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Sample records for relap5-3d multidimensional model

  1. RELAP5-3D multidimensional heat conduction enclosure model for RBMK reactor application

    Energy Technology Data Exchange (ETDEWEB)

    Paik, S.

    1999-10-01

    A heat conduction enclosure model is conceived and implemented by RELAP5-3D between heat structures. The suggested model uses a lumped parameter model that is generally applicable to multidimensional calculational domain. This new model is applied to calculation of RBMK reactor core graphite blocks and is compared to the commercially available Fluid Dynamics Analysis Package (FIDAP) finite element code. Reasonably good agreement between the results of RELAP5-3D and FIDAP is obtained. The new heat conduction enclosure model gives RELAP5-3D a general multidimensional heat conduction capability. It also provides new routes for temperature cooloff of the RBMK graphite blocks from the ruptured channel to the surrounding ones. This ability to predict graphite temperature cooloff is very important during accidents or for transient simulation, especially concerning long-term coolability of the RBMK reactor core.

  2. RELAP5-3D Compressor Model

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    James E. Fisher; Cliff B. Davis; Walter L. Weaver

    2005-06-01

    A compressor model has been implemented in the RELAP5-3D© code. The model is similar to that of the existing pump model, and performs the same function on a gas as the pump performs on a single-phase or two-phase fluid. The compressor component consists of an inlet junction and a control volume, and optionally, an outlet junction. This feature permits cascading compressor components in series. The equations describing the physics of the compressor are derived from first principles. These equations are used to obtain the head, the torque, and the energy dissipation. Compressor performance is specified using a map, specific to the design of the machine, in terms of the ratio of outlet-to-inlet total (or stagnation) pressure and adiabatic efficiency as functions of rotational velocity and flow rate. The input quantities are specified in terms of dimensionless variables, which are corrected to stagnation density and stagnation sound speed. A small correction was formulated for the input of efficiency to account for the error introduced by assumption of constant density when integrating the momentum equation. Comparison of the results of steady-state operation of the compressor model to those of the MIT design calculation showed excellent agreement for both pressure ratio and power.

  3. RELAP5-3D Code Includes Athena Features and Models

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    Richard A. Riemke; Cliff B. Davis; Richard R. Schultz

    2006-07-01

    Version 2.3 of the RELAP5-3D computer program includes all features and models previously available only in the ATHENA version of the code. These include the addition of new working fluids (i.e., ammonia, blood, carbon dioxide, glycerol, helium, hydrogen, lead-bismuth, lithium, lithium-lead, nitrogen, potassium, sodium, and sodium-potassium) and a magnetohydrodynamic model that expands the capability of the code to model many more thermal-hydraulic systems. In addition to the new working fluids along with the standard working fluid water, one or more noncondensable gases (e.g., air, argon, carbon dioxide, carbon monoxide, helium, hydrogen, krypton, nitrogen, oxygen, sf6, xenon) can be specified as part of the vapor/gas phase of the working fluid. These noncondensable gases were in previous versions of RELAP5- 3D. Recently four molten salts have been added as working fluids to RELAP5-3D Version 2.4, which has had limited release. These molten salts will be in RELAP5-3D Version 2.5, which will have a general release like RELAP5-3D Version 2.3. Applications that use these new features and models are discussed in this paper.

  4. High Temperature Test Facility Preliminary RELAP5-3D Input Model Description

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    Bayless, Paul David [Idaho National Laboratory

    2015-12-01

    A RELAP5-3D input model is being developed for the High Temperature Test Facility at Oregon State University. The current model is described in detail. Further refinements will be made to the model as final as-built drawings are released and when system characterization data are available for benchmarking the input model.

  5. Modeling and thermal investigations of the HTTR using the RELAP5-3D

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    Scari, Maria E.; Nunes, Joao V. V.; Costa, Antonella L.; Pereira, Claubia; Mantecon, Javier G.; Veloso, Maria A. F., E-mail: melizabethscari@yahoo.com, E-mail: joaovitorn2@hotmail.com, E-mail: antonella@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: mantecon1987@gmail.com, E-mail: dora@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear

    2015-07-01

    A thermal model for the HTTR (High Temperature Engineering Test Reactor) has been developed using the RELAP5-3D code. The HTTR is a high temperature gas-cooled reactor (HTGR) developed, designed, constructed, and operated by the Japan Atomic Energy Research Institute (JAERI). It is a helium-cooled and graphite-moderated with a thermal power of 30 MW. In this work, a HTTR core inlet and outlet coolant temperatures, heat structures temperature and pressure drop have been reproduced using a RELAP5 model. The results have been compared with the available data. The calculations were performed using the point kinetic model. It is demonstrated that the developed model in the RELAP5-3D is capable of reproduce the thermal behavior of the reactor in steady state operation; however, more investigations are necessary to approach some parameters to those from the references. The next step is to complete the plant modeling and simulate transient conditions. (author)

  6. Modification of blowdown heat transfer models for RELAP5-3D in accordance with appendix K of 10CFR50

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    Chin-Jang, Chang; Liang, T.K.S. [Nuclear Engineering Div. Institute of Nuclear Energy Research, Lung-Tan, Taiwan (China); Huan-Jen, Hung; Wang, L.C. [Power Research Institute, Taiwan Power Company (China)

    2001-07-01

    The objective of this paper is to implement the blowdown heat transfer models accepted by Appendix K of 10CFR50 into RELAP5-3D and to rename it as RELAP5-3D/K. Modifications of critical heat flux (CHF) model, post-CHF model, and the heat transfer logic for nucleate and transition boiling lockout are included. Also the assessments against separate-effect experiments were evaluated for RELAP 5-3D/K. From calculation results, the conservative predictions of surface peak temperatures using RELAP5-3D/K are obtained. It demonstrated that the blowdown heat transfer models were successfully modified and implemented into RELAP5-3D in accordance with Appendix K of 10CFR50. (authors)

  7. Simulation of a channel blockage transient in the Angra 2 Nuclear Reactor using a RELAP5-3D model

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Mantecon, Javier; Costa, Antonella L.; Veloso, Maria Auxiliadora F.; Pereira, Claubia; Reis, Patricia A.L.; Scari, Maria E., E-mail: mantecon1987@gmail.com, E-mail: antonella@nuclear.ufmg.br, E-mail: dora@nuclear.ufmg.br, E-mail: claubia@nuclear.ufmg.br, E-mail: patricialire@yahoo.com.br, E-mail: melizabethscari@yahoo.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear

    2015-07-01

    The Angra 2 Nuclear Power Plant (NPP) is a Pressurized Water Reactor (PWR) type with electrical output of about 1350 MW. The RELAP5-3D code was used to develop a detailed thermal hydraulic model of such reactor using reference data from the Angra 2 Final Safety Analysis Report (FSAR). In this work, a blockage transient has been investigated at full power operation. The transient herein considered is related to total obstruction of a core cooling channel of one fuel assembly. The calculations were performed using a point kinetic model. The reactor behavior after this transient was analyzed and the time evolution of cladding and coolant temperatures mass flow and void fraction are presented. (author)

  8. Modeling a Helical-coil Steam Generator in RELAP5-3D for the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    Nathan V. Hoffer; Piyush Sabharwall; Nolan A. Anderson

    2011-01-01

    Options for the primary heat transport loop heat exchangers for the Next Generation Nuclear Plant are currently being evaluated. A helical-coil steam generator is one heat exchanger design under consideration. Safety is an integral part of the helical-coil steam generator evaluation. Transient analysis plays a key role in evaluation of the steam generators safety. Using RELAP5-3D to model the helical-coil steam generator, a loss of pressure in the primary side of the steam generator is simulated. This report details the development of the steam generator model, the loss of pressure transient, and the response of the steam generator primary and secondary systems to the loss of primary pressure. Back ground on High Temperature Gas-cooled reactors, steam generators, the Next Generation Nuclear Plant is provided to increase the readers understanding of the material presented.

  9. Benchmark of Atucha-2 PHWR RELAP5-3D control rod model by Monte Carlo MCNP5 core calculation

    Energy Technology Data Exchange (ETDEWEB)

    Pecchia, M.; D' Auria, F. [San Piero A Grado Nuclear Research Group GRNSPG, Univ. of Pisa, via Diotisalvi, 2, 56122 - Pisa (Italy); Mazzantini, O. [Nucleo-electrica Argentina Societad Anonima NA-SA, Buenos Aires (Argentina)

    2012-07-01

    Atucha-2 is a Siemens-designed PHWR reactor under construction in the Republic of Argentina. Its geometrical complexity and peculiarities require the adoption of advanced Monte Carlo codes for performing realistic neutronic simulations. Therefore core models of Atucha-2 PHWR were developed using MCNP5. In this work a methodology was set up to collect the flux in the hexagonal mesh by which the Atucha-2 core is represented. The scope of this activity is to evaluate the effect of obliquely inserted control rod on neutron flux in order to validate the RELAP5-3D{sup C}/NESTLE three dimensional neutron kinetic coupled thermal-hydraulic model, applied by GRNSPG/UNIPI for performing selected transients of Chapter 15 FSAR of Atucha-2. (authors)

  10. Modeling and Analysis of a Lunar Space Reactor with the Computer Code RELAP5-3D/ATHENA

    Energy Technology Data Exchange (ETDEWEB)

    Carbajo, Juan J [ORNL; Qualls, A L [ORNL

    2008-01-01

    The transient analysis 3-dimensional (3-D) computer code RELAP5-3D/ATHENA has been employed to model and analyze a space reactor of 180 kW(thermal), 40 kW (net, electrical) with eight Stirling engines (SEs). Each SE will generate over 6 kWe; the excess power will be needed for the pumps and other power management devices. The reactor will be cooled by NaK (a eutectic mixture of sodium and potassium which is liquid at ambient temperature). This space reactor is intended to be deployed over the surface of the Moon or Mars. The reactor operating life will be 8 to 10 years. The RELAP5-3D/ATHENA code is being developed and maintained by Idaho National Laboratory. The code can employ a variety of coolants in addition to water, the original coolant employed with early versions of the code. The code can also use 3-D volumes and 3-D junctions, thus allowing for more realistic representation of complex geometries. A combination of 3-D and 1-D volumes is employed in this study. The space reactor model consists of a primary loop and two secondary loops connected by two heat exchangers (HXs). Each secondary loop provides heat to four SEs. The primary loop includes the nuclear reactor with the lower and upper plena, the core with 85 fuel pins, and two vertical heat exchangers (HX). The maximum coolant temperature of the primary loop is 900 K. The secondary loops also employ NaK as a coolant at a maximum temperature of 877 K. The SEs heads are at a temperature of 800 K and the cold sinks are at a temperature of ~400 K. Two radiators will be employed to remove heat from the SEs. The SE HXs surrounding the SE heads are of annular design and have been modeled using 3-D volumes. These 3-D models have been used to improve the HX design by optimizing the flows of coolant and maximizing the heat transferred to the SE heads. The transients analyzed include failure of one or more Stirling engines, trip of the reactor pump, and trips of the secondary loop pumps feeding the HXs of the

  11. Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-01

    The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.

  12. Comparison of the PHISICS/RELAP5-3D Ring and Block Model Results for Phase I of the OECD MHTGR-350 Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard Strydom

    2014-04-01

    The INL PHISICS code system consists of three modules providing improved core simulation capability: INSTANT (performing 3D nodal transport core calculations), MRTAU (depletion and decay heat generation) and a perturbation/mixer module. Coupling of the PHISICS code suite to the thermal hydraulics system code RELAP5-3D has recently been finalized, and as part of the code verification and validation program the exercises defined for Phase I of the OECD/NEA MHTGR 350 MW Benchmark were completed. This paper provides an overview of the MHTGR Benchmark, and presents selected results of the three steady state exercises 1-3 defined for Phase I. For Exercise 1, a stand-alone steady-state neutronics solution for an End of Equilibrium Cycle Modular High Temperature Reactor (MHTGR) was calculated with INSTANT, using the provided geometry, material descriptions, and detailed cross-section libraries. Exercise 2 required the modeling of a stand-alone thermal fluids solution. The RELAP5-3D results of four sub-cases are discussed, consisting of various combinations of coolant bypass flows and material thermophysical properties. Exercise 3 combined the first two exercises in a coupled neutronics and thermal fluids solution, and the coupled code suite PHISICS/RELAP5-3D was used to calculate the results of two sub-cases. The main focus of the paper is a comparison of the traditional RELAP5-3D “ring” model approach vs. a much more detailed model that include kinetics feedback on individual block level and thermal feedbacks on a triangular sub-mesh. The higher fidelity of the block model is illustrated with comparison results on the temperature, power density and flux distributions, and the typical under-predictions produced by the ring model approach are highlighted.

  13. Architectural Advancements in RELAP5-3D

    Energy Technology Data Exchange (ETDEWEB)

    Dr. George L. Mesina

    2005-11-01

    As both the computer industry and field of nuclear science and engineering move forward, there is a need to improve the computing tools used in the nuclear industry to keep pace with these changes. By increasing the capability of the codes, the growing modeling needs of nuclear plant analysis will be met and advantage can be taken of more powerful computer languages and architecture. In the past eighteen months, improvements have been made to RELAP5-3D [1] for these reasons. These architectural advances include code restructuring, conversion to Fortran 90, high performance computing upgrades, and rewriting of the RELAP5 Graphical User Interface (RGUI) [2] and XMGR5 [3] in Java. These architectural changes will extend the lifetime of RELAP5-3D, reduce the costs for development and maintenance, and improve it speed and reliability.

  14. Streamlining of the RELAP5-3D Code

    Energy Technology Data Exchange (ETDEWEB)

    Mesina, George L; Hykes, Joshua; Guillen, Donna Post

    2007-11-01

    RELAP5-3D is widely used by the nuclear community to simulate general thermal hydraulic systems and has proven to be so versatile that the spectrum of transient two-phase problems that can be analyzed has increased substantially over time. To accommodate the many new types of problems that are analyzed by RELAP5-3D, both the physics and numerical methods of the code have been continuously improved. In the area of computational methods and mathematical techniques, many upgrades and improvements have been made decrease code run time and increase solution accuracy. These include vectorization, parallelization, use of improved equation solvers for thermal hydraulics and neutron kinetics, and incorporation of improved library utilities. In the area of applied nuclear engineering, expanded capabilities include boron and level tracking models, radiation/conduction enclosure model, feedwater heater and compressor components, fluids and corresponding correlations for modeling Generation IV reactor designs, and coupling to computational fluid dynamics solvers. Ongoing and proposed future developments include improvements to the two-phase pump model, conversion to FORTRAN 90, and coupling to more computer programs. This paper summarizes the general improvements made to RELAP5-3D, with an emphasis on streamlining the code infrastructure for improved maintenance and development. With all these past, present and planned developments, it is necessary to modify the code infrastructure to incorporate modifications in a consistent and maintainable manner. Modifying a complex code such as RELAP5-3D to incorporate new models, upgrade numerics, and optimize existing code becomes more difficult as the code grows larger. The difficulty of this as well as the chance of introducing errors is significantly reduced when the code is structured. To streamline the code into a structured program, a commercial restructuring tool, FOR_STRUCT, was applied to the RELAP5-3D source files. The

  15. Uncertainty Analysis of RELAP5-3D

    Energy Technology Data Exchange (ETDEWEB)

    Alexandra E Gertman; Dr. George L Mesina

    2012-07-01

    As world-wide energy consumption continues to increase, so does the demand for the use of alternative energy sources, such as Nuclear Energy. Nuclear Power Plants currently supply over 370 gigawatts of electricity, and more than 60 new nuclear reactors have been commissioned by 15 different countries. The primary concern for Nuclear Power Plant operation and lisencing has been safety. The safety of the operation of Nuclear Power Plants is no simple matter- it involves the training of operators, design of the reactor, as well as equipment and design upgrades throughout the lifetime of the reactor, etc. To safely design, operate, and understand nuclear power plants, industry and government alike have relied upon the use of best-estimate simulation codes, which allow for an accurate model of any given plant to be created with well-defined margins of safety. The most widely used of these best-estimate simulation codes in the Nuclear Power industry is RELAP5-3D. Our project focused on improving the modeling capabilities of RELAP5-3D by developing uncertainty estimates for its calculations. This work involved analyzing high, medium, and low ranked phenomena from an INL PIRT on a small break Loss-Of-Coolant Accident as wall as an analysis of a large break Loss-Of- Coolant Accident. Statistical analyses were performed using correlation coefficients. To perform the studies, computer programs were written that modify a template RELAP5 input deck to produce one deck for each combination of key input parameters. Python scripting enabled the running of the generated input files with RELAP5-3D on INL’s massively parallel cluster system. Data from the studies was collected and analyzed with SAS. A summary of the results of our studies are presented.

  16. AUTOMATED, HIGHLY ACCURATE VERIFICATION OF RELAP5-3D

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    George L Mesina; David Aumiller; Francis Buschman

    2014-07-01

    Computer programs that analyze light water reactor safety solve complex systems of governing, closure and special process equations to model the underlying physics. In addition, these programs incorporate many other features and are quite large. RELAP5-3D[1] has over 300,000 lines of coding for physics, input, output, data management, user-interaction, and post-processing. For software quality assurance, the code must be verified and validated before being released to users. Verification ensures that a program is built right by checking that it meets its design specifications. Recently, there has been an increased importance on the development of automated verification processes that compare coding against its documented algorithms and equations and compares its calculations against analytical solutions and the method of manufactured solutions[2]. For the first time, the ability exists to ensure that the data transfer operations associated with timestep advancement/repeating and writing/reading a solution to a file have no unintended consequences. To ensure that the code performs as intended over its extensive list of applications, an automated and highly accurate verification method has been modified and applied to RELAP5-3D. Furthermore, mathematical analysis of the adequacy of the checks used in the comparisons is provided.

  17. Recent Hydrodynamics Improvements to the RELAP5-3D Code

    Energy Technology Data Exchange (ETDEWEB)

    Richard A. Riemke; Cliff B. Davis; Richard.R. Schultz

    2009-07-01

    The hydrodynamics section of the RELAP5-3D computer program has been recently improved. Changes were made as follows: (1) improved turbine model, (2) spray model for the pressurizer model, (3) feedwater heater model, (4) radiological transport model, (5) improved pump model, and (6) compressor model.

  18. RELAP5-3D Developer Guidelines and Programming Practices

    Energy Technology Data Exchange (ETDEWEB)

    Dr. George L Mesina

    2014-03-01

    Our ultimate goal is to create and maintain RELAP5-3D as the best software tool available to analyze nuclear power plants. This begins with writing excellent programming and requires thorough testing. This document covers development of RELAP5-3D software, the behavior of the RELAP5-3D program that must be maintained, and code testing. RELAP5-3D must perform in a manner consistent with previous code versions with backward compatibility for the sake of the users. Thus file operations, code termination, input and output must remain consistent in form and content while adding appropriate new files, input and output as new features are developed. As computer hardware, operating systems, and other software change, RELAP5-3D must adapt and maintain performance. The code must be thoroughly tested to ensure that it continues to perform robustly on the supported platforms. The coding must be written in a consistent manner that makes the program easy to read to reduce the time and cost of development, maintenance and error resolution. The programming guidelines presented her are intended to institutionalize a consistent way of writing FORTRAN code for the RELAP5-3D computer program that will minimize errors and rework. A common format and organization of program units creates a unifying look and feel to the code. This in turn increases readability and reduces time required for maintenance, development and debugging. It also aids new programmers in reading and understanding the program. Therefore, when undertaking development of the RELAP5-3D computer program, the programmer must write computer code that follows these guidelines. This set of programming guidelines creates a framework of good programming practices, such as initialization, structured programming, and vector-friendly coding. It sets out formatting rules for lines of code, such as indentation, capitalization, spacing, etc. It creates limits on program units, such as subprograms, functions, and modules. It

  19. RELAP5-3D Restart and Backup Verification Testing

    Energy Technology Data Exchange (ETDEWEB)

    Dr. George L Mesina

    2013-09-01

    Existing testing methodology for RELAP5-3D employs a set of test cases collected over two decades to test a variety of code features and run on a Linux or Windows platform. However, this set has numerous deficiencies in terms of code coverage, detail of comparison, running time, and testing fidelity of RELAP5-3D restart and backup capabilities. The test suite covers less than three quarters of the lines of code in the relap directory and just over half those in the environmental library. Even in terms of code features, many are not covered. Moreover, the test set runs many problems long past the point necessary to test the relevant features. It requires standard problems to run to completion. This is unnecessary for features can be tested in a short-running problem. For example, many trips and controls can be tested in the first few time steps, as can a number of fluid flow options. The testing system is also inaccurate. For the past decade, the diffem script has been the primary tool for checking that printouts from two different RELAP5-3D executables agree. This tool compares two output files to verify that all characters are the same except for those relating to date, time and a few other excluded items. The variable values printed on the output file are accurate to no more than eight decimal places. Therefore, calculations with errors in decimal places beyond those printed remain undetected. Finally, fidelity of restart is not tested except in the PVM sub-suite and backup is not specifically tested at all. When a restart is made from any midway point of the base-case transient, the restart must produce the same values. When a backup condition occurs, the code repeats advancements with the same time step. A perfect backup can be tested by forcing RELAP5 to perform a backup by falsely setting a backup condition flag at a user-specified-time. Comparison of the calculations of that run and those produced by the same input w/o the spurious condition should be

  20. A generic semi-implicit coupling methodology for use in RELAP5-3D{copyright}

    Energy Technology Data Exchange (ETDEWEB)

    Aumiller, D.L.; Tomlinson, E.T.; Weaver, W.L.

    2000-09-01

    A generic semi-implicit coupling methodology has been developed and implemented in the RELAP5-3D{copyright} computer program. This methodology allows RELAP5-3D{copyright} to be used with other computer programs to perform integrated analyses of nuclear power reactor systems and related experimental facilities. The coupling methodology potentially allows different programs to be used to model different portions of the system. The programs are chosen based on their capability to model the phenomena that are important in the simulation in the various portions of the system being considered. The methodology was demonstrated using a test case in which the test geometry was divided into two parts each of which was solved as a RELAP5-3D{copyright} simulation. This test problem exercised all of the semi-implicit coupling features which were installed in RELAP5-3D0. The results of this verification test case show that the semi-implicit coupling methodology produces the same answer as the simulation of the test system as a single process.

  1. RELAP5-3D Resolution of Known Restart/Backup Issues

    Energy Technology Data Exchange (ETDEWEB)

    Mesina, George L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Anderson, Nolan A. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-12-01

    The state-of-the-art nuclear reactor system safety analysis computer program developed at the Idaho National Laboratory (INL), RELAP5-3D, continues to adapt to changes in computer hardware and software and to develop to meet the ever-expanding needs of the nuclear industry. To continue at the forefront, code testing must evolve with both code and industry developments, and it must work correctly. To best ensure this, the processes of Software Verification and Validation (V&V) are applied. Verification compares coding against its documented algorithms and equations and compares its calculations against analytical solutions and the method of manufactured solutions. A form of this, sequential verification, checks code specifications against coding only when originally written then applies regression testing which compares code calculations between consecutive updates or versions on a set of test cases to check that the performance does not change. A sequential verification testing system was specially constructed for RELAP5-3D to both detect errors with extreme accuracy and cover all nuclear-plant-relevant code features. Detection is provided through a “verification file” that records double precision sums of key variables. Coverage is provided by a test suite of input decks that exercise code features and capabilities necessary to model a nuclear power plant. A matrix of test features and short-running cases that exercise them is presented. This testing system is used to test base cases (called null testing) as well as restart and backup cases. It can test RELAP5-3D performance in both standalone and coupled (through PVM to other codes) runs. Application of verification testing revealed numerous restart and backup issues in both standalone and couple modes. This document reports the resolution of these issues.

  2. RELAP5-3D version 4.0.3: installation and tests for applications to space reactors

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, Paulo D.C.; Braz Filho, Francisco A.; Borges, Eduardo M.; Guimaraes, Lamartine N.F., E-mail: plobo.a@uol.com.br, E-mail: fbraz@ieav.cta.br, E-mail: eduardo@ieav.cta.br, E-mail: guimarae@ieav.cta.br [Instituto de Estudos Avancados (IEAv), Sao Jose dos Campos, SP (Brazil); Sabundjian, Gaiane, E-mail: gdjian@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    To attend the TERRA project (Tecnologia de Reatores Rapidos Avancados), currently conducted by the Nuclear Energy Division (ENU) of the IEAv, this work presents the RELAP5-3D, Version 4.0.3, prepared in July 12, 2012, also known as r3d403is, received recently by the IEAv from the Idaho National Laboratory (INL). This version of RELAP5-3D is configured for the International User Group source Code Group and is developed and maintained at the INL for the US Department of Energy. RELAP5-3D, the latest in the series of RELAP5 codes, is a highly generic code that, in addition to calculating the behavior of a reactor coolant system during a transient, can be used for simulation of a wide variety of hydraulic and thermal transients in both nuclear and nonnuclear systems involving mixtures of vapor, liquid, noncondensable gases, and nonvolatile solute. Enhancements include all features and models previously available in the ATHENA configuration version of the code which are as follows: addition of new work fluids and a magneto-hydrodynamic mode. Following the instructions from the README file, the RELAP5-3D, version 4.0.3 was installed creating the necessaries subdirectories, by using the LINUX platform and applying both Intel Fortran 95 and C-language compilers. Many input examples were executed and the same results were observed as compared to the received documentation. A sample of the Edwards-O'Brien test was evaluated to verify if the code could simulate a LOCA type accident properly. The test executed by the RELAP5-3D demonstrated good agreement with test data including a new output involving the mass flow during the test. (author)

  3. PHISICS/RELAP5-3D Adaptive Time-Step Method Demonstrated for the HTTR LOFC#1 Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Robin Ivey [Idaho National Lab. (INL), Idaho Falls, ID (United States); Balestra, Paolo [Univ. of Rome (Italy); Strydom, Gerhard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2017-05-01

    A collaborative effort between Japan Atomic Energy Agency (JAEA) and Idaho National Laboratory (INL) as part of the Civil Nuclear Energy Working Group is underway to model the high temperature engineering test reactor (HTTR) loss of forced cooling (LOFC) transient that was performed in December 2010. The coupled version of RELAP5-3D, a thermal fluids code, and PHISICS, a neutronics code, were used to model the transient. The focus of this report is to summarize the changes made to the PHISICS-RELAP5-3D code for implementing an adaptive time step methodology into the code for the first time, and to test it using the full HTTR PHISICS/RELAP5-3D model developed by JAEA and INL and the LOFC simulation. Various adaptive schemes are available based on flux or power convergence criteria that allow significantly larger time steps to be taken by the neutronics module. The report includes a description of the HTTR and the associated PHISICS/RELAP5-3D model test results as well as the University of Rome sub-contractor report documenting the adaptive time step theory and methodology implemented in PHISICS/RELAP5-3D. Two versions of the HTTR model were tested using 8 and 26 energy groups. It was found that most of the new adaptive methods lead to significant improvements in the LOFC simulation time required without significant accuracy penalties in the prediction of the fission power and the fuel temperature. In the best performing 8 group model scenarios, a LOFC simulation of 20 hours could be completed in real-time, or even less than real-time, compared with the previous version of the code that completed the same transient 3-8 times slower than real-time. A few of the user choice combinations between the methodologies available and the tolerance settings did however result in unacceptably high errors or insignificant gains in simulation time. The study is concluded with recommendations on which methods to use for this HTTR model. An important caveat is that these findings

  4. Development and New Directions for the RELAP5-3D Graphical Users Interface

    Energy Technology Data Exchange (ETDEWEB)

    Mesina, George Lee

    2001-09-01

    The direction of development for the RELAP5 Graphical User Interfaces (RGUI) has been extended. In addition to existing plans for displaying all aspects of RELAP5 calculations, the plan now includes plans to display the calculations of a variety of codes including SCDAP, RETRAN and FLUENT. Recent work has included such extensions along with the previously planned and user-requested improvements and extensions. Visualization of heat-structures has been added. Adaptations were made for another computer program, SCDAP-3D, including plant core views. An input model builder for generating RELAP5-3D input files was partially implemented. All these are reported. Plans for future work are also summarized. These include an input processor that transfers steady-state conditions into an input file.

  5. Reformulation RELAP5-3D in FORTRAN 95 and Results

    Energy Technology Data Exchange (ETDEWEB)

    Dr. George L Mesina

    2010-08-01

    RELAP5-3D is a nuclear power plant code used worldwide for safety analysis, design, and operator training. In keeping with ongoing developments in the computing industry, we have re-architected the code in the FORTRAN 95 language, the current, fully-available, FORTRAN language. These changes include a complete reworking of the database and conversion of the source code to take advantage of new constructs. The improvements and impacts to the code are manifold. It is a completely machine-independent code that produces machine independent fluid property and plot files and expands to the exact size needed to accommodate the user’s input. Runtime is generally better for larger input models. Other impacts of code conversion are improved code readability, reduced maintenance and development time, increased adaptability to new computing platforms, and increased code longevity. The conversion methodology, code improvements and testing upgrades are presented in a manner that will be useful to future conversion projects for other such large codes. Comparison between the pre- and post-conversion code are made on the basis of code metrics and code performance.

  6. RELAP5-3D Results for Phase I (Exercise 2) of the OECD/NEA MHTGR-350 MW Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard Strydom

    2012-06-01

    The coupling of the PHISICS code suite to the thermal hydraulics system code RELAP5-3D has recently been initiated at the Idaho National Laboratory (INL) to provide a fully coupled prismatic Very High Temperature Reactor (VHTR) system modeling capability as part of the NGNP methods development program. The PHISICS code consists of three modules: INSTANT (performing 3D nodal transport core calculations), MRTAU (depletion and decay heat generation) and a perturbation/mixer module. As part of the verification and validation activities, steady state results have been obtained for Exercise 2 of Phase I of the newly-defined OECD/NEA MHTGR-350 MW Benchmark. This exercise requires participants to calculate a steady-state solution for an End of Equilibrium Cycle 350 MW Modular High Temperature Reactor (MHTGR), using the provided geometry, material, and coolant bypass flow description. The paper provides an overview of the MHTGR Benchmark and presents typical steady state results (e.g. solid and gas temperatures, thermal conductivities) for Phase I Exercise 2. Preliminary results are also provided for the early test phase of Exercise 3 using a two-group cross-section library and the Relap5-3D model developed for Exercise 2.

  7. User Guide for the R5EXEC Coupling Interface in the RELAP5-3D Code

    Energy Technology Data Exchange (ETDEWEB)

    Forsmann, J. Hope [Idaho National Lab. (INL), Idaho Falls, ID (United States); Weaver, Walter L. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-04-01

    This report describes the R5EXEC coupling interface in the RELAP5-3D computer code from the users perspective. The information in the report is intended for users who want to couple RELAP5-3D to other thermal-hydraulic, neutron kinetics, or control system simulation codes.

  8. Validation of coupled Relap5-3D code in the analysis of RBMK-1500 specific transients

    Energy Technology Data Exchange (ETDEWEB)

    Evaldas, Bubelis; Algirdas, Kaliatka; Eugenijus, Uspuras [Lithuanian Energy Institute, Kaunas (Lithuania)

    2003-07-01

    This paper deals with the modelling of RBMK-1500 specific transients taking place at Ignalina NPP. These transients include: measurements of void and fast power reactivity coefficients, change of graphite cooling conditions and reactor power reduction transients. The simulation of these transients was performed using RELAP5-3D code model of RBMK-1500 reactor. At the Ignalina NPP void and fast power reactivity coefficients are measured on a regular basis and, based on the total reactor power, reactivity, control and protection system control rods positions and the main circulation circuit parameter changes during the experiments, the actual values of these reactivity coefficients are determined. Graphite temperature reactivity coefficient at the plant is determined by changing graphite cooling conditions in the reactor cavity. This type of transient is very unique and important from the gap between fuel channel and the graphite bricks model validation point of view. The measurement results, obtained during this transient, allowed to determine the thermal conductivity coefficient for this gap and to validate the graphite temperature reactivity feedback model. Reactor power reduction is a regular operation procedure during the entire lifetime of the reactor. In all cases it starts by either a scram or a power reduction signal activation by the reactor control and protection system or by an operator. The obtained calculation results demonstrate reasonable agreement with Ignalina NPP measured data. Behaviours of the separate MCC thermal-hydraulic parameters as well as physical processes are predicted reasonably well to the real processes, occurring in the primary circuit of RBMK-1500 reactor. Reasonable agreement of the measured and the calculated total reactor power change in time demonstrates the correct modelling of the neutronic processes taking place in RBMK- 1500 reactor core. And finally, the performed validation of RELAP5-3D model of Ignalina NPP RBMK-1500

  9. Development and application of a dual RELAP5-3D-based engineering simulator for ABWR

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C.-Y. [Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Liang, Thomas K.S. [Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)], E-mail: ksliang@alum.mit.edu; Pei, B.S.; Shih, C.K. [Institute of Nuclear Engineering and Science, National Tsing Hua University, 101 Sec. 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Chiang, S.C.; Wang, L.C. [Department of Nuclear Safety, Taiwan Power Company, 242 Sec. 3, Roosevelt Road, Taipei 10016, Taiwan (China)

    2009-10-15

    For any innovated plant design, the designed paper plant can be converted into a computer as a digital plant with advanced simulation techniques before being constructed into a real plant. A digital plant, namely engineering simulator, can be applied for: (1) verification of system design and system integration, (2) power test simulation, (3) plant transient and accident analyses, (4) plant abnormal and emergency procedure development and verification, (5) design change verification and analysis, etc. An advanced engineering simulator was successfully developed for the LungMen advanced boiling water reactor (ABWR) plant to support various applications before and after commercial operation. This plant specific engineering simulator was developed based on two separate RELAP5-3D modules synchronized on a commercial simulation platform, namely 3-Key Master. On this advanced LungMen plant simulation (ALPS) platform, major plant dynamics were simulated by two separate RELAP5-3D modules, one for reactor system modeling and the other for balance of plant (BOP) system modeling. Moreover, major control systems as well as emergency core cooling system (ECCS) were all simulated in great detail with built-in tasks of this commercial simulation platform. Different from real time calculation on training simulator, precision of engineering calculation is intentionally kept by synchronizing modules based on the most time-consuming one. During synchronization, each module will check its' own converge criteria in each small time advancement. This plant specific advanced ABWR engineering simulator has been successfully applied on: (1) licensing blowdown analysis of feed water line break (FWLB) for containment design; (2) phenomena investigation of low-pressure ECC injection bypass during FWLB; (3) analysis of FW pump performance during power ascending; (4) verification of plant vendor's pre-test calculations of each start-up test.

  10. Implementation of Molten Salt Properties into RELAP5-3D/ATHENA

    Energy Technology Data Exchange (ETDEWEB)

    Cliff Davis

    2005-01-01

    Molten salts are being considered as coolants for the Next Generation Nuclear Plant (NGNP) in both the reactor and the heat transport loop between the reactor and the hydrogen production plant because of their superior thermophysical properties compared to helium. Because specific molten salts have not been selected for either application, four separate molten salts were implemented into the RELAP5-3D/ATHENA computer program as working fluids. The implemented salts were LiF-BeF2 in a molar mixture that is 66% LiF and 34% BeF2, respectively, NaBF4-NaF (92% and 8%), LiF-NaF-KF (11.5%, 46.5%, and 42%), and NaF-ZrF4 (50% and 50%). LiF-BeF2 is currently the first choice for the primary coolant for the Advanced High- Temperature Reactor, while NaF-ZrF4 is being considered as an alternate. NaBF4-NaF and LiFNaF- KF are being considered as possible coolants for the heat transport loop. The molten salts were implemented into ATHENA using a simplified equation of state based on data and correlations obtained from Oak Ridge National Laboratory. The simplified equation of state assumes that the liquid density is a function of temperature and pressure and that the liquid heat capacity is constant. The vapor is assumed to have the same composition as the liquid and is assumed to be a perfect gas. The implementation of the thermodynamic properties into ATHENA for LiF-BeF2 was verified by comparisons with results from a detailed equation of state that utilized a soft-sphere model. The comparisons between the simplified and soft-sphere models were in reasonable agreement for liquid. The agreement for vapor properties was not nearly as good as that obtained for liquid. Large uncertainties are possible in the vapor properties because of a lack of experimental data. The simplified model used here is not expected to be accurate for boiling or single-phase vapor conditions. Because neither condition is expected during NGNP applications, the simplified equation of state is considered

  11. RELAP5-3D Developmental Assessment: Comparison of Version 4.2.1i on Linux and Windows

    Energy Technology Data Exchange (ETDEWEB)

    Paul D. Bayless

    2014-06-01

    Figures have been generated comparing the parameters used in the developmental assessment of the RELAP5-3D code, version 4.2i, compiled on Linux and Windows platforms. The figures, which are the same as those used in Volume III of the RELAP5-3D code manual, compare calculations using the semi-implicit solution scheme with available experiment data. These figures provide a quick, visual indication of how the code predictions differ between the Linux and Windows versions.

  12. RELAP5-3D developmental assessment: Comparison of version 4.2.1i on Linux and Windows

    Energy Technology Data Exchange (ETDEWEB)

    Bayless, Paul D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-06-01

    Figures have been generated comparing the parameters used in the developmental assessment of the RELAP5-3D code, version 4.2i, compiled on Linux and Windows platforms. The figures, which are the same as those used in Volume III of the RELAP5-3D code manual, compare calculations using the semi-implicit solution scheme with available experiment data. These figures provide a quick, visual indication of how the code predictions differ between the Linux and Windows versions.

  13. RELAP5-3D Developmental Assessment. Comparison of Version 4.3.4i on Linux and Windows

    Energy Technology Data Exchange (ETDEWEB)

    Bayless, Paul David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-01

    Figures have been generated comparing the parameters used in the developmental assessment of the RELAP5-3D code, version 4.3i, compiled on Linux and Windows platforms. The figures, which are the same as those used in Volume III of the RELAP5-3D code manual, compare calculations using the semi-implicit solution scheme with available experiment data. These figures provide a quick, visual indication of how the code predictions differ between the Linux and Windows versions.

  14. Comparisons of RELAP5-3D Analyses to Experimental Data from the Natural Convection Shutdown Heat Removal Test Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bucknor, Matthew; Hu, Rui; Lisowski, Darius; Kraus, Adam

    2016-04-17

    The Reactor Cavity Cooling System (RCCS) is an important passive safety system being incorporated into the overall safety strategy for high temperature advanced reactor concepts such as the High Temperature Gas- Cooled Reactors (HTGR). The Natural Convection Shutdown Heat Removal Test Facility (NSTF) at Argonne National Laboratory (Argonne) reflects a 1/2-scale model of the primary features of one conceptual air-cooled RCCS design. The project conducts ex-vessel, passive heat removal experiments in support of Department of Energy Office of Nuclear Energy’s Advanced Reactor Technology (ART) program, while also generating data for code validation purposes. While experiments are being conducted at the NSTF to evaluate the feasibility of the passive RCCS, parallel modeling and simulation efforts are ongoing to support the design, fabrication, and operation of these natural convection systems. Both system-level and high fidelity computational fluid dynamics (CFD) analyses were performed to gain a complete understanding of the complex flow and heat transfer phenomena in natural convection systems. This paper provides a summary of the RELAP5-3D NSTF model development efforts and provides comparisons between simulation results and experimental data from the NSTF. Overall, the simulation results compared favorably to the experimental data, however, further analyses need to be conducted to investigate any identified differences.

  15. Implementation of a New DTSTEP Algorithm for use in RELAP5-3D and PVMEXEC Completion Report

    Energy Technology Data Exchange (ETDEWEB)

    Dr. George L Mesina

    2010-12-01

    The PVM Coupling methodology for decomposing a complex model into domains onto which individual programs may be applied has proven effective for solving many multi-physics problems. There have been, from the outset, some detailed and/or long-running models that cause the process to fail. This project addressed the PVM coupling issues surrounding the DTSTEP subroutines on RELAP5-3D and PVMEXEC. Some 25 errors are listed in Tables 1 and 18 and in Section 11. These arise from deficiencies in the floating point calculation and testing of time steps, cumulative time, and time targets. The algorithmic replacement of floating point control of these items with integer based timestepping was developed and implemented. The result of the first phase, undertaken by the INL was that all but three of these issues were resolved. Moreover, two conceptual errors in DTSTEP that were not PVM coupling related were discovered and solved. The final, and most difficult three PVM Bettis User Problems, were solved during the Bettis phase of development and debugging. In 8 months since the conclusion of the project, no further DTSTEP related PVM Coupling errors have been reported.

  16. New Multi-group Transport Neutronics (PHISICS) Capabilities for RELAP5-3D and its Application to Phase I of the OECD/NEA MHTGR-350 MW Benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Gerhard Strydom; Cristian Rabiti; Andrea Alfonsi

    2012-10-01

    PHISICS is a neutronics code system currently under development at the Idaho National Laboratory (INL). Its goal is to provide state of the art simulation capability to reactor designers. The different modules for PHISICS currently under development are a nodal and semi-structured transport core solver (INSTANT), a depletion module (MRTAU) and a cross section interpolation (MIXER) module. The INSTANT module is the most developed of the mentioned above. Basic functionalities are ready to use, but the code is still in continuous development to extend its capabilities. This paper reports on the effort of coupling the nodal kinetics code package PHISICS (INSTANT/MRTAU/MIXER) to the thermal hydraulics system code RELAP5-3D, to enable full core and system modeling. This will enable the possibility to model coupled (thermal-hydraulics and neutronics) problems with more options for 3D neutron kinetics, compared to the existing diffusion theory neutron kinetics module in RELAP5-3D (NESTLE). In the second part of the paper, an overview of the OECD/NEA MHTGR-350 MW benchmark is given. This benchmark has been approved by the OECD, and is based on the General Atomics 350 MW Modular High Temperature Gas Reactor (MHTGR) design. The benchmark includes coupled neutronics thermal hydraulics exercises that require more capabilities than RELAP5-3D with NESTLE offers. Therefore, the MHTGR benchmark makes extensive use of the new PHISICS/RELAP5-3D coupling capabilities. The paper presents the preliminary results of the three steady state exercises specified in Phase I of the benchmark using PHISICS/RELAP5-3D.

  17. Use of RELAP5-3D for Dynamic Analysis of a Closed-Loop Brayton Cycle Coupled To a Nuclear Reactor

    Science.gov (United States)

    McCann, Larry D.

    2007-01-01

    This paper describes results of a dynamic system model for a pair of closed Brayton-cycle (CBC) loops running in parallel that are connected to a nuclear gas reactor. The model assumes direct coupling between the reactor and the Brayton-cycle loops. The RELAP5-3D (version 2.4.1) computer program was used to perform the analysis. Few reactors have ever been coupled to closed Brayton-cycle systems. As such their behavior under dynamically varying loads, startup and shut down conditions, and requirements for safe and autonomous operation are largely unknown. The model described in this paper represents the reactor, turbine, compressor, recuperator, heat rejection system and alternator. The initial results of the model indicate stable operation of the reactor-driven Brayton-cycle system. However, for analysts with mostly pressurized water reactor experience, the Brayton cycle loops coupled to a gas-cooled reactor also indicate some counter-intuitive behavior for the complete coupled system. This model has provided crucial information in evaluating the reactor design and would have been further developed for use in developing procedures for safe start up, shut down, safe-standby, and other autonomous operating modes had the plant development cycle been completed.

  18. RGUI 1.0, New Graphical User Interface for RELAP5-3D

    Energy Technology Data Exchange (ETDEWEB)

    G. L. Mesina; J. Galbraith

    1999-04-01

    With the advent of three-dimensional modeling in nuclear safety analysis codes, the need has arisen for a new display methodology. Currently, analysts either sort through voluminous numerical displays of data at points in a region, or view color coded interpretations of the data on a two-dimensional rendition of the plant. RGUI 1.0 provides 3D capability for displaying data. The 3D isometric hydrodynamic image is built automatically from the input deck without additional input from the user. Standard view change features allow the user to focus on only the important data. Familiar features that are standard to the nuclear industry, such as run, interact, and monitor, are included. RGUI 1.0 reduces the difficulty of analyzing complex three-dimensional plants.

  19. RGUI 1.0, New Graphical User Interface for RELAP5-3D

    Energy Technology Data Exchange (ETDEWEB)

    Mesina, George Lee; Galbraith, James Andrew

    1999-04-01

    With the advent of three-dimensional modeling in nuclear safety analysis codes, the need has arisen for a new display methodology. Currently, analysts either sort through voluminous numerical displays of data at points in a region, or view color coded interpretations of the data on a two-dimensional rendition of the plant. RGUI 1.0 provides 3D capability for displaying data. The 3D isometric hydrodynamic image is built automatically from the input deck without additional input from the user. Standard view change features allow the user to focus on only the important data. Familiar features that are standard to the nuclear industry, such as run, interact, and monitor, are included. RGUI 1.0 reduces the difficulty of analyzing complex three dimensional plants.

  20. RELAP5-3D Developmental Assessment: Comparison of Versions 4.2.1i and 4.1.3i

    Energy Technology Data Exchange (ETDEWEB)

    Bayless, Paul D. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-06-01

    Figures have been generated comparing the parameters used in the developmental assessment of the RELAP5-3D code using versions 4.2.1i and 4.1.3i. The figures, which are the same as those used in Volume III of the RELAP5-3D code manual, compare calculations using the semi-implicit solution scheme with available experiment data. These figures provide a quick, visual indication of how the code predictions changed between these two code versions and can be used to identify cases in which the assessment judgment may need to be changed in Volume III of the code manual. Changes to the assessment judgments made after reviewing all of the assessment cases are also provided.

  1. RELAP5-3D Developmental Assessment: Comparison of Versions 4.3.4i and 4.2.1i

    Energy Technology Data Exchange (ETDEWEB)

    Bayless, Paul David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-10-01

    Figures have been generated comparing the parameters used in the developmental assessment of the RELAP5-3D code using versions 4.3.4i and 4.2.1i. The figures, which are the same as those used in Volume III of the RELAP5-3D code manual, compare calculations using the semi-implicit solution scheme with available experiment data. These figures provide a quick, visual indication of how the code predictions changed between these two code versions and can be used to identify cases in which the assessment judgment may need to be changed in Volume III of the code manual. Changes to the assessment judgments made after reviewing all of the assessment cases are also provided.

  2. Coupled RELAP5, 3D CFD and FEM analysis of postulated cracks in RPVs subjected to PTS loading

    Energy Technology Data Exchange (ETDEWEB)

    González-Albuixech, V.F., E-mail: vicente.gonzalez@psi.ch [Paul Scherrer Institut (PSI), Nuclear Energy and Safety Department, Structural Integrity Group, Villigen CH-5232 (Switzerland); Qian, G., E-mail: guian.qian@psi.ch [Paul Scherrer Institut (PSI), Nuclear Energy and Safety Department, Structural Integrity Group, Villigen CH-5232 (Switzerland); Sharabi, M. [Paul Scherrer Institut (PSI), Nuclear Energy and Safety Department, Structural Integrity Group, Villigen CH-5232 (Switzerland); Mechanical Power Engineering Department, Faculty of Engineering, Mansoura University, 35516 Mansoura (Egypt); Niffenegger, M.; Niceno, B.; Lafferty, N. [Paul Scherrer Institut (PSI), Nuclear Energy and Safety Department, Structural Integrity Group, Villigen CH-5232 (Switzerland)

    2016-02-15

    Highlights: • RPV fracture mechanics model based on RELAP5. • RPV fracture mechanics model based on CFD. • RPV fracture mechanics analysis. - Abstract: The fracture mechanic analysis of a reactor pressure vessel subjected to pressurized thermal shock loading is one of the most important issues for the assessment of life time extension of a nuclear power plant. The most severe scenario occurs during cold water injection in the cold leg due to a Loss-Of-Coolant Accident (LOCA). In the present study a comprehensive fracture mechanics analysis is performed. Two hypothetical LOCAs are assumed for an adopted reference design of a two-loop Pressurized Water Reactor. Boundary conditions obtained from the RELAP5 code are used as input for Computational Fluid Dynamics (CFD) simulations. For the structural integrity analysis, submodeling technique and the eXtended Finite Element Method (XFEM) based on temperatures calculated by CFD are applied. The results from the 3D FEM calculations are compared to those from a simplified axisymmetric model based on axisymmetric thermal hydraulic model results. The analysis identifies the worst crack orientation and location. It also proves that a complete model is needed for a correct analysis as the simplified model is not conservative and fails to describe accurately the local plume effect.

  3. New RELAP5-3D Lead and LBE Thermophysical Properties Implementation for Safety Analysis of Gen IV Reactors

    Directory of Open Access Journals (Sweden)

    P. Balestra

    2016-01-01

    Full Text Available The latest versions of RELAP5-3D© code allow the simulation of thermodynamic system, using different type of working fluids, that is, liquid metals, molten salt, diathermic oil, and so forth, thanks to the ATHENA code integration. The RELAP5-3D© water thermophysical properties are largely verified and validated; however there are not so many experiments to generate the liquid metals ones in particular for the Lead and the Lead Bismuth Eutectic. Recently, new and more accurate experimental data are available for liquid metals. The comparison between these state-of-the-art data and the RELAP5-3D© default thermophysical properties shows some discrepancy; therefore a tool for the generation of new properties binary files has been developed. All the available data came from experiments performed at atmospheric pressure. Therefore, to extend the pressure domain below and above this pressure, the tool fits a semiempirical model (soft sphere model with inverse-power-law potential, specific for the liquid metals. New binary files of thermophysical properties, with a detailed mesh grid of point to reduce the code mass error (especially for the Lead, were generated with this tool. Finally, calculations using a simple natural circulation loop were performed to understand the differences between the default and the new properties.

  4. XML Multidimensional Modelling and Querying

    CERN Document Server

    Boucher, Serge; Zimányi, Esteban

    2009-01-01

    As XML becomes ubiquitous and XML storage and processing becomes more efficient, the range of use cases for these technologies widens daily. One promising area is the integration of XML and data warehouses, where an XML-native database stores multidimensional data and processes OLAP queries written in the XQuery interrogation language. This paper explores issues arising in the implementation of such a data warehouse. We first compare approaches for multidimensional data modelling in XML, then describe how typical OLAP queries on these models can be expressed in XQuery. We then show how, regardless of the model, the grouping features of XQuery 1.1 improve performance and readability of these queries. Finally, we evaluate the performance of query evaluation in each modelling choice using the eXist database, which we extended with a grouping clause implementation.

  5. Executive Information Systems' Multidimensional Models

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Executive Information Systems are design to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing, integrating and presenting data in such a way that the organizational knowledge filters can easily associate with this data and turn it into information for the organization. These technologies are known as Business Intelligence Tools. But in order to build analytic reports for Executive Information Systems (EIS in an organization we need to design a multidimensional model based on the business model from the organization. This paper presents some multidimensional models that can be used in EIS development and propose a new model that is suitable for strategic business requests.

  6. Minimal models of multidimensional computations.

    Directory of Open Access Journals (Sweden)

    Jeffrey D Fitzgerald

    2011-03-01

    Full Text Available The multidimensional computations performed by many biological systems are often characterized with limited information about the correlations between inputs and outputs. Given this limitation, our approach is to construct the maximum noise entropy response function of the system, leading to a closed-form and minimally biased model consistent with a given set of constraints on the input/output moments; the result is equivalent to conditional random field models from machine learning. For systems with binary outputs, such as neurons encoding sensory stimuli, the maximum noise entropy models are logistic functions whose arguments depend on the constraints. A constraint on the average output turns the binary maximum noise entropy models into minimum mutual information models, allowing for the calculation of the information content of the constraints and an information theoretic characterization of the system's computations. We use this approach to analyze the nonlinear input/output functions in macaque retina and thalamus; although these systems have been previously shown to be responsive to two input dimensions, the functional form of the response function in this reduced space had not been unambiguously identified. A second order model based on the logistic function is found to be both necessary and sufficient to accurately describe the neural responses to naturalistic stimuli, accounting for an average of 93% of the mutual information with a small number of parameters. Thus, despite the fact that the stimulus is highly non-Gaussian, the vast majority of the information in the neural responses is related to first and second order correlations. Our results suggest a principled and unbiased way to model multidimensional computations and determine the statistics of the inputs that are being encoded in the outputs.

  7. Multi-dimensional model order selection

    Directory of Open Access Journals (Sweden)

    Roemer Florian

    2011-01-01

    Full Text Available Abstract Multi-dimensional model order selection (MOS techniques achieve an improved accuracy, reliability, and robustness, since they consider all dimensions jointly during the estimation of parameters. Additionally, from fundamental identifiability results of multi-dimensional decompositions, it is known that the number of main components can be larger when compared to matrix-based decompositions. In this article, we show how to use tensor calculus to extend matrix-based MOS schemes and we also present our proposed multi-dimensional model order selection scheme based on the closed-form PARAFAC algorithm, which is only applicable to multi-dimensional data. In general, as shown by means of simulations, the Probability of correct Detection (PoD of our proposed multi-dimensional MOS schemes is much better than the PoD of matrix-based schemes.

  8. Development of a model for the thermal-hydraulic characterization of the He-FUS3 loop

    Energy Technology Data Exchange (ETDEWEB)

    Barone, G., E-mail: gianluca.barone@for.unipi.it [University of Pisa, Department of Civil and Industrial Engineering (DICI), Pisa (Italy); Coscarelli, E.; Forgione, N.; Martelli, D. [University of Pisa, Department of Civil and Industrial Engineering (DICI), Pisa (Italy); Del Nevo, A.; Tarantino, M.; Utili, M. [ENEA UTIS-TCI, CR Brasimone, Camugnano (Italy); Ricapito, I.; Calderoni, P. [TBM& MD Project, Fusion for Energy, EU Commission, Carrer J. Pla, 2, Building B3, 08019 Barcelona (Spain)

    2015-10-15

    Highlights: • RELAP5-3D model of He-FUS3 facility and turbo circulator (TC). • Cold and hot facility T/H numerical analysis for the TC operanting range. • Effect of the cold by-pass opening on the facility performances. - Abstract: He-FUS3 is a helium facility designed and realized by ENEA in order to test the thermal-mechanical properties of prototypical breeding blanket module assemblies of a DEMO reactor. The actual facility has been upgraded with a high performance turbo circulator and a water heat exchanger integrating the pre-existent air cooler. In addition, a new test section located in the loop hot zone has been settled down with the objective of investigating safety relevant transient conditions of “In-TBM” LOCA scenarios. A RELAP5-3D{sup ©} model has been developed to perform a set of preliminary simulations on the new He-FUS3 layout. Both cold and hot stationary conditions have been analyzed evaluating the turbo circulator performances for a wide range of helium flow rate. Outcomes have shown that RELAP5-3D{sup ©} is an effective tool in reproducing the most significant phenomena of He-FUS3 system, providing relevant insight supporting future experimental campaigns. The post-test analysis phase will be, of course, fundamental for the qualification of a consistent numerical model.

  9. Identification of limiting case between DBA and SBDBA (CL break area sensitivity): A new model for the boron injection system

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez Gonzalez, R., E-mail: r.gonzalez@ing.unipi.it [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, 56122 San Piero a Grado, Pisa (Italy); Petruzzi, A., E-mail: a.petruzzi@ing.unipi.it [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, 56122 San Piero a Grado, Pisa (Italy); D’Auria, F., E-mail: f.dauria@ing.unipi.it [San Piero a Grado Nuclear Research Group (GRNSPG), University of Pisa, Via Livornese 1291, 56122 San Piero a Grado, Pisa (Italy); Mazzantini, O., E-mail: mazzantini@na-sa.com.ar [Nucleo-electrica Argentina Sociedad Anonima (NA-SA), Buenos Aires (Argentina)

    2014-08-15

    Atucha-2 is a Siemens-designed Pressurized Heavy Water Reactor (PHWR) reactor under construction in the Republic of Argentina. Its geometrical complexity and peculiarity (e.g. oblique Control Rods, Positive Void coefficient) required a developed and validated complex three dimensional (3D) neutron kinetics (NK) coupled thermal hydraulic (TH) model. Reactor shut-down is obtained by oblique CRs and, during accidental conditions, by an emergency shut-down system (JDJ) injecting a highly concentrated boron solution (boron clouds) in the moderator tank. The boron clouds reconstruction is obtained using a Computational Fluid Dynamics (CFD) CFX code calculation. A complete Large Break Loss Of Coolant Accident (LBLOCA) calculation implies the application of the RELAP5-3D{sup ©} system code. Within the framework of the third Agreement “Nucleoelèctrica Argentina-Sociedad Anonima (NA-SA) – University of Pisa/GRNSPG” (Contract, 2009), a new RELAP5-3D control system for the boron injection system was developed and implemented in the validated coupled RELAP5-3D/NESTLE model of the Atucha 2 NPP. The aim of this activity is to find out the limiting case (maximum break area size) for the Peak Cladding Temperature for LOCAs under fixed boundary conditions.

  10. Multi-dimensional indoor location information model

    NARCIS (Netherlands)

    Xiong, Q.; Zhu, Q.; Zlatanova, S.; Huang, L.; Zhou, Y.; Du, Z.

    2013-01-01

    Aiming at the increasing requirements of seamless indoor and outdoor navigation and location service, a Chinese standard of Multidimensional Indoor Location Information Model is being developed, which defines ontology of indoor location. The model is complementary to 3D concepts like CityGML and

  11. Application of multidimensional item response theory models to longitudinal data

    NARCIS (Netherlands)

    Marvelde, te Janneke M.; Glas, Cees A.W.; Van Landeghem, Georges; Van Damme, Jan

    2006-01-01

    The application of multidimensional item response theory (IRT) models to longitudinal educational surveys where students are repeatedly measured is discussed and exemplified. A marginal maximum likelihood (MML) method to estimate the parameters of a multidimensional generalized partial credit model

  12. Geometrical model of multidimensional orbital motion

    Energy Technology Data Exchange (ETDEWEB)

    Jacak, D [Institute of Mathematics and Computer Science, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wroclaw (Poland)], E-mail: dorota.jacak@pwr.wroc.pl

    2008-05-15

    We consider a geometrical n-dimensional model of orbital-type rotation, for n{>=}4. The vectors generating this process are defined and the Fibonacci sequence is found in representation of their lengths. Within the dimension analysis of Planck units, we consider an example of the multidimensional whirl and define a sequence of formal fields. Special attention is paid to the three subsequent elements of this sequence, called here magnetic, electric and energy fields, which allow for some physical interpretations.

  13. Multidimensional Big Spatial Data Modeling Through A Case Study: Lte Rf Subsystem Power Consumption Modeling

    DEFF Research Database (Denmark)

    Antón Castro, Francesc/François; Musiige, Deogratius; Mioc, Darka

    2016-01-01

    This paper presents a case study for comparing different multidimensional mathematical modeling methodologies used in multidimensional spatial big data modeling and proposing a new technique. An analysis of multidimensional modeling approaches (neural networks, polynomial interpolation and homotopy...

  14. Multidimensional modelling of anaerobic granules

    DEFF Research Database (Denmark)

    Picioreanu, C.; Batstone, Damien J.; van Loosdrecht, M.C.M.

    2005-01-01

    . The model uses individual-based representation of biomass particles within the granule (biofilm), and describes spreading by an iterative pushing technique. The overall computational domain consists of one granule, and is divided into a grid with Cartesian coordinates. The number of grid elements does...

  15. A multidimensional representation model of geographic features

    Science.gov (United States)

    Usery, E. Lynn; Timson, George; Coletti, Mark

    2016-01-28

    A multidimensional model of geographic features has been developed and implemented with data from The National Map of the U.S. Geological Survey. The model, programmed in C++ and implemented as a feature library, was tested with data from the National Hydrography Dataset demonstrating the capability to handle changes in feature attributes, such as increases in chlorine concentration in a stream, and feature geometry, such as the changing shoreline of barrier islands over time. Data can be entered directly, from a comma separated file, or features with attributes and relationships can be automatically populated in the model from data in the Spatial Data Transfer Standard format.

  16. The Conceptual Integration Modeling Framework: Abstracting from the Multidimensional Model

    CERN Document Server

    Rizzolo, Flavio; Pottinger, Rachel; Wong, Kwok

    2010-01-01

    Data warehouses are overwhelmingly built through a bottom-up process, which starts with the identification of sources, continues with the extraction and transformation of data from these sources, and then loads the data into a set of data marts according to desired multidimensional relational schemas. End user business intelligence tools are added on top of the materialized multidimensional schemas to drive decision making in an organization. Unfortunately, this bottom-up approach is costly both in terms of the skilled users needed and the sheer size of the warehouses. This paper proposes a top-down framework in which data warehousing is driven by a conceptual model. The framework offers both design time and run time environments. At design time, a business user first uses the conceptual modeling language as a multidimensional object model to specify what business information is needed; then she maps the conceptual model to a pre-existing logical multidimensional representation. At run time, a system will tra...

  17. Multidimensional modelling of classical pulsating stars

    CERN Document Server

    Muthsam, Herbert J

    2016-01-01

    After an overview of general aspects of modelling the pulsation- convection interaction we present reasons why such simulations (in multidimensions) are needed but, at the same time, pose a considerable challenge. We then discuss, for several topics, what insights multidimensional simulations have either already provided or can be expected to yield in the future. We finally discuss properties of our ANTARES code. Many of these features can be expected to be characteristic of other codes which may possibly be applied to these physical questions in the foreseeable future.

  18. Multidimensional Learner Model In Intelligent Learning System

    Science.gov (United States)

    Deliyska, B.; Rozeva, A.

    2009-11-01

    The learner model in an intelligent learning system (ILS) has to ensure the personalization (individualization) and the adaptability of e-learning in an online learner-centered environment. ILS is a distributed e-learning system whose modules can be independent and located in different nodes (servers) on the Web. This kind of e-learning is achieved through the resources of the Semantic Web and is designed and developed around a course, group of courses or specialty. An essential part of ILS is learner model database which contains structured data about learner profile and temporal status in the learning process of one or more courses. In the paper a learner model position in ILS is considered and a relational database is designed from learner's domain ontology. Multidimensional modeling agent for the source database is designed and resultant learner data cube is presented. Agent's modules are proposed with corresponding algorithms and procedures. Multidimensional (OLAP) analysis guidelines on the resultant learner module for designing dynamic learning strategy have been highlighted.

  19. Applying XML for designing and interchanging information for multidimensional model

    Institute of Scientific and Technical Information of China (English)

    Lu Changhui; Deng Su; Zhang Weiming

    2005-01-01

    In order to exchange and share information among the conceptual models of data warehouse, and to build a solid base for the integration and share of metadata, a new multidimensional concept model is presented based on XML and its DTD is defined, which can perfectly describe various semantic characteristics of multidimensional conceptual model. According to the multidimensional conceptual modeling technique which is based on UML, the mapping algorithm between the multidimensional conceptual model is described based on XML and UML class diagram, and an application base for the wide use of this technique is given.

  20. Constraint theory multidimensional mathematical model management

    CERN Document Server

    Friedman, George J

    2017-01-01

    Packed with new material and research, this second edition of George Friedman’s bestselling Constraint Theory remains an invaluable reference for all engineers, mathematicians, and managers concerned with modeling. As in the first edition, this text analyzes the way Constraint Theory employs bipartite graphs and presents the process of locating the “kernel of constraint” trillions of times faster than brute-force approaches, determining model consistency and computational allowability. Unique in its abundance of topological pictures of the material, this book balances left- and right-brain perceptions to provide a thorough explanation of multidimensional mathematical models. Much of the extended material in this new edition also comes from Phan Phan’s PhD dissertation in 2011, titled “Expanding Constraint Theory to Determine Well-Posedness of Large Mathematical Models.” Praise for the first edition: "Dr. George Friedman is indisputably the father of the very powerful methods of constraint theory...

  1. Un modelo multidimensional conceptual espacio-temporal A conceptual spatio-temporal multidimensional model

    Directory of Open Access Journals (Sweden)

    Francisco Moreno

    2010-07-01

    Full Text Available Hoy, gracias a los sistemas de posicionamiento global y dispositivos móviles equipados con sensores de rastreo, se puede recopilar una gran cantidad de datos sobre objetos móviles, es decir, datos espacio-temporales relacionados con el movimiento seguido por esos objetos. Por otro lado, las bodegas de datos, usualmente modeladas mediante una vista multidimensional de los datos, son bases de datos especializadas para soportar la toma de decisiones. Desafortunadamente, las bodegas de datos convencionales están principalmente orientadas al manejo de datos alfanuméricos. En este artículo, se incorporan elementos temporales a un modelo multidimensional conceptual espacial dando origen a un modelo multidimensional conceptual espacio-temporal. La propuesta se ilustra con un caso de estudio relacionado con la migración de animalesToday, thanks to global positioning systems technologies and mobile devices equipped with tracking sensors, and a lot of data about moving objects can be collected, e.g., spatio-temporal data related to the movement followed by objects. On the other hand, data warehouses, usually modeled using a multidimensional view of data, are specialized databases to support the decision-making process. Unfortunately, conventional data warehouses are mainly oriented to manage alphanumeric data. In this article, we incorporate temporal elements to a conceptual spatial multidimensional model resulting in a spatio-temporal multidimensional model. We illustrate our proposal with a case study related to animal migration.

  2. Multidimensional numerical modeling of heat exchangers

    Science.gov (United States)

    Sha, W. T.; Yang, C. I.; Kao, T. T.; Cho, S. M.

    A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchangers for liquid-metal services. For the shellside fluid, the conservation equations of mass, momentum, and energy for continuum fluids are modified using the concept of porosity, surface permeability and distributed resistance to account for the blockage effects due to the presence of heat-transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, the heat-transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phase on the shell side and may undergo phase-change on the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reactor (LMFBR) intermediate heat exchangers (IHX) and steam generators (SG).

  3. Multidimensional Data Modeling For Location-Based Services

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Kligys, Augustas; Pedersen, Torben Bach

    2004-01-01

    and requests of their users in multidimensional databases, i.e., data warehouses, and content delivery may be based on the results of complex queries on these data warehouses. Such queries aggregate detailed data in order to find useful patterns, e.g., in the interaction of a particular user with the services....... The application of multidimensional technology in this context poses a range of new challenges. The specific challenge addressed here concerns the provision of an appropriate multidimensional data model. In particular, the paper extends an existing multidimensional data model and algebraic query language...... to accommodate spatial values that exhibit partial containment relationships instead of the total containment relationships normally assumed in multidimensional data models. Partial containment introduces imprecision in aggregation paths. The paper proposes a method for evaluating the imprecision of such paths...

  4. Multidimensional Data Modeling For Location-Based Services

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Kligys, A.; Pedersen, Torben Bach

    2003-01-01

    and requests of their users in multidimensional databases, i.e., data warehouses; and content delivery may be based on the results of complex queries on these data warehouses. Such queries aggregate detailed data in order to find useful patterns, e.g., in the interaction of a particular user with the services....... The application of multidimensional technology in this context poses a range of new challenges. The specific challenge addressed here concerns the provision of an appropriate multidimensional data model. In particular, the paper extends an existing multidimensional data model and algebraic query language...... to accommodate spatial values that exhibit partial containment relationships instead of the total containment relationships normally assumed in multidimensional data models. Partial containment introduces imprecision in aggregation paths. The paper proposes a method for evaluating the imprecision of such paths...

  5. Global Langevin model of multidimensional biomolecular dynamics

    Science.gov (United States)

    Schaudinnus, Norbert; Lickert, Benjamin; Biswas, Mithun; Stock, Gerhard

    2016-11-01

    Molecular dynamics simulations of biomolecular processes are often discussed in terms of diffusive motion on a low-dimensional free energy landscape F ( 𝒙 ) . To provide a theoretical basis for this interpretation, one may invoke the system-bath ansatz á la Zwanzig. That is, by assuming a time scale separation between the slow motion along the system coordinate x and the fast fluctuations of the bath, a memory-free Langevin equation can be derived that describes the system's motion on the free energy landscape F ( 𝒙 ) , which is damped by a friction field and driven by a stochastic force that is related to the friction via the fluctuation-dissipation theorem. While the theoretical formulation of Zwanzig typically assumes a highly idealized form of the bath Hamiltonian and the system-bath coupling, one would like to extend the approach to realistic data-based biomolecular systems. Here a practical method is proposed to construct an analytically defined global model of structural dynamics. Given a molecular dynamics simulation and adequate collective coordinates, the approach employs an "empirical valence bond"-type model which is suitable to represent multidimensional free energy landscapes as well as an approximate description of the friction field. Adopting alanine dipeptide and a three-dimensional model of heptaalanine as simple examples, the resulting Langevin model is shown to reproduce the results of the underlying all-atom simulations. Because the Langevin equation can also be shown to satisfy the underlying assumptions of the theory (such as a delta-correlated Gaussian-distributed noise), the global model provides a correct, albeit empirical, realization of Zwanzig's formulation. As an application, the model can be used to investigate the dependence of the system on parameter changes and to predict the effect of site-selective mutations on the dynamics.

  6. A study of multidimensional modeling approaches for data warehouse

    Science.gov (United States)

    Yusof, Sharmila Mat; Sidi, Fatimah; Ibrahim, Hamidah; Affendey, Lilly Suriani

    2016-08-01

    Data warehouse system is used to support the process of organizational decision making. Hence, the system must extract and integrate information from heterogeneous data sources in order to uncover relevant knowledge suitable for decision making process. However, the development of data warehouse is a difficult and complex process especially in its conceptual design (multidimensional modeling). Thus, there have been various approaches proposed to overcome the difficulty. This study surveys and compares the approaches of multidimensional modeling and highlights the issues, trend and solution proposed to date. The contribution is on the state of the art of the multidimensional modeling design.

  7. Multidimensional thermal-chemical cookoff modeling

    Energy Technology Data Exchange (ETDEWEB)

    Baer, M.R.; Gross, R.J.; Gartling, D.K.; Hobbs, M.L.

    1994-08-01

    Multidimensional thermal/chemical modeling is an essential step in the development of a predictive capability for cookoff of energetic materials in systems subjected to abnormal thermal environments. COYOTE II is a state-of-the-art two- and three-dimensional finite element code for the solution of heat conduction problems including surface-to-surface thermal radiation heat transfer and decomposition chemistry. Multistep finite rate chemistry is incorporated into COYOTE II using an operator-splitting methodology; rate equations are solved element-by-element with a modified matrix-free stiff solver, CHEMEQ. COYOTE II is purposely designed with a user-oriented input structure compatible with the database, the pre-processing mesh generation, and the post-processing tools for data visualization shared with other engineering analysis codes available at Sandia National Laboratories. As demonstrated in a companion paper, decomposition during cookoff in a confined or semi-confined system leads to significant mechanical behavior. Although mechanical effect are not presently considered in COYOTE II, the formalism for including mechanics in multidimensions is under development.

  8. A multidimensional subdiffusion model: An arbitrage-free market

    Science.gov (United States)

    Li, Guo-Hua; Zhang, Hong; Luo, Mao-Kang

    2012-12-01

    To capture the subdiffusive characteristics of financial markets, the subordinated process, directed by the inverse α-stale subordinator Sα(t) for 0 process is a multidimensional subdiffusion process directed by the inverse α-stable subordinator. This model describes the period of stagnation for each stock and the behavior of the dependency between multiple stocks. Moreover, we derive the multidimensional fractional backward Kolmogorov equation for the subordinated process using the Laplace transform technique. Finally, using a martingale approach, we prove that the multidimensional subdiffusion model is arbitrage-free, and also gives an arbitrage-free pricing rule for contingent claims associated with the martingale measure.

  9. Multidimensional IRT Models for Composite Scores

    Science.gov (United States)

    Yen, Shu Jing; Walker, Leah

    2007-01-01

    Tests of English Language Proficiency are often designed such that each section of the test measures a single latent ability. For instance an English Proficiency Assessment might consist of sections measuring Speaking, Listening, and Reading ability. However, Overall English Proficiency and composite abilities are naturally multidimensional. This…

  10. Multidimensional Data Modeling For Location-Based Services

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Kligys, Augustas; Pedersen, Torben Bach

    2004-01-01

    With the recent and continuing advances in areas such as wireless communications and positioning technologies, mobile, location-based services are becoming possible. Such services deliver location-dependent content to their users. More specifically, these services may capture the movements...... and requests of their users in multidimensional databases, i.e., data warehouses, and content delivery may be based on the results of complex queries on these data warehouses. Such queries aggregate detailed data in order to find useful patterns, e.g., in the interaction of a particular user with the services....... The application of multidimensional technology in this context poses a range of new challenges. The specific challenge addressed here concerns the provision of an appropriate multidimensional data model. In particular, the paper extends an existing multidimensional data model and algebraic query language...

  11. Multidimensional Data Modeling For Location-Based Services

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Kligys, A.; Pedersen, Torben Bach

    2003-01-01

    With the recent and continuing advances in areas such as wireless communications and positioning technologies, mobile, location-based services are becoming possible. Such services deliver location-dependent content to their users. More specifically, these services may capture the movements...... and requests of their users in multidimensional databases, i.e., data warehouses; and content delivery may be based on the results of complex queries on these data warehouses. Such queries aggregate detailed data in order to find useful patterns, e.g., in the interaction of a particular user with the services....... The application of multidimensional technology in this context poses a range of new challenges. The specific challenge addressed here concerns the provision of an appropriate multidimensional data model. In particular, the paper extends an existing multidimensional data model and algebraic query language...

  12. Multidimensional Vector Model of Stimulus-Response Compatibility

    Science.gov (United States)

    Yamaguchi, Motonori; Proctor, Robert W.

    2012-01-01

    The present study proposes and examines the multidimensional vector (MDV) model framework as a modeling schema for choice response times. MDV extends the Thurstonian model, as well as signal detection theory, to classification tasks by taking into account the influence of response properties on stimulus discrimination. It is capable of accounting…

  13. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, X.; Xia, C.; Keppens, R. [Centre for mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, B-3001 Leuven (Belgium)

    2013-07-10

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  14. Analysis of local dependence and multidimensionality in graphical loglinear Rasch models

    DEFF Research Database (Denmark)

    Kreiner, Svend; Christensen, Karl Bang

    local independence; multidimensionality, differential item functioning; uniform local dependency and DIF; graphical Rasch models; loglinear Rasch models......local independence; multidimensionality, differential item functioning; uniform local dependency and DIF; graphical Rasch models; loglinear Rasch models...

  15. Analysis of Local Dependence and Multidimensionality in Graphical Loglinear Rasch Models

    DEFF Research Database (Denmark)

    Kreiner, Svend; Christensen, Karl Bang

    2004-01-01

    Local independence; Multidimensionality; Differential item functioning; Uniform local dependence and DIF; Graphical Rasch models; Loglinear Rasch model......Local independence; Multidimensionality; Differential item functioning; Uniform local dependence and DIF; Graphical Rasch models; Loglinear Rasch model...

  16. Study of a model equation in detonation theory: multidimensional effects

    CERN Document Server

    Faria, Luiz M; Rosales, Rodolfo R

    2015-01-01

    We extend the reactive Burgers equation presented in Kasimov et al. Phys. Rev. Lett., 110 (2013) and Faria et al. SIAM J. Appl. Maths, 74 (2014), to include multidimensional effects. Furthermore, we explain how the model can be rationally justified following the ideas of the asymptotic theory developed in Faria et al. JFM (2015). The proposed model is a forced version of the unsteady small disturbance transonic flow equations. We show that for physically reasonable choices of forcing functions, traveling wave solutions akin to detonation waves exist. It is demonstrated that multidimensional effects play an important role in the stability and dynamics of the traveling waves. Numerical simulations indicate that solutions of the model tend to form multi-dimensional patterns analogous to cells in gaseous detonations.

  17. Multidimensional modeling of coronal rain dynamics

    CERN Document Server

    Fang, X; Keppens, R

    2013-01-01

    We present the first multidimensional, magnetohydrodynamic simulations which capture the initial formation and the long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in-situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match with modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into $V$-shaped like features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views on blobs which evaporate in situ, or get siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys o...

  18. Modelling of multidimensional quantum systems by the numerical functional integration

    Energy Technology Data Exchange (ETDEWEB)

    Lobanov, Yu.Yu.; Zhidkov, E.P. (Joint Inst. for Nuclear Research, Dubna (USSR)); Shahbagian, R.R. (Yerevan Physics Inst., Erevan (USSR))

    1990-01-01

    The employment of the numerical functional integration for the description of multidimensional systems in quantum and statistical physics is considered. For the multiple functional integrals with respect to Gaussian measures in the full separable metric spaces the new approximation formulas exact on a class of polynomial functionals of a given summary degree are constructed. The use of the formulas is demonstrated on example of computation of the Green function and the ground state energy in multidimensional Calogero model. The comparison of numerical results with the data obtained by the other authors which used the Monte Carlo method combined with iterative algorithms indicates that our formulas provide the higher efficiency of computations.

  19. Linear and Nonlinear Thinking: A Multidimensional Model and Measure

    Science.gov (United States)

    Groves, Kevin S.; Vance, Charles M.

    2015-01-01

    Building upon previously developed and more general dual-process models, this paper provides empirical support for a multidimensional thinking style construct comprised of linear thinking and multiple dimensions of nonlinear thinking. A self-report assessment instrument (Linear/Nonlinear Thinking Style Profile; LNTSP) is presented and…

  20. Multidimensional Model of Trauma and Correlated Antisocial Personality Disorder

    Science.gov (United States)

    Martens, Willem H. J.

    2005-01-01

    Many studies have revealed an important relationship between psychosocial trauma and antisocial personality disorder. A multidimensional model is presented which describes the psychopathological route from trauma to antisocial development. A case report is also included that can illustrate the etiological process from trauma to severe antisocial…

  1. A multidimensional scaling model accommodating differential stimulus familiarity

    NARCIS (Netherlands)

    Bijmolt, THA; DeSarbo, WS; Wedel, M

    1998-01-01

    We introduce a multidimensional scaling procedure that attempts to derive a spatial representation of stimuli unconfounded by the effect of subjects' degrees of familiarity with these stimuli. The proposed model assumes that stimulus unfamiliarity produces a tendency for a subject to anchor his/her

  2. A Framework for Dimensionality Assessment for Multidimensional Item Response Models

    Science.gov (United States)

    Svetina, Dubravka; Levy, Roy

    2014-01-01

    A framework is introduced for considering dimensionality assessment procedures for multidimensional item response models. The framework characterizes procedures in terms of their confirmatory or exploratory approach, parametric or nonparametric assumptions, and applicability to dichotomous, polytomous, and missing data. Popular and emerging…

  3. A multi-dimensional model for search intent.

    NARCIS (Netherlands)

    Kraaij, W.; Hinne, M.; Heijden, M. van der; Verberne, S.

    2011-01-01

    The interaction of users with search engines is part of goal driven behaviour involving an underlying information need. Information needs range from simple lookups to complex long-term desk studies. This paper proposes a new multi-dimensional model for search intent, which can be used for the

  4. Linear and Nonlinear Thinking: A Multidimensional Model and Measure

    Science.gov (United States)

    Groves, Kevin S.; Vance, Charles M.

    2015-01-01

    Building upon previously developed and more general dual-process models, this paper provides empirical support for a multidimensional thinking style construct comprised of linear thinking and multiple dimensions of nonlinear thinking. A self-report assessment instrument (Linear/Nonlinear Thinking Style Profile; LNTSP) is presented and…

  5. Bayesian Dimensionality Assessment for the Multidimensional Nominal Response Model

    Directory of Open Access Journals (Sweden)

    Javier Revuelta

    2017-06-01

    Full Text Available This article introduces Bayesian estimation and evaluation procedures for the multidimensional nominal response model. The utility of this model is to perform a nominal factor analysis of items that consist of a finite number of unordered response categories. The key aspect of the model, in comparison with traditional factorial model, is that there is a slope for each response category on the latent dimensions, instead of having slopes associated to the items. The extended parameterization of the multidimensional nominal response model requires large samples for estimation. When sample size is of a moderate or small size, some of these parameters may be weakly empirically identifiable and the estimation algorithm may run into difficulties. We propose a Bayesian MCMC inferential algorithm to estimate the parameters and the number of dimensions underlying the multidimensional nominal response model. Two Bayesian approaches to model evaluation were compared: discrepancy statistics (DIC, WAICC, and LOO that provide an indication of the relative merit of different models, and the standardized generalized discrepancy measure that requires resampling data and is computationally more involved. A simulation study was conducted to compare these two approaches, and the results show that the standardized generalized discrepancy measure can be used to reliably estimate the dimensionality of the model whereas the discrepancy statistics are questionable. The paper also includes an example with real data in the context of learning styles, in which the model is used to conduct an exploratory factor analysis of nominal data.

  6. CFD Model Development and validation for High Temperature Gas Cooled Reactor Cavity Cooling System (RCCS) Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hassan, Yassin [Univ. of Wisconsin, Madison, WI (United Texas A & M Univ., College Station, TX (United States); Corradini, Michael; Tokuhiro, Akira; Wei, Thomas Y.C.

    2014-07-14

    The Reactor Cavity Cooling Systems (RCCS) is a passive safety system that will be incorporated in the VTHR design. The system was designed to remove the heat from the reactor cavity and maintain the temperature of structures and concrete walls under desired limits during normal operation (steady-state) and accident scenarios. A small scale (1:23) water-cooled experimental facility was scaled, designed, and constructed in order to study the complex thermohydraulic phenomena taking place in the RCCS during steady-state and transient conditions. The facility represents a portion of the reactor vessel with nine stainless steel coolant risers and utilizes water as coolant. The facility was equipped with instrumentation to measure temperatures and flow rates and a general verification was completed during the shakedown. A model of the experimental facility was prepared using RELAP5-3D and simulations were performed to validate the scaling procedure. The experimental data produced during the steady-state run were compared with the simulation results obtained using RELAP5-3D. The overall behavior of the facility met the expectations. The facility capabilities were confirmed to be very promising in performing additional experimental tests, including flow visualization, and produce data for code validation.

  7. Multidimensional DDT modeling of energetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Baer, M.R.; Hertel, E.S.; Bell, R.L.

    1995-07-01

    To model the shock-induced behavior of porous or damaged energetic materials, a nonequilibrium mixture theory has been developed and incorporated into the shock physics code, CTH. The foundation for this multiphase model is based on a continuum mixture formulation given by Baer and Nunziato. This multiphase mixture model provides a thermodynamic and mathematically-consistent description of the self-accelerated combustion processes associated with deflagration-to-detonation and delayed detonation behavior which are key modeling issues in safety assessment of energetic systems. An operator-splitting method is used in the implementation of this model, whereby phase diffusion effects are incorporated using a high resolution transport method. Internal state variables, forming the basis for phase interaction quantities, are resolved during the Lagrangian step requiring the use of a stiff matrix-free solver. Benchmark calculations are presented which simulate low-velocity piston impact on a propellant porous bed and experimentally-measured wave features are well replicated with this model. This mixture model introduces micromechanical models for the initiation and growth of reactive multicomponent flow that are key features to describe shock initiation and self-accelerated deflagration-to-detonation combustion behavior. To complement one-dimensional simulation, two-dimensional numerical calculations are presented which indicate wave curvature effects due to the loss of wall confinement. This study is pertinent for safety analysis of weapon systems.

  8. Theme section: Multi-dimensional modelling, analysis and visualization

    Science.gov (United States)

    Guilbert, Éric; Çöltekin, Arzu; Castro, Francesc Antón; Pettit, Chris

    2016-07-01

    Spatial data are now collected and processed in larger amounts, and used by larger populations than ever before. While most geospatial data have traditionally been recorded as two-dimensional data, the evolution of data collection methods and user demands have led to data beyond the two dimensions describing complex multidimensional phenomena. An example of the relevance of multidimensional modelling is seen with the development of urban modelling where several dimensions have been added to the traditional 2D map representation (Sester et al., 2011). These include obviously the third spatial dimension (Biljecki et al., 2015) as well as the temporal, but also the scale dimension (Van Oosterom and Stoter, 2010) or, as mentioned by (Lu et al., 2016), multi-spectral and multi-sensor data. Such a view provides an organisation of multidimensional data around these different axes and it is time to explore each axis as the availability of unprecedented amounts of new data demands new solutions. The availability of such large amounts of data induces an acute need for developing new approaches to assist with their dissemination, visualisation, and analysis by end users. Several issues need to be considered in order to provide a meaningful representation and assist in data visualisation and mining, modelling and analysis; such as data structures allowing representation at different scales or in different contexts of thematic information.

  9. Multidimensional chemical modelling, II. Irradiated outflow walls

    CERN Document Server

    Bruderer, Simon; Doty, Steven D; van Dishoeck, Ewine F; Bourke, Tyler L

    2009-01-01

    Observations of the high-mass star forming region AFGL 2591 reveal a large abundance of CO+, a molecule known to be enhanced by far UV (FUV) and X-ray irradiation. In chemical models assuming a spherically symmetric envelope, the volume of gas irradiated by protostellar FUV radiation is very small due to the high extinction by dust. The abundance of CO+ is thus underpredicted by orders of magnitude. In a more realistic model, FUV photons can escape through an outflow region and irradiate gas at the border to the envelope. Thus, we introduce the first 2D axi-symmetric chemical model of the envelope of a high-mass star forming region to explain the CO+ observations as a prototypical FUV tracer. The model assumes an axi-symmetric power-law density structure with a cavity due to the outflow. The local FUV flux is calculated by a Monte Carlo radiative transfer code taking scattering on dust into account. A grid of precalculated chemical abundances, introduced in the first part of this series of papers, is used to ...

  10. Museum: Multidimensional web page segment evaluation model

    CERN Document Server

    Kuppusamy, K S

    2012-01-01

    The evaluation of a web page with respect to a query is a vital task in the web information retrieval domain. This paper proposes the evaluation of a web page as a bottom-up process from the segment level to the page level. A model for evaluating the relevancy is proposed incorporating six different dimensions. An algorithm for evaluating the segments of a web page, using the above mentioned six dimensions is proposed. The benefits of fine-granining the evaluation process to the segment level instead of the page level are explored. The proposed model can be incorporated for various tasks like web page personalization, result re-ranking, mobile device page rendering etc.

  11. Deterministic multidimensional growth model for small-world networks

    CERN Document Server

    Peng, Aoyuan

    2011-01-01

    We proposed a deterministic multidimensional growth model for small-world networks. The model can characterize the distinguishing properties of many real-life networks with geometric space structure. Our results show the model possesses small-world effect: larger clustering coefficient and smaller characteristic path length. We also obtain some accurate results for its properties including degree distribution, clustering coefficient and network diameter and discuss them. It is also worth noting that we get an accurate analytical expression for calculating the characteristic path length. We verify numerically and experimentally these main features.

  12. A Multi-Dimensional Classification Model for Scientific Workflow Characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Ramakrishnan, Lavanya; Plale, Beth

    2010-04-05

    Workflows have been used to model repeatable tasks or operations in manufacturing, business process, and software. In recent years, workflows are increasingly used for orchestration of science discovery tasks that use distributed resources and web services environments through resource models such as grid and cloud computing. Workflows have disparate re uirements and constraints that affects how they might be managed in distributed environments. In this paper, we present a multi-dimensional classification model illustrated by workflow examples obtained through a survey of scientists from different domains including bioinformatics and biomedical, weather and ocean modeling, astronomy detailing their data and computational requirements. The survey results and classification model contribute to the high level understandingof scientific workflows.

  13. Bifactor Approach to Modeling Multidimensionality of Physical Self-Perception Profile

    Science.gov (United States)

    Chung, ChihMing; Liao, Xiaolan; Song, Hairong; Lee, Taehun

    2016-01-01

    The multi-dimensionality of Physical Self-Perception Profile (PSPP) has been acknowledged by the use of correlated-factor model and second-order model. In this study, the authors critically endorse the bifactor model, as a substitute to address the multi-dimensionality of PSPP. To cross-validate the models, analyses are conducted first in…

  14. A CONCEPTUAL MULTIDIMENSIONAL MODEL FOR ASSESSING SMART SUSTAINABLE CITIES

    Directory of Open Access Journals (Sweden)

    Sukaina Al-Nasrawi

    2015-12-01

    Full Text Available The concept of Smart Sustainable Cities (SSC is gaining increasing attention by the countries around the globe, particularly in response to potential future environmental challenges and increased proportion of populations living in cities. Several countries claim to have implemented or in the process of implementing SSCs, and there are many models that can be used to measure how 'smart' the initiatives and cities are. This paper critically evaluates the main models to measure city smartness and identifies deficiencies, namely that they are not sensitive to the needs, resources, priorities and wider context for individual cities. The paper suggests a multidimensional methodological model that assists in evaluating the smartness level of a city while being sensitive to its context. It provides further contribution by combining sustainable and smart attributes of a city

  15. Mechanistic Multidimensional Modeling of Forced Convection Boiling Heat Transfer

    Directory of Open Access Journals (Sweden)

    Michael Z. Podowski

    2009-01-01

    Full Text Available Due to the importance of boiling heat transfer in general, and boiling crisis in particular, for the analysis of operation and safety of both nuclear reactors and conventional thermal power systems, extensive efforts have been made in the past to develop a variety of methods and tools to evaluate the boiling heat transfer coefficient and to assess the onset of temperature excursion and critical heat flux (CHF at various operating conditions of boiling channels. The objective of this paper is to present mathematical modeling concepts behind the development of mechanistic multidimensional models of low-quality forced convection boiling, including the mechanisms leading to temperature excursion and the onset of CHF.

  16. Applying Unidimensional and Multidimensional Item Response Theory Models in Testlet-Based Reading Assessment

    Science.gov (United States)

    Min, Shangchao; He, Lianzhen

    2014-01-01

    This study examined the relative effectiveness of the multidimensional bi-factor model and multidimensional testlet response theory (TRT) model in accommodating local dependence in testlet-based reading assessment with both dichotomously and polytomously scored items. The data used were 14,089 test-takers' item-level responses to the testlet-based…

  17. Empirically indistinguishable multidimensional IRT and locally dependent unidimensional item response models.

    Science.gov (United States)

    Ip, Edward Haksing

    2010-05-01

    Multidimensionality is a core concept in the measurement and analysis of psychological data. In personality assessment, for example, constructs are mostly theoretically defined as unidimensional, yet responses collected from the real world are almost always determined by multiple factors. Significant research efforts have concentrated on the use of simulated studies to evaluate the robustness of unidimensional item response models when applied to multidimensional data with a dominant dimension. In contrast, in the present paper, I report the result from a theoretical investigation that a multidimensional item response model is empirically indistinguishable from a locally dependent unidimensional model, of which the single dimension represents the actual construct of interest. A practical implication of this result is that multidimensional response data do not automatically require the use of multidimensional models. Circumstances under which the alternative approach of locally dependent unidimensional models may be useful are discussed.

  18. A Summary of Interfacial Heat Transfer Models and Correlations

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Sung Won; Cho, Hyung Kyu; Lee, Young Jin; Kim, Hee Chul; Jung, Young Jong; Kim, K. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2007-10-15

    A long term project has been launched in October 2006 to develop a plant safety analysis code. 5 organizations are joining together for the harmonious coworking to build up the code. In this project, KAERI takes the charge of the building up the physical models and correlations about the transport phenomena. The momentum and energy transfer terms as well as the mass are surveyed from the RELAP5/MOD3, RELAP5-3D, CATHARE, and TRAC-M does. Also the recent papers are surveyed. Among these resources, most of the CATHARE models are based on their own experiment and test results. Thus, the CATHARE models are only used as the comparison purposes. In this paper, a summary of the models and the correlations about the interfacial heat transfer are represented. These surveyed models and correlations will be tested numerically and one correlation is selected finally.

  19. A log-linear multidimensional Rasch model for capture-recapture.

    Science.gov (United States)

    Pelle, E; Hessen, D J; van der Heijden, P G M

    2016-02-20

    In this paper, a log-linear multidimensional Rasch model is proposed for capture-recapture analysis of registration data. In the model, heterogeneity of capture probabilities is taken into account, and registrations are viewed as dichotomously scored indicators of one or more latent variables that can account for correlations among registrations. It is shown how the probability of a generic capture profile is expressed under the log-linear multidimensional Rasch model and how the parameters of the traditional log-linear model are derived from those of the log-linear multidimensional Rasch model. Finally, an application of the model to neural tube defects data is presented.

  20. Multidimensional modelling to investigate interspecies hydrogen transfer in anaerobic biofilms.

    Science.gov (United States)

    Batstone, D J; Picioreanu, C; van Loosdrecht, M C M

    2006-09-01

    Anaerobic digestion is a multistep process, mediated by a functionally and phylogenetically diverse microbial population. One of the crucial steps is oxidation of organic acids, with electron transfer via hydrogen or formate from acetogenic bacteria to methanogens. This syntrophic microbiological process is strongly restricted by a thermodynamic limitation on the allowable hydrogen or formate concentration. In order to study this process in more detail, we developed an individual-based biofilm model which enables to describe the processes at a microbial resolution. The biochemical model is the ADM1, implemented in a multidimensional domain. With this model, we evaluated three important issues for the syntrophic relationship: (i) Is there a fundamental difference in using hydrogen or formate as electron carrier? (ii) Does a thermodynamic-based inhibition function produced substantially different results from an empirical function? and; (iii) Does the physical co-location of acetogens and methanogens follow directly from a general model. Hydrogen or formate as electron carrier had no substantial impact on model results. Standard inhibition functions or thermodynamic inhibition function gave similar results at larger substrate field grid sizes (> 10 microm), but at smaller grid sizes, the thermodynamic-based function reduced the number of cells with long interspecies distances (> 2.5 microm). Therefore, a very fine grid resolution is needed to reflect differences between the thermodynamic function, and a more generic inhibition form. The co-location of syntrophic bacteria was well predicted without a need to assume a microbiological based mechanism (e.g., through chemotaxis) of biofilm formation.

  1. Item Vector Plots for the Multidimensional Three-Parameter Logistic Model

    Science.gov (United States)

    Bryant, Damon; Davis, Larry

    2011-01-01

    This brief technical note describes how to construct item vector plots for dichotomously scored items fitting the multidimensional three-parameter logistic model (M3PLM). As multidimensional item response theory (MIRT) shows promise of being a very useful framework in the test development life cycle, graphical tools that facilitate understanding…

  2. Modeling and multidimensional optimization of a tapered free electron laser

    Directory of Open Access Journals (Sweden)

    Y. Jiao

    2012-05-01

    Full Text Available Energy extraction efficiency of a free electron laser (FEL can be greatly increased using a tapered undulator and self-seeding. However, the extraction rate is limited by various effects that eventually lead to saturation of the peak intensity and power. To better understand these effects, we develop a model extending the Kroll-Morton-Rosenbluth, one-dimensional theory to include the physics of diffraction, optical guiding, and radially resolved particle trapping. The predictions of the model agree well with that of the GENESIS single-frequency numerical simulations. In particular, we discuss the evolution of the electron-radiation interaction along the tapered undulator and show that the decreasing of refractive guiding is the major cause of the efficiency reduction, particle detrapping, and then saturation of the radiation power. With this understanding, we develop a multidimensional optimization scheme based on GENESIS simulations to increase the energy extraction efficiency via an improved taper profile and variation in electron beam radius. We present optimization results for hard x-ray tapered FELs, and the dependence of the maximum extractable radiation power on various parameters of the initial electron beam, radiation field, and the undulator system. We also study the effect of the sideband growth in a tapered FEL. Such growth induces increased particle detrapping and thus decreased refractive guiding that together strongly limit the overall energy extraction efficiency.

  3. Model Based Defect Detection in Multi-Dimensional Vector Spaces

    Science.gov (United States)

    Honda, Toshifumi; Obara, Kenji; Harada, Minoru; Igarashi, Hajime

    A highly sensitive inspection algorithm is proposed that extracts defects in multidimensional vector spaces from multiple images. The proposed algorithm projects subtraction vectors calculated from test and reference images to control the noise by reducing the dimensionality of vector spaces. The linear projection vectors are optimized using a physical defect model, and the noise distribution is calculated from the images. Because the noise distribution varies with the intensity or texture of the pixels, the target image is divided into small regions and the noise distribution of the subtraction images are calculated for each divided region. The bidirectional local perturbation pattern matching (BD-LPPM) which is an enhanced version of the LPPM, is proposed to increase the sensitivity when calculating the subtraction vectors, especially when the reference image contains more high-frequency components than the test image. The proposed algorithm is evaluated using defect samples for three different scanning electron microscopy images. The results reveal that the proposed algorithm increases the signal-to-noise ratio by a factor of 1.32 relative to that obtained using the Mahalanobis distance algorithm.

  4. A CONCEPTUAL TRAJECTORY MULTIDIMENSIONAL MODEL: AN APPLICATION TO PUBLIC TRANSPORTATION

    Directory of Open Access Journals (Sweden)

    FRANCISCO MORENO

    2011-01-01

    Full Text Available Actualmente, gracias a tecnologías como los sistemas de posicionamiento global y dispositivos móviles provistos de sensores, se puede recopilar una gran cantidad de datos sobre objetos móviles, e.g., datos relacionados con la trayectoria seguida por estos objetos. Por otra parte, las Bodegas de Datos (BDs, usualmente modeladas mediante una vista multidimensional de los datos, son bases de datos especializadas para ayudar en la toma de decisiones. Desafortunadamente, las BDs convencionales ofrecen poco soporte para la gestión de trayectorias. Aunque existen algunas propuestas que tratan con BDs de trayectorias, ninguna de ellas se enfoca en su modelamiento conceptual multidimensional. En este artículo se extiende un modelo conceptual multidimensional espacial donde se incorporan las trayectorias como conceptos de primera clase. Con el fi n de mostrar la conveniencia de la propuesta, se presenta un ejemplo relacionado con transporte público.

  5. Multidimensional analysis and probabilistic model of volcanic and seismic activities

    Science.gov (United States)

    Fedorov, V.

    2009-04-01

    .I. Gushchenko, 1979) and seismological (database of USGS/NEIC Significant Worldwide Earthquakes, 2150 B.C.- 1994 A.D.) information which displays dynamics of endogenic relief-forming processes over a period of 1900 to 1994. In the course of the analysis, a substitution of calendar variable by a corresponding astronomical one has been performed and the epoch superposition method was applied. In essence, the method consists in that the massifs of information on volcanic eruptions (over a period of 1900 to 1977) and seismic events (1900-1994) are differentiated with respect to value of astronomical parameters which correspond to the calendar dates of the known eruptions and earthquakes, regardless of the calendar year. The obtained spectra of volcanic eruptions and violent earthquake distribution in the fields of the Earth orbital movement parameters were used as a basis for calculation of frequency spectra and diurnal probability of volcanic and seismic activity. The objective of the proposed investigations is a probabilistic model development of the volcanic and seismic events, as well as GIS designing for monitoring and forecast of volcanic and seismic activities. In accordance with the stated objective, three probability parameters have been found in the course of preliminary studies; they form the basis for GIS-monitoring and forecast development. 1. A multidimensional analysis of volcanic eruption and earthquakes (of magnitude 7) have been performed in terms of the Earth orbital movement. Probability characteristics of volcanism and seismicity have been defined for the Earth as a whole. Time intervals have been identified with a diurnal probability twice as great as the mean value. Diurnal probability of volcanic and seismic events has been calculated up to 2020. 2. A regularity is found in duration of dormant (repose) periods has been established. A relationship has been found between the distribution of the repose period probability density and duration of the period. 3

  6. Multi-Dimensional Piece-Wise Self-Affine Fractal Interpolation Model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Tong; ZHUANG Zhuo

    2007-01-01

    Iterated function system (IFS) models have been used to represent discrete sequences where the attractor of the IFS is piece-wise self-affine in R2 or R3 (R is the set of real numbers). In this paper, the piece-wise self-affine IFS model is extended from R3 to Rn (n is an integer greater than 3), which is called the multi-dimensional piece-wise self-affine fractal interpolation model. This model uses a "mapping partial derivative", and a constrained inverse algorithm to identify the model parameters. The model values depend continuously on all the model parameters, and represent most data which are not multi-dimensional self-affine in Rn. Therefore, the result is very general. The class of functions obtained is much more diverse because their values depend continuously on all of the variables, with all the coefficients of the possible multi-dimensional affine maps determining the functions.

  7. The Structure of Multidimensional Perfectionism: Support for a Bifactor Model With a Dominant General Factor.

    Science.gov (United States)

    Smith, Martin M; Saklofske, Donald H

    2016-08-05

    Evidence suggests perfectionism is a multidimensional construct composed of 2 higher order factors: perfectionistic strivings and perfectionistic concerns. However, the substantial overlap between perfectionistic strivings and perfectionistic concerns is problematic, as are the unanswered questions regarding the structure of perfectionism following removal of common variance. This research addressed this through bifactor modeling. Three student samples (N = 742) completed Hewitt and Flett's ( 1991 ) Multidimensional Perfectionism Scale, Frost, Marten, Lahart, and Rosenblate's ( 1990 ) Multidimensional Perfectionism Scale, and Slaney, Rice, Mobley, Trippi, and Ashby's ( 2001 ) Almost Perfect Scale-Revised. Greater support was consistently found for the bifactor model, relative to the 2-factor model. Results suggest the bifactor model best represents the structure of perfectionism and provide preliminary support for the use of a general factor score. Researchers are cautioned that removal of general variance may render the reliability of specific factors (i.e., perfectionistic strivings and perfectionistic concerns) suspect.

  8. Exploring the Estimation of Examinee Locations Using Multidimensional Latent Trait Models under Different Distributional Assumptions

    Science.gov (United States)

    Jang, Hyesuk

    2014-01-01

    This study aims to evaluate a multidimensional latent trait model to determine how well the model works in various empirical contexts. Contrary to the assumption of these latent trait models that the traits are normally distributed, situations in which the latent trait is not shaped with a normal distribution may occur (Sass et al, 2008; Woods…

  9. A Multidimensional Model for Child Maltreatment Prevention Readiness in Low- and Middle-Income Countries

    Science.gov (United States)

    Mikton, Christopher; Mehra, Radhika; Butchart, Alexander; Addiss, David; Almuneef, Maha; Cardia, Nancy; Cheah, Irene; Chen, JingQi; Makoae, Mokhantso; Raleva, Marija

    2011-01-01

    The study's aim was to develop a multidimensional model for the assessment of child maltreatment prevention readiness in low- and middle-income countries. The model was developed based on a conceptual review of relevant existing models and approaches, an international expert consultation, and focus groups in six countries. The final model…

  10. Conversion of the Forces Mobilization Model (FORCEMOB) from FORTRAN to C

    Science.gov (United States)

    2015-08-01

    FORTRAN, hindering maintenance or modification of FORCEMOB. The greater power of modern computers can, in certain cases, negate the speed advantage of...Guillen, Donna, George Mesina, and Joshua Hykes. “Restructuring RELAP5-3D for Next Generation Nuclear Plant Analysis.” American Nuclear Society 2006...34 COBALT BLUE, INC, 2006. Guillen, Donna, George Mesina, and Joshua Hykes. Restructuring RELAP5-3D for Next- Generation Nuclear Plant Analysis. American

  11. A Quasi-Nonmetric Method for Multidimensional Scaling via an Extended Euclidean Model.

    Science.gov (United States)

    Winsberg, Suzanne; Carroll, J. Douglas

    1989-01-01

    An Extended Two-Way Euclidean Multidimensional Scaling (MDS) model that assumes both common and specific dimensions is described and contrasted with the "standard" (Two-Way) MDS model. Illustrations with both artificial and real data on the judged similarity of nations are provided. (TJH)

  12. Finite Mixture Multilevel Multidimensional Ordinal IRT Models for Large Scale Cross-Cultural Research

    NARCIS (Netherlands)

    M.G. de Jong (Martijn); J-B.E.M. Steenkamp (Jan-Benedict)

    2009-01-01

    textabstractWe present a class of finite mixture multilevel multidimensional ordinal IRT models for large scale cross-cultural research. Our model is proposed for confirmatory research settings. Our prior for item parameters is a mixture distribution to accommodate situations where different groups

  13. Putting Theory to the Test: Modeling a Multidimensional, Developmentally-Based Approach to Preschool Disruptive Behavior

    Science.gov (United States)

    Wakschlag, Lauren S.; Henry, David B.; Tolan, Patrick H.; Carter, Alice S.; Burns, James L.; Briggs-Gowan, Margaret J.

    2012-01-01

    Objective: There is increasing emphasis on dimensional conceptualizations of psychopathology, but empirical evidence of their utility is just emerging. In particular, although a range of multidimensional models have been proposed, the relative fit of competing models has rarely been tested. Furthermore, developmental considerations have received…

  14. Integration of Generic Multi-dimensional Model and Operational Policies for Batch Cooling Crystallization

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli; Singh, Ravendra; Sin, Gürkan

    2011-01-01

    A generic multi-dimensional modeling framework for studying batch cooling crystallization processes under generated operational policies is presented. The generic nature of the modeling allows the study of a wide range of chemical systems under different operational scenarios, enabling thereby, t...

  15. Putting Theory to the Test: Modeling a Multidimensional, Developmentally-Based Approach to Preschool Disruptive Behavior

    Science.gov (United States)

    Wakschlag, Lauren S.; Henry, David B.; Tolan, Patrick H.; Carter, Alice S.; Burns, James L.; Briggs-Gowan, Margaret J.

    2012-01-01

    Objective: There is increasing emphasis on dimensional conceptualizations of psychopathology, but empirical evidence of their utility is just emerging. In particular, although a range of multidimensional models have been proposed, the relative fit of competing models has rarely been tested. Furthermore, developmental considerations have received…

  16. Evidencing Learning Outcomes: A Multi-Level, Multi-Dimensional Course Alignment Model

    Science.gov (United States)

    Sridharan, Bhavani; Leitch, Shona; Watty, Kim

    2015-01-01

    This conceptual framework proposes a multi-level, multi-dimensional course alignment model to implement a contextualised constructive alignment of rubric design that authentically evidences and assesses learning outcomes. By embedding quality control mechanisms at each level for each dimension, this model facilitates the development of an aligned…

  17. Application of stochastic weighted algorithms to a multidimensional silica particle model

    Energy Technology Data Exchange (ETDEWEB)

    Menz, William J. [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Patterson, Robert I.A.; Wagner, Wolfgang [Weierstrass Institute for Applied Analysis and Stochastics, Mohrenstrasse 39, Berlin 10117 (Germany); Kraft, Markus, E-mail: mk306@cam.ac.uk [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA (United Kingdom)

    2013-09-01

    Highlights: •Stochastic weighted algorithms (SWAs) are developed for a detailed silica model. •An implementation of SWAs with the transition kernel is presented. •The SWAs’ solutions converge to the direct simulation algorithm’s (DSA) solution. •The efficiency of SWAs is evaluated for this multidimensional particle model. •It is shown that SWAs can be used for coagulation problems in industrial systems. -- Abstract: This paper presents a detailed study of the numerical behaviour of stochastic weighted algorithms (SWAs) using the transition regime coagulation kernel and a multidimensional silica particle model. The implementation in the SWAs of the transition regime coagulation kernel and associated majorant rates is described. The silica particle model of Shekar et al. [S. Shekar, A.J. Smith, W.J. Menz, M. Sander, M. Kraft, A multidimensional population balance model to describe the aerosol synthesis of silica nanoparticles, Journal of Aerosol Science 44 (2012) 83–98] was used in conjunction with this coagulation kernel to study the convergence properties of SWAs with a multidimensional particle model. High precision solutions were calculated with two SWAs and also with the established direct simulation algorithm. These solutions, which were generated using large number of computational particles, showed close agreement. It was thus demonstrated that SWAs can be successfully used with complex coagulation kernels and high dimensional particle models to simulate real-world systems.

  18. A Multidimensional Partial Credit Model with Associated Item and Test Statistics: An Application to Mixed-Format Tests

    Science.gov (United States)

    Yao, Lihua; Schwarz, Richard D.

    2006-01-01

    Multidimensional item response theory (IRT) models have been proposed for better understanding the dimensional structure of data or to define diagnostic profiles of student learning. A compensatory multidimensional two-parameter partial credit model (M-2PPC) for constructed-response items is presented that is a generalization of those proposed to…

  19. Aspects of data modeling and query processing for complex multidimensional data

    DEFF Research Database (Denmark)

    Pedersen, Torben Bach

    by existing OLAP systems, enable practical pre-aggregation. The algorithms have low computational complexity and may be applied incrementally to reduce the cost of updating OLAP structures. The transformations can be made transparently to the user. A prototype implementation of the techniques is reported......This thesis is about data modeling and query processing for complex multidimensional data. Multidimensional data has become the subject of much attention in both academia and industry in recent years, fueled by the popularity of data warehousing and On-Line Analytical Processing (OLAP) applications....... One application area where complex multidimensional data is common is within medical informatics, an area that may benefit significantly from the functionality offered by data warehousing and OLAP. However, the special nature of clinical applications poses different and new requirements to data...

  20. Latent Variable Selection for Multidimensional Item Response Theory Models via [Formula: see text] Regularization.

    Science.gov (United States)

    Sun, Jianan; Chen, Yunxiao; Liu, Jingchen; Ying, Zhiliang; Xin, Tao

    2016-12-01

    We develop a latent variable selection method for multidimensional item response theory models. The proposed method identifies latent traits probed by items of a multidimensional test. Its basic strategy is to impose an [Formula: see text] penalty term to the log-likelihood. The computation is carried out by the expectation-maximization algorithm combined with the coordinate descent algorithm. Simulation studies show that the resulting estimator provides an effective way in correctly identifying the latent structures. The method is applied to a real dataset involving the Eysenck Personality Questionnaire.

  1. Selection of unidimensional scales from a multidimensional item bank in the polytomous Mokken IRT model

    NARCIS (Netherlands)

    Hemker, BT; Sijtsma, Klaas; Molenaar, Ivo W

    1995-01-01

    An automated item selection procedure for selecting unidimensional scales of polytomous items from multidimensional datasets is developed for use in the context of the Mokken item response theory model of monotone homogeneity (Mokken & Lewis, 1982). The selection procedure is directly based on the s

  2. Alternative Multidimensional Models Explaining and Improving Academic Achievement in Latino Students

    Science.gov (United States)

    Gonzalez, Virginia; Soltero, Sonia W.

    2011-01-01

    Our objective is to provide two multidimensional models (i.e., contextual-interaction and Ethnic Educator) including sociopolitical, socioeconomic, sociocultural, and sociohistorical factors explaining underachievement in Latinos. First, we critically discuss single-factor theories (i.e., deficit, resistance, social reproduction, cultural…

  3. Measuring the Perceived Quality of an AR-Based Learning Application: A Multidimensional Model

    Science.gov (United States)

    Pribeanu, Costin; Balog, Alexandru; Iordache, Dragos Daniel

    2017-01-01

    Augmented reality (AR) technologies could enhance learning in several ways. The quality of an AR-based educational platform is a combination of key features that manifests in usability, usefulness, and enjoyment for the learner. In this paper, we present a multidimensional model to measure the quality of an AR-based application as perceived by…

  4. A Multidimensional Item Response Modeling Approach for Improving Subscale Proficiency Estimation and Classification

    Science.gov (United States)

    Yao, Lihua; Boughton, Keith A.

    2007-01-01

    Several approaches to reporting subscale scores can be found in the literature. This research explores a multidimensional compensatory dichotomous and polytomous item response theory modeling approach for subscale score proficiency estimation, leading toward a more diagnostic solution. It also develops and explores the recovery of a Markov chain…

  5. TSCALE: A New Multidimensional Scaling Procedure Based on Tversky's Contrast Model.

    Science.gov (United States)

    DeSarbo, Wayne S.; And Others

    1992-01-01

    TSCALE, a multidimensional scaling procedure based on the contrast model of A. Tversky for asymmetric three-way, two-mode proximity data, is presented. TSCALE conceptualizes a latent dimensional structure to describe the judgmental stimuli. A Monte Carlo analysis and two consumer psychology applications illustrate the procedure. (SLD)

  6. Bifactor models and rotations: exploring the extent to which multidimensional data yield univocal scale scores.

    Science.gov (United States)

    Reise, Steven P; Moore, Tyler M; Haviland, Mark G

    2010-11-01

    The application of psychological measures often results in item response data that arguably are consistent with both unidimensional (a single common factor) and multidimensional latent structures (typically caused by parcels of items that tap similar content domains). As such, structural ambiguity leads to seemingly endless "confirmatory" factor analytic studies in which the research question is whether scale scores can be interpreted as reflecting variation on a single trait. An alternative to the more commonly observed unidimensional, correlated traits, or second-order representations of a measure's latent structure is a bifactor model. Bifactor structures, however, are not well understood in the personality assessment community and thus rarely are applied. To address this, herein we (a) describe issues that arise in conceptualizing and modeling multidimensionality, (b) describe exploratory (including Schmid-Leiman [Schmid & Leiman, 1957] and target bifactor rotations) and confirmatory bifactor modeling, (c) differentiate between bifactor and second-order models, and (d) suggest contexts where bifactor analysis is particularly valuable (e.g., for evaluating the plausibility of subscales, determining the extent to which scores reflect a single variable even when the data are multidimensional, and evaluating the feasibility of applying a unidimensional item response theory (IRT) measurement model). We emphasize that the determination of dimensionality is a related but distinct question from either determining the extent to which scores reflect a single individual difference variable or determining the effect of multidimensionality on IRT item parameter estimates. Indeed, we suggest that in many contexts, multidimensional data can yield interpretable scale scores and be appropriately fitted to unidimensional IRT models.

  7. Efficient Full Information Maximum Likelihood Estimation for Multidimensional IRT Models. Research Report. ETS RR-09-03

    Science.gov (United States)

    Rijmen, Frank

    2009-01-01

    Maximum marginal likelihood estimation of multidimensional item response theory (IRT) models has been hampered by the calculation of the multidimensional integral over the ability distribution. However, the researcher often has a specific hypothesis about the conditional (in)dependence relations among the latent variables. Exploiting these…

  8. Establishing the construct validity of conversational C-Tests using a multidimensional Rasch model

    Directory of Open Access Journals (Sweden)

    Purya Baghaei

    2014-03-01

    Full Text Available C-Test is a variation of cloze test where the second half of every second word is deleted. The number of words correctly reconstructed by the test taker is considered to be a measure of general language proficiency. In this pilot study the componential structure of an English C-Test consisting of two spoken-discourse passages and two written-discourse passages is investigated with the help of both unidimensional and multidimensional Rasch model. In a sample of 99 fairly advanced Iranian students of English the data fitted better the multidimensional partial credit model as defined in multidimensional random coefficients multinomial logit model (Adams, Wilson, & Wang, 1997 than Masters’ (1982 unidimensional partial credit model. This indicates that spoken-discourse and written-discourse C-Test passages form distinct dimensions. We argue that spoken-discourse C-Test texts may tap better into students’ listening/speaking skills than C-Test based solely on written discourse texts and that therefore C-Tests consisting of both conversational and written-discourse passages can more adequately operationalize the construct of general language proficiency than C-Tests containing only written discourse passages. Considering the small sample size of the study the findings should be interpreted cautiously.

  9. A Multidimensional Markov Chain Model for Simulating Stochastic Permeability Conditioned by Pressure Measures

    Directory of Open Access Journals (Sweden)

    S Zein

    2016-09-01

    Full Text Available In this paper, we are interested in simulating a stochastic permeability distribution constrained by some pressure measures coming from a steady flow (Poisson problem over a two-dimensional domain. The permeability is discretized over a regular rectangular gird and considered to be constant by cell but it can take randomly a finite number of values. When such permeability is modeled using a multidimensional Markov chain, it can be constrained by some permeability measures. The purpose of this work is to propose an algorithm that simulates stochastic permeability constrained not only by some permeability measures but also by pressure measures at some points of the domain. The simulation algorithm couples the MCMC sampling technique with the multidimensional Markov chain model in a Bayesian framework.

  10. A framework for analyzing ecological trait-based models in multi-dimensional niche spaces

    OpenAIRE

    Biancalani, Tommaso; DeVille, Lee; Goldenfeld, Nigel

    2014-01-01

    We develop an theoretical approach for predicting biodiversity in multi-dimensional niche spaces, arising due to ecological drivers such as competitive exclusion. The novelty of our approach relies on the fact that ecological niches are described by sequences of strings, which allows us to describe multiple traits. We define the mathematical framework for analyzing pattern forming instabilities in these models, showing surprisingly that the analytic linear theory predicts the asymptotically l...

  11. Integrated Flight Mechanic and Aeroelastic Modelling and Control of a Flexible Aircraft Considering Multidimensional Gust Input

    Science.gov (United States)

    2000-05-01

    INTEGRATED FLIGHT MECHANIC AND AEROELASTIC MODELLING AND CONTROL OF A FLEXIBLE AIRCRAFT CONSIDERING MULTIDIMENSIONAL GUST INPUT Patrick Teufel, Martin Hanel...the lateral separation distance have been developed by ’ = matrix of two dimensional spectrum function Eichenbaum 4 and are described by Bessel...Journal of Aircraft, Vol. 30, No. 5, Sept.-Oct. 1993 Relations to Risk Sensitivity, System & Control Letters 11, [4] Eichenbaum F.D., Evaluation of 3D

  12. Multi-dimensional population balance models of crystallization processes

    DEFF Research Database (Denmark)

    Meisler, Kresten Troelstrup; von Solms, Nicolas

    A generic and model-based framework for batch cooling crystallization operations has been extended to incorporate continuous and fed-batch processes. Modules for the framework have been developed, including a module for reactions, allowing the study of reactive crystallization within the framework...... and parameters for the simulation can be found in the database. A procedure for parameter estimation has been illustrated based on experimental work. The identifiability of the models has been discussed in relation to parameter estimation using sensitivity analysis. Some important identifiability issues have...... been investigated using the model structure to simulate perfect data and data with white noise added to it. It is found that the kinetic models may not be reliably estimated from the concentration profile using the parameter estimation procedure for both perfect and noisy data. The framework has been...

  13. Evaluation of multidimensional models of WAIS-IV subtest performance.

    Science.gov (United States)

    McFarland, Dennis J

    2017-04-21

    The present study examined the extent to which the covariance structure of the WAIS-IV is best accounted for by models that assume that test performance is the result of group-level factors and multiple independent general factors. Structural models with one to four general factors were evaluated with either four or five group-level factors. Simulations based on four general factors were run to clarify the adequacy of the estimates of the allocation of covariance by the models. Four independent general factors provided better fit than a single general factor for either model with four or five group-level factors. While one of the general factors had much larger loadings than all other factors, simulation results suggested that this might be an artifact of the statistical procedure rather than a reflection of the nature of individual differences in cognitive abilities. These results argue against the contention that clinical interpretation of cognitive test batteries should primarily be at the level of general intelligence. It is a fallacy to assume that factor analysis can reveal the structure of human abilities. Test validity should not be based solely on the results of modeling the covariance of test batteries.

  14. Multidimensional Model of Disability and Role Functioning in Rheumatoid Arthritis.

    Science.gov (United States)

    Ormseth, Sarah R; Draper, Taylor L; Irwin, Michael R; Weisman, Michael H; Aréchiga, Adam E; Hartoonian, Narineh; Bui, Thuy; Nicassio, Perry M

    2015-12-01

    To examine a model addressing the roles of rheumatoid arthritis (RA) disease burden, mood disturbance, and disability as determinants of impairments in role functioning. In a cross-sectional design, 103 RA patients recruited from the community to participate in a clinical trial completed assessments of self-assessed disease burden (total joint pain and disease activity), mood disturbance (Center for Epidemiological Studies Depression Scale depressed mood, somatic symptoms, lack of positive affect, and interpersonal problems), disability (Health Assessment Questionnaire disability index gross and fine motor), and role functioning (Short Form 36 health survey physical and social). Structural equation modeling (SEM) was used to examine direct and indirect mechanisms linking disease burden to role functioning. SEM results indicated that the model had excellent fit: S-Bχ(2)(30) = 38.59, P = 0.135; comparative fit index = 0.977, standardized root mean residual = 0.062, and root mean square error of approximation = 0.053. Mediational analyses demonstrated that, while disease burden was associated with poor role functioning, its effects were jointly mediated by mood disturbance and disability. After the effects of mood disturbance and disability were taken into account, the effect of disease burden on role functioning was not significant. The results indicate that mood disturbance and disability may serve as important pathways through which RA disease burden affects role functioning. Future longitudinal research is suggested to replicate these findings and further explore the mediational mechanisms examined in this study. © 2015, American College of Rheumatology.

  15. Ultralow-velocity zone geometries resolved by multidimensional waveform modelling

    Science.gov (United States)

    Vanacore, E. A.; Rost, S.; Thorne, M. S.

    2016-07-01

    Ultralow-velocity zones (ULVZs) are thin patches of material with strongly reduced seismic wave speeds situated on top of the core-mantle boundary (CMB). A common phase used to detect ULVZs is SPdKS (SKPdS), an SKS wave with a short diffracted P leg along the CMB. Most previous efforts have examined ULVZ properties using 1-D waveform modelling approaches. We present waveform modelling results using the 2.5-D finite-difference algorithm PSVaxi allowing us better insight into ULVZ structure and location. We characterize ULVZ waveforms based on ULVZ elastic properties, shape and position along the SPdKS ray path. In particular, we vary the ULVZ location (e.g. source or receiver side), ULVZ topographical profiles (e.g. boxcar, trapezoidal or Gaussian) and ULVZ lateral scale along great circle path (2.5°, 5°, 10°). We observe several waveform effects absent in 1-D ULVZ models and show evidence for waveform effects allowing the differentiation between source and receiver side ULVZs. Early inception of the SPdKS/SKPdS phase is difficult to detect for receiver-side ULVZs with maximum shifts in SKPdS initiation of ˜3° in epicentral distance, whereas source-side ULVZs produce maximum shifts of SPdKS initiation of ˜5°, allowing clear separation of source- versus receiver-side structure. We present a case study using data from up to 300 broad-band stations in Turkey recorded between 2005 and 2010. We observe a previously undetected ULVZ in the southern Atlantic Ocean region centred near 45°S, 12.5°W, with a lateral scale of ˜3°, VP reduction of 10 per cent, VS reduction of 30 per cent and density increase of 10 per cent relative to PREM.

  16. Influence of precompensation curves on multidimensional color modeling

    Science.gov (United States)

    Tuijn, Chris

    1996-03-01

    One of the major challenges in the prepress environment consists of controlling the electronic color reproduction process such that a perfect match of any original can be realized. Whether this goal can be reached depends on many factors such as the dynamic range of the input device (scanner, camera), the color gamut of the output device (dye sublimation printer, ink- jet printer, offset), the color management software etc. It is obvious that the reliability or, rather, the reproducibility of a particular device is of extreme importance in order to have a permanently correct color characterization. A technique which is often used to ensure this reliability is to carry out a local 1D calibration. Through this 1D calibration the particular device is brought into a reliable and generic state. Applying 1D calibration curves is not only useful to create reliable devices but can also be used to model devices more accurately, at least, if these calibration curves are carefully selected. In this article, we will discuss the overall suitability of applying 1D precompensation curves before applying colorimetric characterization. More specifically, we address problems related to the reliability of devices and the quality of the color characterization. The use of precompensation curves for calibration purposes is merely restricted to output devices. For input devices, precompensation curves are mainly used for quality purposes. Indeed, the careful selection of so-called input luts (lookup tables) is very important to have good-quality scans. In addition, we discuss how the so-called gamma curves relate to these precompensation curves for both scanners and monitors. This article is organized as follows. In the first section, we discuss the benefits of 1D precompensation curves for modeling output devices. We will cover both topics related to the calibration and the mathematical modeling of output devices. In the second section, we address several issues related to the

  17. Billiard representation for multidimensional multi-scalar cosmological model with exponential potentials

    CERN Document Server

    Dehnen, H; Melnikov, V N

    2003-01-01

    Multidimensional cosmological-type model with n Einstein factor spaces in the theory with l scalar fields and multiple exponential potential is considered. The dynamics of the model near the singularity is reduced to a billiard on the (N-1)-dimensional Lobachevsky space H^{N-1}, N = n+l. It is shown that for n > 1 the oscillating behaviour near the singularity is absent and solutions have an asymptotical Kasner-like behavior. For the case of one scale factor (n =1) billiards with finite volumes (e.g. coinciding with that of the Bianchi-IX model) are described and oscillating behaviour of scalar fields near the singularity is obtained.

  18. Framework for analyzing ecological trait-based models in multidimensional niche spaces

    Science.gov (United States)

    Biancalani, Tommaso; DeVille, Lee; Goldenfeld, Nigel

    2015-05-01

    We develop a theoretical framework for analyzing ecological models with a multidimensional niche space. Our approach relies on the fact that ecological niches are described by sequences of symbols, which allows us to include multiple phenotypic traits. Ecological drivers, such as competitive exclusion, are modeled by introducing the Hamming distance between two sequences. We show that a suitable transform diagonalizes the community interaction matrix of these models, making it possible to predict the conditions for niche differentiation and, close to the instability onset, the asymptotically long time population distributions of niches. We exemplify our method using the Lotka-Volterra equations with an exponential competition kernel.

  19. Music training and inhibitory control: a multidimensional model.

    Science.gov (United States)

    Moreno, Sylvain; Farzan, Faranak

    2015-03-01

    Training programs aimed to improve cognitive skills have either yielded mixed results or remain to be validated. The limited benefits of such regimens are largely attributable to weak understanding of (1) how (and which) interventions provide the most cognitive improvements; and (2) how brain networks and neural mechanisms that underlie specific cognitive abilities can be modified selectively. Studies indicate that music training leads to robust and long-lasting benefits to behavior. Importantly, behavioral advantages conferred by music extend beyond perceptual abilities to even nonauditory functions, such as inhibitory control (IC) and its neural correlates. Alternative forms of arts engagement or brain training do not appear to yield such enhancements, which suggests that music uniquely taps into brain networks subserving a variety of auditory as well as domain-general mechanisms such as IC. To account for such widespread benefits of music training, we propose a framework of transfer effects characterized by three dimensions: level of processing, nature of the transfer, and involvement of executive functions. We suggest that transfer of skills is mediated through modulation of general cognitive processes, in particular IC. We believe that this model offers a viable framework to test the extent and limitations of music-related changes.

  20. A General Fuzzy Cerebellar Model Neural Network Multidimensional Classifier Using Intuitionistic Fuzzy Sets for Medical Identification

    Directory of Open Access Journals (Sweden)

    Jing Zhao

    2016-01-01

    Full Text Available The diversity of medical factors makes the analysis and judgment of uncertainty one of the challenges of medical diagnosis. A well-designed classification and judgment system for medical uncertainty can increase the rate of correct medical diagnosis. In this paper, a new multidimensional classifier is proposed by using an intelligent algorithm, which is the general fuzzy cerebellar model neural network (GFCMNN. To obtain more information about uncertainty, an intuitionistic fuzzy linguistic term is employed to describe medical features. The solution of classification is obtained by a similarity measurement. The advantages of the novel classifier proposed here are drawn out by comparing the same medical example under the methods of intuitionistic fuzzy sets (IFSs and intuitionistic fuzzy cross-entropy (IFCE with different score functions. Cross verification experiments are also taken to further test the classification ability of the GFCMNN multidimensional classifier. All of these experimental results show the effectiveness of the proposed GFCMNN multidimensional classifier and point out that it can assist in supporting for correct medical diagnoses associated with multiple categories.

  1. A General Fuzzy Cerebellar Model Neural Network Multidimensional Classifier Using Intuitionistic Fuzzy Sets for Medical Identification.

    Science.gov (United States)

    Zhao, Jing; Lin, Lo-Yi; Lin, Chih-Min

    2016-01-01

    The diversity of medical factors makes the analysis and judgment of uncertainty one of the challenges of medical diagnosis. A well-designed classification and judgment system for medical uncertainty can increase the rate of correct medical diagnosis. In this paper, a new multidimensional classifier is proposed by using an intelligent algorithm, which is the general fuzzy cerebellar model neural network (GFCMNN). To obtain more information about uncertainty, an intuitionistic fuzzy linguistic term is employed to describe medical features. The solution of classification is obtained by a similarity measurement. The advantages of the novel classifier proposed here are drawn out by comparing the same medical example under the methods of intuitionistic fuzzy sets (IFSs) and intuitionistic fuzzy cross-entropy (IFCE) with different score functions. Cross verification experiments are also taken to further test the classification ability of the GFCMNN multidimensional classifier. All of these experimental results show the effectiveness of the proposed GFCMNN multidimensional classifier and point out that it can assist in supporting for correct medical diagnoses associated with multiple categories.

  2. Assessment of wall friction model in multi-dimensional component of MARS with air–water cross flow experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jin-Hwa [Nuclear Thermal-Hydraulic Engineering Laboratory, Seoul National University, Gwanak 599, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Korea Atomic Energy Research Institute, 989-111, Daedeok-daero, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Choi, Chi-Jin [Nuclear Thermal-Hydraulic Engineering Laboratory, Seoul National University, Gwanak 599, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Cho, Hyoung-Kyu, E-mail: chohk@snu.ac.kr [Nuclear Thermal-Hydraulic Engineering Laboratory, Seoul National University, Gwanak 599, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Euh, Dong-Jin [Korea Atomic Energy Research Institute, 989-111, Daedeok-daero, Yuseong-gu, Daejeon 305-600 (Korea, Republic of); Park, Goon-Cherl [Nuclear Thermal-Hydraulic Engineering Laboratory, Seoul National University, Gwanak 599, Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of)

    2017-02-15

    Recently, high precision and high accuracy analysis on multi-dimensional thermal hydraulic phenomena in a nuclear power plant has been considered as state-of-the-art issues. System analysis code, MARS, also adopted a multi-dimensional module to simulate them more accurately. Even though it was applied to represent the multi-dimensional phenomena, but implemented models and correlations in that are one-dimensional empirical ones based on one-dimensional pipe experimental results. Prior to the application of the multi-dimensional simulation tools, however, the constitutive models for a two-phase flow need to be carefully validated, such as the wall friction model. Especially, in a Direct Vessel Injection (DVI) system, the injected emergency core coolant (ECC) on the upper part of the downcomer interacts with the lateral steam flow during the reflood phase in the Large-Break Loss-Of-Coolant-Accident (LBLOCA). The interaction between the falling film and lateral steam flow induces a multi-dimensional two-phase flow. The prediction of ECC flow behavior plays a key role in determining the amount of coolant that can be used as core cooling. Therefore, the wall friction model which is implemented to simulate the multi-dimensional phenomena should be assessed by multidimensional experimental results. In this paper, the air–water cross film flow experiments simulating the multi-dimensional phenomenon in upper part of downcomer as a conceptual problem will be introduced. The two-dimensional local liquid film velocity and thickness data were used as benchmark data for code assessment. And then the previous wall friction model of the MARS-MultiD in the annular flow regime was modified. As a result, the modified MARS-MultiD produced improved calculation result than previous one.

  3. Development of realistic thermal-hydraulic system analysis codes ; development of thermal hydraulic test requirements for multidimensional flow modeling

    Energy Technology Data Exchange (ETDEWEB)

    Suh, Kune Yull; Yoon, Sang Hyuk; Noh, Sang Woo; Lee, Il Suk [Seoul National University, Seoul (Korea)

    2002-03-01

    This study is concerned with developing a multidimensional flow model required for the system analysis code MARS to more mechanistically simulate a variety of thermal hydraulic phenomena in the nuclear stem supply system. The capability of the MARS code as a thermal hydraulic analysis tool for optimized system design can be expanded by improving the current calculational methods and adding new models. In this study the relevant literature was surveyed on the multidimensional flow models that may potentially be applied to the multidimensional analysis code. Research items were critically reviewed and suggested to better predict the multidimensional thermal hydraulic behavior and to identify test requirements. A small-scale preliminary test was performed in the downcomer formed by two vertical plates to analyze multidimensional flow pattern in a simple geometry. The experimental result may be applied to the code for analysis of the fluid impingement to the reactor downcomer wall. Also, data were collected to find out the controlling parameters for the one-dimensional and multidimensional flow behavior. 22 refs., 40 figs., 7 tabs. (Author)

  4. Meta-modelling, visualization and emulation of multi-dimensional data for virtual production intelligence

    Science.gov (United States)

    Schulz, Wolfgang; Hermanns, Torsten; Al Khawli, Toufik

    2017-07-01

    Decision making for competitive production in high-wage countries is a daily challenge where rational and irrational methods are used. The design of decision making processes is an intriguing, discipline spanning science. However, there are gaps in understanding the impact of the known mathematical and procedural methods on the usage of rational choice theory. Following Benjamin Franklin's rule for decision making formulated in London 1772, he called "Prudential Algebra" with the meaning of prudential reasons, one of the major ingredients of Meta-Modelling can be identified finally leading to one algebraic value labelling the results (criteria settings) of alternative decisions (parameter settings). This work describes the advances in Meta-Modelling techniques applied to multi-dimensional and multi-criterial optimization by identifying the persistence level of the corresponding Morse-Smale Complex. Implementations for laser cutting and laser drilling are presented, including the generation of fast and frugal Meta-Models with controlled error based on mathematical model reduction Reduced Models are derived to avoid any unnecessary complexity. Both, model reduction and analysis of multi-dimensional parameter space are used to enable interactive communication between Discovery Finders and Invention Makers. Emulators and visualizations of a metamodel are introduced as components of Virtual Production Intelligence making applicable the methods of Scientific Design Thinking and getting the developer as well as the operator more skilled.

  5. Is the mental wellbeing of young Australians best represented by a single, multidimensional or bifactor model?

    Science.gov (United States)

    Hides, Leanne; Quinn, Catherine; Stoyanov, Stoyan; Cockshaw, Wendell; Mitchell, Tegan; Kavanagh, David J

    2016-07-30

    Internationally there is a growing interest in the mental wellbeing of young people. However, it is unclear whether mental wellbeing is best conceptualized as a general wellbeing factor or a multidimensional construct. This paper investigated whether mental wellbeing, measured by the Mental Health Continuum-Short Form (MHC-SF), is best represented by: (1) a single-factor general model; (2) a three-factor multidimensional model or (3) a combination of both (bifactor model). 2220 young Australians aged between 16 and 25 years completed an online survey including the MHC-SF and a range of other wellbeing and mental ill-health measures. Exploratory factor analysis supported a bifactor solution, comprised of a general wellbeing factor, and specific group factors of psychological, social and emotional wellbeing. Confirmatory factor analysis indicated that the bifactor model had a better fit than competing single and three-factor models. The MHC-SF total score was more strongly associated with other wellbeing and mental ill-health measures than the social, emotional or psychological subscale scores. Findings indicate that the mental wellbeing of young people is best conceptualized as an overarching latent construct (general wellbeing) to which emotional, social and psychological domains contribute. The MHC-SF total score is a valid and reliable measure of this general wellbeing factor.

  6. Multidimensional spectrometer

    Science.gov (United States)

    Zanni, Martin Thomas; Damrauer, Niels H.

    2010-07-20

    A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

  7. Multi-dimensional modeling of the application of catalytic combustion to homogeneous charge compression ignition engine

    Science.gov (United States)

    Zeng, Wen; Xie, Maozhao

    2006-12-01

    The detailed surface reaction mechanism of methane on rhodium catalyst was analyzed. Comparisons between numerical simulation and experiments showed a basic agreement. The combustion process of homogeneous charge compression ignition (HCCI) engine whose piston surface has been coated with catalyst (rhodium and platinum) was numerically investigated. A multi-dimensional model with detailed chemical kinetics was built. The effects of catalytic combustion on the ignition timing, the temperature and CO concentration fields, and HC, CO and NOx emissions of the HCCI engine were discussed. The results showed the ignition timing of the HCCI engine was advanced and the emissions of HC and CO were decreased by the catalysis.

  8. A Bifactor Multidimensional Item Response Theory Model for Differential Item Functioning Analysis on Testlet-Based Items

    Science.gov (United States)

    Fukuhara, Hirotaka; Kamata, Akihito

    2011-01-01

    A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…

  9. A multidimensional discontinuous Galerkin modeling framework for overland flow and channel routing

    Science.gov (United States)

    West, Dustin W.; Kubatko, Ethan J.; Conroy, Colton J.; Yaufman, Mariah; Wood, Dylan

    2017-04-01

    In this paper, we present the development and application of a new multidimensional, unstructured-mesh model for simulating coupled overland/open-channel flows in the kinematic wave approximation regime. The modeling approach makes use of discontinuous Galerkin (DG) finite element spatial discretizations of variable polynomial degree p, paired with explicit Runge-Kutta time steppers, and is supported by advancements made to an automatic mesh generation tool, ADMESH +, that is used to construct constrained triangulations for channel routing. The developed modeling framework is applied to a set of four test cases, where numerical results are found to compare well with known analytic solutions, experimental data and results from another well-established (structured, finite difference) model within the area of application. The numerical results obtained demonstrate the accuracy and robustness of the developed modeling framework and highlight the potential benefits of using p (polynomial) refinement for hydrological simulations.

  10. Explanatory multidimensional multilevel random item response model: an application to simultaneous investigation of word and person contributions to multidimensional lexical representations.

    Science.gov (United States)

    Cho, Sun-Joo; Gilbert, Jennifer K; Goodwin, Amanda P

    2013-10-01

    This paper presents an explanatory multidimensional multilevel random item response model and its application to reading data with multilevel item structure. The model includes multilevel random item parameters that allow consideration of variability in item parameters at both item and item group levels. Item-level random item parameters were included to model unexplained variance remaining when item related covariates were used to explain variation in item difficulties. Item group-level random item parameters were included to model dependency in item responses among items having the same item stem. Using the model, this study examined the dimensionality of a person's word knowledge, termed lexical representation, and how aspects of morphological knowledge contributed to lexical representations for different persons, items, and item groups.

  11. Multi-dimensional constraint relativistic mean field model and applications in actinide and transfermium nuclei

    CERN Document Server

    Lu, Bing-Nan; Zhao, En-Guang; Zhou, Shan-Gui

    2013-01-01

    In this contribution we present some results of potential energy surfaces of actinide and transfermium nuclei from multi-dimensional constrained relativistic mean field (MDC-RMF) models. Recently we developed multi-dimensional constrained covariant density functional theories (MDC-CDFT) in which all shape degrees of freedom $\\beta_{\\lambda\\mu}$ with even $\\mu$ are allowed and the functional can be one of the following four forms: the meson exchange or point-coupling nucleon interactions combined with the non-linear or density-dependent couplings. In MDC-RMF models, the pairing correlations are treated with the BCS method. With MDC-RMF models, the potential energy surfaces of even-even actinide nuclei were investigated and the effect of triaxiality on the fission barriers in these nuclei was discussed. The non-axial reflection-asymmetric $\\beta_{32}$ shape in some transfermium nuclei with $N=150$, namely $^{246}$Cm, $^{248}$Cf, $^{250}$Fm, and $^{252}$No were also studied.

  12. Multidimensional k-nearest neighbor model based on EEMD for financial time series forecasting

    Science.gov (United States)

    Zhang, Ningning; Lin, Aijing; Shang, Pengjian

    2017-07-01

    In this paper, we propose a new two-stage methodology that combines the ensemble empirical mode decomposition (EEMD) with multidimensional k-nearest neighbor model (MKNN) in order to forecast the closing price and high price of the stocks simultaneously. The modified algorithm of k-nearest neighbors (KNN) has an increasingly wide application in the prediction of all fields. Empirical mode decomposition (EMD) decomposes a nonlinear and non-stationary signal into a series of intrinsic mode functions (IMFs), however, it cannot reveal characteristic information of the signal with much accuracy as a result of mode mixing. So ensemble empirical mode decomposition (EEMD), an improved method of EMD, is presented to resolve the weaknesses of EMD by adding white noise to the original data. With EEMD, the components with true physical meaning can be extracted from the time series. Utilizing the advantage of EEMD and MKNN, the new proposed ensemble empirical mode decomposition combined with multidimensional k-nearest neighbor model (EEMD-MKNN) has high predictive precision for short-term forecasting. Moreover, we extend this methodology to the case of two-dimensions to forecast the closing price and high price of the four stocks (NAS, S&P500, DJI and STI stock indices) at the same time. The results indicate that the proposed EEMD-MKNN model has a higher forecast precision than EMD-KNN, KNN method and ARIMA.

  13. A multidimensional item response model : Constrained latent class analysis using the Gibbs sampler and posterior predictive checks

    NARCIS (Netherlands)

    Hoijtink, H; Molenaar, IW

    1997-01-01

    In this paper it will be shown that a certain class of constrained latent class models may be interpreted as a special case of nonparametric multidimensional item response models. The parameters of this latent class model will be estimated using an application of the Gibbs sampler. It will be illust

  14. Bridging Multidimensional Models of Ethnic-Racial and Gender Identity Among Ethnically Diverse Emerging Adults.

    Science.gov (United States)

    Wilson, Antoinette R; Leaper, Campbell

    2016-08-01

    The purpose of this study was to integrate and validate a multidimensional model of ethnic-racial identity and gender identity borrowing constructs and measures based on social identity and gender identity theories. Participants included 662 emerging adults (M age  = 19.86 years; 75 % female) who self-identified either as Asian American, Latino/a, or White European American. We assessed the following facets separately for ethnic-racial identity and gender identity: centrality, in-group affect, in-group ties, self-perceived typicality, and felt conformity pressure. Within each identity domain (gender or ethnicity/race), the five dimensions generally indicated small-to-moderate correlations with one another. Also, correlations between domains for each dimension (e.g., gender typicality and ethnic-racial typicality) were mostly moderate in magnitude. We also noted some group variations based on participants' ethnicity/race and gender in how strongly particular dimensions were associated with self-esteem. Finally, participants who scored positively on identity dimensions for both gender and ethnic-racial domains indicated higher self-esteem than those who scored high in only one domain or low in both domains. We recommend the application of multidimensional models to study social identities in multiple domains as they may relate to various outcomes during development.

  15. Data-driven modeling based on volterra series for multidimensional blast furnace system.

    Science.gov (United States)

    Gao, Chuanhou; Jian, Ling; Liu, Xueyi; Chen, Jiming; Sun, Youxian

    2011-12-01

    The multidimensional blast furnace system is one of the most complex industrial systems and, as such, there are still many unsolved theoretical and experimental difficulties, such as silicon prediction and blast furnace automation. For this reason, this paper is concerned with developing data-driven models based on the Volterra series for this complex system. Three kinds of different low-order Volterra filters are designed to predict the hot metal silicon content collected from a pint-sized blast furnace, in which a sliding window technique is used to update the filter kernels timely. The predictive results indicate that the linear Volterra predictor can describe the evolvement of the studied silicon sequence effectively with the high percentage of hitting the target, very low root mean square error and satisfactory confidence level about the reliability of the future prediction. These advantages and the low computational complexity reveal that the sliding-window linear Volterra filter is full of potential for multidimensional blast furnace system. Also, the lack of the constructed Volterra models is analyzed and the possible direction of future investigation is pointed out.

  16. Statistical resolution limit for the multidimensional harmonic retrieval model: hypothesis test and Cramér-Rao Bound approaches

    Directory of Open Access Journals (Sweden)

    El Korso Mohammed

    2011-01-01

    Full Text Available Abstract The statistical resolution limit (SRL, which is defined as the minimal separation between parameters to allow a correct resolvability, is an important statistical tool to quantify the ultimate performance for parametric estimation problems. In this article, we generalize the concept of the SRL to the multidimensional SRL (MSRL applied to the multidimensional harmonic retrieval model. In this article, we derive the SRL for the so-called multidimensional harmonic retrieval model using a generalization of the previously introduced SRL concepts that we call multidimensional SRL (MSRL. We first derive the MSRL using an hypothesis test approach. This statistical test is shown to be asymptotically an uniformly most powerful test which is the strongest optimality statement that one could expect to obtain. Second, we link the proposed asymptotic MSRL based on the hypothesis test approach to a new extension of the SRL based on the Cramér-Rao Bound approach. Thus, a closed-form expression of the asymptotic MSRL is given and analyzed in the framework of the multidimensional harmonic retrieval model. Particularly, it is proved that the optimal MSRL is obtained for equi-powered sources and/or an equi-distributed number of sensors on each multi-way array.

  17. Reduced entropic model for studies of multidimensional nonlocal transport in high-energy-density plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Del Sorbo, D.; Feugeas, J.-L.; Nicolaï, Ph.; Olazabal-Loumé, M.; Dubroca, B.; Guisset, S.; Touati, M.; Tikhonchuk, V. [Centre Lasers Intenses et Applications, Université de Bordeaux-CNRS-CEA, UMR 5107, F-33405 Talence (France)

    2015-08-15

    Hydrodynamic simulations of high-energy-density plasmas require a detailed description of energy fluxes. For low and intermediate atomic number materials, the leading mechanism is the electron transport, which may be a nonlocal phenomenon requiring a kinetic modeling. In this paper, we present and test the results of a nonlocal model based on the first angular moments of a simplified Fokker-Planck equation. This multidimensional model is closed thanks to an entropic relation (the Boltzman H-theorem). It provides a better description of the electron distribution function, thus enabling studies of small scale kinetic effects within the hydrodynamic framework. Examples of instabilities of electron plasma and ion-acoustic waves, driven by the heat flux, are presented and compared with the classical formula.

  18. Reduced entropic model for studies of multidimensional nonlocal transport in high-energy-density plasmas

    Science.gov (United States)

    Del Sorbo, D.; Feugeas, J.-L.; Nicolaï, Ph.; Olazabal-Loumé, M.; Dubroca, B.; Guisset, S.; Touati, M.; Tikhonchuk, V.

    2015-08-01

    Hydrodynamic simulations of high-energy-density plasmas require a detailed description of energy fluxes. For low and intermediate atomic number materials, the leading mechanism is the electron transport, which may be a nonlocal phenomenon requiring a kinetic modeling. In this paper, we present and test the results of a nonlocal model based on the first angular moments of a simplified Fokker-Planck equation. This multidimensional model is closed thanks to an entropic relation (the Boltzman H-theorem). It provides a better description of the electron distribution function, thus enabling studies of small scale kinetic effects within the hydrodynamic framework. Examples of instabilities of electron plasma and ion-acoustic waves, driven by the heat flux, are presented and compared with the classical formula.

  19. Nonlinear kinetic modeling of stimulated Raman scattering in a multidimensional geometry

    Energy Technology Data Exchange (ETDEWEB)

    Benisti, D.; Morice, O.; Gremillet, L.; Friou, A.; Lefebvre, E. [CEA, DAM, DIF F-91297 Arpajon (France)

    2012-05-15

    In this paper, we derive coupled envelope equations modeling the growth of stimulated Raman scattering (SRS) in a multi-dimensional geometry and accounting for nonlinear kinetic effects. In particular, our envelope equations allow for the nonlinear reduction of the Landau damping rate, whose decrease with the plasma wave amplitude depends on the rate of side-loss. Account is also made of the variations in the extent of the plasma wave packet entailed by the collisionless dissipation due to trapping. The dephasing between the electron plasma wave (EPW) and the laser drive, as well as the self-focussing of the plasma wave, both induced by the EPW nonlinear frequency shift, are also included in our envelope equations. These equations are solved in a multi-dimensional geometry using our code dubbed BRAMA, whose predictions regarding the evolution of Raman reflectivity as a function of the laser intensity are compared against previously published particle in cell results, thus illustrating the ability of BRAMA simulations to provide the correct laser threshold intensity for SRS as well as the right order of magnitude of Raman reflectivity above threshold.

  20. Putting theory to the test: modeling a multidimensional, developmentally-based approach to preschool disruptive behavior.

    Science.gov (United States)

    Wakschlag, Lauren S; Henry, David B; Tolan, Patrick H; Carter, Alice S; Burns, James L; Briggs-Gowan, Margaret J

    2012-06-01

    There is increasing emphasis on dimensional conceptualizations of psychopathology, but empirical evidence of their utility is just emerging. In particular, although a range of multidimensional models have been proposed, the relative fit of competing models has rarely been tested. Furthermore, developmental considerations have received scant attention. In this study, we tested a developmentally based, four-dimensional model of disruptive behavior theorized to represent the defining features of disruptive behavior at preschool age: Temper Loss, Noncompliance, Aggression, and Low Concern for Others. Model testing was conducted in two independent samples of preschoolers: Clinically Enriched Sample (n = 336) and Epidemiologic Sample (n = 532). The tau-equivalent confirmatory factor analyses were used to test the fit of the Developmental Model relative to three leading competing models (DSM opositional defiant disorder (ODD)/conduct disorder (CD) Model, "Callous" Model, and an "Irritable/Headstrong/Hurtful" Model). Reliability of the four dimensions was also tested. Validity of the dimensions was tested by predicting multi-informant, multi-method ratings of disruptive behavior and impairment, and incremental utility relative to DSM symptoms. In both samples, the Developmental Model demonstrated a superior fit compared with the competing models within the full sample, and across key demographic subgroups. Validity was also demonstrated, including incremental utility relative to DSM-IV disruptive behavior symptoms. Critical next steps for achieving scientific consensus about the optimal dimensional model of disruptive behavior and its clinical application are discussed. Copyright © 2012 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  1. Assessment of Grade-Level Differences in Coping Behavior among Adolescents Using Multidimensional Scaling Single-Ideal-Point Model

    Science.gov (United States)

    Ding, Cody; Yang, Dong

    2013-01-01

    The purpose of the study was to examine grade-level differences in coping behaviors among adolescents using a probabilistic multidimensional scaling (MDS) single-ideal-point model. Using data from students in middle school and at college, this article illustrated the MDS single-ideal-point model as an alternative to examine students' typical…

  2. Development and assessment of Multi-dimensional flow models in the thermal-hydraulic system analysis code MARS

    Energy Technology Data Exchange (ETDEWEB)

    Chung, B. D.; Bae, S. W.; Jeong, J. J.; Lee, S. M

    2005-04-15

    A new multi-dimensional component has been developed to allow for more flexible 3D capabilities in the system code, MARS. This component can be applied in the Cartesian and cylindrical coordinates. For the development of this model, the 3D convection and diffusion terms are implemented in the momentum and energy equation. And a simple Prandtl's mixing length model is applied for the turbulent viscosity. The developed multi-dimensional component was assessed against five conceptual problems with analytic solution. And some SETs are calculated and compared with experimental data. With this newly developed multi-dimensional flow module, the MARS code can realistic calculate the flow fields in pools such as those occurring in the core, steam generators and IRWST.

  3. Validation of a multidimensional computational fluid dynamics model for subcooled flow boiling analysis

    Energy Technology Data Exchange (ETDEWEB)

    Braz Filho, Francisco A.; Caldeira, Alexandre D.; Borges, Eduardo M., E-mail: fbraz@ieav.cta.b, E-mail: alexdc@ieav.cta.b, E-mail: eduardo@ieav.cta.b [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil). Div. de Energia Nuclear

    2011-07-01

    In a heated vertical channel, the subcooled flow boiling regime occurs when the bulk fluid temperature is lower than the saturation temperature, but the fluid temperature reaches the saturation point near the channel wall. This phenomenon produces a significant increase in heat flux, limited by the critical heat flux. This study is particularly important to the thermal-hydraulics analysis of pressurized water reactors. The purpose of this work is the validation of a multidimensional model to analyze the subcooled flow boiling comparing the results with experimental data found in literature. The computational fluid dynamics code FLUENT was used with Eulerian multiphase model option. The calculated values of wall temperature in the liquid-solid interface presented an excellent agreement when compared to the experimental data. Void fraction calculations presented satisfactory results in relation to the experimental data in pressures of 15, 30 and 45 bars. (author)

  4. Advancing Nucleosynthesis in Self-consistent, Multidimensional Models of Core-Collapse Supernovae

    CERN Document Server

    Harris, J Austin; Chertkow, Merek A; Bruenn, Stephen W; Lentz, Eric J; Messer, O E Bronson; Mezzacappa, Anthony; Blondin, John M; Marronetti, Pedro; Yakunin, Konstantin N

    2014-01-01

    We investigate core-collapse supernova (CCSN) nucleosynthesis in polar axisymmetric simulations using the multidimensional radiation hydrodynamics code CHIMERA. Computational costs have traditionally constrained the evolution of the nuclear composition in CCSN models to, at best, a 14-species $\\alpha$-network. Such a simplified network limits the ability to accurately evolve detailed composition, neutronization and the nuclear energy generation rate. Lagrangian tracer particles are commonly used to extend the nuclear network evolution by incorporating more realistic networks in post-processing nucleosynthesis calculations. Limitations such as poor spatial resolution of the tracer particles, estimation of the expansion timescales, and determination of the "mass-cut" at the end of the simulation impose uncertainties inherent to this approach. We present a detailed analysis of the impact of these uncertainties on post-processing nucleosynthesis calculations and implications for future models.

  5. A Relevance-Extended Multi-dimensional Model for a Data Warehouse Contextualized with Documents

    DEFF Research Database (Denmark)

    Perez, Juan Manuel; Pedersen, Torben Bach; Berlanga, Rafael

    2005-01-01

    Current data warehouse and OLAP technologies can be applied to analyze the structured data that companies store in their databases. The circumstances that describe the context associated with these data can be found in other internal and external sources of documents. In this paper we propose...... to combine the traditional corporate data warehouse with a document warehouse, resulting in a contextualized warehouse. Thus, contextualized warehouses keep a historical record of the facts and their contexts as described by the documents. In this framework, the user selects an analysis context which...... with the documents that explain their circumstances. In this work we extend an existing multi-dimensional data model and algebra for representing the R-cubes....

  6. Multi-dimensional Modeling of the Application of Catalytic Combustion to Homogeneous Charge Compression Ignition Engine

    Institute of Scientific and Technical Information of China (English)

    Wen Zeng; MaoZhao Xie

    2006-01-01

    The detailed surface reaction mechanism of methane on rhodium catalyst was analyzed.Comparisons between numerical simulation and experiments showed a basic agreement.The combustion process of homogeneous charge compression ignition (HCCI) engine whose piston surface has been coated with catalyst (rhodium and platinum) was numerically investigated.A multi-dimensional model with detailed chemical kinetics was built.The effects of catalytic combustion on the ignition timing,the temperature and CO concentration fields,and HC,CO and NOx emissions of the HCCI engine were discussed.The results showed the ignition timing of the HCCI engine was advanced and the emissions of HC and CO were decreased by the catalysis.

  7. Fast low-rank approximations of multidimensional integrals in ion-atomic collisions modelling

    CERN Document Server

    Litsarev, M S

    2015-01-01

    An efficient technique based on low-rank separated approximations is proposed for computation of three-dimensional integrals arising in the energy deposition model that describes ion-atomic collisions. Direct tensor-product quadrature requires grids of size $4000^3$ which is unacceptable. Moreover, several of such integrals have to be computed simultaneously for different values of parameters. To reduce the complexity, we use the structure of the integrand and apply numerical linear algebra techniques for the construction of low-rank approximation. The resulting algorithm is $10^3$ faster than spectral quadratures in spherical coordinates used in the original DEPOSIT code. The approach can be generalized to other multidimensional problems in physics.

  8. Comparative exploration of multidimensional flow cytometry software: a model approach evaluating T cell polyfunctional behavior.

    Science.gov (United States)

    Spear, Timothy T; Nishimura, Michael I; Simms, Patricia E

    2017-08-01

    Advancement in flow cytometry reagents and instrumentation has allowed for simultaneous analysis of large numbers of lineage/functional immune cell markers. Highly complex datasets generated by polychromatic flow cytometry require proper analytical software to answer investigators' questions. A problem among many investigators and flow cytometry Shared Resource Laboratories (SRLs), including our own, is a lack of access to a flow cytometry-knowledgeable bioinformatics team, making it difficult to learn and choose appropriate analysis tool(s). Here, we comparatively assess various multidimensional flow cytometry software packages for their ability to answer a specific biologic question and provide graphical representation output suitable for publication, as well as their ease of use and cost. We assessed polyfunctional potential of TCR-transduced T cells, serving as a model evaluation, using multidimensional flow cytometry to analyze 6 intracellular cytokines and degranulation on a per-cell basis. Analysis of 7 parameters resulted in 128 possible combinations of positivity/negativity, far too complex for basic flow cytometry software to analyze fully. Various software packages were used, analysis methods used in each described, and representative output displayed. Of the tools investigated, automated classification of cellular expression by nonlinear stochastic embedding (ACCENSE) and coupled analysis in Pestle/simplified presentation of incredibly complex evaluations (SPICE) provided the most user-friendly manipulations and readable output, evaluating effects of altered antigen-specific stimulation on T cell polyfunctionality. This detailed approach may serve as a model for other investigators/SRLs in selecting the most appropriate software to analyze complex flow cytometry datasets. Further development and awareness of available tools will help guide proper data analysis to answer difficult biologic questions arising from incredibly complex datasets. © Society

  9. A formulation of multidimensional growth models for the assessment and forecast of technology attributes

    Science.gov (United States)

    Danner, Travis W.

    modeling technique begins to diminish. With the introduction of multiple objectives, researchers often abandon technology growth models for scoring models and technology frontiers. While both approaches possess advantages over current growth models for the assessment of multi-objective technologies, each lacks a necessary dimension for comprehensive technology assessment. By collapsing multiple system metrics into a single, non-intuitive technology measure, scoring models provide a succinct framework for multi-objective technology assessment and forecasting. Yet, with no consideration of physical limits, scoring models provide no insight as to the feasibility of a particular combination of system capabilities. They only indicate that a given combination of system capabilities yields a particular score. Conversely, technology frontiers are constructed with the distinct objective of providing insight into the feasibility of system capability combinations. Yet again, upper limits to overall system performance are ignored. Furthermore, the data required to forecast subsequent technology frontiers is often inhibitive. In an attempt to reincorporate the fundamental nature of technology advancement as bound by physical principles, researchers have sought to normalize multi-objective systems whereby the variability of a single system objective is eliminated as a result of changes in the remaining objectives. This drastically limits the applicability of the resulting technology model because it is only applicable for a single setting of all other system attributes. Attempts to maintain the interaction between the growth curves of each technical objective of a complex system have thus far been limited to qualitative and subjective consideration. This research proposes the formulation of multidimensional growth models as an approach to simulating the advancement of multi-objective technologies towards their upper limits. Multidimensional growth models were formulated by noticing and

  10. GEFCom2012: Statement and the Concept of Multidimensional Stochastic Distributed Energy Consumption Model Identification

    Directory of Open Access Journals (Sweden)

    Alexander G. Janovsky

    2013-01-01

    Full Text Available A task statement and a concept of solution of GEFCom2012 (USA problem are considered as a contribution. The aspects of solution including (i methods of correlation-spectral analysis and rank analysis for multidimensional stochastic processes, (ii identification and forecasting of multidimensional stochastic systems are proposed

  11. A statistical model for multidimensional irreversible electroporation cell death in tissue

    Directory of Open Access Journals (Sweden)

    Rubinsky Boris

    2010-02-01

    Full Text Available Abstract Background Irreversible electroporation (IRE is a minimally invasive tissue ablation technique which utilizes electric pulses delivered by electrodes to a targeted area of tissue to produce high amplitude electric fields, thus inducing irreversible damage to the cell membrane lipid bilayer. An important application of this technique is for cancer tissue ablation. Mathematical modelling is considered important in IRE treatment planning. In the past, IRE mathematical modelling used a deterministic single value for the amplitude of the electric field required for causing cell death. However, tissue, particularly cancerous tissue, is comprised of a population of different cells of different sizes and orientations, which in conventional IRE are exposed to complex electric fields; therefore, using a deterministic single value is overly simplistic. Methods We introduce and describe a new methodology for evaluating IRE induced cell death in tissue. Our approach employs a statistical Peleg-Fermi model to correlate probability of cell death in heterogeneous tissue to the parameters of electroporation pulses such as the number of pulses, electric field amplitude and pulse length. For treatment planning, the Peleg-Fermi model is combined with a numerical solution of the multidimensional electric field equation cast in a dimensionless form. This is the first time in which this concept is used for evaluating IRE cell death in multidimensional situations. Results We illustrate the methodology using data reported in literature for prostate cancer cell death by IRE. We show how to fit this data to a Fermi function in order to calculate the critical statistic parameters. To illustrate the use of the methodology, we simulated 2-D irreversible electroporation protocols and produced 2-D maps of the statistical distribution of cell death in the treated region. These plots were compared to plots produced using a deterministic model of cell death by IRE and

  12. Women's steps of change and entry into drug abuse treatment. A multidimensional stages of change model.

    Science.gov (United States)

    Brown, V B; Melchior, L A; Panter, A T; Slaughter, R; Huba, G J

    2000-04-01

    The Transtheoretical, or Stages of Change Model, has been applied to the investigation of help-seeking related to a number of addictive behaviors. Overall, the model has shown to be very important in understanding the process of help-seeking. However, substance abuse rarely exists in isolation from other health, mental health, and social problems. The present work extends the original Stages of Change Model by proposing "Steps of Change" as they relate to entry into substance abuse treatment programs for women. Readiness to make life changes in four domains-domestic violence, HIV sexual risk behavior, substance abuse, and mental health-is examined in relation to entry into four substance abuse treatment modalities (12-step, detoxification, outpatient, and residential). The Steps of Change Model hypothesizes that help-seeking behavior of substance-abusing women may reflect a hierarchy of readiness based on the immediacy, or time urgency, of their treatment issues. For example, women in battering relationships may be ready to make changes to reduce their exposure to violence before admitting readiness to seek substance abuse treatment. The Steps of Change Model was examined in a sample of 451 women contacted through a substance abuse treatment-readiness program in Los Angeles, California. A series of logistic regression analyses predict entry into four separate treatment modalities that vary. Results suggest a multidimensional Stages of Change Model that may extend to other populations and to other types of help-seeking behaviors.

  13. Detailed Multi-dimensional Modeling of Direct Internal Reforming Solid Oxide Fuel Cells.

    Science.gov (United States)

    Tseronis, K; Fragkopoulos, I S; Bonis, I; Theodoropoulos, C

    2016-06-01

    Fuel flexibility is a significant advantage of solid oxide fuel cells (SOFCs) and can be attributed to their high operating temperature. Here we consider a direct internal reforming solid oxide fuel cell setup in which a separate fuel reformer is not required. We construct a multidimensional, detailed model of a planar solid oxide fuel cell, where mass transport in the fuel channel is modeled using the Stefan-Maxwell model, whereas the mass transport within the porous electrodes is simulated using the Dusty-Gas model. The resulting highly nonlinear model is built into COMSOL Multiphysics, a commercial computational fluid dynamics software, and is validated against experimental data from the literature. A number of parametric studies is performed to obtain insights on the direct internal reforming solid oxide fuel cell system behavior and efficiency, to aid the design procedure. It is shown that internal reforming results in temperature drop close to the inlet and that the direct internal reforming solid oxide fuel cell performance can be enhanced by increasing the operating temperature. It is also observed that decreases in the inlet temperature result in smoother temperature profiles and in the formation of reduced thermal gradients. Furthermore, the direct internal reforming solid oxide fuel cell performance was found to be affected by the thickness of the electrochemically-active anode catalyst layer, although not always substantially, due to the counter-balancing behavior of the activation and ohmic overpotentials.

  14. Comparing Multiple-Group Multinomial Log-Linear Models for Multidimensional Skill Distributions in the General Diagnostic Model. Research Report. ETS RR-08-35

    Science.gov (United States)

    Xu, Xueli; von Davier, Matthias

    2008-01-01

    The general diagnostic model (GDM) utilizes located latent classes for modeling a multidimensional proficiency variable. In this paper, the GDM is extended by employing a log-linear model for multiple populations that assumes constraints on parameters across multiple groups. This constrained model is compared to log-linear models that assume…

  15. Two-Dimensional Core-Collapse Supernova Models with Multi-Dimensional Transport

    CERN Document Server

    Dolence, Joshua C; Zhang, Weiqun

    2014-01-01

    We present new two-dimensional (2D) axisymmetric neutrino radiation/hydrodynamic models of core-collapse supernova (CCSN) cores. We use the CASTRO code, which incorporates truly multi-dimensional, multi-group, flux-limited diffusion (MGFLD) neutrino transport, including all relevant $\\mathcal{O}(v/c)$ terms. Our main motivation for carrying out this study is to compare with recent 2D models produced by other groups who have obtained explosions for some progenitor stars and with recent 2D VULCAN results that did not incorporate $\\mathcal{O}(v/c)$ terms. We follow the evolution of 12, 15, 20, and 25 solar-mass progenitors to approximately 600 milliseconds after bounce and do not obtain an explosion in any of these models. Though the reason for the qualitative disagreement among the groups engaged in CCSN modeling remains unclear, we speculate that the simplifying ``ray-by-ray' approach employed by all other groups may be compromising their results. We show that ``ray-by-ray' calculations greatly exaggerate the ...

  16. The Multidimensional Testlet-Effect Rasch Model%多维题组效应Rasch模型

    Institute of Scientific and Technical Information of China (English)

    詹沛达; 王文中; 王立君; 李晓敏

    2014-01-01

    Testlet design has been widely adopted in educational and psychological assessment. A testlet is a cluster of items that share a common stimulus (e.g., a reading comprehension passage or a figure), and the possible local dependence among items within a testlet is called testlet-effect. Various models have been developed to take into account such testlet effect. Examples included the Rasch testlet model, two-parameter logistic Bayesian testlet model, and higher-order testlet model. However, these existing models all assume that an item is affected by only one single testlet effect. Therefore, they are essentially unidimensional testlet-effect models. In practice, multiple testlet effects may simultaneously affect item responses in a testlet. For example, in addition to common stimulus, items can be grouped according to their domains, knowledge units, or item format, such that multiple testlet effects are involved. In essence, an item measures multiple latent traits, in addition to the target latent trait(s) that the test was designed to measure. Existing unidimensional testlet-effect models become inapplicable when multiple testlet effects are involved. To account for multiple testlet effect, in this study we develop the so-called (within-item) multidimensional testlet-effect Rasch model. The parameters can be estimated with marginal maximum likelihood estimation methods or Bayesian methods with Markov chain Monte Carlo (MCMC) algorithms. In this study, a popular computer program for Rasch models, ConQuest, was used. A series of simulations were conducted to evaluate parameter recovery of the new model, consequences of model misspecification, and the effectiveness of model-data fit statistics. Results show that the parameters of the new model can be recovered fairly well; and ignoring the multiple testlet effects resulted in a biased estimation of item parameters, and an overestimation of test reliability. Additionally, it did little harm on parameter estimation to

  17. Acculturation of Iranians in the United States, the United Kingdom, and the Netherlands A Test of the Multidimensional Individual Difference Acculturation (MIDA) Model

    NARCIS (Netherlands)

    Safdar, Saba; Struthers, Ward; van Oudenhoven, Jan Pieter

    2009-01-01

    The present study tested the generalizability of a multidimensional individual difference acculturation (MIDA) model in three cultural contexts. The model includes three predictor variables (Psychosocial Resources, Connectedness, and Hassles), predicting three outcome adaptation variables (In-Group

  18. Acculturation of Iranians in the United States, the United Kingdom, and the Netherlands A Test of the Multidimensional Individual Difference Acculturation (MIDA) Model

    NARCIS (Netherlands)

    Safdar, S.; Struthers, W.; Van Oudenhoven, J.P.

    The present study tested the generalizability of a multidimensional individual difference acculturation (MIDA) model in three cultural contexts. The model includes three predictor variables (Psychosocial Resources, Connectedness, and Hassles), predicting three outcome adaptation variables (In-Group

  19. Multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates.

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ken Shuang

    2004-11-01

    This report documents the author's efforts in the deterministic modeling of copper-sulfidation corrosion on non-planar substrates such as diodes and electrical connectors. A new framework based on Goma was developed for multi-dimensional modeling of atmospheric copper-sulfidation corrosion on non-planar substrates. In this framework, the moving sulfidation front is explicitly tracked by treating the finite-element mesh as a pseudo solid with an arbitrary Lagrangian-Eulerian formulation and repeatedly performing re-meshing using CUBIT and re-mapping using MAPVAR. Three one-dimensional studies were performed for verifying the framework in asymptotic regimes. Limited model validation was also carried out by comparing computed copper-sulfide thickness with experimental data. The framework was first demonstrated in modeling one-dimensional copper sulfidation with charge separation. It was found that both the thickness of the space-charge layers and the electrical potential at the sulfidation surface decrease rapidly as the Cu{sub 2}S layer thickens initially but eventually reach equilibrium values as Cu{sub 2}S layer becomes sufficiently thick; it was also found that electroneutrality is a reasonable approximation and that the electro-migration flux may be estimated by using the equilibrium potential difference between the sulfidation and annihilation surfaces when the Cu{sub 2}S layer is sufficiently thick. The framework was then employed to model copper sulfidation in the solid-state-diffusion controlled regime (i.e. stage II sulfidation) on a prototypical diode until a continuous Cu{sub 2}S film was formed on the diode surface. The framework was also applied to model copper sulfidation on an intermittent electrical contact between a gold-plated copper pin and gold-plated copper pad; the presence of Cu{sub 2}S was found to raise the effective electrical resistance drastically. Lastly, future research needs in modeling atmospheric copper sulfidation are discussed.

  20. Sample Size Requirements for Estimation of Item Parameters in the Multidimensional Graded Response Model

    Directory of Open Access Journals (Sweden)

    Shengyu eJiang

    2016-02-01

    Full Text Available Likert types of rating scales in which a respondent chooses a response from an ordered set of response options are used to measure a wide variety of psychological, educational, and medical outcome variables. The most appropriate item response theory model for analyzing and scoring these instruments when they provide scores on multiple scales is the multidimensional graded response model (MGRM. A simulation study was conducted to investigate the variables that might affect item parameter recovery for the MGRM. Data were generated based on different sample sizes, test lengths, and scale intercorrelations. Parameter estimates were obtained through the flexiMIRT software. The quality of parameter recovery was assessed by the correlation between true and estimated parameters as well as bias and root- mean-square-error. Results indicated that for the vast majority of cases studied a sample size of N = 500 provided accurate parameter estimates, except for tests with 240 items when 1,000 examinees were necessary to obtain accurate parameter estimates. Increasing sample size beyond N = 1,000 did not increase the accuracy of MGRM parameter estimates.

  1. A multidimensional model of mothers' perceptions of parent alcohol socialization and adolescent alcohol misuse.

    Science.gov (United States)

    Ennett, Susan T; Jackson, Christine; Cole, Veronica T; Haws, Susan; Foshee, Vangie A; Reyes, Heathe Luz McNaughton; Burns, Alison Reimuller; Cox, Melissa J; Cai, Li

    2016-02-01

    We assessed a multidimensional model of parent alcohol socialization in which key socialization factors were considered simultaneously to identify combinations of factors that increase or decrease risk for development of adolescent alcohol misuse. Of interest was the interplay between putative risk and protective factors, such as whether the typically detrimental effects on youth drinking of parenting practices tolerant of some adolescent alcohol use are mitigated by an effective overall approach to parenting and parental modeling of modest alcohol use. The sample included 1,530 adolescents and their mothers; adolescents' mean age was 13.0 (SD = .99) at the initial assessment. Latent profile analysis was conducted of mothers' reports of their attitude toward teen drinking, alcohol-specific parenting practices, parental alcohol use and problem use, and overall approach to parenting. The profiles were used to predict trajectories of adolescent alcohol misuse from early to middle adolescence. Four profiles were identified: 2 profiles reflected conservative alcohol-specific parenting practices and 2 reflected alcohol-tolerant practices, all in the context of other attributes. Alcohol misuse accelerated more rapidly from Grade 6 through 10 in the 2 alcohol-tolerant compared with conservative profiles. Results suggest that maternal tolerance of some youth alcohol use, even in the presence of dimensions of an effective parenting style and low parental alcohol use and problem use, is not an effective strategy for reducing risky adolescent alcohol use. (PsycINFO Database Record

  2. An Examination of the Relationship of the 16PF Fifth Edition to a Multidimensional Model of Self-Esteem

    Directory of Open Access Journals (Sweden)

    Dale Pietrzak

    2015-10-01

    Full Text Available The regression equation needed to predict the self-esteem score from the Sixteen Personality Factor Questionnaire (16PF Fifth Edition is not available for hand scoring. This score is derived from the Coopersmith’s Self-Esteem Inventory (SEI, which is based on a unitary model of self-esteem. The SEI may be subject to gender and extroversion biases. Moreover, there is a gap in the literature on the 16PF fifth edition and self-esteem. For these reasons, we investigated the relationship of the Culture-Free Self-Esteem Inventory–II Form AD (CFSEI-II, a multidimensional model of self-esteem, using multiple regression to the scales of the 16PF. Based on the adult sample of 234 in this study, we developed and made available to users of the 16PF split sample–validated regression equations for this multidimensional model of self-esteem.

  3. Virtual multi-dimensional internal bonds model and its application in simulation of rock mass

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZhenNan; GE XiuRun

    2008-01-01

    VMIB (virtual multi-dimensional internal bonds) is a multiscale mechanical model developed from the VIB (virtual internal bond) theory. In VIB theory, the solid material is considered to consist of random-distributed material particles in microscale. These particles are connected with normal bonds. The macro constitutive relation is derived from the cohesive law between particles. However, in VMIB, the micro particles are connected with both normal and shear bonds. The macro constitutive relation is derived in terms of bond stiffness coefficients. It has been theoretically certified that there exists a corresponding relationship between the two bond stiffness coefficients and the two macro material constants, i.e. the Young's modulus and Poisson ratio. This corresponding relationship suggests that it should be necessary and sufficient to simultaneously account for the normal and shear interactions between particles. Due to the fact that the fracture criterion is directly incorporated into the constitutive relation, both VIB and VMIB present many advantages in simulating fractures of materials. In the damage model of rock mass, a damage tensor is usually defined to describe the distribution of cracks. The damage value in one direction determines the relative stiffness of rock mass in this direction. In VMIB solid, the relative distribution density of micro bonds in one direction determines the relative macro stiffness of the material in this direction. The effects of the damage value and the relative distribution density of bonds are consistent. To simulate the failure behavior of rock mass with VMIB, the presented paper sets up a quantitative relationship between the damage tensor and the relative distribution density of bonds. Comparison of the theoretical and the experimental results shows that VMIB model can represent the effect of distributed cracks on rock mass with this relationship. The presented work provides a foundation for further simulating fracture

  4. A multidimensional analysis of the epistemic origins of nursing theories, models, and frameworks.

    Science.gov (United States)

    Beckstead, Jason W; Beckstead, Laura Grace

    2006-01-01

    The purpose of this article is to introduce our notion of epistemic space and to demonstrate its utility for understanding the origins and trajectories of nursing theory in the 20th century using multidimensional scaling (MDS). A literature review was conducted on primary and secondary sources written by and about 20 nurse theorists to investigate whether or not they cited 129 different scholars in the fields of anthropology, biology, nursing, philosophy, psychology, and sociology. Seventy-four scholars were identified as having been cited by at least two nurse theorists (319 citations total). Proximity scores, quantifying the similarity among nurse theorists based on proportions of shared citations, were calculated and analyzed using MDS. The emergent model of epistemic space that accommodated these similarities among nurse theorists revealed the systematic influence of scholars from various fields, notably psychology, biology, and philosophy. We believe that this schema and resulting taxonomy will prove useful for furthering our understanding of the relationships among nursing theories and theories in other fields of science.

  5. Multidimensional extremal dependence coefficients

    OpenAIRE

    2017-01-01

    Extreme values modeling has attracting the attention of researchers in diverse areas such as the environment, engineering, or finance. Multivariate extreme value distributions are particularly suitable to model the tails of multidimensional phenomena. The analysis of the dependence among multivariate maxima is useful to evaluate risk. Here we present new multivariate extreme value models, as well as, coefficients to assess multivariate extremal dependence.

  6. The Simulation of Mahabad Dam Eutrophication by Multidimensional CE-QUAL-W2 model

    Directory of Open Access Journals (Sweden)

    Ahmad Khatami

    2016-06-01

    Full Text Available Entering nutrients such as (Nitrogen & phosphorus into the dam’s reservoir causes downgrade of the water reservoir quality and eutrophication which is one of the main problems of the water quality in the dam. Among the signs of eutrophication are unlimited growth of algae in the water margin and surface, reduction of water transparency and dissolved oxygen especially in the sub layers, reduction of water channel capacity, clogging filters at water treatment plants and Toxic, smelly and bad tasting water. This paper tries to simulating the eutrophication of Mahabad Dam by CE-QUAL-W2 multidimensional model; therefore, in order to simulate Eutrophication and qualitative parameters of Mahabad dam reservoir from January 2011 to December 2011, the model have been used and validation of the model was performed based on qualitative parameters (includes: total phosphorous, dissolved oxygen and total nitrogen. According to the parameters calibration results, the values of root mean square error which is less than one show conformity between the observation and simulation data, in a way that the values of root mean square error of dissolved oxygen were calculated 0.0166, 0.541, 0.291 and 0.7381 mg/liter and the values of root mean square error of total nitrogen were calculated 0.062, 0.142, 0.586 and 0.21 mg/liter and for total phosphorus are 0.062, 0.0142, 0.586 and 0.21 for winter, spring, summer and fall seasons respectively. Checking the Nitrogen & Phosphorous calibration diagrams show clearly that the Eutrophication in Mahabad dam reservoir has occurred.

  7. Multi-dimensional classification of GABAergic interneurons with Bayesian network-modeled label uncertainty

    Science.gov (United States)

    Mihaljević, Bojan; Bielza, Concha; Benavides-Piccione, Ruth; DeFelipe, Javier; Larrañaga, Pedro

    2014-01-01

    Interneuron classification is an important and long-debated topic in neuroscience. A recent study provided a data set of digitally reconstructed interneurons classified by 42 leading neuroscientists according to a pragmatic classification scheme composed of five categorical variables, namely, of the interneuron type and four features of axonal morphology. From this data set we now learned a model which can classify interneurons, on the basis of their axonal morphometric parameters, into these five descriptive variables simultaneously. Because of differences in opinion among the neuroscientists, especially regarding neuronal type, for many interneurons we lacked a unique, agreed-upon classification, which we could use to guide model learning. Instead, we guided model learning with a probability distribution over the neuronal type and the axonal features, obtained, for each interneuron, from the neuroscientists' classification choices. We conveniently encoded such probability distributions with Bayesian networks, calling them label Bayesian networks (LBNs), and developed a method to predict them. This method predicts an LBN by forming a probabilistic consensus among the LBNs of the interneurons most similar to the one being classified. We used 18 axonal morphometric parameters as predictor variables, 13 of which we introduce in this paper as quantitative counterparts to the categorical axonal features. We were able to accurately predict interneuronal LBNs. Furthermore, when extracting crisp (i.e., non-probabilistic) predictions from the predicted LBNs, our method outperformed related work on interneuron classification. Our results indicate that our method is adequate for multi-dimensional classification of interneurons with probabilistic labels. Moreover, the introduced morphometric parameters are good predictors of interneuron type and the four features of axonal morphology and thus may serve as objective counterparts to the subjective, categorical axonal features

  8. A Multidimensional Model of Sexual Health and Sexual and Prevention Behavior Among Adolescent Women

    Science.gov (United States)

    Hensel, Devon J.; Fortenberry, J. Dennis

    2013-01-01

    Purpose Sexual health refers a state of lifespan well-being related to sexuality. Among young people, sexual health has multiple dimensions, including the positive developmental contributions of sexuality, as well as the acquisition of skills pertinent to avoiding adverse sexual outcomes such as unintended pregnancy and sexually transmitted infections (STIs). Existing efforts to understand sexual health, however, have yet to empirically operationalize a multi-dimensional model of sexual health and to evaluate its association to different sexual/prevention behaviors. Methods Sexual health dimensions and sexual/prevention behaviors were drawn from a larger longitudinal cohort study of sexual relationships among adolescent women (N =387, 14–17 years). Second order latent variable modeling (AMOS/19.0) evaluated the relationship between sexual health and dimensions and analyzed the effect of sexual health to sexual/prevention outcomes. Results All first order latent variables were significant indicators of sexual health (β: 0.192 – 0.874, all p sexual health was significantly associated with sexual abstinence, as well as with more frequent non-coital and vaginal sex, condom use at last sex, a higher proportion of condom-protected events, use of hormonal or other methods of pregnancy control and absence of STI. All models showed good fit. Conclusions Sexual health is an empirically coherent structure, in which the totality of its dimensions is significantly linked to a wide range of outcomes, including sexual abstinence, condom use and absence of STI. This means that, regardless of a young person’s experiences, sexual health is an important construct for promoting positive sexual development and for primary prevention. PMID:23332488

  9. Multidimensional modeling of the stenosed carotid artery: A novel CAD approach accompanied by an extensive lumped model

    Science.gov (United States)

    Kashefi, A.; Mahdinia, M.; Firoozabadi, B.; Amirkhosravi, M.; Ahmadi, G.; Saidi, M. S.

    2014-04-01

    This study describes a multidimensional 3D/lumped parameter (LP) model which contains appropriate inflow/outflow boundary conditions in order to model the entire human arterial trees. A new extensive LP model of the entire arterial network (48 arteries) was developed including the effect of vessel diameter tapering and the parameterization of resistance, conductor and inductor variables. A computer aided-design (CAD) algorithm was proposed to efficiently handle the coupling of two or more 3D models with the LP model, and substantially lessen the coupling processing time. Realistic boundary conditions and Navier-Stokes equations in healthy and stenosed models of carotid artery bifurcation (CAB) were used to investigate the unsteady Newtonian blood flow velocity distribution in the internal carotid artery (ICA). The present simulation results agree well with previous experimental and numerical studies. The outcomes of a pure LP model and those of the coupled 3D healthy model were found to be nearly the same in both cases. Concerning the various analyzed 3D zones, the stenosis growth in the ICA was not found as a crucial factor in determining the absorbing boundary conditions. This paper demonstrates the advantages of coupling local and systemic models to comprehend physiological diseases of the cardiovascular system. [Figure not available: see fulltext.

  10. Modelo multidimensional espacio-temporal y lenguaje de consulta para temporadas / A spatio-temporal multidimensional model and a query language for seasons

    OpenAIRE

    Moreno Arboleda, Francisco Javier

    2010-01-01

    Una bodega de datos (BD) se modela usualmente mediante una vista multidimensional de los datos. En un modelo multidimensional, un conjunto de dimensiones se asocia con un tema de análisis denominado hecho. Cada dimensión se compone de un conjunto no vacío de niveles los cuales están organizados jerárquicamente. Usualmente, una dimensión se considera estática en una BD; sin embargo, el esquema y los datos de una dimensión pueden evolucionar. Esta tesis se enfoca en un tipo de cambio de datos d...

  11. Virtual multi-dimensional internal bonds model and its application in simulation of rock mass

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    VMIB (virtual multi-dimensional internal bonds) is a multiscale mechanical model developed from the VIB (virtual internal bond) theory. In VIB theory,the solid mate-rial is considered to consist of random-distributed material particles in microscale. These particles are connected with normal bonds. The macro constitutive relation is derived from the cohesive law between particles. However,in VMIB,the micro particles are connected with both normal and shear bonds. The macro constitutive relation is derived in terms of bond stiffness coefficients. It has been theoretically certified that there exists a corresponding relationship between the two bond stiffness coefficients and the two macro material constants,i.e. the Young’s modulus and Poisson ratio. This corresponding relationship suggests that it should be necessary and sufficient to simultaneously account for the normal and shear interactions between particles. Due to the fact that the fracture criterion is directly incorporated into the constitutive relation,both VIB and VMIB present many advantages in simulating fractures of materials. In the damage model of rock mass,a damage tensor is usually defined to describe the distribution of cracks. The damage value in one direction determines the relative stiffness of rock mass in this direction. In VMIB solid,the relative distribution density of micro bonds in one direction determines the relative macro stiffness of the material in this direction. The effects of the damage value and the relative distribution density of bonds are consistent. To simulate the failure behavior of rock mass with VMIB,the presented paper sets up a quantitative relationship between the damage tensor and the rela-tive distribution density of bonds. Comparison of the theoretical and the experi-mental results shows that VMIB model can represent the effect of distributed cracks on rock mass with this relationship. The presented work provides a founda-tion for further simulating fracture

  12. Partially Compensatory Multidimensional Item Response Theory Models: Two Alternate Model Forms

    Science.gov (United States)

    DeMars, Christine E.

    2016-01-01

    Partially compensatory models may capture the cognitive skills needed to answer test items more realistically than compensatory models, but estimating the model parameters may be a challenge. Data were simulated to follow two different partially compensatory models, a model with an interaction term and a product model. The model parameters were…

  13. The Role of Psychometric Modeling in Test Validation: An Application of Multidimensional Item Response Theory

    Science.gov (United States)

    Schilling, Stephen G.

    2007-01-01

    In this paper the author examines the role of item response theory (IRT), particularly multidimensional item response theory (MIRT) in test validation from a validity argument perspective. The author provides justification for several structural assumptions and interpretations, taking care to describe the role he believes they should play in any…

  14. Multidimensional Item Response Theory Models in Vocational Interest Measurement: An Illustration Using the AIST-R

    Science.gov (United States)

    Wetzel, Eunike; Hell, Benedikt

    2014-01-01

    Vocational interest inventories are commonly analyzed using a unidimensional approach, that is, each subscale is analyzed separately. However, the theories on which these inventories are based often postulate specific relationships between the interest traits. This article presents a multidimensional approach to the analysis of vocational interest…

  15. Physical Activity Motivation in Late Adolescence: Refinement of a Recent Multidimensional Model

    Science.gov (United States)

    Martin, Andrew J.

    2010-01-01

    Recent research (Martin et al., 2006) presented a new, multidimensional approach to physical activity motivation (using the Physical Activity Motivation Scale [PAMS]) operationalized through four factors: adaptive cognition, adaptive behavior, impeding/maladaptive cognition, and maladaptive behavior. The present study extends this early research…

  16. Multidimensional Item Response Theory Models in Vocational Interest Measurement: An Illustration Using the AIST-R

    Science.gov (United States)

    Wetzel, Eunike; Hell, Benedikt

    2014-01-01

    Vocational interest inventories are commonly analyzed using a unidimensional approach, that is, each subscale is analyzed separately. However, the theories on which these inventories are based often postulate specific relationships between the interest traits. This article presents a multidimensional approach to the analysis of vocational interest…

  17. The Reflective Model of Intercultural Competency: A Multidimensional, Qualitative Approach to Study Abroad Assessment

    Science.gov (United States)

    Williams, Tracy Rundstrom

    2009-01-01

    Judging from the recent surge in research on outcomes assessment, many study abroad offices rely on quantitative surveys and measures to collect student outcomes data. This paper presents a multidimensional, qualitative approach to data collection. This approach makes qualitative data easy to collect and encourages students to reflect and…

  18. Distributed multi-dimensional hidden Markov model: theory and application in multiple-object trajectory classification and recognition

    Science.gov (United States)

    Ma, Xiang; Schonfeld, Dan; Khokhar, Ashfaq

    2008-01-01

    In this paper, we propose a novel distributed causal multi-dimensional hidden Markov model (DHMM). The proposed model can represent, for example, multiple motion trajectories of objects and their interaction activities in a scene; it is capable of conveying not only dynamics of each trajectory, but also interactions information between multiple trajectories, which can be critical in many applications. We firstly provide a solution for non-causal, multi-dimensional hidden Markov model (HMM) by distributing the non-causal model into multiple distributed causal HMMs. We approximate the simultaneous solution of multiple HMMs on a sequential processor by an alternate updating scheme. Subsequently we provide three algorithms for the training and classification of our proposed model. A new Expectation-Maximization (EM) algorithm suitable for estimation of the new model is derived, where a novel General Forward-Backward (GFB) algorithm is proposed for recursive estimation of the model parameters. A new conditional independent subset-state sequence structure decomposition of state sequences is proposed for the 2D Viterbi algorithm. The new model can be applied to many other areas such as image segmentation and image classification. Simulation results in classification of multiple interacting trajectories demonstrate the superior performance and higher accuracy rate of our distributed HMM in comparison to previous models.

  19. Formal Relations and an Empirical Comparison among the Bi-Factor, the Testlet, and a Second-Order Multidimensional IRT Model

    Science.gov (United States)

    Rijmen, Frank

    2010-01-01

    Testlet effects can be taken into account by incorporating specific dimensions in addition to the general dimension into the item response theory model. Three such multidimensional models are described: the bi-factor model, the testlet model, and a second-order model. It is shown how the second-order model is formally equivalent to the testlet…

  20. A SCATTERING MATRIX MODEL OF SEMICONDUCTOR SUPERLATTICES IN MULTIDIMENSIONAL WAVE-VECTOR SPACE AND ITS DIFFUSION LIMIT

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The authors first establish a quantum microscopic scattering matrix model in multidimen-sional wave-vector space, which relates the phase space density of each superlattice cell withthat of the neighbouring cells. Then, in the limit of a large number of cells, a SHE (SphericalHarmonics Expansion)-type model of diffusion equations for the particle number density in theposition-energy space is obtained. The crucial features of diffusion constants on retaining thememory of the quantum scattering characteristics of the superlattice elementary cell (like e.g.transmission resonances) are shown in order. Two examples are treated with the analyticallycomputation of the diffusion constants.

  1. An integrated approach for the knowledge discovery in computer simulation models with a multi-dimensional parameter space

    Science.gov (United States)

    Khawli, Toufik Al; Gebhardt, Sascha; Eppelt, Urs; Hermanns, Torsten; Kuhlen, Torsten; Schulz, Wolfgang

    2016-06-01

    In production industries, parameter identification, sensitivity analysis and multi-dimensional visualization are vital steps in the planning process for achieving optimal designs and gaining valuable information. Sensitivity analysis and visualization can help in identifying the most-influential parameters and quantify their contribution to the model output, reduce the model complexity, and enhance the understanding of the model behavior. Typically, this requires a large number of simulations, which can be both very expensive and time consuming when the simulation models are numerically complex and the number of parameter inputs increases. There are three main constituent parts in this work. The first part is to substitute the numerical, physical model by an accurate surrogate model, the so-called metamodel. The second part includes a multi-dimensional visualization approach for the visual exploration of metamodels. In the third part, the metamodel is used to provide the two global sensitivity measures: i) the Elementary Effect for screening the parameters, and ii) the variance decomposition method for calculating the Sobol indices that quantify both the main and interaction effects. The application of the proposed approach is illustrated with an industrial application with the goal of optimizing a drilling process using a Gaussian laser beam.

  2. An integrated approach for the knowledge discovery in computer simulation models with a multi-dimensional parameter space

    Energy Technology Data Exchange (ETDEWEB)

    Khawli, Toufik Al; Eppelt, Urs; Hermanns, Torsten [RWTH Aachen University, Chair for Nonlinear Dynamics, Steinbachstr. 15, 52047 Aachen (Germany); Gebhardt, Sascha [RWTH Aachen University, Virtual Reality Group, IT Center, Seffenter Weg 23, 52074 Aachen (Germany); Kuhlen, Torsten [Forschungszentrum Jülich GmbH, Institute for Advanced Simulation (IAS), Jülich Supercomputing Centre (JSC), Wilhelm-Johnen-Straße, 52425 Jülich (Germany); Schulz, Wolfgang [Fraunhofer, ILT Laser Technology, Steinbachstr. 15, 52047 Aachen (Germany)

    2016-06-08

    In production industries, parameter identification, sensitivity analysis and multi-dimensional visualization are vital steps in the planning process for achieving optimal designs and gaining valuable information. Sensitivity analysis and visualization can help in identifying the most-influential parameters and quantify their contribution to the model output, reduce the model complexity, and enhance the understanding of the model behavior. Typically, this requires a large number of simulations, which can be both very expensive and time consuming when the simulation models are numerically complex and the number of parameter inputs increases. There are three main constituent parts in this work. The first part is to substitute the numerical, physical model by an accurate surrogate model, the so-called metamodel. The second part includes a multi-dimensional visualization approach for the visual exploration of metamodels. In the third part, the metamodel is used to provide the two global sensitivity measures: i) the Elementary Effect for screening the parameters, and ii) the variance decomposition method for calculating the Sobol indices that quantify both the main and interaction effects. The application of the proposed approach is illustrated with an industrial application with the goal of optimizing a drilling process using a Gaussian laser beam.

  3. Multidimensional HAM-conditions

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    . The effect on the moisture and temperature conditions of the addition of a vapour barrier and an outer cladding on timber frame walls was studied. The report contains comprehensive appendices documenting the full-scale tests. The tests were performed as a part of the project 'Model for Multidimensional Heat...

  4. IRETHERM: Multidimensional geophysical modeling of the southern margin of the Dublin Basin

    Science.gov (United States)

    Vozar, Jan; Jones, Alan G.; Rath, Volker; Campanya, Joan; Pasquali, Riccardo

    2015-04-01

    Multi-dimensional magnetotelluric (MT) modelling of data from the Newcastle area west of Dublin, acquired as part of the geothermal potential of Ireland (IRETHERM) project, is presented. The Newcastle area, situated on the southern margin of the Carboniferous Dublin Basin, exhibits elevated geothermal gradient (>30 ° C/km) in the exploratory boreholes drilled by GT Energy. The MT soundings were carried out in the highly urbanized Dublin suburb and are heavily noise-contaminated and distorted due to EM noise from nearby industry and the DC tram system (LUAS). We obtained reliable and interpretable MT impedance and geomagnetic transfer functions at most sites by processing the 'quietest' 4-hour night time subsets of data using several robust codes and the ELICIT method. Tensor decomposition was applied at each site to ascertain if the data are suitable for 2-D modelling and to determine the appropriate geoelectric strike direction. The obtained 2-D models underwent examination using a new stability technique, and the final two 2-D profiles with reliability estimations, expressed through conductance and resistivity, were derived. 3-D models, including all usable MT data in the Newcastle area, have also been determined with and without resistivity constrains for shallow structures from resistivity measurements in one of the boreholes (borehole NGE1). The 3-D models exhibit structures with higher conductivity in comparison to the 2-D models, with similarly resistive background rocks. The shallow conductive structures, to a depth of 1 km, have north-south elongations correlated with the surface traces of faults that are perpendicular to the regional Blackrock to Newcastle Fault (BNF). Deeper structures become more oriented to a regional geoelectric strike similar to 2-D regional strike. To obtain superior characterization of the thermal transport properties of the investigated area, we used porosity and resistivity data from borehole NGE1 to estimate relation between

  5. The Application of Genetic Algorithms and Multidimensional Distinguishing Model in Forecasting and Evaluating Credits for Mobile Clients

    Institute of Scientific and Technical Information of China (English)

    Li Zhan; Xu Ji-sheng

    2003-01-01

    To solve the arrearage problem that puzzled most of the mobile corporations, we propose an approach to forecast and evaluate the credits for mobile clients, devising a method that is of the coalescence of genetic algorithm and multidimensional distinguishing model. In the end of this pa-per, a result of a testing application in Zhuhai Branch, GMCC was provided. The precision of the forecasting and evaluation of the client's credit is near 90%. This study is very signifi-cant to the mobile communication corporation at all levels.The popularization of the techniques and the result would pro-duce great benefits of both society and economy.

  6. The Application of Genetic Algorithms and Multidimensional Distinguishing Model in Forecasting and Evaluating Credits for Mobile Clients

    Institute of Scientific and Technical Information of China (English)

    LiZhan; XuJi-sheng

    2003-01-01

    To solve the arrearage problem that puzzled most of the mobile corporations, we propose an approach to forecast and evaluate the credits for mobile clients, devising a method that is of the coalescence of genetic algorithm and multidimensional distinguishing model. In the end of this paper, a result of a testing application in Zhuhai Branch, GMCC was provided. The precision of the forecasting and evaluation of the client's credit is near 90%. This study is very significant to the mobile communication corporation at all levels.The popularization o{ the techniques and the result would produce great benefits of both society and economy.

  7. Three Multidimensional Models for Testlet-Based Tests: Formal Relations and an Empirical Comparison. Research Report. ETS RR-09-37

    Science.gov (United States)

    Rijmen, Frank

    2009-01-01

    Three multidimensional item response theory (IRT) models for testlet-based tests are described. In the bifactor model (Gibbons & Hedeker, 1992), each item measures a general dimension in addition to a testlet-specific dimension. The testlet model (Bradlow, Wainer, & Wang, 1999) is a bifactor model in which the loadings on the specific dimensions…

  8. Effectiveness of the multidimensional ergonomic intervention model to reduce musculoskeletal discomfort among street sweepers in Chiang Rai Province, Thailand.

    Science.gov (United States)

    Pintakham, Kanjanar; Siriwong, Wattasit

    2016-01-01

    The aim of this study was to evaluate the effectiveness of multidimensional ergonomic intervention (MEI) model to reduce musculoskeletal discomfort (MSD) among street sweepers. A quasi-experimental study was conducted in Chiang Rai Province. The MEI model was designed on the basis of four core components: cognitive behavior therapy, ergonomic education training, stretching exercise, and the foam sleeve broom handle grip. Seventy-five street sweepers volunteered for the screening process on MSD of having level score ≥4 by physiotherapist. Face to face interviews were used mainly in order to diagnose MSD. Physical examination was performed by physiotherapist and physical performance by sports scientist. The findings showed that the MEI model among the intervention group significantly reduced MSD compared with that among control group at exit model and follow-up (P<0.01). This research suggests that the MEI model was appropriate to reduce MSD associated with repetitive movement and awkward postures on task.

  9. Multidimensional Databases and Data Warehousing

    CERN Document Server

    Jensen, Christian

    2010-01-01

    The present book's subject is multidimensional data models and data modeling concepts as they are applied in real data warehouses. The book aims to present the most important concepts within this subject in a precise and understandable manner. The book's coverage of fundamental concepts includes data cubes and their elements, such as dimensions, facts, and measures and their representation in a relational setting; it includes architecture-related concepts; and it includes the querying of multidimensional databases.The book also covers advanced multidimensional concepts that are considered to b

  10. Multidimensional realistic modelling of Cepheid-like variables-II: Analysis of a Cepheid model

    CERN Document Server

    Mundprecht, Eva; Kupka, Friedrich

    2015-01-01

    Non-local, time-dependent convection models have been used in the literature to explain the location of double-mode pulsations in Cepheids in the HR diagram as well as the existence and location of the red edge of the Cepheid instability strip. These properties are highly sensitive to model parameters. We use 2D radiation hydrodynamical simulations with realistic microphysics and grey radiative-transfer to model the upper 42 % of a short period Cepheid. The simulations show that the strength of the convection zone varies significantly over the pulsation period and exhibits a phase shift of the convective flux relative to the variations in radius. We evaluate the convective flux and the work performed by volume expansion as predicted by the most commonly used convection models. It turns out that over one pulsation cycle the model parameter $\\alpha_{\\rm c}$, which is proportional to the convective flux, has to be varied by up to a factor of beyond 2 to match the convective flux obtained from the simulations. To...

  11. A multidimensional risk factor model for suicide attempts in later life

    Directory of Open Access Journals (Sweden)

    Chan SMS

    2014-09-01

    Full Text Available Sau Man Sandra Chan,1 Fung Kum Helen Chiu,1 Chiu Wa Linda Lam,1 Sau Man Corine Wong,1 Yeates Conwell2 1Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong, People’s Republic of China; 2Department of Psychiatry, University of Rochester, Rochester, NY, USA Background: Elderly suicide is a public health problem worldwide, and the risk factors are multidimensional. Chronic mental health problems, personality traits, stressful life events, comorbid medical conditions, social isolation, unemployment, and poverty are associated with higher risk for suicide in later life. There was a relative paucity of data on the neurobiological markers of elderly suicide. Objective: This study examines the conjoint roles of cerebrovascular risk factors (CVRFs and other established biopsychosocial risk factors in older adults who had made a recent suicide attempt.Design: A cross-sectional, case-controlled study.Setting: A tertiary care setting in a public sector and a community setting.Subjects and methods: Cases (N=77 were nondemented Chinese adults aged ≥65 years, enrolled in a regional psychogeriatric service following a suicide attempt; comparison subjects (N=99 were community-dwelling nondemented older adults with no lifetime history of suicide. Measures of sociodemographic profile, life events, suicidal behavior, Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV Axis I psychopathology, personality traits, functional status, physical health, CVRFs, and executive cognitive functions were administered. Results: Weighted sum of CVRF score was significantly higher in older women who had made a recent suicide attempt (mean: 10.56; standard deviation [SD]: 5.46 than comparison subjects (mean: 7.24; SD: 4.04 (t=3.52, P=0.001; df=99. Logistic regression showed that CVRF score (Exp[B]: 1.289, P=0.033, DSM-IV depressive disorders (current (Exp[B]: 348, P<0.001, number of life events in the past 12 weeks (Exp[B]: 10.4; P

  12. Multidimensional model of apathy in older adults using partial least squares--path modeling.

    Science.gov (United States)

    Raffard, Stéphane; Bortolon, Catherine; Burca, Marianna; Gely-Nargeot, Marie-Christine; Capdevielle, Delphine

    2016-06-01

    Apathy defined as a mental state characterized by a lack of goal-directed behavior is prevalent and associated with poor functioning in older adults. The main objective of this study was to identify factors contributing to the distinct dimensions of apathy (cognitive, emotional, and behavioral) in older adults without dementia. One hundred and fifty participants (mean age, 80.42) completed self-rated questionnaires assessing apathy, emotional distress, anticipatory pleasure, motivational systems, physical functioning, quality of life, and cognitive functioning. Data were analyzed using partial least squares variance-based structural equation modeling in order to examine factors contributing to the three different dimensions of apathy in our sample. Overall, the different facets of apathy were associated with cognitive functioning, anticipatory pleasure, sensitivity to reward, and physical functioning, but the contribution of these different factors to the three dimensions of apathy differed significantly. More specifically, the impact of anticipatory pleasure and physical functioning was stronger for the cognitive than for emotional apathy. Conversely, the impact of sensibility to reward, although small, was slightly stronger on emotional apathy. Regarding behavioral apathy, again we found similar latent variables except for the cognitive functioning whose impact was not statistically significant. Our results highlight the need to take into account various mechanisms involved in the different facets of apathy in older adults without dementia, including not only cognitive factors but also motivational variables and aspects related to physical disability. Clinical implications are discussed.

  13. Multi-dimensional boron transport modeling in subchannel approach: Part II. Validation of CTF boron tracking model and adding boron precipitation model

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, Ozkan Emre, E-mail: ozdemir@psu.edu; Avramova, Maria N., E-mail: mna109@psu.edu

    2014-10-15

    Highlights: • Validation of implemented multi-dimensional subchannel boron transport model. • Extension of boron transport model to entrained droplets. • Implementation of boron precipitation model. • Testing of the boron precipitation model under transient condition. - Abstract: The risk of small-break loss of coolant accident (SB-LOCA) and other reactivity initiated transients caused by boron dilution in the light water reactors (LWRs), and the complications of tracking the soluble boron concentration experimentally inside the primary coolant have stimulated the interest in computational studies for accurate boron tracking simulations in nuclear reactors. In Part I of this study, the development and implementation of a multi-dimensional boron transport model with modified Godunov scheme based on a subchannel approach within the COBRA-TF (CTF) thermal-hydraulic code was presented. The modified Godunov scheme approach with a physical diffusion term was determined to provide the most accurate and precise solution. Current paper extends these conclusions and presents the model validation studies against experimental data from the Rossendorf coolant mixing model (ROCOM) test facility. In addition, the importance of the two-phase flow characteristics in modeling boron transient are emphasized, especially during long-term cooling period after the loss of coolant accident (LOCA) condition in pressurized water reactors (PWRs). The CTF capabilities of boron transport modeling are further improved based on the three-field representation of the two-phase flow utilized in the code. The boron transport within entrained droplets is modeled, and a model for predicting the boron precipitation under transient conditions is developed and tested. It is aimed to extend the applicability of CTF to reactor transient simulations, and particularly to a large-break loss of coolant accident (LB-LOCA) analysis.

  14. Comparison of Multidimensional Item Response Models: Multivariate Normal Ability Distributions versus Multivariate Polytomous Ability Distributions. Research Report. ETS RR-08-45

    Science.gov (United States)

    Haberman, Shelby J.; von Davier, Matthias; Lee, Yi-Hsuan

    2008-01-01

    Multidimensional item response models can be based on multivariate normal ability distributions or on multivariate polytomous ability distributions. For the case of simple structure in which each item corresponds to a unique dimension of the ability vector, some applications of the two-parameter logistic model to empirical data are employed to…

  15. Multidimensional Databases and Data Warehousing

    DEFF Research Database (Denmark)

    Jensen, Christian S.; Pedersen, Torben Bach; Thomsen, Christian

    techniques that are particularly important to multidimensional databases, including materialized views, bitmap indices, join indices, and star join processing. The book ends with a chapter that presents the literature on which the book is based and offers further readings for those readers who wish to engage......The present book's subject is multidimensional data models and data modeling concepts as they are applied in real data warehouses. The book aims to present the most important concepts within this subject in a precise and understandable manner. The book's coverage of fundamental concepts includes...... data cubes and their elements, such as dimensions, facts, and measures and their representation in a relational setting; it includes architecture-related concepts; and it includes the querying of multidimensional databases. The book also covers advanced multidimensional concepts that are considered...

  16. Testing the Multidimensionality in Teacher Interpersonal Behavior: Validating the Questionnaire on Teacher Interaction Using the Rasch Measurement Model.

    Science.gov (United States)

    Fulmer, Gavin W; Lang, Quek Choon

    2015-01-01

    This study investigated the perceptions of 1235 students of their form teachers' interpersonal behaviors across 40 classrooms in 24 Singaporean secondary schools. The 32-item Questionnaire on Teacher Interaction (QTI) survey was administered to obtain the initial quantitative data of teacher behaviors perceived by the students in these classrooms. The eight scales of QTI are: Leadership, Helping/Friendly, Understanding, Student Responsibility/ Freedom, Uncertain, Dissatisfied, Admonishing, and Strict. The Rasch measurement model was used to estimate students' traits with respect to each subscale, and then to examine its proposed multidimensional structure. Findings demonstrate overall good fit of the responses with the Rasch model for each subscale. Findings also support the hypothesized relationships among the eight dimensions proposed for the QTI.

  17. Transport and concentration processes in the multidimensional zero-pressure gas dynamics model with the energy conservation law

    CERN Document Server

    Albeverio, S; Shelkovich, V M

    2011-01-01

    We introduce integral identities to define delta-shock wave type solutions for the multidimensional zero-pressure gas dynamics Using these integral identities, the Rankine-Hugoniot conditions for delta-shocks are obtained. We derive the balance laws describing mass, momentum, and energy transport from the area outside the delta-shock wave front onto this front. These processes are going on in such a way that the total mass, momentum, and energy are conserved and at the same time mass and energy of the moving delta-shock wave front are increasing quantities. In addition, the total kinetic energy transfers into the total internal energy. The process of propagation of delta-shock waves is also described. These results can be used in modeling of mediums which can be treated as a {pressureless continuum} (dusty gases, two-phase flows with solid particles or droplets, granular gases).

  18. Multi-dimensional boron transport modeling in subchannel approach: Part I. Model selection, implementation and verification of COBRA-TF boron tracking model

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, Ozkan Emre, E-mail: ozdemir@psu.edu [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Avramova, Maria N., E-mail: mna109@psu.edu [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Sato, Kenya, E-mail: kenya_sato@mhi.co.jp [Mitsubishi Heavy Industries (MHI), Kobe (Japan)

    2014-10-15

    Highlights: ► Implementation of multidimensional boron transport model in a subchannel approach. ► Studies on cross flow mechanism, heat transfer and lateral pressure drop effects. ► Verification of the implemented model via code-to-code comparison with CFD code. - Abstract: The risk of reflux condensation especially during a Small Break Loss Of Coolant Accident (SB-LOCA) and the complications of tracking the boron concentration experimentally inside the primary coolant system have stimulated and subsequently have been a focus of many computational studies on boron tracking simulations in nuclear reactors. This paper presents the development and implementation of a multidimensional boron transport model with Modified Godunov Scheme within a thermal-hydraulic code based on a subchannel approach. The cross flow mechanism in multiple-subchannel rod bundle geometry as well as the heat transfer and lateral pressure drop effects are considered in the performed studies on simulations of deboration and boration cases. The Pennsylvania State University (PSU) version of the COBRA-TF (CTF) code was chosen for the implementation of three different boron tracking models: First Order Accurate Upwind Difference Scheme, Second Order Accurate Godunov Scheme, and Modified Godunov Scheme. Based on the performed nodalization sensitivity studies, the Modified Godunov Scheme approach with a physical diffusion term was determined to provide the best solution in terms of precision and accuracy. As a part of the verification and validation activities, a code-to-code comparison was carried out with the STAR-CD computational fluid dynamics (CFD) code and presented here. The objective of this study was two-fold: (1) to verify the accuracy of the newly developed CTF boron tracking model against CFD calculations; and (2) to investigate its numerical advantages as compared to other thermal-hydraulics codes.

  19. Innovative application of a multidimensional item response model in assessing the influence of social desirability on the pseudo-relationship between self-efficacy and behavior

    Science.gov (United States)

    This study examined multidimensional item response theory (MIRT) modeling to assess social desirability (SocD) influences on self-reported physical activity self-efficacy (PASE) and fruit and vegetable self-efficacy (FVSE). The observed sample included 473 Houston-area adolescent males (10–14 years)...

  20. Effectiveness of the multidimensional ergonomic intervention model to reduce musculoskeletal discomfort among street sweepers in Chiang Rai Province, Thailand

    Directory of Open Access Journals (Sweden)

    Pintakham K

    2016-12-01

    Full Text Available Kanjanar Pintakham,1,2 Wattasit Siriwong1 1College of Public Health Sciences, Chulalongkorn University, Bangkok, 2School of Health Science, Chiang Rai Rajabhat University, Chiang Rai, Thailand Abstract: The aim of this study was to evaluate the effectiveness of multidimensional ergonomic intervention (MEI model to reduce musculoskeletal discomfort (MSD among street sweepers. A quasi-experimental study was conducted in Chiang Rai Province. The MEI model was designed on the basis of four core components: cognitive behavior therapy, ergonomic education training, stretching exercise, and the foam sleeve broom handle grip. Seventy-five street sweepers volunteered for the screening process on MSD of having level score ≥4 by physiotherapist. Face to face interviews were used mainly in order to diagnose MSD. Physical examination was performed by physiotherapist and physical performance by sports scientist. The findings showed that the MEI model among the intervention group significantly reduced MSD compared with that among control group at exit model and follow-up (P<0.01. This research suggests that the MEI model was appropriate to reduce MSD associated with repetitive movement and awkward postures on task. Keywords: repetitive movement, cognitive behavior therapy, stretching exercise, street sweepers

  1. A multi-dimensional quasi-discrete model for the analysis of Diesel fuel droplet heating and evaporation

    KAUST Repository

    Sazhin, Sergei S.

    2014-08-01

    A new multi-dimensional quasi-discrete model is suggested and tested for the analysis of heating and evaporation of Diesel fuel droplets. As in the original quasi-discrete model suggested earlier, the components of Diesel fuel with close thermodynamic and transport properties are grouped together to form quasi-components. In contrast to the original quasi-discrete model, the new model takes into account the contribution of not only alkanes, but also various other groups of hydrocarbons in Diesel fuels; quasi-components are formed within individual groups. Also, in contrast to the original quasi-discrete model, the contributions of individual components are not approximated by the distribution function of carbon numbers. The formation of quasi-components is based on taking into account the contributions of individual components without any approximations. Groups contributing small molar fractions to the composition of Diesel fuel (less than about 1.5%) are replaced with characteristic components. The actual Diesel fuel is simplified to form six groups: alkanes, cycloalkanes, bicycloalkanes, alkylbenzenes, indanes & tetralines, and naphthalenes, and 3 components C19H34 (tricycloalkane), C13H 12 (diaromatic), and C14H10 (phenanthrene). It is shown that the approximation of Diesel fuel by 15 quasi-components and components, leads to errors in estimated temperatures and evaporation times in typical Diesel engine conditions not exceeding about 3.7% and 2.5% respectively, which is acceptable for most engineering applications. © 2014 Published by Elsevier Ltd. All rights reserved.

  2. Effective multidimensional crossover behavior in a one-dimensional voter model with long-range probabilistic interactions

    Science.gov (United States)

    Rodriguez, D. E.; Bab, M. A.; Albano, E. V.

    2011-01-01

    A variant of the standard voter model, where a randomly selected site of a one-dimensional lattice (d=1) adopts the state of another site placed at a distance r from the previous one, is proposed and studied by means of numerical simulations that are rationalized with the aid of dynamical and finite-size scaling arguments. The distance between the two sites is also selected randomly with a probability given by P(r)∝r-(d+σ), where σ is a control parameter. In this way one can study how the introduction of these long-range interactions influences the dynamic behavior of the standard voter model with nearest-neighbor interactions. It is found that the dynamics strongly depends on the range of the interactions, which is parameterized by σ, leading to an interesting effective multidimensional crossover behavior, as follows. (a) For σ2, as well as the case of both scale-free and small-world networks. (b) For σ>1, an ordering dynamics is observed, such that ρ(t)∝t-α, where the exponent α increases with σ until it reaches the value α=1/2 for σ⩾5, which corresponds to the behavior of the standard voter model with short-range interactions in d=1. (c) Finally, for σ≈1 we show evidence of a critical-type behavior as in the case of the critical dimension (dc=2) of the standard voter model.

  3. A multidimensional ambivalence model of chocolate craving: construct validity and associations with chocolate consumption and disordered eating.

    Science.gov (United States)

    Cartwright, Fiona; Stritzke, Werner G K

    2008-01-01

    This study tested the construct validity of a multidimensional ambivalence model of chocolate craving, and examined the concurrent and discriminant validity of the model with respect to chocolate consumption and disordered eating behaviors. The Orientation to Chocolate Questionnaire (OCQ) was administered to 312 university students (79.5% female) along with measures of chocolate consumption and disordered eating. Results supported a three-factor model of chocolate craving incorporating approach and avoidance inclinations and feelings of guilt. These craving dimensions differentially predicted frequency and quantity of chocolate consumption as well as a range of disordered eating behaviors. Chocolate-related guilt was a consistent indicator of dysfunctional eating patterns, but was unrelated to external or functional eating. Approach inclinations positively predicted consumption-oriented eating behaviors and negatively predicted avoidance-oriented behaviors. Active avoidance inclinations facilitated restraint and inhibited frequency of consumption, but were unrelated to quantity consumed. In line with contemporary theories of substance craving, chocolate craving can be conceptualized as a net action disposition resulting from the relative strength of the competing processes underlying indulgence and restraint.

  4. Tetrahedral shapes of neutron-rich Zr isotopes from multidimensionally-constrained relativistic Hartree-Bogoliubov model

    CERN Document Server

    Zhao, Jie; Zhao, En-Guang; Zhou, Shan-Gui

    2016-01-01

    We develop a multidimensionally-constrained relativistic Hartree-Bogoliubov (MDC-RHB) model in which the pairing correlations are taken into account by making the Bogoliubov transformation. In this model, the nuclear shape is assumed to be invariant under the reversion of $x$ and $y$ axes, i.e., the intrinsic symmetry group is $V_4$ and all shape degrees of freedom $\\beta_{\\lambda\\mu}$ with even $\\mu$ are included self-consistently. The RHB equation is solved in an axially deformed harmonic oscillator basis. A separable pairing force of finite range is adopted in the MDC-RHB model. The potential energy curves of neutron-rich even-even Zr isotopes are calculated. The ground state shapes of $^{108-112}$Zr are predicted to be tetrahedral with both functionals DD-PC1 and PC-PK1 and $^{106}$Zr is also predicted to have a tetrahedral ground state with the functional PC-PK1. The tetrahedral ground states are caused by large energy gaps at $Z=40$ and $N=70$ when $\\beta_{32}$ deformation is included. Although the incl...

  5. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  6. Integrating Diverse Geophysical and Geological Data to Construct Multi-Dimensional Earth Models: The Open Earth Framework

    Science.gov (United States)

    Baru, C.; Keller, R.; Wallet, B.; Crosby, C.; Moreland, J.; Nadeau, D.

    2008-12-01

    Currently, many large geoscientific efforts (e.g., EarthScope, Continental Dynamics, and GeoSwath) have emphasized that a crucial need in advancing our understanding of the structure and evolution of the continents is high-resolution, 3-D models of lithospheric structure. In addition, the geoscience community recognizes that our ultimate goal is the addition of the dimension of time to make the problem 4-D. Adding the dimension of time is a complex problem that is strongly dependent on the integration of a variety of geological data into our analyses (e.g., geochronology, paleontology, stratigraphy, pressure-time histories, structural geology, paleogeography, etc.). The geoscience community also recognizes that solutions to the scientific and societal questions that they seek to answer require innovative integration of many types of data so that many physical properties (x, y, z, P-wave velocity, S-wave velocity, density, electrical conductivity, etc.) are measured and included in 3-D models. The problem is, therefore, truly multidimensional in nature. We are developing an Open Earth Framework (OEF) as an open data model for integration of such multidimensional Earth Sciences data. In our work and interactions with the community on building and visualizing complex earth models, several issues have emerged on which there is consensus. First of all, integration efforts should work from the surface down because we have the most data there (e.g., geologic maps, remote sensing data such as LIDAR and ASTER, digital elevation models, gravity and magnetic measurements, etc.) and because the complex conditions near surface always have a potential to mask deeper features. Secondly since we cannot expect uniform coverage of a variety of high-resolution data in anything but special circumstances, a data integration effort should first establish a regional context using lower resolution (and usually wide coverage) data and then proceed to modeling the data sets with the highest

  7. A Two-Temperature Open-Source CFD Model for Hypersonic Reacting Flows, Part Two: Multi-Dimensional Analysis †

    Directory of Open Access Journals (Sweden)

    Vincent Casseau

    2016-12-01

    Full Text Available hy2Foam is a newly-coded open-source two-temperature computational fluid dynamics (CFD solver that has previously been validated for zero-dimensional test cases. It aims at (1 giving open-source access to a state-of-the-art hypersonic CFD solver to students and researchers; and (2 providing a foundation for a future hybrid CFD-DSMC (direct simulation Monte Carlo code within the OpenFOAM framework. This paper focuses on the multi-dimensional verification of hy2Foam and firstly describes the different models implemented. In conjunction with employing the coupled vibration-dissociation-vibration (CVDV chemistry–vibration model, novel use is made of the quantum-kinetic (QK rates in a CFD solver. hy2Foam has been shown to produce results in good agreement with previously published data for a Mach 11 nitrogen flow over a blunted cone and with the dsmcFoam code for a Mach 20 cylinder flow for a binary reacting mixture. This latter case scenario provides a useful basis for other codes to compare against.

  8. Hybrid attribute-based recommender system for learning material using genetic algorithm and a multidimensional information model

    Directory of Open Access Journals (Sweden)

    Mojtaba Salehi

    2013-03-01

    Full Text Available In recent years, the explosion of learning materials in the web-based educational systems has caused difficulty of locating appropriate learning materials to learners. A personalized recommendation is an enabling mechanism to overcome information overload occurred in the new learning environments and deliver suitable materials to learners. Since users express their opinions based on some specific attributes of items, this paper proposes a hybrid recommender system for learning materials based on their attributes to improve the accuracy and quality of recommendation. The presented system has two main modules: explicit attribute-based recommender and implicit attribute-based recommender. In the first module, weights of implicit or latent attributes of materials for learner are considered as chromosomes in genetic algorithm then this algorithm optimizes the weights according to historical rating. Then, recommendation is generated by Nearest Neighborhood Algorithm (NNA using the optimized weight vectors implicit attributes that represent the opinions of learners. In the second, preference matrix (PM is introduced that can model the interests of learner based on explicit attributes of learning materials in a multidimensional information model. Then, a new similarity measure between PMs is introduced and recommendations are generated by NNA. The experimental results show that our proposed method outperforms current algorithms on accuracy measures and can alleviate some problems such as cold-start and sparsity.

  9. Multi-Dimensional Path Queries

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    1998-01-01

    We present the path-relationship model that supports multi-dimensional data modeling and querying. A path-relationship database is composed of sets of paths and sets of relationships. A path is a sequence of related elements (atoms, paths, and sets of paths). A relationship is a binary path...... to create nested path structures. We present an SQL-like query language that is based on path expressions and we show how to use it to express multi-dimensional path queries that are suited for advanced data analysis in decision support environments like data warehousing environments...

  10. Multidimensional Datawarehouse with Combination Formula

    OpenAIRE

    Warnars, Spits

    2010-01-01

    Multidimensional in data warehouse is a compulsion and become the most important for information delivery, without multidimensional Multidimensional in data warehouse is a compulsion and become the most important for information delivery, without multidimensional datawarehouse is incomplete. Multidimensional give ability to analyze business measurement in many different ways. Multidimensional is also synonymous with online analytical processing (OLAP). By using some concepts in datawarehouse ...

  11. Ethnicity, work-related stress and subjective reports of health by migrant workers: a multi-dimensional model.

    Science.gov (United States)

    Capasso, Roberto; Zurlo, Maria Clelia; Smith, Andrew P

    2016-11-16

    This study integrates different aspects of ethnicity and work-related stress dimensions (based on the Demands-Resources-Individual-Effects model, DRIVE [Mark, G. M., and A. P. Smith. 2008. "Stress Models: A Review and Suggested New Direction." In Occupational Health Psychology, edited by J. Houdmont and S. Leka, 111-144. Nottingham: Nottingham University Press]) and aims to test a multi-dimensional model that combines individual differences, ethnicity dimensions, work characteristics, and perceived job satisfaction/stress as independent variables in the prediction of subjectives reports of health by workers differing in ethnicity. A questionnaire consisting of the following sections was submitted to 900 workers in Southern Italy: for individual and cultural characteristics, coping strategies, personality behaviours, and acculturation strategies; for work characteristics, perceived job demands and job resources/rewards; for appraisals, perceived job stress/satisfaction and racial discrimination; for subjective reports of health, psychological disorders and general health. To test the reliability and construct validity of the extracted factors referred to all dimensions involved in the proposed model and logistic regression analyses to evaluate the main effects of the independent variables on the health outcomes were conducted. Principal component analysis (PCA) yielded seven factors for individual and cultural characteristics (emotional/relational coping, objective coping, Type A behaviour, negative affectivity, social inhibition, affirmation/maintenance culture, and search identity/adoption of the host culture); three factors for work characteristics (work demands, intrinsic/extrinsic rewards, and work resources); three factors for appraisals (perceived job satisfaction, perceived job stress, perceived racial discrimination) and three factors for subjective reports of health (interpersonal disorders, anxious-depressive disorders, and general health). Logistic

  12. Validating the European Health Literacy Survey Questionnaire in people with type 2 diabetes: Latent trait analyses applying multidimensional Rasch modelling and confirmatory factor analysis.

    Science.gov (United States)

    Finbråten, Hanne Søberg; Pettersen, Kjell Sverre; Wilde-Larsson, Bodil; Nordström, Gun; Trollvik, Anne; Guttersrud, Øystein

    2017-11-01

    To validate the European Health Literacy Survey Questionnaire (HLS-EU-Q47) in people with type 2 diabetes mellitus. The HLS-EU-Q47 latent variable is outlined in a framework with four cognitive domains integrated in three health domains, implying 12 theoretically defined subscales. Valid and reliable health literacy measurers are crucial to effectively adapt health communication and education to individuals and groups of patients. Cross-sectional study applying confirmatory latent trait analyses. Using a paper-and-pencil self-administered approach, 388 adults responded in March 2015. The data were analysed using the Rasch methodology and confirmatory factor analysis. Response violation (response dependency) and trait violation (multidimensionality) of local independence were identified. Fitting the "multidimensional random coefficients multinomial logit" model, 1-, 3- and 12-dimensional Rasch models were applied and compared. Poor model fit and differential item functioning were present in some items, and several subscales suffered from poor targeting and low reliability. Despite multidimensional data, we did not observe any unordered response categories. Interpreting the domains as distinct but related latent dimensions, the data fit a 12-dimensional Rasch model and a 12-factor confirmatory factor model best. Therefore, the analyses did not support the estimation of one overall "health literacy score." To support the plausibility of claims based on the HLS-EU score(s), we suggest: removing the health care aspect to reduce the magnitude of multidimensionality; rejecting redundant items to avoid response dependency; adding "harder" items and applying a six-point rating scale to improve subscale targeting and reliability; and revising items to improve model fit and avoid bias owing to person factors. © 2017 John Wiley & Sons Ltd.

  13. Multi-Dimensional Aggregation for Temporal Data

    DEFF Research Database (Denmark)

    Böhlen, M. H.; Gamper, J.; Jensen, Christian Søndergaard

    2006-01-01

    Business Intelligence solutions, encompassing technologies such as multi-dimensional data modeling and aggregate query processing, are being applied increasingly to non-traditional data. This paper extends multi-dimensional aggregation to apply to data with associated interval values that capture...

  14. Open framework for management and processing of multi-modality and multidimensional imaging data for analysis and modelling muscular function

    Science.gov (United States)

    García Juan, David; Delattre, Bénédicte M. A.; Trombella, Sara; Lynch, Sean; Becker, Matthias; Choi, Hon Fai; Ratib, Osman

    2014-03-01

    Musculoskeletal disorders (MSD) are becoming a big healthcare economical burden in developed countries with aging population. Classical methods like biopsy or EMG used in clinical practice for muscle assessment are invasive and not accurately sufficient for measurement of impairments of muscular performance. Non-invasive imaging techniques can nowadays provide effective alternatives for static and dynamic assessment of muscle function. In this paper we present work aimed toward the development of a generic data structure for handling n-dimensional metabolic and anatomical data acquired from hybrid PET/MR scanners. Special static and dynamic protocols were developed for assessment of physical and functional images of individual muscles of the lower limb. In an initial stage of the project a manual segmentation of selected muscles was performed on high-resolution 3D static images and subsequently interpolated to full dynamic set of contours from selected 2D dynamic images across different levels of the leg. This results in a full set of 4D data of lower limb muscles at rest and during exercise. These data can further be extended to a 5D data by adding metabolic data obtained from PET images. Our data structure and corresponding image processing extension allows for better evaluation of large volumes of multidimensional imaging data that are acquired and processed to generate dynamic models of the moving lower limb and its muscular function.

  15. Original article Multidimensional versus unidimensional models of emotional contagion: the Emotional Contagion Scale in a Polish sample

    Directory of Open Access Journals (Sweden)

    Monika Wróbel

    2014-07-01

    Full Text Available Background The Emotional Contagion Scale (ECS measures individual differences in susceptibility to catching emotions expressed by others. Although initially the scale was reported to have a unidimensional structure, recent validation studies have suggested that the concept of emotional contagion is multidimensional. The aim of the study was therefore to test whether the structure of the ECS in a Polish sample corresponds with that observed for other non-English speaking populations. Participants and procedure The scale, translated into Polish, was completed by 633 university students in four independent samples. To investigate the factor structure of the ECS, confirmatory factor analyses of five alternative models were conducted. Results The results supported a multifaceted solution, which confirmed that susceptibility to emotional contagion may be differentiated not only across positive vs. negative states but also across discrete emotions. Moreover, the verification of internal consistency, test-retest reliability and construct validity of the Polish version indicated that its parameters are acceptable and comparable with the characteristics of other adaptations. Conclusions The Polish ECS, together with other adaptations of the scale, shows that the construct developed in the United States can be successfully measured in other cultural contexts. Thus, the Polish version can be treated as a useful tool for measuring individual differences in susceptibility to emotional contagion.

  16. Multidimensional modeling of Dimethyl Ether(DME) spray combustion in DI diesel engine

    Institute of Scientific and Technical Information of China (English)

    WEN Hua; LIU Yong-chang; WEI Ming-rui; ZHANG Yu-sheng

    2005-01-01

    In the present study a modified CFD code KIVA3V was used to simulate the spray combustion in a small DI diesel engine fueled with DME. The improved spray models consider more spray phenomena such as cavitation flow in nozzle hole, jet atomization, droplet second breakup and spray wall interaction. Otherwise, a reduced DME reaction mechanism is implemented in the combustion model, and a new turbulent combustion model-Partial Stirred Reactor (PaSR) model is selected to simulate the spray combustion process, the effects of turbulent mixing on the reaction rate are considered. The results of engine modeling based on those models agreed well with the experimental measurements. Study of temperature fields variation and particle traces in the combustion chamber revealed that the engine combustion system originally used for diesel fuel must be optimized for DME.

  17. Multi-dimensional project management models for mega-construction companies and their applications

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    China is undertaking an increasing number of mega-infrastructure projects along with its rapid economic expansion.For participants in these projects,understand how to adapt the proper and efficient management strategies is critical.In this paper,we propose three distinct models for companies under various background and management requirements,based on sophisticated data analysis and model development.Moreover,we successfully committed these models with hydropower development projects and achieved a great progress in enhancing management efficiency.

  18. A multi-dimensional model for localization of highly variable objects

    Science.gov (United States)

    Ruppertshofen, Heike; Bülow, Thomas; von Berg, Jens; Schmidt, Sarah; Beyerlein, Peter; Salah, Zein; Rose, Georg; Schramm, Hauke

    2012-02-01

    In this work, we present a new type of model for object localization, which is well suited for anatomical objects exhibiting large variability in size, shape and posture, for usage in the discriminative generalized Hough transform (DGHT). The DGHT combines the generalized Hough transform (GHT) with a discriminative training approach to automatically obtain robust and efficient models. It has been shown to be a strong tool for object localization capable of handling a rather large amount of shape variability. For some tasks, however, the variability exhibited by different occurrences of the target object becomes too large to be represented by a standard DGHT model. To be able to capture such highly variable objects, several sub-models, representing the modes of variability as seen by the DGHT, are created automatically and are arranged in a higher dimensional model. The modes of variability are identified on-the-fly during training in an unsupervised manner. Following the concept of the DGHT, the sub-models are jointly trained with respect to a minimal localization error employing the discriminative training approach. The procedure is tested on a dataset of thorax radiographs with the target to localize the clavicles. Due to different arm positions, the posture and arrangement of the target and surrounding bones differs strongly, which hampers the training of a good localization model. Employing the new model approach the localization rate improves by 13% on unseen test data compared to the standard model.

  19. Quantifying variability in earthquake rupture models using multidimensional scaling: application to the 2011 Tohoku earthquake

    KAUST Repository

    Razafindrakoto, Hoby

    2015-04-22

    Finite-fault earthquake source inversion is an ill-posed inverse problem leading to non-unique solutions. In addition, various fault parametrizations and input data may have been used by different researchers for the same earthquake. Such variability leads to large intra-event variability in the inferred rupture models. One way to understand this problem is to develop robust metrics to quantify model variability. We propose a Multi Dimensional Scaling (MDS) approach to compare rupture models quantitatively. We consider normalized squared and grey-scale metrics that reflect the variability in the location, intensity and geometry of the source parameters. We test the approach on two-dimensional random fields generated using a von Kármán autocorrelation function and varying its spectral parameters. The spread of points in the MDS solution indicates different levels of model variability. We observe that the normalized squared metric is insensitive to variability of spectral parameters, whereas the grey-scale metric is sensitive to small-scale changes in geometry. From this benchmark, we formulate a similarity scale to rank the rupture models. As case studies, we examine inverted models from the Source Inversion Validation (SIV) exercise and published models of the 2011 Mw 9.0 Tohoku earthquake, allowing us to test our approach for a case with a known reference model and one with an unknown true solution. The normalized squared and grey-scale metrics are respectively sensitive to the overall intensity and the extension of the three classes of slip (very large, large, and low). Additionally, we observe that a three-dimensional MDS configuration is preferable for models with large variability. We also find that the models for the Tohoku earthquake derived from tsunami data and their corresponding predictions cluster with a systematic deviation from other models. We demonstrate the stability of the MDS point-cloud using a number of realizations and jackknife tests, for

  20. Multi-dimensional digital human models for ergonomic analysis based on natural data representations

    NARCIS (Netherlands)

    Moes, C.C.M.

    2015-01-01

    Digital human models are often used for ergonomic analysis of product designs, before physical prototypes are available. However, existing digital human models cannot be used to simultaneously: 1) consider the tissue loads and the physiological effects of the tissue loads; 2) optimise the product pr

  1. Improving Breast Cancer Survival Analysis through Competition-Based Multidimensional Modeling

    Science.gov (United States)

    Bilal, Erhan; Dutkowski, Janusz; Guinney, Justin; Jang, In Sock; Logsdon, Benjamin A.; Pandey, Gaurav; Sauerwine, Benjamin A.; Shimoni, Yishai; Moen Vollan, Hans Kristian; Mecham, Brigham H.; Rueda, Oscar M.; Tost, Jorg; Curtis, Christina; Alvarez, Mariano J.; Kristensen, Vessela N.; Aparicio, Samuel; Børresen-Dale, Anne-Lise; Caldas, Carlos; Califano, Andrea; Friend, Stephen H.; Ideker, Trey; Schadt, Eric E.; Stolovitzky, Gustavo A.; Margolin, Adam A.

    2013-01-01

    Breast cancer is the most common malignancy in women and is responsible for hundreds of thousands of deaths annually. As with most cancers, it is a heterogeneous disease and different breast cancer subtypes are treated differently. Understanding the difference in prognosis for breast cancer based on its molecular and phenotypic features is one avenue for improving treatment by matching the proper treatment with molecular subtypes of the disease. In this work, we employed a competition-based approach to modeling breast cancer prognosis using large datasets containing genomic and clinical information and an online real-time leaderboard program used to speed feedback to the modeling team and to encourage each modeler to work towards achieving a higher ranked submission. We find that machine learning methods combined with molecular features selected based on expert prior knowledge can improve survival predictions compared to current best-in-class methodologies and that ensemble models trained across multiple user submissions systematically outperform individual models within the ensemble. We also find that model scores are highly consistent across multiple independent evaluations. This study serves as the pilot phase of a much larger competition open to the whole research community, with the goal of understanding general strategies for model optimization using clinical and molecular profiling data and providing an objective, transparent system for assessing prognostic models. PMID:23671412

  2. Improving breast cancer survival analysis through competition-based multidimensional modeling.

    Directory of Open Access Journals (Sweden)

    Erhan Bilal

    Full Text Available Breast cancer is the most common malignancy in women and is responsible for hundreds of thousands of deaths annually. As with most cancers, it is a heterogeneous disease and different breast cancer subtypes are treated differently. Understanding the difference in prognosis for breast cancer based on its molecular and phenotypic features is one avenue for improving treatment by matching the proper treatment with molecular subtypes of the disease. In this work, we employed a competition-based approach to modeling breast cancer prognosis using large datasets containing genomic and clinical information and an online real-time leaderboard program used to speed feedback to the modeling team and to encourage each modeler to work towards achieving a higher ranked submission. We find that machine learning methods combined with molecular features selected based on expert prior knowledge can improve survival predictions compared to current best-in-class methodologies and that ensemble models trained across multiple user submissions systematically outperform individual models within the ensemble. We also find that model scores are highly consistent across multiple independent evaluations. This study serves as the pilot phase of a much larger competition open to the whole research community, with the goal of understanding general strategies for model optimization using clinical and molecular profiling data and providing an objective, transparent system for assessing prognostic models.

  3. Multi-dimensional profiling of medical students' cognitive models about learning.

    Science.gov (United States)

    Askell-Williams, Helen; Lawson, Michael J

    2006-02-01

    In current constructivist paradigms, learners' previous subject-matter knowledge, or cognitive models, provide the foundations for the construction of new knowledge. Learners' cognitive models about learning also mediate students' capacities to learn in their chosen topics of study. The diverse backgrounds of students entering medicine suggest that they might come to medical studies equipped with a wide variety of cognitive models about learning. Some current theories tend to reduce students' cognitions about learning to parsimonious representations, such as surface-deep approaches or mastery-performance goals. It is possible that such reduced representations underrepresent, or misrepresent, the complexity of students' cognitive models about learning. Good quality teaching needs to take account of learners' cognitive models, not just about subject matter, but also about learning. This study investigated the diversity and complexity of medical students' cognitive models about learning. A total of 7 graduate entry, clinical-year medical students volunteered for in-depth interviews about learning. NUD*IST text analysis software and correspondence analysis were employed to identify dimensions and to profile students' responses. The correspondence analysis identified a significant 4-dimensional solution that illustrates the contributions of multiple variables to students' cognitive models about learning. Individual profiles highlight diversity between participants. This study provides evidence that students' cognitive models about learning are complex and highly differentiated. Representations of what students know about learning need to take account of such complexity in order to inform instructional practice more adequately.

  4. Probing Lexical Representations: Simultaneous Modeling of Word and Reader Contributions to Multidimensional Lexical Representations

    Science.gov (United States)

    Goodwin, Amanda P.; Gilbert, Jennifer K.; Cho, Sun-Joo; Kearns, Devin M.

    2014-01-01

    The current study models reader, item, and word contributions to the lexical representations of 39 morphologically complex words for 172 middle school students using a crossed random-effects item response model with multiple outcomes. We report 3 findings. First, results suggest that lexical representations can be characterized by separate but…

  5. Multi-dimensional digital human models for ergonomic analysis based on natural data representations

    NARCIS (Netherlands)

    Moes, C.C.M.

    2015-01-01

    Digital human models are often used for ergonomic analysis of product designs, before physical prototypes are available. However, existing digital human models cannot be used to simultaneously: 1) consider the tissue loads and the physiological effects of the tissue loads; 2) optimise the product

  6. Probing Lexical Representations: Simultaneous Modeling of Word and Reader Contributions to Multidimensional Lexical Representations

    Science.gov (United States)

    Goodwin, Amanda P.; Gilbert, Jennifer K.; Cho, Sun-Joo; Kearns, Devin M.

    2014-01-01

    The current study models reader, item, and word contributions to the lexical representations of 39 morphologically complex words for 172 middle school students using a crossed random-effects item response model with multiple outcomes. We report 3 findings. First, results suggest that lexical representations can be characterized by separate but…

  7. Non-local first-order modelling of crowd dynamics: a multidimensional framework with applications

    CERN Document Server

    Bruno, Luca; Tricerri, Paolo; Venuti, Fiammetta

    2010-01-01

    In this work a physical modelling framework is presented, describing the intelligent, non-local, and anisotropic behaviour of pedestrians. Its phenomenological basics and constitutive elements are detailed, and a qualitative analysis is provided. Within this common framework, two first-order mathematical models, along with related numerical solution techniques, are derived. The models are oriented to specific real world applications: a one-dimensional model of crowd-structure interaction in footbridges and a two-dimensional model of pedestrian flow in an underground station with several obstacles and exits. The noticeable heterogeneity of the applications demonstrates the significance of the physical framework and its versatility in addressing different engineering problems. The results of the simulations point out the key role played by the physiological and psychological features of human perception on the overall crowd dynamics.

  8. Multidimensional modeling of biofilm development and fluid dynamics in a hydrogen-based, membrane biofilm reactor (MBfR).

    Science.gov (United States)

    Martin, Kelly J; Picioreanu, Cristian; Nerenberg, Robert

    2013-09-01

    A two-dimensional, particle-based biofilm model coupled with mass transport and computational fluid dynamics was developed to simulate autotrophic denitrification in a spiral-wound membrane biofilm reactor (MBfR), where hydrogen is supplied via hollow-fiber membrane fabric. The spiral-wound configuration consists of alternating layers of plastic spacer net and membrane fabric that create rows of flow channels, with the top and bottom walls comprised of membranes. The transversal filaments of the spacer partially obstruct the channel flow, producing complex mixing and shear patterns that require multidimensional representation. This study investigated the effect of hydrogen and nitrate concentrations, as well as spacer configuration, on biofilm development and denitrification fluxes. The model results indicate that the cavity spacer filaments, which rest on the bottom membranes, cause uneven biofilm growth. Most biofilm resided on the bottom membranes, only in the wake of the filaments where low shear zones formed. In this way, filament configuration may help achieve a desired biofilm thickness. For the conditions tested in this study, the highest nitrate fluxes were attained by minimizing the filament diameter and maximizing the filament spacing. This lowered the shear stress at the top membranes, allowing for more biofilm growth. For the scenarios studied, biomass limitation at the top membranes hindered performance more significantly than diffusion limitation in the thick biofilms at the bottom membranes. The results also highlighted the importance of two-dimensional modeling to capture uneven biofilm growth on a substratum with geometrical complexity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Multi-dimensional Magnetotelluric Modeling of General Anisotropy and Its Implication for Structural Interpretation

    Science.gov (United States)

    Guo, Z.; Wei, W.; Egbert, G. D.

    2015-12-01

    Although electrical anisotropy is likely at various scales in the Earth, present 3D inversion codes only allow for isotropic models. In fact, any effects of anisotropy present in any real data can always be accommodated by (possibly fine scale) isotropic structures. This suggests that some complex structures found in 3D inverse solutions (e.g., alternating elongate conductive and resistive "streaks" of Meqbel et al. (2014)), may actually represent anisotropic layers. As a step towards better understanding how anisotropy is manifest in 3D inverse models, and to better incorporate anisotropy in 3D MT interpretations, we have implemented new 1D, 2D AND 3D forward modeling codes which allow for general anisotropy and are implemented in matlab using an object oriented (OO) approach. The 1D code is used primarily to provide boundary conditions (BCs). For the 2D case we have used the OO approach to quickly develop and compare several variants including different formulations (three coupled electric field components, one electric and one magnetic component coupled) and different discretizations (staggered and fixed grids). The 3D case is implemented in integral form on a staggered grid, using either 1D or 2D BC. Iterative solvers, including divergence correction, allow solution for large model grids. As an initial application of these codes we are conducting synthetic inversion tests. We construct test models by replacing streaky conductivity layers, as found at the top of the mantle in the EarthScope models of Meqbel et al. (2014), with simpler smoothly varying anisotropic layers. The modeling process is iterated to obtain a reasonable match to actual data. Synthetic data generated from these 3D anisotropic models can then be inverted with a 3D code (ModEM) and compared to the inversions obtained with actual data. Results will be assessed, taking into account the diffusive nature of EM imaging, to better understand how actual anisotropy is mapped to structure by 3D

  10. Modelling the multidimensional niche by linking functional traits to competitive performance.

    Science.gov (United States)

    Maynard, Daniel S; Leonard, Kenneth E; Drake, John M; Hall, David W; Crowther, Thomas W; Bradford, Mark A

    2015-07-22

    Linking competitive outcomes to environmental conditions is necessary for understanding species' distributions and responses to environmental change. Despite this importance, generalizable approaches for predicting competitive outcomes across abiotic gradients are lacking, driven largely by the highly complex and context-dependent nature of biotic interactions. Here, we present and empirically test a novel niche model that uses functional traits to model the niche space of organisms and predict competitive outcomes of co-occurring populations across multiple resource gradients. The model makes no assumptions about the underlying mode of competition and instead applies to those settings where relative competitive ability across environments correlates with a quantifiable performance metric. To test the model, a series of controlled microcosm experiments were conducted using genetically related strains of a widespread microbe. The model identified trait microevolution and performance differences among strains, with the predicted competitive ability of each organism mapped across a two-dimensional carbon and nitrogen resource space. Areas of coexistence and competitive dominance between strains were identified,and the predicted competitive outcomes were validated in approximately 95% of the pairings. By linking trait variation to competitive ability, our work demonstrates a generalizable approach for predicting and modelling competitive outcomes across changing environmental contexts.

  11. 3D digital image processing for biofilm quantification from confocal laser scanning microscopy: Multidimensional statistical analysis of biofilm modeling

    Science.gov (United States)

    Zielinski, Jerzy S.

    that were addressed in this work: (i) registration, i.e. automated methods of data acquisition and the ability to align multiple data sets with each other; (ii) visualization and reconstruction, i.e. the environment in which registered data sets can be displayed on a plane or in multidimensional space; (iii) segmentation, i.e. automated and semi-automated methods to create models of relevant anatomy from images; (iv) simulation and prediction, i.e. techniques that can be used to simulate growth end evolution of researched phenomenon. Mathematical models can not only be used to verify experimental findings, but also to make qualitative and quantitative predictions, that might serve as guidelines for the future development of technology and/or treatment.

  12. Brown Dwarf Model Atmospheres Based on Multi-Dimensional Radiation Hydrodynamics

    Science.gov (United States)

    Allard, France; Freytag, Bernd

    2010-11-01

    The atmospheres of Brown Dwarfs (BDs) are the site of molecular opacities and cloud formation, and control their cooling rate, radius and brightness evolution. Brown dwarfs evolve from stellar-like properties (magnetic activity, spots, flares, mass loss) to planet-like properties (electron degeneracy of the interior, cloud formation, dynamical molecular transport) while retaining, due to their fully convective interior, larger rotational velocities (≤ 30 km/s i.e. P objects. While the pure gas-phase based NextGen model atmospheres (Allard et al. 1997, Hauschildt et al. 1999) have allowed the understanding of the several populations of Very Low Mass Stars (VLMs), the AMES-Dusty models (Allard et al. 2001) based on equilibrium chemistry have reproduced some near-IR photometric properties of M and L-type brown dwarfs, and played a key role in the determination of the mass of brown dwarfs and Planetary Mass Objects (PMOs) in the eld and in young stellar clusters. In this paper, we present a new model atmosphere grid for VLMs, BDs, PMOs named BT-Settl, which includes a cloud model and dynamical molecular transport based on mixing information from 2D Radiation Hydrodynamic (RHD) simulations (Freytag et al. 2009). We also present the status of our 3D RHD simulations including rotation (Coriolis forces) of a cube on the surface of a brown dwarf. The BT-Settl model atmosphere grid will be available shortly via the Phoenix web simulator (http://phoenix.ens-lyon.fr/simulator/).

  13. A fluid dynamics multidimensional model of biofilm growth: stability, influence of environment and sensitivity

    CERN Document Server

    Clarelli, Fabrizio; Natalini, Roberto; Ribot, Magali

    2014-01-01

    In this article, we study in details the fluid dynamics system proposed in Clarelli et al (2013) to model the formation of cyanobacteria biofilms. After analyzing the linear stability of the unique non trivial equilibrium of the system, we introduce in the model the influence of light and temperature, which are two important factors for the development of cyanobacteria biofilm. Since the values of the coefficients we use for our simulations are estimated through information found in the literature, some sensitivity and robustness analyses on these parameters are performed. All these elements enable us to control and to validate the model we have already derived and to present some numerical simulations in the 2D and the 3D cases.

  14. Multidimensional MHD Model Studies of the Ionospheres of Venus and Mars

    Science.gov (United States)

    Nagy, Andrew

    1998-01-01

    Continuing efforts have been made towards an increased understanding of the solar wind interaction and ionospheric processes at Venus and Mars. This work centered on a systematic development of a new generation of three dimensional magnetohydrodynamic (MHD) numerical code, which models the interaction processes of the solar wind with non-magnetic planets, such as Venus and Mars. We have also worked on a number of different, more specific and discrete studies, as various opportunities arose. We have developed new numerical codes for magnetospheric and cometary studies. As a first step in this process we built an axisymmetric model in which the solar wind interacts with a hard, perfectly conducting sphere. Even that model provided, in certain respects, significant improvements over previous ones.

  15. A fluid dynamics multidimensional model of biofilm growth: stability, influence of environment and sensitivity.

    Science.gov (United States)

    Clarelli, F; Di Russo, C; Natalini, R; Ribot, M

    2016-12-01

    In this article, we study in detail the fluid dynamics system proposed in Clarelli et al. (2013, J. Math. Biol., 66, 1387-1408) to model the formation of cyanobacteria biofilms. After analysing the linear stability of the unique non-trivial equilibrium of the system, we introduce in the model the influence of light and temperature, which are two important factors for the development of a cyanobacteria biofilm. Since the values of the coefficients we use for our simulations are estimated through information found in the literature, some sensitivity and robustness analyses on these parameters are performed. All these elements enable us to control and to validate the model we have already derived and to present some numerical simulations in the 2D and the 3D cases.

  16. An optimal modeling of multidimensional wave digital filtering network for free vibration analysis of symmetrically laminated composite FSDT plates

    Science.gov (United States)

    Tseng, Chien-Hsun

    2015-02-01

    The technique of multidimensional wave digital filtering (MDWDF) that builds on traveling wave formulation of lumped electrical elements, is successfully implemented on the study of dynamic responses of symmetrically laminated composite plate based on the first order shear deformation theory. The philosophy applied for the first time in this laminate mechanics relies on integration of certain principles involving modeling and simulation, circuit theory, and MD digital signal processing to provide a great variety of outstanding features. Especially benefited by the conservation of passivity gives rise to a nonlinear programming problem (NLP) for the issue of numerical stability of a MD discrete system. Adopting the augmented Lagrangian genetic algorithm, an effective optimization technique for rapidly achieving solution spaces of NLP models, numerical stability of the MDWDF network is well received at all time by the satisfaction of the Courant-Friedrichs-Levy stability criterion with the least restriction. In particular, optimum of the NLP has led to the optimality of the network in terms of effectively and accurately predicting the desired fundamental frequency, and thus to give an insight into the robustness of the network by looking at the distribution of system energies. To further explore the application of the optimum network, more numerical examples are engaged in efforts to achieve a qualitative understanding of the behavior of the laminar system. These are carried out by investigating various effects based on different stacking sequences, stiffness and span-to-thickness ratios, mode shapes and boundary conditions. Results are scrupulously validated by cross referencing with early published works, which show that the present method is in excellent agreement with other numerical and analytical methods.

  17. Multidimensional Scaling and Its Applications.

    Science.gov (United States)

    Davison, Mark L., Ed.; Jones, Lawrence E., Ed.

    1983-01-01

    This special issues describes multidimensional scaling (MDS), with emphasis on proximity and preference models. An introduction and six papers review statistical developments in MDS study design and scrutinize MDS research in four areas of application (consumer, social, cognitive, and vocational psychology). (SLD)

  18. A Multi-Dimensional Model of Groupwork for Adolescent Girls Who Have Been Sexually Abused.

    Science.gov (United States)

    Lindon, Jillian; Nourse, Carol A.

    1994-01-01

    A treatment approach for sexually abused adolescent girls, using a group work model, incorporated three treatment modalities: a skills component, a psychotherapeutic component, and an educative component. Abused girls demonstrated difficulties in many areas of their lives. The six participants showed improvement according to self-statements and…

  19. Predicting Healthcare Fraud in Medicaid: A Multidimensional Data Model and Analysis Techniques for Fraud Detection

    NARCIS (Netherlands)

    Thornton, Dallas; Mueller, Roland; Schoutsen, Paulus; van Hillegersberg, Jos

    2013-01-01

    It is estimated that approximately $700 billion is lost due to fraud, waste, and abuse in the US healthcare system. Medicaid has been particularly susceptible target for fraud in recent years, with a distributed management model, limited cross- program communications, and a difficult-to-track

  20. What can we learn about HiPIMS process from the multidimensional plasma modeling?

    Science.gov (United States)

    Minea, Tiberiu

    2016-09-01

    The modeling of PVD process and especially magnetron plasma is widely reported. The novel way to excite the plasma applying to the cathode very high power pulses brings the temporal dimension to the system together with new phenomena. From the kinetic model of the dense plasma region, so called Ionization Region - IR, one can quantify the global behavior of the plasma parameters during the pulse. The most significant are the plasma composition, especially in the case of reactive gases, the fraction of back-attracted sputtered ions, the rarefaction due to wind effect, but also the discharge heating mechanisms and contribution to the discharge current. From the 2D particle modeling of the plasma new insights are revealed concerning the shape of the dense plasma region, the time evolution of the sheath, the electron energy distribution function, but also the characteristics of the diffusion plasma facing the substrate. Adding the third dimension to the model, the results reveal the complex transport of electrons especially in the azimuthal direction (instabilities and drifts), the formation of spokes and flares, and the strong relation between the secondary emission of electrons from the target and the plasma structuring. Warm thanks to Peter Awakowicz and Ante Hecimovic for inviting me to this GEC edition.

  1. Thinking about Fashion Models' Looks: A Multidimensional Approach to the Structure of Perceived Physical Attractiveness.

    Science.gov (United States)

    Ashmore, Richard D.; And Others

    1996-01-01

    Used a functional framework of the perception of female physical attractiveness in a sample of 96 college students viewing 96 photographs of female fashion models. Suggests perceivers should differentiate sexual (sexy), youthful, nonsexual (cute), and up-to-date clothed and groomed (trendy) dimensions. Indicates areas of both convergence and…

  2. Quantum billiards in multidimensional models with fields of forms on product of Einstein spaces

    CERN Document Server

    Ivashchuk, V D

    2016-01-01

    Gravitational D-dimensional model with l scalar fields, cosmological term and several forms is considered. When cosmological type block-diagonal metric defined on product of one-dimensional interval and n oriented Einstein spaces is chosen, an electromagnetic composite brane ansatz is adopted and certain restrictions on the branes are imposed the conformally covariant Wheeler-DeWitt (WDW) equation for the model is studied. Under certain restrictions asymptotic solutions to WDW equation are found in the limit of the formation of the billiard walls which reduce the problem to the so-called quantum billiard on the (n + l -1)-dimensional hyperbolic space. Several examples of billiards in the model with n non-intersecting electric branes, e.g. corresponding to hyperbolic Kac-Moody algebras, are considered. In the classical case any of these billiards describe the never ending oscillating behaviour of scale factors in approaching to the singularity, which is either space-like or time-like one. For n=2 the model is ...

  3. Fostering Meaning, Purpose, and Enduring Commitments to Community Service in College: A Multidimensional Conceptual Model

    Science.gov (United States)

    Rockenbach, Alyssa Bryant; Hudson, Tara D.; Tuchmayer, Jeremy B.

    2014-01-01

    Using longitudinal data collected as part of the 2004/09 Beginning Postsecondary Students Longitudinal Study, this study employed structural equation modeling to examine how multiple dimensions of college students' service participation shape life goals oriented toward meaning, purpose, and citizenship and subsequent service engagement. The…

  4. The Status of Multi-Dimensional Core-Collapse Supernova Models

    CERN Document Server

    Müller, B

    2016-01-01

    Models of core-collapse supernova explosions powered by the neutrino-driven mechanism have matured considerable in recent years. Explosions at the low-mass end of the progenitor spectrum can routinely be simulated in 1D, 2D, and 3D and allow us to study supernova nucleosynthesis based on first-principle models. Results of nucleosynthesis calculations indicate that supernovae of the lowest masses could be important contributors of some lighter n-rich elements beyond iron. The explosion mechanism of more massive stars is still under investigation, although first 3D models of neutrino-driven explosions employing multi-group neutrino transport have recently become available. Together with earlier 2D models and more simplified 3D simulations, these have elucidated the interplay between neutrino heating and hydrodynamic instabilities in the post-shock region that is essential for shock revival. However, some physical ingredients may still need to be added or improved before simulations can robustly explain supernov...

  5. A multidimensional stability model for predicting shallow landslide size and shape across landscapes.

    Science.gov (United States)

    Milledge, David G; Bellugi, Dino; McKean, Jim A; Densmore, Alexander L; Dietrich, William E

    2014-11-01

    The size of a shallow landslide is a fundamental control on both its hazard and geomorphic importance. Existing models are either unable to predict landslide size or are computationally intensive such that they cannot practically be applied across landscapes. We derive a model appropriate for natural slopes that is capable of predicting shallow landslide size but simple enough to be applied over entire watersheds. It accounts for lateral resistance by representing the forces acting on each margin of potential landslides using earth pressure theory and by representing root reinforcement as an exponential function of soil depth. We test our model's ability to predict failure of an observed landslide where the relevant parameters are well constrained by field data. The model predicts failure for the observed scar geometry and finds that larger or smaller conformal shapes are more stable. Numerical experiments demonstrate that friction on the boundaries of a potential landslide increases considerably the magnitude of lateral reinforcement, relative to that due to root cohesion alone. We find that there is a critical depth in both cohesive and cohesionless soils, resulting in a minimum size for failure, which is consistent with observed size-frequency distributions. Furthermore, the differential resistance on the boundaries of a potential landslide is responsible for a critical landslide shape which is longer than it is wide, consistent with observed aspect ratios. Finally, our results show that minimum size increases as approximately the square of failure surface depth, consistent with observed landslide depth-area data.

  6. Thinking about Fashion Models' Looks: A Multidimensional Approach to the Structure of Perceived Physical Attractiveness.

    Science.gov (United States)

    Ashmore, Richard D.; And Others

    1996-01-01

    Used a functional framework of the perception of female physical attractiveness in a sample of 96 college students viewing 96 photographs of female fashion models. Suggests perceivers should differentiate sexual (sexy), youthful, nonsexual (cute), and up-to-date clothed and groomed (trendy) dimensions. Indicates areas of both convergence and…

  7. Identifying Admired Models to Increase Emulation: Development of a Multidimensional Admiration Scale

    Science.gov (United States)

    Sarapin, Susan H.; Christy, Katheryn; Lareau, Louise; Krakow, Melinda; Jensen, Jakob D.

    2015-01-01

    According to social cognitive theory, people are most likely to emulate the behaviors of admired models. Though potentially valuable to researchers and practitioners, this postulate remains untested, as there is no validated measure of admiration. To facilitate research on admiration, a 14-item measure was constructed and the resulting scores were…

  8. Coherence of Personal Narratives across the Lifespan: A Multidimensional Model and Coding Method

    Science.gov (United States)

    Reese, Elaine; Haden, Catherine A.; Baker-Ward, Lynne; Bauer, Patricia; Fivush, Robyn; Ornstein, Peter A.

    2011-01-01

    Personal narratives are integral to autobiographical memory and to identity, with coherent personal narratives being linked to positive developmental outcomes across the lifespan. In this article, we review the theoretical and empirical literature that sets the stage for a new lifespan model of personal narrative coherence. This new model…

  9. Simulation of photosynthetically active radiation distribution in algal photobioreactors using a multidimensional spectral radiation model.

    Science.gov (United States)

    Kong, Bo; Vigil, R Dennis

    2014-04-01

    A numerical method for simulating the spectral light distribution in algal photobioreactors is developed by adapting the discrete ordinate method for solving the radiative transport equation. The technique, which was developed for two and three spatial dimensions, provides a detailed accounting for light absorption and scattering by algae in the culture medium. In particular, the optical properties of the algal cells and the radiative properties of the turbid culture medium were calculated using a method based on Mie theory and that makes use of information concerning algal pigmentation, shape, and size distribution. The model was validated using a small cylindrical bioreactor, and subsequently simulations were carried out for an annular photobioreactor configuration. It is shown that even in this relatively simple geometry, nontrivial photon flux distributions arise that cannot be predicted by one-dimensional models.

  10. Complex and Multidimensional Lipid Raft Alterations in a Murine Model of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Wayne Chadwick

    2010-01-01

    Full Text Available Various animal models of Alzheimer's disease (AD have been created to assist our appreciation of AD pathophysiology, as well as aid development of novel therapeutic strategies. Despite the discovery of mutated proteins that predict the development of AD, there are likely to be many other proteins also involved in this disorder. Complex physiological processes are mediated by coherent interactions of clusters of functionally related proteins. Synaptic dysfunction is one of the hallmarks of AD. Synaptic proteins are organized into multiprotein complexes in high-density membrane structures, known as lipid rafts. These microdomains enable coherent clustering of synergistic signaling proteins. We have used mass analytical techniques and multiple bioinformatic approaches to better appreciate the intricate interactions of these multifunctional proteins in the 3xTgAD murine model of AD. Our results show that there are significant alterations in numerous receptor/cell signaling proteins in cortical lipid rafts isolated from 3xTgAD mice.

  11. On multidimensional solutions in the Einstein-Gauss-Bonnet model with a cosmological term

    CERN Document Server

    Kobtsev, A A; Ernazarov, K K

    2016-01-01

    A D-dimensional gravitational model with Gauss-Bonnet and cosmological term is considered. When ansatz with diagonal cosmological metrics is adopted, we overview recent solutions for zero cosmological term and find new examples of solutions for non-zero cosmological term and D = 8 with exponential dependence of scale factors which describe an expansion of our 3-dimensional factor-space and contraction of 4-dimensional internal space.

  12. Creating a Multi-Dimensional Model for Analyzing Costs in a Health Unit

    Directory of Open Access Journals (Sweden)

    Radu LIXANDROIU

    2012-11-01

    Full Text Available This paper aims to develop a model based on existing historical financial data in a health unit, with a view to facilitating the decision-maker’s task, who, starting from the analysis of historical data, can better manage the present decisions. Also the publication of reports on the Internet of the use of public money can increase the transparency of the public institutions concerned.

  13. The Status of Multi-Dimensional Core-Collapse Supernova Models

    Science.gov (United States)

    Müller, B.

    2016-09-01

    Models of neutrino-driven core-collapse supernova explosions have matured considerably in recent years. Explosions of low-mass progenitors can routinely be simulated in 1D, 2D, and 3D. Nucleosynthesis calculations indicate that these supernovae could be contributors of some lighter neutron-rich elements beyond iron. The explosion mechanism of more massive stars remains under investigation, although first 3D models of neutrino-driven explosions employing multi-group neutrino transport have become available. Together with earlier 2D models and more simplified 3D simulations, these have elucidated the interplay between neutrino heating and hydrodynamic instabilities in the post-shock region that is essential for shock revival. However, some physical ingredients may still need to be added/improved before simulations can robustly explain supernova explosions over a wide range of progenitors. Solutions recently suggested in the literature include uncertainties in the neutrino rates, rotation, and seed perturbations from convective shell burning. We review the implications of 3D simulations of shell burning in supernova progenitors for the `perturbations-aided neutrino-driven mechanism,' whose efficacy is illustrated by the first successful multi-group neutrino hydrodynamics simulation of an 18 solar mass progenitor with 3D initial conditions. We conclude with speculations about the impact of 3D effects on the structure of massive stars through convective boundary mixing.

  14. Multidimensional extremal dilatonic black holes in string-like model with cosmological term

    CERN Document Server

    Ivashchuk, V D

    1996-01-01

    A string-like model with the "cosmological constant" \\Lambda is considered. The Maki-Shiraishi multi-black-hole solution \\cite{MS1} is generalized to space-times with a Ricci-flat internal space. For \\Lambda = 0 the obtained solution in the one-black-hole case is shown to coincide with the extreme limit of the charged dilatonic black hole solution \\cite{BI,BM}. The Hawking temperature T_H for the solution \\cite{BI,BM} is presented and its extreme limit is considered. For the string value of dilatonic coupling the temperature T_H does not depend upon the internal space dimension.

  15. Gaussian Cubes: Real-Time Modeling for Visual Exploration of Large Multidimensional Datasets.

    Science.gov (United States)

    Wang, Zhe; Ferreira, Nivan; Wei, Youhao; Bhaskar, Aarthy Sankari; Scheidegger, Carlos

    2017-01-01

    Recently proposed techniques have finally made it possible for analysts to interactively explore very large datasets in real time. However powerful, the class of analyses these systems enable is somewhat limited: specifically, one can only quickly obtain plots such as histograms and heatmaps. In this paper, we contribute Gaussian Cubes, which significantly improves on state-of-the-art systems by providing interactive modeling capabilities, which include but are not limited to linear least squares and principal components analysis (PCA). The fundamental insight in Gaussian Cubes is that instead of precomputing counts of many data subsets (as state-of-the-art systems do), Gaussian Cubes precomputes the best multivariate Gaussian for the respective data subsets. As an example, Gaussian Cubes can fit hundreds of models over millions of data points in well under a second, enabling novel types of visual exploration of such large datasets. We present three case studies that highlight the visualization and analysis capabilities in Gaussian Cubes, using earthquake safety simulations, astronomical catalogs, and transportation statistics. The dataset sizes range around one hundred million elements and 5 to 10 dimensions. We present extensive performance results, a discussion of the limitations in Gaussian Cubes, and future research directions.

  16. Empirical Research on China’s Carbon Productivity Decomposition Model Based on Multi-Dimensional Factors

    Directory of Open Access Journals (Sweden)

    Jianchang Lu

    2015-04-01

    Full Text Available Based on the international community’s analysis of the present CO2 emissions situation, a Log Mean Divisia Index (LMDI decomposition model is proposed in this paper, aiming to reflect the decomposition of carbon productivity. The model is designed by analyzing the factors that affect carbon productivity. China’s contribution to carbon productivity is analyzed from the dimensions of influencing factors, regional structure and industrial structure. It comes to the conclusions that: (a economic output, the provincial carbon productivity and energy structure are the most influential factors, which are consistent with China’s current actual policy; (b the distribution patterns of economic output, carbon productivity and energy structure in different regions have nothing to do with the Chinese traditional sense of the regional economic development patterns; (c considering the regional protectionism, regional actual situation need to be considered at the same time; (d in the study of the industrial structure, the contribution value of industry is the most prominent factor for China’s carbon productivity, while the industrial restructuring has not been done well enough.

  17. Multi-dimensional Inversion Modeling of Surface Nuclear Magnetic Resonance (SNMR Data for Groundwater Exploration

    Directory of Open Access Journals (Sweden)

    Warsa

    2014-07-01

    Full Text Available Groundwater is an important economic source of water supply for drinking water and irrigation water for agriculture. Surface nuclear magnetic resonance (SNMR sounding is a relatively new geophysical method that can be used to determine the presence of culturally and economically important substances, such as subsurface water or hydrocarbon distribution. SNMR sounding allows the determination of water content and pore size distribution directly from the surface. The SNMR method is performed by stimulating an alternating current pulse through an antenna at the surface in order to confirm the existence of water in the subsurface. This paper reports the development of a 3-D forward modeling code for SNMR amplitudes and decay times, after which an improved 2-D and 3-D inversion algorithm is investigated, consisting of schemes for regularizing model parameterization. After briefly reviewing inversion schemes generally used in geophysics, the special properties of SNMR or magnetic resonance sounding (MRS inversion are evaluated. We present an extension of MRS to magnetic resonance tomography (MRT, i.e. an extension for 2-D and 3-D investigation, and the appropriate inversions.

  18. AGN Obscuration Through Dusty Infrared Dominated Flows. II. Multidimensional, Radiation-Hydrodynamics Modeling

    Science.gov (United States)

    Dorodnitsyn, Anton; Kallman, Tim; Bisno\\vatyiI-Kogan, Gennadyi

    2011-01-01

    We explore a detailed model in which the active galactic nucleus (AGN) obscuration results from the extinction of AGN radiation in a global ow driven by the pressure of infrared radiation on dust grains. We assume that external illumination by UV and soft X-rays of the dusty gas located at approximately 1pc away from the supermassive black hole is followed by a conversion of such radiation into IR. Using 2.5D, time-dependent radiation hydrodynamics simulations in a ux-limited di usion approximation we nd that the external illumination can support a geometrically thick obscuration via out ows driven by infrared radiation pressure in AGN with luminosities greater than 0:05 L(sub edd) and Compton optical depth, Tau(sub T) approx > & 1.

  19. Multigrid Method for Modeling Multi-Dimensional Combustion with Detailed Chemistry

    Science.gov (United States)

    Zheng, Xiaoqing; Liu, Chaoqun; Liao, Changming; Liu, Zhining; McCormick, Steve

    1996-01-01

    A highly accurate and efficient numerical method is developed for modeling 3-D reacting flows with detailed chemistry. A contravariant velocity-based governing system is developed for general curvilinear coordinates to maintain simplicity of the continuity equation and compactness of the discretization stencil. A fully-implicit backward Euler technique and a third-order monotone upwind-biased scheme on a staggered grid are used for the respective temporal and spatial terms. An efficient semi-coarsening multigrid method based on line-distributive relaxation is used as the flow solver. The species equations are solved in a fully coupled way and the chemical reaction source terms are treated implicitly. Example results are shown for a 3-D gas turbine combustor with strong swirling inflows.

  20. Problematic aspects of Kaluza–Klein excitations in multidimensional models with Einstein internal spaces

    Energy Technology Data Exchange (ETDEWEB)

    Chopovsky, Alexey, E-mail: a.chopovsky@yandex.ru [Department of Theoretical Physics, Odessa National University, Dvoryanskaya st. 2, Odessa 65082 (Ukraine); Astronomical Observatory, Odessa National University, Dvoryanskaya st. 2, Odessa 65082 (Ukraine); Eingorn, Maxim, E-mail: maxim.eingorn@gmail.com [CREST and NASA Research Centers, North Carolina Central University, Fayetteville st. 1801, Durham, NC 27707 (United States); Zhuk, Alexander, E-mail: ai.zhuk2@gmail.com [Astronomical Observatory, Odessa National University, Dvoryanskaya st. 2, Odessa 65082 (Ukraine)

    2014-09-07

    We consider Kaluza–Klein (KK) models where internal spaces are compact Einstein spaces. These spaces are stabilized by background matter (e.g., monopole form-fields). We perturb this background by a compact matter source (e.g., the system of gravitating masses) with the zero pressure in the external/our space and an arbitrary pressure in the internal space. We show that the Einstein equations are compatible only if the matter source is smeared over the internal space and perturbed metric components do not depend on coordinates of extra dimensions. The latter means the absence of KK modes corresponding to the metric fluctuations. Maybe, the absence of KK particles in LHC experiments is explained by such mechanism.

  1. A Multi-Dimensional Assessment Model to Evaluate Web Based Learning Systems

    Directory of Open Access Journals (Sweden)

    Anal ACHARYA

    2015-01-01

    Full Text Available The growth of communication technology in the last decade has prompted researchers to develop web based learning systems for various types of applications. The entities involved in the development of such systems are learners, instructors, system designers, administrators to name a few. With varying nature of applications and entities involved, the task of evaluating these web based learning systems appears quite challenging. The present study uses factor analysis to develop an assessment model for evaluating the web based learning systems developed by the authors. The analysis is performed on a data set derived by applying a survey instrument on a set of 140 learners using these systems. These learners ranked 20 items used for evaluation in order of their perceived degree of importance. It was found that the most important dimension was learning outcome which coincides with the general outcome of any mode of learning.

  2. Designing Multidimensional Policing Strategy And Organization: Towards A Synthesis Of Professional And Community Police Models

    Directory of Open Access Journals (Sweden)

    Suve Priit

    2015-06-01

    Full Text Available In this article we analyse professional police and community policing in view of professionalism, strategy and structures. We aim to find ways for synthesizing these models that are usually seen as incompatible. Unlike many earlier studies of police organizations or strategies, we view strategies in the organization at the corporate, functional and operational levels, and argue that by combining them with functional and divisional principles of structuring, it is possible to place professional strategy at the core of policing, while using the community policing strategy mainly as a component part of the strategy in the framework of divisional organization. This way it is possible to avoid the risk of alienating police from the community and to ensure the successful implementation of corporate strategy through providing professional police units that perform the narrow functions, with quick and adequate information from the community.

  3. Hyper-Fit: Fitting Linear Models to Multidimensional Data with Multivariate Gaussian Uncertainties

    CERN Document Server

    Robotham, A S G

    2015-01-01

    Astronomical data is often uncertain with errors that are heteroscedastic (different for each data point) and covariant between different dimensions. Assuming that a set of D-dimensional data points can be described by a (D - 1)-dimensional plane with intrinsic scatter, we derive the general likelihood function to be maximised to recover the best fitting model. Alongside the mathematical description, we also release the hyper-fit package for the R statistical language (github.com/asgr/hyper.fit) and a user-friendly web interface for online fitting (hyperfit.icrar.org). The hyper-fit package offers access to a large number of fitting routines, includes visualisation tools, and is fully documented in an extensive user manual. Most of the hyper-fit functionality is accessible via the web interface. In this paper we include applications to toy examples and to real astronomical data from the literature: the mass-size, Tully-Fisher, Fundamental Plane, and mass-spin-morphology relations. In most cases the hyper-fit ...

  4. Brain activity and connectivity during poetry composition: Toward a multidimensional model of the creative process.

    Science.gov (United States)

    Liu, Siyuan; Erkkinen, Michael G; Healey, Meghan L; Xu, Yisheng; Swett, Katherine E; Chow, Ho Ming; Braun, Allen R

    2015-09-01

    Creativity, a multifaceted construct, can be studied in various ways, for example, investigating phases of the creative process, quality of the creative product, or the impact of expertise. Previous neuroimaging studies have assessed these individually. Believing that each of these interacting features must be examined simultaneously to develop a comprehensive understanding of creative behavior, we examined poetry composition, assessing process, product, and expertise in a single experiment. Distinct activation patterns were associated with generation and revision, two major phases of the creative process. Medial prefrontal cortex (MPFC) was active during both phases, yet responses in dorsolateral prefrontal and parietal executive systems (DLPFC/IPS) were phase-dependent, indicating that while motivation remains unchanged, cognitive control is attenuated during generation and re-engaged during revision. Experts showed significantly stronger deactivation of DLPFC/IPS during generation, suggesting that they may more effectively suspend cognitive control. Importantly however, similar overall patterns were observed in both groups, indicating the same cognitive resources are available to experts and novices alike. Quality of poetry, assessed by an independent panel, was associated with divergent connectivity patterns in experts and novices, centered upon MPFC (for technical facility) and DLPFC/IPS (for innovation), suggesting a mechanism by which experts produce higher quality poetry. Crucially, each of these three key features can be understood in the context of a single neurocognitive model characterized by dynamic interactions between medial prefrontal areas regulating motivation, dorsolateral prefrontal, and parietal areas regulating cognitive control and the association of these regions with language, sensorimotor, limbic, and subcortical areas distributed throughout the brain. © 2015 Wiley Periodicals, Inc.

  5. Multilevel Architecture for Multidimensional Data Base

    OpenAIRE

    Salahli, M.

    2016-01-01

    A Multidimensional Data Base is an essential element of decision support, which allows to process complex queries. In this paper, a multilevel distributed Data Model for MDDB is presented. Metadata for ML)DB on relations is introduced. To improve efficiency of query processing, fuzzy cache fact table is proposed.A Multidimensional Data Base is an essential element of decision support, which allows to process complex queries. In this paper, a multilevel distributed Data Model for MDDB is prese...

  6. An approach to model reactor core nodalization for deterministic safety analysis

    Energy Technology Data Exchange (ETDEWEB)

    Salim, Mohd Faiz, E-mail: mohdfaizs@tnb.com.my; Samsudin, Mohd Rafie, E-mail: rafies@tnb.com.my [Nuclear Energy Department, Regulatory Economics & Planning Division, Tenaga Nasional Berhad (Malaysia); Mamat Ibrahim, Mohd Rizal, E-mail: m-rizal@nuclearmalaysia.gov.my [Prototypes & Plant Development Center, Malaysian Nuclear Agency (Malaysia); Roslan, Ridha, E-mail: ridha@aelb.gov.my; Sadri, Abd Aziz [Nuclear Installation Divisions, Atomic Energy Licensing Board (Malaysia); Farid, Mohd Fairus Abd [Reactor Technology Center, Malaysian Nuclear Agency (Malaysia)

    2016-01-22

    Adopting good nodalization strategy is essential to produce an accurate and high quality input model for Deterministic Safety Analysis (DSA) using System Thermal-Hydraulic (SYS-TH) computer code. The purpose of such analysis is to demonstrate the compliance against regulatory requirements and to verify the behavior of the reactor during normal and accident conditions as it was originally designed. Numerous studies in the past have been devoted to the development of the nodalization strategy for small research reactor (e.g. 250kW) up to the bigger research reactor (e.g. 30MW). As such, this paper aims to discuss the state-of-arts thermal hydraulics channel to be employed in the nodalization for RTP-TRIGA Research Reactor specifically for the reactor core. At present, the required thermal-hydraulic parameters for reactor core, such as core geometrical data (length, coolant flow area, hydraulic diameters, and axial power profile) and material properties (including the UZrH{sub 1.6}, stainless steel clad, graphite reflector) have been collected, analyzed and consolidated in the Reference Database of RTP using standardized methodology, mainly derived from the available technical documentations. Based on the available information in the database, assumptions made on the nodalization approach and calculations performed will be discussed and presented. The development and identification of the thermal hydraulics channel for the reactor core will be implemented during the SYS-TH calculation using RELAP5-3D{sup ®} computer code. This activity presented in this paper is part of the development of overall nodalization description for RTP-TRIGA Research Reactor under the IAEA Norwegian Extra-Budgetary Programme (NOKEBP) mentoring project on Expertise Development through the Analysis of Reactor Thermal-Hydraulics for Malaysia, denoted as EARTH-M.

  7. ANALYTICAL SYNTHESIS OF THE METHOD OF TARGETING A SUPERSONIC UNMANNED AERIAL VECHICLE BASED ON MULTI-DIMENSIONAL NONLINEAR DYNAMIC MODEL

    Directory of Open Access Journals (Sweden)

    V. E. Markevich

    2017-01-01

    Full Text Available A method of analytical synthesis of an optimal controller for the terminal control task of supersonic unmanned aerial vehicles based on synergetic approach to the design of control systems for nonlinear multidimensional dynamic objects is considered.The article provides analytical expressions describing the algorithm for control the velocity vector position of a supersonic UAV, the simulation results and the comparative analysis of the proposed control algorithm with the modified method of proportional navigation.

  8. Ordinal Comparison of Multidimensional Deprivation

    DEFF Research Database (Denmark)

    Sonne-Schmidt, Christoffer Scavenius; Tarp, Finn; Østerdal, Lars Peter

    This paper develops an ordinal method of comparison of multidimensional inequality. In our model, population distribution g is more unequal than f when the distributions have common median and can be obtained from f  by one or more shifts in population density that increase inequality. For our be...... benchmark 2x2 case (i.e. the case of two binary outcome variables), we derive an empirical method for making inequality comparisons. As an illustration, we apply the model to childhood poverty in Mozambique.......This paper develops an ordinal method of comparison of multidimensional inequality. In our model, population distribution g is more unequal than f when the distributions have common median and can be obtained from f  by one or more shifts in population density that increase inequality. For our...

  9. MULTIDIMENSIONALITY OF INCLUSION

    Directory of Open Access Journals (Sweden)

    T. V. Semenovskikh

    2016-01-01

    Full Text Available The article reveals the phenomenon of "multidime nsionality of inclusion", which is considered by the author  in  two  dimensions:  "vertical"  and  "horizontal". "Vertical" dimensional model includes five fu ndamental systems functioning inclusive society: social, economic, institutional, territorial and symbolic. "Horizontal" multidimensionality of inclusion – the inclusion of a person in group activities, his su bjective feeling. The author gives a classification of socio-cultural markers of inclusion in University of Tyumen, with an emphasis on availability and motivation of quality education, additional educational opportunities,  professional  training  (described  by the course "Tutor in inclusive education". The tutor in the inclusive educational environment – the person  having  the  higher  vocational  education  in  the field of special pedagogy and psychology; experience  of  pedagogical,  practical  activities  with  persons with limited opportunities of health; having practical  ideas  of  those  spheres  of  activity  which have a direct bearing on their training. The tutor in inclusion is the reflexive and reflexing personality understanding and holding a framework of the pr ofessional activity. The tutor, during the work with the resource card of the person is also neutral. "The multidimensionality of inclusion" is a metaphor, the translational motion vector from inclusive education to inclusive society.

  10. [Demographic analysis of family-related life cycles of Austrian women: a multidimensional model of marriage, fertility, and divorce behavior in the years 1976-1986].

    Science.gov (United States)

    Aufhauser, E; Lutz, W

    1989-01-01

    Summary results are presented from a research project designed to investigate the family life cycle of Austrian women by using a multidimensional model of marriage, fertility, and divorce. Data are from the 1976 and 1986 microcensuses. Topics discussed include the impact of illegitimate birth on women's future marital status, the relationship between number of children and the probability of divorce and of remarriage, the average number of years spent in different phases of the family life cycle, and the implications of current behavior patterns for future family structure in Austria.

  11. Simulation of Streamflow Using a Multidimensional Flow Model for White Sturgeon Habitat, Kootenai River near Bonners Ferry, Idaho - Supplement to Scientific Investigations Report 2005-5230

    Science.gov (United States)

    Barton, Gary J.; McDonald, Richard R.; Nelson, Jonathan M.

    2009-01-01

    During 2005, the U.S. Geological Survey (USGS) developed, calibrated, and validated a multidimensional flow model for simulating streamflow in the white sturgeon spawning habitat of the Kootenai River in Idaho. The model was developed as a tool to aid understanding of the physical factors affecting quality and quantity of spawning and rearing habitat used by the endangered white sturgeon (Acipenser transmontanus) and for assessing the feasibility of various habitat-enhancement scenarios to re-establish recruitment of white sturgeon. At the request of the Kootenai Tribe of Idaho, the USGS extended the two-dimensional flow model developed in 2005 into a braided reach upstream of the current white sturgeon spawning reach. Many scientists consider the braided reach a suitable substrate with adequate streamflow velocities for re-establishing recruitment of white sturgeon. The 2005 model was extended upstream to help assess the feasibility of various strategies to encourage white sturgeon to spawn in the reach. At the request of the Idaho Department of Fish and Game, the USGS also extended the two-dimensional flow model several kilometers downstream of the white sturgeon spawning reach. This modified model can quantify the physical characteristics of a reach that white sturgeon pass through as they swim upstream from Kootenay Lake to the spawning reach. The USGS Multi-Dimensional Surface-Water Modeling System was used for the 2005 modeling effort and for this subsequent modeling effort. This report describes the model applications and limitations, presents the results of a few simple simulations, and demonstrates how the model can be used to link physical characteristics of streamflow to the location of white sturgeon spawning events during 1994-2001. Model simulations also were used to report on the length and percentage of longitudinal profiles that met the minimum criteria during May and June 2006 and 2007 as stipulated in the U.S. Fish and Wildlife Biological Opinion.

  12. A spatially stabilized TDG based finite element framework for modeling biofilm growth with a multi-dimensional multi-species continuum biofilm model

    Science.gov (United States)

    Feng, D.; Neuweiler, I.; Nackenhorst, U.

    2017-02-01

    We consider a model for biofilm growth in the continuum mechanics framework, where the growth of different components of biomass is governed by a time dependent advection-reaction equation. The recently developed time-discontinuous Galerkin (TDG) method combined with two different stabilization techniques, namely the Streamline Upwind Petrov Galerkin (SUPG) method and the finite increment calculus (FIC) method, are discussed as solution strategies for a multi-dimensional multi-species biofilm growth model. The biofilm interface in the model is described by a convective movement following a potential flow coupled to the reaction inside of the biofilm. Growth limiting substrates diffuse through a boundary layer on top of the biofilm interface. A rolling ball method is applied to obtain a boundary layer of constant height. We compare different measures of the numerical dissipation and dispersion of the simulation results in particular for those with non-trivial patterns. By using these measures, a comparative study of the TDG-SUPG and TDG-FIC schemes as well as sensitivity studies on the time step size, the spatial element size and temporal accuracy are presented.

  13. A spatially stabilized TDG based finite element framework for modeling biofilm growth with a multi-dimensional multi-species continuum biofilm model

    Science.gov (United States)

    Feng, D.; Neuweiler, I.; Nackenhorst, U.

    2017-06-01

    We consider a model for biofilm growth in the continuum mechanics framework, where the growth of different components of biomass is governed by a time dependent advection-reaction equation. The recently developed time-discontinuous Galerkin (TDG) method combined with two different stabilization techniques, namely the Streamline Upwind Petrov Galerkin (SUPG) method and the finite increment calculus (FIC) method, are discussed as solution strategies for a multi-dimensional multi-species biofilm growth model. The biofilm interface in the model is described by a convective movement following a potential flow coupled to the reaction inside of the biofilm. Growth limiting substrates diffuse through a boundary layer on top of the biofilm interface. A rolling ball method is applied to obtain a boundary layer of constant height. We compare different measures of the numerical dissipation and dispersion of the simulation results in particular for those with non-trivial patterns. By using these measures, a comparative study of the TDG-SUPG and TDG-FIC schemes as well as sensitivity studies on the time step size, the spatial element size and temporal accuracy are presented.

  14. Multi-dimensional potential energy surfaces and non-axial octupole correlations in actinide and transfermium nuclei from relativistic mean field models

    CERN Document Server

    Lu, Bing-Nan; Zhao, En-Guang; Zhou, Shan-Gui

    2013-01-01

    We have developed multi-dimensional constrained covariant density functional theories (MDC-CDFT) for finite nuclei in which the shape degrees of freedom \\beta_{\\lambda\\mu} with even \\mu, e.g., \\beta_{20}, \\beta_{22}, \\beta_{30}, \\beta_{32}, \\beta_{40}, etc., can be described simultaneously. The functional can be one of the following four forms: the meson exchange or point-coupling nucleon interactions combined with the non-linear or density-dependent couplings. For the pp channel, either the BCS approach or the Bogoliubov transformation is implemented. The MDC-CDFTs with the BCS approach for the pairing (in the following labelled as MDC-RMF models with RMF standing for "relativistic mean field") have been applied to investigate multi-dimensional potential energy surfaces and the non-axial octupole $Y_{32}$-correlations in N=150 isotones. In this contribution we present briefly the formalism of MDC-RMF models and some results from these models. The potential energy surfaces with and without triaxial deformatio...

  15. Discovering Multidimensional Structure in Relational Data

    DEFF Research Database (Denmark)

    Jensen, Mikael Rune; Holmgren, Thomas; Pedersen, Torben Bach

    2004-01-01

    On-Line Analytical Processing (OLAP) systems based on multidimensional databases are essential elements of decision support. However, most existing data is stored in “ordinary” relational OLTP databases, i.e., data has to be (re-) modeled as multidimensional cubes before the advantages of OLAP...... tools are available. In this paper we present an approach for the automatic construction of multidimensional OLAP database schemas from existing relational OLTP databases, enabling easy OLAP design and analysis for most existing data sources. This is achieved through a set of practical and effective...... algorithms for discovering multidimensional schemas from relational databases. The algorithms take a wide range of available metadata into account in the discovery process, including functional and inclusion dependencies, and key and cardinality information....

  16. Modelo multidimensional para o controle da dengue: uma proposta com base na reprodução social e situações de riscos Multidimensional model for dengue control: a proposal based on social reproduction and risk situations

    Directory of Open Access Journals (Sweden)

    Solange Laurentino dos Santos

    2011-01-01

    Full Text Available O objetivo do artigo consiste em apresentar e discutir um modelo compreensivo/explicativo, de caráter ecossistêmico, sobre o processo de transmissão da dengue nos níveis de micro e macrocontexto, a partir da identificação das situações de riscos envolvidas. Considerou-se a dengue como doença infecciosa viral de transmissão vetorial que traz, na sua dinâmica de transmissão, elementos das dimensões biológicas, de conduta, ecológicas, políticas e econômicas, o que a caracteriza como um problema complexo e exige um enfoque sistêmico para seu controle. Assim, para a construção da modelagem, utilizaram-se o enfoque teórico da reprodução social de Juan Samaja e seus condicionantes de macro e microcontexto, e o enfoque operativo ecossistêmico, que buscou responder à pergunta condutora desta construção: quais são as situações de risco para transmissão da dengue, considerando as diversas dimensões da "reprodução social da saúde" no nível local? A visão ampliada das inter-relações entre as diversas situações de risco envolvidas na determinação multidimensional da dengue poderá servir como eixo direcionador para uma gestão integrada das ações do programa de controle da doença, articuladas entre os diversos setores envolvidos.This paper aims to present and discuss a comprehensive / explanatory model, of ecosystem approach, on the process of transmission of dengue in the levels of micro and macro context, from the identification of the risks involved. Dengue was considered a viral infectious disease of vectorial transmission that carries on its transmission dynamics, elements of the biological, behavioral, ecological, political and economic dimensions, that make it a complex problem and require a systemic approach to its control. Thus, for the construction of modeling, we used the theoretical framework of social reproduction of Juan Samaja and its conditions of macro and micro-context, and the operating

  17. Development of multi-dimensional thermal hydraulic modeling using mixing factors for wire wrapped fuel pin bundles with inter-subassembly heat transfer in fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Nishimura, M.; Kamide, H.; Ohshima, H. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1996-10-01

    Temperature distributions in fuel subassemblies of fast reactors interactively affect heat transfer from center to outer region of the core (inter-subassembly heat transfer) and cooling capability of an inter-wrapper flow, as well as maximum cladding temperature. The prediction of temperature distribution in the sub-assembly is, therefore one of the important issues for the reactor safety assessment. To treat the complex phenomena in the core, a multi-dimensional thermal hydraulic analysis is the most promising method. From the studies on the multi-dimensional thermal hydraulic modeling for the fuel sub-assemblies, the modeling have been recommended through the analysis of sodium experiments using driver subassembly test rig PLANDTL-DHX and blanket subassembly test rig CCTL-CFR. Computations of steady states experiments in the test rigs using the above modeling showed quite good agreement to the experimental data. In the present study, the use of this modeling was extended to transient analyses, and its applicability was examined. Firstly, non-dimensional parameters used to determine the mixing factors were modified from the ones based on bundle-averaged values to the ones by local values. Secondly, a new threshold function was derived and introduced to cut off the mixing factor of thermal plumes under inertia force dominant conditions. In the results of this validation, the accuracy was comparable between the modeling and the experimental instrumentation. Thus the present modeling is capable of predicting the thermal hydraulic fields of the wire wrapped fuel pin bundles with inter-subassembly heat transfer under the conditions from rated steady operations to transitions toward natural circulation decay heat removal modes. (J.P.N.)

  18. A New Multi-Dimensional General Relativistic Neutrino Hydrodynamics Code for Core-Collapse Supernovae II. Relativistic Explosion Models of Core-Collapse Supernovae

    CERN Document Server

    Mueller, B; Marek, A

    2012-01-01

    We present the first two-dimensional general relativistic (GR) simulations of stellar core collapse and explosion with the CoCoNuT hydrodynamics code in combination with the VERTEX solver for energy-dependent, three-flavor neutrino transport, using the extended conformal flatness condition for approximating the spacetime metric and a ray-by-ray-plus ansatz to tackle the multi-dimensionality of the transport. For both of the investigated 11.2 and 15 solar mass progenitors we obtain successful, though seemingly marginal, neutrino-driven supernova explosions. This outcome and the time evolution of the models basically agree with results previously obtained with the PROMETHEUS hydro solver including an approximative treatment of relativistic effects by a modified Newtonian potential. However, GR models exhibit subtle differences in the neutrinospheric conditions compared to Newtonian and pseudo-Newtonian simulations. These differences lead to significantly higher luminosities and mean energies of the radiated ele...

  19. The joint return period analysis of natural disasters based on monitoring and statistical modeling of multidimensional hazard factors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xueqin [State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875 (China); National Marine Environmental Monitoring Center, State Oceanic Administration, Dalian 116023 (China); School of Social Development and Public Policy, Beijing Normal University, Beijing 100875 (China); Li, Ning [State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875 (China); Yuan, Shuai, E-mail: syuan@nmemc.org.cn [National Marine Environmental Monitoring Center, State Oceanic Administration, Dalian 116023 (China); Xu, Ning; Shi, Wenqin; Chen, Weibin [National Marine Environmental Monitoring Center, State Oceanic Administration, Dalian 116023 (China)

    2015-12-15

    As a random event, a natural disaster has the complex occurrence mechanism. The comprehensive analysis of multiple hazard factors is important in disaster risk assessment. In order to improve the accuracy of risk analysis and forecasting, the formation mechanism of a disaster should be considered in the analysis and calculation of multi-factors. Based on the consideration of the importance and deficiencies of multivariate analysis of dust storm disasters, 91 severe dust storm disasters in Inner Mongolia from 1990 to 2013 were selected as study cases in the paper. Main hazard factors from 500-hPa atmospheric circulation system, near-surface meteorological system, and underlying surface conditions were selected to simulate and calculate the multidimensional joint return periods. After comparing the simulation results with actual dust storm events in 54 years, we found that the two-dimensional Frank Copula function showed the better fitting results at the lower tail of hazard factors and that three-dimensional Frank Copula function displayed the better fitting results at the middle and upper tails of hazard factors. However, for dust storm disasters with the short return period, three-dimensional joint return period simulation shows no obvious advantage. If the return period is longer than 10 years, it shows significant advantages in extreme value fitting. Therefore, we suggest the multivariate analysis method may be adopted in forecasting and risk analysis of serious disasters with the longer return period, such as earthquake and tsunami. Furthermore, the exploration of this method laid the foundation for the prediction and warning of other nature disasters. - Highlights: • A method to estimate the multidimensional joint return periods is presented. • 2D function allows better fitting results at the lower tail of hazard factors. • Three-dimensional simulation has obvious advantages in extreme value fitting. • Joint return periods are closer to the reality

  20. Ordinal Comparison of Multidimensional Deprivation

    DEFF Research Database (Denmark)

    Sonne-Schmidt, Christoffer Scavenius; Tarp, Finn; Østerdal, Lars Peter

    This paper develops an ordinal method of comparison of multidimensional inequality. In our model, population distribution g is more unequal than f when the distributions have common median and can be obtained from f  by one or more shifts in population density that increase inequality. For our be...... benchmark 2x2 case (i.e. the case of two binary outcome variables), we derive an empirical method for making inequality comparisons. As an illustration, we apply the model to childhood poverty in Mozambique....

  1. Applied multidimensional systems theory

    CERN Document Server

    Bose, Nirmal K

    2017-01-01

    Revised and updated, this concise new edition of the pioneering book on multidimensional signal processing is ideal for a new generation of students. Multidimensional systems or m-D systems are the necessary mathematical background for modern digital image processing with applications in biomedicine, X-ray technology and satellite communications. Serving as a firm basis for graduate engineering students and researchers seeking applications in mathematical theories, this edition eschews detailed mathematical theory not useful to students. Presentation of the theory has been revised to make it more readable for students, and introduce some new topics that are emerging as multidimensional DSP topics in the interdisciplinary fields of image processing. New topics include Groebner bases, wavelets, and filter banks.

  2. Multidimensional data visualization.

    Science.gov (United States)

    Pastizzo, Matthew J; Erbacher, Robert F; Feldman, Laurie B

    2002-05-01

    Historically, data visualization has been limited primarily to two dimensions (e.g., histograms or scatter plots). Available software packages (e.g., Data Desk 6.1, MatLab 6.1, SAS-JMP 4.04, SPSS 10.0) are capable of producing three-dimensional scatter plots with (varying degrees of) user interactivity. We constructed our own data visualization application with the Visualization Toolkit (Schroeder, Martin, & Lorensen, 1998) and Tcl/Tk to display multivariate data through the application of glyphs (Ware, 2000). A glyph is a visual object onto which many data parameters may be mapped, each with a different visual attribute (e.g., size or color). We used our Multi-Dimensional data Viewer to explore data from several psycholinguistic experiments. The graphical interface provides flexibility when users dynamically explore the multidimensional image rendered from raw experimental data. We highlight advantages of multidimensional data visualization and consider some potential limitations.

  3. An Efficient and Accurate Numerical Algorithm for Multi-Dimensional Modeling of Casting Solidification, Part Ⅱ: Combination of FEM and FDM

    Institute of Scientific and Technical Information of China (English)

    Jin Xuesong; Tsai Hailung

    1994-01-01

    This paper is a continuation of Ref. [1]. It employs frist-order accurate Taylor-Galerkin-based finite element approach for casting solidification. The approach is based on expressing the finite-difference approximation of the transient time derivative of temperature, while the expressions of the governing equations are discretized in space via the classical Galerkin scheme using finiteelement formulations. The detailed technique is reported in this study. Several casting solidification examples are solved to demonstrate the excellent agreements in comparison with the results obtained by using the control volume method, and to show the availability of combination of the finite element method and the finite difference method in multi-dimensional modeling of casting solidification.

  4. Defining the construct of reactive aggression in borderline personality disorder: Commentary on "Aggression in borderline personality disorder--A multidimensional model".

    Science.gov (United States)

    Flory, Janine D

    2015-07-01

    Comments on the article by F. Mancke et al. (see record 2015-31349-001). The article presents a multidimensional model of aggression in the context of borderline personality disorder (BPD), with a selective review of the research literature. BPD is arguably the most widely researched personality disorder, and the review suggests that there has been extensive progress in characterizing behavioral and biological correlates of aggression. What is not clear from the review, and indeed, the broader literature, is whether the research cited in this review is specific to BPD or can generally be applied to reactive aggression in the context of other disorders (or by extension into the normative range of the behavior). The review by Mancke et al. also highlights the fact that there is a general lack of research establishing predictive validity of aggression in BPD, with most research comparing two groups sampled at one time point.

  5. The discharge behavior of lithium-ion batteries using the Dual-Potential Multi-Scale Multi-Dimensional (MSMD) Battery Model

    DEFF Research Database (Denmark)

    Saeed Madani, Seyed; Swierczynski, Maciej Jozef; Kær, Søren Knudsen

    2017-01-01

    This paper gives insight into the discharge behavior of lithium-ion batteries based on the investigations, which have been done by the researchers [1– 19]. In this article, the battery's discharge behaviour at various discharge rates is studied and surface monitor, discharge curve, volume monitor...... to analysis the discharge behaviour of lithium-ion batteries. The results show that surface monitor plot of discharge curve at 1 C has a decreasing trend and volume monitor plot of maximum temperature in the domain has slightly increasing pattern over the simulation time. For the curves of discharge...... plot of maximum temperature in the domain and maximum temperature in the area are illustrated. Additionally, an external and internal short-circuit treatment for three cases have been studied. The Dual-Potential Multi-Scale Multi-Dimensional (MSMD) Battery Model (BM) was used by ANSYS FLUENT software...

  6. Multi-dimensional imaging

    CERN Document Server

    Javidi, Bahram; Andres, Pedro

    2014-01-01

    Provides a broad overview of advanced multidimensional imaging systems with contributions from leading researchers in the field Multi-dimensional Imaging takes the reader from the introductory concepts through to the latest applications of these techniques. Split into 3 parts covering 3D image capture, processing, visualization and display, using 1) a Multi-View Approach and 2.) a Holographic Approach, followed by a 3rd part addressing other 3D systems approaches, applications and signal processing for advanced 3D imaging. This book describes recent developments, as well as the prospects and

  7. Multidimensional Datawarehouse with Combination Formula

    CERN Document Server

    Warnars, Spits

    2010-01-01

    Multidimensional in data warehouse is a compulsion and become the most important for information delivery, without multidimensional Multidimensional in data warehouse is a compulsion and become the most important for information delivery, without multidimensional datawarehouse is incomplete. Multidimensional give ability to analyze business measurement in many different ways. Multidimensional is also synonymous with online analytical processing (OLAP). By using some concepts in datawarehouse like slice-dice,drill down and roll up will increase the ability of multidimensional datawarehouse. The research question and the discussing for this paper are how much deepest the multidimensional ability from each fact table in datawarehouse. By using the statistic combination formula we try to explore the combination that can be yielded from each dimension in hypercubes, the entire of dimensi combination, minimum combination and maximum combination.

  8. Symbolic Multidimensional Scaling

    NARCIS (Netherlands)

    P.J.F. Groenen (Patrick); Y. Terada

    2015-01-01

    markdownabstract__Abstract__ Multidimensional scaling (MDS) is a technique that visualizes dissimilarities between pairs of objects as distances between points in a low dimensional space. In symbolic MDS, a dissimilarity is not just a value but can represent an interval or even a histogram. Here, w

  9. Accelerating multidimensional cosmologies with scalar fields

    CERN Document Server

    Victor, B

    2004-01-01

    We study multidimensional cosmological models with a higher-dimensional product manifold, that consists of spherical and flat spaces, in the presence of a minimal free scalar field. Dynamical behaviour of the model is analyzed both in Einstein and Brans-Dicke conformal frames. For a number of particular cases, it is shown that external space-time undergoes an accelerated expansion

  10. Unidimensional Interpretations for Multidimensional Test Items

    Science.gov (United States)

    Kahraman, Nilufer

    2013-01-01

    This article considers potential problems that can arise in estimating a unidimensional item response theory (IRT) model when some test items are multidimensional (i.e., show a complex factorial structure). More specifically, this study examines (1) the consequences of model misfit on IRT item parameter estimates due to unintended minor item-level…

  11. Unidimensional Interpretations for Multidimensional Test Items

    Science.gov (United States)

    Kahraman, Nilufer

    2013-01-01

    This article considers potential problems that can arise in estimating a unidimensional item response theory (IRT) model when some test items are multidimensional (i.e., show a complex factorial structure). More specifically, this study examines (1) the consequences of model misfit on IRT item parameter estimates due to unintended minor item-level…

  12. Difference-Huffman Coding of Multidimensional Databases

    CERN Document Server

    Szépkúti, István

    2011-01-01

    A new compression method called difference-Huffman coding (DHC) is introduced in this paper. It is verified empirically that DHC results in a smaller multidimensional physical representation than those for other previously published techniques (single count header compression, logical position compression, base-offset compression and difference sequence compression). The article examines how caching influences the expected retrieval time of the multidimensional and table representations of relations. A model is proposed for this, which is then verified with empirical data. Conclusions are drawn, based on the model and the experiment, about when one physical representation outperforms another in terms of retrieval time. Over the tested range of available memory, the performance for the multidimensional representation was always much quicker than for the table representation.

  13. Multidimensional Physical Self-Concept of Athletes with Physical Disabilities

    Science.gov (United States)

    Shapiro, Deborah R.; Martin, Jeffrey J.

    2010-01-01

    The purposes of this investigation were first to predict reported PA (physical activity) behavior and self-esteem using a multidimensional physical self-concept model and second to describe perceptions of multidimensional physical self-concept (e.g., strength, endurance, sport competence) among athletes with physical disabilities. Athletes (N =…

  14. Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology

    Science.gov (United States)

    Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei

    2015-01-01

    This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…

  15. Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology

    Science.gov (United States)

    Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei

    2015-01-01

    This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…

  16. Multidimensional Linking for Tests with Mixed Item Types

    Science.gov (United States)

    Yao, Lihua; Boughton, Keith

    2009-01-01

    Numerous assessments contain a mixture of multiple choice (MC) and constructed response (CR) item types and many have been found to measure more than one trait. Thus, there is a need for multidimensional dichotomous and polytomous item response theory (IRT) modeling solutions, including multidimensional linking software. For example,…

  17. The joint return period analysis of natural disasters based on monitoring and statistical modeling of multidimensional hazard factors.

    Science.gov (United States)

    Liu, Xueqin; Li, Ning; Yuan, Shuai; Xu, Ning; Shi, Wenqin; Chen, Weibin

    2015-12-15

    As a random event, a natural disaster has the complex occurrence mechanism. The comprehensive analysis of multiple hazard factors is important in disaster risk assessment. In order to improve the accuracy of risk analysis and forecasting, the formation mechanism of a disaster should be considered in the analysis and calculation of multi-factors. Based on the consideration of the importance and deficiencies of multivariate analysis of dust storm disasters, 91 severe dust storm disasters in Inner Mongolia from 1990 to 2013 were selected as study cases in the paper. Main hazard factors from 500-hPa atmospheric circulation system, near-surface meteorological system, and underlying surface conditions were selected to simulate and calculate the multidimensional joint return periods. After comparing the simulation results with actual dust storm events in 54years, we found that the two-dimensional Frank Copula function showed the better fitting results at the lower tail of hazard factors and that three-dimensional Frank Copula function displayed the better fitting results at the middle and upper tails of hazard factors. However, for dust storm disasters with the short return period, three-dimensional joint return period simulation shows no obvious advantage. If the return period is longer than 10years, it shows significant advantages in extreme value fitting. Therefore, we suggest the multivariate analysis method may be adopted in forecasting and risk analysis of serious disasters with the longer return period, such as earthquake and tsunami. Furthermore, the exploration of this method laid the foundation for the prediction and warning of other nature disasters.

  18. Numeric invariants from multidimensional persistence

    Energy Technology Data Exchange (ETDEWEB)

    Skryzalin, Jacek [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carlsson, Gunnar [Stanford Univ., Stanford, CA (United States)

    2017-05-19

    In this paper, we analyze the space of multidimensional persistence modules from the perspectives of algebraic geometry. We first build a moduli space of a certain subclass of easily analyzed multidimensional persistence modules, which we construct specifically to capture much of the information which can be gained by using multidimensional persistence over one-dimensional persistence. We argue that the global sections of this space provide interesting numeric invariants when evaluated against our subclass of multidimensional persistence modules. Lastly, we extend these global sections to the space of all multidimensional persistence modules and discuss how the resulting numeric invariants might be used to study data.

  19. Measures for a multidimensional multiverse

    Science.gov (United States)

    Chung, Hyeyoun

    2015-04-01

    We explore the phenomenological implications of generalizing the causal patch and fat geodesic measures to a multidimensional multiverse, where the vacua can have differing numbers of large dimensions. We consider a simple model in which the vacua are nucleated from a D -dimensional parent spacetime through dynamical compactification of the extra dimensions, and compute the geometric contribution to the probability distribution of observations within the multiverse for each measure. We then study how the shape of this probability distribution depends on the time scales for the existence of observers, for vacuum domination, and for curvature domination (tobs,tΛ , and tc, respectively.) In this work we restrict ourselves to bubbles with positive cosmological constant, Λ . We find that in the case of the causal patch cutoff, when the bubble universes have p +1 large spatial dimensions with p ≥2 , the shape of the probability distribution is such that we obtain the coincidence of time scales tobs˜tΛ˜tc . Moreover, the size of the cosmological constant is related to the size of the landscape. However, the exact shape of the probability distribution is different in the case p =2 , compared to p ≥3 . In the case of the fat geodesic measure, the result is even more robust: the shape of the probability distribution is the same for all p ≥2 , and we once again obtain the coincidence tobs˜tΛ˜tc . These results require only very mild conditions on the prior probability of the distribution of vacua in the landscape. Our work shows that the observed double coincidence of time scales is a robust prediction even when the multiverse is generalized to be multidimensional; that this coincidence is not a consequence of our particular Universe being (3 +1 )-dimensional; and that this observable cannot be used to preferentially select one measure over another in a multidimensional multiverse.

  20. Multidimensional energy operator for image processing

    Science.gov (United States)

    Maragos, Petros; Bovik, Alan C.; Quatieri, Thomas F.

    1992-11-01

    The 1-D nonlinear differential operator (Psi) (f) equals (f')2 - ff' has been recently introduced to signal processing and has been found very useful for estimating the parameters of sinusoids and the modulating signals of AM-FM signals. It is called an energy operator because it can track the energy of an oscillator source generating a sinusoidal signal. In this paper we introduce the multidimensional extension (Phi) (f) equals (parallel)DELf(parallel)2 - fDEL2f of the 1-D energy operator and briefly outline some of its applications to image processing. We discuss some interesting properties of the multidimensional operator and develop demodulation algorithms to estimate the amplitude envelope and instantaneous frequencies of 2-D spatially-varying AM-FM signals, which can model image texture. The attractive features of the multidimensional operator and the related amplitude/frequency demodulation algorithms are their simplicity, efficiency, and ability to track instantaneously- varying spatial modulation patterns.

  1. Multi-Dimensional Recurrent Neural Networks

    CERN Document Server

    Graves, Alex; Schmidhuber, Juergen

    2007-01-01

    Recurrent neural networks (RNNs) have proved effective at one dimensional sequence learning tasks, such as speech and online handwriting recognition. Some of the properties that make RNNs suitable for such tasks, for example robustness to input warping, and the ability to access contextual information, are also desirable in multidimensional domains. However, there has so far been no direct way of applying RNNs to data with more than one spatio-temporal dimension. This paper introduces multi-dimensional recurrent neural networks (MDRNNs), thereby extending the potential applicability of RNNs to vision, video processing, medical imaging and many other areas, while avoiding the scaling problems that have plagued other multi-dimensional models. Experimental results are provided for two image segmentation tasks.

  2. A Multidimensional Code For Isothermal Magnetohydrodynamic Flows

    CERN Document Server

    Kim, J; Jones, T W; Hong, S S; Kim, Jongsoo; Ryu, Dongsu

    1999-01-01

    We present a multi-dimensional numerical code to solve isothermal magnetohydrodynamic (IMHD) equations for use in modeling astrophysical flows. First, we have built a one-dimensional code which is based on an explicit finite-difference method on an Eulerian grid, called the total variation diminishing (TVD) scheme. Recipes for building the one-dimensional IMHD code, including the normalized right and left eigenvectors of the IMHD Jacobian matrix, are presented. Then, we have extended the one-dimensional code to a multi-dimensional IMHD code through a Strang-type dimensional splitting. In the multi-dimensional code, an explicit cleaning step has been included to eliminate non-zero $\

  3. AdS and stabilized extra dimensions in multidimensional gravitational models with nonlinear scalar curvature terms 1/R and R^4

    CERN Document Server

    Günther, U; Bezerra, V; Romero, C; Guenther, Uwe; Zhuk, Alexander; Bezerra, Valdir; Romero, Carlos

    2004-01-01

    We study multidimensional gravitational models with scalar curvature nonlinearities of the type 1/R and R^4. It is assumed that the corresponding higher dimensional spacetime manifolds undergo a spontaneous compactification to manifolds with warped product structure. Special attention is paid to the stability of the extra-dimensional factor spaces. It is shown that for certain parameter regions the systems allow for a freezing stabilization of these spaces. In particular, we find for the 1/R model that configurations with stabilized extra dimensions do not provide a late-time acceleration (they are AdS), whereas the solution branch which allows for accelerated expansion (the dS branch) is incompatible with stabilized factor spaces. In the case of the R^4 model, we obtain that the stability region in parameter space depends on the total dimension D=dim(M) of the higher dimensional spacetime M. For D>8 the stability region consists of a single (absolutely stable) sector which is shielded from a conformal singul...

  4. Computing multidimensional persistence

    Directory of Open Access Journals (Sweden)

    Gunnar Carlsson

    2010-11-01

    Full Text Available The theory of multidimensional persistence captures the topology of a multifiltration - a multiparameter family of increasing spaces.  Multifiltrations arise naturally in the topological analysis of scientific data.  In this paper, we give a polynomial time algorithm for computing multidimensional persistence.  We recast this computation as a problem within computational commutative algebra and utilize algorithms from this area to solve it.  While the resulting problem is EXPSPACE-complete and the standard algorithms take doubly-exponential time, we exploit the structure inherent withing multifiltrations to yield practical algorithms.  We implement all algorithms in the paper and provide statistical experiments to demonstrate their feasibility.

  5. Multidimensional capillary electrophoresis.

    Science.gov (United States)

    Grochocki, Wojciech; Markuszewski, Michał J; Quirino, Joselito P

    2015-01-01

    Multidimensional separation where two or more orthogonal displacement mechanisms are combined is a promising approach to increase peak capacity in CE. The combinations allow dramatic improvement of analytical performance since the total peak capacity is given by a product of the peak capacities of all methods. The initial reports were concentrated on the construction of effective connections between capillaries for 2D analysis. Today, 2D and 3D CE systems are now able to separate real complex biological or environmental mixtures with good repeatability, improved resolution with minimal loss of sample. This review will present the developments in the field of multidimensional CE during the last 15 years. The endeavors in this specific field were on the development of interfaces, interface-free techniques including integrated separations, microdevices, and on-line sample concentration techniques to improve detection sensitivity.

  6. Multidimensional nonlinear descriptive analysis

    CERN Document Server

    Nishisato, Shizuhiko

    2006-01-01

    Quantification of categorical, or non-numerical, data is a problem that scientists face across a wide range of disciplines. Exploring data analysis in various areas of research, such as the social sciences and biology, Multidimensional Nonlinear Descriptive Analysis presents methods for analyzing categorical data that are not necessarily sampled randomly from a normal population and often involve nonlinear relations. This reference not only provides an overview of multidimensional nonlinear descriptive analysis (MUNDA) of discrete data, it also offers new results in a variety of fields. The first part of the book covers conceptual and technical preliminaries needed to understand the data analysis in subsequent chapters. The next two parts contain applications of MUNDA to diverse data types, with each chapter devoted to one type of categorical data, a brief historical comment, and basic skills peculiar to the data types. The final part examines several problems and then concludes with suggestions for futu...

  7. On exact solutions in multidimensional gravity with antisymmetric forms

    CERN Document Server

    Ivashchuk, V D

    2001-01-01

    This short review deals with a multidimensional gravitational model containing dilatonic scalar fields and antisymmetric forms. The manifold is chosen in the product form. The sigma-model approach and exact solutions are reviewed.

  8. The Multidimensional Darboux Transformation

    CERN Document Server

    González-López, A; González-López, Artemio; Kamran, Niky

    1996-01-01

    A generalization of the classical one-dimensional Darboux transformation to arbitrary n-dimensional oriented Riemannian manifolds is constructed using an intrinsic formulation based on the properties of twisted Hodge Laplacians. The classical two-dimensional Moutard transformation is also generalized to non-compact oriented Riemannian manifolds of dimension n greater than one. New examples of quasi-exactly solvable multidimensional matrix Schrödinger operators on curved manifolds are obtained by applying the above results.

  9. Multidimensional diffusion MRI

    Science.gov (United States)

    Topgaard, Daniel

    2017-02-01

    Principles from multidimensional NMR spectroscopy, and in particular solid-state NMR, have recently been transferred to the field of diffusion MRI, offering non-invasive characterization of heterogeneous anisotropic materials, such as the human brain, at an unprecedented level of detail. Here we revisit the basic physics of solid-state NMR and diffusion MRI to pinpoint the origin of the somewhat unexpected analogy between the two fields, and provide an overview of current diffusion MRI acquisition protocols and data analysis methods to quantify the composition of heterogeneous materials in terms of diffusion tensor distributions with size, shape, and orientation dimensions. While the most advanced methods allow estimation of the complete multidimensional distributions, simpler methods focus on various projections onto lower-dimensional spaces as well as determination of means and variances rather than actual distributions. Even the less advanced methods provide simple and intuitive scalar parameters that are directly related to microstructural features that can be observed in optical microscopy images, e.g. average cell eccentricity, variance of cell density, and orientational order - properties that are inextricably entangled in conventional diffusion MRI. Key to disentangling all these microstructural features is MRI signal acquisition combining isotropic and directional dimensions, just as in the field of multidimensional solid-state NMR from which most of the ideas for the new methods are derived.

  10. Multidimensional radar picture

    Science.gov (United States)

    Waz, Mariusz

    2010-05-01

    In marine navigation systems, the three-dimensional (3D) visualization is often and often used. Echosonders and sonars working in hydroacustic systems can present pictures in three dimensions. Currently, vector maps also offer 3D presentation. This presentation is used in aviation and underwater navigation. In the nearest future three-dimensional presentation may be obligatory presentation in displays of navigation systems. A part of these systems work with radar and communicates with it transmitting data in a digital form. 3D presentation of radar picture require a new technology to develop. In the first step it is necessary to compile digital form of radar signal. The modern navigation radar do not present data in three-dimensional form. Progress in technology of digital signal processing make it possible to create multidimensional radar pictures. For instance, the RSC (Radar Scan Converter) - digital radar picture recording and transforming tool can be used to create new picture online. Using RSC and techniques of modern computer graphics multidimensional radar pictures can be generated. The radar pictures mentioned should be readable for ECDIS. The paper presents a method for generating multidimensional radar picture from original signal coming from radar receiver.

  11. Numerical methods in multidimensional radiative transfer

    CERN Document Server

    Meinköhn, Erik

    2008-01-01

    Offers an overview of the numerical modelling of radiation fields in multidimensional geometries. This book covers advances and problems in the mathematical treatment of the radiative transfer equation, a partial integro-differential equation of high dimension that describes the propagation of the radiation in various fields.

  12. Non-commutative multi-dimensional cosmology

    CERN Document Server

    Khosravi, N; Sepangi, H R

    2006-01-01

    A non-commutative multi-dimensional cosmological model is introduced and used to address the issues of compactification and stabilization of extra dimensions and the cosmological constant problem. We show that in such a scenario these problems find natural solutions in a universe described by an increasing time parameter.

  13. Multilevel Architecture for Multidimensional Data Base

    OpenAIRE

    Salahli, M.

    2003-01-01

    A Multidimensional Data Base is an essential element of decision support, which allows to process complex queries. In this paper, a multilevel distributed Data Model for MDDB is presented. Metadata for MDDB on relations is introduced. To improve efficiency of query processing, fuzzy cache fact table is proposed.

  14. A systematic review of patient self-reported barriers of adherence to antihypertensive medications using the world health organization multidimensional adherence model.

    Science.gov (United States)

    AlGhurair, Suliman A; Hughes, Christine A; Simpson, Scot H; Guirguis, Lisa M

    2012-12-01

    Multiple barriers can influence adherence to antihypertensive medications. The aim of this systematic review was to determine what adherence barriers were included in each instrument and to describe the psychometric properties of the identified surveys. Barriers were characterized using the World Health Organization (WHO) Multidimensional Adherence Model with patient, condition, therapy, socioeconomic, and health care system/team-related barriers. Five databases (Medline, Embase, Health and Psychological Instruments, CINHAL, and International Pharmaceutical Abstracts [IPA]) were searched from 1980 to September 2011. Our search identified 1712 citations; 74 articles met inclusion criteria and 51 unique surveys were identified. The Morisky Medication Adherence Scale was the most commonly used survey. Only 20 surveys (39%) have established reliability and validity evidence. According to the WHO Adherence Model domains, patient-related barriers were most commonly addressed, while condition, therapy, and socioeconomic barriers were underrepresented. The complexity of adherence behavior requires robust self-report measurements and the inclusion of barriers relevant to each unique patient population and intervention.

  15. The Multidimensional Testlet-Effect Cognitive Diagnostic Models%多维题组效应认知诊断模型

    Institute of Scientific and Technical Information of China (English)

    詹沛达; 李晓敏; 王文中; 边玉芳; 王立君

    2015-01-01

    most commonly used formats is the testlet design, which is a cluster of items that share a common stimulus (e.g., a reading comprehension passage or a figure). Under the framework of item response theory (IRT), various testlet response models (TRM) have been proposed, such as the Rasch testlet model (Wang & Wilson, 2005) and the multidimensional testlet-effect Rasch model (MTERM) (Zhan, Wang, Wang, & Li, 2014). However, limited efforts have been contributed to the development of testlet models for CDMs. A question then naturally arises is the searching for a way to account for testlet effect under CDMs. To address this issue, this study proposed two testlet-CDMs. One followed the compensatory approach and the other followed the noncompensatory approach: (1) the compensatory multidimensional testlet-effect CDM (C-MTECDM) was based on the combination of LLM and MTERM, while (2) the noncompensatory multidimensional testlet-effect CDM (N-MTECDM) was based on the combination of (logit)DINA model and MTERM, respectively. Model parameters can be estimated by the Bayesian methods with Markov chain Monte Carlo (MCMC) algorithms, which have been implemented with the freeware WinBUGS. In study 1, a series of simulations were conducted to evaluate parameter recovery of two new models, and results showed that the model parameters could be recovered fairly well under all simulated conditions. In study 2, the two new models were compared with the LLM and the (logit)DINA model, respectively. Results showed that ignoring testlet effect would result in biased item parameter estimations and worse person classification rates. Additionally, fitting a more complicated model (i.e., MTECDM) to data with a simpler structure did litter harm on parameter recovery. In conclusion, the new models is feasible and flexible.

  16. Simulation of flow and sediment mobility using a multidimensional flow model for the White Sturgeon critical-habitat reach, Kootenai River near Bonners Ferry, Idaho

    Science.gov (United States)

    Barton, Gary J.; McDonald, Richard R.; Nelson, Jonathan M.; Dinehart, Randal L.

    2005-01-01

    In 1994, the Kootenai River white sturgeon (Acipenser transmontanus) was listed as an Endangered Species as a direct result of two related observations. First, biologists observed that the white sturgeon population in the Kootenai River was declining. Second, they observed a decline in recruitment of juvenile sturgeon beginning in the 1950s with an almost total absence of recruitment since 1974, following the closure of Libby Dam in 1972. This second observation was attributed to changes in spawning and (or) rearing habitat resulting from alterations in the physical habitat, including flow regime, sediment-transport regime, and bed morphology of the river. The Kootenai River White Sturgeon Recovery Team was established to find and implement ways to improve spawning and rearing habitat used by white sturgeon. They identified the need to develop and apply a multidimensional flow model to certain reaches of the river to quantify physical habitat in a spatially distributed manner. The U.S. Geological Survey has addressed these needs by developing, calibrating, and validating a multidimensional flow model used to simulate streamflow and sediment mobility in the white sturgeon critical-habitat reach of the Kootenai River. This report describes the model and limitations, presents the results of a few simple simulations, and demonstrates how the model can be used to link physical characteristics of streamflow to biological or other habitat data. This study was conducted in cooperation with the Kootenai Tribe of Idaho along a 23-kilometer reach of the Kootenai River, including the white sturgeon spawning reach near Bonners Ferry, Idaho that is about 108 to 131 kilometers below Libby Dam. U.S. Geological Survey's MultiDimensional Surface-Water Modeling System was used to construct a flow model for the critical-habitat reach of the Kootenai River white sturgeon, between river kilometers 228.4 and 245.9. Given streamflow, bed roughness, and downstream water-surface elevation

  17. MULTIDIMENSIONAL RELIABILITY OF INSTRUMENT STUDENTS’ SATISFACTION USING CONFIRMATORY FACTOR ANALYSIS

    Directory of Open Access Journals (Sweden)

    Gaguk Margono

    2014-11-01

    Full Text Available The purpose of this paper is to compare unidimensional reliability and multidimensional reliability of instrument students’ satisfaction as an internal costumer. Multidimensional reliability measurement is rarely used in the field of research. Multidimensional reliability is estimated by using Confirmatory Factor Analysis (CFA on the Structural Equation Model (SEM. Measurements and calculations are described in this article using instrument students’ satisfaction as an internal costumer. Survey method used in this study and sampling used simple random sampling. This instrument has been tried out to 173 students. The result is concluded that the measuringinstrument of students’ satisfaction as an internal costumer by using multidimensional reliability coefficient has higher accuracy when compared with a unidimensional reliability coefficient. Expected in advanced research used another formula multidimensional reliability, including when using SEM.

  18. A Latent Class Multidimensional Scaling Model for Two-Way One-Mode Continuous Rating Dissimilarity Data

    Science.gov (United States)

    Vera, J. Fernando; Macias, Rodrigo; Heiser, Willem J.

    2009-01-01

    In this paper, we propose a cluster-MDS model for two-way one-mode continuous rating dissimilarity data. The model aims at partitioning the objects into classes and simultaneously representing the cluster centers in a low-dimensional space. Under the normal distribution assumption, a latent class model is developed in terms of the set of…

  19. A Multi-Dimensional Heat Transfer Model of a Tie-Tube and Hexagonal Fuel Element for Nuclear Thermal Propulsion

    Science.gov (United States)

    Gomez, C. F.; Mireles, O. R.; Stewart, E.

    2016-01-01

    The Space Capable Cryogenic Thermal Engine (SCCTE) effort considers a nuclear thermal rocket design based around a Low-Enriched Uranium (LEU) design fission reactor. The reactor core is comprised of bundled hexagonal fuel elements that directly heat hydrogen for expansion in a thrust chamber and hexagonal tie-tubes that house zirconium hydride moderator mass for the purpose of thermalizing fast neutrons resulting from fission events. Created 3D steady state Hex fuel rod model with 1D flow channels. Hand Calculation were used to set up initial conditions for fluid flow. The Hex Fuel rod uses 1D flow paths to model the channels using empirical correlations for heat transfer in a pipe. Created a 2-D axisymmetric transient to steady state model using the CFD turbulent flow and Heat Transfer module in COMSOL. This model was developed to find and understand the hydrogen flow that might effect the thermal gradients axially and at the end of the tie tube where the flow turns and enters an annulus. The Hex fuel rod and Tie tube models were made based on requirements given to us by CSNR and the SCCTE team. The models helped simplify and understand the physics and assumptions. Using pipe correlations reduced the complexity of the 3-D fuel rod model and is numerically more stable and computationally more time-efficient compared to the CFD approach. The 2-D axisymmetric tie tube model can be used as a reference "Virtual test model" for comparing and improving 3-D Models.

  20. Multi-dimensional modelling of X-ray spectra for AGN accretion-disk outflows III: application to a hydrodynamical simulation

    CERN Document Server

    Sim, S A; Miller, L; Long, K S; Turner, T J

    2010-01-01

    We perform multi-dimensional radiative transfer simulations to compute spectra for a hydrodynamical simulation of a line-driven accretion disk wind from an active galactic nucleus. The synthetic spectra confirm expectations from parameterized models that a disk wind can imprint a wide variety of spectroscopic signatures including narrow absorption lines, broad emission lines and a Compton hump. The formation of these features is complex with contributions originating from many of the different structures present in the hydrodynamical simulation. In particular, spectral features are shaped both by gas in a successfully launched outflow and in complex flows where material is lifted out of the disk plane but ultimately falls back. We also confirm that the strong Fe Kalpha line can develop a weak, red-skewed line wing as a result of Compton scattering in the outflow. In addition, we demonstrate that X-ray radiation scattered and reprocessed in the flow has a pivotal part in both the spectrum formation and determi...

  1. Research on Security Model of Multi-dimensional Campus Network%多维校园网安全模型研究

    Institute of Scientific and Technical Information of China (English)

    孙晓乐; 高东怀; 靳豪杰

    2011-01-01

    介绍了生物免疫原理,简要分析了生物免疫系统为构建健壮的计算机安全系统提供的线索,并将其思想融合在多维校园网安全模型的研究设计中.在网络安全层面分析了安全产品互操作和联动管理的需求,介绍了开放式管理框架OPSEC的相关技术,研究了网络安全监控系统与其他安全产品(如防火墙、入侵检测系统)之间联动管理的实现方式及对整体网络安全性能的影响.%The basic principle of biological immunology is introduced, which was used in the design of multidimensional campus network security model. Several important clues for constructing a robust network security system by biological immunology system are analyzed. Moreover, the inter-operation and interaction management requirements of network security products (belongs to the network security layer) are analyzed. The related technologies of open system management framework OPSEC are introduced. The implementation of interaction management between network security monitoring system and other security products is studied, such as firewall and IDS. All of these make campus network more secure.

  2. A multidimensional model of the antecedents of stress and coping appraisals: an approach to studying patients' perceptions of post cardiac surgery pain and their coping strategies.

    Science.gov (United States)

    Shih, F J; Huang, L H

    1996-04-01

    Lazarus' stress and coping theory has been recognized as a valued conceptual framework for nursing scholars who are interested in studying their client's experiences of stress and coping. However, little data provide in-depth critiques in concepts, availability and limitations of employing Lazarus' theory in nursing phenomena in Taiwan, nor did data provide culturally sensitive propositions for Taiwanese nursing scholars to better understand their clients' stress experience such as post cardiac surgery pain. In order to help Taiwanese critical care nurses better understand the process of theoretical development while assessing their clients' perceptions of post cardiac surgery pain, the historical perspective of the concept of stress and the core components of Lazarus' theory are examined. Following is a critical critique of Lazarus' theory as a conceptual framework with which to study how patients perceive post cardiac surgery pain as a stressor. A multidimensional model of the antecedents of stress and coping appraisals for nurses to assess their clients' perceptions of pain and the resulting coping behaviors is further developed based on the aforementioned critiques. Finally, suggestions for testing theoretical propositions related to this phenomenon, as well as implications for nursing practice, research, as theory are delineated and discussed.

  3. Multidimensional Localized Solitons

    CERN Document Server

    Boiti, M; Martina, L; Boiti, Marco

    1993-01-01

    Abstract: Recently it has been discovered that some nonlinear evolution equations in 2+1 dimensions, which are integrable by the use of the Spectral Transform, admit localized (in the space) soliton solutions. This article briefly reviews some of the main results obtained in the last five years thanks to the renewed interest in soliton theory due to this discovery. The theoretical tools needed to understand the unexpected richness of behaviour of multidimensional localized solitons during their mutual scattering are furnished. Analogies and especially discrepancies with the unidimensional case are stressed.

  4. An extension of the talbot-ogden hydrology model to an affine multi-dimensional moisture content domain

    KAUST Repository

    Yu, Han

    2013-09-01

    The Talbot-Ogden hydrology model provides a fast mass conservative method to compute infiltration in unsaturated soils. As a replacement for a model based on Richards equation, it separates the groundwater movement into infiltration and redistribution for every time step. The typical feature making this method fast is the discretization of the moisture content domain rather than the spatial one. The Talbot-Ogden model rapidly determines how well ground water and aquifers are recharged only. Hence, it differs from models based on advanced reservoir modeling that are uniformly far more expensive computationally since they determine where the water moves in space instead, a completely different and more complex problem.According to the pore-size distribution curve for many soils, this paper extends the one dimensional moisture content domain into a two dimensional one by keeping the vertical spatial axis. The proposed extension can describe any pore-size or porosity distribution as an important soil feature. Based on this extension, infiltration and redistribution are restudied. The unconditional conservation of mass in the Talbot-Ogden model is inherited in this extended model. A numerical example is given for the extended model.

  5. A NEW MULTI-DIMENSIONAL GENERAL RELATIVISTIC NEUTRINO HYDRODYNAMICS CODE FOR CORE-COLLAPSE SUPERNOVAE. II. RELATIVISTIC EXPLOSION MODELS OF CORE-COLLAPSE SUPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Bernhard; Janka, Hans-Thomas; Marek, Andreas, E-mail: bjmuellr@mpa-garching.mpg.de, E-mail: thj@mpa-garching.mpg.de [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany)

    2012-09-01

    We present the first two-dimensional general relativistic (GR) simulations of stellar core collapse and explosion with the COCONUT hydrodynamics code in combination with the VERTEX solver for energy-dependent, three-flavor neutrino transport, using the extended conformal flatness condition for approximating the space-time metric and a ray-by-ray-plus ansatz to tackle the multi-dimensionality of the transport. For both of the investigated 11.2 and 15 M{sub Sun} progenitors we obtain successful, though seemingly marginal, neutrino-driven supernova explosions. This outcome and the time evolution of the models basically agree with results previously obtained with the PROMETHEUS hydro solver including an approximative treatment of relativistic effects by a modified Newtonian potential. However, GR models exhibit subtle differences in the neutrinospheric conditions compared with Newtonian and pseudo-Newtonian simulations. These differences lead to significantly higher luminosities and mean energies of the radiated electron neutrinos and antineutrinos and therefore to larger energy-deposition rates and heating efficiencies in the gain layer with favorable consequences for strong nonradial mass motions and ultimately for an explosion. Moreover, energy transfer to the stellar medium around the neutrinospheres through nucleon recoil in scattering reactions of heavy-lepton neutrinos also enhances the mentioned effects. Together with previous pseudo-Newtonian models, the presented relativistic calculations suggest that the treatment of gravity and energy-exchanging neutrino interactions can make differences of even 50%-100% in some quantities and is likely to contribute to a finally successful explosion mechanism on no minor level than hydrodynamical differences between different dimensions.

  6. Inflation in multidimensional quantum cosmology

    CERN Document Server

    Carugno, E; Occhionero, F; Pollifrone, G; Carugno, Enrico; Litterio, Marco; Occhionero, Franco; Pollifrone, Giuseppe

    1996-01-01

    We extend to multidimensional cosmology Vilenkin's prescription of tunnelling from nothing for the quantum origin of the observable Universe. Our model consists of a D+4-dimensional spacetime of topology {\\cal R}\\times {\\cal S}^3 \\times{\\cal S}^D, with a scalar field (``chaotic inflaton'') for the matter component. Einstein gravity and Casimir compactification are assumed. The resulting minisuperspace is 3--dimensional. Patchwise we find an approximate analytic solution of the Wheeler--DeWitt equation through which we discuss the tunnelling picture and the probability of nucleation of the classical Universe with compactifying extra dimensions. Our conclusion is that the most likely initial conditions, although they do not lead to the compactification of the internal space, still yield (power-law) inflation for the outer space. The scenario is physically acceptable because the inner space growth is limited to \\sim 10^{11} in 100 e-foldings of inflation, starting from the Planck scale.

  7. Multidimensional sexual perfectionism.

    Science.gov (United States)

    Stoeber, Joachim; Harvey, Laura N; Almeida, Isabel; Lyons, Emma

    2013-11-01

    Perfectionism is a multidimensional personality characteristic that can affect all areas of life. This article presents the first systematic investigation of multidimensional perfectionism in the domain of sexuality exploring the unique relationships that different forms of sexual perfectionism show with positive and negative aspects of sexuality. A sample of 272 university students (52 male, 220 female) completed measures of four forms of sexual perfectionism: self-oriented, partner-oriented, partner-prescribed, and socially prescribed. In addition, they completed measures of sexual esteem, sexual self-efficacy, sexual optimism, sex life satisfaction (capturing positive aspects of sexuality) and sexual problem self-blame, sexual anxiety, sexual depression, and negative sexual perfectionism cognitions during sex (capturing negative aspects). Results showed unique patterns of relationships for the four forms of sexual perfectionism, suggesting that partner-prescribed and socially prescribed sexual perfectionism are maladaptive forms of sexual perfectionism associated with negative aspects of sexuality whereas self-oriented and partner-oriented sexual perfectionism emerged as ambivalent forms associated with positive and negative aspects.

  8. Multidimensional Potential Burgers Turbulence

    Science.gov (United States)

    Boritchev, Alexandre

    2016-03-01

    We consider the multidimensional generalised stochastic Burgers equation in the space-periodic setting: partial {u}/partial t+(nabla f({u}) \\cdot nabla) {u}-ν Δ {u}= nabla η, quad t ≥ 0, {x} in{T}^d=({R}/ {Z})^d, under the assumption that u is a gradient. Here f is strongly convex and satisfies a growth condition, ν is small and positive, while η is a random forcing term, smooth in space and white in time. For solutions u of this equation, we study Sobolev norms of u averaged in time and in ensemble: each of these norms behaves as a given negative power of ν. These results yield sharp upper and lower bounds for natural analogues of quantities characterising the hydrodynamical turbulence, namely the averages of the increments and of the energy spectrum. These quantities behave as a power of the norm of the relevant parameter, which is respectively the separation ℓ in the physical space and the wavenumber k in the Fourier space. Our bounds do not depend on the initial condition and hold uniformly in {ν}. We generalise the results obtained for the one-dimensional case in [10], confirming the physical predictions in [4, 30]. Note that the form of the estimates does not depend on the dimension: the powers of {ν, |{{k}}|, ℓ} are the same in the one- and the multi-dimensional setting.

  9. Assessing microbial competition in a hydrogen-based membrane biofilm reactor (MBfR) using multidimensional modeling.

    Science.gov (United States)

    Martin, Kelly J; Picioreanu, Cristian; Nerenberg, Robert

    2015-09-01

    The membrane biofilm reactor (MBfR) is a novel technology that safely delivers hydrogen to the base of a denitrifying biofilm via gas-supplying membranes. While hydrogen is an effective electron donor for denitrifying bacteria (DNB), it also supports sulfate-reducing bacteria (SRB) and methanogens (MET), which consume hydrogen and create undesirable by-products. SRB and MET are only competitive for hydrogen when local nitrate concentrations are low, therefore SRB and MET primarily grow near the base of the biofilm. In an MBfR, hydrogen concentrations are greatest at the base of the biofilm, making SRB and MET more likely to proliferate in an MBfR system than a conventional biofilm reactor. Modeling results showed that because of this, control of the hydrogen concentration via the intramembrane pressure was a key tool for limiting SRB and MET development. Another means is biofilm management, which supported both sloughing and erosive detachment. For the conditions simulated, maintaining thinner biofilms promoted higher denitrification fluxes and limited the presence of SRB and MET. The 2-d modeling showed that periodic biofilm sloughing helped control slow-growing SRB and MET. Moreover, the rough (non-flat) membrane assembly in the 2-d model provided a special niche for SRB and MET that was not represented in the 1-d model. This study compared 1-d and 2-d biofilm model applicability for simulating competition in counter-diffusional biofilms. Although more computationally expensive, the 2-d model captured important mechanisms unseen in the 1-d model. © 2015 Wiley Periodicals, Inc.

  10. Multidimensional human dynamics in mobile phone communications.

    Science.gov (United States)

    Quadri, Christian; Zignani, Matteo; Capra, Lorenzo; Gaito, Sabrina; Rossi, Gian Paolo

    2014-01-01

    In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process.

  11. Multidimensional human dynamics in mobile phone communications.

    Directory of Open Access Journals (Sweden)

    Christian Quadri

    Full Text Available In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages. Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process.

  12. MODELING THE AMBIENT CONDITION EFFECTS OF AN AIR-COOLED NATURAL CIRCULATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Rui; Lisowski, Darius D.; Bucknor, Matthew; Kraus, Adam R.; Lv, Qiuping

    2017-07-02

    empirical model was also implemented in the computational models of the NSTF using both RELAP5-3D and STARCCM+ codes. Accounting for the effects of ambient conditions, simulations from both codes predicted the natural circulation flow rates very well.

  13. The HTA Core Model(®)-10 Years of Developing an International Framework to Share Multidimensional Value Assessment.

    Science.gov (United States)

    Kristensen, Finn Børlum; Lampe, Kristian; Wild, Claudia; Cerbo, Marina; Goettsch, Wim; Becla, Lidia

    2017-02-01

    The HTA Core Model(®) as a science-based framework for assessing dimensions of value was developed as a part of the European network for Health Technology Assessment project in the period 2006 to 2008 to facilitate production and sharing of health technology assessment (HTA) information, such as evidence on efficacy and effectiveness and patient aspects, to inform decisions. It covers clinical value as well as organizational, economic, and patient aspects of technologies and has been field-tested in two consecutive joint actions in the period 2010 to 2016. A large number of HTA institutions were involved in the work. The model has undergone revisions and improvement after iterations of piloting and can be used in a local, national, or international context to produce structured HTA information that can be taken forward by users into their own frameworks to fit their specific needs when informing decisions on technology. The model has a broad scope and offers a common ground to various stakeholders through offering a standard structure and a transparent set of proposed HTA questions. It consists of three main components: 1) the HTA ontology, 2) methodological guidance, and 3) a common reporting structure. It covers domains such as effectiveness, safety, and economics, and also includes domains covering organizational, patient, social, and legal aspects. There is a full model and a focused rapid relative effectiveness assessment model, and a third joint action is to continue till 2020. The HTA Core Model is now available for everyone around the world as a framework for assessing value. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  14. Multidimensional Chemical Modeling of Young Stellar Objects. II. Irradiated Outflow Walls in a High-Mass Star-Forming Region

    Science.gov (United States)

    Bruderer, S.; Benz, A. O.; Doty, S. D.; van Dishoeck, E. F.; Bourke, T. L.

    2009-07-01

    Observations of the high-mass star-forming region AFGL 2591 reveal a large abundance of CO+, a molecule known to be enhanced by far-ultraviolet (FUV) and X-ray irradiation. In chemical models assuming a spherically symmetric envelope, the volume of gas irradiated by protostellar FUV radiation is very small due to the high extinction by dust. The abundance of CO+ is thus underpredicted by orders of magnitude. In a more realistic model, FUV photons can escape through an outflow region and irradiate gas at the border to the envelope. Thus, we introduce the first two-dimensional axisymmetric chemical model of the envelope of a high-mass star-forming region to explain the CO+ observations as a prototypical FUV tracer. The model assumes an axisymmetric power-law density structure with a cavity due to the outflow. The local FUV flux is calculated by a Monte Carlo radiative transfer code taking scattering on dust into account. A grid of precalculated chemical abundances, introduced in the first part of this series of papers, is used to quickly interpolate chemical abundances. This approach allows us to calculate the temperature structure of the FUV-heated outflow walls self-consistently with the chemistry. Synthetic maps of the line flux are calculated using a raytracer code. Single-dish and interferometric observations are simulated and the model results are compared to published and new JCMT and Submillimeter Array (SMA) observations. The two-dimensional model of AFGL 2591 is able to reproduce the JCMT single-dish observations and also explains the nondetection by the SMA. We conclude that the observed CO+ line flux and its narrow width can be interpreted by emission from the warm and dense outflow walls irradiated by protostellar FUV radiation.

  15. Multi-dimensional Vlasov simulations and modeling of trapped-electron-driven filamentation of electron plasma waves

    Energy Technology Data Exchange (ETDEWEB)

    Berger, R. L., E-mail: berger5@llnl.gov; Cohen, B. I. [Lawrence Livermore National Laboratory, University of California, P.O. Box 808, Livermore, California 94551 (United States); Brunner, S., E-mail: stephan.brunner@epfl.ch [Centre de Recherches en Physique des Plasmas, Association Euratom-Confédération Suisse, Ecole Polytechnique Fédérale de Lausanne, CRPP-PPB, CH-1015 Lausanne (Switzerland); Banks, J. W. [Department of Mathematical Sciences, Rensselaer Polytechnic Institute, AE 301, 110 8th Street, Troy, New York 12180 (United States); Winjum, B. J. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States)

    2015-05-15

    Kinetic simulations of two-dimensional finite-amplitude electron plasma waves are performed in a one-wavelength long system. A systematic study of the most unstable linear sideband mode, in particular its growth rate γ and wavenumber k{sub y}, is carried out by scanning the amplitude and wavenumber of the initial wave. Simulation results are compared with numerical and analytical solutions to a two-dimensional nonlinear Schrödinger model [H. A. Rose and L. Yin, Phys. Plasmas 15, 042311 (2008)] and to the reduced model by Kruer et al. [Phys. Rev. Lett. 23, 838 (1969)] generalized to two dimensions.

  16. A numerical analysis of Stefan problems for generalized multi-dimensional phase-change structures using the enthalpy transforming model

    Science.gov (United States)

    Cao, Yiding; Faghri, Amir; Chang, Won Soon

    1989-01-01

    An enthalpy transforming scheme is proposed to convert the energy equation into a nonlinear equation with the enthalpy, E, being the single dependent variable. The existing control-volume finite-difference approach is modified so it can be applied to the numerical performance of Stefan problems. The model is tested by applying it to a three-dimensional freezing problem. The numerical results are in agreement with those existing in the literature. The model and its algorithm are further applied to a three-dimensional moving heat source problem showing that the methodology is capable of handling complicated phase-change problems with fixed grids.

  17. Theta vocabulary II. Multidimensional case

    CERN Document Server

    Kharchev, S

    2015-01-01

    It is shown that the Jacobi and Riemann identities of degree four for the multidimensional theta functions as well as the Weierstrass identities emerge as algebraic consequences of the fundamental multidimensional binary identities connecting the theta functions with Riemann matrices $\\tau$ and $2\\tau$.

  18. Theta vocabulary II. Multidimensional case

    Science.gov (United States)

    Kharchev, S.; Zabrodin, A.

    2016-06-01

    It is shown that the Jacobi and Riemann identities of degree four for the multidimensional theta functions as well as the Weierstrass identities emerge as algebraic consequences of the fundamental multidimensional binary identities connecting the theta functions with Riemann matrices τ and 2 τ.

  19. A Comparison of Item Parameter Standard Error Estimation Procedures for Unidimensional and Multidimensional Item Response Theory Modeling

    Science.gov (United States)

    Paek, Insu; Cai, Li

    2014-01-01

    The present study was motivated by the recognition that standard errors (SEs) of item response theory (IRT) model parameters are often of immediate interest to practitioners and that there is currently a lack of comparative research on different SE (or error variance-covariance matrix) estimation procedures. The present study investigated item…

  20. A Multidimensional/Non-Linear Teaching and Learning Model: Teaching and Learning Music in an Authentic and Holistic Context

    Science.gov (United States)

    Crawford, Renée

    2014-01-01

    This article discusses the conceptual framework that leads to the design of a teaching and learning model as part of a recent ethnographic study that considered the effectiveness of current Victorian government secondary school music teaching and learning practices when engaged with technology. The philosophical and theoretical basis for this…

  1. A Comparison of Item Parameter Standard Error Estimation Procedures for Unidimensional and Multidimensional Item Response Theory Modeling

    Science.gov (United States)

    Paek, Insu; Cai, Li

    2014-01-01

    The present study was motivated by the recognition that standard errors (SEs) of item response theory (IRT) model parameters are often of immediate interest to practitioners and that there is currently a lack of comparative research on different SE (or error variance-covariance matrix) estimation procedures. The present study investigated item…

  2. User-driven health care: answering multidimensional information needs in individual patients utilizing post-EBM approaches: an operational model.

    Science.gov (United States)

    Biswas, Rakesh; Maniam, Jayanthy; Lee, Edwin Wen Huo; Gopal, Premalatha; Umakanth, Shashikiran; Dahiya, Sumit; Ahmed, Sayeed

    2008-10-01

    The hypothesis in the conceptual model was that a user-driven innovation in presently available information and communication technology infrastructure would be able to meet patient and health professional users information needs and help them attain better health outcomes. An operational model was created to plan a trial on a sample diabetic population utilizing a randomized control trial design, assigning one randomly selected group of diabetics to receive electronic information intervention and analyse if it would improve their health outcomes in comparison with a matched diabetic population who would only receive regular medical intervention. Diabetes was chosen for this particular trial, as it is a major chronic illness in Malaysia as elsewhere in the world. It is in essence a position paper for how the study concept should be organized to stimulate wider discussion prior to beginning the study.

  3. Application of kinetic flux vector splitting scheme for solving multi-dimensional hydrodynamical models of semiconductor devices

    Science.gov (United States)

    Nisar, Ubaid Ahmed; Ashraf, Waqas; Qamar, Shamsul

    In this article, one and two-dimensional hydrodynamical models of semiconductor devices are numerically investigated. The models treat the propagation of electrons in a semiconductor device as the flow of a charged compressible fluid. It plays an important role in predicting the behavior of electron flow in semiconductor devices. Mathematically, the governing equations form a convection-diffusion type system with a right hand side describing the relaxation effects and interaction with a self consistent electric field. The proposed numerical scheme is a splitting scheme based on the kinetic flux-vector splitting (KFVS) method for the hyperbolic step, and a semi-implicit Runge-Kutta method for the relaxation step. The KFVS method is based on the direct splitting of macroscopic flux functions of the system on the cell interfaces. The second order accuracy of the scheme is achieved by using MUSCL-type initial reconstruction and Runge-Kutta time stepping method. Several case studies are considered. For validation, the results of current scheme are compared with those obtained from the splitting scheme based on the NT central scheme. The effects of various parameters such as low field mobility, device length, lattice temperature and voltage are analyzed. The accuracy, efficiency and simplicity of the proposed KFVS scheme validates its generic applicability to the given model equations. A two dimensional simulation is also performed by KFVS method for a MESFET device, producing results in good agreement with those obtained by NT-central scheme.

  4. Stem cell-derived vasculature: A potent and multidimensional technology for basic research, disease modeling, and tissue engineering.

    Science.gov (United States)

    Lowenthal, Justin; Gerecht, Sharon

    2016-05-06

    Proper blood vessel networks are necessary for constructing and re-constructing tissues, promoting wound healing, and delivering metabolic necessities throughout the body. Conversely, an understanding of vascular dysfunction has provided insight into the pathogenesis and progression of diseases both common and rare. Recent advances in stem cell-based regenerative medicine - including advances in stem cell technologies and related progress in bioscaffold design and complex tissue engineering - have allowed rapid advances in the field of vascular biology, leading in turn to more advanced modeling of vascular pathophysiology and improved engineering of vascularized tissue constructs. In this review we examine recent advances in the field of stem cell-derived vasculature, providing an overview of stem cell technologies as a source for vascular cell types and then focusing on their use in three primary areas: studies of vascular development and angiogenesis, improved disease modeling, and the engineering of vascularized constructs for tissue-level modeling and cell-based therapies. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. An improved hybrid multi-criteria/multidimensional model for strategic industrial location selection: Casablanca industrial zones as a case study.

    Science.gov (United States)

    Boutkhoum, Omar; Hanine, Mohamed; Agouti, Tarik; Tikniouine, Abdessadek

    2015-01-01

    In this paper, we examine the issue of strategic industrial location selection in uncertain decision making environments for implanting new industrial corporation. In fact, the industrial location issue is typically considered as a crucial factor in business research field which is related to many calculations about natural resources, distributors, suppliers, customers, and most other things. Based on the integration of environmental, economic and social decisive elements of sustainable development, this paper presents a hybrid decision making model combining fuzzy multi-criteria analysis with analytical capabilities that OLAP systems can provide for successful and optimal industrial location selection. The proposed model mainly consists in three stages. In the first stage, a decision-making committee has been established to identify the evaluation criteria impacting the location selection process. In the second stage, we develop fuzzy AHP software based on the extent analysis method to assign the importance weights to the selected criteria, which allows us to model the linguistic vagueness, ambiguity, and incomplete knowledge. In the last stage, OLAP analysis integrated with multi-criteria analysis employs these weighted criteria as inputs to evaluate, rank and select the strategic industrial location for implanting new business corporation in the region of Casablanca, Morocco. Finally, a sensitivity analysis is performed to evaluate the impact of criteria weights and the preferences given by decision makers on the final rankings of strategic industrial locations.

  6. Towards Conceptual Multidimensional Design in Decision Support Systems

    CERN Document Server

    Teste, Olivier

    2010-01-01

    Multidimensional databases support efficiently on-line analytical processing (OLAP). In this paper, we depict a model dedicated to multidimensional databases. The approach we present designs decisional information through a constellation of facts and dimensions. Each dimension is possibly shared between several facts and it is organised according to multiple hierarchies. In addition, we define a comprehensive query algebra regrouping the more popular multidimensional operations in current commercial systems and research approaches. We introduce new operators dedicated to a constellation. Finally, we describe a prototype that allows managers to query constellations of facts, dimensions and multiple hierarchies.

  7. Generelle aspekter ved mediereception? – Et bud på en multidimensional model for analyse af kvalitative receptionsinterviews

    Directory of Open Access Journals (Sweden)

    Kim Schrøder

    2003-09-01

    Full Text Available Findes der generelle aspekter ved receptionen af medieprodukter, som det kan være analytisk frugtbart at orientere sig efter, og som man altid bør belyse, når man analyserer kvalitative receptionsdata – og måske også allerede når man skal planlægge det empiriske feltarbejde i et em- pirisk receptionsprojekt? Denne artikel bygger på, at dette spørgsmål kan besvares bekræftende, og fremlægger et bud på, hvordan en multi- dimensional model for kvalitativ receptionsanalyse kunne se ud.

  8. Developing the Green Building Challenge (GBC evaluation model: a multidimensional framework for the assessment of regional and urban regeneration interventions

    Directory of Open Access Journals (Sweden)

    Sergio Mattia

    2013-08-01

    Full Text Available The enhancement process of urban systems is currently developed by interventions with increasing complexity, as they should achieve the economical and social requirements of sustainability, beside the environmental ones. This is a central issue that is growing in importance also at the neighborhood level. Within the present sustainability assessment tools at neighborhood level, this paper suggests the Local Sustainability Index (Lo.S.I. evaluation model in order to measure the efforts to achieve a satisfying degree of sustainability in regional and urban regeneration interventions, both enhancing/transferring new knowledge about the present condition and the possible development options of abandoned urban areas.

  9. Multi-Dimensional Inheritance

    CERN Document Server

    Erbach, G

    1994-01-01

    In this paper, we present an alternative approach to multiple inheritance for typed feature structures. In our approach, a feature structure can be associated with several types coming from different hierarchies (dimensions). In case of multiple inheritance a type has supertypes from different hierarchies. We contrast this approach with approaches based on a single type hierarchy where a feature structure has only one unique most general type, and multiple inheritance involves computation of greatest lower bounds in the hierarchy. The proposed approach supports current linguistic analyses in constraint-based formalisms like HPSG, inheritance in the lexicon, and knowledge representation for NLP systems. Finally, we show that multi-dimensional inheritance hierarchies can be compiled into a Prolog term representation, which allows to compute the conjunction of two types efficiently by Prolog term unification.

  10. Generalized Multidimensional Association Rules

    Institute of Scientific and Technical Information of China (English)

    周傲英; 周水庚; 金文; 田增平

    2000-01-01

    The problem of association rule mining has gained considerable prominence in the data mining community for its use as an important tool of knowl-edge discovery from large-scale databases. And there has been a spurt of research activities around this problem. Traditional association rule mining is limited to intra-transaction. Only recently the concept of N-dimensional inter-transaction as-sociation rule (NDITAR) was proposed by H.J. Lu. This paper modifies and extends Lu's definition of NDITAR based on the analysis of its limitations, and the general-ized multidimensional association rule (GMDAR) is subsequently introduced, which is more general, flexible and reasonable than NDITAR.

  11. Multidimensional Profiles of Health Status: An Application of the Grade of Membership Model to the World Health Survey

    Science.gov (United States)

    Andreotti, Alessandra; Minicuci, Nadia; Kowal, Paul; Chatterji, Somnath

    2009-01-01

    Background The World Health Organization (WHO) conducted the World Health Survey (WHS) between 2002 and 2004 in 70 countries to provide cross-population comparable data on health, health-related outcomes and risk factors. The aim of this study was to apply Grade of Membership (GoM) modelling as a means to condense extensive health information from the WHS into a set of easily understandable health profiles and to assign the degree to which an individual belongs to each profile. Principal Findings This paper described the application of the GoM models to summarize population health status using World Health Survey data. Grade of Membership analysis is a flexible, non-parametric, multivariate method, used to calculate health profiles from WHS self-reported health state and health conditions. The WHS dataset was divided into four country economic categories based on the World Bank economic groupings (high, upper-middle, lower-middle and low income economies) for separate GoM analysis. Three main health profiles were produced for each of the four areas: I. Robust; II. Intermediate; III. Frail; moreover population health, wealth and inequalities are defined for countries in each economic area as a means to put the health results into perspective. Conclusions These analyses have provided a robust method to better understand health profiles and the components which can help to identify healthy and non-healthy individuals. The obtained profiles have described concrete levels of health and have clearly delineated characteristics of healthy and non-healthy respondents. The GoM results provided both a useable way of summarising complex individual health information and a selection of intermediate determinants which can be targeted for interventions to improve health. As populations' age, and with limited budgets for additional costs for health care and social services, applying the GoM methods may assist with identifying higher risk profiles for decision-making and resource

  12. Multidimensional profiles of health status: an application of the grade of membership model to the world health survey.

    Directory of Open Access Journals (Sweden)

    Alessandra Andreotti

    Full Text Available BACKGROUND: The World Health Organization (WHO conducted the World Health Survey (WHS between 2002 and 2004 in 70 countries to provide cross-population comparable data on health, health-related outcomes and risk factors. The aim of this study was to apply Grade of Membership (GoM modelling as a means to condense extensive health information from the WHS into a set of easily understandable health profiles and to assign the degree to which an individual belongs to each profile. PRINCIPAL FINDINGS: This paper described the application of the GoM models to summarize population health status using World Health Survey data. Grade of Membership analysis is a flexible, non-parametric, multivariate method, used to calculate health profiles from WHS self-reported health state and health conditions. The WHS dataset was divided into four country economic categories based on the World Bank economic groupings (high, upper-middle, lower-middle and low income economies for separate GoM analysis. Three main health profiles were produced for each of the four areas: I. Robust; II. Intermediate; III. Frail; moreover population health, wealth and inequalities are defined for countries in each economic area as a means to put the health results into perspective. CONCLUSIONS: These analyses have provided a robust method to better understand health profiles and the components which can help to identify healthy and non-healthy individuals. The obtained profiles have described concrete levels of health and have clearly delineated characteristics of healthy and non-healthy respondents. The GoM results provided both a useable way of summarising complex individual health information and a selection of intermediate determinants which can be targeted for interventions to improve health. As populations' age, and with limited budgets for additional costs for health care and social services, applying the GoM methods may assist with identifying higher risk profiles for decision

  13. The Synthesis Map Is a Multidimensional Educational Tool That Provides Insight into Students' Mental Models and Promotes Students' Synthetic Knowledge Generation

    Science.gov (United States)

    Ortega, Ryan A.; Brame, Cynthia J.

    2015-01-01

    Concept mapping was developed as a method of displaying and organizing hierarchical knowledge structures. Using the new, multidimensional presentation software Prezi, we have developed a new teaching technique designed to engage higher-level skills in the cognitive domain. This tool, synthesis mapping, is a natural evolution of concept mapping,…

  14. The Synthesis Map Is a Multidimensional Educational Tool That Provides Insight into Students' Mental Models and Promotes Students' Synthetic Knowledge Generation

    Science.gov (United States)

    Ortega, Ryan A.; Brame, Cynthia J.

    2015-01-01

    Concept mapping was developed as a method of displaying and organizing hierarchical knowledge structures. Using the new, multidimensional presentation software Prezi, we have developed a new teaching technique designed to engage higher-level skills in the cognitive domain. This tool, synthesis mapping, is a natural evolution of concept mapping,…

  15. Multi-dimensional modelling of electrostatic force distance curve over dielectric surface: Influence of tip geometry and correlation with experiment

    Science.gov (United States)

    Boularas, A.; Baudoin, F.; Villeneuve-Faure, C.; Clain, S.; Teyssedre, G.

    2014-08-01

    Electric Force-Distance Curves (EFDC) is one of the ways whereby electrical charges trapped at the surface of dielectric materials can be probed. To reach a quantitative analysis of stored charge quantities, measurements using an Atomic Force Microscope (AFM) must go with an appropriate simulation of electrostatic forces at play in the method. This is the objective of this work, where simulation results for the electrostatic force between an AFM sensor and the dielectric surface are presented for different bias voltages on the tip. The aim is to analyse force-distance curves modification induced by electrostatic charges. The sensor is composed by a cantilever supporting a pyramidal tip terminated by a spherical apex. The contribution to force from cantilever is neglected here. A model of force curve has been developed using the Finite Volume Method. The scheme is based on the Polynomial Reconstruction Operator—PRO-scheme. First results of the computation of electrostatic force for different tip-sample distances (from 0 to 600 nm) and for different DC voltages applied to the tip (6 to 20 V) are shown and compared with experimental data in order to validate our approach.

  16. Multi-dimensional modeling of a thermal energy storage canister. M.S. Thesis - Cleveland State Univ., Dec. 1990

    Science.gov (United States)

    Kerslake, Thomas W.

    1991-01-01

    The Solar Dynamic Power Module being developed for Space Station Freedom uses a eutectic mixture of LiF-CaF2 phase change material (PCM) contained in toroidal canisters for thermal energy storage. Presented are the results from heat transfer analyses of a PCM containment canister. One and two dimensional finite difference computer models are developed to analyze heat transfer in the canister walls, PCM, void, and heat engine working fluid coolant. The modes of heat transfer considered include conduction in canister walls and solid PCM, conduction and pseudo-free convection in liquid PCM, conduction and radiation across PCM vapor filled void regions, and forced convection in the heat engine working fluid. Void shape, location, growth or shrinkage (due to density difference between the solid and liquid PCM phases) are prescribed based on engineering judgment. The PCM phase change process is analyzed using the enthalpy method. The discussion of the results focuses on how canister thermal performance is affected by free convection in the liquid PCM and void heat transfer. Characterizing these effects is important for interpreting the relationship between ground-based canister performance (in 1-g) and expected on-orbit performance (in micro-g). Void regions accentuate canister hot spots and temperature gradients due to their large thermal resistance. Free convection reduces the extent of PCM superheating and lowers canister temperatures during a portion of the PCM thermal charge period. Surprisingly small differences in canister thermal performance result from operation on the ground and operation on-orbit. This lack of a strong gravity dependency is attributed to the large contribution of container walls in overall canister energy redistribution by conduction.

  17. Computer Simulations on a Multidimensional Continuum:

    DEFF Research Database (Denmark)

    Girault, Isabelle; Pfeffer, Melanie; Chiocarriello, Augusto

    2016-01-01

    Computer simulations exist on a multidimensional continuum with other educational technologies including static animations, serious games, and virtual worlds. The act of defining simulations is context dependent. In our context of science education, we define simulations as algorithmic, dynamic...... with emphasis on simulations’ algorithmic, dynamic, and simple features. Defined as models, simulations can be computational or conceptual in nature and may reflect hypothetical or real events; such distinctions are addressed. Examples of programs that demonstrate the features of simulations emphasized in our...

  18. Multilayer Multidimensional Extension Set Theory

    Institute of Scientific and Technical Information of China (English)

    CAO Shao-zhong; YANG Guo-wei; TU Xu-yan

    2006-01-01

    In order to study the contradiction problem of multilayer multidimensional complex systems, the concepts of extension field and stable field of intersection and union of multilayer multidimensional extension set are given. Then the related operations and properties are discussed. The results of study expand the concepts of intersection and union of extension set to a general situation, and provide the theoretical basis for production of the concepts of intersection and union of multilayer multidimensional matter element system extension set. In this way, it will be possible that matter element system theory is used to creative designs of complex systems.

  19. Multi-Dimensional Aggregation for Temporal Data

    DEFF Research Database (Denmark)

    Böhlen, M. H.; Gamper, J.; Jensen, Christian Søndergaard

    2006-01-01

    when the data hold. In temporal databases, intervals typically capture the states of reality that the data apply to, or capture when the data are, or were, part of the current database state. This paper proposes a new aggregation operator that addresses several challenges posed by interval data. First......Business Intelligence solutions, encompassing technologies such as multi-dimensional data modeling and aggregate query processing, are being applied increasingly to non-traditional data. This paper extends multi-dimensional aggregation to apply to data with associated interval values that capture......, the intervals to be associated with the result tuples may not be known in advance, but depend on the actual data. Such unknown intervals are accommodated by allowing result groups that are specified only partially. Second, the operator contends with the case where an interval associated with data expresses...

  20. Análise multidimensional

    Directory of Open Access Journals (Sweden)

    SARDINHA Tony Berber

    2000-01-01

    Full Text Available Este trabalho oferece uma retrospectiva da abordagem conhecida por 'Análise Multidimensional', iniciada por Douglas Biber. O trabalho apresenta os conceitos centrais relacionados a esta abordagem e resenha os estudos principais que a utilizaram. Trabalhos ainda inéditos, realizados no Brasil, também são resenhados. O artigo ainda inclui uma discussão acerca das principais críticas relacionadas à Análise Multidimensional.

  1. Poverty Analysis of Rice Farming Households: A Multidimensional Approach

    Directory of Open Access Journals (Sweden)

    Adenuga A. H

    2013-12-01

    Full Text Available The official measurement and analysis of poverty in Nigeria has historically relied upon the single dimension, consumption based monetary approach with little attention on multidimensional poverty assessment. This study was therefore carried out to assess the multidimensional poverty index of rice farming households in Nasarawa/Benue Rice Hub, Nigeria. The study employed stratified random sampling technique to select 149 rice farming households in the study area. Descriptive statistics, the Alkire and Foster Multidimensional Poverty Index Methodology using two different cut-off points and the Tobit regression model were the main analytical tools employed for the study. The results of the multidimensional poverty index analysis revealed that female headed households were poorer than the male headed households. On the overall, 66 percent of the rice farming households was multidimensionally poor. The study also showed that the rice farming households were deprived in 48 percent of the dimensions. A multidimensional poverty index of 0.32 was obtained for the rice farming households in the study area with varying values obtained for the male and female headed households. The result of the Tobit regression model showed that gender of the household head, health, marital status and membership of association were the major determinants of multidimensional poverty of the rice farming households in the study area. The study concluded that the rice farming households in the study area were multidimensionally poor. It was recommended that the government should give priorities to the development of the rural areas with special consideration for women through the provision of essential infrastructural facilities.

  2. Measures for a Multidimensional Multiverse

    CERN Document Server

    Chung, Hyeyoun

    2012-01-01

    We explore the phenomenological consequences of generalizing the causal patch and scale factor cutoff measures to a multidimensional multiverse, where the vacua can have differing numbers of large dimensions. We consider a simple model in which the vacua are nucleated from a $D$-dimensional parent spacetime through dynamical compactification of the extra dimensions, and compute the geometric contribution to the probability distribution of observations within the multiverse for each measure. We then study how the shape of this probability distribution depends on the timescale for the existence of observers, the timescale for vacuum domination, and the timescale for curvature domination ($t_{obs}, t_{\\Lambda},$ and $t_c$, respectively.) We find that in the case of the causal patch cutoff, when the bubble universes have $p+1$ large spatial dimensions with $p \\geq 2$, the shape of the probability distribution is such that we obtain the coincidence of timescales $t_{obs} \\sim t_{\\Lambda} \\sim t_c$. Moreover, the s...

  3. Capturing Complex Multidimensional Data in Location-Based Data Warehouses

    DEFF Research Database (Denmark)

    Timko, Igor; Pedersen, Torben Bach

    2004-01-01

    Motivated by the increasing need to handle complex multidimensional data inlocation-based data warehouses, this paper proposes apowerful data model that is able to capture the complexities of such data. The model provides a foundation for handling complex transportationinfrastructures and the att......Motivated by the increasing need to handle complex multidimensional data inlocation-based data warehouses, this paper proposes apowerful data model that is able to capture the complexities of such data. The model provides a foundation for handling complex transportationinfrastructures...

  4. Approach to conceptual data integration for multidimensional data analysis in e-commerce

    Institute of Scientific and Technical Information of China (English)

    Zhang Zhe; Huang Pei

    2006-01-01

    In e-commerce the multidimensional data analysis based on the Web data needs integrating various data sources such as XML data and relational data on the conceptual level. A conceptual data description approach to multidimensional data model --the UML galaxy diagram is presented in order to conduct multidimensional data analysis for multiple subjects. The approach is illuminated using a case of 2_roots UML galaxy diagram that takes marketing analysis of TV products involved one retailer and several suppliers into consideration.

  5. Multidimensional Gravity with Einstein Internal Spaces

    CERN Document Server

    Ivashchuk, V D

    1996-01-01

    A multidimensional gravitational model on the manifold $M = M_0 \\times For $N_0 = dim M_0 > 2$ the $\\sigma$ model representation is considered and it is shown that the corresponding Euclidean Toda-like system does not satisfy the Adler-van-Moerbeke criterion. For $M_0 = R^{N_0}$, $N_0 = 3, 4, 6$ (and the total dimension $D = dim M = 11, 10, 11$, respectively) nonsingular spherically symmetric solutions to vacuum Einstein equations are obtained and their generalizations to arbitrary signatures are considered. It is proved that for a non-Euclidean signature the Riemann tensor squared of the solutions diverges on certain hypersurfaces in $R^{N_0}$.

  6. Más allá de la cultura: validación de un modelo multidimensional de autoconcepto en adolescentes argentinos (Beyond culture: Validation of a multidimensional model of self-concept among Argentine adolescents

    Directory of Open Access Journals (Sweden)

    Alejandra Daniela Calero

    2016-04-01

    Full Text Available It has been shown that self-concept and self-esteem are key constructs to explain adolescent development. One of the most well-known models of this stage of development comprises eight specific self-concept domains and another domain, representing general self-esteem, with a higher level of abstraction. This theoretical model is operationalized by the Self-Perception Profile for Adolescents (SPPA. The aim of this study was to statistically test the theoretical structure of the SPPA in an adolescent population of the City of Buenos Aires, Argentina (CABA/AR. The SPPA was administered to 467 adolescents attending a middle school in CABA/AR. A confirmatory factor analysis (CFA was used to contrast the proposed theoretical structure; two alternative models of the self-concept domain and one model of the self-esteem domain were tested. The results confirmed the proposed theoretical structure of the SPPA in adolescent population attending the CABA/AR.

  7. 多维数据建模在短消息通信数据分析中的应用%Application of Multidimensional Data Modeling in Data Analysis of Short Message Communication

    Institute of Scientific and Technical Information of China (English)

    林菁

    2011-01-01

    联机分析处理(OLAP)是支持复杂的数据分析需求的重要技术。将OLAP多维数据建模应用于电信行业的短消息通信业务。针对特定的短消息通信的数据分析需求.设计短消息通信数据分析系统的多维模型,并利用SQL Server以及相关工具成功地实现该系统。%Online Analytical Processing (OLAP) is the important technology to process complicated analytical requirements. Applies OLAP multidimensional data modeling methods to short message communication service in telecommunications. In order to meet the data analysis objectives in short messages communication, designs a multidimensional data model of short message communication data analysis system and realizes it by using SQL Server and related tools.

  8. Multidimensional real analysis I differentiation

    CERN Document Server

    Duistermaat, J J; van Braam Houckgeest, J P

    2004-01-01

    Part one of the authors' comprehensive and innovative work on multidimensional real analysis. This book is based on extensive teaching experience at Utrecht University and gives a thorough account of differential analysis in multidimensional Euclidean space. It is an ideal preparation for students who wish to go on to more advanced study. The notation is carefully organized and all proofs are clean, complete and rigorous. The authors have taken care to pay proper attention to all aspects of the theory. In many respects this book presents an original treatment of the subject and it contains man

  9. The importance of statistical modelling in clinical research : Comparing multidimensional Rasch-, structural equation and linear regression models for analyzing the depression of relatives of psychiatric patients.

    Science.gov (United States)

    Alexandrowicz, Rainer W; Jahn, Rebecca; Friedrich, Fabian; Unger, Anne

    2016-06-01

    Various studies have shown that caregiving relatives of schizophrenic patients are at risk of suffering from depression. These studies differ with respect to the applied statistical methods, which could influence the findings. Therefore, the present study analyzes to which extent different methods may cause differing results. The present study contrasts by means of one data set the results of three different modelling approaches, Rasch Modelling (RM), Structural Equation Modelling (SEM), and Linear Regression Modelling (LRM). The results of the three models varied considerably, reflecting the different assumptions of the respective models. Latent trait models (i. e., RM and SEM) generally provide more convincing results by correcting for measurement error and the RM specifically proves superior for it treats ordered categorical data most adequately.

  10. Variations of fundamental constants and multidimensional gravity

    Science.gov (United States)

    Bronnikova, K. A.; Skvortsova, M. V.

    We try to explain the recently reported large-scale spatial variations of the fine structure constant α, in agreement with other cosmological observations, in the framework of curvature-nonlinear multidimensional gravity. The original theory is reduced to a scalar-tensor theory in four dimensions, and the corresponding isotropic cosmologies are considered in both Einstein and Jordan conformal frames. In the Jordan frame one obtains simultaneous variations of α and the gravitational constant G, equal in magnitude. Long-wave small inhomogeneous perturbations of isotropic models allow for explaining spatial variations of α.

  11. A Multidimensional Software Engineering Course

    Science.gov (United States)

    Barzilay, O.; Hazzan, O.; Yehudai, A.

    2009-01-01

    Software engineering (SE) is a multidimensional field that involves activities in various areas and disciplines, such as computer science, project management, and system engineering. Though modern SE curricula include designated courses that address these various subjects, an advanced summary course that synthesizes them is still missing. Such a…

  12. A Multidimensional Software Engineering Course

    Science.gov (United States)

    Barzilay, O.; Hazzan, O.; Yehudai, A.

    2009-01-01

    Software engineering (SE) is a multidimensional field that involves activities in various areas and disciplines, such as computer science, project management, and system engineering. Though modern SE curricula include designated courses that address these various subjects, an advanced summary course that synthesizes them is still missing. Such a…

  13. Multidimensional child deprivation in Iran

    NARCIS (Netherlands)

    Yousefzadeh Faal Daghati, Sepideh; Mideros-Mora, Andrés; De Neubourg, Chris; Minujin, Alberto; Nandy, Shailen

    2012-01-01

    The chapter analyses children's multidimensional deprivation in Iran in 2009 and explores inequalities in different regions. The study focused on outcome indicators, with the level of analysis focusing on the individual child as well as the household. A child rights approach is applied to define dim

  14. Multidimensional Perfectionism and Ego Defenses

    Science.gov (United States)

    Dickinson, Wendy L.; Ashby, Jeffrey S.

    2005-01-01

    This study examined the relationship between multidimensional perfectionism and ego defense style among 130 college students. Cluster analysis results facilitated the identification of groups of adaptive perfectionists, maladaptive perfectionists, and non-perfectionists. The researchers found that identified maladaptive perfectionists used…

  15. Multidimensional Perfectionism and Ego Defenses

    Science.gov (United States)

    Dickinson, Wendy L.; Ashby, Jeffrey S.

    2005-01-01

    This study examined the relationship between multidimensional perfectionism and ego defense style among 130 college students. Cluster analysis results facilitated the identification of groups of adaptive perfectionists, maladaptive perfectionists, and non-perfectionists. The researchers found that identified maladaptive perfectionists used…

  16. Spatio-temporal change detection from multidimensional arrays

    NARCIS (Netherlands)

    Lu, Meng; Pebesma, Edzer; Sanchez, Alber; Verbesselt, Jan

    2016-01-01

    Growing availability of long-term satellite imagery enables change modeling with advanced spatio-temporal statistical methods. Multidimensional arrays naturally match the structure of spatio-temporal satellite data and can provide a clean modeling process for complex spatio-temporal analysis over

  17. Construct continuity in the presence of multidimensionality

    Science.gov (United States)

    Staniewska, Dorota

    Unidimensionality -- a condition, under which only one dominant construct is being measured by the test, is a fundamental assumption of most modern day psychometric models. However, some tests are multidimensional by design. A test, for instance, might measure physics, biology and chemistry subscales combined to measure a "general science" composite. The relative magnitudes of those subscales sometimes shift from administration to administration, which results in an altered composite. This study examined the conditions under which two different forms of a multidimensional test measure the same composite construct to a degree that allows them to be equated, i.e. used interchangeably. IRT true-score equating was used in a simulation study to assess the closeness of the scores on the forms. Conditions examined included the correlations between subscales, varying number of items per subscale form to form, and different subpopulation ability estimates on the subscales. Differences in the equating errors due to generating model (1PL or 3PL) were also examined. A way of calculating a unidimensional composite from a two-dimensional ability was devised and compared to the unidimensional composite obtained from Parscale. It was found that in general, the errors increase with decreasing correlation between traits and increased divergence of the two forms to be equated, with the later being the main predictor of the equating errors. However, the magnitude of those errors was small for the population as a whole especially when all examinee abilities are drawn from the same distribution. It was concluded that IRT true score equating is relatively robust to multidimensionality for the conditions examined, especially if the overall population score is desired. However, when accurate estimate of the equated score for individuals at the extremes of the population is needed, or whenever population abilities are drawn from more than one distribution, the unidimensional true score

  18. Biological evolution in a multidimensional fitness landscape.

    Science.gov (United States)

    Saakian, David B; Kirakosyan, Zara; Hu, Chin-Kun

    2012-09-01

    We considered a multiblock molecular model of biological evolution, in which fitness is a function of the mean types of alleles located at different parts (blocks) of the genome. We formulated an infinite population model with selection and mutation, and calculated the mean fitness. For the case of recombination, we formulated a model with a multidimensional fitness landscape (the dimension of the space is equal to the number of blocks) and derived a theorem about the dynamics of initially narrow distribution. We also considered the case of lethal mutations. We also formulated the finite population version of the model in the case of lethal mutations. Our models, derived for the virus evolution, are interesting also for the statistical mechanics and the Hamilton-Jacobi equation as well.

  19. A Multidimensional Scaling (INDSCAL) Approach to Pain: Comparison of Cancer Patients and Healthy Volunteers.

    Science.gov (United States)

    Clark, W. Crawford; Ferrer-Brechner, Theresa

    Multidimensional scaling (MDS) offers a rigorous approach to many problems in perception, emotion, personality, and cognition, where the stimuli are too complex to be quantified by other means. In these procedures similarity ratings of the stimulus objects are modeled as points in multidimensional space, such that perceived similarity is…

  20. A MULTIDIMENSIONAL AND MULTIPHYSICS APPROACH TO NUCLEAR FUEL BEHAVIOR SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    R. L. Williamson; J. D. Hales; S. R. Novascone; M. R. Tonks; D. R. Gaston; C. J. Permann; D. Andrs; R. C. Martineau

    2012-04-01

    Important aspects of fuel rod behavior, for example pellet-clad mechanical interaction (PCMI), fuel fracture, oxide formation, non-axisymmetric cooling, and response to fuel manufacturing defects, are inherently multidimensional in addition to being complicated multiphysics problems. Many current modeling tools are strictly 2D axisymmetric or even 1.5D. This paper outlines the capabilities of a new fuel modeling tool able to analyze either 2D axisymmetric or fully 3D models. These capabilities include temperature-dependent thermal conductivity of fuel; swelling and densification; fuel creep; pellet fracture; fission gas release; cladding creep; irradiation growth; and gap mechanics (contact and gap heat transfer). The need for multiphysics, multidimensional modeling is then demonstrated through a discussion of results for a set of example problems. The first, a 10-pellet rodlet, demonstrates the viability of the solution method employed. This example highlights the effect of our smeared cracking model and also shows the multidimensional nature of discrete fuel pellet modeling. The second example relies on our the multidimensional, multiphysics approach to analyze a missing pellet surface problem. As a final example, we show a lower-length-scale simulation coupled to a continuum-scale simulation.

  1. Testlet-based Multidimensional Adaptive Testing

    Directory of Open Access Journals (Sweden)

    Andreas Frey

    2016-11-01

    Full Text Available Multidimensional adaptive testing (MAT is a highly efficient method for the simultaneous measurement of several latent traits. Currently, no psychometrically sound approach is available for the use of MAT in testlet-based tests. Testlets are sets of items sharing a common stimulus such as a graph or a text. They are frequently used in large operational testing programs like TOEFL, PISA, PIRLS, or NAEP. To make MAT accessible for such testing programs, we present a novel combination of MAT with a multidimensional generalization of the random effects testlet model (MAT-MTIRT. MAT-MTIRT compared to non-adaptive testing is examined for several combinations of testlet effect variances (0.0, 0.5, 1.0, 1.5 and testlet sizes (3 items, 6 items, 9 items with a simulation study considering three ability dimensions with simple loading structure. MAT-MTIRT outperformed non-adaptive testing regarding the measurement precision of the ability estimates. Further, the measurement precision decreased when testlet effect variances and testlet sizes increased. The suggested combination of the MTIRT model therefore provides a solution to the substantial problems of testlet-based tests while keeping the length of the test within an acceptable range.

  2. Testlet-Based Multidimensional Adaptive Testing.

    Science.gov (United States)

    Frey, Andreas; Seitz, Nicki-Nils; Brandt, Steffen

    2016-01-01

    Multidimensional adaptive testing (MAT) is a highly efficient method for the simultaneous measurement of several latent traits. Currently, no psychometrically sound approach is available for the use of MAT in testlet-based tests. Testlets are sets of items sharing a common stimulus such as a graph or a text. They are frequently used in large operational testing programs like TOEFL, PISA, PIRLS, or NAEP. To make MAT accessible for such testing programs, we present a novel combination of MAT with a multidimensional generalization of the random effects testlet model (MAT-MTIRT). MAT-MTIRT compared to non-adaptive testing is examined for several combinations of testlet effect variances (0.0, 0.5, 1.0, and 1.5) and testlet sizes (3, 6, and 9 items) with a simulation study considering three ability dimensions with simple loading structure. MAT-MTIRT outperformed non-adaptive testing regarding the measurement precision of the ability estimates. Further, the measurement precision decreased when testlet effect variances and testlet sizes increased. The suggested combination of the MTIRT model therefore provides a solution to the substantial problems of testlet-based tests while keeping the length of the test within an acceptable range.

  3. Multi-Dimensional Customer Data Analysis in Online Auctions

    Institute of Scientific and Technical Information of China (English)

    LAO Guoling; XIONG Kuan; QIN Zheng

    2007-01-01

    In this paper, we designed a customer-centered data warehouse system with five subjects: listing, bidding, transaction,accounts, and customer contact based on the business process of online auction companies. For each subject, we analyzed its fact indexes and dimensions. Then take transaction subject as example,analyzed the data warehouse model in detail, and got the multi-dimensional analysis structure of transaction subject. At last, using data mining to do customer segmentation, we divided customers into four types: impulse customer, prudent customer, potential customer, and ordinary customer. By the result of multi-dimensional customer data analysis, online auction companies can do more target marketing and increase customer loyalty.

  4. 地方普通高校立体实践技能培养模式探讨%Exploration of Multi-dimensional Practical Skill Training Model in Local Common Colleges

    Institute of Scientific and Technical Information of China (English)

    陈大山; 夏立国

    2013-01-01

    To maximize the local college orientation for territorial service capabilities, the characteristics of college differentiated attributes was discussed from many aspects. Multi-dimensional practical skills model was build, innovation training strategies, then the students' development are more targeted, comprehensive and acceptable.%  为充分发挥地方普通高校对属地的定向服务能力,考虑到高校的差异化特征属性,从多个方面探讨构建立体实践技能培养模式,创新培养策略,使得学生的培养更加有针对性、综合性与目标性。

  5. Cuba: Multidimensional numerical integration library

    Science.gov (United States)

    Hahn, Thomas

    2016-08-01

    The Cuba library offers four independent routines for multidimensional numerical integration: Vegas, Suave, Divonne, and Cuhre. The four algorithms work by very different methods, and can integrate vector integrands and have very similar Fortran, C/C++, and Mathematica interfaces. Their invocation is very similar, making it easy to cross-check by substituting one method by another. For further safeguarding, the output is supplemented by a chi-square probability which quantifies the reliability of the error estimate.

  6. Analysis of stock market indices through multidimensional scaling

    Science.gov (United States)

    Machado, J. Tenreiro; Duarte, Fernando B.; Duarte, Gonçalo Monteiro

    2011-12-01

    We propose a graphical method to visualize possible time-varying correlations between fifteen stock market values. The method is useful for observing stable or emerging clusters of stock markets with similar behaviour. The graphs, originated from applying multidimensional scaling techniques (MDS), may also guide the construction of multivariate econometric models.

  7. Individual and Institutional Determinants of Multidimensional Poverty: A European Comparison

    Science.gov (United States)

    Dewilde, Caroline

    2008-01-01

    In this article we evaluate to what extent between-country differences in the probability of being "multidimensional" poor can be explained by a range of "domain-specific" indicators of welfare regime arrangements. To this end, a so-called micro-macro model is estimated, testing the "independent" effect of…

  8. The synthesis map is a multidimensional educational tool that provides insight into students' mental models and promotes students' synthetic knowledge generation.

    Science.gov (United States)

    Ortega, Ryan A; Brame, Cynthia J

    2015-01-01

    Concept mapping was developed as a method of displaying and organizing hierarchical knowledge structures. Using the new, multidimensional presentation software Prezi, we have developed a new teaching technique designed to engage higher-level skills in the cognitive domain. This tool, synthesis mapping, is a natural evolution of concept mapping, which utilizes embedding to layer information within concepts. Prezi's zooming user interface lets the author of the presentation use both depth as well as distance to show connections between data, ideas, and concepts. Students in the class Biology of Cancer created synthesis maps to illustrate their knowledge of tumorigenesis. Students used multiple organizational schemes to build their maps. We present an analysis of student work, placing special emphasis on organization within student maps and how the organization of knowledge structures in student maps can reveal strengths and weaknesses in student understanding or instruction. We also provide a discussion of best practices for instructors who would like to implement synthesis mapping in their classrooms. © 2015 R. A. Ortega and C. J. Brame et al. CBE—Life Sciences Education © 2015 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  9. Lay versus expert understandings of workplace risk in the food service industry: a multi-dimensional model with implications for participatory ergonomics.

    Science.gov (United States)

    Cann, Adam P; MacEachen, Ellen; Vandervoort, Anthony A

    2008-01-01

    The recent trend towards cooperative management and prevention of workplace injuries has introduced numerous health and safety actors to the workplace with varying amounts and types of expertise. The purpose of this qualitative research project was to explore the understandings of risk as experienced by food service workers (FSW) and how these compare with an 'expert' in risk assessment. In total 13 FSW, selected based on age, work location, and gender, and one experienced Ergonomist participated in the study. In-depth semi-structured telephone interviews were conducted with each participant and transcripts of the interviews were analyzed using thematic analysis by drawing on methods closely related to grounded theory. The findings of this study indicated that the risks for occupational injury as experienced by FSW were multi-dimensional in nature representing not only the physical requirements of the individual's job, but also the social interactions of the FSW with their coworkers, management, and the organization. FSW were also found to be a rich source of knowledge and experience concerning occupational risk and may be under-utilized when designing interventions. The results of this study support a cooperative team approach to reduce the risks of injury in the workplace, with a specific emphasis on inclusion of the worker.

  10. Multidimensional model to assess the readiness of Saudi Arabia to implement evidence based child maltreatment prevention programs at a large scale.

    Science.gov (United States)

    Almuneef, Maha A; Qayad, Mohamed; Noor, Ismail K; Al-Eissa, Majid A; Albuhairan, Fadia S; Inam, Sarah; Mikton, Christopher

    2014-03-01

    There has been increased awareness of child maltreatment in Saudi Arabia recently. This study assessed the readiness for implementing large-scale evidence-based child maltreatment prevention programs in Saudi Arabia. Key informants, who were key decision makers and senior managers in the field of child maltreatment, were invited to participate in the study. A multidimensional tool, developed by WHO and collaborators from several middle and low income countries, was used to assess 10 dimensions of readiness. A group of experts also gave an objective assessment of the 10 dimensions and key informants' and experts' scores were compared. On a scale of 100, the key informants gave a readiness score of 43% for Saudi Arabia to implement large-scale, evidence-based CM prevention programs, and experts gave an overall readiness score of 40%. Both the key informants and experts agreed that 4 of the dimensions (attitudes toward child maltreatment prevention, institutional links and resources, material resources, and human and technical resources) had low readiness scores (child maltreatment prevention, scientific data on child maltreatment prevention, and will to address child maltreatment problem) had high readiness scores (≥5) each. There was significant disagreement between key informants and experts on the remaining 3 dimensions. Overall, Saudi Arabia has a moderate/fair readiness to implement large-scale child maltreatment prevention programs. Capacity building; strengthening of material resources; and improving institutional links, collaborations, and attitudes toward the child maltreatment problem are required to improve the country's readiness to implement such programs.

  11. Multidimensional Cosmology with a Generalized Maxwell Field Integrable Cases

    CERN Document Server

    Bronnikov, K A

    1997-01-01

    We consider multidimensional cosmologies in even-dimensional space-times (D=2n) containg perfect fluid and a multidimensional generalization of the Maxwell field, preserving its conformal invariance (the F field, an n-form). Among models with an isotropic physical 3-space some integrable cases are found: vacuum models (which are integrable in the general case) and some perfect fluid models with barotropic equations of state. All of them contain a component of the F field appearing as an additional scalar in 4 dimensions. A two-parameter family of spatially flat models and four one-parameter families, including non-spatially flat models, have been obtained (where the parameters are constants from the fluid equation of state). All these integrable models admit the inclusion of a massless scalar field or an additional fluid with ultrastiff equation of state. Basic properties of vacuum models in the physical conformal frame are outlined.

  12. The Multidimensional Nutritional Niche.

    Science.gov (United States)

    Machovsky-Capuska, Gabriel E; Senior, Alistair M; Simpson, Stephen J; Raubenheimer, David

    2016-05-01

    The dietary generalist-specialist distinction plays a pivotal role in theoretical and applied ecology, conservation, invasion biology, and evolution and yet the concept remains poorly characterised. Diets, which are commonly used to define niche breadth, are almost exclusively considered in terms of foods, with little regard for the mixtures of nutrients and other compounds they contain. We use nutritional geometry (NG) to integrate nutrition with food-level approaches to the dietary niche and illustrate the application of our framework in the important context of invasion biology. We use an example that involves a model with four hypothetical nonexclusive scenarios. We additionally show how this approach can provide fresh theoretical insight into the ways nutrition and food choices impact trait evolution and trophic interactions.

  13. Analysis of the multidimensionality of hallucination-like experiences in clinical and nonclinical Spanish samples and their relation to clinical symptoms: implications for the model of continuity.

    Science.gov (United States)

    Langer, Alvaro I; Cangas, Adolfo J; Serper, Mark

    2011-02-01

    Numerous studies have found that hallucinatory experiences occur in the general population. But to date, few studies have been conducted to compare clinical and nonclinical groups across a broad array of clinical symptoms that may co-occur with hallucinations. Likewise, hallucination-like experiences are measured as a multidimensional construct, with clinical and subclinical components related to vivid daydreams, intrusive thoughts, perceptual disturbance, and clinical hallucinatory experiences. Nevertheless, these individual subcomponents have not been examined across a broad spectrum of clinically disordered and nonclinical groups. The goal of the present study was to analyze the differences and similarities in the distribution of responses to hallucination-like experience in clinical and nonclinical populations and to determine the relation of these hallucination-like experiences with various clinical symptoms. These groups included patients with schizophrenia, non-psychotic clinically disordered patients, and a group of individuals with no psychiatric diagnoses. The results revealed that hallucination-like experiences are related to various clinical symptoms across diverse groups of individuals. Regression analysis found that the Psychoticism dimension of the Symptom Check List (SCL-90-R) was the most important predictor of hallucination-like experiences. Additionally, increased auditory and visual hallucination was the only subcomponent that differentiated schizophrenic patients from other groups. This distribution of responses in the dimensions of hallucination-like experiences suggests that not all the dimensions are characteristic of people hearing voices. Vivid daydreams, intrusive thoughts, and auditory distortions and visual perceptual distortions may represent a state of general vulnerability that does not denote a specific risk for clinical hallucinations. Overall, these results support the notion that hallucination-like experiences are closer to a

  14. Multidimensional fatigue and its correlates in hospitalised advanced cancer patients.

    NARCIS (Netherlands)

    Echteld, M.A.; Passchier, J.; Teunissen, S.; Claessen, S.; Wit, R. de; Rijt, C.C.D. van der

    2007-01-01

    Although fatigue is a multidimensional concept, multidimensional fatigue is rarely investigated in hospitalised cancer patients. We determined the levels and correlates of multidimensional fatigue in 100 advanced cancer patients admitted for symptom control. Fatigue dimensions were general fatigue (

  15. 面向多维 KE 模型构建的产品特征解构方法%Product feature deconstruction method by constructing a multi-dimensional kansei engineering model

    Institute of Scientific and Technical Information of China (English)

    刘玲玲; 薛澄岐

    2014-01-01

    传统感性工学(kansei engineering ,KE)使用的形态学图表法(morphological charts ,MC)聚焦于形态“轮廓”变量以及各产品构件拆解,造成一维变量表达的研究结果在外观感性设计阶段价值微弱。以“造型特征”取代“产品构件”为解构原则,融入认知科学、形态学观点,丰富“外观层面”特征解析要素。除视觉认知的“外观层面”外,融入“使用交互”及“文化象征”层次,且提出一种多感官通道的多维度的特征解析步骤,更符合造型设计规律。结合空气净化器产品案例验证该方法的具体使用过程,确保KE模型更可靠。%In the light of the situation that former kansei engineering (KE) model tends to be one-dimensional variables in expression w hich causes low practical value ,this paper proposes to con-struct KE model with multi-dimensional variables in expression .Guided by cognition and mor-phology theory ,a product deconstruction method was proposed to obtain multi-dimensional de-sign elements .Taking morphological characteristics as a breakthrough point instead of product parts as extraction principle ,the feature deconstruction framework was proposed which induced by appearance ,operation and cultural symbol three levels .A morphological characteristics proce-dure of deconstruction was analyzed ,to validate the performance of the KE model ,by taking air cleaner as an example .

  16. Nuclear Forensic Inferences Using Iterative Multidimensional Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Robel, M; Kristo, M J; Heller, M A

    2009-06-09

    Nuclear forensics involves the analysis of interdicted nuclear material for specific material characteristics (referred to as 'signatures') that imply specific geographical locations, production processes, culprit intentions, etc. Predictive signatures rely on expert knowledge of physics, chemistry, and engineering to develop inferences from these material characteristics. Comparative signatures, on the other hand, rely on comparison of the material characteristics of the interdicted sample (the 'questioned sample' in FBI parlance) with those of a set of known samples. In the ideal case, the set of known samples would be a comprehensive nuclear forensics database, a database which does not currently exist. In fact, our ability to analyze interdicted samples and produce an extensive list of precise materials characteristics far exceeds our ability to interpret the results. Therefore, as we seek to develop the extensive databases necessary for nuclear forensics, we must also develop the methods necessary to produce the necessary inferences from comparison of our analytical results with these large, multidimensional sets of data. In the work reported here, we used a large, multidimensional dataset of results from quality control analyses of uranium ore concentrate (UOC, sometimes called 'yellowcake'). We have found that traditional multidimensional techniques, such as principal components analysis (PCA), are especially useful for understanding such datasets and drawing relevant conclusions. In particular, we have developed an iterative partial least squares-discriminant analysis (PLS-DA) procedure that has proven especially adept at identifying the production location of unknown UOC samples. By removing classes which fell far outside the initial decision boundary, and then rebuilding the PLS-DA model, we have consistently produced better and more definitive attributions than with a single pass classification approach. Performance of the

  17. ¿Qué factores explican la pobreza multidimensional en España? Una aproximación a través de los modelos de ecuaciones estructurales || What Factors Explain the Multimensional Poverty in Spain? An Approach by Means of Structural Equation Models

    Directory of Open Access Journals (Sweden)

    Poza Lara, Carlos

    2011-01-01

    Full Text Available La finalidad de este estudio es presentar los factores más importantes que explican la pobreza multidimensional en España, destacando las interrelaciones entre los propios elementos explicativos, con el ánimo de potenciar los efectos de la política económica contra la pobreza. Para ello, se ha construido un modelo de ecuaciones estructurales utilizando la muestra ampliada del Panel de Hogares de la Unión Europea del año 2000. El nivel de educación y el empleo parecen ser los constructos más determinantes. Concretamente,el nivel de formación y el tipo de contrato son las variables con mayor poder explicativo sobre la pobreza multidimensional. || The aim of this study is to present the most important factors that explain multidimensional poverty in Spain, highlighting the relationships between the explanatory elements themselves in the spirit of enhancing the effects of poverty policy. For this purpose, we have designed a Structural Equation Model using the enlarged sample of Household Panel European Union in 2000. Education and employment seem to be the most determining latent construct. In particular, the level of education and the type of employment contract are the most important variables to explain the multidimensional poverty.

  18. Modeling Individual Subtests of the WAIS IV with Multiple Latent Factors: e74980

    National Research Council Canada - National Science Library

    Dennis J McFarland

    2013-01-01

    ... multidimensional models of the Wechsler Adult Intelligence Scales- fourth edition (WAIS-IV) subtests. Multidimensional models of subtest performance provided better model fit as compared to several...

  19. Modeling individual subtests of the WAIS IV with multiple latent factors

    National Research Council Canada - National Science Library

    McFarland, Dennis J

    2013-01-01

    ... multidimensional models of the Wechsler Adult Intelligence Scales-fourth edition (WAIS-IV) subtests. Multidimensional models of subtest performance provided better model fit as compared to several...

  20. IAEA CRP on HTGR Uncertainties in Modeling: Assessment of Phase I Lattice to Core Model Uncertainties

    Energy Technology Data Exchange (ETDEWEB)

    Rouxelin, Pascal Nicolas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Strydom, Gerhard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    II 1a. The steady state core calculations were simulated with the INL coupled-code system known as the Parallel and Highly Innovative Simulation for INL Code System (PHISICS) and the system thermal-hydraulics code known as the Reactor Excursion and Leak Analysis Program (RELAP) 5 3D using the nuclear data libraries previously generated with NEWT. It was observed that significant differences in terms of multiplication factor and neutron flux exist between the various permutations of the Phase I super-cell lattice calculations. The use of these cross section libraries only leads to minor changes in the Phase II core simulation results for fresh fuel but shows significantly larger discrepancies for spent fuel cores. Furthermore, large incongruities were found between the SCALE NEWT and KENO VI results for the super cells, and while some trends could be identified, a final conclusion on this issue could not yet be reached. This report will be revised in mid 2016 with more detailed analyses of the super-cell problems and their effects on the core models, using the latest version of SCALE (6.2). The super-cell models seem to show substantial improvements in terms of neutron flux as compared to single-block models, particularly at thermal energies.

  1. 构建联通移动网络多维价值区域分析模型浅析%Analysis of Multidimensional Valued Region Model Construction for China Unicom Mobile Network

    Institute of Scientific and Technical Information of China (English)

    熊壮; 陈燕芬

    2014-01-01

    With the rapid development of mobile broad band (MBB) networks, the telecom operators should consider more and more factors in the construction, operation, maintenance and development of mobile networks. They should found region and cell multidimensional valued models. Through the dimension analysis for the factors affecting network value, the selection and decision methods of valued model are given and the valued regions are divided. In addition, the applications for valued regions are introduced and typical cases are analyzed.%移动宽带网络的快速发展,要求电信运营商在考虑移动网建设、运维、发展方面关注更多的因素,积极构建区域和小区多维度价值模型。通过对影响网络价值的维度分析,给出了价值模型选取与确定方法,划分了价值区域,并对价值区域应用进行介绍和典型案例分析。

  2. Modeling of local steam condensation on walls in presence of non-condensable gases. Application to a loca calculation in reactor containment using the multidimensional geyser/tonus code

    Energy Technology Data Exchange (ETDEWEB)

    Benet, L.V.; Caroli, C.; Cornet, P. [Commissariat a l`Energie Atomique, Gif sur Yvette (France)] [and others

    1995-09-01

    This paper reports part of a study of possible severe pressurized water reactor (PWR) accidents. The need for containment modeling, and in particular for a hydrogen risk study, was reinforced in France after 1990, with the requirement that severe accidents must be taken into account in the design of future plants. This new need of assessing the transient local hydrogen concentration led to the development, in the Mechanical Engineering and Technology Department of the French Atomic Energy Commission (CEA/DMT), of the multidimensional code GEYSER/TONUS for containment analysis. A detailed example of the use of this code is presented. The mixture consisted of noncondensable gases (air or air plus hydrogen) and water vapor and liquid water. This is described by a compressible homogeneous two-phase flow model and wall condensation is based on the Chilton-Colburn formula and the analogy between heat and mass transfer. Results are given for a transient two-dimensional axially-symmetric computation for the first hour of a simplified accident sequence. In this there was an initial injection of a large amount of water vapor followed by a smaller amount and by hydrogen injection.

  3. SUSTAINABLE DEVELOPMENT, A MULTIDIMENSIONAL CONCEPT

    Directory of Open Access Journals (Sweden)

    TEODORESCU ANA MARIA

    2015-06-01

    Full Text Available Sustainable development imposed itself as a corollary of economic term "development". Sustainable development is meant to be the summation of economic, environmental and social considerations for the present and especially for the future. The concept of sustainable development plays an important role in european and global meetings since 1972, the year it has been set for the first time. Strategies necessary to achieve the objectives of sustainable development have been developed, indicators meant to indicate the result of the implementation of policies have been created, national plans were oriented towards achieving the proposed targets. I wanted to highlight the multidimensional character of the concept of sustainable development. Thus, using specialized national and international literature, I have revealed different approaches of one pillar to the detriment of another pillar depending on the specific field. In the different concepts of sustainable development, the consensus is undoubtedly agreed on its components: economic, social, environmental. Based on this fact, the concept of sustainability has different connotations depending on the specific content of each discipline: biology, economics, sociology, environmental ethics. The multidimensional valence of sustainable development consists of three pillars ability to act together for the benefit of present and future generations. Being a multidimensional concept, importance attached to a pillar over another is directed according to the particularities of each field: in economy profit prevails, in ecology care of natural resources is the most important, the social aims improving human living conditions. The challenge of sustainable development is to combine all the economic, environmental and social benefits and the present generation to come. Ecological approach is reflected in acceptance of limited natural resources by preserving natural capital. In terms of the importance of

  4. NASA Multidimensional Stirling Convertor Code Developed

    Science.gov (United States)

    Tew, Roy C.; Thieme, Lanny G.

    2004-01-01

    A high-efficiency Stirling Radioisotope Generator (SRG) for use on potential NASA Space Science missions is being developed by the Department of Energy, Lockheed Martin, Stirling Technology Company, and the NASA Glenn Research Center. These missions may include providing spacecraft onboard electric power for deep space missions or power for unmanned Mars rovers. Glenn is also developing advanced technology for Stirling convertors, aimed at substantially improving the specific power and efficiency of the convertor and the overall power system. Performance and mass improvement goals have been established for second- and third-generation Stirling radioisotope power systems. Multiple efforts are underway to achieve these goals, both in house at Glenn and under various grants and contracts. These efforts include the development of a multidimensional Stirling computational fluid dynamics code, high-temperature materials, advanced controllers, an end-to-end system dynamics model, low-vibration techniques, advanced regenerators, and a lightweight convertor. Under a NASA grant, Cleveland State University (CSU) and its subcontractors, the University of Minnesota (UMN) and Gedeon Associates, have developed a twodimensional computer simulation of a CSUmod Stirling convertor. The CFD-ACE commercial software developed by CFD Research Corp. of Huntsville, Alabama, is being used. The CSUmod is a scaled version of the Stirling Technology Demonstrator Convertor (TDC), which was designed and fabricated by the Stirling Technology Company and is being tested by NASA. The schematic illustrates the structure of this model. Modeled are the fluid-flow and heat-transfer phenomena that occur in the expansion space, the heater, the regenerator, the cooler, the compression space, the surrounding walls, and the moving piston and displacer. In addition, the overall heat transfer, the indicated power, and the efficiency can be calculated. The CSUmod model is being converted to a two

  5. Second order multidimensional sign-preserving remapping for ALE methods

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Ryan N [Los Alamos National Laboratory; Szmelter, J. [LOUGHBOROUGH UNIV.

    2010-12-15

    A second-order conservative sign-preserving remapping scheme for Arbitrary Lagrangian-Eulerian (ALE) methods is developed utilising concepts of the Multidimensional Positive Definite Advection Transport Algorithm (MPDATA). The algorithm is inherently multidimensional, and so does not introduce splitting errors. The remapping is implemented in a two-dimensional, finite element ALE solver employing staggered quadrilateral meshes. The MPDATA remapping uses a finite volume discretization developed for volume coordinates. It is applied for the remapping of density and internal energy arranged as cell centered, and velocity as nodal, dependent variables. In the paper, the advection of scalar fields is examined first for test cases with prescribed mesh movement. A direct comparison of MPDATA with the performance of the van Leer MUSCL scheme indicates advantages of a multidimensional approach. Furthermore, distinctly different performance between basic MPDATA and the infinite gauge option is illustrated using benchmarks involving transport of a sign changing velocity field. Further development extends the application of MPDATA remapping to the full ALE solver with a staggered mesh arrangement for density, internal energy and momentum using volume coordinates. At present, two options of the algorithm - basic and infinite gauge - are implemented. To ensure a meaningful assessment, an identical Lagrangian solver and computational mesh update routines are used with either MPDATA or van Leer MUSCL remapping. The evaluation places particular focus on the abilities of both schemes to accurately model multidimensional problems. Theoretical considerations are supported with numerical examples. In addition to the prescribed mesh movement cases for advection of scalars, the demonstrations include two-dimensional Eulerian and ALE flow simulations on quadrilateral meshes with both fixed and variable timestep control. The key comparisons include the standard test cases of Sod and Noh

  6. Heuristics for Multidimensional Packing Problems

    DEFF Research Database (Denmark)

    Egeblad, Jens

    for a minimum height container required for the items. The main contributions of the thesis are three new heuristics for strip-packing and knapsack packing problems where items are both rectangular and irregular. In the two first papers we describe a heuristic for the multidimensional strip-packing problem...... for a three-dimensional knapsack packing problem involving furniture is presented in the fourth paper. The heuristic is based on a variety of techniques including tree-search, wall-building, and sequential placement. The solution process includes considerations regarding stability and load bearing strength...... paper. Ensuring that a loaded consignment of items are balanced throughout a container can reduce fuel consumption and prolong the life-span of vehicles. The heuristic can be used as a post-processing tool to reorganize an existing solution to a packing problem. A method for optimizing the placement...

  7. Motivation and Engagement in the Workplace: Examining a Multidimensional Framework and Instrument from a Measurement and Evaluation Perspective

    Science.gov (United States)

    Martin, Andrew J.

    2009-01-01

    This investigation conducts measurement and evaluation of a multidimensional model of workplace motivation and engagement from a construct validation perspective. Two studies were conducted, one using the multi-item multidimensional Motivation and Engagement Scale-Work (N = 637 school personnel) and one using a parallel short form (N = 574 school…

  8. Motivation and Engagement in the Workplace: Examining a Multidimensional Framework and Instrument from a Measurement and Evaluation Perspective

    Science.gov (United States)

    Martin, Andrew J.

    2009-01-01

    This investigation conducts measurement and evaluation of a multidimensional model of workplace motivation and engagement from a construct validation perspective. Two studies were conducted, one using the multi-item multidimensional Motivation and Engagement Scale-Work (N = 637 school personnel) and one using a parallel short form (N = 574 school…

  9. Multidimensional GIS modeling of magnetic mineralogy as a proxy for fire use and spatial patterning: evidence from the Middle Stone Age bearing sea cave of Pinnacle Point 13B (Western Cape, South Africa).

    Science.gov (United States)

    Herries, Andy I R; Fisher, Erich C

    2010-01-01

    This paper aims to identify the spatial patterning of burning and occupation within an early Middle Stone Age (MSA) sea cave in the Western Cape Province of South Africa by creating a multidimensional model of archaeomagnetic data recovered from all excavated units. Magnetic susceptibility and other mineral magnetic parameters are shown to provide an excellent proxy for the anthropogenic alteration and spread of burnt material into the surrounding unaltered cave deposits. The identification of combustion features and areas of occupation or different activities within the site can be determined because the movement of people throughout the cave mixes magnetically strong hearth material with magnetically weak unaltered sediments. This is also indicated by micromorphological analysis. The degree of enhancement is also shown to indicate the extent to which a deposit has been altered, and therefore, intensity of occupation, because multiple heatings of deposits are needed to form the concentrations of iron minerals occurring in some layers. This is further supported by a comparison with artifact density for the layers. Variation in the magnetic values between different areas of the site is noted with major occupation or fire building occurring in the front of the cave during earlier MIS 6 periods, while during later MIS 5 periods the entire cave is occupied intensively. The oldest, MIS 11 deposits at the rear of the cave indicate no evidence of enhancement and an apparent absence of any anthropogenic signature. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. General and specific attention-deficit/hyperactivity disorder factors of children 4 to 6 years of age: An exploratory structural equation modeling approach to assessing symptom multidimensionality.

    Science.gov (United States)

    Arias, Víctor B; Ponce, Fernando P; Martínez-Molina, Agustín; Arias, Benito; Núñez, Daniel

    2016-01-01

    We tested first-order factor and bifactor models of attention-deficit/hyperactivity disorder (ADHD) using confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM) to adequately summarize the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, (DSM-IV-TR) symptoms observed in a Spanish sample of preschoolers and kindergarteners. Six ESEM and CFA models were estimated based on teacher evaluations of the behavior of 638 children 4 to 6 years of age. An ESEM bifactor model with a central dimension plus 3 specific factors (inattention, hyperactivity, and impulsivity) showed the best fit and interpretability. Strict invariance between the sexes was observed. The bifactor model provided a solution to previously encountered inconsistencies in the factorial models of ADHD in young children. However, the low reliability of the specific factors casts doubt on the utility of the subscales for ADHD measurement. More research is necessary to clarify the nature of G and S factors of ADHD.

  11. Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour

    Science.gov (United States)

    Lee, Cheng-Hsien; Low, Ying Min; Chiew, Yee-Meng

    2016-05-01

    Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial, and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k - ɛ turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results.

  12. Multi-dimensional rheology-based two-phase model for sediment transport and applications to sheet flow and pipeline scour

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Cheng-Hsien [Centre for Offshore Research and Engineering, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576 (Singapore); Department of Water Resources and Environmental Engineering, Tamkang University, New Taipei City 25137, Taiwan (China); Low, Ying Min, E-mail: ceelowym@nus.edu.sg [Centre for Offshore Research and Engineering, Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576 (Singapore); Chiew, Yee-Meng [School of Civil and Environmental Engineering, Nanyang Technological University (Singapore)

    2016-05-15

    Sediment transport is fundamentally a two-phase phenomenon involving fluid and sediments; however, many existing numerical models are one-phase approaches, which are unable to capture the complex fluid-particle and inter-particle interactions. In the last decade, two-phase models have gained traction; however, there are still many limitations in these models. For example, several existing two-phase models are confined to one-dimensional problems; in addition, the existing two-dimensional models simulate only the region outside the sand bed. This paper develops a new three-dimensional two-phase model for simulating sediment transport in the sheet flow condition, incorporating recently published rheological characteristics of sediments. The enduring-contact, inertial, and fluid viscosity effects are considered in determining sediment pressure and stresses, enabling the model to be applicable to a wide range of particle Reynolds number. A k − ε turbulence model is adopted to compute the Reynolds stresses. In addition, a novel numerical scheme is proposed, thus avoiding numerical instability caused by high sediment concentration and allowing the sediment dynamics to be computed both within and outside the sand bed. The present model is applied to two classical problems, namely, sheet flow and scour under a pipeline with favorable results. For sheet flow, the computed velocity is consistent with measured data reported in the literature. For pipeline scour, the computed scour rate beneath the pipeline agrees with previous experimental observations. However, the present model is unable to capture vortex shedding; consequently, the sediment deposition behind the pipeline is overestimated. Sensitivity analyses reveal that model parameters associated with turbulence have strong influence on the computed results.

  13. Multidimensional singular integrals and integral equations

    CERN Document Server

    Mikhlin, Solomon Grigorievich; Stark, M; Ulam, S

    1965-01-01

    Multidimensional Singular Integrals and Integral Equations presents the results of the theory of multidimensional singular integrals and of equations containing such integrals. Emphasis is on singular integrals taken over Euclidean space or in the closed manifold of Liapounov and equations containing such integrals. This volume is comprised of eight chapters and begins with an overview of some theorems on linear equations in Banach spaces, followed by a discussion on the simplest properties of multidimensional singular integrals. Subsequent chapters deal with compounding of singular integrals

  14. Analytical chemistry, multidimensional spectral signatures, and the future of coherent multidimensional spectroscopy

    Science.gov (United States)

    Wright, John C.

    2016-10-01

    Spectroscopy is a dominant measurement methodology because it resolves molecular level details over a wide concentration range. Its limitations, however, become challenged when applied to complex materials. Coherent multidimensional spectroscopy (CMDS) is the optical analogue of multidimensional NMR and like NMR, its multidimensionality promises to increase the spectral selectivity of vibrational and electronic spectroscopy. This article explores whether this promise can make CMDS a dominant spectroscopic method throughout the sciences. In order for CMDS to become a dominant methodology, it must create multidimensional spectral fingerprints that provide the selectivity required for probing complex samples. Pump-CMDS probe methods separate the pump's measurement of dynamics from a multidimensional and selective probe. Fully coherent CMDS methods are ideal multidimensional probes because they avoid relaxation effects, spectrally isolate the output signals, and provide unique and invariant spectral signatures using any combination of vibrational and electronic quantum states.

  15. XLDM: AN XLINK-BASED MULTIDIMENSIONAL METAMODEL

    Directory of Open Access Journals (Sweden)

    Paulo Caetano da Silva

    2011-12-01

    Full Text Available The growth of data available on the Internet and the improvement of ways to handle them consist of an important issue while designing a data model. In this context, XML provides the necessary formalism to establish a standard to represent and exchange data. Since the technologies of data warehouse are often used for data analysis, it is necessary to define a cube model data to XML. However, data representation in XML may generate syntactic, semantic and structural heterogeneity problems on XML documents, which are not considered by related approaches. To solve these problems, it is required the definition of a data schema. This paper proposes a metamodel to specify XML document cubes, based on relationships between elements and XML documents. This approach solves the XML data heterogeneity problems by taking advantages of data schema definition and relationships defined by XLink. The methodology used provides formal rules to define the concepts proposed. Following this formalism is then instantiated using XML Schema and XLink. It also presents a case study in the medical field and a comparison with XBRL Dimensions and a financial and multidimensional data model which uses XLink

  16. Multidimensional multiphysics simulation of nuclear fuel behavior

    Science.gov (United States)

    Williamson, R. L.; Hales, J. D.; Novascone, S. R.; Tonks, M. R.; Gaston, D. R.; Permann, C. J.; Andrs, D.; Martineau, R. C.

    2012-04-01

    Nuclear fuel operates in an environment that induces complex multiphysics phenomena, occurring over distances ranging from inter-atomic spacing to meters, and times scales ranging from microseconds to years. This multiphysics behavior is often tightly coupled and many important aspects are inherently multidimensional. Most current fuel modeling codes employ loose multiphysics coupling and are restricted to 2D axisymmetric or 1.5D approximations. This paper describes a new modeling tool able to simulate coupled multiphysics and multiscale fuel behavior, for either 2D axisymmetric or 3D geometries. Specific fuel analysis capabilities currently implemented in this tool are described, followed by a set of demonstration problems which include a 10-pellet light water reactor fuel rodlet, three-dimensional analysis of pellet clad mechanical interaction in the vicinity of a defective fuel pellet, coupled heat transfer and fission product diffusion in a TRISO-coated fuel particle, a demonstration of the ability to couple to lower-length scale models to account for material property variation with microstructural evolution, and a demonstration of the tool's ability to efficiently solve very large and complex problems using massively-parallel computing. A final section describes an early validation exercise, comparing simulation results to a light water reactor fuel rod experiment.

  17. Multi-dimensional modelling of spray, in-cylinder air motion and fuel–air mixing in a direct-injection engine

    Indian Academy of Sciences (India)

    N Abani; S Bakshi; R V Ravikrishna

    2007-10-01

    In this work, three-dimensional fuel–air mixing inside a conventional spark ignition engine cylinder is simulated under direct injection conditions. The motivation is to explore retrofitting of conventional engines for direct injection to take advantage of low emissions and high thermal efficiency of the direct injection concept. Fuel–air mixing is studied at different loads by developing and applying a model based on the Lagrangian-drop and Eulerian-fluid (LDEF) procedure for modelling the two-phase flow. The Taylor Analogy Breakup (TAB) model for modelling the hollow cone spray and appropriate models for droplet impingement, drag and evaporation are used. Moving boundary algorithm and two-way interaction between both phases are implemented. Fuel injection timing and quantity is varied with load. Results show that near-stoichiometric fuel–air ratio region is observed at different locations depending on the load. The model developed serves to predict the fuel–air mixing spatially and temporally, and hence is a useful tool in design and optimization of direct injection engines with regards to injector and spark plug locations. Simulations over a range of speed and load indicate the need for a novel ignition strategy involving dual spark plugs and also provide guidelines in deciding spark plug locations.

  18. A splitting scheme based on the space-time CE/SE method for solving multi-dimensional hydrodynamical models of semiconductor devices

    Science.gov (United States)

    Nisar, Ubaid Ahmed; Ashraf, Waqas; Qamar, Shamsul

    2016-08-01

    Numerical solutions of the hydrodynamical model of semiconductor devices are presented in one and two-space dimension. The model describes the charge transport in semiconductor devices. Mathematically, the models can be written as a convection-diffusion type system with a right hand side describing the relaxation effects and interaction with a self consistent electric field. The proposed numerical scheme is a splitting scheme based on the conservation element and solution element (CE/SE) method for hyperbolic step, and a semi-implicit scheme for the relaxation step. The numerical results of the suggested scheme are compared with the splitting scheme based on Nessyahu-Tadmor (NT) central scheme for convection step and the same semi-implicit scheme for the relaxation step. The effects of various parameters such as low field mobility, device length, lattice temperature and voltages for one-space dimensional hydrodynamic model are explored to further validate the generic applicability of the CE/SE method for the current model equations. A two dimensional simulation is also performed by CE/SE method for a MESFET device, producing results in good agreement with those obtained by NT-central scheme.

  19. VH-1: Multidimensional ideal compressible hydrodynamics code

    Science.gov (United States)

    Hawley, John; Blondin, John; Lindahl, Greg; Lufkin, Eric

    2012-04-01

    VH-1 is a multidimensional ideal compressible hydrodynamics code written in FORTRAN for use on any computing platform, from desktop workstations to supercomputers. It uses a Lagrangian remap version of the Piecewise Parabolic Method developed by Paul Woodward and Phil Colella in their 1984 paper. VH-1 comes in a variety of versions, from a simple one-dimensional serial variant to a multi-dimensional version scalable to thousands of processors.

  20. RELATIVE PARAMETRIZATION OF LINEAR MULTIDIMENSIONAL SYSTEMS

    OpenAIRE

    Pommaret, Jean-François

    2012-01-01

    Presented for publication in the Springer journal MSSP:Multidimensional Systems and Signal Processing; In the last chapter of his book "The Algebraic Theory of Modular Systems " published in 1916, F. S. Macaulay developped specific techniques for dealing with " unmixed polynomial ideals " by introducing what he called " inverse systems ". The purpose of this paper is to extend such a point of view to differential modules defined by linear multidimensional systems, that is by linear systems of...

  1. Evaluating Multidimensional Queries by Diamond Dicing

    CERN Document Server

    Webb, Hazel; Lemire, Daniel

    2010-01-01

    Queries that constrain multiple dimensions simultaneously are difficult to express and compute efficiently in both Structured Query Language (SQL) and multidimensional languages. We introduce the diamond cube operator to facilitate the expression of one such class of multidimensional query. We have developed, implemented and tested algorithms to compute diamonds on both real and synthetic large data sets. We show that our custom implementation is more than twenty-five times faster, on a large data set, than popular database engines.

  2. Indices de Pobreza Multidimensional: alcances y limitaciones

    OpenAIRE

    Mercado, Ruben

    2016-01-01

    En éste trabajo se presentan las características de los principales índices de pobreza multidimensional, y se analizan sus alcances y limitaciones tanto para la medida de la pobreza como para servir como guías de las políticas públicas. This paper presents the characteristics of the main indices of multidimensional poverty, and analyses their scope and limitations as measures of poverty and as guides for public policy.

  3. A Multi-Dimensional Model of the Origins of Attitude Certainty: Teachers' Attitudes toward Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Anderson, Donnah L.; Watt, Susan E.; Shanley, Dianne C.

    2014-01-01

    This research tested and extended a laboratory-derived model of the origins of attitude certainty using a real attitude object: Teaching children with attention-deficit/hyperactivity disorder (ADHD). In Study 1, an experiment manipulated the amount of information, thought, and consistency of information delivered to pre-service teachers (n = 224)…

  4. Multidimensionally encoded magnetic resonance imaging.

    Science.gov (United States)

    Lin, Fa-Hsuan

    2013-07-01

    Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled.

  5. On the relationship of polar mesospheric cloud ice water content, particle radius and mesospheric temperature and its use in multi-dimensional models

    Directory of Open Access Journals (Sweden)

    E. J. Jensen

    2009-11-01

    Full Text Available The distribution of ice layers in the polar summer mesosphere (called polar mesospheric clouds or PMCs is sensitive to background atmospheric conditions and therefore affected by global-scale dynamics. To investigate this coupling it is necessary to simulate the global distribution of PMCs within a 3-dimensional (3-D model that couples large-scale dynamics with cloud microphysics. However, modeling PMC microphysics within 3-D global chemistry climate models (GCCM is a challenge due to the high computational cost associated with particle following (Lagrangian or sectional microphysical calculations. By characterizing the relationship between the PMC effective radius, ice water content (iwc, and local temperature (T from an ensemble of simulations from the sectional microphysical model, the Community Aerosol and Radiation Model for Atmospheres (CARMA, we determined that these variables can be described by a robust empirical formula. The characterized relationship allows an estimate of an altitude distribution of PMC effective radius in terms of local temperature and iwc. For our purposes we use this formula to predict an effective radius as part of a bulk parameterization of PMC microphysics in a 3-D GCCM to simulate growth, sublimation and sedimentation of ice particles without keeping track of the time history of each ice particle size or particle size bin. This allows cost effective decadal scale PMC simulations in a 3-D GCCM to be performed. This approach produces realistic PMC simulations including estimates of the optical properties of PMCs. We validate the relationship with PMC data from the Solar Occultation for Ice Experiment (SOFIE.

  6. Multidimensional Poverty and Child Survival in India

    Science.gov (United States)

    Mohanty, Sanjay K.

    2011-01-01

    Background Though the concept of multidimensional poverty has been acknowledged cutting across the disciplines (among economists, public health professionals, development thinkers, social scientists, policy makers and international organizations) and included in the development agenda, its measurement and application are still limited. Objectives and Methodology Using unit data from the National Family and Health Survey 3, India, this paper measures poverty in multidimensional space and examine the linkages of multidimensional poverty with child survival. The multidimensional poverty is measured in the dimension of knowledge, health and wealth and the child survival is measured with respect to infant mortality and under-five mortality. Descriptive statistics, principal component analyses and the life table methods are used in the analyses. Results The estimates of multidimensional poverty are robust and the inter-state differentials are large. While infant mortality rate and under-five mortality rate are disproportionately higher among the abject poor compared to the non-poor, there are no significant differences in child survival among educationally, economically and health poor at the national level. State pattern in child survival among the education, economical and health poor are mixed. Conclusion Use of multidimensional poverty measures help to identify abject poor who are unlikely to come out of poverty trap. The child survival is significantly lower among abject poor compared to moderate poor and non-poor. We urge to popularize the concept of multiple deprivations in research and program so as to reduce poverty and inequality in the population. PMID:22046384

  7. Multidimensional poverty and child survival in India.

    Directory of Open Access Journals (Sweden)

    Sanjay K Mohanty

    Full Text Available BACKGROUND: Though the concept of multidimensional poverty has been acknowledged cutting across the disciplines (among economists, public health professionals, development thinkers, social scientists, policy makers and international organizations and included in the development agenda, its measurement and application are still limited. OBJECTIVES AND METHODOLOGY: Using unit data from the National Family and Health Survey 3, India, this paper measures poverty in multidimensional space and examine the linkages of multidimensional poverty with child survival. The multidimensional poverty is measured in the dimension of knowledge, health and wealth and the child survival is measured with respect to infant mortality and under-five mortality. Descriptive statistics, principal component analyses and the life table methods are used in the analyses. RESULTS: The estimates of multidimensional poverty are robust and the inter-state differentials are large. While infant mortality rate and under-five mortality rate are disproportionately higher among the abject poor compared to the non-poor, there are no significant differences in child survival among educationally, economically and health poor at the national level. State pattern in child survival among the education, economical and health poor are mixed. CONCLUSION: Use of multidimensional poverty measures help to identify abject poor who are unlikely to come out of poverty trap. The child survival is significantly lower among abject poor compared to moderate poor and non-poor. We urge to popularize the concept of multiple deprivations in research and program so as to reduce poverty and inequality in the population.

  8. An investigation into multi-dimensional prediction models to estimate the pose error of a quadcopter in a CSP plant setting

    Science.gov (United States)

    Lock, Jacobus C.; Smit, Willie J.; Treurnicht, Johann

    2016-05-01

    The Solar Thermal Energy Research Group (STERG) is investigating ways to make heliostats cheaper to reduce the total cost of a concentrating solar power (CSP) plant. One avenue of research is to use unmanned aerial vehicles (UAVs) to automate and assist with the heliostat calibration process. To do this, the pose estimation error of each UAV must be determined and integrated into a calibration procedure. A computer vision (CV) system is used to measure the pose of a quadcopter UAV. However, this CV system contains considerable measurement errors. Since this is a high-dimensional problem, a sophisticated prediction model must be used to estimate the measurement error of the CV system for any given pose measurement vector. This paper attempts to train and validate such a model with the aim of using it to determine the pose error of a quadcopter in a CSP plant setting.

  9. A Multidimensional Rasch Analysis of the Functional Independence Measure Based on the National Institute on Disability, Independent Living, and Rehabilitation Research Traumatic Brain Injury Model Systems National Database.

    Science.gov (United States)

    Pretz, Christopher R; Kean, Jacob; Heinemann, Allen W; Kozlowski, Allan J; Bode, Rita K; Gebhardt, Eveline

    2016-07-15

    A number of studies have evaluated the psychometric properties of the Functional Independence Measure (FIM™) using Rasch analysis, although none has done so using the National Institute on Disability, Independent Living, and Rehabilitation Research Traumatic Brain Injury Model Systems National Database, a longitudinal database that captures demographic and outcome information on persons with moderate to severe traumatic brain injury across the United States. In the current study, we examine the psychometric properties of the FIM as represented by persons within this database and demonstrate that the FIM comprises three subscales representing cognitive, self-care, and mobility domains. These subscales were analyzed simultaneously using a multivariate Rasch model in combination with a time dependent concurrent calibration scheme with the goal of creating a raw score-to-logit transformation that can be used to improve the accuracy of parametric statistical analyses. The bowel and bladder function items were removed because of misfit with the motor and cognitive items. Some motor items exhibited step disorder, which was addressed by collapsing Categories 1-3 for Toileting, Stairs, Locomotion, Tub/Shower Transfers; Categories 1 and 2 for Toilet and Bed Transfers; and Categories 2 and 3 for Grooming. The strong correlations (r = 0.82-0.96) among the three subscales suggest they should be modeled together. Coefficient alpha of 0.98 indicates high internal consistency. Keyform maps are provided to enhance clinical interpretation and application of study results.

  10. Exact solutions in multidimensional gravity with antisymmetric forms

    CERN Document Server

    Ivashchuk, V D

    2001-01-01

    This topical review deals with a multidimensional gravitational model containing dilatonic scalar fields and antisymmetric forms. The manifold is chosen in the form M = M_0 x M_1 x ...x M_n, where M_i are Einstein spaces (i >0). The sigma-model approach and exact solutions in the model are reviewed and the solutions with p-branes (e.g. Majumdar-Papapetrou-type, cosmological, spherically symmetric, black-brane and Freund-Rubin-type ones) are considered.

  11. Research on a Bio-Inspired Multidimensional Network Security Model and Its Implementation Mode%生物启发的多维网络安全模型及实现模式研究

    Institute of Scientific and Technical Information of China (English)

    郑瑞娟; 王慧强; 徐东

    2006-01-01

    在多变的生态环境中,生物系统的安全机制展示了非凡的适应性和鲁棒性.当前网络安全面临巨大挑战,生物启发理论为该问题的解决提供一条新思路,但当前该领域的研究仅停留在人体内部系统--免疫系统上,无法建立完整的空间模型.首次依据生物系统安全机制的层次性、系统性和多网并行等特征,综合子网类型、群体规模和时序阶段3个角度提出了基于"三网并行(three-net parallel, TNP)"结构的生物启发多维网络安全模型(bio-inspired multidimensional network security model, BMNSM).首先提取网络与生物系统安全运行机制的拟合点,建立BMNSM概念模型;然后在状态分析抽象的基础上,证明模型的线性状态空间特性,验证其完备性、可行性;最后依据Markov平稳分布理论,定量比较 TNP结构优化实现模式的平稳性,验证了BMNSM的优良性能.

  12. A New Multi-Dimensional General Relativistic Neutrino Hydrodynamics Code of Core-Collapse Supernovae III. Gravitational Wave Signals from Supernova Explosion Models

    CERN Document Server

    Mueller, Bernhard; Marek, Andreas

    2012-01-01

    We present a detailed theoretical analysis of the gravitational-wave (GW) signal of the post-bounce evolution of core-collapse supernovae (SNe), employing for the first time relativistic, two-dimensional (2D) explosion models with multi-group, three-flavor neutrino transport based on the ray-by-ray-plus approximation. The waveforms reflect the accelerated mass motions associated with the characteristic evolutionary stages that were also identified in previous works: A quasi-periodic modulation by prompt postshock convection is followed by a phase of relative quiescence before growing amplitudes signal violent hydrodynamical activity due to convection and the standing accretion shock instability during the accretion period of the stalled shock. Finally, a high-frequency, low-amplitude variation from proto-neutron star (PNS) convection below the neutrinosphere appears superimposed on the low-frequency trend associated with the aspherical expansion of the SN shock after the onset of the explosion. Relativistic e...

  13. Disruptive behavior disorders: Multidimensional analysis

    Directory of Open Access Journals (Sweden)

    José Antonio López-Villalobos

    2012-01-01

    Full Text Available El estudio tiene como objetivo el análisis de la contribución de variables sociodemográficas, clínicas, familiares y académicas en la probabilidad de presentar trastorno de comportamiento perturbador (TC. Se utiliza un diseño ex post facto, retrospectivo, transversal, comparativo con dos grupos (casos de TC y controles clínicos. La muestra es incidental y consta de 1.847 casos clínicos, con edades comprendidas entre los 6 y 16 años. Casos y controles se han definido mediante entrevista clínica según criterios DSM-IV-TR. El procedimiento incluye una fase descriptiva y un método estimativo multivariable de regresión logística para dar respuesta al objetivo principal. El modelo de regresión logística propuesto es significativo y clasifica el 87,2% de los casos. Las variables sexo varón (OR = 1,82; p = 0,00, comorbilidad (OR = 7,68; p = 0,00, CI límite (OR = 3,15; p = 0,00, menor nivel educativo madres (OR = 1,57; p = 0,04 y repetir curso (OR = 2; p = 0,00 incrementan significativamente la probabilidad para TC. Las variables edad, antecedentes psiquiátricos, padres separados y educación de padres no resultan significativas en el modelo. El TC presenta asociación multidimensional con variables clínicas, académicas y familiares, susceptibles de inclusión en programas preventivos.

  14. Code Coupling for Multi-Dimensional Core Transient Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Woo; Park, Guen-Tae; Park, Min-Ho; Ryu, Seok-Hee; Um, Kil-Sup; Lee Jae-Il [KEPCO NF, Daejeon (Korea, Republic of)

    2015-05-15

    After the CEA ejection, the nuclear power of the reactor dramatically increases in an exponential behavior until the Doppler effect becomes important and turns the reactivity balance and power down to lower levels. Although this happens in a very short period of time, only few seconds, the energy generated can be very significant and cause fuel failures. The current safety analysis methodology which is based on overly conservative assumptions with the point kinetics model results in quite adverse consequences. Thus, KEPCO Nuclear Fuel(KNF) is developing the multi-dimensional safety analysis methodology to mitigate the consequences of the single CEA ejection accident. For this purpose, three-dimensional core neutron kinetics code ASTRA, sub-channel analysis code THALES, and fuel performance analysis code FROST, which have transient calculation performance, were coupled using message passing interface (MPI). This paper presents the methodology used for code coupling and the preliminary simulation results with the coupled code system (CHASER). Multi-dimensional core transient analysis code system, CHASER, has been developed and it was applied to simulate a single CEA ejection accident. CHASER gave a good prediction of multi-dimensional core transient behaviors during transient. In the near future, the multi-dimension CEA ejection analysis methodology using CHASER is planning to be developed. CHASER is expected to be a useful tool to gain safety margin for reactivity initiated accidents (RIAs), such as a single CEA ejection accident.

  15. Construct validity of multidimensional personality questionnaire (MPQ

    Directory of Open Access Journals (Sweden)

    Mitrović Dušanka

    2007-01-01

    Full Text Available The paper presents two studies aimed at the examination of the factor structure of The Multidimensional Personality Questionnaire (MPQ and joint factor structure of the scales of MPQ and SPSRQ (The Sensitivity to Punishment and Sensitivity to Reward Questionnaire. In the first research conducted on the sample of 1127 participants of both sexes, age 18 to 67, the results of the principal component analysis of the MPQ scales point to the existence of three higher-order dimensions, named General Adaptedness, Psychopathic Tendencies and Negative Emotionality. These dimensions correspond to the dimensions of the Eysenck’s PEN model to the greater extent than they achieve the assumed similarity with the dimensions of the Reinforcement Sensitivity Theory. In the second study conducted on the sample of 199 respondents of both sexes, age 18 to 59, the results of the joint principal component analysis of the MPQ and SPSRQ scales point to the existence of three higher order dimensions, which correspond to the Tellegen’s Positive Emotionality, Negative Emotionality, and Constraint. .

  16. Multidimensional gene set analysis of genomic data.

    Directory of Open Access Journals (Sweden)

    David Montaner

    Full Text Available Understanding the functional implications of changes in gene expression, mutations, etc., is the aim of most genomic experiments. To achieve this, several functional profiling methods have been proposed. Such methods study the behaviour of different gene modules (e.g. gene ontology terms in response to one particular variable (e.g. differential gene expression. In spite to the wealth of information provided by functional profiling methods, a common limitation to all of them is their inherent unidimensional nature. In order to overcome this restriction we present a multidimensional logistic model that allows studying the relationship of gene modules with different genome-scale measurements (e.g. differential expression, genotyping association, methylation, copy number alterations, heterozygosity, etc. simultaneously. Moreover, the relationship of such functional modules with the interactions among the variables can also be studied, which produces novel results impossible to be derived from the conventional unidimensional functional profiling methods. We report sound results of gene sets associations that remained undetected by the conventional one-dimensional gene set analysis in several examples. Our findings demonstrate the potential of the proposed approach for the discovery of new cell functionalities with complex dependences on more than one variable.

  17. Dynamics Modeling and Simplification of a 6-UPS Parallel Multi-dimensional Loading Device%6-UPS并联多维力加载装置的动力学建模及简化

    Institute of Scientific and Technical Information of China (English)

    刘少欣; 王丹; 陈五一

    2014-01-01

    By using Kane Equation,the dynamic characteristic of the multi-dimensional loading device was analyzed,and dy-namic mathematical model was established. Aimed at the different parameters of motion about the loading device,the effect of the grav-ity,inertial force and the Coriolis force in the dynamic model to the generalized force of system output was analyzed with simulation, under conditions of different acceleration and velocity. The results show that when the velocity or acceleration of the moving platform is within the working limits,the effect of the inertia force branch and the Coriolis force to the system is smaller than 2%,can be omitted, while the gravity of that is greater than 2%,can not. A simplified system dynamic model is gotten according to the analyzed results, which provides the theoretical basis for the control system of parallel device.%使用Kane方法对6-UPS并联机构多维力加载装置进行了动力学特性分析,并建立了动力学数学模型。针对该加载装置不同的运动参数,仿真分析了在不同速度及加速度条件下,动力学模型中惯性力、哥氏力和重力项对系统输出广义力的影响。结果表明:当动平台的速度或加速度在工作范围内,支链惯性力和哥氏力对系统影响小于2%,可以忽略,而重力影响大于2%,不可忽略。依据这一分析结果对系统动力学模型进行了简化,为并联机构的控制系统提供了理论依据。

  18. Genuinely Multidimensional Kinetic Scheme For Euler Equations

    CERN Document Server

    Tiwari, Praveer

    2015-01-01

    A new framework based on Boltzmann equation which is genuinely multidimensional and mesh-less is developed for solving Euler's equations. The idea is to use the method of moment of Boltzmann equation to operate in multidimensions using polar coordinates. The aim is to develop a framework which is genuinely multidimensional and can be implemented with different methodologies, no matter whether it is in finite difference, finite volume or finite element form. There is a considerable improvement in capturing shocks and other discontinuities. Also, since the method is multidimensional, the flow features are captured isotropically. The method is further extended to second order using 'Arc of Approach' concept. The framework is developed as a finite difference method (called as GINEUS) and is tested on the benchmark test cases. The results are compared against Kinetic Flux Vector Splitting Method.

  19. Multidimensional Convergence in Future 5G Networks

    Science.gov (United States)

    Ruffini, Marco

    2017-02-01

    Future 5G services are characterised by unprecedented need for high rate, ubiquitous availability, ultra-low latency and high reliability. The fragmented network view that is widespread in current networks will not stand the challenge posed by next generations of users. A new vision is required, and this paper provides an insight on how network convergence and application-centric approaches will play a leading role towards enabling the 5G vision. The paper, after expressing the view on the need for an end-to-end approach to network design, brings the reader into a journey on the expected 5G network requirements and outlines some of the work currently carried out by main standardisation bodies. It then proposes the use of the concept of network convergence for providing the overall architectural framework to bring together all the different technologies within a unifying and coherent network ecosystem. The novel interpretation of multi-dimensional convergence we introduce leads us to the exploration of aspects of node consolidation and converged network architectures, delving into details of optical-wireless integration and future convergence of optical data centre and access-metro networks. We then discuss how ownership models enabling network sharing will be instrumental in realising the 5G vision. The paper concludes with final remarks on the role SDN will play in 5G and on the need for new business models that reflect the application-centric view of the network. Finally, we provide some insight on growing research areas in 5G networking.

  20. Building dynamic thermal simulation of low-order multi-dimensional heat transfer

    Institute of Scientific and Technical Information of China (English)

    高岩; 范蕊; 张群力

    2014-01-01

    Multi-dimensional heat transfers modeling is crucial for building simulations of insulated buildings, which are widely used and have multi-dimensional heat transfers characteristics. For this work, state-model-reduction techniques were used to develop a reduced low-order model of multi-dimensional heat transfers. With hot box experiment of hollow block wall, heat flow relative errors between experiment and low-order model predication were less than 8%and the largest errors were less than 3%. Also, frequency responses of five typical walls, each with different thermal masses or insulation modes, the low-order model and the complete model showed that the low-order model results agree very well in the lower excitation frequency band with deviations appearing only at high frequency. Furthermore, low-order model was used on intersection thermal bridge of a floor slab and exterior wall. Results show that errors between the two models are very small. This low-order model could be coupled with most existing simulation software for different thermal mass envelope analyses to make up for differences between the multi-dimensional and one-dimensional models, simultaneously simplifying simulation calculations.

  1. Statistical image processing and multidimensional modeling

    CERN Document Server

    Fieguth, Paul

    2010-01-01

    Images are all around us! The proliferation of low-cost, high-quality imaging devices has led to an explosion in acquired images. When these images are acquired from a microscope, telescope, satellite, or medical imaging device, there is a statistical image processing task: the inference of something - an artery, a road, a DNA marker, an oil spill - from imagery, possibly noisy, blurry, or incomplete. A great many textbooks have been written on image processing. However this book does not so much focus on images, per se, but rather on spatial data sets, with one or more measurements taken over

  2. Conceptual Model of Multidimensional Marketing Information System

    Science.gov (United States)

    Kriksciuniene, Dalia; Urbanskiene, Ruta

    This article is aimed to analyse, why the information systems at the enterprise not always satisfy the expectations of marketing management specialists. The computerized systems more and more successfully serve information needs of those areas of enterprise management, where they can create the information equivalent of real management processes. Yet their inability to effectively fulfill marketing needs indicate the gaps not only in ability to structure marketing processes, but in the conceptual development of marketing information systems (MkIS) as well.

  3. Developments in multidimensional spatial data models

    CERN Document Server

    Abdul Rahman, Alias; Gold, Christopher; Said, Mohamad Nor

    2014-01-01

    This book presents the latest research developments in geoinformation science, including such sub-disciplines as geomatic engineering, GIS, remote sensing, digital photogrammetry, digital cartography and more.

  4. Advancing a multidimensional, developmental spectrum approach to preschool disruptive behavior.

    Science.gov (United States)

    Wakschlag, Lauren S; Briggs-Gowan, Margaret J; Choi, Seung W; Nichols, Sara R; Kestler, Jacqueline; Burns, James L; Carter, Alice S; Henry, David

    2014-01-01

    Dimensional approaches are gaining scientific traction. However, their potential for elucidating developmental aspects of psychopathology has not been fully realized. The goal of this article is to apply a multidimensional, developmental framework to model the normal-abnormal spectrum of preschool disruptive behavior. The Multidimensional Assessment of Preschool Disruptive Behavior (MAP-DB), a novel measure, was used to model dimensional severity across developmental parameters theorized to distinguish the normative misbehavior of early childhood from clinically salient disruptive behavior. The 4 MAP-DB dimensions are Temper Loss, Noncompliance, Aggression, and Low Concern for Others. Parents of a diverse sample of 1,488 preschoolers completed the MAP-DB. Multidimensional item response theory (IRT) was used for dimensional modeling. The 4-dimensional, developmentally informed model demonstrated excellent fit. Its factor loadings did not differ across demographic subgroups. All dimensions provided good coverage of the abnormal end of the severity continuum, but only Temper Loss and Noncompliance provided good coverage of milder, normatively occurring behaviors. The developmental expectability and quality of behaviors distinguished normative from atypical behaviors. The point at which frequency of behaviors was atypical varied based on dimensional location for Temper Loss, Noncompliance, and Aggression. The MAP-DB provides an innovative method for operationalizing developmentally specified, dimensional phenotypes in early childhood. Establishing the validity of these dimensional phenotypes in relation to clinical outcomes, neurocognitive substrates, and etiologic pathways will be a crucial test of their clinical utility. Copyright © 2014 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. Preface: Special Topic on Multidimensional Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mukamel, Shaul, E-mail: smukamel@uci.edu [Department of Chemistry, University of California, Irvine, Irvine, California 92697 (United States); Bakker, Huib J. [FOM Institute for Atomic and Molecular Physics, Amsterdam 1098 XG (Netherlands)

    2015-06-07

    Multidimensional signals are generated by subjecting molecules to sequences of short optical pulses and recording correlation plots related to the various controlled delay periods. These techniques which span all the way from the THz to the x-ray regimes provide qualitatively new structural and dynamical molecular information not available from conventional one-dimensional techniques. This issue surveys the recent experimental and theoretical progresses in this rapidly developing 20 year old field which illustrates the novel insights provided by multidimensional techniques into electronic and nuclear motions. It should serve as a valuable source for experts in the field and help introduce newcomers to this exciting and challenging branch of nonlinear spectroscopy.

  6. Preface: Special Topic on Multidimensional Spectroscopy

    Science.gov (United States)

    Mukamel, Shaul; Bakker, Huib J.

    2015-06-01

    Multidimensional signals are generated by subjecting molecules to sequences of short optical pulses and recording correlation plots related to the various controlled delay periods. These techniques which span all the way from the THz to the x-ray regimes provide qualitatively new structural and dynamical molecular information not available from conventional one-dimensional techniques. This issue surveys the recent experimental and theoretical progresses in this rapidly developing 20 year old field which illustrates the novel insights provided by multidimensional techniques into electronic and nuclear motions. It should serve as a valuable source for experts in the field and help introduce newcomers to this exciting and challenging branch of nonlinear spectroscopy.

  7. Manycore Performance-Portability: Kokkos Multidimensional Array Library

    Directory of Open Access Journals (Sweden)

    H. Carter Edwards

    2012-01-01

    Full Text Available Large, complex scientific and engineering application code have a significant investment in computational kernels to implement their mathematical models. Porting these computational kernels to the collection of modern manycore accelerator devices is a major challenge in that these devices have diverse programming models, application programming interfaces (APIs, and performance requirements. The Kokkos Array programming model provides library-based approach to implement computational kernels that are performance-portable to CPU-multicore and GPGPU accelerator devices. This programming model is based upon three fundamental concepts: (1 manycore compute devices each with its own memory space, (2 data parallel kernels and (3 multidimensional arrays. Kernel execution performance is, especially for NVIDIA® devices, extremely dependent on data access patterns. Optimal data access pattern can be different for different manycore devices – potentially leading to different implementations of computational kernels specialized for different devices. The Kokkos Array programming model supports performance-portable kernels by (1 separating data access patterns from computational kernels through a multidimensional array API and (2 introduce device-specific data access mappings when a kernel is compiled. An implementation of Kokkos Array is available through Trilinos [Trilinos website, http://trilinos.sandia.gov/, August 2011].

  8. Quantum and Multidimensional Explanations in a Neurobiological Context of Mind

    NARCIS (Netherlands)

    Korf, Jakob

    2015-01-01

    This article examines the possible relevance of physical-mathematical multidimensional or quantum concepts aiming at understanding the (human) mind in a neurobiological context. Some typical features of the quantum and multidimensional concepts are briefly introduced, including entanglement, superpo

  9. The emergence and evolution of the multidimensional organization

    NARCIS (Netherlands)

    Strikwerda, J.; Stoelhorst, J.W.

    2009-01-01

    The article discusses multidimensional organizations and the evolution of complex organizations. The six characteristics of multidimensional organizations, disadvantages of the successful organizational structure that is categorized as a multidivisional, multi-unit or M-form, research by the

  10. The emergence and evolution of the multidimensional organization

    NARCIS (Netherlands)

    Strikwerda, J.; Stoelhorst, J.W.

    2009-01-01

    The article discusses multidimensional organizations and the evolution of complex organizations. The six characteristics of multidimensional organizations, disadvantages of the successful organizational structure that is categorized as a multidivisional, multi-unit or M-form, research by the Foundat

  11. Nursing care systematization as a multidimensional and interactive phenomenon.

    Science.gov (United States)

    Backes, Dirce Stein; Koerich, Magda Santos; Nascimento, Keyla Cristiane do; Erdmann, Alacoque Lorenzini

    2008-01-01

    This study aimed to understand the meaning of Nursing Care Systematization (NCS) for multiprofessional health team professionals based on the relationships, interactions and associations of Complex thought. This qualitative study uses Grounded Theory as a methodological reference framework. Data were obtained through interviews with three sample groups, totaling 15 professionals from different institutions. Simultaneous data codification and analysis identified the central theme: 'Glimpsing nursing care systematization as an interactive and multidimensional phenomenon' and the respective reference model. NCS appoints, in addition to interactivity and professional complementarity, the importance of dialog and connection between the academy, health practices and regulatory offices, based on new reference frameworks for the organization of health practices.

  12. Overview of the BISON Multidimensional Fuel Performance Code

    Energy Technology Data Exchange (ETDEWEB)

    R. L. Williamson; J. D. Hales; S. R. Novascone; B. W. Spencer; D. M. Perez; G. Pastore; R. C. Martineau

    2013-10-01

    BISON is a modern multidimensional multiphysics finite-element based nuclear fuel performance code that has been under development at the Idaho National Laboratory (USA) since 2009. A brief background is provided on the code’s computational framework (MOOSE), governing equations, and material and behavioral models. Ongoing code verification and validation work is outlined, and comparative results are provided for select validation cases. Recent applications are discussed, including specific description of two applications where 3D treatment is important. A summary of future code development and validation activities is given. Numerous references to published work are provided where interested readers can find more complete information.

  13. MULTIDIMENSIONAL RELAXATION APPROXIMATIONS FOR HYPERBOLIC SYSTEMS OF CONSERVATION LAWS

    Institute of Scientific and Technical Information of China (English)

    Mohammed Sea(l)d

    2007-01-01

    We construct and implement a non-oscillatory relaxation scheme for multidimensional hyperbolic systems of conservation laws. The method transforms the nonlinear hyperbolic system to a semilinear model with a relaxation source term and linear characteristics which can be solved numerically without using either Riemann solver or linear iterations.To discretize the relaxation system we consider a high-resolution reconstruction in space and a TVD Runge-Kutta time integration. Detailed formulation of the scheme is given for problems in three space dimensions and numerical experiments are implemented in both scalar and system cases to show the effectiveness of the method.

  14. Multidimensional and multiscalar analisis of territorial rural development in Brazil

    Directory of Open Access Journals (Sweden)

    Sergio Schneider

    2013-09-01

    Full Text Available Of late, there have been several political, practical and analytical changes to our understanding of rural development. Diverse efforts have emerged in the analysis and discussion of spatial dynamics such as “rurality”, territories, in the construction of a territorial perspective of rural development. These changes in the forms of identification and measurement of rural development lead us to question the validity and effectiveness of applied methods, inviting us to establish methodologies and analytical criteria coherent with the multiple manifestations and scales of development. This article offers a multidimensional and multi-scalar analytical model for territorial rural development, using our methodology tested in four rural territories of Brazil.

  15. Web Data Cube Construction in Multidimensional On-line Analytical Processing Environment

    Institute of Scientific and Technical Information of China (English)

    ZHU Yan

    2007-01-01

    This paper investigates how to integrate Web data into a multidimensional data warehouse (cube) for comprehensive on-line analytical processing (OLAP) and decision making. An approach for Web data-based cube construction is proposed, which includes Web data modeling based on MIX (Metadata based Integration model for data X-change), generic and specific mapping rules design, and a transformation algorithm for mapping Web data to a multidimensional array. Besides, the structure and implementation of the prototype of a Web data base cube are discussed.

  16. Multidimensional Scaling Applied to Linguistic Relationships.

    Science.gov (United States)

    Black, Paul

    1973-01-01

    As the several specific applications in this paper demonstrate, multidimensional scaling provides a long-needed means for investigating and describing spatial relationships among speech varieties. It is especially applicable to the relationships among varieties of a single language (or more properly, linguistic "cline"), which, as is…

  17. A Multidimensional Construct of Self-Esteem

    Science.gov (United States)

    Norem-Hebeisen, Ardyth A.

    1976-01-01

    Evidence for construct validity of this multi-dimensional concept of self esteem includes the relative congruence of the factor structure with the theoretical construct, the stability of the structure when subjected to a series of empirical tests, increasingly positive self-referent responses with increasing age, willingness to become more…

  18. Alternative weighting structures for multidimensional poverty assessment

    NARCIS (Netherlands)

    Cavapozzi, Danilo; Han, Wei; Miniaci, Raffaele

    2013-01-01

    A multidimensional poverty assessment requires a weighting scheme to aggregate the well-being dimensions considered. We use Alkire and Foster’s (2011a) framework to discuss the channels through which a change of the weighting structure affects the outcomes of the analysis in terms of overall poverty

  19. Passive seismic interferometry by multidimensional deconvolution

    NARCIS (Netherlands)

    Wapenaar, C.P.A.; Van der Neut, J.R.; Ruigrok, E.N.

    2008-01-01

    We introduce seismic interferometry of passive data by multidimensional deconvolution (MDD) as an alternative to the crosscorrelation method. Interferometry by MDD has the potential to correct for the effects of source irregularity, assuming the first arrival can be separated from the full response.

  20. Optimal online bounded space multidimensional packing

    NARCIS (Netherlands)

    L. Epstein (Lea); R. van Stee (Rob)

    2003-01-01

    textabstractWe solve an open problem in the literature by providing an online algorithm for multidimensional bin packing that uses only bounded space. We show that it is optimal among bounded space algorithms for any dimension $d>1$. Its asymptotic performance ratio is $(Pi_{infty})^d$, where

  1. New bounds for multi-dimensional packing

    NARCIS (Netherlands)

    S. Seiden; R. van Stee (Rob)

    2001-01-01

    textabstractNew upper and lower bounds are presented for a multi-dimensional generalization of bin packing called box packing. Several variants of this problem, including bounded space box packing, square packing, variable sized box packing and resource augmented box packing are also studied. The

  2. Multidimensional wave field signal theory: Mathematical foundations

    Directory of Open Access Journals (Sweden)

    Natalie Baddour

    2011-06-01

    Full Text Available Many important physical phenomena are described by wave or diffusion-wave type equations. Since these equations are linear, it would be useful to be able to use tools from the theory of linear signals and systems in solving related forward or inverse problems. In particular, the transform domain signal description from linear system theory has shown concrete promise for the solution of problems that are governed by a multidimensional wave field. The aim is to develop a unified framework for the description of wavefields via multidimensional signals. However, certain preliminary mathematical results are crucial for the development of this framework. This first paper on this topic thus introduces the mathematical foundations and proves some important mathematical results. The foundation of the framework starts with the inhomogeneous Helmholtz or pseudo-Helmholtz equation, which is the mathematical basis of a large class of wavefields. Application of the appropriate multi-dimensional Fourier transform leads to a transfer function description. To return to the physical spatial domain, certain mathematical results are necessary and these are presented and proved here as six fundamental theorems. These theorems are crucial for the evaluation of a certain class of improper integrals which arise in the evaluation of inverse multi-dimensional Fourier and Hankel transforms, upon which the framework is based. Subsequently, applications of these theorems are demonstrated, in particular for the derivation of Green's functions in different coordinate systems.

  3. New bounds for multi-dimensional packing

    NARCIS (Netherlands)

    Seiden, S.; Stee, R. van

    2001-01-01

    New upper and lower bounds are presented for a multi-dimensional generalization of bin packing called box packing. Several variants of this problem, including bounded space box packing, square packing, variable sized box packing and resource augmented box packing are also studied. The main results,

  4. Multidimensional Treatment of Fear of Death.

    Science.gov (United States)

    Hoelter, Jon W.

    1979-01-01

    Presents a multidimensional conception of fear of death and provides subscales for measuring suggested dimensions (fear of the dying process, of the dead, of being destroyed, for significant others, of the unknown, of conscious death, for body after death, and of premature death). Evidence for construct validity is provided. (Author/BEF)

  5. Multidimensional perfectionism and narcissism: Grandiose or vulnerable?

    OpenAIRE

    Stoeber, Joachim; Sherry, Simon B.; Logan J Nealis

    2015-01-01

    Multidimensional perfectionism is related to grandiose narcissism, with other-oriented perfectionism showing the strongest, most consistent relationships. The relationships with vulnerable narcissism, however, are unclear. Our study investigated how three forms of perfectionism--self-oriented, other-oriented, and socially prescribed perfectionism (Hewitt & Flett, 1991)--are related to narcissistic grandiosity and vulnerability. A sample of 375 university students completed the Narcissistic Pe...

  6. Multi-dimensional quasitoeplitz Markov chains

    Directory of Open Access Journals (Sweden)

    Alexander N. Dudin

    1999-01-01

    Full Text Available This paper deals with multi-dimensional quasitoeplitz Markov chains. We establish a sufficient equilibrium condition and derive a functional matrix equation for the corresponding vector-generating function, whose solution is given algorithmically. The results are demonstrated in the form of examples and applications in queues with BMAP-input, which operate in synchronous random environment.

  7. Visualizing multidimensional data similarities : Improvements and applications

    NARCIS (Netherlands)

    Rodrigues Oliveira da Silva, Renato

    2016-01-01

    Multidimensional data is increasingly more prominent and important in many application domains. Such data typically consist of a large set of elements, each of which described by several measurements (dimensions). During the design of techniques and tools to process this data, a key component is to

  8. Alternative weighting structures for multidimensional poverty assessment

    NARCIS (Netherlands)

    Cavapozzi, Danilo; Han, Wei; Miniaci, Raffaele

    2013-01-01

    A multidimensional poverty assessment requires a weighting scheme to aggregate the well-being dimensions considered. We use Alkire and Foster’s (2011a) framework to discuss the channels through which a change of the weighting structure affects the outcomes of the analysis in terms of overall poverty

  9. A combined multidimensional scaling and hierarchical clustering view for the exploratory analysis of multidimensional data

    Science.gov (United States)

    Craig, Paul; Roa-Seïler, Néna

    2013-01-01

    This paper describes a novel information visualization technique that combines multidimensional scaling and hierarchical clustering to support the exploratory analysis of multidimensional data. The technique displays the results of multidimensional scaling using a scatter plot where the proximity of any two items' representations is approximate to their similarity according to a Euclidean distance metric. The results of hierarchical clustering are overlaid onto this view by drawing smoothed outlines around each nested cluster. The difference in similarity between successive cluster combinations is used to colour code clusters and make stronger natural clusters more prominent in the display. When a cluster or group of items is selected, multidimensional scaling and hierarchical clustering are re-applied to a filtered subset of the data, and animation is used to smooth the transition between successive filtered views. As a case study we demonstrate the technique being used to analyse survey data relating to the appropriateness of different phrases to different emotionally charged situations.

  10. Multi-dimensional Gain Scheduling with Application to Power Plant Control

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Stoustrup, Jakob; Trangbæk, Klaus

    2003-01-01

    This paper deals with gain scheduling control of a power plant model, which is an example of a multi-dimensional nonlinear system. Linear observer-based controllers are designed for a number of linear approximations of the system model in a set of operating points, and gain-scheduling control can...

  11. Variations of $\\alpha$ and $G$ from nonlinear multidimensional gravity

    CERN Document Server

    Bronnikov, K A

    2013-01-01

    To explain the recently reported large-scale spatial variations of the fine structure constant $\\alpha$, we apply some models of curvature-nonlinear multidimensional gravity. Under the reasonable assumption of slow changes of all quantities as compared with the Planck scale, the original theory reduces to a multi-scalar field theory in four dimensions. On this basis, we consider different variants of isotropic cosmological models in both Einstein and Jordan conformal frames. One of the models turns out to be equally viable in both frames, but in the Jordan frame the model predicts simultaneous variations of $\\alpha$ and the gravitational constant $G$, equal in magnitude. Large-scale small inhomogeneous perturbations of these models allow for explaining the observed spatial distribution of $\\alpha$ values.

  12. On the monotonicity of multidimensional finite difference schemes

    Science.gov (United States)

    Kovyrkina, O.; Ostapenko, V.

    2016-10-01

    The classical concept of monotonicity, introduced by Godunov for linear one-dimensional difference schemes, is extended to multidimensional case. Necessary and sufficient conditions of monotonicity are obtained for linear multidimensional difference schemes of first order. The constraints on the numerical viscosity are given that ensure the monotonicity of a difference scheme in the multidimensional case. It is proposed a modification of the second order multidimensional CABARET scheme that preserves the monotonicity of one-dimensional discrete solutions and, as a result, ensures higher smoothness in the computation of multidimensional discontinuous solutions. The results of two-dimensional test computations illustrating the advantages of the modified CABARET scheme are presented.

  13. Multidimensional Analysis of Nuclear Detonations

    Science.gov (United States)

    2015-09-17

    Sensing Image Generation model and validation using historic thermal output data in combination with a 1-dimensional heat flux technique. This same...40 Thermal Yield Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 3.4...Plate Image . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 12. Difference in Scans (Minutes Apart

  14. Cosmology in nonlinear multidimensional gravity and the Casimir effect

    Science.gov (United States)

    Bolokhov, S. V.; Bronnikov, K. A.

    2017-01-01

    We study the possible cosmological models in Kaluza-Klein-type multidimensional gravity with a curvature-nonlinear Lagrangian and a spherical extra space, taking into account the Casimir energy. First, we find a minimum of the effective potential of extra dimensions, leading to a physically reasonable value of the effective cosmological constant in our 4D space-time. In this model, the huge Casimir energy density is compensated by a fine-tuned contribution of the curvature-nonlinear terms in the original action. Second, we present a viable model with slowly evolving extra dimensions and power-law inflation in our space-time. In both models, the results formulated in Einstein and Jordan frames are compared.

  15. The reliability of multidimensional neuropsychological measures: from alpha to omega.

    Science.gov (United States)

    Watkins, Marley W

    2017-04-21

    To demonstrate that Coefficient omega, a model-based estimate, is more a more appropriate index of reliability than coefficient alpha for the multidimensional scales that are commonly employed by neuropsychologists. As an illustration, a structural model of an overarching general factor and four first-order factors for the WAIS-IV based on the standardization sample of 2200 participants was identified and omega coefficients were subsequently computed for WAIS-IV composite scores. Alpha coefficients were ≥ .90 and omega coefficients ranged from .75 to .88 for WAIS-IV factor index scores, indicating that the blend of general and group factor variance in each index score created a reliable multidimensional composite. However, the amalgam of variance from general and group factors did not allow the precision of Full Scale IQ (FSIQ) and factor index scores to be disentangled. In contrast, omega hierarchical coefficients were low for all four factor index scores (.10-.41), indicating that most of the reliable variance of each factor index score was due to the general intelligence factor. In contrast, the omega hierarchical coefficient for the FSIQ score was .84. Meaningful interpretation of WAIS-IV factor index scores as unambiguous indicators of group factors is imprecise, thereby fostering unreliable identification of neurocognitive strengths and weaknesses, whereas the WAIS-IV FSIQ score can be interpreted as a reliable measure of general intelligence. It was concluded that neuropsychologists should base their clinical decisions on reliable scores as indexed by coefficient omega.

  16. Multidimensional entropy landscape of quantum criticality

    Science.gov (United States)

    Grube, K.; Zaum, S.; Stockert, O.; Si, Q.; Löhneysen, H. V.

    2017-08-01

    The third law of thermodynamics states that the entropy of any system in equilibrium has to vanish at absolute zero temperature. At nonzero temperatures, on the other hand, matter is expected to accumulate entropy near a quantum critical point, where it undergoes a continuous transition from one ground state to another. Here, we determine, based on general thermodynamic principles, the spatial-dimensional profile of the entropy S near a quantum critical point and its steepest descent in the corresponding multidimensional stress space. We demonstrate this approach for the canonical quantum critical compound CeCu 6-xAux near its onset of antiferromagnetic order. We are able to link the directional stress dependence of S to the previously determined geometry of quantum critical fluctuations. Our demonstration of the multidimensional entropy landscape provides the foundation to understand how quantum criticality nucleates novel phases such as high-temperature superconductivity.

  17. Multidimensional integral representations problems of analytic continuation

    CERN Document Server

    Kytmanov, Alexander M

    2015-01-01

    The monograph is devoted to integral representations for holomorphic functions in several complex variables, such as Bochner-Martinelli, Cauchy-Fantappiè, Koppelman, multidimensional logarithmic residue etc., and their boundary properties. The applications considered are problems of analytic continuation of functions from the boundary of a bounded domain in C^n. In contrast to the well-known Hartogs-Bochner theorem, this book investigates functions with the one-dimensional property of holomorphic extension along complex lines, and includes the problems of receiving multidimensional boundary analogs of the Morera theorem.   This book is a valuable resource for specialists in complex analysis, theoretical physics, as well as graduate and postgraduate students with an understanding of standard university courses in complex, real and functional analysis, as well as algebra and geometry.

  18. Cuba - a library for multidimensional numerical integration

    CERN Document Server

    Hahn, T

    2004-01-01

    The Cuba library provides new implementations of four general-purpose multidimensional integration algorithms: Vegas, Suave, Divonne, and Cuhre. Suave is a new algorithm, Divonne is a known algorithm to which important details have been added, and Vegas and Cuhre are new implementations of existing algorithms with only few improvements over the original versions. All four algorithms can integrate vector integrands and have very similar Fortran, C/C++, and Mathematica interfaces.

  19. Multidimensional Scaling Visualization using Parametric Similarity Indices

    OpenAIRE

    Tenreiro Machado, J. A.; António M. Lopes; Alexandra M. Galhano

    2015-01-01

    In this paper, we apply multidimensional scaling (MDS) and parametric similarity indices (PSI) in the analysis of complex systems (CS). Each CS is viewed as a dynamical system, exhibiting an output time-series to be interpreted as a manifestation of its behavior. We start by adopting a sliding window to sample the original data into several consecutive time periods. Second, we define a given PSI for tracking pieces of data. We then compare the windows for different values of the parameter, an...

  20. New bounds for multi-dimensional packing

    OpenAIRE

    Seiden, S.; Stee, van, Rob

    2001-01-01

    New upper and lower bounds are presented for a multi-dimensional generalization of bin packing called box packing. Several variants of this problem, including bounded space box packing, square packing, variable sized box packing and resource augmented box packing are also studied. The main results, stated for d=2, are as follows: A new upper bound of 2.66013 for online box packing, a new $14/9 + varepsilon$ polynomial time offline approximation algorithm for square packing, a new upper bound ...