Sample records for automated modelling interface

  1. Testing of the Automated Fluid Interface System

    NASA Technical Reports Server (NTRS)

    Johnston, A. S.; Tyler, Tony R.

    1998-01-01

    The Automated Fluid Interface System (AFIS) is an advanced development prototype satellite servicer. The device was designed to transfer consumables from one spacecraft to another. An engineering model was built and underwent development testing at Marshall Space Flight Center. While the current AFIS is not suitable for spaceflight, testing and evaluation of the AFIS provided significant experience which would be beneficial in building a flight unit.

  2. Adaptation in automated user-interface design

    Microsoft Academic Search

    Jacob Eisenstein; Angel R. Puerta

    2000-01-01

    Design problems involve issues of stylistic preference and flexible standards of success; human designers often proceed by intuition and are unaware of following any strict rule-based procedures. These features make design tasks especially difficult to automate. Adaptation is proposed as a means to overcome these challenges. We describe a system that applies an adaptive algorithm to automated user interface design

  3. Development and testing of the Automated Fluid Interface System

    NASA Technical Reports Server (NTRS)

    Milton, Martha E.; Tyler, Tony R.

    1993-01-01

    The Automated Fluid Interface System (AFIS) is an advanced development program aimed at becoming the standard interface for satellite servicing for years to come. The AFIS will be capable of transferring propellants, fluids, gasses, power, and cryogens from a tanker to an orbiting satellite. The AFIS program currently under consideration is a joint venture between the NASA/Marshall Space Flight Center and Moog, Inc. An engineering model has been built and is undergoing development testing to investigate the mechanism's abilities.

  4. Semi-automated in vivo solid-phase microextraction sampling and the diffusion-based interface calibration model to determine the pharmacokinetics of methoxyfenoterol and fenoterol in rats.

    PubMed

    Yeung, Joanne Chung Yan; de Lannoy, Inés; Gien, Brad; Vuckovic, Dajana; Yang, Yingbo; Bojko, Barbara; Pawliszyn, Janusz

    2012-09-12

    In vivo solid-phase microextraction (SPME) can be used to sample the circulating blood of animals without the need to withdraw a representative blood sample. In this study, in vivo SPME in combination with liquid-chromatography tandem mass spectrometry (LC-MS/MS) was used to determine the pharmacokinetics of two drug analytes, R,R-fenoterol and R,R-methoxyfenoterol, administered as 5 mg kg(-1) i.v. bolus doses to groups of 5 rats. This research illustrates, for the first time, the feasibility of the diffusion-based calibration interface model for in vivo SPME studies. To provide a constant sampling rate as required for the diffusion-based interface model, partial automation of the SPME sampling of the analytes from the circulating blood was accomplished using an automated blood sampling system. The use of the blood sampling system allowed automation of all SPME sampling steps in vivo, except for the insertion and removal of the SPME probe from the sampling interface. The results from in vivo SPME were compared to the conventional method based on blood withdrawal and sample clean up by plasma protein precipitation. Both whole blood and plasma concentrations were determined by the conventional method. The concentrations of methoxyfenoterol and fenoterol obtained by SPME generally concur with the whole blood concentrations determined by the conventional method indicating the utility of the proposed method. The proposed diffusion-based interface model has several advantages over other kinetic calibration models for in vivo SPME sampling including (i) it does not require the addition of a standard into the sample matrix during in vivo studies, (ii) it is simple and rapid and eliminates the need to pre-load appropriate standard onto the SPME extraction phase and (iii) the calibration constant for SPME can be calculated based on the diffusion coefficient, extraction time, fiber length and radius, and size of the boundary layer. In the current study, the experimental calibration constants of 338.9±30 mm(-3) and 298.5±25 mm(-3) are in excellent agreement with the theoretical calibration constants of 307.9 mm(-3) and 316.0 mm(-3) for fenoterol and methoxyfenoterol respectively. PMID:22884205

  5. Automated Student Model Improvement

    ERIC Educational Resources Information Center

    Koedinger, Kenneth R.; McLaughlin, Elizabeth A.; Stamper, John C.

    2012-01-01

    Student modeling plays a critical role in developing and improving instruction and instructional technologies. We present a technique for automated improvement of student models that leverages the DataShop repository, crowd sourcing, and a version of the Learning Factors Analysis algorithm. We demonstrate this method on eleven educational…

  6. Automation Interfaces of the Orion GNC Executive Architecture

    NASA Technical Reports Server (NTRS)

    Hart, Jeremy

    2009-01-01

    This viewgraph presentation describes Orion mission's automation Guidance, Navigation and Control (GNC) architecture and interfaces. The contents include: 1) Orion Background; 2) Shuttle/Orion Automation Comparison; 3) Orion Mission Sequencing; 4) Orion Mission Sequencing Display Concept; and 5) Status and Forward Plans.

  7. User interface design for an automated part recognition system

    E-print Network

    Avitts, Tommie Annette

    1991-01-01

    USER INTERFACE DESIGN FOR AN AUTOMATED PART RECOGNITION SYSTEM A Thesis by TOMMIE ANNETTE AVITTS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1991 Major Subject: Industrial Engineering USER INTERFACE DESIGN FOR AN AUTOMATED PART RECOGNITION SYSTEM A Thesis by TOMMIE ANNETTE AVITTS Approved as to style and content by: Deborah A. Mitts (Co-Chair of Committee) R, Dale Huching...

  8. Adaptation in Automated User-Interface Design Jacob Eisenstein and Angel Puerta

    E-print Network

    Adaptation in Automated User-Interface Design Jacob Eisenstein and Angel Puerta RedWhale Software these challenges. We describe a system that applies an adaptive algorithm to automated user interface design within experiments indicate that adaptation improves the performance of the automated user interface design system

  9. Space station automation and robotics study. Operator-systems interface

    NASA Technical Reports Server (NTRS)

    1984-01-01

    This is the final report of a Space Station Automation and Robotics Planning Study, which was a joint project of the Boeing Aerospace Company, Boeing Commercial Airplane Company, and Boeing Computer Services Company. The study is in support of the Advanced Technology Advisory Committee established by NASA in accordance with a mandate by the U.S. Congress. Boeing support complements that provided to the NASA Contractor study team by four aerospace contractors, the Stanford Research Institute (SRI), and the California Space Institute. This study identifies automation and robotics (A&R) technologies that can be advanced by requirements levied by the Space Station Program. The methodology used in the study is to establish functional requirements for the operator system interface (OSI), establish the technologies needed to meet these requirements, and to forecast the availability of these technologies. The OSI would perform path planning, tracking and control, object recognition, fault detection and correction, and plan modifications in connection with extravehicular (EV) robot operations.

  10. On the Interface Debonding Models

    Microsoft Academic Search

    J. L. Chaboche; R. Girard; P. Levasseur

    1997-01-01

    Interface debonding models offer the possibility to simulate numerically the interface crack growth, and the eventual contact friction behaviour on the cracked area. The paper considers models in the framework of an Interface Damage Mechanics, relating displacement discontinuities across the interface to the corresponding tractions, through various constitutive and damage equations. The approach is based on the initial works by

  11. Sharing Control Between Human and Automation Using Haptic Interface: Primary and

    E-print Network

    Gillespie, Brent

    Sharing Control Between Human and Automation Using Haptic Interface: Primary and Secondary Task-- In this paper, a paradigm for hu- man/automation control sharing is described in which a machine's manual the actions of the automatic controller. While perceiving the automation actions, the human may express his

  12. Spherical model of growing interfaces

    E-print Network

    Henkel, Malte

    2015-01-01

    Building on an analogy between the ageing behaviour of magnetic systems and growing interfaces, the Arcetri model, a new exactly solvable model for growing interfaces is introduced, which shares many properties with the kinetic spherical model. The long-time behaviour of the interface width and of the two-time correlators and responses is analysed. For all dimensions $d\

  13. Automation in teleoperation from a man-machine interface viewpoint

    NASA Technical Reports Server (NTRS)

    Bejczy, A. K.; Corker, K.

    1984-01-01

    Teleoperation can be defined as the use of robotic devices having mobility, manipulative and some sensing capabilities, and remotely controlled by a human operator. The purpose of this paper is to discuss and exemplify technology issues related to the use of robots as man-extension or teleoperator systems in space. The main thrust of the paper is focused at research and development in the area of sensing- and computer-based automation from the viewpoint of man-machine interface devices and techniques. The objective of this R and D effort is to render space teleoperation efficient and safe through the use of devices and techniques which will permit integrated and task-level ('intelligent') two-way control communication between human operator and teleoperator machine in earth orbit.

  14. Automated ultrareliability models - A review

    NASA Technical Reports Server (NTRS)

    Bridgman, M. S.; Ness, W. G.

    1984-01-01

    Analytic models are required to assess the reliability of systems designed to ultrareliability requirements. This paper reviews the capabilities and limitations of five currently available automated reliability models which are applicable to fault-tolerant flight control systems. 'System' includes sensors, computers, and actuators. A set of review criteria including validation, configuration adaptability, and resource requirements for model evaluation are described. Five models, ARIES, CARE II, CARE III, CARSRA, and CAST, are assessed against the criteria, thereby characterizing their capabilities and limitations. This review should be helpful to potential users of the models.

  15. Semi-Automated Linking of User Interface Design Artifacts

    Microsoft Academic Search

    Said Elnaffar; Nicholas C. Graham

    1999-01-01

    User centered design involves the creation of design artifacts such as task and architecture models, typically by people with different backgrounds using inconsistent terminology. Communication between user interface designers can potentially be improved if the viewpoints represented by these design artifacts can be correlated. This research demonstrates how different design artifacts can be linked semi-automatically. We illustrate this technique using

  16. Automated semiconductor modeling

    NASA Astrophysics Data System (ADS)

    Tobak, John P.

    1987-05-01

    A procedure is presented for the automatic creation of diode and transistor models used by the circuit and systems analysis computer program SUPER*SCEPTRE. A Hewlett Packard 9816s microcomputer and 4145B semiconductor parameter analyzer are used to control the process.

  17. Automated semiconductor modeling

    Microsoft Academic Search

    John P. Tobak

    1987-01-01

    A procedure is presented for the automatic creation of diode and transistor models used by the circuit and systems analysis computer program SUPER*SCEPTRE. A Hewlett Packard 9816s microcomputer and 4145B semiconductor parameter analyzer are used to control the process.

  18. Database-driven web interface automating gyrokinetic simulations for validation

    NASA Astrophysics Data System (ADS)

    Ernst, D. R.

    2010-11-01

    We are developing a web interface to connect plasma microturbulence simulation codes with experimental data. The website automates the preparation of gyrokinetic simulations utilizing plasma profile and magnetic equilibrium data from TRANSP analysis of experiments, read from MDSPLUS over the internet. This database-driven tool saves user sessions, allowing searches of previous simulations, which can be restored to repeat the same analysis for a new discharge. The website includes a multi-tab, multi-frame, publication quality java plotter Webgraph, developed as part of this project. Input files can be uploaded as templates and edited with context-sensitive help. The website creates inputs for GS2 and GYRO using a well-tested and verified back-end, in use for several years for the GS2 code [D. R. Ernst et al., Phys. Plasmas 11(5) 2637 (2004)]. A centralized web site has the advantage that users receive bug fixes instantaneously, while avoiding the duplicated effort of local compilations. Possible extensions to the database to manage run outputs, toward prototyping for the Fusion Simulation Project, are envisioned. Much of the web development utilized support from the DoE National Undergraduate Fellowship program [e.g., A. Suarez and D. R. Ernst, http://meetings.aps.org/link/BAPS.2005.DPP.GP1.57.

  19. An Automated System for Converting App Inventor Apps to Java Interface For Creating and Managing Projects

    E-print Network

    Gray, Jeffrey G.

    An Automated System for Converting App Inventor Apps to Java Interface For Creating and Managing Projects Drag And Drop Components App Is Fully Laid Out Christopher Hodapp (Student) The Univeristy of Computer Science Graphical Environment For Creating Layouts MIT App Inventor An Automated System

  20. The state of the art in automating usability evaluation of user interfaces

    Microsoft Academic Search

    Melody Y. Ivory; Marti A. Hearst

    2001-01-01

    Usability evaluation is an increasingly important part of the user interface design process. However, usability evaluation can be expensive in terms of time and human resources, and automation is therefore a promising way to augment existing approaches. This article presents an extensive survey of usability evaluation methods, organized according to a new taxonomy that emphasizes the role of automation. The

  1. On Abstractions and Simplifications in the Design of Human-Automation Interfaces

    NASA Technical Reports Server (NTRS)

    Heymann, Michael; Degani, Asaf; Clancy, Daniel (Technical Monitor)

    2002-01-01

    This report addresses the design of human-automation interaction from a formal perspective that focuses on the information content of the interface, rather than the design of the graphical user interface. It also addresses the issue of the information provided to the user (e.g., user-manuals, training material, and all other resources). In this report, we propose a formal procedure for generating interfaces and user-manuals. The procedure is guided by two criteria: First, the interface must be correct, that is, with the given interface the user will be able to perform the specified tasks correctly. Second, the interface should be succinct. The report discusses the underlying concepts and the formal methods for this approach. Two examples are used to illustrate the procedure. The algorithm for constructing interfaces can be automated, and a preliminary software system for its implementation has been developed.

  2. On Abstractions and Simplifications in the Design of Human-Automation Interfaces

    NASA Technical Reports Server (NTRS)

    Heymann, Michael; Degani, Asaf; Shafto, Michael; Meyer, George; Clancy, Daniel (Technical Monitor)

    2001-01-01

    This report addresses the design of human-automation interaction from a formal perspective that focuses on the information content of the interface, rather than the design of the graphical user interface. It also addresses the, issue of the information provided to the user (e.g., user-manuals, training material, and all other resources). In this report, we propose a formal procedure for generating interfaces and user-manuals. The procedure is guided by two criteria: First, the interface must be correct, i.e., that with the given interface the user will be able to perform the specified tasks correctly. Second, the interface should be as succinct as possible. The report discusses the underlying concepts and the formal methods for this approach. Several examples are used to illustrate the procedure. The algorithm for constructing interfaces can be automated, and a preliminary software system for its implementation has been developed.

  3. Automated generation of reliability models

    NASA Technical Reports Server (NTRS)

    Johnson, Sally C.; Butler, Ricky W.

    1988-01-01

    The abstract semi-Markov specification interface to the SURE (Semi-Markov Range Evaluator) tool (ASSIST) program allows the user to describe the Markov model in a high-level language. Instead of listing the individual states of the model, the user specifies the rules governing the behavior of the system, and these are used to automatically generate the model. A small number of statements in the abstract language can describe a large, complex model. Becuase no assumptions are made about the system being modeled, ASSIST can be used to generate models describing the behavior of any type of system. The abstract model definition and the automatic model generation strategy are described. Analysis of an example fault-tolerant architecture, a triad of processor with cold spare processors, shows how the behavior of a system can be captured by a few general rules. The syntax of the ASSIST input language is then described and demonstrated by creating a model to describe the fault behavior of the example architecture. The flexibility of the abstract language is demonstrated by expanding the example to model multiple triads of processors sharing a pool of cold spare processors.

  4. Human-Machine Interface in Building Automation Systems

    E-print Network

    Sobczak, N. L.

    1981-01-01

    With the evolution of the Building Automation System industry there has been an increasing emphasis on the development and utilization of complex energy saving and control features. The complexity of this operation has surfaced a communication...

  5. SWISS-MODEL: an automated protein homology-modeling server

    Microsoft Academic Search

    Torsten Schwede; Jürgen Kopp; Nicolas Guex; Manuel C. Peitsch

    2003-01-01

    SWISS-MODEL (http:\\/\\/swissmodel.expasy.org) is a server for automated comparative modeling of three- dimensional (3D) protein structures. It pioneered the field of automated modeling starting in 1993 and is the most widely-used free web-based automated modeling facility today. In 2002 the server computed 120 000 user requests for 3D protein models. SWISS- MODEL provides several levels of user interaction through its World

  6. Model-Based Design of Air Traffic Controller-Automation Interaction

    NASA Technical Reports Server (NTRS)

    Romahn, Stephan; Callantine, Todd J.; Palmer, Everett A.; Null, Cynthia H. (Technical Monitor)

    1998-01-01

    A model of controller and automation activities was used to design the controller-automation interactions necessary to implement a new terminal area air traffic management concept. The model was then used to design a controller interface that provides the requisite information and functionality. Using data from a preliminary study, the Crew Activity Tracking System (CATS) was used to help validate the model as a computational tool for describing controller performance.

  7. Cooperative control - The interface challenge for men and automated machines

    NASA Technical Reports Server (NTRS)

    Hankins, W. W., III; Orlando, N. E.

    1984-01-01

    The research issues associated with the increasing autonomy and independence of machines and their evolving relationships to human beings are explored. The research, conducted by Langley Research Center (LaRC), will produce a new social work order in which the complementary attributes of robots and human beings, which include robots' greater strength and precision and humans' greater physical and intellectual dexterity, are necessary for systems of cooperation. Attention is given to the tools for performing the research, including the Intelligent Systems Research Laboratory (ISRL) and industrial manipulators, as well as to the research approaches taken by the Automation Technology Branch (ATB) of LaRC to achieve high automation levels. The ATB is focusing on artificial intelligence research through DAISIE, a system which tends to organize its environment into hierarchical controller/planner abstractions.

  8. The State of the Art in Automating Usability Evaluation of User Interfaces

    E-print Network

    Hearst, Marti

    The State of the Art in Automating Usability Evaluation of User Interfaces MELODY Y. IVORY fellowship, and Kaiser Permanente. Authors' addresses: M. Y. Ivory, Computer Science Division, University of California, Berkeley, Berkeley, CA 94720-1776; email: ivory@CS.Berkeley.edu; M. A. Hearst, School

  9. Automation and Accountability in Decision Support System Interface Design M.L. Cummings1

    E-print Network

    Cummings, Mary "Missy"

    1 Automation and Accountability in Decision Support System Interface Design M.L. Cummings1 Massachusetts Institute of Technology ABSTRACT When the human element is introduced into decision support system. This paper discusses those ethical and social impact issues specific to decision support systems

  10. Model - based User Interface Design

    Microsoft Academic Search

    2002-01-01

    Abstract This work is about supporting user interface design by means of explicit design representa tions, in particular models We take as a starting point two different development traditions: the formal, analytic, top down engineering approach and the informal, synthetic, bottom are based on specific design representations tailored to the respective approaches, and are found to have strengths and weaknesses

  11. Interface Model of Cold Fusion

    Microsoft Academic Search

    Talbot A. Chubb

    The interface theory of cold fusion is a variant of Ion Band State (IBS) Theory.1 It models Bloch symmetry deuterons in a 2-dimensional metal lattice instead of the 3-dimensional metal lattice first used. Both IBS variants recognize that the required lattice symmetry has limited extent, with the reactive deuterons being bound inside a closed volume like a box. The reactive

  12. Alloy Interface Interdiffusion Modeled

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo H.; Garces, Jorge E.; Abel, Phillip B.

    2003-01-01

    With renewed interest in developing nuclear-powered deep space probes, attention will return to improving the metallurgical processing of potential nuclear fuels so that they remain dimensionally stable over the years required for a successful mission. Previous work on fuel alloys at the NASA Glenn Research Center was primarily empirical, with virtually no continuing research. Even when empirical studies are exacting, they often fail to provide enough insight to guide future research efforts. In addition, from a fundamental theoretical standpoint, the actinide metals (which include materials used for nuclear fuels) pose a severe challenge to modern electronic-structure theory. Recent advances in quantum approximate atomistic modeling, coupled with first-principles derivation of needed input parameters, can help researchers develop new alloys for nuclear propulsion.

  13. Interface development for cost effective automated IC orientation checking systems

    Microsoft Academic Search

    Nowshad Amin; Mohammad Shajib Khadem

    2007-01-01

    IC packages, in semiconductor industries, are being marked through certain sequence by either laser marker or ink markers. A critical step in the final visual inspection is the orientation check of ICs that can be determined by detecting images of pin-1 notch or pin-1 dimple, which are molded\\/marked on the IC packages. This study accomplishes a software interface for a

  14. Automation and Accountability in Decision Support System Interface Design

    ERIC Educational Resources Information Center

    Cummings, Mary L.

    2006-01-01

    When the human element is introduced into decision support system design, entirely new layers of social and ethical issues emerge but are not always recognized as such. This paper discusses those ethical and social impact issues specific to decision support systems and highlights areas that interface designers should consider during design with an…

  15. User interface design principles for the SSM/PMAD automated power system

    NASA Astrophysics Data System (ADS)

    Jakstas, Laura M.; Myers, Chris J.

    Martin Marietta has developed a user interface for the space station module power management and distribution (SSM/PMAD) automated power system testbed which provides human access to the functionality of the power system, as well as exemplifying current techniques in user interface design. The testbed user interface was designed to enable an engineer to operate the system easily without having significant knowledge of computer systems, as well as provide an environment in which the engineer can monitor and interact with the SSM/PMAD system hardware. The design of the interface supports a global view of the most important data from the various hardware and software components, as well as enabling the user to obtain additional or more detailed data when needed. The components and representations of the SSM/PMAD testbed user interface are examined. An engineer's interactions with the system are also described.

  16. User interface design principles for the SSM/PMAD automated power system

    NASA Technical Reports Server (NTRS)

    Jakstas, Laura M.; Myers, Chris J.

    1991-01-01

    Martin Marietta has developed a user interface for the space station module power management and distribution (SSM/PMAD) automated power system testbed which provides human access to the functionality of the power system, as well as exemplifying current techniques in user interface design. The testbed user interface was designed to enable an engineer to operate the system easily without having significant knowledge of computer systems, as well as provide an environment in which the engineer can monitor and interact with the SSM/PMAD system hardware. The design of the interface supports a global view of the most important data from the various hardware and software components, as well as enabling the user to obtain additional or more detailed data when needed. The components and representations of the SSM/PMAD testbed user interface are examined. An engineer's interactions with the system are also described.

  17. Task-focused modeling in automated agriculture

    NASA Astrophysics Data System (ADS)

    Vriesenga, Mark R.; Peleg, K.; Sklansky, Jack

    1993-01-01

    Machine vision systems analyze image data to carry out automation tasks. Our interest is in machine vision systems that rely on models to achieve their designed task. When the model is interrogated from an a priori menu of questions, the model need not be complete. Instead, the machine vision system can use a partial model that contains a large amount of information in regions of interest and less information elsewhere. We propose an adaptive modeling scheme for machine vision, called task-focused modeling, which constructs a model having just sufficient detail to carry out the specified task. The model is detailed in regions of interest to the task and is less detailed elsewhere. This focusing effect saves time and reduces the computational effort expended by the machine vision system. We illustrate task-focused modeling by an example involving real-time micropropagation of plants in automated agriculture.

  18. MODELLING OF INTERFACES IN UNSATURATED POROUS MEDIA

    Microsoft Academic Search

    Mario Ohlberger; Ben Schweizer

    In this contribution we discuss interface conditions for unsaturated flow in porous media. Typical applications are subsurface flow and technical applications like fuel cells. After an analysis of suitable interface conditions at the contact interface of two porous materials of different kind, we introduce a model for outflow boundary conditions at the interface of a porous material with open space.

  19. Models for Automated Earthmoving Howard Cannon

    E-print Network

    Singh, Sanjiv

    , IL 61656 cannohn@cat.com Sanjiv Singh Robotics Institute Carnegie Mellon University Pittsburgh, PA developed a robotic earthmoving system that completely automates the task of mass excavation and truck in the literature on the modeling of hydraulic actuators (such as [2],[6]) do not pro- vide the requisite

  20. Models for Automated Earthmoving Howard Cannon

    E-print Network

    Singh, Sanjiv

    , IL 61656 cannohn@cat.com Sanjiv Singh Robotics Institute Carnegie Mellon University Pittsburgh, PA developed a robotic earthmoving system that completely automates the task of mass excavation and truck described in the literature on the modeling of hydraulic actuators (such as [2],[6]) do not pro­ vide

  1. Design Through Manufacturing: The Solid Model - Finite Element Analysis Interface

    NASA Technical Reports Server (NTRS)

    Rubin, Carol

    2003-01-01

    State-of-the-art computer aided design (CAD) presently affords engineers the opportunity to create solid models of machine parts which reflect every detail of the finished product. Ideally, these models should fulfill two very important functions: (1) they must provide numerical control information for automated manufacturing of precision parts, and (2) they must enable analysts to easily evaluate the stress levels (using finite element analysis - FEA) for all structurally significant parts used in space missions. Today's state-of-the-art CAD programs perform function (1) very well, providing an excellent model for precision manufacturing. But they do not provide a straightforward and simple means of automating the translation from CAD to FEA models, especially for aircraft-type structures. The research performed during the fellowship period investigated the transition process from the solid CAD model to the FEA stress analysis model with the final goal of creating an automatic interface between the two. During the period of the fellowship a detailed multi-year program for the development of such an interface was created. The ultimate goal of this program will be the development of a fully parameterized automatic ProE/FEA translator for parts and assemblies, with the incorporation of data base management into the solution, and ultimately including computational fluid dynamics and thermal modeling in the interface.

  2. Automated two-dimensional interface for capillary gas chromatography

    DOEpatents

    Strunk, Michael R. (Albuquerque, NM); Bechtold, William E. (Albuquerque, NM)

    1996-02-20

    A multidimensional gas chromatograph (GC) system having wide bore capillary and narrow bore capillary GC columns in series and having a novel system interface. Heart cuts from a high flow rate sample, separated by a wide bore GC column, are collected and directed to a narrow bore GC column with carrier gas injected at a lower flow compatible with a mass spectrometer. A bimodal six-way valve is connected with the wide bore GC column outlet and a bimodal four-way valve is connected with the narrow bore GC column inlet. A trapping and retaining circuit with a cold trap is connected with the six-way valve and a transfer circuit interconnects the two valves. The six-way valve is manipulated between first and second mode positions to collect analyte, and the four-way valve is manipulated between third and fourth mode positions to allow carrier gas to sweep analyte from a deactivated cold trap, through the transfer circuit, and then to the narrow bore GC capillary column for separation and subsequent analysis by a mass spectrometer. Rotary valves have substantially the same bore width as their associated columns to minimize flow irregularities and resulting sample peak deterioration. The rotary valves are heated separately from the GC columns to avoid temperature lag and resulting sample deterioration.

  3. Automated two-dimensional interface for capillary gas chromatography

    DOEpatents

    Strunk, M.R.; Bechtold, W.E.

    1996-02-20

    A multidimensional gas chromatograph (GC) system is disclosed which has wide bore capillary and narrow bore capillary GC columns in series and has a novel system interface. Heart cuts from a high flow rate sample, separated by a wide bore GC column, are collected and directed to a narrow bore GC column with carrier gas injected at a lower flow compatible with a mass spectrometer. A bimodal six-way valve is connected with the wide bore GC column outlet and a bimodal four-way valve is connected with the narrow bore GC column inlet. A trapping and retaining circuit with a cold trap is connected with the six-way valve and a transfer circuit interconnects the two valves. The six-way valve is manipulated between first and second mode positions to collect analyte, and the four-way valve is manipulated between third and fourth mode positions to allow carrier gas to sweep analyte from a deactivated cold trap, through the transfer circuit, and then to the narrow bore GC capillary column for separation and subsequent analysis by a mass spectrometer. Rotary valves have substantially the same bore width as their associated columns to minimize flow irregularities and resulting sample peak deterioration. The rotary valves are heated separately from the GC columns to avoid temperature lag and resulting sample deterioration. 3 figs.

  4. Modeling Increased Complexity and the Reliance on Automation: FLightdeck Automation Problems (FLAP) Model

    NASA Technical Reports Server (NTRS)

    Ancel, Ersin; Shih, Ann T.

    2014-01-01

    This paper highlights the development of a model that is focused on the safety issue of increasing complexity and reliance on automation systems in transport category aircraft. Recent statistics show an increase in mishaps related to manual handling and automation errors due to pilot complacency and over-reliance on automation, loss of situational awareness, automation system failures and/or pilot deficiencies. Consequently, the aircraft can enter a state outside the flight envelope and/or air traffic safety margins which potentially can lead to loss-of-control (LOC), controlled-flight-into-terrain (CFIT), or runway excursion/confusion accidents, etc. The goal of this modeling effort is to provide NASA's Aviation Safety Program (AvSP) with a platform capable of assessing the impacts of AvSP technologies and products towards reducing the relative risk of automation related accidents and incidents. In order to do so, a generic framework, capable of mapping both latent and active causal factors leading to automation errors, is developed. Next, the framework is converted into a Bayesian Belief Network model and populated with data gathered from Subject Matter Experts (SMEs). With the insertion of technologies and products, the model provides individual and collective risk reduction acquired by technologies and methodologies developed within AvSP.

  5. RCrane: semi-automated RNA model building.

    PubMed

    Keating, Kevin S; Pyle, Anna Marie

    2012-08-01

    RNA crystals typically diffract to much lower resolutions than protein crystals. This low-resolution diffraction results in unclear density maps, which cause considerable difficulties during the model-building process. These difficulties are exacerbated by the lack of computational tools for RNA modeling. Here, RCrane, a tool for the partially automated building of RNA into electron-density maps of low or intermediate resolution, is presented. This tool works within Coot, a common program for macromolecular model building. RCrane helps crystallographers to place phosphates and bases into electron density and then automatically predicts and builds the detailed all-atom structure of the traced nucleotides. RCrane then allows the crystallographer to review the newly built structure and select alternative backbone conformations where desired. This tool can also be used to automatically correct the backbone structure of previously built nucleotides. These automated corrections can fix incorrect sugar puckers, steric clashes and other structural problems. PMID:22868764

  6. Trust Model for Security Automation Data 1.0 (TMSAD)

    E-print Network

    Trust Model for Security Automation Data 1.0 (TMSAD) HaroldBooth AdamHalbardier NIST Interagency Report 7802 #12;NIST Interagency Report 7802 Trust Model for Security Automation Data 1.0 (TMSAD) Harold FOR SECURITY AUTOMATION DATA 1.0 (TMSAD) iii Reports on Computer Systems Technology The Information Technology

  7. Automating risk analysis of software design models.

    PubMed

    Frydman, Maxime; Ruiz, Guifré; Heymann, Elisa; César, Eduardo; Miller, Barton P

    2014-01-01

    The growth of the internet and networked systems has exposed software to an increased amount of security threats. One of the responses from software developers to these threats is the introduction of security activities in the software development lifecycle. This paper describes an approach to reduce the need for costly human expertise to perform risk analysis in software, which is common in secure development methodologies, by automating threat modeling. Reducing the dependency on security experts aims at reducing the cost of secure development by allowing non-security-aware developers to apply secure development with little to no additional cost, making secure development more accessible. To automate threat modeling two data structures are introduced, identification trees and mitigation trees, to identify threats in software designs and advise mitigation techniques, while taking into account specification requirements and cost concerns. These are the components of our model for automated threat modeling, AutSEC. We validated AutSEC by implementing it in a tool based on data flow diagrams, from the Microsoft security development methodology, and applying it to VOMS, a grid middleware component, to evaluate our model's performance. PMID:25136688

  8. Automating Risk Analysis of Software Design Models

    PubMed Central

    Ruiz, Guifré; Heymann, Elisa; César, Eduardo; Miller, Barton P.

    2014-01-01

    The growth of the internet and networked systems has exposed software to an increased amount of security threats. One of the responses from software developers to these threats is the introduction of security activities in the software development lifecycle. This paper describes an approach to reduce the need for costly human expertise to perform risk analysis in software, which is common in secure development methodologies, by automating threat modeling. Reducing the dependency on security experts aims at reducing the cost of secure development by allowing non-security-aware developers to apply secure development with little to no additional cost, making secure development more accessible. To automate threat modeling two data structures are introduced, identification trees and mitigation trees, to identify threats in software designs and advise mitigation techniques, while taking into account specification requirements and cost concerns. These are the components of our model for automated threat modeling, AutSEC. We validated AutSEC by implementing it in a tool based on data flow diagrams, from the Microsoft security development methodology, and applying it to VOMS, a grid middleware component, to evaluate our model's performance. PMID:25136688

  9. CollageMachine: Model of ``Interface Ecology''

    E-print Network

    Mohri, Mehryar

    CollageMachine: Model of ``Interface Ecology'' By Andruid Kerne dissertation submitted partial addresses browsing creatively, been co­developed with the metadisciplinary framework interface ecology, in addition inside them, open process without definite bounds. a metadiscipline, interface ecology brings

  10. Atomistic modeling of dislocation-interface interactions

    SciTech Connect

    Wang, Jian [Los Alamos National Laboratory; Valone, Steven M [Los Alamos National Laboratory; Beyerlein, Irene J [Los Alamos National Laboratory; Misra, Amit [Los Alamos National Laboratory; Germann, T. C. [Los Alamos National Laboratory

    2011-01-31

    Using atomic scale models and interface defect theory, we first classify interface structures into a few types with respect to geometrical factors, then study the interfacial shear response and further simulate the dislocation-interface interactions using molecular dynamics. The results show that the atomic scale structural characteristics of both heterophases and homophases interfaces play a crucial role in (i) their mechanical responses and (ii) the ability of incoming lattice dislocations to transmit across them.

  11. Automated dynamic analytical model improvement

    NASA Technical Reports Server (NTRS)

    Berman, A.

    1981-01-01

    A method is developed and illustrated which finds minimum changes in analytical mass and stiffness matrices to make them consistent with a set of measured normal modes and natural frequencies. The corrected model is an improved base for studies of physical changes, changes in boundary conditions, and for prediction of forced responses. Features of the method are: efficient procedures not requiring solutions of the eigenproblem; the model may have more degrees of freedom than the test data; modal displacements at all the analytical degrees of freedom are obtained; the frequency dependence of the coordinate transformations are properly treated.

  12. Automated statistical modeling of analytical measurement systems

    SciTech Connect

    Jacobson, J J

    1992-08-01

    The statistical modeling of analytical measurement systems at the Idaho Chemical Processing Plant (ICPP) has been completely automated through computer software. The statistical modeling of analytical measurement systems is one part of a complete quality control program used by the Remote Analytical Laboratory (RAL) at the ICPP. The quality control program is an integration of automated data input, measurement system calibration, database management, and statistical process control. The quality control program and statistical modeling program meet the guidelines set forth by the American Society for Testing Materials and American National Standards Institute. A statistical model is a set of mathematical equations describing any systematic bias inherent in a measurement system and the precision of a measurement system. A statistical model is developed from data generated from the analysis of control standards. Control standards are samples which are made up at precise known levels by an independent laboratory and submitted to the RAL. The RAL analysts who process control standards do not know the values of those control standards. The object behind statistical modeling is to describe real process samples in terms of their bias and precision and, to verify that a measurement system is operating satisfactorily. The processing of control standards gives us this ability.

  13. Visual Interfaces for Solids Modeling Cindy Grimmy

    E-print Network

    Grimm, Cindy

    for solids modeling. We focus on designing interfaces for free-form operators such as blends, sweeps, and object representations, Splines; Additional Keywords: User Interfaces. 1 Introduction Modeling free-form usually one-ortwo-dimensional,but the operatorsthemselves are intrinsically three-dimensional

  14. Enhancing SCADA and distribution automation through advanced remote terminal unit interfaces

    SciTech Connect

    Rose, M. [Mississippi Power Co., Gulfport, MS (United States); Lawrence, S.J.; Bassiouni, R. [ATI Systems, E. Boston, MA (United States)

    1995-12-31

    One of the essential features of a SCADA or Distribution Automation system is its ability to communicate to intelligent electronic devices (IEDs). With advances in interface hardware such as Remote Terminal Units (RTUs), utilities can more efficiently and effectively communicate with their field equipment. Mississippi Power Company (MPC) has been successful in implementing its SCADA systems with IEDs to maximize its system`s effectiveness. In general, the benefits of this technology are observed in overall cost savings, increased system information, and improved reliability and control. In many cases, MPC uses a single RTU on its SCADA system to communicate to and control a group of IEDs, minimizing the amount of hardware necessary to streamline the system and its simplifies the integration process of the IEDs. Interfaces to many intelligent field devices through a RTU such as Quantum Smart Meters, Schweitzer Relays and Cooper 4C Recolsers will be discussed. These interfaces can help any utility by providing them with more information, more reliable control, and a cost effective method of communication throughout their SCADA system. The details of how these interfaces work and the information they can provide will be illustrated as well as the open communication system the RTU can create in various types of SCADA systems.

  15. Visual Interfaces for Solids Modeling Cindy Grimmy

    E-print Network

    Utah, University of

    representations, Splines; Additional Keywords: User Interfaces. 1 Introduction Modeling free-form surfaces visualoperatorsfor solidsmodeling. We focus on designing interfaces for free-form operators such as blends, sweeps. These parametersareusuallyone-ortwo-dimensional,but theoperatorsthemselves are intrinsically three-dimensional

  16. Models for MetaVCeramic Interface Fracture

    E-print Network

    Suo, Zhigang

    ChaDter 12 Models for MetaVCeramic Interface Fracture ZHIGANG SUO C. FONG SHIH Metal shortcomingthat haslimited their wide- spread use-their tendency to fracture easily. In many systems, the low on interface fracture are reviewed in this chapter. With few exceptions, attention is limited to continuum

  17. Individual user interfaces and model-based user interface software tools

    Microsoft Academic Search

    Egbert Schlungbaum

    1997-01-01

    Currently, most of model-based user interface software tools use task, application, and presentation models to generate the running user interface. The point of this paper is to use an additional user model to create individual user interfaces. For it, individual user interfaces and model-based tools are analyzed briefly to define the starting point for this research work. The viability of

  18. Micromechanical modeling of rough interface behavior

    E-print Network

    Huang, Shiping

    2011-07-28

    In this dissertation, the interface behavior of contacting rough surfaces was studied systematically based upon micromechanical modeling. Firstly, asperity contact mechanics was further developed. It was found that tangential tractions, displacement...

  19. A Diffuse Interface Model with Immiscibility Preservation

    PubMed Central

    Tiwari, Arpit; Freund, Jonathan B.; Pantano, Carlos

    2013-01-01

    A new, simple, and computationally efficient interface capturing scheme based on a diffuse interface approach is presented for simulation of compressible multiphase flows. Multi-fluid interfaces are represented using field variables (interface functions) with associated transport equations that are augmented, with respect to an established formulation, to enforce a selected interface thickness. The resulting interface region can be set just thick enough to be resolved by the underlying mesh and numerical method, yet thin enough to provide an efficient model for dynamics of well-resolved scales. A key advance in the present method is that the interface regularization is asymptotically compatible with the thermodynamic mixture laws of the mixture model upon which it is constructed. It incorporates first-order pressure and velocity non-equilibrium effects while preserving interface conditions for equilibrium flows, even within the thin diffused mixture region. We first quantify the improved convergence of this formulation in some widely used one-dimensional configurations, then show that it enables fundamentally better simulations of bubble dynamics. Demonstrations include both a spherical bubble collapse, which is shown to maintain excellent symmetry despite the Cartesian mesh, and a jetting bubble collapse adjacent a wall. Comparisons show that without the new formulation the jet is suppressed by numerical diffusion leading to qualitatively incorrect results. PMID:24058207

  20. A diffuse interface model with immiscibility preservation

    SciTech Connect

    Tiwari, Arpit, E-mail: atiwari2@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)] [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Freund, Jonathan B., E-mail: jbfreund@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Department of Aerospace Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Pantano, Carlos [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)] [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2013-11-01

    A new, simple, and computationally efficient interface capturing scheme based on a diffuse interface approach is presented for simulation of compressible multiphase flows. Multi-fluid interfaces are represented using field variables (interface functions) with associated transport equations that are augmented, with respect to an established formulation, to enforce a selected interface thickness. The resulting interface region can be set just thick enough to be resolved by the underlying mesh and numerical method, yet thin enough to provide an efficient model for dynamics of well-resolved scales. A key advance in the present method is that the interface regularization is asymptotically compatible with the thermodynamic mixture laws of the mixture model upon which it is constructed. It incorporates first-order pressure and velocity non-equilibrium effects while preserving interface conditions for equilibrium flows, even within the thin diffused mixture region. We first quantify the improved convergence of this formulation in some widely used one-dimensional configurations, then show that it enables fundamentally better simulations of bubble dynamics. Demonstrations include both a spherical-bubble collapse, which is shown to maintain excellent symmetry despite the Cartesian mesh, and a jetting bubble collapse adjacent a wall. Comparisons show that without the new formulation the jet is suppressed by numerical diffusion leading to qualitatively incorrect results.

  1. Automation life-cycle cost model

    NASA Technical Reports Server (NTRS)

    Gathmann, Thomas P.; Reeves, Arlinda J.; Cline, Rick; Henrion, Max; Ruokangas, Corinne

    1992-01-01

    The problem domain being addressed by this contractual effort can be summarized by the following list: Automation and Robotics (A&R) technologies appear to be viable alternatives to current, manual operations; Life-cycle cost models are typically judged with suspicion due to implicit assumptions and little associated documentation; and Uncertainty is a reality for increasingly complex problems and few models explicitly account for its affect on the solution space. The objectives for this effort range from the near-term (1-2 years) to far-term (3-5 years). In the near-term, the envisioned capabilities of the modeling tool are annotated. In addition, a framework is defined and developed in the Decision Modelling System (DEMOS) environment. Our approach is summarized as follows: Assess desirable capabilities (structure into near- and far-term); Identify useful existing models/data; Identify parameters for utility analysis; Define tool framework; Encode scenario thread for model validation; and Provide transition path for tool development. This report contains all relevant, technical progress made on this contractual effort.

  2. Automated sample preparation and analysis using a sequential-injection-capillary electrophoresis (SI-CE) interface.

    PubMed

    Kulka, Stephan; Quintás, Guillermo; Lendl, Bernhard

    2006-06-01

    A fully automated sequential-injection-capillary electrophoresis (SI-CE) system was developed using commercially available components as the syringe pump, the selection and injection valves and the high voltage power supply. The interface connecting the SI with the CE unit consisted of two T-pieces, where the capillary was inserted in one T-piece and a Pt electrode in the other (grounded) T-piece. By pressurising the whole system using a syringe pump, hydrodynamic injection was feasible. For characterisation, the system was applied to a mixture of adenosine and adenosine monophosphate at different concentrations. The calibration curve obtained gave a detection limit of 0.5 microg g(-1) (correlation coefficient of 0.997). The reproducibility of the injection was also assessed, resulting in a RSD value (5 injections) of 5.4%. The total time of analysis, from injection, conditioning and separation to cleaning the capillary again was 15 minutes. In another application, employing the full power of the automated SIA-CE system, myoglobin was mixed directly using the flow system with different concentrations of sodium dodecyl sulfate (SDS), a known denaturing agent. The different conformations obtained in this way were analysed with the CE system and a distinct shift in migration time and decreasing of the native peak of myoglobin (Mb) could be observed. The protein samples prepared were also analysed with off-line infrared spectroscopy (IR), confirming these results. PMID:16732362

  3. Model compilation: An approach to automated model derivation

    NASA Technical Reports Server (NTRS)

    Keller, Richard M.; Baudin, Catherine; Iwasaki, Yumi; Nayak, Pandurang; Tanaka, Kazuo

    1990-01-01

    An approach is introduced to automated model derivation for knowledge based systems. The approach, model compilation, involves procedurally generating the set of domain models used by a knowledge based system. With an implemented example, how this approach can be used to derive models of different precision and abstraction is illustrated, and models are tailored to different tasks, from a given set of base domain models. In particular, two implemented model compilers are described, each of which takes as input a base model that describes the structure and behavior of a simple electromechanical device, the Reaction Wheel Assembly of NASA's Hubble Space Telescope. The compilers transform this relatively general base model into simple task specific models for troubleshooting and redesign, respectively, by applying a sequence of model transformations. Each transformation in this sequence produces an increasingly more specialized model. The compilation approach lessens the burden of updating and maintaining consistency among models by enabling their automatic regeneration.

  4. Generating user interface code in a model based user interface development environment

    Microsoft Academic Search

    Paulo Pinheiro da Silva; Tony Griffiths; Norman W. Paton

    2000-01-01

    Declarative models play an important role in most software design activities, by allowing designs to be constructed that selectively abstract over complex implementation details. In the user interface setting, Model-Based User Interface Development Environments (MB-UIDEs) provide a context within which declarative models can be constructed and related, as part of the interface design process. However, such declarative models are not

  5. Modeling and Extracting Deep-Web Query Interfaces

    Microsoft Academic Search

    Wensheng Wu; AnHai Doan; Clement T. Yu; Weiyi Meng

    2009-01-01

    Interface modeling & extraction is a fundamental step in building a uni- form query interface to a multitude of databases on the Web. Existing solutions are limited in that they assume interfaces are flat and thus ignore the inherent struc- ture of interfaces, which then seriously hampers the effectiveness of interface in- tegration. To address this limitation, in this chapter,

  6. Modeling strategic behavior in human-automation interaction - Why an 'aid' can (and should) go unused

    NASA Technical Reports Server (NTRS)

    Kirlik, Alex

    1993-01-01

    Task-offload aids (e.g., an autopilot, an 'intelligent' assistant) can be selectively engaged by the human operator to dynamically delegate tasks to automation. Introducing such aids eliminates some task demands but creates new ones associated with programming, engaging, and disengaging the aiding device via an interface. The burdens associated with managing automation can sometimes outweigh the potential benefits of automation to improved system performance. Aid design parameters and features of the overall multitask context combine to determine whether or not a task-offload aid will effectively support the operator. A modeling and sensitivity analysis approach is presented that identifies effective strategies for human-automation interaction as a function of three task-context parameters and three aid design parameters. The analysis and modeling approaches provide resources for predicting how a well-adapted operator will use a given task-offload aid, and for specifying aid design features that ensure that automation will provide effective operator support in a multitask environment.

  7. An interface tracking model for droplet electrocoalescence.

    SciTech Connect

    Erickson, Lindsay Crowl

    2013-09-01

    This report describes an Early Career Laboratory Directed Research and Development (LDRD) project to develop an interface tracking model for droplet electrocoalescence. Many fluid-based technologies rely on electrical fields to control the motion of droplets, e.g. microfluidic devices for high-speed droplet sorting, solution separation for chemical detectors, and purification of biodiesel fuel. Precise control over droplets is crucial to these applications. However, electric fields can induce complex and unpredictable fluid dynamics. Recent experiments (Ristenpart et al. 2009) have demonstrated that oppositely charged droplets bounce rather than coalesce in the presence of strong electric fields. A transient aqueous bridge forms between approaching drops prior to pinch-off. This observation applies to many types of fluids, but neither theory nor experiments have been able to offer a satisfactory explanation. Analytic hydrodynamic approximations for interfaces become invalid near coalescence, and therefore detailed numerical simulations are necessary. This is a computationally challenging problem that involves tracking a moving interface and solving complex multi-physics and multi-scale dynamics, which are beyond the capabilities of most state-of-the-art simulations. An interface-tracking model for electro-coalescence can provide a new perspective to a variety of applications in which interfacial physics are coupled with electrodynamics, including electro-osmosis, fabrication of microelectronics, fuel atomization, oil dehydration, nuclear waste reprocessing and solution separation for chemical detectors. We present a conformal decomposition finite element (CDFEM) interface-tracking method for the electrohydrodynamics of two-phase flow to demonstrate electro-coalescence. CDFEM is a sharp interface method that decomposes elements along fluid-fluid boundaries and uses a level set function to represent the interface.

  8. A Web Interface for Eco System Modeling

    NASA Astrophysics Data System (ADS)

    McHenry, K.; Kooper, R.; Serbin, S. P.; LeBauer, D. S.; Desai, A. R.; Dietze, M. C.

    2012-12-01

    We have developed the Predictive Ecosystem Analyzer (PEcAn) as an open-source scientific workflow system and ecoinformatics toolbox that manages the flow of information in and out of regional-scale terrestrial biosphere models, facilitates heterogeneous data assimilation, tracks data provenance, and enables more effective feedback between models and field research. The over-arching goal of PEcAn is to make otherwise complex analyses transparent, repeatable, and accessible to a diverse array of researchers, allowing both novice and expert users to focus on using the models to examine complex ecosystems rather than having to deal with complex computer system setup and configuration questions in order to run the models. Through the developed web interface we hide much of the data and model details and allow the user to simply select locations, ecosystem models, and desired data sources as inputs to the model. Novice users are guided by the web interface through setting up a model execution and plotting the results. At the same time expert users are given enough freedom to modify specific parameters before the model gets executed. This will become more important as more and more models are added to the PEcAn workflow as well as more and more data that will become available as NEON comes online. On the backend we support the execution of potentially computationally expensive models on different High Performance Computers (HPC) and/or clusters. The system can be configured with a single XML file that gives it the flexibility needed for configuring and running the different models on different systems using a combination of information stored in a database as well as pointers to files on the hard disk. While the web interface usually creates this configuration file, expert users can still directly edit it to fine tune the configuration.. Once a workflow is finished the web interface will allow for the easy creation of plots over result data while also allowing the user to download the results for further processing. The current workflow in the web interface is a simple linear workflow, but will be expanded to allow for more complex workflows. We are working with Kepler and Cyberintegrator to allow for these more complex workflows as well as collecting provenance of the workflow being executed. This provenance regarding model executions is stored in a database along with the derived results. All of this information is then accessible using the BETY database web frontend. The PEcAn interface.

  9. Eye gaze tracking for endoscopic camera positioning: an application of a hardware/software interface developed to automate Aesop.

    PubMed

    Ali, S M; Reisner, L A; King, B; Cao, A; Auner, G; Klein, M; Pandya, A K

    2008-01-01

    A redesigned motion control system for the medical robot Aesop allows automating and programming its movements. An IR eye tracking system has been integrated with this control interface to implement an intelligent, autonomous eye gaze-based laparoscopic positioning system. A laparoscopic camera held by Aesop can be moved based on the data from the eye tracking interface to keep the user's gaze point region at the center of a video feedback monitor. This system setup provides autonomous camera control that works around the surgeon, providing an optimal robotic camera platform. PMID:18391246

  10. Mental Models and Hypermedia User Interface Design.

    ERIC Educational Resources Information Center

    Corry, Michael D.

    1998-01-01

    This survey of the research into user interface design and its impact on the development of hypermedia users' mental models discusses various design issues including the functionality of the system, system purpose, differences in user background, and system usability. (Author/AEF)

  11. Automating a human factors evaluation of graphical user interfaces for NASA applications: An update on CHIMES

    NASA Technical Reports Server (NTRS)

    Jiang, Jian-Ping; Murphy, Elizabeth D.; Bailin, Sidney C.; Truszkowski, Walter F.

    1993-01-01

    Capturing human factors knowledge about the design of graphical user interfaces (GUI's) and applying this knowledge on-line are the primary objectives of the Computer-Human Interaction Models (CHIMES) project. The current CHIMES prototype is designed to check a GUI's compliance with industry-standard guidelines, general human factors guidelines, and human factors recommendations on color usage. Following the evaluation, CHIMES presents human factors feedback and advice to the GUI designer. The paper describes the approach to modeling human factors guidelines, the system architecture, a new method developed to convert quantitative RGB primaries into qualitative color representations, and the potential for integrating CHIMES with user interface management systems (UIMS). Both the conceptual approach and its implementation are discussed. This paper updates the presentation on CHIMES at the first International Symposium on Ground Data Systems for Spacecraft Control.

  12. Ultrasonic scattering from imperfect interfaces: A quasi-static model

    Microsoft Academic Search

    Jai-Man Baik; R. Bruce Thompson

    1984-01-01

    A quasi-static model for the ultrasonic transmission and reflection at imperfect interfaces is developed. The interface is represented by a distributed spring, determined by the change in static compliance of the medium with respect to one with a perfect interface, and a distributed mass, representing excess mass at the interface. Comparison of the model predictions to exact solutions for two

  13. An Automated Translator for Model Checking Time Constrained Workflow Systems

    NASA Astrophysics Data System (ADS)

    Mashiyat, Ahmed Shah; Rabbi, Fazle; Wang, Hao; Maccaull, Wendy

    Workflows have proven to be a useful conceptualization for the automation of business processes. While formal verification methods (e.g., model checking) can help ensure the reliability of workflow systems, the industrial uptake of such methods has been slow largely due to the effort involved in modeling and the memory required to verify complex systems. Incorporation of time constraints in such systems exacerbates the latter problem. We present an automated translator, YAWL2DVE-t, which takes as input a time constrained workflow model built with the graphical modeling tool YAWL, and outputs the model in DVE, the system specification language for the distributed LTL model checker DiVinE. The automated translator, together with the graphical editor and the distributed model checker, provides a method for rapid design, verification and refactoring of time constrained workflow systems. We present a realistic case study developed through collaboration with the local health authority.

  14. Development and Design of a User Interface for a Computer Automated Heating, Ventilation, and Air Conditioning System

    SciTech Connect

    Anderson, B.; /Fermilab

    1999-10-08

    A user interface is created to monitor and operate the heating, ventilation, and air conditioning system. The interface is networked to the system's programmable logic controller. The controller maintains automated control of the system. The user through the interface is able to see the status of the system and override or adjust the automatic control features. The interface is programmed to show digital readouts of system equipment as well as visual queues of system operational statuses. It also provides information for system design and component interaction. The interface is made easier to read by simple designs, color coordination, and graphics. Fermi National Accelerator Laboratory (Fermi lab) conducts high energy particle physics research. Part of this research involves collision experiments with protons, and anti-protons. These interactions are contained within one of two massive detectors along Fermilab's largest particle accelerator the Tevatron. The D-Zero Assembly Building houses one of these detectors. At this time detector systems are being upgraded for a second experiment run, titled Run II. Unlike the previous run, systems at D-Zero must be computer automated so operators do not have to continually monitor and adjust these systems during the run. Human intervention should only be necessary for system start up and shut down, and equipment failure. Part of this upgrade includes the heating, ventilation, and air conditioning system (HVAC system). The HVAC system is responsible for controlling two subsystems, the air temperatures of the D-Zero Assembly Building and associated collision hall, as well as six separate water systems used in the heating and cooling of the air and detector components. The BYAC system is automated by a programmable logic controller. In order to provide system monitoring and operator control a user interface is required. This paper will address methods and strategies used to design and implement an effective user interface. Background material pertinent to the BYAC system will cover the separate water and air subsystems and their purposes. In addition programming and system automation will also be covered.

  15. Automation Marketplace 2010: New Models, Core Systems

    ERIC Educational Resources Information Center

    Breeding, Marshall

    2010-01-01

    In a year when a difficult economy presented fewer opportunities for immediate gains, the major industry players have defined their business strategies with fundamentally different concepts of library automation. This is no longer an industry where companies compete on the basis of the best or the most features in similar products but one where…

  16. Modelling Satisfaction with Automated Banking Channels

    Microsoft Academic Search

    Malcolm Beynon; Mark M. H. Goode; Luiz A. Moutinho; Helena R. Snee

    2005-01-01

    The aim of this paper is to apply a new technique, i.e., Variable Precision Rough Set Theory (VPRS) to explaining consumer satisfaction with automated banking channels. VPRS is a new development on the original Rough Set Theory (RST) (for a discussion of RST see Slowinski et al. (1997) or Dimitras et al. (1999), for a discussion of VPRS see Ziarko,

  17. MSG: A Computer System for Automated Modeling of Heat Transfer

    E-print Network

    Steinberg, Louis

    MSG: A Computer System for Automated Modeling of Heat Transfer Sui­ky Ringo Ling Louis Steinberg a computer system, MSG for generating mathematical models to analyze physical systems involving heat transfer equations and partial differential equations. MSG uses the strong domain theory to guide model construction

  18. An automated hydride generation interface to ICPMS for measuring total arsenic in environmental samples.

    PubMed

    Sengupta, Mrinal K; Dasgupta, Purnendu K

    2009-12-01

    An automated hydride generation (AHG) interface to inductive coupled plasma mass spectroscopy (ICPMS) was developed for measuring arsenic in environmental samples. This technique provides statistically indistinguishable response slopes (within about 3%) for hydride generation-ICPMS (HG-ICPMS) analysis of all major As species, inorganic As(III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and inorganic As(V); this has not previously been achieved. Previously, sample pretreatment to convert all forms of As into As(V) has been a prerequisite for measuring total arsenic in complex matrices. Under our operating conditions, arsenobetaine (AsB), until now regarded to be inert, also generates a hydride (albeit the response is only approximately 7% of others). The limit of detection (LOD) based on three times the standard deviation of the blank with this technique for AsB, DMA, As(III), MMA, and As(V) is 90, 66, 63, 63, and 63 pg As, respectively. This AHG-ICPMS technique was compared with a flow injection-UV photolysis-HG-ICPMS (FI-UV-ICPMS) and liquid chromatography-UV-HG-ICPMS analysis of arsenic content in National Institute of Standards & Technology (NIST) standard rice flour (standard reference material: SRM 1568a) and rice samples collected from West Bengal, India. Both oxidative acid digestion and methanol:water (1:1) extraction were used. The analytical results for total As in the SRM 1568a digest were 99.2 +/- 0.6 and 100.2 +/- 0.8% of the certified value (290 +/- 3 microg As/kg) by the AHG-ICPMS and the FI-UV-HG-ICPMS techniques, respectively. For rice extracts and the digests, the two techniques provided results that were correlated with linear r2 values of 0.9988 and 0.9987 with intercepts statistically indistinguishable from zero. Chromatographic analysis indicated that As in these rice samples were 75-90% inorganic. PMID:19891455

  19. XRLSim model specifications and user interfaces

    Microsoft Academic Search

    K. D. Young; E. Breitfeller; J. P. Woodruff

    1989-01-01

    The two chapters in this manual document the engineering development leading to modification of XRLSim -- an Ada-based computer program developed to provide a realistic simulation of an x-ray laser weapon platform. Complete documentation of the FY88 effort to develop XRLSim was published in April 1989, as UCID-21736:XRLSIM Model Specifications and User Interfaces, by L. C. Ng, D. T. Gavel,

  20. Comparison of Interface Models for Earthquake Dynamics

    NASA Astrophysics Data System (ADS)

    Henninger, C.; Raous, M.; Vilotte, J.

    2008-12-01

    Understanding seismological and geodesical earthquake observations critically relies upon phenomenological models allowing rupture propagation and wave radiation simulations. In such models, faults are idealized as discontinuity surfaces and with a surface energy, formulated in terms of slip discontinuity and other internal surface variables, leading to contact laws. These contact laws are designed to capture the phenomenology of the inelastic processes which occur within the fault zone during the earthquake rupture nucleation, propagation and arrest. A lot of work has therefore been devoted in seismology and rock mechanics in the formulation of such contact laws and its identification from finite wavelength seismological observations.Classical contact laws used in seismology have been formulated in terms of slip weakening or rate-and-state friction laws and a lot of work has been devoted to characterize their implications in terms of instability and initiation phase for earthquakes. However these contact laws are not completely formulated, in particular in terms of unloading, and can not be characterized as interface constitutive laws which lead to some difficulty when using them in the earthquake dynamic simulation models.The aim of this work is to introduce a fault interface model based on the RCCM model developed at the LMA in Marseille (Raous et al.(1999), Raous and Monerie(2002)) coupling friction, adhesion and unilateral contact. This interface model takes into account unloading, unilateral contact and viscosity. Friction is progressively introduced when adhesion decreases. The model is based on the notion of adhesion intensity which is very similar to a damage variable. It provides a well-characterized energy partition between damage, friction and viscosity. It incorporates the behaviours obtained when slip weakening or rate-and-state laws are used.Implications of this interface model in terms of stability analysis and nucleation will be presented and systematically compared with slip weakening and rate-and-state friction laws. Such a comparison will be illustrated using simple 1D and 2D mass-springs systems. In conclusion we will discuss how this new contact law can be easily incorporated in dynamic rupture simulation codes using a Non-Smooth Contact Dynamics formulation (Jean(1999), Raous and Monerie(2002)). M. Jean, 1999. The NSCD method, CMAME, 177, 235-257. M. Raous, L. Cangémi, M. Cocou, 1999. A consistent model coupling adhesion, friction, and unilateral contact, CMAME, 177, 383-399. M. Raous, Y. Monerie, 2002. Unilateral contact, friction and adhesion in composite materials~: 3D cracks in composite material, in "Contact Mechanics", Martins, Monteiro Marques (Eds), Col. Solid Mech. and its Applic., Kluwer, 333-346.

  1. Modeling the user in intelligent user interfaces

    SciTech Connect

    Stoddard, M.L.; Douglass, R.J.

    1983-01-01

    A methodology for explicitly defining a model of a program's users and for evaluating the effectiveness of the user interface is presented. The development of an explicit user model will reduce user costs by both reducing the cost of software development and increasing user productivity. The components of the methodology are described, and an example of using the methodology in the development of an expert consultant system is given. The methodology can be useful in preliminary design and testing of such interactive software as electronic mail, information retrieval systems, editors, and management information systems.

  2. MODELLING AND IMPLEMENTING THE CONTROL OF AUTOMATED PRODUCTION

    E-print Network

    Paris-Sud XI, Université de

    a controller program compliant with the previously elaborated control model. With concern for standardisationMODELLING AND IMPLEMENTING THE CONTROL OF AUTOMATED PRODUCTION SYSTEMS USING STATECHARTS AND PLC is concerned with the applicability of statecharts for the discrete control of production systems. We show

  3. Automated Segmentation of Multiple Sclerosis Lesions by Model Outlier Detection

    Microsoft Academic Search

    Koen Van Leemput; Frederik Maes; Dirk Vandermeulen; Alan C. F. Colchester; Paul Suetens

    2001-01-01

    This paper presents a fully automated algorithm for segmentation of multiple sclerosis (MS) lesions from multispec- tral magnetic resonance (MR) images. The method performs inten- sity-based tissue classification using a stochastic model for normal brain images and simultaneously detects MS lesions as outliers that are not well explained by the model. It corrects for MR field in- homogeneities, estimates tissue-specific

  4. HIGHER-ORDER MODELING AND AUTOMATED DESIGN-SPACE EXPLORATION

    E-print Network

    Esser, Robert

    HIGHER-ORDER MODELING AND AUTOMATED DESIGN-SPACE EXPLORATION J¨orn W. Janneck EECS Department in the same set of languages used to model the original sys- tem. Hence the set of design space exploration for an investigation into different solutions--an exploration of the design space. In many real-world systems

  5. Parmodel: a web server for automated comparative modeling of proteins.

    PubMed

    Uchôa, Hugo Brandão; Jorge, Guilherme Eberhart; Freitas Da Silveira, Nelson José; Camera, João Carlos; Canduri, Fernanda; De Azevedo, Walter Filgueira

    2004-12-24

    Parmodel is a web server for automated comparative modeling and evaluation of protein structures. The aim of this tool is to help inexperienced users to perform modeling, assessment, visualization, and optimization of protein models as well as crystallographers to evaluate structures solved experimentally. It is subdivided in four modules: Parmodel Modeling, Parmodel Assessment, Parmodel Visualization, and Parmodel Optimization. The main module is the Parmodel Modeling that allows the building of several models for a same protein in a reduced time, through the distribution of modeling processes on a Beowulf cluster. Parmodel automates and integrates the main softwares used in comparative modeling as MODELLER, Whatcheck, Procheck, Raster3D, Molscript, and Gromacs. This web server is freely accessible at . PMID:15555595

  6. A model for types and levels of human interaction with automation

    Microsoft Academic Search

    Raja Parasuraman; Thomas B. Sheridan; Christopher D. Wickens

    2000-01-01

    We outline a model for types and levels of automation that provides a framework and an objective basis for deciding which system functions should be automated and to what extent. Appropriate selection is important because automation does not merely supplant but changes human activity and can impose new coordination demands on the human operator. We propose that automation can be

  7. AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT (AGWA): A GIS-BASED HYRDOLOGIC MODELING TOOL FOR WATERSHED ASSESSMENT AND ANALYSIS

    EPA Science Inventory

    The Automated Geospatial Watershed Assessment tool (AGWA) is a GIS interface jointly developed by the USDA Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parame...

  8. An Ontology-based Model to Determine the Automation Level of an Automated Vehicle for

    E-print Network

    Paris-Sud XI, Université de

    the 70s, and if total automation is even offered with drones since the 2000s, full automation still a safety point of view, should offer automation options. From a socio-economical point of view, driving

  9. GoSam 2.0: Automated one loop calculations within and beyond the Standard Model

    E-print Network

    Nicolas Greiner

    2014-10-13

    We present GoSam 2.0, a fully automated framework for the generation and evaluation of one loop amplitudes in multi leg processes. The new version offers numerous improvements both on generational aspects as well as on the reduction side. This leads to a faster and more stable code for calculations within and beyond the Standard Model. Furthermore it contains the extended version of the standardized interface to Monte Carlo programs which allows for an easy combination with other existing tools. We briefly describe the conceptual innovations and present some phenomenological results.

  10. Automated particulate sampler field test model operations guide

    SciTech Connect

    Bowyer, S.M.; Miley, H.S.

    1996-10-01

    The Automated Particulate Sampler Field Test Model Operations Guide is a collection of documents which provides a complete picture of the Automated Particulate Sampler (APS) and the Field Test in which it was evaluated. The Pacific Northwest National Laboratory (PNNL) Automated Particulate Sampler was developed for the purpose of radionuclide particulate monitoring for use under the Comprehensive Test Ban Treaty (CTBT). Its design was directed by anticipated requirements of small size, low power consumption, low noise level, fully automatic operation, and most predominantly the sensitivity requirements of the Conference on Disarmament Working Paper 224 (CDWP224). This guide is intended to serve as both a reference document for the APS and to provide detailed instructions on how to operate the sampler. This document provides a complete description of the APS Field Test Model and all the activity related to its evaluation and progression.

  11. Modeling and deadlock avoidance of automated manufacturing systems with multiple automated guided vehicles.

    PubMed

    Wu, Naiqi; Zhou, MengChu

    2005-12-01

    An automated manufacturing system (AMS) contains a number of versatile machines (or workstations), buffers, an automated material handling system (MHS), and is computer-controlled. An effective and flexible alternative for implementing MHS is to use automated guided vehicle (AGV) system. The deadlock issue in AMS is very important in its operation and has extensively been studied. The deadlock problems were separately treated for parts in production and transportation and many techniques were developed for each problem. However, such treatment does not take the advantage of the flexibility offered by multiple AGVs. In general, it is intractable to obtain maximally permissive control policy for either problem. Instead, this paper investigates these two problems in an integrated way. First we model an AGV system and part processing processes by resource-oriented Petri nets, respectively. Then the two models are integrated by using macro transitions. Based on the combined model, a novel control policy for deadlock avoidance is proposed. It is shown to be maximally permissive with computational complexity of O (n2) where n is the number of machines in AMS if the complexity for controlling the part transportation by AGVs is not considered. Thus, the complexity of deadlock avoidance for the whole system is bounded by the complexity in controlling the AGV system. An illustrative example shows its application and power. PMID:16366245

  12. The Teallach Tool: Using Models for Flexible User Interface Design

    E-print Network

    Paton, Norman

    The Teallach Tool: Using Models for Flexible User Interface Design Peter J. Barclay2 , Tony://www.dcs.gla.ac.uk/research/teallach/ Abstract Model-based user interface development environments aim to provide designers with a more systematic approach to user interface development using a particular design method. This method is realised

  13. Automated data acquisition technology development:Automated modeling and control development

    NASA Technical Reports Server (NTRS)

    Romine, Peter L.

    1995-01-01

    This report documents the completion of, and improvements made to, the software developed for automated data acquisition and automated modeling and control development on the Texas Micro rackmounted PC's. This research was initiated because a need was identified by the Metal Processing Branch of NASA Marshall Space Flight Center for a mobile data acquisition and data analysis system, customized for welding measurement and calibration. Several hardware configurations were evaluated and a PC based system was chosen. The Welding Measurement System (WMS), is a dedicated instrument strickly for use of data acquisition and data analysis. In addition to the data acquisition functions described in this thesis, WMS also supports many functions associated with process control. The hardware and software requirements for an automated acquisition system for welding process parameters, welding equipment checkout, and welding process modeling were determined in 1992. From these recommendations, NASA purchased the necessary hardware and software. The new welding acquisition system is designed to collect welding parameter data and perform analysis to determine the voltage versus current arc-length relationship for VPPA welding. Once the results of this analysis are obtained, they can then be used to develop a RAIL function to control welding startup and shutdown without torch crashing.

  14. Automated Verification of Model Transformations in the Automotive Industry

    E-print Network

    Cordy, James R.

    knowledge we are the first reporting on its application to an industrial-sized verification problem. WhileAutomated Verification of Model Transformations in the Automotive Industry Gehan M. K. Selim1 reported on such industrial expe- riences by discussing the effects of MDD and the issues that still need

  15. Computational design of patterned interfaces using reduced order models

    PubMed Central

    Vattré, A. J.; Abdolrahim, N.; Kolluri, K.; Demkowicz, M. J.

    2014-01-01

    Patterning is a familiar approach for imparting novel functionalities to free surfaces. We extend the patterning paradigm to interfaces between crystalline solids. Many interfaces have non-uniform internal structures comprised of misfit dislocations, which in turn govern interface properties. We develop and validate a computational strategy for designing interfaces with controlled misfit dislocation patterns by tailoring interface crystallography and composition. Our approach relies on a novel method for predicting the internal structure of interfaces: rather than obtaining it from resource-intensive atomistic simulations, we compute it using an efficient reduced order model based on anisotropic elasticity theory. Moreover, our strategy incorporates interface synthesis as a constraint on the design process. As an illustration, we apply our approach to the design of interfaces with rapid, 1-D point defect diffusion. Patterned interfaces may be integrated into the microstructure of composite materials, markedly improving performance. PMID:25169868

  16. Model coupling friction and adhesion for steel-concrete interfaces

    E-print Network

    Boyer, Edmond

    Model coupling friction and adhesion for steel- concrete interfaces Michel Raous Laboratoire de: In this paper the interface behaviour between steel and concrete, during pull out tests, is numerically a variable friction coefficient in order to simulate the behaviour of the steel-concrete interface during

  17. Hybrid modeling and dynamic simulation of automated batch plants.

    PubMed

    Sanchez, A; Parra, L F; Baird, R; Macchietto, S

    2003-07-01

    A proposal is presented for the hybrid modeling and dynamic simulation of automated batch processing plants with dominant discrete-event behavior. The proposal encompasses current techniques for modeling continuous-time/discrete-event processes, synthesizing discrete-event controllers as well as the use of industrial standards for batch control. The result is a hierarchical-modular model of a plant in which process and control tasks are clearly differentiated. Implementation rules are established for a specific dynamic simulator capable of handling hybrid systems. The approach is demonstrated by building and verifying a complete model for an automated milk pasteurization plant. Results show that handling problems of realistic complexity is feasible using state-of-the-art technology. PMID:12858975

  18. A framework for modeling the consequences of the propagation of automation degradation: application to

    E-print Network

    Paris-Sud XI, Université de

    A framework for modeling the consequences of the propagation of automation degradation: application of automation degradation in the context of a socio-technical network. This modelling approach involves two integrating these two views for describing the evolution of system performances under automation degradation

  19. Automated Adaptor Generation for Behavioral Mismatching Services Based on Pushdown Model Checking

    NASA Astrophysics Data System (ADS)

    Lin, Hsin-Hung; Aoki, Toshiaki; Katayama, Takuya

    In this paper, we introduce an approach of service adaptation for behavior mismatching services using pushdown model checking. This approach uses pushdown systems as model of adaptors so that capturing non-regular behavior in service interactions is possible. Also, the use of pushdown model checking integrates adaptation and verification. This guarantees that an adaptor generated by our approach not only solves behavior mismatches but also satisfies usual verification properties if specified. Unlike conventional approaches, we do not count on specifications of adaptor contracts but take only information from behavior interfaces of services and perform fully automated adaptor generation. Three requirements relating to behavior mismatches, unbounded messages, and branchings are retrieved from behavior interfaces and used to build LTL properties for pushdown model checking. Properties for unbounded messages, i.e., messages sent and received arbitrary multiple times, are especially addressed since it characterizes non-regular behavior in service composition. This paper also shows some experimental results from a prototype tool and provides directions for building BPEL adaptors from behavior interface of generated adaptor. The results show that our approach does solve behavior mismatches and successfully capture non-regular behavior in service composition under the scale of real service applications.

  20. Facilitating the exploration of interface design alternatives: the HUMANOID model of interface design

    Microsoft Academic Search

    Pedro A. Szekely; Ping Luo; Robert Neches

    1992-01-01

    HUMANOID is a user interface design tool that lets designers express abstract conceptualizations of an interface in an executable form, allowing designers to experiment with scenarios and dialogues even before the application model is completely worked out. Three properties of the HUMANOID approach allow it to do so: a modularization of design issues into independent dimensions, support for multiple levels

  1. Beyond Hacking: a Model Based Approach to User Interface Design

    Microsoft Academic Search

    S. Wilson; P. Johnson; C. Kelly; J. Cunningham; P. Markopoulos

    1993-01-01

    This paper discusses the role of models in the design of user interfaces, with particular emphasis on integration across different modelling stages. We are concerned with bridging the gap between psychologically motivated mod- elling approaches to HCI and implementation oriented interaction models, to produce a task-informed user interface design process. An early version of a UIDE which provides support for

  2. Hexapods with fieldbus interfaces for automated manufacturing of opto-mechanical components

    NASA Astrophysics Data System (ADS)

    Schreiber, Steffen; Muellerleile, Christian; Frietsch, Markus; Gloess, Rainer

    2013-09-01

    The adjustment of opto-mechanical components in manufacturing processes often requires precise motion in all six degrees of freedom with nanometer range resolution and absence of hysteresis. Parallel kinematic systems are predestined for such tasks due to their compact design, low inertia and high stiffness resulting in rapid settling behavior. To achieve adequate system performance, specialized motion controllers are required to handle the complex kinematic models for the different types of Hexapods and the associated extensive calculations of inverse kinematics. These controllers often rely on proprietary command languages, a fact that demands a high level of familiarization. This paper describes how the integration of fieldbus interfaces into Hexapod controllers simplifies the communication while providing higher flexibility. By using standardized communication protocols with cycle times down to 12.5 ?s it is straightforward to control multiple Hexapods and other devices by superordinate PLCs of different manufacturers. The paper also illustrates how to simplify adjustment and alignment processes by combining scanning algorithms with user defined coordinate systems.

  3. Automating the identification of structural model parameters

    SciTech Connect

    Allen, J.J.; Martinez, D.R.

    1989-01-01

    System identification methods are analytical techniques for resolving the correct model form and parametric values. However, for system identification to become a practical tool for engineering analysis, the estimation techniques/codes must communicate with finite element software packages, without intensive analyst intervention and supervision. This paper presents a technique used to integrate commercial software packages for finite element modeling (MSC/NASTRAN), mathematical programming techniques (ADS), and general linear system analysis (PRO-MATLAB). The parameter estimation techniques and the software for controlling the overall system were programmed in PRO-MATLAB. Two examples of application of this software are presented. The examples consist of a truss structure in which the model form is well defined and an electronics package whose model form is ill-defined since it is difficult to model with finite elements. A comparison of the resulting updated models with the experimental data showed significant improvement. 19 refs., 8 figs., 2 tabs.

  4. Automated Two Higgs Doublet Model at NLO

    E-print Network

    Celine Degrande

    2014-12-22

    The Two Higgs Doublet Model at NLO is generated automatically by FeynRules and NLOCT and allows any computation to be performed at NLO in QCD inside MadGraph5_aMC@NLO. The model can handle both four and five massless flavours. Preliminary results of the shape comparison between the two schemes are shown.

  5. Physical models of hydrofracturing across material interfaces

    SciTech Connect

    Blair, S.C.; Thorpe, R.K.; Heuze, F.E.

    1988-10-01

    We have performed a series of laboratory tests to study the propagation of a hydrofracture into and through an interface between two rock-like materials. The aim of this research is to provide improved diagnostics for stimulating lenticular gas sand reservoirs by interpreting features of the injection pressure-time record caused by interaction of a hydrofracture with a geologic discontinuity. Results will also be used to validate conceptual models of hydrofracture behavior in discontinuous media, such as are embodied in the LLNL FEFFLAP code, a two-dimensional fracture propagation computer program. We prepared test specimens by embedding sandstone tablets (lenses) in blocks of gypsum cement. These blocks were hydrofractured under true triaxial loading conditions, at a constant injection rate. The injection path was designed so that we obtained a single-wing fracture, propagating in a plane perpendicular to the interface. The vertical extent of the fractures was controlled by means of wire mesh screen embedded in the blocks, perpendicular to the injection tube. Growth of the fractures was tracked via extension failure of fine tungsten wires embedded in the gypsum. After testing, we dissected the blocks and recorded the extent of fracturing and fluid penetration. Cross-sections of the fractures indicate that they were of constant height and propagated through the sandstone tablet. All the fractures showed step-crack behavior upon entering or exiting the sandstone tablet. Pressure-time and fracture tracking data were consistent for all tests. Distinct step increases on the pressure- time record were also noted in all tests, and are related to the interaction of the hydrofracture with the sandstone lens. 16 refs., 19 figs., 4 tabs.

  6. Monitoring interface and automated testing for Seaweed, a web-based economic game system

    E-print Network

    Yuan, Jessica

    2010-01-01

    Seaweed is a web-based economic game system that allows end users to design and deploy simple two-player economic games. To improve the usability of the system, we have created two new features. One: a monitoring interface ...

  7. Towards Automated Models of Activities of Daily Life

    Microsoft Academic Search

    Michael Beetz; Jan Bandouch; Dominik Jain; Moritz Tenorth

    We propose automated probabilistic models of ev- eryday activities (AM-EvA) as a novel technical means for the perception, interpretation, and analysis of everyday ma- nipulation tasks and activities of daily life. AM-EvAs are based on action-related concepts in everyday activities such as action-related places (the place where cups are taken from the cupboard), capabilities (the objects that can be picked

  8. Automated refinement and inference of analytical models for metabolic networks.

    PubMed

    Schmidt, Michael D; Vallabhajosyula, Ravishankar R; Jenkins, Jerry W; Hood, Jonathan E; Soni, Abhishek S; Wikswo, John P; Lipson, Hod

    2011-10-01

    The reverse engineering of metabolic networks from experimental data is traditionally a labor-intensive task requiring a priori systems knowledge. Using a proven model as a test system, we demonstrate an automated method to simplify this process by modifying an existing or related model--suggesting nonlinear terms and structural modifications--or even constructing a new model that agrees with the system's time series observations. In certain cases, this method can identify the full dynamical model from scratch without prior knowledge or structural assumptions. The algorithm selects between multiple candidate models by designing experiments to make their predictions disagree. We performed computational experiments to analyze a nonlinear seven-dimensional model of yeast glycolytic oscillations. This approach corrected mistakes reliably in both approximated and overspecified models. The method performed well to high levels of noise for most states, could identify the correct model de novo, and make better predictions than ordinary parametric regression and neural network models. We identified an invariant quantity in the model, which accurately derived kinetics and the numerical sensitivity coefficients of the system. Finally, we compared the system to dynamic flux estimation and discussed the scaling and application of this methodology to automated experiment design and control in biological systems in real time. PMID:21832805

  9. Automated Environment Generation for Software Model Checking

    NASA Technical Reports Server (NTRS)

    Tkachuk, Oksana; Dwyer, Matthew B.; Pasareanu, Corina S.

    2003-01-01

    A key problem in model checking open systems is environment modeling (i.e., representing the behavior of the execution context of the system under analysis). Software systems are fundamentally open since their behavior is dependent on patterns of invocation of system components and values defined outside the system but referenced within the system. Whether reasoning about the behavior of whole programs or about program components, an abstract model of the environment can be essential in enabling sufficiently precise yet tractable verification. In this paper, we describe an approach to generating environments of Java program fragments. This approach integrates formally specified assumptions about environment behavior with sound abstractions of environment implementations to form a model of the environment. The approach is implemented in the Bandera Environment Generator (BEG) which we describe along with our experience using BEG to reason about properties of several non-trivial concurrent Java programs.

  10. Models for Automated Tube Performance Calculations

    SciTech Connect

    C. Brunkhorst

    2002-12-12

    High power radio-frequency systems, as typically used in fusion research devices, utilize vacuum tubes. Evaluation of vacuum tube performance involves data taken from tube operating curves. The acquisition of data from such graphical sources is a tedious process. A simple modeling method is presented that will provide values of tube currents for a given set of element voltages. These models may be used as subroutines in iterative solutions of amplifier operating conditions for a specific loading impedance.

  11. A power line data communication interface using spread spectrum technology in home automation

    SciTech Connect

    Shwehdi, M.H.; Khan, A.Z. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Electrical Engineering] [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Electrical Engineering

    1996-07-01

    Building automation technology is rapidly developing towards more reliable communication systems, devices that control electronic equipments. These equipment if controlled leads to efficient energy management, and savings on the monthly electricity bill. Power Line communication (PLC) has been one of the dreams of the electronics industry for decades, especially for building automation. It is the purpose of this paper to demonstrate communication methods among electronic control devices through an AC power line carrier within the buildings for more efficient energy control. The paper outlines methods of communication over a powerline, namely the X-10 and CE bus. It also introduces the spread spectrum technology as to increase speed to 100--150 times faster than the X-10 system. The powerline carrier has tremendous applications in the field of building automation. The paper presents an attempt to realize a smart house concept, so called, in which all home electronic devices from a coffee maker to a water heater microwave to chaos robots will be utilized by an intelligent network whenever one wishes to do so. The designed system may be applied very profitably to help in energy management for both customer and utility.

  12. Perturbations of Planar Interfaces in Ginzburg--Landau Models

    Microsoft Academic Search

    H. Arodz; R. Pelka; L. Stepien

    2001-01-01

    Certain dissipative Ginzburg-Landau models predict existence of planar interfaces moving with constant velocity. In most cases the interface solutions are hard to obtain because pertinent evolution equations are nonlinear. We present a systematic perturbative expansion which allows us to compute effects of small terms added to the free energy functional of a soluble model. As an example, we take the

  13. Automated Techniques for Road Network Modeling

    Microsoft Academic Search

    Martin A. Fischler; Aaron J. Heller

    1998-01-01

    In this paper, we present the results of work directed at the problem of radically reducing the amount of human effort required to model a road network vis- ible in a collection of images with overlapping cov- erage of some geographic extent.

  14. Automated retrieval of 3D CAD model objects in construction range images

    Microsoft Academic Search

    F. Bosche; C. T. Haas

    2008-01-01

    Automated and robust retrieval of three-dimensional (3D) Computer-Aided Design (CAD) objects from laser scanned data would have many potentially valuable applications in construction engineering and management. For example, it would enable automated progress assessment for effortless productivity tracking, automated 3D image database searching for forensic and legal analysis, and real-time local modeling for automated equipment control and safety. After reviewing

  15. Diffuse interface field approach to modeling arbitrarily-shaped particles at fluid-fluid interfaces

    SciTech Connect

    Paul C. Millett; Yu. U. Wang

    2011-01-01

    We present a novel mesoscale simulation approach to modeling the evolution of solid particles segregated at fluid-fluid interfaces. The approach involves a diffuse- interface field description of each fluid phase in addition to the set of solid particles. The unique strength of the model is its generality to include particles of arbitrary shapes and orientations, as well as the ability to incorporate electrostatic particle interactions and external forces via a previous work [Millett PC, Wang YU, Acta Mater 2009;57:3101]. In this work, we verify that the model produces the correct capillary forces and contact angles by comparing with a well-defined analytical solution. In addition, simulation results of rotations of various-shaped particles at fluid-fluid interfaces, external force- induced capillary attraction/repulsion between particles, and spinodal decomposition arrest due to colloidal particle jamming at the interfaces are presented.

  16. Sharp interface limits of phase-field models.

    PubMed

    Elder, K R; Grant, M; Provatas, N; Kosterlitz, J M

    2001-08-01

    The use of continuum phase-field models to describe the motion of well-defined interfaces is discussed for a class of phenomena that includes order-disorder transitions, spinodal decomposition and Ostwald ripening, dendritic growth, and the solidification of eutectic alloys. The projection operator method is used to extract the "sharp-interface limit" from phase-field models which have interfaces that are diffuse on a length scale xi. In particular, phase-field equations are mapped onto sharp-interface equations in the limits xi(kappa)<1 and xi(v)/D<1, where kappa and v are, respectively, the interface curvature and velocity and D is the diffusion constant in the bulk. The calculations provide one general set of sharp-interface equations that incorporate the Gibbs-Thomson condition, the Allen-Cahn equation, and the Kardar-Parisi-Zhang equation. PMID:11497600

  17. Sharp interface limits of phase-field models

    E-print Network

    K. R. Elder; Martin Grant; Nikolas Provatas; J. M. Kosterlitz

    2000-11-01

    The use of continuum phase-field models to describe the motion of well-defined interfaces is discussed for a class of phenomena, that includes order/disorder transitions, spinodal decomposition and Ostwald ripening, dendritic growth, and the solidification of eutectic alloys. The projection operator method is used to extract the ``sharp interface limit'' from phase field models which have interfaces that are diffuse on a length scale $\\xi$. In particular,phase-field equations are mapped onto sharp interface equations in the limits $\\xi \\kappa \\ll 1$ and $\\xi v/D \\ll 1$, where $\\kappa$ and $v$ are respectively the interface curvature and velocity and $D$ is the diffusion constant in the bulk. The calculations provide one general set of sharp interface equations that incorporate the Gibbs-Thomson condition, the Allen-Cahn equation and the Kardar-Parisi-Zhang equation.

  18. The Application of the Cumulative Logistic Regression Model to Automated Essay Scoring

    ERIC Educational Resources Information Center

    Haberman, Shelby J.; Sinharay, Sandip

    2010-01-01

    Most automated essay scoring programs use a linear regression model to predict an essay score from several essay features. This article applied a cumulative logit model instead of the linear regression model to automated essay scoring. Comparison of the performances of the linear regression model and the cumulative logit model was performed on a…

  19. Rapid Automated Aircraft Simulation Model Updating from Flight Data

    NASA Technical Reports Server (NTRS)

    Brian, Geoff; Morelli, Eugene A.

    2011-01-01

    Techniques to identify aircraft aerodynamic characteristics from flight measurements and compute corrections to an existing simulation model of a research aircraft were investigated. The purpose of the research was to develop a process enabling rapid automated updating of aircraft simulation models using flight data and apply this capability to all flight regimes, including flight envelope extremes. The process presented has the potential to improve the efficiency of envelope expansion flight testing, revision of control system properties, and the development of high-fidelity simulators for pilot training.

  20. Diffuse-Interface Model for Smoothed Particle Hydrodynamics

    SciTech Connect

    Zhijie Xu; Paul Meakin; Alexandre Tartakovsky

    2009-03-01

    Diffuse-interface theory provides a foundation for the modeling and simulation of microstructure evolution in a very wide range of materials, and for the tracking/capturing of dynamic interfaces between different materials on larger scales. Smoothed particle hydrodynamics (SPH) is also widely used to simulate fluids and solids that are subjected to large deformations and have complex dynamic boundaries and/or interfaces, but no explicit interface tracking/capturing is required, even when topological changes such as fragmentation and coalescence occur, because of its Lagrangian particle nature. Here we developed an SPH model for two component single phase fluids that is based on diffuse-interface theory. In the model, the interface has a finite thickness and a surface tension that depend on the coefficient, k, of the gradient contribution to the Helmholtz free energy functional and the density dependent homogeneous free energy. In this model, there is no need to locate the surface (or interface) or to compute the curvature at and near the interface. One- and two-dimensional SPH simulations were used to validate the model.

  1. Diffuse-interface model for smoothed particle hydrodynamics

    SciTech Connect

    Xu, Zhijie; Meakin, Paul; Tartakovsky, Alexandre M.

    2009-03-01

    Diffuse-interface theory provides a foundation for the modeling and simulation of microstructure evolution in a very wide range of materials, and for the tracking/capturing of dynamic interfaces between different materials on larger scales. Smoothed particle hydrodynamics (SPH) is also widely used to simulate fluids and solids that are subjected to large deformations and have complex dynamic boundaries and/or interfaces, but no explicit interface tracking/capturing is required, even when topological changes such as fragmentation and coalescence occur, because of its Lagrangian particle nature. Here we developed an SPH model for single-two component singletwo- phase fluids that is based on diffuse-interface theory. In the model, the interface has a finite thickness and a surface tension that depend on the coefficient, k, of the gradient contribution to the Helmholtz free energy functional and the density dependent homogeneous free energy. In this model, there is no need to locate the surface (or interface) or to compute the curvature at and near the interface. One- and two-dimensional SPH simulations were used to validate the model.

  2. WIZER: What-If Analyzer for Automated Social Model Space Exploration and Validation

    E-print Network

    Sadeh, Norman M.

    WIZER: What-If Analyzer for Automated Social Model Space Exploration and Validation Alex Yahja, or the US Government. #12;WIZER: What-If Analyzer for Automated Social Model Space Exploration and model space exploration [Prietula, Carley & Gasser 1998]. One of the computational models is the multi

  3. On linear modeling of interface damping in vibrating structures

    NASA Astrophysics Data System (ADS)

    Dovstam, Krister; Göransson, Peter; Gartmeier, Otto

    2012-09-01

    Dissipation of mechanical vibration energy at contact interfaces in a structure, commonly referred to as interface damping, is an important source of vibration damping in built-up structures and its modeling is the focus of the present study. The approach taken uses interface forces which are linearly dependent on the relative vibration displacements at the contact interfaces. The main objective is to demonstrate a straightforward technique for simulation of interface damping in built-up structures using FE modeling and simple, distributed, damping forces localized to interfaces where the damping occurs. As an illustration of the resulting damping the dissipated power is used for evaluation purposes. This is calculated from surface integrals over the contact interfaces and allows for explicit assessment of the effect of simulated interface forces for different cases and frequencies. The resulting loss factor at resonance is explicitly evaluated and, using linear simulations, it is demonstrated that high damping levels may arise even though the displacement differences between contacting surfaces at damped interfaces may be very small.

  4. Interfacing BIM with Building Thermal and Daylighting Modeling

    E-print Network

    Yan, Wei; Clayton, Mark; Haberl, Jeff; WoonSeong, Jeong; Bun Kim, Jong; Sandeep, Kota; Bermudez, Jose; Dixit, Manish

    INTERFACING BIM WITH BUILDING THERMAL AND DAYLIGHTING MODELING Wei Yan, Mark Clayton, Jeff Haberl, WoonSeong Jeong, Jong Bum Kim, Sandeep Kota, Jose Luis Bermudez Alcocer, and Manish Dixit Texas A&M University, College Station, USA... ABSTRACT This paper presents our research and development of system interfaces between Building Information Modeling (BIM) and Building Energy Modeling (BEM), for supporting integrated architectural design and energy simulation. Our methods utilize...

  5. Computationally efficient phase-field models with interface kinetics.

    PubMed

    Vetsigian, Kalin; Goldenfeld, Nigel

    2003-12-01

    We present a phase-field model of solidification which allows efficient computations in the regime when interface kinetic effects dominate over capillary effects. The asymptotic analysis required to relate the parameters in the phase field with those of the original sharp-interface model is straightforward, and the resultant phase-field model can be used for a wide range of material parameters. PMID:14754170

  6. Phase-field model with a reduced interface diffuseness

    Microsoft Academic Search

    Seong Gyoon Kim; Won Tae Kim; Toshio Suzuki

    2004-01-01

    We reduce the interface diffuseness in phase-field modeling of solidification by localizing the solute redistribution (or latent heat release) into a narrow region within the phase-field interface. The numerical computations on the dendritic solidification in a symmetric case and in an one-sided system yield quantitatively the same results with the standard phase field model and the anti-trapping model [Phys. Rev.

  7. Flexible dynamic models for user interfaces

    NASA Astrophysics Data System (ADS)

    Vogelsang, Holger; Brinkschulte, Uwe; Siormanolakis, Marios

    1997-04-01

    This paper describes an approach for a platform- and implementation-independent design of user interfaces using the UIMS idea. It is a result of a detailed examination of object-oriented techniques for program specification and implementation. This analysis leads to a description of the requirements for man-machine interaction from the software- developers point of view. On the other hand, the final user of the whole system has a different view of this system. He needs metaphors of his own world to fulfill his tasks. It's the job of the user interface designer to bring these views together. The approach, described in this paper, helps bringing both kinds of developers together, using a well defined interface with minimal communication overhead.

  8. Multibody dynamics model building using graphical interfaces

    NASA Technical Reports Server (NTRS)

    Macala, Glenn A.

    1989-01-01

    In recent years, the extremely laborious task of manually deriving equations of motion for the simulation of multibody spacecraft dynamics has largely been eliminated. Instead, the dynamicist now works with commonly available general purpose dynamics simulation programs which generate the equations of motion either explicitly or implicitly via computer codes. The user interface to these programs has predominantly been via input data files, each with its own required format and peculiarities, causing errors and frustrations during program setup. Recent progress in a more natural method of data input for dynamics programs: the graphical interface, is described.

  9. Automated Physico-Chemical Cell Model Development through Information Theory

    SciTech Connect

    Peter J. Ortoleva

    2005-11-29

    The objective of this project was to develop predictive models of the chemical responses of microbial cells to variations in their surroundings. The application of these models is optimization of environmental remediation and energy-producing biotechnical processes.The principles on which our project is based are as follows: chemical thermodynamics and kinetics; automation of calibration through information theory; integration of multiplex data (e.g. cDNA microarrays, NMR, proteomics), cell modeling, and bifurcation theory to overcome cellular complexity; and the use of multiplex data and information theory to calibrate and run an incomplete model. In this report we review four papers summarizing key findings and a web-enabled, multiple module workflow we have implemented that consists of a set of interoperable systems biology computational modules.

  10. Automated extraction of knowledge for model-based diagnostics

    NASA Technical Reports Server (NTRS)

    Gonzalez, Avelino J.; Myler, Harley R.; Towhidnejad, Massood; Mckenzie, Frederic D.; Kladke, Robin R.

    1990-01-01

    The concept of accessing computer aided design (CAD) design databases and extracting a process model automatically is investigated as a possible source for the generation of knowledge bases for model-based reasoning systems. The resulting system, referred to as automated knowledge generation (AKG), uses an object-oriented programming structure and constraint techniques as well as internal database of component descriptions to generate a frame-based structure that describes the model. The procedure has been designed to be general enough to be easily coupled to CAD systems that feature a database capable of providing label and connectivity data from the drawn system. The AKG system is capable of defining knowledge bases in formats required by various model-based reasoning tools.

  11. Finite element modeling of frictionally restrained composite interfaces

    NASA Technical Reports Server (NTRS)

    Ballarini, Roberto; Ahmed, Shamim

    1989-01-01

    The use of special interface finite elements to model frictional restraint in composite interfaces is described. These elements simulate Coulomb friction at the interface, and are incorporated into a standard finite element analysis of a two-dimensional isolated fiber pullout test. Various interfacial characteristics, such as the distribution of stresses at the interface, the extent of slip and delamination, load diffusion from fiber to matrix, and the amount of fiber extraction or depression are studied for different friction coefficients. The results are compared to those obtained analytically using a singular integral equation approach, and those obtained by assuming a constant interface shear strength. The usefulness of these elements in micromechanical modeling of fiber-reinforced composite materials is highlighted.

  12. The design of the computer-human interface of integrated resource management automation (IRMA)

    E-print Network

    Holtfrerich, David Russell

    1991-01-01

    of IRMA's final release version 33 Figure Figure Figure 15 16 17 An example save and paste query SQL prompt An example online help screen The original method for a two layer GIS function 35 36 38 Figure 18 The release version's method for a... two layer GIS function . 39 Figure 19 The table command with a reminder message 41 Figure 20 The elements of a transition diagram 43 INTRODUCTION The design of the human interface should be an integral segment in the development of computer...

  13. ALC: automated reduction of rule-based models

    PubMed Central

    Koschorreck, Markus; Gilles, Ernst Dieter

    2008-01-01

    Background Combinatorial complexity is a challenging problem for the modeling of cellular signal transduction since the association of a few proteins can give rise to an enormous amount of feasible protein complexes. The layer-based approach is an approximative, but accurate method for the mathematical modeling of signaling systems with inherent combinatorial complexity. The number of variables in the simulation equations is highly reduced and the resulting dynamic models show a pronounced modularity. Layer-based modeling allows for the modeling of systems not accessible previously. Results ALC (Automated Layer Construction) is a computer program that highly simplifies the building of reduced modular models, according to the layer-based approach. The model is defined using a simple but powerful rule-based syntax that supports the concepts of modularity and macrostates. ALC performs consistency checks on the model definition and provides the model output in different formats (C MEX, MATLAB, Mathematica and SBML) as ready-to-run simulation files. ALC also provides additional documentation files that simplify the publication or presentation of the models. The tool can be used offline or via a form on the ALC website. Conclusion ALC allows for a simple rule-based generation of layer-based reduced models. The model files are given in different formats as ready-to-run simulation files. PMID:18973705

  14. Interfaces and Free Boundaries: Modeling, Analysis and

    E-print Network

    Granick, Steve

    , online only), £50, $80 (individual) Albert-László Barabási The alarming loss of biodiversity is accom, but they are scattered across disciplines. Interfaces and Free Boundaries is one such safe haven, offering a fertile soil

  15. A PREDICTIVE MODEL OF FLIGHT CREW PERFORMANCE IN AUTOMATED AIR TRAFFIC CONTROL AND FLIGHT MANAGEMENT OPERATIONS

    Microsoft Academic Search

    Gregory M. Pisanich; Kevin M. Corker

    This paper describes Air-MIDAS, a model of pilot performance in interaction with varied levels of automation in flight management operations. The model was used to predict the performance of a two person flight crew responding to clearance information generated by the Center TRACON Automation System (CTAS). The model represents the information requirements, decision processes, communication processes, and motor performance required

  16. Numerical study of a model for driven interface dynamics

    Microsoft Academic Search

    N. Govind; H. Guo

    1992-01-01

    The authors study a nonlinear Langevin model for interface dynamics where relaxation is controlled by surface diffusion. While the linear part of the model can be solved analytically, a renormalization group analysis on the nonlinear model does not yield a stable fixed point. They have thus solved the model numerically in both two and three spatial dimensions. The dynamical scaling

  17. A generalized mechanical model for suture interfaces of arbitrary geometry

    NASA Astrophysics Data System (ADS)

    Li, Yaning; Ortiz, Christine; Boyce, Mary C.

    2013-04-01

    Suture interfaces with a triangular wave form commonly found in nature have recently been shown to exhibit exceptional mechanical behavior, where geometric parameters such as amplitude, frequency, and hierarchy can be used to nonlinearly tailor and amplify mechanical properties. In this study, using the principle of complementary virtual work, we formulate a generalized, composite mechanical model for arbitrarily-shaped interdigitating suture interfaces in order to more broadly investigate the influence of wave-form geometry on load transmission, deformation mechanisms, anisotropy, and stiffness, strength, and toughness of the suture interface for tensile and shear loading conditions. The application of this suture interface model is exemplified for the case of the general trapezoidal wave-form. Expressions for the in-plane stiffness, strength and fracture toughness and failure mechanisms are derived as nonlinear functions of shape factor ? (which characterizes the general trapezoidal shape as triangular, trapezoidal, rectangular or anti-trapezoidal), the wavelength/amplitude ratio, the interface width/wavelength ratio, and the stiffness and strength ratios of the skeletal/interfacial phases. These results provide guidelines for choosing and tailoring interface geometry to optimize the mechanical performance in resisting different loads. The presented model provides insights into the relation between the mechanical function and the morphological diversity of suture interface geometries observed in natural systems.

  18. Automation on the generation of genome-scale metabolic models.

    PubMed

    Reyes, R; Gamermann, D; Montagud, A; Fuente, D; Triana, J; Urchueguía, J F; de Córdoba, P Fernández

    2012-12-01

    Nowadays, the reconstruction of genome-scale metabolic models is a nonautomatized and interactive process based on decision making. This lengthy process usually requires a full year of one person's work in order to satisfactory collect, analyze, and validate the list of all metabolic reactions present in a specific organism. In order to write this list, one manually has to go through a huge amount of genomic, metabolomic, and physiological information. Currently, there is no optimal algorithm that allows one to automatically go through all this information and generate the models taking into account probabilistic criteria of unicity and completeness that a biologist would consider. This work presents the automation of a methodology for the reconstruction of genome-scale metabolic models for any organism. The methodology that follows is the automatized version of the steps implemented manually for the reconstruction of the genome-scale metabolic model of a photosynthetic organism, Synechocystis sp. PCC6803. The steps for the reconstruction are implemented in a computational platform (COPABI) that generates the models from the probabilistic algorithms that have been developed. For validation of the developed algorithm robustness, the metabolic models of several organisms generated by the platform have been studied together with published models that have been manually curated. Network properties of the models, like connectivity and average shortest mean path of the different models, have been compared and analyzed. PMID:23210477

  19. Molecular modeling of cracks at interfaces in nanoceramic composites

    NASA Astrophysics Data System (ADS)

    Pavia, F.; Curtin, W. A.

    2013-10-01

    Toughness in Ceramic Matrix Composites (CMCs) is achieved if crack deflection can occur at the fiber/matrix interface, preventing crack penetration into the fiber and enabling energy-dissipating fiber pullout. To investigate toughening in nanoscale CMCs, direct atomistic models are used to study how matrix cracks behave as a function of the degree of interfacial bonding/sliding, as controlled by the density of C interstitial atoms, at the interface between carbon nanotubes (CNTs) and a diamond matrix. Under all interface conditions studied, incident matrix cracks do not penetrate into the nanotube. Under increased loading, weaker interfaces fail in shear while stronger interfaces do not fail and, instead, the CNT fails once the stress on the CNT reaches its tensile strength. An analytic shear lag model captures all of the micromechanical details as a function of loading and material parameters. Interface deflection versus fiber penetration is found to depend on the relative bond strengths of the interface and the CNT, with CNT failure occurring well below the prediction of the toughness-based continuum He-Hutchinson model. The shear lag model, in contrast, predicts the CNT failure point and shows that the nanoscale embrittlement transition occurs at an interface shear strength scaling as ?s~?? rather than ?s~? typically prevailing for micron scale composites, where ? and ? are the CNT failure strain and stress, respectively. Interface bonding also lowers the effective fracture strength in SWCNTs, due to formation of defects, but does not play a role in DWCNTs having interwall coupling, which are weaker than SWCNTs but less prone to damage in the outerwall.

  20. Application of a Micromechanical Model to Wave Propagation Through Nonlinear Rough Interfaces

    E-print Network

    Boyer, Edmond

    Application of a Micromechanical Model to Wave Propagation Through Nonlinear Rough Interfaces Under such interfaces. A micromechanical methodology is applied to explicitly model the initial normal and shear. Micromechanical approaches that explicitly include interface surface topography and incorporate material

  1. A LIBRARY OF HVAC COMPONENT MODELS FOR USE IN AUTOMATED1 DIAGNOSTICS2

    E-print Network

    control and management systems heightens the need for the devolvement of tools to assist in monitoringA LIBRARY OF HVAC COMPONENT MODELS FOR USE IN AUTOMATED1 DIAGNOSTICS2 3 4 Peng Xu, Philip Haves a library of equipment reference models developed for automated fault detection and diagnosis of secondary

  2. Automated Proof for Authorization Protocols of TPM 2.0 in Computational Model (full version)

    E-print Network

    Automated Proof for Authorization Protocols of TPM 2.0 in Computational Model (full version) Weijin,qin_yu,feng,chuxiaobo}@tca.iscas.ac.cn Abstract. We present the first automated proof of the authorization protocols in TPM 2.0 in the computational model. The Trusted Plat- form Module(TPM) is a chip that enables trust in computing platforms

  3. A Comparison Study: Sketch-Based Interfaces versus WIMP Interfaces in Three Dimensional Modeling Tasks

    Microsoft Academic Search

    Tiago Lemos De Araujo Machado; Alex Sandro Gomes; Marcelo Walter

    2009-01-01

    Sketch-Based Interfaces are becoming a popular interaction style for many applications. The interaction style tries to recreate the experience of sketching that is similar to real paper and pencil drawings.They are being used to accomplish tasks related to geometric modeling, animation, architecture, design, music, and learning, among others. In this work we evaluate and compare two interaction approaches, Sketch and

  4. The Teallach Tool: Using Models for Flexible User Interface Design

    Microsoft Academic Search

    Peter J. Barclay; Tony Griffiths; Jo Mckirdy; Norman W. Paton; Richard Cooper; Jessie B. Kennedy

    1999-01-01

    Model-based user interface development environments aim to provide designers with a more systematic approach to user i nterface development using a particular design method. This method is re alised through tools which support the construction and linkage of the support ed models. This paper presents the tools which support the construction o f the Teallach models in the context of

  5. A 2-D constitutive model for cyclic interface behaviour

    NASA Astrophysics Data System (ADS)

    Mortara, Giuseppe; Boulon, Marc; Ghionna, Vito Nicola

    2002-09-01

    The paper concerns a 2-D constitutive model for interface behaviour between sand and solid inclusions under cyclic loading. The model is based on the experimental results obtained from laboratory direct shear interface tests conducted under both constant normal load (CNL) and constant normal stiffness (CNS) conditions. The model is formulated in terms of interface stresses and relative velocities and has been derived by extending an elastoplastic isotropic model previously formulated for monotonic loading to stress reversal paths. Such extension consists in adding to the isotropic hardening mechanism a kinematic rotational one defined by an inner conical surface rotating around the origin of the stress space. This allows one to store the memory of the previous stress and relative displacement history giving to the model the capability to analyse the interface behaviour under cyclic loading. After a brief description of the criteria governing the monotonic model, the paper describes in detail the features of the kinematic hardening. Finally, the predictions of the model are compared with the experimental results obtained from CNL and CNS interface tests.

  6. Empirical rheological model for rough or grooved bonded interfaces.

    PubMed

    Belloncle, Valentina Vlasie; Rousseau, Martine

    2007-12-01

    In the industrial sector, it is common to use metal/adhesive/metal structural bonds. The cohesion of such structures can be improved by preliminary chemical treatments (degreasing with solvents, alkaline, or acid pickling), electrochemical treatments (anodising), or mechanical treatments (abrasion, sandblasting, grooving) of the metallic plates. All these pretreatments create some asperities, ranging from roughnesses to grooves. On the other hand, in damage solid mechanics and in non-destructive testing, rheological models are used to measure the strength of bonded interfaces. However, these models do not take into account the interlocking of the adhesive in the porosities. Here, an empirical rheological model taking into account the interlocking effects is developed. This model depends on a characteristic parameter representing the average porosity along the interface, which considerably simplifies the corresponding stress and displacement jump conditions. The paper deals with the influence of this interface model on the ultrasonic guided modes of the structure. PMID:17659313

  7. Numerical modeling of capillary electrophoresis - electrospray mass spectrometry interface design.

    PubMed

    Jarvas, Gabor; Guttman, Andras; Foret, Frantisek

    2014-03-26

    Capillary electrophoresis hyphenated with electrospray mass spectrometry (CE-ESI-MS) has emerged in the past decade as one of the most powerful bioanalytical techniques. As the sensitivity and efficiency of new CE-ESI-MS interface designs are continuously improving, numerical modeling can play important role during their development. In this review, different aspects of computer modeling and simulation of CE-ESI-MS interfaces are comprehensively discussed. Relevant essentials of hydrodynamics as well as state-of-the-art modeling techniques are critically evaluated. Sheath liquid-, sheathless-, and liquid-junction interfaces are reviewed from the viewpoint of multidisciplinary numerical modeling along with details of single and multiphase models together with electric field mediated flows, electrohydrodynamics, and free fluid-surface methods. Practical examples are given to help non-specialists to understand the basic principles and applications. Finally, alternative approaches like air amplifiers are also included. © 2014 Wiley Periodicals, Inc. Mass Spec Rev. PMID:24676884

  8. Flightdeck Automation Problems (FLAP) Model for Safety Technology Portfolio Assessment

    NASA Technical Reports Server (NTRS)

    Ancel, Ersin; Shih, Ann T.

    2014-01-01

    NASA's Aviation Safety Program (AvSP) develops and advances methodologies and technologies to improve air transportation safety. The Safety Analysis and Integration Team (SAIT) conducts a safety technology portfolio assessment (PA) to analyze the program content, to examine the benefits and risks of products with respect to program goals, and to support programmatic decision making. The PA process includes systematic identification of current and future safety risks as well as tracking several quantitative and qualitative metrics to ensure the program goals are addressing prominent safety risks accurately and effectively. One of the metrics within the PA process involves using quantitative aviation safety models to gauge the impact of the safety products. This paper demonstrates the role of aviation safety modeling by providing model outputs and evaluating a sample of portfolio elements using the Flightdeck Automation Problems (FLAP) model. The model enables not only ranking of the quantitative relative risk reduction impact of all portfolio elements, but also highlighting the areas with high potential impact via sensitivity and gap analyses in support of the program office. Although the model outputs are preliminary and products are notional, the process shown in this paper is essential to a comprehensive PA of NASA's safety products in the current program and future programs/projects.

  9. AUTOMATED GEOSPATICAL WATERSHED ASSESSMENT (AGWA): A GIS-BASED HYDROLOICAL MODELING TOOL FOR WATERSHED ASSESSMENT AND ANALYSIS

    EPA Science Inventory

    The Automated Geospatial Watershed Assessment tool (AGWA) is a GIS interface jointly developed by the USDA Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execut...

  10. AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT (AGWA): A GIS-BASED HYDROLOGIC MODELING TOOL FOR WATERSHED MANAGEMENT AND LANDSCAPE ASSESSMENT 1798

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Automated Geospatial Watershed Assessment (AGWA, see: www.tucson.ars.ag.gov/agwa) tool is a GIS interface jointly developed by the USDA-ARS, US-EPA, U. Arizona, and U. Wyoming to automate the parameterization and execution of the Soil Water Assessment Tool (SWAT) and KINEmatic Runoff and EROSion...

  11. AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT (AGWA): A GIS-BASED HYDROLOGIC MODELING TOOL FOR WATERSHED ASSESSMENT AND ANALYSIS

    EPA Science Inventory

    The Automated Geospatial Watershed Assessment tool (AGWA) is a GIS interface jointly developed by the USDA Agricultural Research Service, the U.S. Environmental Protection Agency, the University of Arizona, and the University of Wyoming to automate the parameterization and execu...

  12. The Model of Stiff Imperfect Interface and Its Application in Interaction between Dislocation and Interface

    Microsoft Academic Search

    Shi-Xiang Ma; Hong Hu; Xin-Ming Zhang; Hui Fan

    2007-01-01

    Most of the existing studies on interface\\/dislocation treat the interface either as ideal contact interface, or as soft imperfect interface. In present study, the imperfect interface conditions for anti-plane problem are derived systematically on the basis of asymptotic expansion for the elastic field in a layer. Furthermore, the interaction of a screw dislocation with a stiff imperfect interface described by

  13. A distributed data component for the open modeling interface

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the volume of collected data continues to increase in the environmental sciences, so does the need for effective means for accessing those data. We have developed an Open Modeling Interface (OpenMI) data component that retrieves input data for model components from environmental information syste...

  14. Graspable Interfaces as Tool for Cooperative Modelling

    E-print Network

    Hornecker, Eva

    modelling. It examines positive effects of graspable models on social interaction and presents a model how using a graspable medium support the hypothesis. They show the im- portance of parallel activity, how gestures, talk and artefacts interact in shared understanding, enforce focus and clarification, and how non

  15. Solid phase extraction-liquid chromatography (SPE-LC) interface for automated peptide separation and identification by tandem mass spectrometry

    NASA Astrophysics Data System (ADS)

    Hørning, Ole Bjeld; Theodorsen, Søren; Vorm, Ole; Jensen, Ole Nørregaard

    2007-12-01

    Reversed-phase solid phase extraction (SPE) is a simple and widely used technique for desalting and concentration of peptide and protein samples prior to mass spectrometry analysis. Often, SPE sample preparation is done manually and the samples eluted, dried and reconstituted into 96-well titer plates for subsequent LC-MS/MS analysis. To reduce the number of sample handling stages and increase throughput, we developed a robotic system to interface off-line SPE to LC-ESI-MS/MS. Samples were manually loaded onto disposable SPE tips that subsequently were connected in-line with a capillary chromatography column. Peptides were recovered from the SPE column and separated on the RP-LC column using isocratic elution conditions and analysed by electrospray tandem mass spectrometry. Peptide mixtures eluted within approximately 5 min, with individual peptide peak resolution of ~7 s (FWHM), making the SPE-LC suited for analysis of medium complex samples (3-12 protein components). For optimum performance, the isocratic flow rate was reduced to 30 nL/min, producing nanoelectrospray like conditions which ensure high ionisation efficiency and sensitivity. Using a modified autosampler for mounting and disposing of the SPE tips, the SPE-LC-MS/MS system could analyse six samples per hour, and up to 192 SPE tips in one batch. The relatively high sample throughput, medium separation power and high sensitivity makes the automated SPE-LC-MS/MS setup attractive for proteomics experiments as demonstrated by the identification of the components of simple protein mixtures and of proteins recovered from 2DE gels.

  16. Aviation Safety: Modeling and Analyzing Complex Interactions between Humans and Automated Systems

    NASA Technical Reports Server (NTRS)

    Rungta, Neha; Brat, Guillaume; Clancey, William J.; Linde, Charlotte; Raimondi, Franco; Seah, Chin; Shafto, Michael

    2013-01-01

    The on-going transformation from the current US Air Traffic System (ATS) to the Next Generation Air Traffic System (NextGen) will force the introduction of new automated systems and most likely will cause automation to migrate from ground to air. This will yield new function allocations between humans and automation and therefore change the roles and responsibilities in the ATS. Yet, safety in NextGen is required to be at least as good as in the current system. We therefore need techniques to evaluate the safety of the interactions between humans and automation. We think that current human factor studies and simulation-based techniques will fall short in front of the ATS complexity, and that we need to add more automated techniques to simulations, such as model checking, which offers exhaustive coverage of the non-deterministic behaviors in nominal and off-nominal scenarios. In this work, we present a verification approach based both on simulations and on model checking for evaluating the roles and responsibilities of humans and automation. Models are created using Brahms (a multi-agent framework) and we show that the traditional Brahms simulations can be integrated with automated exploration techniques based on model checking, thus offering a complete exploration of the behavioral space of the scenario. Our formal analysis supports the notion of beliefs and probabilities to reason about human behavior. We demonstrate the technique with the Ueberligen accident since it exemplifies authority problems when receiving conflicting advices from human and automated systems.

  17. Individual Differences in Response to Automation: The Five Factor Model of Personality

    ERIC Educational Resources Information Center

    Szalma, James L.; Taylor, Grant S.

    2011-01-01

    This study examined the relationship of operator personality (Five Factor Model) and characteristics of the task and of adaptive automation (reliability and adaptiveness--whether the automation was well-matched to changes in task demand) to operator performance, workload, stress, and coping. This represents the first investigation of how the Five…

  18. Perturbations of Planar Interfaces in Ginzburg--Landau Models

    NASA Astrophysics Data System (ADS)

    Arodz, H.; Pelka, R.; Stepien, L.

    2001-04-01

    Certain dissipative Ginzburg-Landau models predict existence of planar interfaces moving with constant velocity. In most cases the interface solutions are hard to obtain because pertinent evolution equations are nonlinear. We present a systematic perturbative expansion which allows us to compute effects of small terms added to the free energy functional of a soluble model. As an example, we take the exactly soluble model with single order parameter \\varphi and the potential V0(\\varphi ) = A \\varphi 2 + B \\varphi 3 + \\varphi 4, and we perturb it by adding V1(? ) = 1/2 \\varepsilon 1\\varphi 2 partial i\\varphi partial i\\varphi + 1/5 \\varepsilon 2 \\varphi 5 + 1/6 \\varepsilon 3 \\varphi 6. We discuss the corresponding changes of the velocity of the planar interface.

  19. Perturbations of planar interfaces in Ginzburg-Landau models

    E-print Network

    H. Arodz; R. Pelka; L. Stepien

    2001-03-06

    Certain dissipative Ginzburg-Landau models predict existence of planar interfaces moving with constant velocity. In most cases the interface solutions are hard to obtain because pertinent evolution equations are nonlinear. We present a systematic perturbative expansion which allows us to compute effects of small terms added to the free energy functional of a soluble model. As an example, we take the exactly soluble model with single order parameter $\\phi$ and the potential $V_0(\\phi) = A\\phi^2 + B \\phi^3 + \\phi^4$, and we perturb it by adding $V_1(\\phi) = {1/2} \\epsilon_1 \\phi^2 \\partial_i \\phi \\partial_i \\phi + 1/5 \\epsilon_2 \\phi^5 + 1/6 \\epsilon_3 \\phi^6. $ We discuss the corresponding changes of the velocity of the planar interface.

  20. An interface model for dosage adjustment connects hematotoxicity to pharmacokinetics.

    PubMed

    Meille, C; Iliadis, A; Barbolosi, D; Frances, N; Freyer, G

    2008-12-01

    When modeling is required to describe pharmacokinetics and pharmacodynamics simultaneously, it is difficult to link time-concentration profiles and drug effects. When patients are under chemotherapy, despite the huge amount of blood monitoring numerations, there is a lack of exposure variables to describe hematotoxicity linked with the circulating drug blood levels. We developed an interface model that transforms circulating pharmacokinetic concentrations to adequate exposures, destined to be inputs of the pharmacodynamic process. The model is materialized by a nonlinear differential equation involving three parameters. The relevance of the interface model for dosage adjustment is illustrated by numerous simulations. In particular, the interface model is incorporated into a complex system including pharmacokinetics and neutropenia induced by docetaxel and by cisplatin. Emphasis is placed on the sensitivity of neutropenia with respect to the variations of the drug amount. This complex system including pharmacokinetic, interface, and pharmacodynamic hematotoxicity models is an interesting tool for analysis of hematotoxicity induced by anticancer agents. The model could be a new basis for further improvements aimed at incorporating new experimental features. PMID:19107581

  1. Designing a flexible grid enabled scientific modeling interface.

    SciTech Connect

    Dvorak, M.; Taylor, J.; Mickelson, S.

    2002-08-15

    The Espresso Scientific Modeling Interface (Espresso) is a scientific modeling productivity tool developed from climate modelers. Espresso was designed to be an extensible interface to both scientific models and Grid resources. It also aims to be a contemporary piece of software that relies on Globus.org's Java CoG Kit for a Grid toolkit, Sun's Java 2 API and is configured using XML. This article covers the design implementation of Espresso's Grid functionality and how it interacts with existing scientific models. The authors give specific examples of how they have designed Espresso to perform climate simulations using the PSU/NCAR MM5 atmospheric model. Plans to incorporate the CCSM and FOAM climate models are also discussed.

  2. Improved Sharp Interface Models in Coastal Aquifers of Finite Dimensions

    NASA Astrophysics Data System (ADS)

    Christelis, Vasileios; Mantoglou, Aristotelis

    2013-04-01

    Coastal aquifer management often involves aquifers of finite dimensions where optimal pumping rates must be calculated through a combined simulation-optimization procedure. Variable-density numerical models are considered more exact than sharp interface models as they better describe the governing flow and transport equations. However, such models are not always preferable in pumping optimization studies, due to their complexity and computational burden. On the other hand, sharp interface models are approximate and can lead to large errors if they are not applied properly, particularly when model boundaries are not treated correctly. The present paper proposes improved sharp interface models considering aquifer boundaries in a proper way. Two sharp interface models are investigated based on the single potential formulation and the Ghyben-Herzberg relation. The first model (Strack, 1976) is based on the assumption of a semi-infinite aquifer with a sea-boundary only. The second model (Mantoglou, 2003) is based on an analytical solution developed for coastal aquifers of finite size and accounts for inland and lateral aquifer boundaries. Next, both models are modified using an empirical correction factor (similar to Pool and Carrera, 2011) which accounts for mixing. A simple pumping optimization problem with a single well in a confined coastal aquifer of finite size with four boundaries (sea, inland and lateral impervious boundaries) is employed. The constraint prevents the toe of the interface to reach the well and the optimal pumping rates are calculated for different locations of the pumping well and different combinations of aquifer parameters. Then the results of the sharp interface models are compared to the 'true' results of the corresponding variable-density numerical model in order to evaluate the performance of the sharp interface models. The results indicate that when the location of the well is close to the sea-boundary, the semi-infinite and the finite sized models produce similar, underestimated optimal solutions. However, when the well is placed inland, or near the lateral boundaries, the semi-infinite model yields much higher pumping rates than the finite sized model which are not always realistic and sustainable. This unrealistic performance is further exacerbated when the correction factor is applied to this model. Furthermore, it is observed that the correction factor is sensitive to different combinations of aquifer parameters in the case of the semi-infinite model. On the other hand, the finite sized sharp interface model of Mantoglou (2003), improved using the correction factor, yields increased and sustainable pumping rates regardless of the well location. This is because this model considers inland and lateral boundaries and is better suited for finite sized aquifers whereas the unrealistic behavior of the semi-infinite model is expected since it neglects those boundaries. We conclude that the finite sized sharp interface model, improved with an appropriate correction factor is a better alternative when applied to aquifers of finite dimensions.

  3. Critical interfaces and duality in the Ashkin-Teller model

    SciTech Connect

    Picco, Marco [Laboratoire de Physique Theorique et Hautes Energies, CNRS, Universite Pierre et Marie Curie, UMR 7589, 4 Place Jussieu, F-75252 Paris Cedex 05 (France); Santachiara, Raoul [Laboratoire de Physique Theorique et Modeles Statistiques, CNRS, Batiment 100, Universite Paris-Sud, UMR 8626, F-91405 Orsay (France)

    2011-06-15

    We report on the numerical measures on different spin interfaces and Fortuin-Kasteleyn (FK) cluster boundaries in the Askhin-Teller (AT) model. For a general point on the AT critical line, we find that the fractal dimension of a generic spin cluster interface can take one of four different possible values. In particular we found spin interfaces whose fractal dimension is d{sub f}=3/2 all along the critical line. Furthermore, the fractal dimension of the boundaries of FK clusters was found to satisfy all along the AT critical line a duality relation with the fractal dimension of their outer boundaries. This result provides clear numerical evidence that such duality, which is well known in the case of the O(n) model, exists in an extended conformal field theory.

  4. NEW GRAPHICAL REASONING MODELS UNDERSTANDING GRAPHICAL INTERFACES

    E-print Network

    Furnas, George W.

    , production-system models of Kieras and Polson[7]. Karat [4] attempted just such an analysis to compare, and studied a file deletion task. Karat indeed found that the graphical system was easier, and though the CCT

  5. Modeling nonspecific interactions at biological interfaces

    NASA Astrophysics Data System (ADS)

    White, Andrew D.

    Difficulties in applied biomaterials often arise from the complexities of interactions in biological environments. These interactions can be broadly broken into two categories: those which are important to function (strong binding to a single target) and those which are detrimental to function (weak binding to many targets). These will be referred to as specific and nonspecific interactions, respectively. Nonspecific interactions have been central to failures of biomaterials, sensors, and surface coatings in harsh biological environments. There is little modeling work on studying nonspecific interactions. Modeling all possible nonspecific interactions within a biological system is difficult, yet there are ways to both indirectly model nonspecific interactions and directly model many interactions using machine-learning. This research utilizes bioinformatics, phenomenological modeling, molecular simulations, experiments, and stochastic modeling to study nonspecific interactions. These techniques are used to study the hydration molecules which resist nonspecific interactions, the formation of salt bridges, the chemistry of protein surfaces, nonspecific stabilization of proteins in molecular chaperones, and analysis of high-throughput screening experiments. The common aspect for these systems is that nonspecific interactions are more important than specific interactions. Studying these disparate systems has created a set of principles for resisting nonspecific interactions which have been experimentally demonstrated with the creation and testing of novel materials which resist nonspecific interactions.

  6. Automated model selection in covariance estimation and spatial whitening of MEG and EEG signals.

    PubMed

    Engemann, Denis A; Gramfort, Alexandre

    2015-03-01

    Magnetoencephalography and electroencephalography (M/EEG) measure non-invasively the weak electromagnetic fields induced by post-synaptic neural currents. The estimation of the spatial covariance of the signals recorded on M/EEG sensors is a building block of modern data analysis pipelines. Such covariance estimates are used in brain-computer interfaces (BCI) systems, in nearly all source localization methods for spatial whitening as well as for data covariance estimation in beamformers. The rationale for such models is that the signals can be modeled by a zero mean Gaussian distribution. While maximizing the Gaussian likelihood seems natural, it leads to a covariance estimate known as empirical covariance (EC). It turns out that the EC is a poor estimate of the true covariance when the number of samples is small. To address this issue the estimation needs to be regularized. The most common approach downweights off-diagonal coefficients, while more advanced regularization methods are based on shrinkage techniques or generative models with low rank assumptions: probabilistic PCA (PPCA) and factor analysis (FA). Using cross-validation all of these models can be tuned and compared based on Gaussian likelihood computed on unseen data. We investigated these models on simulations, one electroencephalography (EEG) dataset as well as magnetoencephalography (MEG) datasets from the most common MEG systems. First, our results demonstrate that different models can be the best, depending on the number of samples, heterogeneity of sensor types and noise properties. Second, we show that the models tuned by cross-validation are superior to models with hand-selected regularization. Hence, we propose an automated solution to the often overlooked problem of covariance estimation of M/EEG signals. The relevance of the procedure is demonstrated here for spatial whitening and source localization of MEG signals. PMID:25541187

  7. Designers' models of the human-computer interface

    NASA Technical Reports Server (NTRS)

    Gillan, Douglas J.; Breedin, Sarah D.

    1993-01-01

    Understanding design models of the human-computer interface (HCI) may produce two types of benefits. First, interface development often requires input from two different types of experts: human factors specialists and software developers. Given the differences in their backgrounds and roles, human factors specialists and software developers may have different cognitive models of the HCI. Yet, they have to communicate about the interface as part of the design process. If they have different models, their interactions are likely to involve a certain amount of miscommunication. Second, the design process in general is likely to be guided by designers' cognitive models of the HCI, as well as by their knowledge of the user, tasks, and system. Designers do not start with a blank slate; rather they begin with a general model of the object they are designing. The author's approach to a design model of the HCI was to have three groups make judgments of categorical similarity about the components of an interface: human factors specialists with HCI design experience, software developers with HCI design experience, and a baseline group of computer users with no experience in HCI design. The components of the user interface included both display components such as windows, text, and graphics, and user interaction concepts, such as command language, editing, and help. The judgments of the three groups were analyzed using hierarchical cluster analysis and Pathfinder. These methods indicated, respectively, how the groups categorized the concepts, and network representations of the concepts for each group. The Pathfinder analysis provides greater information about local, pairwise relations among concepts, whereas the cluster analysis shows global, categorical relations to a greater extent.

  8. Monte Carlo Modeling of Phonons at Crystal Interfaces

    NASA Astrophysics Data System (ADS)

    Page, W. A.; Brandt, D.; Msall, M. E.

    2014-08-01

    One of the strategies in the effort to directly detect dark matter particles is to measure the phonon and charge signals produced in an incidental collision of a weakly interacting massive particle with a nucleon in a crystalline detector. Proper calibration of the detected phonon energy relies on detailed models of phonon propagation through the crystal to the instrumented surface. Previous Detector Monte Carlo incorporate probabalistic anharmonic decay and mass defect scattering but neglect the mode dependent scattering at crystal boundaries. We calculate mode specific reflection and transmission at detector interfaces with a simple acoustic mismatch model. We find that mode preserving transmission is the most probable outcome at germanium-aluminum detector interfaces, but the probability of reflection is not negligible. The average phonon reflection probability at near normal angles of incidence at a Ge/Al interface is near 20 %, but grows dramatically for oblique incidence. We develop a code using Geant4, which should allow modeling extensions to all phonon mediated dark matter detection schemes. Our models are adaptable to other crystal materials and are generally useful in any phonon interface problem.

  9. Understanding and modelling built environments for mobile guide interface design

    Microsoft Academic Search

    Jeni Paay; Jesper Kjeldskov

    2005-01-01

    The research presented in this paper aims to inform interface design for mobile guides by understanding and modelling the built environments in which the guide will be used. This is important because research into the use of mobile guides has shown that people have a strong ability to make sense of the physical space in which they are situated and

  10. Modeling Software Applications and User Interfaces Using Metaphorical Entities

    Microsoft Academic Search

    Christian Nill; Vishal Sikka

    The power of metaphor has long been recognized in user interface design and more broadly in human interaction circles. More recently metaphor also found its way into the software development process. This paper aims to combine occurrences of metaphor in the two fields with ideas from the field of model driven architecture. We suggest that it is possible to create

  11. Automated MRI cerebellar size measurements using active appearance modeling.

    PubMed

    Price, Mathew; Cardenas, Valerie A; Fein, George

    2014-12-01

    Although the human cerebellum has been increasingly identified as an important hub that shows potential for helping in the diagnosis of a large spectrum of disorders, such as alcoholism, autism, and fetal alcohol spectrum disorder, the high costs associated with manual segmentation, and low availability of reliable automated cerebellar segmentation tools, has resulted in a limited focus on cerebellar measurement in human neuroimaging studies. We present here the CATK (Cerebellar Analysis Toolkit), which is based on the Bayesian framework implemented in FMRIB's FIRST. This approach involves training Active Appearance Models (AAMs) using hand-delineated examples. CATK can currently delineate the cerebellar hemispheres and three vermal groups (lobules I-V, VI-VII, and VIII-X). Linear registration with the low-resolution MNI152 template is used to provide initial alignment, and Point Distribution Models (PDM) are parameterized using stellar sampling. The Bayesian approach models the relationship between shape and texture through computation of conditionals in the training set. Our method varies from the FIRST framework in that initial fitting is driven by 1D intensity profile matching, and the conditional likelihood function is subsequently used to refine fitting. The method was developed using T1-weighted images from 63 subjects that were imaged and manually labeled: 43 subjects were scanned once and were used for training models, and 20 subjects were imaged twice (with manual labeling applied to both runs) and used to assess reliability and validity. Intraclass correlation analysis shows that CATK is highly reliable (average test-retest ICCs of 0.96), and offers excellent agreement with the gold standard (average validity ICC of 0.87 against manual labels). Comparisons against an alternative atlas-based approach, SUIT (Spatially Unbiased Infratentorial Template), that registers images with a high-resolution template of the cerebellum, show that our AAM approach offers superior reliability and validity. Extensions of CATK to cerebellar hemisphere parcels are envisioned. PMID:25192657

  12. ITER plasma safety interface models and assessments

    SciTech Connect

    Uckan, N.A. [Oak Ridge National Lab., TN (United States); Bartels, H-W. [ITER San Diego Joint Work Site, La Jolla, CA (United States); Honda, T. [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.; Putvinski, S. [ITER San Diego Joint Work Site, La Jolla, CA (United States); Amano, T. [National Inst. for Fusion Science, Nagoya (Japan); Boucher, D.; Post, D.; Wesley, J. [ITER San Diego Joint Work Site, La Jolla, CA (United States)

    1996-12-31

    Physics models and requirements to be used as a basis for safety analysis studies are developed and physics results motivated by safety considerations are presented for the ITER design. Physics specifications are provided for enveloping plasma dynamic events for Category I (operational event), Category II (likely event), and Category III (unlikely event). A safety analysis code SAFALY has been developed to investigate plasma anomaly events. The plasma response to ex-vessel component failure and machine response to plasma transients are considered.

  13. NASA: Model development for human factors interfacing

    NASA Technical Reports Server (NTRS)

    Smith, L. L.

    1984-01-01

    The results of an intensive literature review in the general topics of human error analysis, stress and job performance, and accident and safety analysis revealed no usable techniques or approaches for analyzing human error in ground or space operations tasks. A task review model is described and proposed to be developed in order to reduce the degree of labor intensiveness in ground and space operations tasks. An extensive number of annotated references are provided.

  14. Atomic Models of Strong Solids Interfaces Viewed as Composite Structures

    NASA Astrophysics Data System (ADS)

    Staffell, I.; Shang, J. L.; Kendall, K.

    2014-02-01

    This paper looks back through the 1960s to the invention of carbon fibres and the theories of Strong Solids. In particular it focuses on the fracture mechanics paradox of strong composites containing weak interfaces. From Griffith theory, it is clear that three parameters must be considered in producing a high strength composite:- minimising defects; maximising the elastic modulus; and raising the fracture energy along the crack path. The interface then introduces two further factors:- elastic modulus mismatch causing crack stopping; and debonding along a brittle interface due to low interface fracture energy. Consequently, an understanding of the fracture energy of a composite interface is needed. Using an interface model based on atomic interaction forces, it is shown that a single layer of contaminant atoms between the matrix and the reinforcement can reduce the interface fracture energy by an order of magnitude, giving a large delamination effect. The paper also looks to a future in which cars will be made largely from composite materials. Radical improvements in automobile design are necessary because the number of cars worldwide is predicted to double. This paper predicts gains in fuel economy by suggesting a new theory of automobile fuel consumption using an adaptation of Coulomb's friction law. It is demonstrated both by experiment and by theoretical argument that the energy dissipated in standard vehicle tests depends only on weight. Consequently, moving from metal to fibre construction can give a factor 2 improved fuel economy performance, roughly the same as moving from a petrol combustion drive to hydrogen fuel cell propulsion. Using both options together can give a factor 4 improvement, as demonstrated by testing a composite car using the ECE15 protocol.

  15. Industrial Automation Mechanic Model Curriculum Project. Final Report.

    ERIC Educational Resources Information Center

    Toledo Public Schools, OH.

    This document describes a demonstration program that developed secondary level competency-based instructional materials for industrial automation mechanics. Program activities included task list compilation, instructional materials research, learning activity packet (LAP) development, construction of lab elements, system implementation,…

  16. Atomistic modeling of the interaction of glide dislocations with “weak” interfaces

    Microsoft Academic Search

    J. Wang; R. G. Hoagland; J. P. Hirth; A. Misra

    2008-01-01

    Using atomistic modeling and anisotropic elastic theory, the interaction of glide dislocations with interfaces in a model Cu–Nb system was explored. The incoherent Cu–Nb interfaces have relatively low shear strength and are referred to as “weak” interfaces. This work shows that such interfaces are very strong traps for glide dislocations and, thus, effective barriers for slip transmission. The key aspects

  17. Determining the Composition of Phyllosilicates Using Automated Gaussian Modeling of Spectral Features

    Microsoft Academic Search

    H. D. Makarewicz; M. Parente; J. L. Bishop

    2009-01-01

    Kaolinite-montmorillonite and nontronite-ferrihydrite mixture spectrawere analyzed using automated modified Gaussian modeling in order torelate relative band depths with endmember composition in lab spectra,and eventually in CRISM spectra on Mars.

  18. An interface model for dosage adjustment connects hematotoxicity to pharmacokinetics

    Microsoft Academic Search

    C. Meille; A. Iliadis; D. Barbolosi; N. Frances; G. Freyer

    2008-01-01

    When modeling is required to describe pharmacokinetics and pharmacodynamics simultaneously, it is difficult to link time-concentration\\u000a profiles and drug effects. When patients are under chemotherapy, despite the huge amount of blood monitoring numerations,\\u000a there is a lack of exposure variables to describe hematotoxicity linked with the circulating drug blood levels. We developed\\u000a an interface model that transforms circulating pharmacokinetic concentrations

  19. Modeling extended Petri nets compatible with GHENeSys IEC61131 for industrial automation

    Microsoft Academic Search

    José Reinaldo Silva; Israel Benítez; Luisa Villafruela; Oriol Gomis; Antoni Sudrià

    2008-01-01

    Petri net (PN) modeling is one of the most used formal methods in the automation applications field, together with programmable\\u000a logic controllers (PLCs). Therefore, the creation of a modeling methodology for PNs compatible with the IEC61131 standard\\u000a is a necessity of automation specialists. Different works dealing with this subject have been carried out; they are presented\\u000a in the first part

  20. The MineTool Software Suite: A Novel Data Mining Palette of Tools for Automated Modeling of Space Physics Data

    NASA Astrophysics Data System (ADS)

    Sipes, T.; Karimabadi, H.; Roberts, A.

    2009-12-01

    We present a new data mining software tool called MineTool for analysis and modeling of space physics data. MineTool is a graphical user interface implementation that merges two data mining algorithms into an easy-to-use software tool: an algorithm for analysis and modeling of static data [Karimabadi et al, 2007] and MineTool-TS, an algorithm for data mining of time series data [Karimabadi et al, 2009]. By virtue of automating the modeling process and model evaluations, MineTool makes data mining and predictive modeling more accessible to non-experts. The software is entirely in Java and freeware. By ranking all inputs as predictors of the outcome before constructing a model, MineTool enables inclusion of only relevant variables as well. The technique aggregates the various stages of model building into a four-step process consisting of (i) data segmentation and sampling, (ii) variable pre-selection and transform generation, (iii) predictive model estimation and validation, and (iv) final model selection. Optimal strategies are chosen for each modeling step. A notable feature of the technique is that the final model is always in closed analytical form rather than “black box” form characteristic of some other techniques. Having the analytical model enables deciphering the importance of various variables to affecting the outcome. MineTool suite also provides capabilities for data preparation for data mining as well as visualization of the datasets. MineTool has successfully been used to develop models for automated detection of flux transfer events (FTEs) at Earth’s magnetopause in the Cluster spacecraft time series data and 3D magnetopause modeling. In this presentation, we demonstrate the ease of use of the software through examples including how it was used in the FTE problem.

  1. Automated MRI segmentation for individualized modeling of current flow in the human head

    NASA Astrophysics Data System (ADS)

    Huang, Yu; Dmochowski, Jacek P.; Su, Yuzhuo; Datta, Abhishek; Rorden, Christopher; Parra, Lucas C.

    2013-12-01

    Objective. High-definition transcranial direct current stimulation (HD-tDCS) and high-density electroencephalography require accurate models of current flow for precise targeting and current source reconstruction. At a minimum, such modeling must capture the idiosyncratic anatomy of the brain, cerebrospinal fluid (CSF) and skull for each individual subject. Currently, the process to build such high-resolution individualized models from structural magnetic resonance images requires labor-intensive manual segmentation, even when utilizing available automated segmentation tools. Also, accurate placement of many high-density electrodes on an individual scalp is a tedious procedure. The goal was to develop fully automated techniques to reduce the manual effort in such a modeling process. Approach. A fully automated segmentation technique based on Statical Parametric Mapping 8, including an improved tissue probability map and an automated correction routine for segmentation errors, was developed, along with an automated electrode placement tool for high-density arrays. The performance of these automated routines was evaluated against results from manual segmentation on four healthy subjects and seven stroke patients. The criteria include segmentation accuracy, the difference of current flow distributions in resulting HD-tDCS models and the optimized current flow intensities on cortical targets.Main results. The segmentation tool can segment out not just the brain but also provide accurate results for CSF, skull and other soft tissues with a field of view extending to the neck. Compared to manual results, automated segmentation deviates by only 7% and 18% for normal and stroke subjects, respectively. The predicted electric fields in the brain deviate by 12% and 29% respectively, which is well within the variability observed for various modeling choices. Finally, optimized current flow intensities on cortical targets do not differ significantly.Significance. Fully automated individualized modeling may now be feasible for large-sample EEG research studies and tDCS clinical trials.

  2. Computer modelling of nanoscale diffusion phenomena at epitaxial interfaces

    NASA Astrophysics Data System (ADS)

    Michailov, M.; Ranguelov, B.

    2014-05-01

    The present study outlines an important area in the application of computer modelling to interface phenomena. Being relevant to the fundamental physical problem of competing atomic interactions in systems with reduced dimensionality, these phenomena attract special academic attention. On the other hand, from a technological point of view, detailed knowledge of the fine atomic structure of surfaces and interfaces correlates with a large number of practical problems in materials science. Typical examples are formation of nanoscale surface patterns, two-dimensional superlattices, atomic intermixing at an epitaxial interface, atomic transport phenomena, structure and stability of quantum wires on surfaces. We discuss here a variety of diffusion mechanisms that control surface-confined atomic exchange, formation of alloyed atomic stripes and islands, relaxation of pure and alloyed atomic terraces, diffusion of clusters and their stability in an external field. The computational model refines important details of diffusion of adatoms and clusters accounting for the energy barriers at specific atomic sites: smooth domains, terraces, steps and kinks. The diffusion kinetics, integrity and decomposition of atomic islands in an external field are considered in detail and assigned to specific energy regions depending on the cluster stability in mass transport processes. The presented ensemble of diffusion scenarios opens a way for nanoscale surface design towards regular atomic interface patterns with exotic physical features.

  3. Developing A Laser Shockwave Model For Characterizing Diffusion Bonded Interfaces

    SciTech Connect

    James A. Smith; Jeffrey M. Lacy; Barry H. Rabin

    2014-07-01

    12. Other advances in QNDE and related topics: Preferred Session Laser-ultrasonics Developing A Laser Shockwave Model For Characterizing Diffusion Bonded Interfaces 41st Annual Review of Progress in Quantitative Nondestructive Evaluation Conference QNDE Conference July 20-25, 2014 Boise Centre 850 West Front Street Boise, Idaho 83702 James A. Smith, Jeffrey M. Lacy, Barry H. Rabin, Idaho National Laboratory, Idaho Falls, ID ABSTRACT: The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) which is assigned with reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU. The new LEU fuel is based on a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to complete the fuel qualification process, the laser shock technique is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. The Laser Shockwave Technique (LST) is being investigated to characterize interface strength in fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However the deposition of laser energy into the containment layer on specimen’s surface is intractably complex. The shock wave energy is inferred from the velocity on the backside and the depth of the impression left on the surface from the high pressure plasma pulse created by the shock laser. To help quantify the stresses and strengths at the interface, a finite element model is being developed and validated by comparing numerical and experimental results for back face velocities and front face depressions with experimental results. This paper will report on initial efforts to develop a finite element model for laser shock.

  4. Thermal Edge-Effects Model for Automated Tape Placement of Thermoplastic Composites

    NASA Technical Reports Server (NTRS)

    Costen, Robert C.

    2000-01-01

    Two-dimensional thermal models for automated tape placement (ATP) of thermoplastic composites neglect the diffusive heat transport that occurs between the newly placed tape and the cool substrate beside it. Such lateral transport can cool the tape edges prematurely and weaken the bond. The three-dimensional, steady state, thermal transport equation is solved by the Green's function method for a tape of finite width being placed on an infinitely wide substrate. The isotherm for the glass transition temperature on the weld interface is used to determine the distance inward from the tape edge that is prematurely cooled, called the cooling incursion Delta a. For the Langley ATP robot, Delta a = 0.4 mm for a unidirectional lay-up of PEEK/carbon fiber composite, and Delta a = 1.2 mm for an isotropic lay-up. A formula for Delta a is developed and applied to a wide range of operating conditions. A surprise finding is that Delta a need not decrease as the Peclet number Pe becomes very large, where Pe is the dimensionless ratio of inertial to diffusive heat transport. Conformable rollers that increase the consolidation length would also increase Delta a, unless other changes are made, such as proportionally increasing the material speed. To compensate for premature edge cooling, the thermal input could be extended past the tape edges by the amount Delta a. This method should help achieve uniform weld strength and crystallinity across the width of the tape.

  5. Model-based user interface design by example and by interview

    Microsoft Academic Search

    Martin R. Frank; James D. Foley

    1993-01-01

    Model-based user interface design is centered around a de- scription of application objects and operations at a level of abstraction higher than that of code. A good model can be used to support multiple interfaces, help separate interface and application, describe input sequencing in a simple way, check consistency and completeness of the interface, evalu- ate the interface's speed-of-use, generate

  6. Symmetric model of compressible granular mixtures with permeable interfaces

    NASA Astrophysics Data System (ADS)

    Saurel, Richard; Le Martelot, Sébastien; Tosello, Robert; Lapébie, Emmanuel

    2014-12-01

    Compressible granular materials are involved in many applications, some of them being related to energetic porous media. Gas permeation effects are important during their compaction stage, as well as their eventual chemical decomposition. Also, many situations involve porous media separated from pure fluids through two-phase interfaces. It is thus important to develop theoretical and numerical formulations to deal with granular materials in the presence of both two-phase interfaces and gas permeation effects. Similar topic was addressed for fluid mixtures and interfaces with the Discrete Equations Method (DEM) [R. Abgrall and R. Saurel, "Discrete equations for physical and numerical compressible multiphase mixtures," J. Comput. Phys. 186(2), 361-396 (2003)] but it seemed impossible to extend this approach to granular media as intergranular stress [K. K. Kuo, V. Yang, and B. B. Moore, "Intragranular stress, particle-wall friction and speed of sound in granular propellant beds," J. Ballist. 4(1), 697-730 (1980)] and associated configuration energy [J. B. Bdzil, R. Menikoff, S. F. Son, A. K. Kapila, and D. S. Stewart, "Two-phase modeling of deflagration-to-detonation transition in granular materials: A critical examination of modeling issues," Phys. Fluids 11, 378 (1999)] were present with significant effects. An approach to deal with fluid-porous media interfaces was derived in Saurel et al. ["Modelling dynamic and irreversible powder compaction," J. Fluid Mech. 664, 348-396 (2010)] but its validity was restricted to weak velocity disequilibrium only. Thanks to a deeper analysis, the DEM is successfully extended to granular media modelling in the present paper. It results in an enhanced version of the Baer and Nunziato ["A two-phase mixture theory for the deflagration-to-detonation transition (DDT) in reactive granular materials," Int. J. Multiphase Flow 12(6), 861-889 (1986)] model as symmetry of the formulation is now preserved. Several computational examples are shown to validate and illustrate method's capabilities.

  7. Model formulation: Formulation of a model for automating infection surveillance: algorithmic detection of central-line associated bloodstream infection

    Microsoft Academic Search

    Bala Hota; Michael Lin; Joshua A. Doherty; Tara Borlawsky; Keith Woeltje; Kurt Stevenson; Yosef Khan; Jeremy Young; Robert A. Weinstein; William E. Trick

    2010-01-01

    ObjectiveTo formulate a model for translating manual infection control surveillance methods to automated, algorithmic approaches.DesignWe propose a model for creating electronic surveillance algorithms by translating existing manual surveillance practices into automated electronic methods. Our model suggests that three dimensions of expert knowledge be consulted: clinical, surveillance, and informatics. Once collected, knowledge should be applied through a process of conceptualization, synthesis,

  8. Modeling the Photoionized Interface in Blister HII Regions

    E-print Network

    Ravi Sankrit; J. Jeff Hester

    2000-01-20

    We present a grid of photoionization models for the emission from photoevaporative interfaces between the ionized gas and molecular cloud in blister HII regions. For the density profiles of the emitting gas in the models, we use a general power law form calculated for photoionized, photoevaporative flows by Bertoldi (1989). We find that the spatial emission line profiles are dependent on the incident flux, the shape of the ionizing continuum and the elemental abundances. In particular, we find that the peak emissivity of the [SII] and [NII] lines are more sensitive to the elemental abundances than are the total line intensities. The diagnostics obtained from the grid of models can be used in conjunction with high spatial resolution data to infer the properties of ionized interfaces in blister HII regions. As an example, we consider a location at the tip of an ``elephant trunk'' structure in M16 (the Eagle Nebula) and show how narrow band HST-WFPC2 images constrain the HII region properties. We present a photoionization model that explains the ionization structure and emission from the interface seen in these high spatial resolution data.

  9. Joint opening nonlinear mechanism: Interface smeared crack model

    NASA Astrophysics Data System (ADS)

    Kuo, J. S. H.

    1982-08-01

    Contraction joint opening behavior is studied. An economical model called the Interface Smeared Crack Model is developed to simulate the joint opening nonlinear mechanism. The model is based on the general smeared crack approach, with a specially introduced pushing back operation which is intended to correct the local structure response at element level. This method dramatically reduces the computational cost compared with that of a standard joint element analysis. It is demonstrated that it would be beneficial to include joint opening mechanism in the dynamic analysis of arch dams, because joint opening will limit the peak tensile arch stresses and thus improve the seismic resistance of the structure.

  10. A second generation user interface design environment: the model and the runtime architecture

    Microsoft Academic Search

    Piyawadee Noi Sukaviriya; James D. Foley; Todd Griffith

    1993-01-01

    Several obstacles exist in the user interface design process which distract a developer from designing a good user interface. One of the problems is the lack of an application model to keep the designer in perspective with the application. The other problem is having to deal with massive user interface programming to achieve a desired interface and to provide users

  11. Modeling and Extracting Deep-Web Query Interfaces

    E-print Network

    Meng, Weiyi

    Modeling and Extracting Deep-Web Query Interfaces Wensheng Wu, AnHai Doan, Clement Yu, and Weiyi 251, pp. 65­90. springerlink.com c Springer-Verlag Berlin Heidelberg 2009 #12;66 W. Wu et al. the Deep-Web, and they are the Deep-Web data sources [4]. The Deep-Web was es- timated to be at least 500 times larger than

  12. Model-Based User Interface Design Using Markup Concepts

    Microsoft Academic Search

    Andreas Mueller; Peter Forbrig; Clemens H. Cap

    2001-01-01

    In the field of model-based development of interactive systems, several approaches have been proposed to integrate task and\\u000a object knowledge into the development process and its underlying representations. This paper follows such an approach with\\u000a a special focus on mobile devices. It presents a concept of device independent user interface design based on the XML-technology.\\u000a The concept is applied to

  13. Automated Eukaryotic Gene Structure Annotation Using EVidenceModeler and the Program to Assemble Spliced Alignments

    SciTech Connect

    Haas, B J; Salzberg, S L; Zhu, W; Pertea, M; Allen, J E; Orvis, J; White, O; Buell, C R; Wortman, J R

    2007-12-10

    EVidenceModeler (EVM) is presented as an automated eukaryotic gene structure annotation tool that reports eukaryotic gene structures as a weighted consensus of all available evidence. EVM, when combined with the Program to Assemble Spliced Alignments (PASA), yields a comprehensive, configurable annotation system that predicts protein-coding genes and alternatively spliced isoforms. Our experiments on both rice and human genome sequences demonstrate that EVM produces automated gene structure annotation approaching the quality of manual curation.

  14. A Feedback Model for Automated Real Estate Assessment

    Microsoft Academic Search

    Robert Carbone; Richard L. Longini

    1977-01-01

    Pressing changes are needed in the administration of real estate taxation that will not only ensure that all properties be assessed accurately and equitably, but will enable taxpayers to perceive that they are being treated fairly. In this paper, we examine what properties an automated mass appraisal system should exhibit so as to meet efficacy, equity and public acceptability criteria.

  15. An approach to use model driven design in industrial automation

    Microsoft Academic Search

    Elisabet Estevez; Marga Marcos

    2008-01-01

    Current industrial applications demand the design of more and more complex, safe and trustworthy control systems which exhibit a high degree of flexibility and reutilization. To achieve this, the engineering process has to be improved through the integration of the tools involved in the development process. To achieve this goal the definition of Markup Languages for factory automation has been

  16. Bacterial Adhesion to Hexadecane (Model NAPL)-Water Interfaces

    NASA Astrophysics Data System (ADS)

    Ghoshal, S.; Zoueki, C. R.; Tufenkji, N.

    2009-05-01

    The rates of biodegradation of NAPLs have been shown to be influenced by the adhesion of hydrocarbon- degrading microorganisms as well as their proximity to the NAPL-water interface. Several studies provide evidence for bacterial adhesion or biofilm formation at alkane- or crude oil-water interfaces, but there is a significant knowledge gap in our understanding of the processes that influence initial adhesion of bacteria on to NAPL-water interfaces. In this study bacterial adhesion to hexadecane, and a series of NAPLs comprised of hexadecane amended with toluene, and/or with asphaltenes and resins, which are the surface active fractions of crude oils, were examined using a Microbial Adhesion to Hydrocarbons (MATH) assay. The microorganisms employed were Mycobacterium kubicae, Pseudomonas aeruginosa and Pseudomonas putida, which are hydrocarbon degraders or soil microorganisms. MATH assays as well as electrophoretic mobility measurements of the bacterial cells and the NAPL droplet surfaces in aqueous solutions were conducted at three solution pHs (4, 6 and 7). Asphaltenes and resins were shown to generally decrease microbial adhesion. Results of the MATH assay were not in qualitative agreement with theoretical predictions of bacteria- hydrocarbon interactions based on the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) model of free energy of interaction between the cell and NAPL droplets. In this model the free energy of interaction between two colloidal particles is predicted based on electrical double layer, van der Waals and hydrophobic forces. It is likely that the steric repulsion between bacteria and NAPL surfaces, caused by biopolymers on bacterial surfaces and aphaltenes and resins at the NAPL-water interface contributed to the decreased adhesion compared to that predicted by the XDLVO model.

  17. Behavior of asphaltene model compounds at w/o interfaces.

    PubMed

    Nordgård, Erland L; Sørland, Geir; Sjöblom, Johan

    2010-02-16

    Asphaltenes, present in significant amounts in heavy crude oil, contains subfractions capable of stabilizing water-in-oil emulsions. Still, the composition of these subfractions is not known in detail, and the actual mechanism behind emulsion stability is dependent on perceived interfacial concentrations and compositions. This study aims at utilizing polyaromatic surfactants which contains an acidic moiety as model compounds for the surface-active subfraction of asphaltenes. A modified pulse-field gradient (PFG) NMR method has been used to study droplet sizes and stability of emulsions prepared with asphaltene model compounds. The method has been compared to the standard microscopy droplet counting method. Arithmetic and volumetric mean droplet sizes as a function of surfactant concentration and water content clearly showed that the interfacial area was dependent on the available surfactant at the emulsion interface. Adsorption of the model compounds onto hydrophilic silica has been investigated by UV depletion, and minor differences in the chemical structure of the model compounds caused significant differences in the affinity toward this highly polar surface. The cross-sectional areas obtained have been compared to areas from the surface-to-volume ratio found by NMR and gave similar results for one of the two model compounds. The mean molecular area for this compound suggested a tilted geometry of the aromatic core with respect to the interface, which has also been proposed for real asphaltenic samples. The film behavior was further investigated using a liquid-liquid Langmuir trough supporting the ability to form stable interfacial films. This study supports that acidic, or strong hydrogen-bonding fractions, can promote stable water-in-oil emulsion. The use of model compounds opens up for studying emulsion behavior and demulsifier efficiency based on true interfacial concentrations rather than perceived interfaces. PMID:19852481

  18. Language Model Applications to Spelling with Brain-Computer Interfaces

    PubMed Central

    Mora-Cortes, Anderson; Manyakov, Nikolay V.; Chumerin, Nikolay; Van Hulle, Marc M.

    2014-01-01

    Within the Ambient Assisted Living (AAL) community, Brain-Computer Interfaces (BCIs) have raised great hopes as they provide alternative communication means for persons with disabilities bypassing the need for speech and other motor activities. Although significant advancements have been realized in the last decade, applications of language models (e.g., word prediction, completion) have only recently started to appear in BCI systems. The main goal of this article is to review the language model applications that supplement non-invasive BCI-based communication systems by discussing their potential and limitations, and to discern future trends. First, a brief overview of the most prominent BCI spelling systems is given, followed by an in-depth discussion of the language models applied to them. These language models are classified according to their functionality in the context of BCI-based spelling: the static/dynamic nature of the user interface, the use of error correction and predictive spelling, and the potential to improve their classification performance by using language models. To conclude, the review offers an overview of the advantages and challenges when implementing language models in BCI-based communication systems when implemented in conjunction with other AAL technologies. PMID:24675760

  19. An Ambient Agent Model for Automated Mindreading by Identifying and Monitoring Representation Relations

    E-print Network

    Treur, Jan

    1 An Ambient Agent Model for Automated Mindreading by Identifying and Monitoring Representation, treur}@cs.vu.nl URL: http://www.cs.vu.nl/~{sharp, treur} ABSTRACT In this paper an ambient agent model, representation relation, monitoring, verification, ambient agent model. 1. INTRODUCTION Applications within

  20. A Model of Process-Based Automation: Cost and Quality Implications in the Medication Management Process

    ERIC Educational Resources Information Center

    Spaulding, Trent Joseph

    2011-01-01

    The objective of this research is to understand how a set of systems, as defined by the business process, creates value. The three studies contained in this work develop the model of process-based automation. The model states that complementarities among systems are specified by handoffs in the business process. The model also provides theory to…

  1. The Voter Model Chordal Interface in Two Dimensions

    NASA Astrophysics Data System (ADS)

    Holmes, Mark; Mohylevskyy, Yevhen; Newman, Charles M.

    2015-02-01

    Consider the voter model on a box of side length L (in the triangular lattice) with boundary votes fixed forever as type 0 or type 1 on two different halves of the boundary. Motivated by analogous questions in percolation, we study several geometric objects at stationarity, as L? ?. One is the interface between the (large—i.e., boundary connected) 0-cluster and 1-cluster. Another is the set of large "coalescing classes" determined by the coalescing walk process dual to the voter model.

  2. Model-Based User Interface Design in the Context of Workflow Models

    Microsoft Academic Search

    Renate Kristiansen; Hallvard Trætteberg

    2007-01-01

    Within ERP systems, workflow models are used by business analysts to specify which business processes the system supports.\\u000a The workflow model specify which actors that performs what activity in what sequence and the required resources. Within user\\u000a interface (UI) design task models are used to develop task-centric user interfaces. Task-centric UIs can increase systems’\\u000a usability as it focuses on the

  3. GoSam-2.0: a tool for automated one-loop calculations within the Standard Model and beyond

    E-print Network

    G. Cullen; H. van Deurzen; N. Greiner; G. Heinrich; G. Luisoni; P. Mastrolia; E. Mirabella; G. Ossola; T. Peraro; J. Schlenk; J. F. von Soden-Fraunhofen; F. Tramontano

    2014-04-28

    We present the version 2.0 of the program package GoSam for the automated calculation of one-loop amplitudes. GoSam is devised to compute one-loop QCD and/or electroweak corrections to multi-particle processes within and beyond the Standard Model. The new code contains improvements in the generation and in the reduction of the amplitudes, performs better in computing time and numerical accuracy, and has an extended range of applicability. The extended version of the "Binoth-Les-Houches-Accord" interface to Monte Carlo programs is also implemented. We give a detailed description of installation and usage of the code, and illustrate the new features in dedicated examples.

  4. Cellular Automation Model of Traffic Flow Based on the Car-Following Model

    NASA Astrophysics Data System (ADS)

    Li, Ke-Ping; Gao, Zi-You

    2004-11-01

    We propose a new cellular automation (CA) traffic model that is based on the car-following model. A class of driving strategies is used in the car-following model instead of the acceleration in the NaSch traffic model. In our model, some realistic driver behaviour and detailed vehicle characteristics have been taken into account, such as distance-headway and safe distance, etc. The simulation results show that our model can exhibit some traffic flow states that have been observed in the real traffic, and both of the maximum flux and the critical density are very close to the real measurement. Moreover, it is easy to extend our method to multi-lane traffic.

  5. Formulation of a model for automating infection surveillance: algorithmic detection of central-line associated bloodstream infection

    Microsoft Academic Search

    Bala Hota; Michael Lin; Joshua A Doherty; Tara Borlawsky; Keith Woeltje; Kurt Stevenson; Yosef Khan; Jeremy Young; Robert A Weinstein; William Trick

    2010-01-01

    Objective To formulate a model for translating manual infection control surveillance methods to automated, algorithmic approaches. Design We propose a model for creating electronic surveillance algorithms by translating existing manual surveillance practices into automated electronic methods. Our model suggests that three dimensions of expert knowledge be consulted: clinical, surveillance, and informatics. Once collected, knowledge should be applied through a process

  6. A biological model for controlling interface growth and morphology.

    SciTech Connect

    Hoyt, Jeffrey John; Holm, Elizabeth Ann

    2004-01-01

    Biological systems create proteins that perform tasks more efficiently and precisely than conventional chemicals. For example, many plants and animals produce proteins to control the freezing of water. Biological antifreeze proteins (AFPs) inhibit the solidification process, even below the freezing point. These molecules bond to specific sites at the ice/water interface and are theorized to suppress solidification chemically or geometrically. In this project, we investigated the theoretical and experimental data on AFPs and performed analyses to understand the unique physics of AFPs. The experimental literature was analyzed to determine chemical mechanisms and effects of protein bonding at ice surfaces, specifically thermodynamic freezing point depression, suppression of ice nucleation, decrease in dendrite growth kinetics, solute drag on the moving solid/liquid interface, and stearic pinning of the ice interface. Stearic pinning was found to be the most likely candidate to explain experimental results, including freezing point depression, growth morphologies, and thermal hysteresis. A new stearic pinning model was developed and applied to AFPs, with excellent quantitative results. Understanding biological antifreeze mechanisms could enable important medical and engineering applications, but considerable future work will be necessary.

  7. Design and Evaluation of Intelligent Menu Interface through Cognitive Walkthrough Procedure and Automated Logging for Management Information System

    Microsoft Academic Search

    Xiangyu Wang

    2007-01-01

    One of the critcal issues in Managment Information System (MIS) is the information overload from complicated hierachical menu.\\u000a Novice users easily get lost when an important and frequently used menu item is rooted and hidden in a deeper level of a poorly\\u000a designed menu interface. Therefore, usability of menu interface critically affects the quality of MIS applications. This paper\\u000a developed

  8. User interface using a 3D model for video surveillance

    NASA Astrophysics Data System (ADS)

    Hata, Toshihiko; Boh, Satoru; Tsukada, Akihiro; Ozaki, Minoru

    1998-02-01

    These days fewer people, who must carry out their tasks quickly and precisely, are required in industrial surveillance and monitoring applications such as plant control or building security. Utilizing multimedia technology is a good approach to meet this need, and we previously developed Media Controller, which is designed for the applications and provides realtime recording and retrieval of digital video data in a distributed environment. In this paper, we propose a user interface for such a distributed video surveillance system in which 3D models of buildings and facilities are connected to the surveillance video. A novel method of synchronizing camera field data with each frame of a video stream is considered. This method records and reads the camera field data similarity to the video data and transmits it synchronously with the video stream. This enables the user interface to have such useful functions as comprehending the camera field immediately and providing clues when visibility is poor, for not only live video but also playback video. We have also implemented and evaluated the display function which makes surveillance video and 3D model work together using Media Controller with Java and Virtual Reality Modeling Language employed for multi-purpose and intranet use of 3D model.

  9. A symbolic/subsymbolic interface protocol for cognitive modeling

    PubMed Central

    Simen, Patrick; Polk, Thad

    2009-01-01

    Researchers studying complex cognition have grown increasingly interested in mapping symbolic cognitive architectures onto subsymbolic brain models. Such a mapping seems essential for understanding cognition under all but the most extreme viewpoints (namely, that cognition consists exclusively of digitally implemented rules; or instead, involves no rules whatsoever). Making this mapping reduces to specifying an interface between symbolic and subsymbolic descriptions of brain activity. To that end, we propose parameterization techniques for building cognitive models as programmable, structured, recurrent neural networks. Feedback strength in these models determines whether their components implement classically subsymbolic neural network functions (e.g., pattern recognition), or instead, logical rules and digital memory. These techniques support the implementation of limited production systems. Though inherently sequential and symbolic, these neural production systems can exploit principles of parallel, analog processing from decision-making models in psychology and neuroscience to explain the effects of brain damage on problem solving behavior. PMID:20711520

  10. Wheat stress indicator model, Crop Condition Assessment Division (CCAD) data base interface driver, user's manual

    NASA Technical Reports Server (NTRS)

    Hansen, R. F. (principal investigator)

    1981-01-01

    The use of the wheat stress indicator model CCAD data base interface driver is described. The purpose of this system is to interface the wheat stress indicator model with the CCAD operational data base. The interface driver routine decides what meteorological stations should be processed and calls the proper subroutines to process the stations.

  11. GLEAN: A Computer-Based Tool for Rapid GOMS Model Usability Evaluation of User Interface Designs

    E-print Network

    Hornof, Anthony

    GLEAN: A Computer-Based Tool for Rapid GOMS Model Usability Evaluation of User Interface Designs Interface Design The standard accepted technique for developing a usable system, empirical user testing engineering models in the user interface design process is as follows: Following an initial task analysis

  12. Towards an Improved Pilot-Vehicle Interface for Highly Automated Aircraft: Evaluation of the Haptic Flight Control System

    NASA Technical Reports Server (NTRS)

    Schutte, Paul; Goodrich, Kenneth; Williams, Ralph

    2012-01-01

    The control automation and interaction paradigm (e.g., manual, autopilot, flight management system) used on virtually all large highly automated aircraft has long been an exemplar of breakdowns in human factors and human-centered design. An alternative paradigm is the Haptic Flight Control System (HFCS) that is part of NASA Langley Research Center s Naturalistic Flight Deck Concept. The HFCS uses only stick and throttle for easily and intuitively controlling the actual flight of the aircraft without losing any of the efficiency and operational benefits of the current paradigm. Initial prototypes of the HFCS are being evaluated and this paper describes one such evaluation. In this evaluation we examined claims regarding improved situation awareness, appropriate workload, graceful degradation, and improved pilot acceptance. Twenty-four instrument-rated pilots were instructed to plan and fly four different flights in a fictitious airspace using a moderate fidelity desktop simulation. Three different flight control paradigms were tested: Manual control, Full Automation control, and a simplified version of the HFCS. Dependent variables included both subjective (questionnaire) and objective (SAGAT) measures of situation awareness, workload (NASA-TLX), secondary task performance, time to recognize automation failures, and pilot preference (questionnaire). The results showed a statistically significant advantage for the HFCS in a number of measures. Results that were not statistically significant still favored the HFCS. The results suggest that the HFCS does offer an attractive and viable alternative to the tactical components of today s FMS/autopilot control system. The paper describes further studies that are planned to continue to evaluate the HFCS.

  13. An Automated Method for High-Definition Transcranial Direct Current Stimulation Modeling*

    E-print Network

    Parra, Lucas C.

    An Automated Method for High-Definition Transcranial Direct Current Stimulation Modeling* Yu Huang1 stimulation (tDCS) therapy. I. INTRODUCTION Transcranial direct current stimulation (tDCS) applies weak transcranial stimulation with electric currents requires accurate models of the current flow from scalp

  14. Data for Environmental Modeling (D4EM): Background and Applications of Data Automation

    EPA Science Inventory

    The Data for Environmental Modeling (D4EM) project demonstrates the development of a comprehensive set of open source software tools that overcome obstacles to accessing data needed by automating the process of populating model input data sets with environmental data available fr...

  15. A Grey-box Approach for Automated GUI-Model Generation of Mobile Applications

    E-print Network

    Xie, Tao

    , and mobile applications, or mobile apps for short, on this platform tend to be faulty just like other types of software, there is a growing need for automated testing techniques for mobile apps. Model- based testing grey-box approach for automatically extracting a model of a given mobile app. In our approach, static

  16. Towards automated 3D finite element modeling of direct fiber reinforced composite dental bridge

    Microsoft Academic Search

    Wei Li; Michael V. Swain; Qing Li; Grant P. Steven

    2005-01-01

    An automated 3D finite element (FE) modeling procedure for direct fiber rein- forced dental bridge is established on the basis of computer tomography (CT) scan data. The model presented herein represents a two-unit anterior cantilever bridge that includes a maxillary right incisor as an abutment and a maxillary left incisor as a cantilever pontic bonded by adhesive and reinforced fibers.

  17. Integrated approach to course and engineering model for automation related topics

    Microsoft Academic Search

    J. Gati; Gy. Kartyas

    2011-01-01

    This paper introduces a new approach to integrated education of engineering. For this purpose the authors studied higher education and industrial product modeling and proposed an integrated approach where higher education course and production equipment modeling are integrated with the controlled job floor automation environment. For the purpose of this environment, flexible manufacturing system was selected. The paper starts with

  18. Automated Model-Based Tissue Classification of MR Images of the Brain

    Microsoft Academic Search

    Koen Van Leemput; Frederik Maes; Dirk Vandermeulen; Paul Suetens

    1999-01-01

    We describe a fully automated method for model- based tissue classification of magnetic resonance (MR) images of the brain. The method interleaves classification with estimation of the model parameters, improving the classification at each iteration. The algorithm is able to segment single- and multi- spectral MR images, corrects for MR signal inhomogeneities, and incorporates contextual information by means of Markov

  19. Implementation and performance evaluation of Profibus in the automation systems

    Microsoft Academic Search

    Seung Ho Hong; Ki Am Kim

    1997-01-01

    Profibus interface S\\/W is implemented on a PC and embedded controller. In order to enable the Profibus interface S\\/W to handle many application tasks and communication services, two kinds of real time\\/multi tasking operating system, CTask and OS-9, are utilized. Using the Profibus interface S\\/W, the study develops an experimental model of an automation system, and evaluates the message delay

  20. Interface Design and Software Development for PEM Fuel Cell Modeling Based on Matlab\\/Simulink Environment

    Microsoft Academic Search

    Yancheng Xiao; Kodjo Agbossou

    2009-01-01

    This paper is dealing with the interface design and software development for proton exchange membrane (PEM) fuel cell modeling based on Matlab\\/Simulink environment. Three models used in the software, steady-state mode, dynamic model and thermodynamic model, are described first. These models are then implemented through the graphic user interface (GUI) programming by Simulink, and the simulation results are visualized. There

  1. A fatigue damage model for the cement-bone interface.

    PubMed

    Kim, Do-Gyoon; Miller, Mark A; Mann, Kenneth A

    2004-10-01

    Loss of fixation at the cement-bone interface can contribute to clinical loosening of cemented total hip replacements. In this study, the fatigue damage response was determined for cement-bone constructs subjected to shear fatigue loading. A typical three-phase fatigue response was observed with substantial early damage, followed by a long constant damage rate region and a final abrupt increase in damage to fracture. All of the damage resulted from creep (permanent) deformation during fatigue loading and there was no loss in cyclic stiffness. Using a Von Mises equivalent stress/strain concept, a general damage model was developed to describe the fatigue creep response of the cement-bone interface under either shear or tensile fatigue loading. Time to failure was highly correlated (r2=0.971) with equivalent creep strain rate and moderately related (r2=0.428) with equivalent initial strain for the two loading regimes. The equivalent creep strain at failure (0.052+/-0.018) was found to be independent of the applied equivalent stress. A combination of the creep damage model (to describe the damage process) with a constant final equivalent strain (as a failure criteria) could be used to assess the cement-bone failure response of cemented implant systems. PMID:15336925

  2. Reliable Modeling of Complex Organic/Metal Interfaces

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Filimonov, Sergey; Ruiz, Victor G.; Scheffler, Matthias; Tkatchenko, Alexandre

    2013-03-01

    The understanding of electronic properties of complex organic/metal interfaces requires a reliable method for the prediction of their structure and stability. The bonding at complex interfaces arises from delicate balance between covalent bonds, van der Waals (vdW) forces, charge transfer, and Pauli repulsion. We developed a method based on density-functional theory with vdW interactions (PBE+vdW^surf [1]) to accurately model adsorbates on surfaces, by a synergetic linkage of the PBE+vdW [2] for intermolecular interactions with the Lifshitz-Zaremba-Kohn theory [3] for the dielectric screening within the substrate surface. This method is demonstrated to reliably model a multitude of molecules on metal surfaces [1,4], leading to an accuracy of 0.1 å in adsorption heights and 0.1 eV in binding energies wrt experiments. To demonstrate the predictive power of the PBE+vdW^surf, we design a novel type of single-molecule push button switch, by carefully controlling the stability and activation barrier between a chemically bound state and a physically bound state for benzene derivatives adsorbed on metal surfaces.[4pt] [1] Ruiz, et al., PRL (2012).[0pt] [2] Tkatchenko and Scheffler, PRL (2009).[0pt] [3] Zaremba and Kohn, PRB (1976).[0pt] [4] Wagner, et al., PRL (2012).

  3. Model based TTCN-3 testing of industrial automation systems — First results

    Microsoft Academic Search

    Barath Kumar; Bjoern Czybik; Juergen Jasperneite

    2011-01-01

    Model-driven system\\/protocol engineering has been successfully applied in the industrial automation domain over the recent years. However, its cousin model-based testing (MBT) is relatively a new kid in the block - who is being curiously observed by domain experts. MBT lever­ ages behavior models (e.g. software models) to automat­ ically generate a large set of test cases. Testing indus­ trial

  4. Hybrid Powertrain Optimization for Plug-In Microgrid Power Generation Automated Modeling Laboratory Slide 1 of 28

    E-print Network

    Krstic, Miroslav

    Hybrid Powertrain Optimization for Plug-In Microgrid Power Generation Automated Modeling LaboratoryPlug--InIn MicrogridMicrogrid Power GenerationPower Generation Scott J. MouraScott J. Moura DongsukDongsuk KumKum Hosam Powertrain Optimization for Plug-In Microgrid Power Generation Automated Modeling Laboratory Slide 2 of 28

  5. IEEE/ASME TRANSACTIONS ON MECHATRONICS, VOL. 11, NO. 4, AUGUST 2006 381 Automated Onboard Modeling of Cartridge

    E-print Network

    Yao, Bin

    IEEE/ASME TRANSACTIONS ON MECHATRONICS, VOL. 11, NO. 4, AUGUST 2006 381 Automated Onboard Modeling significant problem, this paper focuses on the automated onboard modeling of the cartridge valve flow mappings the entire domain of the flow mapping during onboard experiments. Experimental results are obtained

  6. AUTOMATED GEOSPATIAL WATERSHED ASSESSMENT (AGWA): A GIS-BASED HYDROLOGICAL MODELING TOOL FOR WATERSHED MANAGEMENT AND LANDSCAPE ASSESSMENT

    EPA Science Inventory

    The Automated Geospatial Watershed Assessment (http://www.epa.gov/nerlesd1/land-sci/agwa/introduction.htm and www.tucson.ars.ag.gov/agwa) tool is a GIS interface jointly developed by the U.S. Environmental Protection Agency, USDA-Agricultural Research Service, and the University ...

  7. Combining Compound Conceptual User Interface Components with Modelling Patterns - A Promising Direction for Model-Based Cross-Platform User Interface Development

    Microsoft Academic Search

    Erik G. Nilsson

    2002-01-01

    In this paper we examine why model-based user interface development languages and tools only have had a limited dissemination\\u000a outside the research communities, and argue that there will be an increasing need for cross-platform user interface development\\u000a in the future. To meet these needs, user interface development languages and tools must use new approaches. We examine some\\u000a alternatives, and conclude

  8. Int. J. Human-Computer Studies 64 (2006) 527540 Investigation of multi-modal interface features for adaptive automation

    E-print Network

    Kaber, David B.

    ­robot interaction 1. Introduction Many complex systems, like advanced commercial/ military aircraft, teleoperation­computer interfaces for real telerobotic systems, including those used for military tactical operations, which support operator achievement and maintenance of SA and promote performance in using AA. r 2005 Elsevier Ltd. All

  9. Model Based Control Design Using SLPS "Simulink PSpice Interface"

    NASA Astrophysics Data System (ADS)

    Moslehpour, Saeid; Kulcu, Ercan K.; Alnajjar, Hisham

    This paper elaborates on the new integration offered with the PSpice SLPS interface and the MATLAB simulink products. SLPS links the two widely used design products, PSpice and Mathwork's Simulink simulator. The SLPS simulation environment supports the substitution of an actual electronic block with an "ideal model", better known as the mathematical simulink model. Thus enabling the designer to identify and correct integration issues of electronics within a system. Moreover, stress audit can be performed by using the PSpice smoke analysis which helps to verify whether the components are working within the manufacturer's safe operating limits. It is invaluable since many companies design and test the electronics separately from the system level. Therefore, integrations usually are not discovered until the prototype level, causing critical time delays in getting a product to the market.

  10. ORIGAMI -- The Oak Ridge Geometry Analysis and Modeling Interface

    SciTech Connect

    Burns, T.J.

    1996-04-01

    A revised ``ray-tracing`` package which is a superset of the geometry specifications of the radiation transport codes MORSE, MASH (GIFT Versions 4 and 5), HETC, and TORT has been developed by ORNL. Two additional CAD-based formats are also included as part of the superset: the native format of the BRL-CAD system--MGED, and the solid constructive geometry subset of the IGES specification. As part of this upgrade effort, ORNL has designed an Xwindows-based utility (ORIGAMI) to facilitate the construction, manipulation, and display of the geometric models required by the MASH code. Since the primary design criterion for this effort was that the utility ``see`` the geometric model exactly as the radiation transport code does, ORIGAMI is designed to utilize the same ``ray-tracing`` package as the revised version of MASH. ORIGAMI incorporates the functionality of two previously developed graphical utilities, CGVIEW and ORGBUG, into a single consistent interface.

  11. The use of analytical models in human-computer interface design

    NASA Technical Reports Server (NTRS)

    Gugerty, Leo

    1991-01-01

    Some of the many analytical models in human-computer interface design that are currently being developed are described. The usefulness of analytical models for human-computer interface design is evaluated. Can the use of analytical models be recommended to interface designers? The answer, based on the empirical research summarized here, is: not at this time. There are too many unanswered questions concerning the validity of models and their ability to meet the practical needs of design organizations.

  12. Time-domain matched interface and boundary (MIB) modeling of Debye dispersive media with curved interfaces

    NASA Astrophysics Data System (ADS)

    Nguyen, Duc Duy; Zhao, Shan

    2014-12-01

    A new finite-difference time-domain (FDTD) method is introduced for solving transverse magnetic Maxwell's equations in Debye dispersive media with complex interfaces and discontinuous wave solutions. Based on the auxiliary differential equation approach, a hybrid Maxwell-Debye system is constructed, which couples the wave equation for the electric component with Maxwell's equations for the magnetic components. This hybrid formulation enables the calculation of the time dependent parts of the interface jump conditions, so that one can track the transient changes in the regularities of the electromagnetic fields across a dispersive interface. Effective matched interface and boundary (MIB) treatments are proposed to rigorously impose the physical jump conditions which are not only time dependent, but also couple both Cartesian directions and both magnetic field components. Based on a staggered Yee lattice, the proposed MIB scheme can deal with arbitrarily curved interfaces and nonsmooth interfaces with sharped edges. Second order convergences are numerically achieved in solving dispersive interface problems with constant curvatures, general curvatures, and nonsmooth corners.

  13. An intracardiac navigation interface for electrophysiology modeling tools

    E-print Network

    Ocholi, Ojonimi A

    2006-01-01

    This thesis describes an interface that has been developed to assist in medical procedures. Several commercial systems are currently available each with their own strength and weaknesses and the goal of this interface is ...

  14. Computational design of patterned interfaces using reduced order models

    E-print Network

    Vattre, Aurelien

    Patterning is a familiar approach for imparting novel functionalities to free surfaces. We extend the patterning paradigm to interfaces between crystalline solids. Many interfaces have non-uniform internal structures ...

  15. The electrical behavior of GaAs-insulator interfaces - A discrete energy interface state model

    NASA Technical Reports Server (NTRS)

    Kazior, T. E.; Lagowski, J.; Gatos, H. C.

    1983-01-01

    The relationship between the electrical behavior of GaAs Metal Insulator Semiconductor (MIS) structures and the high density discrete energy interface states (0.7 and 0.9 eV below the conduction band) was investigated utilizing photo- and thermal emission from the interface states in conjunction with capacitance measurements. It was found that all essential features of the anomalous behavior of GaAs MIS structures, such as the frequency dispersion and the C-V hysteresis, can be explained on the basis of nonequilibrium charging and discharging of the high density discrete energy interface states.

  16. The Interface Between Theory and Data in Structural Equation Models

    USGS Publications Warehouse

    Grace, James B.; Bollen, Kenneth A.

    2006-01-01

    Structural equation modeling (SEM) holds the promise of providing natural scientists the capacity to evaluate complex multivariate hypotheses about ecological systems. Building on its predecessors, path analysis and factor analysis, SEM allows for the incorporation of both observed and unobserved (latent) variables into theoretically based probabilistic models. In this paper we discuss the interface between theory and data in SEM and the use of an additional variable type, the composite, for representing general concepts. In simple terms, composite variables specify the influences of collections of other variables and can be helpful in modeling general relationships of the sort commonly of interest to ecologists. While long recognized as a potentially important element of SEM, composite variables have received very limited use, in part because of a lack of theoretical consideration, but also because of difficulties that arise in parameter estimation when using conventional solution procedures. In this paper we present a framework for discussing composites and demonstrate how the use of partially reduced form models can help to overcome some of the parameter estimation and evaluation problems associated with models containing composites. Diagnostic procedures for evaluating the most appropriate and effective use of composites are illustrated with an example from the ecological literature. It is argued that an ability to incorporate composite variables into structural equation models may be particularly valuable in the study of natural systems, where concepts are frequently multifaceted and the influences of suites of variables are often of interest.

  17. Mathematical modeling of dispersion in single interface flow analysis.

    PubMed

    Rodrigues, S Sofia M; Marques, Karine L; Lopes, João A; Santos, João L M; Lima, José L F C

    2010-03-24

    This work describes the optimization of the recently proposed fluid management methodology single interface flow analysis (SIFA) using chemometrics modelling. The influence of the most important physical and hydrodynamic flow parameters of SIFA systems on the axial dispersion coefficients estimated with the axially dispersed plug-flow model, was evaluated with chemometrics linear (multivariate linear regression) and non-linear (simple multiplicative and feed-forward neural networks) models. A D-optimal experimental design built with three reaction coil properties (length, configuration and internal diameter), flow-cell volume and flow rate, was adopted to generate the experimental data. Bromocresol green was used as the dye solution and the analytical signals were monitored by spectrophotometric detection at 614 nm. Results demonstrate that, independent of the model type, the statistically relevant parameters were the reactor coil length and internal diameter and the flow rate. The linear and non-linear multiplicative models were able to estimate the axial dispersion coefficient with validation r(2)=0.86. Artificial neural networks estimated the same parameter with an increased accuracy (r(2)=0.93), demonstrating that relations between the physical parameters and the dispersion phenomena are highly non-linear. The analysis of the response surface control charts simulated with the developed models allowed the interpretation of the relationships between the physical parameters and the dispersion processes. PMID:20206008

  18. Modeling primary atomization and interface evaporation in turbulent two-phase flows by

    E-print Network

    Helluy, Philippe

    Outline Modeling primary atomization and interface evaporation in turbulent two-phase flows Modeling Spray Primary Breakup Modeling approach split into primary & secondary atomization track for secondary breakup couple with secondary atomization models Goal: understand the complex breakup mechanisms

  19. MobiGUITAR A Tool for Automated Model-Based Testing of Mobile Apps

    E-print Network

    Memon, Atif M.

    MobiGUITAR ­ A Tool for Automated Model-Based Testing of Mobile Apps Domenico Amalfitano, Anna Rita that mobile platforms are largely adopted because of the apps they offer [1], [2]. The issue of app quality testing, one of the most frequently used QA techniques, even in the mobile app context. A relevant family

  20. Automated substrate resistance extraction in nanoscale VLSI by exploiting a geometry-based analytical model

    Microsoft Academic Search

    Yiorgos I. Bontzios; Michael G. Dimopoulos; Alkis A. Hatzopoulos

    2011-01-01

    In this work, a new automated method for determining the substrate resistance is presented. It exploits a geometric formulation of the current streamlines between coupled structures and builds an analytical model for the substrate resistance. Both simulation and measurement data are utilized in order to show the validity of the proposed scheme. The measurement data are obtained from a fabricated

  1. An automated design flow from linguistic models to piecewise polynomial digital circuits

    Microsoft Academic Search

    Iluminada Baturone; Santiago Sánchez-Solano; Andrés A. Gersnoviez; María Brox

    2010-01-01

    This paper describes how the different CAD tools of the environment Xfuzzy 3, developed in Microelectronics Institute of Seville and University of Seville, allow to translate expressive linguistic models into mathematical ones, in particular, into a combination of piecewise polynomial systems that can be implemented efficiently in hardware. The new synthesis tool of Xfuzzy 3 automates communication with Xilinx System

  2. Modeling Human-Automation Interaction in a Unified Cognitive Architecture Junya Morita

    E-print Network

    Ritter, Frank

    . To prevent these mistakes, this study explores factors of reaching an appropriate reliance on automation systems by using cognitive modeling. We have conducted psychological experiments on this problem using the perceptual/motor modules. The perceptual module finds and attends to the vehicle and the road on the screen

  3. Modeling Multiple Human-Automation Distributed Systems using Network-form Games

    NASA Technical Reports Server (NTRS)

    Brat, Guillaume

    2012-01-01

    The paper describes at a high-level the network-form game framework (based on Bayes net and game theory), which can be used to model and analyze safety issues in large, distributed, mixed human-automation systems such as NextGen.

  4. Evaluation of automated cell disruptor methods for oomycetous and ascomycetous model organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two automated cell disruptor-based methods for RNA extraction; disruption of thawed cells submerged in TRIzol Reagent (method QP), and direct disruption of frozen cells on dry ice (method CP), were optimized for a model oomycete, Phytophthora capsici, and compared with grinding in a mortar and pestl...

  5. Automating the Import of Electronic Timetable Data to EMME/2-Based Public Transport Models

    E-print Network

    and Transport for London, respectively. This issue was highlighted during passenger demand forecasting work1 Automating the Import of Electronic Timetable Data to EMME/2-Based Public Transport Models John Armstrong, John Preston Transportation Research Group, School of Civil Engineering and the Environment

  6. AUTOMATED MODELING OF 3D BUILDING ROOFS USING IMAGE AND LIDAR DATA

    E-print Network

    Schindler, Konrad

    AUTOMATED MODELING OF 3D BUILDING ROOFS USING IMAGE AND LIDAR DATA N. Demir* , E. Baltsavias)@geod.baug.ethz.ch Commission IV, WG IV/2 KEY WORDS: Buildings, Multispectral classification, LiDAR data, DSM/DTM, Edge Matching as well as classification of multispectral images, elevation data and vertical LiDAR point density

  7. Comparison of different automated strategies for calibration of rainfall-runoff models

    Microsoft Academic Search

    Henrik Madsen; Geoffrey Wilson; Hans Christian Ammentorp

    2002-01-01

    Three different automated methods for calibration of rainfall-runoff models are presented and compared. The methods represent various calibration strategies that utilise multiple objectives and allow user intervention on different levels and different stages in the calibration process. The methods have been applied for calibration of a test catchment and compared on validation data with respect to overall performance measures in

  8. Using Formal Modelling with an Automated Analysis Tool to Design and Parametrically Analyze

    E-print Network

    Kim, Moonzoo

    . In this case study, we apply the formal modelling paradigm to a team of mobile robots. The linear hybrid on the restrictiveness of these assumptions and the overall utility of this automated analysis approach in designing and continuous time dynamics of such system can produce rich and unexpected behavior. Unfortunately designing

  9. SANE (Structure Assisted NOE Evaluation): an automated model-based approach for NOE assignment.

    PubMed

    Duggan, B M; Legge, G B; Dyson, H J; Wright, P E

    2001-04-01

    A reliable automated approach for assignment of NOESY spectra would allow more rapid determination of protein structures by NMR. In this paper we describe a semi-automated procedure for complete NOESY assignment (SANE, Structure Assisted NOE Evaluation), coupled to an iterative procedure for NMR structure determination where the user is directly involved. Our method is similar to ARIA [Nilges et al. (1997) J. Mol. Biol., 269, 408-422], but is compatible with the molecular dynamics suites AMBER and DYANA. The method is ideal for systems where an initial model or crystal structure is available, but has also been used successfully for ab initio structure determination. Use of this semi-automated iterative approach assists in the identification of errors in the NOE assignments to short-cut the path to an NMR solution structure. PMID:11370778

  10. SN_GUI: a graphical user interface for snowpack modeling

    NASA Astrophysics Data System (ADS)

    Spreitzhofer, G.; Fierz, C.; Lehning, M.

    2004-10-01

    SNOWPACK is a physical snow cover model. The model not only serves as a valuable research tool, but also runs operationally on a network of high Alpine automatic weather and snow measurement sites. In order to facilitate the operation of SNOWPACK and the interpretation of the results obtained by this model, a user-friendly graphical user interface for snowpack modeling, named SN_GUI, was created. This Java-based and thus platform-independent tool can be operated in two modes, one designed to fulfill the requirements of avalanche warning services (e.g. by providing information about critical layers within the snowpack that are closely related to the avalanche activity), and the other one offering a variety of additional options satisfying the needs of researchers. The user of SN_GUI is graphically guided through the entire process of creating snow cover simulations. The starting point is the efficient creation of input parameter files for SNOWPACK, followed by the launching of SNOWPACK with a variety of parameter settings. Finally, after the successful termination of the run, a number of interactive display options may be used to visualize the model output. Among these are vertical profiles and time profiles for many parameters. Besides other features, SN_GUI allows the use of various color, time and coordinate scales, and the comparison of measured and observed parameters.

  11. Deconstructing Classical Water Models at Interfaces and in Bulk

    NASA Astrophysics Data System (ADS)

    Remsing, Richard C.; Rodgers, Jocelyn M.; Weeks, John D.

    2011-10-01

    Using concepts from perturbation and local molecular field theories of liquids we divide the potential of the SPC/E water model into short and long ranged parts. The short ranged parts define a minimal reference network model that captures very well the structure of the local hydrogen bond network in bulk water while ignoring effects of the remaining long ranged interactions. This deconstruction can provide insight into the different roles that the local hydrogen bond network, dispersion forces, and long ranged dipolar interactions play in determining a variety of properties of SPC/E and related classical models of water. Here we focus on the anomalous behavior of the internal pressure and the temperature dependence of the density of bulk water. We further utilize these short ranged models along with local molecular field theory to quantify the influence of these interactions on the structure of hydrophobic interfaces and the crossover from small to large scale hydration behavior. The implications of our findings for theories of hydrophobicity and possible refinements of classical water models are also discussed.

  12. Interfacing dispersion models in the HGSYSTEM hazard-assessment package

    NASA Astrophysics Data System (ADS)

    Witlox, H. W. M.; McFarlane, K.

    The hazard-assessment software package HGSYSTEM consists of mathematical models for simulating one or more of the consecutive phases between spillage and far-field dispersion of a gaseous pollutant or hydrogen fluoride in moist air. HGSYSTEM can be used for both an unpressurised, low-momentum release and a pressurised, high-momentum release. For a pressurised release. the HGSYSTEM model HFPLUME (for HF) or PLUME (for ideal gas) calculates the flashing (depressurisation), jet flow and near-field dispersion and the HGSYSTEM model HEGADAS calculates the ground-level far-field heavy-gas dispersion. Transition and matching criteria are formulated for interfacing near-fieldjet models with far-field dispersion models. These criteria are validated by means of a HFPLUME HEGADAS simulation of the Goldfish experiments (steady-state and finite-duration pressurised release of HF). A sensitivity analysis to the problem parameters has been carried out to study the dispersion behaviour for a wider range of problems.

  13. Growth/reflectance model interface for wheat and corresponding model

    NASA Technical Reports Server (NTRS)

    Suits, G. H.; Sieron, R.; Odenweller, J.

    1984-01-01

    The use of modeling to explore the possibility of discovering new and useful crop condition indicators which might be available from the Thematic Mapper and to connect these symptoms to the biological causes in the crop is discussed. A crop growth model was used to predict the day to day growth features of the crop as it responds biologically to the various environmental factors. A reflectance model was used to predict the character of the interaction of daylight with the predicted growth features. An atmospheric path radiance was added to the reflected daylight to simulate the radiance appearing at the sensor. Finally, the digitized data sent to a ground station were calculated. The crop under investigation is wheat.

  14. Parallelization of a hydrological model using the message passing interface

    USGS Publications Warehouse

    Wu, Yiping; Li, Tiejian; Sun, Liqun; Chen, Ji

    2013-01-01

    With the increasing knowledge about the natural processes, hydrological models such as the Soil and Water Assessment Tool (SWAT) are becoming larger and more complex with increasing computation time. Additionally, other procedures such as model calibration, which may require thousands of model iterations, can increase running time and thus further reduce rapid modeling and analysis. Using the widely-applied SWAT as an example, this study demonstrates how to parallelize a serial hydrological model in a Windows® environment using a parallel programing technology—Message Passing Interface (MPI). With a case study, we derived the optimal values for the two parameters (the number of processes and the corresponding percentage of work to be distributed to the master process) of the parallel SWAT (P-SWAT) on an ordinary personal computer and a work station. Our study indicates that model execution time can be reduced by 42%–70% (or a speedup of 1.74–3.36) using multiple processes (two to five) with a proper task-distribution scheme (between the master and slave processes). Although the computation time cost becomes lower with an increasing number of processes (from two to five), this enhancement becomes less due to the accompanied increase in demand for message passing procedures between the master and all slave processes. Our case study demonstrates that the P-SWAT with a five-process run may reach the maximum speedup, and the performance can be quite stable (fairly independent of a project size). Overall, the P-SWAT can help reduce the computation time substantially for an individual model run, manual and automatic calibration procedures, and optimization of best management practices. In particular, the parallelization method we used and the scheme for deriving the optimal parameters in this study can be valuable and easily applied to other hydrological or environmental models.

  15. Automated NMR Fragment Based Screening Identified a Novel Interface Blocker to the LARG/RhoA Complex

    PubMed Central

    Gao, Jia; Ma, Rongsheng; Wang, Wei; Wang, Na; Sasaki, Ryan; Snyderman, David; Wu, Jihui; Ruan, Ke

    2014-01-01

    The small GTPase cycles between the inactive GDP form and the activated GTP form, catalyzed by the upstream guanine exchange factors. The modulation of such process by small molecules has been proven to be a fruitful route for therapeutic intervention to prevent the over-activation of the small GTPase. The fragment based approach emerging in the past decade has demonstrated its paramount potential in the discovery of inhibitors targeting such novel and challenging protein-protein interactions. The details regarding the procedure of NMR fragment screening from scratch have been rarely disclosed comprehensively, thus restricts its wider applications. To achieve a consistent screening applicable to a number of targets, we developed a highly automated protocol to cover every aspect of NMR fragment screening as possible, including the construction of small but diverse libray, determination of the aqueous solubility by NMR, grouping compounds with mutual dispersity to a cocktail, and the automated processing and visualization of the ligand based screening spectra. We exemplified our streamlined screening in RhoA alone and the complex of the small GTPase RhoA and its upstream guanine exchange factor LARG. Two hits were confirmed from the primary screening in cocktail and secondary screening over individual hits for LARG/RhoA complex, while one of them was also identified from the screening for RhoA alone. HSQC titration of the two hits over RhoA and LARG alone, respectively, identified one compound binding to RhoA.GDP at a 0.11 mM affinity, and perturbed the residues at the switch II region of RhoA. This hit blocked the formation of the LARG/RhoA complex, validated by the native gel electrophoresis, and the titration of RhoA to 15N labeled LARG in the absence and presence the compound, respectively. It therefore provides us a starting point toward a more potent inhibitor to RhoA activation catalyzed by LARG. PMID:24505392

  16. Computational Modeling of Electrolyte/Cathode Interfaces in Proton Exchange Membrane Fuel Cells

    E-print Network

    Bjørnstad, Ottar Nordal

    Computational Modeling of Electrolyte/Cathode Interfaces in Proton Exchange Membrane Fuel Cells Dr Proton exchange membrane fuel cells (PEMFCs) are alternative energy conversion devices that efficiently

  17. THE CRITICAL STRESS FOR TRANSMISSION OF A DISLOCATION ACROSS AN INTERFACE: RESULTS FROM PEIERLS AND EMBEDDED ATOM MODELS

    Microsoft Academic Search

    P. M. ANDERSON; S. RAO; Y. CHENG; P. M. HAZZLEDINE

    A continuum Peierls model of a screw dislocation being pushed through an interface and an atomistic EAM study of dislocation transmission across a (0 0 1) Al-Ni interface suggest that core spreading into the interface and misfit dislocations in the interface are both potent effects that can significantly increase barrier strength of interfaces.

  18. Does screw-bone interface modelling matter in finite element analyses?

    PubMed

    MacLeod, Alisdair R; Pankaj, Pankaj; Simpson, A Hamish R W

    2012-06-01

    The effect of screw-bone interface modelling strategies was evaluated in the setting of a tibial mid-shaft fracture stabilised using locking plates. Three interface models were examined: fully bonded interface; screw with sliding contact with bone; and screw with sliding contact with bone in an undersized pilot hole. For the simulation of the last interface condition we used a novel thermal expansion approach to generate the pre-stress that the bone would be exposed to during screw insertion. The study finds that the global load-deformation response is not influenced by the interface modelling approach employed; the deformation varied by less than 1% between different interaction models. However, interface modelling is found to have a considerable impact on the local stress-strain environment within the bone in the vicinity of the screws. Frictional and tied representations did not have significantly different peak strain values (<5% difference); the frictional interface had higher peak compressive strains while the tied interface had higher tensile strains. The undersized pilot hole simulation produced the largest strains. The peak minimum principal strains for the frictional interface were 26% of those for the undersized pilot hole simulation at a load of 770 N. It is concluded that the commonly used tie constraint can be used effectively when the only interest is the global load-deformation behaviour. Different contact interface models, however, alter the mechanical response around screw holes leading to different predictions for screw loosening, bone damage and stress shielding. PMID:22537570

  19. Phase field modeling of a glide dislocation transmission across a coherent sliding interface

    NASA Astrophysics Data System (ADS)

    Zheng, Songlin; Ni, Yong; He, Linghui

    2015-04-01

    Three-dimensional phase field microelasticity modeling and simulation capable of representing core structure and elastic interactions of dislocations are used to study a glide dislocation transmission across a coherent sliding interface in face-centered cubic metals. We investigate the role of the interface sliding process, which is described as the reversible motion of interface dislocation on the interfacial barrier strength to transmission. Numerical results show that a wider transient interface sliding zone develops on the interface with a lower interfacial unstable stacking fault energy to trap the glide dislocation leading to a stronger barrier to transmission. The interface sliding zone shrinks in the case of high applied stress and low mobility for the interfacial dislocation. This indicates that such interfacial barrier strength might be rate dependent. We discuss the calculated interfacial barrier strength for the Cu/Ni interface from the contribution of interface sliding comparable to previous atomistic simulations.

  20. INTERFACE CRACK PROPAGATION IN POROUS AND TIME-DEPENDENT MATERIALS ANALYZED WITH DISCRETE MODELS

    Microsoft Academic Search

    THEOCHARIS BAXEVANIS; ERIC DUFOUR; GILLES PIJAUDIER-CABOT

    2008-01-01

    A model describing the crack propagation at the interface between a rigid substratum and a beam is considered. The interface is modeled using a b er bundle model (i.e. using a discrete set of elements having a random strength). The distribution of avalanches, dened as the distance over which the crack is propagated under a xed force, is studied in

  1. DaisyViz: A model-based user interface toolkit for interactive information visualization systems

    E-print Network

    Giles, C. Lee

    DaisyViz: A model-based user interface toolkit for interactive information visualization systems), various visualization, interaction tasks. To address these issues, we designed DaisyViz, a model visualization applications without traditional programming. DaisyViz is based on a user interface model

  2. Efficient Parallel Levenberg-Marquardt Model Fitting towards Real-Time Automated Parametric Imaging Microscopy

    PubMed Central

    Zhu, Xiang; Zhang, Dianwen

    2013-01-01

    We present a fast, accurate and robust parallel Levenberg-Marquardt minimization optimizer, GPU-LMFit, which is implemented on graphics processing unit for high performance scalable parallel model fitting processing. GPU-LMFit can provide a dramatic speed-up in massive model fitting analyses to enable real-time automated pixel-wise parametric imaging microscopy. We demonstrate the performance of GPU-LMFit for the applications in superresolution localization microscopy and fluorescence lifetime imaging microscopy. PMID:24130785

  3. Efficient Model Checking by Automated Ordering of Transition Relation Partitions

    Microsoft Academic Search

    Daniel Geist; Ilan Beer

    1994-01-01

    In symbolic model checking, the behavior of a model to be verified is captured by the transition relation of the state space implied by the model. Unfortunately, the size of the transition relation grows rapidly with the number of states even for small models, rendering them impossible to verify. A recent work (5) described a method for partitioning the transition

  4. Petri net-based modelling of human-automation conflicts in aviation.

    PubMed

    Pizziol, Sergio; Tessier, Catherine; Dehais, Frédéric

    2014-01-01

    Analyses of aviation safety reports reveal that human-machine conflicts induced by poor automation design are remarkable precursors of accidents. A review of different crew-automation conflicting scenarios shows that they have a common denominator: the autopilot behaviour interferes with the pilot's goal regarding the flight guidance via 'hidden' mode transitions. Considering both the human operator and the machine (i.e. the autopilot or the decision functions) as agents, we propose a Petri net model of those conflicting interactions, which allows them to be detected as deadlocks in the Petri net. In order to test our Petri net model, we designed an autoflight system that was formally analysed to detect conflicting situations. We identified three conflicting situations that were integrated in an experimental scenario in a flight simulator with 10 general aviation pilots. The results showed that the conflicts that we had a-priori identified as critical had impacted the pilots' performance. Indeed, the first conflict remained unnoticed by eight participants and led to a potential collision with another aircraft. The second conflict was detected by all the participants but three of them did not manage the situation correctly. The last conflict was also detected by all the participants but provoked typical automation surprise situation as only one declared that he had understood the autopilot behaviour. These behavioural results are discussed in terms of workload and number of fired 'hidden' transitions. Eventually, this study reveals that both formal and experimental approaches are complementary to identify and assess the criticality of human-automation conflicts. Practitioner Summary: We propose a Petri net model of human-automation conflicts. An experiment was conducted with general aviation pilots performing a scenario involving three conflicting situations to test the soundness of our formal approach. This study reveals that both formal and experimental approaches are complementary to identify and assess the criticality conflicts. PMID:24444329

  5. Comparing the quality and predictiveness between 3D QSAR models obtained from manual and automated alignment.

    PubMed

    Tervo, Anu J; Nyrönen, Tommi H; Rönkkö, Toni; Poso, Antti

    2004-01-01

    A set of 113 flexible cyclic urea inhibitors of human immunodeficiency virus protease (HIV-1 PR) was used to compare the quality and predictive power of CoMFA and CoMSIA models for manually or automatically aligned inhibitor set. Inhibitors that were aligned automatically with molecular docking were in agreement with information obtained from existing X-ray structures. Both alignment methods produced statistically significant CoMFA and CoMSIA models, with the best q(2) value being 0.649 and the best predictive r(2) being 0.754. The manual alignment gave statistically higher values, whereas the automated alignment gave more robust models for predicting the activities of an external inhibitor set. Both models utilized similar amino acids in the HIV-1 PR active site, supporting the idea that hydrogen bonds form between an inhibitor and the backbone carbonyl oxygens of Gly48 and Gly48' and also the backbone NH group of Asp30, Gly48, Asp29', and Gly48' of the enzyme. These results suggest that an automated inhibitor alignment can yield predictive 3D QSAR models that are well comparable to manual methods. Thus, an automated alignment method in creating 3D QSAR models is encouragable when a well-characterized structure of the target protein is available. PMID:15154745

  6. Graphical User Interface for Simulink Integrated Performance Analysis Model

    NASA Technical Reports Server (NTRS)

    Durham, R. Caitlyn

    2009-01-01

    The J-2X Engine (built by Pratt & Whitney Rocketdyne,) in the Upper Stage of the Ares I Crew Launch Vehicle, will only start within a certain range of temperature and pressure for Liquid Hydrogen and Liquid Oxygen propellants. The purpose of the Simulink Integrated Performance Analysis Model is to verify that in all reasonable conditions the temperature and pressure of the propellants are within the required J-2X engine start boxes. In order to run the simulation, test variables must be entered at all reasonable values of parameters such as heat leak and mass flow rate. To make this testing process as efficient as possible in order to save the maximum amount of time and money, and to show that the J-2X engine will start when it is required to do so, a graphical user interface (GUI) was created to allow the input of values to be used as parameters in the Simulink Model, without opening or altering the contents of the model. The GUI must allow for test data to come from Microsoft Excel files, allow those values to be edited before testing, place those values into the Simulink Model, and get the output from the Simulink Model. The GUI was built using MATLAB, and will run the Simulink simulation when the Simulate option is activated. After running the simulation, the GUI will construct a new Microsoft Excel file, as well as a MATLAB matrix file, using the output values for each test of the simulation so that they may graphed and compared to other values.

  7. Calibration and application of an automated seepage meter for monitoring water flow across the sediment-water interface.

    PubMed

    Zhu, Tengyi; Fu, Dafang; Jenkinson, Byron; Jafvert, Chad T

    2015-04-01

    The advective flow of sediment pore water is an important parameter for understanding natural geochemical processes within lake, river, wetland, and marine sediments and also for properly designing permeable remedial sediment caps placed over contaminated sediments. Automated heat pulse seepage meters can be used to measure the vertical component of sediment pore water flow (i.e., vertical Darcy velocity); however, little information on meter calibration as a function of ambient water temperature exists in the literature. As a result, a method with associated equations for calibrating a heat pulse seepage meter as a function of ambient water temperature is fully described in this paper. Results of meter calibration over the temperature range 7.5 to 21.2 ° C indicate that errors in accuracy are significant if proper temperature-dependence calibration is not performed. The proposed calibration method allows for temperature corrections to be made automatically in the field at any ambient water temperature. The significance of these corrections is discussed. PMID:25754860

  8. An ion-binding model for ionic surfactant adsorption at aqueous-fluid interfaces

    Microsoft Academic Search

    V. V. Kalinin; C. J. Radke

    1996-01-01

    A simple ion-binding model is presented to quantify the equilibrium adsorption of ionic surfactants at aqueous-fluid interfaces. The proposed model adopts a triple layer structure for the interface: a plane of adsorbed surfactants (interface plane), a plane of partially dehydrated, contact-bound counterions (inner Helmholtz plane), and a plane of hydrated counterions (outer Helmholtz plane). An analytic expression for the surface

  9. Automated creation of transparent fuzzy models based on decision trees--application to diabetes diagnosis.

    PubMed

    Tsipouras, Markos G; Exarchos, Themis P; Fotiadis, Dimitrios I

    2008-01-01

    In this paper we propose a novel approach for the simplification of a fuzzy model. Initially, we employ a methodology for the automated generation of fuzzy models based on decision trees. The methodology is realized in three stages. Initially, a crisp model is created from a decision tree, induced from the data. Then, the crisp model it is transformed to a fuzzy one. Finally, in the third stage, all parameters entering the fuzzy model are optimized. The simplification technique is based on the pruning of the initial decision tree. The proposed approach is applied for diabetes diagnosis and the obtained results indicate its efficiency and effectiveness. PMID:19163539

  10. Paper presented at the 4th International Conference Working on Safety, Crete, Greece, 2008 Functional modeling for risk assessment of automation in a changing air

    E-print Network

    Zhao, Yuxiao

    Functional modeling for risk assessment of automation in a changing air traffic management environment R or to let automation act autonomously. The Functional Resonance Analysis Method (FRAM) provides a framework from ERASMUS automation. Various instantiations of a partial model resulting from the application

  11. Computer-automated multiparadigm modeling in control systems technology

    Microsoft Academic Search

    P. J. Mosterman; J. Sztipanovits; S. Engell

    2004-01-01

    The use of model-based technologies has made it imperative for the development of a feedback control system to deal with many different tasks such as: plant modeling in all its variety; model reduction to achieve a complexity or level of abstraction suitable for the design task at hand; synthesis of control laws that vary from discrete event reactive control to

  12. Modelling the inhomogeneous SiC Schottky interface

    NASA Astrophysics Data System (ADS)

    Gammon, P. M.; Pérez-Tomás, A.; Shah, V. A.; Vavasour, O.; Donchev, E.; Pang, J. S.; Myronov, M.; Fisher, C. A.; Jennings, M. R.; Leadley, D. R.; Mawby, P. A.

    2013-12-01

    For the first time, the I-V-T dataset of a Schottky diode has been accurately modelled, parameterised, and fully fit, incorporating the effects of interface inhomogeneity, patch pinch-off and resistance, and ideality factors that are both heavily temperature and voltage dependent. A Ni/SiC Schottky diode is characterised at 2 K intervals from 20 to 320 K, which, at room temperature, displays low ideality factors (n < 1.01) that suggest that these diodes may be homogeneous. However, at cryogenic temperatures, excessively high (n > 8), voltage dependent ideality factors and evidence of the so-called "thermionic field emission effect" within a T0-plot, suggest significant inhomogeneity. Two models are used, each derived from Tung's original interactive parallel conduction treatment of barrier height inhomogeneity that can reproduce these commonly seen effects in single temperature I-V traces. The first model incorporates patch pinch-off effects and produces accurate and reliable fits above around 150 K, and at current densities lower than 10-5 A cm-2. Outside this region, we show that resistive effects within a given patch are responsible for the excessive ideality factors, and a second simplified model incorporating these resistive effects as well as pinch-off accurately reproduces the entire temperature range. Analysis of these fitting parameters reduces confidence in those fits above 230 K, and questions are raised about the physical interpretation of the fitting parameters. Despite this, both methods used are shown to be useful tools for accurately reproducing I-V-T data over a large temperature range.

  13. The evaluation of an adaptive user interface model

    Microsoft Academic Search

    Bronwin Jason; André P. Calitz; Jéan H. Greyling

    2010-01-01

    User expertise and skill affects the way users interact with software. It is envisaged that an adaptive user interface (AUI) which dynamically changes from a novice user interface (UI) to an expert UI could possibly improve users' performance. Contact centres (CCs), are the primary interaction point between a company and its customers and an important challenge is to increase the

  14. Coupled Stokes-Darcy Model with Beavers-Joseph Interface Boundary Condition

    E-print Network

    Cao, Yanzhao

    Coupled Stokes-Darcy Model with Beavers-Joseph Interface Boundary Condition Yanzhao Cao Max Stokes-Darcy model with Beavers-Joseph in- terface boundary conditions. In the steady-state case, the well-posedness is established under the assumption of small coefficient in the Beavers-Joseph interface

  15. GLEAN: a computer-based tool for rapid GOMS model usability evaluation of user interface designs

    Microsoft Academic Search

    David E. Kieras; Scott D. Wood; Kasem Abotel; Anthony J. Hornof

    1995-01-01

    Engineering models of human performance permit some aspects of usability of interface designs to be predicted from an analysis of the task, and thus can replace to some extent expensive user testing data. The best developed such tools are GOMS models, which have been shown to be accurate and effective in predicting usability of the procedural aspects of interface designs.

  16. A cognitive model of user interaction as a guideline for designing novel interfaces

    E-print Network

    Guerrero, Luis

    A cognitive model of user interaction as a guideline for designing novel interfaces Felipe Aguilera]. This concept is used in GUI interfaces design: it exploit users' knowledge about the world such as pointing for the design of these environments. In this paper we present a methodology for designing user models for MRE

  17. Comparison of Joint Modeling Approaches Including Eulerian Sliding Interfaces

    SciTech Connect

    Lomov, I; Antoun, T; Vorobiev, O

    2009-12-16

    Accurate representation of discontinuities such as joints and faults is a key ingredient for high fidelity modeling of shock propagation in geologic media. The following study was done to improve treatment of discontinuities (joints) in the Eulerian hydrocode GEODYN (Lomov and Liu 2005). Lagrangian methods with conforming meshes and explicit inclusion of joints in the geologic model are well suited for such an analysis. Unfortunately, current meshing tools are unable to automatically generate adequate hexahedral meshes for large numbers of irregular polyhedra. Another concern is that joint stiffness in such explicit computations requires significantly reduced time steps, with negative implications for both the efficiency and quality of the numerical solution. An alternative approach is to use non-conforming meshes and embed joint information into regular computational elements. However, once slip displacement on the joints become comparable to the zone size, Lagrangian (even non-conforming) meshes could suffer from tangling and decreased time step problems. The use of non-conforming meshes in an Eulerian solver may alleviate these difficulties and provide a viable numerical approach for modeling the effects of faults on the dynamic response of geologic materials. We studied shock propagation in jointed/faulted media using a Lagrangian and two Eulerian approaches. To investigate the accuracy of this joint treatment the GEODYN calculations have been compared with results from the Lagrangian code GEODYN-L which uses an explicit treatment of joints via common plane contact. We explore two approaches to joint treatment in the code, one for joints with finite thickness and the other for tight joints. In all cases the sliding interfaces are tracked explicitly without homogenization or blending the joint and block response into an average response. In general, rock joints will introduce an increase in normal compliance in addition to a reduction in shear strength. In the present work we consider the limiting case of stiff discontinuities that only affect the shear strength of the material.

  18. Automated Inspection of Textile Fabrics Using Textural Models

    Microsoft Academic Search

    Fernand S. Cohen; Zhigang Fan; Stephane Attali

    1991-01-01

    The authors discuss the problem of textile fabric inspection using the visual textural properties of the fabric. The problem is to detect and locate the various kinds of defects that might be present in a given fabric sample based on an image of the fabric. Stochastic models are used to model the visual fabric texture. The authors use the Gaussian

  19. Automated fault model discretization for inversions for coseismic slip distributions

    Microsoft Academic Search

    W. D. Barnhart; R. B. Lohman

    2010-01-01

    Geoscientists increasingly rely on coseismic slip distributions inferred from geodetic observations to drive sophisticated models of the seismic cycle. To date, little work has been done on optimizing the parameterization of these fault models so that they reflect the resolving power of observed surface displacements. The locations of noisy surface displacement observations are often widely scattered far from features we

  20. Automated protein model building combined with iterative structure refinement

    Microsoft Academic Search

    Richard Morris; Victor S. Lamzin; Anastassis Perrakis

    1999-01-01

    In protein crystallography, much time and effort are often required to trace an initial model from an interpretable electron density map and to refine it until it best agrees with the crystallographic data. Here, we present a method to build and refine a protein model automatically and without user intervention, starting from diffraction data extending to resolution higher than 2.3

  1. Man power/cost estimation model: Automated planetary projects

    NASA Technical Reports Server (NTRS)

    Kitchen, L. D.

    1975-01-01

    A manpower/cost estimation model is developed which is based on a detailed level of financial analysis of over 30 million raw data points which are then compacted by more than three orders of magnitude to the level at which the model is applicable. The major parameter of expenditure is manpower (specifically direct labor hours) for all spacecraft subsystem and technical support categories. The resultant model is able to provide a mean absolute error of less than fifteen percent for the eight programs comprising the model data base. The model includes cost saving inheritance factors, broken down in four levels, for estimating follow-on type programs where hardware and design inheritance are evident or expected.

  2. An Automated Method for Large-Scale, Ground-Based City Model Acquisition

    Microsoft Academic Search

    Christian Früh; Avideh Zakhor

    2004-01-01

    In this paper, we describe an automated method for fast, ground-based acquisition of large-scale 3D city models. Our experimental set up consists of a truck equipped with one camera and two fast, inexpensive 2D laser scanners, being driven on city streets under normal traffic conditions. One scanner is mounted vertically to capture building facades, and the other one is mounted

  3. Model-Driven Web Engineering for the Automated Configuration of Web Content Management Systems

    Microsoft Academic Search

    Jurriaan Souer; Thijs Kupers; Remko Helms; Sjaak Brinkkemper

    2009-01-01

    With the growing use of Web Content Management Systems for the support of complex online business processes, traditional implementation\\u000a solutions proofed to be inefficient. Specifically the gap between business requirements and the realized Web application should\\u000a be closed. This paper presents the development of a modeling tool for the automated configuration of Web Content Management\\u000a Systems (WCM) which aims to

  4. Automated compact dynamical modeling: An enabling tool for analog designers

    E-print Network

    Bond, Bradley N.

    In this paper we summarize recent developments in compact dynamical modeling for both linear and nonlinear systems arising in analog applications. These techniques include methods based on the projection framework, rational ...

  5. Automated mask creation from a 3D model using Faethm.

    SciTech Connect

    Schiek, Richard Louis; Schmidt, Rodney Cannon

    2007-11-01

    We have developed and implemented a method which given a three-dimensional object can infer from topology the two-dimensional masks needed to produce that object with surface micro-machining. The masks produced by this design tool can be generic, process independent masks, or if given process constraints, specific for a target process. This design tool calculates the two-dimensional mask set required to produce a given three-dimensional model by investigating the vertical topology of the model.

  6. Models for identification of erroneous atom-to-atom mapping of reactions performed by automated algorithms.

    PubMed

    Muller, Christophe; Marcou, Gilles; Horvath, Dragos; Aires-de-Sousa, João; Varnek, Alexandre

    2012-12-21

    Machine learning (SVM and JRip rule learner) methods have been used in conjunction with the Condensed Graph of Reaction (CGR) approach to identify errors in the atom-to-atom mapping of chemical reactions produced by an automated mapping tool by ChemAxon. The modeling has been performed on the three first enzymatic classes of metabolic reactions from the KEGG database. Each reaction has been converted into a CGR representing a pseudomolecule with conventional (single, double, aromatic, etc.) bonds and dynamic bonds characterizing chemical transformations. The ChemAxon tool was used to automatically detect the matching atom pairs in reagents and products. These automated mappings were analyzed by the human expert and classified as "correct" or "wrong". ISIDA fragment descriptors generated for CGRs for both correct and wrong mappings were used as attributes in machine learning. The learned models have been validated in n-fold cross-validation on the training set followed by a challenge to detect correct and wrong mappings within an external test set of reactions, never used for learning. Results show that both SVM and JRip models detect most of the wrongly mapped reactions. We believe that this approach could be used to identify erroneous atom-to-atom mapping performed by any automated algorithm. PMID:23167287

  7. Diffuse interface model for incompressible two-phase flows with large density ratios

    Microsoft Academic Search

    Hang Ding; Peter D. M. Spelt; Chang Shu

    2007-01-01

    We investigate the applicability of an incompressible diffuse interface model for two-phase incompressible fluid flows with large viscosity and density contrasts. Diffuse-interface models have been used previously primarily for density-matched fluids, and it remains unclear to what extent such models can be used for fluids of different density, thereby potentially limiting the application of these models. In this paper, the

  8. Atomistic modelling of interaction between dislocations and misfit interface

    Microsoft Academic Search

    A. Kuronen; K. Kaski; L. F. Perondi; J. Rintala

    2001-01-01

    Mechanisms responsible for the formation of a misfit dislocation in a lattice-mismatched system -that involve gliding of the dislocation to the misfit interface-have been studied using Molecular Dynamics simulations of a two-dimensional Lennard-Jones system. Results show clearly how the strain due to the lattice-mismatched interface acts as a driving force for dislocation migration. Moreover, we observe dislocation reactions in which

  9. Using a sharp interface to model the capillary fringe: a model comparison

    NASA Astrophysics Data System (ADS)

    Bandilla, K.; Celia, M. A.; Nordbotten, J. M.; Court, B.; Elliot, T. J.

    2010-12-01

    Geologic carbon sequestration is seen as one option to reduce anthropogenic carbon emissions in the short term. The largest storage capacity is generally ascribed to deep saline aquifers where supercritical CO2 is trapped beneath a sufficiently impermeable cap rock. One approach to better understand the processes involved in CO2 sequestration in deep saline aquifers is the use of mathematical models. These models span the full spectrum of complexity from highly simplified models such as a single well, single aquifer Theis solution, to highly complex 3D multi-phase flow numerical simulators like THOUGH2 and ECLIPSE. While numerical simulators allow for a suite of subsurface processes to be modeled, the high computational cost makes Monte Carlo type risk analysis studies problematic. One approach to reduce computational cost is model simplification by dimensionality reduction and/or other assumptions such as a sharp interface separating the native brine and the injected CO2. The demand for computationally efficient models has also lead to a renewed interest in analytical and semi-analytical models. As analytical and semi-analytical models are becoming more sophisticated, the impact of capillary forces and relative permeability effects are becoming an active research area. This presentation explores the use and validity of sharp interface semi-analytical and numerical solutions with regard to their ability to model a capillary fringe and the resulting non-linear saturation profile and relative permeability distribution. In particular, the impact of using different capillary pressure - saturation relationships and relative permeability - saturation relationships in different model types (i.e., semi-analytical, numerical) is discussed. For perspective on previously published numerical results, these models are similarly applied to a single layer, single well system. The saturation profiles and pressure perturbations produced by our models are evaluated using results from the numerical reservoir simulator ECLIPSE as a criteria for predicting CO2 plume behavior through sharp interface models in cases with saturation profiles impacted by a capillary fringe.

  10. ASPOGAMO: Automated Sports Game Analysis Models Michael Beetz1

    E-print Network

    Cremers, Daniel

    , SPORTS VIDEO PROCESSING, MODEL BUILDING 1 Introduction Providing effective support for the interpretation building blocks; ­ represent the interaction between ball actions, game situations, and the effects of ball of comparing the final results only after the end of the game. In computer vision, video indexing

  11. Automated biowaste sampling system urine subsystem operating model, part 1

    NASA Technical Reports Server (NTRS)

    Fogal, G. L.; Mangialardi, J. K.; Rosen, F.

    1973-01-01

    The urine subsystem automatically provides for the collection, volume sensing, and sampling of urine from six subjects during space flight. Verification of the subsystem design was a primary objective of the current effort which was accomplished thru the detail design, fabrication, and verification testing of an operating model of the subsystem.

  12. IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 10, NO. 3, MAY/JUNE 2004 445 Model-Based Optoelectronic Packaging Automation

    E-print Network

    Kurzweg, Timothy P.

    -Based Optoelectronic Packaging Automation Timothy P. Kurzweg, Member, IEEE, Allon Guez, and Shubham K. Bhat Abstract--In this paper, we present an automation technique that yields high-performance, low-cost optoelectronic of the automation system. In addition to this feed-forward model, the controller is designed with feed- back

  13. Automation Reliability in Unmanned Aerial Vehicle Control: A Reliance-Compliance Model of Automation Dependence in High Workload

    Microsoft Academic Search

    Stephen R. Dixon; Christopher D. Wickens

    2006-01-01

    Objective: Two experiments were conducted in which participants navigated a simu- lated unmanned aerial vehicle (UAV) through a series of mission legs while searching for targets and monitoring system parameters. The goal of the study was to highlight the qualitatively different effects of automation false alarms and misses as they relate to operator compliance and reliance, respectively. Background: Background data

  14. Automated calibration of a stream solute transport model: Implications for interpretation of biogeochemical parameters

    USGS Publications Warehouse

    Scott, D.T.; Gooseff, M.N.; Bencala, K.E.; Runkel, R.L.

    2003-01-01

    The hydrologic processes of advection, dispersion, and transient storage are the primary physical mechanisms affecting solute transport in streams. The estimation of parameters for a conservative solute transport model is an essential step to characterize transient storage and other physical features that cannot be directly measured, and often is a preliminary step in the study of reactive solutes. Our study used inverse modeling to estimate parameters of the transient storage model OTIS (One dimensional Transport with Inflow and Storage). Observations from a tracer injection experiment performed on Uvas Creek, California, USA, are used to illustrate the application of automated solute transport model calibration to conservative and nonconservative stream solute transport. A computer code for universal inverse modeling (UCODE) is used for the calibrations. Results of this procedure are compared with a previous study that used a trial-and-error parameter estimation approach. The results demonstrated 1) importance of the proper estimation of discharge and lateral inflow within the stream system; 2) that although the fit of the observations is not much better when transient storage is invoked, a more randomly distributed set of residuals resulted (suggesting non-systematic error), indicating that transient storage is occurring; 3) that inclusion of transient storage for a reactive solute (Sr2+) provided a better fit to the observations, highlighting the importance of robust model parameterization; and 4) that applying an automated calibration inverse modeling estimation approach resulted in a comprehensive understanding of the model results and the limitation of input data.

  15. NeuroGPS: automated localization of neurons for brain circuits using L1 minimization model

    PubMed Central

    Quan, Tingwei; Zheng, Ting; Yang, Zhongqing; Ding, Wenxiang; Li, Shiwei; Li, Jing; Zhou, Hang; Luo, Qingming; Gong, Hui; Zeng, Shaoqun

    2013-01-01

    Drawing the map of neuronal circuits at microscopic resolution is important to explain how brain works. Recent progresses in fluorescence labeling and imaging techniques have enabled measuring the whole brain of a rodent like a mouse at submicron-resolution. Considering the huge volume of such datasets, automatic tracing and reconstruct the neuronal connections from the image stacks is essential to form the large scale circuits. However, the first step among which, automated location the soma across different brain areas remains a challenge. Here, we addressed this problem by introducing L1 minimization model. We developed a fully automated system, NeuronGlobalPositionSystem (NeuroGPS) that is robust to the broad diversity of shape, size and density of the neurons in a mouse brain. This method allows locating the neurons across different brain areas without human intervention. We believe this method would facilitate the analysis of the neuronal circuits for brain function and disease studies. PMID:23546385

  16. IDEF3 and IDEF4 automation system requirements document and system environment models

    NASA Technical Reports Server (NTRS)

    Blinn, Thomas M.

    1989-01-01

    The requirements specification is provided for the IDEF3 and IDEF4 tools that provide automated support for IDEF3 and IDEF4 modeling. The IDEF3 method is a scenario driven process flow description capture method intended to be used by domain experts to represent the knowledge about how a particular system or process works. The IDEF3 method provides modes to represent both (1) Process Flow Description to capture the relationships between actions within the context of a specific scenario, and (2) Object State Transition to capture the allowable transitions of an object in the domain. The IDEF4 method provides a method for capturing the (1) Class Submodel or object hierarchy, (2) Method Submodel or the procedures associated with each classes of objects, and (3) the Dispath Matching or the relationships between the objects and methods in the object oriented design. The requirements specified describe the capabilities that a fully functional IDEF3 or IDEF4 automated tool should support.

  17. An Improvement in Thermal Modelling of Automated Tape Placement Process

    NASA Astrophysics Data System (ADS)

    Barasinski, Anaïs; Leygue, Adrien; Soccard, Eric; Poitou, Arnaud

    2011-01-01

    The thermoplastic tape placement process offers the possibility of manufacturing large laminated composite parts with all kinds of geometries (double curved i.e.). This process is based on the fusion bonding of a thermoplastic tape on a substrate. It has received a growing interest during last years because of its non autoclave abilities. In order to control and optimize the quality of the manufactured part, we need to predict the temperature field throughout the processing of the laminate. In this work, we focus on a thermal modeling of this process which takes in account the imperfect bonding existing between the different layers of the substrate by introducing thermal contact resistance in the model. This study is leaning on experimental results which inform us that the value of the thermal resistance evolves with temperature and pressure applied on the material.

  18. Automated classification of atherosclerotic plaque from magnetic resonance images using predictive models.

    PubMed

    Anderson, Russell W; Stomberg, Christopher; Hahm, Charles W; Mani, Venkatesh; Samber, Daniel D; Itskovich, Vitalii V; Valera-Guallar, Laura; Fallon, John T; Nedanov, Pavel B; Huizenga, Joel; Fayad, Zahi A

    2007-01-01

    The information contained within multicontrast magnetic resonance images (MRI) promises to improve tissue classification accuracy, once appropriately analyzed. Predictive models capture relationships empirically, from known outcomes thereby combining pattern classification with experience. In this study, we examine the applicability of predictive modeling for atherosclerotic plaque component classification of multicontrast ex vivo MR images using stained, histopathological sections as ground truth. Ten multicontrast images from seven human coronary artery specimens were obtained on a 9.4 T imaging system using multicontrast-weighted fast spin-echo (T1-, proton density-, and T2-weighted) imaging with 39-mum isotropic voxel size. Following initial data transformations, predictive modeling focused on automating the identification of specimen's plaque, lipid, and media. The outputs of these three models were used to calculate statistics such as total plaque burden and the ratio of hard plaque (fibrous tissue) to lipid. Both logistic regression and an artificial neural network model (Relevant Input Processor Network-RIPNet) were used for predictive modeling. When compared against segmentation resulting from cluster analysis, the RIPNet models performed between 25 and 30% better in absolute terms. This translates to a 50% higher true positive rate over given levels of false positives. This work indicates that it is feasible to build an automated system of plaque detection using MRI and data mining. PMID:17254700

  19. INCORPORATION OF A LANGUAGE MODEL INTO A BRAIN COMPUTER INTERFACE BASED SPELLER THROUGH HMMs

    E-print Network

    Yanikoglu, Berrin

    of establishing direct communication pathways between the brain and external devices. The primary motivationINCORPORATION OF A LANGUAGE MODEL INTO A BRAIN COMPUTER INTERFACE BASED SPELLER THROUGH HMMs Ã?ada, 34956 Istanbul, Turkey ABSTRACT Brain computer interface (BCI) research deals with the problem

  20. Inferring Intent in Eye-Based Interfaces: Tracing Eye Movements with Process Models

    E-print Network

    Salvucci, Dario D.

    Inferring Intent in Eye-Based Interfaces: Tracing Eye Movements with Process Models Dario D dario+@cs.cmu.edu ABSTRACT While current eye-based interfaces offer enormous potential for efficient human-computer interaction, they also manifest the difficulty of inferring intent from user eye

  1. Counting Interface Automata and their Application in Static Analysis of Actor Models

    E-print Network

    theory Counting Interface Automata (CIA). We present a method to extract the interface infor- mation of an actor written in the Cal Actor Language (Cal) [8, 1] into a CIA, and we also present how to cre- ate a CIA of a composition framework with a dataflow model of computation. With the successful composition

  2. Three-Dimensional Modeling of Complex Fusion Devices Using CAD-MCNPX Interface Mengkuo Wang

    E-print Network

    California at San Diego, University of

    a user-friendly interface. They also provide functionalities that can evaluate the geometryThree-Dimensional Modeling of Complex Fusion Devices Using CAD-MCNPX Interface Mengkuo Wang 1 for the ARIES-CS[2] design, is described. I. INTRODUCTION For a commercial power plant fusion device, many

  3. Extending UML Use Case Modelling to Support Graphical User Interface Design

    Microsoft Academic Search

    Chris Phillips; Elizabeth A. Kemp; Sai Mei Kek

    2001-01-01

    UML supports the construction of several views of a software system. The paper reviews use case modelling in UML from the viewpoint of its suitability as input to the early stages of graphical user interface design. Three use case representations are compared, and an extended tabular representation is proposed which assists with the identification of user interface elements. This is

  4. Interactive Thin Shells A Model Interface for the Analysis of Physically-based Animation James Skorupski

    E-print Network

    Wood, Zoë J.

    , a thin shell animation, which focuses on visualization, experimentation, and control. Through the useInteractive Thin Shells ­ A Model Interface for the Analysis of Physically-based Animation James, and sensitive to changes in experimental parameters. We present an interface to a physically-based algorithm

  5. Model-based automation of baker's yeast production.

    PubMed

    Ringbom, K; Rothberg, A; Saxén, B

    1996-10-18

    An on-line model, estimating key state variables in bioprocesses, is utilized for control of fed-batch baker's yeast production. The state estimates are produced by balances and phenomenological expressions combined with on-line measurements. The goal of the control strategy is to maintain the highest possible glucose flux that can be entirely respiratively assimilated by the cells, resulting in the highest possible yeast growth without formation of metabolic products, such as acetic acid and ethanol. Stepwise improvement of the control algorithm is carried out in order to find a strategy to avoid undesired, irreversible metabolic pathways. In the final algorithm, such undesired changes in metabolism are predicted from an estimate of intracellular storage carbohydrates. A considerable decrease in the estimate indicates future metabolic changes at a time early enough to avoid them. At maximal yield, a growth rate near the highest possible is obtained in laboratory-scale Saccharomyces cerevisiae cultivations with the control strategy developed. PMID:8987630

  6. Piloted Simulation of a Model-Predictive Automated Recovery System

    NASA Technical Reports Server (NTRS)

    Liu, James (Yuan); Litt, Jonathan; Sowers, T. Shane; Owens, A. Karl; Guo, Ten-Huei

    2014-01-01

    This presentation describes a model-predictive automatic recovery system for aircraft on the verge of a loss-of-control situation. The system determines when it must intervene to prevent an imminent accident, resulting from a poor approach. It estimates the altitude loss that would result from a go-around maneuver at the current flight condition. If the loss is projected to violate a minimum altitude threshold, the maneuver is automatically triggered. The system deactivates to allow landing once several criteria are met. Piloted flight simulator evaluation showed the system to provide effective envelope protection during extremely unsafe landing attempts. The results demonstrate how flight and propulsion control can be integrated to recover control of the vehicle automatically and prevent a potential catastrophe.

  7. EST2uni: an open, parallel tool for automated EST analysis and database creation, with a data mining web interface and microarray expression data integration

    PubMed Central

    Forment, Javier; Gilabert, Francisco; Robles, Antonio; Conejero, Vicente; Nuez, Fernando; Blanca, Jose M

    2008-01-01

    Background Expressed sequence tag (EST) collections are composed of a high number of single-pass, redundant, partial sequences, which need to be processed, clustered, and annotated to remove low-quality and vector regions, eliminate redundancy and sequencing errors, and provide biologically relevant information. In order to provide a suitable way of performing the different steps in the analysis of the ESTs, flexible computation pipelines adapted to the local needs of specific EST projects have to be developed. Furthermore, EST collections must be stored in highly structured relational databases available to researchers through user-friendly interfaces which allow efficient and complex data mining, thus offering maximum capabilities for their full exploitation. Results We have created EST2uni, an integrated, highly-configurable EST analysis pipeline and data mining software package that automates the pre-processing, clustering, annotation, database creation, and data mining of EST collections. The pipeline uses standard EST analysis tools and the software has a modular design to facilitate the addition of new analytical methods and their configuration. Currently implemented analyses include functional and structural annotation, SNP and microsatellite discovery, integration of previously known genetic marker data and gene expression results, and assistance in cDNA microarray design. It can be run in parallel in a PC cluster in order to reduce the time necessary for the analysis. It also creates a web site linked to the database, showing collection statistics, with complex query capabilities and tools for data mining and retrieval. Conclusion The software package presented here provides an efficient and complete bioinformatics tool for the management of EST collections which is very easy to adapt to the local needs of different EST projects. The code is freely available under the GPL license and can be obtained at . This site also provides detailed instructions for installation and configuration of the software package. The code is under active development to incorporate new analyses, methods, and algorithms as they are released by the bioinformatics community. PMID:18179701

  8. Modelling of transient heat conduction with diffuse interface methods

    NASA Astrophysics Data System (ADS)

    Ettrich, J.; Choudhury, A.; Tschukin, O.; Schoof, E.; August, A.; Nestler, B.

    2014-12-01

    We present a survey on different numerical interpolation schemes used for two-phase transient heat conduction problems in the context of interface capturing phase-field methods. Examples are general transport problems in the context of diffuse interface methods with a non-equal heat conductivity in normal and tangential directions to the interface. We extend the tonsorial approach recently published by Nicoli M et al (2011 Phys. Rev. E 84 1–6) to the general three-dimensional (3D) transient evolution equations. Validations for one-dimensional, two-dimensional and 3D transient test cases are provided, and the results are in good agreement with analytical and numerical reference solutions.

  9. A semi-automated vascular access system for preclinical models

    NASA Astrophysics Data System (ADS)

    Berry-Pusey, B. N.; Chang, Y. C.; Prince, S. W.; Chu, K.; David, J.; Taschereau, R.; Silverman, R. W.; Williams, D.; Ladno, W.; Stout, D.; Tsao, T. C.; Chatziioannou, A.

    2013-08-01

    Murine models are used extensively in biological and translational research. For many of these studies it is necessary to access the vasculature for the injection of biologically active agents. Among the possible methods for accessing the mouse vasculature, tail vein injections are a routine but critical step for many experimental protocols. To perform successful tail vein injections, a high skill set and experience is required, leaving most scientists ill-suited to perform this task. This can lead to a high variability between injections, which can impact experimental results. To allow more scientists to perform tail vein injections and to decrease the variability between injections, a vascular access system (VAS) that semi-automatically inserts a needle into the tail vein of a mouse was developed. The VAS uses near infrared light, image processing techniques, computer controlled motors, and a pressure feedback system to insert the needle and to validate its proper placement within the vein. The VAS was tested by injecting a commonly used radiolabeled probe (FDG) into the tail veins of five mice. These mice were then imaged using micro-positron emission tomography to measure the percentage of the injected probe remaining in the tail. These studies showed that, on average, the VAS leaves 3.4% of the injected probe in the tail. With these preliminary results, the VAS system demonstrates the potential for improving the accuracy of tail vein injections in mice.

  10. Automated Finite Element Modeling of Wing Structures for Shape Optimization

    NASA Technical Reports Server (NTRS)

    Harvey, Michael Stephen

    1993-01-01

    The displacement formulation of the finite element method is the most general and most widely used technique for structural analysis of airplane configurations. Modem structural synthesis techniques based on the finite element method have reached a certain maturity in recent years, and large airplane structures can now be optimized with respect to sizing type design variables for many load cases subject to a rich variety of constraints including stress, buckling, frequency, stiffness and aeroelastic constraints (Refs. 1-3). These structural synthesis capabilities use gradient based nonlinear programming techniques to search for improved designs. For these techniques to be practical a major improvement was required in computational cost of finite element analyses (needed repeatedly in the optimization process). Thus, associated with the progress in structural optimization, a new perspective of structural analysis has emerged, namely, structural analysis specialized for design optimization application, or.what is known as "design oriented structural analysis" (Ref. 4). This discipline includes approximation concepts and methods for obtaining behavior sensitivity information (Ref. 1), all needed to make the optimization of large structural systems (modeled by thousands of degrees of freedom and thousands of design variables) practical and cost effective.

  11. Simulation of evaporation of a sessile drop using a diffuse interface model

    NASA Astrophysics Data System (ADS)

    Sefiane, Khellil; Ding, Hang; Sahu, Kirti; Matar, Omar

    2008-11-01

    We consider here the evaporation dynamics of a Newtonian liquid sessile drop using an improved diffuse interface model. The governing equations for the drop and surrounding vapour are both solved, and separated by the order parameter (i.e. volume fraction), based on the previous work of Ding et al. JCP 2007. The diffuse interface model has been shown to be successful in modelling the moving contact line problems (Jacqmin 2000; Ding and Spelt 2007, 2008). Here, a pinned contact line of the drop is assumed. The evaporative mass flux at the liquid-vapour interface is a function of local temperature constitutively and treated as a source term in the interface evolution equation, i.e. Cahn-Hilliard equation. The model is validated by comparing its predictions with data available in the literature. The evaporative dynamics are illustrated in terms of drop snapshots, and a quantitative comparison with the results using a free surface model are made.

  12. An architecture and model for cognitive engineering simulation analysis - Application to advanced aviation automation

    NASA Technical Reports Server (NTRS)

    Corker, Kevin M.; Smith, Barry R.

    1993-01-01

    The process of designing crew stations for large-scale, complex automated systems is made difficult because of the flexibility of roles that the crew can assume, and by the rapid rate at which system designs become fixed. Modern cockpit automation frequently involves multiple layers of control and display technology in which human operators must exercise equipment in augmented, supervisory, and fully automated control modes. In this context, we maintain that effective human-centered design is dependent on adequate models of human/system performance in which representations of the equipment, the human operator(s), and the mission tasks are available to designers for manipulation and modification. The joint Army-NASA Aircrew/Aircraft Integration (A3I) Program, with its attendant Man-machine Integration Design and Analysis System (MIDAS), was initiated to meet this challenge. MIDAS provides designers with a test bed for analyzing human-system integration in an environment in which both cognitive human function and 'intelligent' machine function are described in similar terms. This distributed object-oriented simulation system, its architecture and assumptions, and our experiences from its application in advanced aviation crew stations are described.

  13. Interface-capturing lattice Boltzmann equation model for two-phase flows

    NASA Astrophysics Data System (ADS)

    Lou, Qin; Guo, Zhaoli

    2015-01-01

    In this work, an interface-capturing lattice Boltzmann equation (LBE) model is proposed for two-phase flows. In the model, a Lax-Wendroff propagation scheme and a properly chosen equilibrium distribution function are employed. The Lax-Wendroff scheme is used to provide an adjustable Courant-Friedrichs-Lewy (CFL) number, and the equilibrium distribution is presented to remove the dependence of the relaxation time on the CFL number. As a result, the interface can be captured accurately by decreasing the CFL number. A theoretical expression is derived for the chemical potential gradient by solving the LBE directly for a two-phase system with a flat interface. The result shows that the gradient of the chemical potential is proportional to the square of the CFL number, which explains why the proposed model is able to capture the interface naturally with a small CFL number, and why large interface error exists in the standard LBE model. Numerical tests, including a one-dimensional flat interface problem, a two-dimensional circular droplet problem, and a three-dimensional spherical droplet problem, demonstrate that the proposed LBE model performs well and can capture a sharp interface with a suitable CFL number.

  14. Interface-capturing lattice Boltzmann equation model for two-phase flows.

    PubMed

    Lou, Qin; Guo, Zhaoli

    2015-01-01

    In this work, an interface-capturing lattice Boltzmann equation (LBE) model is proposed for two-phase flows. In the model, a Lax-Wendroff propagation scheme and a properly chosen equilibrium distribution function are employed. The Lax-Wendroff scheme is used to provide an adjustable Courant-Friedrichs-Lewy (CFL) number, and the equilibrium distribution is presented to remove the dependence of the relaxation time on the CFL number. As a result, the interface can be captured accurately by decreasing the CFL number. A theoretical expression is derived for the chemical potential gradient by solving the LBE directly for a two-phase system with a flat interface. The result shows that the gradient of the chemical potential is proportional to the square of the CFL number, which explains why the proposed model is able to capture the interface naturally with a small CFL number, and why large interface error exists in the standard LBE model. Numerical tests, including a one-dimensional flat interface problem, a two-dimensional circular droplet problem, and a three-dimensional spherical droplet problem, demonstrate that the proposed LBE model performs well and can capture a sharp interface with a suitable CFL number. PMID:25679734

  15. Keratocyte Apoptosis and Not Myofibroblast Differentiation Mark the Graft/Host Interface at Early Time-Points Post-DSAEK in a Cat Model

    PubMed Central

    Weis, Adam J.; Huxlin, Krystel R.; Callan, Christine L.; DeMagistris, Margaret A.; Hindman, Holly B.

    2013-01-01

    Purpose To evaluate myofibroblast differentiation as an etiology of haze at the graft-host interface in a cat model of Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK). Methods DSAEK was performed on 10 eyes of 5 adult domestic short-hair cats. In vivo corneal imaging with slit lamp, confocal, and optical coherence tomography (OCT) were performed twice weekly. Cats were sacrificed and corneas harvested 4 hours, and 2, 4, 6, and 9 days post-DSAEK. Corneal sections were stained with the TUNEL method and immunohistochemistry was performed for ?-smooth muscle actin (?-SMA) and fibronectin with DAPI counterstain. Results At all in vivo imaging time-points, corneal OCT revealed an increase in backscatter of light and confocal imaging revealed an acellular zone at the graft-host interface. At all post-mortem time-points, immunohistochemistry revealed a complete absence of ?-SMA staining at the graft-host interface. At 4 hours, extracellular fibronectin staining was identified along the graft-host interface and both fibronectin and TUNEL assay were positive within adjacent cells extending into the host stroma. By day 2, fibronectin and TUNEL staining diminished and a distinct acellular zone was present in the region of previously TUNEL-positive cells. Conclusions OCT imaging consistently showed increased reflectivity at the graft-host interface in cat corneas in the days post-DSAEK. This was not associated with myofibroblast differentiation at the graft-host interface, but rather with apoptosis and the development of a subsequent acellular zone. The roles of extracellular matrix changes and keratocyte cell death and repopulation should be investigated further as potential contributors to the interface optical changes. PMID:24098706

  16. Statistical modelling of networked human-automation performance using working memory capacity.

    PubMed

    Ahmed, Nisar; de Visser, Ewart; Shaw, Tyler; Mohamed-Ameen, Amira; Campbell, Mark; Parasuraman, Raja

    2014-01-01

    This study examines the challenging problem of modelling the interaction between individual attentional limitations and decision-making performance in networked human-automation system tasks. Analysis of real experimental data from a task involving networked supervision of multiple unmanned aerial vehicles by human participants shows that both task load and network message quality affect performance, but that these effects are modulated by individual differences in working memory (WM) capacity. These insights were used to assess three statistical approaches for modelling and making predictions with real experimental networked supervisory performance data: classical linear regression, non-parametric Gaussian processes and probabilistic Bayesian networks. It is shown that each of these approaches can help designers of networked human-automated systems cope with various uncertainties in order to accommodate future users by linking expected operating conditions and performance from real experimental data to observable cognitive traits like WM capacity. Practitioner Summary: Working memory (WM) capacity helps account for inter-individual variability in operator performance in networked unmanned aerial vehicle supervisory tasks. This is useful for reliable performance prediction near experimental conditions via linear models; robust statistical prediction beyond experimental conditions via Gaussian process models and probabilistic inference about unknown task conditions/WM capacities via Bayesian network models. PMID:24308716

  17. Diuse interface surface tension models in an expanding ow

    E-print Network

    Soatto, Stefano

    under compressible ow. The equation of interest is the Cahn-Hilliard or Allen-Cahn equation for a compressible ow, with the price of a more complicated set of equations, e.g. [9]. The original Cahn-Hilliard interface dynamics associated with surface energies. The Cahn-Hilliard equation can be written as an H-1

  18. Structure of liquid-vapor interfaces in the Ising model

    SciTech Connect

    Moseley, L.L. [Univ. of the West Indies, Cave Hill (Barbados)] [Univ. of the West Indies, Cave Hill (Barbados)

    1997-06-01

    The asymptotic behavior of the density profile of the fluid-fluid interface is investigated by computer simulation and is found to be better described by the error function than by the hyperbolic tangent in three dimensions. For higher dimensions the hyperbolic tangent is a better approximation.

  19. Ab-initio molecular modeling of interfaces in tantalum-carbon system

    NASA Astrophysics Data System (ADS)

    Balani, Kantesh; Bakshi, Srinivasa Rao; Mungole, Tarang; Agarwal, Arvind

    2012-03-01

    Processing of ultrahigh temperature TaC ceramic material with sintering additives of B4C and reinforcement of carbon nanotubes (CNTs) gives rise to possible formation of several interfaces (Ta2C-TaC, TaC-CNT, Ta2C-CNT, TaB2-TaC, and TaB2-CNT) that could influence the resultant properties. Current work focuses on interfaces developed during spark plasma sintering of TaC-system and performing ab initio molecular modeling of the interfaces generated during processing of TaC-B4C and TaC-CNT composites. The energy of the various interfaces has been evaluated and compared with TaC-Ta2C interface. The iso-surface electronic contours are extracted from the calculations eliciting the enhanced stability of TaC-CNT interface by 72.2%. CNTs form stable interfaces with Ta2C and TaB2 phases with a reduction in the energy by 35.8% and 40.4%, respectively. The computed Ta-C-B interfaces are also compared with experimentally observed interfaces in high resolution TEM images.

  20. Ab-initio molecular modeling of interfaces in tantalum-carbon system

    SciTech Connect

    Balani, Kantesh; Mungole, Tarang [Materials Science and Engineering, Indian Institute of Technology, Kanpur-208016 (India); Bakshi, Srinivasa Rao [Mechanical and Materials Engineering, Florida International University, Miami, Florida 33174 (United States); Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Agarwal, Arvind [Mechanical and Materials Engineering, Florida International University, Miami, Florida 33174 (United States)

    2012-03-15

    Processing of ultrahigh temperature TaC ceramic material with sintering additives of B{sub 4}C and reinforcement of carbon nanotubes (CNTs) gives rise to possible formation of several interfaces (Ta{sub 2}C-TaC, TaC-CNT, Ta{sub 2}C-CNT, TaB{sub 2}-TaC, and TaB{sub 2}-CNT) that could influence the resultant properties. Current work focuses on interfaces developed during spark plasma sintering of TaC-system and performing ab initio molecular modeling of the interfaces generated during processing of TaC-B{sub 4}C and TaC-CNT composites. The energy of the various interfaces has been evaluated and compared with TaC-Ta{sub 2}C interface. The iso-surface electronic contours are extracted from the calculations eliciting the enhanced stability of TaC-CNT interface by 72.2%. CNTs form stable interfaces with Ta{sub 2}C and TaB{sub 2} phases with a reduction in the energy by 35.8% and 40.4%, respectively. The computed Ta-C-B interfaces are also compared with experimentally observed interfaces in high resolution TEM images.

  1. Automated alignment-based curation of gene models in filamentous fungi

    PubMed Central

    2014-01-01

    Background Automated gene-calling is still an error-prone process, particularly for the highly plastic genomes of fungal species. Improvement through quality control and manual curation of gene models is a time-consuming process that requires skilled biologists and is only marginally performed. The wealth of available fungal genomes has not yet been exploited by an automated method that applies quality control of gene models in order to obtain more accurate genome annotations. Results We provide a novel method named alignment-based fungal gene prediction (ABFGP) that is particularly suitable for plastic genomes like those of fungi. It can assess gene models on a gene-by-gene basis making use of informant gene loci. Its performance was benchmarked on 6,965 gene models confirmed by full-length unigenes from ten different fungi. 79.4% of all gene models were correctly predicted by ABFGP. It improves the output of ab initio gene prediction software due to a higher sensitivity and precision for all gene model components. Applicability of the method was shown by revisiting the annotations of six different fungi, using gene loci from up to 29 fungal genomes as informants. Between 7,231 and 8,337 genes were assessed by ABFGP and for each genome between 1,724 and 3,505 gene model revisions were proposed. The reliability of the proposed gene models is assessed by an a posteriori introspection procedure of each intron and exon in the multiple gene model alignment. The total number and type of proposed gene model revisions in the six fungal genomes is correlated to the quality of the genome assembly, and to sequencing strategies used in the sequencing centre, highlighting different types of errors in different annotation pipelines. The ABFGP method is particularly successful in discovering sequence errors and/or disruptive mutations causing truncated and erroneous gene models. Conclusions The ABFGP method is an accurate and fully automated quality control method for fungal gene catalogues that can be easily implemented into existing annotation pipelines. With the exponential release of new genomes, the ABFGP method will help decreasing the number of gene models that require additional manual curation. PMID:24433567

  2. AIDE, A SYSTEM FOR DEVELOPING INTERACTIVE USER INTERFACES FOR ENVIRONMENTAL MODELS

    EPA Science Inventory

    Recent progress in environmental science and engineering has seen increasing use of interactive interfaces for computer models. nitial applications centered on the use of interactive software to assist in building complicated input sequences required by batch programs. rom these ...

  3. The enhanced Software Life Cyle Support Environment (ProSLCSE): Automation for enterprise and process modeling

    NASA Technical Reports Server (NTRS)

    Milligan, James R.; Dutton, James E.

    1993-01-01

    In this paper, we have introduced a comprehensive method for enterprise modeling that addresses the three important aspects of how an organization goes about its business. FirstEP includes infrastructure modeling, information modeling, and process modeling notations that are intended to be easy to learn and use. The notations stress the use of straightforward visual languages that are intuitive, syntactically simple, and semantically rich. ProSLCSE will be developed with automated tools and services to facilitate enterprise modeling and process enactment. In the spirit of FirstEP, ProSLCSE tools will also be seductively easy to use. Achieving fully managed, optimized software development and support processes will be long and arduous for most software organizations, and many serious problems will have to be solved along the way. ProSLCSE will provide the ability to document, communicate, and modify existing processes, which is the necessary first step.

  4. Intelligent sensor-model automated control of PMR-15 autoclave processing

    NASA Astrophysics Data System (ADS)

    Hart, S.; Kranbuehl, D.; Loos, A.; Hinds, B.; Koury, J.

    An intelligent sensor model system has been built and used for automated control of the PMR-15 cure process in the autoclave. The system uses frequency-dependent FM sensing (FDEMS), the Loos processing model, and the Air Force QPAL intelligent software shell. The Loos model is used to predict and optimize the cure process including the time-temperature dependence of the extent of reaction, flow, and part consolidation. The FDEMS sensing system in turn monitors, in situ, the removal of solvent, changes in the viscosity, reaction advancement and cure completion in the mold continuously throughout the processing cycle. The sensor information is compared with the optimum processing conditions from the model. The QPAL composite cure control system allows comparison of the sensor monitoring with the model predictions to be broken down into a series of discrete steps and provides a language for making decisions on what to do next regarding time-temperature and pressure.

  5. Design Through Manufacturing: The Solid Model-Finite Element Analysis Interface

    NASA Technical Reports Server (NTRS)

    Rubin, Carol

    2002-01-01

    State-of-the-art computer aided design (CAD) presently affords engineers the opportunity to create solid models of machine parts reflecting every detail of the finished product. Ideally, in the aerospace industry, these models should fulfill two very important functions: (1) provide numerical. control information for automated manufacturing of precision parts, and (2) enable analysts to easily evaluate the stress levels (using finite element analysis - FEA) for all structurally significant parts used in aircraft and space vehicles. Today's state-of-the-art CAD programs perform function (1) very well, providing an excellent model for precision manufacturing. But they do not provide a straightforward and simple means of automating the translation from CAD to FEA models, especially for aircraft-type structures. Presently, the process of preparing CAD models for FEA consumes a great deal of the analyst's time.

  6. A semi-automated method for patient-specific computational flow modelling of left ventricles.

    PubMed

    Nguyen, Vinh-Tan; Loon, Chong Jia; Nguyen, Hoang Huy; Liang, Zhong; Leo, Hwa Liang

    2015-01-01

    Patient-specific computational fluid dynamics (CFD) modelling of the left ventricle (LV) is a promising technique for the visualisation of ventricular flow patterns throughout a cardiac cycle. While significant progress has been made in improving the physiological quality of such simulations, the methodologies involved for several key steps remain significantly operator-dependent to this day. This dependency limits both the efficiency of the process as well as the consistency of CFD results due to the labour-intensive nature of current methods as well as operator introduced uncertainties in the modelling process. In order to mitigate this dependency, we propose a semi-automated method for patient-specific computational flow modelling of the LV. Using magnetic resonance imaging derived coarse geometry data of a patient's LV endocardium shape throughout a cardiac cycle, we then proceed to refine the geometry to eliminate rough edges before reconstructing meshes for all time frames and finally numerically solving for the intra-ventricular flow. Using a sample of patient-specific volunteer data, we demonstrate that our semi-automated, minimal operator involvement approach is capable of yielding CFD results of the LV that are comparable to other clinically validated LV flow models in the literature. PMID:23947745

  7. Automated quantitative analysis of angiogenesis in the rat aorta model using Image-Pro Plus 4.1

    Microsoft Academic Search

    Rebecca J. Blatt; Adam N. Clark; Jama Courtney; Chris Tully; Amy L. Tucker

    2004-01-01

    This paper explains the automated image-processing steps for the quantification of microvascular growth formation in the rat thoracic aortic ring model, an ex vivo model using excised rings of rat aorta embedded in a collagen matrix which produce outgrowths of microvessels. This model of angiogenesis is useful to study the mechanism by which external agents inhibit or stimulate endothelial cell

  8. A computational comparison of the atomic models of the actomyosin interface

    Microsoft Academic Search

    Douglas D. Root

    2002-01-01

    Several atomic models of the actomyosin interface have been proposed based on the docking together of their component structures\\u000a using electron microscopy and resonance energy-transfer measurements. Although these models are in approximate agreement in\\u000a the location of the binding interfaces when myosin is tightly bound to actin, their relationships to molecular docking simulations\\u000a based on computational free-energy calculations are investigated

  9. A coupled interface-body nonlocal damage model for FRP strengthening detachment

    Microsoft Academic Search

    S. Marfia; E. Sacco; J. Toti

    2011-01-01

    Aim of the paper is to propose a new coupled interface-body damage model for the study of the detachment process in concrete\\u000a or masonry structures strengthened with fiber reinforced polymers (FRP). In particular, a model of the FRP-concrete or -masonry\\u000a interface, accounting for the coupling between the degradation of the cohesive material and the FRP detachment, is presented.\\u000a To this

  10. Automated Metrology for SEM Calibration and CD Line Measurements Using Image Analysis and SEM Modeling Methods

    NASA Astrophysics Data System (ADS)

    Khvatkov, Vitali; Alievski, Vasily; Kadushnikov, Radi; Babin, Sergey

    2007-09-01

    Due to shrinking size of lithographic feature and limitations of SEM process, the native accuracy of CD-SEM instrument falls outside of ITRS requirements for characterization of lithographic structures for technology node 45 nm and smaller. This work provides overview and feasibility study of metrology system that can deliver accurate CD measurements from CD-SEM by using combination of image metrology and SEM beam modeling methods for automated evaluation and correction of CD-SEM bias. Open issues and further metrology needs are also discussed.

  11. The Murine Femoral Allograft Model and a Semi-automated Histomorphometric Analysis Tool

    PubMed Central

    Dhillon, Robinder S.; Zhang, Longze; Schwarz, Edward M.; Boyce, Brendan F.; Xie, Chao

    2014-01-01

    SUMMARY Preclinical studies on bone repair remain a high priority due to the unresolved clinical problems associated with treating critical segmental defects and complications of fracture healing. Over the last decade the murine femoral allograft model has gained popularity due to its standardized surgery and potential for examining a vast array of radiographic, biomechanical and histological outcome measures. Here, we describe these methods and a novel semi-automated histomorphometric approach to quantify the amount of bone, cartilage and undifferentiated mesenchymal tissue in demineralized paraffin sections of allografted murine femurs using the VisioPharm Image Analysis Software System. PMID:24482164

  12. A gradient-descent-based approach for transparent linguistic interface generation in fuzzy models.

    PubMed

    Chen, Long; Chen, C L Philip; Pedrycz, Witold

    2010-10-01

    Linguistic interface is a group of linguistic terms or fuzzy descriptions that describe variables in a system utilizing corresponding membership functions. Its transparency completely or partly decides the interpretability of fuzzy models. This paper proposes a GRadiEnt-descEnt-based Transparent lInguistic iNterface Generation (GREETING) approach to overcome the disadvantage of traditional linguistic interface generation methods where the consideration of the interpretability aspects of linguistic interface is limited. In GREETING, the widely used interpretability criteria of linguistic interface are considered and optimized. The numeric experiments on the data sets from University of California, Irvine (UCI) machine learning databases demonstrate the feasibility and superiority of the proposed GREETING method. The GREETING method is also applied to fuzzy decision tree generation. It is shown that GREETING generates better transparent fuzzy decision trees in terms of better classification rates and comparable tree sizes. PMID:19963699

  13. Cannabinoid CB2/CB1 selectivity. Receptor modeling and automated docking analysis.

    PubMed

    Tuccinardi, Tiziano; Ferrarini, Pier Luigi; Manera, Clementina; Ortore, Gabriella; Saccomanni, Giuseppe; Martinelli, Adriano

    2006-02-01

    Three-dimensional models of the CB1 and CB2 cannabinoid receptors were constructed by means of a molecular modeling procedure, using the X-ray structure of bovine rhodopsin as the initial template, and taking into account the available site-directed mutagenesis data. The cannabinoid system was studied by means of docking techniques. An analysis of the interaction of WIN55212-2 with both receptors showed that CB2/CB1 selectivity is mainly determined by the interaction in the CB2 with the nonconserved residues S3.31 and F5.46, whose importance was suggested by site-directed mutagenesis data. We also carried out an automated docking of several ligands into the CB2 model, using the AUTODOCK 3.0 program; the good correlation obtained between the estimated free energy binding and the experimental binding data confirmed our binding hypothesis and the reliability of the model. PMID:16451064

  14. Generating Phenotypical Erroneous Human Behavior to Evaluate Human-automation Interaction Using Model Checking

    PubMed Central

    Bolton, Matthew L.; Bass, Ellen J.; Siminiceanu, Radu I.

    2012-01-01

    Breakdowns in complex systems often occur as a result of system elements interacting in unanticipated ways. In systems with human operators, human-automation interaction associated with both normative and erroneous human behavior can contribute to such failures. Model-driven design and analysis techniques provide engineers with formal methods tools and techniques capable of evaluating how human behavior can contribute to system failures. This paper presents a novel method for automatically generating task analytic models encompassing both normative and erroneous human behavior from normative task models. The generated erroneous behavior is capable of replicating Hollnagel’s zero-order phenotypes of erroneous action for omissions, jumps, repetitions, and intrusions. Multiple phenotypical acts can occur in sequence, thus allowing for the generation of higher order phenotypes. The task behavior model pattern capable of generating erroneous behavior can be integrated into a formal system model so that system safety properties can be formally verified with a model checker. This allows analysts to prove that a human-automation interactive system (as represented by the model) will or will not satisfy safety properties with both normative and generated erroneous human behavior. We present benchmarks related to the size of the statespace and verification time of models to show how the erroneous human behavior generation process scales. We demonstrate the method with a case study: the operation of a radiation therapy machine. A potential problem resulting from a generated erroneous human action is discovered. A design intervention is presented which prevents this problem from occurring. We discuss how our method could be used to evaluate larger applications and recommend future paths of development. PMID:23105914

  15. A comparison of molecular dynamics and diffuse interface model predictions of Lennard-Jones fluid evaporation

    NASA Astrophysics Data System (ADS)

    Barbante, Paolo; Frezzotti, Aldo; Gibelli, Livio

    2014-12-01

    The unsteady evaporation of a thin planar liquid film is studied by molecular dynamics simulations of Lennard-Jones fluid. The obtained results are compared with the predictions of a diffuse interface model in which capillary Korteweg contributions are added to hydrodynamic equations, in order to obtain a unified description of the liquid bulk, liquid-vapor interface and vapor region. Particular care has been taken in constructing a diffuse interface model matching the thermodynamic and transport properties of the Lennard-Jones fluid. The comparison of diffuse interface model and molecular dynamics results shows that, although good agreement is obtained in equilibrium conditions, remarkable deviations of diffuse interface model predictions from the reference molecular dynamics results are observed in the simulation of liquid film evaporation. It is also observed that molecular dynamics results are in good agreement with preliminary results obtained from a composite model which describes the liquid film by a standard hydrodynamic model and the vapor by the Boltzmann equation. The two mathematical model models are connected by kinetic boundary conditions assuming unit evaporation coefficient.

  16. Aspects of automation mode confusion

    E-print Network

    Wheeler, Paul H. (Paul Harrison)

    2007-01-01

    Complex systems such as commercial aircraft are difficult for operators to manage. Designers, intending to simplify the interface between the operator and the system, have introduced automation to assist the operator. In ...

  17. An automated method to build groundwater model hydrostratigraphy from airborne electromagnetic data and lithological borehole logs

    NASA Astrophysics Data System (ADS)

    Marker, P. A.; Foged, N.; He, X.; Christiansen, A. V.; Refsgaard, J. C.; Auken, E.; Bauer-Gottwein, P.

    2015-02-01

    Large-scale integrated hydrological models are important decision support tools in water resources management. The largest source of uncertainty in such models is the hydrostratigraphic model. Geometry and configuration of hydrogeological units are often poorly determined from hydrogeological data alone. Due to sparse sampling in space, lithological borehole logs may overlook structures that are important for groundwater flow at larger scales. Good spatial coverage along with high spatial resolution makes airborne time-domain electromagnetic (AEM) data valuable for the structural input to large-scale groundwater models. We present a novel method to automatically integrate large AEM data-sets and lithological information into large-scale hydrological models. Clay-fraction maps are produced by translating geophysical resistivity into clay-fraction values using lithological borehole information. Voxel models of electrical resistivity and clay fraction are classified into hydrostratigraphic zones using k-means clustering. Hydraulic conductivity values of the zones are estimated by hydrological calibration using hydraulic head and stream discharge observations. The method is applied to a Danish case study. Benchmarking hydrological performance by comparison of simulated hydrological state variables, the cluster model performed competitively. Calibrations of 11 hydrostratigraphic cluster models with 1-11 hydraulic conductivity zones showed improved hydrological performance with increasing number of clusters. Beyond the 5-cluster model hydrological performance did not improve. Due to reproducibility and possibility of method standardization and automation, we believe that hydrostratigraphic model generation with the proposed method has important prospects for groundwater models used in water resources management.

  18. Pilot interaction with cockpit automation 2: An experimental study of pilots' model and awareness of the Flight Management System

    NASA Technical Reports Server (NTRS)

    Sarter, Nadine B.; Woods, David D.

    1994-01-01

    Technological developments have made it possible to automate more and more functions on the commercial aviation flight deck and in other dynamic high-consequence domains. This increase in the degrees of freedom in design has shifted questions away from narrow technological feasibility. Many concerned groups, from designers and operators to regulators and researchers, have begun to ask questions about how we should use the possibilities afforded by technology skillfully to support and expand human performance. In this article, we report on an experimental study that addressed these questions by examining pilot interaction with the current generation of flight deck automation. Previous results on pilot-automation interaction derived from pilot surveys, incident reports, and training observations have produced a corpus of features and contexts in which human-machine coordination is likely to break down (e.g., automation surprises). We used these data to design a simulated flight scenario that contained a variety of probes designed to reveal pilots' mental model of one major component of flight deck automation: the Flight Management System (FMS). The events within the scenario were also designed to probe pilots' ability to apply their knowledge and understanding in specific flight contexts and to examine their ability to track the status and behavior of the automated system (mode awareness). Although pilots were able to 'make the system work' in standard situations, the results reveal a variety of latent problems in pilot-FMS interaction that can affect pilot performance in nonnormal time critical situations.

  19. Modeling and stabilities of Mg/MgH2 interfaces: A first-principles investigation

    NASA Astrophysics Data System (ADS)

    Tang, Jia-Jun; Yang, Xiao-Bao; Chen, Li-Juan; Zhao, Yu-Jun

    2014-07-01

    We have theoretically investigated the modeling and the structural stabilities of various Mg/MgH2 interfaces, i.e. Mg(10bar 10)/MgH2(210), Mg(0001)/MgH2(101) and Mg(10bar 10)/MgH2(101), and provided illuminating insights into Mg/MgH2 interface. Specifically, the main factors, which impact the interfacial energies, are fully considered, including surface energies of two phases, mutual lattice constants of interface model, and relative position of two phases. The surface energies of Mg and MgH2, on the one hand, are found to be greatly impacting the interfacial energies, reflected by the lowest interfacial energy of Mg(0001)/MgH2(101) which is comprised of two lowest energy surfaces. On the other hand, it is demonstrated that the mutual lattice constants and the relative position of two phases lead to variations of interfacial energies, thus influencing the interface stabilities dramatically. Moreover, the Mg-H bonding at interface is found to be the determinant of Mg/MgH2 interface stability. Lastly, interfacial and strain effects on defect formations are also studied, both of which are highly facilitating the defect formations. Our results provide a detailed insight into Mg/MgH2 interface structures and the corresponding stabilities.

  20. Toward the virtual cell: Automated approaches to building models of subcellular organization “learned” from microscopy images

    PubMed Central

    Buck, Taráz E.; Li, Jieyue; Rohde, Gustavo K.; Murphy, Robert F.

    2012-01-01

    We review state-of-the-art computational methods for constructing, from image data, generative statistical models of cellular and nuclear shapes and the arrangement of subcellular structures and proteins within them. These automated approaches allow consistent analysis of images of cells for the purposes of learning the range of possible phenotypes, discriminating between them, and informing further investigation. Such models can also provide realistic geometry and initial protein locations to simulations in order to better understand cellular and subcellular processes. To determine the structures of cellular components and how proteins and other molecules are distributed among them, the generative modeling approach described here can be coupled with high throughput imaging technology to infer and represent subcellular organization from data with few a priori assumptions. We also discuss potential improvements to these methods and future directions for research. PMID:22777818

  1. Effective automated prediction of vertebral column pathologies based on logistic model tree with SMOTE preprocessing.

    PubMed

    Karabulut, Esra Mahsereci; Ibrikci, Turgay

    2014-05-01

    This study develops a logistic model tree based automation system based on for accurate recognition of types of vertebral column pathologies. Six biomechanical measures are used for this purpose: pelvic incidence, pelvic tilt, lumbar lordosis angle, sacral slope, pelvic radius and grade of spondylolisthesis. A two-phase classification model is employed in which the first step is preprocessing the data by use of Synthetic Minority Over-sampling Technique (SMOTE), and the second one is feeding the classifier Logistic Model Tree (LMT) with the preprocessed data. We have achieved an accuracy of 89.73 %, and 0.964 Area Under Curve (AUC) in computer based automatic detection of the pathology. This was validated via a 10-fold-cross-validation experiment conducted on clinical records of 310 patients. The study also presents a comparative analysis of the vertebral column data with the use of several machine learning algorithms. PMID:24753003

  2. Automation, Control and Modeling of Compound Semiconductor Thin-Film Growth

    SciTech Connect

    Breiland, W.G.; Coltrin, M.E.; Drummond, T.J.; Horn, K.M.; Hou, H.Q.; Klem, J.F.; Tsao, J.Y.

    1999-02-01

    This report documents the results of a laboratory-directed research and development (LDRD) project on control and agile manufacturing in the critical metalorganic chemical vapor deposition (MOCVD) and molecular beam epitaxy (MBE) materials growth processes essential to high-speed microelectronics and optoelectronic components. This effort is founded on a modular and configurable process automation system that serves as a backbone allowing integration of process-specific models and sensors. We have developed and integrated MOCVD- and MBE-specific models in this system, and demonstrated the effectiveness of sensor-based feedback control in improving the accuracy and reproducibility of semiconductor heterostructures. In addition, within this framework we have constructed ''virtual reactor'' models for growth processes, with the goal of greatly shortening the epitaxial growth process development cycle.

  3. The use of analytical models in human-computer interface design

    NASA Technical Reports Server (NTRS)

    Gugerty, Leo

    1993-01-01

    Recently, a large number of human-computer interface (HCI) researchers have investigated building analytical models of the user, which are often implemented as computer models. These models simulate the cognitive processes and task knowledge of the user in ways that allow a researcher or designer to estimate various aspects of an interface's usability, such as when user errors are likely to occur. This information can lead to design improvements. Analytical models can supplement design guidelines by providing designers rigorous ways of analyzing the information-processing requirements of specific tasks (i.e., task analysis). These models offer the potential of improving early designs and replacing some of the early phases of usability testing, thus reducing the cost of interface design. This paper describes some of the many analytical models that are currently being developed and evaluates the usefulness of analytical models for human-computer interface design. This paper will focus on computational, analytical models, such as the GOMS model, rather than less formal, verbal models, because the more exact predictions and task descriptions of computational models may be useful to designers. The paper also discusses some of the practical requirements for using analytical models in complex design organizations such as NASA.

  4. Towards a 3-Dimensional Phase-Field Model of Dendritic Solidification with Physically Realistic Interface Width

    E-print Network

    Jimack, Peter

    Towards a 3-Dimensional Phase-Field Model of Dendritic Solidification with Physically Realistic that such models are tractable even as the interface width approaches the solute capillary length. Keywords: Phase-field complexities involved with front tracking methods. However, phase-field modelling presents significant

  5. Dynamic behavior of driven interfaces in models with two absorbing states.

    PubMed

    Kwon, S; Hwang, W; Park, H

    1999-05-01

    We study the dynamics of an interface (active domain) between different absorbing regions in models with two absorbing states in one dimension: probabilistic cellular automata models and interacting monomer-dimer models. These models exhibit a continuous transition from an active phase into an absorbing phase, which belongs to the directed Ising (DI) universality class. In the active phase, the interface spreads ballistically into the absorbing regions and the interface width diverges linearly in time. Approaching the critical point, the spreading velocity of the interface vanishes algebraically with a DI critical exponent. Introducing a symmetry-breaking field h that prefers one absorbing state over the other drives the interface to move asymmetrically toward the unpreferred absorbing region. In Monte Carlo simulations, we find that the spreading velocity of this driven interface shows a discontinuous jump at criticality. We explain that this unusual behavior is due to a finite relaxation time in the absorbing phase. The crossover behavior from the symmetric case (DI class) to the asymmetric case (directed percolation class) is also studied. We find the scaling dimension of the symmetry-breaking field y(h)=1.21(5). PMID:11969448

  6. Automated defect detection system using wavelet packet frame and Gaussian mixture model

    NASA Astrophysics Data System (ADS)

    Kim, Soo Chang; Kang, Tae Jin

    2006-11-01

    This paper proposes an approach for automated defect detection in homogeneous textiles using texture analysis. The texture features are extracted by the wavelet packet frame decomposition followed by the Karhunen-Loève transform. The texture feature vector for each pixel is used as an input to a Gaussian mixture model that determines whether or not each pixel is defective. The parameters of the Gaussian mixture model are estimated with nondefective textile images in supervised defect detection. An approach for unsupervised defect detection is also presented that can identify the heterogeneous subblocks on the basis of the Kullback-Leibler divergence between two Gaussian mixtures. The proposed method was evaluated on 25 different homogeneous textile image pairs, one of each pair with a defect and the other with no defect, and was compared with existing methods using texture analysis. The experimental results yielded visually good segmentation and an excellent detection rate with a low false alarm rate for both supervised and unsupervised defect detection. This confirms the validity of the proposed approach for automated defect detection and localization.

  7. Anisotropic fluctuation model for surfactant-laden liquid-liquid crystal interfaces.

    PubMed

    Rey, Alejandro D

    2006-04-11

    A model for thermal fluctuations on surfactant-laden liquid-liquid crystal interfaces is formulated and used to derive the expression of the mean square displacement as a function of four elastic moduli of the interface. The measurable liquid crystal contributions to thermal roughness include the average molecular orientation, the interfacial anchoring modulus, and the bulk elasticity modulus. Surfactant-driven interfacial orientation transitions provide an additional means to extract interfacial elastic moduli parameters in surfactant-laden liquid-liquid crystal interfaces in conjunction with thermal roughness measurements. PMID:16584218

  8. Traffic Management for Automated Highway Systems Using Model-Based Predictive Control

    Microsoft Academic Search

    Lakshmi Dhevi Baskar; Bart De Schutter; Hans Hellendoorn

    2012-01-01

    We present an integrated traffic management and control approach for automated highway systems (AHS). The AHS consist of interacting roadside controllers and intelligent vehicles that are organized in platoons with short intraplatoon distances and larger distances between platoons. All vehicles are assumed to be fully automated, i.e., throttle, braking, and steering commands are determined by an automated onboard controller. The

  9. Library Automation: A Year on.

    ERIC Educational Resources Information Center

    Electronic Library, 1997

    1997-01-01

    A follow-up interview with librarians from Hong Kong, Mexico, Australia, Canada, and New Zealand about library automation systems in their libraries and their plans for the future. Discusses system performance, upgrades, services, resources, intranets, trends in automation, Web interfaces, full-text image/document systems, document delivery, OPACs…

  10. Automated 3D Damaged Cavity Model Builder for Lower Surface Acreage Tile on Orbiter

    NASA Technical Reports Server (NTRS)

    Belknap, Shannon; Zhang, Michael

    2013-01-01

    The 3D Automated Thermal Tool for Damaged Acreage Tile Math Model builder was developed to perform quickly and accurately 3D thermal analyses on damaged lower surface acreage tiles and structures beneath the damaged locations on a Space Shuttle Orbiter. The 3D model builder created both TRASYS geometric math models (GMMs) and SINDA thermal math models (TMMs) to simulate an idealized damaged cavity in the damaged tile(s). The GMMs are processed in TRASYS to generate radiation conductors between the surfaces in the cavity. The radiation conductors are inserted into the TMMs, which are processed in SINDA to generate temperature histories for all of the nodes on each layer of the TMM. The invention allows a thermal analyst to create quickly and accurately a 3D model of a damaged lower surface tile on the orbiter. The 3D model builder can generate a GMM and the correspond ing TMM in one or two minutes, with the damaged cavity included in the tile material. A separate program creates a configuration file, which would take a couple of minutes to edit. This configuration file is read by the model builder program to determine the location of the damage, the correct tile type, tile thickness, structure thickness, and SIP thickness of the damage, so that the model builder program can build an accurate model at the specified location. Once the models are built, they are processed by the TRASYS and SINDA.

  11. Positive charges at buried oxide interface of RESURF: An analytical model for the breakdown voltage

    NASA Astrophysics Data System (ADS)

    Orouji, Ali A.; Mehrad, Mahsa

    2014-08-01

    A new analytical model of reduced surface field (RESURF) transistor on silicon-on-insulator (SOI) technology with positive charges at the buried oxide interface is proposed. Interface charges at the interface of the buried oxide (BOX) and drift region increase the electric field in the BOX and decrease the surface electric field in the silicon region. So, this approach is suitable to enhance the breakdown voltage with increasing the electric field at the BOX. Two-dimensional Poisson equation is solved for the new structure and surface potential, surface electric field and breakdown voltage are derived. Moreover, the validity of this novel model is demonstrated by comparing with numerical simulation of ATLAS simulator. The influence of drift region doping, density of positive charges at the buried oxide interface and also the thicknesses of field oxide and BOX are discussed in this paper. Furthermore, the analytical results have the best agreement with numerical simulation.

  12. Using physical potentials and learned models to distinguish native binding interfaces from de novo designed interfaces that do not bind.

    PubMed

    Demerdash, Omar N A; Mitchell, Julie C

    2013-11-01

    Protein-protein interactions are a fundamental aspect of many biological processes. The advent of recombinant protein and computational techniques has allowed for the rational design of proteins with novel binding capabilities. It is therefore desirable to predict which designed proteins are capable of binding in vitro. To this end, we have developed a learned classification model that combines energetic and non-energetic features. Our feature set is adapted from specialized potentials for aromatic interactions, hydrogen bonds, electrostatics, shape, and desolvation. A binding model built on these features was initially developed for CAPRI Round 21, achieving top results in the independent assessment. Here, we present a more thoroughly trained and validated model, and compare various support-vector machine kernels. The Gaussian kernel model classified both high-resolution complexes and designed nonbinders with 79-86% accuracy on independent test data. We also observe that multiple physical potentials for dielectric-dependent electrostatics and hydrogen bonding contribute to the enhanced predictive accuracy, suggesting that their combined information is much greater than that of any single energetics model. We also study the change in predictive performance as the model features or training data are varied, observing unusual patterns of prediction in designed interfaces as compared with other data types. PMID:23760773

  13. A multilayered sharp interface model of coupled freshwater and saltwater flow in coastal systems: model development and application

    USGS Publications Warehouse

    Essaid, H.I.

    1990-01-01

    The model allows for regional simulation of coastal groundwater conditions, including the effects of saltwater dynamics on the freshwater system. Vertically integrated freshwater and saltwater flow equations incorporating the interface boundary condition are solved within each aquifer. Leakage through confining layers is calculated by Darcy's law, accounting for density differences across the layer. The locations of the interface tip and toe, within grid blocks, are tracked by linearly extrapolating the position of the interface. The model has been verified using available analytical solutions and experimental results and applied to the Soquel-Aptos basin, Santa Cruz County, California. -from Author

  14. Numerical modeling of heterojunctions including the thermionic emission mechanism at the heterojunction interface

    Microsoft Academic Search

    K. Horio; H. Yanai

    1990-01-01

    A numerical model for heterojunctions is discussed in which current transport across the heterojunction interface is taken into account by using thermionic emission current in series with drift-diffusion current in the bulk. The thermionic emission current is regarded as a boundary condition, which is used to obtain a relationship between quasi-Fermi-levels on both sides of the interface. GaAs-AlGaAs heterojunctions are

  15. Sharp-interface projection of a fluctuating phase-field model

    Microsoft Academic Search

    R. Ben ´ õtez; L. Ram ´ õrez-Piscina

    We present a derivation of the sharp-interface limit of a generic fluctuating phase-field model for solidification. As a main result, we obtain a sharp-interface projection which presents noise terms in both the diffusion equation and in the moving boundary conditions. The presented procedure does not rely on the fluctuation-dissipation theorem, and can therefore be applied to account for both internal

  16. Sharp-interface projection of a fluctuating phase-field model

    Microsoft Academic Search

    R. Benítez; L. Ramírez-Piscina

    2005-01-01

    We present a derivation of the sharp-interface limit of a generic fluctuating phase-field model for solidification. As a main result, we obtain a sharp-interface projection which presents noise terms in both the diffusion equation and in the moving boundary conditions. The presented procedure does not rely on the fluctuation-dissipation theorem, and can therefore be applied to account for both internal

  17. Sharp-Interface Limit of a Fluctuating Phase-Field Model

    Microsoft Academic Search

    R. Benítez; L. Ramírez-Piscina

    2004-01-01

    We present a derivation of the sharp-interface limit of a generic fluctuating\\u000aphase-field model for solidification. As a main result, we obtain a\\u000asharp-interface projection which presents noise terms in both the diffusion\\u000aequation and in the moving boundary conditions. The presented procedure does\\u000anot rely on the fluctuation-dissipation theorem, and can therefore be applied\\u000ato account for both internal

  18. An Accuracy Assessment of Automated Photogrammetric Techniques for 3d Modeling of Complex Interiors

    NASA Astrophysics Data System (ADS)

    Georgantas, A.; Brédif, M.; Pierrot-Desseilligny, M.

    2012-07-01

    This paper presents a comparison of automatic photogrammetric techniques to terrestrial laser scanning for 3D modelling of complex interior spaces. We try to evaluate the automated photogrammetric techniques not only in terms of their geometric quality compared to laser scanning but also in terms of cost in money, acquisition and computational time. To this purpose we chose as test site a modern building's stairway. APERO/MICMAC ( ©IGN )which is an Open Source photogrammetric software was used for the production of the 3D photogrammetric point cloud which was compared to the one acquired by a Leica Scanstation 2 laser scanner. After performing various qualitative and quantitative controls we present the advantages and disadvantages of each 3D modelling method applied in a complex interior of a modern building.

  19. CHANNEL MORPHOLOGY TOOL (CMT): A GIS-BASED AUTOMATED EXTRACTION MODEL FOR CHANNEL GEOMETRY

    SciTech Connect

    JUDI, DAVID [Los Alamos National Laboratory; KALYANAPU, ALFRED [Los Alamos National Laboratory; MCPHERSON, TIMOTHY [Los Alamos National Laboratory; BERSCHEID, ALAN [Los Alamos National Laboratory

    2007-01-17

    This paper describes an automated Channel Morphology Tool (CMT) developed in ArcGIS 9.1 environment. The CMT creates cross-sections along a stream centerline and uses a digital elevation model (DEM) to create station points with elevations along each of the cross-sections. The generated cross-sections may then be exported into a hydraulic model. Along with the rapid cross-section generation the CMT also eliminates any cross-section overlaps that might occur due to the sinuosity of the channels using the Cross-section Overlap Correction Algorithm (COCoA). The CMT was tested by extracting cross-sections from a 5-m DEM for a 50-km channel length in Houston, Texas. The extracted cross-sections were compared directly with surveyed cross-sections in terms of the cross-section area. Results indicated that the CMT-generated cross-sections satisfactorily matched the surveyed data.

  20. An Overview of Workflow Management: From Process Modeling to Workflow Automation Infrastructure

    E-print Network

    Diimitrios Georgakopoulos; Mark Hornick; Amit Sheth

    1995-01-01

    Today’s business enterprises must deal with global competition, reduce the cost of doing business, and rapidly develop new services and products. To address these requirements enterprises must constantly reconsider and optimize the way they do business and change their information systems and applications to support evolving business processes. Workflow technology facilitates these by providing methodologies and software to support (i) business process modeling to capture business processes as workflow specifications, (ii) business process reengineering to optimize specified processes, and (iii) workflow automation to generate workflow implementations from workflow specifications. This paper provides a high-level overview of the current workflow management methodologies and software products. In addition, we discuss the infrastructure technologies that can address the limitations of current commercial workflow technology and extend the scope and mission of workflow management systems to support increased workflow automation in complex real-world environments involving heterogeneous, autonomous, and distributed information systems. In particular, we discuss how distributed object management and customized transaction management can support further advances in the commercial state of the art in this area.

  1. A methodology for model-based development and automated verification of software for aerospace systems

    NASA Astrophysics Data System (ADS)

    Martin, L.; Schatalov, M.; Hagner, M.; Goltz, U.; Maibaum, O.

    Today's software for aerospace systems typically is very complex. This is due to the increasing number of features as well as the high demand for safety, reliability, and quality. This complexity also leads to significant higher software development costs. To handle the software complexity, a structured development process is necessary. Additionally, compliance with relevant standards for quality assurance is a mandatory concern. To assure high software quality, techniques for verification are necessary. Besides traditional techniques like testing, automated verification techniques like model checking become more popular. The latter examine the whole state space and, consequently, result in a full test coverage. Nevertheless, despite the obvious advantages, this technique is rarely yet used for the development of aerospace systems. In this paper, we propose a tool-supported methodology for the development and formal verification of safety-critical software in the aerospace domain. The methodology relies on the V-Model and defines a comprehensive work flow for model-based software development as well as automated verification in compliance to the European standard series ECSS-E-ST-40C. Furthermore, our methodology supports the generation and deployment of code. For tool support we use the tool SCADE Suite (Esterel Technology), an integrated design environment that covers all the requirements for our methodology. The SCADE Suite is well established in avionics and defense, rail transportation, energy and heavy equipment industries. For evaluation purposes, we apply our approach to an up-to-date case study of the TET-1 satellite bus. In particular, the attitude and orbit control software is considered. The behavioral models for the subsystem are developed, formally verified, and optimized.

  2. Automated Reconstruction of Walls from Airborne LIDAR Data for Complete 3d Building Modelling

    NASA Astrophysics Data System (ADS)

    He, Y.; Zhang, C.; Awrangjeb, M.; Fraser, C. S.

    2012-07-01

    Automated 3D building model generation continues to attract research interests in photogrammetry and computer vision. Airborne Light Detection and Ranging (LIDAR) data with increasing point density and accuracy has been recognized as a valuable source for automated 3D building reconstruction. While considerable achievements have been made in roof extraction, limited research has been carried out in modelling and reconstruction of walls, which constitute important components of a full building model. Low point density and irregular point distribution of LIDAR observations on vertical walls render this task complex. This paper develops a novel approach for wall reconstruction from airborne LIDAR data. The developed method commences with point cloud segmentation using a region growing approach. Seed points for planar segments are selected through principle component analysis, and points in the neighbourhood are collected and examined to form planar segments. Afterwards, segment-based classification is performed to identify roofs, walls and planar ground surfaces. For walls with sparse LIDAR observations, a search is conducted in the neighbourhood of each individual roof segment to collect wall points, and the walls are then reconstructed using geometrical and topological constraints. Finally, walls which were not illuminated by the LIDAR sensor are determined via both reconstructed roof data and neighbouring walls. This leads to the generation of topologically consistent and geometrically accurate and complete 3D building models. Experiments have been conducted in two test sites in the Netherlands and Australia to evaluate the performance of the proposed method. Results show that planar segments can be reliably extracted in the two reported test sites, which have different point density, and the building walls can be correctly reconstructed if the walls are illuminated by the LIDAR sensor.

  3. A Demonstration of Automated DNA Sequencing.

    ERIC Educational Resources Information Center

    Latourelle, Sandra; Seidel-Rogol, Bonnie

    1998-01-01

    Details a simulation that employs a paper-and-pencil model to demonstrate the principles behind automated DNA sequencing. Discusses the advantages of automated sequencing as well as the chemistry of automated DNA sequencing. (DDR)

  4. Bone-cement interface micromechanical model under cyclic loading J.A. Sanz-Herrera1, a

    E-print Network

    Ariza Moreno, Pilar

    Bone-cement interface micromechanical model under cyclic loading J.A. Sanz-Herrera1, a , H-cement interface, Micromechanics, Fatigue damage, Viscoelasticity. Abstract. Total hip replacement is one loosening due to fatigue of one of the two microscopic interfaces. In this work, a micromechanical analysis

  5. An Agent-Based Interface to Terrestrial Ecological Forecasting

    NASA Technical Reports Server (NTRS)

    Golden, Keith; Nemani, Ramakrishna; Pang, Wan-Lin; Votava, Petr; Etzioni, Oren

    2004-01-01

    This paper describes a flexible agent-based ecological forecasting system that combines multiple distributed data sources and models to provide near-real-time answers to questions about the state of the Earth system We build on novel techniques in automated constraint-based planning and natural language interfaces to automatically generate data products based on descriptions of the desired data products.

  6. Fullerene film on metal surface: Diffusion of metal atoms and interface model

    NASA Astrophysics Data System (ADS)

    Li, Wen-jie; Wang, Peng; Wang, Xiao-Xiong; Wang, Jia-Ou; Wu, Rui; Qian, Hai-Jie; Ibrahim, Kurash; Li, Hai-Yang; Li, Hong-Nian

    2014-05-01

    We try to understand the fact that fullerene film behaves as n-type semiconductor in electronic devices and establish a model describing the energy level alignment at fullerene/metal interfaces. The C60/Ag(100) system was taken as a prototype and studied with photoemission measurements. The photoemission spectra revealed that the Ag atoms of the substrate diffused far into C60 film and donated electrons to the molecules. So the C60 film became n-type semiconductor with the Ag atoms acting as dopants. The C60/Ag(100) interface should be understood as two sub-interfaces on both sides of the molecular layer directly contacting with the substrate. One sub-interface is Fermi level alignment, and the other is vacuum level alignment.

  7. Fullerene film on metal surface: Diffusion of metal atoms and interface model

    SciTech Connect

    Li, Wen-jie; Li, Hai-Yang; Li, Hong-Nian, E-mail: Phylihn@mail.zju.edu.cn [Department of Physics, Zhejiang University, Hangzhou 310027 (China); Wang, Peng [Department of Applied Physics, Shandong University of Science and Technology, Qingdao 266590 (China); Wang, Xiao-Xiong [College of Science, Nanjing University of Science and Technology, Nanjing 210094 (China); Wang, Jia-Ou; Wu, Rui; Qian, Hai-Jie; Ibrahim, Kurash [Laboratory of Synchrotron Radiation, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100039 (China)

    2014-05-12

    We try to understand the fact that fullerene film behaves as n-type semiconductor in electronic devices and establish a model describing the energy level alignment at fullerene/metal interfaces. The C{sub 60}/Ag(100) system was taken as a prototype and studied with photoemission measurements. The photoemission spectra revealed that the Ag atoms of the substrate diffused far into C{sub 60} film and donated electrons to the molecules. So the C{sub 60} film became n-type semiconductor with the Ag atoms acting as dopants. The C{sub 60}/Ag(100) interface should be understood as two sub-interfaces on both sides of the molecular layer directly contacting with the substrate. One sub-interface is Fermi level alignment, and the other is vacuum level alignment.

  8. GIS Interfaced OECD/PIARC QRA Model for Road Transportation ofHazardous Goods.

    E-print Network

    Paris-Sud XI, Université de

    GIS Interfaced OECD/PIARC QRA Model for Road Transportation ofHazardous Goods. Dr RUFFIN Emmanuel* Program manager for Tunnel Safety and Transportation of Hazardous Goods, BOUISSOU Charlotte, DEFERT (QRA model) for the transport of Hazardous Goods on roads including tunnel sections. This work was also

  9. Multiplatform user interface models by means of the Abstract Platform concept

    Microsoft Academic Search

    Matthias Freund; Annerose Braune

    2012-01-01

    Model-based user interface development methods offer capabilities to cope with the increasing effort needed for the development of industrial visualization systems. This increasing effort emerges among others from new device classes like smart phones or tablets to be supported. Current modeling languages usually support a dedicated class of platforms, e.g. either PCs or smart phones. Thus, despite of comparable functionality

  10. MATHEMATICAL MODELING OF CHANNEL POROUS LAYER INTERFACES IN PEM FUEL CELLS

    E-print Network

    Ehrhardt, Matthias

    MATHEMATICAL MODELING OF CHANNEL ­ POROUS LAYER INTERFACES IN PEM FUEL CELLS M. EHRHARDT, J, Germany ABSTRACT In proton exchange membrane (PEM) fuel cells, the transport of the fuel to the active diffusion layers. In order to improve existing mathematical and numerical models of PEM fuel cells, a deeper

  11. Rethinking Design Process: Using 3D Digital Models as an Interface in Collaborative Session

    ERIC Educational Resources Information Center

    Ding, Suining

    2008-01-01

    This paper describes a pilot study for an alternative design process by integrating a designer-user collaborative session with digital models. The collaborative session took place in a 3D AutoCAD class for a real world project. The 3D models served as an interface for designer-user collaboration during the design process. Students not only learned…

  12. Enhanced layerwise model for laminates with imperfect interfaces Part 1: Equations and theoretical validation

    E-print Network

    Boyer, Edmond

    to the analysis of laminates with thin layers of an elastic-plastic adhesive. The thin adhesive layers are modeled of operational models for computing stresses, strains and displacements. A 3D finite element calculation saving in computational cost is achieved. Keywords: Interfaces; Laminates; Stress Analysis; Plasticity

  13. 3-D shear lag model for the analysis of interface damage in ceramic matrix composites

    SciTech Connect

    Dharani, L.R.; Ji, F. [Univ. of Missouri, Rolla, MO (United States)

    1995-12-31

    In this paper a micromechanics analytical model is presented for characterizing the behavior of a unidirectional brittle matrix composite containing initial matrix flaws, specifically, as they approach a fiber-matrix interface. It is contemplated that when a matrix crack impinges on the interface it may go around the fiber or go through the fiber by breaking it or debond the fiber/matrix interface. It has been experimentally observed that the crack front does not remain straight, rather it bows once it impinges on a row of fibers. If a unit cell approach is used, the problem is clearly non-axisymmetric and three-dimensional. Since most of the previous analyses dealing with self-similar cracking and interface debonding have considered axisymmetric cracking or two-dimensional planar geometries, the development of an analytical micromechanics model using a 3-D (non-axisymmetric) formulation is needed. The model is based on the consistent shear lag constitutive relations and does account for the large stiffness of the ceramic matrix. Since the present consistent shear lag model is for Cartesian coordinates, we have first derived the consistent shear lag constitutive relations in cylindrical coordinates. The governing equations are obtained by minimizing the potential energy in which the three displacements are represented by means of finite exponential series. Since the full field stresses and displacements are known, the strain energy release rates for self-similar extension of the matrix crack (Gp) and the interface debonding (Gd) are calculated using the Compliance method. The competition between various failure modes will be assessed based on the above strain energy release rates and the corresponding critical (toughness) values. The type of interfaces addressed include fictional, elastic, and gradient with varying properties (interphase). An extensive parametric study will be presented involving different constitutive properties and interface conditions.

  14. A marketing orientation to modeling the hospital-supplier interface: a probabilistic approach.

    PubMed

    Malhotra, N K

    1987-06-01

    The author adopts a marketing orientation to model the hospital-supplier interface. A probabilistic approach using logit models is employed. Internal validity of the models estimated is examined and found to be satisfactory. The implications of the modeling process and findings for both hospitals and linen service contractors are discussed. The study reported is the second in a programmatic inquiry. The results of the first study were reported in the March 1986 issue of this journal. PMID:10282713

  15. Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing

    SciTech Connect

    Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

    2011-08-15

    Controlling electric loads to deliver power system services presents a number of interesting challenges. For example, changes in electricity consumption of Commercial and Industrial (C&I) facilities are usually estimated using counterfactual baseline models, and model uncertainty makes it difficult to precisely quantify control responsiveness. Moreover, C&I facilities exhibit variability in their response. This paper seeks to understand baseline model error and demand-side variability in responses to open-loop control signals (i.e. dynamic prices). Using a regression-based baseline model, we define several Demand Response (DR) parameters, which characterize changes in electricity use on DR days, and then present a method for computing the error associated with DR parameter estimates. In addition to analyzing the magnitude of DR parameter error, we develop a metric to determine how much observed DR parameter variability is attributable to real event-to-event variability versus simply baseline model error. Using data from 38 C&I facilities that participated in an automated DR program in California, we find that DR parameter errors are large. For most facilities, observed DR parameter variability is likely explained by baseline model error, not real DR parameter variability; however, a number of facilities exhibit real DR parameter variability. In some cases, the aggregate population of C&I facilities exhibits real DR parameter variability, resulting in implications for the system operator with respect to both resource planning and system stability.

  16. Automated parameter space searches for calibrating mix models in NIF ignition implosions

    NASA Astrophysics Data System (ADS)

    Hoffman, Nelson; Hammel, Bruce; Schilling, Oleg

    2009-11-01

    Turbulent transport (``mix'') models typically have many adjustable coefficents, which must be calibrated against experimental or numerical simulation data. We calibrate mix models against high-resolution 2D simulations of NIF ignition capsules [Hammel et al., J. Phys.: Conf. Ser. 112, 022007 (2008)]. The time-varying radial profiles of species composition in the imploding capsule serve as the calibration reference. We perform one-dimensional implosion simulations using two mix models: one from Zhou, Zimmerman, and Burke [Phys. Rev. E 65, 056303 (2002)] and a k-? model by one of us (OS). We can calibrate so that one-dimensional composition profiles roughly match the simulation profiles for a Rev3 CH(Ge) ignition capsule at several times, although non-monotonic features of the profiles cannot be represented by the mix models. For fitting, we use automated scripts and fitting metrics, which allow parameter spaces of up to five dimensions to be searched rapidly. Besides identifying optimal coefficient sets, such searches reveal the sensitivity of model results to variations in inputs.

  17. Control of enterprise interfaces for supply chain enterprise modeling

    SciTech Connect

    Interrante, L.D. [Sandia National Labs., Albuquerque, NM (United States); Macfarlane, J.F. [Lawrence Berkeley Lab., CA (United States). Information and Computing Sciences Div.

    1995-04-01

    There is a current trend for manufacturing enterprises in a supply chain of a particular industry to join forces in an attempt to promote efficiencies and improve competitive position. Such alliances occur in the context of specific legal and business agreements such that each enterprise retains a majority of its business and manufacturing information as private and shares other information with its trading partners. Shared information may include enterprise demand projections, capacities, finished goods inventories, and aggregate production schedules. Evidence of the trend toward information sharing includes the recent emphases on vendor-managed inventories, quick response, and Electronic Data Interchange (EDI) standards. The increased competition brought on by the global marketplace is driving industries to consider the advantages of trading partner agreements. Aggregate-level forecasts, supply-chain production smoothing, and aggregate-level inventory policies can reduce holding costs, record-keeping overhead, and lead time in product development. The goal of this research is to orchestrate information exchange among trading partners to allow for aggregate-level analysis to enhance supply chain efficiency. The notion of Enterprise Interface Control (EIC) is introduced as a means of accomplishing this end.

  18. Mathematical modeling of the head-disk interface (abstract)

    NASA Astrophysics Data System (ADS)

    Crone, Robert M.; Jhon, Myung S.

    1993-05-01

    State-of-the-art theoretical and numerical techniques required to simulate the head-disk interface (HDI) of future magnetic storage devices is presented. The severity of operating conditions (i.e., attempts to achieve flying heights as low as 40 nm) pose several challenges. Large transient pressure gradients can be established within air bearing leading to numerical oscillations as well as to increased program execution times. Enhanced gaseous rarefaction effects must also be incorporated into the analysis. In the present study, accurate nonoscillatory air bearing pressure distributions were obtained using a high resolution finite element algorithm to solve the generalized Reynolds equation. Higher order gaseous rarefaction effects are incorporated into generalized Reynolds equations using the total mass flow rate coefficient predicted from the linearized Boltzmann equation. The form of the generalized Reynolds equation that is presented in this paper is an improved version of the continued fraction approximation previously proposed by Crone et al.1 A simple scaling analysis, which is based upon the results of the linearized Boltzmann equation, will also be presented to study the effect of slider miniaturization, as well as to obtain a novel interpretation of accelerated wear and accelerated flyability test results.

  19. Distribution automation applications of fiber optics

    NASA Technical Reports Server (NTRS)

    Kirkham, Harold; Johnston, A.; Friend, H.

    1989-01-01

    Motivations for interest and research in distribution automation are discussed. The communication requirements of distribution automation are examined and shown to exceed the capabilities of power line carrier, radio, and telephone systems. A fiber optic based communication system is described that is co-located with the distribution system and that could satisfy the data rate and reliability requirements. A cost comparison shows that it could be constructed at a cost that is similar to that of a power line carrier system. The requirements for fiber optic sensors for distribution automation are discussed. The design of a data link suitable for optically-powered electronic sensing is presented. Empirical results are given. A modeling technique that was used to understand the reflections of guided light from a variety of surfaces is described. An optical position-indicator design is discussed. Systems aspects of distribution automation are discussed, in particular, the lack of interface, communications, and data standards. The economics of distribution automation are examined.

  20. An automated statistical shape model developmental pipeline: application to the human scapula and humerus.

    PubMed

    Mutsvangwa, Tinashe; Burdin, Valerie; Schwartz, Cedric; Roux, Christian

    2015-04-01

    This paper presents development of statistical shape models based on robust and rigid-groupwise registration followed by pointset nonrigid registration. The main advantages of the pipeline include automation in that the method does not rely on manual landmarks or a regionalization step; there is no bias in the choice of reference during the correspondence steps and the use of the probabilistic principal component analysis framework increases the domain of the shape variability. A comparison between the widely used expectation maximization-iterative closest point algorithm and a recently reported groupwise method on publicly available data (hippocampus) using the well-known criteria of generality, specificity, and compactness is also presented. The proposed method gives similar values but the curves of generality and specificity are superior to those of the other two methods. Finally, the method is applied to the human scapula, which is a known difficult structure, and the human humerus. PMID:25389238

  1. Random Sample Consensus: A Paradigm for Model Fitting with Applicationsto Image Analysis and Automated Cartography

    Microsoft Academic Search

    Martin A. Fischler; Robert C. Bolles

    1981-01-01

    A new paradigm, Random Sample Consensus (RANSAC), for fitting a model\\u000d\\u000a\\u0009to experimental data is introduced. RANSAC is capable of interpreting\\/smoothing\\u000d\\u000a\\u0009data containing a significant percentage of gross errors, and is\\u000d\\u000a\\u0009thus ideally suited for applications in automated image analysis\\u000d\\u000a\\u0009where interpretation is based on the data provided by error-prone\\u000d\\u000a\\u0009feature detectors. A major portion of this paper describes the

  2. A multi-dimensional Hidden Markov Model approach to automated identification of fetal cardiac valve motion.

    PubMed

    Marzbanrad, Faezeh; Khandoker, Ahsan H; Endo, Miyuki; Kimura, Yoshitaka; Palaniswami, Marimuthu

    2014-08-01

    Fetal cardiac assessment techniques are aimed to identify fetuses at risk of intrauterine compromise or death. Evaluation of the electromechanical coupling as a fundamental part of the fetal heart physiology, provides valuable information about the fetal wellbeing during pregnancy. It is based on the opening and closing time of the cardiac valves and the onset of the QRS complex of the fetal electrocardiogram (fECG). The focus of this paper is on the automated identification of the fetal cardiac valve opening and closing from Doppler Ultrasound signal and fECG as a reference. To this aim a novel combination of Emprical Mode Decomposition (EMD) and multi-dimensional Hidden Markov Models (MD-HMM) was employed which provided beat-to-beat estimation of cardiac valve event timings with improved precision (82.9%) compared to the one dimensional HMM (77.4%) and hybrid HMM-Support Vector Machine (SVM) (79.8%) approaches. PMID:25570346

  3. Intuitive control engineering for mechatronic components in distributed automation systems based on the reference model of IEC 61499

    Microsoft Academic Search

    Christoph SUNDER; Alois ZOITL; T. Strasser; B. Favre-Bulle

    2005-01-01

    Current research on mechatronic engineering focuses mainly on engineering methodologies. This paper presents a new architecture based on the reference model of IEC 61499. This architecture includes both, the engineering view of a device represented by its services and their representation within the control application as function blocks that are used within the whole distributed automation system. The services of

  4. 1997 IEEE International Conference on Robotics and Automation, April 21-27, Albuquerque, NM. Modeling and Identification of an

    E-print Network

    Papadopoulos, Evangelos

    1997 IEEE International Conference on Robotics and Automation, April 21-27, Albuquerque, NM. 1 grade computers and hydraulic actuation systems; i.e. high- end workstations and expensive servovalves performance robotic systems. In particular, in this paper we are concerned with modeling the electrohydraulic

  5. The performance of automated case-mix adjustment regression model building methods in a health outcome prediction setting.

    PubMed

    Jen, Min-Hua; Bottle, Alex; Kirkwood, Graham; Johnston, Ron; Aylin, Paul

    2011-09-01

    We have previously described a system for monitoring a number of healthcare outcomes using case-mix adjustment models. It is desirable to automate the model fitting process in such a system if monitoring covers a large number of outcome measures or subgroup analyses. Our aim was to compare the performance of three different variable selection strategies: "manual", "automated" backward elimination and re-categorisation, and including all variables at once, irrespective of their apparent importance, with automated re-categorisation. Logistic regression models for predicting in-hospital mortality and emergency readmission within 28 days were fitted to an administrative database for 78 diagnosis groups and 126 procedures from 1996 to 2006 for National Health Services hospital trusts in England. The performance of models was assessed with Receiver Operating Characteristic (ROC) c statistics, (measuring discrimination) and Brier score (assessing the average of the predictive accuracy). Overall, discrimination was similar for diagnoses and procedures and consistently better for mortality than for emergency readmission. Brier scores were generally low overall (showing higher accuracy) and were lower for procedures than diagnoses, with a few exceptions for emergency readmission within 28 days. Among the three variable selection strategies, the automated procedure had similar performance to the manual method in almost all cases except low-risk groups with few outcome events. For the rapid generation of multiple case-mix models we suggest applying automated modelling to reduce the time required, in particular when examining different outcomes of large numbers of procedures and diseases in routinely collected administrative health data. PMID:21556848

  6. Comparison of Joint Modeling Approaches Including Eulerian Sliding Interfaces

    Microsoft Academic Search

    I Lomov; T Antoun; O Vorobiev

    2009-01-01

    Accurate representation of discontinuities such as joints and faults is a key ingredient for high fidelity modeling of shock propagation in geologic media. The following study was done to improve treatment of discontinuities (joints) in the Eulerian hydrocode GEODYN (Lomov and Liu 2005). Lagrangian methods with conforming meshes and explicit inclusion of joints in the geologic model are well suited

  7. Automated and reproducible read-across like models for predicting carcinogenic potency.

    PubMed

    Lo Piparo, Elena; Maunz, Andreas; Helma, Christoph; Vorgrimmler, David; Schilter, Benoît

    2014-10-01

    Several qualitative (hazard-based) models for chronic toxicity prediction are available through commercial and freely available software, but in the context of risk assessment a quantitative value is mandatory in order to be able to apply a Margin of Exposure (predicted toxicity/exposure estimate) approach to interpret the data. Recently quantitative models for the prediction of the carcinogenic potency have been developed, opening some hopes in this area, but this promising approach is currently limited by the fact that the proposed programs are neither publically nor commercially available. In this article we describe how two models (one for mouse and one for rat) for the carcinogenic potency (TD50) prediction have been developed, using lazar (Lazy Structure Activity Relationships), a procedure similar to read-across, but automated and reproducible. The models obtained have been compared with the recently published ones, resulting in a similar performance. Our aim is also to make the models freely available in the near future thought a user friendly internet web site. PMID:25047023

  8. Progress and challenges in the automated construction of Markov state models for full protein systems

    NASA Astrophysics Data System (ADS)

    Bowman, Gregory R.; Beauchamp, Kyle A.; Boxer, George; Pande, Vijay S.

    2009-09-01

    Markov state models (MSMs) are a powerful tool for modeling both the thermodynamics and kinetics of molecular systems. In addition, they provide a rigorous means to combine information from multiple sources into a single model and to direct future simulations/experiments to minimize uncertainties in the model. However, constructing MSMs is challenging because doing so requires decomposing the extremely high dimensional and rugged free energy landscape of a molecular system into long-lived states, also called metastable states. Thus, their application has generally required significant chemical intuition and hand-tuning. To address this limitation we have developed a toolkit for automating the construction of MSMs called MSMBUILDER (available at https://simtk.org/home/msmbuilder). In this work we demonstrate the application of MSMBUILDER to the villin headpiece (HP-35 NleNle), one of the smallest and fastest folding proteins. We show that the resulting MSM captures both the thermodynamics and kinetics of the original molecular dynamics of the system. As a first step toward experimental validation of our methodology we show that our model provides accurate structure prediction and that the longest timescale events correspond to folding.

  9. Laboratory measurements and theoretical modeling of seismoelectric interface response and coseismic wave fields

    SciTech Connect

    Schakel, M. D.; Slob, E. C.; Heller, H. K. J. [Department of Geotechnology, Delft University of Technology, PO Box 5048, 2600 GA, Delft (Netherlands); Smeulders, D. M. J. [Department of Geotechnology, Delft University of Technology, PO Box 5048, 2600 GA, Delft (Netherlands); Department of Mechanical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven (Netherlands)

    2011-04-01

    A full-waveform seismoelectric numerical model incorporating the directivity pattern of a pressure source is developed. This model provides predictions of coseismic electric fields and the electromagnetic waves that originate from a fluid/porous-medium interface. An experimental setup in which coseismic electric fields and interface responses are measured is constructed. The seismo-electric origin of the signals is confirmed. The numerically predicted polarity reversal of the interfacial signal and seismoelectric effects due to multiple scattering are detected in the measurements. Both the simulated coseismic electric fields and the electromagnetic waves originating from interfaces agree with the measurements in terms of travel times, waveform, polarity, amplitude, and spatial amplitude decay, demonstrating that seismoelectric effects are comprehensively described by theory.

  10. Time integration for diffuse interface models for two-phase flow

    NASA Astrophysics Data System (ADS)

    Aland, Sebastian

    2014-04-01

    We propose a variant of the ?-scheme for diffuse interface models for two-phase flow, together with three new linearization techniques for the surface tension. These involve either additional stabilizing force terms, or a fully implicit coupling of the Navier-Stokes and Cahn-Hilliard equation. In the common case that the equations for interface and flow are coupled explicitly, we find a time step restriction which is very different to other two-phase flow models and in particular is independent of the grid size. We also show that the proposed stabilization techniques can lift this time step restriction. Even more pronounced is the performance of the proposed fully implicit scheme which is stable for arbitrarily large time steps. We demonstrate in a Taylor-flow application that this superior coupling between flow and interface equation can decrease the computation time by several orders of magnitude.

  11. Time integration for diffuse interface models for two-phase flow

    SciTech Connect

    Aland, Sebastian, E-mail: sebastian.aland@tu-dresden.de

    2014-04-01

    We propose a variant of the ?-scheme for diffuse interface models for two-phase flow, together with three new linearization techniques for the surface tension. These involve either additional stabilizing force terms, or a fully implicit coupling of the Navier–Stokes and Cahn–Hilliard equation. In the common case that the equations for interface and flow are coupled explicitly, we find a time step restriction which is very different to other two-phase flow models and in particular is independent of the grid size. We also show that the proposed stabilization techniques can lift this time step restriction. Even more pronounced is the performance of the proposed fully implicit scheme which is stable for arbitrarily large time steps. We demonstrate in a Taylor-flow application that this superior coupling between flow and interface equation can decrease the computation time by several orders of magnitude.

  12. SENSPECTRA : an elastic, strain-aware physical modeling interface

    E-print Network

    Leclerc, Vincent, S.M. Massachusetts Institute of Technology

    2006-01-01

    Senspectra is a computationally augmented physical modeling toolkit designed for sensing and visualization of structural strain. The system functions as a distributed sensor network consisting of nodes, embedded with ...

  13. ARpm: An Augmented Reality Interface for Polygonal Modeling

    Microsoft Academic Search

    Peter Fiala; Nicoletta Adamo-villani

    2005-01-01

    We present a prototype system called ARpm, (augmented reality for polygonal modeling). Created as a front-end to a commercially available 3D animation program (3D Studio Max), it does not require it's modification through inaccessible software code. Users look through a head mounted display (HMD) and the object being modeled appears as a 3D augmentation in the real world. This object

  14. Atomistic Cohesive Zone Models for Interface Decohesion in Metals

    NASA Technical Reports Server (NTRS)

    Yamakov, Vesselin I.; Saether, Erik; Glaessgen, Edward H.

    2009-01-01

    Using a statistical mechanics approach, a cohesive-zone law in the form of a traction-displacement constitutive relationship characterizing the load transfer across the plane of a growing edge crack is extracted from atomistic simulations for use within a continuum finite element model. The methodology for the atomistic derivation of a cohesive-zone law is presented. This procedure can be implemented to build cohesive-zone finite element models for simulating fracture in nanocrystalline or ultrafine grained materials.

  15. ?-conome: an automated tissue counting platform of cone photoreceptors for rodent models of retinitis pigmentosa

    PubMed Central

    2011-01-01

    Background Retinitis pigmentosa is characterized by the sequential loss of rod and cone photoreceptors. The preservation of cones would prevent blindness due to their essential role in human vision. Rod-derived Cone Viability Factor is a thioredoxin-like protein that is secreted by rods and is involved in cone survival. To validate the activity of Rod-derived Cone Viability Factors (RdCVFs) as therapeutic agents for treating retinitis Pigmentosa, we have developed e-conome, an automated cell counting platform for retinal flat mounts of rodent models of cone degeneration. This automated quantification method allows for faster data analysis thereby accelerating translational research. Methods An inverted fluorescent microscope, motorized and coupled to a CCD camera records images of cones labeled with fluorescent peanut agglutinin lectin on flat-mounted retinas. In an average of 300 fields per retina, nine Z-planes at magnification X40 are acquired after two-stage autofocus individually for each field. The projection of the stack of 9 images is subject to a threshold, filtered to exclude aberrant images based on preset variables. The cones are identified by treating the resulting image using 13 variables empirically determined. The cone density is calculated over the 300 fields. Results The method was validated by comparison to the conventional stereological counting. The decrease in cone density in rd1 mouse was found to be equivalent to the decrease determined by stereological counting. We also studied the spatiotemporal pattern of the degeneration of cones in the rd1 mouse and show that while the reduction in cone density starts in the central part of the retina, cone degeneration progresses at the same speed over the whole retinal surface. We finally show that for mice with an inactivation of the Nucleoredoxin-like genes Nxnl1 or Nxnl2 encoding RdCVFs, the loss of cones is more pronounced in the ventral retina. Conclusion The automated platform ?-conome used here for retinal disease is a tool that can broadly accelerate translational research for neurodegenerative diseases. PMID:22185426

  16. Context based mixture model for cell phase identification in automated fluorescence microscopy

    PubMed Central

    Wang, Meng; Zhou, Xiaobo; King, Randy W; Wong, Stephen TC

    2007-01-01

    Background Automated identification of cell cycle phases of individual live cells in a large population captured via automated fluorescence microscopy technique is important for cancer drug discovery and cell cycle studies. Time-lapse fluorescence microscopy images provide an important method to study the cell cycle process under different conditions of perturbation. Existing methods are limited in dealing with such time-lapse data sets while manual analysis is not feasible. This paper presents statistical data analysis and statistical pattern recognition to perform this task. Results The data is generated from Hela H2B GFP cells imaged during a 2-day period with images acquired 15 minutes apart using an automated time-lapse fluorescence microscopy. The patterns are described with four kinds of features, including twelve general features, Haralick texture features, Zernike moment features, and wavelet features. To generate a new set of features with more discriminate power, the commonly used feature reduction techniques are used, which include Principle Component Analysis (PCA), Linear Discriminant Analysis (LDA), Maximum Margin Criterion (MMC), Stepwise Discriminate Analysis based Feature Selection (SDAFS), and Genetic Algorithm based Feature Selection (GAFS). Then, we propose a Context Based Mixture Model (CBMM) for dealing with the time-series cell sequence information and compare it to other traditional classifiers: Support Vector Machine (SVM), Neural Network (NN), and K-Nearest Neighbor (KNN). Being a standard practice in machine learning, we systematically compare the performance of a number of common feature reduction techniques and classifiers to select an optimal combination of a feature reduction technique and a classifier. A cellular database containing 100 manually labelled subsequence is built for evaluating the performance of the classifiers. The generalization error is estimated using the cross validation technique. The experimental results show that CBMM outperforms all other classifies in identifying prophase and has the best overall performance. Conclusion The application of feature reduction techniques can improve the prediction accuracy significantly. CBMM can effectively utilize the contextual information and has the best overall performance when combined with any of the previously mentioned feature reduction techniques. PMID:17263881

  17. Diffuse interface models of locally inextensible vesicles in a viscous fluid.

    PubMed

    Aland, Sebastian; Egerer, Sabine; Lowengrub, John; Voigt, Axel

    2014-11-15

    We present a new diffuse interface model for the dynamics of inextensible vesicles in a viscous fluid with inertial forces. A new feature of this work is the implementation of the local inextensibility condition in the diffuse interface context. Local inextensibility is enforced by using a local Lagrange multiplier, which provides the necessary tension force at the interface. We introduce a new equation for the local Lagrange multiplier whose solution essentially provides a harmonic extension of the multiplier off the interface while maintaining the local inextensibility constraint near the interface. We also develop a local relaxation scheme that dynamically corrects local stretching/compression errors thereby preventing their accumulation. Asymptotic analysis is presented that shows that our new system converges to a relaxed version of the inextensible sharp interface model. This is also verified numerically. To solve the equations, we use an adaptive finite element method with implicit coupling between the Navier-Stokes and the diffuse interface inextensibility equations. Numerical simulations of a single vesicle in a shear flow at different Reynolds numbers demonstrate that errors in enforcing local inextensibility may accumulate and lead to large differences in the dynamics in the tumbling regime and smaller differences in the inclination angle of vesicles in the tank-treading regime. The local relaxation algorithm is shown to prevent the accumulation of stretching and compression errors very effectively. Simulations of two vesicles in an extensional flow show that local inextensibility plays an important role when vesicles are in close proximity by inhibiting fluid drainage in the near contact region. PMID:25246712

  18. Automated method for modeling seven-helix transmembrane receptors from experimental data.

    PubMed Central

    Herzyk, P; Hubbard, R E

    1995-01-01

    A rule-based automated method is presented for modeling the structures of the seven transmembrane helices of G-protein-coupled receptors. The structures are generated by using a simulated annealing Monte Carlo procedure that positions and orients rigid helices to satisfy structural restraints. The restraints are derived from analysis of experimental information from biophysical studies on native and mutant proteins, from analysis of the sequences of related proteins, and from theoretical considerations of protein structure. Calculations are presented for two systems. The method was validated through calculations using appropriate experimental information for bacteriorhodopsin, which produced a model structure with a root mean square (rms) deviation of 1.87 A from the structure determined by electron microscopy. Calculations are also presented using experimental and theoretical information available for bovine rhodopsin to assign the helices to a projection density map and to produce a model of bovine rhodopsin that can be used as a template for modeling other G-protein-coupled receptors. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 8 FIGURE 11 PMID:8599649

  19. Interface modeling to predict well casing damage for big hill strategic petroleum reserve.

    SciTech Connect

    Ehgartner, Brian L.; Park, Byoung Yoon

    2012-02-01

    Oil leaks were found in well casings of Caverns 105 and 109 at the Big Hill Strategic Petroleum Reserve site. According to the field observations, two instances of casing damage occurred at the depth of the interface between the caprock and top of salt. This damage could be caused by interface movement induced by cavern volume closure due to salt creep. A three dimensional finite element model, which allows each cavern to be configured individually, was constructed to investigate shear and vertical displacements across each interface. The model contains interfaces between each lithology and a shear zone to examine the interface behavior in a realistic manner. This analysis results indicate that the casings of Caverns 105 and 109 failed by shear stress that exceeded shear strength due to the horizontal movement of the top of salt relative to the caprock, and tensile stress due to the downward movement of the top of salt from the caprock, respectively. The casings of Caverns 101, 110, 111 and 114, located at the far ends of the field, are predicted to be failed by shear stress in the near future. The casings of inmost Caverns 107 and 108 are predicted to be failed by tensile stress in the near future.

  20. Automated generation of high-quality training data for appearance-based object models

    NASA Astrophysics Data System (ADS)

    Becker, Stefan; Voelker, Arno; Kieritz, Hilke; Hübner, Wolfgang; Arens, Michael

    2013-11-01

    Methods for automated person detection and person tracking are essential core components in modern security and surveillance systems. Most state-of-the-art person detectors follow a statistical approach, where prototypical appearances of persons are learned from training samples with known class labels. Selecting appropriate learning samples has a significant impact on the quality of the generated person detectors. For example, training a classifier on a rigid body model using training samples with strong pose variations is in general not effective, irrespective of the classifiers capabilities. Generation of high-quality training data is, apart from performance issues, a very time consuming process, comprising a significant amount of manual work. Furthermore, due to inevitable limitations of freely available training data, corresponding classifiers are not always transferable to a given sensor and are only applicable in a well-defined narrow variety of scenes and camera setups. Semi-supervised learning methods are a commonly used alternative to supervised training, in general requiring only few labeled samples. However, as a drawback semi-supervised methods always include a generative component, which is known to be difficult to learn. Therefore, automated processes for generating training data sets for supervised methods are needed. Such approaches could either help to better adjust classifiers to respective hardware, or serve as a complement to existing data sets. Towards this end, this paper provides some insights into the quality requirements of automatically generated training data for supervised learning methods. Assuming a static camera, labels are generated based on motion detection by background subtraction with respect to weak constraints on the enclosing bounding box of the motion blobs. Since this labeling method consists of standard components, we illustrate the effectiveness by adapting a person detector to cameras of a sensor network. While varying the training data and keeping the detection framework identical, we derive statements about the sample quality.

  1. Automated estimation of fetal cardiac timing events from Doppler ultrasound signal using hybrid models.

    PubMed

    Marzbanrad, Faezeh; Kimura, Yoshitaka; Funamoto, Kiyoe; Sugibayashi, Rika; Endo, Miyuki; Ito, Takuya; Palaniswami, Marimuthu; Khandoker, Ahsan H

    2014-07-01

    In this paper, a new noninvasive method is proposed for automated estimation of fetal cardiac intervals from Doppler Ultrasound (DUS) signal. This method is based on a novel combination of empirical mode decomposition (EMD) and hybrid support vector machines-hidden Markov models (SVM/HMM). EMD was used for feature extraction by decomposing the DUS signal into different components (IMFs), one of which is linked to the cardiac valve motions, i.e. opening (o) and closing (c) of the Aortic (A) and Mitral (M) valves. The noninvasive fetal electrocardiogram (fECG) was used as a reference for the segmentation of the IMF into cardiac cycles. The hybrid SVM/HMM was then applied to identify the cardiac events, based on the amplitude and timing of the IMF peaks as well as the sequence of the events. The estimated timings were verified using pulsed doppler images. Results show that this automated method can continuously evaluate beat-to-beat valve motion timings and identify more than 91% of total events which is higher than previous methods. Moreover, the changes of the cardiac intervals were analyzed for three fetal age groups: 16-29, 30-35, and 36-41 weeks. The time intervals from Q-wave of fECG to Ac (Systolic Time Interval, STI), Ac to Mo (Isovolumic Relaxation Time, IRT), Q-wave to Ao (Preejection Period, PEP) and Ao to Ac (Ventricular Ejection Time, VET) were found to change significantly ( ) across these age groups. In particular, STI, IRT, and PEP of the fetuses with 36-41 week were significantly ( ) different from other age groups. These findings can be used as sensitive markers for evaluating the fetal cardiac performance. PMID:24144677

  2. 76 FR 34740 - Agency Information Collection Activities: Automated Clearinghouse

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ...Automated Clearinghouse (ACH) allows participants in the Automated Broker Interface (ABI) to transmit daily statements, deferred tax, and bill payments electronically through a financial institution directly to a CBP account. ACH debit allows...

  3. 76 FR 19121 - Agency Information Collection Activities: Automated Clearinghouse

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-06

    ...Automated Clearinghouse (ACH) allows participants in the Automated Broker Interface (ABI) to transmit daily statements, deferred tax, and bill payments electronically through a financial institution directly to a CBP account. ACH debit allows...

  4. Equivalence of the train model of earthquake and boundary driven Edwards-Wilkinson interface

    NASA Astrophysics Data System (ADS)

    Biswas, Soumyajyoti; Ray, Purusattam; Chakrabarti, Bikas K.

    2013-09-01

    A discretized version of the Burridge-Knopoff train model with (non-linear friction force replaced by) random pinning is studied in one and two dimensions. A scale free distribution of avalanches and the Omori law type behaviour for after-shocks are obtained. The avalanche dynamics of this model becomes precisely similar (identical exponent values) to the Edwards-Wilkinson (EW) model of interface propagation. It also allows the complimentary observation of depinning velocity growth (with exponent value identical with that for EW model) in this train model and Omori law behaviour of after-shock (depinning) avalanches in the EW model.

  5. Concurrent multiscale computational modeling for dense dry granular materials interfacing

    E-print Network

    Regueiro, Richard A.

    of interfacial mechanics between granular soil and tire, tool, or penetrometer, while properly representing far, agricultural grains (in silo flows), dry soils (sand, silt, gravel), and lunar and martian regolith (soil found computational modeling of interfacial mechanics between granular materials and deformable solid bodies

  6. Matrix and Interface Stresses in a Discontinuous Fiber Composite Model

    Microsoft Academic Search

    Anthony S. Carrara; Frederick J. Mcgarry

    1968-01-01

    The method of finite element analysis is applied to an axially symmetrical model of a single filament glass-resin composite under tension. Fiber end geometries are varied by considering ellipsoids of revolution with one axis length equal to the fiber diameter while the second varies from one-tenth to ten times the fiber diameter. Tapered tips with these same axis ratios are

  7. Towards diffuse interface models with a nonlinear polycrystalline elastic energy

    E-print Network

    Blesgen, Thomas

    exemplary for the Allen-Cahn/Cahn- Hilliard equations. Since segregated phases in typical physical to the Allen-Cahn/Cahn-Hilliard equations (AC-CH equations for short). This model, first introduced in [13], contains both the Allen-Cahn equation and the Cahn-Hilliard equation as special cases, which are the two

  8. Modelling, Formality and the PhoneticsPhonology Interface Julian Bradfield

    E-print Network

    Bradfield, Julian

    -mathematical universe such as set theory) leaves in principle no room for argument about what it does ­ although predictions about reality; and the sciences of artificial systems, such as software design and verification of formal models. A pitfall common in the `artificial' sciences is `throwing the baby out with the bathwater

  9. What determines the take-over time? An integrated model approach of driver take-over after automated driving.

    PubMed

    Zeeb, Kathrin; Buchner, Axel; Schrauf, Michael

    2015-05-01

    In recent years the automation level of driver assistance systems has increased continuously. One of the major challenges for highly automated driving is to ensure a safe driver take-over of the vehicle guidance. This must be ensured especially when the driver is engaged in non-driving related secondary tasks. For this purpose it is essential to find indicators of the driver's readiness to take over and to gain more knowledge about the take-over process in general. A simulator study was conducted to explore how drivers' allocation of visual attention during highly automated driving influences a take-over action in response to an emergency situation. Therefore we recorded drivers' gaze behavior during automated driving while simultaneously engaging in a visually demanding secondary task, and measured their reaction times in a take-over situation. According to their gaze behavior the drivers were categorized into "high", "medium" and "low-risk". The gaze parameters were found to be suitable for predicting the readiness to take-over the vehicle, in such a way that high-risk drivers reacted late and more often inappropriately in the take-over situation. However, there was no difference among the driver groups in the time required by the drivers to establish motor readiness to intervene after the take-over request. An integrated model approach of driver behavior in emergency take-over situations during automated driving is presented. It is argued that primarily cognitive and not motor processes determine the take-over time. Given this, insights can be derived for further research and the development of automated systems. PMID:25794922

  10. View Planning for Automated Site Modeling Paul S. Blaer and Peter K. Allen

    E-print Network

    Allen, Peter K.

    and the acquisition process is fast and automated, there is still a major human component involved. The scanning in- creased in accuracy and have evolved from manual methods to more automated methods sensor must be physically moved from location to location, and each scanning operation itself can take up

  11. Influence of active sites organisation on calcium carbonate formation at model biomolecular interfaces

    Microsoft Academic Search

    S. Hacke; D. Möbius; V.-T. Lieu

    2005-01-01

    In an approach to understand the influence of structural parameters of interfaces on calcification in biomineralisation, the distribution and conformation of head groups as active sites in an inert matrix were varied using two-component phospholipid model monolayers. Dimyristoylphosphatidic acid (DMPA) and dipalmitoylphosphatidylcholin (DPPC), respectively, were the active components, and methyl octadecanoate (MOD) was used as inactive matrix. Surface pressure–area isotherms

  12. Seismic traveltime inversion of 3D velocity model with triangulated interfaces

    NASA Astrophysics Data System (ADS)

    Li, Fei; Xu, Tao; Zhang, Minghui; Wu, Zhenbo; Wu, Chenglong; Zhang, Zhongjie; Teng, Jiwen

    2014-04-01

    Seismic traveltime tomographic inversion has played an important role in detecting the internal structure of the solid earth. We use a set of blocks to approximate geologically complex media that cannot be well described by layered models or cells. The geological body is described as an aggregate of arbitrarily shaped blocks, which are separated by triangulated interfaces. We can describe the media as homogenous or heterogeneous in each block. We define the velocities at the given rectangle grid points for each block, and the heterogeneous velocities in each block can be calculated by a linear interpolation algorithm. The parameters of the velocity grid positions are independent of the model parameterization, which is advantageous in the joint inversion of the velocities and the node depths of an interface. We implement a segmentally iterative ray tracer to calculate traveltimes in the 3D heterogeneous block models. The damped least squares method is employed in seismic traveltime inversion, which includes the partial derivatives of traveltime with respect to the depths of nodes in the triangulated interfaces and velocities defined in rectangular grids. The numerical tests indicate that the node depths of a triangulated interface and homogeneous velocity distributions can be well inverted in a stratified model.

  13. A Monthly Water-Balance Model Driven By a Graphical User Interface

    USGS Publications Warehouse

    McCabe, Gregory J.; Markstrom, Steven L.

    2007-01-01

    This report describes a monthly water-balance model driven by a graphical user interface, referred to as the Thornthwaite monthly water-balance program. Computations of monthly water-balance components of the hydrologic cycle are made for a specified location. The program can be used as a research tool, an assessment tool, and a tool for classroom instruction.

  14. The integrity of welded interfaces in ultra high molecular weight polyethylene: Part 1-Model.

    PubMed

    Buckley, C Paul; Wu, Junjie; Haughie, David W

    2006-06-01

    The difficulty of eradicating memory of powder-particle interfaces in UHMWPE for bearing surfaces for hip and knee replacements is well-known, and 'fusion defects' have been implicated frequently in joint failures. During processing the polymer is formed into solid directly from the reactor powder, under pressure and at temperatures above the melting point, and two types of inter-particle defect occur: Type 1 (consolidation-deficient) and Type 2 (diffusion-deficient). To gain quantitative information on the extent of the problem, the formation of macroscopic butt welds in this material was studied, by (1) modelling the process and (2) measuring experimentally the resultant evolution of interface toughness. This paper reports on the model. A quantitative measure of interface structural integrity is defined, and related to the "maximum reptated molecular weight" introduced previously. The model assumes an idealised surface topography. It is used to calculate the evolution of interface integrity during welding, for given values of temperature, pressure, and parameters describing the surfaces, and a given molar mass distribution. Only four material properties are needed for the calculation; all of them available for polyethylene. The model shows that, for UHMWPE typically employed in knee transplants, the rate of eradication of Type 1 defects is highly sensitive to surface topography, process temperature and pressure. Also, even if Type 1 defects are prevented, Type 2 defects heal extremely slowly. They must be an intrinsic feature of UHMWPE for all reasonable forming conditions, and products and forming processes should be designed accordingly. PMID:16490249

  15. Modeling Selective Stimulation With A Flat Interface Nerve Electrode for Standing Neuroprosthetic Systems

    Microsoft Academic Search

    Matthew A. Schiefer; Ronald J. Triolo; Dominique M. Durand; Dustin J. Tyler

    2005-01-01

    The long-term goal of our research is to restore standing function through selective activation of target fascicles within the femoral nerve by a flat interface nerve electrode (FINE). The optimal number and location of contacts within a FINE had not been determined previously. A realistic three-dimensional finite element model based on a cross section of human femoral nerve and FINE

  16. Models of Selective Stimulation with a Flat Interface Nerve Electrode for Standing Neuroprosthetic Systems

    Microsoft Academic Search

    Matthew A. Schiefer; Ronald J. Triolo; Dustin J. Tyler

    2006-01-01

    The long-term goal of our research is to restore standing function via selective activation of target fascicles in the femoral nerve by a flat interface nerve electrode (FINE). The optimal number and location of contacts within a FINE had not been determined previously. A realistic three-dimensional finite element model based on a cross section of human femoral nerve and FINE

  17. Situation Awareness Modeling and Pilot State Estimation for Tactical Cockpit Interfaces

    Microsoft Academic Search

    Sandeep Mulgund; Gerard Rinkus; Christine Illgen; Greg Zacharias

    1997-01-01

    This paper desribes a study that assessed the feasibility of developing an adaptive pilot\\/vehicle interface (PVI) prototype that uses measures of pilot workload and computational situation assessment models to drive the content, format, and modality of military cockpit displays. The system architecture consists of three distinct modules: 1) an on-line situation assessor that generates a \\

  18. Facial pressure zones of an oronasal interface for noninvasive ventilation: a computer model analysis* **

    PubMed Central

    Barros, Luana Souto; Talaia, Pedro; Drummond, Marta; Natal-Jorge, Renato

    2014-01-01

    OBJECTIVE: To study the effects of an oronasal interface (OI) for noninvasive ventilation, using a three-dimensional (3D) computational model with the ability to simulate and evaluate the main pressure zones (PZs) of the OI on the human face. METHODS: We used a 3D digital model of the human face, based on a pre-established geometric model. The model simulated soft tissues, skull, and nasal cartilage. The geometric model was obtained by 3D laser scanning and post-processed for use in the model created, with the objective of separating the cushion from the frame. A computer simulation was performed to determine the pressure required in order to create the facial PZs. We obtained descriptive graphical images of the PZs and their intensity. RESULTS: For the graphical analyses of each face-OI model pair and their respective evaluations, we ran 21 simulations. The computer model identified several high-impact PZs in the nasal bridge and paranasal regions. The variation in soft tissue depth had a direct impact on the amount of pressure applied (438-724 cmH2O). CONCLUSIONS: The computer simulation results indicate that, in patients submitted to noninvasive ventilation with an OI, the probability of skin lesion is higher in the nasal bridge and paranasal regions. This methodology could increase the applicability of biomechanical research on noninvasive ventilation interfaces, providing the information needed in order to choose the interface that best minimizes the risk of skin lesion. PMID:25610506

  19. Automated Geometric Model Builder Using Range Image Sensor Data: Final Acquistion

    SciTech Connect

    Diegert, C.; Sackos, J.

    1999-02-01

    This report documents a data collection where we recorded redundant range image data from multiple views of a simple scene, and recorded accurate survey measurements of the same scene. Collecting these data was a focus of the research project Automated Geometric Model Builder Using Range Image Sensor Data (96-0384), supported by Sandia's Laboratory-Directed Research and Development (LDRD) Program during fiscal years 1996, 1997, and 1998. The data described here are available from the authors on CDROM, or electronically over the Internet. Included in this data distribution are Computer-Aided Design (CAD) models we constructed from the survey measurements. The CAD models are compatible with the SolidWorks 98 Plus system, the modern Computer-Aided Design software system that is central to Sandia's DeskTop Engineering Project (DTEP). Integration of our measurements (as built) with the constructive geometry process of the CAD system (as designed) delivers on a vision of the research project. This report on our final data collection will also serve as a final report on the project.

  20. Evaluation of Automated Model Calibration Techniques for Residential Building Energy Simulation

    SciTech Connect

    Robertson, J.; Polly, B.; Collis, J.

    2013-09-01

    This simulation study adapts and applies the general framework described in BESTEST-EX (Judkoff et al 2010) for self-testing residential building energy model calibration methods. BEopt/DOE-2.2 is used to evaluate four mathematical calibration methods in the context of monthly, daily, and hourly synthetic utility data for a 1960's-era existing home in a cooling-dominated climate. The home's model inputs are assigned probability distributions representing uncertainty ranges, random selections are made from the uncertainty ranges to define 'explicit' input values, and synthetic utility billing data are generated using the explicit input values. The four calibration methods evaluated in this study are: an ASHRAE 1051-RP-based approach (Reddy and Maor 2006), a simplified simulated annealing optimization approach, a regression metamodeling optimization approach, and a simple output ratio calibration approach. The calibration methods are evaluated for monthly, daily, and hourly cases; various retrofit measures are applied to the calibrated models and the methods are evaluated based on the accuracy of predicted savings, computational cost, repeatability, automation, and ease of implementation.

  1. Automated Modeling of 3d Building Roofs Using Image and LIDAR Data

    NASA Astrophysics Data System (ADS)

    Demir, N.; Baltsavias, E.

    2012-07-01

    In this work, an automated approach for 3D building roof modelling is presented. The method consists of two main parts, namely roof detection and 3D geometric modelling. For the detection, a combined approach of four methods achieved the best results, using slope-based DSM filtering as well as classification of multispectral images, elevation data and vertical LiDAR point density. In the evaluation, the combination of the four methods yields 94% correct detection at an omission error of 12%. Roof modelling is done by plane detection with RANSAC, followed by geometric refinement and merging of neighbouring segments to clean up oversegmentation. Walls are then detected and excluded, and the roof shapes are vectorised with the alpha-shape method. The resulting polygons are refined using 3D straight edges reconstructed by automatic straight edge extraction and matching, as well as 3D corner points constructed by intersection of the 3D edges. The results are quantitatively assessed by comparing to ground truth manually extracted from high-quality images, using several metrics for both the correctness and completeness of the roof polygons and for their geometric accuracy. The median value of correctness of the roof polygons is calculated as 96%, while the median value of completeness is 88%.

  2. ITER physics-safety interface: models and assessments

    SciTech Connect

    Uckan, N.A. [Oak Ridge National Lab., TN (United States); Putvinski, S.; Wesley, J.; Bartels, H-W. [ITER San Diego Joint Work Site, CA (United States); Honda, T. [Hitachi Ltd., Ibaraki (Japan). Hitachi Research Lab.; Amano, T. [National Inst. for Fusion Science, Nagoya (Japan); Boucher, D.; Fujisawa, N.; Post, D.; Rosenbluth, M. [ITER San Diego Joint Work Site, CA (United States)

    1996-10-01

    Plasma operation conditions and physics requirements to be used as a basis for safety analysis studies are developed and physics results motivated by safety considerations are presented for the ITER design. Physics guidelines and specifications for enveloping plasma dynamic events for Category I (operational event), Category II (likely event), and Category III (unlikely event) are characterized. Safety related physics areas that are considered are: (i) effect of plasma on machined and safety (disruptions, runaway electrons, fast plasma shutdown) and (ii) plasma response to ex-vessel LOCA from first wall providing a potential passive plasma shutdown due to Be evaporation. Physics models and expressions developed are implemented in safety analysis code (SAFALY, couples 0-D dynamic plasma model to thermal response of the in-vessel components). Results from SAFALY are presented.

  3. Model studies of Rayleigh instabilities via microdesigned interfaces

    SciTech Connect

    Glaeser, Andreas M.

    2000-10-17

    The energetic and kinetic properties of surfaces play a critical role in defining the microstructural changes that occur during sintering and high-temperature use of ceramics. Characterization of surface diffusion in ceramics is particularly difficult, and significant variations in reported values of surface diffusivities arise even in well-studied systems. Effects of impurities, surface energy anisotropy, and the onset of surface attachment limited kinetics (SALK) are believed to contribute to this variability. An overview of the use of Rayleigh instabilities as a means of characterizing surface diffusivities is presented. The development of models of morphological evolution that account for effects of surface energy anisotropy is reviewed, and the potential interplay between impurities and surface energy anisotropy is addressed. The status of experimental studies of Rayleigh instabilities in sapphire utilizing lithographically introduced pore channels of controlled geometry and crystallography is summarized. Results of model studies indicate that impurities can significantly influence both the spatial and temporal characteristics of Rayleigh instabilities; this is attributed at least in part to impurity effects on the surface energy anisotropy. Related model experiments indicate that the onset of SALK may also contribute significantly to apparent variations in surface diffusion coefficients.

  4. A prototype natural language interface to a large complex knowledge base, the Foundational Model of Anatomy.

    PubMed

    Distelhorst, Gregory; Srivastava, Vishrut; Rosse, Cornelius; Brinkley, James F

    2003-01-01

    We describe a constrained natural language interface to a large knowledge base, the Foundational Model of Anatomy (FMA). The interface, called GAPP, handles simple or nested questions that can be parsed to the form, subject-relation-object, where subject or object is unknown. With the aid of domain-specific dictionaries the parsed sentence is converted to queries in the StruQL graph-searching query language, then sent to a server we developed, called OQAFMA, that queries the FMA and returns output as XML. Preliminary evaluation shows that GAPP has the potential to be used in the evaluation of the FMA by domain experts in anatomy. PMID:14728162

  5. Efficient loads analyses of Shuttle-payloads using dynamic models with linear or nonlinear interfaces

    NASA Technical Reports Server (NTRS)

    Spanos, P. D.; Cao, T. T.; Hamilton, D. A.; Nelson, D. A. R.

    1989-01-01

    An efficient method for the load analysis of Shuttle-payload systems with linear or nonlinear attachment interfaces is presented which allows the kinematics of the interface degrees of freedom at a given time to be evaluated without calculating the combined system modal representation of the Space Shuttle and its payload. For the case of a nonlinear dynamic model, an iterative procedure is employed to converge the nonlinear terms of the equations of motion to reliable values. Results are presented for a Shuttle abort landing event.

  6. Coarse Grained Modeling of The Interface BetweenWater and Heterogeneous Surfaces

    SciTech Connect

    Willard, Adam; Chandler, David

    2008-06-23

    Using coarse grained models we investigate the behavior of water adjacent to an extended hydrophobic surface peppered with various fractions of hydrophilic patches of different sizes. We study the spatial dependence of the mean interface height, the solvent density fluctuations related to drying the patchy substrate, and the spatial dependence of interfacial fluctuations. We find that adding small uniform attractive interactions between the substrate and solvent cause the mean position of the interface to be very close to the substrate. Nevertheless, the interfacial fluctuations are large and spatially heterogeneous in response to the underlying patchy substrate. We discuss the implications of these findings to the assembly of heterogeneous surfaces.

  7. Automated de novo phasing and model building of coiled-coil proteins.

    PubMed

    Rämisch, Sebastian; Lizatovi?, Robert; André, Ingemar

    2015-03-01

    Models generated by de novo structure prediction can be very useful starting points for molecular replacement for systems where suitable structural homologues cannot be readily identified. Protein-protein complexes and de novo-designed proteins are examples of systems that can be challenging to phase. In this study, the potential of de novo models of protein complexes for use as starting points for molecular replacement is investigated. The approach is demonstrated using homomeric coiled-coil proteins, which are excellent model systems for oligomeric systems. Despite the stereotypical fold of coiled coils, initial phase estimation can be difficult and many structures have to be solved with experimental phasing. A method was developed for automatic structure determination of homomeric coiled coils from X-ray diffraction data. In a benchmark set of 24 coiled coils, ranging from dimers to pentamers with resolutions down to 2.5?Å, 22 systems were automatically solved, 11 of which had previously been solved by experimental phasing. The generated models contained 71-103% of the residues present in the deposited structures, had the correct sequence and had free R values that deviated on average by 0.01 from those of the respective reference structures. The electron-density maps were of sufficient quality that only minor manual editing was necessary to produce final structures. The method, named CCsolve, combines methods for de novo structure prediction, initial phase estimation and automated model building into one pipeline. CCsolve is robust against errors in the initial models and can readily be modified to make use of alternative crystallographic software. The results demonstrate the feasibility of de novo phasing of protein-protein complexes, an approach that could also be employed for other small systems beyond coiled coils. PMID:25760609

  8. Numerical modeling of flow in a differential chamber of the gas-dynamic interface of a portable mass-spectrometer

    NASA Astrophysics Data System (ADS)

    Pivovarova, E. A.; Smirnovsky, A. A.; Schmidt, A. A.

    2013-11-01

    Mathematical modeling of flow in the differential chamber of the gas-dynamic interface of a portable mass-spectrometer was carried out to comprehensively study the flow structure and make recommendations for the optimization of the gas-dynamic interface. Modeling was performed using an OpenFOAM open computational platform. Conditions for an optimal operating mode of the differential chamber were determined.

  9. Nuclear Reactor/Hydrogen Process Interface Including the HyPEP Model

    SciTech Connect

    Steven R. Sherman

    2007-05-01

    The Nuclear Reactor/Hydrogen Plant interface is the intermediate heat transport loop that will connect a very high temperature gas-cooled nuclear reactor (VHTR) to a thermochemical, high-temperature electrolysis, or hybrid hydrogen production plant. A prototype plant called the Next Generation Nuclear Plant (NGNP) is planned for construction and operation at the Idaho National Laboratory in the 2018-2021 timeframe, and will involve a VHTR, a high-temperature interface, and a hydrogen production plant. The interface is responsible for transporting high-temperature thermal energy from the nuclear reactor to the hydrogen production plant while protecting the nuclear plant from operational disturbances at the hydrogen plant. Development of the interface is occurring under the DOE Nuclear Hydrogen Initiative (NHI) and involves the study, design, and development of high-temperature heat exchangers, heat transport systems, materials, safety, and integrated system models. Research and development work on the system interface began in 2004 and is expected to continue at least until the start of construction of an engineering-scale demonstration plant.

  10. Open boundary conditions for the Diffuse Interface Model in 1-D

    NASA Astrophysics Data System (ADS)

    Desmarais, J. L.; Kuerten, J. G. M.

    2014-04-01

    New techniques are developed for solving multi-phase flows in unbounded domains using the Diffuse Interface Model in 1-D. They extend two open boundary conditions originally designed for the Navier-Stokes equations. The non-dimensional formulation of the DIM generalizes the approach to any fluid. The equations support a steady state whose analytical approximation close to the critical point depends only on temperature. This feature enables the use of detectors at the boundaries switching between conventional boundary conditions in bulk phases and a multi-phase strategy in interfacial regions. Moreover, the latter takes advantage of the steady state approximation to minimize the interface-boundary interactions. The techniques are applied to fluids experiencing a phase transition and where the interface between the phases travels through one of the boundaries. When the interface crossing the boundary is fully developed, the technique greatly improves results relative to cases where conventional boundary conditions can be used. Limitations appear when the interface crossing the boundary is not a stable equilibrium between the two phases: the terms responsible for creating the true balance between the phases perturb the interior solution. Both boundary conditions present good numerical stability properties: the error remains bounded when the initial conditions or the far field values are perturbed. For the PML, the influence of its main parameters on the global error is investigated to make a compromise between computational costs and maximum error. The approach can be extended to multiple spatial dimensions.

  11. NURBS- and T-spline-based isogeometric cohesive zone modeling of interface debonding

    NASA Astrophysics Data System (ADS)

    Dimitri, R.; De Lorenzis, L.; Wriggers, P.; Zavarise, G.

    2014-08-01

    Cohesive zone (CZ) models have long been used by the scientific community to analyze the progressive damage of materials and interfaces. In these models, non-linear relationships between tractions and relative displacements are assumed, which dictate both the work of separation per unit fracture surface and the peak stress that has to be reached for the crack formation. This contribution deals with isogeometric CZ modeling of interface debonding. The interface is discretized with generalized contact elements which account for both contact and cohesive debonding within a unified framework. The formulation is suitable for non-matching discretizations of the interacting surfaces in presence of large deformations and large relative displacements. The isogeometric discretizations are based on non uniform rational B-splines as well as analysis-suitable T-splines enabling local refinement. Conventional Lagrange polynomial discretizations are also used for comparison purposes. Some numerical examples demonstrate that the proposed formulation based on isogeometric analysis is a computationally accurate and efficient technology to solve challenging interface debonding problems in 2D and 3D.

  12. Modeling of tunneling current in ultrathin MOS structure with interface trap charge and fixed oxide charge

    NASA Astrophysics Data System (ADS)

    Hu, Bo; Huang, Shi-Hua; Wu, Feng-Min

    2013-01-01

    A model based on analysis of the self-consistent Poisson—Schrodinger equation is proposed to investigate the tunneling current of electrons in the inversion layer of a p-type metal-oxide-semiconductor (MOS) structure. In this model, the influences of interface trap charge (ITC) at the Si—SiO2 interface and fixed oxide charge (FOC) in the oxide region are taken into account, and one-band effective mass approximation is used. The tunneling probability is obtained by employing the transfer matrix method. Further, the effects of in-plane momentum on the quantization in the electron motion perpendicular to the Si—SiO2 interface of a MOS device are investigated. Theoretical simulation results indicate that both ITC and FOC have great influence on the tunneling current through a MOS structure when their densities are larger than 1012 cm-2, which results from the great change of bound electrons near the Si—SiO2 interface and the oxide region. Therefore, for real ultrathin MOS structures with ITC and FOC, this model can give a more accurate description for the tunneling current in the inversion layer.

  13. Nanoscale modelling of mechanical properties of asphalt–aggregate interface under tensile loading

    Microsoft Academic Search

    Yang Lu; Linbing Wang

    2010-01-01

    This paper presents an investigation on the elastic constants of a quartz structure, tensile stress–strain state and adhesion failure behaviour of asphalt–rock interfaces by using an atomistic modelling method. A molecular mechanics method is applied to calculate the quartz bulk elastic constants, e.g. stiffness matrix, shear modulus, Young's modulus and Poisson's ratio. Molecular dynamics (MD) simulations are employed to model

  14. Nano-mechanics modelling of deformation and failure behaviours at asphalt–aggregate interfaces

    Microsoft Academic Search

    Yang Lu; Linbing Wang

    2011-01-01

    The nano-mechanics method has recently emerged as a powerful computational approach to model from nano to macro microstructure deformation and failure behaviours in materials. This paper reviews the advances of nano-mechanics modelling method. Then it introduces the recent advances of our research on the molecular origin of deformation and failure processes of asphalt–aggregate interfaces. This research includes studies of bulk

  15. International Journal of Industrial Ergonomics 36 (2006) 511526 A dynamic model of interaction between reliance on automation and

    E-print Network

    Lee, John D.

    2006-01-01

    between reliance on automation and cooperation in multi-operator multi-automation situations Ji Gaoa elements of automation. The success of such multi-operator multi-automation systems depends not only on individual operator's appropriate use of automation, but also on cooperation between operators. Inappropriate

  16. Micromechanical modeling of the cement-bone interface: the effect of friction, morphology and material properties on the micromechanical response

    PubMed Central

    Janssen, Dennis; Mann, Kenneth A.; Verdonschot, Nico

    2008-01-01

    In order to gain insight into the micro-mechanical behavior of the cement-bone interface, the effect of parametric variations of frictional, morphological and material properties on the mechanical response of the cement-bone interface were analyzed using a finite element approach. Finite element models of a cement-bone interface specimen were created from micro-computed tomography data of a physical specimen that was sectioned from an in vitro cemented total hip arthroplasty. In five models the friction coefficient was varied (?= 0.0; 0.3; 0.7; 1.0 and 3.0), while in one model an ideally bonded interface was assumed. In two models cement interface gaps and an optimal cement penetration were simulated. Finally, the effect of bone cement stiffness variations was simulated (2.0 and 2.5 GPa, relative to the default 3.0 GPa). All models were loaded for a cycle of fully reversible tension-compression. From the simulated stress-displacement curves the interface deformation, stiffness and hysteresis were calculated. The results indicate that in the current model the mechanical properties of the cement-bone interface were caused by frictional phenomena at the shape-closed interlock rather than by adhesive properties of the cement. Our findings furthermore show that in our model maximizing cement penetration improved the micromechanical response of the cement-bone interface stiffness, while interface gaps had a detrimental effect. Relative to the frictional and morphological variations, variations in the cement stiffness had only a modest effect on the micromechanical behavior of the cement-bone interface. The current study provides information that may help to better understand the load transfer mechanisms taking place at the cement-bone interface. PMID:18848699

  17. MaxMod: a hidden Markov model based novel interface to MODELLER for improved prediction of protein 3D models.

    PubMed

    Parida, Bikram K; Panda, Prasanna K; Misra, Namrata; Mishra, Barada K

    2015-02-01

    Modeling the three-dimensional (3D) structures of proteins assumes great significance because of its manifold applications in biomolecular research. Toward this goal, we present MaxMod, a graphical user interface (GUI) of the MODELLER program that combines profile hidden Markov model (profile HMM) method with Clustal Omega program to significantly improve the selection of homologous templates and target-template alignment for construction of accurate 3D protein models. MaxMod distinguishes itself from other existing GUIs of MODELLER software by implementing effortless modeling of proteins using templates that bear modified residues. Additionally, it provides various features such as loop optimization, express modeling (a feature where protein model can be generated directly from its sequence, without any further user intervention) and automatic update of PDB database, thus enhancing the user-friendly control of computational tasks. We find that HMM-based MaxMod performs better than other modeling packages in terms of execution time and model quality. MaxMod is freely available as a downloadable standalone tool for academic and non-commercial purpose at http://www.immt.res.in/maxmod/. PMID:25636267

  18. Atomic and Electronic Structure of the Fe?O? (111)/MgO(111) Model Polar Oxide Interface

    SciTech Connect

    Lazarov, Vlado; Weinert, M; Chambers, Scott A.; Gajdardziska-josifovska, Marija

    2005-11-01

    High resolution transmission electron microscopy (HRTEM) and density functional calculations are used to study the effect of interface polarity on the atomic and electronic structure of the prototype Fe?O?(111)/MgO(111) polar oxide interface. We show that atomically abrupt interfaces exist between the MgO(111)-substrate and magnetite(111) film in regions separated by Fe nanocrystals, and propose a solution for this oxide-oxide interface structure. Comparisons of through-focus/through-thickness experimental HRTEM images with calculated images for model interface structures suggest metal-oxygen-metal (i.e., Mg-O-Fe) interface bonding with octahedral (B) coordination of the first Fe monolayer, rather than the combination of tetrahedral-octahedral-tetrahedral (ABA) stacking also found in Fe?O?. First-principles calculations for all the different models find metal-induced gap states in the interface oxygen layer. Consistent with the HRTEM results, the MgO-Fe?O? interface stacking Mg/O/Mg/O/3FeB/O/FeAFeBFeA? is calculated to be the energetically most favorable, and effectively screening the MgO(111) substrate surface polarity. The data and calculations exclude mixing of Mg and Fe across the interface, in contrast to the commonly invoked mechanism of cation mixing at compound semiconductor polar interfaces.

  19. Integration Of Heat Transfer Coefficient In Glass Forming Modeling With Special Interface Element

    NASA Astrophysics Data System (ADS)

    Moreau, P.; César de Sá, J.; Grégoire, S.; Lochegnies, D.

    2007-05-01

    Numerical modeling of the glass forming processes requires the accurate knowledge of the heat exchange between the glass and the forming tools. A laboratory testing is developed to determine the evolution of the heat transfer coefficient in different glass/mould contact conditions (contact pressure, temperature, lubrication…). In this paper, trials are performed to determine heat transfer coefficient evolutions in experimental conditions close to the industrial blow-and-blow process conditions. In parallel of this work, a special interface element is implemented in a commercial Finite Element code in order to deal with heat transfer between glass and mould for non-meshing meshes and evolutive contact. This special interface element, implemented by using user subroutines, permits to introduce the previous heat transfer coefficient evolutions in the numerical modelings at the glass/mould interface in function of the local temperatures, contact pressures, contact time and kind of lubrication. The blow-and-blow forming simulation of a perfume bottle is finally performed to assess the special interface element performance.

  20. Bilinear modeling of EMG signals to extract user-independent features for multiuser myoelectric interface.

    PubMed

    Matsubara, Takamitsu; Morimoto, Jun

    2013-08-01

    In this study, we propose a multiuser myoelectric interface that can easily adapt to novel users. When a user performs different motions (e.g., grasping and pinching), different electromyography (EMG) signals are measured. When different users perform the same motion (e.g., grasping), different EMG signals are also measured. Therefore, designing a myoelectric interface that can be used by multiple users to perform multiple motions is difficult. To cope with this problem, we propose for EMG signals a bilinear model that is composed of two linear factors: 1) user dependent and 2) motion dependent. By decomposing the EMG signals into these two factors, the extracted motion-dependent factors can be used as user-independent features. We can construct a motion classifier on the extracted feature space to develop the multiuser interface. For novel users, the proposed adaptation method estimates the user-dependent factor through only a few interactions. The bilinear EMG model with the estimated user-dependent factor can extract the user-independent features from the novel user data. We applied our proposed method to a recognition task of five hand gestures for robotic hand control using four-channel EMG signals measured from subject forearms. Our method resulted in 73% accuracy, which was statistically significantly different from the accuracy of standard nonmultiuser interfaces, as the result of a two-sample t -test at a significance level of 1%. PMID:23475334

  1. Model for Hydrodynamic Instabilities of a Fluid Interface Using Coupled Conformal Mappings

    NASA Astrophysics Data System (ADS)

    Sokolov, Igor; Velikovich, Alexender

    2003-10-01

    The development of hydrodynamic instabilities at the interface between two fluids of different densities is one of the major limiting factors in the Inertial Confinement Fusion. To study this effect, the incompressible fluid model is widely used for describing the motion near the interface separating the two fluids (see Refs. 1, 2 and references therein). We obtain a new set of 1D partial differential equations, which fully describe the 2D dynamics for such fluid interfaces. To achieve this we found, for any instant of time, a pair of conformal mappings which map the highly distorted interface contour into a simpler domain, for which a boundary value problem can be easily solved. These equations are convenient for numerical solution, they describe the linear and non-linear Richtmyer-Meshkov (RM), Rayleigh-Taylor (RT) and Kelvin-Helmholtz instabilities in incompressible without any additional simplifying assumptions. This approach can be also generalized for the instabilities of the ablation front, as well as for the MHD instabilities To verify the model we performed numerical simulations for the RM and RT instabilities. For the particular case of the RM instability at Atwood# =1, we compare the new results with the predictions of the analytical theory [1], for other cases - with the results obtained using the vortex method [3]. The work of A. V. was supported by the U. S. Department of Energy, Defense Programs.

  2. Integration Of Heat Transfer Coefficient In Glass Forming Modeling With Special Interface Element

    SciTech Connect

    Moreau, P.; Gregoire, S.; Lochegnies, D. [LAMIH UMR CNRS 8530, University of Valenciennes, Le Mont-Houy, 59313 Valenciennes Cedex 9 (France); Cesar de Sa, J. [DEMEGI, University of Porto, Rua Dr Roberto Frias, s/n 4200-465 Porto (Portugal)

    2007-05-17

    Numerical modeling of the glass forming processes requires the accurate knowledge of the heat exchange between the glass and the forming tools. A laboratory testing is developed to determine the evolution of the heat transfer coefficient in different glass/mould contact conditions (contact pressure, temperature, lubrication...). In this paper, trials are performed to determine heat transfer coefficient evolutions in experimental conditions close to the industrial blow-and-blow process conditions. In parallel of this work, a special interface element is implemented in a commercial Finite Element code in order to deal with heat transfer between glass and mould for non-meshing meshes and evolutive contact. This special interface element, implemented by using user subroutines, permits to introduce the previous heat transfer coefficient evolutions in the numerical modelings at the glass/mould interface in function of the local temperatures, contact pressures, contact time and kind of lubrication. The blow-and-blow forming simulation of a perfume bottle is finally performed to assess the special interface element performance.

  3. CS 525: Advanced Database Organization Study of relational, semantic, and object-oriented data models and interfaces. Database management system

    E-print Network

    Heller, Barbara

    -oriented data models and interfaces. Database management system techniques for query optimization, concurrency History of database management. Goals of database system development. Relational systems Data models Date's requirements for distributed data management. Problems of distributed database management Object

  4. Interfacing MATLAB and Python Optimizers to Black-Box Environmental Simulation Models

    NASA Astrophysics Data System (ADS)

    Matott, L. S.; Leung, K.; Tolson, B.

    2009-12-01

    A common approach for utilizing environmental models in a management or policy-analysis context is to incorporate them into a simulation-optimization framework - where an underlying process-based environmental model is linked with an optimization search algorithm. The optimization search algorithm iteratively adjusts various model inputs (i.e. parameters or design variables) in order to minimize an application-specific objective function computed on the basis of model outputs (i.e. response variables). Numerous optimization algorithms have been applied to the simulation-optimization of environmental systems and this research investigated the use of optimization libraries and toolboxes that are readily available in MATLAB and Python - two popular high-level programming languages. Inspired by model-independent calibration codes (e.g. PEST and UCODE), a small piece of interface software (known as PIGEON) was developed. PIGEON allows users to interface Python and MATLAB optimizers with arbitrary black-box environmental models without writing any additional interface code. An initial set of benchmark tests (involving more than 20 MATLAB and Python optimization algorithms) were performed to validate the interface software - results highlight the need to carefully consider such issues as numerical precision in output files and enforcement (or not) of parameter limits. Additional benchmark testing considered the problem of fitting isotherm expressions to laboratory data - with an emphasis on dual-mode expressions combining non-linear isotherms with a linear partitioning component. With respect to the selected isotherm fitting problems, derivative-free search algorithms significantly outperformed gradient-based algorithms. Attempts to improve gradient-based performance, via parameter tuning and also via several alternative multi-start approaches, were largely unsuccessful.

  5. Automation based on knowledge modeling theory and its applications in engine diagnostic systems using Space Shuttle Main Engine vibrational data. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Kim, Jonnathan H.

    1995-01-01

    Humans can perform many complicated tasks without explicit rules. This inherent and advantageous capability becomes a hurdle when a task is to be automated. Modern computers and numerical calculations require explicit rules and discrete numerical values. In order to bridge the gap between human knowledge and automating tools, a knowledge model is proposed. Knowledge modeling techniques are discussed and utilized to automate a labor and time intensive task of detecting anomalous bearing wear patterns in the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP).

  6. Modeling and control of tissue compression and temperature for automation in robot-assisted surgery.

    PubMed

    Sinha, Utkarsh; Li, Baichun; Sankaranarayanan, Ganesh

    2014-01-01

    Robotic surgery is being used widely due to its various benefits that includes reduced patient trauma and increased dexterity and ergonomics for the operating surgeon. Making the whole or part of the surgical procedure autonomous increases patient safety and will enable the robotic surgery platform to be used in telesurgery. In this work, an Electrosurgery procedure that involves tissue compression and application of heat such as the coaptic vessel closure has been automated. A MIMO nonlinear model characterizing the tissue stiffness and conductance under compression was feedback linearized and tuned PID controllers were used to control the system to achieve both the displacement and temperature constraints. A reference input for both the constraints were chosen as a ramp and hold trajectory which reflect the real constraints that exist in an actual surgical procedure. Our simulations showed that the controllers successfully tracked the reference trajectories with minimal deviation and in finite time horizon. The MIMO system with controllers developed in this work can be used to drive a surgical robot autonomously and perform electrosurgical procedures such as coaptic vessel closures. PMID:25569973

  7. A Hybrid Geometric–Statistical Deformable Model for Automated 3-D Segmentation in Brain MRI

    PubMed Central

    Abugharbieh, Rafeef; Tam, Roger

    2010-01-01

    We present a novel 3-D deformable model-based approach for accurate, robust, and automated tissue segmentation of brain MRI data of single as well as multiple magnetic resonance sequences. The main contribution of this study is that we employ an edge-based geodesic active contour for the segmentation task by integrating both image edge geometry and voxel statistical homogeneity into a novel hybrid geometric–statistical feature to regularize contour convergence and extract complex anatomical structures. We validate the accuracy of the segmentation results on simulated brain MRI scans of both single T1-weighted and multiple T1/T2/PD-weighted sequences. We also demonstrate the robustness of the proposed method when applied to clinical brain MRI scans. When compared to a current state-of-the-art region-based level-set segmentation formulation, our white matter and gray matter segmentation resulted in significantly higher accuracy levels with a mean improvement in Dice similarity indexes of 8.55% (p < 0.0001) and 10.18% (p < 0.0001), respectively. PMID:19336280

  8. Automated segmentation and geometrical modeling of the tricuspid aortic valve in 3D echocardiographic images

    PubMed Central

    Pouch, Alison M.; Wang, Hongzhi; Takabe, Manabu; Jackson, Benjamin M.; Sehgal, Chandra M.; Gorman, Joseph H.; Gorman, Robert C.; Yushkevich, Paul A.

    2013-01-01

    The aortic valve has been described with variable anatomical definitions, and the consistency of 2D manual measurement of valve dimensions in medical image data has been questionable. Given the importance of image-based morphological assessment in the diagnosis and surgical treatment of aortic valve disease, there is considerable need to develop a standardized framework for 3D valve segmentation and shape representation. Towards this goal, this work integrates template-based medial modeling and multi-atlas label fusion techniques to automatically delineate and quantitatively describe aortic leaflet geometry in 3D echocardiographic (3DE) images, a challenging task that has been explored only to a limited extent. The method makes use of expert knowledge of aortic leaflet image appearance, generates segmentations with consistent topology, and establishes a shape-based coordinate system on the aortic leaflets that enables standardized automated measurements. In this study, the algorithm is evaluated on 11 3DE images of normal human aortic leaflets acquired at mid systole. The clinical relevance of the method is its ability to capture leaflet geometry in 3DE image data with minimal user interaction while producing consistent measurements of 3D aortic leaflet geometry. PMID:24505702

  9. Structure and application of an interface program between a geographic-information system and a ground-water flow model

    USGS Publications Warehouse

    Van Metre, P.C.

    1990-01-01

    A computer-program interface between a geographic-information system and a groundwater flow model links two unrelated software systems for use in developing the flow models. The interface program allows the modeler to compile and manage geographic components of a groundwater model within the geographic information system. A significant savings of time and effort is realized in developing, calibrating, and displaying the groundwater flow model. Four major guidelines were followed in developing the interface program: (1) no changes to the groundwater flow model code were to be made; (2) a data structure was to be designed within the geographic information system that follows the same basic data structure as the groundwater flow model; (3) the interface program was to be flexible enough to support all basic data options available within the model; and (4) the interface program was to be as efficient as possible in terms of computer time used and online-storage space needed. Because some programs in the interface are written in control-program language, the interface will run only on a computer with the PRIMOS operating system. (USGS)

  10. A DIFFUSE-INTERFACE APPROACH FOR MODELING TRANSPORT, DIFFUSION AND ADSORPTION/DESORPTION OF MATERIAL QUANTITIES ON A DEFORMABLE INTERFACE*

    PubMed Central

    Teigen, Knut Erik; Li, Xiangrong; Lowengrub, John; Wang, Fan; Voigt, Axel

    2010-01-01

    A method is presented to solve two-phase problems involving a material quantity on an interface. The interface can be advected, stretched, and change topology, and material can be adsorbed to or desorbed from it. The method is based on the use of a diffuse interface framework, which allows a simple implementation using standard finite-difference or finite-element techniques. Here, finite-difference methods on a block-structured adaptive grid are used, and the resulting equations are solved using a non-linear multigrid method. Interfacial flow with soluble surfactants is used as an example of the application of the method, and several test cases are presented demonstrating its accuracy and convergence. PMID:21373370

  11. Including nonequilibrium interface kinetics in a continuum model for melting nanoscaled particles

    PubMed Central

    Back, Julian M.; McCue, Scott W.; Moroney, Timothy J.

    2014-01-01

    The melting temperature of a nanoscaled particle is known to decrease as the curvature of the solid-melt interface increases. This relationship is most often modelled by a Gibbs–Thomson law, with the decrease in melting temperature proposed to be a product of the curvature of the solid-melt interface and the surface tension. Such a law must break down for sufficiently small particles, since the curvature becomes singular in the limit that the particle radius vanishes. Furthermore, the use of this law as a boundary condition for a Stefan-type continuum model is problematic because it leads to a physically unrealistic form of mathematical blow-up at a finite particle radius. By numerical simulation, we show that the inclusion of nonequilibrium interface kinetics in the Gibbs–Thomson law regularises the continuum model, so that the mathematical blow up is suppressed. As a result, the solution continues until complete melting, and the corresponding melting temperature remains finite for all time. The results of the adjusted model are consistent with experimental findings of abrupt melting of nanoscaled particles. This small-particle regime appears to be closely related to the problem of melting a superheated particle. PMID:25399918

  12. Multiscale Modeling of Intergranular Fracture in Aluminum: Constitutive Relation For Interface Debonding

    NASA Technical Reports Server (NTRS)

    Yamakov, V.; Saether, E.; Glaessgen, E. H.

    2008-01-01

    Intergranular fracture is a dominant mode of failure in ultrafine grained materials. In the present study, the atomistic mechanisms of grain-boundary debonding during intergranular fracture in aluminum are modeled using a coupled molecular dynamics finite element simulation. Using a statistical mechanics approach, a cohesive-zone law in the form of a traction-displacement constitutive relationship, characterizing the load transfer across the plane of a growing edge crack, is extracted from atomistic simulations and then recast in a form suitable for inclusion within a continuum finite element model. The cohesive-zone law derived by the presented technique is free of finite size effects and is statistically representative for describing the interfacial debonding of a grain boundary (GB) interface examined at atomic length scales. By incorporating the cohesive-zone law in cohesive-zone finite elements, the debonding of a GB interface can be simulated in a coupled continuum-atomistic model, in which a crack starts in the continuum environment, smoothly penetrates the continuum-atomistic interface, and continues its propagation in the atomistic environment. This study is a step towards relating atomistically derived decohesion laws to macroscopic predictions of fracture and constructing multiscale models for nanocrystalline and ultrafine grained materials.

  13. Including nonequilibrium interface kinetics in a continuum model for melting nanoscaled particles

    NASA Astrophysics Data System (ADS)

    Back, Julian M.; McCue, Scott W.; Moroney, Timothy J.

    2014-11-01

    The melting temperature of a nanoscaled particle is known to decrease as the curvature of the solid-melt interface increases. This relationship is most often modelled by a Gibbs-Thomson law, with the decrease in melting temperature proposed to be a product of the curvature of the solid-melt interface and the surface tension. Such a law must break down for sufficiently small particles, since the curvature becomes singular in the limit that the particle radius vanishes. Furthermore, the use of this law as a boundary condition for a Stefan-type continuum model is problematic because it leads to a physically unrealistic form of mathematical blow-up at a finite particle radius. By numerical simulation, we show that the inclusion of nonequilibrium interface kinetics in the Gibbs-Thomson law regularises the continuum model, so that the mathematical blow up is suppressed. As a result, the solution continues until complete melting, and the corresponding melting temperature remains finite for all time. The results of the adjusted model are consistent with experimental findings of abrupt melting of nanoscaled particles. This small-particle regime appears to be closely related to the problem of melting a superheated particle.

  14. The DaveMLTranslator: An Interface for DAVE-ML Aerodynamic Models

    NASA Technical Reports Server (NTRS)

    Hill, Melissa A.; Jackson, E. Bruce

    2007-01-01

    It can take weeks or months to incorporate a new aerodynamic model into a vehicle simulation and validate the performance of the model. The Dynamic Aerospace Vehicle Exchange Markup Language (DAVE-ML) has been proposed as a means to reduce the time required to accomplish this task by defining a standard format for typical components of a flight dynamic model. The purpose of this paper is to describe an object-oriented C++ implementation of a class that interfaces a vehicle subsystem model specified in DAVE-ML and a vehicle simulation. Using the DaveMLTranslator class, aerodynamic or other subsystem models can be automatically imported and verified at run-time, significantly reducing the elapsed time between receipt of a DAVE-ML model and its integration into a simulation environment. The translator performs variable initializations, data table lookups, and mathematical calculations for the aerodynamic build-up, and executes any embedded static check-cases for verification. The implementation is efficient, enabling real-time execution. Simple interface code for the model inputs and outputs is the only requirement to integrate the DaveMLTranslator as a vehicle aerodynamic model. The translator makes use of existing table-lookup utilities from the Langley Standard Real-Time Simulation in C++ (LaSRS++). The design and operation of the translator class is described and comparisons with existing, conventional, C++ aerodynamic models of the same vehicle are given.

  15. Cockpit automation - In need of a philosophy

    NASA Technical Reports Server (NTRS)

    Wiener, E. L.

    1985-01-01

    Concern has been expressed over the rapid development and deployment of automatic devices in transport aircraft, due mainly to the human interface and particularly the role of automation in inducing human error. The paper discusses the need for coherent philosophies of automation, and proposes several approaches: (1) flight management by exception, which states that as long as a crew stays within the bounds of regulations, air traffic control and flight safety, it may fly as it sees fit; (2) exceptions by forecasting, where the use of forecasting models would predict boundary penetration, rather than waiting for it to happen; (3) goal-sharing, where a computer is informed of overall goals, and subsequently has the capability of checking inputs and aircraft position for consistency with the overall goal or intentions; and (4) artificial intelligence and expert systems, where intelligent machines could mimic human reason.

  16. Automating spectral measurements

    NASA Astrophysics Data System (ADS)

    Goldstein, Fred T.

    2008-09-01

    This paper discusses the architecture of software utilized in spectroscopic measurements. As optical coatings become more sophisticated, there is mounting need to automate data acquisition (DAQ) from spectrophotometers. Such need is exacerbated when 100% inspection is required, ancillary devices are utilized, cost reduction is crucial, or security is vital. While instrument manufacturers normally provide point-and-click DAQ software, an application programming interface (API) may be missing. In such cases automation is impossible or expensive. An API is typically provided in libraries (*.dll, *.ocx) which may be embedded in user-developed applications. Users can thereby implement DAQ automation in several Windows languages. Another possibility, developed by FTG as an alternative to instrument manufacturers' software, is the ActiveX application (*.exe). ActiveX, a component of many Windows applications, provides means for programming and interoperability. This architecture permits a point-and-click program to act as automation client and server. Excel, for example, can control and be controlled by DAQ applications. Most importantly, ActiveX permits ancillary devices such as barcode readers and XY-stages to be easily and economically integrated into scanning procedures. Since an ActiveX application has its own user-interface, it can be independently tested. The ActiveX application then runs (visibly or invisibly) under DAQ software control. Automation capabilities are accessed via a built-in spectro-BASIC language with industry-standard (VBA-compatible) syntax. Supplementing ActiveX, spectro-BASIC also includes auxiliary serial port commands for interfacing programmable logic controllers (PLC). A typical application is automatic filter handling.

  17. Continental hydrosystem modelling: the concept of nested stream-aquifer interfaces

    NASA Astrophysics Data System (ADS)

    Flipo, N.; Mouhri, A.; Labarthe, B.; Biancamaria, S.; Rivière, A.; Weill, P.

    2014-08-01

    Coupled hydrological-hydrogeological models, emphasising the importance of the stream-aquifer interface, are more and more used in hydrological sciences for pluri-disciplinary studies aiming at investigating environmental issues. Based on an extensive literature review, stream-aquifer interfaces are described at five different scales: local [10 cm-~10 m], intermediate [~10 m-~1 km], watershed [10 km2-~1000 km2], regional [10 000 km2-~1 M km2] and continental scales [>10 M km2]. This led us to develop the concept of nested stream-aquifer interfaces, which extends the well-known vision of nested groundwater pathways towards the surface, where the mixing of low frequency processes and high frequency processes coupled with the complexity of geomorphological features and heterogeneities creates hydrological spiralling. This conceptual framework allows the identification of a hierarchical order of the multi-scale control factors of stream-aquifer hydrological exchanges, from the larger scale to the finer scale. The hyporheic corridor, which couples the river to its 3-D hyporheic zone, is then identified as the key component for scaling hydrological processes occurring at the interface. The identification of the hyporheic corridor as the support of the hydrological processes scaling is an important step for the development of regional studies, which is one of the main concerns for water practitioners and resources managers. In a second part, the modelling of the stream-aquifer interface at various scales is investigated with the help of the conductance model. Although the usage of the temperature as a tracer of the flow is a robust method for the assessment of stream-aquifer exchanges at the local scale, there is a crucial need to develop innovative methodologies for assessing stream-aquifer exchanges at the regional scale. After formulating the conductance model at the regional and intermediate scales, we address this challenging issue with the development of an iterative modelling methodology, which ensures the consistency of stream-aquifer exchanges between the intermediate and regional scales. Finally, practical recommendations are provided for the study of the interface using the innovative methodology MIM (Measurements-Interpolation-Modelling), which is graphically developed, scaling in space the three pools of methods needed to fully understand stream-aquifer interfaces at various scales. In the MIM space, stream-aquifer interfaces that can be studied by a given approach are localised. The efficiency of the method is demonstrated with two examples. The first one proposes an upscaling framework, structured around river reaches of ~10-100 m, from the local to the watershed scale. The second example highlights the usefulness of space borne data to improve the assessment of stream-aquifer exchanges at the regional and continental scales. We conclude that further developments in modelling and field measurements have to be undertaken at the regional scale to enable a proper modelling of stream-aquifer exchanges from the local to the continental scale.

  18. Modeling of ultrasound transmission through a solid-liquid interface comprising a network of gas pockets

    SciTech Connect

    Paumel, K.; Baque, F. [CEA, DEN, Nuclear Technology Department, F-13108 Saint-Paul-lez-Durance (France); Moysan, J.; Corneloup, G. [Laboratoire de Caracterisation Non Destructive, Universite de la Mediterranee, IUT Aix-en-Provence, Avenue Gaston Berger, 13625 Aix-en-Provence (France); Chatain, D. [CNRS, Aix-Marseille Universite, CINAM-UPR3118, Campus de Luminy, Case 913, 13288 Marseille cedex 09 (France)

    2011-08-15

    Ultrasonic inspection of sodium-cooled fast reactor requires a good acoustic coupling between the transducer and the liquid sodium. Ultrasonic transmission through a solid surface in contact with liquid sodium can be complex due to the presence of microscopic gas pockets entrapped by the surface roughness. Experiments are run using substrates with controlled roughness consisting of a network of holes and a modeling approach is then developed. In this model, a gas pocket stiffness at a partially solid-liquid interface is defined. This stiffness is then used to calculate the transmission coefficient of ultrasound at the entire interface. The gas pocket stiffness has a static, as well as an inertial component, which depends on the ultrasonic frequency and the radiative mass.

  19. Modeling Geometry and Progressive Failure of Material Interfaces in Plain Weave Composites

    NASA Technical Reports Server (NTRS)

    Hsu, Su-Yuen; Cheng, Ron-Bin

    2010-01-01

    A procedure combining a geometrically nonlinear, explicit-dynamics contact analysis, computer aided design techniques, and elasticity-based mesh adjustment is proposed to efficiently generate realistic finite element models for meso-mechanical analysis of progressive failure in textile composites. In the procedure, the geometry of fiber tows is obtained by imposing a fictitious expansion on the tows. Meshes resulting from the procedure are conformal with the computed tow-tow and tow-matrix interfaces but are incongruent at the interfaces. The mesh interfaces are treated as cohesive contact surfaces not only to resolve the incongruence but also to simulate progressive failure. The method is employed to simulate debonding at the material interfaces in a ceramic-matrix plain weave composite with matrix porosity and in a polymeric matrix plain weave composite without matrix porosity, both subject to uniaxial cyclic loading. The numerical results indicate progression of the interfacial damage during every loading and reverse loading event in a constant strain amplitude cyclic process. However, the composites show different patterns of damage advancement.

  20. A surfactantless emulsion as a model for the liquid-liquid interface

    NASA Astrophysics Data System (ADS)

    Knight, Katherine Mary

    An electrochemically polarised liquid-liquid interface in the form of a surfactantless oil-in-water emulsion has been developed, and its creation, stabilisation and use as a model liquid-liquid system for structural characterisation using Small Angle Neutron Scattering (SANS) are described. The emulsion, composed of 1,2-dichloroethane (DCE)-in-D20, was created using a condensation method and the two main processes of destabilisation, sedimentation and coalescence, were minimised using density-matching and electrochemistry. The stabilised emulsion interface was then studied with SANS, using the Dll and D22 diffractometers at the ILL and LOQ at ISIS. This was to determine structural information regarding a layer of adsorbed Bovine Serum Albumin (BSA) protein at the interface with and without stabilising salts and the only analysable results were obtained using Dll, due to the lower Q-range accessible. The BSA layer thickness was determined to be 40 and 48 A for emulsions with and without salts respectively, and this was comparable with the literature thickness of 40 A. Another use for the surfactantless emulsion would be for electrodeless electrodeposition of metals at the interface, utilising the interfacial potential, and preliminary experiments were carried out using both oil-in-water and water-in-oil emulsions.

  1. Rigorous interpolation near tilted interfaces in 3-D finite-difference EM modelling

    NASA Astrophysics Data System (ADS)

    Shantsev, Daniil V.; Maaø, Frank A.

    2015-02-01

    We present a rigorous method for interpolation of electric and magnetic fields close to an interface with a conductivity contrast. The method takes into account not only a well-known discontinuity in the normal electric field, but also discontinuity in all the normal derivatives of electric and magnetic tangential fields. The proposed method is applied to marine 3-D controlled-source electromagnetic modelling (CSEM) where sources and receivers are located close to the seafloor separating conductive seawater and resistive formation. For the finite-difference scheme based on the Yee grid, the new interpolation is demonstrated to be much more accurate than alternative methods (interpolation using nodes on one side of the interface or interpolation using nodes on both sides, but ignoring the derivative jumps). The rigorous interpolation can handle arbitrary orientation of interface with respect to the grid, which is demonstrated on a marine CSEM example with a dipping seafloor. The interpolation coefficients are computed by minimizing a misfit between values at the nearest nodes and linear expansions of the continuous field components in the coordinate system aligned with the interface. The proposed interpolation operators can handle either uniform or non-uniform grids and can be applied to interpolation for both sources and receivers.

  2. Characterizing and Modeling Brittle Bi-material Interfaces Subjected to Shear

    NASA Astrophysics Data System (ADS)

    Anyfantis, Konstantinos N.; Berggreen, Christian

    2014-12-01

    This work is based on the investigation, both experimentally and numerically, of the Mode II fracture process and bond strength of bondlines formed in co-cured composite/metal joints. To this end, GFRP-to-steel double strap joints were tested in tension, so that the bi-material interface was subjected to shear with debonding occurring under Mode II conditions. The study of the debonding process and thus failure of the joints was based both on stress and energy considerations. Analytical formulas were utilized for the derivation of the respective shear strength and fracture toughness measures which characterize the bi-material interface, by considering the joint's failure load, geometry and involved materials. The derived stress and toughness magnitudes were further utilized as the parameters of an extrinsic cohesive law, applied in connection with the modeling the bi-material interface in a finite element simulation environment. It was concluded that interfacial fracture in the considered joints was driven by the fracture toughness and not by strength considerations, and that LEFM is well suited to analyze the failure of the joint. Additionally, the double strap joint geometry was identified and utilized as a characterization test for measuring the Mode II fracture toughness of brittle bi-material interfaces.

  3. A study of the ice-water interface using the TIP4P/2005 water model

    E-print Network

    Jorge Benet; Luis G. MacDowell; Eduardo Sanz

    2014-10-01

    In this work we study the ice-water interface under coexistence conditions by means of molecular simulations using the TIP4P/2005 water model. Following the methodology proposed by Hoyt and co-workers [J. J. Hoyt, M. Asta and A. Karma, Phys. Rev. Lett., 86, 5530, (2001)] we measure the interfacial free energy of ice with liquid water by analysing the spectrum of capillary fluctuations of the interface. We get an orientationally averaged interfacial free energy of 27(2) mN/m, in good agreement with a recent estimate obtained from simulation data of the size of critical clusters [E. Sanz, C. Vega, J. R. Espinosa, R. Caballero-Bernal, J. L. F. Abascal and C. Valeriani, JACS, 135, 15008, (2013)]. We also estimate the interfacial free energy of different planes and obtain 27(2), 28(2)and 28(2) mN/m for the basal, the primary prismatic and the secondary prismatic planes respectively. Finally, we inspect the structure of the interface and find that its thickness is of approximately 4-5 molecular diameters. Moreover, we find that when the basal plane is exposed to the fluid the interface alternates regions of cubic ice with regions of hexagonal ice.

  4. Formulation of consumables management models: Mission planning processor payload interface definition

    NASA Technical Reports Server (NTRS)

    Torian, J. G.

    1977-01-01

    Consumables models required for the mission planning and scheduling function are formulated. The relation of the models to prelaunch, onboard, ground support, and postmission functions for the space transportation systems is established. Analytical models consisting of an orbiter planning processor with consumables data base is developed. A method of recognizing potential constraint violations in both the planning and flight operations functions, and a flight data file storage/retrieval of information over an extended period which interfaces with a flight operations processor for monitoring of the actual flights is presented.

  5. An approximate model and empirical energy function for solute interactions with a water-phosphatidylcholine interface.

    PubMed Central

    Sanders, C R; Schwonek, J P

    1993-01-01

    An empirical model of a liquid crystalline (L alpha phase) phosphatidylcholine (PC) bilayer interface is presented along with a function which calculates the position-dependent energy of associated solutes. The model approximates the interface as a gradual two-step transition, the first step being from an aqueous phase to a phase of reduced polarity, but which maintains a high enough concentration of water and/or polar head group moieties to satisfy the hydrogen bond-forming potential of the solute. The second transition is from the hydrogen bonding/low polarity region to an effectively anhydrous hydrocarbon phase. The "interfacial energies" of solutes within this variable medium are calculated based upon atomic positions and atomic parameters describing general polarity and hydrogen bond donor/acceptor propensities. This function was tested for its ability to reproduce experimental water-solvent partitioning energies and water-bilayer partitioning data. In both cases, the experimental data was reproduced fairly well. Energy minimizations carried out on beta-hexyl glucopyranoside led to identification of a global minimum for the interface-associated glycolipid which exhibited glycosidic torsion angles in agreement with prior results (Hare, B.J., K.P. Howard, and J.H. Prestegard. 1993. Biophys. J. 64:392-398). Molecular dynamics simulations carried out upon this same molecule within the simulated interface led to results which were consistent with a number of experimentally based conclusions from previous work, but failed to quantitatively reproduce an available NMR quadrupolar/dipolar coupling data set (Sanders, C.R., and J.H. Prestegard. 1991. J. Am. Chem. Soc. 113:1987-1996). The proposed model and functions are readily incorporated into computational energy modeling algorithms and may prove useful in future studies of membrane-associated molecules. PMID:8241401

  6. Degenerate Ising model for atomistic simulation of crystal-melt interfaces

    SciTech Connect

    Schebarchov, D., E-mail: Dmitri.Schebarchov@gmail.com [University Chemical Laboratories, Lensfield Road, Cambridge CB2 1EW (United Kingdom); Schulze, T. P., E-mail: schulze@math.utk.edu [Department of Mathematics, University of Tennessee, Knoxville, Tennessee 37996-1300 (United States); Hendy, S. C. [The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand) [The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6140 (New Zealand); Department of Physics, University of Auckland, Auckland 1010 (New Zealand)

    2014-02-21

    One of the simplest microscopic models for a thermally driven first-order phase transition is an Ising-type lattice system with nearest-neighbour interactions, an external field, and a degeneracy parameter. The underlying lattice and the interaction coupling constant control the anisotropic energy of the phase boundary, the field strength represents the bulk latent heat, and the degeneracy quantifies the difference in communal entropy between the two phases. We simulate the (stochastic) evolution of this minimal model by applying rejection-free canonical and microcanonical Monte Carlo algorithms, and we obtain caloric curves and heat capacity plots for square (2D) and face-centred cubic (3D) lattices with periodic boundary conditions. Since the model admits precise adjustment of bulk latent heat and communal entropy, neither of which affect the interface properties, we are able to tune the crystal nucleation barriers at a fixed degree of undercooling and verify a dimension-dependent scaling expected from classical nucleation theory. We also analyse the equilibrium crystal-melt coexistence in the microcanonical ensemble, where we detect negative heat capacities and find that this phenomenon is more pronounced when the interface is the dominant contributor to the total entropy. The negative branch of the heat capacity appears smooth only when the equilibrium interface-area-to-volume ratio is not constant but varies smoothly with the excitation energy. Finally, we simulate microcanonical crystal nucleation and subsequent relaxation to an equilibrium Wulff shape, demonstrating the model's utility in tracking crystal-melt interfaces at the atomistic level.

  7. Stable and runaway bubble merger in a model for Rayleigh-Taylor unstable interfaces

    NASA Astrophysics Data System (ADS)

    Glimm, J.; McBryan, O.; Menikoff, R.; Sharp, D. H.

    1987-08-01

    A statistical model for the growth of bubbles in a Rayleigh-Taylor unstable interface is analyzed. Runaway and uniform growth regimes are observed. Starting from a random configuration, in which neighboring bubbles are uncorrelated, runaway is found to be the expected initial transient with velocities and accelerations growing exponentially. However neighboring bubble correlations develop dynamically, which may lead to a self-limiting regime of uniform growth and constant acceleration. The observed constant acceleration rate is non-universal.

  8. Model based generalization analysis of common spatial pattern in brain computer interfaces

    Microsoft Academic Search

    Gan Huang; Guangquan Liu; Jianjun Meng; Dingguo Zhang; Xiangyang Zhu

    2010-01-01

    In the motor imagery based Brain Computer Interface (BCI) research, Common Spatial Pattern (CSP) algorithm is used widely\\u000a as a spatial filter on multi-channel electroencephalogram (EEG) recordings. Recently the overfitting effect of CSP has been\\u000a gradually noticed, but what influence the overfitting is still unclear. In this work, the generalization of CSP is investigated\\u000a by a simple linear mixing model.

  9. Automation of one-loop QCD corrections

    E-print Network

    Valentin Hirschi; Rikkert Frederix; Stefano Frixione; Maria Vittoria Garzelli; Fabio Maltoni; Roberto Pittau

    2013-05-14

    We present the complete automation of the computation of one-loop QCD corrections, including UV renormalization, to an arbitrary scattering process in the Standard Model. This is achieved by embedding the OPP integrand reduction technique, as implemented in CutTools, into the MadGraph framework. By interfacing the tool so constructed, which we dub MadLoop, with MadFKS, the fully automatic computation of any infrared-safe observable at the next-to-leading order in QCD is attained. We demonstrate the flexibility and the reach of our method by calculating the production rates for a variety of processes at the 7 TeV LHC.

  10. Thin interface asymptotics for an energy\\/entropy approach to phase-field models with unequal conductivities

    Microsoft Academic Search

    G. B. McFadden; A. A. Wheeler; D. M. Anderson

    2000-01-01

    Karma and Rappel [Phys. Rev. E 57 (1998) 4342] recently developed a new sharp interface asymptotic analysis of the phase-field equations that is especially appropriate for modeling dendritic growth at low undercoolings. Their approach relieves a stringent restriction on the interface thickness that applies in the conventional asymptotic analysis, and has the added advantage that interfacial kinetic effects can also

  11. An Automated Method to Identify Mesoscale Convective Complexes in the Regional Climate Model Evaluation System

    NASA Astrophysics Data System (ADS)

    Whitehall, K. D.; Jenkins, G. S.; Mattmann, C. A.; Waliser, D. E.; Kim, J.; Goodale, C. E.; Hart, A. F.; Ramirez, P.; Whittell, J.; Zimdars, P. A.

    2012-12-01

    Mesoscale convective complexes (MCCs) are large (2 - 3 x 105 km2) nocturnal convectively-driven weather systems that are generally associated with high precipitation events in short durations (less than 12hrs) in various locations through out the tropics and midlatitudes (Maddox 1980). These systems are particularly important for climate in the West Sahel region, where the precipitation associated with them is a principal component of the rainfall season (Laing and Fritsch 1993). These systems occur on weather timescales and are historically identified from weather data analysis via manual and more recently automated processes (Miller and Fritsch 1991, Nesbett 2006, Balmey and Reason 2012). The Regional Climate Model Evaluation System (RCMES) is an open source tool designed for easy evaluation of climate and Earth system data through access to standardized datasets, and intrinsic tools that perform common analysis and visualization tasks (Hart et al. 2011). The RCMES toolkit also provides the flexibility of user-defined subroutines for further metrics, visualization and even dataset manipulation. The purpose of this study is to present a methodology for identifying MCCs in observation datasets using the RCMES framework. TRMM 3 hourly datasets will be used to demonstrate the methodology for 2005 boreal summer. This method promotes the use of open source software for scientific data systems to address a concern to multiple stakeholders in the earth sciences. A historical MCC dataset provides a platform with regards to further studies of the variability of frequency on various timescales of MCCs that is important for many including climate scientists, meteorologists, water resource managers, and agriculturalists. The methodology of using RCMES for searching and clipping datasets will engender a new realm of studies as users of the system will no longer be restricted to solely using the datasets as they reside in their own local systems; instead will be afforded rapid, effective, and transparent access, processing and visualization of the wealth of remote sensing datasets and climate model outputs available.

  12. Simplifying the interaction between cognitive models and task environments with the JSON Network Interface.

    PubMed

    Hope, Ryan M; Schoelles, Michael J; Gray, Wayne D

    2014-12-01

    Process models of cognition, written in architectures such as ACT-R and EPIC, should be able to interact with the same software with which human subjects interact. By eliminating the need to simulate the experiment, this approach would simplify the modeler's effort, while ensuring that all steps required of the human are also required by the model. In practice, the difficulties of allowing one software system to interact with another present a significant barrier to any modeler who is not also skilled at this type of programming. The barrier increases if the programming language used by the modeling software differs from that used by the experimental software. The JSON Network Interface simplifies this problem for ACT-R modelers, and potentially, modelers using other systems. PMID:24338626

  13. Experiments and modeling of freshwater lenses in layered aquifers: Steady state interface geometry

    NASA Astrophysics Data System (ADS)

    Dose, Eduardo J.; Stoeckl, Leonard; Houben, Georg J.; Vacher, H. L.; Vassolo, Sara; Dietrich, Jörg; Himmelsbach, Thomas

    2014-02-01

    The interface geometry of freshwater lenses in layered aquifers was investigated by physical 2D laboratory experiments. The resulting steady-state geometries of the lenses were compared to existing analytical expressions from Dupuit-Ghyben-Herzberg (DGH) analysis of strip-island lenses for various cases of heterogeneity. Despite the vertical exaggeration of the physical models, which would seem to vitiate the assumption of vertical equipotentials, the fits with the DGH models were generally satisfactory. Observed deviations between the analytical and physical models can be attributed mainly to outflow zones along the shore line, which are not considered in the analytical models. As unconfined natural lenses have small outflow zones compared to their overall dimensions, and flow is mostly horizontal, the DGH analytical models should perform even better at full scale. Numerical models that do consider the outflow face generally gave a good fit to the physical models.

  14. A coupled cohesive zone model for transient analysis of thermoelastic interface debonding

    NASA Astrophysics Data System (ADS)

    Sapora, Alberto; Paggi, Marco

    2014-04-01

    A coupled cohesive zone model based on an analogy between fracture and contact mechanics is proposed to investigate debonding phenomena at imperfect interfaces due to thermomechanical loading and thermal fields in bodies with cohesive cracks. Traction-displacement and heat flux-temperature relations are theoretically derived and numerically implemented in the finite element method. In the proposed formulation, the interface conductivity is a function of the normal gap, generalizing the Kapitza constant resistance model to partial decohesion effects. The case of a centered interface in a bimaterial component subjected to thermal loads is used as a test problem. The analysis focuses on the time evolution of the displacement and temperature fields during the transient regime before debonding, an issue not yet investigated in the literature. The solution of the nonlinear numerical problem is gained via an implicit scheme both in space and in time. The proposed model is finally applied to a case study in photovoltaics where the evolution of the thermoelastic fields inside a defective solar cell is predicted.

  15. Reduction of nonlinear embedded boundary models for problems with evolving interfaces

    NASA Astrophysics Data System (ADS)

    Balajewicz, Maciej; Farhat, Charbel

    2014-10-01

    Embedded boundary methods alleviate many computational challenges, including those associated with meshing complex geometries and solving problems with evolving domains and interfaces. Developing model reduction methods for computational frameworks based on such methods seems however to be challenging. Indeed, most popular model reduction techniques are projection-based, and rely on basis functions obtained from the compression of simulation snapshots. In a traditional interface-fitted computational framework, the computation of such basis functions is straightforward, primarily because the computational domain does not contain in this case a fictitious region. This is not the case however for an embedded computational framework because the computational domain typically contains in this case both real and ghost regions whose definitions complicate the collection and compression of simulation snapshots. The problem is exacerbated when the interface separating both regions evolves in time. This paper addresses this issue by formulating the snapshot compression problem as a weighted low-rank approximation problem where the binary weighting identifies the evolving component of the individual simulation snapshots. The proposed approach is application independent and therefore comprehensive. It is successfully demonstrated for the model reduction of several two-dimensional, vortex-dominated, fluid-structure interaction problems.

  16. Automated extraction of digital terrain models, roads and buildings using airborne lidar data

    NASA Astrophysics Data System (ADS)

    Hu, Yong

    Airborne lidar has become a commercially viable remote sensing platform, and can provide accurate elevation data about both topographic surfaces and non-terrain objects. Its capability of mapping topography and 3-D models of civil objects is uncommon to other remote sensing technologies. This dissertation presents a collection of algorithms developed for automatically extracting useful information from lidar data exclusively. The algorithms focus on automated extraction of DTMs, 3-D roads and buildings utilizing single- or multi-return lidar range and intensity data. The hierarchical terrain recovery algorithm can intelligently discriminate between terrain and non-terrain lidar points by adaptive and robust filtering. It processes the range data bottom up and top down to estimate high quality DTMs using the hierarchical strategy. Road ribbons are detected by classifying lidar intensity and height data. The 3-D grid road networks are reconstructed using a sequential Hough transformation, and are verified using road ribbons and lidar-derived DTMs. The attributes of road segments including width, length and slope are computed. Building models are created with a high level of accuracy. The building boundaries are detected by segmenting lidar height data. A sequential linking technique is proposed to reconstruct building boundaries to regular polygons, which are then rectified to be of cartographical quality. Then prismatic models are created for flat roof buildings, and polyhedral models are created for non-flat roof buildings by the incremental selective refining and vertical wall rectification procedures. Many attributes of these building models are derived from the lidar data. These algorithms have been tested using many lidar datasets of varying terrain type, coverage type and point density. The results show that in most areas the lidar-derived DTMs retain most terrain details and remove non-terrain objects reliably; the road ribbons and grid road networks are sketched well in built-up areas; and the extracted building footprints have high positioning accuracy equivalent to ground-truth data surveyed in field. A toolkit, called Lidar Expert, has been developed to bundle these algorithms and to offer the capability of performing fast information extraction from lidar data.

  17. Automation for System Safety Analysis

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Fleming, Land; Throop, David; Thronesbery, Carroll; Flores, Joshua; Bennett, Ted; Wennberg, Paul

    2009-01-01

    This presentation describes work to integrate a set of tools to support early model-based analysis of failures and hazards due to system-software interactions. The tools perform and assist analysts in the following tasks: 1) extract model parts from text for architecture and safety/hazard models; 2) combine the parts with library information to develop the models for visualization and analysis; 3) perform graph analysis and simulation to identify and evaluate possible paths from hazard sources to vulnerable entities and functions, in nominal and anomalous system-software configurations and scenarios; and 4) identify resulting candidate scenarios for software integration testing. There has been significant technical progress in model extraction from Orion program text sources, architecture model derivation (components and connections) and documentation of extraction sources. Models have been derived from Internal Interface Requirements Documents (IIRDs) and FMEA documents. Linguistic text processing is used to extract model parts and relationships, and the Aerospace Ontology also aids automated model development from the extracted information. Visualizations of these models assist analysts in requirements overview and in checking consistency and completeness.

  18. Interface Generation and Compositional Verification in JavaPathfinder

    NASA Technical Reports Server (NTRS)

    Giannakopoulou, Dimitra; Pasareanu, Corina

    2009-01-01

    We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.

  19. An automated method to determine angular preferentiality using LFPs recorded from rat barrel cortex by brain-chip interface under mechanical whisker stimulation.

    PubMed

    Mahmud, Mufti; Girardi, Stefano; Maschietto, Marta; Pasqualotto, Elisabetta; Vassanelli, Stefano

    2011-01-01

    The sensory information processing in the rodents is mainly done by whisking, through which they explore the environment, perform object localization, texture and shape discrimination very precisely. During whisking, microcircuits in the corresponding barrel columns get activated to segregate and integrate the tactile information through the information processing pathway. To primarily understand the whisking mechanism angular preferentiality determination is very important. In this work we propose an automated method to determine different events present in the local field potentials (LFPs), calculate latencies and amplitudes related to those events and use them along with the stimulation angle information to determine the angular preferentiality. The method is extensively tested on LFPs recorded from S1 barrel cortex of anesthetized rats using EOSFET (Electrolyte-Oxide-Semiconductor Field Effect Transistor) based neuronal probes. PMID:22254802

  20. An improved sharp-interface model for assessing NAPL contamination and remediation of groundwater systems

    NASA Astrophysics Data System (ADS)

    Huyakorn, P. S.; Wu, Yu-Shu; Park, N. S.

    1994-08-01

    A numerical model is presented for areal analyses of the three-dimensional (3-D) flow behavior of non-aqueous-phase liquids (NAPL's) in groundwater systems. The model is designed for specific application to chemical or petroleum spills and leaks, and remedial design and evaluation of a NAPL-contaminated site. The mathematical formulation is based on vertical integration of the 3-D two-phase flow equations and incorporation of the modified concept of gravity-segregated vertical equilibrium (GSVE) which yields sharp interfaces separating the zones of mobile NAPL and groundwater. History-dependent pseudo constitutive relations are developed for LNAPL's and DNAPL's (light and dense NAPL's) scenarios taking into account the effects of residual saturations. Owing to the sharp-interface assumption, the soil capillary pressure and relative permeability curves are not needed in the evaluation of pseudo functions. Efficient and mass-conservative nonlinear numerical techniques are adopted for solving the governing equations and treating practical boundary conditions which include injection and recovery wells and trenches. Simulation and application examples are provided to demonstrate verification and utility of the model. Numerical results obtained using the sharp-interface modeling approach are compared with analytical solutions and rigorous multiphase numerical solutions that account for vertical flow components and capillary effects. The verification results show the validity of the GSVE modeling assumptions and accuracy of the proposed formulation and computational schemes in predicting the NAPL recovery. The numerical study also indicates that the present model is highly efficient and is thus suitable for preliminary analyses of site-specific problems with limited data and personal computer resources.

  1. Design of an automated cocktail mixing experience

    E-print Network

    Aguirre, Alejandro, S.B. Massachusetts Institute of Technology

    2013-01-01

    This thesis describes the design concept development of an automated cocktail mixing device and user interface that is capable of dispensing a variety of alcoholic and non-alcoholic ingredients to produce a myriad of drink ...

  2. Configuring a Graphical User Interface for Managing Local HYSPLIT Model Runs Through AWIPS

    NASA Technical Reports Server (NTRS)

    Wheeler, mark M.; Blottman, Peter F.; Sharp, David W.; Hoeth, Brian; VanSpeybroeck, Kurt M.

    2009-01-01

    Responding to incidents involving the release of harmful airborne pollutants is a continual challenge for Weather Forecast Offices in the National Weather Service. When such incidents occur, current protocol recommends forecaster-initiated requests of NOAA's Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model output through the National Centers of Environmental Prediction to obtain critical dispersion guidance. Individual requests are submitted manually through a secured web site, with desired multiple requests submitted in sequence, for the purpose of obtaining useful trajectory and concentration forecasts associated with the significant release of harmful chemical gases, radiation, wildfire smoke, etc., into local the atmosphere. To help manage the local HYSPLIT for both routine and emergency use, a graphical user interface was designed for operational efficiency. The interface allows forecasters to quickly determine the current HYSPLIT configuration for the list of predefined sites (e.g., fixed sites and floating sites), and to make any necessary adjustments to key parameters such as Input Model. Number of Forecast Hours, etc. When using the interface, forecasters will obtain desired output more confidently and without the danger of corrupting essential configuration files.

  3. Automated Detection and Predictive Modeling of Flux Transfer Events using CLUSTER Data

    NASA Astrophysics Data System (ADS)

    Sipes, T. B.; Karimabadi, H.; Driscoll, J.; Wang, Y.; Lavraud, B.; Slavin, J. A.

    2006-12-01

    Almost all statistical studies of flux ropes (FTEs) and traveling compression regions (TCRs) have been based on (i) visual inspection of data to compile a list of events and (ii) use of histograms and simple linear correlation analysis to study their properties and potential causes and dependencies. This approach has several major drawbacks including being highly subjective and inefficient. The traditional use of histograms and simple linear correlation analysis is also only useful for analysis of systems that show dominant dependencies on one or two variables at the most. However, if the system has complex dependencies, more sophisticated statistical techniques are required. For example, Wang et al. [2006] showed evidence that FTE occurrence rate are affected by IMF Bygsm, Bzgsm, and magnitude, and the IMF clock, tilt, spiral, and cone angles. If the initial findings were correct that FTEs occur only during periods of southward IMF, one could use the direction of IMF as a predictor of occurrence of FTEs. But in light of Wang et al. result, one cannot draw quantitative conclusions about conditions under which FTEs occur. It may be that a certain combination of these parameters is the true controlling parameter. To uncover this, one needs to deploy more sophisticated techniques. We have developed a new, sophisticated data mining tool called MineTool. MineTool is highly accurate, flexible and capable of handling difficult and even noisy datasets extremely well. It has the ability to outperform standard data mining tools such as artificial neural networks, decision/regression trees and support vector machines. Here we present preliminary results of the application of this tool to the CLUSTER data to perform two tasks: (i) automated detection of FTEs, and (ii) predictive modeling of occurrences of FTEs based on IMF and magnetospheric conditions.

  4. Automated identification of potential snow avalanche release areas based on digital elevation models

    NASA Astrophysics Data System (ADS)

    Bühler, Y.; Kumar, S.; Veitinger, J.; Christen, M.; Stoffel, A.; Snehmani

    2013-05-01

    The identification of snow avalanche release areas is a very difficult task. The release mechanism of snow avalanches depends on many different terrain, meteorological, snowpack and triggering parameters and their interactions, which are very difficult to assess. In many alpine regions such as the Indian Himalaya, nearly no information on avalanche release areas exists mainly due to the very rough and poorly accessible terrain, the vast size of the region and the lack of avalanche records. However avalanche release information is urgently required for numerical simulation of avalanche events to plan mitigation measures, for hazard mapping and to secure important roads. The Rohtang tunnel access road near Manali, Himachal Pradesh, India, is such an example. By far the most reliable way to identify avalanche release areas is using historic avalanche records and field investigations accomplished by avalanche experts in the formation zones. But both methods are not feasible for this area due to the rough terrain, its vast extent and lack of time. Therefore, we develop an operational, easy-to-use automated potential release area (PRA) detection tool in Python/ArcGIS which uses high spatial resolution digital elevation models (DEMs) and forest cover information derived from airborne remote sensing instruments as input. Such instruments can acquire spatially continuous data even over inaccessible terrain and cover large areas. We validate our tool using a database of historic avalanches acquired over 56 yr in the neighborhood of Davos, Switzerland, and apply this method for the avalanche tracks along the Rohtang tunnel access road. This tool, used by avalanche experts, delivers valuable input to identify focus areas for more-detailed investigations on avalanche release areas in remote regions such as the Indian Himalaya and is a precondition for large-scale avalanche hazard mapping.

  5. Temperature Control of Fimbriation Circuit Switch in Uropathogenic Escherichia coli: Quantitative Analysis via Automated Model Abstraction

    PubMed Central

    Kuwahara, Hiroyuki; Myers, Chris J.; Samoilov, Michael S.

    2010-01-01

    Uropathogenic Escherichia coli (UPEC) represent the predominant cause of urinary tract infections (UTIs). A key UPEC molecular virulence mechanism is type 1 fimbriae, whose expression is controlled by the orientation of an invertible chromosomal DNA element—the fim switch. Temperature has been shown to act as a major regulator of fim switching behavior and is overall an important indicator as well as functional feature of many urologic diseases, including UPEC host-pathogen interaction dynamics. Given this panoptic physiological role of temperature during UTI progression and notable empirical challenges to its direct in vivo studies, in silico modeling of corresponding biochemical and biophysical mechanisms essential to UPEC pathogenicity may significantly aid our understanding of the underlying disease processes. However, rigorous computational analysis of biological systems, such as fim switch temperature control circuit, has hereto presented a notoriously demanding problem due to both the substantial complexity of the gene regulatory networks involved as well as their often characteristically discrete and stochastic dynamics. To address these issues, we have developed an approach that enables automated multiscale abstraction of biological system descriptions based on reaction kinetics. Implemented as a computational tool, this method has allowed us to efficiently analyze the modular organization and behavior of the E. coli fimbriation switch circuit at different temperature settings, thus facilitating new insights into this mode of UPEC molecular virulence regulation. In particular, our results suggest that, with respect to its role in shutting down fimbriae expression, the primary function of FimB recombinase may be to effect a controlled down-regulation (rather than increase) of the ON-to-OFF fim switching rate via temperature-dependent suppression of competing dynamics mediated by recombinase FimE. Our computational analysis further implies that this down-regulation mechanism could be particularly significant inside the host environment, thus potentially contributing further understanding toward the development of novel therapeutic approaches to UPEC-caused UTIs. PMID:20361050

  6. Using the ARTMO toolbox for automated retrieval of biophysical parameters through radiative transfer model inversion: Optimizing LUT-based inversion

    NASA Astrophysics Data System (ADS)

    Verrelst, J.; Rivera, J. P.; Leonenko, G.; Alonso, L.; Moreno, J.

    2012-04-01

    Radiative transfer (RT) modeling plays a key role for earth observation (EO) because it is needed to design EO instruments and to develop and test inversion algorithms. The inversion of a RT model is considered as a successful approach for the retrieval of biophysical parameters because of being physically-based and generally applicable. However, to the broader community this approach is considered as laborious because of its many processing steps and expert knowledge is required to realize precise model parameterization. We have recently developed a radiative transfer toolbox ARTMO (Automated Radiative Transfer Models Operator) with the purpose of providing in a graphical user interface (GUI) essential models and tools required for terrestrial EO applications such as model inversion. In short, the toolbox allows the user: i) to choose between various plant leaf and canopy RT models (e.g. models from the PROSPECT and SAIL family, FLIGHT), ii) to choose between spectral band settings of various air- and space-borne sensors or defining own sensor settings, iii) to simulate a massive amount of spectra based on a look up table (LUT) approach and storing it in a relational database, iv) to plot spectra of multiple models and compare them with measured spectra, and finally, v) to run model inversion against optical imagery given several cost options and accuracy estimates. In this work ARTMO was used to tackle some well-known problems related to model inversion. According to Hadamard conditions, mathematical models of physical phenomena are mathematically invertible if the solution of the inverse problem to be solved exists, is unique and depends continuously on data. This assumption is not always met because of the large number of unknowns and different strategies have been proposed to overcome this problem. Several of these strategies have been implemented in ARTMO and were here analyzed to optimize the inversion performance. Data came from the SPARC-2003 dataset, which was acquired on the agricultural test site Barrax, Spain. LUTs were created using the 4SAIL and FLIGHT models and were inverted against CHRIS data in order to retrieve maps of chlorophyll content (chl) and leaf area index (LAI). The following inversion steps have been optimized: 1. Cost function. The performances of about 50 different cost functions (i.e. minimum distance functions) were compared. Remarkably, in none of the studied cases the widely used root mean square error (RMSE) led to most accurate results. Depending on the retrieved parameter, more successful functions were: 'Sharma and Mittal', 'Shanno?s entropy', 'Hellinger distance', 'Pearso?s chi-square'. 2. Gaussian noise. Earth observation data typically encompass a certain degree of noise due to errors related to radiometric and geometric processing. In all cases, adding 5% Gaussian noise to the simulated spectra led to more accurate retrievals as compared to without noise. 3. Average of multiple best solutions. Because multiple parameter combinations may lead to the same spectra, a way to overcome this problem is not searching for the top best match but for a percentage of best matches. Optimized retrievals were encountered when including an average of 7% (Chl) to 10% (LAI) top best matches. 4. Integration of estimates. The option is provided to integrate estimates of biochemical contents at the canopy level (e.g., total chlorophyll: Chl × LAI, or water: Cw × LAI), which can lead to increased robustness and accuracy. 5. Class-based inversion. This option is probably ARTMÓs most powerful feature as it allows model parameterization depending on the imagés land cover classes (e.g. different soil or vegetation types). Class-based inversion can lead to considerably improved accuracies compared to one generic class. Results suggest that 4SAIL and FLIGHT performed alike for Chl but not for LAI. While both models rely on the leaf model PROSPECT for Chl retrieval, their different nature (e.g. numerical vs. ray tracing) may cause that retrieval of structural parameters such as LAI differ. Finally, i

  7. Definition of common support equipment and space station interface requirements for IOC model technology experiments

    NASA Technical Reports Server (NTRS)

    Russell, Richard A.; Waiss, Richard D.

    1988-01-01

    A study was conducted to identify the common support equipment and Space Station interface requirements for the IOC (initial operating capabilities) model technology experiments. In particular, each principal investigator for the proposed model technology experiment was contacted and visited for technical understanding and support for the generation of the detailed technical backup data required for completion of this study. Based on the data generated, a strong case can be made for a dedicated technology experiment command and control work station consisting of a command keyboard, cathode ray tube, data processing and storage, and an alert/annunciator panel located in the pressurized laboratory.

  8. A multiphase electrokinetic flow model for electrolytes with liquid/liquid interfaces

    SciTech Connect

    Berry, J.D., E-mail: joe.d.berry@gmail.com; Davidson, M.R., E-mail: m.davidson@unimelb.edu.au; Harvie, D.J.E., E-mail: daltonh@unimelb.edu.au

    2013-10-15

    A numerical model for electrokinetic flow of multiphase systems with deformable interfaces is presented, based on a combined level set-volume of fluid technique. A new feature is a multiphase formulation of the Nernst–Planck transport equation for advection, diffusion and conduction of individual charge carrier species that ensures their conservation in each fluid phase. The numerical model is validated against the analytical results of Zholkovskij et al. (2002) [1], and results for the problem of two drops coalescing in the presence of mobile charge carriers are presented. The time taken for two drops containing ions to coalesce decreases with increasing ion concentration.

  9. Multiclass Diffuse Interface Models for Semi-Supervised Learning on Graphs

    E-print Network

    Garcia-Cardona, Cristina; Percus, Allon G

    2012-01-01

    We present a graph-based variational algorithm for multiclass classification of high-dimensional data, motivated by total variation techniques. The energy functional is based on a diffuse interface model with a periodic potential. We augment the model by introducing an alternative measure of smoothness that preserves symmetry among the class labels. Through this modification of the standard Laplacian, we construct an efficient multiclass method that allows for sharp transitions between classes. The experimental results demonstrate that our approach is competitive with the state of the art among other graph-based algorithms.

  10. Testing of Environmental Satellite Bus-Instrument Interfaces Using Engineering Models

    NASA Technical Reports Server (NTRS)

    Gagnier, Donald; Hayner, Rick; Nosek, Thomas; Roza, Michael; Hendershot, James E.; Razzaghi, Andrea I.

    2004-01-01

    This paper discusses the formulation and execution of a laboratory test of the electrical interfaces between multiple atmospheric scientific instruments and the spacecraft bus that carries them. The testing, performed in 2002, used engineering models of the instruments and the Aura spacecraft bus electronics. Aura is one of NASA s Earth Observatory System missions. The test was designed to evaluate the complex interfaces in the command and data handling subsystems prior to integration of the complete flight instruments on the spacecraft. A problem discovered during the flight integration phase of the observatory can cause significant cost and schedule impacts. The tests successfully revealed problems and led to their resolution before the full-up integration phase, saving significant cost and schedule. This approach could be beneficial for future environmental satellite programs involving the integration of multiple, complex scientific instruments onto a spacecraft bus.

  11. Achieving realistic interface kinetics in phase-field models with a diffusional contrast.

    PubMed

    Boussinot, G; Brener, Efim A

    2014-06-01

    Phase-field models are powerful tools to tackle free-boundary problems. For phase transformations involving diffusion, the evolution of the nonconserved phase field is coupled to the evolution of the conserved diffusion field. Introducing the kinetic cross coupling between these two fields [E. A. Brener and G. Boussinot, Phys. Rev. E 86, 060601(R) (2012)], we solve the long-standing problem of a realistic description of interface kinetics when a diffusional contrast between the phases is taken into account. Using the case of the solidification of a pure substance, we show how to eliminate the temperature jump at the interface and to recover full equilibrium boundary conditions. We confirm our results by numerical simulations. PMID:25019706

  12. Automating ground-fixed target modeling with the smart target model generator

    NASA Astrophysics Data System (ADS)

    Verner, D.; Dukes, R.

    2007-04-01

    The Smart Target Model Generator (STMG) is an AFRL/MNAL sponsored tool for generating 3D building models for use in various weapon effectiveness tools. These tools include tri-service approved tools such as Modular Effectiveness/Vulnerability Assessment (MEVA), Building Analysis Module in Joint Weaponeering System (JWS), PENCRV3D, and WinBlast. It also supports internal dispersion modeling of chemical contaminants. STMG also has capabilities to generate infrared or other sensor images. Unlike most CAD-models, STMG provides physics-based component properties such as strength, density, reinforcement, and material type. Interior components such as electrical and mechanical equipment, rooms, and ducts are also modeled. Buildings can be manually created with a graphical editor or automatically generated using rule-bases which size and place the structural components using rules based on structural engineering principles. In addition to its primary purposes of supporting conventional kinetic munitions, it can also be used to support sensor modeling and automatic target recognition.

  13. Prediction of hot spots in protein interfaces using a random forest model with hybrid features.

    PubMed

    Wang, Lin; Liu, Zhi-Ping; Zhang, Xiang-Sun; Chen, Luonan

    2012-03-01

    Prediction of hot spots in protein interfaces provides crucial information for the research on protein-protein interaction and drug design. Existing machine learning methods generally judge whether a given residue is likely to be a hot spot by extracting features only from the target residue. However, hot spots usually form a small cluster of residues which are tightly packed together at the center of protein interface. With this in mind, we present a novel method to extract hybrid features which incorporate a wide range of information of the target residue and its spatially neighboring residues, i.e. the nearest contact residue in the other face (mirror-contact residue) and the nearest contact residue in the same face (intra-contact residue). We provide a novel random forest (RF) model to effectively integrate these hybrid features for predicting hot spots in protein interfaces. Our method can achieve accuracy (ACC) of 82.4% and Matthew's correlation coefficient (MCC) of 0.482 in Alanine Scanning Energetics Database, and ACC of 77.6% and MCC of 0.429 in Binding Interface Database. In a comparison study, performance of our RF model exceeds other existing methods, such as Robetta, FOLDEF, KFC, KFC2, MINERVA and HotPoint. Of our hybrid features, three physicochemical features of target residues (mass, polarizability and isoelectric point), the relative side-chain accessible surface area and the average depth index of mirror-contact residues are found to be the main discriminative features in hot spots prediction. We also confirm that hot spots tend to form large contact surface areas between two interacting proteins. Source data and code are available at: http://www.aporc.org/doc/wiki/HotSpot. PMID:22258275

  14. Deconstructing Classical Water Models at Interfaces and in Bulk: Hydrophobic Interactions and Hydrogen Bonding

    NASA Astrophysics Data System (ADS)

    Weeks, John D.

    2012-02-01

    Using concepts from perturbation and local molecular field theories of liquids we divide the potential of the SPC/E water model into short and long ranged parts. The short ranged parts define a minimal reference network model that captures very well the structure of the local hydrogen bond network in bulk water while ignoring effects of the remaining long ranged interactions. This deconstruction can provide insight into the different roles that the local hydrogen bond network, dispersion forces, and long ranged dipolar interactions play in determining a variety of solvation and other properties of SPC/E and related classical models of water. We use these short ranged models along with local molecular field theory to quantify the influence of these interactions on the structure of hydrophobic interfaces and the crossover from small to large scale hydration behavior. The implications of our findings for theories of hydrophobicity and possible refinements of classical water models will also be discussed.

  15. Fracture permeability and seismic wave scattering--Poroelastic linear-slip interface model for heterogeneous fractures

    SciTech Connect

    Nakagawa, S.; Myer, L.R.

    2009-06-15

    Schoenberg's Linear-slip Interface (LSI) model for single, compliant, viscoelastic fractures has been extended to poroelastic fractures for predicting seismic wave scattering. However, this extended model results in no impact of the in-plane fracture permeability on the scattering. Recently, we proposed a variant of the LSI model considering the heterogeneity in the in-plane fracture properties. This modified model considers wave-induced, fracture-parallel fluid flow induced by passing seismic waves. The research discussed in this paper applies this new LSI model to heterogeneous fractures to examine when and how the permeability of a fracture is reflected in the scattering of seismic waves. From numerical simulations, we conclude that the heterogeneity in the fracture properties is essential for the scattering of seismic waves to be sensitive to the permeability of a fracture.

  16. Work Practice Simulation of Complex Human-Automation Systems in Safety Critical Situations: The Brahms Generalized berlingen Model

    NASA Technical Reports Server (NTRS)

    Clancey, William J.; Linde, Charlotte; Seah, Chin; Shafto, Michael

    2013-01-01

    The transition from the current air traffic system to the next generation air traffic system will require the introduction of new automated systems, including transferring some functions from air traffic controllers to on­-board automation. This report describes a new design verification and validation (V&V) methodology for assessing aviation safety. The approach involves a detailed computer simulation of work practices that includes people interacting with flight-critical systems. The research is part of an effort to develop new modeling and verification methodologies that can assess the safety of flight-critical systems, system configurations, and operational concepts. The 2002 Ueberlingen mid-air collision was chosen for analysis and modeling because one of the main causes of the accident was one crew's response to a conflict between the instructions of the air traffic controller and the instructions of TCAS, an automated Traffic Alert and Collision Avoidance System on-board warning system. It thus furnishes an example of the problem of authority versus autonomy. It provides a starting point for exploring authority/autonomy conflict in the larger system of organization, tools, and practices in which the participants' moment-by-moment actions take place. We have developed a general air traffic system model (not a specific simulation of Überlingen events), called the Brahms Generalized Ueberlingen Model (Brahms-GUeM). Brahms is a multi-agent simulation system that models people, tools, facilities/vehicles, and geography to simulate the current air transportation system as a collection of distributed, interactive subsystems (e.g., airports, air-traffic control towers and personnel, aircraft, automated flight systems and air-traffic tools, instruments, crew). Brahms-GUeM can be configured in different ways, called scenarios, such that anomalous events that contributed to the Überlingen accident can be modeled as functioning according to requirements or in an anomalous condition, as occurred during the accident. Brahms-GUeM thus implicitly defines a class of scenarios, which include as an instance what occurred at Überlingen. Brahms-GUeM is a modeling framework enabling "what if" analysis of alternative work system configurations and thus facilitating design of alternative operations concepts. It enables subsequent adaption (reusing simulation components) for modeling and simulating NextGen scenarios. This project demonstrates that BRAHMS provides the capacity to model the complexity of air transportation systems, going beyond idealized and simple flights to include for example the interaction of pilots and ATCOs. The research shows clearly that verification and validation must include the entire work system, on the one hand to check that mechanisms exist to handle failures of communication and alerting subsystems and/or failures of people to notice, comprehend, or communicate problematic (unsafe) situations; but also to understand how people must use their own judgment in relating fallible systems like TCAS to other sources of information and thus to evaluate how the unreliability of automation affects system safety. The simulation shows in particular that distributed agents (people and automated systems) acting without knowledge of each others' actions can create a complex, dynamic system whose interactive behavior is unexpected and is changing too quickly to comprehend and control.

  17. A model of blind zone for in situ monitoring the solid/liquid interface using ultrasonic wave.

    PubMed

    Peng, Song; Ouyang, Qi; Zhu, Z Z; Zhang, X L

    2015-07-01

    To in situ monitor a solid/liquid interface to control metal qualities, the paper analysis blind models of the ultrasonic propagation in the solidifying molten metal with a solid/liquid interface in the Bridgman type furnace, and a mathematical calculation model of blind zone with different source locations and surface concavities is built. The study points out that the blind zone I is caused by ray bending in the interface edge, and the blind zone II is caused by totally reflection which is related with initial ray angle, critical refraction angle of solid/liquid media. A serial of simulation experiments are operated on the base of the model, and numerical computation results coincide with model calculated results very well. Therefore, receiver should locate beyond these blind zones in the right boundary to obtain time of flight data which is used to reconstruct the solid/liquid interface. PMID:25783779

  18. Strain of bone-implant interface and insertion torque regarding different miniscrew thread designs using an artificial bone model.

    PubMed

    Cha, Jung-Yul; Hwang, Chung-Ju; Kwon, Sung Hwang; Jung, Han-Sung; Kim, Kwang-Mahn; Yu, Hyung Seog

    2014-10-01

    Summary OBJECTIVES: To evaluate the initial stability of dual-thread miniscrews by analyzing the strain at the bone-implant interface and insertion torque during implantation in artificial bone models with different cortical bone thicknesses. PMID:25296728

  19. Particles at fluid-fluid interfaces: A new Navier-Stokes-Cahn-Hilliard surface-phase-field-crystal model

    PubMed Central

    Aland, Sebastian; Lowengrub, John; Voigt, Axel

    2013-01-01

    Colloid particles that are partially wetted by two immiscible fluids can become confined to fluid-fluid interfaces. At sufficiently high volume fractions, the colloids may jam and the interface may crystallize. The fluids together with the interfacial colloids form an emulsion with interesting material properties and offer an important route to new soft materials. A promising approach to simulate these emulsions was presented in Aland et al. [Phys. Fluids 23, 062103 (2011)], where a Navier-Stokes-Cahn-Hilliard model for the macroscopic two-phase fluid system was combined with a surface phase-field-crystal model for the microscopic colloidal particles along the interface. Unfortunately this model leads to spurious velocities which require very fine spatial and temporal resolutions to accurately and stably simulate. In this paper we develop an improved Navier-Stokes-Cahn-Hilliard-surface phase-field-crystal model based on the principles of mass conservation and thermodynamic consistency. To validate our approach, we derive a sharp interface model and show agreement with the improved diffuse interface model. Using simple flow configurations, we show that the new model has much better properties and does not lead to spurious velocities. Finally, we demonstrate the solid-like behavior of the crystallized interface by simulating the fall of a solid ball through a colloid-laden multiphase fluid. PMID:23214691

  20. BOADICEA breast cancer risk prediction model: updates to cancer incidences, tumour pathology and web interface

    PubMed Central

    Lee, A J; Cunningham, A P; Kuchenbaecker, K B; Mavaddat, N; Easton, D F; Antoniou, A C

    2014-01-01

    Background: The Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) is a risk prediction model that is used to compute probabilities of carrying mutations in the high-risk breast and ovarian cancer susceptibility genes BRCA1 and BRCA2, and to estimate the future risks of developing breast or ovarian cancer. In this paper, we describe updates to the BOADICEA model that extend its capabilities, make it easier to use in a clinical setting and yield more accurate predictions. Methods: We describe: (1) updates to the statistical model to include cancer incidences from multiple populations; (2) updates to the distributions of tumour pathology characteristics using new data on BRCA1 and BRCA2 mutation carriers and women with breast cancer from the general population; (3) improvements to the computational efficiency of the algorithm so that risk calculations now run substantially faster; and (4) updates to the model's web interface to accommodate these new features and to make it easier to use in a clinical setting. Results: We present results derived using the updated model, and demonstrate that the changes have a significant impact on risk predictions. Conclusion: All updates have been implemented in a new version of the BOADICEA web interface that is now available for general use: http://ccge.medschl.cam.ac.uk/boadicea/. PMID:24346285