neurons. In addition, the mice exhibited SZ-like behavioral abnormalities, including hyperlocomotor activity, deficits in prepulse inhibition, increased anxiety, impaired social interaction, and working memory deficit. Notably, the S-SCAM transgenic mice showed a unique sex difference in showing these behavioral symptoms, which is reminiscent of human conditions. These behavioral abnormalities were accompanied by hyperglutamatergic function associated with increased synaptic AMPA receptor levels and impaired long-term potentiation. Importantly, reducing glutamate release by the group 2 metabotropic glutamate receptor agonist LY379268 ameliorated the working memory deficits in the transgenic mice, suggesting that hyperglutamatergic function underlies the cognitive functional deficits. Together, these results contribute to validate a causal relationship of the rare S-SCAM CNV and provide supporting evidence for the rare CNV hypothesis in SZ pathogenesis. Furthermore, the S-SCAM transgenic mice provide a valuable new animal model for studying SZ pathogenesis.

  19. Historical Account to the State of the Art in Debris Flow Modeling

    Science.gov (United States)

    Pudasaini, Shiva P.

    2013-04-01

    In this contribution, I present a historical account of debris flow modelling leading to the state of the art in simulations and applications. A generalized two-phase model is presented that unifies existing avalanche and debris flow theories. The new model (Pudasaini, 2012) covers both the single-phase and two-phase scenarios and includes many essential and observable physical phenomena. In this model, the solid-phase stress is closed by Mohr-Coulomb plasticity, while the fluid stress is modeled as a non-Newtonian viscous stress that is enhanced by the solid-volume-fraction gradient. A generalized interfacial momentum transfer includes viscous drag, buoyancy and virtual mass forces, and a new generalized drag force is introduced to cover both solid-like and fluid-like drags. Strong couplings between solid and fluid momentum transfer are observed. The two-phase model is further extended to describe the dynamics of rock-ice avalanches with new mechanical models. This model explains dynamic strength weakening and includes internal fluidization, basal lubrication, and exchanges of mass and momentum. The advantages of the two-phase model over classical (effectively single-phase) models are discussed. Advection and diffusion of the fluid through the solid are associated with non-linear fluxes. Several exact solutions are constructed, including the non-linear advection-diffusion of fluid, kinematic waves of debris flow front and deposition, phase-wave speeds, and velocity distribution through the flow depth and through the channel length. The new model is employed to study two-phase subaerial and submarine debris flows, the tsunami generated by the debris impact at lakes/oceans, and rock-ice avalanches. Simulation results show that buoyancy enhances flow mobility. The virtual mass force alters flow dynamics by increasing the kinetic energy of the fluid. Newtonian viscous stress substantially reduces flow deformation, whereas non-Newtonian viscous stress may change the

  20. Modelling overbank flow on farmed catchments taking into account spatial hydrological discontinuities

    Science.gov (United States)

    Moussa, R.; Tilma, M.; Chahinian, N.; Huttel, O.

    2003-04-01

    In agricultural catchments, hydrological processes are largely variable in space due to human impact causing hydrological discontinuities such as ditch network, field limits and terraces. The ditch network accelerates runoff by concentrating flows, drains the water table or replenishes it by reinfiltration of the runoff water. During extreme flood events, overbank flow occurs and surface pathflows are modified. The purpose of this study is to assess the influence of overbank flow on hydrograph shape during flood events. For that, MHYDAS, a physically based distributed hydrological model, was especially developed to take into account these hydrological discontinuities. The model considers the catchment as a series of interconnected hydrological unit. Runoff from each unit is estimated using a deterministic model based on the pounding-time algorithm and then routed through the ditch network using the diffusive wave equation. Overbank flow is modelled by modifying links between the hydrological units and the ditch network. The model was applied to simulate the main hydrological processes on a small headwater farmed Mediterranean catchment located in Southern France. The basic hydrometeorological equipment consists of a meteorological station, rain gauges, a tensio-neutronic and a piezometric measurement network, and eight water flow measurements. A multi-criteria and multi-scale approach was used. Three independent error criteria (Nash, error on volume and error on peak flow) were calculated and combined using the Pareto technique. Then, a multi-scale approach was used to calibrate and validate the model for the eight water flow measurements. The application of MHYDAS on the extreme ten flood events of the last decade enables to identify the ditches where overbank flows occur and to calculate discharge at various points of the ditch network. Results show that for the extreme flood event, more than 45% of surface runoff occur due to overbank flow. Discussion shows that

  1. Use of the Sacramento Soil Moisture Accounting Model in Areas with Insufficient Forcing Data

    Science.gov (United States)

    Kuzmin, V.

    2009-04-01

    The Sacramento Soil Moisture Accounting model (SAC-SMA) is known as a very reliable and effective hydrological model. It is widely used by the U.S. National Weather Service (NWS) and many organizations in other countries for operational forecasting of flash floods. As a purely conceptual model, the SAC-SMA requires a periodic re-calibration. However, this procedure is not trivial in watersheds with little or no historical data, in areas with changing watershed properties, in a changing climate environment, in regions with low quality and low spatial resolution forcing data etc. In such cases, so-called physically based models with measurable parameters also may not be an alternative, because they usually require high quality forcing data and, hence, are quite expensive. Therefore, this type of models can not be implemented in countries with scarce surface observation data. To resolve this problem, we offer using a very fast and efficient automatic calibration algorithm, a Stepwise Line Search (SLS), which has been implementing in NWS since 2005, and also its modifications that were developed especially for automated operational forecasting of flash floods in regions where high resolution and high quality forcing data are not available. The SLS-family includes several simple yet efficient calibration algorithms: 1) SLS-F, which supposes simultaneous natural smoothing of the response surface by quasi-local estimation of F-indices, what allows finding the most stable and reliable parameters that can be different from "global" optima in usual sense. (Thus, this method slightly transforms the original objective function); 2) SLS-2L (Two-Loop SLS), which is suitable for basins where hydraulic properties of soil are unknown; 3) SLS-2LF, which represents a conjunction of the SLS-F and SLS-2L algorithms and allows obtaining the SAC-SMA parameters that can be transferred to ungauged catchments; 4) SLS-E, which also supposes stochastic filtering of the model input through

  2. Do current connectionist learning models account for reading development in different languages?

    Science.gov (United States)

    Hutzler, Florian; Ziegler, Johannes C; Perry, Conrad; Wimmer, Heinz; Zorzi, Marco

    2004-04-01

    Learning to read a relatively irregular orthography, such as English, is harder and takes longer than learning to read a relatively regular orthography, such as German. At the end of grade 1, the difference in reading performance on a simple set of words and nonwords is quite dramatic. Whereas children using regular orthographies are already close to ceiling, English children read only about 40% of the words and nonwords correctly. It takes almost 4 years for English children to come close to the reading level of their German peers. In the present study, we investigated to what extent recent connectionist learning models are capable of simulating this cross-language learning rate effect as measured by nonword decoding accuracy. We implemented German and English versions of two major connectionist reading models, Plaut et al.'s (Plaut, D. C., McClelland, J. L., Seidenberg, M. S., & Patterson, K. (1996). Understanding normal and impaired word reading: computational principles in quasi-regular domains. Psychological Review, 103, 56-115) parallel distributed model and Zorzi et al.'s (Zorzi, M., Houghton, G., & Butterworth, B. (1998a). Two routes or one in reading aloud? A connectionist dual-process model. Journal of Experimental Psychology: Human Perception and Performance, 24, 1131-1161); two-layer associative network. While both models predicted an overall advantage for the more regular orthography (i.e. German over English), they failed to predict that the difference between children learning to read regular versus irregular orthographies is larger earlier on. Further investigations showed that the two-layer network could be brought to simulate the cross-language learning rate effect when cross-language differences in teaching methods (phonics versus whole-word approach) were taken into account. The present work thus shows that in order to adequately capture the pattern of reading acquisition displayed by children, current connectionist models must not only be

  3. Estimation of the physico-chemical parameters of materials based on rare earth elements with the application of computational model

    Science.gov (United States)

    Mamaev, K.; Obkhodsky, A.; Popov, A.

    2016-01-01

    Computational model, technique and the basic principles of operation program complex for quantum-chemical calculations of material's physico-chemical parameters with rare earth elements are discussed. The calculating system is scalable and includes CPU and GPU computational resources. Control and operation of computational jobs and also Globus Toolkit 5 software provides the possibility to join computer users in a unified system of data processing with peer-to-peer architecture. CUDA software is used to integrate graphic processors into calculation system.

  4. The Charitable Trust Model: An Alternative Approach For Department Of Defense Accounting

    Science.gov (United States)

    2016-12-01

    Constitution declares, “No Money shall be drawn from the Treasury, but in Consequence of Appropriations made by Law ; and a regular Statement and Account...accounting to supplant the current corporate-style financial management and reporting practices mandated by federal law . First, the researcher identifies... administration . The researcher then analyzes how the misapplied logic of private sector accounting creates weakness and inconsistencies in federal

  5. Accounting for spatial correlation errors in the assimilation of GRACE into hydrological models through localization

    Science.gov (United States)

    Khaki, M.; Schumacher, M.; Forootan, E.; Kuhn, M.; Awange, J. L.; van Dijk, A. I. J. M.

    2017-10-01

    Assimilation of terrestrial water storage (TWS) information from the Gravity Recovery And Climate Experiment (GRACE) satellite mission can provide significant improvements in hydrological modelling. However, the rather coarse spatial resolution of GRACE TWS and its spatially correlated errors pose considerable challenges for achieving realistic assimilation results. Consequently, successful data assimilation depends on rigorous modelling of the full error covariance matrix of the GRACE TWS estimates, as well as realistic error behavior for hydrological model simulations. In this study, we assess the application of local analysis (LA) to maximize the contribution of GRACE TWS in hydrological data assimilation. For this, we assimilate GRACE TWS into the World-Wide Water Resources Assessment system (W3RA) over the Australian continent while applying LA and accounting for existing spatial correlations using the full error covariance matrix. GRACE TWS data is applied with different spatial resolutions including 1° to 5° grids, as well as basin averages. The ensemble-based sequential filtering technique of the Square Root Analysis (SQRA) is applied to assimilate TWS data into W3RA. For each spatial scale, the performance of the data assimilation is assessed through comparison with independent in-situ ground water and soil moisture observations. Overall, the results demonstrate that LA is able to stabilize the inversion process (within the implementation of the SQRA filter) leading to less errors for all spatial scales considered with an average RMSE improvement of 54% (e.g., 52.23 mm down to 26.80 mm) for all the cases with respect to groundwater in-situ measurements. Validating the assimilated results with groundwater observations indicates that LA leads to 13% better (in terms of RMSE) assimilation results compared to the cases with Gaussian errors assumptions. This highlights the great potential of LA and the use of the full error covariance matrix of GRACE TWS

  6. Short-run analysis of fiscal policy and the current account in a finite horizon model

    OpenAIRE

    Heng-fu Zou

    1995-01-01

    This paper utilizes a technique developed by Judd to quantify the short-run effects of fiscal policies and income shocks on the current account in a small open economy. It is found that: (1) a future increase in government spending improves the short-run current account; (2) a future tax increase worsens the short-run current account; (3) a present increase in the government spending worsens the short-run current account dollar by dollar, while a present increase in the income improves the cu...

  7. Process Accounting

    OpenAIRE

    Gilbertson, Keith

    2002-01-01

    Standard utilities can help you collect and interpret your Linux system's process accounting data. Describes the uses of process accounting, standard process accounting commands, and example code that makes use of process accounting utilities.

  8. Allowed rare pion and muon decays as tests of the Standard Model

    CERN Document Server

    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^+\

  9. Underwriting information-theoretic accounts of quantum mechanics with a realist, psi-epistemic model

    Science.gov (United States)

    Stuckey, W. M.; Silberstein, Michael; McDevitt, Timothy

    2016-05-01

    We propose an adynamical interpretation of quantum theory called Relational Blockworld (RBW) where the fundamental ontological element is a 4D graphical amalgam of space, time and sources called a “spacetimesource element.” These are fundamental elements of space, time and sources, not source elements in space and time. The transition amplitude for a spacetimesource element is computed using a path integral with discrete graphical action. The action for a spacetimesource element is constructed from a difference matrix K and source vector J on the graph, as in lattice gauge theory. K is constructed from graphical field gradients so that it contains a non-trivial null space and J is then restricted to the row space of K, so that it is divergence-free and represents a conserved exchange of energy-momentum. This construct of K and J represents an adynamical global constraint between sources, the spacetime metric and the energy-momentum content of the spacetimesource element, rather than a dynamical law for time-evolved entities. To illustrate this interpretation, we explain the simple EPR-Bell and twin-slit experiments. This interpretation of quantum mechanics constitutes a realist, psi-epistemic model that might underwrite certain information-theoretic accounts of the quantum.

  10. Design of a Competency-Based Assessment Model in the Field of Accounting

    Science.gov (United States)

    Ciudad-Gómez, Adelaida; Valverde-Berrocoso, Jesús

    2012-01-01

    This paper presents the phases involved in the design of a methodology to contribute both to the acquisition of competencies and to their assessment in the field of Financial Accounting, within the European Higher Education Area (EHEA) framework, which we call MANagement of COMpetence in the areas of Accounting (MANCOMA). Having selected and…

  11. Modeling of rare earth element sorption to the Gram positive Bacillus subtilis bacteria surface.

    Science.gov (United States)

    Martinez, Raul E; Pourret, Olivier; Takahashi, Yoshio

    2014-01-01

    In this study, rare earth element (REE) binding constants and site concentration on the Gram+ bacteria surfaces were quantified using a multi-site Langmuir isotherm model, along with a linear programming regression method (LPM), applied to fit experimental REE sorption data. This approach found one discrete REE binding site on the Gram+ Bacillus subtilis surface for the pH range of 2.5-4.5. Average log10 REE binding constants for a site j on these bacteria ranged from 1.08±0.04 to 1.40±0.04 for the light REE (LREE: La to Eu), and from 1.36±0.03 to 2.18±0.14 for the heavy REE (HREE: Gd to Lu) at the highest biomass concentration of 1.3 g/L of B. subtilis bacteria. Similar values were obtained for bacteria concentrations of 0.39 and 0.67 g/L indicating the independence of REE sorption constants on biomass concentration. Within the experimental pH range in this study, B. subtilis was shown to have a lower affinity for LREE (e.g. La, Ce, Pr, Nd) and a higher affinity for HREE (e.g. Tm, Yb, Lu) suggesting an enrichment of HREE on the surface of Gram+ bacteria. Total surface binding site concentrations of 6.73±0.06 to 5.67±0.06 and 5.53±0.07 to 4.54±0.03 mol/g of bacteria were observed for LREE and HREE respectively, with the exception of Y, which showed a total site concentration of 9.53±0.03, and a log K(REE,j) of 1.46±0.02 for a biomass content of 1.3 g/L. The difference in these values (e.g. a lower affinity and increased binding site concentration for LREE, and the contrary for the HREE) suggests a distinction between the LREE and HREE binding modes to the Gram+ bacteria reactive surface at low pH. This further implies that HREE may bind more than one monoprotic reactive group on the cell surface. A multisite Langmuir isotherm approach along with the LPM regression method, not requiring prior knowledge of the number or concentration of cell surface REE complexation sites, were able to distinguish between the sorption constant and binding site concentration

  12. A pluralistic account of homology: adapting the models to the data.

    Science.gov (United States)

    Haggerty, Leanne S; Jachiet, Pierre-Alain; Hanage, William P; Fitzpatrick, David A; Lopez, Philippe; O'Connell, Mary J; Pisani, Davide; Wilkinson, Mark; Bapteste, Eric; McInerney, James O

    2014-03-01

    Defining homologous genes is important in many evolutionary studies but raises obvious issues. Some of these issues are conceptual and stem from our assumptions of how a gene evolves, others are practical, and depend on the algorithmic decisions implemented in existing software. Therefore, to make progress in the study of homology, both ontological and epistemological questions must be considered. In particular, defining homologous genes cannot be solely addressed under the classic assumptions of strong tree thinking, according to which genes evolve in a strictly tree-like fashion of vertical descent and divergence and the problems of homology detection are primarily methodological. Gene homology could also be considered under a different perspective where genes evolve as "public goods," subjected to various introgressive processes. In this latter case, defining homologous genes becomes a matter of designing models suited to the actual complexity of the data and how such complexity arises, rather than trying to fit genetic data to some a priori tree-like evolutionary model, a practice that inevitably results in the loss of much information. Here we show how important aspects of the problems raised by homology detection methods can be overcome when even more fundamental roots of these problems are addressed by analyzing public goods thinking evolutionary processes through which genes have frequently originated. This kind of thinking acknowledges distinct types of homologs, characterized by distinct patterns, in phylogenetic and nonphylogenetic unrooted or multirooted networks. In addition, we define "family resemblances" to include genes that are related through intermediate relatives, thereby placing notions of homology in the broader context of evolutionary relationships. We conclude by presenting some payoffs of adopting such a pluralistic account of homology and family relationship, which expands the scope of evolutionary analyses beyond the traditional, yet

  13. Situated sentence processing: the coordinated interplay account and a neurobehavioral model.

    Science.gov (United States)

    Crocker, Matthew W; Knoeferle, Pia; Mayberry, Marshall R

    2010-03-01

    Empirical evidence demonstrating that sentence meaning is rapidly reconciled with the visual environment has been broadly construed as supporting the seamless interaction of visual and linguistic representations during situated comprehension. Based on recent behavioral and neuroscientific findings, however, we argue for the more deeply rooted coordination of the mechanisms underlying visual and linguistic processing, and for jointly considering the behavioral and neural correlates of scene-sentence reconciliation during situated comprehension. The Coordinated Interplay Account (CIA; Knoeferle, P., & Crocker, M. W. (2007). The influence of recent scene events on spoken comprehension: Evidence from eye movements. Journal of Memory and Language, 57(4), 519-543) asserts that incremental linguistic interpretation actively directs attention in the visual environment, thereby increasing the salience of attended scene information for comprehension. We review behavioral and neuroscientific findings in support of the CIA's three processing stages: (i) incremental sentence interpretation, (ii) language-mediated visual attention, and (iii) the on-line influence of non-linguistic visual context. We then describe a recently developed connectionist model which both embodies the central CIA proposals and has been successfully applied in modeling a range of behavioral findings from the visual world paradigm (Mayberry, M. R., Crocker, M. W., & Knoeferle, P. (2009). Learning to attend: A connectionist model of situated language comprehension. Cognitive Science). Results from a new simulation suggest the model also correlates with event-related brain potentials elicited by the immediate use of visual context for linguistic disambiguation (Knoeferle, P., Habets, B., Crocker, M. W., & Münte, T. F. (2008). Visual scenes trigger immediate syntactic reanalysis: Evidence from ERPs during situated spoken comprehension. Cerebral Cortex, 18(4), 789-795). Finally, we argue that the mechanisms

  14. Toward an Human Resource Accounting (HRA)-Based Model for Designing an Organizational Effectiveness Audit in Education.

    Science.gov (United States)

    Myroon, John L.

    The major purpose of this paper was to develop a Human Resource Accounting (HRA) macro-model that could be used for designing a school organizational effectiveness audit. Initially, the paper reviewed the advent and definition of HRA. In order to develop the proposed model, the different approaches to measuring effectiveness were reviewed,…

  15. An Interactive Activation Model of Context Effects in Letter Perception: Part 1. An Account of Basic Findings.

    Science.gov (United States)

    McClelland, James L.; Rumelhart, David E.

    1981-01-01

    A model of context effects in perception is applied to perception of letters. Perception results from excitatory and inhibitory interactions of detectors for visual features, letters, and words. The model produces facilitation for letters in pronounceable pseudowords as well as words and accounts for rule-governed performance without any rules.…

  16. Materials measurement and accounting in an operating plutonium conversion and purification process. Phase I. Process modeling and simulation. [PUCSF code

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, C.C. Jr.; Ostenak, C.A.; Gutmacher, R.G.; Dayem, H.A.; Kern, E.A.

    1981-04-01

    A model of an operating conversion and purification process for the production of reactor-grade plutonium dioxide was developed as the first component in the design and evaluation of a nuclear materials measurement and accountability system. The model accurately simulates process operation and can be used to identify process problems and to predict the effect of process modifications.

  17. An Interactive Activation Model of Context Effects in Letter Perception: Part 1. An Account of Basic Findings.

    Science.gov (United States)

    McClelland, James L.; Rumelhart, David E.

    1981-01-01

    A model of context effects in perception is applied to perception of letters. Perception results from excitatory and inhibitory interactions of detectors for visual features, letters, and words. The model produces facilitation for letters in pronounceable pseudowords as well as words and accounts for rule-governed performance without any rules.…

  18. Analysis of Λb → Λl+ l- rare decays in a non-universal Z‧ model

    Science.gov (United States)

    Banerjee, D.; Sahoo, S.

    2017-08-01

    We investigate the rare baryonic Λb → Λl+l- decays in a non-universal Z‧ model, which is one of the well-motivated extensions of the standard model (SM). Considering the effects of Z‧-mediated flavour-changing neutral currents (FCNCs) we analyse the differential decay rate, forward-backward asymmetries and lepton polarisation asymmetries for the Λb → Λl+l- decays. We find significant deviations from their SM predictions, which could indicate new physics arising from the Z‧ gauge boson.

  19. Extended temperature-accelerated dynamics: enabling long-time full-scale modeling of large rare-event systems.

    Science.gov (United States)

    Bochenkov, Vladimir; Suetin, Nikolay; Shankar, Sadasivan

    2014-09-07

    A new method, the Extended Temperature-Accelerated Dynamics (XTAD), is introduced for modeling long-timescale evolution of large rare-event systems. The method is based on the Temperature-Accelerated Dynamics approach [M. Sørensen and A. Voter, J. Chem. Phys. 112, 9599 (2000)], but uses full-scale parallel molecular dynamics simulations to probe a potential energy surface of an entire system, combined with the adaptive on-the-fly system decomposition for analyzing the energetics of rare events. The method removes limitations on a feasible system size and enables to handle simultaneous diffusion events, including both large-scale concerted and local transitions. Due to the intrinsically parallel algorithm, XTAD not only allows studies of various diffusion mechanisms in solid state physics, but also opens the avenue for atomistic simulations of a range of technologically relevant processes in material science, such as thin film growth on nano- and microstructured surfaces.

  20. Review of Searches for Rare Processes and Physics Beyond the Standard Model at HERA

    OpenAIRE

    South, David M.; Turcato, Monica

    2016-01-01

    The electron–proton collisions collected by the H1 and ZEUS experiments at HERA comprise a unique particle physics data set, and a comprehensive range of measurements has been performed to provide new insight into the structure of the proton. The high centre of mass energy at HERA has also allowed rare processes to be studied, including the production of W and Z0 bosons and events with multiple leptons in the final state. The data have also opened up a new domain to searches for physics beyon...

  1. Rare Power

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China begins to reinvigorate the rare earth industry after decades of underselling the valuable metals On May 19,the State Council released Guidelines to Promote Sustainable and Sound Development of the Rare Earth Industry,delivering a strong boost to the fragmented industry.

  2. Rare Security

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China’s regulation on rare earth accords with WTO rules Worries abound Western countries may use a recent WTO ruling on China’s exports restriction on nine raw materials to launch actions against China’s curbs on rare earth exports.

  3. Replacement Value - Representation of Fair Value in Accounting. Techniques and Modeling Suitable for the Income Based Approach

    OpenAIRE

    MANEA MARINELA – DANIELA

    2011-01-01

    The term fair value is spread within the sphere of international standards without reference to any detailed guidance on how to apply. However, specialized tangible assets, which are rarely sold, the rule IAS 16 "Intangible assets " makes it possible to estimate fair value using an income approach or a replacement cost or depreciation. The following material is intended to identify potential modeling of fair value as an income-based approach, appealing to techniques used by professional evalu...

  4. Contribution of rare and common variants determine complex diseases-Hirschsprung disease as a model.

    Science.gov (United States)

    Alves, Maria M; Sribudiani, Yunia; Brouwer, Rutger W W; Amiel, Jeanne; Antiñolo, Guillermo; Borrego, Salud; Ceccherini, Isabella; Chakravarti, Aravinda; Fernández, Raquel M; Garcia-Barcelo, Maria-Mercè; Griseri, Paola; Lyonnet, Stanislas; Tam, Paul K; van Ijcken, Wilfred F J; Eggen, Bart J L; te Meerman, Gerard J; Hofstra, Robert M W

    2013-10-01

    Finding genes for complex diseases has been the goal of many genetic studies. Most of these studies have been successful by searching for genes and mutations in rare familial cases, by screening candidate genes and by performing genome wide association studies. However, only a small fraction of the total genetic risk for these complex genetic diseases can be explained by the identified mutations and associated genetic loci. In this review we focus on Hirschsprung disease (HSCR) as an example of a complex genetic disorder. We describe the genes identified in this congenital malformation and postulate that both common 'low penetrant' variants in combination with rare or private 'high penetrant' variants determine the risk on HSCR, and likely, on other complex diseases. We also discuss how new technological advances can be used to gain further insights in the genetic background of complex diseases. Finally, we outline a few steps to develop functional assays in order to determine the involvement of these variants in disease development.

  5. Crash Simulation of Roll Formed Parts by Damage Modelling Taking Into Account Preforming Effects

    Science.gov (United States)

    Till, Edwin T.; Hackl, Benjamin; Schauer, Hermann

    2011-08-01

    Complex phase steels of strength levels up to 1200 MPa are suitable to roll forming. These may be applied in automotive structures for enhancing the crashworthiness, e. g. as stiffeners in doors. Even though the strain hardening of the material is low there is considerable bending formability. However ductility decreases with the strength level. Higher strength requires more focus to the structural integrity of the part during the process planning stage and with respect to the crash behavior. Nowadays numerical simulation is used as a process design tool for roll-forming in a production environment. The assessment of the stability of a roll forming process is quite challenging for AHSS grades. There are two objectives of the present work. First to provide a reliable assessment tool to the roll forming analyst for failure prediction. Second to establish simulation procedures in order to predict the part's behavior in crash applications taking into account damage and failure. Today adequate ductile fracture models are available which can be used in forming and crash applications. These continuum models are based on failure strain curves or surfaces which depend on the stress triaxiality (e. g. Crach or GISSMO) and may additionally include the Lode angle (extended Mohr Coulomb or extended GISSMO model). A challenging task is to obtain the respective failure strain curves. In the paper the procedure is described in detail how these failure strain curves are obtained using small scale tests within voestalpine Stahl, notch tensile-, bulge and shear tests. It is shown that capturing the surface strains is not sufficient for obtaining reliable material failure parameters. The simulation tool for roll-forming at the site of voestalpine Krems is Copra® FEA RF, which is a 3D continuum finite element solver based on MSC.Marc. The simulation environment for crash applications is LS-DYNA. Shell elements are used for this type of analyses. A major task is to provide results of

  6. Constraints on the rare tau decays from {mu} {yields} e{gamma} in the supersymmetric see-saw model

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Simonetto, C. [Technische Univ., Muenchen (Germany). Physik-Department

    2008-02-15

    It is now a firmly established fact that all family lepton numbers are violated in Nature. In this paper we discuss the implications of this observation for future searches for rare tau decays in the supersymmetric see-saw model. Using the two loop renormalization group evolution of the soft terms and the Yukawa couplings we show that there exists a lower bound on the rate of the rare process {mu}{yields}e{gamma} of the form BR({mu}{yields}e{gamma})>or similar C x BR({tau}{yields}{mu}{gamma})BR({tau}{yields}e{gamma}), where C is a constant that depends on supersymmetric parameters. Our only assumption is the absence of cancellations among the high-energy see-saw parameters. We also discuss the implications of this bound for future searches for rare tau decays. In particular, for large regions of the mSUGRA parameter space, we show that present B-factories could discover either {tau}{yields}{mu}{gamma} or {tau}{yields}e{gamma}, but not both. (orig.)

  7. Hierarchical generalized linear models for multiple groups of rare and common variants: jointly estimating group and individual-variant effects.

    Directory of Open Access Journals (Sweden)

    Nengjun Yi

    2011-12-01

    Full Text Available Complex diseases and traits are likely influenced by many common and rare genetic variants and environmental factors. Detecting disease susceptibility variants is a challenging task, especially when their frequencies are low and/or their effects are small or moderate. We propose here a comprehensive hierarchical generalized linear model framework for simultaneously analyzing multiple groups of rare and common variants and relevant covariates. The proposed hierarchical generalized linear models introduce a group effect and a genetic score (i.e., a linear combination of main-effect predictors for genetic variants for each group of variants, and jointly they estimate the group effects and the weights of the genetic scores. This framework includes various previous methods as special cases, and it can effectively deal with both risk and protective variants in a group and can simultaneously estimate the cumulative contribution of multiple variants and their relative importance. Our computational strategy is based on extending the standard procedure for fitting generalized linear models in the statistical software R to the proposed hierarchical models, leading to the development of stable and flexible tools. The methods are illustrated with sequence data in gene ANGPTL4 from the Dallas Heart Study. The performance of the proposed procedures is further assessed via simulation studies. The methods are implemented in a freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/.

  8. Hierarchical Generalized Linear Models for Multiple Groups of Rare and Common Variants: Jointly Estimating Group and Individual-Variant Effects

    Science.gov (United States)

    Yi, Nengjun; Liu, Nianjun; Zhi, Degui; Li, Jun

    2011-01-01

    Complex diseases and traits are likely influenced by many common and rare genetic variants and environmental factors. Detecting disease susceptibility variants is a challenging task, especially when their frequencies are low and/or their effects are small or moderate. We propose here a comprehensive hierarchical generalized linear model framework for simultaneously analyzing multiple groups of rare and common variants and relevant covariates. The proposed hierarchical generalized linear models introduce a group effect and a genetic score (i.e., a linear combination of main-effect predictors for genetic variants) for each group of variants, and jointly they estimate the group effects and the weights of the genetic scores. This framework includes various previous methods as special cases, and it can effectively deal with both risk and protective variants in a group and can simultaneously estimate the cumulative contribution of multiple variants and their relative importance. Our computational strategy is based on extending the standard procedure for fitting generalized linear models in the statistical software R to the proposed hierarchical models, leading to the development of stable and flexible tools. The methods are illustrated with sequence data in gene ANGPTL4 from the Dallas Heart Study. The performance of the proposed procedures is further assessed via simulation studies. The methods are implemented in a freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). PMID:22144906

  9. Do prevailing societal models influence reports of near-death experiences?: a comparison of accounts reported before and after 1975.

    Science.gov (United States)

    Athappilly, Geena K; Greyson, Bruce; Stevenson, Ian

    2006-03-01

    Transcendental near-death experiences show some cross-cultural variation that suggests they may be influenced by societal beliefs. The prevailing Western model of near-death experiences was defined by Moody's description of the phenomenon in 1975. To explore the influence of this cultural model, we compared near-death experience accounts collected before and after 1975. We compared the frequency of 15 phenomenological features Moody defined as characteristic of near-death experiences in 24 accounts collected before 1975 and in 24 more recent accounts matched on relevant demographic and situational variables. Near-death experience accounts collected after 1975 differed from those collected earlier only in increased frequency of tunnel phenomena, which other research has suggested may not be integral to the experience, and not in any of the remaining 14 features defined by Moody as characteristic of near-death experiences. These data challenge the hypothesis that near-death experience accounts are substantially influenced by prevailing cultural models.

  10. Evaluating rare amino acid substitutions (RGC_CAMs in a yeast model clade.

    Directory of Open Access Journals (Sweden)

    Kenneth Polzin

    Full Text Available When inferring phylogenetic relationships, not all sites in a sequence alignment are equally informative. One recently proposed approach that takes advantage of this inequality relies on sites that contain amino acids whose replacement requires multiple substitutions. Identifying these so-called RGC_CAM substitutions (after Rare Genomic Changes as Conserved Amino acids-Multiple substitutions requires that, first, at any given site in the amino acid sequence alignment, there must be a minimum of two different amino acids; second, each amino acid must be present in at least two taxa; and third, the amino acids must require a minimum of two nucleotide substitutions to replace each other. Although theory suggests that RGC_CAM substitutions are expected to be rare and less likely to be homoplastic, the informativeness of RGC_CAM substitutions has not been extensively evaluated in biological data sets. We investigated the quality of RGC_CAM substitutions by examining their degree of homoplasy and internode certainty in nearly 2.7 million aligned amino acid sites from 5,261 proteins from five species belonging to the yeast Saccharomyces sensu stricto clade whose phylogeny is well-established. We identified 2,647 sites containing RGC_CAM substitutions, a number that contrasts sharply with the 100,887 sites containing RGC_non-CAM substitutions (i.e., changes between amino acids that require only a single nucleotide substitution. We found that RGC_CAM substitutions had significantly lower homoplasy than RGC_non-CAM ones; specifically RGC_CAM substitutions showed a per-site average homoplasy index of 0.100, whereas RGC_non-CAM substitutions had a homoplasy index of 0.215. Internode certainty values were also higher for sites containing RGC_CAM substitutions than for RGC_non-CAM ones. These results suggest that RGC_CAM substitutions possess a strong phylogenetic signal and are useful markers for phylogenetic inference despite their rarity.

  11. 工业企业会计的集中核算模式%Centralized Accounting Model on Industrial Enterprises

    Institute of Scientific and Technical Information of China (English)

    李宇

    2012-01-01

    工业企业会计管理工作关系到企业的发展,当前的会计核算模式已经无法适应工业企业发展的需要。我们需要建立会计集中核算制度,提高工业企业会计管理水平,促使降低生产经营成本。涉及资金利用问题企业的可持续发展,资金利用率是会计工作的重要内容。工业企业需要实现从资金会计核算向会计监督管理转变,从根苯上提升会计管理水平。%Management of industrial enterprises in accounting related to the business development, the current accounting model is unable to adapt the needs of industrial enterprises. We need to estaldish the centralized accounting system, to improve the management level of industrial enterprises, to promote lower costs. Utilization of the funds of industrial enterprises related to the sustainable development. Capital utilization rate is an important part of accounting. Industrial companies need to achieve a transformation from accoumting of funds to accounting supervision and manangement. Fundamentally enhance the accounting management.

  12. THE MODEL OF MATERIALS AND STRUCTURES ENDURANCE, WITH TAKING INTO ACCOUNT THE EVOLUTION OF THEIR MECHANICAL CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    V. L. Gorobets

    2008-03-01

    Full Text Available In the article the mathematical model describing the process of changing a limit of durability of the railway rolling stock materials and structures with taking into account the change of parameters of durability curve during loading them is presented.

  13. Accounting for non-linear chemistry of ship plumes in the GEOS-Chem global chemistry transport model

    NARCIS (Netherlands)

    Vinken, G.C.M.; Boersma, K.F.; Jacob, D.J.; Meijer, E.W.

    2011-01-01

    We present a computationally efficient approach to account for the non-linear chemistry occurring during the dispersion of ship exhaust plumes in a global 3-D model of atmospheric chemistry (GEOS-Chem). We use a plume-in-grid formulation where ship emissions age chemically for 5 h before being relea

  14. Accounting for non-linear chemistry of ship plumes in the GEOS-Chem global chemistry transport model

    NARCIS (Netherlands)

    Meijer, E.W.; Vinken, G.C.M.; Boersma, K.F.; Jacob, D.J.

    2011-01-01

    Abstract. We present a computationally efficient approach to account for the non-linear chemistry occurring during the dispersion of ship exhaust plumes in a global 3-D model of atmospheric chemistry (GEOS-Chem). We use a plume-ingrid formulation where ship emissions age chemically for 5 h before be

  15. Closing the Gaps : Taking into Account the Effects of Heat stress and Fatique Modeling in an Operational Analysis

    NARCIS (Netherlands)

    Woodill, G.; Barbier, R.R.; Fiamingo, C.

    2010-01-01

    Traditional, combat model based analysis of Dismounted Combatant Operations (DCO) has focused on the ‘lethal’ aspects in an engagement, and to a limited extent the environment in which the engagement takes place. These are however only two of the factors that should be taken into account when conduc

  16. Structural equation models using partial least squares: an example of the application of SmartPLS® in accounting research

    Directory of Open Access Journals (Sweden)

    João Carlos Hipólito Bernardes do Nascimento

    2016-08-01

    Full Text Available In view of the Accounting academy’s increasing in the investigation of latent phenomena, researchers have used robust multivariate techniques. Although Structural Equation Models are frequently used in the international literature, however, the Accounting academy has made little use of the variant based on Partial Least Squares (PLS-SEM, mostly due to lack of knowledge on the applicability and benefits of its use for Accounting research. Even if the PLS-SEM approach is regularly used in surveys, this method is appropriate to model complex relations with multiple relationships of dependence and independence between latent variables. In that sense, it is very useful for application in experiments and file data. In that sense, a literature review is presented of Accounting studies that used the PLS-SEM technique. Next, as no specific publications were observed that exemplified the application of the technique in Accounting, a PLS-SEM application is developed to encourage exploratory research by means of the software SmartPLS®, being particularly useful to graduate students. Therefore, the main contribution of this article is methodological, given its objective to clearly identify the guidelines for the appropriate use of PLS. By presenting an example of how to conduct an exploratory research using PLS-SEM, the intention is to contribute to researchers’ enhanced understanding of how to use and report on the technique in their research.

  17. Current-account effects of a devaluation in an optimizing model with capital accumulation

    DEFF Research Database (Denmark)

    Nielsen, Søren Bo

    1991-01-01

    short, the devaluation is bound to improve the current account on impact, whereas this will deteriorate in the case of a long contract period, and the more so the smaller are adjustment costs in investment. In addition, we study the consequences for the terms of trade and for the stocks of foreign...

  18. A two-phase moisture transport model accounting for sorption hysteresis in layered porous building constructions

    DEFF Research Database (Denmark)

    Johannesson, Björn; Janz, Mårten

    2009-01-01

    , with account also to sorption hysteresis. The different materials in the considered layered construction are assigned different properties, i.e. vapor and liquid water diffusivities and boundary (wetting and drying) sorption curves. Further, the scanning behavior between wetting and drying boundary curves...

  19. Accounting Department Chairpersons' Perceptions of Business School Performance Using a Market Orientation Model

    Science.gov (United States)

    Webster, Robert L.; Hammond, Kevin L.; Rothwell, James C.

    2013-01-01

    This manuscript is part of a stream of continuing research examining market orientation within higher education and its potential impact on organizational performance. The organizations researched are business schools and the data collected came from chairpersons of accounting departments of AACSB member business schools. We use a reworded Narver…

  20. Accounting Department Chairpersons' Perceptions of Business School Performance Using a Market Orientation Model

    Science.gov (United States)

    Webster, Robert L.; Hammond, Kevin L.; Rothwell, James C.

    2013-01-01

    This manuscript is part of a stream of continuing research examining market orientation within higher education and its potential impact on organizational performance. The organizations researched are business schools and the data collected came from chairpersons of accounting departments of AACSB member business schools. We use a reworded Narver…

  1. Internet Accounting

    NARCIS (Netherlands)

    Pras, Aiko; Beijnum, van Bert-Jan; Sprenkels, Ron; Párhonyi, Robert

    2001-01-01

    This article provides an introduction to Internet accounting and discusses the status of related work within the IETF and IRTF, as well as certain research projects. Internet accounting is different from accounting in POTS. To understand Internet accounting, it is important to answer questions like

  2. FCNC, CP violation and implications for some rare decays in a SU(4)_L X U(1)_X extension of the standard model

    CERN Document Server

    Jaramillo, Alejandro

    2011-01-01

    Extensions of the standard model (SM) with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X (3-4-1 extensions) where anomaly cancellation takes place between the fermion families (three-family models) predict the existence of two new heavy neutral gauge bosons which transmit flavor changing neutral currents (FCNC) at tree-level. In this work, in the context of a three-family 3-4-1 extension which does not contain particles with exotic electric charges, we study the constraints coming from neutral meson mixing on the parameters of the extension associated to tree level FCNC effects. Taking into account experimental measurements of observables related to $K$ and $B$ meson mixing and including new CP-violating phases, we study the resulting bounds for angles and phases in the mixing matrix for the down-quark sector, as well as the implications of these bounds for the modifications in the amplitudes of the clean rare decays K^+ \\to \\pi^+ \\bar\

  3. Modeling of point defects and rare gas incorporation in uranium mono-carbide

    Science.gov (United States)

    Chartier, A.; Van Brutzel, L.

    2007-02-01

    An embedded atom method (EAM) potential has been established for uranium mono-carbide. This EAM potential was fitted on structural properties of metallic uranium and uranium mono-carbide. The formation energies of point defects, as well as activation energies for self migration, have been evaluated in order to cross-check the suitability of the potential. Assuming that the carbon vacancies are the main defects in uranium mono-carbide compounds, the migration paths and energies are consistent with experimental data selected by Catlow[C.R.A. Catlow, J. Nucl. Mater. 60 (1976) 151]. The insertion and migration energies for He, Kr and Xe have also been evaluated with available inter-atomic potentials [H.H. Andersen, P. Sigmund, Nucl. Instr. and Meth. B 38 (1965) 238]. Results show that the most stable defect configuration for rare gases is within uranium vacancies. The migration energy of an interstitial Xe is 0.5 eV, in agreement with the experimental value of 0.5 eV [Hj. Matzke, Science of advanced LMFBR fuels, Solid State Physics, Chemistry and Technology of Carbides, Nitrides and Carbonitrides of Uranium and Plutonium, North-Holland, 1986].

  4. Assessment of inbreeding resulting from selection for scrapie resistance: a model for rare sheep breeds.

    Science.gov (United States)

    Brown, C; Orford, M; Tzamaloukas, O; Mavrogenis, A P; Miltiadou, D

    Inbreeding in a small population of Chios sheep undergoing intense selection for the PrP gene was assessed 10 years after the beginning of a scrapie resistance selection programme. Inbreeding in this stock, already under selection for production traits, was analysed by using pedigree records containing 10,492 animals from 1968 to 2008, and also by genotyping 192 individuals with a panel of 15 microsatellites. Genetic markers indicated a loss of heterozygosity (FIS over all loci was 0.059) and allelic diversity (mean effective number of alleles was 3.075±0.275). The annual rate of inbreeding increased significantly after the start of the scrapie resistance programme, ΔF=0.005 compared with ΔF=0.001 before 1999, and was subjected to several genetic bottlenecks, mainly due to the low initial frequency of resistant animals. However, the mean individual inbreeding coefficient estimated from the pedigree - in this closed stock resembling the case of a rare breed - stood at the level of 4.5 per cent, five generations after the implementation of selection for the PrP gene. The inbreeding coefficient estimated by genetic markers was 4.37 per cent, implying that such a marker panel could be a useful and cost-effective tool for estimating inbreeding in unrecorded populations.

  5. A regional-scale, high resolution dynamical malaria model that accounts for population density, climate and surface hydrology.

    Science.gov (United States)

    Tompkins, Adrian M; Ermert, Volker

    2013-02-18

    The relative roles of climate variability and population related effects in malaria transmission could be better understood if regional-scale dynamical malaria models could account for these factors. A new dynamical community malaria model is introduced that accounts for the temperature and rainfall influences on the parasite and vector life cycles which are finely resolved in order to correctly represent the delay between the rains and the malaria season. The rainfall drives a simple but physically based representation of the surface hydrology. The model accounts for the population density in the calculation of daily biting rates. Model simulations of entomological inoculation rate and circumsporozoite protein rate compare well to data from field studies from a wide range of locations in West Africa that encompass both seasonal endemic and epidemic fringe areas. A focus on Bobo-Dioulasso shows the ability of the model to represent the differences in transmission rates between rural and peri-urban areas in addition to the seasonality of malaria. Fine spatial resolution regional integrations for Eastern Africa reproduce the malaria atlas project (MAP) spatial distribution of the parasite ratio, and integrations for West and Eastern Africa show that the model grossly reproduces the reduction in parasite ratio as a function of population density observed in a large number of field surveys, although it underestimates malaria prevalence at high densities probably due to the neglect of population migration. A new dynamical community malaria model is publicly available that accounts for climate and population density to simulate malaria transmission on a regional scale. The model structure facilitates future development to incorporate migration, immunity and interventions.

  6. Adaptation of an Electrochemistry-based Li-Ion Battery Model to Account for Deterioration Observed Under Randomized Use

    Science.gov (United States)

    2014-10-02

    Adaptation of an Electrochemistry -based Li-Ion Battery Model to Account for Deterioration Observed Under Randomized Use Brian Bole1, Chetan S...application’s accuracy requirements and available resources (Daigle et al., 2011). In this paper, we use an electrochemistry -based lithium ion (Li-ion...the use of UKF not only to estimate the states in an electrochemistry model that vary over a charge- discharge cycle, but also to adapt certain

  7. Accounting Automation

    OpenAIRE

    Laynebaril1

    2017-01-01

    Accounting Automation   Click Link Below To Buy:   http://hwcampus.com/shop/accounting-automation/  Or Visit www.hwcampus.com Accounting Automation” Please respond to the following: Imagine you are a consultant hired to convert a manual accounting system to an automated system. Suggest the key advantages and disadvantages of automating a manual accounting system. Identify the most important step in the conversion process. Provide a rationale for your response. ...

  8. Physical and Theoretical Models of Heat Pollution Applied to Cramped Conditions Welding Taking into Account the Different Types of Heat

    Science.gov (United States)

    Bulygin, Y. I.; Koronchik, D. A.; Legkonogikh, A. N.; Zharkova, M. G.; Azimova, N. N.

    2017-05-01

    The standard k-epsilon turbulence model, adapted for welding workshops, equipped with fixed workstations with sources of pollution took into account only the convective component of heat transfer, which is quite reasonable for large-volume rooms (with low density distribution of sources of pollution) especially the results of model calculations taking into account only the convective component correlated well with experimental data. For the purposes of this study, when we are dealing with a small confined space where necessary to take account of the body heated to a high temperature (for welding), located next to each other as additional sources of heat, it can no longer be neglected radiative heat exchange. In the task - to experimentally investigate the various types of heat transfer in a limited closed space for welding and behavior of a mathematical model, describing the contribution of the various components of the heat exchange, including radiation, influencing the formation of fields of concentration, temperature, air movement and thermal stress in the test environment. Conducted field experiments to model cubic body, allowing you to configure and debug the model of heat and mass transfer processes with the help of the developed approaches, comparing the measurement results of air flow velocity and temperature with the calculated data showed qualitative and quantitative agreement between process parameters, that is an indicator of the adequacy of heat and mass transfer model.

  9. Investigation of a new model accounting for rotors of finite tip-speed ratio in yaw or tilt

    DEFF Research Database (Denmark)

    Branlard, Emmanuel; Gaunaa, Mac; Machefaux, Ewan

    2014-01-01

    from the MEXICO experiment are used as a basis for validation. Three tools using the same 2D airfoil coefficient data are compared: a BEM code, an Actuator-Line and a vortex code. The vortex code is further used to validate the results from the newly implemented BEM yaw-model. Significant improvements......The main results from a recently developed vortex model are implemented into a Blade Element Momentum(BEM) code. This implementation accounts for the effect of finite tip-speed ratio, an effect which was not considered in standard BEM yaw-models. The model and its implementation are presented. Data...

  10. Highly sensitive measurements of disease progression in rare disorders: Developing and validating a multimodal model of retinal degeneration in Stargardt disease

    Science.gov (United States)

    Bax, Nathalie M.; Fakin, Ana; Groenewoud, Joannes M. M.; Klevering, B. Jeroen; Moore, Anthony T.; Michaelides, Michel; Webster, Andrew R.; van der Wilt, Gert Jan; Hoyng, Carel B.

    2017-01-01

    Background Each inherited retinal disorder is rare, but together, they affect millions of people worldwide. No treatment is currently available for these blinding diseases, but promising new options—including gene therapy—are emerging. Arguably, the most prevalent retinal dystrophy is Stargardt disease. In each case, the specific combination of ABCA4 variants (> 900 identified to date) and modifying factors is virtually unique. It accounts for the vast phenotypic heterogeneity including variable rates of functional and structural progression, thereby potentially limiting the ability of phase I/II clinical trials to assess efficacy of novel therapies with few patients. To accommodate this problem, we developed and validated a sensitive and reliable composite clinical trial endpoint for disease progression based on structural measurements of retinal degeneration. Methods and findings We used longitudinal data from early-onset Stargardt patients from the Netherlands (development cohort, n = 14) and the United Kingdom (external validation cohort, n = 18). The composite endpoint was derived from best-corrected visual acuity, fundus autofluorescence, and spectral-domain optical coherence tomography. Weighting optimization techniques excluded visual acuity from the composite endpoint. After optimization, the endpoint outperformed each univariable outcome, and showed an average progression of 0.41° retinal eccentricity per year (95% confidence interval, 0.30–0.52). Comparing with actual longitudinal values, the model accurately predicted progression (R2, 0.904). These properties were largely preserved in the validation cohort (0.43°/year [0.33–0.53]; prediction: R2, 0.872). We subsequently ran a two-year trial simulation with the composite endpoint, which detected a 25% decrease in disease progression with 80% statistical power using only 14 patients. Conclusions These results suggest that a multimodal endpoint, reflecting structural macular changes, provides a

  11. On the treatment of evapotranspiration, soil moisture accounting, and aquifer recharge in monthly water balance models.

    Science.gov (United States)

    Alley, W.M.

    1984-01-01

    Several two- to six-parameter regional water balance models are examined by using 50-year records of monthly streamflow at 10 sites in New Jersey. These models include variants of the Thornthwaite-Mather model, the Palmer model, and the more recent Thomas abcd model. Prediction errors are relatively similar among the models. However, simulated values of state variables such as soil moisture storage differ substantially among the models, and fitted parameter values for different models sometimes indicated an entirely different type of basin response to precipitation.-from Author

  12. 会计监督的数学模型%The Math Model for the Accounting Supervision

    Institute of Scientific and Technical Information of China (English)

    韩英

    2001-01-01

    应用概率论和优化理论,对会计行为进行了系统的分析 ,建立了会计监督的数学模型,确定了会计单位和监督者的反应函数及最优行动选择,同时 给出监管者对会计单位违规处罚的最低值。%By analyzing the profit distributing of the managers and account ing units with probability and optimization theories,reaction function of manage rs and accounting units is present,and the math model of the accounting supervis ion is established.Minimum value of the punishment to the illegality in the acco unting units is determined.

  13. d- $\\overline{B}$ mixing and rare D decays in the Littlest Higgs model with non-unitarity matrix

    CERN Document Server

    Chen, Chuan-Hung; Yuan, Tzu-Chiang

    2007-01-01

    We study the $D-\\bar D$ mixing and rare D decays in the Littlest Higgs model. As the new weak singlet quark with the electric charge of 2/3 is introduced to cancel the quadratic divergence induced by the top-quark, the standard unitary $3\\times 3$ Cabibbo-Kobayashi-Maskawa matrix is extended to a non-unitary $4\\times 3$ matrix in the quark charged currents and Z-mediated flavor changing neutral currents are generated at tree level. In this model, we show that the $D-\\bar D$ mixing parameter can be as large as the current experimental value and the decay branching ratio (BR) of $D\\to X_u \\ga$ is small but its direct CP asymmetry could be $O(10%)$. In addition, we find that the BRs of $D\\to X_u \\ell^{+} \\ell^{-}$, $D\\to X_u\

  14. A simple model to quantitatively account for periodic outbreaks of the measles in the Dutch Bible Belt

    Science.gov (United States)

    Bier, Martin; Brak, Bastiaan

    2015-04-01

    In the Netherlands there has been nationwide vaccination against the measles since 1976. However, in small clustered communities of orthodox Protestants there is widespread refusal of the vaccine. After 1976, three large outbreaks with about 3000 reported cases of the measles have occurred among these orthodox Protestants. The outbreaks appear to occur about every twelve years. We show how a simple Kermack-McKendrick-like model can quantitatively account for the periodic outbreaks. Approximate analytic formulae to connect the period, size, and outbreak duration are derived. With an enhanced model we take the latency period in account. We also expand the model to follow how different age groups are affected. Like other researchers using other methods, we conclude that large scale underreporting of the disease must occur.

  15. Accounting for Slipping and Other False Negatives in Logistic Models of Student Learning

    Science.gov (United States)

    MacLellan, Christopher J.; Liu, Ran; Koedinger, Kenneth R.

    2015-01-01

    Additive Factors Model (AFM) and Performance Factors Analysis (PFA) are two popular models of student learning that employ logistic regression to estimate parameters and predict performance. This is in contrast to Bayesian Knowledge Tracing (BKT) which uses a Hidden Markov Model formalism. While all three models tend to make similar predictions,…

  16. Equity Valuation and Accounting Numbers: Applying Zhang (2000 and Zhang and Chen (2007 models to Brazilian Market

    Directory of Open Access Journals (Sweden)

    Fernando Caio Galdi

    2011-03-01

    Full Text Available This paper investigates how accounting variables explain cross-sectional stocks returns in Brazilian capital markets. The analysis is based on Zhang (2000 and Zhang and Chen (2007 models. These models predict that stock returns are a function of net income, change in profitability, invested capital, changes in opportunity growths and discount rate. Generally, the empirical results for the Brazilian capital market are consistent with the theoretical relations that models describe, similarly to the results found in the US. Using different empirical tests (pooled regressions, Fama-Macbeth and panel data the results and coefficients remain similar, what support the robustness of our findings.

  17. A rare opportunity beckons

    Energy Technology Data Exchange (ETDEWEB)

    Gschneidner, K

    2011-02-01

    There is a great deal of uncertainty for the future of rare-earth production. Rare-earths are a collection of 17 chemical elements in the periodic table, which include scandium and yttrium as well as the 15 lanthanides, such as dysprosium and ytterbium. China has a stranglehold on today's rare-earth market, which was worth about $3bn in 2010, with the country accounting for about 95% of worldwide production. Yet China's future actions can only be guessed at best. In September it halted shipments of rare-earth elements to Japan over a diplomatic spat concerning the detention of a Chinese trawler captain. Although the ban was later lifted, the episode raised concerns around the world about China's rare-earth monopoly and its use in diplomacy. China has already warned that it will not export any rare-earth material in the coming years as it expects its own consumption of rare-earth metals to increase. The country has introduced export taxes as well as production and export quotas, and also refused to grant any new rare-earth mining licences. Furthermore, because its reserves are limited and China's internal markets are growing so rapidly, the country has suggested it will no longer export products that require rare-earth elements, especially those that need heavy rare-earth elements, such as terbium and dysprosium. China's actions have led to huge rises in the cost of rare-earth materials and products. Dysprosium oxide, for example, has shot up from $36 per kilogram in 2005 to a massive $305 per kilogram by late last year. This could have a huge impact on much of today's electronics industry, given that rare-earth elements are ubiquitous in electric motors, computers, batteries, liquid-crystal displays (LCDs) and mobile phones. Neodymium-iron-boron permanent magnets, for example, are used as computer spindle drives. The question is: what can be done to ensure that China's dominance of the rare-earth industry does not affect the

  18. Educational Accountability

    Science.gov (United States)

    Pincoffs, Edmund L.

    1973-01-01

    Discusses educational accountability as the paradigm of performance contracting, presents some arguments for and against accountability, and discusses the goals of education and the responsibility of the teacher. (Author/PG)

  19. Efficient modeling of sun/shade canopy radiation dynamics explicitly accounting for scattering

    Directory of Open Access Journals (Sweden)

    P. Bodin

    2012-04-01

    Full Text Available The separation of global radiation (Rg into its direct (Rb and diffuse constituents (Rg is important when modeling plant photosynthesis because a high Rd:Rg ratio has been shown to enhance Gross Primary Production (GPP. To include this effect in vegetation models, the plant canopy must be separated into sunlit and shaded leaves. However, because such models are often too intractable and computationally expensive for theoretical or large scale studies, simpler sun-shade approaches are often preferred. A widely used and computationally efficient sun-shade model was developed by Goudriaan (1977 (GOU. However, compared to more complex models, this model's realism is limited by its lack of explicit treatment of radiation scattering.

    Here we present a new model based on the GOU model, but which in contrast explicitly simulates radiation scattering by sunlit leaves and the absorption of this radiation by the canopy layers above and below (2-stream approach. Compared to the GOU model our model predicts significantly different profiles of scattered radiation that are in better agreement with measured profiles of downwelling diffuse radiation. With respect to these data our model's performance is equal to a more complex and much slower iterative radiation model while maintaining the simplicity and computational efficiency of the GOU model.

  20. Detection of Rare Drug Resistance Mutations by Digital PCR in a Human Influenza A Virus Model System and Clinical Samples.

    Science.gov (United States)

    Whale, Alexandra S; Bushell, Claire A; Grant, Paul R; Cowen, Simon; Gutierrez-Aguirre, Ion; O'Sullivan, Denise M; Žel, Jana; Milavec, Mojca; Foy, Carole A; Nastouli, Eleni; Garson, Jeremy A; Huggett, Jim F

    2016-02-01

    Digital PCR (dPCR) is being increasingly used for the quantification of sequence variations, including single nucleotide polymorphisms (SNPs), due to its high accuracy and precision in comparison with techniques such as quantitative PCR (qPCR) and melt curve analysis. To develop and evaluate dPCR for SNP detection using DNA, RNA, and clinical samples, an influenza virus model of resistance to oseltamivir (Tamiflu) was used. First, this study was able to recognize and reduce off-target amplification in dPCR quantification, thereby enabling technical sensitivities down to 0.1% SNP abundance at a range of template concentrations, a 50-fold improvement on the qPCR assay used routinely in the clinic. Second, a method was developed for determining the false-positive rate (background) signal. Finally, comparison of dPCR with qPCR results on clinical samples demonstrated the potential impact dPCR could have on clinical research and patient management by earlier (trace) detection of rare drug-resistant sequence variants. Ultimately this could reduce the quantity of ineffective drugs taken and facilitate early switching to alternative medication when available. In the short term such methods could advance our understanding of microbial dynamics and therapeutic responses in a range of infectious diseases such as HIV, viral hepatitis, and tuberculosis. Furthermore, the findings presented here are directly relevant to other diagnostic areas, such as the detection of rare SNPs in malignancy, monitoring of graft rejection, and fetal screening. Copyright © 2016 Whale et al.

  1. Accounting outsourcing

    OpenAIRE

    Richtáriková, Paulína

    2012-01-01

    The thesis deals with accounting outsourcing and provides a comprehensive explanation of the topic. At first the thesis defines basic concepts (outsourcing, insourcing, offshoring and outplacement) and describes differences between the accounting outsourcing and outsourcing of other business activities. The emphasis is put on a decision whether or not to implement the accounting outsourcing. Thus the thesis describes main reasons why to implement the accounting outsourcing and risks that are ...

  2. An individual-based model of zebrafish population dynamics accounting for energy dynamics.

    Directory of Open Access Journals (Sweden)

    Rémy Beaudouin

    Full Text Available Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model was coupled to an individual based model of zebrafish population dynamics (IBM model. Next, we fitted the DEB model to new experimental data on zebrafish growth and reproduction thus improving existing models. We further analysed the DEB-model and DEB-IBM using a sensitivity analysis. Finally, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding, it can already serve to predict the impact of compounds at the population level.

  3. A comparison of Graham and Piotroski investment models using accounting information and efficacy measurement

    OpenAIRE

    2016-01-01

    We examine the investment models of Benjamin Graham and Joseph Piotroski and compare the efficacy of these two models by running backtest, using screening rules and ranking systems built in Portfolio 123. Using different combinations of screening rules and ranking systems, we also examine the performance of Piotroski and Graham investment models. We find that the combination of Piotroski and Graham investment models performs better than S&P 500. We also find that the Piotroski screening with ...

  4. Accounting outsourcing

    OpenAIRE

    Klečacká, Tereza

    2009-01-01

    This thesis gives a complex view on accounting outsourcing, deals with the outsourcing process from its beginning (condition of collaboration, making of contract), through collaboration to its possible ending. This work defines outsourcing, indicates the main advatages, disadvatages and arguments for its using. The main object of thesis is mainly practical side of accounting outsourcing and providing of first quality accounting services.

  5. Accounting standards

    NARCIS (Netherlands)

    Stellinga, B.; Mügge, D.

    2014-01-01

    The European and global regulation of accounting standards have witnessed remarkable changes over the past twenty years. In the early 1990s, EU accounting practices were fragmented along national lines and US accounting standards were the de facto global standards. Since 2005, all EU listed companie

  6. Accounting for subgrid scale topographic variations in flood propagation modeling using MODFLOW

    DEFF Research Database (Denmark)

    Milzow, Christian; Kinzelbach, W.

    2010-01-01

    To be computationally viable, grid-based spatially distributed hydrological models of large wetlands or floodplains must be set up using relatively large cells (order of hundreds of meters to kilometers). Computational costs are especially high when considering the numerous model runs or model time...

  7. Test of the standard model in the B-meson sector by mixing phenomena and rare decays

    CERN Document Server

    Urbán, J

    1999-01-01

    Calculations for the rare decays b -> s gamma and b -> s g, as well as the BB sup - -mixing inclusive QCD-corrections in Next-to-Leading-Log-Approximation are presented throughout this work. The decays and the mixing are caused by Flavor Changing Neutral Current (FCNC) processes, which are absent on the tree-level within the framework of the Standard-Model. Hence these processes are qualified to test the validity of the Standard-Model, because possible extensions may provide similar contributions. Considered extensions are the 2-Higgs-Doublet-Model, Left-Right-Models and the Minimal Supersymmetric Standard-Model. It is shown that the determination of the Wilson-coefficients is independent of the treatment of the light fields for the case of the BB sup - -mixing. For this proof the dimensional regularisation of the IR-divergences on one side and a regulator mass for the light fields on the other side is utilized. The well-known value for the mass splitting ''Delta m B'' available from the BB sup - -oscillation...

  8. Modeling Rare Species Distribution at the Edge: The Case for the Vulnerable Endemic Pyrenean Desman in France

    Directory of Open Access Journals (Sweden)

    M. Williams-Tripp

    2012-01-01

    Full Text Available The endemic Pyrenean Desman (Galemys pyrenaicus is an elusive, rare, and vulnerable species declining over its entire and narrow range (Spain, Portugal, France, and Andorra. The principal set of conservation measures in France is a 5-years National Action Plan based on 25 conservation actions. Priority is given to update its present distribution and develop tools for predictive distribution models. We aim at building the first species distribution model and map for the northern edge of the range of the Desman and confronting the outputs of the model to target conservation efforts in the context of environmental change. Contrasting to former comparable studies, we derive a simpler model emphasizing the importance of factors linked to precipitation and not to the temperature. If temperature is one of the climate change key factors, depicted shrinkage in Desman distribution could be lower or null at the northern (French edge suggesting thus a major role for this northern population in terms of conservation of the species. Finally, we question the applied issue of temporal and spatial transferability for such environmental favourability models when it is made at the edge of the distribution range.

  9. THE CURRENT ACCOUNT DEFICIT AND THE FIXED EXCHANGE RATE. ADJUSTING MECHANISMS AND MODELS.

    Directory of Open Access Journals (Sweden)

    HATEGAN D.B. Anca

    2010-07-01

    Full Text Available The main purpose of the paper is to explain what measures can be taken in order to fix the trade deficit, and the pressure that is upon a country by imposing such measures. The international and the national supply and demand conditions change rapidly, and if a country doesn’t succeed in keeping a tight control over its deficit, a lot of factors will affect its wellbeing. In order to reduce the external trade deficit, the government needs to resort to several techniques. The desired result is to have a balanced current account, and therefore, the government is free to use measures such as fixing its exchange rate, reducing government spending etc. We have shown that all these measures will have a certain impact upon an economy, by allowing its exports to thrive and eliminate the danger from excessive imports, or vice-versa. The main conclusion our paper is that government intervention is allowed in order to maintain the balance of the current account.

  10. Nonlinear analysis of a new car-following model accounting for the global average optimal velocity difference

    Science.gov (United States)

    Peng, Guanghan; Lu, Weizhen; He, Hongdi

    2016-09-01

    In this paper, a new car-following model is proposed by considering the global average optimal velocity difference effect on the basis of the full velocity difference (FVD) model. We investigate the influence of the global average optimal velocity difference on the stability of traffic flow by making use of linear stability analysis. It indicates that the stable region will be enlarged by taking the global average optimal velocity difference effect into account. Subsequently, the mKdV equation near the critical point and its kink-antikink soliton solution, which can describe the traffic jam transition, is derived from nonlinear analysis. Furthermore, numerical simulations confirm that the effect of the global average optimal velocity difference can efficiently improve the stability of traffic flow, which show that our new consideration should be taken into account to suppress the traffic congestion for car-following theory.

  11. Research on the Accounting Model of Circular Economy%循环经济会计模式的研究

    Institute of Scientific and Technical Information of China (English)

    王傲舒媞

    2015-01-01

    In this paper, the author combined with the characteristics of circular economy, the important significance of developing circular economy and points out the limitations of current accounting model in the development of circular economy, and puts forward the accounting model suitable for the development of circular economy.%笔者结合循环经济的特点,从发展循环经济的重要意义入手,指出我国现行会计模式在循环经济发展中的局限性,提出适合循环经济发展的会计模式,以期为进一步促进我国循环经济会计体系的良好构建做出有益的参考.

  12. Busy period analysis, rare events and transient behavior in fluid flow models

    Directory of Open Access Journals (Sweden)

    Søren Asmussen

    1994-01-01

    Full Text Available We consider a process {(Jt,Vt}t≥0 on E×[0,∞, such that {Jt} is a Markov process with finite state space E, and {Vt} has a linear drift ri on intervals where Jt=i and reflection at 0. Such a process arises as a fluid flow model of current interest in telecommunications engineering for the purpose of modeling ATM technology. We compute the mean of the busy period and related first passage times, show that the probability of buffer overflow within a busy cycle is approximately exponential, and give conditioned limit theorems for the busy cycle with implications for quick simulation. Further, various inequalities and approximations for transient behavior are given. Also explicit expressions for the Laplace transform of the busy period are found. Mathematically, the key tool is first passage probabilities and exponential change of measure for Markov additive processes.

  13. Modeling rare earth complexes: Sparkle/PM3 parameters for thulium(III)

    Science.gov (United States)

    Freire, Ricardo O.; Rocha, Gerd B.; Simas, Alfredo M.

    2006-07-01

    The Sparkle model, recently defined for Tm(III) within AM1 [R.O. Freire, G.B. Rocha, A.M. Simas, Chem. Phys. Lett. 411 (2005) 61], is now extended to PM3. For the same 15 complexes previously used, the Sparkle/PM3 unsigned mean error, for all interatomic distances between the Tm(III) ion and the directly coordinating oxygen or nitrogen atoms, is 0.08 Å, a level of accuracy equivalent to the Sparkle/AM1 figure of 0.07 Å, as well as to results from present day ab initio effective core potential calculations. The results thus indicate that both Sparkle/AM1 and Sparkle/PM3 models may prove useful for luminescent Tm(III) complex design.

  14. Studying Impact of Organizational Factors in Information Technology Acceptance in Accounting Occupation by Use of TAM Model (Iranian Case Study)

    OpenAIRE

    Akbar Allahyari; Morteza Ramazani

    2012-01-01

    Nowadays, information technology attitudes as the beneficial part of industry, economic and culture. Accounting posits as profession that provide information for decision- making of users and in the complex world, organizations must use information technology to present information for users in time. This research is by purpose of studying impact of organizational factors in information technology acceptance by use of TAM model in study descriptive-surveying method that researcher has used to...

  15. Accounting for spatial effects in land use regression for urban air pollution modeling.

    Science.gov (United States)

    Bertazzon, Stefania; Johnson, Markey; Eccles, Kristin; Kaplan, Gilaad G

    2015-01-01

    In order to accurately assess air pollution risks, health studies require spatially resolved pollution concentrations. Land-use regression (LUR) models estimate ambient concentrations at a fine spatial scale. However, spatial effects such as spatial non-stationarity and spatial autocorrelation can reduce the accuracy of LUR estimates by increasing regression errors and uncertainty; and statistical methods for resolving these effects--e.g., spatially autoregressive (SAR) and geographically weighted regression (GWR) models--may be difficult to apply simultaneously. We used an alternate approach to address spatial non-stationarity and spatial autocorrelation in LUR models for nitrogen dioxide. Traditional models were re-specified to include a variable capturing wind speed and direction, and re-fit as GWR models. Mean R(2) values for the resulting GWR-wind models (summer: 0.86, winter: 0.73) showed a 10-20% improvement over traditional LUR models. GWR-wind models effectively addressed both spatial effects and produced meaningful predictive models. These results suggest a useful method for improving spatially explicit models.

  16. JOMAR - A model for accounting the environmental loads from building constructions

    Energy Technology Data Exchange (ETDEWEB)

    Roenning, Anne; Nereng, Guro; Vold, Mie; Bjoerberg, Svein; Lassen, Niels

    2008-07-01

    The objective for this project was to develop a model as a basis for calculation of environmental profile for whole building constructions, based upon data from databases and general LCA software, in addition to the model structure from the Nordic project on LCC assessment of buildings. The model has been tested on three building constructions; timber based, flexible and heavy as well as heavy. Total energy consumption and emissions contributing to climate change are calculated in a total life cycle perspective. The developed model and exemplifying case assessments have shown that a holistic model including operation phase is both important and possible to implement. The project has shown that the operation phase causes the highest environmental loads when it comes to the exemplified impact categories. A suggestion on further development of the model along two different axes in collaboration with a broader representation from the building sector is given in the report (author)(tk)

  17. The Neighborhood Context of Hate Crime: A Comparison of Violent and Property Offenses Using Rare Events Modeling.

    Science.gov (United States)

    Benier, Kathryn

    2017-08-01

    Many studies into the antecedents of hate crime in the neighborhood combine offense categories, meaning that it is unclear whether or not there are distinct contextual factors associated with violent and property hate offenses. This study uses rare events modeling to examine the household and neighborhood factors associated with violent and property offenses. Using the Australian Community Capacity Study, the study focuses on the neighborhood characteristics influencing self-reported violent and property hate crime for 4,396 residents in Brisbane. Findings demonstrate important differences between the offense types. Violence is predicted by household renting and non-English language, whereas property offenses are predicted by household non-English language, neighborhood median income, and change in non-English-speaking residents. In both offense types, neighborhood place attachment acts as a protective factor. These findings highlight the theoretical implications of combining distinct hate crime types for methodological reasons.

  18. Modelling reverse characteristics of power LEDs with thermal phenomena taken into account

    Science.gov (United States)

    Ptak, Przemysław; Górecki, Krzysztof

    2016-01-01

    This paper refers to modelling characteristics of power LEDs with a particular reference to thermal phenomena. Special attention is paid to modelling characteristics of the circuit protecting the considered device against the excessive value of the reverse voltage and to the description of the temperature influence on optical power. The network form of the worked out model is presented and some results of experimental verification of this model for the selected diodes operating at different cooling conditions are described. The very good agreement between the calculated and measured characteristics is obtained.

  19. Mathematical modeling taking into account of intrinsic kinetic properties of cylinder-type vanadium catalyst

    Institute of Scientific and Technical Information of China (English)

    陈振兴; 李洪桂; 王零森

    2004-01-01

    The method to calculate internal surface effective factor of cylinder-type vanadium catalyst Ls-9 was given. Based on hypothesis of subjunctive one dimension diffusion and combined shape adjustment factor with threestep catalytic mechanism model, the macroscopic kinetic model equation about SO2 oxidation on Ls-9 was deduced.With fixed-bed integral reactor and under the conditions of temperature 350 - 410 ℃, space velocity 1 800 - 5 000h-1, SO2 inlet content 7 %- 12%, the macroscopic kinetic data were detected. Through model parameter estimation,the macroscopic kinetic model equation was obtained.

  20. A hybrid mode choice model to account for the dynamic effect of inertia over time

    DEFF Research Database (Denmark)

    Cherchi, Elisabetta; Börjesson, Maria; Bierlaire, Michel

    gathered over a continuous period of time, six weeks, to study both inertia and the influence of habits. Tendency to stick with the same alternative is measured through lagged variables that link the current choice with the previous trip made with the same purpose, mode and time of day. However, the lagged......The influence of habits, giving rise to inertia effect, in the choice process has been intensely debated in the literature. Typically inertia is accounted for by letting the indirect utility functions of the alternatives of the choice situation at time t depend on the outcome of the choice made...... at a previous point in time. However, according to the psychological literature, inertia is the results of a habit, which is formed in a longer process where many past decisions (not only the immediately previous one) remain in the memory of the consumer and influence behavior. In this study we use panel data...

  1. Modeling the pulse shape of Q-switched lasers to account for terminal-level relaxation

    Institute of Scientific and Technical Information of China (English)

    Zeng Qin-Yong; Wan Yong; Xiong Ji-Chuan; Zhu Da-Yong

    2011-01-01

    To account for the effect of lower-level relaxation, we have derived a characteristic equation for describing the laser pulse from the modified rate equations for Q-switched lasers. The pulse temporal profile is related to the ratio of the lower-level lifetime to the cavity lifetime and the number of times the population inversion density is above the threshold. By solving the coupled rate equations numerically, the effect of terminal-level lifetime on pulse temporal behaviour is analysed. The mode is applied to the case of a diode-pumped Nd:YAG laser that is passively Q-switched by a Cr4+:YAG absorber. Theoretical results show good agreement with the experiments.

  2. Microsimulation Model Estimating Czech Farm Income from Farm Accountancy Data Network Database

    Directory of Open Access Journals (Sweden)

    Z. Hloušková

    2014-09-01

    Full Text Available Agricultural income is one of the most important measures of economic status of agricultural farms and the whole agricultural sector. This work is focused on finding the optimal method of estimating national agricultural income from micro-economic database managed by the Farm Accountancy Data Network (FADN. Use of FADN data base is relevant due to the representativeness of the results for the whole country and the opportunity to carry out micro-level analysis. The main motivation for this study was a first forecast of national agricultural income from FADN data undertaken 9 months before the final official FADN results were published. Our own method of estimating the income estimation and the simulation procedure were established and successfully tested on the whole database on data from two preceding years. Present paper also provides information on used method of agricultural income prediction and on tests of its suitability.

  3. Molecular Characterization of Three Canine Models of Human Rare Bone Diseases: Caffey, van den Ende-Gupta, and Raine Syndromes.

    Science.gov (United States)

    Hytönen, Marjo K; Arumilli, Meharji; Lappalainen, Anu K; Owczarek-Lipska, Marta; Jagannathan, Vidhya; Hundi, Sruthi; Salmela, Elina; Venta, Patrick; Sarkiala, Eva; Jokinen, Tarja; Gorgas, Daniela; Kere, Juha; Nieminen, Pekka; Drögemüller, Cord; Lohi, Hannes

    2016-05-01

    One to two percent of all children are born with a developmental disorder requiring pediatric hospital admissions. For many such syndromes, the molecular pathogenesis remains poorly characterized. Parallel developmental disorders in other species could provide complementary models for human rare diseases by uncovering new candidate genes, improving the understanding of the molecular mechanisms and opening possibilities for therapeutic trials. We performed various experiments, e.g. combined genome-wide association and next generation sequencing, to investigate the clinico-pathological features and genetic causes of three developmental syndromes in dogs, including craniomandibular osteopathy (CMO), a previously undescribed skeletal syndrome, and dental hypomineralization, for which we identified pathogenic variants in the canine SLC37A2 (truncating splicing enhancer variant), SCARF2 (truncating 2-bp deletion) and FAM20C (missense variant) genes, respectively. CMO is a clinical equivalent to an infantile cortical hyperostosis (Caffey disease), for which SLC37A2 is a new candidate gene. SLC37A2 is a poorly characterized member of a glucose-phosphate transporter family without previous disease associations. It is expressed in many tissues, including cells of the macrophage lineage, e.g. osteoclasts, and suggests a disease mechanism, in which an impaired glucose homeostasis in osteoclasts compromises their function in the developing bone, leading to hyperostosis. Mutations in SCARF2 and FAM20C have been associated with the human van den Ende-Gupta and Raine syndromes that include numerous features similar to the affected dogs. Given the growing interest in the molecular characterization and treatment of human rare diseases, our study presents three novel physiologically relevant models for further research and therapy approaches, while providing the molecular identity for the canine conditions.

  4. Yukawa Unified Supersymmetric SO(10) Model Cosmology, Rare Decays and Collider Searches

    CERN Document Server

    Baer, Howard W; Díaz, M A; Ferrandis, J; Mercadante, P G; Quintana, P; Tata, Xerxes; Baer, Howard; Brhlik, Michal; Diaz, Marco A.; Ferrandis, Javier; Mercadante, Pedro; Quintana, Pam; Tata, Xerxes

    2001-01-01

    It has recently been pointed out that viable sparticle mass spectra can be generated in Yukawa unified SO(10) supersymmetric grand unified models consistent with radiative breaking of electroweak symmetry. Model solutions are obtained only if $\\tan\\beta \\sim 50$, $\\mu <0$ and positive $D$-term contributions to scalar masses from SO(10) gauge symmetry breaking are used. In this paper, we attempt to systematize the parameter space regions where solutions are obtained. We go on to calculate the relic density of neutralinos as a function of parameter space. No regions of the parameter space explored were actually cosmologically excluded, and very reasonable relic densities were found in much of parameter space. Direct neutralino detection rates could exceed 1 event/kg/day for a $^{73}$Ge detector, for low values of GUT scale gaugino mass $m_{1/2}$. We also calculate the branching fraction for $b\\to s \\gamma$ decays, and find that it is beyond the 95% CL experimental limits in much, but not all, of the paramete...

  5. Rare Decay Bc →Ds*μ+μ-in a Family Non-Universal Z' Model

    Institute of Scientific and Technical Information of China (English)

    L(U) Lin-Xia; ZHANG Guo-Fang; WANG Shuai-Wei; ZHANG Zhi-Qing

    2013-01-01

    Using the form factors calculated in the three-point QCD sum rules,we calculate the new physics contributions to the physical observables of Bc → Ds*μ+ μ-decay in a family non-universal Z' model.Under the consideration of three cases of the new physics parameters,we find that:(a) the Z' boson can provide large contributions to the differential decay rates; (b) the forward-backward asymmetry (FBA) can be increased by about 47%,38%,and 110% at most in S1,S2,and extreme limit values (ELV),respectively.In addition,the zero crossing can be shifted in all the cases; (c) when (s) > 0.08,the value of PL can be changed from-1 in the Standard Model (SM) to-0.5 in S1,-0.6 in S2,and 0 in extreme limit values,respectively; (d) the new physics corrections to PT will decrease the SM prediction about 25% for the cases of S1 and S2,100% for the case of ELV.

  6. Development and Evaluation of Model Algorithms to Account for Chemical Transformation in the Nearroad Environment

    Science.gov (United States)

    We describe the development and evaluation of two new model algorithms for NOx chemistry in the R-LINE near-road dispersion model for traffic sources. With increased urbanization, there is increased mobility leading to higher amount of traffic related activity on a global scale. ...

  7. Accounting for correlated observations in an age-based state-space stock assessment model

    DEFF Research Database (Denmark)

    Berg, Casper Willestofte; Nielsen, Anders

    2016-01-01

    Fish stock assessment models often relyon size- or age-specific observations that are assumed to be statistically independent of each other. In reality, these observations are not raw observations, but rather they are estimates from a catch-standardization model or similar summary statistics based...

  8. Development and Evaluation of Model Algorithms to Account for Chemical Transformation in the Nearroad Environment

    Science.gov (United States)

    We describe the development and evaluation of two new model algorithms for NOx chemistry in the R-LINE near-road dispersion model for traffic sources. With increased urbanization, there is increased mobility leading to higher amount of traffic related activity on a global scale. ...

  9. Value-Added Models of Assessment: Implications for Motivation and Accountability

    Science.gov (United States)

    Anderman, Eric M.; Anderman, Lynley H.; Yough, Michael S.; Gimbert, Belinda G.

    2010-01-01

    In this article, we examine the relations of value-added models of measuring academic achievement to student motivation. Using an achievement goal orientation theory perspective, we argue that value-added models, which focus on the progress of individual students over time, are more closely aligned with research on student motivation than are more…

  10. Demand model for production of an enterprise taking into account factor of consumer expectations

    Directory of Open Access Journals (Sweden)

    L.V. Potrashkova

    2012-12-01

    Full Text Available This article presents a dynamic mathematical model of demand for innovative and uninnovative production of enterprises. The model allows to estimate future demand as a result of consumer expectations of production quality. Consumer expectations are considered as the resource component of enterprise marketing potential.

  11. Rare three-body decay t {yields} ch{gamma} in the standard model and the two-Higgs doublet model

    Energy Technology Data Exchange (ETDEWEB)

    Cordero-Cid, A [Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla, Pue. (Mexico); Garcia-Luna, J L [Departamento de Fisica, Centro Universitario de Ciencias Exactas e Ingenierias, Universidad de Guadalajara, Blvd. Marcelino Garcia Barragan 1508, CP 44840, Guadalajara Jal. (Mexico); Ramirez-Zavaleta, F [Departamento de Fisica, CINVESTAV, Apartado Postal 14-740, 07000, Mexico DF (Mexico); Tavares-Velasco, G [Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla, Pue. (Mexico); Toscano, J J [Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla, Apartado Postal 1152, Puebla, Pue. (Mexico)

    2006-04-01

    A complete calculation of the rare three-body decay t {yields} ch{gamma} is presented in the framework of the standard model. In the unitary gauge, such a calculation involves about 20 Feynman diagrams. We also calculate this decay in the general two-Higgs doublet model (model III), in which it arises at the tree level. While in the standard model the decay t {yields} ch{gamma} is extremely suppressed, with a branching fraction of the order of 10{sup -15} for a Higgs boson mass of the order of 115 GeV, in the model III it may have a branching ratio up to 10{sup -5}. We also discuss the crossed decay h {yields} bs-bar{gamma}.

  12. Modelling of L-valine Repeated Fed-batch Fermentation Process Taking into Account the Dissolved Oxygen Tension

    Directory of Open Access Journals (Sweden)

    Tzanko Georgiev

    2009-03-01

    Full Text Available This article deals with synthesis of dynamic unstructured model of variable volume fed-batch fermentation process with intensive droppings for L-valine production. The presented approach of the investigation includes the following main procedures: description of the process by generalized stoichiometric equations; preliminary data processing and calculation of specific rates for main kinetic variables; identification of the specific rates takes into account the dissolved oxygen tension; establishment and optimisation of dynamic model of the process; simulation researches. MATLAB is used as a research environment.

  13. Rare Z-decay into light pseudoscalar bosons in the simplest little Higgs model

    Energy Technology Data Exchange (ETDEWEB)

    Wang Lei [Department of Physics, Yantai University, Yantai 264005 (China); Han Xiaofang, E-mail: xfhan@itp.ac.cn [Department of Physics, Yantai University, Yantai 264005 (China)

    2011-12-21

    The simplest little Higgs model predicts a light pseudoscalar boson {eta} and opens up some new decay modes for Z-boson, such as Z{yields}f-barf{eta}, Z{yields}{eta}{eta}{eta}, Z{yields}{eta}{gamma} and Z{yields}{eta}gg. We examine these decay modes in the parameter space allowed by current experiments, and find that the branching ratios can reach 10{sup -7} for Z{yields}b-barb{eta}, 10{sup -8} for Z{yields}{tau}-bar{tau}{eta}, and 10{sup -8} for Z{yields}{eta}{gamma}, which should be accessible at the GigaZ option of the ILC. However, the branching ratios can reach 10{sup -12} for Z{yields}{eta}{eta}{eta}, and 10{sup -11} for Z{yields}{eta}gg, which are hardly accessible at the GigaZ option.

  14. Modeling rare earth complexes: Sparkle/AM1 parameters for thulium (III)

    Science.gov (United States)

    Freire, Ricardo O.; Rocha, Gerd B.; Simas, Alfredo M.

    2005-08-01

    The Sparkle/AM1 model, recently defined for Eu(III), Gd(III) and Tb(III) [R.O. Freire, G.B. Rocha, A.M., Simas, Inorg. Chem. 44 (2005) 3299], is extended to Tm(III). A set of 15 structures of high crystallographic quality from the Cambridge Crystallographic Database, with ligands chosen to be representative of all complexes with nitrogen or oxygen directly bonded to the Tm(III) ion, was used as a training set. For the 15 complexes, the Sparkle/AM1 unsigned mean error, for all interatomic distances between the Tm(III) ion and the oxygen or nitrogen ligand atoms of the first sphere of coordination, is 0.07 Å, a level of accuracy useful for luminescent complex design.

  15. Modeling coral calcification accounting for the impacts of coral bleaching and ocean acidification

    Directory of Open Access Journals (Sweden)

    C. Evenhuis

    2014-01-01

    Full Text Available Coral reefs are diverse ecosystems threatened by rising CO2 levels that are driving the observed increases in sea surface temperature and ocean acidification. Here we present a new unified model that links changes in temperature and carbonate chemistry to coral health. Changes in coral health and population are able to explicitly modelled by linking the rates of growth, recovery and calcification to the rates of bleaching and temperature stress induced mortality. The model is underpinned by four key principles: the Arrhenius equation, thermal specialisation, resource allocation trade-offs, and adaption to local environments. These general relationships allow this model to be constructed from a range of experimental and observational data. The different characteristics of this model are also assessed against independent data to show that the model captures the observed response of corals. We also provide new insights into the factors that determine calcification rates and provide a framework based on well-known biological principles for understanding the observed global distribution of calcification rates. Our results suggest that, despite the implicit complexity of the coral reef environment, a simple model based on temperature, carbonate chemistry and different species can reproduce much of the observed response of corals to changes in temperature and ocean acidification.

  16. Modeling coral calcification accounting for the impacts of coral bleaching and ocean acidification

    Science.gov (United States)

    Evenhuis, C.; Lenton, A.; Cantin, N. E.; Lough, J. M.

    2014-01-01

    Coral reefs are diverse ecosystems threatened by rising CO2 levels that are driving the observed increases in sea surface temperature and ocean acidification. Here we present a new unified model that links changes in temperature and carbonate chemistry to coral health. Changes in coral health and population are able to explicitly modelled by linking the rates of growth, recovery and calcification to the rates of bleaching and temperature stress induced mortality. The model is underpinned by four key principles: the Arrhenius equation, thermal specialisation, resource allocation trade-offs, and adaption to local environments. These general relationships allow this model to be constructed from a range of experimental and observational data. The different characteristics of this model are also assessed against independent data to show that the model captures the observed response of corals. We also provide new insights into the factors that determine calcification rates and provide a framework based on well-known biological principles for understanding the observed global distribution of calcification rates. Our results suggest that, despite the implicit complexity of the coral reef environment, a simple model based on temperature, carbonate chemistry and different species can reproduce much of the observed response of corals to changes in temperature and ocean acidification.

  17. Reduced models accounting for parallel magnetic perturbations: gyrofluid and finite Larmor radius-Landau fluid approaches

    Science.gov (United States)

    Tassi, E.; Sulem, P. L.; Passot, T.

    2016-12-01

    Reduced models are derived for a strongly magnetized collisionless plasma at scales which are large relative to the electron thermal gyroradius and in two asymptotic regimes. One corresponds to cold ions and the other to far sub-ion scales. By including the electron pressure dynamics, these models improve the Hall reduced magnetohydrodynamics (MHD) and the kinetic Alfvén wave model of Boldyrev et al. (2013 Astrophys. J., vol. 777, 2013, p. 41), respectively. We show that the two models can be obtained either within the gyrofluid formalism of Brizard (Phys. Fluids, vol. 4, 1992, pp. 1213-1228) or as suitable weakly nonlinear limits of the finite Larmor radius (FLR)-Landau fluid model of Sulem and Passot (J. Plasma Phys., vol 81, 2015, 325810103) which extends anisotropic Hall MHD by retaining low-frequency kinetic effects. It is noticeable that, at the far sub-ion scales, the simplifications originating from the gyroaveraging operators in the gyrofluid formalism and leading to subdominant ion velocity and temperature fluctuations, correspond, at the level of the FLR-Landau fluid, to cancellation between hydrodynamic contributions and ion finite Larmor radius corrections. Energy conservation properties of the models are discussed and an explicit example of a closure relation leading to a model with a Hamiltonian structure is provided.

  18. An individual-based model of Zebrafish population dynamics accounting for energy dynamics

    DEFF Research Database (Denmark)

    Beaudouin, Remy; Goussen, Benoit; Piccini, Benjamin

    2015-01-01

    Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model......, the predictions of the DEB-IBM were compared to existing observations on natural zebrafish populations and the predicted population dynamics are realistic. While our zebrafish DEB-IBM model can still be improved by acquiring new experimental data on the most uncertain processes (e.g. survival or feeding), it can...

  19. Mathematical modelling of complex equilibria taking into account experimental data on activities of components

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaeva, L.S.; Evseev, A.M.; Rozen, A.M.; Bobytev, A.P.; Kir' yanov, Yu.A. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1981-09-01

    The extraction systems, the application of which is possible when reprocessing irradiated nuclear fuels are considered. It is shown that the selection of the component activities as the observed properties of the system (responses) provides a possibility to model the equilibria using methods of the regression analysis. The mathematical model of nitric acid extraction with tributyl phosphate is presented. The data on the composition of the complexes in the system studied, obtained by the method of mathematical modelling, are confirmed with the study of the IR spectra of the extracts.

  20. A new computational account of cognitive control over reinforcement-based decision-making: Modeling of a probabilistic learning task.

    Science.gov (United States)

    Zendehrouh, Sareh

    2015-11-01

    Recent work on decision-making field offers an account of dual-system theory for decision-making process. This theory holds that this process is conducted by two main controllers: a goal-directed system and a habitual system. In the reinforcement learning (RL) domain, the habitual behaviors are connected with model-free methods, in which appropriate actions are learned through trial-and-error experiences. However, goal-directed behaviors are associated with model-based methods of RL, in which actions are selected using a model of the environment. Studies on cognitive control also suggest that during processes like decision-making, some cortical and subcortical structures work in concert to monitor the consequences of decisions and to adjust control according to current task demands. Here a computational model is presented based on dual system theory and cognitive control perspective of decision-making. The proposed model is used to simulate human performance on a variant of probabilistic learning task. The basic proposal is that the brain implements a dual controller, while an accompanying monitoring system detects some kinds of conflict including a hypothetical cost-conflict one. The simulation results address existing theories about two event-related potentials, namely error related negativity (ERN) and feedback related negativity (FRN), and explore the best account of them. Based on the results, some testable predictions are also presented. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. An agent-based simulation model of patient choice of health care providers in accountable care organizations.

    Science.gov (United States)

    Alibrahim, Abdullah; Wu, Shinyi

    2016-10-04

    Accountable care organizations (ACO) in the United States show promise in controlling health care costs while preserving patients' choice of providers. Understanding the effects of patient choice is critical in novel payment and delivery models like ACO that depend on continuity of care and accountability. The financial, utilization, and behavioral implications associated with a patient's decision to forego local health care providers for more distant ones to access higher quality care remain unknown. To study this question, we used an agent-based simulation model of a health care market composed of providers able to form ACO serving patients and embedded it in a conditional logit decision model to examine patients capable of choosing their care providers. This simulation focuses on Medicare beneficiaries and their congestive heart failure (CHF) outcomes. We place the patient agents in an ACO delivery system model in which provider agents decide if they remain in an ACO and perform a quality improving CHF disease management intervention. Illustrative results show that allowing patients to choose their providers reduces the yearly payment per CHF patient by $320, reduces mortality rates by 0.12 percentage points and hospitalization rates by 0.44 percentage points, and marginally increases provider participation in ACO. This study demonstrates a model capable of quantifying the effects of patient choice in a theoretical ACO system and provides a potential tool for policymakers to understand implications of patient choice and assess potential policy controls.

  2. Making Collaborative Innovation Accountable

    DEFF Research Database (Denmark)

    Sørensen, Eva

    The public sector is increasingly expected to be innovative, but the prize for a more innovative public sector might be that it becomes difficult to hold public authorities to account for their actions. The article explores the tensions between innovative and accountable governance, describes...... the foundation for these tensions in different accountability models, and suggest directions to take in analyzing the accountability of collaborative innovation processes....

  3. Accounting for scattering in the Landauer-Datta-Lundstrom transport model

    Directory of Open Access Journals (Sweden)

    Юрій Олексійович Кругляк

    2015-03-01

    Full Text Available Scattering of carriers in the LDL transport model during the changes of the scattering times in the collision processes is considered qualitatively. The basic relationship between the transmission coefficient T and the average mean free path  is derived for 1D conductor. As an example, the experimental data for Si MOSFET are analyzed with the use of various models of reliability.

  4. A retinal circuit model accounting for wide-field amacrine cells

    OpenAIRE

    SAĞLAM, Murat; Hayashida, Yuki; Murayama, Nobuki

    2008-01-01

    In previous experimental studies on the visual processing in vertebrates, higher-order visual functions such as the object segregation from background were found even in the retinal stage. Previously, the “linear–nonlinear” (LN) cascade models have been applied to the retinal circuit, and succeeded to describe the input-output dynamics for certain parts of the circuit, e.g., the receptive field of the outer retinal neurons. And recently, some abstract models composed of LN cascades as the cir...

  5. Loading Processes Dynamics Modelling Taking into Account the Bucket-Soil Interaction

    Directory of Open Access Journals (Sweden)

    Carmen Debeleac

    2007-10-01

    Full Text Available The author propose three dynamic models specialized for the vibrations and resistive forces analysis that appear at the loading process with different construction equipment like frontal loaders and excavators.The models used putting into evidence the components of digging: penetration, cutting, and loading.The conclusions of this study consist by evidentiate the dynamic overloads that appear on the working state and that induced the self-oscillations into the equipment structure.

  6. An extended continuum model accounting for the driver's timid and aggressive attributions

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Rongjun; Ge, Hongxia [Faculty of Maritime and Transportation, Ningbo University, Ningbo 315211 (China); Jiangsu Province Collaborative Innovation Center for Modern Urban Traffic Technologies, Nanjing 210096 (China); National Traffic Management Engineering and Technology Research Centre Ningbo University Sub-centre, Ningbo 315211 (China); Wang, Jufeng, E-mail: wjf@nit.zju.edu.cn [Ningbo Institute of Technology, Zhejiang University, Ningbo 315100 (China)

    2017-04-18

    Considering the driver's timid and aggressive behaviors simultaneously, a new continuum model is put forwarded in this paper. By applying the linear stability theory, we presented the analysis of new model's linear stability. Through nonlinear analysis, the KdV–Burgers equation is derived to describe density wave near the neutral stability line. Numerical results verify that aggressive driving is better than timid act because the aggressive driver will adjust his speed timely according to the leading car's speed. The key improvement of this new model is that the timid driving deteriorates traffic stability while the aggressive driving will enhance traffic stability. The relationship of energy consumption between the aggressive and timid driving is also studied. Numerical results show that aggressive driver behavior can not only suppress the traffic congestion but also reduce the energy consumption. - Highlights: • A new continuum model is developed with the consideration of the driver's timid and aggressive behaviors simultaneously. • Applying the linear stability theory, the new model's linear stability is obtained. • Through nonlinear analysis, the KdV–Burgers equation is derived. • The energy consumption for this model is studied.

  7. A retinal circuit model accounting for wide-field amacrine cells.

    Science.gov (United States)

    Sağlam, Murat; Hayashida, Yuki; Murayama, Nobuki

    2009-03-01

    In previous experimental studies on the visual processing in vertebrates, higher-order visual functions such as the object segregation from background were found even in the retinal stage. Previously, the "linear-nonlinear" (LN) cascade models have been applied to the retinal circuit, and succeeded to describe the input-output dynamics for certain parts of the circuit, e.g., the receptive field of the outer retinal neurons. And recently, some abstract models composed of LN cascades as the circuit elements could explain the higher-order retinal functions. However, in such a model, each class of retinal neurons is mostly omitted and thus, how those neurons play roles in the visual computations cannot be explored. Here, we present a spatio-temporal computational model of the vertebrate retina, based on the response function for each class of retinal neurons and on the anatomical inter-cellular connections. This model was capable of not only reproducing the spatio-temporal filtering properties of the outer retinal neurons, but also realizing the object segregation mechanism in the inner retinal circuit involving the "wide-field" amacrine cells. Moreover, the first-order Wiener kernels calculated for the neurons in our model showed a reasonable fit to the kernels previously measured in the real retinal neuron in situ.

  8. Analysis of homogeneous/non-homogeneous nanofluid models accounting for nanofluid-surface interactions

    Science.gov (United States)

    Ahmad, R.

    2016-07-01

    This article reports an unbiased analysis for the water based rod shaped alumina nanoparticles by considering both the homogeneous and non-homogeneous nanofluid models over the coupled nanofluid-surface interface. The mechanics of the surface are found for both the homogeneous and non-homogeneous models, which were ignored in previous studies. The viscosity and thermal conductivity data are implemented from the international nanofluid property benchmark exercise. All the simulations are being done by using the experimentally verified results. By considering the homogeneous and non-homogeneous models, the precise movement of the alumina nanoparticles over the surface has been observed by solving the corresponding system of differential equations. For the non-homogeneous model, a uniform temperature and nanofluid volume fraction are assumed at the surface, and the flux of the alumina nanoparticle is taken as zero. The assumption of zero nanoparticle flux at the surface makes the non-homogeneous model physically more realistic. The differences of all profiles for both the homogeneous and nonhomogeneous models are insignificant, and this is due to small deviations in the values of the Brownian motion and thermophoresis parameters.

  9. Modelling coral calcification accounting for the impacts of coral bleaching and ocean acidification

    Science.gov (United States)

    Evenhuis, C.; Lenton, A.; Cantin, N. E.; Lough, J. M.

    2015-05-01

    Coral reefs are diverse ecosystems that are threatened by rising CO2 levels through increases in sea surface temperature and ocean acidification. Here we present a new unified model that links changes in temperature and carbonate chemistry to coral health. Changes in coral health and population are explicitly modelled by linking rates of growth, recovery and calcification to rates of bleaching and temperature-stress-induced mortality. The model is underpinned by four key principles: the Arrhenius equation, thermal specialisation, correlated up- and down-regulation of traits that are consistent with resource allocation trade-offs, and adaption to local environments. These general relationships allow this model to be constructed from a range of experimental and observational data. The performance of the model is assessed against independent data to demonstrate how it can capture the observed response of corals to stress. We also provide new insights into the factors that determine calcification rates and provide a framework based on well-known biological principles to help understand the observed global distribution of calcification rates. Our results suggest that, despite the implicit complexity of the coral reef environment, a simple model based on temperature, carbonate chemistry and different species can give insights into how corals respond to changes in temperature and ocean acidification.

  10. Carbon accounting and economic model uncertainty of emissions from biofuels-induced land use change.

    Science.gov (United States)

    Plevin, Richard J; Beckman, Jayson; Golub, Alla A; Witcover, Julie; O'Hare, Michael

    2015-03-03

    Few of the numerous published studies of the emissions from biofuels-induced "indirect" land use change (ILUC) attempt to propagate and quantify uncertainty, and those that have done so have restricted their analysis to a portion of the modeling systems used. In this study, we pair a global, computable general equilibrium model with a model of greenhouse gas emissions from land-use change to quantify the parametric uncertainty in the paired modeling system's estimates of greenhouse gas emissions from ILUC induced by expanded production of three biofuels. We find that for the three fuel systems examined--US corn ethanol, Brazilian sugar cane ethanol, and US soybean biodiesel--95% of the results occurred within ±20 g CO2e MJ(-1) of the mean (coefficient of variation of 20-45%), with economic model parameters related to crop yield and the productivity of newly converted cropland (from forestry and pasture) contributing most of the variance in estimated ILUC emissions intensity. Although the experiments performed here allow us to characterize parametric uncertainty, changes to the model structure have the potential to shift the mean by tens of grams of CO2e per megajoule and further broaden distributions for ILUC emission intensities.

  11. Possibilities for testing the predictions of the standard model in rare semileptonic decays of B mesons with the ATLAS detector

    CERN Document Server

    Nikitin, N V; Smirnova, L N

    1999-01-01

    The features of the rare semileptonic B-meson decays B/sub d//sup 0/ to K/sup 0/* mu /sup +/ mu /sup -/ and B/sub d//sup 0/ to rho /sup 0/ mu /sup -/ mu /sup -/ have been considered. It has been shown that the dependence of the lepton charge asymmetry A/sub FB/ on the dilepton effective mass has different forms in the Standard Model and in certain versions of the minimal supersymmetric model. In particular, distinctions of this type have been found in the angular distributions d Gamma /dcos theta * of K mesons produced in the decay B/sub d//sup 0/ to (K/sup 0/* to K pi ) mu /sup +/ mu /sup -/ in the K/sup 0/* rest frame. The numbers of events that can be recorded by the ATLAS detector have been estimated for the above decays. The statistical errors in the measurements of A/sub FB/ and d Gamma /dcos theta * have been assessed. It has been shown that, under certain conditions. The expected numbers of detected events will be sufficient for observing deviations from the predictions of the Standard Model. (15 refs...

  12. Accounting for anthropogenic actions in modeling of stream flow at the regional scale

    Science.gov (United States)

    David, C. H.; Famiglietti, J. S.

    2013-12-01

    The modeling of the horizontal movement of water from land to coasts at scales ranging from 10^5 km^2 to 10^6 km^2 has benefited from extensive research within the past two decades. In parallel, community technology for gathering/sharing surface water observations and datasets for describing the geography of terrestrial water bodies have recently had groundbreaking advancements. Yet, the fields of computational hydrology and hydroinformatics have barely started to work hand-in-hand, and much research remains to be performed before we can better understand the anthropogenic impact on surface water through combined observations and models. Here, we build on our existing river modeling approach that leverages community state-of-the-art tools such as atmospheric data from the second phase of the North American Land Data Assimilation System (NLDAS2), river networks from the enhanced National Hydrography Dataset (NHDPlus), and observations from the U.S. Geological Survey National Water Information System (NWIS) obtained through CUAHSI webservices. Modifications are made to our integrated observational/modeling system to include treatment for anthropogenic actions such as dams, pumping and divergences in river networks. Initial results of a study focusing on the entire State of California suggest that availability of data describing human alterations on natural river networks associated with proper representation of such actions in our models could help advance hydrology further. Snapshot from an animation of flow in California river networks. The full animation is available at: http://www.ucchm.org/david/rapid.htm.

  13. An extended continuum model accounting for the driver's timid and aggressive attributions

    Science.gov (United States)

    Cheng, Rongjun; Ge, Hongxia; Wang, Jufeng

    2017-04-01

    Considering the driver's timid and aggressive behaviors simultaneously, a new continuum model is put forwarded in this paper. By applying the linear stability theory, we presented the analysis of new model's linear stability. Through nonlinear analysis, the KdV-Burgers equation is derived to describe density wave near the neutral stability line. Numerical results verify that aggressive driving is better than timid act because the aggressive driver will adjust his speed timely according to the leading car's speed. The key improvement of this new model is that the timid driving deteriorates traffic stability while the aggressive driving will enhance traffic stability. The relationship of energy consumption between the aggressive and timid driving is also studied. Numerical results show that aggressive driver behavior can not only suppress the traffic congestion but also reduce the energy consumption.

  14. Model of Environmental Development of the Urbanized Areas: Accounting of Ecological and other Factors

    Science.gov (United States)

    Abanina, E. N.; Pandakov, K. G.; Agapov, D. A.; Sorokina, Yu V.; Vasiliev, E. H.

    2017-05-01

    Modern cities and towns are often characterized by poor administration, which could be the reason of environmental degradation, the poverty growth, decline in economic growth and social isolation. In these circumstances it is really important to conduct fresh researches forming new ways of sustainable development of administrative districts. This development of the urban areas depends on many interdependent factors: ecological, economic, social. In this article we show some theoretical aspects of forming a model of environmental progress of the urbanized areas. We submit some model containing four levels including natural resources capacities of the territory, its social features, economic growth and human impact. The author describes the interrelations of elements of the model. In this article the program of environmental development of a city is offered and it could be used in any urban area.

  15. Multiphysics Model of Palladium Hydride Isotope Exchange Accounting for Higher Dimensionality

    Energy Technology Data Exchange (ETDEWEB)

    Gharagozloo, Patricia E.; Eliassi, Mehdi; Bon, Bradley Luis

    2015-03-01

    This report summarizes computational model developm ent and simulations results for a series of isotope exchange dynamics experiments i ncluding long and thin isothermal beds similar to the Foltz and Melius beds and a lar ger non-isothermal experiment on the NENG7 test bed. The multiphysics 2D axi-symmetr ic model simulates the temperature and pressure dependent exchange reactio n kinetics, pressure and isotope dependent stoichiometry, heat generation from the r eaction, reacting gas flow through porous media, and non-uniformities in the bed perme ability. The new model is now able to replicate the curved reaction front and asy mmetry of the exit gas mass fractions over time. The improved understanding of the exchange process and its dependence on the non-uniform bed properties and te mperatures in these larger systems is critical to the future design of such sy stems.

  16. Does Don Fisher's high-pressure manifold model account for phloem transport and resource partitioning?

    Science.gov (United States)

    Patrick, John W

    2013-01-01

    The pressure flow model of phloem transport envisaged by Münch (1930) has gained wide acceptance. Recently, however, the model has been questioned on structural and physiological grounds. For instance, sub-structures of sieve elements may reduce their hydraulic conductances to levels that impede flow rates of phloem sap and observed magnitudes of pressure gradients to drive flow along sieve tubes could be inadequate in tall trees. A variant of the Münch pressure flow model, the high-pressure manifold model of phloem transport introduced by Donald Fisher may serve to reconcile at least some of these questions. To this end, key predicted features of the high-pressure manifold model of phloem transport are evaluated against current knowledge of the physiology of phloem transport. These features include: (1) An absence of significant gradients in axial hydrostatic pressure in sieve elements from collection to release phloem accompanied by transport properties of sieve elements that underpin this outcome; (2) Symplasmic pathways of phloem unloading into sink organs impose a major constraint over bulk flow rates of resources translocated through the source-path-sink system; (3) Hydraulic conductances of plasmodesmata, linking sieve elements with surrounding phloem parenchyma cells, are sufficient to support and also regulate bulk flow rates exiting from sieve elements of release phloem. The review identifies strong circumstantial evidence that resource transport through the source-path-sink system is consistent with the high-pressure manifold model of phloem transport. The analysis then moves to exploring mechanisms that may link demand for resources, by cells of meristematic and expansion/storage sinks, with plasmodesmal conductances of release phloem. The review concludes with a brief discussion of how these mechanisms may offer novel opportunities to enhance crop biomass yields.

  17. Taking dietary habits into account: A computational method for modeling food choices that goes beyond price.

    Science.gov (United States)

    Beheshti, Rahmatollah; Jones-Smith, Jessica C; Igusa, Takeru

    2017-01-01

    Computational models have gained popularity as a predictive tool for assessing proposed policy changes affecting dietary choice. Specifically, they have been used for modeling dietary changes in response to economic interventions, such as price and income changes. Herein, we present a novel addition to this type of model by incorporating habitual behaviors that drive individuals to maintain or conform to prior eating patterns. We examine our method in a simulated case study of food choice behaviors of low-income adults in the US. We use data from several national datasets, including the National Health and Nutrition Examination Survey (NHANES), the US Bureau of Labor Statistics and the USDA, to parameterize our model and develop predictive capabilities in 1) quantifying the influence of prior diet preferences when food budgets are increased and 2) simulating the income elasticities of demand for four food categories. Food budgets can increase because of greater affordability (due to food aid and other nutritional assistance programs), or because of higher income. Our model predictions indicate that low-income adults consume unhealthy diets when they have highly constrained budgets, but that even after budget constraints are relaxed, these unhealthy eating behaviors are maintained. Specifically, diets in this population, before and after changes in food budgets, are characterized by relatively low consumption of fruits and vegetables and high consumption of fat. The model results for income elasticities also show almost no change in consumption of fruit and fat in response to changes in income, which is in agreement with data from the World Bank's International Comparison Program (ICP). Hence, the proposed method can be used in assessing the influences of habitual dietary patterns on the effectiveness of food policies.

  18. Mathematical modeling of pigment dispersion taking into account the full agglomerate particle size distribution

    DEFF Research Database (Denmark)

    Kiil, Søren

    2017-01-01

    particle size distribution was simulated. Data from two previous experimental investigations were used for model validation. The first concerns two different yellow organic pigments dispersed in nitrocellulose/ethanol vehicles in a ball mill and the second a red organic pigment dispersed in a solvent-based....... The only adjustable parameter used was an apparent rate constant for the linear agglomerate erosion rate. Model simulations, at selected values of time, for the full agglomerate particle size distribution were in good qualitative agreement with the measured values. A quantitative match of the experimental...

  19. Creative Accounting Model for Increasing Banking Industries’ Competitive Advantage in Indonesia

    Directory of Open Access Journals (Sweden)

    Supriyati

    2015-12-01

    Full Text Available Bank Indonesia demands that the national banks should improve their transparency of financial condition and performance for public in line with the development of their products and activities. Furthermore, the banks’ financial statements of Bank Indonesia have become the basis for determining the status of their soundness. In fact, they tend to practice earnings management in order that they can meet the crite-ria required by Bank Indonesia. For internal purposes, the initiative of earning management has a positive impact on the performance of management. However, for the users of financial statements, it may dif-fer, for example for the value of company, length of time the financial audit, and other aspects of tax evasion by the banks. This study tries to find out 1 the effect of GCG on Earnings Management, 2 the effect of earning management on Company value, theAudit Report Lag, and Taxation, and 3 the effect of Audit Report Lag on Corporate Value and Taxation. This is a quantitative research with the data collected from the bank financial statements, GCG implementation report, and the banks’ annual reports of 2003-2013. There were 41 banks taken using purposive sampling, as listed on the Indonesia Stock Exchange. The results showed that the implementation of GCG affects the occurrence of earning management. Accounting policy flexibility through earning management is expected to affect the length of the audit process and the accuracy of the financial statements presentation on public side. This research is expected to provide managerial implications in order to consider the possibility of earnings management practices in the banking industry. In the long term, earning management is expected to improve the banks’ competitiveness through an increase in the value of the company. Explicitly, earning management also affects the tax avoidance; therefore, the banks intend to pay lower taxes without breaking the existing legislation Taxation

  20. Creative Accounting Model for Increasing Banking Industries’ Competitive Advantage in Indonesia (P.197-207

    Directory of Open Access Journals (Sweden)

    Supriyati Supriyati

    2017-01-01

    Full Text Available Bank Indonesia demands that the national banks should improve their transparency of financial condition and performance for public in line with the development of their products and activities. Furthermore, the banks’ financial statements of Bank Indonesia have become the basis for determining the status of their soundness. In fact, they tend to practice earnings management in order that they can meet the criteria required by Bank Indonesia. For internal purposes, the initiative of earning management has a positive impact on the performance of management. However, for the users of financial statements, it may differ, for example for the value of company, length of time the financial audit, and other aspects of tax evasion by the banks. This study tries to find out 1 the effect of GCG on Earnings Management, 2 the effect of earning management on Company value, the Audit Report Lag, and Taxation, and 3 the effect of Audit Report Lag on Corporate Value and Taxation. This is a quantitative research with the data collected from the bank financial statements, GCG implementation report, and the banks’ annual reports of 2003-2013. There were 41 banks taken using purposive sampling, as listed on the Indonesia Stock Exchange. The results showed that the implementation of GCG affects the occurrence of earning management. Accounting policy flexibility through earning management is expected to affect the length of the audit process and the accuracy of the financial statements presentation on public side. This research is expected to provide managerial implications in order to consider the possibility of earnings management practices in the banking industry. In the long term, earning management is expected to improve the banks’ competitiveness through an increase in the value of the company. Explicitly, earning management also affects the tax avoidance; therefore, the banks intend to pay lower taxes without breaking the existing legislation Taxation

  1. Accountability and non-proliferation nuclear regime: a review of the mutual surveillance Brazilian-Argentine model for nuclear safeguards; Accountability e regime de nao proliferacao nuclear: uma avaliacao do modelo de vigilancia mutua brasileiro-argentina de salvaguardas nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Xavier, Roberto Salles

    2014-08-01

    The regimes of accountability, the organizations of global governance and institutional arrangements of global governance of nuclear non-proliferation and of Mutual Vigilance Brazilian-Argentine of Nuclear Safeguards are the subject of research. The starting point is the importance of the institutional model of global governance for the effective control of non-proliferation of nuclear weapons. In this context, the research investigates how to structure the current arrangements of the international nuclear non-proliferation and what is the performance of model Mutual Vigilance Brazilian-Argentine of Nuclear Safeguards in relation to accountability regimes of global governance. For that, was searched the current literature of three theoretical dimensions: accountability, global governance and global governance organizations. In relation to the research method was used the case study and the treatment technique of data the analysis of content. The results allowed: to establish an evaluation model based on accountability mechanisms; to assess how behaves the model Mutual Vigilance Brazilian-Argentine Nuclear Safeguards front of the proposed accountability regime; and to measure the degree to which regional arrangements that work with systems of global governance can strengthen these international systems. (author)

  2. An Exemplar-Model Account of Feature Inference from Uncertain Categorizations

    Science.gov (United States)

    Nosofsky, Robert M.

    2015-01-01

    In a highly systematic literature, researchers have investigated the manner in which people make feature inferences in paradigms involving uncertain categorizations (e.g., Griffiths, Hayes, & Newell, 2012; Murphy & Ross, 1994, 2007, 2010a). Although researchers have discussed the implications of the results for models of categorization and…

  3. Teachers' Conceptions of Assessment in Chinese Contexts: A Tripartite Model of Accountability, Improvement, and Irrelevance

    Science.gov (United States)

    Brown, Gavin T. L.; Hui, Sammy K. F.; Yu, Flora W. M.; Kennedy, Kerry J.

    2011-01-01

    The beliefs teachers have about assessment influence classroom practices and reflect cultural and societal differences. This paper reports the development of a new self-report inventory to examine beliefs teachers in Hong Kong and southern China contexts have about the nature and purpose of assessment. A statistically equivalent model for Hong…

  4. A Mathematical Model Accounting for the Organisation in Multiplets of the Genetic Code

    OpenAIRE

    Sciarrino, A.

    2001-01-01

    Requiring stability of genetic code against translation errors, modelised by suitable mathematical operators in the crystal basis model of the genetic code, the main features of the organisation in multiplets of the mitochondrial and of the standard genetic code are explained.

  5. Practical Model for First Hyperpolarizability Dispersion Accounting for Both Homogeneous and Inhomogeneous Broadening Effects.

    Science.gov (United States)

    Campo, Jochen; Wenseleers, Wim; Hales, Joel M; Makarov, Nikolay S; Perry, Joseph W

    2012-08-16

    A practical yet accurate dispersion model for the molecular first hyperpolarizability β is presented, incorporating both homogeneous and inhomogeneous line broadening because these affect the β dispersion differently, even if they are indistinguishable in linear absorption. Consequently, combining the absorption spectrum with one free shape-determining parameter Ginhom, the inhomogeneous line width, turns out to be necessary and sufficient to obtain a reliable description of the β dispersion, requiring no information on the homogeneous (including vibronic) and inhomogeneous line broadening mechanisms involved, providing an ideal model for practical use in extrapolating experimental nonlinear optical (NLO) data. The model is applied to the efficient NLO chromophore picolinium quinodimethane, yielding an excellent fit of the two-photon resonant wavelength-dependent data and a dependable static value β0 = 316 × 10(-30) esu. Furthermore, we show that including a second electronic excited state in the model does yield an improved description of the NLO data at shorter wavelengths but has only limited influence on β0.

  6. Fluid Simulations with Atomistic Resolution: Multiscale Model with Account of Nonlocal Momentum Transfer

    NARCIS (Netherlands)

    Svitenkov, A.I.; Chivilikhin, S.A.; Hoekstra, A.G.; Boukhanovsky, A.V.

    2015-01-01

    Nano- and microscale flow phenomena turn out to be highly non-trivial for simulation and require the use of heterogeneous modeling approaches. While the continuum Navier-Stokes equations and related boundary conditions quickly break down at those scales, various direct simulation methods and hybrid

  7. Accountability in Training Transfer: Adapting Schlenker's Model of Responsibility to a Persistent but Solvable Problem

    Science.gov (United States)

    Burke, Lisa A.; Saks, Alan M.

    2009-01-01

    Decades have been spent studying training transfer in organizational environments in recognition of a transfer problem in organizations. Theoretical models of various antecedents, empirical studies of transfer interventions, and studies of best practices have all been advanced to address this continued problem. Yet a solution may not be so…

  8. Working Memory Span Development: A Time-Based Resource-Sharing Model Account

    Science.gov (United States)

    Barrouillet, Pierre; Gavens, Nathalie; Vergauwe, Evie; Gaillard, Vinciane; Camos, Valerie

    2009-01-01

    The time-based resource-sharing model (P. Barrouillet, S. Bernardin, & V. Camos, 2004) assumes that during complex working memory span tasks, attention is frequently and surreptitiously switched from processing to reactivate decaying memory traces before their complete loss. Three experiments involving children from 5 to 14 years of age…

  9. A coupled surface/subsurface flow model accounting for air entrapment and air pressure counterflow

    DEFF Research Database (Denmark)

    Delfs, Jens Olaf; Wang, Wenqing; Kalbacher, Thomas

    2013-01-01

    This work introduces the soil air system into integrated hydrology by simulating the flow processes and interactions of surface runoff, soil moisture and air in the shallow subsurface. The numerical model is formulated as a coupled system of partial differential equations for hydrostatic (diffusive...

  10. Taking the Error Term of the Factor Model into Account: The Factor Score Predictor Interval

    Science.gov (United States)

    Beauducel, Andre

    2013-01-01

    The problem of factor score indeterminacy implies that the factor and the error scores cannot be completely disentangled in the factor model. It is therefore proposed to compute Harman's factor score predictor that contains an additive combination of factor and error variance. This additive combination is discussed in the framework of classical…

  11. Spatial modelling and ecosystem accounting for land use planning: addressing deforestation and oil palm expansion in Central Kalimantan, Indonesia

    NARCIS (Netherlands)

    Sumarga, E.

    2015-01-01

    Ecosystem accounting is a new area of environmental economic accounting that aims to measure ecosystem services in a way that is in line with national accounts. The key characteristics of ecosystem accounting include the extension of the valuation boundary of the System of National Accounts, allowin

  12. Spatial modelling and ecosystem accounting for land use planning: addressing deforestation and oil palm expansion in Central Kalimantan, Indonesia

    NARCIS (Netherlands)

    Sumarga, E.

    2015-01-01

    Ecosystem accounting is a new area of environmental economic accounting that aims to measure ecosystem services in a way that is in line with national accounts. The key characteristics of ecosystem accounting include the extension of the valuation boundary of the System of National Accounts,

  13. Thermodynamic Modeling of Developed Structural Turbulence Taking into Account Fluctuations of Energy Dissipation

    Science.gov (United States)

    Kolesnichenko, A. V.

    2004-03-01

    A thermodynamic approach to the construction of a phenomenological macroscopic model of developed turbulence in a compressible fluid is considered with regard for the formation of space-time dissipative structures. A set of random variables were introduced into the model as internal parameters of the turbulent-chaos subsystem. This allowed us to obtain, by methods of nonequilibrium thermodynamics, the kinetic Fokker-Planck equation in the configuration space. This equation serves to determine the temporary evolution of the conditional probability distribution function of structural parameters pertaining to the cascade process of fragmentation of large-scale eddies and temperature inhomogeneities and to analyze Markovian stochastic processes of transition from one nonequilibrium stationary turbulent-motion state to another as a result of successive loss of stability caused by a change in the governing parameters. An alternative method for investigating the mechanisms of such transitions, based on the stochastic Langevin-type equation intimately related to the derived kinetic equation, is also considered. Some postulates and physical and mathematical assumptions used in the thermodynamic model of structurized turbulence are discussed in detail. In particular, we considered, using the deterministic transport equation for conditional means, the cardinal problem of the developed approach-the possibility of the existence of asymptotically stable stationary states of the turbulent-chaos subsystem. Also proposed is the nonequilibrium thermodynamic potential for internal coordinates, which extends the well-known Boltzmann-Planck relationship for equilibrium states to the nonequilibrium stationary states of the representing ensemble. This potential is shown to be the Lyapunov function for such states. The relation is also explored between the internal intermittence in the inertial interval of scales and the fluctuations of the energy of dissipation. This study is aimed at

  14. MODIS Inundation Estimate Assimilation into Soil Moisture Accounting Hydrologic Model: A Case Study in Southeast Asia

    Directory of Open Access Journals (Sweden)

    Ari Posner

    2014-11-01

    Full Text Available Flash Flood Guidance consists of indices that estimate the amount of rain of a certain duration that is needed over a given small basin in order to cause minor flooding. Backwater catchment inundation from swollen rivers or regional groundwater inputs are not significant over the spatial and temporal scales for the majority of upland flash flood prone basins, as such, these effects are not considered. However, some lowland areas and flat terrain near large rivers experience standing water long after local precipitation has ceased. NASA is producing an experimental product from the MODIS that detects standing water. These observations were assimilated into the hydrologic model in order to more accurately represent soil moisture conditions within basins, from sources of water from outside of the basin. Based on the upper soil water content, relations are used to derive an error estimate for the modeled soil saturation fraction; whereby, the soil saturation fraction model state can be updated given the availability of satellite observed inundation. Model error estimates were used in a Monte Carlo ensemble forecast of soil water and flash flood potential. Numerical experiments with six months of data (July 2011–December 2011 showed that MODIS inundation data, when assimilated to correct soil moisture estimates, increased the likelihood that bankfull flow would occur, over non-assimilated modeling, at catchment outlets for approximately 44% of basin-days during the study time period. While this is a much more realistic representation of conditions, no actual events occurred allowing for validation during the time period.

  15. A Semi-Empirical Model for Tilted-Gun Planar Magnetron Sputtering Accounting for Chimney Shadowing

    Science.gov (United States)

    Bunn, J. K.; Metting, C. J.; Hattrick-Simpers, J.

    2015-01-01

    Integrated computational materials engineering (ICME) approaches to composition and thickness profiles of sputtered thin-film samples are the key to expediting materials exploration for these materials. Here, an ICME-based semi-empirical approach to modeling the thickness of thin-film samples deposited via magnetron sputtering is developed. Using Yamamura's dimensionless differential angular sputtering yield and a measured deposition rate at a point in space for a single experimental condition, the model predicts the deposition profile from planar DC sputtering sources. The model includes corrections for off-center, tilted gun geometries as well as shadowing effects from gun chimneys used in most state-of-the-art sputtering systems. The modeling algorithm was validated by comparing its results with experimental deposition rates obtained from a sputtering system utilizing sources with a multi-piece chimney assembly that consists of a lower ground shield and a removable gas chimney. Simulations were performed for gun-tilts ranging from 0° to 31.3° from the vertical with and without the gas chimney installed. The results for the predicted and experimental angular dependence of the sputtering deposition rate were found to have an average magnitude of relative error of for a 0°-31.3° gun-tilt range without the gas chimney, and for a 17.7°-31.3° gun-tilt range with the gas chimney. The continuum nature of the model renders this approach reverse-optimizable, providing a rapid tool for assisting in the understanding of the synthesis-composition-property space of novel materials.

  16. Using state-and-transition modeling to account for imperfect detection in invasive species management

    Science.gov (United States)

    Frid, Leonardo; Holcombe, Tracy; Morisette, Jeffrey T.; Olsson, Aaryn D.; Brigham, Lindy; Bean, Travis M.; Betancourt, Julio L.; Bryan, Katherine

    2013-01-01

    Buffelgrass, a highly competitive and flammable African bunchgrass, is spreading rapidly across both urban and natural areas in the Sonoran Desert of southern and central Arizona. Damages include increased fire risk, losses in biodiversity, and diminished revenues and quality of life. Feasibility of sustained and successful mitigation will depend heavily on rates of spread, treatment capacity, and cost–benefit analysis. We created a decision support model for the wildland–urban interface north of Tucson, AZ, using a spatial state-and-transition simulation modeling framework, the Tool for Exploratory Landscape Scenario Analyses. We addressed the issues of undetected invasions, identifying potentially suitable habitat and calibrating spread rates, while answering questions about how to allocate resources among inventory, treatment, and maintenance. Inputs to the model include a state-and-transition simulation model to describe the succession and control of buffelgrass, a habitat suitability model, management planning zones, spread vectors, estimated dispersal kernels for buffelgrass, and maps of current distribution. Our spatial simulations showed that without treatment, buffelgrass infestations that started with as little as 80 ha (198 ac) could grow to more than 6,000 ha by the year 2060. In contrast, applying unlimited management resources could limit 2060 infestation levels to approximately 50 ha. The application of sufficient resources toward inventory is important because undetected patches of buffelgrass will tend to grow exponentially. In our simulations, areas affected by buffelgrass may increase substantially over the next 50 yr, but a large, upfront investment in buffelgrass control could reduce the infested area and overall management costs.

  17. Not so Rare, Rare Diseases

    Science.gov (United States)

    Waldman, H. Barry; Perlman, Steven P.; Munter, Beverly L.; Chaudhry, Ramiz A.

    2008-01-01

    A rare disease or condition is defined by federal legislation such that it: (1) affects less than 200,000 persons in the U.S.; or (2) affects more than 200,000 persons in the U.S. but for which there is no reasonable expectation that the cost of developing and making available in the U.S. a drug for such disease or condition will be recovered from…

  18. Rare earth elements: end use and recyclability

    Science.gov (United States)

    Goonan, Thomas G.

    2011-01-01

    Rare earth elements are used in mature markets (such as catalysts, glassmaking, lighting, and metallurgy), which account for 59 percent of the total worldwide consumption of rare earth elements, and in newer, high-growth markets (such as battery alloys, ceramics, and permanent magnets), which account for 41 percent of the total worldwide consumption of rare earth elements. In mature market segments, lanthanum and cerium constitute about 80 percent of rare earth elements used, and in new market segments, dysprosium, neodymium, and praseodymium account for about 85 percent of rare earth elements used. Regardless of the end use, rare earth elements are not recycled in large quantities, but could be if recycling became mandated or very high prices of rare earth elements made recycling feasible.

  19. Codon-substitution models to detect adaptive evolution that account for heterogeneous selective pressures among site classes.

    Science.gov (United States)

    Yang, Ziheng; Swanson, Willie J

    2002-01-01

    The nonsynonymous to synonymous substitution rate ratio (omega = d(N)/d(S)) provides a sensitive measure of selective pressure at the protein level, with omega values 1 indicating purifying selection, neutral evolution, and diversifying selection, respectively. Maximum likelihood models of codon substitution developed recently account for variable selective pressures among amino acid sites by employing a statistical distribution for the omega ratio among sites. Those models, called random-sites models, are suitable when we do not know a priori which sites are under what kind of selective pressure. Sometimes prior information (such as the tertiary structure of the protein) might be available to partition sites in the protein into different classes, which are expected to be under different selective pressures. It is then sensible to use such information in the model. In this paper, we implement maximum likelihood models for prepartitioned data sets, which account for the heterogeneity among site partitions by using different omega parameters for the partitions. The models, referred to as fixed-sites models, are also useful for combined analysis of multiple genes from the same set of species. We apply the models to data sets of the major histocompatibility complex (MHC) class I alleles from human populations and of the abalone sperm lysin genes. Structural information is used to partition sites in MHC into two classes: those in the antigen recognition site (ARS) and those outside. Positive selection is detected in the ARS by the fixed-sites models. Similarly, sites in lysin are classified into the buried and solvent-exposed classes according to the tertiary structure, and positive selection was detected at the solvent-exposed sites. The random-sites models identified a number of sites under positive selection in each data set, confirming and elaborating the results of the fixed-sites models. The analysis demonstrates the utility of the fixed-sites models, as well as

  20. Refining Sunrise/set Prediction Models by Accounting for the Effects of Refraction

    Science.gov (United States)

    Wilson, Teresa; Bartlett, Jennifer L.

    2016-01-01

    Current atmospheric models used to predict the times of sunrise and sunset have an error of one to four minutes at mid-latitudes (0° - 55° N/S). At higher latitudes, slight changes in refraction may cause significant discrepancies, including determining even whether the Sun appears to rise or set. While different components of refraction are known, how they affect predictions of sunrise/set has not yet been quantified. A better understanding of the contributions from temperature profile, pressure, humidity, and aerosols, could significantly improve the standard prediction. Because sunrise/set times and meteorological data from multiple locations will be necessary for a thorough investigation of the problem, we will collect this data using smartphones as part of a citizen science project. This analysis will lead to more complete models that will provide more accurate times for navigators and outdoorsman alike.

  1. Tree biomass in the Swiss landscape: nationwide modelling for improved accounting for forest and non-forest trees.

    Science.gov (United States)

    Price, B; Gomez, A; Mathys, L; Gardi, O; Schellenberger, A; Ginzler, C; Thürig, E

    2017-03-01

    Trees outside forest (TOF) can perform a variety of social, economic and ecological functions including carbon sequestration. However, detailed quantification of tree biomass is usually limited to forest areas. Taking advantage of structural information available from stereo aerial imagery and airborne laser scanning (ALS), this research models tree biomass using national forest inventory data and linear least-square regression and applies the model both inside and outside of forest to create a nationwide model for tree biomass (above ground and below ground). Validation of the tree biomass model against TOF data within settlement areas shows relatively low model performance (R (2) of 0.44) but still a considerable improvement on current biomass estimates used for greenhouse gas inventory and carbon accounting. We demonstrate an efficient and easily implementable approach to modelling tree biomass across a large heterogeneous nationwide area. The model offers significant opportunity for improved estimates on land use combination categories (CC) where tree biomass has either not been included or only roughly estimated until now. The ALS biomass model also offers the advantage of providing greater spatial resolution and greater within CC spatial variability compared to the current nationwide estimates.

  2. Modelling and experimental validation for off-design performance of the helical heat exchanger with LMTD correction taken into account

    Energy Technology Data Exchange (ETDEWEB)

    Phu, Nguyen Minh; Trinh, Nguyen Thi Minh [Vietnam National University, Ho Chi Minh City (Viet Nam)

    2016-07-15

    Today the helical coil heat exchanger is being employed widely due to its dominant advantages. In this study, a mathematical model was established to predict off-design works of the helical heat exchanger. The model was based on the LMTD and e-NTU methods, where a LMTD correction factor was taken into account to increase accuracy. An experimental apparatus was set-up to validate the model. Results showed that errors of thermal duty, outlet hot fluid temperature, outlet cold fluid temperature, shell-side pressure drop, and tube-side pressure drop were respectively +-5%, +-1%, +-1%, +-5% and +-2%. Diagrams of dimensionless operating parameters and a regression function were also presented as design-maps, a fast calculator for usage in design and operation of the exchanger. The study is expected to be a good tool to estimate off-design conditions of the single-phase helical heat exchangers.

  3. Where's the problem? Considering Laing and Esterson's account of schizophrenia, social models of disability, and extended mental disorder.

    Science.gov (United States)

    Cooper, Rachel

    2017-08-01

    In this article, I compare and evaluate R. D. Laing and A. Esterson's account of schizophrenia as developed in Sanity, Madness and the Family (1964), social models of disability, and accounts of extended mental disorder. These accounts claim that some putative disorders (schizophrenia, disability, certain mental disorders) should not be thought of as reflecting biological or psychological dysfunction within the afflicted individual, but instead as external problems (to be located in the family, or in the material and social environment). In this article, I consider the grounds on which such claims might be supported. I argue that problems should not be located within an individual putative patient in cases where there is some acceptable test environment in which there is no problem. A number of cases where such an argument can show that there is no internal disorder are discussed. I argue, however, that Laing and Esterson's argument-that schizophrenia is not within diagnosed patients-does not work. The problem with their argument is that they fail to show that the diagnosed women in their study function adequately in any environment.

  4. Method for determining the duration of construction basing on evolutionary modeling taking into account random organizational expectations

    Directory of Open Access Journals (Sweden)

    Alekseytsev Anatoliy Viktorovich

    2016-10-01

    Full Text Available One of the problems of construction planning is failure to meet time constraints and increase of workflow duration. In the recent years informational technologies are efficiently used to solve the problem of estimation of construction period. The issue of optimal estimate of the duration of construction, taking into account the possible organizational expectations is considered in the article. In order to solve this problem the iteration scheme of evolutionary modeling, in which random values of organizational expectations are used as variable parameters is developed. Adjustable genetic operators are used to improve the efficiency of the search for solutions. The reliability of the proposed approach is illustrated by an example of formation of construction schedules of monolithic foundations for buildings, taking into account possible disruptions of supply of concrete and reinforcement cages. Application of the presented methodology enables automated acquisition of several alternative scheduling of construction in accordance with standard or directive duration. Application of this computational procedure has the prospects of taking into account of construction downtime due to weather, accidents related to construction machinery breakdowns or local emergency collapses of the structures being erected.

  5. Accounting for non-linear chemistry of ship plumes in the GEOS-Chem global chemistry transport model

    Directory of Open Access Journals (Sweden)

    G. C. M. Vinken

    2011-11-01

    Full Text Available We present a computationally efficient approach to account for the non-linear chemistry occurring during the dispersion of ship exhaust plumes in a global 3-D model of atmospheric chemistry (GEOS-Chem. We use a plume-in-grid formulation where ship emissions age chemically for 5 h before being released in the global model grid. Besides reducing the original ship NOx emissions in GEOS-Chem, our approach also releases the secondary compounds ozone and HNO3, produced during the 5 h after the original emissions, into the model. We applied our improved method and also the widely used "instant dilution" approach to a 1-yr GEOS-Chem simulation of global tropospheric ozone-NOx-VOC-aerosol chemistry. We also ran simulations with the standard model (emitting 10 molecules O3 and 1 molecule HNO3 per ship NOx molecule, and a model without any ship emissions at all. The model without any ship emissions simulates up to 0.1 ppbv (or 50% lower NOx concentrations over the North Atlantic in July than our improved GEOS-Chem model. "Instant dilution" overestimates NOx concentrations by 0.1 ppbv (50% and ozone by 3–5 ppbv (10–25%, compared to our improved model over this region. These conclusions are supported by comparing simulated and observed NOx and ozone concentrations in the lower troposphere over the Pacific Ocean. The comparisons show that the improved GEOS-Chem model simulates NOx concentrations in between the instant dilution model and the model without ship emissions, which results in lower O3 concentrations than the instant dilution model. The relative differences in simulated NOx and ozone between our improved approach and instant dilution are smallest over strongly polluted seas (e.g. North Sea, suggesting that accounting for in-plume chemistry is most relevant for pristine marine areas.

  6. A method for improving predictive modeling by taking into account lag time: Example of selenium bioaccumulation in a flowing system

    Energy Technology Data Exchange (ETDEWEB)

    Beckon, William N., E-mail: William_Beckon@fws.gov

    2016-07-15

    Highlights: • A method for estimating response time in cause-effect relationships is demonstrated. • Predictive modeling is appreciably improved by taking into account this lag time. • Bioaccumulation lag is greater for organisms at higher trophic levels. • This methodology may be widely applicable in disparate disciplines. - Abstract: For bioaccumulative substances, efforts to predict concentrations in organisms at upper trophic levels, based on measurements of environmental exposure, have been confounded by the appreciable but hitherto unknown amount of time it may take for bioaccumulation to occur through various pathways and across several trophic transfers. The study summarized here demonstrates an objective method of estimating this lag time by testing a large array of potential lag times for selenium bioaccumulation, selecting the lag that provides the best regression between environmental exposure (concentration in ambient water) and concentration in the tissue of the target organism. Bioaccumulation lag is generally greater for organisms at higher trophic levels, reaching times of more than a year in piscivorous fish. Predictive modeling of bioaccumulation is improved appreciably by taking into account this lag. More generally, the method demonstrated here may improve the accuracy of predictive modeling in a wide variety of other cause-effect relationships in which lag time is substantial but inadequately known, in disciplines as diverse as climatology (e.g., the effect of greenhouse gases on sea levels) and economics (e.g., the effects of fiscal stimulus on employment).

  7. Accounting for Long Term Sediment Storage in a Watershed Scale Numerical Model for Suspended Sediment Routing

    Science.gov (United States)

    Keeler, J. J.; Pizzuto, J. E.; Skalak, K.; Karwan, D. L.; Benthem, A.; Ackerman, T. R.

    2015-12-01

    Quantifying the delivery of suspended sediment from upland sources to downstream receiving waters is important for watershed management, but current routing models fail to accurately represent lag times in delivery resulting from sediment storage. In this study, we route suspended sediment tagged by a characteristic tracer using a 1-dimensional model that implicitly includes storage and remobilization processes and timescales. From an input location where tagged sediment is added, the model advects suspended sediment downstream at the velocity of the stream (adjusted for the intermittency of transport events). Deposition rates are specified by the fraction of the suspended load stored per kilometer of downstream transport (presumably available from a sediment budget). Tagged sediment leaving storage is evaluated from a convolution equation based on the probability distribution function (pdf) of sediment storage waiting times; this approach avoids the difficulty of accurately representing complex processes of sediment remobilization from floodplain and other deposits. To illustrate the role of storage on sediment delivery, we compare exponential and bounded power-law waiting time pdfs with identical means of 94 years. In both cases, the median travel time for sediment to reach the depocenter in fluvial systems less than 40km long is governed by in-channel transport and is unaffected by sediment storage. As the channel length increases, however, the median sediment travel time reflects storage rather than in-channel transport; travel times do not vary significantly between the two different waiting time functions. At distances of 50, 100, and 200 km, the median travel time for suspended sediment is 36, 136, and 325 years, orders of magnitude slower than travel times associated with in-channel transport. These computations demonstrate that storage can be neglected for short rivers, but for longer systems, storage controls the delivery of suspended sediment.

  8. An extended macro traffic flow model accounting for multiple optimal velocity functions with different probabilities

    Science.gov (United States)

    Cheng, Rongjun; Ge, Hongxia; Wang, Jufeng

    2017-08-01

    Due to the maximum velocity and safe headway distance of the different vehicles are not exactly the same, an extended macro model of traffic flow with the consideration of multiple optimal velocity functions with probabilities is proposed in this paper. By means of linear stability theory, the new model's linear stability condition considering multiple probabilities optimal velocity is obtained. The KdV-Burgers equation is derived to describe the propagating behavior of traffic density wave near the neutral stability line through nonlinear analysis. The numerical simulations of influences of multiple maximum velocities and multiple safety distances on model's stability and traffic capacity are carried out. The cases of two different kinds of maximum speeds with same safe headway distance, two different types of safe headway distances with same maximum speed and two different max velocities and two different time-gaps are all explored by numerical simulations. First cases demonstrate that when the proportion of vehicles with a larger vmax increase, the traffic tends to unstable, which also means that jerk and brakes is not conducive to traffic stability and easier to result in stop and go phenomenon. Second cases show that when the proportion of vehicles with greater safety spacing increases, the traffic tends to be unstable, which also means that too cautious assumptions or weak driving skill is not conducive to traffic stability. Last cases indicate that increase of maximum speed is not conducive to traffic stability, while reduction of the safe headway distance is conducive to traffic stability. Numerical simulation manifests that the mixed driving and traffic diversion does not have effect on the traffic capacity when traffic density is low or heavy. Numerical results also show that mixed driving should be chosen to increase the traffic capacity when the traffic density is lower, while the traffic diversion should be chosen to increase the traffic capacity when

  9. Regional input-output models and the treatment of imports in the European System of Accounts

    OpenAIRE

    Kronenberg, Tobias

    2011-01-01

    Input-output models are often used in regional science due to their versatility and their ability to capture many of the distinguishing features of a regional economy. Input-output tables are available for all EU member countries, but they are hard to find at the regional level, since many regional governments lack the resources or the will to produce reliable, survey-based regional input-output tables. Therefore, in many cases researchers adopt nonsurvey techniques to derive regional input-o...

  10. Accounting for heaping in retrospectively reported event data - a mixture-model approach.

    Science.gov (United States)

    Bar, Haim Y; Lillard, Dean R

    2012-11-30

    When event data are retrospectively reported, more temporally distal events tend to get 'heaped' on even multiples of reporting units. Heaping may introduce a type of attenuation bias because it causes researchers to mismatch time-varying right-hand side variables. We develop a model-based approach to estimate the extent of heaping in the data and how it affects regression parameter estimates. We use smoking cessation data as a motivating example, but our method is general. It facilitates the use of retrospective data from the multitude of cross-sectional and longitudinal studies worldwide that collect and potentially could collect event data.

  11. Research destruction ice under dynamic loading. Part 1. Modeling explosive ice cover into account the temperature

    Directory of Open Access Journals (Sweden)

    Bogomolov Gennady N.

    2017-01-01

    Full Text Available In the research, the behavior of ice under shock and explosive loads is analyzed. Full-scale experiments were carried out. It is established that the results of 2013 practically coincide with the results of 2017, which is explained by the temperature of the formation of river ice. Two research objects are considered, including freshwater ice and river ice cover. The Taylor test was simulated numerically. The results of the Taylor test are presented. Ice is described by an elastoplastic model of continuum mechanics. The process of explosive loading of ice by emulsion explosives is numerically simulated. The destruction of the ice cover under detonation products is analyzed in detail.

  12. 物流作业成本核算模型研究%Study on Logistics Activity Cost Accounting Model

    Institute of Scientific and Technical Information of China (English)

    李淼; 程国全

    2011-01-01

    通过对物流中心作业流程的标准化设计,基于作业成本法的思想,运用表格工具进行各项作业的成本参数设置,从而建立起物流作业成本核算模型.%Through designing the standard logistics center activity process and using the method of activity-based costing, the paper employs diagram and table drawing softwares to the setting of the cost parameters of various logistics activities which are then used to formulate the cost accounting model of logistics activities.

  13. Account of near-cathode sheath in numerical models of high-pressure arc discharges

    Science.gov (United States)

    Benilov, M. S.; Almeida, N. A.; Baeva, M.; Cunha, M. D.; Benilova, L. G.; Uhrlandt, D.

    2016-06-01

    Three approaches to describing the separation of charges in near-cathode regions of high-pressure arc discharges are compared. The first approach employs a single set of equations, including the Poisson equation, in the whole interelectrode gap. The second approach employs a fully non-equilibrium description of the quasi-neutral bulk plasma, complemented with a newly developed description of the space-charge sheaths. The third, and the simplest, approach exploits the fact that significant power is deposited by the arc power supply into the near-cathode plasma layer, which allows one to simulate the plasma-cathode interaction to the first approximation independently of processes in the bulk plasma. It is found that results given by the different models are generally in good agreement, and in some cases the agreement is even surprisingly good. It follows that the predicted integral characteristics of the plasma-cathode interaction are not strongly affected by details of the model provided that the basic physics is right.

  14. Singing with yourself: evidence for an inverse modeling account of poor-pitch singing.

    Science.gov (United States)

    Pfordresher, Peter Q; Mantell, James T

    2014-05-01

    Singing is a ubiquitous and culturally significant activity that humans engage in from an early age. Nevertheless, some individuals - termed poor-pitch singers - are unable to match target pitches within a musical semitone while singing. In the experiments reported here, we tested whether poor-pitch singing deficits would be reduced when individuals imitate recordings of themselves as opposed to recordings of other individuals. This prediction was based on the hypothesis that poor-pitch singers have not developed an abstract "inverse model" of the auditory-vocal system and instead must rely on sensorimotor associations that they have experienced directly, which is true for sequences an individual has already produced. In three experiments, participants, both accurate and poor-pitch singers, were better able to imitate sung recordings of themselves than sung recordings of other singers. However, this self-advantage was enhanced for poor-pitch singers. These effects were not a byproduct of self-recognition (Experiment 1), vocal timbre (Experiment 2), or the absolute pitch of target recordings (i.e., the advantage remains when recordings are transposed, Experiment 3). Results support the conceptualization of poor-pitch singing as an imitative deficit resulting from a deficient inverse model of the auditory-vocal system with respect to pitch. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Taking into account topography rapid variations in forward modelling and inverse problems in seismology

    Science.gov (United States)

    Capdeville, Y.; Jean-Jacques, M.

    2011-12-01

    The modeling of seismic elastic wave full waveform in a limited frequency band is now well established with a set of efficient numerical methods like the spectral element, the discontinuous Galerking or the finite difference methods. The constant increase of computing power with time has now allowed the use of seismic elastic wave full waveforms in a limited frequency band to image the elastic properties of the earth. Nevertheless, inhomogeneities of scale much smaller the minimum wavelength of the wavefield associated to the maximum frequency of the limited frequency band, are still a challenge for both forward and inverse problems. In this work, we tackle the problem of a topography varying much faster than the minimum wavelength. Using a non periodic homogenization theory and a matching asymptotic technique, we show how to remove the fast variation of the topography and replace it by a smooth Dirichlet to Neumann operator at the surface. After showing some 2D forward modeling numerical examples, we will discuss the implications of such a development for both forward and inverse problems.

  16. One-dimensional model of oxygen transport impedance accounting for convection perpendicular to the electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mainka, J. [Laboratorio Nacional de Computacao Cientifica (LNCC), CMC 6097, Av. Getulio Vargas 333, 25651-075 Petropolis, RJ, Caixa Postal 95113 (Brazil); Maranzana, G.; Thomas, A.; Dillet, J.; Didierjean, S.; Lottin, O. [Laboratoire d' Energetique et de Mecanique Theorique et Appliquee (LEMTA), Universite de Lorraine, 2, avenue de la Foret de Haye, 54504 Vandoeuvre-les-Nancy (France); LEMTA, CNRS, 2, avenue de la Foret de Haye, 54504 Vandoeuvre-les-Nancy (France)

    2012-10-15

    A one-dimensional (1D) model of oxygen transport in the diffusion media of proton exchange membrane fuel cells (PEMFC) is presented, which considers convection perpendicular to the electrode in addition to diffusion. The resulting analytical expression of the convecto-diffusive impedance is obtained using a convection-diffusion equation instead of a diffusion equation in the case of classical Warburg impedance. The main hypothesis of the model is that the convective flux is generated by the evacuation of water produced at the cathode which flows through the porous media in vapor phase. This allows the expression of the convective flux velocity as a function of the current density and of the water transport coefficient {alpha} (the fraction of water being evacuated at the cathode outlet). The resulting 1D oxygen transport impedance neglects processes occurring in the direction parallel to the electrode that could have a significant impact on the cell impedance, like gas consumption or concentration oscillations induced by the measuring signal. However, it enables us to estimate the impact of convection perpendicular to the electrode on PEMFC impedance spectra and to determine in which conditions the approximation of a purely diffusive oxygen transport is valid. Experimental observations confirm the numerical results. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. Modeling co-occurrence of northern spotted and barred owls: accounting for detection probability differences

    Science.gov (United States)

    Bailey, Larissa L.; Reid, Janice A.; Forsman, Eric D.; Nichols, James D.

    2009-01-01

    Barred owls (Strix varia) have recently expanded their range and now encompass the entire range of the northern spotted owl (Strix occidentalis caurina). This expansion has led to two important issues of concern for management of northern spotted owls: (1) possible competitive interactions between the two species that could contribute to population declines of northern spotted owls, and (2) possible changes in vocalization behavior and detection probabilities of northern spotted owls induced by presence of barred owls. We used a two-species occupancy model to investigate whether there was evidence of competitive exclusion between the two species at study locations in Oregon, USA. We simultaneously estimated detection probabilities for both species and determined if the presence of one species influenced the detection of the other species. Model selection results and associated parameter estimates provided no evidence that barred owls excluded spotted owls from territories. We found strong evidence that detection probabilities differed for the two species, with higher probabilities for northern spotted owls that are the object of current surveys. Non-detection of barred owls is very common in surveys for northern spotted owls, and detection of both owl species was negatively influenced by the presence of the congeneric species. Our results suggest that analyses directed at hypotheses of barred owl effects on demographic or occupancy vital rates of northern spotted owls need to deal adequately with imperfect and variable detection probabilities for both species.

  18. Accounting emergy flows to determine the best production model of a coffee plantation

    Energy Technology Data Exchange (ETDEWEB)

    Giannetti, B.F.; Ogura, Y.; Bonilla, S.H. [Universidade Paulista, Programa de Pos Graduacao em Engenharia de Producao, R. Dr. Bacelar, 1212 Sao Paulo SP (Brazil); Almeida, C.M.V.B., E-mail: cmvbag@terra.com.br [Universidade Paulista, Programa de Pos Graduacao em Engenharia de Producao, R. Dr. Bacelar, 1212 Sao Paulo SP (Brazil)

    2011-11-15

    Cerrado, a savannah region, is Brazil's second largest ecosystem after the Amazon rainforest and is also threatened with imminent destruction. In the present study emergy synthesis was applied to assess the environmental performance of a coffee farm located in Coromandel, Minas Gerais, in the Brazilian Cerrado. The effects of land use on sustainability were evaluated by comparing the emergy indices along ten years in order to assess the energy flows driving the production process, and to determine the best production model combining productivity and environmental performance. The emergy indices are presented as a function of the annual crop. Results show that Santo Inacio farm should produce approximately 20 bags of green coffee per hectare to accomplish its best performance regarding both the production efficiency and the environment. The evaluation of coffee trade complements those obtained by contrasting productivity and environmental performance, and despite of the market prices variation, the optimum interval for Santo Inacio's farm is between 10 and 25 coffee bags/ha. - Highlights: > Emergy synthesis is used to assess the environmental performance of a coffee farm in Brazil. > The effects of land use on sustainability were evaluated along ten years. > The energy flows driving the production process were assessed. > The best production model combining productivity and environmental performance was determined.

  19. Mitigating BeiDou Satellite-Induced Code Bias: Taking into Account the Stochastic Model of Corrections.

    Science.gov (United States)

    Guo, Fei; Li, Xin; Liu, Wanke

    2016-06-18

    The BeiDou satellite-induced code biases have been confirmed to be orbit type-, frequency-, and elevation-dependent. Such code-phase divergences (code bias variations) severely affect absolute precise applications which use code measurements. To reduce their adverse effects, an improved correction model is proposed in this paper. Different from the model proposed by Wanninger and Beer (2015), more datasets (a time span of almost two years) were used to produce the correction values. More importantly, the stochastic information, i.e., the precision indexes, were given together with correction values in the improved model. However, only correction values were given while the precision indexes were completely missing in the traditional model. With the improved correction model, users may have a better understanding of their corrections, especially the uncertainty of corrections. Thus, it is helpful for refining the stochastic model of code observations. Validation tests in precise point positioning (PPP) reveal that a proper stochastic model is critical. The actual precision of the corrected code observations can be reflected in a more objective manner if the stochastic model of the corrections is taken into account. As a consequence, PPP solutions with the improved model outperforms the traditional one in terms of positioning accuracy, as well as convergence speed. In addition, the Melbourne-Wübbena (MW) combination which serves for ambiguity fixing were verified as well. The uncorrected MW values show strong systematic variations with an amplitude of half a wide-lane cycle, which prevents precise ambiguity determination and successful ambiguity resolution. After application of the code bias correction models, the systematic variations can be greatly removed, and the resulting wide lane ambiguities are more likely to be fixed. Moreover, the code residuals show more reasonable distributions after code bias corrections with either the traditional or the improved model.

  20. Mitigating BeiDou Satellite-Induced Code Bias: Taking into Account the Stochastic Model of Corrections

    Science.gov (United States)

    Guo, Fei; Li, Xin; Liu, Wanke

    2016-01-01

    The BeiDou satellite-induced code biases have been confirmed to be orbit type-, frequency-, and elevation-dependent. Such code-phase divergences (code bias variations) severely affect absolute precise applications which use code measurements. To reduce their adverse effects, an improved correction model is proposed in this paper. Different from the model proposed by Wanninger and Beer (2015), more datasets (a time span of almost two years) were used to produce the correction values. More importantly, the stochastic information, i.e., the precision indexes, were given together with correction values in the improved model. However, only correction values were given while the precision indexes were completely missing in the traditional model. With the improved correction model, users may have a better understanding of their corrections, especially the uncertainty of corrections. Thus, it is helpful for refining the stochastic model of code observations. Validation tests in precise point positioning (PPP) reveal that a proper stochastic model is critical. The actual precision of the corrected code observations can be reflected in a more objective manner if the stochastic model of the corrections is taken into account. As a consequence, PPP solutions with the improved model outperforms the traditional one in terms of positioning accuracy, as well as convergence speed. In addition, the Melbourne-Wübbena (MW) combination which serves for ambiguity fixing were verified as well. The uncorrected MW values show strong systematic variations with an amplitude of half a wide-lane cycle, which prevents precise ambiguity determination and successful ambiguity resolution. After application of the code bias correction models, the systematic variations can be greatly removed, and the resulting wide lane ambiguities are more likely to be fixed. Moreover, the code residuals show more reasonable distributions after code bias corrections with either the traditional or the improved model

  1. Modelling of trace metal uptake by roots taking into account complexation by exogenous organic ligands

    Science.gov (United States)

    Jean-Marc, Custos; Christian, Moyne; Sterckeman, Thibault

    2010-05-01

    The context of this study is phytoextraction of soil trace metals such as Cd, Pb or Zn. Trace metal transfer from soil to plant depends on physical and chemical processes such as minerals alteration, transport, adsorption/desorption, reactions in solution and biological processes including the action of plant roots and of associated micro-flora. Complexation of metal ions by organic ligands is considered to play a role on the availability of trace metals for roots in particular in the event that synthetic ligands (EDTA, NTA, etc.) are added to the soil to increase the solubility of the contaminants. As this role is not clearly understood, we wanted to simulate it in order to quantify the effect of organic ligands on root uptake of trace metals and produce a tool which could help in optimizing the conditions of phytoextraction.We studied the effect of an aminocarboxilate ligand on the absorption of the metal ion by roots, both in hydroponic solution and in soil solution, for which we had to formalize the buffer power for the metal. We assumed that the hydrated metal ion is the only form which can be absorbed by the plants. Transport and reaction processes were modelled for a system made up of the metal M, a ligand L and the metal complex ML. The Tinker-Nye-Barber model was adapted to describe the transport of solutes M, L and ML in the soil and absorption of M by the roots. This allowed to represent the interactions between transport, chelating reactions, absorption of the solutes at the root surface, root growth with time, in order to simulate metal uptake by a whole root system.Several assumptions were tested such as i) absorption of the metal by an infinite sink and according to a Michaelis-Menten kinetics, solutes transport by diffusion with and without ii) mass flow and iii) soil buffer power for the ligand L. In hydroponic solution (without soil buffer power), ligands decreased the trace metal flux towards roots, as they reduced the concentration of hydrated

  2. The application of multilevel modelling to account for the influence of walking speed in gait analysis.

    Science.gov (United States)

    Keene, David J; Moe-Nilssen, Rolf; Lamb, Sarah E

    2016-01-01

    Differences in gait performance can be explained by variations in walking speed, which is a major analytical problem. Some investigators have standardised speed during testing, but this can result in an unnatural control of gait characteristics. Other investigators have developed test procedures where participants walking at their self-selected slow, preferred and fast speeds, with computation of gait characteristics at a standardised speed. However, this analysis is dependent upon an overlap in the ranges of gait speed observed within and between participants, and this is difficult to achieve under self-selected conditions. In this report a statistical analysis procedure is introduced that utilises multilevel modelling to analyse data from walking tests at self-selected speeds, without requiring an overlap in the range of speeds observed or the routine use of data transformations.

  3. Accounting for crustal magnetization in models of the core magnetic field

    Science.gov (United States)

    Jackson, Andrew

    1990-01-01

    The problem of determining the magnetic field originating in the earth's core in the presence of remanent and induced magnetization is considered. The effect of remanent magnetization in the crust on satellite measurements of the core magnetic field is investigated. The crust as a zero-mean stationary Gaussian random process is modelled using an idea proposed by Parker (1988). It is shown that the matrix of second-order statistics is proportional to the Gram matrix, which depends only on the inner-products of the appropriate Green's functions, and that at a typical satellite altitude of 400 km the data are correlated out to an angular separation of approximately 15 deg. Accurate and efficient means of calculating the matrix elements are given. It is shown that the variance of measurements of the radial component of a magnetic field due to the crust is expected to be approximately twice that in horizontal components.

  4. A coupled surface/subsurface flow model accounting for air entrapment and air pressure counterflow

    DEFF Research Database (Denmark)

    Delfs, Jens Olaf; Wang, Wenqing; Kalbacher, Thomas

    2013-01-01

    This work introduces the soil air system into integrated hydrology by simulating the flow processes and interactions of surface runoff, soil moisture and air in the shallow subsurface. The numerical model is formulated as a coupled system of partial differential equations for hydrostatic (diffusive...... algorithm, leakances operate as a valve for gas pressure in a liquid-covered porous medium facilitating the simulation of air out-break events through the land surface. General criteria are stated to guarantee stability in a sequential iterative coupling algorithm and, in addition, for leakances to control...... the mass exchange between compartments. A benchmark test, which is based on a classic experimental data set on infiltration excess (Horton) overland flow, identified a feedback mechanism between surface runoff and soil air pressures. Our study suggests that air compression in soils amplifies surface runoff...

  5. Accounting for sex differences in PTSD: A multi-variable mediation model

    DEFF Research Database (Denmark)

    Christiansen, Dorte M.; Hansen, Maj

    2015-01-01

    ABSTRACT Background: Approximately twice as many females as males are diagnosed with posttraumatic stress disorder (PTSD). However, little is known about why females report more PTSD symptoms than males. Prior studies have generally focused on few potential mediators at a time and have often used...... specifically to test a multiple mediator model. Results: Females reported more PTSD symptoms than males and higher levels of neuroticism, depression, physical anxiety sensitivity, peritraumatic fear, horror, and helplessness (the A2 criterion), tonic immobility, panic, dissociation, negative posttraumatic...... that females report more PTSD symptoms because they experience higher levels of associated risk factors. The results are relevant to other trauma populations and to other trauma- related psychiatric disorders more prevalent in females, such as depression and anxiety. Keywords: Posttraumatic stress disorder...

  6. A hybrid mode choice model to account for the dynamic effect of inertia over time

    DEFF Research Database (Denmark)

    Cherchi, Elisabetta; Börjesson, Maria; Bierlaire, Michel

    gathered over a continuous period of time, six weeks, to study both inertia and the influence of habits. Tendency to stick with the same alternative is measured through lagged variables that link the current choice with the previous trip made with the same purpose, mode and time of day. However, the lagged...... effect of the previous trips is not constant but it depends on the individual propensity to undertake habitual trips which is captured by the individual specific latent variable. And the frequency of the trips in the previous week is used as an indicator of the habitual behavior. The model estimation...... confirms that the tendency to stick with the same alternative varies not only among modes but also across individuals as a function of the individual propensity to undertake habitual behavior....

  7. Accounting for subordinate perceptions of supervisor power: an identity-dependence model.

    Science.gov (United States)

    Farmer, Steven M; Aguinis, Herman

    2005-11-01

    The authors present a model that explains how subordinates perceive the power of their supervisors and the causal mechanisms by which these perceptions translate into subordinate outcomes. Drawing on identity and resource-dependence theories, the authors propose that supervisors have power over their subordinates when they control resources needed for the subordinates' enactment and maintenance of current and desired identities. The joint effect of perceptions of supervisor power and supervisor intentions to provide such resources leads to 4 conditions ranging from highly functional to highly dysfunctional: confirmation, hope, apathy, and progressive withdrawal. Each of these conditions is associated with specific outcomes such as the quality of the supervisor-subordinate relationship, turnover, and changes in the type and centrality of various subordinate identities. ((c) 2005 APA, all rights reserved).

  8. Does Reading Cause Later Intelligence? Accounting for Stability in Models of Change.

    Science.gov (United States)

    Bailey, Drew H; Littlefield, Andrew K

    2016-11-08

    This study reanalyzes data presented by Ritchie, Bates, and Plomin (2015) who used a cross-lagged monozygotic twin differences design to test whether reading ability caused changes in intelligence. The authors used data from a sample of 1,890 monozygotic twin pairs tested on reading ability and intelligence at five occasions between the ages of 7 and 16, regressing twin differences in intelligence on twin differences in prior intelligence and twin differences in prior reading ability. Results from a state-trait model suggest that reported effects of reading ability on later intelligence may be artifacts of previously uncontrolled factors, both environmental in origin and stable during this developmental period, influencing both constructs throughout development. Implications for cognitive developmental theory and methods are discussed. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

  9. Afganistan and rare earths

    Directory of Open Access Journals (Sweden)

    Emilian M. Dobrescu

    2013-05-01

    Full Text Available On our planet, over a quarter of new technologies for the economic production of industrial goods, are using rare earths, which are also called critical minerals and industries that rely on these precious items being worth of an estimated nearly five trillion dollars, or 5 percent of world gross domestic product. In the near future, competition will increase for the control of rare earth minerals embedded in high-tech products. Rare minerals are in the twenty-first century what oil accounted for in the twentieth century and coal in the nineteenth century: the engine of a new industrial revolution. Future energy will be produced increasingly by more sophisticated technological equipment based not just on steel and concrete, but incorporating significant quantities of metals and rare earths. Widespread application of these technologies will result in an exponential increase in demand for such minerals, and what is worrying is that minerals of this type are almost nowhere to be found in Europe and in other industrialized countries in the world, such as U.S. and Japan, but only in some Asian countries, like China and Afghanistan.

  10. Pore Network Modeling: Alternative Methods to Account for Trapping and Spatial Correlation

    KAUST Repository

    De La Garza Martinez, Pablo

    2016-05-01

    Pore network models have served as a predictive tool for soil and rock properties with a broad range of applications, particularly in oil recovery, geothermal energy from underground reservoirs, and pollutant transport in soils and aquifers [39]. They rely on the representation of the void space within porous materials as a network of interconnected pores with idealised geometries. Typically, a two-phase flow simulation of a drainage (or imbibition) process is employed, and by averaging the physical properties at the pore scale, macroscopic parameters such as capillary pressure and relative permeability can be estimated. One of the most demanding tasks in these models is to include the possibility of fluids to remain trapped inside the pore space. In this work I proposed a trapping rule which uses the information of neighboring pores instead of a search algorithm. This approximation reduces the simulation time significantly and does not perturb the accuracy of results. Additionally, I included spatial correlation to generate the pore sizes using a matrix decomposition method. Results show higher relative permeabilities and smaller values for irreducible saturation, which emphasizes the effects of ignoring the intrinsic correlation seen in pore sizes from actual porous media. Finally, I implemented the algorithm from Raoof et al. (2010) [38] to generate the topology of a Fontainebleau sandstone by solving an optimization problem using the steepest descent algorithm with a stochastic approximation for the gradient. A drainage simulation is performed on this representative network and relative permeability is compared with published results. The limitations of this algorithm are discussed and other methods are suggested to create a more faithful representation of the pore space.

  11. Rare earth element sorption by basaltic rock: Experimental data and modeling results using the “Generalised Composite approach”

    Science.gov (United States)

    Tertre, E.; Hofmann, A.; Berger, G.

    2008-02-01

    Sorption of the 14 rare earth elements (REE) by basaltic rock is investigated as a function of pH, ionic strength and aqueous REE concentrations. The rock sample, originating from a terrestrial basalt flow (Rio Grande do Sul State, Brazil), is composed of plagioclase, pyroxene and cryptocrystalline phases. Small amounts of clay minerals are present, due to rock weathering. Batch sorption experiments are carried out under controlled temperature conditions of 20 °C with the XNa sites, and surface complexation at >SOH sites. Total site density (>XNa + >SOH) is determined by measuring the cation exchange capacity (CEC = 52 μmol/m 2). Specific concentrations of exchange sites and complexation sites are determined by fitting the Langmuir equation to sorption isotherms of REE and phosphate ions. Site densities of 22 ± 5 and 30 ± 5 μmol/m 2 are obtained for [>XNa] and [>SOH], respectively. The entire set of REE experimental data is modeled using a single exchange constant (log Kex = 9.7) and a surface complexation constant that progressively increases from log K = -1.15 for La(III) to -0.4 for Lu(III). The model proves to be fairly robust in describing other aluminosilicate systems. Maintaining the same set of sorption constants and only adjusting the site densities, we obtain good agreement with the literature data on REE/kaolinite and REE/smectite sorption. The Generalised Composite non-electrostatic model appears as an easy and efficient tool for describing sorption by complex aluminosilicate mineral assemblages.

  12. Accounting for non-linear chemistry of ship plumes in the GEOS-Chem global chemistry transport model

    Directory of Open Access Journals (Sweden)

    G. C. M. Vinken

    2011-06-01

    Full Text Available We present a computationally efficient approach to account for the non-linear chemistry occurring during the dispersion of ship exhaust plumes in a global 3-D model of atmospheric chemistry (GEOS-Chem. We use a plume-in-grid formulation where ship emissions age chemically for 5 h before being released in the global model grid. Besides reducing the original ship NOx emissions in GEOS-Chem, our approach also releases the secondary compounds ozone and HNO3, produced in the 5 h after the original emissions, into the model. We applied our improved method and also the widely used "instant dilution" approach to a 1-yr GEOS-Chem simulation of global tropospheric ozone-NOx-VOC-aerosol chemistry. We also ran simulations with the standard model, and a model without any ship emissions at all. Our improved GEOS-Chem model simulates up to 0.1 ppbv (or 90 % more NOx over the North Atlantic in July than GEOS-Chem versions without any ship NOx emissions at all. "Instant dilution" overestimates NOx concentrations by 50 % (0.1 ppbv and ozone by 10–25 % (3–5 ppbv over this region. These conclusions are supported by comparing simulated and observed NOx and ozone concentrations in the lower troposphere over the Pacific Ocean. The comparisons show that the improved GEOS-Chem model simulates NOx concentrations in between the instant diluting model and the model with no ship emissions, and results in lower O3 concentrations than the instant diluting model. The relative differences in simulated NOx and ozone between our improved approach and instant dilution are smallest over strongly polluted seas (e.g. North Sea, suggesting that accounting for in-plume chemistry is most relevant for pristine marine areas.

  13. Speciation of rare earth elements in natural terrestrial waters: assessing the role of dissolved organic matter from the modeling approach

    Science.gov (United States)

    Tang, Jianwu; Johannesson, Karen H.

    2003-07-01

    Humic Ion-Binding Model V, which focuses on metal complexation with humic and fulvic acids, was modified to assess the role of dissolved natural organic matter in the speciation of rare earth elements (REEs) in natural terrestrial waters. Intrinsic equilibrium constants for cation-proton exchange with humic substances (i.e., p KMHA for type A sites, consisting mainly of carboxylic acids), required by the model for each REE, were initially estimated using linear free-energy relationships between the first hydrolysis constants and stability constants for REE metal complexation with lactic and acetic acid. p KMHA values were further refined by comparison of calculated Model V "fits" to published data sets describing complexation of Eu, Tb, and Dy with humic substances. A subroutine that allows for the simultaneous evaluation of REE complexation with inorganic ligands (e.g., Cl -, F -, OH -, SO 42-, CO 32-, PO 43-), incorporating recently determined stability constants for REE complexes with these ligands, was also linked to Model V. Humic Ion-Binding Model V's ability to predict REE speciation with natural organic matter in natural waters was evaluated by comparing model results to "speciation" data determined previously with ultrafiltration techniques (i.e., organic acid-rich waters of the Nsimi-Zoetele catchment, Cameroon; dilute, circumneutral-pH waters of the Tamagawa River, Japan, and the Kalix River, northern Sweden). The model predictions compare well with the ultrafiltration studies, especially for the heavy REEs in circumneutral-pH river waters. Subsequent application of the model to world average river water predicts that organic matter complexes are the dominant form of dissolved REEs in bulk river waters draining the continents. Holding major solute, minor solute, and REE concentrations of world average river water constant while varying pH, the model suggests that organic matter complexes would dominate La, Eu, and Lu speciation within the pH ranges of 5

  14. Modelling of a mecanum wheel taking into account the geometry of road rollers

    Science.gov (United States)

    Hryniewicz, P.; Gwiazda, A.; Banaś, W.; Sękala, A.; Foit, K.

    2017-08-01

    During the process planning in a company one of the basic factors associated with the production costs is the operation time for particular technological jobs. The operation time consists of time units associated with the machining tasks of a workpiece as well as the time associated with loading and unloading and the transport operations of this workpiece between machining stands. Full automation of manufacturing in industry companies tends to a maximal reduction in machine downtimes, thereby the fixed costs simultaneously decreasing. The new construction of wheeled vehicles, using Mecanum wheels, reduces the transport time of materials and workpieces between machining stands. These vehicles have the ability to simultaneously move in two axes and thus more rapid positioning of the vehicle relative to the machining stand. The Mecanum wheel construction implies placing, around the wheel free rollers that are mounted at an angle 450, which allow the movement of the vehicle not only in its axis but also perpendicular thereto. The improper selection of the rollers can cause unwanted vertical movement of the vehicle, which may cause difficulty in positioning of the vehicle in relation to the machining stand and the need for stabilisation. Hence the proper design of the free rollers is essential in designing the whole Mecanum wheel construction. It allows avoiding the disadvantageous and unwanted vertical vibrations of a whole vehicle with these wheels. In the article the process of modelling the free rollers, in order to obtain the desired shape of unchanging, horizontal trajectory of the vehicle is presented. This shape depends on the desired diameter of the whole Mecanum wheel, together with the road rollers, and the width of the drive wheel. Another factor related with the curvature of the trajectory shape is the length of the road roller and its diameter decreases depending on the position with respect to its centre. The additional factor, limiting construction of

  15. Accounting assessment

    Directory of Open Access Journals (Sweden)

    Kafka S.М.

    2017-03-01

    Full Text Available The proper evaluation of accounting objects influences essentially upon the reliability of assessing the financial situation of a company. Thus, the problem in accounting estimate is quite relevant. The works of home and foreign scholars on the issues of assessment of accounting objects, regulatory and legal acts of Ukraine controlling the accounting and compiling financial reporting are a methodological basis for the research. The author uses the theoretical methods of cognition (abstraction and generalization, analysis and synthesis, induction and deduction and other methods producing conceptual knowledge for the synthesis of theoretical and methodological principles in the evaluation of assets accounting, liabilities and equity. The tabular presentation and information comparison methods are used for analytical researches. The article considers the modern approaches to the issue of evaluation of accounting objects and financial statements items. The expedience to keep records under historical value is proved and the articles of financial statements are to be presented according to the evaluation on the reporting date. In connection with the evaluation the depreciation of fixed assets is considered as a process of systematic return into circulation of the before advanced funds on the purchase (production, improvement of fixed assets and intangible assets by means of including the amount of wear in production costs. Therefore it is proposed to amortize only the actual costs incurred, i.e. not to depreciate the fixed assets received free of charge and surplus valuation of different kinds.

  16. An extended macro traffic flow model accounting for the driver's bounded rationality and numerical tests

    Science.gov (United States)

    Tang, Tie-Qiao; Huang, Hai-Jun; Shang, Hua-Yan

    2017-02-01

    In this paper, we propose a macro traffic flow model to explore the effects of the driver's bounded rationality on the evolutions of traffic waves (which include shock and rarefaction waves) and small perturbation, and on the fuel consumption and emissions (that include CO, HC and NOX) during the evolution process. The numerical results illustrate that considering the driver's bounded rationality can prominently smooth the wavefront of the traffic waves and improve the stability of traffic flow, which shows that the driver's bounded rationality has positive impacts on traffic flow; but considering the driver's bounded rationality reduces the fuel consumption and emissions only at the upstream of the rarefaction wave while enhances the fuel consumption and emissions under other situations, which shows that the driver's bounded rationality has positive impacts on the fuel consumption and emissions only at the upstream of the rarefaction wave, while negative effects on the fuel consumption and emissions under other situations. In addition, the numerical results show that the driver's bounded rationality has little prominent impact on the total fuel consumption, and emissions during the whole evolution of small perturbation.

  17. Rapid prediction of damage on a struck ship accounting for side impact scenario models

    Science.gov (United States)

    Prabowo, Aditya Rio; Bae, Dong Myung; Sohn, Jung Min; Zakki, Ahmad Fauzan; Cao, Bo

    2017-04-01

    The impact phenomenon is inseparable part of every physical things, from substantial particle until macrostructure namely ship. In ship collisions, short-period load is distributed during impact process from striking ship into struck ship. The kinetic energy that is used to move striking ship is absorbed by struck ship that makes its structure undergoes plastic deformation and failure. This paper presents study that focuses on predicting occurred damage on side hull of struck ship for various impact scenario models. These scenarios are calculated by finite element approach to obtain characteristic on damage, energy as well as load during and after impact processes. The results indicate that the damages on impact to longitudinal components such as main and car decks are smaller than impact to transverse structure components. The damage and deformation are widely distributed to almost side structures including inner structure. The width between outer and inner shells is very affecting the damage mode where the width below the two meters will make inner shell experience damage beyond plastic deformation. The contribution of structure components is proofed deliver significant effect to damage mode and material strengths clearly affect the results in energy and load characteristic.

  18. A statistical model-based technique for accounting for prostate gland deformation in endorectal coil-based MR imaging.

    Science.gov (United States)

    Tahmasebi, Amir M; Sharifi, Reza; Agarwal, Harsh K; Turkbey, Baris; Bernardo, Marcelino; Choyke, Peter; Pinto, Peter; Wood, Bradford; Kruecker, Jochen

    2012-01-01

    In prostate brachytherapy procedures, combining high-resolution endorectal coil (ERC)-MRI with Computed Tomography (CT) images has shown to improve the diagnostic specificity for malignant tumors. Despite such advantage, there exists a major complication in fusion of the two imaging modalities due to the deformation of the prostate shape in ERC-MRI. Conventionally, nonlinear deformable registration techniques have been utilized to account for such deformation. In this work, we present a model-based technique for accounting for the deformation of the prostate gland in ERC-MR imaging, in which a unique deformation vector is estimated for every point within the prostate gland. Modes of deformation for every point in the prostate are statistically identified using a set of MR-based training set (with and without ERC-MRI). Deformation of the prostate from a deformed (ERC-MRI) to a non-deformed state in a different modality (CT) is then realized by first calculating partial deformation information for a limited number of points (such as surface points or anatomical landmarks) and then utilizing the calculated deformation from a subset of the points to determine the coefficient values for the modes of deformations provided by the statistical deformation model. Using a leave-one-out cross-validation, our results demonstrated a mean estimation error of 1mm for a MR-to-MR registration.

  19. Rooting opinions in the minds: a cognitive model and a formal account of opinions and their dynamics

    CERN Document Server

    Giardini, Francesca; Conte, Rosaria

    2011-01-01

    The study of opinions, their formation and change, is one of the defining topics addressed by social psychology, but in recent years other disciplines, like computer science and complexity, have tried to deal with this issue. Despite the flourishing of different models and theories in both fields, several key questions still remain unanswered. The understanding of how opinions change and the way they are affected by social influence are challenging issues requiring a thorough analysis of opinion per se but also of the way in which they travel between agents' minds and are modulated by these exchanges. To account for the two-faceted nature of opinions, which are mental entities undergoing complex social processes, we outline a preliminary model in which a cognitive theory of opinions is put forward and it is paired with a formal description of them and of their spreading among minds. Furthermore, investigating social influence also implies the necessity to account for the way in which people change their minds...

  20. Model Fitting Versus Curve Fitting: A Model of Renormalization Provides a Better Account of Age Aftereffects Than a Model of Local Repulsion.

    Science.gov (United States)

    O'Neil, Sean F; Mac, Amy; Rhodes, Gillian; Webster, Michael A

    2015-12-01

    Recently, we proposed that the aftereffects of adapting to facial age are consistent with a renormalization of the perceived age (e.g., so that after adapting to a younger or older age, all ages appear slightly older or younger, respectively). This conclusion has been challenged by arguing that the aftereffects can also be accounted for by an alternative model based on repulsion (in which facial ages above or below the adapting age are biased away from the adaptor). However, we show here that this challenge was based on allowing the fitted functions to take on values which are implausible and incompatible across the different adapting conditions. When the fits are constrained or interpreted in terms of standard assumptions about normalization and repulsion, then the two analyses both agree in pointing to a pattern of renormalization in age aftereffects.

  1. Accounting for uncertainty due to 'last observation carried forward' outcome imputation in a meta-analysis model.

    Science.gov (United States)

    Dimitrakopoulou, Vasiliki; Efthimiou, Orestis; Leucht, Stefan; Salanti, Georgia

    2015-02-28

    Missing outcome data are a problem commonly observed in randomized control trials that occurs as a result of participants leaving the study before its end. Missing such important information can bias the study estimates of the relative treatment effect and consequently affect the meta-analytic results. Therefore, methods on manipulating data sets with missing participants, with regard to incorporating the missing information in the analysis so as to avoid the loss of power and minimize the bias, are of interest. We propose a meta-analytic model that accounts for possible error in the effect sizes estimated in studies with last observation carried forward (LOCF) imputed patients. Assuming a dichotomous outcome, we decompose the probability of a successful unobserved outcome taking into account the sensitivity and specificity of the LOCF imputation process for the missing participants. We fit the proposed model within a Bayesian framework, exploring different prior formulations for sensitivity and specificity. We illustrate our methods by performing a meta-analysis of five studies comparing the efficacy of amisulpride versus conventional drugs (flupenthixol and haloperidol) on patients diagnosed with schizophrenia. Our meta-analytic models yield estimates similar to meta-analysis with LOCF-imputed patients. Allowing for uncertainty in the imputation process, precision is decreased depending on the priors used for sensitivity and specificity. Results on the significance of amisulpride versus conventional drugs differ between the standard LOCF approach and our model depending on prior beliefs on the imputation process. Our method can be regarded as a useful sensitivity analysis that can be used in the presence of concerns about the LOCF process.

  2. Temperature dependence of the epidermal growth factor receptor signaling network can be accounted for by a kinetic model.

    Science.gov (United States)

    Moehren, Gisela; Markevich, Nick; Demin, Oleg; Kiyatkin, Anatoly; Goryanin, Igor; Hoek, Jan B; Kholodenko, Boris N

    2002-01-08

    Stimulation of isolated hepatocytes with epidermal growth factor (EGF) causes rapid tyrosine phosphorylation of the EGF receptor (EGFR) and adapter/target proteins, which was monitored with 1 and 2 s resolution at 37, 20, and 4 degrees C. The temporal responses detected for multiple signaling proteins involve both transient and sustained phosphorylation patterns, which change dramatically at low temperatures. To account quantitatively for complex responses, we employed a mechanistic kinetic model of the EGFR pathway, formulated in molecular terms as cascades of protein interactions and phosphorylation and dephosphorylation reactions. Assuming differential temperature dependencies for different reaction groups, such as SH2 and PTB domain-mediated interactions, the EGFR kinase, and the phosphatases, good quantitative agreement was obtained between computer-simulated and measured responses. The kinetic model demonstrates that, for each protein-protein interaction, the dissociation rate constant, k(off), strongly decreases at low temperatures, whereas this decline may or may not be accompanied by a large decrease in the k(on) value. Temperature-induced changes in the maximal activities of the reactions catalyzed by the EGFR kinase were moderate, compared to such changes in the V(max) of the phosphatases. However, strong changes in both the V(max) and K(m) for phosphatases resulted in moderate changes in the V(max)/K(m) ratio, comparable to the corresponding changes in EGFR kinase activity, with a single exception for the receptor phosphatase at 4 degrees C. The model suggests a significant decrease in the rates of the EGF receptor dimerization and its dephosphorylation at 4 degrees C, which can be related to the phase transition in the membrane lipids. A combination of high-resolution experimental monitoring and molecular level kinetic modeling made it possible to quantitatively account for the temperature dependence of the integrative signaling responses.

  3. An update on modeling dose-response relationships: Accounting for correlated data structure and heterogeneous error variance in linear and nonlinear mixed models.

    Science.gov (United States)

    Gonçalves, M A D; Bello, N M; Dritz, S S; Tokach, M D; DeRouchey, J M; Woodworth, J C; Goodband, R D

    2016-05-01

    Advanced methods for dose-response assessments are used to estimate the minimum concentrations of a nutrient that maximizes a given outcome of interest, thereby determining nutritional requirements for optimal performance. Contrary to standard modeling assumptions, experimental data often present a design structure that includes correlations between observations (i.e., blocking, nesting, etc.) as well as heterogeneity of error variances; either can mislead inference if disregarded. Our objective is to demonstrate practical implementation of linear and nonlinear mixed models for dose-response relationships accounting for correlated data structure and heterogeneous error variances. To illustrate, we modeled data from a randomized complete block design study to evaluate the standardized ileal digestible (SID) Trp:Lys ratio dose-response on G:F of nursery pigs. A base linear mixed model was fitted to explore the functional form of G:F relative to Trp:Lys ratios and assess model assumptions. Next, we fitted 3 competing dose-response mixed models to G:F, namely a quadratic polynomial (QP) model, a broken-line linear (BLL) ascending model, and a broken-line quadratic (BLQ) ascending model, all of which included heteroskedastic specifications, as dictated by the base model. The GLIMMIX procedure of SAS (version 9.4) was used to fit the base and QP models and the NLMIXED procedure was used to fit the BLL and BLQ models. We further illustrated the use of a grid search of initial parameter values to facilitate convergence and parameter estimation in nonlinear mixed models. Fit between competing dose-response models was compared using a maximum likelihood-based Bayesian information criterion (BIC). The QP, BLL, and BLQ models fitted on G:F of nursery pigs yielded BIC values of 353.7, 343.4, and 345.2, respectively, thus indicating a better fit of the BLL model. The BLL breakpoint estimate of the SID Trp:Lys ratio was 16.5% (95% confidence interval [16.1, 17.0]). Problems with

  4. IFRS 9 replacing IAS 39 : A study about how the implementation of the Expected Credit Loss Model in IFRS 9 i beleived to impact comparability in accounting

    OpenAIRE

    Klefvenberg, Louise; Nordlander, Viktoria

    2015-01-01

    This thesis examines how the implementation process of Expected Credit Loss Model in the accounting standard IFRS 9 – Financial instruments is perceived and interpreted and how these factors can affect comparability in accounting. One of the main changes with IFRS 9 is that companies need to account for expected credit losses rather than just incurred ones. The data is primarily collected through a web survey where all of Nordic banks and credit institutes with a minimum book value of total a...

  5. Probabilistic modelling in urban drainage – two approaches that explicitly account for temporal variation of model errors

    DEFF Research Database (Denmark)

    Löwe, Roland; Del Giudice, Dario; Mikkelsen, Peter Steen

    to observations. After a brief discussion of the assumptions made for likelihood-based parameter inference, we illustrated the basic principles of both approaches on the example of sewer flow modelling with a conceptual rainfallrunoff model. The results from a real-world case study suggested that both approaches...

  6. A field-scale infiltration model accounting for spatial heterogeneity of rainfall and soil saturated hydraulic conductivity

    Science.gov (United States)

    Morbidelli, Renato; Corradini, Corrado; Govindaraju, Rao S.

    2006-04-01

    This study first explores the role of spatial heterogeneity, in both the saturated hydraulic conductivity Ks and rainfall intensity r, on the integrated hydrological response of a natural slope. On this basis, a mathematical model for estimating the expected areal-average infiltration is then formulated. Both Ks and r are considered as random variables with assessed probability density functions. The model relies upon a semi-analytical component, which describes the directly infiltrated rainfall, and an empirical component, which accounts further for the infiltration of surface water running downslope into pervious soils (the run-on effect). Monte Carlo simulations over a clay loam soil and a sandy loam soil were performed for constructing the ensemble averages of field-scale infiltration used for model validation. The model produced very accurate estimates of the expected field-scale infiltration rate, as well as of the outflow generated by significant rainfall events. Furthermore, the two model components were found to interact appropriately for different weights of the two infiltration mechanisms involved.

  7. A micromechanics-inspired constitutive model for shape-memory alloys that accounts for initiation and saturation of phase transformation

    Science.gov (United States)

    Kelly, Alex; Stebner, Aaron P.; Bhattacharya, Kaushik

    2016-12-01

    A constitutive model to describe macroscopic elastic and transformation behaviors of polycrystalline shape-memory alloys is formulated using an internal variable thermodynamic framework. In a departure from prior phenomenological models, the proposed model treats initiation, growth kinetics, and saturation of transformation distinctly, consistent with physics revealed by recent multi-scale experiments and theoretical studies. Specifically, the proposed approach captures the macroscopic manifestations of three micromechanial facts, even though microstructures are not explicitly modeled: (1) Individual grains with favorable orientations and stresses for transformation are the first to nucleate martensite, and the local nucleation strain is relatively large. (2) Then, transformation interfaces propagate according to growth kinetics to traverse networks of grains, while previously formed martensite may reorient. (3) Ultimately, transformation saturates prior to 100% completion as some unfavorably-oriented grains do not transform; thus the total transformation strain of a polycrystal is modest relative to the initial, local nucleation strain. The proposed formulation also accounts for tension-compression asymmetry, processing anisotropy, and the distinction between stress-induced and temperature-induced transformations. Consequently, the model describes thermoelastic responses of shape-memory alloys subject to complex, multi-axial thermo-mechanical loadings. These abilities are demonstrated through detailed comparisons of simulations with experiments.

  8. Low Energy Atomic Models Suggesting a Pilus Structure that could Account for Electrical Conductivity of Geobacter sulfurreducens Pili.

    Science.gov (United States)

    Xiao, Ke; Malvankar, Nikhil S; Shu, Chuanjun; Martz, Eric; Lovley, Derek R; Sun, Xiao

    2016-03-22

    The metallic-like electrical conductivity of Geobacter sulfurreducens pili has been documented with multiple lines of experimental evidence, but there is only a rudimentary understanding of the structural features which contribute to this novel mode of biological electron transport. In order to determine if it was feasible for the pilin monomers of G. sulfurreducens to assemble into a conductive filament, theoretical energy-minimized models of Geobacter pili were constructed with a previously described approach, in which pilin monomers are assembled using randomized structural parameters and distance constraints. The lowest energy models from a specific group of predicted structures lacked a central channel, in contrast to previously existing pili models. In half of the no-channel models the three N-terminal aromatic residues of the pilin monomer are arranged in a potentially electrically conductive geometry, sufficiently close to account for the experimentally observed metallic like conductivity of the pili that has been attributed to overlapping pi-pi orbitals of aromatic amino acids. These atomic resolution models capable of explaining the observed conductive properties of Geobacter pili are a valuable tool to guide further investigation of the metallic-like conductivity of the pili, their role in biogeochemical cycling, and applications in bioenergy and bioelectronics.

  9. Construction and implications of structural equation modeling network for pediatric cataract: a data mining research of rare diseases

    National Research Council Canada - National Science Library

    Erping Long; Shuangjuan Xu; Zhenzhen Liu; Xiaohang Wu; Xiayin Zhang; Jinghui Wang; Wangting Li; Runzhong Liu; Zicong Chen; Kexin Chen; Tongyong Yu; Dongxuan Wu; Xutu Zhao; Jingjing Chen; Zhuoling Lin; Qianzhong Cao

    2017-01-01

    .... This study aims to investigate the interrelationship and the effectiveness of potential factors of pediatric cataract, for the exploration of data mining strategy in the scenarios of rare diseases...

  10. Goals and Psychological Accounting

    DEFF Research Database (Denmark)

    Koch, Alexander Karl; Nafziger, Julia

    -induced reference points make substandard performance psychologically painful and motivate the individual to stick to his goals. How strong the commitment to goals is depends on the type of psychological account. We provide conditions when it is optimal to evaluate goals in narrow accounts. The key intuition......We model how people formulate and evaluate goals to overcome self-control problems. People often attempt to regulate their behavior by evaluating goal-related outcomes separately (in narrow psychological accounts) rather than jointly (in a broad account). To explain this evidence, our theory...... of endogenous narrow or broad psychological accounts combines insights from the literatures on goals and mental accounting with models of expectations-based reference-dependent preferences. By formulating goals the individual creates expectations that induce reference points for task outcomes. These goal...

  11. Model cortical association fields account for the time course and dependence on target complexity of human contour perception.

    Directory of Open Access Journals (Sweden)

    Vadas Gintautas

    2011-10-01

    Full Text Available Can lateral connectivity in the primary visual cortex account for the time dependence and intrinsic task difficulty of human contour detection? To answer this question, we created a synthetic image set that prevents sole reliance on either low-level visual features or high-level context for the detection of target objects. Rendered images consist of smoothly varying, globally aligned contour fragments (amoebas distributed among groups of randomly rotated fragments (clutter. The time course and accuracy of amoeba detection by humans was measured using a two-alternative forced choice protocol with self-reported confidence and variable image presentation time (20-200 ms, followed by an image mask optimized so as to interrupt visual processing. Measured psychometric functions were well fit by sigmoidal functions with exponential time constants of 30-91 ms, depending on amoeba complexity. Key aspects of the psychophysical experiments were accounted for by a computational network model, in which simulated responses across retinotopic arrays of orientation-selective elements were modulated by cortical association fields, represented as multiplicative kernels computed from the differences in pairwise edge statistics between target and distractor images. Comparing the experimental and the computational results suggests that each iteration of the lateral interactions takes at least [Formula: see text] ms of cortical processing time. Our results provide evidence that cortical association fields between orientation selective elements in early visual areas can account for important temporal and task-dependent aspects of the psychometric curves characterizing human contour perception, with the remaining discrepancies postulated to arise from the influence of higher cortical areas.

  12. Accounting rigid support at the border in a mixed model the finite element method in problems of ice cover destruction

    Directory of Open Access Journals (Sweden)

    V. V. Knyazkov

    2014-01-01

    Full Text Available To evaluate the force to damage the ice covers is necessary for estimation of icebreaking capability of vessels, as well as of hull strength of icebreakers, and navigation of ships in ice conditions. On the other hand, the use of ice cover support to arrange construction works from the ice is also of practical interest.By the present moment a great deal of investigations of ice cover deformation have been carried out to result, usually, in approximate calculations formula which was obtained after making a variety of assumptions. Nevertheless, we believe that it is possible to make further improvement in calculations. Application numerical methods, and, for example, FEM, makes possible to avoid numerous drawbacks of analytical methods dealing with both complex boundaries and load application areas and other problem peculiarities.The article considers an application of mixed models of FEM for investigating ice cover deformation. A simple flexible triangle element of mixed type was taken to solve this problem. Vector of generalized coordinates of the element contains apices flexures and normal bending moments in the middle of its sides. Compared to other elements mixed models easily satisfy compatibility requirements on the boundary of adjacent elements and do not require numerical displacement differentiation to define bending moments, because bending moments are included in vector of element generalized coordinates.The method of account of rigid support plate is proposed. The resulting ratio, taking into account the "stiffening", reduces the number of resolving systems of equations by the number of elements on the plate contour.To evaluate further the results the numerical realization of ice cover stress-strained problem it becomes necessary and correct to check whether calculation results correspond to accurate solution. Using an example of circular plate the convergence of numerical solutions to analytical solutions is showed.The article

  13. A nonlinear BOLD model accounting for refractory effect by applying the longitudinal relaxation in NMR to the linear BOLD model.

    Science.gov (United States)

    Jung, Kwan-Jin

    2009-09-01

    A mathematical model to regress the nonlinear blood oxygen level-dependent (BOLD) fMRI signal has been developed by incorporating the refractory effect into the linear BOLD model of the biphasic gamma variate function. The refractory effect was modeled as a relaxation of two separate BOLD capacities corresponding to the biphasic components of the BOLD signal in analogy with longitudinal relaxation of magnetization in NMR. When tested with the published fMRI data of finger tapping, the nonlinear BOLD model with the refractory effect reproduced the nonlinear BOLD effects such as reduced poststimulus undershoot and saddle pattern in a prolonged stimulation as well as the reduced BOLD signal for repetitive stimulation.

  14. Rare decays at LHCb

    CERN Document Server

    Lafferty, George

    2015-01-01

    We review recent results from the LHCb experiment on studies of particle decays that are forbidden or rare in the Standard Model. The studies include searches for lepton flavour violating decays of the $\\tau$ lepton and the $B$ and $D$ mesons, and of $B$ and $D$ meson decays that would be mediated by Majorana neutrinos. Results are also presented for the rare processes $B_s \\to \\mu^+\\mu^-$ and $B^0 \\to \\mu^+\\mu^-$, $D^0 \\to \\pi^+\\pi^-\\mu^+\\mu^-$, $b \\to s\\gamma$ transitions, and $B \\to K^{(*)}\\mu^+\\mu^-$.

  15. Accounting for geochemical alterations of caprock fracture permeability in basin-scale models of leakage from geologic CO2 reservoirs

    Science.gov (United States)

    Guo, B.; Fitts, J. P.; Dobossy, M.; Bielicki, J. M.; Peters, C. A.

    2012-12-01

    Climate mitigation, public acceptance and energy, markets demand that the potential CO2 leakage rates from geologic storage reservoirs are predicted to be low and are known to a high level of certainty. Current approaches to predict CO2 leakage rates assume constant permeability of leakage pathways (e.g., wellbores, faults, fractures). A reactive transport model was developed to account for geochemical alterations that result in permeability evolution of leakage pathways. The one-dimensional reactive transport model was coupled with the basin-scale Estimating Leakage Semi-Analytical (ELSA) model to simulate CO2 and brine leakage through vertical caprock pathways for different CO2 storage reservoir sites and injection scenarios within the Mt. Simon and St. Peter sandstone formations of the Michigan basin. Mineral dissolution in the numerical reactive transport model expands leakage pathways and increases permeability as a result of calcite dissolution by reactions driven by CO2-acidified brine. A geochemical model compared kinetic and equilibrium treatments of calcite dissolution within each grid block for each time step. For a single fracture, we investigated the effect of the reactions on leakage by performing sensitivity analyses of fracture geometry, CO2 concentration, calcite abundance, initial permeability, and pressure gradient. Assuming that calcite dissolution reaches equilibrium at each time step produces unrealistic scenarios of buffering and permeability evolution within fractures. Therefore, the reactive transport model with a kinetic treatment of calcite dissolution was coupled to the ELSA model and used to compare brine and CO2 leakage rates at a variety of potential geologic storage sites within the Michigan basin. The results are used to construct maps based on the susceptibility to geochemically driven increases in leakage rates. These maps should provide useful and easily communicated inputs into decision-making processes for siting geologic CO2

  16. Modelling the spatial distribution of snow water equivalent at the catchment scale taking into account changes in snow covered area

    Directory of Open Access Journals (Sweden)

    T. Skaugen

    2011-12-01

    Full Text Available A successful modelling of the snow reservoir is necessary for water resources assessments and the mitigation of spring flood hazards. A good estimate of the spatial probability density function (PDF of snow water equivalent (SWE is important for obtaining estimates of the snow reservoir, but also for modelling the changes in snow covered area (SCA, which is crucial for the runoff dynamics in spring. In a previous paper the PDF of SWE was modelled as a sum of temporally correlated gamma distributed variables. This methodology was constrained to estimate the PDF of SWE for snow covered areas only. In order to model the PDF of SWE for a catchment, we need to take into account the change in snow coverage and provide the spatial moments of SWE for both snow covered areas and for the catchment as a whole. The spatial PDF of accumulated SWE is, also in this study, modelled as a sum of correlated gamma distributed variables. After accumulation and melting events the changes in the spatial moments are weighted by changes in SCA. The spatial variance of accumulated SWE is, after both accumulation- and melting events, evaluated by use of the covariance matrix. For accumulation events there are only positive elements in the covariance matrix, whereas for melting events, there are both positive and negative elements. The negative elements dictate that the correlation between melt and SWE is negative. The negative contributions become dominant only after some time into the melting season so at the onset of the melting season, the spatial variance thus continues to increase, for later to decrease. This behaviour is consistent with observations and called the "hysteretic" effect by some authors. The parameters for the snow distribution model can be estimated from observed historical precipitation data which reduces by one the number of parameters to be calibrated in a hydrological model. Results from the model are in good agreement with observed spatial moments

  17. Modelling the spatial distribution of snow water equivalent at the catchment scale taking into account changes in snow covered area

    Science.gov (United States)

    Skaugen, T.; Randen, F.

    2011-12-01

    A successful modelling of the snow reservoir is necessary for water resources assessments and the mitigation of spring flood hazards. A good estimate of the spatial probability density function (PDF) of snow water equivalent (SWE) is important for obtaining estimates of the snow reservoir, but also for modelling the changes in snow covered area (SCA), which is crucial for the runoff dynamics in spring. In a previous paper the PDF of SWE was modelled as a sum of temporally correlated gamma distributed variables. This methodology was constrained to estimate the PDF of SWE for snow covered areas only. In order to model the PDF of SWE for a catchment, we need to take into account the change in snow coverage and provide the spatial moments of SWE for both snow covered areas and for the catchment as a whole. The spatial PDF of accumulated SWE is, also in this study, modelled as a sum of correlated gamma distributed variables. After accumulation and melting events the changes in the spatial moments are weighted by changes in SCA. The spatial variance of accumulated SWE is, after both accumulation- and melting events, evaluated by use of the covariance matrix. For accumulation events there are only positive elements in the covariance matrix, whereas for melting events, there are both positive and negative elements. The negative elements dictate that the correlation between melt and SWE is negative. The negative contributions become dominant only after some time into the melting season so at the onset of the melting season, the spatial variance thus continues to increase, for later to decrease. This behaviour is consistent with observations and called the "hysteretic" effect by some authors. The parameters for the snow distribution model can be estimated from observed historical precipitation data which reduces by one the number of parameters to be calibrated in a hydrological model. Results from the model are in good agreement with observed spatial moments of SWE and SCA

  18. Serviceability limit state related to excessive lateral deformations to account for infill walls in the structural model

    Directory of Open Access Journals (Sweden)

    G. M. S. ALVA

    Full Text Available Brazilian Codes NBR 6118 and NBR 15575 provide practical values for interstory drift limits applied to conventional modeling in order to prevent negative effects in masonry infill walls caused by excessive lateral deformability, however these codes do not account for infill walls in the structural model. The inclusion of infill walls in the proposed model allows for a quantitative evaluation of structural stresses in these walls and an assessment of cracking in these elements (sliding shear diagonal tension and diagonal compression cracking. This paper presents the results of simulations of single-story one-bay infilled R/C frames. The main objective is to show how to check the serviceability limit states under lateral loads when the infill walls are included in the modeling. The results of numerical simulations allowed for an evaluation of stresses and the probable cracking pattern in infill walls. The results also allowed an identification of some advantages and limitations of the NBR 6118 practical procedure based on interstory drift limits.

  19. A statistical human rib cage geometry model accounting for variations by age, sex, stature and body mass index.

    Science.gov (United States)

    Shi, Xiangnan; Cao, Libo; Reed, Matthew P; Rupp, Jonathan D; Hoff, Carrie N; Hu, Jingwen

    2014-07-18

    In this study, we developed a statistical rib cage geometry model accounting for variations by age, sex, stature and body mass index (BMI). Thorax CT scans were obtained from 89 subjects approximately evenly distributed among 8 age groups and both sexes. Threshold-based CT image segmentation was performed to extract the rib geometries, and a total of 464 landmarks on the left side of each subject׳s ribcage were collected to describe the size and shape of the rib cage as well as the cross-sectional geometry of each rib. Principal component analysis and multivariate regression analysis were conducted to predict rib cage geometry as a function of age, sex, stature, and BMI, all of which showed strong effects on rib cage geometry. Except for BMI, all parameters also showed significant effects on rib cross-sectional area using a linear mixed model. This statistical rib cage geometry model can serve as a geometric basis for developing a parametric human thorax finite element model for quantifying effects from different human attributes on thoracic injury risks.

  20. Analytical model and design of spoke-type permanent-magnet machines accounting for saturation and nonlinearity of magnetic bridges

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Peixin; Chai, Feng [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001 (China); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Bi, Yunlong [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Pei, Yulong, E-mail: peiyulong1@163.com [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Cheng, Shukang [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001 (China); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2016-11-01

    Based on subdomain model, this paper presents an analytical method for predicting the no-load magnetic field distribution, back-EMF and torque in general spoke-type motors with magnetic bridges. Taking into account the saturation and nonlinearity of magnetic material, the magnetic bridges are equivalent to fan-shaped saturation regions. For getting standard boundary conditions, a lumped parameter magnetic circuit model and iterative method are employed to calculate the permeability. The final field domain is divided into five types of simple subdomains. Based on the method of separation of variables, the analytical expression of each subdomain is derived. The analytical results of the magnetic field distribution, Back-EMF and torque are verified by finite element method, which confirms the validity of the proposed model for facilitating the motor design and optimization. - Highlights: • The no-load magnetic field of poke-type motors is firstly calculated by analytical method. • The magnetic circuit model and iterative method are employed to calculate the permeability. • The analytical expression of each subdomain is derived.. • The proposed method can effectively reduce the predesign stages duration.

  1. Accounting for Population Structure in Gene-by-Environment Interactions in Genome-Wide Association Studies Using Mixed Models.

    Science.gov (United States)

    Sul, Jae Hoon; Bilow, Michael; Yang, Wen-Yun; Kostem, Emrah; Furlotte, Nick; He, Dan; Eskin, Eleazar

    2016-03-01

    Although genome-wide association studies (GWASs) have discovered numerous novel genetic variants associated with many complex traits and diseases, those genetic variants typically explain only a small fraction of phenotypic variance. Factors that account for phenotypic variance include environmental factors and gene-by-environment interactions (GEIs). Recently, several studies have conducted genome-wide gene-by-environment association analyses and demonstrated important roles of GEIs in complex traits. One of the main challenges in these association studies is to control effects of population structure that may cause spurious associations. Many studies have analyzed how population structure influences statistics of genetic variants and developed several statistical approaches to correct for population structure. However, the impact of population structure on GEI statistics in GWASs has not been extensively studied and nor have there been methods designed to correct for population structure on GEI statistics. In this paper, we show both analytically and empirically that population structure may cause spurious GEIs and use both simulation and two GWAS datasets to support our finding. We propose a statistical approach based on mixed models to account for population structure on GEI statistics. We find that our approach effectively controls population structure on statistics for GEIs as well as for genetic variants.

  2. A sampling design and model for estimating abundance of Nile crocodiles while accounting for heterogeneity of detectability of multiple observers

    Science.gov (United States)

    Shirley, Matthew H.; Dorazio, Robert M.; Abassery, Ekramy; Elhady, Amr A.; Mekki, Mohammed S.; Asran, Hosni H.

    2012-01-01

    As part of the development of a management program for Nile crocodiles in Lake Nasser, Egypt, we used a dependent double-observer sampling protocol with multiple observers to compute estimates of population size. To analyze the data, we developed a hierarchical model that allowed us to assess variation in detection probabilities among observers and survey dates, as well as account for variation in crocodile abundance among sites and habitats. We conducted surveys from July 2008-June 2009 in 15 areas of Lake Nasser that were representative of 3 main habitat categories. During these surveys, we sampled 1,086 km of lake shore wherein we detected 386 crocodiles. Analysis of the data revealed significant variability in both inter- and intra-observer detection probabilities. Our raw encounter rate was 0.355 crocodiles/km. When we accounted for observer effects and habitat, we estimated a surface population abundance of 2,581 (2,239-2,987, 95% credible intervals) crocodiles in Lake Nasser. Our results underscore the importance of well-trained, experienced monitoring personnel in order to decrease heterogeneity in intra-observer detection probability and to better detect changes in the population based on survey indices. This study will assist the Egyptian government establish a monitoring program as an integral part of future crocodile harvest activities in Lake Nasser

  3. Neural Tuning Size in a Model of Primate Visual Processing Accounts for Three Key Markers of Holistic Face Processing.

    Directory of Open Access Journals (Sweden)

    Cheston Tan

    Full Text Available Faces are an important and unique class of visual stimuli, and have been of interest to neuroscientists for many years. Faces are known to elicit certain characteristic behavioral markers, collectively labeled "holistic processing", while non-face objects are not processed holistically. However, little is known about the underlying neural mechanisms. The main aim of this computational simulation work is to investigate the neural mechanisms that make face processing holistic. Using a model of primate visual processing, we show that a single key factor, "neural tuning size", is able to account for three important markers of holistic face processing: the Composite Face Effect (CFE, Face Inversion Effect (FIE and Whole-Part Effect (WPE. Our proof-of-principle specifies the precise neurophysiological property that corresponds to the poorly-understood notion of holism, and shows that this one neural property controls three classic behavioral markers of holism. Our work is consistent with neurophysiological evidence, and makes further testable predictions. Overall, we provide a parsimonious account of holistic face processing, connecting computation, behavior and neurophysiology.

  4. Design Accountability

    DEFF Research Database (Denmark)

    Koskinen, Ilpo; Krogh, Peter

    2015-01-01

    design research is that where classical research is interested in singling out a particular aspect and exploring it in depth, design practice is characterized by balancing numerous concerns in a heterogenous and occasionally paradoxical product. It is on this basis the notion of design accountability...

  5. Design Accountability

    DEFF Research Database (Denmark)

    Koskinen, Ilpo; Krogh, Peter

    2015-01-01

    design research is that where classical research is interested in singling out a particular aspect and exploring it in depth, design practice is characterized by balancing numerous concerns in a heterogenous and occasionally paradoxical product. It is on this basis the notion of design accountability...

  6. A rare East Indian Ocean autumn season tropical cut-off low: impacts and a high-resolution modelling study

    Science.gov (United States)

    Buckley, B. W.; Leslie, L. M.; Sullivan, W.; Leplastrier, M.; Qi, L.

    2007-04-01

    There are two aims of this study. The first is to provide a synoptic description of the lifecycle and impacts of a seasonally rare but intense cut-off low of tropical origin that developed off the northwest coast of Australia, during the Southern Hemisphere autumn months of late April/early May, 2005. The second, and more important, part of this study is an assessment of the capacity of a state-of-the-science numerical model, assimilating all available satellite-derived observational data, to predict the track, intensity, duration, and severe weather that occurred during the life cycle of the cut-off low. The system was unusual in that its initial development occurred over tropical waters and was associated with a strong and highly involuted subtropical jetstream, generating a cloud band that produced record 24 h rainfall totals in northwest Western Australia for this time of the year. The cut-off low then underwent further deepening which produced more unseasonable heavy rainfall. Confirmed tornado reports occurred over the populous southwest corner of Western Australia. The synoptic discussion focuses initially on the intensification phase of the system, next on the period of heavy rainfall and gale to storm force winds that were generated by the cut-off during its most intense phase, and finally on the severe thunderstorm outbreak over southwest Western Australia. The study reveals a possible additional reason for the intensification of the tropical low, namely, the presence of positive SST anomalies of up to 3 °C over which the storm track passed early in its life. The modelling study used a high-resolution version (10 km horizontal grid spacing) of a coupled atmosphere-ocean model developed at the University of Oklahoma. The 96 hour forecast covered the period 00 UTC April 28 to 00 UTC May 2, 2005. The initial and boundary conditions were obtained from the archived analyses and forecasts from the Australian Bureau of Meteorology. The numerical forecasts

  7. Application of the quasi-random lattice model to rare-earth halide solutions for the computation of their osmotic and mean activity coefficients

    Institute of Scientific and Technical Information of China (English)

    Elsa Moggia

    2014-01-01

    This work dealt with the computation of the mean activity coefficients of rare-earth halide aqueous solutions at 25°C, by means of the Quasi Random Lattice (QRL) model. The osmotic coefficients were then calculated consistently, through the integration of the Gibbs-Duhem equation. Using of QRL was mainly motivated by its dependence on one parameter, given in the form of an elec-trolyte-dependent concentration, which was also the highest concentration at which the model could be applied. For all the electrolyte solutions here considered, this parameter was experimentally known and ranged from 1.5 to 2.2 mol/kg, at 25 °C. Accordingly, rare-earth halide concentrations from strong dilution up to 2 mol/kg about could be considered without need for best-fit treatment in order to compute their osmotic and mean activity coefficients. The experimental knowledge about the parameter was an advantageous fea-ture of QRL compared to existing literature models. Following a trend already observed with low charge electrolytes, a satisfactory agreement was obtained with the experimental values for all the investigated rare-earth chlorides and bromides. For the sake of com-pactness, in this work the considered rare-earth halides were all belonging to the P63/m space group in their crystalline (anhydrous) form.

  8. Decay in chest compression quality due to fatigue is rare during prolonged advanced life support in a manikin model

    Directory of Open Access Journals (Sweden)

    Bjørshol Conrad A

    2011-08-01

    Full Text Available Abstract Background The aim of this study was to measure chest compression decay during simulated advanced life support (ALS in a cardiac arrest manikin model. Methods 19 paramedic teams, each consisting of three paramedics, performed ALS for 12 minutes with the same paramedic providing all chest compressions. The patient was a resuscitation manikin found in ventricular fibrillation (VF. The first shock terminated the VF and the patient remained in pulseless electrical activity (PEA throughout the scenario. Average chest compression depth and rate was measured each minute for 12 minutes and divided into three groups based on chest compression quality; good (compression depth ≥ 40 mm, compression rate 100-120/minute for each minute of CPR, bad (initial compression depth 120/minute or decay (change from good to bad during the 12 minutes. Changes in no-flow ratio (NFR, defined as the time without chest compressions divided by the total time of the ALS scenario over time was also measured. Results Based on compression depth, 5 (26%, 9 (47% and 5 (26% were good, bad and with decay, respectively. Only one paramedic experienced decay within the first two minutes. Based on compression rate, 6 (32%, 6 (32% and 7 (37% were good, bad and with decay, respectively. NFR was 22% in both the 1-3 and 4-6 minute periods, respectively, but decreased to 14% in the 7-9 minute period (P = 0.002 and to 10% in the 10-12 minute period (P Conclusions In this simulated cardiac arrest manikin study, only half of the providers achieved guideline recommended compression depth during prolonged ALS. Large inter-individual differences in chest compression quality were already present from the initiation of CPR. Chest compression decay and thereby fatigue within the first two minutes was rare.

  9. Impact of accounting for coloured noise in radar altimetry data on a regional quasi-geoid model

    Science.gov (United States)

    Farahani, H. H.; Slobbe, D. C.; Klees, R.; Seitz, Kurt

    2016-07-01

    We study the impact of an accurate computation and incorporation of coloured noise in radar altimeter data when computing a regional quasi-geoid model using least-squares techniques. Our test area comprises the Southern North Sea including the Netherlands, Belgium, and parts of France, Germany, and the UK. We perform the study by modelling the disturbing potential with spherical radial base functions. To that end, we use the traditional remove-compute-restore procedure with a recent GRACE/GOCE static gravity field model. Apart from radar altimeter data, we use terrestrial, airborne, and shipboard gravity data. Radar altimeter sea surface heights are corrected for the instantaneous dynamic topography and used in the form of along-track quasi-geoid height differences. Noise in these data are estimated using repeat-track and post-fit residual analysis techniques and then modelled as an auto regressive moving average process. Quasi-geoid models are computed with and without taking the modelled coloured noise into account. The difference between them is used as a measure of the impact of coloured noise in radar altimeter along-track quasi-geoid height differences on the estimated quasi-geoid model. The impact strongly depends on the availability of shipboard gravity data. If no such data are available, the impact may attain values exceeding 10 centimetres in particular areas. In case shipboard gravity data are used, the impact is reduced, though it still attains values of several centimetres. We use geometric quasi-geoid heights from GPS/levelling data at height markers as control data to analyse the quality of the quasi-geoid models. The quasi-geoid model computed using a model of the coloured noise in radar altimeter along-track quasi-geoid height differences shows in some areas a significant improvement over a model that assumes white noise in these data. However, the interpretation in other areas remains a challenge due to the limited quality of the control data.

  10. Impact of accounting for coloured noise in radar altimetry data on a regional quasi-geoid model

    Science.gov (United States)

    Farahani, H. H.; Slobbe, D. C.; Klees, R.; Seitz, Kurt

    2017-01-01

    We study the impact of an accurate computation and incorporation of coloured noise in radar altimeter data when computing a regional quasi-geoid model using least-squares techniques. Our test area comprises the Southern North Sea including the Netherlands, Belgium, and parts of France, Germany, and the UK. We perform the study by modelling the disturbing potential with spherical radial base functions. To that end, we use the traditional remove-compute-restore procedure with a recent GRACE/GOCE static gravity field model. Apart from radar altimeter data, we use terrestrial, airborne, and shipboard gravity data. Radar altimeter sea surface heights are corrected for the instantaneous dynamic topography and used in the form of along-track quasi-geoid height differences. Noise in these data are estimated using repeat-track and post-fit residual analysis techniques and then modelled as an auto regressive moving average process. Quasi-geoid models are computed with and without taking the modelled coloured noise into account. The difference between them is used as a measure of the impact of coloured noise in radar altimeter along-track quasi-geoid height differences on the estimated quasi-geoid model. The impact strongly depends on the availability of shipboard gravity data. If no such data are available, the impact may attain values exceeding 10 centimetres in particular areas. In case shipboard gravity data are used, the impact is reduced, though it still attains values of several centimetres. We use geometric quasi-geoid heights from GPS/levelling data at height markers as control data to analyse the quality of the quasi-geoid models. The quasi-geoid model computed using a model of the coloured noise in radar altimeter along-track quasi-geoid height differences shows in some areas a significant improvement over a model that assumes white noise in these data. However, the interpretation in other areas remains a challenge due to the limited quality of the control data.

  11. Interaction of a supersonic NO beam with static and resonant RF fields: Simple theoretical model to account for molecular interferences

    Science.gov (United States)

    Ureña, A. González; Caceres, J. O.; Morato, M.

    2006-09-01

    In previous experimental works from this laboratory two unexpected phenomena were reported: (i) a depletion of ca. 40% in the total intensity of a pulsed He seeded NO beam when these molecules passed a homogeneous and a resonant oscillating RF electric field and (ii) a beam splitting of ca. 0.5° when the transverse beam profile is measured, under the same experimental conditions. In this work a model based on molecular beam interferences is introduced which satisfactorily accounts for these two observations. It is shown how the experimental set-up a simple device used as C-field in early molecular beam electric resonance experiments, can be employed as molecular interferometer to investigate matter-wave interferences in beams of polar molecules.

  12. Accounting for the uncertainty related to building occupants with regards to visual comfort: A literature survey on drivers and models

    DEFF Research Database (Denmark)

    Fabi, Valentina; Andersen, Rune Korsholm; Corgnati, Stefano

    2016-01-01

    energy use during the design stage. Since the reaction to thermal, acoustic, or visual stimuli is not the same for every human being, monitoring the behaviour inside buildings is an essential step to assert differences in energy consumption related to different interactions. Reliable information...... conditions influence occupants' manual controlling of the system in offices and by consequence the energy consumption. The purpose of this study was to investigate the possible drivers for light-switching to model occupant behaviour in office buildings. The probability of switching lighting systems on or off...... who take daylight level into account and switch on lights only if necessary and people who totally disregard the natural lighting. This underlines the importance of how individuality is at the base of the definition of the different types of users....

  13. A 3D finite-strain-based constitutive model for shape memory alloys accounting for thermomechanical coupling and martensite reorientation

    Science.gov (United States)

    Wang, Jun; Moumni, Ziad; Zhang, Weihong; Xu, Yingjie; Zaki, Wael

    2017-06-01

    The paper presents a finite-strain constitutive model for shape memory alloys (SMAs) that accounts for thermomechanical coupling and martensite reorientation. The finite-strain formulation is based on a two-tier, multiplicative decomposition of the deformation gradient into thermal, elastic, and inelastic parts, where the inelastic deformation is further split into phase transformation and martensite reorientation components. A time-discrete formulation of the constitutive equations is proposed and a numerical integration algorithm is presented featuring proper symmetrization of the tensor variables and explicit formulation of the material and spatial tangent operators involved. The algorithm is used for finite element analysis of SMA components subjected to various loading conditions, including uniaxial, non-proportional, isothermal and adiabatic loading cases. The analysis is carried out using the FEA software Abaqus by means of a user-defined material subroutine, which is then utilized to simulate a SMA archwire undergoing large strains and rotations.

  14. Towards ecosystem accounting

    NARCIS (Netherlands)

    Duku, C.; Rathjens, H.; Zwart, S.J.; Hein, L.

    2015-01-01

    Ecosystem accounting is an emerging field that aims to provide a consistent approach to analysing environment-economy interactions. One of the specific features of ecosystem accounting is the distinction between the capacity and the flow of ecosystem services. Ecohydrological modelling to support

  15. How robust are the estimated effects of air pollution on health? Accounting for model uncertainty using Bayesian model averaging.

    Science.gov (United States)

    Pannullo, Francesca; Lee, Duncan; Waclawski, Eugene; Leyland, Alastair H

    2016-08-01

    The long-term impact of air pollution on human health can be estimated from small-area ecological studies in which the health outcome is regressed against air pollution concentrations and other covariates, such as socio-economic deprivation. Socio-economic deprivation is multi-factorial and difficult to measure, and includes aspects of income, education, and housing as well as others. However, these variables are potentially highly correlated, meaning one can either create an overall deprivation index, or use the individual characteristics, which can result in a variety of pollution-health effects. Other aspects of model choice may affect the pollution-health estimate, such as the estimation of pollution, and spatial autocorrelation model. Therefore, we propose a Bayesian model averaging approach to combine the results from multiple statistical models to produce a more robust representation of the overall pollution-health effect. We investigate the relationship between nitrogen dioxide concentrations and cardio-respiratory mortality in West Central Scotland between 2006 and 2012.

  16. An empirical test of Birkett’s competency model for management accountants : A confirmative study conducted in the Netherlands

    NARCIS (Netherlands)

    Bots, J.M.; Groenland, E.A.G.; Swagerman, D.

    2009-01-01

    In 2002, the Accountants-in-Business section of the International Federation of Accountants (IFAC) issued the Competency Profiles for Management Accounting Practice and Practitioners report. This “Birkett Report” presents a framework for competency development during the careers of management accoun

  17. An empirical test of Birkett’s competency model for management accountants : A confirmative study conducted in the Netherlands

    NARCIS (Netherlands)

    Bots, J.M.; Groenland, E.A.G.; Swagerman, D.

    2009-01-01

    In 2002, the Accountants-in-Business section of the International Federation of Accountants (IFAC) issued the Competency Profiles for Management Accounting Practice and Practitioners report. This “Birkett Report” presents a framework for competency development during the careers of management accoun

  18. AMERICAN ACCOUNTING

    Directory of Open Access Journals (Sweden)

    Mihaela Onica

    2005-01-01

    Full Text Available The international Accounting Standards already contribute to the generation of better and more easily comparable financial information on an international level, supporting thus a more effective allocationof the investments resources in the world. Under the circumstances, there occurs the necessity of a consistent application of the standards on a global level. The financial statements are part of thefinancial reporting process. A set of complete financial statements usually includes a balance sheet,a profit and loss account, a report of the financial item change (which can be presented in various ways, for example as a status of the treasury flows and of the funds flows and those notes, as well as those explanatory situations and materials which are part of the financial statements.

  19. A multi-joint model of quiet, upright stance accounts for the "uncontrolled manifold" structure of joint variance.

    Science.gov (United States)

    Reimann, Hendrik; Schöner, Gregor

    2017-09-18

    The upright body in quiet stance is usually modeled as a single-link inverted pendulum. This agrees with most of the relevant sensory organs being at the far end of the pendulum, i.e., the eyes and the vestibular system in the head. Movement of the body in quiet stance has often been explained in terms of the "ankle strategy," where most movement is generated by the ankle musculature, while more proximal muscle groups are only rarely activated for faster movements or in response to perturbations, for instance, by flexing at the hips in what has been called the "hip strategy." Recent empirical evidence, however, shows that instead of being negligible in quiet stance, the movement in the knee and hip joints is even larger on average than the movement in the ankle joints (J Neurophysiol 97:3024-3035, 2007). Moreover, there is a strong pattern of covariation between movements in the ankle, knee and hip joints in a way that most of the observed movements leave the anterior-posterior position of the whole-body center of mass (CoM) invariant, i.e., only change the configuration of the different body parts around the CoM, instead of moving the body as a whole. It is unknown, however, where this covariation between joint angles during quiet stance originates from. In this paper, we aim to answer this question using a comprehensive model of the biomechanical, muscular and neural dynamics of a quietly standing human. We explore four different possible feedback laws for the control of this multi-link pendulum in upright stance that map sensory data to motor commands. We perform simulation studies to compare the generated inter-joint covariance patterns with experimental data. We find that control laws that actively coordinate muscle activation between the different joints generate correct variance patterns, while control laws that control each joint separately do not. Different specific forms of this coordination are compatible with the data.

  20. Explanations, mechanisms, and developmental models: Why the nativist account of early perceptual learning is not a proper mechanistic model

    Directory of Open Access Journals (Sweden)

    Radenović Ljiljana

    2013-01-01

    Full Text Available In the last several decades a number of studies on perceptual learning in early infancy have suggested that even infants seem to be sensitive to the way objects move and interact in the world. In order to explain the early emergence of infants’ sensitivity to causal patterns in the world some psychologists have proposed that core knowledge of objects and causal relations is innate (Leslie & Keeble 1987, Carey & Spelke, 1994; Keil, 1995; Spelke et al., 1994. The goal of this paper is to examine the nativist developmental model by investigating the criteria that a mechanistic model needs to fulfill if it is to be explanatory. Craver (2006 put forth a number of such criteria and developed a few very useful distinctions between explanation sketches and proper mechanistic explanations. By applying these criteria to the nativist developmental model I aim to show, firstly, that nativists only partially characterize the phenomenon at stake without giving us the details of when and under which conditions perception and attention in early infancy take place. Secondly, nativist start off with a description of the phenomena to be explained (even if it is only a partial description but import into it a particular theory of perception that requires further empirical evidence and further defense on its own. Furthermore, I argue that innate knowledge is a good candidate for a filler term (a term that is used to name the still unknown processes and parts of the mechanism and is likely to become redundant. Recent extensive research on early intermodal perception indicates that the mechanism enabling the perception of regularities and causal patterns in early infancy is grounded in our neurophysiology. However, this mechanism is fairly basic and does not involve highly sophisticated cognitive structures or innate core knowledge. I conclude with a remark that a closer examination of the mechanisms involved in early perceptual learning indicates that the nativism

  1. Collisions of halogen (/sup 2/P) and rare gas (/sup 1/S) atoms. [Differential cross sections, elastic model, coupling potential energy, L-S coupling, multiplets

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.H.

    1978-12-01

    Differential cross sections I (THETA) at several collision energies measured in crossed molecular beam experiments are reported for several combinations of halogen atoms (/sup 2/P) scattered off rare gas-rare gas atoms (/sup 1/S/sub 0/), namely, F + Ne, F + Ar, F + Kr, F + Xe, C1 + Xe. The scattering is described by an elastic model appropriate to Hund's case c coupling. With the use of this model, the X 1/2, I 3/2, and II 1/2 interaction potential energy curves are derived by fitting calculated differential cross sections, based on analytic representations of the potentials, to the data. The F - Xe X 1/2 potential shows a significant bonding qualitatively different than for the other F-rare gases. The I 3/2 and II 1/2 potentials closely resemble the van der Waals interactions of the one electron richer ground state rare gas-rare gas systems. Coupled-channel scattering calculations are carried out for F + Ar, F + Xe, and C1 + Xe using the realistic potential curves derived earlier. The results justify the use of the elastic model, and give additional information on intramultiplet and intermultiplet transitions. The transitions are found to be governed by the crossing of the two ..cap omega.. = 1/2 potentials in the complex plane. The measured I (theta) and I (THETA) derived from the coupled-channel computations show small oscillations or perturbations (Stueckelberg oscillations) though quantitative agreement is not obtained.The nature of the anomalous F - Xe X 1/2 potential is discussed as is the approximation of a constant spin orbit coupling over the experimentally accessible range of internuclear distances for these open shell molecules. 55 references.

  2. A statistical human resources costing and accounting model for analysing the economic effects of an intervention at a workplace.

    Science.gov (United States)

    Landstad, Bodil J; Gelin, Gunnar; Malmquist, Claes; Vinberg, Stig

    2002-09-15

    The study had two primary aims. The first aim was to combine a human resources costing and accounting approach (HRCA) with a quantitative statistical approach in order to get an integrated model. The second aim was to apply this integrated model in a quasi-experimental study in order to investigate whether preventive intervention affected sickness absence costs at the company level. The intervention studied contained occupational organizational measures, competence development, physical and psychosocial working environmental measures and individual and rehabilitation measures on both an individual and a group basis. The study is a quasi-experimental design with a non-randomized control group. Both groups involved cleaning jobs at predominantly female workplaces. The study plan involved carrying out before and after studies on both groups. The study included only those who were at the same workplace during the whole of the study period. In the HRCA model used here, the cost of sickness absence is the net difference between the costs, in the form of the value of the loss of production and the administrative cost, and the benefits in the form of lower labour costs. According to the HRCA model, the intervention used counteracted a rise in sickness absence costs at the company level, giving an average net effect of 266.5 Euros per person (full-time working) during an 8-month period. Using an analogue statistical analysis on the whole of the material, the contribution of the intervention counteracted a rise in sickness absence costs at the company level giving an average net effect of 283.2 Euros. Using a statistical method it was possible to study the regression coefficients in sub-groups and calculate the p-values for these coefficients; in the younger group the intervention gave a calculated net contribution of 605.6 Euros with a p-value of 0.073, while the intervention net contribution in the older group had a very high p-value. Using the statistical model it was

  3. On the importance of accounting for competing risks in pediatric brain cancer: II. Regression modeling and sample size.

    Science.gov (United States)

    Tai, Bee-Choo; Grundy, Richard; Machin, David

    2011-03-15

    To accurately model the cumulative need for radiotherapy in trials designed to delay or avoid irradiation among children with malignant brain tumor, it is crucial to account for competing events and evaluate how each contributes to the timing of irradiation. An appropriate choice of statistical model is also important for adequate determination of sample size. We describe the statistical modeling of competing events (A, radiotherapy after progression; B, no radiotherapy after progression; and C, elective radiotherapy) using proportional cause-specific and subdistribution hazard functions. The procedures of sample size estimation based on each method are outlined. These are illustrated by use of data comparing children with ependymoma and other malignant brain tumors. The results from these two approaches are compared. The cause-specific hazard analysis showed a reduction in hazards among infants with ependymoma for all event types, including Event A (adjusted cause-specific hazard ratio, 0.76; 95% confidence interval, 0.45-1.28). Conversely, the subdistribution hazard analysis suggested an increase in hazard for Event A (adjusted subdistribution hazard ratio, 1.35; 95% confidence interval, 0.80-2.30), but the reduction in hazards for Events B and C remained. Analysis based on subdistribution hazard requires a larger sample size than the cause-specific hazard approach. Notable differences in effect estimates and anticipated sample size were observed between methods when the main event showed a beneficial effect whereas the competing events showed an adverse effect on the cumulative incidence. The subdistribution hazard is the most appropriate for modeling treatment when its effects on both the main and competing events are of interest. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Integrated water resources management of the Ichkeul basin taking into account the durability of its wetland ecosystem using WEAP model

    Science.gov (United States)

    Shabou, M.; Lili-Chabaane, Z.; Gastli, W.; Chakroun, H.; Ben Abdallah, S.; Oueslati, I.; Lasram, F.; Laajimi, R.; Shaiek, M.; Romdhane, M. S.; Mnajja, A.

    2012-04-01

    The Conservation of coastal wetlands in the Mediterranean area is generally faced with development issues. It is the case of Tunisia where the precipitation is irregular in time and space. For the equity of water use (drinking, irrigation), there is a planning at the national level allowing the possibility of water transfer from regions rich in water resources to poor ones. This plan was initially done in Tunisia without taking into account the wetlands ecosystems and their specificities. The main purpose of this study is to find a model able to integrate simultaneously available resources and various water demands within a watershed by taking into account the durability of related wetland ecosystems. It is the case of the Ichkeul basin. This later is situated in northern of Tunisia, having an area of 2080 km2 and rainfall of about 600 mm/year. Downstream this basin, the Ichkeul Lake is characterized by a double alternation of seasonal high water and low salinity in winter and spring and low water levels and high salinity in summer and autumn that makes the Ichkeul an exceptional ecosystem. The originality of this hydrological system of Lake-marsh conditions is related to the presence of aquatic vegetation in the lake and special rich and varied hygrophilic in the marshes that constitutes the main source of food for large migrating water birds. After the construction of three dams on the principle rivers that are feeding the Ichkeul Lake, aiming particularly to supply the local irrigation and the drinking water demand of cities in the north and the east of Tunisia, freshwater inflow to the lake is greatly reduced causing a hydrological disequilibrium that influences the ecological conditions of the different species. Therefore, to ensure the sustainability of the water resources management, it's important to find a trade off between the existing hydrological and ecological systems taking into account water demands of various users (drinking, irrigation fishing, and

  5. Taking into account the temporal variation of hydraulic conductivity when calibrating overland flow models on tilled fields.

    Science.gov (United States)

    Chahinian, N.; Andrieux, P.; Moussa, R.; Voltz, M.

    2003-04-01

    Tillage operations are known to change the structure of agricultural soils. In this paper we seek a calibration methodology to take into account the impact of tillage on overland flow simulation at the scale of a tilled field located in southern France. The study site is a 3240 m2 vineyard equipped with a Venturi flume and a tipping bucket rain gauge. 20 monitored rainfall events were used for the study, equally divided between calibration and validation sets. The overland flow model used consists of a modified Green &Ampt equation to simulate infiltration, a surface detention module, and an overland flow routing module based on the unit hydrograph concept. The model parameters that were calibrated for each event are the saturated hydraulic conductivity and the random roughness. The calibrated Ks values decreased monotonously according to the total amount of rainfall since tillage. No clear relationship was observed between the random roughness and cumulated rainfall. A regression curve was fitted to the calibrated Ks values. This curve was then used to determine Ks values for any rainfall event considering the total rainfall since tillage. Fairly good agreement was observed between the simulated and measured hydrographs of the calibration set. The validation results were relatively poorer but remain satisfactory given the uncertainties related to the initial soil moisture conditions. The calibration methodology developed seems robust and may be transposed to other sites.

  6. A method for improving predictive modeling by taking into account lag time: Example of selenium bioaccumulation in a flowing system.

    Science.gov (United States)

    Beckon, William N

    2016-07-01

    For bioaccumulative substances, efforts to predict concentrations in organisms at upper trophic levels, based on measurements of environmental exposure, have been confounded by the appreciable but hitherto unknown amount of time it may take for bioaccumulation to occur through various pathways and across several trophic transfers. The study summarized here demonstrates an objective method of estimating this lag time by testing a large array of potential lag times for selenium bioaccumulation, selecting the lag that provides the best regression between environmental exposure (concentration in ambient water) and concentration in the tissue of the target organism. Bioaccumulation lag is generally greater for organisms at higher trophic levels, reaching times of more than a year in piscivorous fish. Predictive modeling of bioaccumulation is improved appreciably by taking into account this lag. More generally, the method demonstrated here may improve the accuracy of predictive modeling in a wide variety of other cause-effect relationships in which lag time is substantial but inadequately known, in disciplines as diverse as climatology (e.g., the effect of greenhouse gases on sea levels) and economics (e.g., the effects of fiscal stimulus on employment).

  7. Two models to compute an adjusted Green Vegetation Fraction taking into account the spatial variability of soil NDVI

    Science.gov (United States)

    Montandon, L. M.; Small, E.

    2008-12-01

    The green vegetation fraction (Fg) is an important climate and hydrologic model parameter. The commonly- used Fg model is a simple linear mixing of two NDVI end-members: bare soil NDVI (NDVIo) and full vegetation NDVI (NDVI∞). NDVI∞ is generally set as a percentile of the historical maximum NDVI for each land cover. This approach works well for areas where Fg reaches full cover (100%). Because many biomes do not reach Fg=0, however, NDVIo is often determined as a single invariant value for all land cover types. In general, it is selected among the lowest NDVI observed over bare or desert areas, yielding NDVIo close to zero. There are two issues with this approach: large-scale variability of soil NDVI is ignored and observations on a wide range of soils show that soil NDVI is often larger. Here we introduce and test two new approaches to compute Fg that takes into account the spatial variability of soil NDVI. The first approach uses a global soil NDVI database and time series of MODIS NDVI data over the conterminous United States to constrain possible soil NDVI values over each pixel. Fg is computed using a subset of the soils database that respects the linear mixing model condition NDVIo≤NDVIh, where NDVIh is the pixel historical minimum. The second approach uses an empirical soil NDVI model that combines information of soil organic matter content and texture to infer soil NDVI. The U.S. General Soil Map (STATSGO2) database is used as input for spatial soil properties. Using in situ measurements of soil NDVI from sites that span a range of land cover types, we test both models and compare their performance to the standard Fg model. We show that our models adjust the temporal Fg estimates by 40-90% depending on the land cover type and amplitude of the seasonal NDVI signal. Using MODIS NDVI and soil maps over the conterminous U.S., we also study the spatial distribution of Fg adjustments in February and June 2008. We show that the standard Fg method

  8. Modelling of the physico-chemical behaviour of clay minerals with a thermo-kinetic model taking into account particles morphology in compacted material.

    Science.gov (United States)

    Sali, D.; Fritz, B.; Clément, C.; Michau, N.

    2003-04-01

    Modelling of fluid-mineral interactions is largely used in Earth Sciences studies to better understand the involved physicochemical processes and their long-term effect on the materials behaviour. Numerical models simplify the processes but try to preserve their main characteristics. Therefore the modelling results strongly depend on the data quality describing initial physicochemical conditions for rock materials, fluids and gases, and on the realistic way of processes representations. The current geo-chemical models do not well take into account rock porosity and permeability and the particle morphology of clay minerals. In compacted materials like those considered as barriers in waste repositories, low permeability rocks like mudstones or compacted powders will be used : they contain mainly fine particles and the geochemical models used for predicting their interactions with fluids tend to misjudge their surface areas, which are fundamental parameters in kinetic modelling. The purpose of this study was to improve how to take into account the particles morphology in the thermo-kinetic code KINDIS and the reactive transport code KIRMAT. A new function was integrated in these codes, considering the reaction surface area as a volume depending parameter and the calculated evolution of the mass balance in the system was coupled with the evolution of reactive surface areas. We made application exercises for numerical validation of these new versions of the codes and the results were compared with those of the pre-existing thermo-kinetic code KINDIS. Several points are highlighted. Taking into account reactive surface area evolution during simulation modifies the predicted mass transfers related to fluid-minerals interactions. Different secondary mineral phases are also observed during modelling. The evolution of the reactive surface parameter helps to solve the competition effects between different phases present in the system which are all able to fix the chemical

  9. Infrastrukturel Accountability

    DEFF Research Database (Denmark)

    Ubbesen, Morten Bonde

    Hvordan redegør man troværdigt for noget så diffust som en hel nations udledning af drivhusgasser? Det undersøger denne afhandling i et etnografisk studie af hvordan Danmarks drivhusgasregnskab udarbejdes, rapporteres og kontrolleres. Studiet trækker på begreber og forståelser fra 'Science & Tech...... & Technology Studies', og bidrager med begrebet 'infrastrukturel accountability' til nye måder at forstå og tænke om det arbejde, hvormed højt specialiserede praksisser dokumenterer og redegør for kvaliteten af deres arbejde....

  10. Infrastrukturel Accountability

    DEFF Research Database (Denmark)

    Ubbesen, Morten Bonde

    Hvordan redegør man troværdigt for noget så diffust som en hel nations udledning af drivhusgasser? Det undersøger denne afhandling i et etnografisk studie af hvordan Danmarks drivhusgasregnskab udarbejdes, rapporteres og kontrolleres. Studiet trækker på begreber og forståelser fra 'Science & Tech...... & Technology Studies', og bidrager med begrebet 'infrastrukturel accountability' til nye måder at forstå og tænke om det arbejde, hvormed højt specialiserede praksisser dokumenterer og redegør for kvaliteten af deres arbejde....

  11. Emerging accounting trends accounting for leases.

    Science.gov (United States)

    Valletta, Robert; Huggins, Brian

    2010-12-01

    A new model for lease accounting can have a significant impact on hospitals and healthcare organizations. The new approach proposes a "right-of-use" model that involves complex estimates and significant administrative burden. Hospitals and health systems that draw heavily on lease arrangements should start preparing for the new approach now even though guidance and a final rule are not expected until mid-2011. This article highlights a number of considerations from the lessee point of view.

  12. A simple arc column model that accounts for the relationship between voltage, current and electrode gap during VAR

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, R.L. [Sandia National Labs., Albuquerque, NM (United States). Liquid Metal Processing Lab.

    1997-02-01

    Mean arc voltage is a process parameter commonly used in vacuum arc remelting (VAR) control schemes. The response of this parameter to changes in melting current (I) and electrode gap (g{sub e}) at constant pressure may be accurately described by an equation of the form V = V{sub 0} + c{sub 1}g{sub e}I + c{sub 2}g{sub e}{sup 2} + c{sub 3}I{sup 2}, where c{sub 1}, c{sub 2} and c{sub 3} are constants, and where the non-linear terms generally constitute a relatively small correction. If the non-linear terms are ignored, the equation has the form of Ohm`s law with a constant offset (V{sub 0}), c{sub 1}g{sub e} playing the role of resistance. This implies that the arc column may be treated approximately as a simple resistor during constant current VAR, the resistance changing linearly with g{sub e}. The VAR furnace arc is known to originate from multiple cathode spot clusters situated randomly on the electrode tip surface. Each cluster marks a point of exist for conduction electrons leaving the cathode surface and entering the electrode gap. Because the spot clusters re highly localized on the cathode surface, each gives rise to an arc column that may be considered to operate independently of other local arc columns. This approximation is used to develop a model that accounts for the observed arc voltage dependence on electrode gap at constant current. Local arc column resistivity is estimated from elementary plasma physics and used to test the model for consistency by using it to predict local column heavy particle density. Furthermore, it is shown that the local arc column resistance increases as particle density increases. This is used to account for the common observation that the arc stiffens with increasing current, i.e. the arc voltage becomes more sensitive to changes in electrode gap as the melting current is increased. This explains why arc voltage is an accurate electrode gap indicator for high current VAR processes but not low current VAR processes.

  13. Search for the Higgs Boson and Rare Standard Model Processes in the ET+B-Jets Signature at the Collider Detector at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Potamianos, Karolos Jozef [Purdue Univ., West Lafayette, IN (United States)

    2011-12-01

    We study rare processes of the standard model of particle physics (SM) in events with missing transverse energy ET, no leptons, and two or three jets, of which at least one is identified as originating from a $b$-quark (ET+b-jets signature). We present a search for the SM Higgs boson produced in association with a $W$ or $Z$ boson when the Higgs decays into \\bbbar. We consider the scenario where $Z \\to \

  14. Generalization of Rare Variant Association Tests for Longitudinal Family Studies.

    Science.gov (United States)

    Chien, Li-Chu; Hsu, Fang-Chi; Bowden, Donald W; Chiu, Yen-Feng

    2016-02-01

    Given the functional relevance of many rare variants, their identification is frequently critical for dissecting disease etiology. Functional variants are likely to be aggregated in family studies enriched with affected members, and this aggregation increases the statistical power to detect rare variants associated with a trait of interest. Longitudinal family studies provide additional information for identifying genetic and environmental factors associated with disease over time. However, methods to analyze rare variants in longitudinal family data remain fairly limited. These methods should be capable of accounting for different sources of correlations and handling large amounts of sequencing data efficiently. To identify rare variants associated with a phenotype in longitudinal family studies, we extended pedigree-based burden (BT) and kernel (KS) association tests to genetic longitudinal studies. Generalized estimating equation (GEE) approaches were used to generalize the pedigree-based BT and KS to multiple correlated phenotypes under the generalized linear model framework, adjusting for fixed effects of confounding factors. These tests accounted for complex correlations between repeated measures of the same phenotype (serial correlations) and between individuals in the same family (familial correlations). We conducted comprehensive simulation studies to compare the proposed tests with mixed-effects models and marginal models, using GEEs under various configurations. When the proposed tests were applied to data from the Diabetes Heart Study, we found exome variants of POMGNT1 and JAK1 genes were associated with type 2 diabetes.

  15. Paying for the Orphan Drug System: break or bend? Is it time for a new evaluation system for payers in Europe to take account of new rare disease treatments?

    Directory of Open Access Journals (Sweden)

    Hughes-Wilson Wills

    2012-09-01

    Full Text Available Abstract Since its enactment in 2000, the European Orphan Medicinal Products Regulation has allowed the review and approval of approaching 70 treatments for some 55 different conditions in Europe. Success does not come without a price, however. Many of these so-called “orphan drugs” have higher price points than treatments for more common diseases. This has been raising debate as to whether the treatments are worth it, which, in turn risks blocking patient access to treatment. To date, orphan drugs have only accounted for a small percentage of the overall drug budget. It would appear that, with increasing numbers of orphan drugs, governments are concerned about the future budget impact and their cost-effectiveness in comparison with other healthcare interventions. Orphan drugs are under the spotlight, something that is likely to continue as the economic crisis in Europe takes hold and governments respond with austerity measures that include cuts to healthcare expenditures. Formally and informally, governments are looking at how they are going to handle orphan drugs in the future. Collaborative proposals between EU governments to better understand the value of orphan drugs are under consideration. In recent years there has been increasing criticism of behaviours in the orphan drug field, mainly centring on two key perceptions of the system: the high prices of orphan drugs and their inability to meet standard cost-effectiveness thresholds; and the construct of the system itself, which allows companies to gain the benefits that accrue from being badged as an orphan drug. The authors hypothesise that, by examining these criticisms individually, one might be able to turn these different “behaviours” into criteria for the creation of a system to evaluate new orphan drugs coming onto the market. It has been acknowledged that standard methodologies for Health Technology Assessments (HTA will need to be tailored to take into account the

  16. The Objective Model about Disclosure of Accounting Information under the Internet Conditions%Internet网上财务会计信息披露趋势展望

    Institute of Scientific and Technical Information of China (English)

    张美红

    2001-01-01

    The current disclosure model of accounting information has greatly restricted the realization of accounting objective. It is not far away from the era when we can present periodic accounting information through the internet. The present author attempts to systematically construct the objective model for disclosure of financial accounting information under the internet conditions and pose some measures to be taken.%现行上市公司财务会计信息披露模式严重制约会计目标的实现。根据国际互联网技术发展的趋势和实现会计目标的要求,全面构建网上财务会计信息披露的目标模式,并提出为实现这一目标模式应采取的措施。

  17. Using experiments and demographic models to assess rare plant vulnerability to utlity-scale solar energy development

    Science.gov (United States)

    Moore, K. A.

    2015-12-01

    Pressing challenges for the implementation of solar energy are the effects of construction and operation on protected animal and plant species. Siting and mitigation of solar energy often requires understanding of basic biology and distributions of rare species that are unknown. How can we rapidly collect the information necessary on species- and site-specific population dynamics to effectively design mitigation and conservation measures? We have developed an integrated approach to assessing the vulnerability of a suite of representative rare plant species in the region. We implemented a prioritized series of demographic and experimental studies over the past four years to identify the types of species, populations, and life stages most vulnerable to impact or prone to conservation efforts. We have found substantial variation in vegetative and sexual reproduction between study populations for several rare plants, including between populations that vary in putative impact by development and/or effects of experimental solar arrays. For a subset of species, we designed population viability analysis and applied them to identify sensitive vital rates and compare quasi-extinction probabilities under different climate and impact scenarios. By utilizing practical experiments to test for the effects of real or simulated impacts, we found differences in vital rates between natural and disturbed populations adjacent to and within solar installations. We draw conclusions from our work to guide the analysis of benefits, permitting, and design of utility-scale solar energy facilities.

  18. Dorsoventral and Proximodistal Hippocampal Processing Account for the Influences of Sleep and Context on Memory (Reconsolidation: A Connectionist Model

    Directory of Open Access Journals (Sweden)

    Justin Lines

    2017-01-01

    Full Text Available The context in which learning occurs is sufficient to reconsolidate stored memories and neuronal reactivation may be crucial to memory consolidation during sleep. The mechanisms of context-dependent and sleep-dependent memory (reconsolidation are unknown but involve the hippocampus. We simulated memory (reconsolidation using a connectionist model of the hippocampus that explicitly accounted for its dorsoventral organization and for CA1 proximodistal processing. Replicating human and rodent (reconsolidation studies yielded the following results. (1 Semantic overlap between memory items and extraneous learning was necessary to explain experimental data and depended crucially on the recurrent networks of dorsal but not ventral CA3. (2 Stimulus-free, sleep-induced internal reactivations of memory patterns produced heterogeneous recruitment of memory items and protected memories from subsequent interference. These simulations further suggested that the decrease in memory resilience when subjects were not allowed to sleep following learning was primarily due to extraneous learning. (3 Partial exposure to the learning context during simulated sleep (i.e., targeted memory reactivation uniformly increased memory item reactivation and enhanced subsequent recall. Altogether, these results show that the dorsoventral and proximodistal organization of the hippocampus may be important components of the neural mechanisms for context-based and sleep-based memory (reconsolidations.

  19. Accent modulates access to word meaning: Evidence for a speaker-model account of spoken word recognition.

    Science.gov (United States)

    Cai, Zhenguang G; Gilbert, Rebecca A; Davis, Matthew H; Gaskell, M Gareth; Farrar, Lauren; Adler, Sarah; Rodd, Jennifer M

    2017-11-01

    Speech carries accent information relevant to determining the speaker's linguistic and social background. A series of web-based experiments demonstrate that accent cues can modulate access to word meaning. In Experiments 1-3, British participants were more likely to retrieve the American dominant meaning (e.g., hat meaning of "bonnet") in a word association task if they heard the words in an American than a British accent. In addition, results from a speeded semantic decision task (Experiment 4) and sentence comprehension task (Experiment 5) confirm that accent modulates on-line meaning retrieval such that comprehension of ambiguous words is easier when the relevant word meaning is dominant in the speaker's dialect. Critically, neutral-accent speech items, created by morphing British- and American-accented recordings, were interpreted in a similar way to accented words when embedded in a context of accented words (Experiment 2). This finding indicates that listeners do not use accent to guide meaning retrieval on a word-by-word basis; instead they use accent information to determine the dialectic identity of a speaker and then use their experience of that dialect to guide meaning access for all words spoken by that person. These results motivate a speaker-model account of spoken word recognition in which comprehenders determine key characteristics of their interlocutor and use this knowledge to guide word meaning access. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Analytical modeling of demagnetizing effect in magnetoelectric ferrite/PZT/ferrite trilayers taking into account a mechanical coupling

    Science.gov (United States)

    Loyau, V.; Aubert, A.; LoBue, M.; Mazaleyrat, F.

    2017-03-01

    In this paper, we investigate the demagnetizing effect in ferrite/PZT/ferrite magnetoelectric (ME) trilayer composites consisting of commercial PZT discs bonded by epoxy layers to Ni-Co-Zn ferrite discs made by a reactive Spark Plasma Sintering (SPS) technique. ME voltage coefficients (transversal mode) were measured on ferrite/PZT/ferrite trilayer ME samples with different thicknesses or phase volume ratio in order to highlight the influence of the magnetic field penetration governed by these geometrical parameters. Experimental ME coefficients and voltages were compared to analytical calculations using a quasi-static model. Theoretical demagnetizing factors of two magnetic discs that interact together in parallel magnetic structures were derived from an analytical calculation based on a superposition method. These factors were introduced in ME voltage calculations which take account of the demagnetizing effect. To fit the experimental results, a mechanical coupling factor was also introduced in the theoretical formula. This reflects the differential strain that exists in the ferrite and PZT layers due to shear effects near the edge of the ME samples and within the bonding epoxy layers. From this study, an optimization in magnitude of the ME voltage is obtained. Lastly, an analytical calculation of demagnetizing effect was conducted for layered ME composites containing higher numbers of alternated layers (n ≥ 5). The advantage of such a structure is then discussed.

  1. Developing a Global Model of Accounting Education and Examining IES Compliance in Australia, Japan, and Sri Lanka

    Science.gov (United States)

    Watty, Kim; Sugahara, Satoshi; Abayadeera, Nadana; Perera, Luckmika

    2013-01-01

    The introduction of International Education Standards (IES) signals a clear move by the International Accounting Education Standards Board (IAESB) to ensure high quality standards in professional accounting education at a global level. This study investigated how IES are perceived and valued by member bodies and academics in three counties:…

  2. Self-consistent modeling of induced magnetic field in Titan's atmosphere accounting for the generation of Schumann resonance

    Science.gov (United States)

    Béghin, Christian

    2015-02-01

    This model is worked out in the frame of physical mechanisms proposed in previous studies accounting for the generation and the observation of an atypical Schumann Resonance (SR) during the descent of the Huygens Probe in the Titan's atmosphere on 14 January 2005. While Titan is staying inside the subsonic co-rotating magnetosphere of Saturn, a secondary magnetic field carrying an Extremely Low Frequency (ELF) modulation is shown to be generated through ion-acoustic instabilities of the Pedersen current sheets induced at the interface region between the impacting magnetospheric plasma and Titan's ionosphere. The stronger induced magnetic field components are focused within field-aligned arcs-like structures hanging down the current sheets, with minimum amplitude of about 0.3 nT throughout the ramside hemisphere from the ionopause down to the Moon surface, including the icy crust and its interface with a conductive water ocean. The deep penetration of the modulated magnetic field in the atmosphere is thought to be allowed thanks to the force balance between the average temporal variations of thermal and magnetic pressures within the field-aligned arcs. However, there is a first cause of diffusion of the ELF magnetic components, probably due to feeding one, or eventually several SR eigenmodes. A second leakage source is ascribed to a system of eddy-Foucault currents assumed to be induced through the buried water ocean. The amplitude spectrum distribution of the induced ELF magnetic field components inside the SR cavity is found fully consistent with the measurements of the Huygens wave-field strength. Waiting for expected future in-situ exploration of Titan's lower atmosphere and the surface, the Huygens data are the only experimental means available to date for constraining the proposed model.

  3. An Extended Normalization Model of Attention Accounts for Feature-Based Attentional Enhancement of Both Response and Coherence Gain.

    Science.gov (United States)

    Schwedhelm, Philipp; Krishna, B Suresh; Treue, Stefan

    2016-12-01

    Paying attention to a sensory feature improves its perception and impairs that of others. Recent work has shown that a Normalization Model of Attention (NMoA) can account for a wide range of physiological findings and the influence of different attentional manipulations on visual performance. A key prediction of the NMoA is that attention to a visual feature like an orientation or a motion direction will increase the response of neurons preferring the attended feature (response gain) rather than increase the sensory input strength of the attended stimulus (input gain). This effect of feature-based attention on neuronal responses should translate to similar patterns of improvement in behavioral performance, with psychometric functions showing response gain rather than input gain when attention is directed to the task-relevant feature. In contrast, we report here that when human subjects are cued to attend to one of two motion directions in a transparent motion display, attentional effects manifest as a combination of input and response gain. Further, the impact on input gain is greater when attention is directed towards a narrow range of motion directions than when it is directed towards a broad range. These results are captured by an extended NMoA, which either includes a stimulus-independent attentional contribution to normalization or utilizes direction-tuned normalization. The proposed extensions are consistent with the feature-similarity gain model of attention and the attentional modulation in extrastriate area MT, where neuronal responses are enhanced and suppressed by attention to preferred and non-preferred motion directions respectively.

  4. An Extended Normalization Model of Attention Accounts for Feature-Based Attentional Enhancement of Both Response and Coherence Gain.

    Directory of Open Access Journals (Sweden)

    Philipp Schwedhelm

    2016-12-01

    Full Text Available Paying attention to a sensory feature improves its perception and impairs that of others. Recent work has shown that a Normalization Model of Attention (NMoA can account for a wide range of physiological findings and the influence of different attentional manipulations on visual performance. A key prediction of the NMoA is that attention to a visual feature like an orientation or a motion direction will increase the response of neurons preferring the attended feature (response gain rather than increase the sensory input strength of the attended stimulus (input gain. This effect of feature-based attention on neuronal responses should translate to similar patterns of improvement in behavioral performance, with psychometric functions showing response gain rather than input gain when attention is directed to the task-relevant feature. In contrast, we report here that when human subjects are cued to attend to one of two motion directions in a transparent motion display, attentional effects manifest as a combination of input and response gain. Further, the impact on input gain is greater when attention is directed towards a narrow range of motion directions than when it is directed towards a broad range. These results are captured by an extended NMoA, which either includes a stimulus-independent attentional contribution to normalization or utilizes direction-tuned normalization. The proposed extensions are consistent with the feature-similarity gain model of attention and the attentional modulation in extrastriate area MT, where neuronal responses are enhanced and suppressed by attention to preferred and non-preferred motion directions respectively.

  5. Stochastic inverse modelling of hydraulic conductivity fields taking into account independent stochastic structures: A 3D case study

    Science.gov (United States)

    Llopis-Albert, C.; Capilla, J. E.

    2010-09-01

    SummaryMajor factors affecting groundwater flow through fractured rocks include the geometry of each fracture, its properties and the fracture-network connectivity together with the porosity and conductivity of the rock matrix. When modelling fractured rocks this is translated into attaining a characterization of the hydraulic conductivity ( K) as adequately as possible, despite its high heterogeneity. This links with the main goal of this paper, which is to present an improvement of a stochastic inverse model, named as Gradual Conditioning (GC) method, to better characterise K in a fractured rock medium by considering different K stochastic structures, belonging to independent K statistical populations (SP) of fracture families and the rock matrix, each one with its own statistical properties. The new methodology is carried out by applying independent deformations to each SP during the conditioning process for constraining stochastic simulations to data. This allows that the statistical properties of each SPs tend to be preserved during the iterative optimization process. It is worthwhile mentioning that so far, no other stochastic inverse modelling technique, with the whole capabilities implemented in the GC method, is able to work with a domain covered by several different stochastic structures taking into account the independence of different populations. The GC method is based on a procedure that gradually changes an initial K field, which is conditioned only to K data, to approximate the reproduction of other types of information, i.e., piezometric head and solute concentration data. The approach is applied to the Äspö Hard Rock Laboratory (HRL) in Sweden, where, since the middle nineties, many experiments have been carried out to increase confidence in alternative radionuclide transport modelling approaches. Because the description of fracture locations and the distribution of hydrodynamic parameters within them are not accurate enough, we address the

  6. Large-scale determinants of diversity across Spanish forest habitats: accounting for model uncertainty in compositional and structural indicators

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Quller, E.; Torras, O.; Alberdi, I.; Solana, J.; Saura, S.

    2011-07-01

    An integral understanding of forest biodiversity requires the exploration of the many aspects it comprises and of the numerous potential determinants of their distribution. The landscape ecological approach provides a necessary complement to conventional local studies that focus on individual plots or forest ownerships. However, most previous landscape studies used equally-sized cells as units of analysis to identify the factors affecting forest biodiversity distribution. Stratification of the analysis by habitats with a relatively homogeneous forest composition might be more adequate to capture the underlying patterns associated to the formation and development of a particular ensemble of interacting forest species. Here we used a landscape perspective in order to improve our understanding on the influence of large-scale explanatory factors on forest biodiversity indicators in Spanish habitats, covering a wide latitudinal and attitudinal range. We considered six forest biodiversity indicators estimated from more than 30,000 field plots in the Spanish national forest inventory, distributed in 213 forest habitats over 16 Spanish provinces. We explored biodiversity response to various environmental (climate and topography) and landscape configuration (fragmentation and shape complexity) variables through multiple linear regression models (built and assessed through the Akaike Information Criterion). In particular, we took into account the inherent model uncertainty when dealing with a complex and large set of variables, and considered different plausible models and their probability of being the best candidate for the observed data. Our results showed that compositional indicators (species richness and diversity) were mostly explained by environmental factors. Models for structural indicators (standing deadwood and stand complexity) had the worst fits and selection uncertainties, but did show significant associations with some configuration metrics. In general

  7. Response function theories that account for size distribution effects - A review. [mathematical models concerning composite propellant heterogeneity effects on combustion instability

    Science.gov (United States)

    Cohen, N. S.

    1980-01-01

    The paper presents theoretical models developed to account for the heterogeneity of composite propellants in expressing the pressure-coupled combustion response function. It is noted that the model of Lengelle and Williams (1968) furnishes a viable basis to explain the effects of heterogeneity.

  8. Molecular weight​/branching distribution modeling of low-​density-​polyethylene accounting for topological scission and combination termination in continuous stirred tank reactor

    NARCIS (Netherlands)

    Yaghini, N.; Iedema, P.D.

    2014-01-01

    We present a comprehensive model to predict the molecular weight distribution (MWD),(1) and branching distribution of low-density polyethylene (IdPE),(2) for free radical polymerization system in a continuous stirred tank reactor (CSTR).(3) The model accounts for branching, by branching moment or ps

  9. Rare Earth Market Review

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Oversupply of rare earths led to the significant price drop of rare earth mineral products and separated products in Chinese domestic market. To stabilize the price, prevent waste of resources, further improve regulation capability on domestic rare earth market and rare earth price and maintain sustaining and healthy development of rare earth industry, partial rare earth producers in Baotou and Jiangxi province projected to cease the production for one month.

  10. Accounting for the Uncertainty Related to Building Occupants with Regards to Visual Comfort: A Literature Survey on Drivers and Models

    Directory of Open Access Journals (Sweden)

    Valentina Fabi

    2016-02-01

    Full Text Available The interactions between building occupants and control systems have a high influence on energy consumption and on indoor environmental quality. In the perspective of a future of “nearly-zero” energy buildings, it is crucial to analyse the energy-related interactions deeply to predict realistic energy use during the design stage. Since the reaction to thermal, acoustic, or visual stimuli is not the same for every human being, monitoring the behaviour inside buildings is an essential step to assert differences in energy consumption related to different interactions. Reliable information concerning occupants’ behaviours in a building could contribute to a better evaluation of building energy performances and design robustness, as well as supporting the development of occupants’ education to energy awareness. The present literature survey enlarges our understanding of which environmental conditions influence occupants’ manual controlling of the system in offices and by consequence the energy consumption. The purpose of this study was to investigate the possible drivers for light-switching to model occupant behaviour in office buildings. The probability of switching lighting systems on or off was related to the occupancy and differentiated for arrival, intermediate, and departure periods. The switching probability has been reported to be higher during the entering or the leaving time in relation to contextual variables. In the analysis of switch-on actions, users were often clustered between those who take daylight level into account and switch on lights only if necessary and people who totally disregard the natural lighting. This underlines the importance of how individuality is at the base of the definition of the different types of users.

  11. 生态环境经济核算模型及其研究%Study on the Accounting Model of Ecological Environment

    Institute of Scientific and Technical Information of China (English)

    刘颖

    2005-01-01

    This paper explains environmental problems from the point of R to the "System of Integrated Environmental and Economical Accounting" (SEEA) promulgated by United Nations in 1993, the authors have set up a model of environmental and economic accounting after the discussion and m tion of the concepts ction, assets, and environmental costs. Taking ecological environment of Chongqing as an the en tal and economic analyses is done. The results of the model reflect sustainability of ecological environment and mental costs directly or indirectly in macro-economy.

  12. Physically-based modifications to the Sacramento Soil Moisture Accounting model. Part A: Modeling the effects of frozen ground on the runoff generation process

    Science.gov (United States)

    Koren, Victor; Smith, Michael; Cui, Zhengtao

    2014-11-01

    This paper presents the first of two physically-based modifications to a widely-used and well-validated hydrologic precipitation-runoff model. Here, we modify the Sacramento Soil Moisture Accounting (SAC-SMA) model to include a physically-based representation of the effects of freezing and thawing soil on the runoff generation process. This model is called the SAC-SMA Heat Transfer model (SAC-HT). The frozen ground physics are taken from the Noah land surface model which serves as the land surface component of several National Center for Environmental Prediction (NCEP) numerical weather prediction models. SAC-HT requires a boundary condition of the soil temperature at the bottom of the soil column (a climatic annual air temperature is typically used, and parameters derived from readily available soil texture data). A noteworthy feature of SAC-HT is that the frozen ground component needs no parameter calibration. SAC-HT was tested at 11 sites in the U.S. for soil temperature, one site in Russia for soil temperature and soil moisture, eight basins in the upper Midwest for the effects of frozen-ground on streamflow, and one location for frost depth. High correlation coefficients for simulated soil temperature at three depths at 11 stations were achieved. Multi-year simulations of soil moisture and soil temperature agreed very well at the Valdai, Russia test location. In eight basins affected by seasonally frozen soil in the upper Midwest, SAC-HT provided improved streamflow simulations compared to SAC-SMA when both models used a priori parameters. Further improvement was gained through calibration of the non-frozen ground a priori parameters. Frost depth computed by SAC-HT compared well with observed values in the Root River basin in Minnesota.

  13. Whole of Government Accounts

    DEFF Research Database (Denmark)

    Pontoppidan, Caroline Aggestam; Chow, Danny; Day, Ronald

    In our comparative study, we surveyed an emerging literature on the use of consolidation in government accounting and develop a research agenda. We find heterogeneous approaches to the development of consolidation models across the five countries (Australia, New Zealand, UK, Canada and Sweden...... of financial reporting (GAAP)-based reforms when compared with budget-centric systems of accounting, which dominate government decision-making. At a trans-national level, there is a need to examine the embedded or implicit contests or ‘trials of strength’ between nations and/or institutions jockeying...... for influence. We highlight three arenas where such contests are being played out: 1. Statistical versus GAAP notions of accounting value, which features in all accounting debates over the merits and costs of ex-ante versus ex-post notions of value (i.e., the relevance versus reliability debate); 2. Private...

  14. Rarely clicking Muller's ratchets

    Science.gov (United States)

    Eule, Stephan; Metzger, Jakob

    2013-03-01

    In populations of finite size, weakly deleterious mutations can fix by chance. This phenomenon has been termed Muller's ratchet and one click of the ratchet refers to the loss of the fittest class of individuals with the fewest mutations. Despite the simplicity of the classical mathematical model of Muller's ratchet, surprisingly little is known in the biologically relevant regime where a click of the ratchet is a rare event. Here we show numerically that in this regime the rate of the ratchet strongly depends on the applied microscopic formulation (Wiright-Fisher/Moran) of the model, thus challenging the widely used diffusion approximation. Furthermore by employing a WKB-approximation in a simplified model, we obtain analytical results for the click rate, which agree well with the click rate of the full ratchet of the corresponding microscopical model.

  15. Extending the simple linear regression model to account for correlated responses: an introduction to generalized estimating equations and multi-level mixed modelling.

    Science.gov (United States)

    Burton, P; Gurrin, L; Sly, P

    1998-06-15

    Much of the research in epidemiology and clinical science is based upon longitudinal designs which involve repeated measurements of a variable of interest in each of a series of individuals. Such designs can be very powerful, both statistically and scientifically, because they enable one to study changes within individual subjects over time or under varied conditions. However, this power arises because the repeated measurements tend to be correlated with one another, and this must be taken into proper account at the time of analysis or misleading conclusions may result. Recent advances in statistical theory and in software development mean that studies based upon such designs can now be analysed more easily, in a valid yet flexible manner, using a variety of approaches which include the use of generalized estimating equations, and mixed models which incorporate random effects. This paper provides a particularly simple illustration of the use of these two approaches, taking as a practical example the analysis of a study which examined the response of portable peak expiratory flow meters to changes in true peak expiratory flow in 12 children with asthma. The paper takes the reader through the relevant practicalities of model fitting, interpretation and criticism and demonstrates that, in a simple case such as this, analyses based upon these model-based approaches produce reassuringly similar inferences to standard analyses based upon more conventional methods.

  16. Rare Earth Resolution

    Institute of Scientific and Technical Information of China (English)

    Mei Xinyu

    2012-01-01

    BEFORE the early 1970s, China had no rare earth exports, and the world rare earth market was dominated by the United States, Europe and Japan. In the 1970s, China began to enter the world rare earth market and its share has picked up sharply in the following decades. Today, having the monopoly over global rare earth production, China must improve the benefits from rare earth production, not only from producing individual rare earth products, but also from mastering the intensive processing of rare earth products.

  17. Rare Gas Halide (RGH) Kinetics.

    Science.gov (United States)

    1988-02-01

    high-energy electron distributions have been made by Elliot and Green8 , and Bretagne , et al., but these calculations were limited to pure rare gases of...model development begins by using the same basic calculation ’ ’ procedure as presented by Bretagne , et al. 9 The distribution of electron energy is...and Bretagne , et al. have proposed empirical formulas for M-shell ionization of argon gas. For other rare gases, the formulas given by Green " and

  18. In vitro generated Rh(null) red cells recapitulate the in vivo deficiency: a model for rare blood group phenotypes and erythroid membrane disorders.

    Science.gov (United States)

    Cambot, Marie; Mazurier, Christelle; Canoui-Poitrine, Florence; Hebert, Nicolas; Picot, Julien; Clay, Denis; Picard, Véronique; Ripoche, Pierre; Douay, Luc; Dubart-Kupperschmitt, Anne; Cartron, Jean-Pierre

    2013-05-01

    Lentiviral modification combined with ex vivo erythroid differentiation was used to stably inhibit RhAG expression, a critical component of the Rh(rhesus) membrane complex defective in the Rh(null) syndrome. The cultured red cells generated recapitulate the major alterations of native Rh(null) cells regarding antigen expression, membrane deformability, and gas transport function, providing the proof of principle for their use as model of Rh(null) syndrome and to investigate Rh complex biogenesis in human primary erythroid cells. Using this model, we were able to reveal for the first time that RhAG extinction alone is sufficient to explain ICAM-4 and CD47 loss observed on native Rh(null) RBCs. Together with the effects of RhAG forced expression in Rh(null) progenitors, this strongly strengthens the hypothesis that RhAG is critical to Rh complex formation. The strategy is also promising for diagnosis purpose in order to overcome the supply from rare blood donors and is applicable to other erythroid defects and rare phenotypes, providing models to dissect membrane biogenesis of multicomplex proteins in erythroid cells, with potential clinical applications in transfusion medicine.

  19. Drift model of a glow discharge with account for the nonlocal value of the electric field strength in the ionization source

    Science.gov (United States)

    Saifutdinov, A. I.; Timerkaev, B. A.

    2012-09-01

    A drift model of a glow discharge is proposed, which takes account of the nonlocal dependence of the ionization source on the electric field strength. The problem is reduced to solving a nonlinear differential equation of second order for the strength squared using the Newton-Kantorovich quasilinearization method.

  20. Can the Five Factor Model of Personality Account for the Variability of Autism Symptom Expression? Multivariate Approaches to Behavioral Phenotyping in Adult Autism Spectrum Disorder

    Science.gov (United States)

    Schwartzman, Benjamin C.; Wood, Jeffrey J.; Kapp, Steven K.

    2016-01-01

    The present study aimed to: determine the extent to which the five factor model of personality (FFM) accounts for variability in autism spectrum disorder (ASD) symptomatology in adults, examine differences in average FFM personality traits of adults with and without ASD and identify distinct behavioral phenotypes within ASD. Adults (N = 828;…