Systems analysis programs for hands-on integrated reliability evaluations (SAPHIRE), Version 5.0

International Nuclear Information System (INIS)

Russell, K.D.; Kvarfordt, K.J.; Hoffman, C.L.

1995-10-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The Graphical Evaluation Module (GEM) is a special application tool designed for evaluation of operational occurrences using the Accident Sequence Precursor (ASP) program methods. GEM provides the capability for an analyst to quickly and easily perform conditional core damage probability (CCDP) calculations. The analyst can then use the CCDP calculations to determine if the occurrence of an initiating event or a condition adversely impacts safety. It uses models and data developed in the SAPHIRE specially for the ASP program. GEM requires more data than that normally provided in SAPHIRE and will not perform properly with other models or data bases. This is the first release of GEM and the developers of GEM welcome user comments and feedback that will generate ideas for improvements to future versions. GEM is designated as version 5.0 to track GEM codes along with the other SAPHIRE codes as the GEM relies on the same, shared database structure

Simulation of the beam guiding of the SAPHIR experiment by means of a differential-equation model

International Nuclear Information System (INIS)

Greve, T.

1991-08-01

This paper shows the numerical simulation of a beam line by means of a model of differential equations simulating the beam line from the Bonn Electron Stretcher Accelerator ELSA to the SAPHIR spectrometer. Furthermore a method for calculating the initial values based on measurements of beam profiles is being discussed. (orig.) [de

SAPHIRE 8 Volume 2 - Technical Reference

Energy Technology Data Exchange (ETDEWEB)

C. L. Smith; S. T. Wood; W. J. Galyean; J. A. Schroeder; M. B. Sattison

2011-03-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of computer programs that were developed to create and analyze probabilistic risk assessment (PRAs). Herein information is provided on the principles used in the construction and operation of Version 8.0 of the SAPHIRE system. This report summarizes the fundamental mathematical concepts of sets and logic, fault trees, and probability. This volume then describes the algorithms used to construct a fault tree and to obtain the minimal cut sets. It gives the formulas used to obtain the probability of the top event from the minimal cut sets, and the formulas for probabilities that apply for various assumptions concerning reparability and mission time. It defines the measures of basic event importance that SAPHIRE can calculate. This volume gives an overview of uncertainty analysis using simple Monte Carlo sampling or Latin Hypercube sampling, and states the algorithms used by this program to generate random basic event probabilities from various distributions. Also covered are enhance capabilities such as seismic analysis, Workspace algorithms, cut set "recovery," end state manipulation, and use of "compound events."

Systems analysis programs for Hands-on integrated reliability evaluations (SAPHIRE) Version 5.0: Verification and validation (V ampersand V) manual. Volume 9

International Nuclear Information System (INIS)

Jones, J.L.; Calley, M.B.; Capps, E.L.; Zeigler, S.L.; Galyean, W.J.; Novack, S.D.; Smith, C.L.; Wolfram, L.M.

1995-03-01

A verification and validation (V ampersand V) process has been performed for the System Analysis Programs for Hands-on Integrated Reliability Evaluation (SAPHIRE) Version 5.0. SAPHIRE is a set of four computer programs that NRC developed for performing probabilistic risk assessments. They allow an analyst to perform many of the functions necessary to create, quantify, and evaluate the risk associated with a facility or process being analyzed. The programs are Integrated Reliability and Risk Analysis System (IRRAS) System Analysis and Risk Assessment (SARA), Models And Results Database (MAR-D), and Fault tree, Event tree, and Piping and instrumentation diagram (FEP) graphical editor. Intent of this program is to perform a V ampersand V of successive versions of SAPHIRE. Previous efforts have been the V ampersand V of SAPHIRE Version 4.0. The SAPHIRE 5.0 V ampersand V plan is based on the SAPHIRE 4.0 V ampersand V plan with revisions to incorporate lessons learned from the previous effort. Also, the SAPHIRE 5.0 vital and nonvital test procedures are based on the test procedures from SAPHIRE 4.0 with revisions to include the new SAPHIRE 5.0 features as well as to incorporate lessons learned from the previous effort. Most results from the testing were acceptable; however, some discrepancies between expected code operation and actual code operation were identified. Modifications made to SAPHIRE are identified

Nucleonic calculations for possible irradiation experiments in SAPHIR

International Nuclear Information System (INIS)

Caro, M.; Pelloni, S.

1990-01-01

Accurate two-dimensional calculations show that a 'neutronic environment' exists in the SAPHIR reactor at the Paul Scherrer Institute (PSI) to simulate the inner surface of a given trepan of the Gundremmingen reactor. Neutron fluences and DPA rates were calculated at two positions in SAPHIR using the modern codes and nuclear data (from JEF-1). A particular region of the reactor can be found in which fluences and DPA rates agree well within a few percent with the Gundremmingen reference case. (author) 13 figs., 4 tabs., 18 refs

Key attributes of the SAPHIRE risk and reliability analysis software for risk-informed probabilistic applications

International Nuclear Information System (INIS)

Smith, Curtis; Knudsen, James; Kvarfordt, Kellie; Wood, Ted

2008-01-01

The Idaho National Laboratory is a primary developer of probabilistic risk and reliability analysis (PRRA) tools, dating back over 35 years. Evolving from mainframe-based software, the current state-of-the-practice has led to the creation of the SAPHIRE software. Currently, agencies such as the Nuclear Regulatory Commission, the National Aeronautics and Aerospace Agency, the Department of Energy, and the Department of Defense use version 7 of the SAPHIRE software for many of their risk-informed activities. In order to better understand and appreciate the power of software as part of risk-informed applications, we need to recall that our current analysis methods and solution methods have built upon pioneering work done 30-40 years ago. We contrast this work with the current capabilities in the SAPHIRE analysis package. As part of this discussion, we provide information for both the typical features and special analysis capabilities, which are available. We also present the application and results typically found with state-of-the-practice PRRA models. By providing both a high-level and detailed look at the SAPHIRE software, we give a snapshot in time for the current use of software tools in a risk-informed decision arena

The atmosphere simulation chamber SAPHIR: a tool for the investigation of photochemistry.

Science.gov (United States)

Brauers, T.; Bohn, B.; Johnen, F.-J.; Rohrer, R.; Rodriguez Bares, S.; Tillmann, R.; Wahner, A.

2003-04-01

On the campus of the Forschungszentrum Jülich we constructed SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) which was accomplished in fall 2001. The chamber consists of a 280-m^3 double-wall Teflon bag of cylindrical shape that is held by a steel frame. Typically 75% of the outside actinic flux (290~nm~--~420~nm) is available inside the chamber. A louvre system allows switching between full sun light and dark within 40 s giving the opportunity to study relaxation processes of the photo chemical system. The SAPHIR chamber is equipped with a comprehensive set of sensitive instruments including the measurements of OH, HO_2, CO, hydrocarbons, aldehydes, nitrogen-oxides and solar radiation. Moreover, the modular concept of SAPHIR allows fast and flexible integration of new instruments and techniques. In this paper we will show the unique and new features of the SAPHIR chamber, namely the clean air supply and high purity water vapor supply providing a wide range of trace gas concentrations being accessible through the experiments. We will also present examples from the first year of SAPHIR experiment showing the scope of application from high quality instrument inter-comparison and kinetic studies to the simulation of complex mixtures of trace gases at ambient concentrations.

Development of the software of the data taking system SOS for the SAPHIR experiment. Entwicklung der Software des Datennahmesystems SOS fuer das SAPHIR-Experiment

Energy Technology Data Exchange (ETDEWEB)

Manns, J.

1989-02-01

The data acquistion system SOS has been developed for the SAPHIR experiment at the Bonn stretcher ring ELSA. It can handle up to 280 kilobytes of data per second or a maximum triggerrate of 200 Hz. The multiprocessor based online system consists of twenty VIP-microprocessors and two VAX-computers. Each component of the SAPHIR experiment has at least one program in the online system to maintain special functions for this specific component. All of these programs can receive event data without interfering with the transfer of events to a mass storage for offline analysis. A special program SOL has been developed to serve as a user interface to the data acquisition system and as a status display for most of the programs of the online system. Using modern features like windowing and mouse control on a VAX-station the SAPHIR online SOL establishes an easy way of controlling the data acquisition system. (orig.).

Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) Quality Assurance Manual

Energy Technology Data Exchange (ETDEWEB)

C. L. Smith; R. Nims; K. J. Kvarfordt; C. Wharton

2008-08-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) is a software application developed for performing a complete probabilistic risk assessment using a personal computer running the Microsoft Windows operating system. SAPHIRE is primarily funded by the U.S. Nuclear Regulatory Commission (NRC). The role of the INL in this project is that of software developer and tester. This development takes place using formal software development procedures and is subject to quality assurance (QA) processes. The purpose of this document is to describe how the SAPHIRE software QA is performed for Version 6 and 7, what constitutes its parts, and limitations of those processes.

The scintillation counter system at the SAPHIR detector

International Nuclear Information System (INIS)

Bour, D.

1989-10-01

The scintillation-counters system of the SAPHIR-detector at the stretcher accelerator ELSA in Bonn consists of 64 counters. It supplies a fast hadronic trigger and is utilizised for the particle identification by time of flight measurements. Prototypes of the counters (340x21.25 x 6.0 cm 3 ) had been tested. The contribution to the resolution of the time of flight measurement was measured to σ=125 ps, the effective light velocity to 17.5 ns/cm and the attenuation length of 7.8 m. A pion kaon separation is possible up to a momentum of 1 GeV/c with time of flight measurement. With the first photon-beam at SAPHIR the counters were tested, first triggers were obtained and evaluated. (orig.) [de

The trigger and data acquisition system of the SAPHIR detector

International Nuclear Information System (INIS)

Honscheid, K.

1988-10-01

At present SAPHIR, a new experimental facility for medium energy physics is under construction at the Bonn electron accelerator ELSA (energy ≤ 3.5 GeV, duty cycle ≅ 100%). SAPHIR combines a large solid angle coverage with a tagging system and is therefore suited to investigate reactions with multi-particle final states. Structure and function of the multi-stage trigger system, which is used to select such processes, are described in this paper. With this system the trigger decision can be based on the number of charged particles as well as on the number of neutral particle detected. Several VMEbus modules have been developed, using memory look-up tables to make fast trigger decisions possible. In order to determine the number of neutral particles from the cluster distribution in the electromagnetic calorimeter some ideas of cellular had to be added. The system has a modular structure, so it can easily be extended. In the second part of this thesis the SAPHIR data acquisition system is discussed. It consists of a multiprocessor system with the VIP microcomputer as central element. The VIP is a VMEbus modul optimized for a multiprocessor environment. Its description as well as that of the other VMEbus boards developed for the SAPHIR online system can be found in this paper. As a basis for software development the operating system SOS is supplied. With SOS it is possible to write programs independent of the actual hardware configuration and so the complicated multiprocessor environment is hidden. To the user the system looks like a simple multi-tasking system. SOS is not restricted to the VIPs but can also be installed on computers of the VAX family, so that efficient mixed configurations are possible. The SAPHIR online system, based on the VIP microcomputer and the SOS operating system, is presented in the last part of this paper. This includes the read-out system, the monitoring of the different components etc. (orig./HSI) [de

SAPHIRE6.64, System Analysis Programs for Hands-on Integrated Reliability

International Nuclear Information System (INIS)

2001-01-01

1 - Description of program or function: SAPHIRE is a collection of programs developed for the purpose of performing those functions necessary to create and analyze a complete Probabilistic Risk Assessment (PRA) primarily for nuclear power plants. The programs included in this suite are the Integrated Reliability and Risk Analysis System (IRRAS), the System Analysis and Risk Assessment (SARA) system, the Models And Results Database (MAR-D) system, and the Fault tree, Event tree and P and ID (FEP) editors. Previously these programs were released as separate packages. These programs include functions to allow the user to create event trees and fault trees, to define accident sequences and basic event failure data, to solve system and accident sequence fault trees, to quantify cut sets, and to perform uncertainty analysis on the results. Also included in this program are features to allow the analyst to generate reports and displays that can be used to document the results of an analysis. Since this software is a very detailed technical tool, the user of this program should be familiar with PRA concepts and the methods used to perform these analyses. 2 - Methods: SAPHIRE is written in MODULA-2 and uses an integrated commercial graphics package to interactively construct and edit fault trees. The fault tree solving methods used are industry recognized top down algorithms. For quantification, the program uses standard methods to propagate the failure information through the generated cut sets. SAPHIRE includes a separate module called the Graphical Evaluation Module (GEM). GEM provides a highly specialized user interface with SAPHIRE which automates the process for evaluating operational events at commercial nuclear power plants. Using GEM an analyst can estimate the risk associated with operational events (that is, perform a Level 1, Level 2, and Level 3 analysis for operational events) in a very efficient and expeditious manner. This on-line reference guide will

Development and verification of a leningrad NPP unit 1 living PSA model in the INL SAPHIRE code format for prompt operational safety level monitoring

International Nuclear Information System (INIS)

Bronislav, Vinnikov

2007-01-01

The first part of the paper presents results of the work, that was carried out in complete conformity with the Technical Assignment, which was developed by the Leningrad Nuclear Power Plant. The initial scientific and technical information, contained into the In-Depth Safety Assessment Reports, was given to the author of the work. This information included graphical Fault Trees of Safety Systems and Auxiliary Technical Systems, Event Trees for the necessary number of Initial Events, and also information about failure probabilities of basic components of the nuclear unit. On the basis of this information and fueling it to the Usa Idaho National Laboratory (INL) SAPHIRE code, we have developed an electronic version of the Data Base for failure probabilities of the components of technical systems. Then, we have developed both the electronic versions of the necessary Fault Trees, and an electronic versions of the necessary Event Trees. And at last, we have carried out the linkage of the Event Trees. This work has resulted in the Living PSA (LPSA - Living Probabilistic Safety Assessment) Model of the Leningrad NPP Unit 1. The LPSA-model is completely adapted to be consistent with the USA INL SAPHIRE Risk Monitor. The second part of the paper results in analysis of fire consequences in various places of Leningrad NPP Unit 1. The computations were carried out with the help of the LPSA-model, developed in SAPHIRE code format. On the basis of the computations the order of priority of implementation of fire prevention measures was established. (author)

Characterisation of the photolytic HONO-source in the atmosphere simulation chamber SAPHIR

Directory of Open Access Journals (Sweden)

F. Rohrer

2005-01-01

Full Text Available HONO formation has been proposed as an important OH radical source in simulation chambers for more than two decades. Besides the heterogeneous HONO formation by the dark reaction of NO2 and adsorbed water, a photolytic source has been proposed to explain the elevated reactivity in simulation chamber experiments. However, the mechanism of the photolytic process is not well understood so far. As expected, production of HONO and NOx was also observed inside the new atmospheric simulation chamber SAPHIR under solar irradiation. This photolytic HONO and NOx formation was studied with a sensitive HONO instrument under reproducible controlled conditions at atmospheric concentrations of other trace gases. It is shown that the photolytic HONO source in the SAPHIR chamber is not caused by NO2 reactions and that it is the only direct NOy source under illuminated conditions. In addition, the photolysis of nitrate which was recently postulated for the observed photolytic HONO formation on snow, ground, and glass surfaces, can be excluded in the chamber. A photolytic HONO source at the surface of the chamber is proposed which is strongly dependent on humidity, on light intensity, and on temperature. An empirical function describes these dependencies and reproduces the observed HONO formation rates to within 10%. It is shown that the photolysis of HONO represents the dominant radical source in the SAPHIR chamber for typical tropospheric O3/H2O concentrations. For these conditions, the HONO concentrations inside SAPHIR are similar to recent observations in ambient air.

Verification and validation of the SAPHIRE Version 4.0 PRA software package

International Nuclear Information System (INIS)

Bolander, T.W.; Calley, M.B.; Capps, E.L.

1994-02-01

A verification and validation (V ampersand V) process has been performed for the System Analysis Programs for Hands-on Integrated Reliability Evaluation (SAPHIRE). SAPHIRE is a set of four computer programs that the Nuclear Regulatory Commission (NRC) developed to perform probabilistic risk assessments (PRAs). These programs allow an analyst to create, quantify, and evaluate the risk associated with a facility or process being analyzed. The programs included in this set are Integrated Reliability and Risk Analysis System (IRRAS), System Analysis and Risk Assessment (SARA), Models and Results Database (MAR-D), and Fault Tree/Event Tree/Piping and Instrumentation Diagram (FEP) graphical editor. The V ampersand V steps included a V ampersand V plan to describe the process and criteria by which the V ampersand V would be performed; a software requirements documentation review to determine the correctness, completeness, and traceability of the requirements; a user survey to determine the usefulness of the user documentation, identification and testing of vital and non-vital features, and documentation of the test results

Design and construction of the SAPHIR detector

International Nuclear Information System (INIS)

Schwille, W.J.; Bockhorst, M.; Burbach, G.; Burgwinkel, R.; Empt, J.; Guse, B.; Haas, K.M.; Hannappel, J.; Heinloth, K.; Hey, T.; Honscheid, K.; Jahnen, T.; Jakob, H.P.; Joepen, N.; Juengst, H.; Kirch, U.; Klein, F.J.; Kostrewa, D.; Lindemann, L.; Link, J.; Manns, J.; Menze, D.; Merkel, H.; Merkel, R.; Neuerburg, W.; Paul, E.; Ploetzke, R.; Schenk, U.; Schmidt, S.; Scholmann, J.; Schuetz, P.; Schultz-Coulon, H.C.; Schweitzer, M.; Tran, M.Q.; Vogl, W.; Wedemeyer, R.; Wehnes, F.; Wisskirchen, J.; Wolf, A.

1994-01-01

The design, construction, and performance of the large solid angle magnetic spectrometer SAPHIR is described. It was built for the investigation of photon-induced reactions on nucleous and light nuclei with mulit-particle final states up to photon energies of 3.1 GeV. The detector is equipped with a tagged photon beam facility and is operated at the stretcher ring ELSA in Bonn. (orig.)

Design and construction of the SAPHIR detector

Energy Technology Data Exchange (ETDEWEB)

Schwille, W.J. (Bonn Univ. (Germany). Physikalisches Inst.); Bockhorst, M. (Bonn Univ. (Germany). Physikalisches Inst.); Burbach, G. (Bonn Univ. (Germany). Physikalisches Inst.); Burgwinkel, R. (Bonn Univ. (Germany). Physikalisches Inst.); Empt, J. (Bonn Univ. (Germany). Physikalisches Inst.); Guse, B. (Bonn Univ. (Germany). Physikalisches Inst.); Haas, K.M. (Bonn Univ. (Germany). Physikalisches Inst.); Hannappel, J. (Bonn Univ. (Germany). Physikalisches Inst.); Heinloth, K. (Bonn Univ. (Germany). Physikalisches Inst.); Hey, T. (Bonn Univ. (Germany). Physikalisches Inst.); Honscheid, K. (Bonn Univ. (Germany). Physikalisches Inst.); Jahnen, T. (Bonn Univ. (Germany). Physikalisches Inst.); Jakob, H.P. (Bonn Univ. (Germany). Physikalisches Inst.); Joepen, N. (Bonn Univ. (Germany). Physikalisches Inst.); Juengst, H. (Bonn Univ. (Germany). Physikalisches Inst.); Kirch, U. (Bonn Univ. (Germany). Physikalisches Inst.); Klein, F.J. (Bonn Univ. (Germany). Physikalisches Inst.)

1994-05-15

The design, construction, and performance of the large solid angle magnetic spectrometer SAPHIR is described. It was built for the investigation of photon-induced reactions on nucleous and light nuclei with mulit-particle final states up to photon energies of 3.1 GeV. The detector is equipped with a tagged photon beam facility and is operated at the stretcher ring ELSA in Bonn. (orig.)

Development of the software of the data taking system SOS for the SAPHIR experiment

International Nuclear Information System (INIS)

Manns, J.

1989-02-01

The data acquistion system SOS has been developed for the SAPHIR experiment at the Bonn stretcher ring ELSA. It can handle up to 280 kilobytes of data per second or a maximum triggerrate of 200 Hz. The multiprocessor based online system consists of twenty VIP-microprocessors and two VAX-computers. Each component of the SAPHIR experiment has at least one program in the online system to maintain special functions for this specific component. All of these programs can receive event data without interfering with the transfer of events to a mass storage for offline analysis. A special program SOL has been developed to serve as a user interface to the data acquisition system and as a status display for most of the programs of the online system. Using modern features like windowing and mouse control on a VAX-station the SAPHIR online SOL establishes an easy way of controlling the data acquisition system. (orig.)

Independent Verification and Validation SAPHIRE Version 8 Final Report Project Number: N6423 U.S. Nuclear Regulatory Commission

Energy Technology Data Exchange (ETDEWEB)

Kent Norris

2010-04-01

This report provides an evaluation of the SAPHIRE version 8 software product. SAPHIRE version 8 is being developed with a phased or cyclic iterative rapid application development methodology. Due to this approach, a similar approach has been taken for the IV&V activities on each vital software object. IV&V and Software Quality Assurance (SQA) activities occur throughout the entire development life cycle and therefore, will be required through the full development of SAPHIRE version 8. Later phases of the software life cycle, the operation and maintenance phases, are not applicable in this effort since the IV&V is being done prior to releasing Version 8.

The photon detection system of the SAPHIR spectrometer

International Nuclear Information System (INIS)

Joepen, N.

1990-09-01

Worldwide a new generation of Electron Accelerators with energies below 5 GeV and a high duty cycle up to 100% is being built or planned. The first machine of this kind is ELSA, the Electron Stretcher and Accelerator, at the Physics Institute of Bonn University. Due to the high duty cycle of ELSA, experiments with tagged photon beams and a large angular acceptance become possible. At present SAPHIR, a new magnetic detector, especially layed out to detect multi-particle final states with good accuracy, is going into operation. Besides a large arrangement of drift chambers, for a good momentum resolution, and a trigger- and time-of-flight counter system, for particle identification, one of the main features of SAPHIR is a good photon detection capability. This is accomplished by a large electromagnetic calorimeter consisting of 98 modules covering a detection area of about 16 m 2 in forward direction. For the calorimeter a brass-gas-sandwich detector was developed. Its signal wires are strung perpendicular to the converter planes. The chambers are filled with a standard gas mixture Ar/CH 4 (90:10) at atmospheric pressure and operated with a considerably high voltage in the semi-proportional mode. A sample of nine shower counter modules was tested at the electron test beam of the Bonn 2.5 GeV electron synchrotron. An energy resolution of σ(E)/(E*√E(GeV)) = 13.55 ± 0.6% for a single module was achieved. The incident angle of the electrons was varied between 0 and 45 degrees. No significant change of energy resolution and linearity was observed. Combining the information from wire and cathode signals a position resolution (E = 1 GeV:Φ=0deg → σ = 15 mm, Φ=45deg → σ x = 19 mm) was reached. The second part of this paper gives a description of the shower counter arrangement in the SAPHIR detector. It requires a sophisticated control and calibration system, whose details are presented. Further on some aspects of the calorimeter calibration procedure are discussed

Implementation of the FASTBUS data-acquisition system in the readout of the SAPHIR detector

International Nuclear Information System (INIS)

Empt, J.

1993-12-01

The magnetic detector SAPHIR is layed out to detect multiparticle final states with good acuracy, especially a good photon detection capability is designed. Therefore a large electromagnetic calorimeter was built, consisting of 98 modules covering a detection area of about 16 m 2 in forward direction. For this calorimeter a brass-gas-sandwich detector was developed with signal wires perpendicular to the converter planes. For data acquisition of a major part of this calorimeter a modular FASTBUS system is used. In this report the FASTBUS system and its installation in the SAPHIR Online Program are described. (orig.)

The alarm system of the SAPHIR detector

International Nuclear Information System (INIS)

Schultz-Coulon, H.C.

1993-06-01

In order to obtain an effective control of the different detector components an alarm system was built and implemented into the data acquisition system of the SAPHIR experiment. It provides an easy way of indicating errors by either adequate library calls or an appropriate hardware signal, both leading to an active alarm. This allows to react directly to any error detected by one of the specific control systems. In addition for selected kinds of errors the data run can be stopped automatically. Concept and construction of this system are described and some examples for its application are given. (orig.)

Construction and calibration studies of the SAPHIR scintillation counters

International Nuclear Information System (INIS)

Kostrewa, D.

1988-03-01

For the scintillation counter system of the SAPHIR detector at the stretcher ring ELSA in Bonn 50 time of flight counters and 12 trigger counters have been built. Each of them has two photomultipliers, one at each side. A laser calibration system with a pulsed nitrogen laser as central light source to monitor these photomultipliers has been optimized. It was used to adjust the photomultipliers and to test their long and short time instabilities. (orig.)

Contribution to the microwave characterisation of superconductive materials by means of sapphire resonators; Contribution a la caracterisation hyperfrequence de materiaux supraconducteurs par des resonateurs-saphirs

Energy Technology Data Exchange (ETDEWEB)

Hanus, Xavier

1993-12-06

The objective of this research thesis is to find a compact resonant structure which would allow the residual surface impedance of superconductive samples to be simply, quickly and economically characterised. The author first explains why he decided to use a sapphire single-crystal as inner dielectric, given some performance reached by resonant structures equipped with such inner dielectrics, and given constraints adopted from the start. He explains the origin of microwave losses which appear in this type of resonant structure, i.e. respectively the surface impedance as far as metallic losses are concerned, and the sapphire dielectric loss angle for as far as dielectric losses are concerned. The experimental installation and the principle of microwave measurements are described. The performance of different possible solutions of resonant structures from starting criteria is presented. The solution of the cavity-sapphire with a TE{sub 011} resonant mode is derived [French] Le but de cette etude est de trouver une structure resonnante compacte permettant de caracteriser simplement, rapidement et economiquement l'impedance de surface residuelle d'echantillons supraconducteurs. Les contraintes de mise en oeuvre et les performances atteintes par des resonateurs avec saphirs synthetiques justifient le choix d'un tel dielectrique a faible angle de perte. L'evaluation des performances experimentales appuyee par des modelesanalytiques permet de rejeter differentes solutions. Ainsi les resonateurs fermes avec saphirs minces sont rejetes en raison des mauvais contacts metalliques. Les resonateurs ouverts avec saphirs minces et epais sont egalement rejetes, meme pour les modes de resonance en principe confines, en raison des pertes par rayonnement. La seule solution est donc d'utiliser une cavite-saphir TE{sub 011} qui offre une configuration de champs naturellement confines. Des mesures sur une premiere cavite en niobium massif ont permis de selectionner un saphir obtenu par

Track recognition in the central drift chamber of the SAPHIR detector at ELSA and first reconstruction of real tracks

International Nuclear Information System (INIS)

Korn, P.

1991-02-01

The FORTRAN program for pattern recognition in the central drift chamber of SAPHIR has been modified in order to find tracks with more than one missing wire signal and has been optimized in resolving the left/right ambiguities. The second part of this report deals with the reconstruction of some real tracks (γ → e + e - ), which were measured with SAPHIR. The efficiency of the central drift chamber and the space-to-drift time-relation are discussed. (orig.)

Development of a FASTBUS data acquisition system for the SAPHIR calorimeter

International Nuclear Information System (INIS)

Klein, F.J.

1992-01-01

Due to the high duty cycle of the new Electron Accelerator at the Physics Institute of Bonn University, ELSA, experiments with tagged photon beams and a large angular acceptance become possible. The new magnetic detector SAPHIR is layed out to detect multi-particle final states with good accuracy, especially a good photon detection capability is designed. Therefore a large electromagnetic calorimeter is built, consisting of 98 modules covering a detection area of about 16 m 2 in forward direction. For this calorimeter a brass-gas-sandwich detector was developed with signal wires perpendicular to the converter planes. The chambers are filled with a standard gas mixture Ar/CH 4 (90:10) at atmospheric pressure and operated with a considerably high voltage in the semi-proportional mode. A modified shower counter module, containing 20 μm thick signal wires, was tested at the electron test beam of the Bonn 2.5 GeV electron synchrotron. An energy resolution of σ(E)/E*√E(GeV) = 12.2±0.5% was achieved. For data acquisition a modular FASTBUS system was used, which will be installed in the SAPHIR Online Program. (orig.) [de

The graphics system and the data saving for the SAPHIR experiment

International Nuclear Information System (INIS)

Albold, D.

1990-08-01

Important extensions have been made to the data acquisition system SOS for the SAPHIR experiment at the Bonn ELSA facilities. As support for various online-programs, controlling components of the detector, a graphic system for presenting data was developed. This enables any program in the system to use all graphic devices. Main component is a program serving requests for presentation on a 19 inch color monitor. Window-technique allows a presentation of several graphics on one screen. Equipped with a trackball and using menus, this is an easy to use and powerful tool in controlling the experiment. Other important extensions concern data storage. A huge amount of event data can be stored on 8 mm cassettes by the program Eventsaver. This program can be controlled by a component of the SAPHIR-Online SOL running on a VAX-Computer and using windows and menus. The smaller amount of data, containing parameters and programs, which should be accessible within a small period of time, can be stored on a magnetic disk. A program supporting a file-structure for access to this disk is described. (orig./HSI) [de

Independent Verification and Validation Of SAPHIRE 8 Software Requirements Project Number: N6423 U.S. Nuclear Regulatory Commission

Energy Technology Data Exchange (ETDEWEB)

Kent Norris

2009-09-01

The purpose of the Independent Verification and Validation (IV&V) role in the evaluation of the SAPHIRE requirements definition is to assess the activities that results in the specification, documentation, and review of the requirements that the software product must satisfy, including functionality, performance, design constraints, attributes and external interfaces. The IV&V team began this endeavor after the software engineering and software development of SAPHIRE had already been in production. IV&V reviewed the requirements specified in the NRC Form 189s to verify these requirements were included in SAPHIRE’s Software Verification and Validation Plan (SVVP).

TOPAS 2 - a high-resolution tagging system at the Bonn SAPHIR detector

International Nuclear Information System (INIS)

Rappenecker, G.

1989-02-01

For the SAPHIR-arrangement in Bonn a high resolving tagging system has been developed achieving an energy resolution of 2 MeV, covering the range of (0.94-0.34) E 0 photon energy (1.0 GeV 0 2 , ArCH 4 and ArC 2 H 6 in concern of performance, clustersize and coincidence width. (orig.)

A new plant chamber facility PLUS coupled to the atmospheric simulation chamber SAPHIR

Science.gov (United States)

Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

2015-11-01

A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been build and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees are mixed with synthetic air and are transferred to the SAPHIR chamber where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOC) can be studied in detail. In PLUS all important enviromental parameters (e.g. temperature, PAR, soil RH etc.) are well-controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leafes of the plants is constructed such that gases are exposed to FEP Teflon film and other Teflon surfaces only to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 LED panels which have an emission strength up to 800 μmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOC) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light and temperature dependent BVOC emissions are studied using six Quercus Ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus Ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental set up and the utility of the newly added plant chamber.

A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

Science.gov (United States)

Hohaus, T.; Kuhn, U.; Andres, S.; Kaminski, M.; Rohrer, F.; Tillmann, R.; Wahner, A.; Wegener, R.; Yu, Z.; Kiendler-Scharr, A.

2016-03-01

A new PLant chamber Unit for Simulation (PLUS) for use with the atmosphere simulation chamber SAPHIR (Simulation of Atmospheric PHotochemistry In a large Reaction Chamber) has been built and characterized at the Forschungszentrum Jülich GmbH, Germany. The PLUS chamber is an environmentally controlled flow-through plant chamber. Inside PLUS the natural blend of biogenic emissions of trees is mixed with synthetic air and transferred to the SAPHIR chamber, where the atmospheric chemistry and the impact of biogenic volatile organic compounds (BVOCs) can be studied in detail. In PLUS all important environmental parameters (e.g., temperature, photosynthetically active radiation (PAR), soil relative humidity (RH)) are well controlled. The gas exchange volume of 9.32 m3 which encloses the stem and the leaves of the plants is constructed such that gases are exposed to only fluorinated ethylene propylene (FEP) Teflon film and other Teflon surfaces to minimize any potential losses of BVOCs in the chamber. Solar radiation is simulated using 15 light-emitting diode (LED) panels, which have an emission strength up to 800 µmol m-2 s-1. Results of the initial characterization experiments are presented in detail. Background concentrations, mixing inside the gas exchange volume, and transfer rate of volatile organic compounds (VOCs) through PLUS under different humidity conditions are explored. Typical plant characteristics such as light- and temperature- dependent BVOC emissions are studied using six Quercus ilex trees and compared to previous studies. Results of an initial ozonolysis experiment of BVOC emissions from Quercus ilex at typical atmospheric concentrations inside SAPHIR are presented to demonstrate a typical experimental setup and the utility of the newly added plant chamber.

Systems analysis programs for hands-on integrated reliability evaluations (SAPHIRE) version 5.0

International Nuclear Information System (INIS)

Russell, K.D.; Kvarfordt, K.J.; Skinner, N.L.; Wood, S.T.

1994-07-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. This volume is the reference manual for the Systems Analysis and Risk Assessment (SARA) System Version 5.0, a microcomputer-based system used to analyze the safety issues of a open-quotes familyclose quotes [i.e., a power plant, a manufacturing facility, any facility on which a probabilistic risk assessment (PRA) might be performed]. The SARA database contains PRA data primarily for the dominant accident sequences of a family and descriptive information about the family including event trees, fault trees, and system model diagrams. The number of facility databases that can be accessed is limited only by the amount of disk storage available. To simulate changes to family systems, SARA users change the failure rates of initiating and basic events and/or modify the structure of the cut sets that make up the event trees, fault trees, and systems. The user then evaluates the effects of these changes through the recalculation of the resultant accident sequence probabilities and importance measures. The results are displayed in tables and graphs that may be printed for reports. A preliminary version of the SARA program was completed in August 1985 and has undergone several updates in response to user suggestions and to maintain compatibility with the other SAPHIRE programs. Version 5.0 of SARA provides the same capability as earlier versions and adds the ability to process unlimited cut sets; display fire, flood, and seismic data; and perform more powerful cut set editing

The central drift chamber of the SAPHIR detector - implementation into the experiment and study of its properties

International Nuclear Information System (INIS)

Haas, K.M.

1992-01-01

At the Bonn accelerator facility ELSA the large solid angle detector SAPHIR was built for the investigation of photon induced reactions. A main component of SAPHIR is the central drift chamber (CDC) matching the magneto gap of 1m 3 . The diameter of the in total 1828 hexagonal drift cells is about 18 mm. The subject of this paper is the implementation of the CDC in the experiment. After the description of the hardware follows the presentation of the software tools for filtering and monitoring the data, which have been developed and tested. An algorithm for extracting the space time relationship is presented. The properties of the chamber with an improved gas mixture (Helium/Neon/Isobutane8 21.25:63.75:15) have been investigated. A spatial resolution of about 200 μm was achieved. The efficiency of the chamber is 97% at a tagged photon of 5x10 4 per second crossing the chamber. (orig.) [de

The muon trigger of the SAPHIR shower detector

International Nuclear Information System (INIS)

Rufeger-Hurek, H.

1989-12-01

The muon trigger system of the SAPHIR shower counter consists of 4 scintillation counters. The total trigger rate of cosmic muons is about 55 Hz which is reduced to about 45 Hz by the selecting algorithms. This rate of clean muon events allows a simultaneous monitoring of the whole electronics system and the calibration of the gas sandwich detector by measuring the gas gain. The dependences of the signals on the geometry have been simulated with the help of a Monte Carlo program. The comparison of simulated and measured pulse heights shows that faults in the electronics as well as defects in the detector hardware, e.g., the HV system, or temperature effects, can be recognized at the level of a few percent. In addition the muon signals are used to determine the calibration factor for each cathode channel individually. (orig.) [de

Structural Analysis of PTM Hotspots (SAPH-ire) – A Quantitative Informatics Method Enabling the Discovery of Novel Regulatory Elements in Protein Families*

Science.gov (United States)

Dewhurst, Henry M.; Choudhury, Shilpa; Torres, Matthew P.

2015-01-01

Predicting the biological function potential of post-translational modifications (PTMs) is becoming increasingly important in light of the exponential increase in available PTM data from high-throughput proteomics. We developed structural analysis of PTM hotspots (SAPH-ire)—a quantitative PTM ranking method that integrates experimental PTM observations, sequence conservation, protein structure, and interaction data to allow rank order comparisons within or between protein families. Here, we applied SAPH-ire to the study of PTMs in diverse G protein families, a conserved and ubiquitous class of proteins essential for maintenance of intracellular structure (tubulins) and signal transduction (large and small Ras-like G proteins). A total of 1728 experimentally verified PTMs from eight unique G protein families were clustered into 451 unique hotspots, 51 of which have a known and cited biological function or response. Using customized software, the hotspots were analyzed in the context of 598 unique protein structures. By comparing distributions of hotspots with known versus unknown function, we show that SAPH-ire analysis is predictive for PTM biological function. Notably, SAPH-ire revealed high-ranking hotspots for which a functional impact has not yet been determined, including phosphorylation hotspots in the N-terminal tails of G protein gamma subunits—conserved protein structures never before reported as regulators of G protein coupled receptor signaling. To validate this prediction we used the yeast model system for G protein coupled receptor signaling, revealing that gamma subunit–N-terminal tail phosphorylation is activated in response to G protein coupled receptor stimulation and regulates protein stability in vivo. These results demonstrate the utility of integrating protein structural and sequence features into PTM prioritization schemes that can improve the analysis and functional power of modification-specific proteomics data. PMID:26070665

First measurement of the reactions γp→K+Λ and γp→K+Σ0 with SAPHIR at ELSA

International Nuclear Information System (INIS)

Lindemann, L.

1993-04-01

This report can be subdivided into two main parts. The first part concerns the reconstruction program which has been developed to analyse the data taken with the large solid angle detector SAPHIR which is in operation at the Bonn electron accelerator facility ELSA. A survey on this program is given and some improvements as well as the efficiency concerning real data are discussed. The subject of the second part concerns the measurements of the reactions γp→K + Λand γp→K + Σ 0 . The analysis of a sample of data taken with the SAPHIR in June 1992 is discussed in detail. As a result of this analysis total and differential cross sections as well as the recoil polarization for the two processes are presented. In particular the first measurement of the Σ 0 polarization in photoproduction can be reported. (orig.)

Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE), Version 5.0: Models and Results Database (MAR-D) reference manual. Volume 8

International Nuclear Information System (INIS)

Russell, K.D.; Skinner, N.L.

1994-07-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The primary function of MAR-D is to create a data repository for completed PRAs and Individual Plant Examinations (IPEs) by providing input, conversion, and output capabilities for data used by IRRAS, SARA, SETS, and FRANTIC software. As probabilistic risk assessments and individual plant examinations are submitted to the NRC for review, MAR-D can be used to convert the models and results from the study for use with IRRAS and SARA. Then, these data can be easily accessed by future studies and will be in a form that will enhance the analysis process. This reference manual provides an overview of the functions available within MAR-D and step-by-step operating instructions

Level-1 probability safety assessment of the Iranian heavy water reactor using SAPHIRE software

International Nuclear Information System (INIS)

Faghihi, F.; Ramezani, E.; Yousefpour, F.; Mirvakili, S.M.

2008-01-01

The main goal of this review paper is to analyze the total frequency of the core damage of the Iranian Heavy Water Research Reactor (IHWRR) compared with standard criteria and to determine the strengths and the weaknesses of the reactor safety systems towards improving its design and operation. The PSA has been considered for full-power state of the reactor and this article represents a level-1 PSA analysis using System Analysis Programs for Hands-On Integrated Reliability Evaluations (SAPHIRE) software. It is specifically designed to permit a listing of the potential accident sequences, compute their frequencies of occurrence and assign each sequence to a consequence. The method used for modeling the systems and accident sequences, is Large Fault Tree/Small Event Tree method. This PSA level-1 for IHWRR indicates that, based on conservative assumptions, the total frequency of accidents that would lead to core damage from internal initiating events is 4.44E-05 per year of reactor operation

Level-1 probability safety assessment of the Iranian heavy water reactor using SAPHIRE software

Energy Technology Data Exchange (ETDEWEB)

Faghihi, F. [Department of Nuclear Engineering, School of Engineering, Shiraz University, 71348-51153 Shiraz (Iran, Islamic Republic of); Research Center for Radiation Protection, Shiraz University, Shiraz (Iran, Islamic Republic of); Nuclear Safety Research Center, Shiraz University, Shiraz (Iran, Islamic Republic of)], E-mail: faghihif@shirazu.ac.ir; Ramezani, E. [Department of Nuclear Engineering, School of Engineering, Shiraz University, 71348-51153 Shiraz (Iran, Islamic Republic of); Yousefpour, F. [Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of); Mirvakili, S.M. [Department of Nuclear Engineering, School of Engineering, Shiraz University, 71348-51153 Shiraz (Iran, Islamic Republic of)

2008-10-15

The main goal of this review paper is to analyze the total frequency of the core damage of the Iranian Heavy Water Research Reactor (IHWRR) compared with standard criteria and to determine the strengths and the weaknesses of the reactor safety systems towards improving its design and operation. The PSA has been considered for full-power state of the reactor and this article represents a level-1 PSA analysis using System Analysis Programs for Hands-On Integrated Reliability Evaluations (SAPHIRE) software. It is specifically designed to permit a listing of the potential accident sequences, compute their frequencies of occurrence and assign each sequence to a consequence. The method used for modeling the systems and accident sequences, is Large Fault Tree/Small Event Tree method. This PSA level-1 for IHWRR indicates that, based on conservative assumptions, the total frequency of accidents that would lead to core damage from internal initiating events is 4.44E-05 per year of reactor operation.

Measurement of the reaction {gamma}d {yields}pn{pi}{sup +}{pi}{sup -} at SAPHIR and investigation of the decay angular distribution of the {Delta}{sup ++}(1232) resonance; Messung der Reaktion {gamma}d {yields}pn{pi}{sup +}{pi}{sup -} an SAPHIR und Untersuchung der Zerfallswinkelverteilung der {Delta}{sup ++}(1232)-Resonanz

Energy Technology Data Exchange (ETDEWEB)

Schuetz, P.

1993-03-01

SAPHIR, a new experiment at the Bonn electron stretcher ring ELSA, started taking data in spring 1992. It was set up for the investigation of photon induced reactions with multiparticle final states. In the first part of this paper the special design of the target is described. It can be operated with liquefied hydrogen or deuterium and is placed in the middle of the central drift chamber. To project the surrounding chamber in case of a fracture of the target cell as safety system is installed. In addition two independent methods of monitoring the cell are procided. The first measurement was performed with a deuterium target at a photon energy range of E{sub {gamma}} = 500-700 MeV. In the second part of this paper first results of an analysis of the decay angular distribution of the {Delta}{sup ++}(1232) in the reaction {gamma}d {yields} n{Delta}{sup ++}{pi}{sup -} are presented. They are compared to old data from a hydrogen bubble chamber experiment and are discussed on the basis of a spectator model. (orig.) [Deutsch] Im Rahmen dieser Arbeit ist der Aufbau eines Fluessiggas-Targets beschrieben worden, das speziell fuer den Einsatz im SAPHIR-Detektor entwickelt worden ist. Es wurden Funktionen zur Ueberwachung der Targetzelle vorgestellt und ein Sicherheitssystem zum Schutz der zentralen Driftkammer, die das Target unmittelbar umgibt. Weiterhin ist in Simulationsrechnungen untersucht worden, welchen Einfluss die Konstruktion des Targetstreutopfes auf die Messung unterschiedlicher Reaktionen haben kann. Dabei sind bei 50% bis 70% der Ereignisse Treffer in den Aluminiumstuetzen des Targetstreutopfes aufgetreten. Diese starke Beeintraechtigung kann durch eine Neukonstruktion des Streutopfes und der Verwendung von z.B. Rohazell als Streutopffenster vermieden werden. Rohazell zeichnet sich durch eine hohe Festigkeit und grosse Strahlungslaenge aus. An der Neukonstruktion des Streutopfes wird z.Z. gearbeitet. Der zweite Teil der Arbeit beschreibt eine der ersten

Track finding and track reconstruction in the internal forward drift chamber of SAPHIR

International Nuclear Information System (INIS)

Umlauf, G.

1993-03-01

A track finding algorithm has been developed for the inner forward drift chamber of the SAPHIR detector (at ELSA in Bonn) using the Principal Components Analysis as a tool for interpolating track coordinates. The drift chamber consists of twelve planar layers with six different inclinations and is being operated in an inhomogenous magnetic field. The task of track finding is basicly split into a primary stage that defines track candidates without the use of drift-time information and a second stage that serves to verify the track candidate and to resolve the intrinsic left-right ambiguities of the drift chamber signals. Tracks with at most three missing signals can be found. (orig.) [de

Particle identification by time-of-flight measurement in the SAPHIR

International Nuclear Information System (INIS)

Hoffmann-Rothe, P.

1993-02-01

Using photoproduction data which have been measured with the SAPHIR-detector with different target materials (C H 2 solid , H 2 liquid , D 2 liquid ) a detailed investigation and discussion of the detectors performance to measure the time of flight of charged particles and to separate between particles of different mass has been accomplished. A FORTRAN program has been written which provides a calibration of the scintillator panels of the TOF hodoscopes, calculates correction factors for the time-walk effect an finally, by combining the time of flight with track momentum measurement, determines particle masses. The current configuration of the detector makes it possible to separate between proton and pion up to a particle momentum of 1.6 GeV/c. Proton and kaon can be separated up to a momentum of 1.3 GeV/c, kaon and pion up to a momentum of 0.85 GeV/c. (prog.) [de

TOPAS 1 - construction and test of a scintillation counter hodoscope for the tagging of bremsstrahlung photons for the SAPHIR detector

International Nuclear Information System (INIS)

Merkel, R.

1989-09-01

The development of a tagging-hodoscope for the SAPHIR-detector at the stretcher ring ELSA in Bonn is described. The hodoscope covers the energy range 2.175 GeV γ 0 =3.500 GeV. 24 scintillation counters are used for the determination of the photon energy, giving a resolution of ΔE γ =25 MeV. The tagging method requires a good coincidence timing resoluting τ between the tagging hodoscope and the detector for the photon-induced reactions in order to keep the accidental coincidences low. The timing information is given by 8 fast timing counters (40 mm thick), covering 5 up to 7 energy channels each. Fluctuations of the timing signal which result from different impact-locations on the timing counter, due to different light travelling distances, are corrected by the energy defining counters. The timing-component (8 timing counters) is commpleted and tested. The results of first mesurements show an upper limit of σ=250 psec for the resolution of 7 coincidences out of 45 possible channels in the tagging hodscope. These results are obtained with a preliminary adjustment of the SAPHIR beam-line and with a not yet optimized signal to noize ratio in the extracted beam. We hope to obtain a σ<200 psec under optimized conditions. (orig.)

The capabilities and applications of the saphire 5.0 safety assessment software

International Nuclear Information System (INIS)

Russell, K.D.; Wood, S.T.; Kvarfordt, K.J.

1994-01-01

The System Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a suite of computer programs that were developed to create and analyze a probabilistic risk assessment (PRA) of a nuclear power plant. The programs in this suite include: Models and Results Data Base (MAR-D) software, Integrated Reliability and Risk Analysis System (IRRAS) software, System Analysis and Risk Assessment (SARA) software, and Fault tree, Event tree, and Piping and instrumentation diagram (FEP) graphical editor. Each of these programs performs a specific function in taking a PRA from the conceptual state all the way to publication. This paper provides an overview of the features and capabilities provided in version 5.0 of this software system. Some major new features include the ability to store unlimited cut sets, the ability to perform location transformations, the ability to perform seismic analysis, the ability to perform automated rule based recovery analysis and end state cut set partitioning, the ability to perform end state analysis, a new alphanumeric fault tree editor, and a new alphanumeric event tree editor. Many enhancements and improvements to the user interface as well as a significant reduction in the time required to perform an analysis are included in version 5.0. These new features and capabilities provide a powerful set of PC based PRA analysis tools

Comparison of OH concentration measurements by DOAS and LIF during SAPHIR chamber experiments at high OH reactivity and low NO concentration

Directory of Open Access Journals (Sweden)

H. Fuchs

2012-07-01

Full Text Available During recent field campaigns, hydroxyl radical (OH concentrations that were measured by laser-induced fluorescence (LIF were up to a factor of ten larger than predicted by current chemical models for conditions of high OH reactivity and low NO concentration. These discrepancies, which were observed in forests and urban-influenced rural environments, are so far not entirely understood. In summer 2011, a series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, in order to investigate the photochemical degradation of isoprene, methyl-vinyl ketone (MVK, methacrolein (MACR and aromatic compounds by OH. Conditions were similar to those experienced during the PRIDE-PRD2006 campaign in the Pearl River Delta (PRD, China, in 2006, where a large difference between OH measurements and model predictions was found. During experiments in SAPHIR, OH was simultaneously detected by two independent instruments: LIF and differential optical absorption spectroscopy (DOAS. Because DOAS is an inherently calibration-free technique, DOAS measurements are regarded as a reference standard. The comparison of the two techniques was used to investigate potential artifacts in the LIF measurements for PRD-like conditions of OH reactivities of 10 to 30 s⁻¹ and NO mixing ratios of 0.1 to 0.3 ppbv. The analysis of twenty experiment days shows good agreement. The linear regression of the combined data set (averaged to the DOAS time resolution, 2495 data points yields a slope of 1.02 ± 0.01 with an intercept of (0.10 ± 0.03 × 10⁶ cm⁻³ and a linear correlation coefficient of R² = 0.86. This indicates that the sensitivity of the LIF instrument is well-defined by its calibration procedure. No hints for artifacts are observed for isoprene, MACR, and different aromatic compounds. LIF measurements were approximately 30–40% (median larger than those by DOAS after MVK (20 ppbv and

Measurement of the reaction {gamma}p{yields}K{sup 0}{sigma}{sup +} for photon energies up to 2.65 GeV with the SAPHIR detector at ELSA; Messung der Reaktion {gamma}p {yields} K{sup 0}{sigma}{sup +} fuer Photonenergien bis 2.65 GeV mit dem SAPHIR-Detektor an ELSA

Energy Technology Data Exchange (ETDEWEB)

Lawall, R.

2004-01-01

The reaction {gamma}p {yields} K{sup 0}{sigma}{sup +} was measured with the SAPHIR-detector at ELSA during the run periods 1997 and 1998. Results were obtained for cross sections in the photon energy range from threshold up to 2.65 GeV for all production angles and for the {sigma}{sup +}-polarization. Emphasis has been put on the determination and reduction of the contributions of background reactions and the comparison with other measurements and theoretical predictions. (orig.)

Improvement of the drift chamber system in the SAPHIR detector and first measurements of the Φ meson production at threshold

International Nuclear Information System (INIS)

Scholmann, J.N.

1996-09-01

The SAPHIR detector at ELSA enables the measurement of photon induced Φ meson production from threshold up to 3 GeV in the full kinematical range. A considerable improvement of the drift chamber system is a precondition of gaining the necessary data rate in an acceptable time. The research focuses attention on the choice of the chamber gas and on a different mechanical construction, so as to minimize the negative influences of the photon beam crossing the sensitive volume of the drift chamber system. In addition, first preliminary results of the total and the differential cross section for the Φ meson production close to threshold were evaluated. (orig.)

Investigation of OH Radical Regeneration from Isoprene Oxidation Across Different NOx Regimes in the Atmosphere Simulation Chamber SAPHIR

Science.gov (United States)

Novelli, A.; Bohn, B.; Dorn, H. P.; Häseler, R.; Hofzumahaus, A.; Kaminski, M.; Yu, Z.; Li, X.; Tillmann, R.; Wegener, R.; Fuchs, H.; Kiendler-Scharr, A.; Wahner, A.

2017-12-01

The hydroxyl radical (OH) is the dominant daytime oxidant in the troposphere. It starts the degradation of volatile organic compounds (VOC) originating from both anthropogenic and biogenic emissions. Hence, it is a crucial trace species in model simulations as it has a large impact on many reactive trace gases. Many field campaigns performed in isoprene dominated environment in low NOx conditions have shown large discrepancies between the measured and the modelled OH radical concentrations. These results have contributed to the discovery of new regeneration paths for OH radicals from isoprene-OH second generation products with maximum efficiency at low NO. The current chemical models (e.g. MCM 3.3.1) include this novel chemistry allowing for an investigation of the validity of the OH regeneration at different chemical conditions. Over 11 experiments focusing on the OH oxidation of isoprene were performed at the SAPHIR chamber in the Forschungszentrum Jülich. Measurements of VOCs, NOx, O3, HONO were performed together with the measurement of OH radicals (by both LIF-FAGE and DOAS) and OH reactivity. Within the simulation chamber, the NO mixing ratio was varied between 0.05 to 2 ppbv allowing the investigation of both the "new" regeneration path for OH radicals and the well-known NO+HO2 mechanism. A comparison with the MCM 3.3.1 that includes the upgraded LIM1 mechanism showed very good agreement (within 10%) for the OH data at all concentrations of NOx investigated. Comparison with different models, without LIM1 and with updated rates for the OH regeneration, will be presented together with a detailed analysis of the impact of this study on results from previous field campaigns.

Studies of mixed HEU-LEU-MTR cores using 3D models

Energy Technology Data Exchange (ETDEWEB)

Haenggi, P.; Lehmann, E.; Hammer, J.; Christen, R. [Paul Scherrer Institute, Villigen (Switzerland)

1997-08-01

Several different core loadings were assembled at the SAPHIR research reactor in Switzerland combining the available types of MTR-type fuel elements, consisting mainly of both HEU and LEU fuel. Bearing in mind the well known problems which can occur in such configurations (especially power peaking), investigations have been carried out for each new loading with a 2D neutron transport code (BOXER). The axial effects were approximated by a global buckling value and therefore the radial effects could be studied in considerably detail. Some of the results were reported at earlier RERTR meetings and were compared to those obtained by other methods and with experimental values. For the explicit study of the third dimension of the core, another code (SILWER), which has been developed in PSI for LWR power plant cores, has been selected. With the help of an adapted model for the MTR-core of SAPHIR, several important questions have been addressed. Among other aspects, the estimation of the axial contribution to the hot channel factors, the influence of the control rod position and of the Xe-poisoning on the power distribution were studied. Special attention was given to a core position where a new element was assumed placed near a empty, water filled position. The comparison of elements of low and high enrichments at this position was made in terms of the induced power peaks, with explicit consideration of axial effects. The program SILWER has proven to be applicable to MTR-cores for the investigation of axial effects. For routine use as for the support of reactor operation, this 3D code is a good supplement to the standard 2D model.

Measurement of the reaction γd →pnπ+π- at SAPHIR and investigation of the decay angular distribution of the Δ++(1232) resonance

International Nuclear Information System (INIS)

Schuetz, P.

1993-03-01

SAPHIR, a new experiment at the Bonn electron stretcher ring ELSA, started taking data in spring 1992. It was set up for the investigation of photon induced reactions with multiparticle final states. In the first part of this paper the special design of the target is described. It can be operated with liquefied hydrogen or deuterium and is placed in the middle of the central drift chamber. To project the surrounding chamber in case of a fracture of the target cell as safety system is installed. In addition two independent methods of monitoring the cell are procided. The first measurement was performed with a deuterium target at a photon energy range of E γ = 500-700 MeV. In the second part of this paper first results of an analysis of the decay angular distribution of the Δ ++ (1232) in the reaction γd → nΔ ++ π - are presented. They are compared to old data from a hydrogen bubble chamber experiment and are discussed on the basis of a spectator model. (orig.) [de

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Science.gov (United States)

Fuchs, Hendrik; Novelli, Anna; Rolletter, Michael; Hofzumahaus, Andreas; Pfannerstill, Eva Y.; Kessel, Stephan; Edtbauer, Achim; Williams, Jonathan; Michoud, Vincent; Dusanter, Sebastien; Locoge, Nadine; Zannoni, Nora; Gros, Valerie; Truong, Francois; Sarda-Esteve, Roland; Cryer, Danny R.; Brumby, Charlotte A.; Whalley, Lisa K.; Stone, Daniel; Seakins, Paul W.; Heard, Dwayne E.; Schoemaecker, Coralie; Blocquet, Marion; Coudert, Sebastien; Batut, Sebastien; Fittschen, Christa; Thames, Alexander B.; Brune, William H.; Ernest, Cheryl; Harder, Hartwig; Muller, Jennifer B. A.; Elste, Thomas; Kubistin, Dagmar; Andres, Stefanie; Bohn, Birger; Hohaus, Thorsten; Holland, Frank; Li, Xin; Rohrer, Franz; Kiendler-Scharr, Astrid; Tillmann, Ralf; Wegener, Robert; Yu, Zhujun; Zou, Qi; Wahner, Andreas

2017-10-01

Hydroxyl (OH) radical reactivity (kOH) has been measured for 18 years with different measurement techniques. In order to compare the performances of instruments deployed in the field, two campaigns were conducted performing experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich in October 2015 and April 2016. Chemical conditions were chosen either to be representative of the atmosphere or to test potential limitations of instruments. All types of instruments that are currently used for atmospheric measurements were used in one of the two campaigns. The results of these campaigns demonstrate that OH reactivity can be accurately measured for a wide range of atmospherically relevant chemical conditions (e.g. water vapour, nitrogen oxides, various organic compounds) by all instruments. The precision of the measurements (limit of detection CRM) has a higher limit of detection of 2 s-1 at a time resolution of 10 to 15 min. The performances of the instruments were systematically tested by stepwise increasing, for example, the concentrations of carbon monoxide (CO), water vapour or nitric oxide (NO). In further experiments, mixtures of organic reactants were injected into the chamber to simulate urban and forested environments. Overall, the results show that the instruments are capable of measuring OH reactivity in the presence of CO, alkanes, alkenes and aromatic compounds. The transmission efficiency in Teflon inlet lines could have introduced systematic errors in measurements for low-volatile organic compounds in some instruments. CRM instruments exhibited a larger scatter in the data compared to the other instruments. The largest differences to reference measurements or to calculated reactivity were observed by CRM instruments in the presence of terpenes and oxygenated organic compounds (mixing ratio of OH reactants were up to 10 ppbv). In some of these experiments, only a small fraction of the reactivity is detected. The accuracy of CRM

Total OH reactivity study from VOC photochemical oxidation in the SAPHIR chamber

Science.gov (United States)

Yu, Z.; Tillmann, R.; Hohaus, T.; Fuchs, H.; Novelli, A.; Wegener, R.; Kaminski, M.; Schmitt, S. H.; Wahner, A.; Kiendler-Scharr, A.

2015-12-01

It is well known that hydroxyl radicals (OH) act as a dominant reactive species in the degradation of VOCs in the atmosphere. In recent field studies, directly measured total OH reactivity often showed poor agreement with OH reactivity calculated from VOC measurements (e.g. Nölscher et al., 2013; Lu et al., 2012a). This "missing OH reactivity" is attributed to unaccounted biogenic VOC emissions and/or oxidation products. The comparison of total OH reactivity being directly measured and calculated from single component measurements of VOCs and their oxidation products gives us a further understanding on the source of unmeasured reactive species in the atmosphere. This allows also the determination of the magnitude of the contribution of primary VOC emissions and their oxidation products to the missing OH reactivity. A series of experiments was carried out in the atmosphere simulation chamber SAPHIR in Jülich, Germany, to explore in detail the photochemical degradation of VOCs (isoprene, ß-pinene, limonene, and D6-benzene) by OH. The total OH reactivity was determined from the measurement of VOCs and their oxidation products by a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS) with a GC/MS/FID system, and directly measured by a laser-induced fluorescence (LIF) at the same time. The comparison between these two total OH reactivity measurements showed an increase of missing OH reactivity in the presence of oxidation products of VOCs, indicating a strong contribution to missing OH reactivity from uncharacterized oxidation products.

Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE), Version 5.0. Volume 5, Systems Analysis and Risk Assessment (SARA) tutorial manual

International Nuclear Information System (INIS)

Sattison, M.B.; Russell, K.D.; Skinner, N.L.

1994-07-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs) primarily for nuclear power plants. This volume is the tutorial manual for the Systems Analysis and Risk Assessment (SARA) System Version 5.0, a microcomputer-based system used to analyze the safety issues of a open-quotes familyclose quotes [i.e., a power plant, a manufacturing facility, any facility on which a probabilistic risk assessment (PRA) might be performed]. A series of lessons is provided that guides the user through some basic steps common to most analyses performed with SARA. The example problems presented in the lessons build on one another, and in combination, lead the user through all aspects of SARA sensitivity analysis capabilities

Systems analysis programs for hands-on integrated reliability evaluations (SAPHIRE) version 5.0, technical reference manual

International Nuclear Information System (INIS)

Russell, K.D.; Atwood, C.L.; Galyean, W.J.; Sattison, M.B.; Rasmuson, D.M.

1994-07-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. This volume provides information on the principles used in the construction and operation of Version 5.0 of the Integrated Reliability and Risk Analysis System (IRRAS) and the System Analysis and Risk Assessment (SARA) system. It summarizes the fundamental mathematical concepts of sets and logic, fault trees, and probability. This volume then describes the algorithms that these programs use to construct a fault tree and to obtain the minimal cut sets. It gives the formulas used to obtain the probability of the top event from the minimal cut sets, and the formulas for probabilities that are appropriate under various assumptions concerning repairability and mission time. It defines the measures of basic event importance that these programs can calculate. This volume gives an overview of uncertainty analysis using simple Monte Carlo sampling or Latin Hypercube sampling, and states the algorithms used by these programs to generate random basic event probabilities from various distributions. Further references are given, and a detailed example of the reduction and quantification of a simple fault tree is provided in an appendix

Intercomparison of measurements of NO2 concentrations in the atmosphere simulation chamber SAPHIR during the NO3Comp campaign

Directory of Open Access Journals (Sweden)

H. Fuchs

2010-01-01

Full Text Available NO2 concentrations were measured by various instruments during the NO3Comp campaign at the atmosphere simulation chamber SAPHIR at Forschungszentrum Jülich, Germany, in June 2007. Analytical methods included photolytic conversion with chemiluminescence (PC-CLD, broadband cavity ring-down spectroscopy (BBCRDS, pulsed cavity ring-down spectroscopy (CRDS, incoherent broadband cavity-enhanced absorption spectroscopy (IBB\\-CEAS, and laser-induced fluorescence (LIF. All broadband absorption spectrometers were optimized for the detection of the main target species of the campaign, NO3, but were also capable of detecting NO2 simultaneously with reduced sensitivity. NO2 mixing ratios in the chamber were within a range characteristic of polluted, urban conditions, with a maximum mixing ratio of approximately 75 ppbv. The overall agreement between measurements of all instruments was excellent. Linear fits of the combined data sets resulted in slopes that differ from unity only within the stated uncertainty of each instrument. Possible interferences from species such as water vapor and ozone were negligible under the experimental conditions.

Comparison of OH reactivity measurements in the atmospheric simulation chamber SAPHIR

Directory of Open Access Journals (Sweden)

H. Fuchs

2017-10-01

Full Text Available Hydroxyl (OH radical reactivity (kOH has been measured for 18 years with different measurement techniques. In order to compare the performances of instruments deployed in the field, two campaigns were conducted performing experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich in October 2015 and April 2016. Chemical conditions were chosen either to be representative of the atmosphere or to test potential limitations of instruments. All types of instruments that are currently used for atmospheric measurements were used in one of the two campaigns. The results of these campaigns demonstrate that OH reactivity can be accurately measured for a wide range of atmospherically relevant chemical conditions (e.g. water vapour, nitrogen oxides, various organic compounds by all instruments. The precision of the measurements (limit of detection  < 1 s−1 at a time resolution of 30 s to a few minutes is higher for instruments directly detecting hydroxyl radicals, whereas the indirect comparative reactivity method (CRM has a higher limit of detection of 2 s−1 at a time resolution of 10 to 15 min. The performances of the instruments were systematically tested by stepwise increasing, for example, the concentrations of carbon monoxide (CO, water vapour or nitric oxide (NO. In further experiments, mixtures of organic reactants were injected into the chamber to simulate urban and forested environments. Overall, the results show that the instruments are capable of measuring OH reactivity in the presence of CO, alkanes, alkenes and aromatic compounds. The transmission efficiency in Teflon inlet lines could have introduced systematic errors in measurements for low-volatile organic compounds in some instruments. CRM instruments exhibited a larger scatter in the data compared to the other instruments. The largest differences to reference measurements or to calculated reactivity were observed by CRM instruments in

Time series modeling of live-cell shape dynamics for image-based phenotypic profiling.

Science.gov (United States)

Gordonov, Simon; Hwang, Mun Kyung; Wells, Alan; Gertler, Frank B; Lauffenburger, Douglas A; Bathe, Mark

2016-01-01

Live-cell imaging can be used to capture spatio-temporal aspects of cellular responses that are not accessible to fixed-cell imaging. As the use of live-cell imaging continues to increase, new computational procedures are needed to characterize and classify the temporal dynamics of individual cells. For this purpose, here we present the general experimental-computational framework SAPHIRE (Stochastic Annotation of Phenotypic Individual-cell Responses) to characterize phenotypic cellular responses from time series imaging datasets. Hidden Markov modeling is used to infer and annotate morphological state and state-switching properties from image-derived cell shape measurements. Time series modeling is performed on each cell individually, making the approach broadly useful for analyzing asynchronous cell populations. Two-color fluorescent cells simultaneously expressing actin and nuclear reporters enabled us to profile temporal changes in cell shape following pharmacological inhibition of cytoskeleton-regulatory signaling pathways. Results are compared with existing approaches conventionally applied to fixed-cell imaging datasets, and indicate that time series modeling captures heterogeneous dynamic cellular responses that can improve drug classification and offer additional important insight into mechanisms of drug action. The software is available at http://saphire-hcs.org.

Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE), Version 5.0: Integrated Reliability and Risk Analysis System (IRRAS) reference manual. Volume 2

International Nuclear Information System (INIS)

Russell, K.D.; Kvarfordt, K.J.; Skinner, N.L.; Wood, S.T.; Rasmuson, D.M.

1994-07-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The Integrated Reliability and Risk Analysis System (IRRAS) is a state-of-the-art, microcomputer-based probabilistic risk assessment (PRA) model development and analysis tool to address key nuclear plant safety issues. IRRAS is an integrated software tool that gives the use the ability to create and analyze fault trees and accident sequences using a microcomputer. This program provides functions that range from graphical fault tree construction to cut set generation and quantification to report generation. Version 1.0 of the IRRAS program was released in February of 1987. Since then, many user comments and enhancements have been incorporated into the program providing a much more powerful and user-friendly system. This version has been designated IRRAS 5.0 and is the subject of this Reference Manual. Version 5.0 of IRRAS provides the same capabilities as earlier versions and ads the ability to perform location transformations, seismic analysis, and provides enhancements to the user interface as well as improved algorithm performance. Additionally, version 5.0 contains new alphanumeric fault tree and event used for event tree rules, recovery rules, and end state partitioning

Systems analysis programs for hands-on integrated reliability evaluations (SAPHIRE) Version 5.0. Fault tree, event tree, and piping ampersand instrumentation diagram (FEP) editors reference manual: Volume 7

International Nuclear Information System (INIS)

McKay, M.K.; Skinner, N.L.; Wood, S.T.

1994-07-01

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) refers to a set of several microcomputer programs that were developed to create and analyze probabilistic risk assessments (PRAs), primarily for nuclear power plants. The Fault Tree, Event Tree, and Piping and Instrumentation Diagram (FEP) editors allow the user to graphically build and edit fault trees, and event trees, and piping and instrumentation diagrams (P and IDs). The software is designed to enable the independent use of the graphical-based editors found in the Integrated Reliability and Risk Assessment System (IRRAS). FEP is comprised of three separate editors (Fault Tree, Event Tree, and Piping and Instrumentation Diagram) and a utility module. This reference manual provides a screen-by-screen guide of the entire FEP System

Comparison of OH Reactivity Instruments in the Atmosphere Simulation Chamber SAPHIR.

Science.gov (United States)

Fuchs, H.; Novelli, A.; Rolletter, M.; Hofzumahaus, A.; Pfannerstill, E.; Edtbauer, A.; Kessel, S.; Williams, J.; Michoud, V.; Dusanter, S.; Locoge, N.; Zannoni, N.; Gros, V.; Truong, F.; Sarda Esteve, R.; Cryer, D. R.; Brumby, C.; Whalley, L.; Stone, D. J.; Seakins, P. W.; Heard, D. E.; Schoemaecker, C.; Blocquet, M.; Fittschen, C. M.; Thames, A. B.; Coudert, S.; Brune, W. H.; Batut, S.; Tatum Ernest, C.; Harder, H.; Elste, T.; Bohn, B.; Hohaus, T.; Holland, F.; Muller, J. B. A.; Li, X.; Rohrer, F.; Kubistin, D.; Kiendler-Scharr, A.; Tillmann, R.; Andres, S.; Wegener, R.; Yu, Z.; Zou, Q.; Wahner, A.

2017-12-01

Two campaigns were conducted performing experiments in the atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich in October 2015 and April 2016 to compare hydroxyl (OH) radical reactivity (kOH) measurements. Chemical conditions were chosen either to be representative of the atmosphere or to test potential limitations of instruments. The results of these campaigns demonstrate that OH reactivity can be accurately measured for a wide range of atmospherically relevant chemical conditions (e.g. water vapor, nitrogen oxides, various organic compounds) by all instruments. The precision of the measurements is higher for instruments directly detecting hydroxyl radicals (OH), whereas the indirect Comparative Reactivity Method (CRM) has a higher limit of detection of 2s-1 at a time resolution of 10 to 15 min. The performances of the instruments were systematically tested by stepwise increasing, for example, the concentrations of carbon monoxide (CO), water vapor or nitric oxide (NO). In further experiments, mixtures of organic reactants were injected in the chamber to simulate urban and forested environments. Overall, the results show that instruments are capable of measuring OH reactivity in the presence of CO, alkanes, alkenes and aromatic compounds. The transmission efficiency in Teflon inlet lines could have introduced systematic errors in measurements for low-volatile organic compounds in some instruments. CRM instruments exhibited a larger scatter in the data compared to the other instruments. The largest differences to the reference were observed by CRM instruments in the presence of terpenes and oxygenated organic compounds. In some of these experiments, only a small fraction of the reactivity is detected. The accuracy of CRM measurements is most likely limited by the corrections that need to be applied in order to account for known effects of, for example, deviations from pseudo-first order conditions, nitrogen oxides or water vapor on the measurement

Simulation calculations on the construction of the energy-tagged photon beam as well as development and test of the side drift chambers of the Bonn SAPHIR detector

International Nuclear Information System (INIS)

Jahnen, T.

1990-01-01

The SAPHIR-detector is built up at the continuous photon beam of the Electron Stretcher and Accelerator ELSA in Bonn. The equipment is designed for investigations of reactions with more then two particles in the final state and for photon energies up to 3.5 GeV. A tagging-system determines the energy of the Bremsstrahlung-photons and a set-up of five large driftchambers measures the tracks of the charged particles. This work describes a program which was used to develop the best design of the tagging-hodoscope. In a second part the tests of the planar side-chambers and their evaluation is described. These measurements were carried out to fix the gasfilling and the parameters of the best working point. It is shown, that the chambers can reach a resolution of σ≤200 μm. (orig.) [de

Investigation of the oxidation of methyl vinyl ketone (MVK) by OH radicals in the atmospheric simulation chamber SAPHIR

Science.gov (United States)

Fuchs, Hendrik; Albrecht, Sascha; Acir, Ismail-Hakki; Bohn, Birger; Breitenlechner, Martin; Dorn, Hans-Peter; Gkatzelis, Georgios I.; Hofzumahaus, Andreas; Holland, Frank; Kaminski, Martin; Keutsch, Frank N.; Novelli, Anna; Reimer, David; Rohrer, Franz; Tillmann, Ralf; Vereecken, Luc; Wegener, Robert; Zaytsev, Alexander; Kiendler-Scharr, Astrid; Wahner, Andreas

2018-06-01

The photooxidation of methyl vinyl ketone (MVK) was investigated in the atmospheric simulation chamber SAPHIR for conditions at which organic peroxy radicals (RO2) mainly reacted with NO (high NO case) and for conditions at which other reaction channels could compete (low NO case). Measurements of trace gas concentrations were compared to calculated concentration time series applying the Master Chemical Mechanism (MCM version 3.3.1). Product yields of methylglyoxal and glycolaldehyde were determined from measurements. For the high NO case, the methylglyoxal yield was (19 ± 3) % and the glycolaldehyde yield was (65 ± 14) %, consistent with recent literature studies. For the low NO case, the methylglyoxal yield reduced to (5 ± 2) % because other RO2 reaction channels that do not form methylglyoxal became important. Consistent with literature data, the glycolaldehyde yield of (37 ± 9) % determined in the experiment was not reduced as much as implemented in the MCM, suggesting additional reaction channels producing glycolaldehyde. At the same time, direct quantification of OH radicals in the experiments shows the need for an enhanced OH radical production at low NO conditions similar to previous studies investigating the oxidation of the parent VOC isoprene and methacrolein, the second major oxidation product of isoprene. For MVK the model-measurement discrepancy was up to a factor of 2. Product yields and OH observations were consistent with assumptions of additional RO2 plus HO2 reaction channels as proposed in literature for the major RO2 species formed from the reaction of MVK with OH. However, this study shows that also HO2 radical concentrations are underestimated by the model, suggesting that additional OH is not directly produced from RO2 radical reactions, but indirectly via increased HO2. Quantum chemical calculations show that HO2 could be produced from a fast 1,4-H shift of the second most important MVK derived RO2 species (reaction rate constant 0

Study of the photoproduction of the vector meson Φ(1020) and the hyperon Λ(1520) from the production threshold up to a photon energy of 2.65 GeV with SAPHIR

International Nuclear Information System (INIS)

Wiegers, B.

2001-05-01

The photoproduction of the vector meson φ(1020) and the hyperon Λ(1520) have been measured in the finale state pK + K - from their thresholds up to 2.65 GeV using the high duty-factor electron accelerator ELSA and the 4π-detectorsystem SAPHIR. The t-dependence of φ(1020)-production shows an exponential behavior as expected from diffractive production. s-channel helicity conservation can be seen in the decay angular distribution in the helicity frame. The decay angular distribution in the Gottfried-Jackson frame is not conformable with the exchange of a Pomeron in the t-channel. For the first time, differential cross sections of the Λ(1520) photoproduction from the threshold are measured. The production angular distribution and the decay angular distribution in the Gottfried-Jackson frame show a K * exchange in the t-channel. (orig.)

Comparison of N2O5 mixing ratios during NO3Comp 2007 in SAPHIR

Directory of Open Access Journals (Sweden)

A. W. Rollins

2012-11-01

Full Text Available N2O5 detection in the atmosphere has been accomplished using techniques which have been developed during the last decade. Most techniques use a heated inlet to thermally decompose N2O5 to NO3, which can be detected by either cavity based absorption at 662 nm or by laser-induced fluorescence. In summer 2007, a large set of instruments, which were capable of measuring NO3 mixing ratios, were simultaneously deployed in the atmosphere simulation chamber SAPHIR in Jülich, Germany. Some of these instruments measured N2O5 mixing ratios either simultaneously or alternatively. Experiments focused on the investigation of potential interferences from, e.g., water vapour or aerosol and on the investigation of the oxidation of biogenic volatile organic compounds by NO3. The comparison of N2O5 mixing ratios shows an excellent agreement between measurements of instruments applying different techniques (3 cavity ring-down (CRDS instruments, 2 laser-induced fluorescence (LIF instruments. Datasets are highly correlated as indicated by the square of the linear correlation coefficients, R2, which values were larger than 0.96 for the entire datasets. N2O5 mixing ratios well agree within the combined accuracy of measurements. Slopes of the linear regression range between 0.87 and 1.26 and intercepts are negligible. The most critical aspect of N2O5 measurements by cavity ring-down instruments is the determination of the inlet and filter transmission efficiency. Measurements here show that the N2O5 inlet transmission efficiency can decrease in the presence of high aerosol loads, and that frequent filter/inlet changing is necessary to quantitatively sample N2O5 in some environments. The analysis of data also demonstrates that a general correction for degrading filter transmission is not applicable for all conditions encountered during this campaign. Besides the effect of a gradual degradation of the inlet transmission efficiency aerosol exposure, no other interference

Type I supernova models

International Nuclear Information System (INIS)

Canal, Ramon; Labay, Javier; Isern, Jordi

1987-01-01

We briefly describe the characteristics of Type I supernova outbursts and we present the theoretical models so far advanced to explain them. We especially insist on models based on the thermonuclear explosion of a white dwarf in a close binary system, even regarding the recent division of Type I supernovae into the Ia and Ib subtypes. Together with models assuming explosive thermonuclear burning in a fluid interior, we consider in some detail those based on partially solid interiors. We finally discuss models that incorporate nonthermonuclear energy contributions, suggested in order to explain Type Ib outbursts. (Author)

Incorporation of Markov reliability models for digital instrumentation and control systems into existing PRAs

International Nuclear Information System (INIS)

Bucci, P.; Mangan, L. A.; Kirschenbaum, J.; Mandelli, D.; Aldemir, T.; Arndt, S. A.

2006-01-01

Markov models have the ability to capture the statistical dependence between failure events that can arise in the presence of complex dynamic interactions between components of digital instrumentation and control systems. One obstacle to the use of such models in an existing probabilistic risk assessment (PRA) is that most of the currently available PRA software is based on the static event-tree/fault-tree methodology which often cannot represent such interactions. We present an approach to the integration of Markov reliability models into existing PRAs by describing the Markov model of a digital steam generator feedwater level control system, how dynamic event trees (DETs) can be generated from the model, and how the DETs can be incorporated into an existing PRA with the SAPHIRE software. (authors)

TESTING GARCH-X TYPE MODELS

DEFF Research Database (Denmark)

Pedersen, Rasmus Søndergaard; Rahbek, Anders

2017-01-01

We present novel theory for testing for reduction of GARCH-X type models with an exogenous (X) covariate to standard GARCH type models. To deal with the problems of potential nuisance parameters on the boundary of the parameter space as well as lack of identification under the null, we exploit...... a noticeable property of specific zero-entries in the inverse information of the GARCH-X type models. Specifically, we consider sequential testing based on two likelihood ratio tests and as demonstrated the structure of the inverse information implies that the proposed test neither depends on whether...... the nuisance parameters lie on the boundary of the parameter space, nor on lack of identification. Our general results on GARCH-X type models are applied to Gaussian based GARCH-X models, GARCH-X models with Student's t-distributed innovations as well as the integer-valued GARCH-X (PAR-X) models....

Type 2 diabetes models

DEFF Research Database (Denmark)

Gram, Dorte Xenia

2012-01-01

This chapter deals with type 2 diabetes in vivo models and techniques suitable for testing new anti-diabetic compounds. In particular, the testing of TRP antagonist for beneficial effects against type 2 diabetes is considered. There are many choices of both in vitro techniques and in vivo models......, impaired glucose tolerance, impaired insulin secretion, and insulin resistance in vivo and should, thus, be sufficient to demonstrate preclinical proof of concept of a TRP antagonist in type 2 diabetes in rodents. The experiments are suggestions and could be replaced or supplemented by others....

Results of the mock-up experiment on partial LOCA

International Nuclear Information System (INIS)

Dreier, J.; Winkler, H.

1985-01-01

A mockup experiment has been performed to verify the heat transfer model for a partial loss of coolant accident in the swimming pool reactor SAPHIR. Three coolant channels with the same dimensions as in a SAPHIR fuel element were simulated using four electrically heated plates. For a water level such that the heated plates are partially submerged, plate temperatures remain below 160 deg. C for plate powers of up to 650 W. For water levels low enough to just block the channels, plate temperatures of 400 deg. C are reached for plate powers as low as 60 W. Details of the experiment and further results are discussed. (author)

Results of the mockup experiment on partial LOCA

International Nuclear Information System (INIS)

Dreier, J.; Winkler, H.

1985-01-01

A mockup experiment has been performed to verify the heat transfer model for a partial loss of coolant accident in the swimming pool reactor SAPHIR. Three coolant channels with the same dimensions as in a SAPHIR fuel element were simulated using four electrically heated plates. For a water level such that the heated plates are partially submerged, plate temperatures remain below 160 0 C for plate powers of up to 650 W. For water levels low enough to just block the channels, plate temperatures of 400 0 C are reached for plate powers as low as 60 W. Details of the experiment and further results are discussed

Measurement of the reactions γp→K+Λ and γp→K+Σ0 for photon energies up to 2.6 GeV with the SAPHIR detector at ELSA

International Nuclear Information System (INIS)

Glander, K.H.

2003-02-01

The reactions γp→K + Lambda and γp→K + Σ 0 were measured in the energy range from threshold up to a photon energy of 2.6 GeV. The data were taken with the SAPHIR detector at the electron stretcher facility ELSA. Results on cross sections and hyperon polarizations are presented as a function of kaon production angle and photon energy. The total cross section for Λ production shows a strong treshold enhancement wehreas the Σ 0 data have a maximum at about E γ =1.45 GeV. Cross sections together with their angular decompositions into Legendre polynomials suggest contributions from resonance production for both reactions. The K + Λ differential cross section is enhanced for backward produced kaons at E γ ∼1.45 GeV. This might be interpreted as contribution of a so called missing resonance D 13 (1895). In general, the induced polarization of Λ has negative values in the kaon forward direction and positive values in the backward direction. The magnitude varies with energy. The polarization of Σ 0 follows a similar angular and energy dependence as that of Λ, but with opposite sign. (orig.)

Theoretical models for Type I and Type II supernova

International Nuclear Information System (INIS)

Woosley, S.E.; Weaver, T.A.

1985-01-01

Recent theoretical progress in understanding the origin and nature of Type I and Type II supernovae is discussed. New Type II presupernova models characterized by a variety of iron core masses at the time of collapse are presented and the sensitivity to the reaction rate 12 C(α,γ) 16 O explained. Stars heavier than about 20 M/sub solar/ must explode by a ''delayed'' mechanism not directly related to the hydrodynamical core bounce and a subset is likely to leave black hole remnants. The isotopic nucleosynthesis expected from these massive stellar explosions is in striking agreement with the sun. Type I supernovae result when an accreting white dwarf undergoes a thermonuclear explosion. The critical role of the velocity of the deflagration front in determining the light curve, spectrum, and, especially, isotopic nucleosynthesis in these models is explored. 76 refs., 8 figs

A note on tilted Bianchi type VIh models: the type III bifurcation

Science.gov (United States)

Coley, A. A.; Hervik, S.

2008-10-01

In this note we complete the analysis of Hervik, van den Hoogen, Lim and Coley (2007 Class. Quantum Grav. 24 3859) of the late-time behaviour of tilted perfect fluid Bianchi type III models. We consider models with dust, and perfect fluids stiffer than dust, and eludicate the late-time behaviour by studying the centre manifold which dominates the behaviour of the model at late times. In the dust case, this centre manifold is three-dimensional and can be considered a double bifurcation as the two parameters (h and γ) of the type VIh model are varied. We therefore complete the analysis of the late-time behaviour of tilted ever-expanding Bianchi models of types I VIII.

Assessment of core damage frequency owing to possible fires at NPP with RBMK type reactors

Energy Technology Data Exchange (ETDEWEB)

Vinnikov, B. [National Research Centre Kurchatov Inst., 1, Kurchatov Square, Moscow, 123 182 (Russian Federation); NRC Kurchatov Inst. (Russian Federation)

2012-07-01

According to Scientific and Technical Cooperation between the USA and Russia in the field of nuclear engineering the Idaho National Laboratory has transferred to the possession of the National Research Center ' Kurchatov Inst. ' the SAPHIRE software without any fee. With the help of the software Kurchatov Inst. developed a Pilot Living PSA- Model of Leningrad NPP Unit 1. Computations of core damage frequencies were carried out for additional Initiating Events. In the submitted paper such additional Initiating Events are fires in various compartments of the NPP. During the computations of each fire, structure of the PSA - Model was not changed, but Fault Trees for the appropriate systems, which are removed from service during the fire, were changed. It follows from the computations, that for ten fires Core Damaged Frequencies (CDF) are not changed. Other six fires will cause additional core damage. On the basis of the calculated results it is possible to determine a degree of importance of these fires and to establish sequence of performance of fire-prevention measures in various places of the NPP. (authors)

Assessment of core damage frequency owing to possible fires at NPP with RBMK type reactors

International Nuclear Information System (INIS)

Vinnikov, B.

2012-01-01

According to Scientific and Technical Cooperation between the USA and Russia in the field of nuclear engineering the Idaho National Laboratory has transferred to the possession of the National Research Center ' Kurchatov Inst. ' the SAPHIRE software without any fee. With the help of the software Kurchatov Inst. developed a Pilot Living PSA- Model of Leningrad NPP Unit 1. Computations of core damage frequencies were carried out for additional Initiating Events. In the submitted paper such additional Initiating Events are fires in various compartments of the NPP. During the computations of each fire, structure of the PSA - Model was not changed, but Fault Trees for the appropriate systems, which are removed from service during the fire, were changed. It follows from the computations, that for ten fires Core Damaged Frequencies (CDF) are not changed. Other six fires will cause additional core damage. On the basis of the calculated results it is possible to determine a degree of importance of these fires and to establish sequence of performance of fire-prevention measures in various places of the NPP. (authors)

Intercomparison of NO3 radical detection instruments in the atmosphere simulation chamber SAPHIR

Directory of Open Access Journals (Sweden)

H.-P. Dorn

2013-05-01

Full Text Available The detection of atmospheric NO3 radicals is still challenging owing to its low mixing ratios (≈ 1 to 300 pptv in the troposphere. While long-path differential optical absorption spectroscopy (DOAS has been a well-established NO3 detection approach for over 25 yr, newly sensitive techniques have been developed in the past decade. This publication outlines the results of the first comprehensive intercomparison of seven instruments developed for the spectroscopic detection of tropospheric NO3. Four instruments were based on cavity ring-down spectroscopy (CRDS, two utilised open-path cavity-enhanced absorption spectroscopy (CEAS, and one applied "classical" long-path DOAS. The intercomparison campaign "NO3Comp" was held at the atmosphere simulation chamber SAPHIR in Jülich (Germany in June 2007. Twelve experiments were performed in the well-mixed chamber for variable concentrations of NO3, N2O5, NO2, hydrocarbons, and water vapour, in the absence and in the presence of inorganic or organic aerosol. The overall precision of the cavity instruments varied between 0.5 and 5 pptv for integration times of 1 s to 5 min; that of the DOAS instrument was 9 pptv for an acquisition time of 1 min. The NO3 data of all instruments correlated excellently with the NOAA-CRDS instrument, which was selected as the common reference because of its superb sensitivity, high time resolution, and most comprehensive data coverage. The median of the coefficient of determination (r2 over all experiments of the campaign (60 correlations is r2 = 0.981 (quartile 1 (Q1: 0.949; quartile 3 (Q3: 0.994; min/max: 0.540/0.999. The linear regression analysis of the campaign data set yielded very small intercepts (median: 1.1 pptv; Q1/Q3: −1.1/2.6 pptv; min/max: −14.1/28.0 pptv, and the slopes of the regression lines were close to unity (median: 1.01; Q1/Q3: 0.92/1.10; min/max: 0.72/1.36. The deviation of individual regression slopes from unity was always within the combined

Chemical analysis of particulate and gaseous products from the monoterpene oxidation in the SAPHIR chamber during the EUCAARI campaign 2008

Science.gov (United States)

Kahnt, A.; Iinuma, Y.; Herrmann, H.; Mentel, T. F.; Fisseha, R.; Kiendler-Scharr, A.

2009-04-01

The atmospheric oxidation of monoterpenes leads to multifunctional products with lower vapour pressure. These products condense and coagulate to existing particles leading to particle formation and growth. In order to obtain better insights into the mechanisms and the importance of sources to organic aerosol, a mixture of monoterpenes was oxidised in the SAPHIR outdoor chamber during the EUCAARI campaign in 2008. The mixture was made of α-pinene, β-pinene, limonene, 3-carene and ocimene, representing a typical monoterpene emission from a boreal forest. In addition, two sesquiterpenes (α-farnesene and caryophyllene) were reacted together with the monoterpene mixture in some experiments. The VOC (volatile organic compound) mixture was reacted under tropospheric oxidation and light conditions in a prolonged time scale over two days. In the present study, a special emphasis is put on the detection of carbonyl compounds from the off-line analysis of collected filter and denuder samples from the campaign in 2008. The oxidation products which contain carbonyl groups are important first stable intermediates during the monoterpene and sesquiterpene oxidation. They react further with atmospheric oxidants to form lower volatile acidic compounds, contributing to secondary organic aerosol (SOA). Commonly used methods for the analysis of carbonyl compounds involve derivatisation steps prior to separation and subsequent UV or MS detection. In the present study, 2,4-dinitrophenylhydrazine (DNPH) was used to derivatise the extracted filter and denuder samples. The DNPH converts aldehyde- and keto-groups to stable hydrazones, which can be purified afterwards using a solid phase extraction (SPE) cartridge. The derivatised samples were analysed with HPLC/ESI-TOFMS which allowed us to determine the exact chemical formula of unknown products. In addition to known carbonyl compounds from monoterpene oxidation such as pinonaldehyde and nopinon, previously unreported molecular masses

Lanchester-Type Models of Warfare, Volume II

OpenAIRE

Taylor, James G.

1980-01-01

This monograph is a comprehensive treatist on Lanchester-type models of warfare, i.e. differential-equation models of attrition in force-on-force combat operations. Its goal is to provide both an introduction to and current-state-of-the-art overview of Lanchester-type models of warfare as well as a comprehensive and unified in-depth treatment of them. Both deterministic as well as stochastic models are considered. Such models have been widely used in the United States and elsewhere for the...

Risk-Informed External Hazards Analysis for Seismic and Flooding Phenomena for a Generic PWR

Energy Technology Data Exchange (ETDEWEB)

Parisi, Carlo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Prescott, Steve [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ma, Zhegang [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spears, Bob [Idaho National Lab. (INL), Idaho Falls, ID (United States); Szilard, Ronaldo [Idaho National Lab. (INL), Idaho Falls, ID (United States); Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kosbab, Ben [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-07-26

This report describes the activities performed during the FY2017 for the US-DOE Light Water Reactor Sustainability Risk-Informed Safety Margin Characterization (LWRS-RISMC), Industry Application #2. The scope of Industry Application #2 is to deliver a risk-informed external hazards safety analysis for a representative nuclear power plant. Following the advancements occurred during the previous FYs (toolkits identification, models development), FY2017 focused on: increasing the level of realism of the analysis; improving the tools and the coupling methodologies. In particular the following objectives were achieved: calculation of buildings pounding and their effects on components seismic fragility; development of a SAPHIRE code PRA models for 3-loops Westinghouse PWR; set-up of a methodology for performing static-dynamic PRA coupling between SAPHIRE and EMRALD codes; coupling RELAP5-3D/RAVEN for performing Best-Estimate Plus Uncertainty analysis and automatic limit surface search; and execute sample calculations for demonstrating the capabilities of the toolkit in performing a risk-informed external hazards safety analyses.

A Realizability Model for Impredicative Hoare Type Theory

DEFF Research Database (Denmark)

Petersen, Rasmus Lerchedal; Birkedal, Lars; Nanevski, Alexandar

2008-01-01

We present a denotational model of impredicative Hoare Type Theory, a very expressive dependent type theory in which one can specify and reason about mutable abstract data types. The model ensures soundness of the extension of Hoare Type Theory with impredicative polymorphism; makes the connections...... to separation logic clear, and provides a basis for investigation of further sound extensions of the theory, in particular equations between computations and types....

Internal Universes in Models of Homotopy Type Theory

DEFF Research Database (Denmark)

Licata, Daniel R.; Orton, Ian; Pitts, Andrew M.

2018-01-01

We show that universes of fibrations in various models of homotopy type theory have an essentially global character: they cannot be described in the internal language of the presheaf topos from which the model is constructed. We get around this problem by extending the internal language with a mo...... that the interval in cubical sets does indeed have. This leads to a completely internal development of models of homotopy type theory within what we call crisp type theory.......We show that universes of fibrations in various models of homotopy type theory have an essentially global character: they cannot be described in the internal language of the presheaf topos from which the model is constructed. We get around this problem by extending the internal language...

On a Boltzmann-type price formation model

KAUST Repository

Burger, Martin; Caffarelli, Luis A.; Markowich, Peter A.; Wolfram, Marie Therese

2013-01-01

In this paper, we present a Boltzmann-type price formation model, which is motivated by a parabolic free boundary model for the evolution of price presented by Lasry and Lions in 2007. We discuss the mathematical analysis of the Boltzmann-type model and show that its solutions converge to solutions of the model by Lasry and Lions as the transaction rate tends to infinity. Furthermore, we analyse the behaviour of the initial layer on the fast time scale and illustrate the price dynamics with various numerical experiments. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

On a Boltzmann-type price formation model

KAUST Repository

Burger, Martin

2013-06-26

In this paper, we present a Boltzmann-type price formation model, which is motivated by a parabolic free boundary model for the evolution of price presented by Lasry and Lions in 2007. We discuss the mathematical analysis of the Boltzmann-type model and show that its solutions converge to solutions of the model by Lasry and Lions as the transaction rate tends to infinity. Furthermore, we analyse the behaviour of the initial layer on the fast time scale and illustrate the price dynamics with various numerical experiments. © 2013 The Author(s) Published by the Royal Society. All rights reserved.

Type-2 fuzzy logic uncertain systems’ modeling and control

CERN Document Server

Antão, Rómulo

2017-01-01

This book focuses on a particular domain of Type-2 Fuzzy Logic, related to process modeling and control applications. It deepens readers’understanding of Type-2 Fuzzy Logic with regard to the following three topics: using simpler methods to train a Type-2 Takagi-Sugeno Fuzzy Model; using the principles of Type-2 Fuzzy Logic to reduce the influence of modeling uncertainties on a locally linear n-step ahead predictor; and developing model-based control algorithms according to the Generalized Predictive Control principles using Type-2 Fuzzy Sets. Throughout the book, theory is always complemented with practical applications and readers are invited to take their learning process one step farther and implement their own applications using the algorithms’ source codes (provided). As such, the book offers avaluable referenceguide for allengineers and researchers in the field ofcomputer science who are interested in intelligent systems, rule-based systems and modeling uncertainty.

A model of PCF in guarded type theory

DEFF Research Database (Denmark)

Paviotti, Marco; Møgelberg, Rasmus Ejlers; Birkedal, Lars

2015-01-01

Guarded recursion is a form of recursion where recursive calls are guarded by delay modalities. Previous work has shown how guarded recursion is useful for constructing logics for reasoning about programming languages with advanced features, as well as for constructing and reasoning about element...... adequate. The model construction is related to Escardo's metric model for PCF, but here everything is carried out entirely in type theory with guarded recursion, including the formulation of the operational semantics, the model construction and the proof of adequacy...... of coinductive types. In this paper we investigate how type theory with guarded recursion can be used as a metalanguage for denotational semantics useful both for constructing models and for proving properties of these. We do this by constructing a fairly intensional model of PCF and proving it computationally...

A Model of PCF in Guarded Type Theory

DEFF Research Database (Denmark)

Paviotti, Marco; Møgelberg, Rasmus Ejlers; Birkedal, Lars

2015-01-01

Guarded recursion is a form of recursion where recursive calls are guarded by delay modalities. Previous work has shown how guarded recursion is useful for constructing logics for reasoning about programming languages with advanced features, as well as for constructing and reasoning about element...... adequate. The model construction is related to Escardo's metric model for PCF, but here everything is carried out entirely in type theory with guarded recursion, including the formulation of the operational semantics, the model construction and the proof of adequacy....... of coinductive types. In this paper we investigate how type theory with guarded recursion can be used as a metalanguage for denotational semantics useful both for constructing models and for proving properties of these. We do this by constructing a fairly intensional model of PCF and proving it computationally...

Towards an Existential Types Model for Java with Wildcards

DEFF Research Database (Denmark)

Cameron, Nicholas; Drossopoulou, Sophia; Ernst, Erik

2007-01-01

Wildcards extend Java generics by softening the mismatch between subtype and parametric polymorphism. Although they are a key part of the Java 5.0 programming language, a type system including wildcards has never been proven type sound. Wildcards have previously been formalised as existential types....... In this paper we extend FGJ, a featherweight formalisation of Java with generics, with existential types. We prove that this calculus, ExistsJ, is type sound, and illustrate how it models wildcards in the Java Programming Language. ExistsJ is not a full model for Java wildcards, because it does not support...... lower bounds for wildcards. We discuss why ExistsJ can not be easily extended with lower bounds, and how full Java wildcards could be modelled in a type sound way....

Type I supernova models vs observations

International Nuclear Information System (INIS)

Weaver, T.A.; Axelrod, T.S.; Woosley, S.E.

1980-01-01

This paper explores tHe observational consequences of models for Type I supernovae based on the detonation (or deflagration) of the degenerate cores of white dwarfs or intermediate mass (approx. = 9 M/sub sun/) stars. Such nuclear burning can be initiated either at the center of the core or near its edge. The model examined in most detail is that of a 0.5M/sub sun/ C/O white dwarf which undergoes an edge-lit He/C/O detonation after accreting 0.62 M/sub sun/ of he at 10 -8 M/sub sun//yr. The light curve resulting from this model is found to be in excellent agreement with those observed for Type I supernovae, particularly those in the fast subclass. The physical processes involved in the detailed numerical calculations which lead to this conclusion are quantitatively elucidated by simple analytic models, and effects of uncertainties in the input physics are explored

Algebraic Specifications, Higher-order Types and Set-theoretic Models

DEFF Research Database (Denmark)

Kirchner, Hélène; Mosses, Peter David

2001-01-01

, and power-sets. This paper presents a simple framework for algebraic specifications with higher-order types and set-theoretic models. It may be regarded as the basis for a Horn-clause approximation to the Z framework, and has the advantage of being amenable to prototyping and automated reasoning. Standard......In most algebraic  specification frameworks, the type system is restricted to sorts, subsorts, and first-order function types. This is in marked contrast to the so-called model-oriented frameworks, which provide higer-order types, interpreted set-theoretically as Cartesian products, function spaces...... set-theoretic models are considered, and conditions are given for the existence of initial reduct's of such models. Algebraic specifications for various set-theoretic concepts are considered....

Impact of model structure and parameterization on Penman-Monteith type evaporation models

KAUST Repository

Ershadi, A.; McCabe, Matthew; Evans, J.P.; Wood, E.F.

2015-01-01

Overall, the results illustrate the sensitivity of Penman-Monteith type models to model structure, parameterization choice and biome type. A particular challenge in flux estimation relates to developing robust and broadly applicable model formulations. With many choices available for use, providing guidance on the most appropriate scheme to employ is required to advance approaches for routine global scale flux estimates, undertake hydrometeorological assessments or develop hydrological forecasting tools, amongst many other applications. In such cases, a multi-model ensemble or biome-specific tiled evaporation product may be an appropriate solution, given the inherent variability in model and parameterization choice that is observed within single product estimates.

A Budyko-type Model for Human Water Consumption

Science.gov (United States)

Lei, X.; Zhao, J.; Wang, D.; Sivapalan, M.

2017-12-01

With the expansion of human water footprint, water crisis is no longer only a conflict or competition for water between different economic sectors, but also increasingly between human and the environment. In order to describe the emergent dynamics and patterns of the interaction, a theoretical framework that encapsulates the physical and societal controls impacting human water consumption is needed. In traditional hydrology, Budyko-type models are simple but efficient descriptions of vegetation-mediated hydrologic cycle in catchments, i.e., the partitioning of mean annual precipitation into runoff and evapotranspiration. Plant water consumption plays a crucial role in the process. Hypothesized similarities between human-water and vegetation-water interactions, including water demand, constraints and system functioning, give the idea of corresponding Budyko-type framework for human water consumption at the catchment scale. Analogous to variables of Budyko-type models for hydrologic cycle, water demand, water consumption, environmental water use and available water are corresponding to potential evaporation, actual evaporation, runoff and precipitation respectively. Human water consumption data, economic and hydro-meteorological data for 51 human-impacted catchments and 10 major river basins in China are assembled to look for the existence of a Budyko-type relationship for human water consumption, and to seek explanations for the spread in the observed relationship. Guided by this, a Budyko-type analytical model is derived based on application of an optimality principle, that of maximum water benefit. The model derived has the same functional form and mathematical features as those that apply for the original Budyko model. Parameters of the new Budyko-type model for human consumption are linked to economic and social factors. The results of this paper suggest that the functioning of both social and hydrologic subsystems within catchment systems can be explored within

Experience with supermirror production at PSI

International Nuclear Information System (INIS)

Boeni, P.; Elsenhans, O.; Friedli, H.P.; Grimmer, H.; Anderson, I.S.

1993-01-01

Supermirror coatings for the seven neutron guides of the continuous spallation source SINQ at PSI are being produced on a DC-magnetron sputtering plant at PSI since April 1993 at a rate of up to 2 meters of guide per day. All Supermirrors are characterised after production on the test spectrometer TOPSI at reactor Saphir. The more than 300 production runs allow interesting comparisons between coatings made on various types of glasses. (author) 3 figs

A bivariate model for analyzing recurrent multi-type automobile failures

Science.gov (United States)

Sunethra, A. A.; Sooriyarachchi, M. R.

2017-09-01

The failure mechanism in an automobile can be defined as a system of multi-type recurrent failures where failures can occur due to various multi-type failure modes and these failures are repetitive such that more than one failure can occur from each failure mode. In analysing such automobile failures, both the time and type of the failure serve as response variables. However, these two response variables are highly correlated with each other since the timing of failures has an association with the mode of the failure. When there are more than one correlated response variables, the fitting of a multivariate model is more preferable than separate univariate models. Therefore, a bivariate model of time and type of failure becomes appealing for such automobile failure data. When there are multiple failure observations pertaining to a single automobile, such data cannot be treated as independent data because failure instances of a single automobile are correlated with each other while failures among different automobiles can be treated as independent. Therefore, this study proposes a bivariate model consisting time and type of failure as responses adjusted for correlated data. The proposed model was formulated following the approaches of shared parameter models and random effects models for joining the responses and for representing the correlated data respectively. The proposed model is applied to a sample of automobile failures with three types of failure modes and up to five failure recurrences. The parametric distributions that were suitable for the two responses of time to failure and type of failure were Weibull distribution and multinomial distribution respectively. The proposed bivariate model was programmed in SAS Procedure Proc NLMIXED by user programming appropriate likelihood functions. The performance of the bivariate model was compared with separate univariate models fitted for the two responses and it was identified that better performance is secured by

A Type Graph Model for Java Programs

NARCIS (Netherlands)

Rensink, Arend; Zambon, Eduardo

2009-01-01

In this report we present a type graph that models all executable constructs of the Java programming language. Such a model is useful for any graph-based technique that relies on a representation of Java programs as graphs. The model can be regarded as a common representation to which all Java

A Type Graph Model for Java Programs

NARCIS (Netherlands)

Rensink, Arend; Zambon, Eduardo; Lee, D.; Lopes, A.; Poetzsch-Heffter, A.

2009-01-01

In this work we present a type graph that models all executable constructs of the Java programming language. Such a model is useful for any graph-based technique that relies on a representation of Java programs as graphs. The model can be regarded as a common representation to which all Java syntax

Impact of model structure and parameterization on Penman-Monteith type evaporation models

KAUST Repository

Ershadi, A.

2015-04-12

The impact of model structure and parameterization on the estimation of evaporation is investigated across a range of Penman-Monteith type models. To examine the role of model structure on flux retrievals, three different retrieval schemes are compared. The schemes include a traditional single-source Penman-Monteith model (Monteith, 1965), a two-layer model based on Shuttleworth and Wallace (1985) and a three-source model based on Mu et al. (2011). To assess the impact of parameterization choice on model performance, a number of commonly used formulations for aerodynamic and surface resistances were substituted into the different formulations. Model response to these changes was evaluated against data from twenty globally distributed FLUXNET towers, representing a cross-section of biomes that include grassland, cropland, shrubland, evergreen needleleaf forest and deciduous broadleaf forest. Scenarios based on 14 different combinations of model structure and parameterization were ranked based on their mean value of Nash-Sutcliffe Efficiency. Results illustrated considerable variability in model performance both within and between biome types. Indeed, no single model consistently outperformed any other when considered across all biomes. For instance, in grassland and shrubland sites, the single-source Penman-Monteith model performed the best. In croplands it was the three-source Mu model, while for evergreen needleleaf and deciduous broadleaf forests, the Shuttleworth-Wallace model rated highest. Interestingly, these top ranked scenarios all shared the simple lookup-table based surface resistance parameterization of Mu et al. (2011), while a more complex Jarvis multiplicative method for surface resistance produced lower ranked simulations. The highly ranked scenarios mostly employed a version of the Thom (1975) formulation for aerodynamic resistance that incorporated dynamic values of roughness parameters. This was true for all cases except over deciduous broadleaf

Bianchi type-I model with conformally invariant scalar and electromagnetic field

International Nuclear Information System (INIS)

Accioly, A.J.; Vaidya, A.N.; Som, M.M.

1983-01-01

A Bianchi type-I exact solution of the Einstein theory representing the homogeneous anisotropic models with the electromagnetic field and the conformally invariant scalar field is studied. The solution contains Kasner model, pure electromagnetic and pure scalar models as special cases. It is found that the models evolve from an initial Kasner type to a final open Friedmann type universe. (Author) [pt

Stochastic analysis of a pulse-type prey-predator model

Science.gov (United States)

Wu, Y.; Zhu, W. Q.

2008-04-01

A stochastic Lotka-Volterra model, a so-called pulse-type model, for the interaction between two species and their random natural environment is investigated. The effect of a random environment is modeled as random pulse trains in the birth rate of the prey and the death rate of the predator. The generalized cell mapping method is applied to calculate the probability distributions of the species populations at a state of statistical quasistationarity. The time evolution of the population densities is studied, and the probability of the near extinction time, from an initial state to a critical state, is obtained. The effects on the ecosystem behaviors of the prey self-competition term and of the pulse mean arrival rate are also discussed. Our results indicate that the proposed pulse-type model shows obviously distinguishable characteristics from a Gaussian-type model, and may confer a significant advantage for modeling the prey-predator system under discrete environmental fluctuations.

Type-I integrable quantum impurities in the Heisenberg model

Energy Technology Data Exchange (ETDEWEB)

Doikou, Anastasia, E-mail: adoikou@upatras.gr

2013-12-21

Type-I quantum impurities are investigated in the context of the integrable Heisenberg model. This type of defects is associated to the (q)-harmonic oscillator algebra. The transmission matrices associated to this particular type of defects are computed via the Bethe ansatz methodology for the XXX model, as well as for the critical and non-critical XXZ spin chain. In the attractive regime of the critical XXZ spin chain the transmission amplitudes for the breathers are also identified.

Type-I integrable quantum impurities in the Heisenberg model

International Nuclear Information System (INIS)

Doikou, Anastasia

2013-01-01

Type-I quantum impurities are investigated in the context of the integrable Heisenberg model. This type of defects is associated to the (q)-harmonic oscillator algebra. The transmission matrices associated to this particular type of defects are computed via the Bethe ansatz methodology for the XXX model, as well as for the critical and non-critical XXZ spin chain. In the attractive regime of the critical XXZ spin chain the transmission amplitudes for the breathers are also identified

Type IV Wind Turbine Model

DEFF Research Database (Denmark)

Hansen, Anca Daniela; Margaris, Ioannis D.

. In the project, this wind turbine model will be further incorporated in a wind power plant model together with the implementation in the wind power control level of the new control functionalities (inertial response, synchronising power and power system damping). For this purpose an aggregate wind power plant......This document is created as part of the EaseWind project. The goal of this project is to develop and investigate new control features for primary response provided by wind power plants. New control features as inertial response, synchronising power and power system damping are of interest to EaseWind...... project to be incorporated in the wind power plant level. This document describes the Type 4 wind turbine simulation model, implemented in the EaseWind project. The implemented wind turbine model is one of the initial necessary steps toward integrating new control services in the wind power plant level...

Modelling radiative heat transfer inside a basin type solar still

International Nuclear Information System (INIS)

Madhlopa, A.

2014-01-01

Radiative heat transfer inside a basin type solar still has been investigated using two models with (model 1) and without (model 2) taking into account optical view factors. The coefficient of radiative heat exchange (h r,w-gc ) between the water and cover surfaces of a practical solar still was computed using the two models. Simulation results show that model 1 yields lower values of h r,w-gc and the root mean square error than model 2. It is therefore concluded that the accuracy of modelling the performance of a basin-type solar still can be improved by incorporating view factors. - Highlights: • Radiative heat transfer in a basin type solar still has been investigated. • Two models with and without view factors were used. • The model with view factors exhibits a lower magnitude of root mean square error. • View factors affect the accuracy of modelling the performance of the solar still

Modelling of Box Type Solar Cooker Performance in a Tropical ...

African Journals Online (AJOL)

Thermal performance model of box type solar cooker with loaded water is presented. The model was developed using the method of Funk to estimate cooking power in terms of climatic and design parameters for box type solar cooker in a tropical environment. Coefficients for each term used in the model were determined ...

Polarisation Spectral Synthesis For Type Ia Supernova Explosion Models

Science.gov (United States)

Bulla, Mattia

2017-02-01

Despite their relevance across a broad range of astrophysical research topics, Type Ia supernova explosions are still poorly understood and answers to the questions of when, why and how these events are triggered remain unclear. In this respect, polarisation offers a unique opportunity to discriminate between the variety of possible scenarios. The observational evidence that Type Ia supernovae are associated with rather low polarisation signals (smaller than a few per cent) places strong constraints for models and calls for modest asphericities in the progenitor system and/or explosion mechanism.The goal of this thesis is to assess the validity of contemporary Type Ia supernova explosion models by testing whether their predicted polarisation signatures can account for the small signals usually observed. To this end, we have implemented and tested an innovative Monte Carlo scheme in the radiative transfer code artis. Compared to previous Monte Carlo approaches, this technique produces synthetic observables (light curves, flux and polarisation spectra) with a substantial reduction in the Monte Carlo noise and therefore in the required computing time. This improvement is particularly crucial for our study as we aim to extract very weak polarisation signals, comparable to those detected in Type Ia supernovae. We have also demonstrated the applicability of this method to other classes of supernovae via a preliminary study of the first spectropolarimetry observations of superluminous supernovae.Using this scheme, we have calculated synthetic spectropolarimetry for three multi-dimensional explosion models recently proposed as promising candidates to explain Type Ia supernovae. Our findings highlight the power of spectropolarimetry in testing and discriminating between different scenarios. While all the three models predict light curves and flux spectra that are similar to each others and reproduce those observed in Type Ia supernovae comparably well, polarisation does

Discriminating neutrino mass models using Type-II see-saw formula

Indian Academy of Sciences (India)

though a fuller analysis needs the full matrix form when all terms are present. This is followed by the normal hierarchical model (Type [III]) and inverted hierarchical model with opposite CP phase (Type [IIB]). γ ≃ 10−2 for both of them. Our main results on neutrino masses and mixings in Type-II see-saw formula are presented ...

Improvement of TNO type trailing edge noise models

DEFF Research Database (Denmark)

Fischer, Andreas; Bertagnolio, Franck; Aagaard Madsen, Helge

2016-01-01

. It is computed by solving a Poisson equation which includes flow turbulence cross correlation terms. Previously published TNO type models used the assumption of Blake to simplify the Poisson equation. This paper shows that the simplification should not be used. We present a new model which fully models...

Improvement of TNO type trailing edge noise models

DEFF Research Database (Denmark)

Fischer, Andreas; Bertagnolio, Franck; Aagaard Madsen, Helge

2017-01-01

. It is computed by solving a Poisson equation which includes flow turbulence cross correlation terms. Previously published TNO type models used the assumption of Blake to simplify the Poisson equation. This paper shows that the simplification should not be used. We present a new model which fully models...

Type D Personality : a five-factor model perspective

NARCIS (Netherlands)

de Fruyt, F.; Denollet, J.K.L.

2002-01-01

This study investigated the position of Type D (high Negative Affectivity and high Social Inhibition) within the Five-Factor Model (FFM) of personality. A sample of 155 healthy subjects were administered the Type D Scale and the NEO-FFI, assessing the FFM traits. Subjects also filled out the General

Stochastic epidemic-type model with enhanced connectivity: exact solution

International Nuclear Information System (INIS)

Williams, H T; Mazilu, I; Mazilu, D A

2012-01-01

We present an exact analytical solution to a one-dimensional model of the susceptible–infected–recovered (SIR) epidemic type, with infection rates dependent on nearest-neighbor occupations. We use a quantum mechanical approach, transforming the master equation via a quantum spin operator formulation. We calculate exactly the time-dependent density of infected, recovered and susceptible populations for random initial conditions. Our results compare well with those of previous work, validating the model as a useful tool for additional and extended studies in this important area. Our model also provides exact solutions for the n-point correlation functions, and can be extended to more complex epidemic-type models

Chaos in long-term behavior of some Bianchi-type VIII models

Energy Technology Data Exchange (ETDEWEB)

Halpern, P

1987-01-01

The long-term behavior of Bianchi-type VIII models with three different types of stress-energy tensors are examined and compared. The vacuum model, a matter-filled model, and a model with an electromagnetic field are considered. In each case the existence of chaotic behavior and transitions to chaotic behavior are discussed.

Types of electric field distribution and corresponding types of convection in the polar ionosphere. Model

International Nuclear Information System (INIS)

Uvarov, V.M.; Barashkov, P.D.

1989-01-01

All types of distributions, known due to the experiment, for Ee-m electric field evening-morning component along morning-evening meridian are reproduced and corresponding types of convection in polar ionosphere are calculated on the basis of model of continuous distribution of E large-scale electric fields. Two-, three- and four-whirl types of convection are realized depending on conditions in interplanetary medium

A Finite Model Property for Intersection Types

Directory of Open Access Journals (Sweden)

Rick Statman

2015-03-01

Full Text Available We show that the relational theory of intersection types known as BCD has the finite model property; that is, BCD is complete for its finite models. Our proof uses rewriting techniques which have as an immediate by-product the polynomial time decidability of the preorder <= (although this also follows from the so called beta soundness of BCD.

Implementation of Electrical Simulation Model for IEC Standard Type-3A Generator

DEFF Research Database (Denmark)

Subramanian, Chandrasekaran; Casadei, Domenico; Tani, Angelo

2013-01-01

This paper describes the implementation of electrical simulation model for IEC 61400-27-1 standard Type-3A generator. A general overview of the different wind electric generators(WEG) types are given and the main focused on Type-3A WEG standard models, namely a model for a variable speed wind tur...

Type-2 fuzzy graphical models for pattern recognition

CERN Document Server

Zeng, Jia

2015-01-01

This book discusses how to combine type-2 fuzzy sets and graphical models to solve a range of real-world pattern recognition problems such as speech recognition, handwritten Chinese character recognition, topic modeling as well as human action recognition. It covers these recent developments while also providing a comprehensive introduction to the fields of type-2 fuzzy sets and graphical models. Though primarily intended for graduate students, researchers and practitioners in fuzzy logic and pattern recognition, the book can also serve as a valuable reference work for researchers without any previous knowledge of these fields. Dr. Jia Zeng is a Professor at the School of Computer Science and Technology, Soochow University, China. Dr. Zhi-Qiang Liu is a Professor at the School of Creative Media, City University of Hong Kong, China.

Neutrinoless double beta decay in type I+II seesaw models

Energy Technology Data Exchange (ETDEWEB)

Borah, Debasish [Department of Physics, Tezpur University,Tezpur-784028 (India); Dasgupta, Arnab [Institute of Physics, Sachivalaya Marg,Bhubaneshwar-751005 (India)

2015-11-30

We study neutrinoless double beta decay in left-right symmetric extension of the standard model with type I and type II seesaw origin of neutrino masses. Due to the enhanced gauge symmetry as well as extended scalar sector, there are several new physics sources of neutrinoless double beta decay in this model. Ignoring the left-right gauge boson mixing and heavy-light neutrino mixing, we first compute the contributions to neutrinoless double beta decay for type I and type II dominant seesaw separately and compare with the standard light neutrino contributions. We then repeat the exercise by considering the presence of both type I and type II seesaw, having non-negligible contributions to light neutrino masses and show the difference in results from individual seesaw cases. Assuming the new gauge bosons and scalars to be around a TeV, we constrain different parameters of the model including both heavy and light neutrino masses from the requirement of keeping the new physics contribution to neutrinoless double beta decay amplitude below the upper limit set by the GERDA experiment and also satisfying bounds from lepton flavor violation, cosmology and colliders.

Type II pp-wave matrix models from point-like gravitons

International Nuclear Information System (INIS)

Lozano, Yolanda; RodrIguez-Gomez, Diego

2006-01-01

The BMN Matrix model can be regarded as a theory of coincident M-theory gravitons, which expand by Myers dielectric effect into the 2-sphere and 5-sphere giant graviton vacua of the theory. In this note we show that, in the same fashion, Matrix String theory in Type IIA pp-wave backgrounds arises from the action for coincident Type IIA gravitons. In Type IIB, we show that the action for coincident gravitons in the maximally supersymmetric pp-wave background gives rise to a Matrix model which supports fuzzy 3-sphere giant graviton vacua with the right behavior in the classical limit. We discuss the relation between our Matrix model and the Tiny Graviton Matrix theory

Anisotropic Bianchi Type-I and Type-II Bulk Viscous String Cosmological Models Coupled with Zero Mass Scalar Field

Science.gov (United States)

Venkateswarlu, R.; Sreenivas, K.

2014-06-01

The LRS Bianchi type-I and type-II string cosmological models are studied when the source for the energy momentum tensor is a bulk viscous stiff fluid containing one dimensional strings together with zero-mass scalar field. We have obtained the solutions of the field equations assuming a functional relationship between metric coefficients when the metric is Bianchi type-I and constant deceleration parameter in case of Bianchi type-II metric. The physical and kinematical properties of the models are discussed in each case. The effects of Viscosity on the physical and kinematical properties are also studied.

Modeling of luminance distribution in CAVE-type virtual reality systems

Science.gov (United States)

Meironke, Michał; Mazikowski, Adam

2017-08-01

At present, one of the most advanced virtual reality systems are CAVE-type (Cave Automatic Virtual Environment) installations. Such systems are usually consisted of four, five or six projection screens and in case of six screens arranged in form of a cube. Providing the user with a high level of immersion feeling in such systems is largely dependent of optical properties of the system. The modeling of physical phenomena plays nowadays a huge role in the most fields of science and technology. It allows to simulate work of device without a need to make any changes in the physical constructions. In this paper distribution of luminance in CAVE-type virtual reality systems were modelled. Calculations were performed for the model of 6-walled CAVE-type installation, based on Immersive 3D Visualization Laboratory, situated at the Faculty of Electronics, Telecommunications and Informatics at the Gdańsk University of Technology. Tests have been carried out for two different scattering distribution of the screen material in order to check how these characteristicinfluence on the luminance distribution of the whole CAVE. The basis assumption and simplification of modeled CAVE-type installation and results were presented. The brief discussion about the results and usefulness of developed model were also carried out.

Comparison of renormalization group schemes for sine-Gordon-type models

International Nuclear Information System (INIS)

Nandori, I.; Nagy, S.; Sailer, K.; Trombettoni, A.

2009-01-01

The scheme dependence of the renormalization group (RG) flow has been investigated in the local potential approximation for two-dimensional periodic, sine-Gordon type field-theoretic models discussing the applicability of various functional RG methods in detail. It was shown that scheme-independent determination of such physical parameters is possible as the critical frequency (temperature) at which Kosterlitz-Thouless-Berezinskii type phase transition takes place in the sine-Gordon and the layered sine-Gordon models, and the critical ratio characterizing the Ising-type phase transition of the massive sine-Gordon model. For the latter case, the Maxwell construction represents a strong constraint on the RG flow, which results in a scheme-independent infrared value for the critical ratio. For the massive sine-Gordon model also the shrinking of the domain of the phase with spontaneously broken periodicity is shown to take place due to the quantum fluctuations.

The phasor type model of SMES

International Nuclear Information System (INIS)

Shi, J.; Tang, Y.; Ren, L.; Li, J.; Chen, S.

2009-01-01

Superconducting magnetic energy storage (SMES) compensates the dynamic power for the power system through regulating the active and reactive currents between the SMES and the power system. To analyze the influence of SMES on the operation characteristic of the power system, a second-order equivalent model of SMES is adopted in the electromagnetic transient analysis of power system, but the model makes considerable simplifications for the dynamic characteristic of SMES. This paper proposed the phasor type model of SMES. The phasor model has the following characteristics: (1) the model does not considers the switching state of the power electronic converter, which can save the computing time and improve the simulation efficiency; (2) the model considers the performance of the superconducting magnet, the converter and the DC side capacitor, which can accurately reflect the dynamic response characteristics of SMES; and (3) the model includes detailed control system of SMES, which can implement different control methods to the SMES system and evaluate the control effect. Using MATLAB SIMULINK, the dynamic characteristic of the SMES phasor model is evaluated. Then, the phasor model is introduced into the power system stability analysis to analyze the application of SMES in damping out the power system.

Tilted Bianchi type I dust fluid cosmological model in general relativity

Indian Academy of Sciences (India)

Tilted Bianchi type I dust fluid cosmological model in general relativity ... In this paper, we have investigated a tilted Bianchi type I cosmological model filled with dust of perfect fluid in general relativity. ... Pramana – Journal of Physics | News ...

Adaptation of Sing Lee's model to the Filippov type plasma focus geometry

International Nuclear Information System (INIS)

Siahpoush, V; Tafreshi, M A; Sobhanian, S; Khorram, S

2005-01-01

A new model for plasma behaviour in Filippov type plasma focus (PF) systems has been described and used. This model is based on the so-called slug model and Sing Lee's model for Mather type PF devices. Using the model, the discharge current and its derivative as a function of time, and the pinch time and the maximum discharge current as a function of pressure, have been predicted. At the end, the predicted data are compared with the experimental data obtained through a Filippov type PF facility with a nominal maximum energy of 90 kJ

Models of multiparticle production of the eikonal type

International Nuclear Information System (INIS)

Martinis, M.

1974-01-01

A survey of eikonal type models for multiparticle production is given. Empirical rules concerning the nature of multiparticle reactions are outlined. A discussion involving kinematics and cross sections for inclusive processes is presented. The constraints of multiparticle unitarity are considered to be of great importance in eikonal models for multiproduction at high energy. (HFdV)

Modeling neuropeptide transport in various types of nerve terminals containing en passant boutons.

Science.gov (United States)

Kuznetsov, I A; Kuznetsov, A V

2015-03-01

We developed a mathematical model for simulating neuropeptide transport inside dense core vesicles (DCVs) in axon terminals containing en passant boutons. The motivation for this research is a recent experimental study by Levitan and colleagues (Bulgari et al., 2014) which described DCV transport in nerve terminals of type Ib and type III as well as in nerve terminals of type Ib with the transcription factor DIMM. The goal of our modeling is validating the proposition put forward by Levitan and colleagues that the dramatic difference in DCV number in type Ib and type III terminals can be explained by the difference in DCV capture in type Ib and type III boutons rather than by differences in DCV anterograde transport and half-life of resident DCVs. The developed model provides a tool for studying the dynamics of DCV transport in various types of nerve terminals. The model is also an important step in gaining a better mechanistic understanding of transport processes in axons and identifying directions for the development of new models in this area. Copyright © 2014 Elsevier Inc. All rights reserved.

Hop pellets as an interesting source of antioxidant active compounds

Directory of Open Access Journals (Sweden)

Andrea Holubková

2013-02-01

Full Text Available Hop is a plant used by humankind for thousands of years. This plant is one of the main and indispensable raw materials for the beer production. It is used for various dishes preparation in the cuisine. Hop is also used to inhibit bacterial contamination. The hop extracts are used for its sedative, antiseptic and antioxidant properties in medicine, as a part of many phytopharmaceuticals. The present paper have focused on the extraction of polyphenolic compounds from 4 samples of hop pellets varieties of Aurora, Saaz, Lublin and Saphir, on the analyzing of bioactive substances (polyphenolics and flavonoids in prepared extracts and on the determination of antioxidant activity.  The highest content of polyphenolic substances was determined in the sample Lublin (153.06 mg gallic acid (GAE/g and Saaz (151.87 mg GAE/g. The amount of flavonoids in the samples  was descending order Saaz > Saphir > Aurora > Lublin. Hops, as plant, is known by high content of antioxidant active substances. Antioxidant activity was determined using three independent spectrofotometric methods, radical scavenging assays using 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS and 1,1-diphenyl-2-picrylhydrazyl (DPPH radical and ferric reducing antioxidant power (FRAP. The sample Aurora showed the highest ability to scavenge of ABTS radical cation. Antioxidant activity continued to decline in a row Saphir> Lublin> Saaz. The same trend was also observed by using the FRAP assay. The most effective DPPH radical scavengering activity had the sample Saaz a Saphir (p>0.05.doi:10.5219/270 Normal 0 21 false false false SK X-NONE X-NONE

Proteome-wide Structural Analysis of PTM Hotspots Reveals Regulatory Elements Predicted to Impact Biological Function and Disease*

Science.gov (United States)

Dewhurst, Henry; Sundararaman, Niveda

2016-01-01

Post-translational modifications (PTMs) regulate protein behavior through modulation of protein-protein interactions, enzymatic activity, and protein stability essential in the translation of genotype to phenotype in eukaryotes. Currently, less than 4% of all eukaryotic PTMs are reported to have biological function - a statistic that continues to decrease with an increasing rate of PTM detection. Previously, we developed SAPH-ire (Structural Analysis of PTM Hotspots) - a method for the prioritization of PTM function potential that has been used effectively to reveal novel PTM regulatory elements in discrete protein families (Dewhurst et al., 2015). Here, we apply SAPH-ire to the set of eukaryotic protein families containing experimental PTM and 3D structure data - capturing 1,325 protein families with 50,839 unique PTM sites organized into 31,747 modified alignment positions (MAPs), of which 2010 (∼6%) possess known biological function. Here, we show that using an artificial neural network model (SAPH-ire NN) trained to identify MAP hotspots with biological function results in prediction outcomes that far surpass the use of single hotspot features, including nearest neighbor PTM clustering methods. We find the greatest enhancement in prediction for positions with PTM counts of five or less, which represent 98% of all MAPs in the eukaryotic proteome and 90% of all MAPs found to have biological function. Analysis of the top 1092 MAP hotspots revealed 267 of truly unknown function (containing 5443 distinct PTMs). Of these, 165 hotspots could be mapped to human KEGG pathways for normal and/or disease physiology. Many high-ranking hotspots were also found to be disease-associated pathogenic sites of amino acid substitution despite the lack of observable PTM in the human protein family member. Taken together, these experiments demonstrate that the functional relevance of a PTM can be predicted very effectively by neural network models, revealing a large but testable

Proteome-wide Structural Analysis of PTM Hotspots Reveals Regulatory Elements Predicted to Impact Biological Function and Disease.

Science.gov (United States)

Torres, Matthew P; Dewhurst, Henry; Sundararaman, Niveda

2016-11-01

Post-translational modifications (PTMs) regulate protein behavior through modulation of protein-protein interactions, enzymatic activity, and protein stability essential in the translation of genotype to phenotype in eukaryotes. Currently, less than 4% of all eukaryotic PTMs are reported to have biological function - a statistic that continues to decrease with an increasing rate of PTM detection. Previously, we developed SAPH-ire (Structural Analysis of PTM Hotspots) - a method for the prioritization of PTM function potential that has been used effectively to reveal novel PTM regulatory elements in discrete protein families (Dewhurst et al., 2015). Here, we apply SAPH-ire to the set of eukaryotic protein families containing experimental PTM and 3D structure data - capturing 1,325 protein families with 50,839 unique PTM sites organized into 31,747 modified alignment positions (MAPs), of which 2010 (∼6%) possess known biological function. Here, we show that using an artificial neural network model (SAPH-ire NN) trained to identify MAP hotspots with biological function results in prediction outcomes that far surpass the use of single hotspot features, including nearest neighbor PTM clustering methods. We find the greatest enhancement in prediction for positions with PTM counts of five or less, which represent 98% of all MAPs in the eukaryotic proteome and 90% of all MAPs found to have biological function. Analysis of the top 1092 MAP hotspots revealed 267 of truly unknown function (containing 5443 distinct PTMs). Of these, 165 hotspots could be mapped to human KEGG pathways for normal and/or disease physiology. Many high-ranking hotspots were also found to be disease-associated pathogenic sites of amino acid substitution despite the lack of observable PTM in the human protein family member. Taken together, these experiments demonstrate that the functional relevance of a PTM can be predicted very effectively by neural network models, revealing a large but testable

Modeling terminal ballistics using blending-type spline surfaces

Science.gov (United States)

Pedersen, Aleksander; Bratlie, Jostein; Dalmo, Rune

2014-12-01

We explore using GERBS, a blending-type spline construction, to represent deform able thin-plates and model terminal ballistics. Strategies to construct geometry for different scenarios of terminal ballistics are proposed.

Type-specific human papillomavirus biological features: validated model-based estimates.

Directory of Open Access Journals (Sweden)

Iacopo Baussano

Full Text Available Infection with high-risk (hr human papillomavirus (HPV is considered the necessary cause of cervical cancer. Vaccination against HPV16 and 18 types, which are responsible of about 75% of cervical cancer worldwide, is expected to have a major global impact on cervical cancer occurrence. Valid estimates of the parameters that regulate the natural history of hrHPV infections are crucial to draw reliable projections of the impact of vaccination. We devised a mathematical model to estimate the probability of infection transmission, the rate of clearance, and the patterns of immune response following the clearance of infection of 13 hrHPV types. To test the validity of our estimates, we fitted the same transmission model to two large independent datasets from Italy and Sweden and assessed finding consistency. The two populations, both unvaccinated, differed substantially by sexual behaviour, age distribution, and study setting (screening for cervical cancer or Chlamydia trachomatis infection. Estimated transmission probability of hrHPV types (80% for HPV16, 73%-82% for HPV18, and above 50% for most other types; clearance rates decreasing as a function of time since infection; and partial protection against re-infection with the same hrHPV type (approximately 20% for HPV16 and 50% for the other types were similar in the two countries. The model could accurately predict the HPV16 prevalence observed in Italy among women who were not infected three years before. In conclusion, our models inform on biological parameters that cannot at the moment be measured directly from any empirical data but are essential to forecast the impact of HPV vaccination programmes.

Spectral action for Bianchi type-IX cosmological models

International Nuclear Information System (INIS)

Fan, Wentao; Fathizadeh, Farzad; Marcolli, Matilde

2015-01-01

A rationality result previously proved for Robertson-Walker metrics is extended to a homogeneous anisotropic cosmological model, namely the Bianchi type-IX minisuperspace. It is shown that the Seeley-de Witt coefficients appearing in the expansion of the spectral action for the Bianchi type-IX geometry are expressed in terms of polynomials with rational coefficients in the cosmic evolution factors w_1(t),w_2(t),w_3(t), and their higher derivates with respect to time. We begin with the computation of the Dirac operator of this geometry and calculate the coefficients a_0,a_2,a_4 of the spectral action by using heat kernel methods and parametric pseudodifferential calculus. An efficient method is devised for computing the Seeley-de Witt coefficients of a geometry by making use of Wodzicki’s noncommutative residue, and it is confirmed that the method checks out for the cosmological model studied in this article. The advantages of the new method are discussed, which combined with symmetries of the Bianchi type-IX metric, yield an elegant proof of the rationality result.

MODELS OF AN-TYPE INNOVATIVE ENDOGENOUS GROWTH AND THEIR SUBSTANTIATION

Directory of Open Access Journals (Sweden)

Askar A. Akaev

2015-01-01

Full Text Available The article presents an analysis of some classical models of economic growth of exogenous and endogenous type, based on the calculation of the motion of physical capital. It is shown that the simplest AN-type model, based on the calculation of population dynamics and endogenous technological progress, is more adequate for the description of the current economic development and provides a more accurate long-term forecast of economic dynamics.

Including model uncertainty in risk-informed decision making

International Nuclear Information System (INIS)

Reinert, Joshua M.; Apostolakis, George E.

2006-01-01

Model uncertainties can have a significant impact on decisions regarding licensing basis changes. We present a methodology to identify basic events in the risk assessment that have the potential to change the decision and are known to have significant model uncertainties. Because we work with basic event probabilities, this methodology is not appropriate for analyzing uncertainties that cause a structural change to the model, such as success criteria. We use the risk achievement worth (RAW) importance measure with respect to both the core damage frequency (CDF) and the change in core damage frequency (ΔCDF) to identify potentially important basic events. We cross-check these with generically important model uncertainties. Then, sensitivity analysis is performed on the basic event probabilities, which are used as a proxy for the model parameters, to determine how much error in these probabilities would need to be present in order to impact the decision. A previously submitted licensing basis change is used as a case study. Analysis using the SAPHIRE program identifies 20 basic events as important, four of which have model uncertainties that have been identified in the literature as generally important. The decision is fairly insensitive to uncertainties in these basic events. In three of these cases, one would need to show that model uncertainties would lead to basic event probabilities that would be between two and four orders of magnitude larger than modeled in the risk assessment before they would become important to the decision. More detailed analysis would be required to determine whether these higher probabilities are reasonable. Methods to perform this analysis from the literature are reviewed and an example is demonstrated using the case study

Impact of Diabetes Education Based on Type 1 Diabetes management model

OpenAIRE

Ocakçı, Ayşe Ferda

2015-01-01

The diabetes management is considered to be adversely affected when adolescent-specific education methods are not used. In this study, Type 1 Diabetes Management Model which ensures standardisation of the diabetes education and is based on the health promotion model and formed by applying health promotion model (HPM) according to the mastery-learning theory was used. The study was performed to determine effectiveness of diabetes education based on “Type 1 Diabetes Management Model” on adolesc...

Tilted Bianchi type I dust fluid cosmological model in general relativity

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 58; Issue 3. Tilted Bianchi type I dust fluid cosmological model in general ... In this paper, we have investigated a tilted Bianchi type I cosmological model filled with dust of perfect fluid in general relativity. To get a determinate solution, we have assumed a condition  ...

Structural Analysis of PTM Hotspots (SAPH-ire)--A Quantitative Informatics Method Enabling the Discovery of Novel Regulatory Elements in Protein Families.

Science.gov (United States)

Dewhurst, Henry M; Choudhury, Shilpa; Torres, Matthew P

2015-08-01

Predicting the biological function potential of post-translational modifications (PTMs) is becoming increasingly important in light of the exponential increase in available PTM data from high-throughput proteomics. We developed structural analysis of PTM hotspots (SAPH-ire)--a quantitative PTM ranking method that integrates experimental PTM observations, sequence conservation, protein structure, and interaction data to allow rank order comparisons within or between protein families. Here, we applied SAPH-ire to the study of PTMs in diverse G protein families, a conserved and ubiquitous class of proteins essential for maintenance of intracellular structure (tubulins) and signal transduction (large and small Ras-like G proteins). A total of 1728 experimentally verified PTMs from eight unique G protein families were clustered into 451 unique hotspots, 51 of which have a known and cited biological function or response. Using customized software, the hotspots were analyzed in the context of 598 unique protein structures. By comparing distributions of hotspots with known versus unknown function, we show that SAPH-ire analysis is predictive for PTM biological function. Notably, SAPH-ire revealed high-ranking hotspots for which a functional impact has not yet been determined, including phosphorylation hotspots in the N-terminal tails of G protein gamma subunits--conserved protein structures never before reported as regulators of G protein coupled receptor signaling. To validate this prediction we used the yeast model system for G protein coupled receptor signaling, revealing that gamma subunit-N-terminal tail phosphorylation is activated in response to G protein coupled receptor stimulation and regulates protein stability in vivo. These results demonstrate the utility of integrating protein structural and sequence features into PTM prioritization schemes that can improve the analysis and functional power of modification-specific proteomics data. © 2015 by The American

Dosha brain-types: A neural model of individual differences.

Science.gov (United States)

Travis, Frederick T; Wallace, Robert Keith

2015-01-01

This paper explores brain patterns associated with the three categories of regulatory principles of the body, mind, and behavior in Ayurveda, called Vata, Pitta, and Kapha dosha. A growing body of research has reported patterns of blood chemistry, genetic expression, physiological states, and chronic diseases associated with each dosha type. Since metabolic and growth factors are controlled by the nervous system, each dosha type should be associated with patterns of functioning of six major areas of the nervous system: The prefrontal cortex, the reticular activating system, the autonomic nervous system, the enteric nervous system, the limbic system, and the hypothalamus. For instance, the prefrontal cortex, which includes the anterior cingulate, ventral medial, and the dorsal lateral cortices, would exhibit a high range of functioning in the Vata brain-type leading to the possibility of being easily overstimulated. The Vata brain-type performs activity quickly. Learns quickly and forgets quickly. Their fast mind gives them an edge in creative problem solving. The Pitta brain-type reacts strongly to all challenges leading to purposeful and resolute actions. They never give up and are very dynamic and goal oriented. The Kapha brain-type is slow and steady leading to methodical thinking and action. They prefer routine and needs stimulation to get going. A model of dosha brain-types could provide a physiological foundation to understand individual differences. This model could help individualize treatment modalities to address different mental and physical dysfunctions. It also could explain differences in behavior seen in clinical as well as in normal populations.

Dosha brain-types: A neural model of individual differences

Directory of Open Access Journals (Sweden)

Frederick T Travis

2015-01-01

Full Text Available This paper explores brain patterns associated with the three categories of regulatory principles of the body, mind, and behavior in Ayurveda, called Vata, Pitta, and Kapha dosha. A growing body of research has reported patterns of blood chemistry, genetic expression, physiological states, and chronic diseases associated with each dosha type. Since metabolic and growth factors are controlled by the nervous system, each dosha type should be associated with patterns of functioning of six major areas of the nervous system: The prefrontal cortex, the reticular activating system, the autonomic nervous system, the enteric nervous system, the limbic system, and the hypothalamus. For instance, the prefrontal cortex, which includes the anterior cingulate, ventral medial, and the dorsal lateral cortices, would exhibit a high range of functioning in the Vata brain-type leading to the possibility of being easily overstimulated. The Vata brain-type performs activity quickly. Learns quickly and forgets quickly. Their fast mind gives them an edge in creative problem solving. The Pitta brain-type reacts strongly to all challenges leading to purposeful and resolute actions. They never give up and are very dynamic and goal oriented. The Kapha brain-type is slow and steady leading to methodical thinking and action. They prefer routine and needs stimulation to get going. A model of dosha brain-types could provide a physiological foundation to understand individual differences. This model could help individualize treatment modalities to address different mental and physical dysfunctions. It also could explain differences in behavior seen in clinical as well as in normal populations.

Sequence Domain Harmonic Modeling of Type-IV Wind Turbines

DEFF Research Database (Denmark)

Guest, Emerson; Jensen, Kim Høj; Rasmussen, Tonny Wederberg

2017-01-01

-sampled pulsewidth modulation and an analysis of converter generated voltage harmonics due to compensated dead-time. The decoupling capabilities of the proposed the SD harmonic model are verified through a power quality (PQ) assessment of a 3MW Type-IV wind turbine. The assessment shows that the magnitude and phase...... of low-order odd converter generated voltage harmonics are dependent on the converter operating point and the phase of the fundamental component of converter current respectively. The SD harmonic model can be used to make PQ assessments of Type-IV wind turbines or incorporated into harmonic load flows...... for computation of PQ in wind power plants....

Potential overestimation of HPV vaccine impact due to unmasking of non-vaccine types: quantification using a multi-type mathematical model.

Science.gov (United States)

Choi, Yoon Hong; Chapman, Ruth; Gay, Nigel; Jit, Mark

2012-05-14

Estimates of human papillomavirus (HPV) vaccine impact in clinical trials and modelling studies rely on DNA tests of cytology or biopsy specimens to determine the HPV type responsible for a cervical lesion. DNA of several oncogenic HPV types may be detectable in a specimen. However, only one type may be responsible for a particular cervical lesion. Misattribution of the causal HPV type for a particular abnormality may give rise to an apparent increase in disease due to non-vaccine HPV types following vaccination ("unmasking"). To investigate the existence and magnitude of unmasking, we analysed data from residual cytology and biopsy specimens in English women aged 20-64 years old using a stochastic type-specific individual-based model of HPV infection, progression and disease. The model parameters were calibrated to data on the prevalence of HPV DNA and cytological lesion of different grades, and used to assign causal HPV types to cervical lesions. The difference between the prevalence of all disease due to non-vaccine HPV types, and disease due to non-vaccine HPV types in the absence of vaccine HPV types, was then estimated. There could be an apparent maximum increase of 3-10% in long-term cervical cancer incidence due to non-vaccine HPV types following vaccination. Unmasking may be an important phenomenon in HPV post-vaccination epidemiology, in the same way that has been observed following pneumococcal conjugate vaccination. Copyright © 2012 Elsevier Ltd. All rights reserved.

Spectral action for Bianchi type-IX cosmological models

Energy Technology Data Exchange (ETDEWEB)

Fan, Wentao; Fathizadeh, Farzad; Marcolli, Matilde [Division of Physics, Mathematics and Astronomy, California Institute of Technology,1200 E. California Blvd., Pasadena, CA 91125 (United States)

2015-10-13

A rationality result previously proved for Robertson-Walker metrics is extended to a homogeneous anisotropic cosmological model, namely the Bianchi type-IX minisuperspace. It is shown that the Seeley-de Witt coefficients appearing in the expansion of the spectral action for the Bianchi type-IX geometry are expressed in terms of polynomials with rational coefficients in the cosmic evolution factors w{sub 1}(t),w{sub 2}(t),w{sub 3}(t), and their higher derivates with respect to time. We begin with the computation of the Dirac operator of this geometry and calculate the coefficients a{sub 0},a{sub 2},a{sub 4} of the spectral action by using heat kernel methods and parametric pseudodifferential calculus. An efficient method is devised for computing the Seeley-de Witt coefficients of a geometry by making use of Wodzicki’s noncommutative residue, and it is confirmed that the method checks out for the cosmological model studied in this article. The advantages of the new method are discussed, which combined with symmetries of the Bianchi type-IX metric, yield an elegant proof of the rationality result.

Candidate Medical Countermeasures Targeting Ebola Virus Cell Entry

Science.gov (United States)

2017-03-31

ML, Hessell AJ, Oswald WB, Burton DR, Saphire EO. Structure of the 405 Ebola virus glycoprotein bound to an antibody from a human survivor. Nature...virus cell-entry inhibitors 21 17. Gallaher WR. Similar structural models of the transmembrane proteins of Ebola and 408 avian sarcoma viruses. Cell...85(4), 477-478 (1996). 409 18. Weissenhorn W, Carfí A, Lee K-H, Skehel JJ, Wiley DC. Crystal structure of the Ebola 410 virus membrane fusion

Comparison of the WSA-ENLIL model with three CME cone types

Science.gov (United States)

Jang, Soojeong; Moon, Y.; Na, H.

2013-07-01

We have made a comparison of the CME-associated shock propagation based on the WSA-ENLIL model with three cone types using 29 halo CMEs from 2001 to 2002. These halo CMEs have cone model parameters as well as their associated interplanetary (IP) shocks. For this study we consider three different cone types (an asymmetric cone model, an ice-cream cone model and an elliptical cone model) to determine 3-D CME parameters (radial velocity, angular width and source location), which are the input values of the WSA-ENLIL model. The mean absolute error (MAE) of the arrival times for the asymmetric cone model is 10.6 hours, which is about 1 hour smaller than those of the other models. Their ensemble average of MAE is 9.5 hours. However, this value is still larger than that (8.7 hours) of the empirical model of Kim et al. (2007). We will compare their IP shock velocities and densities with those from ACE in-situ measurements and discuss them in terms of the prediction of geomagnetic storms.Abstract (2,250 Maximum Characters): We have made a comparison of the CME-associated shock propagation based on the WSA-ENLIL model with three cone types using 29 halo CMEs from 2001 to 2002. These halo CMEs have cone model parameters as well as their associated interplanetary (IP) shocks. For this study we consider three different cone types (an asymmetric cone model, an ice-cream cone model and an elliptical cone model) to determine 3-D CME parameters (radial velocity, angular width and source location), which are the input values of the WSA-ENLIL model. The mean absolute error (MAE) of the arrival times for the asymmetric cone model is 10.6 hours, which is about 1 hour smaller than those of the other models. Their ensemble average of MAE is 9.5 hours. However, this value is still larger than that (8.7 hours) of the empirical model of Kim et al. (2007). We will compare their IP shock velocities and densities with those from ACE in-situ measurements and discuss them in terms of the

Impairment-Factor-Based Audiovisual Quality Model for IPTV: Influence of Video Resolution, Degradation Type, and Content Type

Directory of Open Access Journals (Sweden)

Garcia MN

2011-01-01

Full Text Available This paper presents an audiovisual quality model for IPTV services. The model estimates the audiovisual quality of standard and high definition video as perceived by the user. The model is developed for applications such as network planning and packet-layer quality monitoring. It mainly covers audio and video compression artifacts and impairments due to packet loss. The quality tests conducted for model development demonstrate a mutual influence of the perceived audio and video quality, and the predominance of the video quality for the overall audiovisual quality. The balance between audio quality and video quality, however, depends on the content, the video format, and the audio degradation type. The proposed model is based on impairment factors which quantify the quality-impact of the different degradations. The impairment factors are computed from parameters extracted from the bitstream or packet headers. For high definition video, the model predictions show a correlation with unknown subjective ratings of 95%. For comparison, we have developed a more classical audiovisual quality model which is based on the audio and video qualities and their interaction. Both quality- and impairment-factor-based models are further refined by taking the content-type into account. At last, the different model variants are compared with modeling approaches described in the literature.

Identification of reverse logistics decision types from mathematical models

Directory of Open Access Journals (Sweden)

Pascual Cortés Pellicer

2018-04-01

Full Text Available Purpose: The increase in social awareness, politics and environmental regulation, the scarcity of raw materials and the desired “green” image, are some of the reasons that lead companies to decide for implement processes of Reverse Logistics (RL. At the time when incorporate new RL processes as key business processes, new and important decisions need to be made. Identification and knowledge of these decisions, including the information available and the implications for the company or supply chain, will be fundamental for decision-makers to achieve the best results. In the present work, the main types of RL decisions are identified. Design/methodology/approach: This paper is based on the analysis of mathematical models designed as tools to aid decision making in the field of RL. Once the types of interest work to be analyzed are defined, those studies that really deal about the object of study are searched and analyzed. The decision variables that are taken at work are identified and grouped according to the type of decision and, finally, are showed the main types of decisions used in mathematical models developed in the field of RL.     Findings: The principal conclusion of the research is that the most commonly addressed decisions with mathematical models in the field of RL are those related to the network’s configuration, followed by tactical/operative decisions such as the selections of product’s treatments to realize and the policy of returns or prices, among other decisions. Originality/value: The identification of the main decisions types of the reverse logistics will allow the managers of these processes to know and understand them better, while offer an integrated vision of them, favoring the achievement of better results.

Multivariate poisson lognormal modeling of crashes by type and severity on rural two lane highways.

Science.gov (United States)

Wang, Kai; Ivan, John N; Ravishanker, Nalini; Jackson, Eric

2017-02-01

In an effort to improve traffic safety, there has been considerable interest in estimating crash prediction models and identifying factors contributing to crashes. To account for crash frequency variations among crash types and severities, crash prediction models have been estimated by type and severity. The univariate crash count models have been used by researchers to estimate crashes by crash type or severity, in which the crash counts by type or severity are assumed to be independent of one another and modelled separately. When considering crash types and severities simultaneously, this may neglect the potential correlations between crash counts due to the presence of shared unobserved factors across crash types or severities for a specific roadway intersection or segment, and might lead to biased parameter estimation and reduce model accuracy. The focus on this study is to estimate crashes by both crash type and crash severity using the Integrated Nested Laplace Approximation (INLA) Multivariate Poisson Lognormal (MVPLN) model, and identify the different effects of contributing factors on different crash type and severity counts on rural two-lane highways. The INLA MVPLN model can simultaneously model crash counts by crash type and crash severity by accounting for the potential correlations among them and significantly decreases the computational time compared with a fully Bayesian fitting of the MVPLN model using Markov Chain Monte Carlo (MCMC) method. This paper describes estimation of MVPLN models for three-way stop controlled (3ST) intersections, four-way stop controlled (4ST) intersections, four-way signalized (4SG) intersections, and roadway segments on rural two-lane highways. Annual Average Daily traffic (AADT) and variables describing roadway conditions (including presence of lighting, presence of left-turn/right-turn lane, lane width and shoulder width) were used as predictors. A Univariate Poisson Lognormal (UPLN) was estimated by crash type and

Asteroseismic modelling of the solar-type subgiant star β Hydri

DEFF Research Database (Denmark)

Brandão, I.M.; Dogan, Gülnur; Christensen-Dalsgaard, Jørgen

2011-01-01

Context. Comparing models and data of pulsating stars is a powerful way to understand the stellar structure better. Moreover, such comparisons are necessary to make improvements to the physics of the stellar models, since they do not yet perfectly represent either the interior or especially...... the surface layers of stars. Because β Hydri is an evolved solar-type pulsator with mixed modes in its frequency spectrum, it is very interesting for asteroseismic studies. Aims: The goal of the present work is to search for a representative model of the solar-type star β Hydri, based on up-to-date non...... frequencies of β Hydri: (i) we assume that the best model is the one that reproduces the star's interior based on the radial oscillation frequencies alone, to which we have applied the correction for the near-surface effects; (ii) we assume that the best model is the one that produces the lowest value...

Type-2 fuzzy elliptic membership functions for modeling uncertainty

DEFF Research Database (Denmark)

Kayacan, Erdal; Sarabakha, Andriy; Coupland, Simon

2018-01-01

Whereas type-1 and type-2 membership functions (MFs) are the core of any fuzzy logic system, there are no performance criteria available to evaluate the goodness or correctness of the fuzzy MFs. In this paper, we make extensive analysis in terms of the capability of type-2 elliptic fuzzy MFs...... in modeling uncertainty. Having decoupled parameters for its support and width, elliptic MFs are unique amongst existing type-2 fuzzy MFs. In this investigation, the uncertainty distribution along the elliptic MF support is studied, and a detailed analysis is given to compare and contrast its performance...... advantages mentioned above, elliptic MFs have comparable prediction results when compared to Gaussian and triangular MFs. Finally, in order to test the performance of fuzzy logic controller with elliptic interval type-2 MFs, extensive real-time experiments are conducted for the 3D trajectory tracking problem...

New spin Calogero-Sutherland models related to BN-type Dunkl operators

International Nuclear Information System (INIS)

Finkel, F.; Gomez-Ullate, D.; Gonzalez-Lopez, A.; Rodriguez, M.A.; Zhdanov, R.

2001-01-01

We construct several new families of exactly and quasi-exactly solvable BC N -type Calogero-Sutherland models with internal degrees of freedom. Our approach is based on the introduction of a new family of Dunkl operators of B N type which, together with the original B N -type Dunkl operators, are shown to preserve certain polynomial subspaces of finite dimension. We prove that a wide class of quadratic combinations involving these three sets of Dunkl operators always yields a spin Calogero-Sutherland model, which is (quasi-)exactly solvable by construction. We show that all the spin Calogero-Sutherland models obtainable within this framework can be expressed in a unified way in terms of a Weierstrass ζ function with suitable half-periods. This provides a natural spin counterpart of the well-known general formula for a scalar completely integrable potential of BC N type due to Olshanetsky and Perelomov. As an illustration of our method, we exactly compute several energy levels and their corresponding wavefunctions of an elliptic quasi-exactly solvable potential for two and three particles of spin 1/2

Desensitization and Modeling Treatments of Spider Fear Using Two Types of Scenes

Science.gov (United States)

Denney, Douglas R.; Sullivan, Bernard J.

1976-01-01

Three types of therapy were combined with two types of scenes. Spider-phobic subjects were assigned to one of the six treatment conditions or to an untreated control group. In general, (a) Desensitization and modeling therapies were equally effective; (b) modeling alone was more effective than mere exposure to the phobic object. (Author)

New approaches for modeling type Ia supernovae

International Nuclear Information System (INIS)

Zingale, Michael; Almgren, Ann S.; Bell, John B.; Day, Marcus S.; Rendleman, Charles A.; Woosley, Stan

2007-01-01

Type Ia supernovae (SNe Ia) are the largest thermonuclear explosions in the Universe. Their light output can be seen across great distances and has led to the discovery that the expansion rate of the Universe is accelerating. Despite the significance of SNe Ia, there are still a large number of uncertainties in current theoretical models. Computational modeling offers the promise to help answer the outstanding questions. However, even with today's supercomputers, such calculations are extremely challenging because of the wide range of length and timescales. In this paper, we discuss several new algorithms for simulations of SNe Ia and demonstrate some of their successes

Late-time behaviour of the tilted Bianchi type VIh models

Science.gov (United States)

Hervik, S.; van den Hoogen, R. J.; Lim, W. C.; Coley, A. A.

2007-08-01

We study tilted perfect fluid cosmological models with a constant equation of state parameter in spatially homogeneous models of Bianchi type VIh using dynamical systems methods and numerical experimentation, with an emphasis on their future asymptotic evolution. We determine all of the equilibrium points of the type VIh state space (which correspond to exact self-similar solutions of the Einstein equations, some of which are new), and their stability is investigated. We find that there are vacuum plane-wave solutions that act as future attractors. In the parameter space, a 'loophole' is shown to exist in which there are no stable equilibrium points. We then show that a Hopf-bifurcation can occur resulting in a stable closed orbit (which we refer to as the Mussel attractor) corresponding to points both inside the loophole and points just outside the loophole; in the former case the closed curves act as late-time attractors while in the latter case these attracting curves will co-exist with attracting equilibrium points. In the special Bianchi type III case, centre manifold theory is required to determine the future attractors. Comprehensive numerical experiments are carried out to complement and confirm the analytical results presented. We note that the Bianchi type VIh case is of particular interest in that it contains many different subcases which exhibit many of the different possible future asymptotic behaviours of Bianchi cosmological models.

Successful use of a linear position-sensitive neutron detector in solid state physics and materials science

International Nuclear Information System (INIS)

Schefer, J.; Fischer, P.; Heer, H.; Isacson, A.; Koch, M.; Thut, R.

1991-01-01

The double axis multicounter diffractometer (DMC) installed at the 10 MW reactor SAPHIR (PSI) has been designed as a good flux-good resolution (presently Δd/d≥4x10 -3 ) neutron poder diffractometer. The detector bank is based on a commercial position-sensitive linear BF 3 detector which may be automatically and precisely positioned on air cushions on inexpensive floors. This detector type has an 80deg angular opening, not allowing any standard collimation in front of the detector. We therefore developed an oscillating collimator system allowing easy use of the instrument even with sample environments such as a dilution cryostat. (orig.)

Dynamic of exact perturbations in Bianchi IX type cosmological models

International Nuclear Information System (INIS)

Mello Neto, J.R.T. de.

1985-01-01

The dynamic of Bianchi IX type cosmological models is studied, after reducing Einstein equations to Hamiltonian system. Using the Melnikov method, the existence of chaos in the dynamic of these models is proved, and some numerical experiments are carried out. (M.C.K.) [pt

A model for cell type localization in the migrating slug of ...

Indian Academy of Sciences (India)

PRAKASH

. Localization of the three major cell types within the migrating slug stage is a dynamic process (Sternfeld 1992;. A model for cell type localization in the migrating slug of Dictyostelium discoideum based on differential chemotactic sensitivity to ...

Analysis and synthesis for interval type-2 fuzzy-model-based systems

CERN Document Server

Li, Hongyi; Lam, Hak-Keung; Gao, Yabin

2016-01-01

This book develops a set of reference methods capable of modeling uncertainties existing in membership functions, and analyzing and synthesizing the interval type-2 fuzzy systems with desired performances. It also provides numerous simulation results for various examples, which fill certain gaps in this area of research and may serve as benchmark solutions for the readers. Interval type-2 T-S fuzzy models provide a convenient and flexible method for analysis and synthesis of complex nonlinear systems with uncertainties.

Bianchi Type-IX viscous fluid cosmological model in general relativity

Indian Academy of Sciences (India)

the de-Sitter universe, the Taub-NUT solutions etc. are of Bianchi Type-IX space- times. In these models, neutrino viscosity does not guarantee isotropy at the present ..... The model (2.11) starts with a big-bang at T = 0 where α > 0 and m < 2, and the expansion in the model decreases as time increases. The expansion in the ...

Improved simulation of two types of El Niño in CMIP5 models

International Nuclear Information System (INIS)

Kug, Jong-Seong; Ham, Yoo-Geun; Lee, June-Yi; Jin, Fei-Fei

2012-01-01

Using the coupled general circulation models (CGCMs) participating in phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5), simulations of the two types of El Niño event are evaluated. Previous studies using CMIP3 models pointed out that most of the models tend to simulate a single type of El Niño, and have serious problems in simulating the two types of El Niño independently. On the average, the CGCMs in CMIP5 have slightly better performance in simulating the two types of El Niño event independently with more distinct spatial patterns, compared to those in CMIP3. It is demonstrated that the precipitation response to Cold Tongue El Niño is one of the important factors in simulating the two types of El Niño independently in coupled models, and this precipitation response is closely related to the dry bias over the equatorial eastern Pacific. (letter)

Image Restoration Based on the Hybrid Total-Variation-Type Model

OpenAIRE

Shi, Baoli; Pang, Zhi-Feng; Yang, Yu-Fei

2012-01-01

We propose a hybrid total-variation-type model for the image restoration problem based on combining advantages of the ROF model with the LLT model. Since two ${L}^{1}$ -norm terms in the proposed model make it difficultly solved by using some classically numerical methods directly, we first employ the alternating direction method of multipliers (ADMM) to solve a general form of the proposed model. Then, based on the ADMM and the Moreau-Yosida decomposition theory, a more efficient method call...

Extended Lipkin-type models with residual proton-neutron interaction

International Nuclear Information System (INIS)

Stoica, S.

1999-01-01

Extended Lipkin-Meshkov-Glick (LMG) models for testing the Random Phase Approximation (RPA) and proton-neutron Random Phase Approximation (pnRPA) methods are developed taking into account explicitly the proton and neutron degrees of freedom. First, an extended LMG model for testing RPA is developed. The proton and neutron Hamiltonians are taken to be of the LMG form and, in addition, a residual proton-neutron interaction is included. Exact solutions in a SU(2) x SU(2) basis as well as the RPA solutions for the energy spectrum of the model Hamiltonian are obtained. Then, the behaviour of the first collective excited state is studied as a function of the interaction parameters of the model using the exact and RPA methods. Secondly, an extended LMG model for testing pnRPA method is developed. Besides the proton and neutron single particle terms two types of residual proton-neutron interactions, one simulating a particle-particle and the other a particle-hole interaction, are included in the model Hamiltonian, so that the model is exactly solvable in an isospin SU(2) x SU(2) basis. The exact and pnRPA spectra of the model Hamiltonian are calculated as a function of the model parameters and compared to each other. Furthermore, charge-changing operators simulating a nuclear beta decay and their action on eigenfunctions of the model Hamiltonian are defined, and transition amplitude of them are calculated using exact and pnRPA wave functions. The best agreement between the exact RPA-type calculations for spectra and transitions, was obtained when the correlated RPA ground state, instead of the uncorrelated HF ground state was employed and when both kinds of residual interactions (i.e. like- and unlike-particle two-body interactions) are included in the model Hamiltonians. (author)

PULSATING REVERSE DETONATION MODELS OF TYPE Ia SUPERNOVAE. II. EXPLOSION

International Nuclear Information System (INIS)

Bravo, Eduardo; Garcia-Senz, Domingo; Cabezon, Ruben M.; DomInguez, Inmaculada

2009-01-01

Observational evidences point to a common explosion mechanism of Type Ia supernovae based on a delayed detonation of a white dwarf (WD). However, all attempts to find a convincing ignition mechanism based on a delayed detonation in a destabilized, expanding, white dwarf have been elusive so far. One of the possibilities that has been invoked is that an inefficient deflagration leads to pulsation of a Chandrasekhar-mass WD, followed by formation of an accretion shock that confines a carbon-oxygen rich core, while transforming the kinetic energy of the collapsing halo into thermal energy of the core, until an inward moving detonation is formed. This chain of events has been termed Pulsating Reverse Detonation (PRD). In this work, we present three-dimensional numerical simulations of PRD models from the time of detonation initiation up to homologous expansion. Different models characterized by the amount of mass burned during the deflagration phase, M defl , give explosions spanning a range of kinetic energies, K ∼ (1.0-1.2) x 10 51 erg, and 56 Ni masses, M( 56 Ni) ∼ 0.6-0.8 M sun , which are compatible with what is expected for typical Type Ia supernovae. Spectra and light curves of angle-averaged spherically symmetric versions of the PRD models are discussed. Type Ia supernova spectra pose the most stringent requirements on PRD models.

Impaired peripheral nerve regeneration in type-2 diabetic mouse model.

Science.gov (United States)

Pham, Vuong M; Tu, Nguyen Huu; Katano, Tayo; Matsumura, Shinji; Saito, Akira; Yamada, Akihiro; Furue, Hidemasa; Ito, Seiji

2018-01-01

Peripheral neuropathy is one of the most common and serious complications of type-2 diabetes. Diabetic neuropathy is characterized by a distal symmetrical sensorimotor polyneuropathy, and its incidence increases in patients 40 years of age or older. In spite of extensive research over decades, there are few effective treatments for diabetic neuropathy besides glucose control and improved lifestyle. The earliest changes in diabetic neuropathy occur in sensory nerve fibers, with initial degeneration and regeneration resulting in pain. To seek its effective treatment, here we prepared a type-2 diabetic mouse model by giving mice 2 injections of streptozotocin and nicotinamide and examining the ability for nerve regeneration by using a sciatic nerve transection-regeneration model previously established by us. Seventeen weeks after the last injection, the mice exhibited symptoms of type-2 diabetes, that is, impaired glucose tolerance, decreased insulin level, mechanical hyperalgesia, and impaired sensory nerve fibers in the plantar skin. These mice showed delayed functional recovery and nerve regeneration by 2 weeks compared with young healthy mice and by 1 week compared with age-matched non-diabetic mice after axotomy. Furthermore, type-2 diabetic mice displayed increased expression of PTEN in their DRG neurons. Administration of a PTEN inhibitor at the cutting site of the nerve for 4 weeks promoted the axonal transport and functional recovery remarkably. This study demonstrates that peripheral nerve regeneration was impaired in type-2 diabetic model and that its combination with sciatic nerve transection is suitable for the study of the pathogenesis and treatment of early diabetic neuropathy. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Development of a Coronary Heart Disease Risk Prediction Model for Type 1 Diabetes: The Pittsburgh CHD in Type 1 Diabetes Risk Mode

NARCIS (Netherlands)

Zgibor, J.C.; Ruppert, K.; Orchard, T.J.; Soedamah-Muthu, S.S.; Fuller, J.H.; Chaturvedi, N.; Roberts, M.S.

2010-01-01

Aim - To create a coronary heart disease (CHD) risk prediction model specific to type 1 diabetes. Methods - Development of the model used data from the Pittsburgh Epidemiology of Diabetes Complications Study (EDC). EDC subjects had type 1 diabetes diagnosed between 1950 and 1980, received their

[Discussion of Chinese syndrome typing in acute hepatic failure model].

Science.gov (United States)

Zhang, Jin-liang; Zeng, Hui; Wang, Xian-bo

2011-05-01

To study Chinese syndrome typing of acute hepatic failure (AHF) mice model by screening effective formulae. Lipoplysaccharides (LPS)/D-galactosamine (D-GaIN) was intraperitoneally injected to mice to establish the AHF mice model. Yinchenhao Decoction, Huanglian Jiedu Decoction, Buzhong Yiqi Decoction, and Xijiao Dihuang Decoction were administered to model mice respectively by gastrogavage. The behavior and the survival rate were monitored. The liver function and pathological changes of liver tissues were detected. In all the tested classic recipes, the survival rate was elevated from 10% to 60% by administration of Xijiao Dihuang Decoction. Five h after modeling, the serum alanine aminotransferase (ALT) level was (183.95 +/- 52.00) U/L, and aspartate aminotransferase (AST) (235.70 +/- 34.03) U/L in Xijiao Di-huang Decoction Group, lower than those of the model control group, but with insignificant difference (ALT: 213.32 +/- 71.93 U/L; AST: 299.48 +/- 70.56 U/L, both P > 0.05). Xijiao Dihuang Decoction could obviously alleviate the liver injury. Xijiao Dihuang Decoction was an effective formula for LPS/D-GaIN induced AHF model. According to syndrome typing through formula effect, heat toxin and blood stasis syndrome dominated in the LPS/D-GalN induced AHF mice model.

Annihilation Prediction for Lanchester-Type Models of Modern Warfare

OpenAIRE

Brown, G.G.; Taylor, J.

1983-01-01

Operations Research, 31, p.752. This paper introduces important new functions for analytic solution of Launch-ester-type equations of modern warfare for combat between two homogeneous forces modeled by power attrtition-rate coefficients with "no offset". Tabulations of these Lanchester-Clifford-Schlatii (or LCS) functions allow one to study this particular variable-coefficient model almost as easily and thoroughly as Lanchester's classic constant-coefficient one. LCS functions allow one ...

Mixed models approaches for joint modeling of different types of responses.

Science.gov (United States)

Ivanova, Anna; Molenberghs, Geert; Verbeke, Geert

2016-01-01

In many biomedical studies, one jointly collects longitudinal continuous, binary, and survival outcomes, possibly with some observations missing. Random-effects models, sometimes called shared-parameter models or frailty models, received a lot of attention. In such models, the corresponding variance components can be employed to capture the association between the various sequences. In some cases, random effects are considered common to various sequences, perhaps up to a scaling factor; in others, there are different but correlated random effects. Even though a variety of data types has been considered in the literature, less attention has been devoted to ordinal data. For univariate longitudinal or hierarchical data, the proportional odds mixed model (POMM) is an instance of the generalized linear mixed model (GLMM; Breslow and Clayton, 1993). Ordinal data are conveniently replaced by a parsimonious set of dummies, which in the longitudinal setting leads to a repeated set of dummies. When ordinal longitudinal data are part of a joint model, the complexity increases further. This is the setting considered in this paper. We formulate a random-effects based model that, in addition, allows for overdispersion. Using two case studies, it is shown that the combination of random effects to capture association with further correction for overdispersion can improve the model's fit considerably and that the resulting models allow to answer research questions that could not be addressed otherwise. Parameters can be estimated in a fairly straightforward way, using the SAS procedure NLMIXED.

Modeling and experimental study of a corrugated wick type solar still: Comparative study with a simple basin type

International Nuclear Information System (INIS)

Matrawy, K.K.; Alosaimy, A.S.; Mahrous, A.-F.

2015-01-01

Highlights: • Performance of corrugated wick type solar still is compared with simple type. • Corrugated porous surface contributes by about 75% of the total productivity. • Productivity of corrugated solar still was 34% more than that for simple type. - Abstract: In the present work, the productivity of a solar still is modified by forming the evaporative surface as a corrugated shape as well as by decreasing the heat capacity with the use of a porous material. This target has been achieved by using black clothes in a corrugated shape that are immersed in water where the clothes absorbs water and get saturated by capillary effect. Along with the proposed corrugated wick type solar still, a simple basin still type was fabricated and tested to compare the enhancement accomplished by the developed solar still. Inclined reflectors were used to augment the solar radiation incident on the plane of the developed solar stills. The energy balance in the developed mathematical models takes into consideration the glass covers, the porous material, along with the portion of water exposed to the transmitted solar radiation as well as the portion of water shaded by the corrugated surface. The developed mathematical model was validated by fabricating and testing two models for the proposed and simple basin solar stills under the same conditions. Good agreement between the simulated and experimental results has been detected. It has been found that an improvement of about 34% in the productivity for the proposed wick type solar still is gained as compared to the simple basin case. Also, the best tilt angle for the inclined reflector has been found to be about 30° with respect to the vertical direction of the setup under consideration.

Analytical calculation of detailed model parameters of cast resin dry-type transformers

International Nuclear Information System (INIS)

Eslamian, M.; Vahidi, B.; Hosseinian, S.H.

2011-01-01

Highlights: → In this paper high frequency behavior of cast resin dry-type transformers was simulated. → Parameters of detailed model were calculated using analytical method and compared with FEM results. → A lab transformer was constructed in order to compare theoretical and experimental results. -- Abstract: Non-flammable characteristic of cast resin dry-type transformers make them suitable for different kind of usages. This paper presents an analytical method of how to obtain parameters of detailed model of these transformers. The calculated parameters are compared and verified with the corresponding FEM results and if it was necessary, correction factors are introduced for modification of the analytical solutions. Transient voltages under full and chopped test impulses are calculated using the obtained detailed model. In order to validate the model, a setup was constructed for testing on high-voltage winding of cast resin dry-type transformer. The simulation results were compared with the experimental data measured from FRA and impulse tests.

Event simulation for the WA80 experiment

International Nuclear Information System (INIS)

Sorensen, S.P.

1986-01-01

The HIJET and LUND event generators are compared. It is concluded that for detector construction and design of experimental setups, the differences between the two models are marginal. The coverage of the WA80 setup in pseudorapidity and energy is demonstrated. The performance of some of the WA80 detectors (zero-degree calorimeter, wall calorimeter, multiplicity array, and SAPHIR lead-glass detector) is evaluated based on calculations with the LUND or the HIJET codes combined with codes simulating the detector responses. 9 refs., 3 figs

A Study of Enhanced, Higher Order Boussinesq-Type Equations and Their Numerical Modelling

DEFF Research Database (Denmark)

Banijamali, Babak

model is designated for the solution of higher-order Boussinesq-type equations, formulated in terms of the horizontal velocity at an arbitrary depth vector. Various discretisation techniques and grid definitions have been considered in this endeavour, undertaking a detailed analysis of the selected......This project has encompassed efforts in two separate veins: on the one hand, the acquiring of highly accurate model equations of the Boussinesq-type, and on the other hand, the theoretical and practical work in implementing such equations in the form of conventional numerical models, with obvious...... potential for applications to the realm of numerical modelling in coastal engineering. The derivation and analysis of several forms of higher-order in dispersion and non-linearity Boussinesq-type equations have been undertaken, obtaining and investigating the properties of a new and generalised class...

Implementation of IEC Generic Models of Type 1 Wind Turbine Generator in DIgSILENT PowerFactory

Institute of Scientific and Technical Information of China (English)

Haoran ZHAO; Qiuwei WU; Ioannis MARGARIS; Poul S(O)RENSEN

2013-01-01

The implementation method for the International Electrotechnical Commission (IEC) generic models of Type 1 wind turbine generator (WTG) in DIgSILENT PowerFactory is presented.The following items are described,i.e.model structure,model blocks and how to implement these blocks in the PowerFactory environment.Case studies under both normal and fault conditions are done with the implemented IEC generic models of Type 1 WTG,and dynamic responses are captured and analyzed.The case study results show that the IEC generic models of Type 1 WTG can correctly represent the performances of Type 1 WTG under both normal and fault conditions.

A Step-indexed Semantic Model of Types for the Call-by-Name Lambda Calculus

OpenAIRE

Meurer, Benedikt

2011-01-01

Step-indexed semantic models of types were proposed as an alternative to purely syntactic safety proofs using subject-reduction. Building upon the work by Appel and others, we introduce a generalized step-indexed model for the call-by-name lambda calculus. We also show how to prove type safety of general recursion in our call-by-name model.

Modeling And Position Control Of Scara Type 3D Printer

Directory of Open Access Journals (Sweden)

Ahmet Saygamp305n Ogulmuamp351

2015-08-01

Full Text Available In this work a scara robot type 3D printer system is dynamically modeled and position control of the system is realized. For this aim computer aided design model of three degrees of freedom robotic system is created using SolidWorks program then obtained model is exported to MATLABSimMechanics software for position control. Also mathematical model of servo motors used in robotic 3D printer system is included in control methodology to design proportional controllers. Uncontrolled and controlled position results are simulated and given in the form of the graphics.

Tests on thirteen navy type model propellers

Science.gov (United States)

Durand, W F

1927-01-01

The tests on these model propellers were undertaken for the purpose of determining the performance coefficients and characteristics for certain selected series of propellers of form and type as commonly used in recent navy designs. The first series includes seven propellers of pitch ratio varying by 0.10 to 1.10, the area, form of blade, thickness, etc., representing an arbitrary standard propeller which had shown good results. The second series covers changes in thickness of blade section, other things equal, and the third series, changes in blade area, other things equal. These models are all of 36-inch diameter. Propellers A to G form the series on pitch ratio, C, N. I. J the series on thickness of section, and K, M, C, L the series on area. (author)

Type inference for correspondence types

DEFF Research Database (Denmark)

Hüttel, Hans; Gordon, Andy; Hansen, Rene Rydhof

2009-01-01

We present a correspondence type/effect system for authenticity in a π-calculus with polarized channels, dependent pair types and effect terms and show how one may, given a process P and an a priori type environment E, generate constraints that are formulae in the Alternating Least Fixed......-Point (ALFP) logic. We then show how a reasonable model of the generated constraints yields a type/effect assignment such that P becomes well-typed with respect to E if and only if this is possible. The formulae generated satisfy a finite model property; a system of constraints is satisfiable if and only...... if it has a finite model. As a consequence, we obtain the result that type/effect inference in our system is polynomial-time decidable....

Six types of multistability in a neuronal model based on slow calcium current.

Directory of Open Access Journals (Sweden)

Tatiana Malashchenko

Full Text Available BACKGROUND: Multistability of oscillatory and silent regimes is a ubiquitous phenomenon exhibited by excitable systems such as neurons and cardiac cells. Multistability can play functional roles in short-term memory and maintaining posture. It seems to pose an evolutionary advantage for neurons which are part of multifunctional Central Pattern Generators to possess multistability. The mechanisms supporting multistability of bursting regimes are not well understood or classified. METHODOLOGY/PRINCIPAL FINDINGS: Our study is focused on determining the bio-physical mechanisms underlying different types of co-existence of the oscillatory and silent regimes observed in a neuronal model. We develop a low-dimensional model typifying the dynamics of a single leech heart interneuron. We carry out a bifurcation analysis of the model and show that it possesses six different types of multistability of dynamical regimes. These types are the co-existence of 1 bursting and silence, 2 tonic spiking and silence, 3 tonic spiking and subthreshold oscillations, 4 bursting and subthreshold oscillations, 5 bursting, subthreshold oscillations and silence, and 6 bursting and tonic spiking. These first five types of multistability occur due to the presence of a separating regime that is either a saddle periodic orbit or a saddle equilibrium. We found that the parameter range wherein multistability is observed is limited by the parameter values at which the separating regimes emerge and terminate. CONCLUSIONS: We developed a neuronal model which exhibits a rich variety of different types of multistability. We described a novel mechanism supporting the bistability of bursting and silence. This neuronal model provides a unique opportunity to study the dynamics of networks with neurons possessing different types of multistability.

Computational Software to Fit Seismic Data Using Epidemic-Type Aftershock Sequence Models and Modeling Performance Comparisons

Science.gov (United States)

Chu, A.

2016-12-01

Modern earthquake catalogs are often analyzed using spatial-temporal point process models such as the epidemic-type aftershock sequence (ETAS) models of Ogata (1998). My work implements three of the homogeneous ETAS models described in Ogata (1998). With a model's log-likelihood function, my software finds the Maximum-Likelihood Estimates (MLEs) of the model's parameters to estimate the homogeneous background rate and the temporal and spatial parameters that govern triggering effects. EM-algorithm is employed for its advantages of stability and robustness (Veen and Schoenberg, 2008). My work also presents comparisons among the three models in robustness, convergence speed, and implementations from theory to computing practice. Up-to-date regional seismic data of seismic active areas such as Southern California and Japan are used to demonstrate the comparisons. Data analysis has been done using computer languages Java and R. Java has the advantages of being strong-typed and easiness of controlling memory resources, while R has the advantages of having numerous available functions in statistical computing. Comparisons are also made between the two programming languages in convergence and stability, computational speed, and easiness of implementation. Issues that may affect convergence such as spatial shapes are discussed.

Mathematical model of snake-type multi-directional wave generation

Science.gov (United States)

Muarif; Halfiani, Vera; Rusdiana, Siti; Munzir, Said; Ramli, Marwan

2018-01-01

Research on extreme wave generation is one intensive research on water wave study because the fact that the occurrence of this wave in the ocean can cause serious damage to the ships and offshore structures. One method to be used to generate the wave is self-correcting. This method controls the signal on the wavemakers in a wave tank. Some studies also consider the nonlinear wave generation in a wave tank by using numerical approach. Study on wave generation is essential in the effectiveness and efficiency of offshore structure model testing before it can be operated in the ocean. Generally, there are two types of wavemakers implemented in the hydrodynamic laboratory, piston-type and flap-type. The flap-type is preferred to conduct a testing to a ship in deep water. Single flap wavemaker has been explained in many studies yet snake-type wavemaker (has more than one flap) is still a case needed to be examined. Hence, the formulation in controlling the wavemaker need to be precisely analyzed such that the given input can generate the desired wave in the space-limited wave tank. By applying the same analogy and methodhology as the previous study, this article represents multi-directional wave generation by implementing snake-type wavemakers.

Review on the HVAC System Modeling Types and the Shortcomings of Their Application

Directory of Open Access Journals (Sweden)

Raad Z. Homod

2013-01-01

Full Text Available The modeling of the heating, ventilation, and air conditioning (HVAC system is a prominent topic because of its relationship with energy savings and environmental, economical, and technological issues. The modeling of the HVAC system is concerned with the indoor thermal sensation, which is related to the modeling of building, air handling unit (AHU equipments, and indoor thermal processes. Until now, many HVAC system modeling approaches are made available, and the techniques have become quite mature. But there are some shortcomings in application and integration methods for the different types of the HVAC model. The application and integration processes will act to accumulate the defective characteristics for both AHU equipments and building models such as nonlinear, pure lag time, high thermal inertia, uncertain disturbance factors, large-scale systems, and constraints. This paper shows types of the HVAC model and the advantages and disadvantages for each application of them, and it finds out that the gray-box type is the best one to represent the indoor thermal comfort. But its application fails at the integration method where its response deviated to unreal behavior.

Model air-supported drum-type homopolar generator

International Nuclear Information System (INIS)

Kustom, R.L.; Fuja, R.E.; Wehrle, R.B.; Smith, R.P.; Kovarik, T.J.

1977-01-01

A single cylinder, drum-type homopolar generator has been designed and built for the purpose of developing a simple air support system for thin cylinder rotors operated at high surface velocities and significant radial drum growth. The model has an aluminum cylinder which is 0.32 cm thick, 25 cm in diameter, and 12.7 cm long. It is designed to operate at a peak current of 2500 A and to store a total of 40 kJ with a surface velocity of 305 m/sec

Generic Business Model Types for Enterprise Mashup Intermediaries

Science.gov (United States)

Hoyer, Volker; Stanoevska-Slabeva, Katarina

The huge demand for situational and ad-hoc applications desired by the mass of business end users led to a new kind of Web applications, well-known as Enterprise Mashups. Users with no or limited programming skills are empowered to leverage in a collaborative manner existing Mashup components by combining and reusing company internal and external resources within minutes to new value added applications. Thereby, Enterprise Mashup environments interact as intermediaries to match the supply of providers and demand of consumers. By following the design science approach, we propose an interaction phase model artefact based on market transaction phases to structure required intermediary features. By means of five case studies, we demonstrate the application of the designed model and identify three generic business model types for Enterprise Mashups intermediaries (directory, broker, and marketplace). So far, intermediaries following a real marketplace business model don’t exist in context of Enterprise Mashups and require further research for this emerging paradigm.

Image Restoration Based on the Hybrid Total-Variation-Type Model

Directory of Open Access Journals (Sweden)

Baoli Shi

2012-01-01

Full Text Available We propose a hybrid total-variation-type model for the image restoration problem based on combining advantages of the ROF model with the LLT model. Since two L1-norm terms in the proposed model make it difficultly solved by using some classically numerical methods directly, we first employ the alternating direction method of multipliers (ADMM to solve a general form of the proposed model. Then, based on the ADMM and the Moreau-Yosida decomposition theory, a more efficient method called the proximal point method (PPM is proposed and the convergence of the proposed method is proved. Some numerical results demonstrate the viability and efficiency of the proposed model and methods.

Study on vertical seismic response model of BWR-type reactor building

International Nuclear Information System (INIS)

Konno, T.; Motohashi, S.; Izumi, M.; Iizuka, S.

1993-01-01

A study on advanced seismic design for LWR has been carried out by the Nuclear Power Engineering Corporation (NUPEC), under the sponsorship of the Ministry of International Trade and Industry (MITI) of Japan. As a part of the study, it has been investigated to construct an accurate analytical model of reactor buildings for a seismic response analysis, which can reasonably represent dynamic characteristics of the building. In Japan, vibration models of reactor buildings for horizontal ground motion have been studied and examined through many simulation analyses for forced vibration tests and earthquake observations of actual buildings. And now it is possible to establish a reliable horizontal vibration model on the basis of multi-lumped mass and spring model. However, vertical vibration models have not been so much studied as horizontal models, due to less observed data for vertical motions. In this paper, the vertical seismic response models of a BWR-type reactor building including soil-structure interaction effect are numerically studied, by comparing the dynamic characteristics of (1) three dimensional finite element model, (2) multi-stick lumped mass model with a flexible base-mat, (3) multi-stick lumped mass model with a rigid base-mat and (4) single-stick lumped mass model. In particular, the BWR-type reactor building has the long span truss roof which is considered to be one of the critical members to vertical excitation. The modelings of the roof trusses are also studied

Model for calculating the boron concentration in PWR type reactors

International Nuclear Information System (INIS)

Reis Martins Junior, L.L. dos; Vanni, E.A.

1986-01-01

A PWR boron concentration model has been developed for use with RETRAN code. The concentration model calculates the boron mass balance in the primary circuit as the injected boron mixes and is transported through the same circuit. RETRAN control blocks are used to calculate the boron concentration in fluid volumes during steady-state and transient conditions. The boron reactivity worth is obtained from the core concentration and used in RETRAN point kinetics model. A FSAR type analysis of a Steam Line Break Accident in Angra I plant was selected to test the model and the results obtained indicate a sucessfull performance. (Author) [pt

Risk score prediction model for dementia in patients with type 2 diabetes.

Science.gov (United States)

Li, Chia-Ing; Li, Tsai-Chung; Liu, Chiu-Shong; Liao, Li-Na; Lin, Wen-Yuan; Lin, Chih-Hsueh; Yang, Sing-Yu; Chiang, Jen-Huai; Lin, Cheng-Chieh

2018-03-30

No study established a prediction dementia model in the Asian populations. This study aims to develop a prediction model for dementia in Chinese type 2 diabetes patients. This retrospective cohort study included 27,540 Chinese type 2 diabetes patients (aged 50-94 years) enrolled in Taiwan National Diabetes Care Management Program. Participants were randomly allocated into derivation and validation sets at 2:1 ratio. Cox proportional hazards regression models were used to identify risk factors for dementia in the derivation set. Steps proposed by Framingham Heart Study were used to establish a prediction model with a scoring system. The average follow-up was 8.09 years, with a total of 853 incident dementia cases in derivation set. Dementia risk score summed up the individual scores (from 0 to 20). The areas under curve of 3-, 5-, and 10-year dementia risks were 0.82, 0.79, and 0.76 in derivation set and 0.84, 0.80, and 0.75 in validation set, respectively. The proposed score system is the first dementia risk prediction model for Chinese type 2 diabetes patients in Taiwan. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

A fuzzy chance-constrained programming model with type 1 and type 2 fuzzy sets for solid waste management under uncertainty

Science.gov (United States)

Ma, Xiaolin; Ma, Chi; Wan, Zhifang; Wang, Kewei

2017-06-01

Effective management of municipal solid waste (MSW) is critical for urban planning and development. This study aims to develop an integrated type 1 and type 2 fuzzy sets chance-constrained programming (ITFCCP) model for tackling regional MSW management problem under a fuzzy environment, where waste generation amounts are supposed to be type 2 fuzzy variables and treated capacities of facilities are assumed to be type 1 fuzzy variables. The evaluation and expression of uncertainty overcome the drawbacks in describing fuzzy possibility distributions as oversimplified forms. The fuzzy constraints are converted to their crisp equivalents through chance-constrained programming under the same or different confidence levels. Regional waste management of the City of Dalian, China, was used as a case study for demonstration. The solutions under various confidence levels reflect the trade-off between system economy and reliability. It is concluded that the ITFCCP model is capable of helping decision makers to generate reasonable waste-allocation alternatives under uncertainties.

Model-based closed-loop glucose control in type 1 diabetes

DEFF Research Database (Denmark)

Schmidt, Signe; Boiroux, Dimitri; Duun-Henriksen, Anne Katrine

2013-01-01

To improve type 1 diabetes mellitus (T1DM) management, we developed a model predictive control (MPC) algorithm for closed-loop (CL) glucose control based on a linear second-order deterministic-stochastic model. The deterministic part of the model is specified by three patient-specific parameters......: insulin sensitivity factor, insulin action time, and basal insulin infusion rate. The stochastic part is identical for all patients but identified from data from a single patient. Results of the first clinical feasibility test of the algorithm are presented....

Modeling and control of Type-2 wind turbines for sub-synchronous resonance damping

International Nuclear Information System (INIS)

Mancilla-David, Fernando; Domínguez-García, José Luis; De Prada, Mikel; Gomis-Bellmunt, Oriol; Singh, Mohit; Muljadi, Eduard

2015-01-01

Highlights: • Dynamic modeling of Type-2 wind turbines for sub-synchronous resonance studies. • Systematic design of a power system stabilizer for Type-2 wind turbines. • Assessment of Type-2 wind turbines to suppress sub-synchronous resonance events. - Abstract: The rapid increase of wind power penetration into power systems around the world has led transmission system operators to enforce stringent grid codes requiring novel functionalities from renewable energy-based power generation. For this reason, there exists a need to asses whether wind turbines (WTs) will comply with such functionalities to ensure power system stability. This paper demonstrates that Type-2 WTs may induce sub-synchronous resonance (SSR) events when connected to a series-compensated transmission line, and with proper control, they may also suppress such events. The paper presents a complete dynamic model tailored to study, via eigenanalysis, SSR events in the presence of Type-2 WTs, and a systematic procedure to design a power system stabilizer using only local and measurable signals. Results are validated through a case study based on the IEEE first benchmark model for SSR studies, as well as with transient computer simulations

A simple model to estimate the optimal doping of p - Type oxide superconductors

Directory of Open Access Journals (Sweden)

Adir Moysés Luiz

2008-12-01

Full Text Available Oxygen doping of superconductors is discussed. Doping high-Tc superconductors with oxygen seems to be more efficient than other doping procedures. Using the assumption of double valence fluctuations, we present a simple model to estimate the optimal doping of p-type oxide superconductors. The experimental values of oxygen content for optimal doping of the most important p-type oxide superconductors can be accounted for adequately using this simple model. We expect that our simple model will encourage further experimental and theoretical researches in superconducting materials.

Study of experimentally undetermined neutrino parameters in the light of baryogenesis considering type I and type II Seesaw models

International Nuclear Information System (INIS)

Kalita, Rupam

2017-01-01

We study to connect all the experimentally undetermined neutrino parameters namely lightest neutrino mass, neutrino CP phases and baryon asymmetry of the Universe within the framework of a model where both type I and type II seesaw mechanisms can contribute to tiny neutrino masses. In this work we study the effects of Dirac and Majorana neutrino phases in the origin of matter-antimatter asymmetry through the mechanism of leptogenesis. Type I seesaw mass matrix considered to a tri-bimaximal (TBM) type neutrino mixing which always gives non zero reactor mixing angle. The type II seesaw mass matrix is then considered in such a way that the necessary deviation from TBM mixing and the best fit values of neutrino parameters can be obtained when both type I and type II seesaw contributions are taken into account. We consider different contribution from type I and type II seesaw mechanism to study the effects of neutrino CP phases in the baryon asymmetry of the universe. We further study to connect all these experimentally undetermined neutrino parameters by considering various contribution of type I and type II seesaw. (author)

Ports: Definition and study of types, sizes and business models

Directory of Open Access Journals (Sweden)

Ivan Roa

2013-09-01

Full Text Available Purpose: In the world today there are thousands of port facilities of different types and sizes, competing to capture some market share of freight by sea, mainly. This article aims to determine the type of port and the most common size, in order to find out which business model is applied in that segment and what is the legal status of the companies of such infrastructure.Design/methodology/approach: To achieve this goal, we develop a research on a representative sample of 800 ports worldwide, which manage 90% of the containerized port loading. Then you can find out the legal status of the companies that manage them.Findings: The results indicate a port type and a dominant size, which are mostly managed by companies subject to a concession model.Research limitations/implications: In this research, we study only those ports that handle freight (basically containerized, ignoring other activities such as fishing, military, tourism or recreational.Originality/value: This is an investigation to show that the vast majority of the studied segment port facilities are governed by a similar corporate model and subject to pressure from the markets, which increasingly demand efficiency and service. Consequently, we tend to concession terminals to private operators in a process that might be called privatization, but in the strictest sense of the term, is not entirely realistic because the ownership of the land never ceases to be public

Development of a model counter-rotating type horizontal-axis tidal turbine

Science.gov (United States)

Huang, B.; Yoshida, K.; Kanemoto, T.

2016-05-01

In the past decade, the tidal energies have caused worldwide concern as it can provide regular and predictable renewable energy resource for power generation. The majority of technologies for exploiting the tidal stream energy are based on the concept of the horizontal axis tidal turbine (HATT). A unique counter-rotating type HATT was proposed in the present work. The original blade profiles were designed according to the developed blade element momentum theory (BEMT). CFD simulations and experimental tests were adopted to the performance of the model counter-rotating type HATT. The experimental data provides an evidence of validation of the CFD model. Further optimization of the blade profiles was also carried out based on the CFD results.

Ports: Definition and study of types, sizes and business models

OpenAIRE

Ivan Roa; Yessica Peña; Beatriz Amante; María Goretti

2013-01-01

Purpose: In the world today there are thousands of port facilities of different types and sizes, competing to capture some market share of freight by sea, mainly. This article aims to determine the type of port and the most common size, in order to find out which business model is applied in that segment and what is the legal status of the companies of such infrastructure.Design/methodology/approach: To achieve this goal, we develop a research on a representative sample of 800 ports worldwide...

Rich dynamics of a food chain model with ratio-dependent type III ...

African Journals Online (AJOL)

Rich dynamics of a food chain model with ratio-dependent type III functional responses. ... Stability analysis of model is carried out by using usual theory of ordinary ... that Hopf bifurcation may also occur when delay passes its critical value.

Perfect fluid Bianchi Type-I cosmological models with time varying G ...

Indian Academy of Sciences (India)

Abstract. Bianchi Type-I cosmological models containing perfect fluid with time vary- ing G and Λ have been presented. The solutions obtained represent an expansion scalar θ bearing a constant ratio to the anisotropy in the direction of space-like unit vector λi. Of the two models obtained, one has negative vacuum energy ...

Sensitivity Analysis on LOCCW of Westinghouse typed Reactors Considering WOG2000 RCP Seal Leakage Model

International Nuclear Information System (INIS)

Na, Jang-Hwan; Jeon, Ho-Jun; Hwang, Seok-Won

2015-01-01

In this paper, we focus on risk insights of Westinghouse typed reactors. We identified that Reactor Coolant Pump (RCP) seal integrity is the most important contributor to Core Damage Frequency (CDF). As we reflected the latest technical report; WCAP-15603(Rev. 1-A), 'WOG2000 RCP Seal Leakage Model for Westinghouse PWRs' instead of the old version, RCP seal integrity became more important to Westinghouse typed reactors. After Fukushima accidents, Korea Hydro and Nuclear Power (KHNP) decided to develop Low Power and Shutdown (LPSD) Probabilistic Safety Assessment (PSA) models and upgrade full power PSA models of all operating Nuclear Power Plants (NPPs). As for upgrading full power PSA models, we have tried to standardize the methodology of CCF (Common Cause Failure) and HRA (Human Reliability Analysis), which are the most influential factors to risk measures of NPPs. Also, we have reviewed and reflected the latest operating experiences, reliability data sources and technical methods to improve the quality of PSA models. KHNP has operating various types of reactors; Optimized Pressurized Reactor (OPR) 1000, CANDU, Framatome and Westinghouse. So, one of the most challengeable missions is to keep the balance of risk contributors of all types of reactors. This paper presents the method of new RCP seal leakage model and the sensitivity analysis results from applying the detailed method to PSA models of Westinghouse typed reference reactors. To perform the sensitivity analysis on LOCCW of the reference Westinghouse typed reactors, we reviewed WOG2000 RCP seal leakage model and developed the detailed event tree of LOCCW considering all scenarios of RCP seal failures. Also, we performed HRA based on the T/H analysis by using the leakage rates for each scenario. We could recognize that HRA was the sensitive contributor to CDF, and the RCP seal failure scenario of 182gpm leakage rate was estimated as the most important scenario

Sensitivity Analysis on LOCCW of Westinghouse typed Reactors Considering WOG2000 RCP Seal Leakage Model

Energy Technology Data Exchange (ETDEWEB)

Na, Jang-Hwan; Jeon, Ho-Jun; Hwang, Seok-Won [KHNP Central Research Institute, Daejeon (Korea, Republic of)

2015-10-15

In this paper, we focus on risk insights of Westinghouse typed reactors. We identified that Reactor Coolant Pump (RCP) seal integrity is the most important contributor to Core Damage Frequency (CDF). As we reflected the latest technical report; WCAP-15603(Rev. 1-A), 'WOG2000 RCP Seal Leakage Model for Westinghouse PWRs' instead of the old version, RCP seal integrity became more important to Westinghouse typed reactors. After Fukushima accidents, Korea Hydro and Nuclear Power (KHNP) decided to develop Low Power and Shutdown (LPSD) Probabilistic Safety Assessment (PSA) models and upgrade full power PSA models of all operating Nuclear Power Plants (NPPs). As for upgrading full power PSA models, we have tried to standardize the methodology of CCF (Common Cause Failure) and HRA (Human Reliability Analysis), which are the most influential factors to risk measures of NPPs. Also, we have reviewed and reflected the latest operating experiences, reliability data sources and technical methods to improve the quality of PSA models. KHNP has operating various types of reactors; Optimized Pressurized Reactor (OPR) 1000, CANDU, Framatome and Westinghouse. So, one of the most challengeable missions is to keep the balance of risk contributors of all types of reactors. This paper presents the method of new RCP seal leakage model and the sensitivity analysis results from applying the detailed method to PSA models of Westinghouse typed reference reactors. To perform the sensitivity analysis on LOCCW of the reference Westinghouse typed reactors, we reviewed WOG2000 RCP seal leakage model and developed the detailed event tree of LOCCW considering all scenarios of RCP seal failures. Also, we performed HRA based on the T/H analysis by using the leakage rates for each scenario. We could recognize that HRA was the sensitive contributor to CDF, and the RCP seal failure scenario of 182gpm leakage rate was estimated as the most important scenario.

Model tests and elasto-plastic finite element analysis on multicavity type PCRV

International Nuclear Information System (INIS)

Nojiri, Y.; Yamazaki, M.; Kotani, K.; Matsuzaki, Y.

1978-01-01

Multicavity type PCRV models were tested to investigate elastic stress distributions, cracking and failure mode of the models, and to determine the adequacy and relative accuracy of finite element structural analyses. The behavior of the models under pressure was investigated, and it was found that the predictions of the analyses showed a good agreement with the test results

A new Preisach-type vector model of hysteresis

Energy Technology Data Exchange (ETDEWEB)

D' Aquino, M. E-mail: mdaquino@unina.it; Serpico, C. E-mail: serpico@unina.it

2004-05-01

A new class of scalar hysteresis operators is obtained from the classical Preisach scalar model of hysteresis by introducing a transformation of variables dependent on a suitable function g. The operators of this class are defined by means of a new type of Play operator and are characterized by the property of having the same scalar input-output relationship. These operators are then extended to the isotropic vector case by using the vector extension of the scalar Play operator. It is shown that the function g, although does not affect the scalar behavior, it does affect the vector behaviour of the mathematical model. The influence of the function g is illustrated by reporting numerically computed rotational hysteresis losses curves for different choices of the function g.

Some five-dimensional Bianchi type-iii string cosmological models in general relativity

International Nuclear Information System (INIS)

Samanta, G.C.; Biswal, S.K.; Mohanty, G.; Rameswarpatna, Bhubaneswar

2011-01-01

In this paper we have constructed some five-dimensional Bianchi type-III cosmological models in general relativity when source of gravitational field is a massive string. We obtained different classes of solutions by considering different functional forms of metric potentials. It is also observed that one of the models is not physically acceptable and the other models possess big-bang singularity. The physical and kinematical behaviors of the models are discussed

Validation of a model of family caregiver communication types and related caregiver outcomes.

Science.gov (United States)

Wittenberg, Elaine; Kravits, Kate; Goldsmith, Joy; Ferrell, Betty; Fujinami, Rebecca

2017-02-01

Caring for the family is included as one of the eight domains of quality palliative care, calling attention to the importance of the family system and family communications about cancer during care and treatment of the disease. Previously, a model of family caregiver communication defined four caregiver communication types-Manager, Carrier, Partner, Lone-each with a unique communication pattern. The purpose of the present study was to extend the model of family caregiver communication in cancer care to further understand the impact of family communication burden on caregiving outcomes. This mixed-method study employed fieldnotes from a family caregiver intervention focused on quality of life and self-reported caregiver communication items to identify a specific family caregiver type. Caregiver types were then analyzed using outcome measures on psychological distress, skills preparedness, family inventory of needs, and quality-of-life domains. Corroboration between fieldnotes and self-reported communication for caregivers (n = 21, 16 women, mean age of 53 years) revealed a definitive classification of the four caregiver types (Manager = 6, Carrier = 5, Partner = 6, Lone = 4). Mean scores on self-reported communication items documented different communication patterns congruent with the theoretical framework of the model. Variation in caregiver outcomes measures confirmed the model of family caregiver communication types. Partner and Lone caregivers reported the lowest psychological distress, with Carrier caregivers feeling least prepared and Manager caregivers reporting the lowest physical quality of life. This study illustrates the impact of family communication on caregiving and increases our knowledge and understanding about the role of communication in caregiver burden. The research provides the first evidence-based validation for a family caregiver communication typology and its relationship to caregiver outcomes. Future research is needed to develop and test

Studying the highly bent spectra of FR II-type radio galaxies with the KDA EXT model

Science.gov (United States)

Kuligowska, Elżbieta

2018-04-01

Context. The Kaiser, Dennett-Thorpe & Alexander (KDA, 1997, MNRAS, 292, 723) EXT model, that is, the extension of the KDA model of Fanaroff & Riley (FR) II-type source evolution, is applied and confronted with the observational data for selected FR II-type radio sources with significantly aged radio spectra. Aim. A sample of FR II-type radio galaxies with radio spectra strongly bent at their highest frequencies is used for testing the usefulness of the KDA EXT model. Methods: The dynamical evolution of FR II-type sources predicted with the KDA EXT model is briefly presented and discussed. The results are then compared to the ones obtained with the classical KDA approach, assuming the source's continuous injection and self-similarity. Results: The results and corresponding diagrams obtained for the eight sample sources indicate that the KDA EXT model predicts the observed radio spectra significantly better than the best spectral fit provided by the original KDA model.

Metallogenic model for continental volcanic-type rich and large uranium deposits

International Nuclear Information System (INIS)

Chen Guihua

1998-01-01

A metallogenic model for continental volcanic-type rich and large/super large uranium deposits has been established on the basis of analysis of occurrence features and ore-forming mechanism of some continental volcanic-type rich and large/super large uranium deposits in the world. The model proposes that uranium-enriched granite or granitic basement is the foundation, premetallogenic polycyclic and multistage volcanic eruptions are prerequisites, intense tectonic-extensional environment is the key for the ore formation, and relatively enclosed geologic setting is the reliable protection condition of the deposit. By using the model the author explains the occurrence regularities of some rich and large/super large uranium deposits such as Strelichof uranium deposit in Russia, Dornot uranium deposit in Mongolia, Olympic Dam Cu-U-Au-REE deposit in Australia, uranium deposit No.460 and Zhoujiashan uranium deposit in China, and then compares the above deposits with a large poor uranium deposit No.661 as well

Asteroseismic modelling of the solar-type subgiant star β Hydri

Science.gov (United States)

Brandão, I. M.; Doğan, G.; Christensen-Dalsgaard, J.; Cunha, M. S.; Bedding, T. R.; Metcalfe, T. S.; Kjeldsen, H.; Bruntt, H.; Arentoft, T.

2011-03-01

Context. Comparing models and data of pulsating stars is a powerful way to understand the stellar structure better. Moreover, such comparisons are necessary to make improvements to the physics of the stellar models, since they do not yet perfectly represent either the interior or especially the surface layers of stars. Because β Hydri is an evolved solar-type pulsator with mixed modes in its frequency spectrum, it is very interesting for asteroseismic studies. Aims: The goal of the present work is to search for a representative model of the solar-type star β Hydri, based on up-to-date non-seismic and seismic data. Methods: We present a revised list of frequencies for 33 modes, which we produced by analysing the power spectrum of the published observations again using a new weighting scheme that minimises the daily sidelobes. We ran several grids of evolutionary models with different input parameters and different physics, using the stellar evolutionary code ASTEC. For the models that are inside the observed error box of β Hydri, we computed their frequencies with the pulsation code ADIPLS. We used two approaches to find the model that oscillates with the frequencies that are closest to the observed frequencies of β Hydri: (i) we assume that the best model is the one that reproduces the star's interior based on the radial oscillation frequencies alone, to which we have applied the correction for the near-surface effects; (ii) we assume that the best model is the one that produces the lowest value of the chi-square (χ2), i.e. that minimises the difference between the observed frequencies of all available modes and the model predictions, after all model frequencies are corrected for near-surface effects. Results: We show that after applying a correction for near-surface effects to the frequencies of the best models, we can reproduce the observed modes well, including those that have mixed mode character. The model that gives the lowest value of the χ2 is a post

Lattice simulation of 2d Gross-Neveu-type models

International Nuclear Information System (INIS)

Limmer, M.; Gattringer, C.; Hermann, V.

2006-01-01

Full text: We discuss a Monte Carlo simulation of 2d Gross-Neveu-type models on the lattice. The four-Fermi interaction is written as a Gaussian integral with an auxiliary field and the fermion determinant is included by reweighting. We present results for bulk quantities and correlators and compare them to a simulation using a fermion-loop representation. (author)

A non-local hidden-variable model that violates Leggett-type inequalities

Energy Technology Data Exchange (ETDEWEB)

Zela, F de [Departamento de Ciencias, Seccion Fisica, Pontificia Universidad Catolica del Peru, Apartado 1761, Lima (Peru)

2008-12-19

Recent experiments of Groeblacher et al proved the violation of a Leggett-type inequality that was claimed to be valid for a broad class of non-local hidden-variable theories. The impossibility of constructing a non-local and realistic theory, unless it entails highly counterintuitive features, seems thus to have been experimentally proved. This would bring us close to a definite refutation of realism. Indeed, realism was proved to be also incompatible with locality, according to a series of experiments testing Bell inequalities. The present paper addresses the said experiments of Groeblacher et al and presents an explicit, contextual and realistic, model that reproduces the predictions of quantum mechanics. It thus violates the Leggett-type inequality that was established with the aim of ruling out a supposedly broad class of non-local models. We can thus conclude that plausible contextual, realistic, models are still tenable. This restates the possibility of a future completion of quantum mechanics by a realistic and contextual theory which is not in a class containing only highly counterintuitive models. The class that was ruled out by the experiments of Groeblacher et al is thus proved to be a limited one, arbitrarily separating models that physically belong in the same class.

A MODEL FOR TYPE 2 CORONAL LINE FOREST (CLiF) AGNs

Energy Technology Data Exchange (ETDEWEB)

Glidden, Ana [Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Rose, Marvin; Elvis, Martin; McDowell, Jonathan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2016-06-10

We present a model for the classification of Coronal Line Forest Active Galactic Nuclei (CLiF AGNs). CLiF AGNs are of special interest due to their remarkably large number of emission lines, especially forbidden high-ionization lines (FHILs). Rose et al. suggest that their emission is dominated by reflection from the inner wall of the obscuring region rather than direct emission from the accretion disk. This makes CLiF AGNs laboratories to test AGN-torus models. Modeling an AGN as an accreting supermassive black hole surrounded by a cylinder of dust and gas, we show a relationship between the viewing angle and the revealed area of the inner wall. From the revealed area, we can determine the amount of FHIL emission at various angles. We calculate the strength of [Fe vii] λ 6087 emission for a number of intermediate angles (30°, 40°, and 50°) and compare the results with the luminosity of the observed emission line from six known CLiF AGNs. We find that there is good agreement between our model and the observational results. The model also enables us to determine the relationship between the type 2:type 1 AGN fraction vs the ratio of torus height to radius, h / r .

A non-local hidden-variable model that violates Leggett-type inequalities

International Nuclear Information System (INIS)

Zela, F de

2008-01-01

Recent experiments of Groeblacher et al proved the violation of a Leggett-type inequality that was claimed to be valid for a broad class of non-local hidden-variable theories. The impossibility of constructing a non-local and realistic theory, unless it entails highly counterintuitive features, seems thus to have been experimentally proved. This would bring us close to a definite refutation of realism. Indeed, realism was proved to be also incompatible with locality, according to a series of experiments testing Bell inequalities. The present paper addresses the said experiments of Groeblacher et al and presents an explicit, contextual and realistic, model that reproduces the predictions of quantum mechanics. It thus violates the Leggett-type inequality that was established with the aim of ruling out a supposedly broad class of non-local models. We can thus conclude that plausible contextual, realistic, models are still tenable. This restates the possibility of a future completion of quantum mechanics by a realistic and contextual theory which is not in a class containing only highly counterintuitive models. The class that was ruled out by the experiments of Groeblacher et al is thus proved to be a limited one, arbitrarily separating models that physically belong in the same class

Quantification of age-related changes in the structure model type and trabecular thickness of human tibial cancellous

DEFF Research Database (Denmark)

Ding, Ming; Hvid, I

2000-01-01

Structure model type and trabecular thickness are important characteristics in describing cancellous bone architecture. It has been qualitatively observed that a radical change of trabeculae from plate-like to rod-like occurs in aging, bone remodeling, and osteoporosis. Thickness of trabeculae has...... traditionally been measured using model-based histomorphometric methods on two-dimensional (2-D) sections. However, no quantitative study has been published based on three-dimensional (3-D) methods on the age-related changes in structure model type and trabecular thickness for human peripheral (tibial......, structure model type and trabecular thickness were quantified by means of novel 3-D methods. Structure model type was assessed by calculating the structure model index (SMI). The SMI was quantified based on a differential analysis of the triangulated bone surface of a structure. This technique allows...

Certain Type Turbofan Engine Whole Vibration Model with Support Looseness Fault and Casing Response Characteristics

Directory of Open Access Journals (Sweden)

H. F. Wang

2014-01-01

Full Text Available Support looseness fault is a type of common fault in aeroengine. Serious looseness fault would emerge under larger unbalanced force, which would cause excessive vibration and even lead to rubbing fault, so it is important to analyze and recognize looseness fault effectively. In this paper, based on certain type turbofan engine structural features, a rotor-support-casing whole model for certain type turbofan aeroengine is established. The rotor and casing systems are modeled by means of the finite element beam method; the support systems are modeled by lumped-mass model; the support looseness fault model is also introduced. The coupled system response is obtained by numerical integral method. In this paper, based on the casing acceleration signals, the impact characteristics of symmetrical stiffness and asymmetric stiffness models are analyzed, finding that the looseness fault would lead to the longitudinal asymmetrical characteristics of acceleration time domain wave and the multiple frequency characteristics, which is consistent with the real trial running vibration signals. Asymmetric stiffness looseness model is verified to be fit for aeroengine looseness fault model.

A model for plasma evolution in Filipov type plasma focus facilities

International Nuclear Information System (INIS)

Siahpoush, V.; Sobhanian, S.; Tafreshi, M. A.; Lamehi, M.

2003-01-01

A model is presented in this paper for the evolution of plasma in Filipov type plasma focus facilities. With the help of this model, one can predict some of the main parameters of the produced plasma and obtain the optimized geometrical an physical properties (anode radius and length, gas pressure, capacitance, bank energy etc) for the primary design purposes. The results obtained by this model will be compared with the experimental data obtained from the 90 kJ plasma focus facility D ena

Modelling of horn-type loudspeakers for outdoor sound reinforcement systems

DEFF Research Database (Denmark)

Schuhmacher, Andreas; Rasmussen, Karsten Bo

1999-01-01

-type loudspeakers is made. The agreement between measured and calculated results is very good provided that a sufficient number of modes is included in the simulation. Simulation models of this kind represent one of the first steps towards a CAD tool for outdoor sound reinforcement systems....

Thermodynamics of spin chains of Haldane–Shastry type and one-dimensional vertex models

International Nuclear Information System (INIS)

Enciso, Alberto; Finkel, Federico; González-López, Artemio

2012-01-01

We study the thermodynamic properties of spin chains of Haldane–Shastry type associated with the A N−1 root system in the presence of a uniform external magnetic field. To this end, we exactly compute the partition function of these models for an arbitrary finite number of spins. We then show that these chains are equivalent to a suitable inhomogeneous classical Ising model in a spatially dependent magnetic field, generalizing the results of Basu-Mallick et al. for the zero magnetic field case. Using the standard transfer matrix approach, we are able to compute in closed form the free energy per site in the thermodynamic limit. We perform a detailed analysis of the chains’ thermodynamics in a unified way, with special emphasis on the zero field and zero temperature limits. Finally, we provide a novel interpretation of the thermodynamic quantities of spin chains of Haldane–Shastry type as weighted averages of the analogous quantities over an ensemble of classical Ising models. - Highlights: ► Partition function of spin chains of Haldane–Shastry type in magnetic field. ► Equivalence to classical inhomogeneous Ising models. ► Free energy per site, other thermodynamic quantities in thermodynamic limit. ► Zero field, zero temperature limits. ► Thermodynamic equivalence with ensemble of classical Ising models.

Modeling and analysis on ring-type piezoelectric transformers.

Science.gov (United States)

Ho, Shine-Tzong

2007-11-01

This paper presents an electromechanical model for a ring-type piezoelectric transformer (PT). To establish this model, vibration characteristics of the piezoelectric ring with free boundary conditions are analyzed in advance. Based on the vibration analysis of the piezoelectric ring, the operating frequency and vibration mode of the PT are chosen. Then, electromechanical equations of motion for the PT are derived based on Hamilton's principle, which can be used to simulate the coupled electromechanical system for the transformer. Such as voltage stepup ratio, input impedance, output impedance, input power, output power, and efficiency are calculated by the equations. The optimal load resistance and the maximum efficiency for the PT will be presented in this paper. Experiments also were conducted to verify the theoretical analysis, and a good agreement was obtained.

Modelling of Performance of Caisson Type Breakwaters under Extreme Waves

Science.gov (United States)

Güney Doǧan, Gözde; Özyurt Tarakcıoǧlu, Gülizar; Baykal, Cüneyt

2016-04-01

Many coastal structures are designed without considering loads of tsunami-like waves or long waves although they are constructed in areas prone to encounter these waves. Performance of caisson type breakwaters under extreme swells is tested in Middle East Technical University (METU) Coastal and Ocean Engineering Laboratory. This paper presents the comparison of pressure measurements taken along the surface of caisson type breakwaters and obtained from numerical modelling of them using IH2VOF as well as damage behavior of the breakwater under the same extreme swells tested in a wave flume at METU. Experiments are conducted in the 1.5 m wide wave flume, which is divided into two parallel sections (0.74 m wide each). A piston type of wave maker is used to generate the long wave conditions located at one end of the wave basin. Water depth is determined as 0.4m and kept constant during the experiments. A caisson type breakwater is constructed to one side of the divided flume. The model scale, based on the Froude similitude law, is chosen as 1:50. 7 different wave conditions are applied in the tests as the wave period ranging from 14.6 s to 34.7 s, wave heights from 3.5 m to 7.5 m and steepness from 0.002 to 0.015 in prototype scale. The design wave parameters for the breakwater were 5m wave height and 9.5s wave period in prototype. To determine the damage of the breakwater which were designed according to this wave but tested under swell waves, video and photo analysis as well as breakwater profile measurements before and after each test are performed. Further investigations are carried out about the acting wave forces on the concrete blocks of the caisson structures via pressure measurements on the surfaces of these structures where the structures are fixed to the channel bottom minimizing. Finally, these pressure measurements will be compared with the results obtained from the numerical study using IH2VOF which is one of the RANS models that can be applied to simulate

Modeling Types of Pedal Applications Using a Driving Simulator.

Science.gov (United States)

Wu, Yuqing; Boyle, Linda Ng; McGehee, Daniel; Roe, Cheryl A; Ebe, Kazutoshi; Foley, James

2015-11-01

The aim of this study was to examine variations in drivers' foot behavior and identify factors associated with pedal misapplications. Few studies have focused on the foot behavior while in the vehicle and the mishaps that a driver can encounter during a potentially hazardous situation. A driving simulation study was used to understand how drivers move their right foot toward the pedals. The study included data from 43 drivers as they responded to a series of rapid traffic signal phase changes. Pedal application types were classified as (a) direct hit, (b) hesitated, (c) corrected trajectory, and (d) pedal errors (incorrect trajectories, misses, slips, or pressed both pedals). A mixed-effects multinomial logit model was used to predict the likelihood of one of these pedal applications, and linear mixed models with repeated measures were used to examine the response time and pedal duration given the various experimental conditions (stimuli color and location). Younger drivers had higher probabilities of direct hits when compared to other age groups. Participants tended to have more pedal errors when responding to a red signal or when the signal appeared to be closer. Traffic signal phases and locations were associated with pedal response time and duration. The response time and pedal duration affected the likelihood of being in one of the four pedal application types. Findings from this study suggest that age-related and situational factors may play a role in pedal errors, and the stimuli locations could affect the type of pedal application. © 2015, Human Factors and Ergonomics Society.

Model Identification using Continuous Glucose Monitoring Data for Type 1 Diabetes

DEFF Research Database (Denmark)

Boiroux, Dimitri; Hagdrup, Morten; Mahmoudi, Zeinab

2016-01-01

This paper addresses model identification of continuous-discrete nonlinear models for people with type 1 diabetes using sampled data from a continuous glucose monitor (CGM). We compare five identification techniques: least squares, weighted least squares, Huber regression, maximum likelihood...... with extended Kalman filter and maximum likelihood with unscented Kalman filter. We perform the identification on a 24-hour simulation of a stochastic differential equation (SDE) version of the Medtronic Virtual Patient (MVP) model including process and output noise. We compare the fits with the actual CGM......, such as parameter tracking, population modeling and handling of outliers....

Models for Type Ia Supernovae and Related Astrophysical Transients

Science.gov (United States)

Röpke, Friedrich K.; Sim, Stuart A.

2018-06-01

We give an overview of recent efforts to model Type Ia supernovae and related astrophysical transients resulting from thermonuclear explosions in white dwarfs. In particular we point out the challenges resulting from the multi-physics multi-scale nature of the problem and discuss possible numerical approaches to meet them in hydrodynamical explosion simulations and radiative transfer modeling. We give examples of how these methods are applied to several explosion scenarios that have been proposed to explain distinct subsets or, in some cases, the majority of the observed events. In case we comment on some of the successes and shortcoming of these scenarios and highlight important outstanding issues.

BGK-type models in strong reaction and kinetic chemical equilibrium regimes

International Nuclear Information System (INIS)

Monaco, R; Bianchi, M Pandolfi; Soares, A J

2005-01-01

A BGK-type procedure is applied to multi-component gases undergoing chemical reactions of bimolecular type. The relaxation process towards local Maxwellians, depending on mass and numerical densities of each species as well as common velocity and temperature, is investigated in two different cases with respect to chemical regimes. These cases are related to the strong reaction regime characterized by slow reactions, and to the kinetic chemical equilibrium regime where fast reactions take place. The consistency properties of both models are stated in detail. The trend to equilibrium is numerically tested and comparisons for the two regimes are performed within the hydrogen-air and carbon-oxygen reaction mechanism. In the spatial homogeneous case, it is also shown that the thermodynamical equilibrium of the models recovers satisfactorily the asymptotic equilibrium solutions to the reactive Euler equations

Predicting the Types of Ion Channel-Targeted Conotoxins Based on AVC-SVM Model.

Science.gov (United States)

Xianfang, Wang; Junmei, Wang; Xiaolei, Wang; Yue, Zhang

2017-01-01

The conotoxin proteins are disulfide-rich small peptides. Predicting the types of ion channel-targeted conotoxins has great value in the treatment of chronic diseases, epilepsy, and cardiovascular diseases. To solve the problem of information redundancy existing when using current methods, a new model is presented to predict the types of ion channel-targeted conotoxins based on AVC (Analysis of Variance and Correlation) and SVM (Support Vector Machine). First, the F value is used to measure the significance level of the feature for the result, and the attribute with smaller F value is filtered by rough selection. Secondly, redundancy degree is calculated by Pearson Correlation Coefficient. And the threshold is set to filter attributes with weak independence to get the result of the refinement. Finally, SVM is used to predict the types of ion channel-targeted conotoxins. The experimental results show the proposed AVC-SVM model reaches an overall accuracy of 91.98%, an average accuracy of 92.17%, and the total number of parameters of 68. The proposed model provides highly useful information for further experimental research. The prediction model will be accessed free of charge at our web server.

Bianchi type-VIh string cloud cosmological models with bulk viscosity

Science.gov (United States)

Tripathy, Sunil K.; Behera, Dipanjali

2010-11-01

String cloud cosmological models are studied using spatially homogeneous and anisotropic Bianchi type VIh metric in the frame work of general relativity. The field equations are solved for massive string cloud in presence of bulk viscosity. A general linear equation of state of the cosmic string tension density with the proper energy density of the universe is considered. The physical and kinematical properties of the models have been discussed in detail and the limits of the anisotropic parameter responsible for different phases of the universe are explored.

A study on modelling of a butterfly-type control valve by a pneumatic actuator

International Nuclear Information System (INIS)

Hwang, I Cheol; Park, Cheol Jae

2009-01-01

This paper studies on the modelling of a butterfly-type control valve actuating by an on-off pneumatic solenoid valve. The mathematical model is composed of nonlinear differential equations three parts: (i) a solenoid valve, (ii) a pneumatic cylinder, (iii) a rotary-type butterfly valve. The flow characteristics of the butterfly control valve is analysed by a computer simulator, then its simple transfer function is identified from the step responses.

Bayesian Analysis of a Simple Measurement Model Distinguishing between Types of Information

Directory of Open Access Journals (Sweden)

Lira Ignacio

2015-12-01

Full Text Available Let a quantity of interest, Y, be modeled in terms of a quantity X and a set of other quantities Z. Suppose that for Z there is type B information, by which we mean that it leads directly to a joint state-of-knowledge probability density function (PDF for that set, without reference to likelihoods. Suppose also that for X there is type A information, which signifies that a likelihood is available. The posterior for X is then obtained by updating its prior with said likelihood by means of Bayes’ rule, where the prior encodes whatever type B information there may be available for X. If there is no such information, an appropriate non-informative prior should be used. Once the PDFs for X and Z have been constructed, they can be propagated through the measurement model to obtain the PDF for Y, either analytically or numerically. But suppose that, at the same time, there is also information of type A, type B or both types together for the quantity Y. By processing such information in the manner described above we obtain another PDF for Y. Which one is right? Should both PDFs be merged somehow? Is there another way of applying Bayes’ rule such that a single PDF for Y is obtained that encodes all existing information? In this paper we examine what we believe should be the proper ways of dealing with such a (not uncommon situation.

Characterization and modeling of a new magnetorheological damper with meandering type valve using neuro-fuzzy

Directory of Open Access Journals (Sweden)

Fitrian Imaduddin

2017-10-01

Full Text Available This paper presents the characterization and hysteresis modeling of magnetorheological (MR damper with meandering type valve. The meandering type MR valve, which employs the combination of multiple annular and radial flow passages, has been introduced as the new type of high performance MR valve with higher achievable pressure drop and controllable performance range than similar counterparts in its class. Since the performance of a damper is highly determined by the valve performance, the utilization of the meandering type MR valve in an MR damper could potentially improve the damper performance. The damping force characterization of the MR damper is conducted by measuring the damping force as a response to the variety of harmonic excitations. The hysteresis behavior of the damper is identified by plotting the damping force relationship to the excitation displacement and velocity. For the hysteresis modeling purpose, some parts of the data are taken as the training data source for the optimization parameters in the neuro-fuzzy model. The performance of the trained neuro-fuzzy model is assessed by validating the model output with the remaining measurement data and benchmarking the results with the output of the parametric hysteresis model. The validation results show that the neuro-fuzzy model is demonstrating good agreement with the measurement results indicated by the average relative error of only around 7%. The model also shows robustness with no tendency of growing error when the input values are changed.

Separation of type and grade in cervical tumours using non-mono-exponential models of diffusion-weighted MRI

International Nuclear Information System (INIS)

Winfield, Jessica M.; Collins, David J.; Morgan, Veronica A.; DeSouza, Nandita M.; Orton, Matthew R.; Ind, Thomas E.J.; Attygalle, Ayoma; Hazell, Steve

2017-01-01

Assessment of empirical diffusion-weighted MRI (DW-MRI) models in cervical tumours to investigate whether fitted parameters distinguish between types and grades of tumours. Forty-two patients (24 squamous cell carcinomas, 14 well/moderately differentiated, 10 poorly differentiated; 15 adenocarcinomas, 13 well/moderately differentiated, two poorly differentiated; three rare types) were imaged at 3 T using nine b-values (0 to 800 s mm -2 ). Mono-exponential, stretched exponential, kurtosis, statistical, and bi-exponential models were fitted. Model preference was assessed using Bayesian Information Criterion analysis. Differences in fitted parameters between tumour types/grades and correlation between fitted parameters were assessed using two-way analysis of variance and Pearson's linear correlation coefficient, respectively. Non-mono-exponential models were preferred by 83 % of tumours with bi-exponential and stretched exponential models preferred by the largest numbers of tumours. Apparent diffusion coefficient (ADC) and diffusion coefficients from non-mono-exponential models were significantly lower in poorly differentiated tumours than well/moderately differentiated tumours. α (stretched exponential), K (kurtosis), f and D* (bi-exponential) were significantly different between tumour types. Strong correlation was observed between ADC and diffusion coefficients from other models. Non-mono-exponential models were preferred to the mono-exponential model in DW-MRI data from cervical tumours. Parameters of non-mono-exponential models showed significant differences between types and grades of tumours. (orig.)

Separation of type and grade in cervical tumours using non-mono-exponential models of diffusion-weighted MRI

Energy Technology Data Exchange (ETDEWEB)

Winfield, Jessica M.; Collins, David J.; Morgan, Veronica A.; DeSouza, Nandita M. [The Royal Marsden NHS Foundation Trust, MRI Unit, Sutton, Surrey (United Kingdom); The Institute of Cancer Research, Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, London (United Kingdom); Orton, Matthew R. [The Institute of Cancer Research, Cancer Research UK Cancer Imaging Centre, Division of Radiotherapy and Imaging, London (United Kingdom); Ind, Thomas E.J. [The Royal Marsden NHS Foundation Trust, Gynaecology Unit, London (United Kingdom); Attygalle, Ayoma; Hazell, Steve [The Royal Marsden NHS Foundation Trust, Department of Histopathology, London (United Kingdom)

2017-02-15

Assessment of empirical diffusion-weighted MRI (DW-MRI) models in cervical tumours to investigate whether fitted parameters distinguish between types and grades of tumours. Forty-two patients (24 squamous cell carcinomas, 14 well/moderately differentiated, 10 poorly differentiated; 15 adenocarcinomas, 13 well/moderately differentiated, two poorly differentiated; three rare types) were imaged at 3 T using nine b-values (0 to 800 s mm{sup -2}). Mono-exponential, stretched exponential, kurtosis, statistical, and bi-exponential models were fitted. Model preference was assessed using Bayesian Information Criterion analysis. Differences in fitted parameters between tumour types/grades and correlation between fitted parameters were assessed using two-way analysis of variance and Pearson's linear correlation coefficient, respectively. Non-mono-exponential models were preferred by 83 % of tumours with bi-exponential and stretched exponential models preferred by the largest numbers of tumours. Apparent diffusion coefficient (ADC) and diffusion coefficients from non-mono-exponential models were significantly lower in poorly differentiated tumours than well/moderately differentiated tumours. α (stretched exponential), K (kurtosis), f and D* (bi-exponential) were significantly different between tumour types. Strong correlation was observed between ADC and diffusion coefficients from other models. Non-mono-exponential models were preferred to the mono-exponential model in DW-MRI data from cervical tumours. Parameters of non-mono-exponential models showed significant differences between types and grades of tumours. (orig.)

Three-dimensional Modeling of Type Ia Supernova Explosions

Science.gov (United States)

Khokhlov, Alexei

2001-06-01

A deflagration explosion of a Type Ia Supernova (SNIa) is studied using three-dimensional, high-resolution, adaptive mesh refinement fluid dynamic calculations. Deflagration speed in an exploding Chandrasekhar-mass carbon-oxygen white dwarf (WD) grows exponentially, reaches approximately 30the speed of sound, and then declines due to a WD expansion. Outermost layers of the WD remain unburned. The explosion energy is comparable to that of a Type Ia supernova. The freezing of turbulent motions by expansion appears to be a crucial physical mechanism regulating the strength of a supernova explosion. In contrast to one-dimensional models, three-dimensional calculations predict the formation of Si-group elements and pockets of unburned CO in the middle and in central regions of a supernova ejecta. This, and the presence of unburned outer layer of carbon-oxygen may pose problems for SNIa spectra. Explosion sensitivity to initial conditions and its relation to a diversity of SNIa is discussed.

Applying the Transtheoretical Model to Investigate Behavioural Change in Type 2 Diabetic Patients

Science.gov (United States)

Lin, Shu-Ping; Wang, Ming-Jye

2013-01-01

Background: Long-term behaviour change in type 2 diabetic patients may provide effective glycemic control. Purpose: To investigate the key factors that promote behaviour change in diabetic subjects using the transtheoretical model. Methods: Subjects were selected by purposive sampling from type 2 diabetes outpatients. Self-administered…

Inhomogeneous generalizations of Bianchi type VIh models with perfect fluid

Science.gov (United States)

Roy, S. R.; Prasad, A.

1991-07-01

Inhomogeneous universes admitting an Abelian G2 of isometry and filled with perfect fluid have been derived. These contain as special cases exact homogeneous universes of Bianchi type VIh. Many of these universes asymptotically tend to homogeneous Bianchi VIh universes. The models have been discussed for their physical and kinematical behaviors.

Types of electric-field distribution and corresponding types of convection in the polar ionosphere - A model

Science.gov (United States)

Uvarov, V. M.; Barashkov, P. D.

1989-08-01

A model for the continuous distribution of large-scale electric fields is used to reproduce all the experimentally known types of distributions of the evening-morning electric field component along the morning-evening meridian. The corresponding convection patterns are then calculated, which are shown to diverge significantly from previous theoretical considerations. Depending on conditions in the interplanetary medium, two-, three-, or four-vortex convection patterns occur.

Nonhuman Primate Models of Type 1 Diabetes Mellitus for Islet Transplantation

Directory of Open Access Journals (Sweden)

Haitao Zhu

2014-01-01

Full Text Available Islet transplantation is an attractive treatment of type 1 diabetes mellitus (T1DM. Animal models of diabetes mellitus (DM contribute a lot to the experimental studies of islet transplantation and to evaluations of isolated islet grafts for future clinical applications. Diabetic nonhuman primates (NHPs represent the suitable models of DMs to better evaluate the effectiveness of islet transplantation, to assess new strategies for controlling blood glucose (BG, relieving immune rejection, or prolonging islet survival, and eventually to translate the preclinical data into tangible clinical practice. This review introduces some NHP models of DM, clarifies why and how the models should be used, and elucidates the usefulness and limitations of the models in islet transplantation.

Modeling of a ring rosen-type piezoelectric transformer by Hamilton's principle.

Science.gov (United States)

Nadal, Clément; Pigache, Francois; Erhart, Jiří

2015-04-01

This paper deals with the analytical modeling of a ring Rosen-type piezoelectric transformer. The developed model is based on a Hamiltonian approach, enabling to obtain main parameters and performance evaluation for the first radial vibratory modes. Methodology is detailed, and final results, both the input admittance and the electric potential distribution on the surface of the secondary part, are compared with numerical and experimental ones for discussion and validation.

Application of the functional integration method to the Dicke-type models

International Nuclear Information System (INIS)

Popov, V.N.; Fedotov, S.A.

1981-01-01

The asymptotics of the statistical model sum of the Dicke-type (Z/Z 6 ) is obtained and strictly proved at large N (N is an atomic number; Z is a statistical model sum; Z 0 is a statistical free system sum) using the functional integration method. The model with one bose-field mode is considered. A detailed proof is carried out at T > Tsub(c). An idea of the proof is planned and asymptotic formulae are presented for T < Tsub(c) and in the vicinity of Tsub(c)

Model-Based Closed-Loop Glucose Control in Type 1 Diabetes: The DiaCon Experience

DEFF Research Database (Denmark)

Schmidt, Signe; Boiroux, Dimitri; Duun-Henriksen, Anne Katrine

2013-01-01

Background: To improve type 1 diabetes mellitus (T1DM) management, we developed a model predictive control (MPC) algorithm for closed-loop (CL) glucose control based on a linear second-order deterministic-stochastic model. The deterministic part of the model is specified by three patient-specific......Background: To improve type 1 diabetes mellitus (T1DM) management, we developed a model predictive control (MPC) algorithm for closed-loop (CL) glucose control based on a linear second-order deterministic-stochastic model. The deterministic part of the model is specified by three patient...... crossover studies. Study 1 compared CL with open-loop (OL) control. Study 2 compared glucose control after CL initiation in the euglycemic (CL-Eu) and hyperglycemic (CL-Hyper) ranges, respectively. Patients were studied from 22:00–07:00 on two separate nights. Results: Each study included six T1DM patients...

Calculation and construction of a beam-transport system for polarized electrons

International Nuclear Information System (INIS)

Marschke, G.

1987-09-01

In the framework of the ELSA-SAPHIR project a transfer channel between ELSA and the large-space detector SAPHIR was calculated and constructed. Existing optical elements were modified corresponding to their application and the missing racks constructed and ordered for fabrication. Furthermore the vacuum system was designed as the whole as well as in the single components. Starting from the architectonic conditions and the optics to be realized the coordinates of the elements were calculated as preconditions fo the geodetic measurements and calibrations. It was shown that both for a polarized and for an unpolarized electron beam an optic was realized corresponding to the requirements up to an energy of 3.5 GeV. Under the given conditions, the applied method of the rotation of the polarization vector, and the geometrical preconditions up to 3.0 GeV also an acceptable longitudinal polarization was reached. (orig./HSI) [de

Electrophysiological characterization of spinal neurons in different models of diabetes type 1- and type 2-induced neuropathy in rats.

Science.gov (United States)

Schuelert, N; Gorodetskaya, N; Just, S; Doods, H; Corradini, L

2015-04-16

Diabetic polyneuropathy (DPN) is a devastating complication of diabetes. The underlying pathogenesis of DPN is still elusive and an effective treatment devoid of side effects presents a challenge. There is evidence that in type-1 and -2 diabetes, metabolic and morphological changes lead to peripheral nerve damage and altered central nociceptive transmission, which may contribute to neuropathic pain symptoms. We characterized the electrophysiological response properties of spinal wide dynamic range (WDR) neurons in three diabetic models. The streptozotocin (STZ) model was used as a drug-induced model of type-1 diabetes, and the BioBreeding/Worcester (BB/Wor) and Zucker diabetic fatty (ZDF) rat models were used for genetic DPN models. Data were compared to the respective control group (BB/Wor diabetic-resistant, Zucker lean (ZL) and saline-injected Wistar rat). Response properties of WDR neurons to mechanical stimulation and spontaneous activity were assessed. We found abnormal response properties of spinal WDR neurons in all diabetic rats but not controls. Profound differences between models were observed. In BB/Wor diabetic rats evoked responses were increased, while in ZDF rats spontaneous activity was increased and in STZ rats mainly after discharges were increased. The abnormal response properties of neurons might indicate differential pathological, diabetes-induced, changes in spinal neuronal transmission. This study shows for the first time that specific electrophysiological response properties are characteristic for certain models of DPN and that these might reflect the diverse and complex symptomatology of DPN in the clinic. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Models for dose assessments. Modules for various biosphere types

Energy Technology Data Exchange (ETDEWEB)

Bergstroem, U.; Nordlinder, S.; Aggeryd, I. [Studsvik Eco and Safety AB, Nykoeping (Sweden)

1999-12-01

The main objective of this study was to provide a basis for illustrations of yearly dose rates to the most exposed individual from hypothetical leakages of radionuclides from a deep bedrock repository for spent nuclear fuel and other radioactive waste. The results of this study will be used in the safety assessment SR 97 and in a study on the design and long-term safety for a repository planned to contain long-lived low and intermediate level waste. The repositories will be designed to isolate the radionuclides for several hundred thousands of years. In the SR 97 study, however, hypothetical scenarios for leakage are postulated. Radionuclides are hence assumed to be transported in the geosphere by groundwater, and probably discharge into the biosphere. This may occur in several types of ecosystems. A number of categories of such ecosystems were identified, and turnover of radionuclides was modelled separately for each ecosystem. Previous studies had focused on generic models for wells, lakes and coastal areas. These models were, in this study, developed further to use site-specific data. In addition, flows of groundwater, containing radionuclides, to agricultural land and peat bogs were considered. All these categories are referred to as modules in this report. The forest ecosystems were not included, due to a general lack of knowledge of biospheric processes in connection with discharge of groundwater in forested areas. Examples of each type of module were run with the assumption of a continuous annual release into the biosphere of 1 Bq for each radionuclide during 10 000 years. The results are presented as ecosystem specific dose conversion factors (EDFs) for each nuclide at the year 10 000, assuming stationary ecosystems and prevailing living conditions and habits. All calculations were performed with uncertainty analyses included. Simplifications and assumptions in the modelling of biospheric processes are discussed. The use of modules may be seen as a step

Models for dose assessments. Modules for various biosphere types

International Nuclear Information System (INIS)

Bergstroem, U.; Nordlinder, S.; Aggeryd, I.

1999-12-01

The main objective of this study was to provide a basis for illustrations of yearly dose rates to the most exposed individual from hypothetical leakages of radionuclides from a deep bedrock repository for spent nuclear fuel and other radioactive waste. The results of this study will be used in the safety assessment SR 97 and in a study on the design and long-term safety for a repository planned to contain long-lived low and intermediate level waste. The repositories will be designed to isolate the radionuclides for several hundred thousands of years. In the SR 97 study, however, hypothetical scenarios for leakage are postulated. Radionuclides are hence assumed to be transported in the geosphere by groundwater, and probably discharge into the biosphere. This may occur in several types of ecosystems. A number of categories of such ecosystems were identified, and turnover of radionuclides was modelled separately for each ecosystem. Previous studies had focused on generic models for wells, lakes and coastal areas. These models were, in this study, developed further to use site-specific data. In addition, flows of groundwater, containing radionuclides, to agricultural land and peat bogs were considered. All these categories are referred to as modules in this report. The forest ecosystems were not included, due to a general lack of knowledge of biospheric processes in connection with discharge of groundwater in forested areas. Examples of each type of module were run with the assumption of a continuous annual release into the biosphere of 1 Bq for each radionuclide during 10 000 years. The results are presented as ecosystem specific dose conversion factors (EDFs) for each nuclide at the year 10 000, assuming stationary ecosystems and prevailing living conditions and habits. All calculations were performed with uncertainty analyses included. Simplifications and assumptions in the modelling of biospheric processes are discussed. The use of modules may be seen as a step

A comprehensive compartmental model of blood glucose regulation for healthy and type 2 diabetic subjects

DEFF Research Database (Denmark)

Vahidi, O; Kwok, K E; Gopaluni, R B

2016-01-01

We have expanded a former compartmental model of blood glucose regulation for healthy and type 2 diabetic subjects. The former model was a detailed physiological model which considered the interactions of three substances, glucose, insulin and glucagon on regulating the blood sugar. The main...... variations of blood glucose concentrations following an oral glucose intake. Another model representing the incretins production in the gastrointestinal tract along with their hormonal effects on boosting pancreatic insulin production is also added to the former model. We have used two sets of clinical data...... obtained during oral glucose tolerance test and isoglycemic intravenous glucose infusion test from both type 2 diabetic and healthy subjects to estimate the model parameters and to validate the model results. The estimation of model parameters is accomplished through solving a nonlinear optimization...

Deformed type 0A matrix model and super-Liouville theory for fermionic black holes

International Nuclear Information System (INIS)

Ahn, Changrim; Kim, Chanju; Park, Jaemo; Suyama, Takao; Yamamoto, Masayoshi

2006-01-01

We consider a c-circumflex = 1 model in the fermionic black hole background. For this purpose we consider a model which contains both the N 1 and the N = 2 super-Liouville interactions. We propose that this model is dual to a recently proposed type 0A matrix quantum mechanics model with vortex deformations. We support our conjecture by showing that non-perturbative corrections to the free energy computed by both the matrix model and the super-Liouville theories agree exactly by treating the N = 2 interaction as a small perturbation. We also show that a two-point function on sphere calculated from the deformed type 0A matrix model is consistent with that of the N = 2 super-Liouville theory when the N = 1 interaction becomes small. This duality between the matrix model and super-Liouville theories leads to a conjecture for arbitrary n-point correlation functions of the N = 1 super-Liouville theory on the sphere

A manufacturing quality assessment model based-on two stages interval type-2 fuzzy logic

Science.gov (United States)

Purnomo, Muhammad Ridwan Andi; Helmi Shintya Dewi, Intan

2016-01-01

This paper presents the development of an assessment models for manufacturing quality using Interval Type-2 Fuzzy Logic (IT2-FL). The proposed model is developed based on one of building block in sustainable supply chain management (SSCM), which is benefit of SCM, and focuses more on quality. The proposed model can be used to predict the quality level of production chain in a company. The quality of production will affect to the quality of product. Practically, quality of production is unique for every type of production system. Hence, experts opinion will play major role in developing the assessment model. The model will become more complicated when the data contains ambiguity and uncertainty. In this study, IT2-FL is used to model the ambiguity and uncertainty. A case study taken from a company in Yogyakarta shows that the proposed manufacturing quality assessment model can work well in determining the quality level of production.

Developing a theoretical maintenance model for disordered eating in Type 1 diabetes.

Science.gov (United States)

Treasure, J; Kan, C; Stephenson, L; Warren, E; Smith, E; Heller, S; Ismail, K

2015-12-01

According to the literature, eating disorders are an increasing problem for more than a quarter of people with Type 1 diabetes and they are associated with accentuated diabetic complications. The clinical outcomes in this group when given standard eating disorder treatments are disappointing. The Medical Research Council guidelines for developing complex interventions suggest that the first step is to develop a theoretical model. To review existing literature to build a theoretical maintenance model for disordered eating in people with Type 1 diabetes. The literature in diabetes relating to models of eating disorder (Fairburn's transdiagnostic model and the dual pathway model) and food addiction was examined and assimilated. The elements common to all eating disorder models include weight/shape concern and problems with mood regulation. The predisposing traits of perfectionism, low self-esteem and low body esteem and the interpersonal difficulties from the transdiagnostic model are also relevant to diabetes. The differences include the use of insulin mismanagement to compensate for breaking eating rules and the consequential wide variations in plasma glucose that may predispose to 'food addiction'. Eating disorder symptoms elicit emotionally driven reactions and behaviours from others close to the individual affected and these are accentuated in the context of diabetes. The next stage is to test the assumptions within the maintenance model with experimental medicine studies to facilitate the development of new technologies aimed at increasing inhibitory processes and moderating environmental triggers. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

3D Simulations of Supernova Remnants from Type Ia Supernova Models

Science.gov (United States)

Johnson, Heather; Reynolds, S. P.; Frohlich, C.; Blondin, J. M.

2014-01-01

Type Ia supernovae (SNe) originate from thermonuclear explosions of white dwarfs. A great deal is still unknown about the explosion mechanisms, particularly the degree of asymmetry. However, Type Ia supernova remnants (SNRs) can bear the imprint of asymmetry long after the explosion. A SNR of interest is G1.9+0.3, the youngest Galactic SNR, which demonstrates an unusual spatial distribution of elements in the ejecta. While its X-ray spectrum is dominated by synchrotron emission, spectral lines of highly ionized Si, S, and Fe are seen in a few locations, with Fe near the edge of the remnant and with strongly varying Fe/Si ratios. An asymmetric explosion within the white dwarf progenitor may be necessary to explain these unusual features of G1.9+0.3, in particular the shocked Fe at large radii. We use the VH-1 hydrodynamics code to evolve initial Type Ia explosion models in 1, 2, and 3 dimensions at an age of 100 seconds provided by other researchers to study asymmetry, the ignition properties, and the nucleosynthesis resulting from these explosions. We follow the evolution of these models interacting with a uniform external medium to a few hundred years in age. We find the abundance and location of ejecta elements from our models to be inconsistent with the observations of G1.9+0.3; while our models show asymmetric element distributions, we find no tendency for iron-group elements to be found beyond intermediate-mass elements, or for significant iron to be reverse-shocked at all at the age of G1.9+0.3. We compare the amounts of shocked iron-group and intermediate-mass elements as a function of time in the different models. Some new kind of explosion asymmetry may be required to explain G1.9+0.3. This work was performed as part of NC State University's Undergraduate Research in Computational Astrophysics (URCA) program, an REU program supported by the National Science Foundation through award AST-1032736.

Kaluza–Klein-type models of de Sitter and Poincaré gauge theories of gravity

International Nuclear Information System (INIS)

Lu Jiaan; Huang Chaoguang

2013-01-01

We construct Kaluza–Klein-type models with a de Sitter or Minkowski bundle in the de Sitter or Poincaré gauge theory of gravity, respectively. A manifestly gauge-invariant formalism has been given. The gravitational dynamics is constructed by the geometry of the de Sitter or Minkowski bundle and a global section which plays an important role in the gauge-invariant formalism. Unlike the old Kaluza–Klein-type models of gauge theory of gravity, a suitable cosmological term can be obtained in the Lagrangian of our models and the models in the spin-current-free and torsion-free limit will come back to general relativity with a corresponding cosmological term. We also generalize the results to the case with a variable cosmological term. (paper)

Numerical modeling and design of a disk-type rotating permanent magnet induction pump

Energy Technology Data Exchange (ETDEWEB)

Koroteeva, E., E-mail: koroteeva@physics.msu.ru [Institute of Physics of University of Latvia, Salaspils 2169 (Latvia); Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Ščepanskis, M. [Laboratory for Mathematical Modelling of Environmental and Technological Processes, University of Latvia, Rīga 1002 (Latvia); Bucenieks, I.; Platacis, E. [Institute of Physics of University of Latvia, Salaspils 2169 (Latvia)

2016-05-15

Highlights: • The design and performance of a disk-type induction pump are described. • A 3D numerical model based on an iterative coupling between EM and hydrodynamic solvers is developed. • The model is verified by comparing with the experiments in a Pb-Bi loop facility. • The suggestions are given to estimate the pump performance in a Pb-Li loop at high pressures. - Abstract: Electromagnetic induction pumps with rotating permanent magnets appear to be the most promising devices to transport liquid metals in high-temperature applications. Here we present a numerical methodology to simulate the operation of one particular modification of these types of pumps: a disk-type induction pump. The numerical model allows for the calculation and analysis of the flow parameters, including the pressure–flow rate characteristics of the pump. The simulations are based on an iterative fully coupled scheme for electromagnetic and hydrodynamic solvers. The developed model is verified by comparing with experimental data obtained using a Pb-Bi loop test facility, for pressures up to 4 bar and flow rates up to 9 kg/s. The verified model is then expanded to higher pressures, beyond the limits of the experimental loop. Based on the numerical simulations, suggestions are given to extrapolate experimental data to higher (industrially important) pressure ranges. Using the numerical model and analytical estimation, the pump performance for the Pb-Li loop is also examined, and the ability of the designed pump to develop pressure heads over 6 bar and to provide flow rates over 15 kg/s is shown.

A Systematic Review of Cost-Effectiveness Models in Type 1 Diabetes Mellitus.

Science.gov (United States)

Henriksson, Martin; Jindal, Ramandeep; Sternhufvud, Catarina; Bergenheim, Klas; Sörstadius, Elisabeth; Willis, Michael

2016-06-01

Critiques of cost-effectiveness modelling in type 1 diabetes mellitus (T1DM) are scarce and are often undertaken in combination with type 2 diabetes mellitus (T2DM) models. However, T1DM is a separate disease, and it is therefore important to appraise modelling methods in T1DM. This review identified published economic models in T1DM and provided an overview of the characteristics and capabilities of available models, thus enabling a discussion of best-practice modelling approaches in T1DM. A systematic review of Embase(®), MEDLINE(®), MEDLINE(®) In-Process, and NHS EED was conducted to identify available models in T1DM. Key conferences and health technology assessment (HTA) websites were also reviewed. The characteristics of each model (e.g. model structure, simulation method, handling of uncertainty, incorporation of treatment effect, data for risk equations, and validation procedures, based on information in the primary publication) were extracted, with a focus on model capabilities. We identified 13 unique models. Overall, the included studies varied greatly in scope as well as in the quality and quantity of information reported, but six of the models (Archimedes, CDM [Core Diabetes Model], CRC DES [Cardiff Research Consortium Discrete Event Simulation], DCCT [Diabetes Control and Complications Trial], Sheffield, and EAGLE [Economic Assessment of Glycaemic control and Long-term Effects of diabetes]) were the most rigorous and thoroughly reported. Most models were Markov based, and cohort and microsimulation methods were equally common. All of the more comprehensive models employed microsimulation methods. Model structure varied widely, with the more holistic models providing a comprehensive approach to microvascular and macrovascular events, as well as including adverse events. The majority of studies reported a lifetime horizon, used a payer perspective, and had the capability for sensitivity analysis. Several models have been developed that provide useful

Multi-tissue computational modeling analyzes pathophysiology of type 2 diabetes in MKR mice.

Directory of Open Access Journals (Sweden)

Amit Kumar

Full Text Available Computational models using metabolic reconstructions for in silico simulation of metabolic disorders such as type 2 diabetes mellitus (T2DM can provide a better understanding of disease pathophysiology and avoid high experimentation costs. There is a limited amount of computational work, using metabolic reconstructions, performed in this field for the better understanding of T2DM. In this study, a new algorithm for generating tissue-specific metabolic models is presented, along with the resulting multi-confidence level (MCL multi-tissue model. The effect of T2DM on liver, muscle, and fat in MKR mice was first studied by microarray analysis and subsequently the changes in gene expression of frank T2DM MKR mice versus healthy mice were applied to the multi-tissue model to test the effect. Using the first multi-tissue genome-scale model of all metabolic pathways in T2DM, we found out that branched-chain amino acids' degradation and fatty acids oxidation pathway is downregulated in T2DM MKR mice. Microarray data showed low expression of genes in MKR mice versus healthy mice in the degradation of branched-chain amino acids and fatty-acid oxidation pathways. In addition, the flux balance analysis using the MCL multi-tissue model showed that the degradation pathways of branched-chain amino acid and fatty acid oxidation were significantly downregulated in MKR mice versus healthy mice. Validation of the model was performed using data derived from the literature regarding T2DM. Microarray data was used in conjunction with the model to predict fluxes of various other metabolic pathways in the T2DM mouse model and alterations in a number of pathways were detected. The Type 2 Diabetes MCL multi-tissue model may explain the high level of branched-chain amino acids and free fatty acids in plasma of Type 2 Diabetic subjects from a metabolic fluxes perspective.

Creep modelling of type 316LN stainless steel

International Nuclear Information System (INIS)

Kim, W. G.; Kim, D. H.; Ryu, W. S.

2000-01-01

Creep curve for type 316LN stainless steel was modelled by using the K-R damage equations. Seven coefficients used in the model, i. e., A, B, κ, m, λ, r, and q were determined from theoretical and calculated data, and their meanings were also analyzed. To quantify damage formation parameter(ω), cavity amount was measured on the crept specimen taken from an interrupted creep test with time variation, and then the amount was reflected into K-R damage equations. Coefficient λ which is regarded as a creep tolerance feature of a material increased with increase of creep strain. Theoretical curve in λ= 3.0 well coincided with an experimental one to the full level of lifetime. Master curve between damage parameter and life fraction matched with the theoretical one in exponent γ= 24 value, which decreased with increase of parameter ω which increased rapidly after 80% life fraction. It is concluded that K-R equation was reliable as the modelling equation for 316LN stainless steel. Coefficient data obtained from 316LN stainless steel can be utilized for remaining life prediction of operating material

A consensus model for group decision making under interval type-2 fuzzy environment

Institute of Scientific and Technical Information of China (English)

Xiao-xiong ZHANG; Bing-feng GE; Yue-jin TAN

2016-01-01

We propose a new consensus model for group decision making (GDM) problems, using an interval type-2 fuzzy environment. In our model, experts are asked to express their preferences using linguistic terms characterized by interval type-2 fuzzy sets (IT2 FSs), because these can provide decision makers with greater freedom to express the vagueness in real-life situa-tions. Consensus and proximity measures based on the arithmetic operations of IT2 FSs are used simultaneously to guide the decision-making process. The majority of previous studies have taken into account only the importance of the experts in the aggregation process, which may give unreasonable results. Thus, we propose a new feedback mechanism that generates different advice strategies for experts according to their levels of importance. In general, experts with a lower level of importance require a larger number of suggestions to change their initial preferences. Finally, we investigate a numerical example and execute com-parable models and ours, to demonstrate the performance of our proposed model. The results indicate that the proposed model provides greater insight into the GDM process.

Comparison between sparsely distributed memory and Hopfield-type neural network models

Science.gov (United States)

Keeler, James D.

1986-01-01

The Sparsely Distributed Memory (SDM) model (Kanerva, 1984) is compared to Hopfield-type neural-network models. A mathematical framework for comparing the two is developed, and the capacity of each model is investigated. The capacity of the SDM can be increased independently of the dimension of the stored vectors, whereas the Hopfield capacity is limited to a fraction of this dimension. However, the total number of stored bits per matrix element is the same in the two models, as well as for extended models with higher order interactions. The models are also compared in their ability to store sequences of patterns. The SDM is extended to include time delays so that contextual information can be used to cover sequences. Finally, it is shown how a generalization of the SDM allows storage of correlated input pattern vectors.

Experiment and analysis of CASTOR type model cask for verification of radiation shielding

Energy Technology Data Exchange (ETDEWEB)

Hattori, Seiichi; Ueki, Kohtaro.

1988-08-01

The radiation shielding system of CASTOR type cask is composed of the graphite cast iron and the polyethylene lod. The former fomes the cylndrical body of the cask to shield gamma rays and the latter is embeded in the body to shield neutrons. Characteristic of radiation shielding of CASTOR type cask is that zigzag arrangement of the polyethylene lod is adopted to unify the penetrating dose rate. It is necessary to use the three-dimensional analysis code to analyse the shielding performance of the cask with the complicated shielding system precisely. However, it takes too much time as well as too much cost. Therefore, the two-dimensional analysis is usually applied, in which the three-dimensional model is equivalently transformed into the two-dimensional calculation. The reseach study was conducted to verify the application of the two-dimensional analysis, in which the experiment and the analysis using CASTOR type model cask was perfomed. The model cask was manufactured by GNS campany in West Germany and the shielding ability test facilities in CRIEPI were used. It was judged from the study that the two-dimensional analysis is useful means for the practical use.

AN-type Dunkl operators and new spin Calogero-Sutherland models

International Nuclear Information System (INIS)

Finkel, F.; Gomez-Ullate, D.; Gonzalez-Lopez, A.; Rodriguez, M.A.; Zhdanov, R.

2001-01-01

A new family of A N -type Dunkl operators preserving a polynomial subspace of finite dimension is constructed. Using a general quadratic combination of these operators and the usual Dunkl operators, several new families of exactly and quasi-exactly solvable quantum spin Calogero-Sutherland models are obtained. These include, in particular, three families of quasi-exactly solvable elliptic spin Hamiltonians. (orig.)

A model for the thermodynamic analysis in a batch type fluidized bed dryer

International Nuclear Information System (INIS)

Özahi, Emrah; Demir, Hacımurat

2013-01-01

An original model for thermodynamic analysis of a batch type fluidized bed dryer is proposed herein considering two separate systems comprised of drying air medium as a control volume and particles to be dried as a control mass. By means of the proposed model, energetic and exergetic analyses of a drying column of a batch type fluidized bed dryer are carried out as an original contribution to literature since there is no such like model in which the analyses are performed considering two separate systems. The energetic efficiencies evaluated by means of the proposed model using the data in literature are compared with those in literature and a good conformity is satisfied with an acceptable error margin of ±9%. A new correlation is also developed with a mean deviation of ±10% in order to evaluate the energetic efficiency for not only corn drying process but also drying processes of other particles at inlet air temperature of 50 °C. Effects of air mass flow rate, mass of particle and ambient temperature on energetic and exergetic efficiencies are analyzed and some concluding remarks are highlighted for further studies. - Highlights: • Energetic and exergetic analyses of a batch type fluidized bed dryer are developed. • An original model is proposed for thermodynamic analyses in a fluidized bed dryer. • The proposed model is compared with the data in literature with an accuracy of ±9%. • Effect of air mass flow rate is more significant than that of ambient temperature. • Effect of mass of particle is more significant than that of ambient temperature

Correlation of microstructure and fatigue crack growth resistance in Ti-6Al-4V alloy

CSIR Research Space (South Africa)

Masete, Stephen

2016-10-01

Full Text Available Opal 450 mounting press. The specimens were ground and polished using an ATM Saphir 550 polisher and were thereafter cleaned in the ultrasonic bath using ethanol for about 10 minutes and then air dried. Etching was done using Kroll’s reagent (1 ml HF...

Application of simple approximate system analysis methods for reliability and availability improvement of reactor WWER-1000

International Nuclear Information System (INIS)

Manchev, B.; Marinova, B.; Nenkova, B.

2001-01-01

The method described on this report provides a set of simple, easily understood 'approximate' models applicable to a large class of system architectures. Constructing a Markov model of each redundant subsystem and its replacement after that by a pseudo-component develops the approximation models. Of equal importance, the models can be easily understood even of non-experts, including managers, high-level decision-makers and unsophisticated consumers. A necessary requirement for their application is the systems to be repairable and the mean time to repair to be much smaller than the mean time to failure. This ia a case most often met in the real practice. Results of the 'approximate' model application on a technological system of Kozloduy NPP are also presented. The results obtained can be compared quite favorably with the results obtained by using SAPHIRE software

Inference of type-specific HPV transmissibility, progression and clearance rates: a mathematical modelling approach.

Directory of Open Access Journals (Sweden)

Helen C Johnson

Full Text Available Quantifying rates governing the clearance of Human Papillomavirus (HPV and its progression to clinical disease, together with viral transmissibility and the duration of naturally-acquired immunity, is essential in estimating the impact of vaccination programmes and screening or testing regimes. However, the complex natural history of HPV makes this difficult. We infer the viral transmissibility, rate of waning natural immunity and rates of progression and clearance of infection of 13 high-risk and 2 non-oncogenic HPV types, making use of a number of rich datasets from Sweden. Estimates of viral transmissibility, clearance of initial infection and waning immunity were derived in a Bayesian framework by fitting a susceptible-infectious-recovered-susceptible (SIRS transmission model to age- and type-specific HPV prevalence data from both a cross-sectional study and a randomised controlled trial (RCT of primary HPV screening. The models fitted well, but over-estimated the prevalence of four high-risk types with respect to the data. Three of these types (HPV-33, -35 and -58 are among the most closely related phylogenetically to the most prevalent HPV-16. The fourth (HPV-45 is the most closely related to HPV-18; the second most prevalent type. We suggest that this may be an indicator of cross-immunity. Rates of progression and clearance of clinical lesions were additionally estimated from longitudinal data gathered as part of the same RCT. Our estimates of progression and clearance rates are consistent with the findings of survival analysis studies and we extend the literature by estimating progression and clearance rates for non-16 and non-18 high-risk types. We anticipate that such type-specific estimates will be useful in the parameterisation of further models and in developing our understanding of HPV natural history.

A Linearized Large Signal Model of an LCL-Type Resonant Converter

Directory of Open Access Journals (Sweden)

Hong-Yu Li

2015-03-01

Full Text Available In this work, an LCL-type resonant dc/dc converter with a capacitive output filter is modeled in two stages. In the first high-frequency ac stage, all ac signals are decomposed into two orthogonal vectors in a synchronous rotating d–q frame using multi-frequency modeling. In the dc stage, all dc quantities are represented by their average values with average state-space modeling. A nonlinear two-stage model is then created by means of a non-linear link. By aligning the transformer voltage on the d-axis, the nonlinear link can be eliminated, and the whole converter can be modeled by a single set of linear state-space equations. Furthermore, a feedback control scheme can be formed according to the steady-state solutions. Simulation and experimental results have proven that the resulted model is good for fast simulation and state variable estimation.

Population pharmacokinetic modeling of glibenclamide in poorly controlled South African type 2 diabetic subjects

Directory of Open Access Journals (Sweden)

Rambiritch V

2016-07-01

Full Text Available Virendra Rambiritch,1 Poobalan Naidoo,2 Breminand Maharaj,1 Goonaseelan Pillai3 1University of KwaZulu-Natal, Durban, 2Department of Internal Medicine, RK Khan Regional Hospital, Chatsworth, South Africa; 3Novartis Pharma AG, Basel, Switzerland Aim: The aim of this study was to describe the pharmacokinetics (PK of glibenclamide in poorly controlled South African type 2 diabetic subjects using noncompartmental and model-based methods. Methods: A total of 24 subjects with type 2 diabetes were administered increasing doses (0 mg/d, 2.5 mg/d, 5 mg/d, 10 mg/d, and 20 mg/d of glibenclamide daily at 2-week intervals. Plasma glibenclamide, glucose, and insulin determinations were performed. Blood sampling times were 0 minute, 30 minutes, 60 minutes, 90 minutes, and 120 minutes (post breakfast sampling and 240 minutes, 270 minutes, 300 minutes, 330 minutes, 360 minutes, and 420 minutes (post lunch sampling on days 14, 28, 42, 56, and 70 for doses of 0 mg, 2.5 mg, 5.0 mg, 10 mg, and 20 mg, respectively. Blood sampling was performed after the steady state was reached.  A total of 24 individuals in the data set contributed to a total of 841 observation records. The PK was analyzed using noncompartmental analysis methods, which were implemented in WinNonLin®, and population PK analysis using NONMEM®. Glibenclamide concentration data were log transformed prior to fitting. Results: A two-compartmental disposition model was selected after evaluating one-, two-, and three-compartmental models to describe the time course of glibenclamide plasma concentration data. The one-compartment model adequately described the data; however, the two-compartment model provided a better fit. The three-compartment model failed to achieve successful convergence. A more complex model, to account for enterohepatic recirculation that was observed in the data, was unsuccessful. Conclusion: In South African diabetic subjects, glibenclamide demonstrates linear PK and was best

Using Factor Mixture Models to Evaluate the Type A/B Classification of Alcohol Use Disorders in a Heterogeneous Treatment Sample

Science.gov (United States)

Hildebrandt, Tom; Epstein, Elizabeth E.; Sysko, Robyn; Bux, Donald A.

2017-01-01

Background The type A/B classification model for alcohol use disorders (AUDs) has received considerable empirical support. However, few studies examine the underlying latent structure of this subtyping model, which has been challenged as a dichotomization of a single drinking severity dimension. Type B, relative to type A, alcoholics represent those with early age of onset, greater familial risk, and worse outcomes from alcohol use. Method We examined the latent structure of the type A/B model using categorical, dimensional, and factor mixture models in a mixed gender community treatment-seeking sample of adults with an AUD. Results Factor analytic models identified 2-factors (drinking severity/externalizing psychopathology and internalizing psychopathology) underlying the type A/B indicators. A factor mixture model with 2-dimensions and 3-classes emerged as the best overall fitting model. The classes reflected a type A class and two type B classes (B1 and B2) that differed on the respective level of drinking severity/externalizing pathology and internalizing pathology. Type B1 had a greater prevalence of women and more internalizing pathology and B2 had a greater prevalence of men and more drinking severity/externalizing pathology. The 2-factor, 3-class model also exhibited predictive validity by explaining significant variance in 12-month drinking and drug use outcomes. Conclusions The model identified in the current study may provide a basis for examining different sources of heterogeneity in the course and outcome of AUDs. PMID:28247423

Theoretical Hill-type muscle and stability: numerical model and application.

Science.gov (United States)

Schmitt, S; Günther, M; Rupp, T; Bayer, A; Häufle, D

2013-01-01

The construction of artificial muscles is one of the most challenging developments in today's biomedical science. The application of artificial muscles is focused both on the construction of orthotics and prosthetics for rehabilitation and prevention purposes and on building humanoid walking machines for robotics research. Research in biomechanics tries to explain the functioning and design of real biological muscles and therefore lays the fundament for the development of functional artificial muscles. Recently, the hyperbolic Hill-type force-velocity relation was derived from simple mechanical components. In this contribution, this theoretical yet biomechanical model is transferred to a numerical model and applied for presenting a proof-of-concept of a functional artificial muscle. Additionally, this validated theoretical model is used to determine force-velocity relations of different animal species that are based on the literature data from biological experiments. Moreover, it is shown that an antagonistic muscle actuator can help in stabilising a single inverted pendulum model in favour of a control approach using a linear torque generator.

Investigation of time and weather effects on crash types using full Bayesian multivariate Poisson lognormal models.

Science.gov (United States)

El-Basyouny, Karim; Barua, Sudip; Islam, Md Tazul

2014-12-01

Previous research shows that various weather elements have significant effects on crash occurrence and risk; however, little is known about how these elements affect different crash types. Consequently, this study investigates the impact of weather elements and sudden extreme snow or rain weather changes on crash type. Multivariate models were used for seven crash types using five years of daily weather and crash data collected for the entire City of Edmonton. In addition, the yearly trend and random variation of parameters across the years were analyzed by using four different modeling formulations. The proposed models were estimated in a full Bayesian context via Markov Chain Monte Carlo simulation. The multivariate Poisson lognormal model with yearly varying coefficients provided the best fit for the data according to Deviance Information Criteria. Overall, results showed that temperature and snowfall were statistically significant with intuitive signs (crashes decrease with increasing temperature; crashes increase as snowfall intensity increases) for all crash types, while rainfall was mostly insignificant. Previous snow showed mixed results, being statistically significant and positively related to certain crash types, while negatively related or insignificant in other cases. Maximum wind gust speed was found mostly insignificant with a few exceptions that were positively related to crash type. Major snow or rain events following a dry weather condition were highly significant and positively related to three crash types: Follow-Too-Close, Stop-Sign-Violation, and Ran-Off-Road crashes. The day-of-the-week dummy variables were statistically significant, indicating a possible weekly variation in exposure. Transportation authorities might use the above results to improve road safety by providing drivers with information regarding the risk of certain crash types for a particular weather condition. Copyright © 2014 Elsevier Ltd. All rights reserved.

The exactly solvable spin Sutherland model of BN type and its related spin chain

International Nuclear Information System (INIS)

Basu-Mallick, B.; Finkel, F.; González-López, A.

2013-01-01

We compute the spectrum of the su(m) spin Sutherland model of B N type, including the exact degeneracy of all energy levels. By studying the large coupling constant limit of this model and of its scalar counterpart, we evaluate the partition function of their associated spin chain of Haldane–Shastry type in closed form. With the help of the formula for the partition function thus obtained we study the chain's spectrum, showing that it cannot be obtained as a limiting case of its BC N counterpart. The structure of the partition function also suggests that the spectrum of the Haldane–Shastry spin chain of B N type is equivalent to that of a suitable vertex model, as is the case for its A N−1 counterpart, and that the density of its eigenvalues is normally distributed when the number of sites N tends to infinity. We analyze this last conjecture numerically using again the explicit formula for the partition function, and check its validity for several values of N and m.

Non-unitarity of the leptonic mixing matrix in the TeV-scale type-I seesaw model

International Nuclear Information System (INIS)

Ohlsson, Tommy; Popa, Christoph; Zhang, He

2010-01-01

The non-unitarity effects in leptonic flavor mixing are regarded as one of the generic features of the type-I seesaw model. Therefore, we explore these effects in the TeV-scale type-I seesaw model, and show that there exist non-trivial correlations among the non-unitarity parameters, stemming from the typical flavor structure of the low-scale seesaw model. In general, it follows from analytical discussions and numerical results that all the six non-unitarity parameters are related to three model parameters, while the widely studied parameters η eτ and η μτ cannot be phenomenologically significant simultaneously.

Calibrating a forest landscape model to simulate frequent fire in Mediterranean-type shrublands

Science.gov (United States)

Syphard, A.D.; Yang, J.; Franklin, J.; He, H.S.; Keeley, J.E.

2007-01-01

In Mediterranean-type ecosystems (MTEs), fire disturbance influences the distribution of most plant communities, and altered fire regimes may be more important than climate factors in shaping future MTE vegetation dynamics. Models that simulate the high-frequency fire and post-fire response strategies characteristic of these regions will be important tools for evaluating potential landscape change scenarios. However, few existing models have been designed to simulate these properties over long time frames and broad spatial scales. We refined a landscape disturbance and succession (LANDIS) model to operate on an annual time step and to simulate altered fire regimes in a southern California Mediterranean landscape. After developing a comprehensive set of spatial and non-spatial variables and parameters, we calibrated the model to simulate very high fire frequencies and evaluated the simulations under several parameter scenarios representing hypotheses about system dynamics. The goal was to ensure that observed model behavior would simulate the specified fire regime parameters, and that the predictions were reasonable based on current understanding of community dynamics in the region. After calibration, the two dominant plant functional types responded realistically to different fire regime scenarios. Therefore, this model offers a new alternative for simulating altered fire regimes in MTE landscapes. ?? 2007 Elsevier Ltd. All rights reserved.

Diversity and plasticity of Th cell types predicted from regulatory network modelling.

Directory of Open Access Journals (Sweden)

Aurélien Naldi

Full Text Available Alternative cell differentiation pathways are believed to arise from the concerted action of signalling pathways and transcriptional regulatory networks. However, the prediction of mammalian cell differentiation from the knowledge of the presence of specific signals and transcriptional factors is still a daunting challenge. In this respect, the vertebrate hematopoietic system, with its many branching differentiation pathways and cell types, is a compelling case study. In this paper, we propose an integrated, comprehensive model of the regulatory network and signalling pathways controlling Th cell differentiation. As most available data are qualitative, we rely on a logical formalism to perform extensive dynamical analyses. To cope with the size and complexity of the resulting network, we use an original model reduction approach together with a stable state identification algorithm. To assess the effects of heterogeneous environments on Th cell differentiation, we have performed a systematic series of simulations considering various prototypic environments. Consequently, we have identified stable states corresponding to canonical Th1, Th2, Th17 and Treg subtypes, but these were found to coexist with other transient hybrid cell types that co-express combinations of Th1, Th2, Treg and Th17 markers in an environment-dependent fashion. In the process, our logical analysis highlights the nature of these cell types and their relationships with canonical Th subtypes. Finally, our logical model can be used to explore novel differentiation pathways in silico.

Self-Assembling Hybrid Nanoparticles During Simultaneous Deposition of Co and C60 on Sapphire

Czech Academy of Sciences Publication Activity Database

Lavrentiev, Vasyl; Vacík, Jiří; Naramoto, H.

2009-01-01

Roč. 9, - (2009), s. 4305-4310 ISSN 1533-4880 R&D Projects: GA AV ČR(CZ) KAN400480701 Institutional research plan: CEZ:AV0Z10480505 Keywords : fullerene * cobalt, saphire * co-depozition Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.435, year: 2009

Algebraic Traveling Wave Solutions of a Non-local Hydrodynamic-type Model

International Nuclear Information System (INIS)

Chen, Aiyong; Zhu, Wenjing; Qiao, Zhijun; Huang, Wentao

2014-01-01

In this paper we consider the algebraic traveling wave solutions of a non-local hydrodynamic-type model. It is shown that algebraic traveling wave solutions exist if and only if an associated first order ordinary differential system has invariant algebraic curve. The dynamical behavior of the associated ordinary differential system is analyzed. Phase portraits of the associated ordinary differential system is provided under various parameter conditions. Moreover, we classify algebraic traveling wave solutions of the model. Some explicit formulas of smooth solitary wave and cuspon solutions are obtained

Craniofacial Statistical Deformation Models of Wild-type mice and Crouzon mice

DEFF Research Database (Denmark)

Ólafsdóttir, Hildur; Darvann, Tron Andre; Ersbøll, Bjarne Kjær

2007-01-01

Crouzon syndrome is characterised by the premature fusion of cranial sutures and synchondroses leading to craniofacial growth disturbances. The gene causing the syndrome was discovered approximately a decade ago and recently the first mouse model of the syndrome was generated. In this study, a set...... of Micro CT scannings of the heads of wild-type (normal) mice and Crouzon mice were investigated. Statistical deformation models were built to assess the anatomical differences between the groups, as well as the within-group anatomical variation. Following the approach by Rueckert et al. we built an atlas...

Dealing with time-varying recruitment and length in Hill-type muscle models.

Science.gov (United States)

Hamouda, Ahmed; Kenney, Laurence; Howard, David

2016-10-03

Hill-type muscle models are often used in muscle simulation studies and also in the design and virtual prototyping of functional electrical stimulation systems. These models have to behave in a sufficiently realistic manner when recruitment level and contractile element (CE) length change continuously. For this reason, most previous models have used instantaneous CE length in the muscle׳s force vs. length (F-L) relationship, but thereby neglect the instability problem on the descending limb (i.e. region of negative slope) of the F-L relationship. Ideally CE length at initial recruitment should be used but this requires a multiple-motor-unit muscle model to properly account for different motor-units having different initial lengths when recruited. None of the multiple-motor-unit models reported in the literature have used initial CE length in the muscle׳s F-L relationship, thereby also neglecting the descending limb instability problem. To address the problem of muscle modelling for continuously varying recruitment and length, and hence different values of initial CE length for different motor-units, a new multiple-motor-unit muscle model is presented which considers the muscle to comprise 1000 individual Hill-type virtual motor-units, which determine the total isometric force. Other parts of the model (F-V relationship and passive elements) are not dependent on the initial CE length and, therefore, they are implemented for the muscle as a whole rather than for the individual motor-units. The results demonstrate the potential errors introduced by using a single-motor-unit model and also the instantaneous CE length in the F-L relationship, both of which are common in FES control studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Type Classes for Lightweight Substructural Types

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Edward Gan

2015-02-01

Full Text Available Linear and substructural types are powerful tools, but adding them to standard functional programming languages often means introducing extra annotations and typing machinery. We propose a lightweight substructural type system design that recasts the structural rules of weakening and contraction as type classes; we demonstrate this design in a prototype language, Clamp. Clamp supports polymorphic substructural types as well as an expressive system of mutable references. At the same time, it adds little additional overhead to a standard Damas-Hindley-Milner type system enriched with type classes. We have established type safety for the core model and implemented a type checker with type inference in Haskell.

Early light curves for Type Ia supernova explosion models

Science.gov (United States)

Noebauer, U. M.; Kromer, M.; Taubenberger, S.; Baklanov, P.; Blinnikov, S.; Sorokina, E.; Hillebrandt, W.

2017-12-01

Upcoming high-cadence transient survey programmes will produce a wealth of observational data for Type Ia supernovae. These data sets will contain numerous events detected very early in their evolution, shortly after explosion. Here, we present synthetic light curves, calculated with the radiation hydrodynamical approach STELLA for a number of different explosion models, specifically focusing on these first few days after explosion. We show that overall the early light curve evolution is similar for most of the investigated models. Characteristic imprints are induced by radioactive material located close to the surface. However, these are very similar to the signatures expected from ejecta-CSM or ejecta-companion interaction. Apart from the pure deflagration explosion models, none of our synthetic light curves exhibit the commonly assumed power-law rise. We demonstrate that this can lead to substantial errors in the determination of the time of explosion. In summary, we illustrate with our calculations that even with very early data an identification of specific explosion scenarios is challenging, if only photometric observations are available.

Elucidating determinants of aerosol composition through particle-type-based receptor modeling

Science.gov (United States)

McGuire, M. L.; Jeong, C.-H.; Slowik, J. G.; Chang, R. Y.-W.; Corbin, J. C.; Lu, G.; Mihele, C.; Rehbein, P. J. G.; Sills, D. M. L.; Abbatt, J. P. D.; Brook, J. R.; Evans, G. J.

2011-08-01

An aerosol time-of-flight mass spectrometer (ATOFMS) was deployed at a semi-rural site in southern Ontario to characterize the size and chemical composition of individual particles. Particle-type-based receptor modelling of these data was used to investigate the determinants of aerosol chemical composition in this region. Individual particles were classified into particle-types and positive matrix factorization (PMF) was applied to their temporal trends to separate and cross-apportion particle-types to factors. The extent of chemical processing for each factor was assessed by evaluating the internal and external mixing state of the characteristic particle-types. The nine factors identified helped to elucidate the coupled interactions of these determinants. Nitrate-laden dust was found to be the dominant type of locally emitted particles measured by ATOFMS. Several factors associated with aerosol transported to the site from intermediate local-to-regional distances were identified: the Organic factor was associated with a combustion source to the north-west; the ECOC Day factor was characterized by nearby local-to-regional carbonaceous emissions transported from the south-west during the daytime; and the Fireworks factor consisted of pyrotechnic particles from the Detroit region following holiday fireworks displays. Regional aerosol from farther emissions sources was reflected through three factors: two Biomass Burning factors and a highly chemically processed Long Range Transport factor. The Biomass Burning factors were separated by PMF due to differences in chemical processing which were in part elucidated by the passage of two thunderstorm gust fronts with different air mass histories. The remaining two factors, ECOC Night and Nitrate Background, represented the night-time partitioning of nitrate to pre-existing particles of different origins. The distinct meteorological conditions observed during this month-long study in the summer of 2007 provided a unique

Evolutionary models of early-type contact binary SV Centauri

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Y; Saio, H [Tohoku Univ., Sendai (Japan). Faculty of Science; Sugimoto, Daiichiro

1978-12-01

Models of the early-type contact binary system SV Centauri are computed with a binary-star evolution program. The effects of mass exchange, i.e., the effects of mass acceptance as well as mass loss, are properly included. With the initial masses of the component stars as 12.4 and 8.0 M sub(solar mass), the following observed configurations are well reproduced; the component stars are definitely in contact and the rate of mass exchange is 4 x 10/sup -4/ M sub(solar mass)yr/sup -1/. The more massive component is less luminous and has a lower effective temperature. Such features are also reproduced quantitatively. Agreement of the computed models with observation indicates that the binary system SV Cen is actually in the phase of rapid mass exchange preceding the mass-ratio reversal.

A murine model of type 2 autoimmune hepatitis: Xenoimmunization with human antigens.

Science.gov (United States)

Lapierre, Pascal; Djilali-Saiah, Idriss; Vitozzi, Susana; Alvarez, Fernando

2004-04-01

Autoimmune hepatitis (AIH) is characterized by an immune-mediated injury of the hepatic parenchyma of unknown pathogenesis. Type 2 AIH is identified by the presence of anti-liver-kidney microsomes type 1 (anti-LKM1) and anti-liver cytosol type 1 (anti-LC1) autoantibodies. The current study shows that a murine model of AIH can be generated by DNA immunization against type 2 AIH self-antigens (P450 2D6 and formiminotransferase-cyclodeaminase). A pCMV plasmid containing the N-terminal region of mouse CTLA-4 and the antigenic region of human CYP2D6 (672-1,377 bp) and human formiminotransferase cyclodeaminase (FTCD; 1,232-1,668 bp) was used for DNA immunization of C57BL/6 female mice. Immunized mice showed elevated levels of alanine aminotransferase (ALT), with peaks at 4 and 7 months postinjection. Periportal, portal, and intralobular liver inflammatory infiltrates were observed at histology. Mainly CD4+ lymphocytes, but also CD8+ and B lymphocytes, were found in the liver. Cytotoxic-specific T cells were found in both the liver and spleen of these animals. Mice developed anti-LKM1 and anti-LC1 antibodies of immunoglobulin G2 (IgG2) subclass, against specific mouse autoantigens. The ALT levels correlated with both the presence of anti-LKM1/anti-LC1 antibodies and the presence of liver necroinflammation. In conclusion, in mice, DNA immunization against human autoantigens breaks tolerance and induces an autoimmune liver disease. Molecular mimicry between foreign and self-antigens explains the liver injury. This model of AIH resembles human type 2 AIH and will be helpful for the study of its pathogenesis.

Realizing three generations of the Standard Model fermions in the type IIB matrix model

International Nuclear Information System (INIS)

Aoki, Hajime; Nishimura, Jun; Tsuchiya, Asato

2014-01-01

We discuss how the Standard Model particles appear from the type IIB matrix model, which is considered to be a nonperturbative formulation of superstring theory. In particular, we are concerned with a constructive definition of the theory, in which we start with finite-N matrices and take the large-N limit afterwards. In that case, it was pointed out recently that realizing chiral fermions in the model is more difficult than it had been thought from formal arguments at N=∞ and that introduction of a matrix version of the warp factor is necessary. Based on this new insight, we show that two generations of the Standard Model fermions can be realized by considering a rather generic configuration of fuzzy S"2 and fuzzy S"2×S"2 in the extra dimensions. We also show that three generations can be obtained by squashing one of the S"2’s that appear in the configuration. Chiral fermions appear at the intersections of the fuzzy manifolds with nontrivial Yukawa couplings to the Higgs field, which can be calculated from the overlap of their wave functions.

A MATHEMATICAL MODEL OF CHP 2000 TYPE PROGRESSIVE GEAR

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Paweł Lonkwic

2016-12-01

Full Text Available The project of CHP2000 type progressive gear has been presented in the article. The offered solution from its construction point of view differs from the existing solutions due to the application of Belleville springs packets supporting the braking roller cam and achieving a flexible range of the gear loading. The standard concept of the gear loading within a mathematical and a geometrical model has been presented in the article. The proposed solution can be used in the friction lifts with the loading capacity from 8500 up to 20000 N.

Refinement of the magnetic composite model of type 304 stainless steel by considering misoriented ferromagnetic martensite particles

Science.gov (United States)

Kinoshita, Katsuyuki

2017-05-01

We improved a magnetic composite model that combines the Jiles-Atherton model and Eshelby's equivalent inclusion method to consider misoriented martensite particles. The magnetic permeability of type 304 stainless steel were analyzed by using both experimental data on the orientation distribution of type 304 stainless steel specimens and the improved model. We found that the model is able to qualitatively explain the variation of permeability with the orientation angle and orientation distribution, an effect that depends on the direction of the excitation magnetic field.

Novel brain arteriovenous malformation mouse models for type 1 hereditary hemorrhagic telangiectasia.

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Eun-Jung Choi

Full Text Available Endoglin (ENG is a causative gene of type 1 hereditary hemorrhagic telangiectasia (HHT1. HHT1 patients have a higher prevalence of brain arteriovenous malformation (AVM than the general population and patients with other HHT subtypes. The pathogenesis of brain AVM in HHT1 patients is currently unknown and no specific medical therapy is available to treat patients. Proper animal models are crucial for identifying the underlying mechanisms for brain AVM development and for testing new therapies. However, creating HHT1 brain AVM models has been quite challenging because of difficulties related to deleting Eng-floxed sequence in Eng(2fl/2fl mice. To create an HHT1 brain AVM mouse model, we used several Cre transgenic mouse lines to delete Eng in different cell-types in Eng(2fl/2fl mice: R26CreER (all cell types after tamoxifen treatment, SM22α-Cre (smooth muscle and endothelial cell and LysM-Cre (lysozyme M-positive macrophage. An adeno-associated viral vector expressing vascular endothelial growth factor (AAV-VEGF was injected into the brain to induce focal angiogenesis. We found that SM22α-Cre-mediated Eng deletion in the embryo caused AVMs in the postnatal brain, spinal cord, and intestines. Induction of Eng deletion in adult mice using R26CreER plus local VEGF stimulation induced the brain AVM phenotype. In both models, Eng-null endothelial cells were detected in the brain AVM lesions, and formed mosaicism with wildtype endothelial cells. However, LysM-Cre-mediated Eng deletion in the embryo did not cause AVM in the postnatal brain even after VEGF stimulation. In this study, we report two novel HHT1 brain AVM models that mimic many phenotypes of human brain AVM and can thus be used for studying brain AVM pathogenesis and testing new therapies. Further, our data indicate that macrophage Eng deletion is insufficient and that endothelial Eng homozygous deletion is required for HHT1 brain AVM development.

Characteristics and model of sandstone type uranium deposit in south of Songliao basin

International Nuclear Information System (INIS)

Yu Wenbin; Yu Zhenqing

2010-01-01

Through analyzing the uranium deposit tectonic environment, upper cretaceous sequence stratigraphy, depositional system, evolutionary characteristics of sand bodies, the effect of subsequent transformation and the characteristic of uranium deposit, the sandstone type uranium deposit in southern basin is different from typical interlayer oxidation zone sandstone type uranium deposit. The formation and evolution of sandstone-type uranium deposit are controlled by structure fensters; the favorable sedimentary facies type is braided river facies, and the ore body is braided river sand body. The size of uranium deposits is controlled by the local oxidation zone with the characteristics of sandstone type uranium deposit in partial oxidation zone. Uranium ore bodies which distribute in the roof wings of structure fenstes, and occur in gray layers between the upper and lower oxidation zone, showing tabular, and the plate of uranium ore body is controlled by the local oxidation zone. Based on the geological features of sandstone-type uranium deposits, the metallogenic model of local oxidation zones sandstone-type uranium deposits has been set up in the south of Songliao Baisn. (authors)

Type-2 fuzzy granular models

CERN Document Server

Sanchez, Mauricio A; Castro, Juan R

2017-01-01

In this book, a series of granular algorithms are proposed. A nature inspired granular algorithm based on Newtonian gravitational forces is proposed. A series of methods for the formation of higher-type information granules represented by Interval Type-2 Fuzzy Sets are also shown, via multiple approaches, such as Coefficient of Variation, principle of justifiable granularity, uncertainty-based information concept, and numerical evidence based. And a fuzzy granular application comparison is given as to demonstrate the differences in how uncertainty affects the performance of fuzzy information granules.

Aligning drivers, contract, and management of IT-outsourcing relationships: a type-dependent model

DEFF Research Database (Denmark)

Arenfeldt, Katrine; Corty Dam, Amalie; Fenger, Kim Harder

2017-01-01

In today’s competitive business environment, information technology outsourcing has become a wide-spread reality across all industries and sectors. Researchers have investigated this complex phenomenon from various angles, and established a sound knowledge base regarding the drivers, management......, and success factors related to IT outsourcing. However, little is known about the relationship between outsourcing drivers and goals on the one hand, and contractual and managerial aspects on the other hand. To overcome this gap, this study presents a synthesized conceptual model of existing literature...... that relates aspects of contractual governance and relationship management to three generic types of IT outsourcing, based on their underlying drivers: task-based, process-based, and partnership-based outsourcing. Our model identifies the specific contractual and managerial factors relevant for each type...

Creating Aerosol Types from CHemistry (CATCH): A New Algorithm to Extend the Link Between Remote Sensing and Models

Science.gov (United States)

Dawson, K. W.; Meskhidze, N.; Burton, S. P.; Johnson, M. S.; Kacenelenbogen, M. S.; Hostetler, C. A.; Hu, Y.

2017-11-01

Current remote sensing methods can identify aerosol types within an atmospheric column, presenting an opportunity to incrementally bridge the gap between remote sensing and models. Here a new algorithm was designed for Creating Aerosol Types from CHemistry (CATCH). CATCH-derived aerosol types—dusty mix, maritime, urban, smoke, and fresh smoke—are based on first-generation airborne High Spectral Resolution Lidar (HSRL-1) retrievals during the Ship-Aircraft Bio-Optical Research (SABOR) campaign, July/August 2014. CATCH is designed to derive aerosol types from model output of chemical composition. CATCH-derived aerosol types are determined by multivariate clustering of model-calculated variables that have been trained using retrievals of aerosol types from HSRL-1. CATCH-derived aerosol types (with the exception of smoke) compare well with HSRL-1 retrievals during SABOR with an average difference in aerosol optical depth (AOD) methods. In the future, spaceborne HSRL-1 and CATCH can be used to gain insight into chemical composition of aerosol types, reducing uncertainties in estimates of aerosol radiative forcing.

Modeling of a split type air conditioner with integrated water heater

International Nuclear Information System (INIS)

Techarungpaisan, P.; Theerakulpisut, S.; Priprem, S.

2007-01-01

This paper presents a steady state simulation model to predict the performance of a small split type air conditioner with integrated water heater. The mathematical model consists of submodels of system components such as evaporator, condenser, compressor, capillary tube, receiver and water heater. These submodels were built based on fundamental principles of heat transfer, thermodynamics, fluid mechanics, empirical relationships and manufacturer's data as necessary. The model was coded into a simulation program and used to predict system parameters of interest such as hot water temperature, condenser exit air temperature, evaporator exit air temperature, mass flow rate of refrigerant, heat rejection in the condenser and cooling capacity of the system. The simulation results were compared with experimental data obtained from an experimental rig built for validating the mathematical model. It was found that the experimental and simulation results are in good agreement

A comprehensive compartmental model of blood glucose regulation for healthy and type 2 diabetic subjects.

Science.gov (United States)

Vahidi, O; Kwok, K E; Gopaluni, R B; Knop, F K

2016-09-01

We have expanded a former compartmental model of blood glucose regulation for healthy and type 2 diabetic subjects. The former model was a detailed physiological model which considered the interactions of three substances, glucose, insulin and glucagon on regulating the blood sugar. The main drawback of the former model was its restriction on the route of glucose entrance to the body which was limited to the intravenous glucose injection. To handle the oral glucose intake, we have added a model of glucose absorption in the gastrointestinal tract to the former model to address the resultant variations of blood glucose concentrations following an oral glucose intake. Another model representing the incretins production in the gastrointestinal tract along with their hormonal effects on boosting pancreatic insulin production is also added to the former model. We have used two sets of clinical data obtained during oral glucose tolerance test and isoglycemic intravenous glucose infusion test from both type 2 diabetic and healthy subjects to estimate the model parameters and to validate the model results. The estimation of model parameters is accomplished through solving a nonlinear optimization problem. The results show acceptable precision of the estimated model parameters and demonstrate the capability of the model in accurate prediction of the body response during the clinical studies.

Estimation of stochastic volatility by using Ornstein-Uhlenbeck type models

Science.gov (United States)

Mariani, Maria C.; Bhuiyan, Md Al Masum; Tweneboah, Osei K.

2018-02-01

In this study, we develop a technique for estimating the stochastic volatility (SV) of a financial time series by using Ornstein-Uhlenbeck type models. Using the daily closing prices from developed and emergent stock markets, we conclude that the incorporation of stochastic volatility into the time varying parameter estimation significantly improves the forecasting performance via Maximum Likelihood Estimation. Furthermore, our estimation algorithm is feasible with large data sets and have good convergence properties.

Modeling of acetate-type fermentation of sugar-containing wastewater under acidic pH conditions.

Science.gov (United States)

Huang, Liang; Pan, Xin-Rong; Wang, Ya-Zhou; Li, Chen-Xuan; Chen, Chang-Bin; Zhao, Quan-Bao; Mu, Yang; Yu, Han-Qing; Li, Wen-Wei

2018-01-01

In this study, a kinetic model was developed based on Anaerobic Digestion Model No. 1 to provide insights into the directed production of acetate and methane from sugar-containing wastewater under low pH conditions. The model sufficiently described the dynamics of liquid-phase and gaseous products in an anaerobic membrane bioreactor by comprehensively considering the syntrophic bioconversion steps of sucrose hydrolysis, acidogenesis, acetogenesis and methanogenesis under acidic pH conditions. The modeling results revealed a significant pH-dependency of hydrogenotrophic methanogenesis and ethanol-producing processes that govern the sucrose fermentative pathway through changing the hydrogen yield. The reaction thermodynamics of such acetate-type fermentation were evaluated, and the implications for process optimization by adjusting the hydraulic retention time were discussed. This work sheds light on the acid-stimulated acetate-type fermentation process and may lay a foundation for optimization of resource-oriented processes for treatment of food wastewater. Copyright © 2017 Elsevier Ltd. All rights reserved.

Implementation of draft IEC Generic Model of Type 1 Wind Turbine Generator in PowerFactory and Simulink

DEFF Research Database (Denmark)

Zhao, Haoran; Wu, Qiuwei; Sørensen, Poul Ejnar

2013-01-01

This paper presents the implementation work of IEC generic model of Type 1 wind turbine generator (WTG) in two commercial simulation tools: DIgSILENT PowerFactory (PF) and Matlab Simulink. The model topology, details of the composite blocks and implementation procedure in PF and Simulink environm......This paper presents the implementation work of IEC generic model of Type 1 wind turbine generator (WTG) in two commercial simulation tools: DIgSILENT PowerFactory (PF) and Matlab Simulink. The model topology, details of the composite blocks and implementation procedure in PF and Simulink...

Theoretical Hill-Type Muscle and Stability: Numerical Model and Application

Directory of Open Access Journals (Sweden)

S. Schmitt

2013-01-01

Full Text Available The construction of artificial muscles is one of the most challenging developments in today’s biomedical science. The application of artificial muscles is focused both on the construction of orthotics and prosthetics for rehabilitation and prevention purposes and on building humanoid walking machines for robotics research. Research in biomechanics tries to explain the functioning and design of real biological muscles and therefore lays the fundament for the development of functional artificial muscles. Recently, the hyperbolic Hill-type force-velocity relation was derived from simple mechanical components. In this contribution, this theoretical yet biomechanical model is transferred to a numerical model and applied for presenting a proof-of-concept of a functional artificial muscle. Additionally, this validated theoretical model is used to determine force-velocity relations of different animal species that are based on the literature data from biological experiments. Moreover, it is shown that an antagonistic muscle actuator can help in stabilising a single inverted pendulum model in favour of a control approach using a linear torque generator.

Modeling the Movement of Homicide by Type to Inform Public Health Prevention Efforts.

Science.gov (United States)

Zeoli, April M; Grady, Sue; Pizarro, Jesenia M; Melde, Chris

2015-10-01

We modeled the spatiotemporal movement of hotspot clusters of homicide by motive in Newark, New Jersey, to investigate whether different homicide types have different patterns of clustering and movement. We obtained homicide data from the Newark Police Department Homicide Unit's investigative files from 1997 through 2007 (n = 560). We geocoded the address at which each homicide victim was found and recorded the date of and the motive for the homicide. We used cluster detection software to model the spatiotemporal movement of statistically significant homicide clusters by motive, using census tract and month of occurrence as the spatial and temporal units of analysis. Gang-motivated homicides showed evidence of clustering and diffusion through Newark. Additionally, gang-motivated homicide clusters overlapped to a degree with revenge and drug-motivated homicide clusters. Escalating dispute and nonintimate familial homicides clustered; however, there was no evidence of diffusion. Intimate partner and robbery homicides did not cluster. By tracking how homicide types diffuse through communities and determining which places have ongoing or emerging homicide problems by type, we can better inform the deployment of prevention and intervention efforts.

Eliciting mixed emotions: A meta-analysis comparing models, types and measures.

Directory of Open Access Journals (Sweden)

Raul eBerrios

2015-04-01

Full Text Available The idea that people can experience two oppositely valenced emotions has been controversial ever since early attempts to investigate the construct of mixed emotions. This meta-analysis examined the robustness with which mixed emotions have been elicited experimentally. A systematic literature search identified 63 experimental studies that instigated the experience of mixed emotions. Studies were distinguished according to the structure of the underlying affect model – dimensional or discrete – as well as according to the type of mixed emotions studied (e.g., happy-sad, fearful-happy, positive-negative. The meta-analysis using a random-effects model revealed a moderate to high effect size for the elicitation of mixed emotions (dIG+ = .77, which remained consistent regardless of the structure of the affect model, and across different types of mixed emotions. Several methodological and design moderators were tested. Studies using the minimum index (i.e., the minimum value between a pair of opposite valenced affects resulted in smaller effect sizes, whereas subjective measures of mixed emotions increased the effect sizes. The presence of more women in the samples was also associated with larger effect sizes. The current study indicates that mixed emotions are a robust, measurable and non-artifactual experience. The results are discussed in terms of the implications for an affect system that has greater versatility and flexibility than previously thought.

Future of Plant Functional Types in Terrestrial Biosphere Models

Science.gov (United States)

Wullschleger, S. D.; Euskirchen, E. S.; Iversen, C. M.; Rogers, A.; Serbin, S.

2015-12-01

Earth system models describe the physical, chemical, and biological processes that govern our global climate. While it is difficult to single out one component as being more important than another in these sophisticated models, terrestrial vegetation is a critical player in the biogeochemical and biophysical dynamics of the Earth system. There is much debate, however, as to how plant diversity and function should be represented in these models. Plant functional types (PFTs) have been adopted by modelers to represent broad groupings of plant species that share similar characteristics (e.g. growth form) and roles (e.g. photosynthetic pathway) in ecosystem function. In this review the PFT concept is traced from its origin in the early 1800s to its current use in regional and global dynamic vegetation models (DVMs). Special attention is given to the representation and parameterization of PFTs and to validation and benchmarking of predicted patterns of vegetation distribution in high-latitude ecosystems. These ecosystems are sensitive to changing climate and thus provide a useful test case for model-based simulations of past, current, and future distribution of vegetation. Models that incorporate the PFT concept predict many of the emerging patterns of vegetation change in tundra and boreal forests, given known processes of tree mortality, treeline migration, and shrub expansion. However, representation of above- and especially belowground traits for specific PFTs continues to be problematic. Potential solutions include developing trait databases and replacing fixed parameters for PFTs with formulations based on trait co-variance and empirical trait-environment relationships. Surprisingly, despite being important to land-atmosphere interactions of carbon, water, and energy, PFTs such as moss and lichen are largely absent from DVMs. Close collaboration among those involved in modelling with the disciplines of taxonomy, biogeography, ecology, and remote sensing will be

Development and validation of a predictive risk model for all-cause mortality in type 2 diabetes.

Science.gov (United States)

Robinson, Tom E; Elley, C Raina; Kenealy, Tim; Drury, Paul L

2015-06-01

Type 2 diabetes is common and is associated with an approximate 80% increase in the rate of mortality. Management decisions may be assisted by an estimate of the patient's absolute risk of adverse outcomes, including death. This study aimed to derive a predictive risk model for all-cause mortality in type 2 diabetes. We used primary care data from a large national multi-ethnic cohort of patients with type 2 diabetes in New Zealand and linked mortality records to develop a predictive risk model for 5-year risk of mortality. We then validated this model using information from a separate cohort of patients with type 2 diabetes. 26,864 people were included in the development cohort with a median follow up time of 9.1 years. We developed three models initially using demographic information and then progressively more clinical detail. The final model, which also included markers of renal disease, proved to give best prediction of all-cause mortality with a C-statistic of 0.80 in the development cohort and 0.79 in the validation cohort (7610 people) and was well calibrated. Ethnicity was a major factor with hazard ratios of 1.37 for indigenous Maori, 0.41 for East Asian and 0.55 for Indo Asian compared with European (P<0.001). We have developed a model using information usually available in primary care that provides good assessment of patient's risk of death. Results are similar to models previously published from smaller cohorts in other countries and apply to a wider range of patient ethnic groups. Copyright © 2015. Published by Elsevier Ireland Ltd.

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

Science.gov (United States)

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

2017-01-01

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

Detailed empirical models for the winds of early-type stars

International Nuclear Information System (INIS)

Olson, G.L.; Castor, J.I.

1981-01-01

Owing to the recent accumulation of ultraviolet data from the IUE satellite, of X-ray data from the Einstein (HEAO 2) satellite, of visible data from ground based electronic detectors, and of radio data from the Very Large Array (VLA) telescope, it is becoming possible to build much more complete models for the winds of early-type stars. The present work takes the empirical approach of assuming that there exists a coronal region at the base of a cool wind (T/sub e/roughly-equalT/sub eff/). This will be an extension of previous papers by Olson and by Cassinelli and Olson; however, refinements to the model will be presented, and the model will be applied to seven O stars and one BO star. Ionization equilibria are computed to match the line strengths found in UV spectra. The coronal fluxes that are required to produce the observed abundance of O +5 are compared to the X-ray fluxes observed by the Einstein satellite

Folding-type coupling potentials in the context of the generalized rotation-vibration model

Science.gov (United States)

Chamon, L. C.; Morales Botero, D. F.

2018-03-01

The generalized rotation-vibration model was proposed in previous works to describe the structure of heavy nuclei. The model was successfully tested in the description of experimental results related to the electron-nucleus elastic and inelastic scattering. In the present work, we consider heavy-ion collisions and assume this model to calculate folding-type coupling potentials for inelastic states, through the corresponding transition densities. As an example, the method is applied to coupled-channel data analyses for the α + 70,72,74,76Ge systems.

Sulfatide-activated type II NKT cells prevent allergic airway inflammation by inhibiting type I NKT cell function in a mouse model of asthma.

Science.gov (United States)

Zhang, Guqin; Nie, Hanxiang; Yang, Jiong; Ding, Xuhong; Huang, Yi; Yu, Hongying; Li, Ruyou; Yuan, Zhuqing; Hu, Suping

2011-12-01

Asthma is a common chronic inflammatory disease involving many different cell types. Recently, type I natural killer T (NKT) cells have been demonstrated to play a crucial role in the development of asthma. However, the roles of type II NKT cells in asthma have not been investigated before. Interestingly, type I and type II NKT cells have been shown to have opposing roles in antitumor immunity, antiparasite immunity, and autoimmunity. We hypothesized that sulfatide-activated type II NKT cells could prevent allergic airway inflammation by inhibiting type I NKT cell function in asthma. Strikingly, in our mouse model, activation of type II NKT cells by sulfatide administration and adoptive transfer of sulfatide-activated type II NKT cells result in reduced-inflammation cell infiltration in the lung and bronchoalveolar lavage fluid, decreased levels of IL-4 and IL-5 in the BALF; and decreased serum levels of ovalbumin-specific IgE and IgG1. Furthermore, it is found that the activation of sulfatide-reactive type II NKT cells leads to the functional inactivation of type I NKT cells, including the proliferation and cytokine secretion. Our data reveal that type II NKT cells activated by glycolipids, such as sulfatide, may serve as a novel approach to treat allergic diseases and other disorders characterized by inappropriate type I NKT cell activation.

Low-energy photoproduction of omega-mesons

CERN Document Server

Barth, J; Glander, K H; Hannappel, J; Jöpen, N; Klein, F; Lawall, R; Menze, D; Neuerburg, W; Ostrick, M; Paul, E; Schulday, I; Schwille, W J; Wiegers, B; Ernst, J; Kalinowsky, H; Klempt, E; Link, J; Pee, H V; Klein, F J; Wieland, F W; Wisskirchen, J; Wu, C

2003-01-01

The photoproduction of the vector meson omega has been studied between threshold and W=2.4 GeV with the SAPHIR detector at the Bonn electron stretcher ring ELSA. Besides, the total cross-sections angular distributions in the CMS and decay angular distributions in the helicity and Gottfried-Jackson systems have been measured.

Low-energy photoproduction of PHI-mesons

CERN Document Server

Barth, J; Glander, K H; Hannappel, J; Jöpen, N; Klein, F J; Klein, F; Lawall, R; Menze, D; Neuerburg, W; Ostrick, M; Paul, E; Schulday, I; Schwille, W J; Wiegers, B; Ernst, J; Kalinowsky, H; Klempt, E; Link, J; Pee, H V; Wieland, F W; Wisskirchen, J; Wu, C

2003-01-01

Photoproduction of PHI-vector-mesons has been studied from reaction threshold up to W=2.4 GeV with the SAPHIR spectrometer at the Bonn electron stretcher ring ELSA. Total cross-sections, differential cross-sections and decay angular distributions were measured. We find evidence for strong non-diffractive contributions to PHI photoproduction. (orig.)

Spin physics at ELSA

International Nuclear Information System (INIS)

Althoff, K.H.

1989-01-01

In 1987 the new Bonn stretcher accelerator ELSA came into operation. In this paper a short description of the accelerator and the three experimental facilities PHOENICS, ELAN and SAPHIR is given. The determination of spin observables is one of the main subjects of the experimental program. Some experiments are discussed in more detail

Investigation on the applicability of Piety's on-line PSD-pattern recognition algorithm to boiling detection by neutron-noise at a swimming-pool reactor

International Nuclear Information System (INIS)

Behringer, K.; Spiekerman, G.; Yadigaroglu, G.

1984-11-01

The neutron noise signal of an initiation-of-boiling experiment performed at the SAPHIR reactor has been analyzed by the PSD-pattern recognition algorithm of Piety (1977); the results indicate that the onset of boiling can be detected by this method. Improved confidence statements for the statistical decision discriminants are given. (Auth.)

Language and Culture: Nigerian Perspective | Obiegbu | African ...

African Journals Online (AJOL)

The power of language to reflect culture and influence thinking was first proposed by an American linguist and anthropologist, Edward Sapir (1884-1939) and his student, Benjamin Whorf (1897-1941). The Saphir-Whorf hypothesis stated that the way we think and view the world is determined by our language. This theory ...

The female gametophyte: an emerging model for cell type-specific systems biology in plant development

Directory of Open Access Journals (Sweden)

Marc William Schmid

2015-11-01

Full Text Available Systems biology, a holistic approach describing a system emerging from the interactions of its molecular components, critically depends on accurate qualitative determination and quantitative measurements of these components. Development and improvement of large-scale profiling methods (omics now facilitates comprehensive measurements of many relevant molecules. For multicellular organisms, such as animals, fungi, algae, and plants, the complexity of the system is augmented by the presence of specialized cell types and organs, and a complex interplay within and between them. Cell type-specific analyses are therefore crucial for the understanding of developmental processes and environmental responses. This review first gives an overview of current methods used for large-scale profiling of specific cell types exemplified by recent advances in plant biology. The focus then lies on suitable model systems to study plant development and cell type specification. We introduce the female gametophyte of flowering plants as an ideal model to study fundamental developmental processes. Moreover, the female reproductive lineage is of importance for the emergence of evolutionary novelties such as an unequal parental contribution to the tissue nurturing the embryo or the clonal production of seeds by asexual reproduction (apomixis. Understanding these processes is not only interesting from a developmental or evolutionary perspective, but bears great potential for further crop improvement and the simplification of breeding efforts. We finally highlight novel methods, which are already available or which will likely soon facilitate large-scale profiling of the specific cell types of the female gametophyte in both model and non-model species. We conclude that it may take only few years until an evolutionary systems biology approach toward female gametogenesis may decipher some of its biologically most interesting and economically most valuable processes.

Autonomous Decentralized Enterprise Model - A New Wave in Web 2.0 Type E-commerce

OpenAIRE

Liu, Feng; Hirano, Makoto

2010-01-01

The rapid popularization of Web 2.0 coupled with the growth of e-commerce gives rise to enormous opportunities as well as changes for the creation of new intra-organization models. In the evolving environment of the E-business, this study has attempted to contribute to the framework description of a new type of inter-organizational model in e-commerce enterprises: Autonomous Decentralized Enterprise Model. From this case study,

One-dimensional Turbulence Models of Type I X-ray Bursts

Energy Technology Data Exchange (ETDEWEB)

Hou, Chen [Univ. of Minnesota, Minneapolis, MN (United States)

2016-01-06

Type I X-ray bursts are caused by thermonuclear explosions occurring on the surface of an accreting neutron star in a binary star system. Observations and simulations of these phenomena are of great importance for understanding the fundamental properties of neutron stars and dense matter because the equation of state for cold dense matter can be constrained by the mass-radius relationship of neutron stars. During the bursts, turbulence plays a key role in mixing the fuels and driving the unstable nuclear burning process. This dissertation presents one-dimensional models of photospheric radius expansion bursts with a new approach to simulate turbulent advection. Compared with the traditional mixing length theory, the one-dimensional turbulence (ODT) model represents turbulent motions by a sequence of maps that are generated according to a stochastic process. The light curves I obtained with the ODT models are in good agreement with those of the KEPLER model in which the mixing length theory and various diffusive processes are applied. The abundance comparison, however, indicates that the differences in turbulent regions and turbulent diffusivities result in more ¹²C survival during the bursts in the ODT models, which can make a difference in the superbursts phenomena triggered by unstable carbon burning.

One-dimensional Turbulence Models of Type I X-ray Bursts

International Nuclear Information System (INIS)

Hou, Chen

2016-01-01

Type I X-ray bursts are caused by thermonuclear explosions occurring on the surface of an accreting neutron star in a binary star system. Observations and simulations of these phenomena are of great importance for understanding the fundamental properties of neutron stars and dense matter because the equation of state for cold dense matter can be constrained by the mass-radius relationship of neutron stars. During the bursts, turbulence plays a key role in mixing the fuels and driving the unstable nuclear burning process. This dissertation presents one-dimensional models of photospheric radius expansion bursts with a new approach to simulate turbulent advection. Compared with the traditional mixing length theory, the one-dimensional turbulence (ODT) model represents turbulent motions by a sequence of maps that are generated according to a stochastic process. The light curves I obtained with the ODT models are in good agreement with those of the KEPLER model in which the mixing length theory and various diffusive processes are applied. The abundance comparison, however, indicates that the differences in turbulent regions and turbulent diffusivities result in more 12 C survival during the bursts in the ODT models, which can make a difference in the superbursts phenomena triggered by unstable carbon burning.

Constructing Dynamic Event Trees from Markov Models

International Nuclear Information System (INIS)

Paolo Bucci; Jason Kirschenbaum; Tunc Aldemir; Curtis Smith; Ted Wood

2006-01-01

In the probabilistic risk assessment (PRA) of process plants, Markov models can be used to model accurately the complex dynamic interactions between plant physical process variables (e.g., temperature, pressure, etc.) and the instrumentation and control system that monitors and manages the process. One limitation of this approach that has prevented its use in nuclear power plant PRAs is the difficulty of integrating the results of a Markov analysis into an existing PRA. In this paper, we explore a new approach to the generation of failure scenarios and their compilation into dynamic event trees from a Markov model of the system. These event trees can be integrated into an existing PRA using software tools such as SAPHIRE. To implement our approach, we first construct a discrete-time Markov chain modeling the system of interest by: (a) partitioning the process variable state space into magnitude intervals (cells), (b) using analytical equations or a system simulator to determine the transition probabilities between the cells through the cell-to-cell mapping technique, and, (c) using given failure/repair data for all the components of interest. The Markov transition matrix thus generated can be thought of as a process model describing the stochastic dynamic behavior of the finite-state system. We can therefore search the state space starting from a set of initial states to explore all possible paths to failure (scenarios) with associated probabilities. We can also construct event trees of arbitrary depth by tracing paths from a chosen initiating event and recording the following events while keeping track of the probabilities associated with each branch in the tree. As an example of our approach, we use the simple level control system often used as benchmark in the literature with one process variable (liquid level in a tank), and three control units: a drain unit and two supply units. Each unit includes a separate level sensor to observe the liquid level in the tank

Modelling the WWER-type reactor dynamics using a hybrid computer. Part 1

International Nuclear Information System (INIS)

Karpeta, C.

Results of simulation studies into reactor and steam generator dynamics of a WWER type power plant are presented. Spatial kinetics of the reactor core is described by a nodal approximation to diffusion equations, xenon poisoning equations and heat transfer equations. The simulation of the reactor model dynamics was performed on a hybrid computer. Models of both a horizontal and a vertical steam generator were developed. The dynamics was investigated over a large range of power by computing the transients on a digital computer. (author)

The Sort on Radioactive Waste Type model: A method to sort single-shell tanks into characteristic groups

International Nuclear Information System (INIS)

Hill, J.G.; Simpson, B.C.

1994-04-01

The Sort on Radioactive Waste Type (SORWT) model presents a method to categorize Hanford Site single-shell tanks (SSTs) into groups of tank expected to exhibit similar chemical and physical characteristics based on their major waste types and processing histories. This model has identified 29 different waste-type groups encompassing 135 of the 149 SSTs and 93% of the total waste volume in SSTs. The remaining 14 SSTs and associated wastes could not be grouped according to the established criteria and were placed in an ungrouped category. This letter report will detail the assumptions and methodologies used to develop the SORWT model and present the grouping results. In the near future, the validity of the predicted groups will be statistically tested using analysis of variance of characterization data obtained from recent (post-1989) core sampling and analysis activities. In addition, the SORWT model will be used to project the nominal waste characteristics of entire waste type groups that have some recent characterization data available. These subsequent activities will be documented along with these initial results in a comprehensive, formal PNL report cleared for public release by September 1994

Pedestal Temperature Model for Type III ELMy H-mode Plasma

International Nuclear Information System (INIS)

Buangam, W.; Suwanna, S.; Onjun, T.; Poolyarat, N.; Picha, R.; Singhsomroje, W.

2009-07-01

Full text: It is widely known that the improved performance of H-mode plasma results mainly from a formation of the pedestal, which is a narrow region of strong pressure gradient near the edge of plasma. A predictive capability for the conditions at the top of the pedestal is important, especially for predictive simulations of future experiments. New models for predicting the temperature values at the top of the pedestal for type III ELMy H-mode plasma are developed by using two different approaches: a theory-based approaches and an empirical approach. For a theory-based approach, a model is developed based on the calculation of thermal energy in the pedestal region and on accepted scaling laws of energy confinement time. For an empirical model, a scaling law for pedestal temperature in terms of plasma controlled parameters, such as plasma current, magnetic field, heating power, is deduced from experimental data. Predictions from these models are compared with experimental data from the Pedestal International Database. Statistical quantities, such as Root-Mean Square Error (RMSE) and offset values, are computed to quantify the predictive capability of the models. It is found that the theory-based model predicts the pedestal temperature values moderately well yielding RMSE between 30% and 40%. The IPB98(y,3) scaling law yields with best agreement with RMSE of 30.4%. The empirical model predicts the pedestal temperature value with better agreement, yield RMSE of 25.9%

A preon model with hidden electric and magnetic type charges

International Nuclear Information System (INIS)

Pati, J.C.; Strathdee, J.

1980-11-01

The U(1) x U(1) binding forces in an earlier preonic composite model of quarks and leptons are interpreted as arising from hidden electric and magnetic type charges. The preons may possess intrinsic spin zero; the half-integer spins of the composites being contributed by the force field. The quark-lepton gauge symmetry is interpreted as an effective low-energy symmetry arising at the composite level. Some remarks are made regarding the possible composite nature of the graviton. (author)

Modeling Niemann Pick type C1 using human embryonic and induced pluripotent stem cells.

Science.gov (United States)

Ordoñez, M Paulina; Steele, John W

2017-02-01

Data generated in Niemann Pick type C1 (NPC1) human embryonic and human induced pluripotent stem cell derived neurons complement on-going studies in animal models and provide the first example, in disease-relevant human cells, of processes that underlie preferential neuronal defects in a NPC1. Our work and that of other investigators in human neurons derived from stem cells highlight the importance of performing rigorous mechanistic studies in relevant cell types to guide drug discovery and therapeutic development, alongside of existing animal models. Through the use of human stem cell-derived models of disease, we can identify and discover or repurpose drugs that revert early events that lead to neuronal failure in NPC1. Together with the study of disease pathogenesis and efficacy of therapies in animal models, these strategies will fulfill the promise of stem cell technology in the development of new treatments for human diseases. This article is part of a Special Issue entitled SI: Exploiting human neurons. Copyright © 2016 Elsevier B.V. All rights reserved.

Galactic chemical evolution in hierarchical formation models - I. Early-type galaxies in the local Universe

NARCIS (Netherlands)

Arrigoni, Matías; Trager, Scott C.; Somerville, Rachel S.; Gibson, Brad K.

We study the metallicities and abundance ratios of early-type galaxies in cosmological semi-analytic models (SAMs) within the hierarchical galaxy formation paradigm. To achieve this we implemented a detailed galactic chemical evolution model and can now predict abundances of individual elements for

Galactic chemical evolution in hierarchical formation models : I. Early-type galaxies in the local Universe

NARCIS (Netherlands)

Arrigoni, Matias; Trager, Scott C.; Somerville, Rachel S.; Gibson, Brad K.

2010-01-01

We study the metallicities and abundance ratios of early-type galaxies in cosmological semi-analytic models (SAMs) within the hierarchical galaxy formation paradigm. To achieve this we implemented a detailed galactic chemical evolution model and can now predict abundances of individual elements for

Quantum Hall conductivity in a Landau type model with a realistic geometry

International Nuclear Information System (INIS)

Chandelier, F.; Georgelin, Y.; Masson, T.; Wallet, J.-C.

2003-01-01

In this paper, we revisit some quantum mechanical aspects related to the quantum Hall effect. We consider a Landau type model, paying a special attention to the experimental and geometrical features of quantum Hall experiments. The resulting formalism is then used to compute explicitly the Hall conductivity from a Kubo formula

Method of renormalization potential for one model of Hartree-Fock-Slater type

CERN Document Server

Zasorin, Y V

2002-01-01

A new method of the potential renormalization for the quasiclassical model of the Hartree-Fock-Slater real potential is proposed. The method makes it possible to easily construct the wave functions and contrary to the majority od similar methods it does not require the knowledge of the real-type potential

Star-type oscillatory networks with generic Kuramoto-type coupling: A model for "Japanese drums synchrony"

Science.gov (United States)

Vlasov, Vladimir; Pikovsky, Arkady; Macau, Elbert E. N.

2015-12-01

We analyze star-type networks of phase oscillators by virtue of two methods. For identical oscillators we adopt the Watanabe-Strogatz approach, which gives full analytical description of states, rotating with constant frequency. For nonidentical oscillators, such states can be obtained by virtue of the self-consistent approach in a parametric form. In this case stability analysis cannot be performed, however with the help of direct numerical simulations we show which solutions are stable and which not. We consider this system as a model for a drum orchestra, where we assume that the drummers follow the signal of the leader without listening to each other and the coupling parameters are determined by a geometrical organization of the orchestra.

A Beddoes-Leishman type dynamic stall model in state-space and indicial formulations

DEFF Research Database (Denmark)

Hansen, M.H.; Gaunaa, Mac; Aagaard Madsen, Helge

2004-01-01

This report contains a description of a Beddoes-Leishman type dynamic stall model in both a state-space and an indicial function formulation. The model predicts the unsteady aerodynamic forces and moment on an airfoil section undergoing arbitrary motionin heave, lead-lag, and pitch. The model...... features, such as overshoot of the lift, in the stall region. The linearized model is shown to give identicalresults to the full model for small amplitude oscillations. Furthermore, it is shown that the response of finite thichkness airfoils can be reproduced to a high accuracy by the use of specific...... is carried out by comparing the response of the model with inviscid solutions and observing the general behavior of the model using known airfoil data as input. Theproposed dynamic model gives results identical to inviscid solutions within the attached-flow region; and it exhibits the expected dynamic...

Mathematical model of the SOS response regulation in wild-type Escherichia coli

International Nuclear Information System (INIS)

Aksenov, S.V.

1997-01-01

Regulation of the SOS response in Escherichia coli, which is a set of inducible cellular reactions introduced after DNA damage, is due to specific interaction of LexA and RecA proteins. LexA protein is a common repressor of the genes of the SOS system, and RecA protein, once transiently activated by the so-called SOS-inducing signal, promotes LexA protein destruction. We have described the SOS regulation by means of differential equations with regard to LexA and RecA concentrations elsewhere. The 'input' function for model equations is the level of the SOS-inducing signal against time. Here we present a means for calculating the concentration of single-stranded DNA (SOS-inducing signal) as a function of time in wild-type cells after ultraviolet irradiation. With model equations one can simulate kinetic curves of SOS regulatory proteins after DNA damage to survey the SOS response kinetics. Simulation of LexA protein kinetics agrees with experimental data. We compare simulated LexA kinetic curves in wild-type and uνr - mutant bacteria, which is useful in investigating the way uνrABC-dependent excision repair modulates the SOS response kinetics. Possible applications of the model to investigating various aspects of the SOS induction are discussed

Bianchi Type I Cosmological Models in Eddington-inspired Born–Infeld Gravity

Directory of Open Access Journals (Sweden)

Tiberiu Harko

2014-10-01

Full Text Available We consider the dynamics of a barotropic cosmological fluid in an anisotropic, Bianchi type I space-time in Eddington-inspired Born–Infeld (EiBI gravity. By assuming isotropic pressure distribution, we obtain the general solution of the field equations in an exact parametric form. The behavior of the geometric and thermodynamic parameters of the Bianchi type I Universe is studied, by using both analytical and numerical methods, for some classes of high density matter, described by the stiff causal, radiation, and pressureless fluid equations of state. In all cases the study of the models with different equations of state can be reduced to the integration of a highly nonlinear second order ordinary differential equation for the energy density. The time evolution of the anisotropic Bianchi type I Universe strongly depends on the initial values of the energy density and of the Hubble function. An important observational parameter, the mean anisotropy parameter, is also studied in detail, and we show that for the dust filled Universe the cosmological evolution always ends into isotropic phase, while for high density matter filled universes the isotropization of Bianchi type I universes is essentially determined by the initial conditions of the energy density.

Mapping forest functional type in a forest-shrubland ecotone using SPOT imagery and predictive habitat distribution modelling

Science.gov (United States)

Assal, Timothy J.; Anderson, Patrick J.; Sibold, Jason

2015-01-01

The availability of land cover data at local scales is an important component in forest management and monitoring efforts. Regional land cover data seldom provide detailed information needed to support local management needs. Here we present a transferable framework to model forest cover by major plant functional type using aerial photos, multi-date Système Pour l’Observation de la Terre (SPOT) imagery, and topographic variables. We developed probability of occurrence models for deciduous broad-leaved forest and needle-leaved evergreen forest using logistic regression in the southern portion of the Wyoming Basin Ecoregion. The model outputs were combined into a synthesis map depicting deciduous and coniferous forest cover type. We evaluated the models and synthesis map using a field-validated, independent data source. Results showed strong relationships between forest cover and model variables, and the synthesis map was accurate with an overall correct classification rate of 0.87 and Cohen’s kappa value of 0.81. The results suggest our method adequately captures the functional type, size, and distribution pattern of forest cover in a spatially heterogeneous landscape.

Intification and modelling of flight characteristics for self-build shock flyer type UAV

Science.gov (United States)

Rashid., Z. A.; Dardin, A. S. F. Syed.; Azid, A. A.; Ahmad, K. A.

2018-02-01

The development of an autonomous Unmanned Aerial Vehicle (UAV) requires a fundamentals studies of the UAV's flight characteristic. The aim of this study is to identify and model the flight characteristic of a conventional fixed-wing type UAV. Subsequence to this, the mode of flight of the UAV can be investigated. One technique to identify the characteristic of a UAV is a flight test where it required specific maneuvering to be executed while measuring the attitude sensor. In this study, a simple shock flyer type UAV was used as the aircraft. The result shows that the modeled flight characteristic has a significant relation with actual values but the fitting value is rather small. It is suggested that the future study is conducted with an improvement of the physical UAV, data filtering and better system identification methods.

A Brief Review on the Baer-Nunziato type Multi-pressure Multi-fluid Models

International Nuclear Information System (INIS)

Lee, Sang Yong; Park, Chan Eok; Lee, Gyu Cheon

2010-01-01

Single pressure two-fluid flow equations have complex characteristics. This causes ill-posedness problem. Even though some authors show that the numerical solutions are well behaved if the number of mesh points is sufficiently small, the stability of the solution is always challenged. There have been several attempts to overcome these problems. Multi-pressure multi-fluid models are one of them. Among them, Baer and Nunziato (BN) derived an interesting two-fluid model. BN model has independent phase pressures. It is closed by inserting volume fraction evolution equation. In this paper, several aspects of the BN type model will be reviewed and some suggestion for the future study will be made

Matérn's hard core models of types I and II with arbitrary compact grains

DEFF Research Database (Denmark)

Kiderlen, Markus; Hörig, Mario

Matérn's classical hard core models can be interpreted as models obtained from a stationary marked Poisson process by dependent thinning. The marks are balls of fixed radius, and a point is retained when its associated ball does not hit any other balls (type I) or when its random birth time is st...... of this model with the process of intact grains of the dead leaves model and the Stienen model leads to analogous results for the latter....

Hierarchical Models for Type Ia Supernova Light Curves in the Optical and Near Infrared

Science.gov (United States)

Mandel, Kaisey; Narayan, G.; Kirshner, R. P.

2011-01-01

I have constructed a comprehensive statistical model for Type Ia supernova optical and near infrared light curves. Since the near infrared light curves are excellent standard candles and are less sensitive to dust extinction and reddening, the combination of near infrared and optical data better constrains the host galaxy extinction and improves the precision of distance predictions to SN Ia. A hierarchical probabilistic model coherently accounts for multiple random and uncertain effects, including photometric error, intrinsic supernova light curve variations and correlations across phase and wavelength, dust extinction and reddening, peculiar velocity dispersion and distances. An improved BayeSN MCMC code is implemented for computing probabilistic inferences for individual supernovae and the SN Ia and host galaxy dust populations. I use this hierarchical model to analyze nearby Type Ia supernovae with optical and near infared data from the PAIRITEL, CfA3, and CSP samples and the literature. Using cross-validation to test the robustness of the model predictions, I find that the rms Hubble diagram scatter of predicted distance moduli is 0.11 mag for SN with optical and near infrared data versus 0.15 mag for SN with only optical data. Accounting for the dispersion expected from random peculiar velocities, the rms intrinsic prediction error is 0.08-0.10 mag for SN with both optical and near infrared light curves. I discuss results for the inferred intrinsic correlation structures of the optical-NIR SN Ia light curves and the host galaxy dust distribution captured by the hierarchical model. The continued observation and analysis of Type Ia SN in the optical and near infrared is important for improving their utility as precise and accurate cosmological distance indicators.

76 FR 62605 - Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes With Supplemental Type...

Science.gov (United States)

2011-10-11

... Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes With Supplemental Type Certificate.... That AD applies to Viking Air Limited Model DHC-3 (Otter) airplanes equipped with a Honeywell TPE331... limitations and marking the airspeed indicator accordingly for Viking Air Limited Model DHC-3 (Otter...

Implementation of IEC Generic Model of Type 1 Wind Turbine Generator in DIgSILENT PowerFactory

DEFF Research Database (Denmark)

Zhao, Haoran; Wu, Qiuwei; Margaris, Ioannis

2013-01-01

The implementation method for the International Electrotechnical Commission (IEC) generic models of Type 1 wind turbine generator (WTG) in DIgSILENT PowerFactory is presented. The following items are described, i.e. model structure, model blocks and how to implement these blocks in the PowerFactory...

Gauge invariant Barr-Zee type contributions to fermionic EDMs in the two-Higgs doublet models

International Nuclear Information System (INIS)

Abe, Tomohiro; Hisano, Junji; Kitahara, Teppei; Tobioka, Kohsaku

2014-01-01

We calculate all gauge invariant Barr-Zee type contributions to fermionic electric dipole moments (EDMs) in the two-Higgs doublet models (2HDM) with softly broken Z 2 symmetry. We start by studying the tensor structure of h→VV′ part in the Barr-Zee diagrams, and we calculate the effective couplings in a gauge invariant way by using the pinch technique. Then we calculate all Barr-Zee diagrams relevant for electron and neutron EDMs. We make bounds on the parameter space in type-I, type-II, type-X, and type-Y 2HDMs. The electron and neutron EDMs are complementary to each other in discrimination of the 2HDMs. Type-II and type-X 2HDMs are strongly constrained by recent ACME experiment’s result, and future experiments of electron and neutron EDMs may search O(10) TeV physics

Model for Simulating Fasting Glucose in Type 2 Diabetes and the Effect of Adherence to Treatment

DEFF Research Database (Denmark)

Aradóttir, Tinna Björk; Boiroux, Dimitri; Bengtsson, Henrik

2017-01-01

trial results where a dose guidance algorithm was used. We investigate sources of variance and through simulations evaluate the contribution of adherence to variance and dose guidance quality. The results suggest that the model for simulation of T2D patients is sufficient for simulating fasting glucose......The primary goal of this paper is to predict fasting glucose levels in type 2 diabetes (T2D) in long-acting insulin treatment. The paper presents a model for simulating insulin-glucose dynamics in T2D patients. The model combines a physiological model of type 1 diabetes (T1D) and an endogenous...... insulin production model in T2D. We include a review of sources of variance in fasting glucose values in long-acting insulin treatment, with respect to dose guidance algorithms. We use the model to simulate fasting glucose levels in T2D long-acting insulin treatment and compare the results with clinical...

Modelling a reliability system governed by discrete phase-type distributions

International Nuclear Information System (INIS)

Ruiz-Castro, Juan Eloy; Perez-Ocon, Rafael; Fernandez-Villodre, Gemma

2008-01-01

We present an n-system with one online unit and the others in cold standby. There is a repairman. When the online fails it goes to repair, and instantaneously a standby unit becomes the online one. The operational and repair times follow discrete phase-type distributions. Given that any discrete distribution defined on the positive integers is a discrete phase-type distribution, the system can be considered a general one. A model with unlimited number of units is considered for approximating a system with a great number of units. We show that the process that governs the system is a quasi-birth-and-death process. For this system, performance reliability measures; the up and down periods, and the involved costs are calculated in a matrix and algorithmic form. We show that the discrete case is not a trivial case of the continuous one. The results given in this paper have been implemented computationally with Matlab

Modelling a reliability system governed by discrete phase-type distributions

Energy Technology Data Exchange (ETDEWEB)

Ruiz-Castro, Juan Eloy [Departamento de Estadistica e Investigacion Operativa, Universidad de Granada, 18071 Granada (Spain)], E-mail: jeloy@ugr.es; Perez-Ocon, Rafael [Departamento de Estadistica e Investigacion Operativa, Universidad de Granada, 18071 Granada (Spain)], E-mail: rperezo@ugr.es; Fernandez-Villodre, Gemma [Departamento de Estadistica e Investigacion Operativa, Universidad de Granada, 18071 Granada (Spain)

2008-11-15

We present an n-system with one online unit and the others in cold standby. There is a repairman. When the online fails it goes to repair, and instantaneously a standby unit becomes the online one. The operational and repair times follow discrete phase-type distributions. Given that any discrete distribution defined on the positive integers is a discrete phase-type distribution, the system can be considered a general one. A model with unlimited number of units is considered for approximating a system with a great number of units. We show that the process that governs the system is a quasi-birth-and-death process. For this system, performance reliability measures; the up and down periods, and the involved costs are calculated in a matrix and algorithmic form. We show that the discrete case is not a trivial case of the continuous one. The results given in this paper have been implemented computationally with Matlab.

Modeling the failure data of a repairable equipment with bathtub type failure intensity

International Nuclear Information System (INIS)

Pulcini, G.

2001-01-01

The paper deals with the reliability modeling of the failure process of large and complex repairable equipment whose failure intensity shows a bathtub type non-monotonic behavior. A non-homogeneous Poisson process arising from the superposition of two power law processes is proposed, and the characteristics and mathematical details of the proposed model are illustrated. A graphical approach is also presented, which allows to determine whether the proposed model can adequately describe a given failure data. A graphical method for obtaining crude but easy estimates of the model parameters is then illustrated, as well as more accurate estimates based on the maximum likelihood method are provided. Finally, two numerical applications are given to illustrate the proposed model and the estimation procedures

Novel lean type 2 diabetic rat model using gestational low-protein programming

Science.gov (United States)

Type 2 diabetes (T2D) in lean individuals is not well studied and up to 26% of diabetes occurs in these individuals. Although the cause is not well understood, it has been primarily attributed to nutritional issues during early development. Our objective was to develop a lean T2D model using gestati...

Optimal crop selection and water allocation under limited water supply in irrigation

Science.gov (United States)

Stange, Peter; Grießbach, Ulrike; Schütze, Niels

2015-04-01

Due to climate change, extreme weather conditions such as droughts may have an increasing impact on irrigated agriculture. To cope with limited water resources in irrigation systems, a new decision support framework is developed which focuses on an integrated management of both irrigation water supply and demand at the same time. For modeling the regional water demand, local (and site-specific) water demand functions are used which are derived from optimized agronomic response on farms scale. To account for climate variability the agronomic response is represented by stochastic crop water production functions (SCWPF). These functions take into account different soil types, crops and stochastically generated climate scenarios. The SCWPF's are used to compute the water demand considering different conditions, e.g., variable and fixed costs. This generic approach enables the consideration of both multiple crops at farm scale as well as of the aggregated response to water pricing at a regional scale for full and deficit irrigation systems. Within the SAPHIR (SAxonian Platform for High Performance IRrigation) project a prototype of a decision support system is developed which helps to evaluate combined water supply and demand management policies.

Survey of non-linear hydrodynamic models of type-II Cepheids

Science.gov (United States)

Smolec, R.

2016-03-01

We present a grid of non-linear convective type-II Cepheid models. The dense model grids are computed for 0.6 M⊙ and a range of metallicities ([Fe/H] = -2.0, -1.5, -1.0), and for 0.8 M⊙ ([Fe/H] = -1.5). Two sets of convective parameters are considered. The models cover the full temperature extent of the classical instability strip, but are limited in luminosity; for the most luminous models, violent pulsation leads to the decoupling of the outermost model shell. Hence, our survey reaches only the shortest period RV Tau domain. In the Hertzsprung-Russell diagram, we detect two domains in which period-doubled pulsation is possible. The first extends through the BL Her domain and low-luminosity W Vir domain (pulsation periods ˜2-6.5 d). The second domain extends at higher luminosities (W Vir domain; periods >9.5 d). Some models within these domains display period-4 pulsation. We also detect very narrow domains (˜10 K wide) in which modulation of pulsation is possible. Another interesting phenomenon we detect is double-mode pulsation in the fundamental mode and in the fourth radial overtone. Fourth overtone is a surface mode, trapped in the outer model layers. Single-mode pulsation in the fourth overtone is also possible on the hot side of the classical instability strip. The origin of the above phenomena is discussed. In particular, the role of resonances in driving different pulsation dynamics as well as in shaping the morphology of the radius variation curves is analysed.

A cerebellar learning model of vestibulo-ocular reflex adaptation in wild-type and mutant mice.

Science.gov (United States)

Clopath, Claudia; Badura, Aleksandra; De Zeeuw, Chris I; Brunel, Nicolas

2014-05-21

Mechanisms of cerebellar motor learning are still poorly understood. The standard Marr-Albus-Ito theory posits that learning involves plasticity at the parallel fiber to Purkinje cell synapses under control of the climbing fiber input, which provides an error signal as in classical supervised learning paradigms. However, a growing body of evidence challenges this theory, in that additional sites of plasticity appear to contribute to motor adaptation. Here, we consider phase-reversal training of the vestibulo-ocular reflex (VOR), a simple form of motor learning for which a large body of experimental data is available in wild-type and mutant mice, in which the excitability of granule cells or inhibition of Purkinje cells was affected in a cell-specific fashion. We present novel electrophysiological recordings of Purkinje cell activity measured in naive wild-type mice subjected to this VOR adaptation task. We then introduce a minimal model that consists of learning at the parallel fibers to Purkinje cells with the help of the climbing fibers. Although the minimal model reproduces the behavior of the wild-type animals and is analytically tractable, it fails at reproducing the behavior of mutant mice and the electrophysiology data. Therefore, we build a detailed model involving plasticity at the parallel fibers to Purkinje cells' synapse guided by climbing fibers, feedforward inhibition of Purkinje cells, and plasticity at the mossy fiber to vestibular nuclei neuron synapse. The detailed model reproduces both the behavioral and electrophysiological data of both the wild-type and mutant mice and allows for experimentally testable predictions. Copyright © 2014 the authors 0270-6474/14/347203-13$15.00/0.

A model for particle and heat losses by type I edge localized modes

International Nuclear Information System (INIS)

Tokar, M Z; Gupta, A; Kalupin, D; Singh, R

2007-01-01

A model to estimate the particle and energy losses caused in tokamaks by type I edge localized modes (ELMs) is proposed. This model is based on the assumption that the increase in transport by ELM is due to flows along magnetic field lines perturbed by ballooning-peeling MHD modes. The model reproduces well the experimentally found variation of losses with the plasma collisionality ν*, namely, the weak dependence of the particle loss and significant reduction of the energy loss with increasing ν*. It is argued that the electron parallel heat conductivity is dominating in the energy loss at not very large ν*

Personality, personal model beliefs, and self-care in adolescents and young adults with Type 1 diabetes

DEFF Research Database (Denmark)

Chas Skinner, T.; Hampson, Sarah E.; Fife-Schaw, Chris

2002-01-01

This study compared 3 models of association between personality, personal model beliefs, and self-care in a cross-sectional design. These models were as follows: (a) Emotional stability determines self-care indirectly through personal model beliefs, and conscientiousness is a direct predictor of ....... Participants (N = 358, aged 12-30 years) with Type 1 diabetes completed measures of personality, personal model beliefs, and self-care. Structural equation modeling indicated that Model C was the best fit to the data....

More supersymmetric standardlike models from intersecting D6-branes on type IIA orientifolds

International Nuclear Information System (INIS)

Cvetic, Mirjam; Papadimitriou, Ioannis

2003-01-01

We present new classes of supersymmetric standardlike models from a type IIA T 6 /(Z 2 xZ 2 ) orientifold with intersecting D6-branes. D6-branes can wrap general supersymmetric three-cycles of T 6 =T 2 xT 2 xT 2 , and any T 2 is allowed to be tilted. The models still suffer from additional exotics; however, we obtain solutions with fewer Higgs doublets, as well as models with all three families of left-handed quarks and leptons arising from the same intersecting sector, and examples of a genuine left-right symmetric model with three copies of left-handed and right-handed families of quarks and leptons

Asteroseismology of solar-type stars with Kepler: II. Stellar modeling

DEFF Research Database (Denmark)

Metcalfe , T.S.; Karoff, Christoffer

2010-01-01

Observations from the Kepler satellite were recently published for three bright G-type stars, which were monitored during the first 33.5 days of science operations. One of these stars, KIC 11026764, exhibits a characteristic pattern of oscillation frequencies suggesting that the star has evolved...... significantly. We have derived initial estimates of the properties of KIC 11026764 from the oscillation frequencies observed by Kepler, combined with ground-based spectroscopic data. We present preliminary results from detailed modeling of this star, employing a variety of independent codes and analyses...

A model for phase evolution and volume expansion in tube type Nb3Sn conductors

Science.gov (United States)

Xu, X.; Sumption, M. D.; Collings, E. W.

2013-12-01

In this work, an analytic model for phase formation and volume expansion during heat treatment in tube type Nb3Sn strands is presented. Tube type Nb3Sn conductors consist of Nb or Nb-Ta alloy tube with a simple Cu/Sn binary metal insert to form the basic subelement (filament). A number of these elements, each with an outer Cu jacket, are restacked to form a multifilamentary strand. The present tube type conductors, with 4.2 K, 12 T non-Cu critical current density (Jc) in the 2000-2500 A mm-2 range and effective subelement diameters (deff) in the 12-36 μm range, are of interest for a number of applications. During the reaction of typical tube type strands, the Sn-Cu becomes molten and reacts with the Nb tube first to form NbSn2, then Nb6Sn5. At later times in the reaction sequence, all of the NbSn2 and Nb6Sn5 is converted to Nb3Sn. Some of the Nb3Sn is formed by a Nb-Sn reaction and has a fine grain (FG) structure, while some is converted from Nb6Sn5, which results in a coarse grain (CG) region. The fractions of FG and CG A15 are important in determining the final conductor properties. In this work we develop an analytic model to predict the radial extents of the various phases, and in particular the final FG and CG fractions based on the starting Nb, Cu, and Sn amounts in the subelements. The model is then compared to experimental results and seen to give reasonable agreement. By virtue of this model we outline an approach to minimize the CG regions in tube type and PIT strands and maximize the final FG area fractions. Furthermore, the volume change during the various reaction stages was also studied. It is proposed that the Sn content in the Cu-Sn alloy has a crucial influence on the radial expansion.

Guarded dependent type theory with coinductive types

DEFF Research Database (Denmark)

Bizjak, Aleš; Grathwohl, Hans Bugge; Clouston, Ranald

2016-01-01

We present guarded dependent type theory, gDTT, an extensional dependent type theory with a later' modality and clock quantifiers for programming and proving with guarded recursive and coinductive types. The later modality is used to ensure the productivity of recursive definitions in a modular......, type based, way. Clock quantifiers are used for controlled elimination of the later modality and for encoding coinductive types using guarded recursive types. Key to the development of gDTT are novel type and term formers involving what we call delayed substitutions’. These generalise the applicative...... functor rules for the later modality considered in earlier work, and are crucial for programming and proving with dependent types. We show soundness of the type theory with respect to a denotational model....

Related Progenitor Models for Long-duration Gamma-Ray Bursts and Type Ic Superluminous Supernovae

Science.gov (United States)

Aguilera-Dena, David R.; Langer, Norbert; Moriya, Takashi J.; Schootemeijer, Abel

2018-05-01

We model the late evolution and mass loss history of rapidly rotating Wolf–Rayet stars in the mass range 5 M ⊙…100 M ⊙). We find that quasi-chemically homogeneously evolving single stars computed with enhanced mixing retain very little or no helium and are compatible with Type Ic supernovae. The more efficient removal of core angular momentum and the expected smaller compact object mass in our lower-mass models lead to core spins in the range suggested for magnetar-driven superluminous supernovae. Our higher-mass models retain larger specific core angular momenta, expected for long-duration gamma-ray bursts in the collapsar scenario. Due to the absence of a significant He envelope, the rapidly increasing neutrino emission after core helium exhaustion leads to an accelerated contraction of the whole star, inducing a strong spin-up and centrifugally driven mass loss at rates of up to {10}-2 {M}ȯ {yr}}-1 in the last years to decades before core collapse. Because the angular momentum transport in our lower-mass models enhances the envelope spin-up, they show the largest relative amounts of centrifugally enforced mass loss, i.e., up to 25% of the expected ejecta mass. Our most massive models evolve into the pulsational pair-instability regime. We would thus expect signatures of interaction with a C/O-rich circumstellar medium for Type Ic superluminous supernovae with ejecta masses below ∼10 M ⊙ as well as for the most massive engine-driven explosions with ejecta masses above ∼30 M ⊙. Signs of such interaction should be observable at early epochs of the supernova explosion; they may be related to bumps observed in the light curves of superluminous supernovae, or to the massive circumstellar CO-shell proposed for Type Ic superluminous supernova Gaia16apd.

Reliability models for a nonrepairable system with heterogeneous components having a phase-type time-to-failure distribution

International Nuclear Information System (INIS)

Kim, Heungseob; Kim, Pansoo

2017-01-01

This research paper presents practical stochastic models for designing and analyzing the time-dependent reliability of nonrepairable systems. The models are formulated for nonrepairable systems with heterogeneous components having phase-type time-to-failure distributions by a structured continuous time Markov chain (CTMC). The versatility of the phase-type distributions enhances the flexibility and practicality of the systems. By virtue of these benefits, studies in reliability engineering can be more advanced than the previous studies. This study attempts to solve a redundancy allocation problem (RAP) by using these new models. The implications of mixing components, redundancy levels, and redundancy strategies are simultaneously considered to maximize the reliability of a system. An imperfect switching case in a standby redundant system is also considered. Furthermore, the experimental results for a well-known RAP benchmark problem are presented to demonstrate the approximating error of the previous reliability function for a standby redundant system and the usefulness of the current research. - Highlights: • Phase-type time-to-failure distribution is used for components. • Reliability model for nonrepairable system is developed using Markov chain. • System is composed of heterogeneous components. • Model provides the real value of standby system reliability not an approximation. • Redundancy allocation problem is used to show usefulness of this model.

Predictive transport modelling of type I ELMy H-mode dynamics using a theory-motivated combined ballooning-peeling model

International Nuclear Information System (INIS)

Loennroth, J-S; Parail, V; Dnestrovskij, A; Figarella, C; Garbet, X; Wilson, H

2004-01-01

This paper discusses predictive transport simulations of the type I ELMy high confinement mode (H-mode) with a theory-motivated edge localized mode (ELM) model based on linear ballooning and peeling mode stability theory. In the model, a total mode amplitude is calculated as a sum of the individual mode amplitudes given by two separate linear differential equations for the ballooning and peeling mode amplitudes. The ballooning and peeling mode growth rates are represented by mutually analogous terms, which differ from zero upon the violation of a critical pressure gradient and an analytical peeling mode stability criterion, respectively. The damping of the modes due to non-ideal magnetohydrodynamic effects is controlled by a term driving the mode amplitude towards the level of background fluctuations. Coupled to simulations with the JETTO transport code, the model qualitatively reproduces the experimental dynamics of type I ELMy H-mode, including an ELM frequency that increases with the external heating power. The dynamics of individual ELM cycles is studied. Each ELM is usually triggered by a ballooning mode instability. The ballooning phase of the ELM reduces the pressure gradient enough to make the plasma peeling unstable, whereby the ELM continues driven by the peeling mode instability, until the edge current density has been depleted to a stable level. Simulations with current ramp-up and ramp-down are studied as examples of situations in which pure peeling and pure ballooning mode ELMs, respectively, can be obtained. The sensitivity with respect to the ballooning and peeling mode growth rates is investigated. Some consideration is also given to an alternative formulation of the model as well as to a pure peeling model

Deep-Water Resedimented Carbonate Exploration Play Types: Controls and Models

Science.gov (United States)

Minzoni, M.; Janson, X.; Kerans, C.; Playton, T.; Winefield, P.; Burgess, P. M.

2016-12-01

Deepwater resedimented deposits have been described in both modern and ancient carbonate sequences, many with good reservoir potential, for example the giant Cretaceous Poza Rica field in Mexico ( 40 MMBoe), the Mississippian Tangiz field in Kazakhstan, and several fields in the U.S. Permian basin (several Tcf gas). Nevertheless, carbonate slope and basin systems remain poorly understood when compared to their siliciclastic counterparts. Legacy published and unpublished work, combined with a global database of surface and sub-surface examples of resedimented carbonates, has highlighted that downslope resedimentation of carbonate material is in large part controlled by the evolution of the parent platform margin, which in turn is best characterized in terms of various controlling processes such as the carbonate factory type, tectonic setting, eustatic variations, and prevailing wind direction and ocean current patterns. Two generic play types emerge: (i) attached carbonate slope play -developed immediately adjacent to the parent carbonate platform and dominated by rock fall and platform collapse deposits or in situ boundstone; and (ii) detached carbonate slope play - deposited further from the platform margin via channelized turbidity currents and other mass-flow processes. High-rising, steep, bypass platform margins with collapse scars and grain-dominated factories have the highest potential to generate channelized and detached deep-water reservoirs with high initial porosity and permeability. Best reservoirs are aragonitic grainstones transported from the platform into the adjacent basin, and undergoing dissolution in submarine undersaturated water with early formation of secondary porosity to further enhance reservoir properties. Any exploration model aiming at identifying potential resedimented carbonate plays should be based on carbonate platform configurations and factory types favorable for re-sedimentation of large sedimentary bodies and preservation or

Different developmental trajectories across feature types support a dynamic field model of visual working memory development.

Science.gov (United States)

Simmering, Vanessa R; Miller, Hilary E; Bohache, Kevin

2015-05-01

Research on visual working memory has focused on characterizing the nature of capacity limits as "slots" or "resources" based almost exclusively on adults' performance with little consideration for developmental change. Here we argue that understanding how visual working memory develops can shed new light onto the nature of representations. We present an alternative model, the Dynamic Field Theory (DFT), which can capture effects that have been previously attributed either to "slot" or "resource" explanations. The DFT includes a specific developmental mechanism to account for improvements in both resolution and capacity of visual working memory throughout childhood. Here we show how development in the DFT can account for different capacity estimates across feature types (i.e., color and shape). The current paper tests this account by comparing children's (3, 5, and 7 years of age) performance across different feature types. Results showed that capacity for colors increased faster over development than capacity for shapes. A second experiment confirmed this difference across feature types within subjects, but also showed that the difference can be attenuated by testing memory for less familiar colors. Model simulations demonstrate how developmental changes in connectivity within the model-purportedly arising through experience-can capture differences across feature types.

Continuum Gyrokinetic Simulations of Turbulence in a Helical Model SOL with NSTX-type parameters

Science.gov (United States)

Hammett, G. W.; Shi, E. L.; Hakim, A.; Stoltzfus-Dueck, T.

2017-10-01

We have developed the Gkeyll code to carry out 3D2V full- F gyrokinetic simulations of electrostatic plasma turbulence in open-field-line geometries, using special versions of discontinuous-Galerkin algorithms to help with the computational challenges of the edge region. (Higher-order algorithms can also be helpful for exascale computing as they reduce the ratio of communications to computations.) Our first simulations with straight field lines were done for LAPD-type cases. Here we extend this to a helical model of an SOL plasma and show results for NSTX-type parameters. These simulations include the basic elements of a scrape-off layer: bad-curvature/interchange drive of instabilities, narrow sources to model plasma leaking from the core, and parallel losses with model sheath boundary conditions (our model allows currents to flow in and out of the walls). The formation of blobs is observed. By reducing the strength of the poloidal magnetic field, the heat flux at the divertor plate is observed to broaden. Supported by the Max-Planck/Princeton Center for Plasma Physics, the SciDAC Center for the Study of Plasma Microturbulence, and DOE Contract DE-AC02-09CH11466.

In-pile modelling of nuclear fuel element for the MTR type reactors. Pt. 2

Energy Technology Data Exchange (ETDEWEB)

Farhadi, Kazem [AEOI, Tehran (Iran, Islamic Republic of). Radiations Application Research School

2014-06-15

In part two of the present paper, neutronic properties of the pool-type research reactor core are used to assess the similitude laws derived for out-of-pile modelling of the fuel element. The benchmark reactor used for this purpose is an IAEA 5 MW thermal pool-type research reactor currently in operation. The neutronic properties analysis are based on typical 2 200 m/sec and neutrons having 0.025 eV energy. The non-leakage capability of the system is estimated in terms of diffusion length. Also the slowing down power and the moderating ratio of the modelled methanol coolant are calculated in terms of lethargy of the diffusing medium. It is shown that the Iron which is substituted for Aluminium cladding is a relatively low absorber of neutrons but has a high neutron leakage. Methanol which replaced ordinary water as coolant is not a suitable coolant due to high neutrons absorbing substance. It is concluded that although Iron as a cladding material and methanol as a coolant meet the modelling out-of-pile criteria but are not satisfying neutronic properties. Therefore, use of them as a model clad and coolant are not suggested for research reactors. (orig.)

Radius stabilization and brane running in the Randall-Sundrum type 1 model

International Nuclear Information System (INIS)

Brevik, Iver; Ghoroku, Kazuo; Yahiro, Masanobu

2004-01-01

We study the effective potential of a scalar field based on the 5D gauged supergravity for the Randall-Sundrum type one brane model in terms of the brane running method. The scalar couples to the brane such that the Bogomolnyi-Prasad-Sommerfield conditions are satisfied for the bulk configuration. The resulting effective potential implies that the interbrane distance is undetermined in this case, and we need a small Bogomolnyi-Prasad-Sommerfield breaking term on the brane to stabilize the interbrane distance at a finite length. We also discuss the relationship to the Goldberger-Wise model

Modelling of series of types of automated trenchless works tunneling

Science.gov (United States)

Gendarz, P.; Rzasinski, R.

2016-08-01

Microtunneling is the newest method for making underground installations. Show method is the result of experience and methods applied in other, previous methods of trenchless underground works. It is considered reasonable to elaborate a series of types of construction of tunneling machines, to develop this particular earthworks method. There are many design solutions of machines, but the current goal is to develop non - excavation robotized machine. Erosion machines with main dimensions of the tunnels which are: 1600, 2000, 2500, 3150 are design with use of the computer aided methods. Series of types of construction of tunneling machines creating process was preceded by analysis of current state. The verification of practical methodology of creating the systematic part series was based on the designed erosion machines series of types. There were developed: method of construction similarity of the erosion machines, algorithmic methods of quantitative construction attributes variant analyzes in the I-DEAS advanced graphical program, relational and program parameterization. There manufacturing process of the parts will be created, which allows to verify the technological process on the CNC machines. The models of designed will be modified and the construction will be consulted with erosion machine users and manufacturers like: Tauber Rohrbau GmbH & Co.KG from Minster, OHL ZS a.s. from Brna,. The companies’ acceptance will result in practical verification by JUMARPOL company.

Developing Livestock Facility Type Information from USDA Agricultural Census Data for Use in Epidemiological and Economic Models

Energy Technology Data Exchange (ETDEWEB)

Melius, C; Robertson, A; Hullinger, P

2006-10-24

The epidemiological and economic modeling of livestock diseases requires knowing the size, location, and operational type of each livestock facility within the US. At the present time, the only national database of livestock facilities that is available to the general public is the USDA's 2002 Agricultural Census data, published by the National Agricultural Statistics Service, herein referred to as the 'NASS data.' The NASS data provides facility data at the county level for various livestock types (i.e., beef cows, milk cows, cattle on feed, other cattle, total hogs and pigs, sheep and lambs, milk goats, and angora goats). However, the number and sizes of facilities for the various livestock types are not independent since some facilities have more than one type of livestock, and some livestock are of more than one type (e.g., 'other cattle' that are being fed for slaughter are also 'cattle on feed'). In addition, any data tabulated by NASS that could identify numbers of animals or other data reported by an individual respondent is suppressed by NASS and coded with a 'D.'. To be useful for epidemiological and economic modeling, the NASS data must be converted into a unique set of facility types (farms having similar operational characteristics). The unique set must not double count facilities or animals. At the same time, it must account for all the animals, including those for which the data has been suppressed. Therefore, several data processing steps are required to work back from the published NASS data to obtain a consistent database for individual livestock operations. This technical report documents data processing steps that were used to convert the NASS data into a national livestock facility database with twenty-eight facility types. The process involves two major steps. The first step defines the rules used to estimate the data that is suppressed within the NASS database. The second step converts the NASS

Studies on the antidiabetic effects of Mangifera indica stem-barks and leaves on nondiabetic, type 1 and type 2 diabetic model rats

Directory of Open Access Journals (Sweden)

Amrita Bhowmik

2009-06-01

Full Text Available Mangifera indica Linn, locally known as mango tree has been claimed to possess antidiabetic properties by many investigators. The present study was undertaken to screen the hypo- and antihyperglycemic activity of both ethanol and water extracts of leaves and stem-barks of M. indica in nondiabetic and diabetic model rats in different prandial states. The results showed that all of the extracts had significant antihyperglycemic effect in type 2 model rats when fed simultaneously with glucose load (p< 0.05-0.01; p< 0.005-0.001. Moreover, the ethanol extract of stem-barks showed significant antihyperglycemic effect when the extract was fed 30 min prior to the glucose load (p< 0.01. Investigations were carried out to evaluate the effect of M. indica on glucose absorption using a rat intestinal preparation in situ. The ethanol extracts of stem-barks reduced glucose absorption gradually during the whole perfusion period in type 2 rats.

Studies on the antidiabetic effects of Mangifera indica stem-barks and leaves on nondiabetic, type 1 and type 2 diabetic model rats

Directory of Open Access Journals (Sweden)

Amrita Bhowmik, Liakot Ali Khan, Masfida Akhter and Begum Rokeya

2009-12-01

Full Text Available Mangifera indica Linn, locally known as mango tree has been claimed to possess antidiabetic properties by many investigators. The present study was undertaken to screen the hypoglycemic and antihyperglycemic activity of both ethanol and water extracts of leaves and stem-barks of M. indica in nondiabetic and diabetic model rats in different prandial state. The results showed that all of the extracts had significant antihyperglycemic effect in type 2 diabetic model rats when fed simultaneously with glucose load (p<0.05-0.01; p<0.005-0.001. Moreover, the ethanol extract of stem-barks showed significant antihyperglycemic effect when the extract was fed 30 min prior to the glucose load (p<0.01. Investigations were carried out to evaluate the effect of M. indica on glucose absorption using a rat intestinal preparation in situ. The ethanol extracts of stem-barks reduced glucose absorption gradually during the whole perfusion period in type 2 diabetic rats.

Cosmological-model-parameter determination from satellite-acquired type Ia and IIP Supernova Data

International Nuclear Information System (INIS)

Podariu, Silviu; Nugent, Peter; Ratra, Bharat

2000-01-01

We examine the constraints that satellite-acquired Type Ia and IIP supernova apparent magnitude versus redshift data will place on cosmological model parameters in models with and without a constant or time-variable cosmological constant lambda. High-quality data which could be acquired in the near future will result in tight constraints on these parameters. For example, if all other parameters of a spatially-flat model with a constant lambda are known, the supernova data should constrain the non-relativistic matter density parameter omega to better than 1 (2, 0.5) at 1 sigma with neutral (worst case, best case) assumptions about data quality

Applied model of through-wall crack of coolant vessels of WWER-type reactors

International Nuclear Information System (INIS)

Petrosyan, V.; Hovakimyan, T.; Vardanyan, M.; Khachatryan, A.; Minasyan, K.

2010-01-01

We propose an applied-model of Through-Wall Crack (TWC) for WWER-type units primary vessels. The model allows to simulate the main morphological parameters of real TWC, i.e. length, area of inlet and outlet openings, channel depth and small and large size unevenness of the crack surface. The model can be used for developing and improving the coolant-leak detectors for the primary circuit vessels of WWER-units. Also, it can be used for research of the coolant two-phase leakage phenomenon through narrow cracks/channels and thermo-physical processes in heat-insulation layer of the Main Coolant Piping (MCP) during the leak

A Linear Programming Model to Optimize Various Objective Functions of a Foundation Type State Support Program.

Science.gov (United States)

Matzke, Orville R.

The purpose of this study was to formulate a linear programming model to simulate a foundation type support program and to apply this model to a state support program for the public elementary and secondary school districts in the State of Iowa. The model was successful in producing optimal solutions to five objective functions proposed for…

Hydrological-niche models predict water plant functional group distributions in diverse wetland types.

Science.gov (United States)

Deane, David C; Nicol, Jason M; Gehrig, Susan L; Harding, Claire; Aldridge, Kane T; Goodman, Abigail M; Brookes, Justin D

2017-06-01

Human use of water resources threatens environmental water supplies. If resource managers are to develop policies that avoid unacceptable ecological impacts, some means to predict ecosystem response to changes in water availability is necessary. This is difficult to achieve at spatial scales relevant for water resource management because of the high natural variability in ecosystem hydrology and ecology. Water plant functional groups classify species with similar hydrological niche preferences together, allowing a qualitative means to generalize community responses to changes in hydrology. We tested the potential for functional groups in making quantitative prediction of water plant functional group distributions across diverse wetland types over a large geographical extent. We sampled wetlands covering a broad range of hydrogeomorphic and salinity conditions in South Australia, collecting both hydrological and floristic data from 687 quadrats across 28 wetland hydrological gradients. We built hydrological-niche models for eight water plant functional groups using a range of candidate models combining different surface inundation metrics. We then tested the predictive performance of top-ranked individual and averaged models for each functional group. Cross validation showed that models achieved acceptable predictive performance, with correct classification rates in the range 0.68-0.95. Model predictions can be made at any spatial scale that hydrological data are available and could be implemented in a geographical information system. We show the response of water plant functional groups to inundation is consistent enough across diverse wetland types to quantify the probability of hydrological impacts over regional spatial scales. © 2017 by the Ecological Society of America.

On the asymptotic behavior of a boltzmann-type price formation model

KAUST Repository

Burger, Martin; Caffarelli, Luis A.; Markowich, Peter A.; Wolfram, Marie-Therese

2014-01-01

In this paper we study the asymptotic behavior of a Boltzmann-type price formation model, which describes the trading dynamics in a financial market. In many of these markets trading happens at high frequencies and low transaction costs. This observation motivates the study of the limit as the number of transactions k tends to infinity, the transaction cost a to zero and ka=const. Furthermore we illustrate the price dynamics with numerical simulations © 2014 International Press.

A Generic Safety Assessment Model for a Trench Type LILW Repository

International Nuclear Information System (INIS)

Lee, Youn-Myoung; Choi, Hee-Joo

2015-01-01

This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various normal circumstances, disruptive events, and scenarios that can occur after a failure of waste packages with associated uncertainty. Despite the conceptual design of a trench type LILW repository system, all parameter values associated with the repository system were assumed for the time being, and the generic model developed through this study should be helpful because the evaluation of such releases is very important. A simple and effective model for a safety assessment of a conceptual trench repository system, in which an LILW that arises from a nuclear power plant and other sources, has been developed. The computer program based on this model has also been developed as a GoldSim template using the commercial GoldSim development tool

A Generic Safety Assessment Model for a Trench Type LILW Repository

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn-Myoung; Choi, Hee-Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-05-15

This program is ready for a total system performance assessment and is able to deterministically and probabilistically evaluate the nuclide release from a repository and farther transport into the geosphere and biosphere under various normal circumstances, disruptive events, and scenarios that can occur after a failure of waste packages with associated uncertainty. Despite the conceptual design of a trench type LILW repository system, all parameter values associated with the repository system were assumed for the time being, and the generic model developed through this study should be helpful because the evaluation of such releases is very important. A simple and effective model for a safety assessment of a conceptual trench repository system, in which an LILW that arises from a nuclear power plant and other sources, has been developed. The computer program based on this model has also been developed as a GoldSim template using the commercial GoldSim development tool.

Damage and failure modeling of lotus-type porous material subjected to low-cycle fatigue

Directory of Open Access Journals (Sweden)

J. Kramberger

2016-01-01

Full Text Available The investigation of low-cycle fatigue behaviour of lotus-type porous material is presented in this paper. Porous materials exhibit some unique features which are useful for a number of various applications. This paper evaluates a numerical approach for determining of damage initiation and evolution of lotus-type porous material with computational simulations, where the considered computational models have different pore topology patterns. The low-cycle fatigue analysis was performed by using a damage evolution law. The damage state was calculated and updated based on the inelastic hysteresis energy for stabilized cycle. Degradation of the elastic stifness was modeled using scalar damage variable. In order to examine crack propagation path finite elements with severe damage were deleted and removed from the mesh during simulation. The direct cyclic analysis capability in Abaqus/Standard was used for low-cycle fatigue analysis to obtain the stabilized response of a model subjected to the periodic loading. The computational results show a qualitative understanding of pores topology influence on low-cycle fatigue under transversal loading conditions in relation to pore orientation.

Public health program planning logic model for community engaged type 2 diabetes management and prevention.

Science.gov (United States)

West, Joseph F

2014-02-01

Diabetes remains a growing epidemic with widening health inequity gaps in disease management, self-management knowledge, access to care and outcomes. Yet there is a paucity of evaluation tools for community engaged interventions aimed at closing the gaps and improving health. The Guide to Community Preventive Services (the Community Guide) developed by the Task Force on Community Preventive Services (the Task Force) at the Centers for Disease Control and Prevention (CDC) recommends two healthcare system level interventions, case management interventions and disease management programs, to improve glycemic control. However, as a public health resource guide for diabetes interventions a model for community engagement is a glaringly absent component of the Community Guide recommendations. In large part there are few evidence-based interventions featuring community engagement as a practice and system-level focus of chronic disease and Type 2 diabetes management. The central argument presented in this paper is that the absence of these types of interventions is due to the lack of tools for modeling and evaluating such interventions, especially among disparate and poor populations. A conceptual model emphasizing action-oriented micro-level community engagement is needed to complement the Community Guide and serve as the basis for testing and evaluation of these kinds of interventions. A unique logic model advancing the Community Guide diabetes recommendations toward measureable and sustainable community engagement for improved Type 2 diabetes outcomes is presented. Copyright © 2013 Elsevier Ltd. All rights reserved.

Instream Physical Habitat Modelling Types

DEFF Research Database (Denmark)

Conallin, John; Boegh, Eva; Krogsgaard, Jørgen

2010-01-01

The introduction of the EU Water Framework Directive (WFD) is providing member state water resource managers with significant challenges in relation to meeting the deadline for 'Good Ecological Status' by 2015. Overall, instream physical habitat modelling approaches have advantages and disadvanta......The introduction of the EU Water Framework Directive (WFD) is providing member state water resource managers with significant challenges in relation to meeting the deadline for 'Good Ecological Status' by 2015. Overall, instream physical habitat modelling approaches have advantages...... suit their situations. This paper analyses the potential of different methods available for water managers to assess hydrological and geomorphological impacts on the habitats of stream biota, as requested by the WFD. The review considers both conventional and new advanced research-based instream...... physical habitat models. In parametric and non-parametric regression models, model assumptions are often not satisfied and the models are difficult to transfer to other regions. Research-based methods such as the artificial neural networks and individual-based modelling have promising potential as water...

Eliciting mixed emotions: a meta-analysis comparing models, types, and measures

Science.gov (United States)

Berrios, Raul; Totterdell, Peter; Kellett, Stephen

2015-01-01

The idea that people can experience two oppositely valenced emotions has been controversial ever since early attempts to investigate the construct of mixed emotions. This meta-analysis examined the robustness with which mixed emotions have been elicited experimentally. A systematic literature search identified 63 experimental studies that instigated the experience of mixed emotions. Studies were distinguished according to the structure of the underlying affect model—dimensional or discrete—as well as according to the type of mixed emotions studied (e.g., happy-sad, fearful-happy, positive-negative). The meta-analysis using a random-effects model revealed a moderate to high effect size for the elicitation of mixed emotions (dIG+ = 0.77), which remained consistent regardless of the structure of the affect model, and across different types of mixed emotions. Several methodological and design moderators were tested. Studies using the minimum index (i.e., the minimum value between a pair of opposite valenced affects) resulted in smaller effect sizes, whereas subjective measures of mixed emotions increased the effect sizes. The presence of more women in the samples was also associated with larger effect sizes. The current study indicates that mixed emotions are a robust, measurable and non-artifactual experience. The results are discussed in terms of the implications for an affect system that has greater versatility and flexibility than previously thought. PMID:25926805

LRS Bianchi Type II Massive String Cosmological Models with Magnetic Field in Lyra's Geometry

Directory of Open Access Journals (Sweden)

Raj Bali

2013-01-01

Full Text Available Bianchi type II massive string cosmological models with magnetic field and time dependent gauge function ( in the frame work of Lyra's geometry are investigated. The magnetic field is in -plane. To get the deterministic solution, we have assumed that the shear ( is proportional to the expansion (. This leads to , where and are metric potentials and is a constant. We find that the models start with a big bang at initial singularity and expansion decreases due to lapse of time. The anisotropy is maintained throughout but the model isotropizes when . The physical and geometrical aspects of the model in the presence and absence of magnetic field are also discussed.

Event and fault tree model for reliability analysis of the greek research reactor

International Nuclear Information System (INIS)

Albuquerque, Tob R.; Guimaraes, Antonio C.F.; Moreira, Maria de Lourdes

2013-01-01

Fault trees and event trees are widely used in industry to model and to evaluate the reliability of safety systems. Detailed analyzes in nuclear installations require the combination of these two techniques. This work uses the methods of fault tree (FT) and event tree (ET) to perform the Probabilistic Safety Assessment (PSA) in research reactors. The PSA according to IAEA (International Atomic Energy Agency) is divided into Level 1, Level 2 and level 3. At Level 1, conceptually safety systems act to prevent the accident, at Level 2, the accident occurred and seeks to minimize the consequences, known as stage management of the accident, and at Level 3 are determined consequences. This paper focuses on Level 1 studies, and searches through the acquisition of knowledge consolidation of methodologies for future reliability studies. The Greek Research Reactor, GRR - 1, was used as a case example. The LOCA (Loss of Coolant Accident) was chosen as the initiating event and from there were developed the possible accident sequences, using event tree, which could lead damage to the core. Furthermore, for each of the affected systems, the possible accidents sequences were made fault tree and evaluated the probability of each event top of the FT. The studies were conducted using a commercial computational tool SAPHIRE. The results thus obtained, performance or failure to act of the systems analyzed were considered satisfactory. This work is directed to the Greek Research Reactor due to data availability. (author)

Event and fault tree model for reliability analysis of the greek research reactor

Energy Technology Data Exchange (ETDEWEB)

Albuquerque, Tob R.; Guimaraes, Antonio C.F.; Moreira, Maria de Lourdes, E-mail: atalbuquerque@ien.gov.br, E-mail: btony@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

2013-07-01

Fault trees and event trees are widely used in industry to model and to evaluate the reliability of safety systems. Detailed analyzes in nuclear installations require the combination of these two techniques. This work uses the methods of fault tree (FT) and event tree (ET) to perform the Probabilistic Safety Assessment (PSA) in research reactors. The PSA according to IAEA (International Atomic Energy Agency) is divided into Level 1, Level 2 and level 3. At Level 1, conceptually safety systems act to prevent the accident, at Level 2, the accident occurred and seeks to minimize the consequences, known as stage management of the accident, and at Level 3 are determined consequences. This paper focuses on Level 1 studies, and searches through the acquisition of knowledge consolidation of methodologies for future reliability studies. The Greek Research Reactor, GRR - 1, was used as a case example. The LOCA (Loss of Coolant Accident) was chosen as the initiating event and from there were developed the possible accident sequences, using event tree, which could lead damage to the core. Furthermore, for each of the affected systems, the possible accidents sequences were made fault tree and evaluated the probability of each event top of the FT. The studies were conducted using a commercial computational tool SAPHIRE. The results thus obtained, performance or failure to act of the systems analyzed were considered satisfactory. This work is directed to the Greek Research Reactor due to data availability. (author)

The Sort on Radioactive Waste Type model: A method to sort single-shell tanks into characteristic groups. Revision 1

International Nuclear Information System (INIS)

Hill, J.G.; Simpson, B.C.

1994-08-01

The Sort on Radioactive Waste Type (SORWT) model presents a method to categorize Hanford Site single-shell tanks (SSTs) into groups of tanks expected to exhibit similar chemical and physical characteristics based on their major waste types and processing histories. This model has identified 29 different waste-type groups encompassing 135 of the 149 SSTs and 93% of the total waste volume in SSTs. The remaining 14 SSTs and associated wastes could not be grouped according to the established criteria and were placed in an ungrouped category. This letter report will detail the assumptions and methodologies used to develop the SORWT model and present the grouping results. Included with this report is a brief description and approximate compositions of the single-shell tank waste types. In the near future, the validity of the predicted groups will be statistically tested using analysis of variance of characterization data obtained from recent (post-1989) core sampling and analysis activities. In addition, the SORWT model will be used to project the nominal waste characteristics of entire waste type groups that have some recent characterization data available. These subsequent activities will be documented along with these initial results in a comprehensive, formal PNL report cleared for public release by September 1994

Development of mapped stress-field boundary conditions based on a Hill-type muscle model.

Science.gov (United States)

Cardiff, P; Karač, A; FitzPatrick, D; Flavin, R; Ivanković, A

2014-09-01

Forces generated in the muscles and tendons actuate the movement of the skeleton. Accurate estimation and application of these musculotendon forces in a continuum model is not a trivial matter. Frequently, musculotendon attachments are approximated as point forces; however, accurate estimation of local mechanics requires a more realistic application of musculotendon forces. This paper describes the development of mapped Hill-type muscle models as boundary conditions for a finite volume model of the hip joint, where the calculated muscle fibres map continuously between attachment sites. The applied muscle forces are calculated using active Hill-type models, where input electromyography signals are determined from gait analysis. Realistic muscle attachment sites are determined directly from tomography images. The mapped muscle boundary conditions, implemented in a finite volume structural OpenFOAM (ESI-OpenCFD, Bracknell, UK) solver, are employed to simulate the mid-stance phase of gait using a patient-specific natural hip joint, and a comparison is performed with the standard point load muscle approach. It is concluded that physiological joint loading is not accurately represented by simplistic muscle point loading conditions; however, when contact pressures are of sole interest, simplifying assumptions with regard to muscular forces may be valid. Copyright © 2014 John Wiley & Sons, Ltd.

PROPERTIES OF 42 SOLAR-TYPE KEPLER TARGETS FROM THE ASTEROSEISMIC MODELING PORTAL

Energy Technology Data Exchange (ETDEWEB)

Metcalfe, T. S.; Mathur, S. [Space Science Institute, 4750 Walnut Street Suite 205, Boulder, CO 80301 (United States); Creevey, O. L. [Institut d' Astrophysique Spatiale, Université Paris XI, UMR 8617, CNRS, Batiment 121, F-91405 Orsay Cedex (France); Doğan, G.; Christensen-Dalsgaard, J.; Karoff, C.; Trampedach, R. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Xu, H. [Computational and Information Systems Laboratory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Bedding, T. R.; Benomar, O. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Chaplin, W. J.; Campante, T. L.; Davies, G. R. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); Brown, B. P. [Department of Astronomy and Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin, Madison, WI 53706 (United States); Buzasi, D. L. [Department of Chemistry and Physics, Florida Gulf Coast University, Fort Myers, FL 33965 (United States); Çelik, Z. [Ege University, Department of Astronomy and Space Sciences, Bornova, 35100, Izmir (Turkey); Cunha, M. S. [Centro de Astrofísica e Faculdade de Ciências, Universidade do Porto, Rua das Estrelas, 4150-762, Porto (Portugal); Deheuvels, S. [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Derekas, A. [Konkoly Observatory, MTA CSFK, H-1121 Budapest, Konkoly Thege M. út 15-17 (Hungary); Mauro, M. P. Di [INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); and others

2014-10-01

Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved into individual mode frequencies has increased dramatically. While only a few such data sets were available for detailed modeling just a decade ago, the Kepler mission has produced suitable observations for hundreds of new targets. This rapid expansion in observational capacity has been accompanied by a shift in analysis and modeling strategies to yield uniform sets of derived stellar properties more quickly and easily. We use previously published asteroseismic and spectroscopic data sets to provide a uniform analysis of 42 solar-type Kepler targets from the Asteroseismic Modeling Portal. We find that fitting the individual frequencies typically doubles the precision of the asteroseismic radius, mass, and age compared to grid-based modeling of the global oscillation properties, and improves the precision of the radius and mass by about a factor of three over empirical scaling relations. We demonstrate the utility of the derived properties with several applications.

New prognostic model for extranodal natural killer/T cell lymphoma, nasal type.

Science.gov (United States)

Cai, Qingqing; Luo, Xiaolin; Zhang, Guanrong; Huang, Huiqiang; Huang, Hui; Lin, Tongyu; Jiang, Wenqi; Xia, Zhongjun; Young, Ken H

2014-09-01

Extranodal natural killer/T cell lymphoma, nasal type (ENKTL) is an aggressive disease with a poor prognosis, requiring risk stratification in affected patients. We designed a new prognostic model specifically for ENKTL to identify high-risk patients who need more aggressive therapy. We retrospectively reviewed 158 patients who were newly diagnosed with ENKTL. The estimated 5-year overall survival rate was 39.4 %. Independent prognostic factors included total protein (TP) 100 mg/dL, and Korean Prognostic Index (KPI) score ≥2. We constructed a new prognostic model by combining these prognostic factors: group 1 (64 cases (41.0 %)), no adverse factors; group 2 (58 cases (37.2 %)), one adverse factor; and group 3 (34 cases (21.8 %)), two or three adverse factors. The 5-year overall survival (OS) rates of these groups were 66.7, 23.0, and 5.9 %, respectively (p KPI model alone (p KPI model alone.

Satellite image simulations for model-supervised, dynamic retrieval of crop type and land use intensity

Science.gov (United States)

Bach, H.; Klug, P.; Ruf, T.; Migdall, S.; Schlenz, F.; Hank, T.; Mauser, W.

2015-04-01

To support food security, information products about the actual cropping area per crop type, the current status of agricultural production and estimated yields, as well as the sustainability of the agricultural management are necessary. Based on this information, well-targeted land management decisions can be made. Remote sensing is in a unique position to contribute to this task as it is globally available and provides a plethora of information about current crop status. M4Land is a comprehensive system in which a crop growth model (PROMET) and a reflectance model (SLC) are coupled in order to provide these information products by analyzing multi-temporal satellite images. SLC uses modelled surface state parameters from PROMET, such as leaf area index or phenology of different crops to simulate spatially distributed surface reflectance spectra. This is the basis for generating artificial satellite images considering sensor specific configurations (spectral bands, solar and observation geometries). Ensembles of model runs are used to represent different crop types, fertilization status, soil colour and soil moisture. By multi-temporal comparisons of simulated and real satellite images, the land cover/crop type can be classified in a dynamically, model-supervised way and without in-situ training data. The method is demonstrated in an agricultural test-site in Bavaria. Its transferability is studied by analysing PROMET model results for the rest of Germany. Especially the simulated phenological development can be verified on this scale in order to understand whether PROMET is able to adequately simulate spatial, as well as temporal (intra- and inter-season) crop growth conditions, a prerequisite for the model-supervised approach. This sophisticated new technology allows monitoring of management decisions on the field-level using high resolution optical data (presently RapidEye and Landsat). The M4Land analysis system is designed to integrate multi-mission data and is

Video Modeling Training Effects on Types of Attention Delivered by Educational Care-Providers.

Science.gov (United States)

Taber, Traci A; Lambright, Nathan; Luiselli, James K

2017-06-01

We evaluated the effects of abbreviated (i.e., one-session) video modeling on delivery of student-preferred attention by educational care-providers. The video depicted a novel care-provider interacting with and delivering attention to the student. Within a concurrent multiple baseline design, video modeling increased delivery of the targeted attention for all participants as well as their delivery of another type of attention that was not trained although these effects were variable within and between care-providers. We discuss the clinical and training implications from these findings.

A model to predict the permeation of type IV hydrogen tanks

Energy Technology Data Exchange (ETDEWEB)

Bayle, Julien; Perreux, Dominique; Chapelle, David; Thiebaud, Frederic [MaHyTec, Dole (France); Nardin, Philippe [Franche Comte Univ. (France)

2010-07-01

In the frame of the certification process of the type IV hydrogen storage tanks MaHyTec aims to manufacture, this innovative SME is developing a numerical model dedicated to the study of permeation issues. Such an approach aims at avoiding complicated, time-consuming and expensive testing. Experimental results obtained under real conditions can moreover be significantly influenced by the scattering of material properties and liner dimensions. From simple testing on small-size flat membranes, the model allows to predict the gas diffusion flow through the whole structure by means of numerous parameters. On every step, theory can be compared with the results obtained from the samples. This document presents a brief review of the mathematical theory describing gas diffusion and the different aspects of the study for better understanding the proposed approach. (orig.)

The double-degenerate model for the progenitors of Type Ia supernovae

Science.gov (United States)

Liu, D.; Wang, B.; Han, Z.

2018-02-01

The double-degenerate (DD) model, involving the merging of massive double carbon-oxygen white dwarfs (CO WDs) driven by gravitational wave radiation, is one of the classical pathways for the formation of Type Ia supernovae (SNe Ia). Recently, it has been proposed that the WD+He subgiant channel has a significant contribution to the production of massive double WDs, in which the primary WD accumulates mass by accreting He-rich matter from an He subgiant. We evolved about 1800 CO WD+He star systems and obtained a large and dense grid for producing SNe Ia through the DD model. We then performed a series of binary population synthesis simulations for the DD model, in which the WD+He subgiant channel is calculated by interpolations in the SN Ia production grid. According to our standard model, the Galactic birth rate of SNe Ia is about 2.4 × 10- 3 yr- 1 for the WD+He subgiant channel of the DD model; the total birth rate is about 3.7 × 10- 3 yr- 1 for all channels, reproducing that of observations. Previous theoretical models still have deficit with the observed SNe Ia with delay times 8 Gyr. After considering the WD+He subgiant channel, we found that the delay time distributions are comparable with the observed results. Additionally, some recent studies proposed that the violent WD mergers are more likely to produce SNe Ia based on the DD model. We estimated that the violent mergers through the DD model may contribute to at most 16 per cent of all SNe Ia.

Stack semantics of type theory

DEFF Research Database (Denmark)

Coquand, Thierry; Mannaa, Bassel; Ruch, Fabian

2017-01-01

We give a model of dependent type theory with one univalent universe and propositional truncation interpreting a type as a stack, generalizing the groupoid model of type theory. As an application, we show that countable choice cannot be proved in dependent type theory with one univalent universe...

Modelling the Effect of Exercise on Insulin Pharmacokinetics in "Continuous Subcutaneous Insulin Infusion" Treated Type 1 Diabetes Patients

DEFF Research Database (Denmark)

Duun-Henriksen, Anne Katrine; Juhl, Rune; Schmidt, Signe

Introduction: The artificial pancreas is believed to ease the burden of constant management of type 1 diabetes for the patients substantially. An important aspect of the artificial pancreas development is the mathematical models used for control, prediction or simulation. A major challenge...... infusion (CSII) treated patients by modelling the absorption rate as a function of exercise. Methods: Three models are estimated from 17 data sequences. All of them are based on a linear three-compartment base model. The models are based on stochastic differential equations to allow noise to enter...... of the measurement variance. Conclusion: A model to predict the insulin appearance in plasma during exercise in CSII treated patients is identified. Further clinical studies are needed to confirm the increase in insulin plasma concentration during exercise in type 1 diabetes patients. These studies should include...

Analysis of recent type Ia supernova data based on evolving dark energy models

International Nuclear Information System (INIS)

Park, Jaehong; Park, Chan-Gyung; Hwang, Jai-chan

2011-01-01

We study characters of recent type Ia supernova data using evolving dark energy models with changing equation-of-state parameter w. We consider a sudden-jump approximation of w for some chosen redshift spans with double transitions and constrain these models based on the Markov chain Monte Carlo method using the type Ia supernova data (Constitution, Union, Union2), together with the baryon acoustic oscillation A parameter and the cosmic microwave background shift parameter in a flat background. In the double-transition model, the Constitution data shows deviation outside 1σ from the Λ cold dark matter (ΛCDM) model at low (z < or approx. 0.2) and middle (0.2 < or approx. z < or approx. 0.4) redshift bins, whereas no such deviations are noticeable in the Union and Union2 data. By analyzing the Union members in the Constitution set, however, we show that the same difference is actually due to different calibration of the same Union sample in the Constitution set and is not due to new data added in the Constitution set. All detected deviations are within 2σ from the ΛCDM world model. From the ΛCDM mock data analysis, we quantify biases in the dark energy equation-of-state parameters induced by insufficient data with inhomogeneous distribution of data points in the redshift space and distance modulus errors. We demonstrate that the location of the peak in the distribution of arithmetic means (computed from the Markov chain Monte Carlo chain for each mock data) behaves as an unbiased estimator for the average bias, which is valid even for nonsymmetric likelihood distributions.

Model of T-Type Fracture in Coal Fracturing and Analysis of Influence Factors of Fracture Morphology

Directory of Open Access Journals (Sweden)

Yuwei Li

2018-05-01

Full Text Available Special T-type fractures can be formed when coal is hydraulically fractured and there is currently no relevant theoretical model to calculate and describe them. This paper first establishes the height calculation model of vertical fractures in multi-layered formations and deduces the stress intensity factor (SIF at the upper and lower sides of the fracture in the process of vertical fracture extension. Combined with the fracture tip stress analysis method of fracture mechanics theory, the horizontal bedding is taken into account for tensile and shear failure, and the critical mechanical conditions for the formation of horizontal fracture in coal are obtained. Finally, the model of T-type fracture in coal fracturing is established, and it is verified by fracturing simulation experiments. The model calculation result shows that the increase of vertical fracture height facilitates the increase of horizontal fracture length. The fracture toughness of coal has a significant influence on the length of horizontal fracture and there is a threshold. When the fracture toughness is less than the threshold, the length of horizontal fracture remains unchanged, otherwise, the length of horizontal fracture increases rapidly with the increase of fracture toughness. When the shear strength of the interface between the coalbed and the interlayer increases, the length of the horizontal fracture of the T-type fracture rapidly decreases.

Higgs potential in the type II seesaw model

International Nuclear Information System (INIS)

Arhrib, A.; Benbrik, R.; Chabab, M.; Rahili, L.; Ramadan, J.; Moultaka, G.; Peyranere, M. C.

2011-01-01

The standard model Higgs sector, extended by one weak gauge triplet of scalar fields with a very small vacuum expectation value, is a very promising setting to account for neutrino masses through the so-called type II seesaw mechanism. In this paper we consider the general renormalizable doublet/triplet Higgs potential of this model. We perform a detailed study of its main dynamical features that depend on five dimensionless couplings and two mass parameters after spontaneous symmetry breaking, and highlight the implications for the Higgs phenomenology. In particular, we determine (i) the complete set of tree-level unitarity constraints on the couplings of the potential and (ii) the exact tree-level boundedness from below constraints on these couplings, valid for all directions. When combined, these constraints delineate precisely the theoretically allowed parameter space domain within our perturbative approximation. Among the seven physical Higgs states of this model, the mass of the lighter (heavier) CP even state h 0 (H 0 ) will always satisfy a theoretical upper (lower) bound that is reached for a critical value μ c of μ (the mass parameter controlling triple couplings among the doublet/triplet Higgses). Saturating the unitarity bounds, we find an upper bound m h 0 or approx. μ c and μ c . In the first regime the Higgs sector is typically very heavy, and only h 0 that becomes SM-like could be accessible to the LHC. In contrast, in the second regime, somewhat overlooked in the literature, most of the Higgs sector is light. In particular, the heaviest state H 0 becomes SM-like, the lighter states being the CP odd Higgs, the (doubly) charged Higgses, and a decoupled h 0 , possibly leading to a distinctive phenomenology at the colliders.

The three-dimensional model for helical columns on type-J synchronous counter-current chromatography.

Science.gov (United States)

Guan, Y H; van den Heuvel, Remco

2011-08-05

Unlike the existing 2-D pseudo-ring model for helical columns undergoing synchronous type-J planetary motion of counter-current chromatograph (CCC), the 3-D "helix" model developed in this work shows that there is a second normal force (i.e. the binormal force) applied virtually in the axial direction of the helical column. This force alternates in the two opposite directions and intensifies phase mixing with increasing the helix angle. On the contrary, the 2-D spiral column operated on the same CCC device lacks this third-dimensional mixing force. The (principal) normal force quantified by this "helix" model has been the same as that by the pseudo-ring model. With β>0.25, this normal centrifugal force has been one-directional and fluctuates cyclically. Different to the spiral column, this "helix" model shows that the centrifugal force (i.e. the hydrostatic force) does not contribute to stationary phase retention in the helical column. Between the popular helical columns and the emerging spiral columns for type-J synchronous CCC, this work has thus illustrated that the former is associated with better phase mixing yet poor retention for the stationary phase whereas the latter has potential for better retention for the stationary phase yet poor phase mixing. The methodology developed in this work may be regarded as a new platform for designing optimised CCC columns for analytical and engineering applications. Copyright © 2011 Elsevier B.V. All rights reserved.

Modelling of the Residual Stress State in a new Type of Residual Stress Specimen

DEFF Research Database (Denmark)

Jakobsen, Johnny; Andreasen, Jens Henrik

2014-01-01

forms the experimental case which is analysed. A FE model of the specimen is used for analysing the curing history and the residual stress build up. The model is validated against experimental strain data which are recorded by a Fibre Brag Grating sensor and good agreement has been achieved.......The paper presents a study on a new type residual stress specimen which is proposed as a simple way to conduct experimental validation for model predictions. A specimen comprising of a steel plate with circular hole embedded into a stack of CSM glass fibre and further infused with an epoxy resin...

Continuous-time interval model identification of blood glucose dynamics for type 1 diabetes

Science.gov (United States)

Kirchsteiger, Harald; Johansson, Rolf; Renard, Eric; del Re, Luigi

2014-07-01

While good physiological models of the glucose metabolism in type 1 diabetic patients are well known, their parameterisation is difficult. The high intra-patient variability observed is a further major obstacle. This holds for data-based models too, so that no good patient-specific models are available. Against this background, this paper proposes the use of interval models to cover the different metabolic conditions. The control-oriented models contain a carbohydrate and insulin sensitivity factor to be used for insulin bolus calculators directly. Available clinical measurements were sampled on an irregular schedule which prompts the use of continuous-time identification, also for the direct estimation of the clinically interpretable factors mentioned above. An identification method is derived and applied to real data from 28 diabetic patients. Model estimation was done on a clinical data-set, whereas validation results shown were done on an out-of-clinic, everyday life data-set. The results show that the interval model approach allows a much more regular estimation of the parameters and avoids physiologically incompatible parameter estimates.

Pore Type Classification on Carbonate Reservoir in Offshore Sarawak using Rock Physics Model and Rock Digital Images

International Nuclear Information System (INIS)

Lubis, L A; Harith, Z Z T

2014-01-01

It has been recognized that carbonate reservoirs are one of the biggest sources of hydrocarbon. Clearly, the evaluation of these reservoirs is important and critical. For rigorous reservoir characterization and performance prediction from geophysical measurements, the exact interpretation of geophysical response of different carbonate pore types is crucial. Yet, the characterization of carbonate reservoir rocks is difficult due to their complex pore systems. The significant diagenesis process and complex depositional environment makes pore systems in carbonates far more complicated than in clastics. Therefore, it is difficult to establish rock physics model for carbonate rock type. In this paper, we evaluate the possible rock physics model of 20 core plugs of a Miocene carbonate platform in Central Luconia, Sarawak. The published laboratory data of this area were used as an input to create the carbonate rock physics models. The elastic properties were analyzed to examine the validity of an existing analytical carbonate rock physics model. We integrate the Xu-Payne Differential Effective Medium (DEM) Model and the elastic modulus which was simulated from a digital carbonate rock image using Finite Element Modeling. The results of this integration matched well for the separation of carbonate pore types and sonic P-wave velocity obtained from laboratory measurement. Thus, the results of this study show that the integration of rock digital image and theoretical rock physics might improve the elastic properties prediction and useful for more advance geophysical techniques (e.g. Seismic Inversion) of carbonate reservoir in Sarawak

Effectiveness of integrated care model for type 2 diabetes: A population-based study in Reggio Emilia (Italy).

Science.gov (United States)

Ballotari, Paola; Venturelli, Francesco; Manicardi, Valeria; Ferrari, Francesca; Vicentini, Massimo; Greci, Marina; Pignatti, Fabio; Storani, Simone; Giorgi Rossi, Paolo

2018-01-01

To compare the effectiveness of integrated care with that of the diabetes clinic care model in terms of mortality and hospitalisation of type 2 diabetes patients with low risk of complications. Out of 27234 people with type 2 diabetes residing in the province of Reggio Emilia on 31/12/2011, 3071 were included in this cohort study as eligible for integrated care (i.e., low risk of complications) and cared for with the same care model for at least two years. These patients were followed up from 2012 to 2016, for all-cause and diabetes-related mortality and hospital admissions. We performed a Poisson regression model, using the proportion of eligible patients included in the integrated care model for each general practitioner as an instrumental variable. 1700 patients were cared for by integrated care and 1371 by diabetes clinics. Mortality rate ratios were 0.83 (95%CI 0.60-1.13) and 0.95 (95%CI 0.54-1.70) for all-cause and cardiovascular mortality, respectively, and incidence rate ratios were 0.90 (95%CI 0.76-1.06) and 0.91 (95%CI 0.69-1.20) for all-cause and cardiovascular disease hospitalisation, respectively. For low risk patients with type 2 diabetes, the integrated care model involving both general practitioner and diabetes clinic professionals showed similar mortality and hospitalisation as a model with higher use of specialized care in an exclusively diabetes clinic setting.

Locally Rotationally Symmetric Bianchi Type-I Model with Time Varying Λ Term

International Nuclear Information System (INIS)

Tiwari, R. K.; Jha, Navin Kumar

2009-01-01

We investigate the locally rotationally symmetric (LRS) Bianchi type-I cosmological model for stiff matter and a vacuum solution with a cosmological term proportional to R −m (R is the scale factor and m is a positive constant). The cosmological term decreases with time. We obtain that for both the cases the present universe is accelerating with a large fraction of cosmological density in the form of a cosmological term

Types of distribution of electric fields and the types of convection corresponding to them in the polar ionosphere. A model.

Science.gov (United States)

Uvarov, V. M.; Barashkov, P. D.

1989-06-01

All types of distributions known from experiment of the evening-morning component of the electric field Ee-m along the morning-evening meridian are reproduced on the basis of a model of the continuous distribution of largescale electric fields E, and the convection patterns corresponding to them, which differ appreciably from the known speculative concepts, are calculated. Two-, three-, and four-vortex convection patterns are realized, depending on the conditions in the interplanetary medium.

Analytical model and design of spoke-type permanent-magnet machines accounting for saturation and nonlinearity of magnetic bridges

Energy Technology Data Exchange (ETDEWEB)

Liang, Peixin; Chai, Feng [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001 (China); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Bi, Yunlong [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Pei, Yulong, E-mail: peiyulong1@163.com [Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China); Cheng, Shukang [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001 (China); Department of Electrical Engineering, Harbin Institute of Technology, Harbin 150001 (China)

2016-11-01

Based on subdomain model, this paper presents an analytical method for predicting the no-load magnetic field distribution, back-EMF and torque in general spoke-type motors with magnetic bridges. Taking into account the saturation and nonlinearity of magnetic material, the magnetic bridges are equivalent to fan-shaped saturation regions. For getting standard boundary conditions, a lumped parameter magnetic circuit model and iterative method are employed to calculate the permeability. The final field domain is divided into five types of simple subdomains. Based on the method of separation of variables, the analytical expression of each subdomain is derived. The analytical results of the magnetic field distribution, Back-EMF and torque are verified by finite element method, which confirms the validity of the proposed model for facilitating the motor design and optimization. - Highlights: • The no-load magnetic field of poke-type motors is firstly calculated by analytical method. • The magnetic circuit model and iterative method are employed to calculate the permeability. • The analytical expression of each subdomain is derived.. • The proposed method can effectively reduce the predesign stages duration.

Analytical model and design of spoke-type permanent-magnet machines accounting for saturation and nonlinearity of magnetic bridges

International Nuclear Information System (INIS)

Liang, Peixin; Chai, Feng; Bi, Yunlong; Pei, Yulong; Cheng, Shukang

2016-01-01

Based on subdomain model, this paper presents an analytical method for predicting the no-load magnetic field distribution, back-EMF and torque in general spoke-type motors with magnetic bridges. Taking into account the saturation and nonlinearity of magnetic material, the magnetic bridges are equivalent to fan-shaped saturation regions. For getting standard boundary conditions, a lumped parameter magnetic circuit model and iterative method are employed to calculate the permeability. The final field domain is divided into five types of simple subdomains. Based on the method of separation of variables, the analytical expression of each subdomain is derived. The analytical results of the magnetic field distribution, Back-EMF and torque are verified by finite element method, which confirms the validity of the proposed model for facilitating the motor design and optimization. - Highlights: • The no-load magnetic field of poke-type motors is firstly calculated by analytical method. • The magnetic circuit model and iterative method are employed to calculate the permeability. • The analytical expression of each subdomain is derived.. • The proposed method can effectively reduce the predesign stages duration.

Accuracy of gastrocnemius muscles forces in walking and running goats predicted by one-element and two-element Hill-type models.

Science.gov (United States)

Lee, Sabrina S M; Arnold, Allison S; Miara, Maria de Boef; Biewener, Andrew A; Wakeling, James M

2013-09-03

Hill-type models are commonly used to estimate muscle forces during human and animal movement-yet the accuracy of the forces estimated during walking, running, and other tasks remains largely unknown. Further, most Hill-type models assume a single contractile element, despite evidence that faster and slower motor units, which have different activation-deactivation dynamics, may be independently or collectively excited. This study evaluated a novel, two-element Hill-type model with "differential" activation of fast and slow contractile elements. Model performance was assessed using a comprehensive data set (including measures of EMG intensity, fascicle length, and tendon force) collected from the gastrocnemius muscles of goats during locomotor experiments. Muscle forces predicted by the new two-element model were compared to the forces estimated using traditional one-element models and to the forces measured in vivo using tendon buckle transducers. Overall, the two-element model resulted in the best predictions of in vivo gastrocnemius force. The coefficient of determination, r(2), was up to 26.9% higher and the root mean square error, RMSE, was up to 37.4% lower for the two-element model than for the one-element models tested. All models captured salient features of the measured muscle force during walking, trotting, and galloping (r(2)=0.26-0.51), and all exhibited some errors (RMSE=9.63-32.2% of the maximum in vivo force). These comparisons provide important insight into the accuracy of Hill-type models. The results also show that incorporation of fast and slow contractile elements within muscle models can improve estimates of time-varying, whole muscle force during locomotor tasks. Copyright © 2013 Elsevier Ltd. All rights reserved.

Late-intervention study with ebselen in an experimental model of type 1 diabetic nephropathy.

Science.gov (United States)

Tan, S M; Sharma, A; Stefanovic, N; de Haan, J B

2015-03-01

Previous studies have shown that preventive treatment with the antioxidant, ebselen, in experimental models of type 1 diabetic nephropathy resulted in an attenuation of structural and functional damage in the kidney. However, evidence for the effectiveness of ebselen in late-intervention studies is lacking. Thus, we aimed to investigate the effects of ebselen in attenuating established renal injury in type 1 diabetic nephropathy using the Akita mouse model. Baseline blood glucose and albumin-to-creatinine ratio (ACR) were measured in wild-type (WT) and heterozygous Akita mice at 9 weeks of age. At 10 weeks of age, WT and Akita mice were randomized to receive either vehicle (5% carboxymethyl cellulose) or ebselen by oral gavage at 10mg/kg twice daily. Kidney and urine were collected after 16 weeks of treatment with ebselen for histological and functional analyses. At 9 weeks of age, Akita mice displayed well-established renal dysfunction with significant increases in ACR and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels when compared with WT controls. After 16 weeks of treatment with ebselen, oxidative stress, as measured by nitrotyrosine immunostaining and urinary 8-OHdG levels, was significantly reduced in the Akita mice. Furthermore, gene expression of the major reactive oxygen species-producing nicotinamide adenine dinucleotide phosphate enzyme, Nox4, was also reduced by ebselen. However, ebselen had no effect on ACR and glomerulosclerosis. Chronic treatment with ebselen significantly reduced oxidative stress in the Akita mice. However, ebselen failed to attenuate functional or structural kidney damage in this late-intervention study using the Akita mouse model.

Generalized Path Analysis and Generalized Simultaneous Equations Model for Recursive Systems with Responses of Mixed Types

Science.gov (United States)

Tsai, Tien-Lung; Shau, Wen-Yi; Hu, Fu-Chang

2006-01-01

This article generalizes linear path analysis (PA) and simultaneous equations models (SiEM) to deal with mixed responses of different types in a recursive or triangular system. An efficient instrumental variable (IV) method for estimating the structural coefficients of a 2-equation partially recursive generalized path analysis (GPA) model and…

Understanding and modeling Förster-type resonance energy transfer (FRET)

CERN Document Server

Hernández Martínez, Pedro Ludwig; Demir, Hilmi Volkan

2017-01-01

This Brief presents a complete study of the generalized theory of Förster-type energy transfer in nanostructures with mixed dimensionality. Here the aim is to obtain a generalized theory of FRET including a comprehensive set of analytical equations for all combinations and configurations of nanostructures and deriving generic expressions for the dimensionality involved. In this brief, the modification of FRET mechanism with respect to the nanostructure serving as the donor vs. the acceptor will be included, focusing on the rate’s distance dependency and the role of the effective dielectric function in FRET, which will be a unique, useful source for those who study and model FRET.

An Empirical Model for Vane-Type Vortex Generators in a Navier-Stokes Code

Science.gov (United States)

Dudek, Julianne C.

2005-01-01

An empirical model which simulates the effects of vane-type vortex generators in ducts was incorporated into the Wind-US Navier-Stokes computational fluid dynamics code. The model enables the effects of the vortex generators to be simulated without defining the details of the geometry within the grid, and makes it practical for researchers to evaluate multiple combinations of vortex generator arrangements. The model determines the strength of each vortex based on the generator geometry and the local flow conditions. Validation results are presented for flow in a straight pipe with a counter-rotating vortex generator arrangement, and the results are compared with experimental data and computational simulations using a gridded vane generator. Results are also presented for vortex generator arrays in two S-duct diffusers, along with accompanying experimental data. The effects of grid resolution and turbulence model are also examined.

The use of typed lambda calculus for comprehension and construction of simulation models in the domain of ecology

Science.gov (United States)

Uschold, Michael

1992-01-01

We are concerned with two important issues in simulation modelling: model comprehension and model construction. Model comprehension is limited because many important choices taken during the modelling process are not documented. This makes it difficult for models to be modified or used by others. A key factor hindering model construction is the vast modelling search space which must be navigated. This is exacerbated by the fact that many modellers are unfamiliar with the terms and concepts catered to by current tools. The root of both problems is the lack of facilities for representing or reasoning about domain concepts in current simulation technology. The basis for our achievements in both of these areas is the development of a language with two distinct levels; one for representing domain information, and the other for representing the simulation model. Of equal importance, is the fact that we make formal connections between these two levels. The domain we are concerned with is ecological modelling. This language, called Elklogic, is based on the typed lambda calculus. Important features include a rich type structure, the use of various higher order functions, and semantics. This enables complex expressions to be constructed from relatively few primitives. The meaning of each expression can be determined in terms of the domain, the simulation model, or the relationship between the two. We describe a novel representation for sets and substructure, and a variety of other general concepts that are especially useful in the ecological domain. We use the type structure in a novel way: for controlling the modelling search space, rather than a proof search space. We facilitate model comprehension by representing modelling decisions that are embodied in the simulation model. We represent the simulation model separately from, but in terms of a domain mode. The explicit links between the two models constitute the modelling decisions. The semantics of Elklogic enables

Use of circulation types classifications to evaluate AR4 climate models over the Euro-Atlantic region

Energy Technology Data Exchange (ETDEWEB)

Pastor, M.A.; Casado, M.J. [Agencia Estatal de Meteorologia (AEMET), Madrid (Spain)

2012-10-15

This paper presents an evaluation of the multi-model simulations for the 4th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) in terms of their ability to simulate the ERA40 circulation types over the Euro-Atlantic region in winter season. Two classification schemes, k-means and SANDRA, have been considered to test the sensitivity of the evaluation results to the classification procedure. The assessment allows establishing different rankings attending spatial and temporal features of the circulation types. Regarding temporal characteristics, in general, all AR4 models tend to underestimate the frequency of occurrence. The best model simulating spatial characteristics is the UKMO-HadGEM1 whereas CCSM3, UKMO-HadGEM1 and CGCM3.1(T63) are the best simulating the temporal features, for both classification schemes. This result agrees with the AR4 models ranking obtained when having analysed the ability of the same AR4 models to simulate Euro-Atlantic variability modes. This study has proved the utility of applying such a synoptic climatology approach as a diagnostic tool for models' assessment. The ability of the models to properly reproduce the position of ridges and troughs and the frequency of synoptic patterns, will therefore improve our confidence in the response of models to future climate changes. (orig.)

An estimation framework for building information modeling (BIM)-based demolition waste by type.

Science.gov (United States)

Kim, Young-Chan; Hong, Won-Hwa; Park, Jae-Woo; Cha, Gi-Wook

2017-12-01

Most existing studies on demolition waste (DW) quantification do not have an official standard to estimate the amount and type of DW. Therefore, there are limitations in the existing literature for estimating DW with a consistent classification system. Building information modeling (BIM) is a technology that can generate and manage all the information required during the life cycle of a building, from design to demolition. Nevertheless, there has been a lack of research regarding its application to the demolition stage of a building. For an effective waste management plan, the estimation of the type and volume of DW should begin from the building design stage. However, the lack of tools hinders an early estimation. This study proposes a BIM-based framework that estimates DW in the early design stages, to achieve an effective and streamlined planning, processing, and management. Specifically, the input of construction materials in the Korean construction classification system and those in the BIM library were matched. Based on this matching integration, the estimates of DW by type were calculated by applying the weight/unit volume factors and the rates of DW volume change. To verify the framework, its operation was demonstrated by means of an actual BIM modeling and by comparing its results with those available in the literature. This study is expected to contribute not only to the estimation of DW at the building level, but also to the automated estimation of DW at the district level.

Inelastic response of PCRV structure model with star-type support under horizontal loads

International Nuclear Information System (INIS)

Suzuki, T.; Yamaguchi, T.; Takeda, T.

1978-01-01

The report presents the test results of scaled models for prestressed concrete reactor vessel (PCRV) structure with star-shaped support under horizontal loads. A scale factor of 1 / 70 to a proto-type PCRV structure for large HTGR is used for both static and dynamic loading test models, while a 1 / 15 scaled model is used for static loading tests. The static behaviors such as a load-deflection envelope of the 1 / 70 model are predicted well by an inelastic analysis in consideration with appearance of concrete cracks and reinforcing bar yielding. It is also ascertained by the test results of the 1 / 15 model under static alternative loads that the same analysis procedure can be applicable to the evaluation of the elastic and inelastic behaviors of PCRV structure with support. Based on the static loading test results of both scaled models, a tri-linearized load-deflection envelope and an equivalent linearized mathematical model for hysteresis loop are assumed in a dynamic analysis. A dynamic response analysis of the 1 / 70 model subjected to earthquake-like base motion is conducted by the similar manner above-mentioned and the calculated results show a good correlation with the test results

Distribution of phytoplankton functional types in high-nitrate low-chlorophyll waters in a new diagnostic ecological indicator model

DEFF Research Database (Denmark)

Palacz, Artur; St. John, Michael; Brevin, R.J.W.

2013-01-01

Modeling and monitoring plankton functional types (PFTs) is challenged by insufficient amount of field measurements to ground-truth both plankton models and bio-optical algorithms. In this study, we combine remote sensing data and a dynamic plankton model to simulate an ecologically-sound spatial...

Modeling the differentiation of A- and C-type baroreceptor firing patterns

DEFF Research Database (Denmark)

Sturdy, Jacob; Ottesen, Johnny T.; Olufsen, Mette

2017-01-01

The baroreceptor neurons serve as the primary transducers of blood pressure for the autonomic nervous system and are thus critical in enabling the body to respond effectively to changes in blood pressure. These neurons can be separated into two types (A and C) based on the myelination...... of their axons and their distinct firing patterns elicited in response to specific pressure stimuli. This study has developed a comprehensive model of the afferent baroreceptor discharge built on physiological knowledge of arterial wall mechanics, firing rate responses to controlled pressure stimuli, and ion...

Dynamics of a Lotka-Volterra type model with applications to marine phage population dynamics

International Nuclear Information System (INIS)

Gavin, C; Pokrovskii, A; Prentice, M; Sobolev, V

2006-01-01

The famous Lotka-Volterra equations play a fundamental role in the mathematical modeling of various ecological and chemical systems. A new modification of these equations has been recently suggested to model the structure of marine phage populations, which are the most abundant biological entities in the biosphere. The purpose of the paper is: (i) to make some methodical remarks concerning this modification; (ii) to discuss new types of canards which arise naturally in this context; (iii) to present results of some numerical experiments

The computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in Northern Xinjiang, China

Energy Technology Data Exchange (ETDEWEB)

Zhengbang, Wang; Mingkuan, Qin; Ruiquan, Zhao; Shenghuang, Tang [Beijing Research Inst. of Uranium Geology, CNNC (China); Baoqun, Wang; Shuangxing, Lin [Geo-prospecting Team No. 216, CNNC (China)

2001-08-01

The process of establishment of the model includes following steps: (1) Systematically studying a known typical in-situ leachable sandstone type uranium deposit--Deposit No. 512 in Yili basin, analyzing its controlling factors and establishing its metallogenetic model; (2) Establishing the metallogenetic models of this type of uranium deposit and uranium-bearing area on the basis of comparison study on the deposit No. 512 with the same type uranium deposits in the world; (3) Creating the computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in northern Xinjiang; (4) Determining the standards of giving a evaluation-mark for each controlling factor of in-situ leachable sandstone type uranium deposit and uranium-bearing area; (5) Evaluating uranium potential and prospect of the unknown objective target.

The computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in Northern Xinjiang, China

International Nuclear Information System (INIS)

Wang Zhengbang; Qin Mingkuan; Zhao Ruiquan; Tang Shenghuang; Wang Baoqun; Lin Shuangxing

2001-01-01

The process of establishment of the model includes following steps: (1) Systematically studying a known typical in-situ leachable sandstone type uranium deposit--Deposit No. 512 in Yili basin, analyzing its controlling factors and establishing its metallogenetic model; (2) Establishing the metallogenetic models of this type of uranium deposit and uranium-bearing area on the basis of comparison study on the deposit No. 512 with the same type uranium deposits in the world; (3) Creating the computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in northern Xinjiang; (4) Determining the standards of giving a evaluation-mark for each controlling factor of in-situ leachable sandstone type uranium deposit and uranium-bearing area; (5) Evaluating uranium potential and prospect of the unknown objective target

Models of Parenting: Implications for Adolescent Well-Being within Different Types of Family Contexts.

Science.gov (United States)

Shucksmith, J.; And Others

1995-01-01

Examines parenting models and parent-child relationships from early to middle adolescence. Focuses on implications for adolescent functioning, including school integration and psychological well being. Results identify four distinct types of parenting styles characterized by different degrees of acceptance and control of young people's behavior.…

Cosmological parameter uncertainties from SALT-II type Ia supernova light curve models

International Nuclear Information System (INIS)

Mosher, J.; Sako, M.; Guy, J.; Astier, P.; Betoule, M.; El-Hage, P.; Pain, R.; Regnault, N.; Kessler, R.; Frieman, J. A.; Marriner, J.; Biswas, R.; Kuhlmann, S.; Schneider, D. P.

2014-01-01

We use simulated type Ia supernova (SN Ia) samples, including both photometry and spectra, to perform the first direct validation of cosmology analysis using the SALT-II light curve model. This validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and a bias on the dark energy equation of state parameter w. Using the SN-analysis package SNANA, we simulate and analyze realistic samples corresponding to the data samples used in the SNLS3 analysis: ∼120 low-redshift (z < 0.1) SNe Ia, ∼255 Sloan Digital Sky Survey SNe Ia (z < 0.4), and ∼290 SNLS SNe Ia (z ≤ 1). To probe systematic uncertainties in detail, we vary the input spectral model, the model of intrinsic scatter, and the smoothing (i.e., regularization) parameters used during the SALT-II model training. Using realistic intrinsic scatter models results in a slight bias in the ultraviolet portion of the trained SALT-II model, and w biases (w input – w recovered ) ranging from –0.005 ± 0.012 to –0.024 ± 0.010. These biases are indistinguishable from each other within the uncertainty; the average bias on w is –0.014 ± 0.007.

Cosmological Parameter Uncertainties from SALT-II Type Ia Supernova Light Curve Models

Energy Technology Data Exchange (ETDEWEB)

Mosher, J. [Pennsylvania U.; Guy, J. [LBL, Berkeley; Kessler, R. [Chicago U., KICP; Astier, P. [Paris U., VI-VII; Marriner, J. [Fermilab; Betoule, M. [Paris U., VI-VII; Sako, M. [Pennsylvania U.; El-Hage, P. [Paris U., VI-VII; Biswas, R. [Argonne; Pain, R. [Paris U., VI-VII; Kuhlmann, S. [Argonne; Regnault, N. [Paris U., VI-VII; Frieman, J. A. [Fermilab; Schneider, D. P. [Penn State U.

2014-08-29

We use simulated type Ia supernova (SN Ia) samples, including both photometry and spectra, to perform the first direct validation of cosmology analysis using the SALT-II light curve model. This validation includes residuals from the light curve training process, systematic biases in SN Ia distance measurements, and a bias on the dark energy equation of state parameter w. Using the SN-analysis package SNANA, we simulate and analyze realistic samples corresponding to the data samples used in the SNLS3 analysis: ~120 low-redshift (z < 0.1) SNe Ia, ~255 Sloan Digital Sky Survey SNe Ia (z < 0.4), and ~290 SNLS SNe Ia (z ≤ 1). To probe systematic uncertainties in detail, we vary the input spectral model, the model of intrinsic scatter, and the smoothing (i.e., regularization) parameters used during the SALT-II model training. Using realistic intrinsic scatter models results in a slight bias in the ultraviolet portion of the trained SALT-II model, and w biases (w (input) – w (recovered)) ranging from –0.005 ± 0.012 to –0.024 ± 0.010. These biases are indistinguishable from each other within the uncertainty, the average bias on w is –0.014 ± 0.007.

Neuropathogenesis of Zika Virus in a Highly Susceptible Immunocompetent Mouse Model after Antibody Blockade of Type I Interferon.

Directory of Open Access Journals (Sweden)

Darci R Smith

2017-01-01

Full Text Available Animal models are needed to better understand the pathogenic mechanisms of Zika virus (ZIKV and to evaluate candidate medical countermeasures. Adult mice infected with ZIKV develop a transient viremia, but do not demonstrate signs of morbidity or mortality. Mice deficient in type I or a combination of type I and type II interferon (IFN responses are highly susceptible to ZIKV infection; however, the absence of a competent immune system limits their usefulness for studying medical countermeasures. Here we employ a murine model for ZIKV using wild-type C57BL/6 mice treated with an antibody to disrupt type I IFN signaling to study ZIKV pathogenesis. We observed 40% mortality in antibody treated mice exposed to ZIKV subcutaneously whereas mice exposed by intraperitoneal inoculation were highly susceptible incurring 100% mortality. Mice infected by both exposure routes experienced weight loss, high viremia, and severe neuropathologic changes. The most significant histopathological findings occurred in the central nervous system where lesions represent an acute to subacute encephalitis/encephalomyelitis that is characterized by neuronal death, astrogliosis, microgliosis, scattered necrotic cellular debris, and inflammatory cell infiltrates. This model of ZIKV pathogenesis will be valuable for evaluating medical countermeasures and the pathogenic mechanisms of ZIKV because it allows immune responses to be elicited in immunologically competent mice with IFN I blockade only induced at the time of infection.

Molecular model of a type III secretion system needle: Implications for host-cell sensing.

Science.gov (United States)

Deane, Janet E; Roversi, Pietro; Cordes, Frank S; Johnson, Steven; Kenjale, Roma; Daniell, Sarah; Booy, Frank; Picking, William D; Picking, Wendy L; Blocker, Ariel J; Lea, Susan M

2006-08-15

Type III secretion systems are essential virulence determinants for many Gram-negative bacterial pathogens. The type III secretion system consists of cytoplasmic, transmembrane, and extracellular domains. The extracellular domain is a hollow needle protruding above the bacterial surface and is held within a basal body that traverses both bacterial membranes. Effector proteins are translocated, via this external needle, directly into host cells, where they subvert normal cell functions to aid infection. Physical contact with host cells initiates secretion and leads to formation of a pore, thought to be contiguous with the needle channel, in the host-cell membrane. Here, we report the crystal structure of the Shigella flexneri needle subunit MxiH and a complete model for the needle assembly built into our three-dimensional EM reconstruction. The model, combined with mutagenesis data, reveals that signaling of host-cell contact is relayed through the needle via intersubunit contacts and suggests a mode of binding for a tip complex.

The Importance of Non-neuronal Cell Types in hiPSC-Based Disease Modeling and Drug Screening

Directory of Open Access Journals (Sweden)

David M. Gonzalez

2017-12-01

Full Text Available Current applications of human induced pluripotent stem cell (hiPSC technologies in patient-specific models of neurodegenerative and neuropsychiatric disorders tend to focus on neuronal phenotypes. Here, we review recent efforts toward advancing hiPSCs toward non-neuronal cell types of the central nervous system (CNS and highlight their potential use for the development of more complex in vitro models of neurodevelopment and disease. We present evidence from previous works in both rodents and humans of the importance of these cell types (oligodendrocytes, microglia, astrocytes in neurological disease and highlight new hiPSC-based models that have sought to explore these relationships in vitro. Lastly, we summarize efforts toward conducting high-throughput screening experiments with hiPSCs and propose methods by which new screening platforms could be designed to better capture complex relationships between neural cell populations in health and disease.

Evaluation of optimal control type models for the human gunner in an Anti-Aircraft Artillery (AAA) system

Science.gov (United States)

Phatak, A. V.; Kessler, K. M.

1975-01-01

The selection of the structure of optimal control type models for the human gunner in an anti aircraft artillery system is considered. Several structures within the LQG framework may be formulated. Two basic types are considered: (1) kth derivative controllers; and (2) proportional integral derivative (P-I-D) controllers. It is shown that a suitable criterion for model structure determination can be based on the ensemble statistics of the tracking error. In the case when the ensemble tracking steady state error is zero, it is suggested that a P-I-D controller formulation be used in preference to the kth derivative controller.

Predictability of two types of El Niño and their climate impacts in boreal spring to summer in coupled models

Science.gov (United States)

Lee, Ray Wai-Ki; Tam, Chi-Yung; Sohn, Soo-Jin; Ahn, Joong-Bae

2017-12-01

The predictability of the two El Niño types and their different impacts on the East Asian climate from boreal spring to summer have been studied, based on coupled general circulation models (CGCM) simulations from the APEC Climate Center (APCC) multi-model ensemble (MME) hindcast experiments. It was found that both the spatial pattern and temporal persistence of canonical (eastern Pacific type) El Niño sea surface temperature (SST) are much better simulated than those for El Niño Modoki (central Pacific type). In particular, most models tend to have El Niño Modoki events that decay too quickly, in comparison to those observed. The ability of these models in distinguishing between the two types of ENSO has also been assessed. Based on the MME average, the two ENSO types become less and less differentiated in the model environment as the forecast leadtime increases. Regarding the climate impact of ENSO, in spring during canonical El Niño, coupled models can reasonably capture the anomalous low-level anticyclone over the western north Pacific (WNP)/Philippine Sea area, as well as rainfall over coastal East Asia. However, most models have difficulties in predicting the springtime dry signal over Indochina to South China Sea (SCS) when El Niño Modoki occurs. This is related to the location of the simulated anomalous anticyclone in this region, which is displaced eastward over SCS relative to the observed. In boreal summer, coupled models still exhibit some skills in predicting the East Asian rainfall during canonical El Nino, but not for El Niño Modoki. Overall, models' performance in spring to summer precipitation forecasts is dictated by their ability in capturing the low-level anticyclonic feature over the WNP/SCS area. The latter in turn is likely to be affected by the realism of the time mean monsoon circulation in models.

Glycogen Storage Disease Type Ia in Canines: A Model for Human Metabolic and Genetic Liver Disease

OpenAIRE

Specht, Andrew; Fiske, Laurie; Erger, Kirsten; Cossette, Travis; Verstegen, John; Campbell-Thompson, Martha; Struck, Maggie B.; Lee, Young Mok; Chou, Janice Y.; Byrne, Barry J.; Correia, Catherine E.; Mah, Cathryn S.; Weinstein, David A.; Conlon, Thomas J.

2011-01-01

A canine model of Glycogen storage disease type Ia (GSDIa) is described. Affected dogs are homozygous for a previously described M121I mutation resulting in a deficiency of glucose-6-phosphatase-α. Metabolic, clinicopathologic, pathologic, and clinical manifestations of GSDIa observed in this model are described and compared to those observed in humans. The canine model shows more complete recapitulation of the clinical manifestations seen in humans including “lactic acidosis”, larger size,...

Description of two-metal biosorption equilibria by Langmuir-type models.

Science.gov (United States)

Chong, K H; Volesky, B

1995-08-20

A biosorbent prepared from Ascophyllum nodosum seaweed biomass, FCAN2, was examined for its sorption capacity. Equilibrium batch sorption studies were performed using two-matal systems containing either (Cu + Zn), (Cu + Cd), or (Zn + Cd). In the evaluation of the two-metal sorption system performance, simple isotherm curves had to be replaced by three-dimensional sorption isotherm surfaces. In order to describe the isotherm surfaces mathematically, three Langmuir-type models were evaluated. The apparent one-parameter Langmuir constant (b) was used to quantify FCAN2 "affinity" for one metal in the presence of another one. The uptake of Zn decreased drastically when Cu or Cd were present. The uptake of Cd wasmuch more sensitive to the presence of Cu than to that of Zn. The presence of Cd and Zn alter the "affinity" of FCAN2 for Cu the least at high Cu equilibrium concentrations. The mathematical model of the two-metal sorption system enabled quantitative estimation of one-metal (bio)sorption inhibition due to the influence of a second metal. (c) 1995 John Wiley & Sons Inc.

Developing Poultry Facility Type Information from USDA Agricultural Census Data for Use in Epidemiological and Economic Models

Energy Technology Data Exchange (ETDEWEB)

Melius, C

2007-12-05

The epidemiological and economic modeling of poultry diseases requires knowing the size, location, and operational type of each poultry type operation within the US. At the present time, the only national database of poultry operations that is available to the general public is the USDA's 2002 Agricultural Census data, published by the National Agricultural Statistics Service, herein referred to as the 'NASS data'. The NASS data provides census data at the county level on poultry operations for various operation types (i.e., layers, broilers, turkeys, ducks, geese). However, the number of farms and sizes of farms for the various types are not independent since some facilities have more than one type of operation. Furthermore, some data on the number of birds represents the number sold, which does not represent the number of birds present at any given time. In addition, any data tabulated by NASS that could identify numbers of birds or other data reported by an individual respondent is suppressed by NASS and coded with a 'D'. To be useful for epidemiological and economic modeling, the NASS data must be converted into a unique set of facility types (farms having similar operational characteristics). The unique set must not double count facilities or birds. At the same time, it must account for all the birds, including those for which the data has been suppressed. Therefore, several data processing steps are required to work back from the published NASS data to obtain a consistent database for individual poultry operations. This technical report documents data processing steps that were used to convert the NASS data into a national poultry facility database with twenty-six facility types (7 egg-laying, 6 broiler, 1 backyard, 3 turkey, and 9 others, representing ducks, geese, ostriches, emus, pigeons, pheasants, quail, game fowl breeders and 'other'). The process involves two major steps. The first step defines the rules used to