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1

Spud 1.0: generalising and automating the user interfaces of scientific computer models  

NASA Astrophysics Data System (ADS)

The interfaces by which users specify the scenarios to be simulated by scientific computer models are frequently primitive, under-documented and ad-hoc text files which make using the model in question difficult and error-prone and significantly increase the development cost of the model. In this paper, we present a model-independent system, Spud, which formalises the specification of model input formats in terms of formal grammars. This is combined with an automated graphical user interface which guides users to create valid model inputs based on the grammar provided, and a generic options reading module, libspud, which minimises the development cost of adding model options. Together, this provides a user friendly, well documented, self validating user interface which is applicable to a wide range of scientific models and which minimises the developer input required to maintain and extend the model interface.

Ham, D. A.; Farrell, P. E.; Gorman, G. J.; Maddison, J. R.; Wilson, C. R.; Kramer, S. C.; Shipton, J.; Collins, G. S.; Cotter, C. J.; Piggott, M. D.

2009-03-01

2

Spud 1.0: generalising and automating the user interfaces of scientific computer models  

NASA Astrophysics Data System (ADS)

The interfaces by which users specify the scenarios to be simulated by scientific computer models are frequently primitive, under-documented and ad-hoc text files which make using the model in question difficult and error-prone and significantly increase the development cost of the model. In this paper, we present a model-independent system, Spud, which formalises the specification of model input formats in terms of formal grammars. This is combined with an automated graphical user interface which guides users to create valid model inputs based on the grammar provided, and a generic options reading module which minimises the development cost of adding model options. Together, this provides a user friendly, well documented, self validating user interface which is applicable to a wide range of scientific models and which minimises the developer input required to maintain and extend the model interface.

Ham, D. A.; Farrell, P. E.; Gorman, G. J.; Maddison, J. R.; Wilson, C. R.; Kramer, S. C.; Shipton, J.; Collins, G. S.; Cotter, C. J.; Piggott, M. D.

2008-07-01

3

Spud and FLML: generalising and automating the user interfaces of scientific computer models  

NASA Astrophysics Data System (ADS)

The interfaces by which users specify the scenarios to be simulated by scientific computer models are frequently primitive, under-documented and ad-hoc text files which make using the model in question difficult and error-prone and significantly increase the development cost of the model. We present a model-independent system, Spud[1], which formalises the specification of model input formats in terms of formal grammars. This is combined with an automatically generated graphical user interface which guides users to create valid model inputs based on the grammar provided, and a generic options reading module which minimises the development cost of adding model options. We further present FLML, the Fluidity Markup Language. FLML applies Spud to the Imperial College Ocean Model (ICOM) resulting in a graphically driven system which radically improves the usability of ICOM. As well as a step forward for ICOM, FLML illustrates how the Spud system can be applied to an existing complex ocean model highlighting the potential of Spud as a user interface for other codes in the ocean modelling community. [1] Ham, D. A. et.al, Spud 1.0: generalising and automating the user interfaces of scientific computer models, Geosci. Model Dev. Discuss., 1, 125-146, 2008.

Ham, D. A.; Farrell, P. E.; Maddison, J. R.; Gorman, G. J.; Wilson, C. R.; Kramer, S. C.; Shipton, J.; Collins, G. S.; Cotter, C. J.; Piggott, M. D.

2009-04-01

4

Automated Fluid Interface System (AFIS).  

National Technical Information Service (NTIS)

Automated remote fluid servicing will be necessary for future space missions, as future satellites will be designed for on-orbit consumable replenishment. In order to develop an on-orbit remote servicing capability, a standard interface between a tanker a...

1990-01-01

5

Assessing Usability of Human-Machine Interfaces for Life Science Automation Using Computational Cognitive Models  

Microsoft Academic Search

The objective of this study was to assess the plausibility of using computational cognitive models for evaluating the usability of human–machine interfaces in supervisory control of high-throughput (biological) screening (HTS) operations. Usability evaluations of new interface prototypes were conducted by comparisons with existing technologies. Model assessment occurred through comparison with human test results. Task completion times and the number of

David B. Kaber; Rebecca S. Green; Sang-Hwan Kim; Noa Segall

2011-01-01

6

Testing of the Automated Fluid Interface System  

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

7

Bridge Over Troubled Wrappers: Automated Interface Synthesis  

Microsoft Academic Search

System-on-Chip (SoC) design methodologies rely heav- ily on reuse of intellectual property (IP) blocks. IP reuse is a labour intensive and time consuming process as IP blocks often have different communication interfaces. We present an algorithm which automates the generation of provably correct HDL descriptions of interfaces between mismatched IP communication protocols. We significantly improve and extend existing work by

Vijay D'silva; S. Ramesh; Arcot Sowmya

2004-01-01

8

Development and testing of the Automated Fluid Interface System  

NASA Technical Reports Server (NTRS)

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.

Milton, Martha E.; Tyler, Tony R.

1993-01-01

9

Development and testing of the Automated Fluid Interface System  

NASA Astrophysics Data System (ADS)

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.

Milton, Martha E.; Tyler, Tony R.

1993-05-01

10

Browser-style interfaces to a home automation network  

Microsoft Academic Search

The design and implementation of a browser-style interface to a home automation network is described. The interface supports browsing and navigation of network devices and context structures and the user can interact with individual devices on the network and access and control content and object structures within these devices. The interface can be used to access a local home automation

Peter M. Corcoran; Joe Desbonnet

1997-01-01

11

Development and Testing of the Automated Fluid Interface System.  

National Technical Information Service (NTIS)

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 fr...

M. E. Milton T. R. Tyler

1993-01-01

12

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

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

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

2012-09-12

13

A multi-interface gateway architecture for home automation networks  

Microsoft Academic Search

This paper presents a multi-interface sensor network gateway architecture for home automation and other distributed monitoring applications. The gateway architecture provides multiple interfaces for supporting various application scenarios in home environments, ranging from on-site configuration to mobile access. A gateway prototype following the proposed architecture has been implemented. A testbed of a simple home automation network which includes the gateway

Guangming Song; Yaoxin Zhou; Weijuan Zhang; Aiguo Song

2008-01-01

14

Automated Student Model Improvement  

ERIC Educational Resources Information Center

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…

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

2012-01-01

15

Towards automation of user interface design  

NASA Technical Reports Server (NTRS)

This paper suggests an approach to automatic software design in the domain of graphical user interfaces. There are still some drawbacks in existing user interface management systems (UIMS's) which basically offer only quantitative layout specifications via direct manipulation. Our approach suggests a convenient way to get a default graphical user interface which may be customized and redesigned easily in further prototyping cycles.

Gastner, Rainer; Kraetzschmar, Gerhard K.; Lutz, Ernst

1992-01-01

16

Automated testing of virtual reality application interfaces  

Microsoft Academic Search

We describe a technique for supporting testing of the interaction aspect of virtual reality (VR) applications. Testing is a fundamental development practice that forms the basis of many software engineering methodologies. It is used to ensure the correct behavior of applications. Currently, there is no common pattern for automated testing of VR application interaction. We review current software engineering practices

Allen Bierbaum; Patrick Hartling; Carolina Cruz-Neira

2003-01-01

17

Visual automated macromolecular model building  

PubMed Central

Automated model-building software aims at the objective interpretation of crystallographic diffraction data by means of the construction or completion of macromolecular models. Automated methods have rapidly gained in popularity as they are easy to use and generate reproducible and consistent results. However, the process of model building has become increasingly hidden and the user is often left to decide on how to proceed further with little feedback on what has preceded the output of the built model. Here, ArpNavigator, a molecular viewer tightly integrated into the ARP/wARP automated model-building package, is presented that directly controls model building and displays the evolving output in real time in order to make the procedure transparent to the user.

Langer, Gerrit G.; Hazledine, Saul; Wiegels, Tim; Carolan, Ciaran; Lamzin, Victor S.

2013-01-01

18

Data-model-driven Software Automation Test Framework  

Microsoft Academic Search

(Abstract)Aiming at the problems in Graphical User Interface(GUI) program automation test, this paper designs and implements a reusable data- model-driven software automation test framework which is based on RFT tool and supports distributed multi-platform network environment. The framework separates test object, test case data, test case logic and execution control reasonably. The implementation of the framework can enhance the reusability,

MO Xi; ZHAO Fang

19

Aircraft automation - The problem of the pilot interface  

NASA Technical Reports Server (NTRS)

In recent years, aviation has been experiencing a rapid growth. This growth is expected to continue, and aircraft operations in the IFR (instrument flight rules) environment, for example, are predicted to increase dramatically in the next 10 to 12 years. However, it has been found the IFR accidents are increasing at about the same rate as IFR operations, because an associated high workload can lead to human error. For this reason, NASA and others are exploring the use of aircraft systems technology as a means for reducing the pilot workload and enhancing the safety and utility of the aircraft operations. However, recent research has shown that automation, implemented with insufficient consideration to the human factors interface, can frequently create more problems than it solves. Some of this research is discussed, examples of the encountered problems are shown, and solutions regarding the arising problems are suggested.

Bergeron, H. P.; Hinton, D. A.

1984-01-01

20

Geographic information system/watershed model interface  

USGS Publications Warehouse

Geographic information systems allow for the interactive analysis of spatial data related to water-resources investigations. A conceptual design for an interface between a geographic information system and a watershed model includes functions for the estimation of model parameter values. Design criteria include ease of use, minimal equipment requirements, a generic data-base management system, and use of a macro language. An application is demonstrated for a 90.1-square-kilometer subbasin of the Patuxent River near Unity, Maryland, that performs automated derivation of watershed parameters for hydrologic modeling.

Fisher, Gary, T.

1989-01-01

21

Building up object-oriented industrial automation systems: experiences interfacing active objects with technical plants  

Microsoft Academic Search

This paper presents an object-oriented approach for interfacing industrial automation software with technical plants. The paper focuses on strategies for structuring the software in objects in such a way that the structure may be applied even when using different communication systems. A case study, the automation of a modular production system based on an industrial fieldbus is presented

Pablo Darscht; Alceu Heinke Frigeri; Carlos Eduardo Pereira

1995-01-01

22

EasyModeller: A graphical interface to MODELLER  

PubMed Central

Background MODELLER is a program for automated protein Homology Modeling. It is one of the most widely used tool for homology or comparative modeling of protein three-dimensional structures, but most users find it a bit difficult to start with MODELLER as it is command line based and requires knowledge of basic Python scripting to use it efficiently. Findings The study was designed with an aim to develop of "EasyModeller" tool as a frontend graphical interface to MODELLER using Perl/Tk, which can be used as a standalone tool in windows platform with MODELLER and Python preinstalled. It helps inexperienced users to perform modeling, assessment, visualization, and optimization of protein models in a simple and straightforward way. Conclusion EasyModeller provides a graphical straight forward interface and functions as a stand-alone tool which can be used in a standard personal computer with Microsoft Windows as the operating system.

2010-01-01

23

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

NASA Technical Reports Server (NTRS)

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.

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

2001-01-01

24

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

25

AN OBJECT ORIENTED FRAMEWORK FOR USER INTERFACE TEST AUTOMATION  

Microsoft Academic Search

Software testing is an important stage in the software projects lifecycles. It is one of the most expensive stages. Effective testing automation is expected to reduce the cost of testing. GUI is increasingly taking a larger portion of the overall program's size and its testing is taking a major rule in the whole project's validation. GUI test automation is a

Izzat Alsmadi; Kenneth Magel

2007-01-01

26

A Classification Model for Automating Compliance  

Microsoft Academic Search

Various approaches to automate the observance of compliance requirements have recently been proposed. Since there is no all-round solution available within the foreseeable future, we propose a classification scheme for existing approaches that address different aspects of automating compliance. A layer model is used for linking laws and regulations with a company's IT system. The \\

Stefan Sackmann; Martin Kähmer; Maike Gilliot; Lutz Lowis

2008-01-01

27

Modelling of an automated manual transmission system  

Microsoft Academic Search

Vehicles with automated manual transmissions (AMT) for gear shift control offer many advantages in terms of reduction of fuel consumption and improvement of driving comfort and shifting quality. Complexity, nonlinearity and high-order dynamics of the automated driveline, combined with strict requirements for high performance gear shifts, demand the development of driveline models, which include a detailed description of the actuators.

Gianluca Lucente; Marcello Montanari; Carlo Rossi

2007-01-01

28

Automated Prototyping of User Interfaces Based on UML Scenarios  

Microsoft Academic Search

User interface (UI) prototyping and scenario engineering have become popular techniques. Yet, the transition from scenario to formal specifications and the generation of UI code is still ill-defined and essentially a manual task, and the two techniques lack integration in the overall requirements engineering process. In this paper, we suggest an approach for requirements engineering that generates a user interface

Mohammed Elkoutbi; Ismaïl Khriss; Rudolf K. Keller

2006-01-01

29

Cooperative control - The interface challenge for men and automated machines  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

30

Model-Based Design of Air Traffic Controller-Automation Interaction  

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

31

Automated, Parametric Geometry Modeling and Grid Generation for Turbomachinery Applications  

NASA Technical Reports Server (NTRS)

The objective of this Phase I project is to develop a highly automated software system for rapid geometry modeling and grid generation for turbomachinery applications. The proposed system features a graphical user interface for interactive control, a direct interface to commercial CAD/PDM systems, support for IGES geometry output, and a scripting capability for obtaining a high level of automation and end-user customization of the tool. The developed system is fully parametric and highly automated, and, therefore, significantly reduces the turnaround time for 3D geometry modeling, grid generation and model setup. This facilitates design environments in which a large number of cases need to be generated, such as for parametric analysis and design optimization of turbomachinery equipment. In Phase I we have successfully demonstrated the feasibility of the approach. The system has been tested on a wide variety of turbomachinery geometries, including several impellers and a multi stage rotor-stator combination. In Phase II, we plan to integrate the developed system with turbomachinery design software and with commercial CAD/PDM software.

Harrand, Vincent J.; Uchitel, Vadim G.; Whitmire, John B.

2000-01-01

32

Tabular Interface for Automated Verification of Event-Based Dialogs.  

National Technical Information Service (NTIS)

In this report, we investigate the feasibility of a tabular interface for the specification and analysis of event-based dialogues. These dialogues are used to define high-level descriptions of interactive systems, and they are based on Olsen's Proposition...

H. M. Wang G. Abowd

1994-01-01

33

Automated EEG feature selection for brain computer interfaces  

Microsoft Academic Search

A brain computer interface (BCI) utilizes signals derived from electroencephalography (EEG) to establish a connection between a person's state of mind and a computer based signal processing system that interprets the EEG signals. The choice of suitable features of the available EEG signals is crucial for good BCI communication. The optimal set of features is strongly dependent on the subjects

Michael Schroder; Martin Bogdan; T. Hinterberger; N. Birbaumer

2003-01-01

34

Automated Covariate Model Building Within NONMEM  

Microsoft Academic Search

Purpose. One important task in population pharmacokinetic\\/pharmacodynamic model building is to identify the relationships between the parameters and demographic factors (covariates). The purpose of this study is to present an automated procedure that accomplishes this. The benefits of the proposed procedure over other commonly used methods are (i) the covariate model is built for all parameters simultaneously, (ii) the covariate

E. Niclas Jonsson; Mats O. Karlsson

1998-01-01

35

Automation of Cyber Penetration Testing Using the Detect, Identify, Predict, React Intelligence Automation Model.  

National Technical Information Service (NTIS)

The design and implementation of a systems approach to a scalable, standardized automated cyber penetration testing system using the Detect, Identify, Predict, React (DIPR) intelligence automation model and data interoperability standards is the focus of ...

K. Deptula

2013-01-01

36

Automated operations planning: Modeling MLRS operations  

SciTech Connect

The multiples launch rocket system (MLRS) is a highly survivable and automated complement to conventional cannon artillery. For best survivability against counter-battery fire, MLRS operations rely on rapid shoot-and-scoot'' tactics by widely dispersed launchers. Such tactics may be difficult to include in a battlefield simulation without requiring players for the individual MLRS items: launchers and resupply vehicles. To reduce this demand on player resources, a computer model has been developed to automate the behavior of the items, consistent with the published operations doctrine. A player is required to determine the area of operation and certain key locations for an MLRS firing platoon. Analysis of trafficability in the operations area and direction the movement of the items, as the perform fire missions, resupply, and replenishment of platoon stocks, is completely automated. A finite state machine representation of the items is used. The model is currently implemented on a VAX 6310. It will be integrated with the Janus battlefield trainer.

Cunningham, C.T.

1992-03-05

37

Automated operations planning: Modeling MLRS operations  

SciTech Connect

The multiples launch rocket system (MLRS) is a highly survivable and automated complement to conventional cannon artillery. For best survivability against counter-battery fire, MLRS operations rely on rapid ``shoot-and-scoot`` tactics by widely dispersed launchers. Such tactics may be difficult to include in a battlefield simulation without requiring players for the individual MLRS items: launchers and resupply vehicles. To reduce this demand on player resources, a computer model has been developed to automate the behavior of the items, consistent with the published operations doctrine. A player is required to determine the area of operation and certain key locations for an MLRS firing platoon. Analysis of trafficability in the operations area and direction the movement of the items, as the perform fire missions, resupply, and replenishment of platoon stocks, is completely automated. A finite state machine representation of the items is used. The model is currently implemented on a VAX 6310. It will be integrated with the Janus battlefield trainer.

Cunningham, C.T.

1992-03-05

38

Interface anisotropy: Simple fitting model  

NASA Astrophysics Data System (ADS)

In studying interface anisotropy, it is common to use a simple model in which the magnetization is assumed uniform (coherent). There are then only two parameters, the bulk anisotropy energy Kbulk and the surface anisotropy energy ?, which can be extracted from the thickness-dependence of the effective anisotropy. This procedure depends on assuming the magnetization is coherent—we show here that incoherence will bias the extracted anisotropy and suggest a method for decreasing this bias. We also suggest an alternative model (also with only two parameters) which includes incoherence effects and may be closer to real systems.

Visscher, P. B.

2014-05-01

39

Models of crack growth along polymer interfaces  

Microsoft Academic Search

Several models of crack growth along polymer\\/polymer interfaces are investigated in this work. The core spirit of these models is the use of a cohesive zone to study the effect of rate dependent inelastic deformation and damage directly ahead of the tip of a growing crack at the polymer interfaces. For each interface model studied, the fracture toughness of the

Daben Xu

1992-01-01

40

Automated two-dimensional interface for capillary gas chromatography  

DOEpatents

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.

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

1996-02-20

41

Automated two-dimensional interface for capillary gas chromatography  

DOEpatents

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.

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

1996-02-20

42

A Method for Automated Detection of Usability Problems from Client User Interface Events  

PubMed Central

Think-aloud usability analysis provides extremely useful data but is very time-consuming and expensive to perform because of the extensive manual video analysis that is required. We describe a simple method for automated detection of usability problems from client user interface events for a developing medical intelligent tutoring system. The method incorporates (1) an agent-based method for communication that funnels all interface events and system responses to a centralized database, (2) a simple schema for representing interface events and higher order subgoals, and (3) an algorithm that reproduces the criteria used for manual coding of usability problems. A correction factor was empirically determining to account for the slower task performance of users when thinking aloud. We tested the validity of the method by simultaneously identifying usability problems using TAU and manually computing them from stored interface event data using the proposed algorithm. All usability problems that did not rely on verbal utterances were detectable with the proposed method.

Saadawi, Gilan M.; Legowski, Elizabeth; Medvedeva, Olga; Chavan, Girish; Crowley, Rebecca S.

2005-01-01

43

Cohesive–frictional interface constitutive model  

Microsoft Academic Search

In the framework of numerical analysis of joined bodies, the present paper is devoted to the constitutive modeling, via an interface kinematic formulation, of mechanical behaviour of internal adhesive layers. The proposed interface constitutive model couples a cohesive behaviour, based on the damage mechanics theory, with a frictional one, defined in a non-associative plasticity framework. Namely, the interface formulation follows

Francesco Parrinello; Boris Failla; Guido Borino

2009-01-01

44

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

NASA Technical Reports Server (NTRS)

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.

Rubin, Carol

2003-01-01

45

Automated modeling of RNA 3D structure.  

PubMed

This chapter gives an overview over the current methods for automated modeling of RNA structures, with emphasis on template-based methods. The currently used approaches to RNA modeling are presented with a side view on the protein world, where many similar ideas have been used. Two main programs for automated template-based modeling are presented: ModeRNA assembling structures from fragments and MacroMoleculeBuilder performing a simulation to satisfy spatial restraints. Both approaches have in common that they require an alignment of the target sequence to a known RNA structure that is used as a modeling template. As a way to find promising template structures and to align the target and template sequences, we propose a pipeline combining the ParAlign and Infernal programs on RNA family data from Rfam. We also briefly summarize template-free methods for RNA 3D structure prediction. Typically, RNA structures generated by automated modeling methods require local or global optimization. Thus, we also discuss methods that can be used for local or global refinement of RNA structures. PMID:24639169

Rother, Kristian; Rother, Magdalena; Skiba, Pawel; Bujnicki, Janusz M

2014-01-01

46

A Generalized Timeline Representation, Services, and Interface for Automating Space Mission Operations  

NASA Technical Reports Server (NTRS)

Most use a timeline based representation for operations modeling. Most model a core set of state, resource types. Most provide similar capabilities on this modeling to enable (semi) automated schedule generation. In this paper we explore the commonality of : representation and services for these timelines. These commonalities offer potential to be harmonized to enable interoperability, re-use.

Chien, Steve; Johnston, Mark; Frank, Jeremy; Giuliano, Mark; Kavelaars, Alicia; Lenzen, Christoph; Policella, Nicola

2012-01-01

47

Designing automation for human use: empirical studies and quantitative models  

Microsoft Academic Search

An emerging knowledge base of human performance research can provide guidelines for designing automation that can be used effectively by human operators of complex systems. Which functions should be automated and to what extent in a given system? A model for types and levels of automation that provides a framework and an objective basis for making such choices is described.

Raja Parasuraman

2000-01-01

48

Automated statistical modeling of analytical measurement systems  

SciTech Connect

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.

Jacobson, J J

1992-08-01

49

Models of crack growth along polymer interfaces  

NASA Astrophysics Data System (ADS)

Several models of crack growth along polymer/polymer interfaces are investigated in this work. The core spirit of these models is the use of a cohesive zone to study the effect of rate dependent inelastic deformation and damage directly ahead of the tip of a growing crack at the polymer interfaces. For each interface model studied, the fracture toughness of the interface is predicted as a function of the crack growth rate, the interface constitutive behavior and the properties of bulk materials surrounding the interface. In chapter 1, we present a general formulation of cohesive zone models in an elastic medium. Asymptotic behavior at the two ends of the cohesive zone is derived. Detailed analyses are carried out for the special case of a crack growing along a power-law creeping interface under steady state condition. Asymptotic and numerical solutions in the cohesive zone for this model are obtained. In chapter 2, we study the problem of steady state crack growth along the interface of two immiscible homopolymers. The interface is strengthened by the addition of a small amount of diblock copolymer. A interface constitutive model based on the concept of polymer chain pull-out is proposed and the results of the analysis are compared with experimental results. In chapter 3 and chapter 4, we study the fracture behavior of weakly joined adhesives between two viscoelastic polymers. In this case, the energy dissipation due to viscoelastic deformation in the bulk materials outside the interface contributes significantly to the measured interface fracture toughness. The presence of viscoelastic deformation implies that the loading parameters governing the crack tip fields are in general dependent on the specimen dimensions as well as the crack growth rate. Therefore, analyses are carried out for both infinite and finite specimens. Our results are compared to some experimental observations. The dependence of the fracture toughness of the interface on the properties of adhesive and the viscoelastic bulk material are derived and discussed.

Xu, Daben

1992-09-01

50

Interface Element for Crack Modelling in Aluminium.  

National Technical Information Service (NTIS)

An interface element is described with a topology that corresponds to that of a solid-like shell element. The application of interface elements make crack modelling in aluminum possible and is a first step toward a three-dimensional numercial model for si...

F. Hashagen

1997-01-01

51

Automated formal verification of visual modeling languages by model checking  

Microsoft Academic Search

Graph transformation has recently become more and more popular as a general, rule-based visual specification paradigm to formally capture (a) requirements or behavior of user models (on the model-level), and (b) the operational semantics of modeling languages (on the meta-level) as demonstrated by benchmark applications around the Unified Modeling Language (UML). The current paper focuses on the model checking-based automated

Dániel Varró

2004-01-01

52

Architectural models for global automation systems  

Microsoft Academic Search

Designing automation systems, as in most engineering endeavors, is primarily an architectural problem, involving hardware and software components. The objective of this paper is to introduce the concept of software architecture and styles in designing automation systems, and to describe an object framework for the development of global automation systems.

Davide Brugali; Giuseppe Menga

2002-01-01

53

Automation life-cycle cost model  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

54

A diffuse interface model with immiscibility preservation  

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

55

Model compilation: An approach to automated model derivation  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

56

An Integration of Model Checking with Automated Proof Checking  

Microsoft Academic Search

Although automated proof checking tools for general-purpose logics have been successfully employed in the verification of digital systems, there are inherent limits to the efficient automation of expressive logics. If the expressiveness is constrained, there are useful logic fragments for which efficient decision procedures can be found. The model checking paradigm yields an important class of decision procedures for establishing

S. Rajan; Natarajan Shankar; Mandayam K. Srivas

1995-01-01

57

Formally verifying human-automation interaction as part of a system model: limitations and tradeoffs.  

PubMed

Both the human factors engineering (HFE) and formal methods communities are concerned with improving the design of safety-critical systems. This work discusses a modeling effort that leveraged methods from both fields to perform formal verification of human-automation interaction with a programmable device. This effort utilizes a system architecture composed of independent models of the human mission, human task behavior, human-device interface, device automation, and operational environment. The goals of this architecture were to allow HFE practitioners to perform formal verifications of realistic systems that depend on human-automation interaction in a reasonable amount of time using representative models, intuitive modeling constructs, and decoupled models of system components that could be easily changed to support multiple analyses. This framework was instantiated using a patient controlled analgesia pump in a two phased process where models in each phase were verified using a common set of specifications. The first phase focused on the mission, human-device interface, and device automation; and included a simple, unconstrained human task behavior model. The second phase replaced the unconstrained task model with one representing normative pump programming behavior. Because models produced in the first phase were too large for the model checker to verify, a number of model revisions were undertaken that affected the goals of the effort. While the use of human task behavior models in the second phase helped mitigate model complexity, verification time increased. Additional modeling tools and technological developments are necessary for model checking to become a more usable technique for HFE. PMID:21572930

Bolton, Matthew L; Bass, Ellen J

2010-03-25

58

VERBAL INTERFACE FOR VAGUE DISCRETE SHAPE MODELER  

Microsoft Academic Search

Due to the nature of the involved human thinking and creative actions, product conceptualization necessitates the ability of handling incompleteness, vagueness, and frequent changes in the models. The user interfaces and modeling schemes of recent CAD systems are typically not able to cope with this kind of information. Verbalism, as the primary communication mode of human beings, is adapted to

György Kuczogi; Imre Horváth; Zoltán Rusák

2002-01-01

59

A Hierarchical Test Model and Automated Test Framework for RTC  

Microsoft Academic Search

This paper presents a hierarchical test model and automated test framework for robot software components of RTC(Robot Technology\\u000a Component) combined with hardware module. The hierarchical test model consists of three levels of testing based on V-model\\u000a : unit test, integration test, and system test. The automated test framework incorporates four components of test data generation,\\u000a test manager, test execution, and

Jae-Hee Lim; Suk-Hoon Song; Tae-Yong Kuc; Hong-Seong Park; Hong-Seak Kim

2009-01-01

60

Model-Based Covert Timing Channels: Automated Modeling and Evasion  

Microsoft Academic Search

The exploration of advanced covert timing channel design is important to understand and defend against covert timing channels.\\u000a In this paper, we introduce a new class of covert timing channels, called model-based covert timing channels, which exploit\\u000a the statistical properties of legitimate network traffic to evade detection in an effective manner. We design and implement\\u000a an automated framework for building

Steven Gianvecchio; Haining Wang; Duminda Wijesekera; Sushil Jajodia

2008-01-01

61

Nonlinear rheological models for structured interfaces  

NASA Astrophysics Data System (ADS)

The GENERIC formalism is a formulation of nonequilibrium thermodynamics ideally suited to develop nonlinear constitutive equations for the stress-deformation behavior of complex interfaces. Here we develop a GENERIC model for multiphase systems with interfaces displaying nonlinear viscoelastic stress-deformation behavior. The link of this behavior to the microstructure of the interface is described by including a scalar and a tensorial structural variable in the set of independent surface variables. We derive an expression for the surface stress tensor in terms of these structural variables, and a set of general nonlinear time evolution equations for these variables, coupling them to the deformation field. We use these general equations to develop a number of specific models, valid for application near equilibrium, or valid for application far beyond equilibrium.

Sagis, Leonard M. C.

2010-05-01

62

A Web Interface for Eco System Modeling  

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

63

Finite Element Modeling of Frictionally Restrained Composite Interfaces.  

National Technical Information Service (NTIS)

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 i...

R. Ballarini S. Ahmed

1989-01-01

64

Action-driven automation test framework for Graphical User Interface (GUI) software testing  

Microsoft Academic Search

In this paper we describe the design and implementation of an action-driven automation test framework especially for GUI software testing. The idea of action-driven automation test framework comes from the core concept of \\

Li Feng; Sheng Zhuang

2007-01-01

65

Modeling and Extracting Deep-Web Query Interfaces  

Microsoft Academic Search

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,

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

2009-01-01

66

Designing for Flexible Interaction Between Humans and Automation: Delegation Interfaces for Supervisory Control  

Microsoft Academic Search

Objective: To develop a method enabling human-like, flexible supervisory control via delegation to automation. Background: Real-time supervisory relationships with automation are rarely as flexible as human task delegation to other humans. Flexibility in human-adaptable automation can provide important benefits, includ- ing improved situation awareness, more accurate automation usage, more balanced mental workload, increased user acceptance, and improved overall performance. Method:

Christopher A. Miller; Raja Parasuraman

2007-01-01

67

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

NASA Technical Reports Server (NTRS)

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.

Kirlik, Alex

1993-01-01

68

Implications of a control-theoretic approach to human-automation-plant interface design  

Microsoft Academic Search

The article critically evaluates some of the design guidelines proposed by researchers investigating human automation interaction. A control theoretic framework is proposed to introduce a set of important conceptual distinctions that need to be respected in automation research and design. The framework is applied to a specific topic of recent research focus, modes in aviation automation. Although previous research in

Greg A. Jamieson; Kim J. Vicente

1998-01-01

69

Dynamic delamination modelling using interface elements  

Microsoft Academic Search

Existing techniques in explicit dynamic Finite Element (FE) codes for the analysis of delamination in composite structures and components can be simplistic, using simple stress-based failure function to initiate and propagate delaminations.This paper presents an interface modelling technique for explicit FE codes. The formulation is based on damage mechanics and uses only two constants for each delamination mode; firstly, a

L. Iannucci

2006-01-01

70

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

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

71

A permeation model for the electrochemical interface  

NASA Astrophysics Data System (ADS)

We show the transferability of the recently introduced concept of permeation from the context of finite dissipation in simple metallic interfaces to much more complicated electrochemical interfaces. The phenomenological bridge is formed by the exchange current, which can be measured by either impedance spectroscopy or by cyclic voltammetry. In a proof-of-concept phase field model, Nernst-Planck diffusion and transport of charged species in a potential gradient as the solution of the Poisson equation are considered. It is shown that charges build up on the outer electrode surface in a fashion resembling the electrochemical double layer.

Preiss, U.; Borukhovich, E.; Alemayehu, N.; Steinbach, I.; LaMantia, F.

2013-10-01

72

Infrared singularities in interface growth models  

SciTech Connect

We show that nonlinear interface growth models with roughness exponent {alpha}{ge}1 have intrinsic nonperturbative infrared singularities which are inaccessible to the usual dynamical renormalization group analysis. We argue that these infrared singularities give rise to a strong-coupling problem in 1+1 dimensions and provide the underlying reason for the difference between local and global dynamic scaling in these models. {copyright} {ital 1996 The American Physical Society.}

Bhattacharjee, J.K.; Das Sarma, S.; Kotlyar, R. [Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)] [Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)

1996-02-01

73

An Automated Translator for Model Checking Time Constrained Workflow Systems  

NASA Astrophysics Data System (ADS)

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.

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

74

Automation Marketplace 2010: New Models, Core Systems  

ERIC Educational Resources Information Center

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…

Breeding, Marshall

2010-01-01

75

A connectionist model of complacency and adaptive recovery under automation.  

PubMed

Automation is intended to reduce the demands on operators in complex environments, thereby enhancing overall system performance. Although automation usually reduces workload, it is often accompanied by a decline in monitoring performance, an effect known as complacency. The circumstances under which complacency occurs and how it can be prevented, for example by intermittently returning control to the operator, are empirically well understood. To date, that empirical knowledge has not been accompanied by strong psychological theory. This article presents a computational model of human performance under automation based on connectionist principles. The model is shown to explain several benchmark findings, among them the basic complacency effect; the effect of the variability of automation reliability on complacency; the effect of task complexity; and the effect of intermittently returning control to the operator. PMID:10764102

Farrell, S; Lewandowsky, S

2000-03-01

76

Ultrasonic scattering from imperfect interfaces: A quasi-static model  

Microsoft Academic Search

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

Jai-Man Baik; R. Bruce Thompson

1984-01-01

77

Interface dynamics in planar neural field models  

PubMed Central

Neural field models describe the coarse-grained activity of populations of interacting neurons. Because of the laminar structure of real cortical tissue they are often studied in two spatial dimensions, where they are well known to generate rich patterns of spatiotemporal activity. Such patterns have been interpreted in a variety of contexts ranging from the understanding of visual hallucinations to the generation of electroencephalographic signals. Typical patterns include localized solutions in the form of traveling spots, as well as intricate labyrinthine structures. These patterns are naturally defined by the interface between low and high states of neural activity. Here we derive the equations of motion for such interfaces and show, for a Heaviside firing rate, that the normal velocity of an interface is given in terms of a non-local Biot-Savart type interaction over the boundaries of the high activity regions. This exact, but dimensionally reduced, system of equations is solved numerically and shown to be in excellent agreement with the full nonlinear integral equation defining the neural field. We develop a linear stability analysis for the interface dynamics that allows us to understand the mechanisms of pattern formation that arise from instabilities of spots, rings, stripes and fronts. We further show how to analyze neural field models with linear adaptation currents, and determine the conditions for the dynamic instability of spots that can give rise to breathers and traveling waves.

2012-01-01

78

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

SciTech Connect

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.

Anderson, B.; /Fermilab

1999-10-08

79

A methodology for modular model-building in discrete automation  

Microsoft Academic Search

Our objective is to develop a general and versatile approach for building structured formal models of complex automated systems in order to facilitate their control and diagnosis. For this purpose, we present a methodology that builds the complete model of a system by composing models of the individual hardware components, their physical coupling, and the associated control logic. We choose

Matteo Sartini; Andrea Paoli; Richard C. Hill; S. Lafortune

2010-01-01

80

Interface of Inference Models with Concept and Medical Record Models  

Microsoft Academic Search

Medical information systems and standards are increasingly based on principled models of at least three distinct sorts of\\u000a information — patient data, concepts (terminology), and guidelines (decision support). Well defined interfaces are required\\u000a between the three types of model to allow development to proceed independently. Two of the major issues to be dealt with in\\u000a the defining of such interfaces

Alan L. Rector; Peter D. Johnson; Samson W. Tu; Chris Wroe; Jeremy Rogers

2001-01-01

81

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

Microsoft Academic Search

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

M. H. Shwehdi; A. Z. Khan

1996-01-01

82

Modeling the user in intelligent user interfaces  

SciTech Connect

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.

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

1983-01-01

83

Modelling Safe Interface Interactions in Web Applications  

NASA Astrophysics Data System (ADS)

Current Web applications embed sophisticated user interfaces and business logic. The original interaction paradigm of the Web based on static content pages that are browsed by hyperlinks is, therefore, not valid anymore. In this paper, we advocate a paradigm shift for browsers and Web applications, that improves the management of user interaction and browsing history. Pages are replaced by States as basic navigation nodes, and Back/Forward navigation along the browsing history is replaced by a full-fledged interactive application paradigm, supporting transactions at the interface level and featuring Undo/Redo capabilities. This new paradigm offers a safer and more precise interaction model, protecting the user from unexpected behaviours of the applications and the browser.

Brambilla, Marco; Cabot, Jordi; Grossniklaus, Michael

84

The Ascender System: Automated Site Modeling from Multiple Aerial Images  

Microsoft Academic Search

The Ascender system acquires, extends, and refines 3D geomet- ric site models from calibrated aerial imagery. To acquire a new site model, an automated building detector is run on one image to hypothesize potential building rooftops. Supporting evidence is located in other images via epipolar line segment matching in con- strained search regions. The precise 3D shape and location of

Robert T. Collins; Christopher O. Jaynes; Yong-qing Cheng; Xiaoguang Wang; Frank Stolle; Edward M. Riseman; Allen R. Hanson

1998-01-01

85

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

PubMed

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

Wu, Naiqi; Zhou, MengChu

2005-12-01

86

A model for types and levels of human interaction with automation  

Microsoft Academic Search

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

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

2000-01-01

87

ModelMate - A graphical user interface for model analysis  

USGS Publications Warehouse

ModelMate is a graphical user interface designed to facilitate use of model-analysis programs with models. This initial version of ModelMate supports one model-analysis program, UCODE_2005, and one model software program, MODFLOW-2005. ModelMate can be used to prepare input files for UCODE_2005, run UCODE_2005, and display analysis results. A link to the GW_Chart graphing program facilitates visual interpretation of results. ModelMate includes capabilities for organizing directories used with the parallel-processing capabilities of UCODE_2005 and for maintaining files in those directories to be identical to a set of files in a master directory. ModelMate can be used on its own or in conjunction with ModelMuse, a graphical user interface for MODFLOW-2005 and PHAST.

Banta, Edward R.

2011-01-01

88

Development of an automated speech recognition interface for personal emergency response systems  

PubMed Central

Background Demands on long-term-care facilities are predicted to increase at an unprecedented rate as the baby boomer generation reaches retirement age. Aging-in-place (i.e. aging at home) is the desire of most seniors and is also a good option to reduce the burden on an over-stretched long-term-care system. Personal Emergency Response Systems (PERSs) help enable older adults to age-in-place by providing them with immediate access to emergency assistance. Traditionally they operate with push-button activators that connect the occupant via speaker-phone to a live emergency call-centre operator. If occupants do not wear the push button or cannot access the button, then the system is useless in the event of a fall or emergency. Additionally, a false alarm or failure to check-in at a regular interval will trigger a connection to a live operator, which can be unwanted and intrusive to the occupant. This paper describes the development and testing of an automated, hands-free, dialogue-based PERS prototype. Methods The prototype system was built using a ceiling mounted microphone array, an open-source automatic speech recognition engine, and a 'yes' and 'no' response dialog modelled after an existing call-centre protocol. Testing compared a single microphone versus a microphone array with nine adults in both noisy and quiet conditions. Dialogue testing was completed with four adults. Results and discussion The microphone array demonstrated improvement over the single microphone. In all cases, dialog testing resulted in the system reaching the correct decision about the kind of assistance the user was requesting. Further testing is required with elderly voices and under different noise conditions to ensure the appropriateness of the technology. Future developments include integration of the system with an emergency detection method as well as communication enhancement using features such as barge-in capability. Conclusion The use of an automated dialog-based PERS has the potential to provide users with more autonomy in decisions regarding their own health and more privacy in their own home.

Hamill, Melinda; Young, Vicky; Boger, Jennifer; Mihailidis, Alex

2009-01-01

89

Automated data acquisition technology development:Automated modeling and control development  

NASA Technical Reports Server (NTRS)

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.

Romine, Peter L.

1995-01-01

90

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...

91

Automated Model-Based Configuration of Enterprise Java Applications  

Microsoft Academic Search

The decentralized process of configuring enterprise applications is complex and error-prone, involving multiple participants\\/roles and numerous configuration changes across multiple files, application server settings, and database decisions. This paper describes an approach to automated enterprise application configuration that uses a feature model, executes a series of probes to verify configuration properties, formalizes feature selection as a constraint satisfaction problem, and

Jules White; Douglas C. Schmidt; Krzysztof Czarnecki; Christoph Wienands; Gunther Lenz; Egon Wuchner; Ludger Fiege

2007-01-01

92

User-interface modelling--adding usability to use cases  

Microsoft Academic Search

User interface modelling (UIM) is basically a method for gathering user requirements that are applicable when designing the user interface to an information system. UIM is to be used as a complement to use case modelling (Jacobson, Christerson, Jonsson & Övergaard, 1992) in the system development process. An actor model, a goal model and a work model are specified during

Magnus Lif

1999-01-01

93

Radiation budget measurement/model interface  

NASA Technical Reports Server (NTRS)

This final report includes research results from the period February, 1981 through November, 1982. Two new results combine to form the final portion of this work. They are the work by Hanna (1982) and Stevens to successfully test and demonstrate a low-order spectral climate model and the work by Ciesielski et al. (1983) to combine and test the new radiation budget results from NIMBUS-7 with earlier satellite measurements. Together, the two related activities set the stage for future research on radiation budget measurement/model interfacing. Such combination of results will lead to new applications of satellite data to climate problems. The objectives of this research under the present contract are therefore satisfied. Additional research reported herein includes the compilation and documentation of the radiation budget data set a Colorado State University and the definition of climate-related experiments suggested after lengthy analysis of the satellite radiation budget experiments.

Vonderhaar, T. H.; Ciesielski, P.; Randel, D.; Stevens, D.

1983-01-01

94

Automated Qualitative Modeling of Dynamic Physical Systems.  

National Technical Information Service (NTIS)

This report describes MM, a computer program that can model a variety of mechanical and fluid systems. It addresses several issues: What is the appropriate input to the modeling process. How should the search for models be organized. What evidence can be ...

J. Amsterdam

1993-01-01

95

User-centered modeling and evaluation of multimodal interfaces  

Microsoft Academic Search

Historically, the development of computer interfaces has been a technology-driven phenomenon. However, new multimodal interfaces are composed of recognition-based technologies that must interpret human speech, gesture, gaze, movement patterns, and other complex natural behaviors, which involve highly automatized skills that are not under full conscious control. As a result, it now is widely acknowledged that multimodal interface design requires modeling

SHARON OVIATT

2003-01-01

96

Solar Interface Dynamos. II. Linear, Kinematic Models in Spherical Geometry  

Microsoft Academic Search

Numerical models of interface dynamos are constructed, and their properties discussed in some detail. These models are extensions in spherical geometry of the Cartesian interface models considered by Parker and in the first paper of this series. The models are cast in the framework of classical mean-field electrodynamics and make use of a realistic solar-like internal differential rotation profile. The

P. Charbonneau; K. B. MacGregor

1997-01-01

97

Modeling gold\\/iron oxide interface system  

Microsoft Academic Search

The effect of gold particle size and Au\\/FeO\\u000a x\\u000a interface on the electronic properties and catalytic activity using samples of Au\\/SiO2\\/Si(100), Au\\/FeO\\u000a x\\u000a \\/SiO2\\/Si(100), FeO\\u000a x\\u000a \\/Au\\/SiO2\\/Si(100) has been modelled. Nanosize gold particles of varying size were fabricated by deposition of a 10 nm thick gold film\\u000a onto SiO2\\/Si(100) substrate by electron beam evaporation followed by modification using low energy Ar+

L. Guczi; Z. Pászti; K. Frey; A. Beck; G. Pet?; Cs. S. Daróczy

2006-01-01

98

Diffuse interface model of bulk heterogeneous nucleation  

SciTech Connect

First order phase transformations from a homogeneous initial state begin with nucleation, i.e. the new phase appears through heterophase fluctuations that are larger than a critical size which is determined by the interplay of the interfacial and volumetric contributions to the Gibbs free energy of the fluctuation. The heterogeneous process plays an essential role in determining the microstructure of solids. In materials science nucleation is usually described by a simple and flexible phenomenological model, the classical nucleation theory (CNT) which postulates that the nuclei are spherical particles characterized by the bulk properties of the nucleating phase and the bulk interfacial free energy [gamma] ('droplet' approximation). This simple picture is often criticized on the grounds that computer simulations and calculations from first principles predict an interface thickness comparable to the size of the nucleus. It is also alarming that for vapor condensation an the nucleation rates predicted by the CNT for crystal nucleation from melts or glasses is not feasible since in the undercooled state the solid/liquid interfacial free energy cannot be measured by independent methods. Nevertheless, the problems in interpreting experiments on bulk nucleation in terms of the CNT raise doubts about the validity of the classical approach. To circumvent these problems a simplified theory of homogeneous nucleation (DIT) that accounts for the diffuseness of the interface has been proposed recently. The new approach led to an improved description of vapor condensation and crystal nucleation from a glass. In the present work this model is generalized for the heterogeneous mechanism and compared to experiments on metallic substances. The results support the expectation that the DIT eliminates the problem of anomalous'' nucleation prefactors.

Granasy, L. (Research Inst. for Solid State Physics, Budapest (Hungary)); Egry, I.; Ratke, L.; Herlach, D.M. (DLR, Koeln (Germany). Institut fuer Raumsimulation)

1994-09-01

99

AUTOMATED WATERSHED MODEL PREPROCESSING USING DOWNLOADABLE DATABASES  

Microsoft Academic Search

* ABSTRACT: The Watershed Analysis Risk Management Framework (WARMF) is GIS based watershed modeling system. To set up WARMF for a river basin, it requires site specific data of Digital Elevation Model (DEM), land use, soil, and meteorology, which are downloadable from public websites. The GIS capabilities of WARMF are used to streamline the importation and processing of the data.

Joel W. Herr; Carl W. Chen; Laura H. Z. Weintraub; Robert A. Goldstein

100

Automated Environment Generation for Software Model Checking  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

101

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

Microsoft Academic Search

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

Pedro A. Szekely; Ping Luo; Robert Neches

1992-01-01

102

Automated sample plan selection for OPC modeling  

NASA Astrophysics Data System (ADS)

It is desired to reduce the time required to produce metrology data for calibration of Optical Proximity Correction (OPC) models and also maintain or improve the quality of the data collected with regard to how well that data represents the types of patterns that occur in real circuit designs. Previous work based on clustering in geometry and/or image parameter space has shown some benefit over strictly manual or intuitive selection, but leads to arbitrary pattern exclusion or selection which may not be the best representation of the product. Forming the pattern selection as an optimization problem, which co-optimizes a number of objective functions reflecting modelers' insight and expertise, has shown to produce models with equivalent quality to the traditional plan of record (POR) set but in a less time.

Casati, Nathalie; Gabrani, Maria; Viswanathan, Ramya; Bayraktar, Zikri; Jaiswal, Om; DeMaris, David; Abdo, Amr Y.; Oberschmidt, James; Krause, Andreas

2014-03-01

103

Grcarma: A fully automated task-oriented interface for the analysis of molecular dynamics trajectories.  

PubMed

We report the availability of grcarma, a program encoding for a fully automated set of tasks aiming to simplify the analysis of molecular dynamics trajectories of biological macromolecules. It is a cross-platform, Perl/Tk-based front-end to the program carma and is designed to facilitate the needs of the novice as well as those of the expert user, while at the same time maintaining a user-friendly and intuitive design. Particular emphasis was given to the automation of several tedious tasks, such as extraction of clusters of structures based on dihedral and Cartesian principal component analysis, secondary structure analysis, calculation and display of root-meansquare deviation (RMSD) matrices, calculation of entropy, calculation and analysis of variance–covariance matrices, calculation of the fraction of native contacts, etc. The program is free-open source software available immediately for download. PMID:24159629

Koukos, Panagiotis I; Glykos, Nicholas M

2013-10-01

104

Travel-Time Models for Automated Storage\\/Retrieval Systems  

Microsoft Academic Search

Travel-time models are developed for automated storage\\/retrieval (AS\\/R) machines. The S\\/R machine travels simultaneously horizontally and vertically as it moves along a storage aisle. For randomized storage conditions expected travel times are determined for both single and dual command cycles. Alternative input\\/output (I\\/O) locations are considered. Additionally, various dwell-point strategies for the storage\\/retrieval machine are examined.

Yavuz A. Bozer; John A. White

1984-01-01

105

Automated modelling of signal transduction networks  

Microsoft Academic Search

Background: Intracellular signal transduction is achieved by networks of proteins and small molecules that transmit information from the cell surface to the nucleus, where they ultimately effect transcriptional changes. Understanding the mechanisms cells use to accomplish this important process requires a detailed molecular description of the networks involved. Results: We have developed a computational approach for generating static models of

Martin Steffen; Allegra Petti; John Aach; Patrik D'haeseleer; George M. Church

2002-01-01

106

Automation of ocean model performance metrics  

Microsoft Academic Search

A system to rapidly and automatically assess the performance of numerical ocean modeling systems was developed by the U.S. Naval Research Laboratory (NRL). This includes the calculation of quantitative, objective metrics of the accuracy of ocean forecasts. We will present results from this system, including metrics of surface and subsurface analysis and forecast fields. This work supports the U.S. Naval

James D. Dykes; Jay F. Shriver; Sean Ziegeler

2009-01-01

107

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

SciTech Connect

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.

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

108

Automated refinement and inference of analytical models for metabolic networks.  

PubMed

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

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

2011-10-01

109

Automated refinement and inference of analytical models for metabolic networks  

PubMed Central

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.

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

2013-01-01

110

Automated refinement and inference of analytical models for metabolic networks  

NASA Astrophysics Data System (ADS)

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.

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

2011-10-01

111

Automated photogrammetry for three-dimensional models of urban spaces  

NASA Astrophysics Data System (ADS)

The location-aware Internet is inspiring intensive work addressing the automated assembly of three-dimensional models of urban spaces with their buildings, circulation spaces, vegetation, signs, even their above-ground and underground utility lines. Two-dimensional geographic information systems (GISs) and municipal utility information exist and can serve to guide the creation of models being built with aerial, sometimes satellite imagery, streetside images, indoor imaging, and alternatively with light detection and ranging systems (LiDARs) carried on airplanes, cars, or mounted on tripods. We review the results of current research to automate the information extraction from sensor data. We show that aerial photography at ground sampling distances (GSD) of 1 to 10 cm is well suited to provide geometry data about building facades and roofs, that streetside imagery at 0.5 to 2 cm is particularly interesting when it is collected within community photo collections (CPCs) by the general public, and that the transition to digital imaging has opened the no-cost option of highly overlapping images in support of a more complete and thus more economical automation. LiDAR-systems are a widely used source of three-dimensional data, but they deliver information not really superior to digital photography.

Leberl, Franz; Meixner, Philipp; Wendel, Andreas; Irschara, Arnold

2012-02-01

112

Consistent set of interfaces derived from a business object model  

US Patent & Trademark Office Database

A business object model, which reflects data that is used during a given business transaction, is utilized to generate interfaces. This business object model facilitates commercial transactions by providing consistent interfaces that are suitable for use across industries, across businesses, and across different departments within a business during a business transaction.

2013-10-22

113

Consistent set of interfaces derived from a business object model  

US Patent & Trademark Office Database

Methods and systems consistent with the present invention provide a data processing system having a business object model reflecting the data used during a business transaction. Consistent interfaces are generated from the business object model. These interfaces are suitable for use across industries, across businesses, and across different departments within a business during a business transaction.

2013-12-10

114

Consistent set of interfaces derived from a business object model  

US Patent & Trademark Office Database

A business object model, which reflects data that used during a given business transaction, is utilized to generate interfaces This business object model facilitates commercial transactions by providing consistent interfaces that are suitable for use across industries, across businesses, and across different departments within a business during a business transaction.

2014-06-03

115

Rapid Automated Aircraft Simulation Model Updating from Flight Data  

NASA Technical Reports Server (NTRS)

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.

Brian, Geoff; Morelli, Eugene A.

2011-01-01

116

A new interface element with progressive damage and osseointegration for modeling of interfaces in hip resurfacing.  

PubMed

Finite element models of orthopedic implants such as hip resurfacing femoral components usually rely on contact elements to model the load-bearing interfaces that connect bone, cement and implant. However, contact elements cannot simulate progressive degradation of bone-cement interfaces or osseointegration. A new interface element is developed to alleviate these shortcomings. This element is capable of simulating the nonlinear progression of bone-cement interface debonding or bone-implant interface osseointegration, based on mechanical stimuli in normal and tangential directions. The new element is applied to a hip resurfacing femoral component with a stem made of a novel biomimetic composite material. Three load cases are applied sequentially to simulate the 6-month period required for osseointegration of the stem. The effect of interdigitation depth of the bone-cement interface is found to be negligible, with only minor variations of micromotions. Numerical results show that the biomimetic stem progressively osseointegrates (alpha averages 0.7 on the stem surface, with spot-welds) and that bone-stem micromotions decrease below 10 microm. Osseointegration also changes the load path within the femoral bone: a decrease of 300 microepsilon was observed in the femoral head, and the inferomedial part of the femoral neck showed a slight increase of 165 microepsilon. There was also increased stress in the implant stem (from 7 to 11 MPa after osseointegration), indicating that part of the load is supported through the stem. The use of the new osseointegratable interface element has shown the osseointegration potential of the biomimetic stem. Its ability to model partially osseointegrated interfaces based on the mechanical conditions at the interface means that the new element could be used to study load transfer and osseointegration patterns on other models of uncemented hip resurfacing femoral components. PMID:23662336

Caouette, Christiane; Bureau, Martin N; Lavigne, Martin; Vendittoli, Pascal-André; Nuño, Natalia

2013-03-01

117

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

ERIC Educational Resources Information Center

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…

Haberman, Shelby J.; Sinharay, Sandip

2010-01-01

118

Automated flux chamber for investigating gas flux at water-air interfaces.  

PubMed

Aquatic ecosystems are major sources of greenhouse gases (GHG). Representative measurements of GHG fluxes from aquatic ecosystems to the atmosphere are vital for quantitative understanding of relationships between biogeochemistry and climate. Fluxes occur at high temporal variability at diel or longer scales, which are not captured by traditional short-term deployments (often in the order of 30 min) of floating flux chambers. High temporal frequency measurements are necessary but also extremely labor intensive if manual flux chamber based methods are used. Therefore, we designed an inexpensive and easily mobile automated flux chamber (AFC) for extended deployments. The AFC was designed to measure in situ accumulation of gas in the chamber and also to collect gas samples in an array of sample bottles for subsequent analysis in the laboratory, providing two independent ways of CH(4) concentration measurements. We here present the AFC design and function together with data from initial laboratory tests and from a field deployment. PMID:23237495

Duc, Nguyen Thanh; Silverstein, Samuel; Lundmark, Lars; Reyier, Henrik; Crill, Patrick; Bastviken, David

2013-01-15

119

Diffuse-interface model for smoothed particle hydrodynamics.  

PubMed

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 and 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 or capturing is required, even when topological changes such as fragmentation and coalescence occur, because of its Lagrangian particle nature. Here we developed a SPH model for single-component two-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. PMID:19392076

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

2009-03-01

120

Automated extraction of knowledge for model-based diagnostics  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

121

Physical Models of Hydrofracturing Across Material Interfaces.  

National Technical Information Service (NTIS)

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 reser...

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

1988-01-01

122

Physical models of hydrofracturing across material interfaces  

Microsoft Academic Search

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

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

1988-01-01

123

Flexible automated parameterization of hydrologic models using fuzzy logic  

NASA Astrophysics Data System (ADS)

Recent developments in model calibration suggest that information obtained from calibration is inherently uncertain in nature. Therefore identification of optimum parameter values is often highly nonspecific. A calibration framework using fuzzy logic is presented to deal with such uncertain information. An application of this technique to calibrate the streamflow of a hydrologic submodel embedded within an ecosystem simulation model demonstrates that objective estimates of parameter values and the range of model output associated with a failure to identify a unique solution can be obtained with suitable choices of objective functions. An iterative refinement in parameter estimates through a process of elimination was possible by incorporating multiple objective functions in calibration, thereby reducing the range of parameter values that capture the streamflow response. It is shown that objective function tradeoffs can lead to suboptimal solutions using the process of elimination without an automated procedure for reevaluation. Owing to its computational simplicity and flexibility this framework could be extended into a nonmonotonic system for automated parameter estimation.

Samanta, Sudeep; Mackay, D. Scott

2003-01-01

124

ALC: automated reduction of rule-based models  

PubMed Central

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.

Koschorreck, Markus; Gilles, Ernst Dieter

2008-01-01

125

An automated algorithm to detect the trabecular-cortical bone interface in micro-computed tomographic images.  

PubMed

Micro-computed tomography (microCT) has become a standard tool for the evaluation of bone morphology in preclinical studies. Unfortunately, the user-dependent definition of contour lines that separate trabecular from cortical bone is not only extremely time-consuming but may also represent a source of data bias and increased variability. Here, an automated image segmentation technique was developed and tested over a large range of bone phenotypes. The principal steps of the algorithm involve blurring, segmentation at different thresholds, and volumetric component labeling to first identify the periosteal edge and then create a cortical mask, the inner edge of which defines the trabecular-cortical interface. The algorithm was tested against (1) eight skilled microCT operators who manually defined the trabecular bone within the distal femur of four adult mice as well as (2) contour lines drawn by a single user in femurs from 71 rodents. Across the four femurs, the coefficient of variation between users was 9% for bone volume fraction, 13% for connectivity density, and 3% for trabecular thickness. Morphometric data produced by the algorithm were within 2% of the mean values of the eight operators. Across the 71 femurs, the slope and intercept of the regressions between morphometric automatic and user data were, with the exception of trabecular thickness, not significantly different from 1 and 0, respectively. Because of the excellent match with the current gold-standard technique, this algorithm may present a valuable tool for the standardized and automated evaluation of bone morphology without the time-consuming task of drawing contour lines. PMID:17828460

Lublinsky, Svetlana; Ozcivici, Engin; Judex, Stefan

2007-10-01

126

Study of the Interface Electronic Structure of a Model Metal-Semiconductor Interface,  

National Technical Information Service (NTIS)

A study is presented of the interface electronic structure of a model simple-cubic metal and a compound semiconductor of the cesium-chloride structure. Both the metal and the semiconductor are described in terms of nearest-neighbor tight-binding models wh...

D. N. Lowy A. Madhukar

1978-01-01

127

Finite element modeling of frictionally restrained composite interfaces  

NASA Technical Reports Server (NTRS)

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.

Ballarini, Roberto; Ahmed, Shamim

1989-01-01

128

QSAR workbench: automating QSAR modeling to drive compound design.  

PubMed

We describe the QSAR Workbench, a system for the building and analysis of QSAR models. The system is built around the Pipeline Pilot workflow tool and provides access to a variety of model building algorithms for both continuous and categorical data. Traditionally models are built on a one by one basis and fully exploring the model space of algorithms and descriptor subsets is a time consuming basis. The QSAR Workbench provides a framework to allow for multiple models to be built over a number of modeling algorithms, descriptor combinations and data splits (training and test sets). Methods to analyze and compare models are provided, enabling the user to select the most appropriate model. The Workbench provides a consistent set of routines for data preparation and chemistry normalization that are also applied for predictions. The Workbench provides a large degree of automation with the ability to publish preconfigured model building workflows for a variety of problem domains, whilst providing experienced users full access to the underlying parameterization if required. Methods are provided to allow for publication of selected models as web services, thus providing integration with the chemistry desktop. We describe the design and implementation of the QSAR Workbench and demonstrate its utility through application to two public domain datasets. PMID:23615761

Cox, Richard; Green, Darren V S; Luscombe, Christopher N; Malcolm, Noj; Pickett, Stephen D

2013-04-01

129

Nonequilibrium Models for Diffusive Cavitation of Grain Interfaces.  

National Technical Information Service (NTIS)

Existing models for the diffusive growth of voids on grain interfaces, at elevated temperature, are for the most part based on quasi-equilibrium assumptions: surface diffusion is assumed to be sufficiently rapid that the cavity has a rounded, equilibrium ...

T. J. Chuang K. I. Kagawa J. R. Rice L. B. Sills

1978-01-01

130

Particle Tracking Model (PTM) in the SMS: I. Graphical Interface.  

National Technical Information Service (NTIS)

This Dredging Operations and Environmental Research (DOER) Technical Note (TN) describes the graphical interface for the Particle Tracking Model (PTM). The Coastal Inlets Research Program (CIRP) and the DOER Program are jointly developing the PTM. The PTM...

2005-01-01

131

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

National Technical Information Service (NTIS)

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 pa...

K. Goodrich, P. Schutte, R. Williams

2012-01-01

132

Development of an automated core model for nuclear reactors  

SciTech Connect

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of this project was to develop an automated package of computer codes that can model the steady-state behavior of nuclear-reactor cores of various designs. As an added benefit, data produced for steady-state analysis also can be used as input to the TRAC transient-analysis code for subsequent safety analysis of the reactor at any point in its operating lifetime. The basic capability to perform steady-state reactor-core analysis already existed in the combination of the HELIOS lattice-physics code and the NESTLE advanced nodal code. In this project, the automated package was completed by (1) obtaining cross-section libraries for HELIOS, (2) validating HELIOS by comparing its predictions to results from critical experiments and from the MCNP Monte Carlo code, (3) validating NESTLE by comparing its predictions to results from numerical benchmarks and to measured data from operating reactors, and (4) developing a linkage code to transform HELIOS output into NESTLE input.

Mosteller, R.D.

1998-12-31

133

A generalized mechanical model for suture interfaces of arbitrary geometry  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

134

Computer automated multi-paradigm modelling: meta-modelling and graph transformation  

Microsoft Academic Search

Computer automated multi-paradigm modelling based on meta-modelling and graph transformation is presented. The syntax of a class of models of interest is graphically meta-modelled in an appropriate formalism such as entity-relationship diagrams. From this abstract syntax, augmented with concrete (visual) information, an interactive, visual modelling environment is generated. As the abstract syntax of all models is graph-like, graph rewriting is

Hans Vangheluwe; Juan de Lara

2003-01-01

135

Stable, reproducible, and automated capillary zone electrophoresis-tandem mass spectrometry system with an electrokinetically pumped sheath-flow nanospray interface.  

PubMed

A PrinCE autosampler was coupled to a Q-Exactive mass spectrometer by an electrokinetically pumped sheath-flow nanospray interface to perform automated capillary zone electrophoresis-electrospray ionization-tandem mass spectrometry (CZE-ESI-MS/MS). 20ng aliquots of an Escherichia coli digest were injected to evaluate the system. Eight sequential injections over an 8-h period identified 1115±70 (relative standard deviation, RSD=6%) peptides and 270±8 (RSD=3%) proteins per run. The average RSDs of migration time, peak intensity, and peak area were 3%, 24% and 19%, respectively, for 340 peptides with high intensity. This is the first report of an automated CZE-ESI-MS/MS system using the electrokinetically pumped sheath-flow nanospray interface. The results demonstrate that this system is capable of reproducibly identifying over 1000 peptides from an E. coli tryptic digest in a 1-h analysis time. PMID:24439510

Zhu, Guijie; Sun, Liangliang; Yan, Xiaojing; Dovichi, Norman J

2014-01-31

136

Automation testing process modeling method of SOA-based isomerous software  

Microsoft Academic Search

On the basis of SOA-based isomerous software integration and automation testing technique, took testing specification as centre, analyzed with the mainstream testing model and dependency relation and applied with extraction technology, a new automation testing process model of SOA-based isomerous software was proposed. It covered the whole testing process including test plan, test design, test case generation, test execution, test

Wu Deng; Shuqin Liu; Jingjing Liu

2009-01-01

137

Phase field modeling with large interface thickness and undercooling  

NASA Astrophysics Data System (ADS)

The interface thickness is the most crucial parameter in the phase field model (PFM) for the accuracy and the computability. However, the Gibbs-Thomson equation can be satisfied only when the interface thickness is sufficiently small, especially with a large undercooling, but this greatly limits the applications of PFM to a realistic problem. The temperature correction in the thin-interface model partially resolves the problem, but the range is rather limited. In this report, we propose a new formulation of PFM by adding extra terms stabilizing the hyperbolic tangent profile of the phase-field, and this allows us to use a much larger interface thickness for simulation, even with a large undercooling. Several benchmark comparisons with analytical solutions are carried out and discussed.

Chen, C. C.; Lin, H. K.; Lan, C. W.

2014-01-01

138

Diffusion processes in a migrating interface: The thick-interface model  

Microsoft Academic Search

During a solid\\/solid diffusive phase transformation from a parent ?-phase to a product ?-phase, dissipative processes due to diffusion in the bulk phases as well as rearrangement of the crystal lattice and diffusion in the interfacial region occur. A model has been developed that accounts for all the above-mentioned dissipative processes. By means of this thick-interface model it is possible

J. Svoboda; E. Gamsjäger; F. D. Fischer; Y. Liu; E. Kozeschnik

2011-01-01

139

Modeling Human Actors in an Intelligent Automated Warehouse  

Microsoft Academic Search

Warehouse automation has progressed at a rapid pace over the last decade. While the tendency has been to implement fully automated\\u000a solutions, most warehouses today exist as a mixture of manually operated and fully automated material handling sections. In\\u000a such a hybrid warehouse, men and machines move around goods in between sections in order to retrieve, transport and stack\\u000a goods

Davy Preuveneers; Yolande Berbers

2009-01-01

140

Integration of finite element modeling with solid modeling through a dynamic interface  

NASA Technical Reports Server (NTRS)

Finite element modeling is dominated by geometric modeling type operations. Therefore, an effective interface to geometric modeling requires access to both the model and the modeling functionality used to create it. The use of a dynamic interface that addresses these needs through the use of boundary data structures and geometric operators is discussed.

Shephard, Mark S.

1987-01-01

141

Radiation budget measurement/model interface research  

NASA Technical Reports Server (NTRS)

The NIMBUS 6 data were analyzed to form an up to date climatology of the Earth radiation budget as a basis for numerical model definition studies. Global maps depicting infrared emitted flux, net flux and albedo from processed NIMBUS 6 data for July, 1977, are presented. Zonal averages of net radiation flux for April, May, and June and zonal mean emitted flux and net flux for the December to January period are also presented. The development of two models is reported. The first is a statistical dynamical model with vertical and horizontal resolution. The second model is a two level global linear balance model. The results of time integration of the model up to 120 days, to simulate the January circulation, are discussed. Average zonal wind, meridonal wind component, vertical velocity, and moisture budget are among the parameters addressed.

Vonderhaar, T. H.

1981-01-01

142

Modeling of subcontinuum thermal transport across semiconductor-gas interfaces  

NASA Astrophysics Data System (ADS)

A physically rigorous computational algorithm is developed and applied to calculate subcontinuum thermal transport in structures containing semiconductor-gas interfaces. The solution is based on a finite volume discretization of the Boltzmann equation for gas molecules (in the gas phase) and phonons (in the semiconductor). A partial equilibrium is assumed between gas molecules and phonons at the interface of the two media, and the degree of this equilibrium is determined by the accommodation coefficients of gas molecules and phonons on either side of the interface. Energy balance is imposed to obtain a value of the interface temperature. The classic problem of temperature drop across a solid-gas interface is investigated with a simultaneous treatment of solid and gas phase properties for the first time. A range of transport regimes is studied, varying from ballistic phonon transport and free molecular flow to continuum heat transfer in both gas and solid. A reduced-order model is developed that captures the thermal resistance of the gas-solid interface. The formulation is then applied to the problem of combined gas-solid heat transfer in a two-dimensional nanoporous bed and the overall thermal resistance of the bed is characterized in terms of the governing parameters. These two examples exemplify the broad utility of the model in practical nanoscale heat transfer applications.

Singh, Dhruv; Guo, Xiaohui; Alexeenko, Alina; Murthy, Jayathi Y.; Fisher, Timothy S.

2009-07-01

143

A cell based particle method for modeling dynamic interfaces  

NASA Astrophysics Data System (ADS)

We propose several modifications to the grid based particle method (GBPM) [21] for moving interface modeling. There are several nice features of the proposed algorithm. The new method can significantly improve the distribution of sampling particles on the evolving interface. Unlike the original GBPM where footpoints (sampling points) tend to cluster to each other, the sampling points in the new method tend to be better separated on the interface. Moreover, by replacing the grid-based discretization using the cell-based discretization, we naturally decompose the interface into segments so that we can easily approximate surface integrals. As a possible alternative to the local polynomial least square approximation, we also study a geometric basis for local reconstruction in the resampling step. We will show that such modification can simplify the overall implementations. Numerical examples in two- and three-dimensions will show that the algorithm is computationally efficient and accurate.

Hon, Sean Y.; Leung, Shingyu; Zhao, Hongkai

2014-09-01

144

Flashover of a vacuum-insulator interface: A statistical model  

Microsoft Academic Search

We have developed a statistical model for the flashover of a 45° vacuum-insulator interface (such as would be found in an accelerator) subject to a pulsed electric field. The model assumes that the initiation of a flashover plasma is a stochastic process, that the characteristic statistical component of the flashover delay time is much greater than the plasma formative time,

W. A. Stygar; H. C. Ives; T. C. Wagoner; J. A. Lott; V. Anaya; H. C. Harjes; J. P. Corley; R. W. Shoup; D. L. Fehl; G. R. Mowrer; Z. R. Wallace; R. A. Anderson; J. D. Boyes; J. W. Douglas; M. L. Horry; T. F. Jaramillo; D. L. Johnson; F. W. Long; T. H. Martin; D. H. McDaniel; O. Milton; M. A. Mostrom; D. A. Muirhead; T. D. Mulville; J. J. Ramirez; L. E. Ramirez; T. M. Romero; J. F. Seamen; J. W. Smith; C. S. Speas; R. B. Spielman; K. W. Struve; G. E. Vogtlin; D. E. Walsh; E. D. Walsh; M. D. Walsh; O. Yamamoto

2004-01-01

145

Hierarchical Control Modelling Architecture for Modular Distributed Automation Systems  

Microsoft Academic Search

Modern design approaches for manufacturing system organize the control architecture in the same way as the functional structure of the plant. This leads to a modular approach that is based on composition of automation components. This paper introduces a hierarchical architecture that is based on a generic internal structure of automation components. This includes logic, diagnostics as well as human

C. Sunder; Alois Zoitl; Michael Rainbauer; Bernard Favre-Bulle

2006-01-01

146

Automated Testing using Symbolic Model Checking and Temporal Monitoring  

Microsoft Academic Search

Software testing is typically an ad hoc process where human testers manually write test inputs and descriptions of expected test results, perhaps automating their execution in a regression suite. This process is cumbersome and costly. This paper reports results on a framework to further automate this process. The framework consists of combining auto- mated test case generation based on systematically

Cyrille Artho; Howard Barringer; Allen Goldberg; Klaus Havelund; Sarfraz Khurshid; Mike Lowry; Corina Pasareanu; Grigore Rosu; Koushik Sen; Willem Visser

147

Standard Product Models for Supporting Automated Erection of Structural Steelwork.  

National Technical Information Service (NTIS)

A piece of automation equipment such as a robotic crane for steel erection has no intrinsic knowledge of the process it automates. Thus, geometric and spatial information about a component such as a steel member, and the motion sequences that must be exec...

R. R. Lipman V. R. Kamat

2006-01-01

148

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...

149

Microfluidics on liquid handling stations (?F-on-LHS): an industry compatible chip interface between microfluidics and automated liquid handling stations.  

PubMed

We describe a generic microfluidic interface design that allows the connection of microfluidic chips to established industrial liquid handling stations (LHS). A molding tool has been designed that allows fabrication of low-cost disposable polydimethylsiloxane (PDMS) chips with interfaces that provide convenient and reversible connection of the microfluidic chip to industrial LHS. The concept allows complete freedom of design for the microfluidic chip itself. In this setup all peripheral fluidic components (such as valves and pumps) usually required for microfluidic experiments are provided by the LHS. Experiments (including readout) can be carried out fully automated using the hardware and software provided by LHS manufacturer. Our approach uses a chip interface that is compatible with widely used and industrially established LHS which is a significant advancement towards near-industrial experimental design in microfluidics and will greatly facilitate the acceptance and translation of microfluidics technology in industry. PMID:23639992

Waldbaur, Ansgar; Kittelmann, Jörg; Radtke, Carsten P; Hubbuch, Jürgen; Rapp, Bastian E

2013-06-21

150

Modeling nonspecific interactions at biological interfaces  

NASA Astrophysics Data System (ADS)

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.

White, Andrew D.

151

Interface tension and interface entropy in the 2+1 flavor Nambu-Jona-Lasinio model  

NASA Astrophysics Data System (ADS)

We study the QCD phases and their transitions in the 2+1 flavor Nambu-Jona-Lasinio model, with a focus on the interface effects such as the interface tension, the interface entropy, and the critical bubble size in the coexistence region of the first-order phase transitions. Our results show that under the thin-wall approximation, the interface contribution to the total entropy density changes its discontinuity scale in the first-order phase transition. However, the entropy density of the dynamical chiral symmetry (DCS) phase is always greater than that of the dynamical chiral symmetry broken (DCSB) phase in both the heating and hadronization processes. To address this entropy puzzle, the thin-wall approximation is evaluated in the present work. We find that the puzzle can be attributed to an overestimate of the critical bubble size at low temperature in the hadronization process. With an improvement on the thin-wall approximation, the entropy puzzle is well solved with the total entropy density of the hadron-DCSB phase exceeding apparently that of the DCS-quark phase at low temperature.

Ke, Wei-yao; Liu, Yu-xin

2014-04-01

152

Model annotation for synthetic biology: automating model to nucleotide sequence conversion  

PubMed Central

Motivation: The need for the automated computational design of genetic circuits is becoming increasingly apparent with the advent of ever more complex and ambitious synthetic biology projects. Currently, most circuits are designed through the assembly of models of individual parts such as promoters, ribosome binding sites and coding sequences. These low level models are combined to produce a dynamic model of a larger device that exhibits a desired behaviour. The larger model then acts as a blueprint for physical implementation at the DNA level. However, the conversion of models of complex genetic circuits into DNA sequences is a non-trivial undertaking due to the complexity of mapping the model parts to their physical manifestation. Automating this process is further hampered by the lack of computationally tractable information in most models. Results: We describe a method for automatically generating DNA sequences from dynamic models implemented in CellML and Systems Biology Markup Language (SBML). We also identify the metadata needed to annotate models to facilitate automated conversion, and propose and demonstrate a method for the markup of these models using RDF. Our algorithm has been implemented in a software tool called MoSeC. Availability: The software is available from the authors' web site http://research.ncl.ac.uk/synthetic_biology/downloads.html. Contact: anil.wipat@ncl.ac.uk Supplementary information: Supplementary data are available at Bioinformatics online.

Misirli, Goksel; Hallinan, Jennifer S.; Yu, Tommy; Lawson, James R.; Wimalaratne, Sarala M.; Cooling, Michael T.; Wipat, Anil

2011-01-01

153

Radiation budget measurement\\/model interface  

Microsoft Academic Search

This final report includes research results from the period February, 1981 through November, 1982. Two new results combine to form the final portion of this work. They are the work by Hanna (1982) and Stevens to successfully test and demonstrate a low-order spectral climate model and the work by Ciesielski et al. (1983) to combine and test the new radiation

T. H. Vonderhaar; P. Ciesielski; D. Randel; D. Stevens

1983-01-01

154

Modeling antennas near to and penetrating a lossy interface  

SciTech Connect

In this paper, we describe a technique for modeling wire objects interacting across or penetrating the planar interface which separates two half spaces. The moment-method treatment is employed, based on the thin wire approximation to the electric-field integral equation, with the effect of the interface included via the usual Sommerfeld integrals. The computation time associated with evaluating the latter is substantially shortened by using an interpolation based technique plus asymptotic field expressions. Although developed specifically for the wire problem, the procedure is also applicable, with slight modification, to modeling surface objects as well. Special account is taken of the charge discontinuity that occurs at the point a wire penetrates the interface. Example calculations are shown for the antenna-ground stake problem; monopole antenna driven against a simple ground screen; the fields of buried objects; and a simple EMP simulator.

Burke, G.J.; Miller, E.K.

1983-09-22

155

Critical interfaces and duality in the Ashkin-Teller model  

SciTech Connect

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.

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

156

Structural motifs at protein-protein interfaces: protein cores versus two-state and three-state model complexes.  

PubMed Central

The general similarity in the forces governing protein folding and protein-protein associations has led us to examine the similarity in the architectural motifs between the interfaces and the monomers. We have carried out extensive, all-against-all structural comparisons between the single-chain protein structural dataset and the interface dataset, derived both from all protein-protein complexes in the structural database and from interfaces generated via an automated crystal symmetry operation. We show that despite the absence of chain connections, the global features of the architectural motifs, present in monomers, recur in the interfaces, a reflection of the limited set of the folding patterns. However, although similarity has been observed, the details of the architectural motifs vary. In particular, the extent of the similarity correlates with the consideration of how the interface has been formed. Interfaces derived from two-state model complexes, where the chains fold cooperatively, display a considerable similarity to architectures in protein cores, as judged by the quality of their geometric superposition. On the other hand, the three-state model interfaces, representing binding of already folded molecules, manifest a larger variability and resemble the monomer architecture only in general outline. The origin of the difference between the monomers and the three-state model interfaces can be understood in terms of the different nature of the folding and the binding that are involved. Whereas in the former all degrees of freedom are available to the backbone to maximize favorable interactions, in rigid body, three-state model binding, only six degrees of freedom are allowed. Hence, residue or atom pair-wise potentials derived from protein-protein associations are expected to be less accurate, substantially increasing the number of computationally acceptable alternate binding modes (Finkelstein et al., 1995).

Tsai, C. J.; Xu, D.; Nussinov, R.

1997-01-01

157

Industrial Automation Mechanic Model Curriculum Project. Final Report.  

ERIC Educational Resources Information Center

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,…

Toledo Public Schools, OH.

158

Designers' models of the human-computer interface  

NASA Technical Reports Server (NTRS)

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.

Gillan, Douglas J.; Breedin, Sarah D.

1993-01-01

159

Hidden Markov Model Symbol Recognition for Sketch-Based Interfaces  

Microsoft Academic Search

A central challenge for sketch-based interfaces is robust symbol recognition. Artifacts such as sketching style, pixelized symbol representation and affine transformations are just a few of the problems. Temporal pattern recognition through Hidden Markov Models (HMM) can be used to recognize and distinguish symbols as pixel-driven gestures. The key challenges of such a system are the type and amount of

Derek Anderson; Craig Bailey; Marjorie Skubic

2004-01-01

160

Measurement and Modeling of Interface Heat Transfer Coefficients.  

National Technical Information Service (NTIS)

The results of preliminary work on the modeling and measurement of the heat transfer coefficients of metal/mold interfaces is reported. The system investigated is the casting of uranium in graphite molds. The motivation for the work is primarily to improv...

A. D. Rollett H. D. Lewis P. S. Dunn

1985-01-01

161

Modeling Antennas Near to and Penetrating a Lossy Interface.  

National Technical Information Service (NTIS)

In this paper, we describe a technique for modeling wire objects interacting across or penetrating the planar interface which separates two half spaces. The moment-method treatment is employed, based on the thin wire approximation to the electric-field in...

E. K. Miller G. J. Burke

1983-01-01

162

Multimodal Interfaces: A Survey of Principles, Models and Frameworks  

Microsoft Academic Search

The grand challenge of multimodal interface creation is to build reliable processing systems able to analyze and understand multiple communication means in real-time. This opens a number of associated issues covered by this chapter, such as heterogeneous data types fusion, architectures for real-time processing, dialog management, machine learning for multimodal interaction, modeling languages, frameworks, etc. This chapter does not intend

Bruno Dumas; Denis Lalanne; Sharon L. Oviatt

2009-01-01

163

A NONLOCAL INTEGRAL APPROACH TO ELASTIC-DAMAGE INTERFACE MODELLING  

Microsoft Academic Search

The paper presents an elastic-damage interface model developed with constitutive relations based on nonlocal concepts. The main motivation for accepting to pay the cost of the extra com- plexities induced by nonlocal features is rooted on the observation that in many mechanical circum- stances the process zone, where decohesion develops, involves a spatially extended microstructure which produces complex bridging spatial

G. Borino; B. Failla; F. Parrinello

164

Atomic Models of Strong Solids Interfaces Viewed as Composite Structures  

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

165

A general graphical user interface for automatic reliability modeling  

NASA Technical Reports Server (NTRS)

Reported here is a general Graphical User Interface (GUI) for automatic reliability modeling of Processor Memory Switch (PMS) structures using a Markov model. This GUI is based on a hierarchy of windows. One window has graphical editing capabilities for specifying the system's communication structure, hierarchy, reconfiguration capabilities, and requirements. Other windows have field texts, popup menus, and buttons for specifying parameters and selecting actions. An example application of the GUI is given.

Liceaga, Carlos A.; Siewiorek, Daniel P.

1991-01-01

166

Foundations of multi-paradigm modeling and simulation: computer automated multi-paradigm modelling: meta-modelling and graph transformation  

Microsoft Academic Search

We present Computer Automated Multi-Paradigm Modelling (CAMPaM) (Mosterman and Vangheluwe 2002) for Model-Driven Development based on Meta-Modelling and Graph Transformation. The syntax of a class of models of interest is graphically meta-modelled in an appropriate formalism such as Entity-Relationship Diagrams. From this description of abstract syntax, augmented with concrete (visual) syntax information, an interactive, visual modelling environment is automatically generated.

Hans Vangheluwe; Juan de Lara

2003-01-01

167

Computer modelling of nanoscale diffusion phenomena at epitaxial interfaces  

NASA Astrophysics Data System (ADS)

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.

Michailov, M.; Ranguelov, B.

2014-05-01

168

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

169

Image quality and performance modeling for automated target detection  

NASA Astrophysics Data System (ADS)

Several methods have been developed for quantifying the information potential of imagery exploited by a human observer. The National Imagery Interpretability Ratings Scale (NIIRS) has proven to be a useful standard for intelligence, surveillance, and reconnaissance (ISR) applications. A comparable standard for automated information extraction would be useful for a variety of applications, including tasking and collection management. This paper examines the applicability of NIIRS to automated exploitation methods. In particular, we compare image-based estimates of the NIIRS to observed performance of an automated target detection (ATD) algorithm. In addition, we examine other image metrics and their relationship to ATD performance. The findings indicate that NIIRS is not a good predictor of ATD performance, but methods that quantify the complexity of the clutter hold promise.

Irvine, John M.; Nelson, Eric

2009-05-01

170

Modeling the Photoionized Interface in Blister H II Regions  

NASA Astrophysics Data System (ADS)

We present a grid of photoionization models for the emission from photoevaporative interfaces between the ionized gas and molecular cloud in blister H II 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. 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 [S II] and [N II] 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 H II regions. As an example, we consider a location at the tip of an ``elephant trunk'' structure in M16 (the Eagle Nebula) and show how narrowband Hubble Space Telescope Wide Field Planetary Camera 2 (HSTWFPC2) images constrain the H II region properties. We present a photoionization model that explains the ionization structure and emission from the interface seen in these high spatial resolution data.

Sankrit, Ravi; Hester, J. Jeff

2000-06-01

171

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

NASA Technical Reports Server (NTRS)

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.

Costen, Robert C.

2000-01-01

172

Stability of finite difference models containing two boundaries or interfaces  

NASA Technical Reports Server (NTRS)

The stability of finite difference models of hyperbolic initial boundary value problems is connected with the propagation and reflection of parasitic waves. Wave propagation ideas are applied to models containing two boundaires or interfaces, where repeated reflection of trapped wave packets is a potential new source of instability. Various known instability phenomena are accounted for in a unified way. Results show: (1) dissipativity does not ensure stability when three or more formulas are concatenated at a boundary or internal interface; (2) algebraic GKS instabilities can be converted by a second boundary to exponential instabilities only when an infinite numerical reflection coefficient is present; and (3) GKS-stability and P-stability can be established in certain problems by showing that all numerical reflection coefficients have modulus less than 1.

Trefethen, L. N.

1984-01-01

173

Electronegativity model for barrier formation at metal/organic interfaces  

NASA Astrophysics Data System (ADS)

An electronegativity model is proposed to characterize the variation of charge injection barrier heights at metal/organic interfaces. In contrast to the traditionally used metal work function, barrier heights at interfaces are shown to be linearly dependent on metal electronegativity for a wide range of organic materials. The physical basis for the better suitability of electronegativity than work function to describe barrier heights is discussed. While barrier formation is caused by charge transfer between metals and organic semiconductors, the variation of the barrier height is related to the electronegativity difference of metals. The applicability of the electronegativity model to compound or alloy electrodes, such as indium tin oxide having no defined electronegativity, is also exemplified.

Tang, J. X.; Lee, C. S.; Lee, S. T.

2005-12-01

174

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

Microsoft Academic Search

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,

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

175

A Feedback Model for Automated Real Estate Assessment  

Microsoft Academic Search

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.

Robert Carbone; Richard L. Longini

1977-01-01

176

Image quality and performance modeling for automated target detection  

Microsoft Academic Search

Several methods have been developed for quantifying the information potential of imagery exploited by a human observer. The National Imagery Interpretability Ratings Scale (NIIRS) has proven to be a useful standard for intelligence, surveillance, and reconnaissance (ISR) applications. A comparable standard for automated information extraction would be useful for a variety of applications, including tasking and collection management. This paper

John M. Irvine; Eric Nelson

2009-01-01

177

Film rupture in the diffuse interface model coupled to hydrodynamics  

Microsoft Academic Search

The process of dewetting of a thin liquid film is usually described using a long-wave approximation yielding a single evolution equation for the film thickness. This equation incorporates an additional pressure term-the disjoining pressure-accounting for the molecular forces. Recently a disjoining pressure was derived coupling hydrodynamics to the diffuse interface model [L. M. Pismen and Y. Pomeau, Phys. Rev. E

Uwe Thiele; Manuel G. Velarde; Kai Neuffer; Yves Pomeau

2001-01-01

178

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

SciTech Connect

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.

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

179

Transforming Collaborative Process Models into Interface Process Models by Applying an MDA Approach  

NASA Astrophysics Data System (ADS)

Collaborative business models among enterprises require defining collaborative business processes. Enterprises implement B2B collaborations to execute these processes. In B2B collaborations the integration and interoperability of processes and systems of the enterprises are required to support the execution of collaborative processes. From a collaborative process model, which describes the global view of the enterprise interactions, each enterprise must define the interface process that represents the role it performs in the collaborative process in order to implement the process in a Business Process Management System. Hence, in this work we propose a method for the automatic generation of the interface process model of each enterprise from a collaborative process model. This method is based on a Model-Driven Architecture to transform collaborative process models into interface process models. By applying this method, interface processes are guaranteed to be interoperable and defined according to a collaborative process.

Lazarte, Ivanna M.; Chiotti, Omar; Villarreal, Pablo D.

180

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

PubMed Central

Targeted transcranial stimulation with electric currents requires accurate models of the current flow from scalp electrodes to the human brain. Idiosyncratic anatomy of individual brains and heads leads to significant variability in such current flows across subjects, thus, necessitating accurate individualized head models. Here we report on an automated processing chain that computes current distributions in the head starting from a structural magnetic resonance image (MRI). The main purpose of automating this process is to reduce the substantial effort currently required for manual segmentation, electrode placement, and solving of finite element models. In doing so, several weeks of manual labor were reduced to no more than 4 hours of computation time and minimal user interaction, while current-flow results for the automated method deviated by less than 27.9% from the manual method. Key facilitating factors are the addition of three tissue types (skull, scalp and air) to a state-of-the-art automated segmentation process, morphological processing to correct small but important segmentation errors, and automated placement of small electrodes based on easily reproducible standard electrode configurations. We anticipate that such an automated processing will become an indispensable tool to individualize transcranial direct current stimulation (tDCS) therapy.

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

2014-01-01

181

An automated method for high-definition transcranial direct current stimulation modeling.  

PubMed

Targeted transcranial stimulation with electric currents requires accurate models of the current flow from scalp electrodes to the human brain. Idiosyncratic anatomy of individual brains and heads leads to significant variability in such current flows across subjects, thus, necessitating accurate individualized head models. Here we report on an automated processing chain that computes current distributions in the head starting from a structural magnetic resonance image (MRI). The main purpose of automating this process is to reduce the substantial effort currently required for manual segmentation, electrode placement, and solving of finite element models. In doing so, several weeks of manual labor were reduced to no more than 4 hours of computation time and minimal user interaction, while current-flow results for the automated method deviated by less than 27.9% from the manual method. Key facilitating factors are the addition of three tissue types (skull, scalp and air) to a state-of-the-art automated segmentation process, morphological processing to correct small but important segmentation errors, and automated placement of small electrodes based on easily reproducible standard electrode configurations. We anticipate that such an automated processing will become an indispensable tool to individualize transcranial direct current stimulation (tDCS) therapy. PMID:23367144

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

2012-01-01

182

Language Model Applications to Spelling with Brain-Computer Interfaces  

PubMed Central

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.

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

2014-01-01

183

Language model applications to spelling with Brain-Computer Interfaces.  

PubMed

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

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

2014-01-01

184

A plasticity model for interface friction: application to sheet metal forming  

Microsoft Academic Search

Successful numerical simulations of forming operations require robust and accurate tool-workpiece interface friction models. In this paper we extend the rate-independent, isotropic, isothermal interface friction model proposed by Anand (Anand, L., 1993. A constitutive model for interface friction. Computational Mechanics 12, 197–213) to a rate-dependent formulation. Material parameters in the friction model are determined for lubricated interfaces between Al6111-T4 sheet

B. P. Gearing; H. S. Moon; L. Anand

2001-01-01

185

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

ERIC Educational Resources Information Center

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…

Spaulding, Trent Joseph

2011-01-01

186

A Model Driven Approach to Automate the Implementation of Clinical Guidelines in Decision Support Systems  

Microsoft Academic Search

Clinical guidelines and protocols are used to aid decision making in health care. This paper presents a model- based approach to the development of decision support systems for clinical guidelines. The guidelines are modelled using the UML Statechart language and the final system is automatically generated using an automated model transformation. Our approach is illustrated with a Spanish clinical guideline

Ivan Porres; Eladio Domínguez; Beatriz Pérez; Áurea Rodríguez; María Antonia Zapata

2008-01-01

187

Experimental studies on multiple-model predictive control for automated regulation of hemodynamic variables  

Microsoft Academic Search

A model-based control methodology was developed for automated regulation of mean arterial pressure and cardiac output in critical care subjects using inotropic and vasoactive drugs. The control algorithm used a multiple-model adaptive approach in a model predictive control framework to account for variability and explicitly handle drug rate constraints. The controller was experimentally evaluated on canines that were pharmacologically altered

Ramesh R. Rao; Brian Aufderheide; B. Wayne Bequette

2003-01-01

188

Sequence annotation of nuclear receptor ligand-binding domains by automated homology modeling  

Microsoft Academic Search

The quality of three-dimensional homology models derived from protein sequences provides an independent measure of the suitability of a protein sequence for a certain fold. We have used automated homology modeling and model assessment tools to identify putative nuclear hormone receptor ligand-binding domains in the genome of Caenorhabditis elegans. Our results indicate that the availability of multiple crystal structures is

C. J. J. Francoijs; J. P. G. Klomp; R. M. A. Knegtel

2000-01-01

189

Numerical modeling of materials processes with fluid-fluid interfaces  

NASA Astrophysics Data System (ADS)

A numerical model has been developed to study material processes that depend on the interaction between fluids with a large discontinuity in thermophysical properties. A base model capable of solving equations of mass, momentum, energy conservation, and solidification has been altered to enable tracking of the interface between two immiscible fluids and correctly predict the interface deformation using a volume of fluid (VOF) method. Two materials processes investigated using this technique are Electroslag Remelting (ESR) and plasma spray deposition. ESR is a secondary melting technique that passes an AC current through an electrically resistive slag to provide the heat necessary to melt the alloy. The simulation tracks the interface between the slag and metal. The model was validated against industrial scale ESR ingots and was able to predict trends in melt rate, sump depth, macrosegregation, and liquid sump depth. In order to better understand the underlying physics of the process, several constant current ESR runs simulated the effects of freezing slag in the model. Including the solidifying slag in the imulations was found to have an effect on the melt rate and sump shape but there is too much uncertainty in ESR slag property data at this time for quantitative predictions. The second process investigated in this work is the deposition of ceramic coatings via plasma spray deposition. In plasma spray deposition, powderized coating material is injected into a plasma that melts and carries the powder towards the substrate were it impacts, flattening out and freezing. The impacting droplets pile up to form a porous coating. The model is used to simulate this rain of liquid ceramic particles impacting the substrate and forming a coating. Trends in local solidification time and porosity are calculated for various particle sizes and velocities. The predictions of decreasing porosity with increasing particle velocity matches previous experimental results. Also, a preliminary study was conducted to investigate the effects of substrate surface defects and droplet impact angle on the propensity to form columnar porosity.

Yanke, Jeffrey Michael

190

Privacy and Security in Multi-modal User Interface Modeling for Social Media  

Microsoft Academic Search

This paper addresses privacy and security issues regarding the modeling of multi-modal user interfaces for social media applications. The proposed approach describes how privacy and security concerns are modeled from the user interface perspective, and how this model is related to a four layer conceptual framework for developing multi-modal and multi platform user interfaces. The approach also explains how to

Mohamed Bourimi; Ricardo Tesoriero; Pedro G. Villanueva; Fatih Karatas; Philipp Schwarte

2011-01-01

191

Privacy and Security in Multi-modal User Interface Modeling for SocialMedia  

Microsoft Academic Search

This paper addresses privacy and security issues regarding the modeling of multi-modal user interfaces for social media applications. The proposed approach describes how privacy and security concerns are modeled from the user interface perspective, and how this model is related to a four layer conceptual framework for developing multi-modal and multi platform user interfaces. The approach also explains how to

M. Bourimi; Ricardo Tesoriero; P. G. Villanueva; F. Karatas; P. Schwarte

2011-01-01

192

A biological model for controlling interface growth and morphology.  

SciTech Connect

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.

Hoyt, Jeffrey John; Holm, Elizabeth Ann

2004-01-01

193

A symbolic/subsymbolic interface protocol for cognitive modeling  

PubMed Central

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.

Simen, Patrick; Polk, Thad

2009-01-01

194

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

NASA Technical Reports Server (NTRS)

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.

Schutte, Paul; Goodrich, Kenneth; Williams, Ralph

2012-01-01

195

Elastoplastic constitutive modelling of soil–structure interfaces under monotonic and cyclic loading  

Microsoft Academic Search

This paper is dedicated to the non-linear numerical modelling of the soil–structure interface. Thus, in a first part, after the presentation of the constitutive model, the soil–structure interface interaction is treated in terms of direct shear test simulations. A strategy for the interface model parameters’ identification is also presented. This strategy is linked to the similitude of soil–structure interface behavior

Sofia Costa D’Aguiar; Arezou Modaressi-Farahmand-Razavi; Jaime Alberto dos Santos; Fernando Lopez-Caballero

2011-01-01

196

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

Microsoft Academic Search

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

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

197

MT-Scribe: an end-user approach to automate software model evolution  

Microsoft Academic Search

evolution is an essential activity in software system modeling, which is traditionally supported by manual editing or writing model transformation rules. However, the current state of practice for model evolution presents challenges to those who are unfamiliar with model transformation languages or metamodel definitions. This demonstration presents a demonstration-based approach that assists end-users through automation of model evolution tasks (e.g.,

Yu Sun; Jeff Gray; Jules White

2011-01-01

198

Building effective formal models to prove time properties of networked automation systems  

Microsoft Academic Search

This paper proposes a method to build formal models of networked automation systems, in the form of sets of communicating timed automata, which are reduced enough to avoid (or limit) combinatory explosion, but accurate enough to provide meaningful proof results, when they are checked. This method starts from a detailed initial model, which includes all behaviours of all components of

Silvain Ruel; Olivier de Smet; Jean-Marc Faure

2009-01-01

199

Building effective formal models to prove time properties of networked automation systems  

Microsoft Academic Search

This paper proposes a method to build formal models of networked automation systems, in the form of sets of communicating timed automata, which are reduced enough to avoid (or limit) combinatory explosion, but accurate enough to provide meaningful proof results, when they are checked. This method starts from a detailed initial model, which includes all behaviours of all components of

Silvain Ruel; Olivier de Smet; Jean-Marc Faure

2008-01-01

200

The Perceived Value of Authoring and Automating Acceptance Tests Using a Model Driven Development Toolset  

Microsoft Academic Search

One approach to applying keyword driven testing in a model-driven development environment is by defining a domain specific language for test cases. The toolset then provides test editors, versioning, validation, reporting and hyperlinks across models - in addition to enabling automated test execution. This case study evaluates the effectiveness of such a solution as perceived by two teams of professional

David Talby

2009-01-01

201

Automated System for Physical Modeling of the Stress-Strain State of Block Structures in Geomedium  

Microsoft Academic Search

Development of construction principles and creation of automated systems for physical modeling of the block geomedium behavior in the varying unequally component stress field are considered currently as one of the strategic problems in nonlinear geomechanics. The scheme of stand for physical modeling and measuring-computational equipment oriented to the solution for fundamental problems of geomechanics are presented.

V. N. Oparin; V. M. Zhigalkin; V. F. Yushkin; B. F. Simonov; A. K. Potashnikov; N. A. Kaniskin

2001-01-01

202

Optimisation model and exact algorithm for Autonomous Straddle Carrier Scheduling at automated container terminals  

Microsoft Academic Search

In this paper, an optimisation model based on Pickup and Delivery Problem with Time Windows (PDPTW), and an exact algorithm based on Branch-and-Bound with Column Generation (BBCG), are presented for Autonomous Straddle Carriers Scheduling (ASCS) problem at automated container terminals. The ASCS problem is firstly modeled into a PDPTW, which is formulated as a Binary Integer Programming (BIP) and then

Binghuang Cai; Shoudong Huang; Dikai Liu; Shuai Yuan; Gamini Dissanayake; Haye Lau; Daniel Pagac

2011-01-01

203

Optimisation model and exact algorithm for autonomous straddle carrier scheduling at automated container terminals  

Microsoft Academic Search

In this paper, an optimisation model based on Pickup and Delivery Problem with Time Windows (PDPTW), and an exact algorithm based on Branch-and-Bound with Column Generation (BBCG), are presented for Autonomous Straddle Carriers Scheduling (ASCS) problem at automated container terminals. The ASCS problem is firstly modeled into a PDPTW, which is formulated as a Binary Integer Programming (BIP) and then

Binghuang Cai; Shoudong Huang; Dikai Liu; Shuai Yuan; Gamini Dissanayake; Haye Lau; Daniel Pagac

2011-01-01

204

Mathematical Modeling Research to Support the Development of Automated Insulin-Delivery Systems  

Microsoft Academic Search

The world leaders in glycemia modeling convened during the Eighth Annual Diabetes Technology Meeting in Bethesda, Maryland, on 14 November 2008, to discuss the current practices in mathematical modeling and make recommendations for its use in developing automated insulin-delivery systems. This report summarizes the collective views of the 25 participating experts in addressing the following four topics: current practices in

Garry M. Steil; Jaques Reifman

2009-01-01

205

A Binary Programming Approach to Automated Test Assembly for Cognitive Diagnosis Models  

ERIC Educational Resources Information Center

Automated test assembly (ATA) has been an area of prolific psychometric research. Although ATA methodology is well developed for unidimensional models, its application alongside cognitive diagnosis models (CDMs) is a burgeoning topic. Two suggested procedures for combining ATA and CDMs are to maximize the cognitive diagnostic index and to use a…

Finkelman, Matthew D.; Kim, Wonsuk; Roussos, Louis; Verschoor, Angela

2010-01-01

206

General Models for Automated Essay Scoring: Exploring an Alternative to the Status Quo  

ERIC Educational Resources Information Center

Powers, Burstein, Chodorow, Fowles, and Kukich (2002) suggested that automated essay scoring (AES) may benefit from the use of "general" scoring models designed to score essays irrespective of the prompt for which an essay was written. They reasoned that such models may enhance score credibility by signifying that an AES system measures the same…

Kelly, P. Adam

2005-01-01

207

User interface derivation from business processes: a model-driven approach for organizational engineering  

Microsoft Academic Search

This paper defines a model-driven approach for organizational engineering in which user interfaces of information systems are derived from business processes. This approach consists of four steps: business process modeling in the context of organizational engineering, task model derivation from the business process model, task refinement, and user interface model derivation from the task model. Each step contributes to specify

Kênia Soares Sousa; Hildeberto Mendonça Filho; Jean Vanderdonckt; Els Rogier; Joannes Vandermeulen

2008-01-01

208

Modeling of Environmentally Significant Interfaces: Two Case Studies  

SciTech Connect

Three case studies of environmentally 'green' interfaces are presented to demonstrate how mathematical models can be used to deconvolute data that are limited by experimental constraints. Such deconvolutions help to quantify the contributions from the various phenomena that contribute to the overall behavior, and enable the scientist to control and manipulate these phenomena, and thus to optimize the performance of the material or device. The three case studies all address green surfaces that are of importance for environmental quality or energy efficiency: (a) calcite growth and dissolution in water (important for the global carbon dioxide cycle), (b) fuel cell catalysts (important for the development of green power sources), and (c) pore shape engineering in mesoporous silicas (important as sorbents for environmental cleanup). Modeling techniques range from Monte Carlo to differential equations to simple algebra, and demonstrate the mutually beneficial interactions between experiment and modeling in the solution of a wide range of problems.

Williford, Rick E.

2006-02-16

209

ORIGAMI -- The Oak Ridge Geometry Analysis and Modeling Interface  

SciTech Connect

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.

Burns, T.J.

1996-04-01

210

An Environment for Automated Test Case Generation from Statechart-based and Finite State Machine-based Behavioral Models  

Microsoft Academic Search

Automated test case generation from behavioral models like finite state machines (FSMs) and statecharts has long been studied. Environments that enable a test designer to model a real complex software and to obtain test cases to validate such a software are mandatory in an automated test approach. This paper presents an environment, GTSC, which enables test sequences to be obtained

Valdivino Santiago; N. L. Vijaykumar; Danielle Guimarães; Ana Silvia Amaral; Érica Ferreira

2008-01-01

211

Interfacing dispersion models in the HGSYSTEM hazard-assessment package  

NASA Astrophysics Data System (ADS)

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.

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

212

Automated volumetric grid generation for finite element modeling of human hand joints  

SciTech Connect

We are developing techniques for finite element analysis of human joints. These techniques need to provide high quality results rapidly in order to be useful to a physician. The research presented here increases model quality and decreases user input time by automating the volumetric mesh generation step.

Hollerbach, K.; Underhill, K. [Lawrence Livermore National Lab., CA (United States); Rainsberger, R. [XYZ Scientific Applications, Inc., Livermore, CA (United States)

1995-02-01

213

Retrieving canopy variables by radiative transfer model inversion : an automated regional approach for imaging spectrometer data  

Microsoft Academic Search

A new, automated, regional approach is presented for the estimation of leaf area index, leaf chlorophyll, dry matter, and water content, based on the inversion of the combined leaf and canopy radiative transfer model PROSPECT+SAILh. The approach, named CRASh, is open to different types of imaging spectrometers, although it has been originally designed for airborne hyperspectral sensors with a wide

Wouter Dorigo; Frédéric Baret; Rolf Richter; Gerd Ruecker; Michael Schaepman; A. Mueller

2007-01-01

214

Validation of Automation Systems using Temporal Logic Model Checking and Groebner Bases  

Microsoft Academic Search

Validation of an automation system is an important issue. The goal is to check if the system under investigation, modeled by a Petri net, never enters the undesired states. Usually, tools dedicated to Petri nets such as DESIGN\\/CPN are used to make reachability analysis. The biggest problem with this approach is that it is impossible to generate the full occurence

Quoc-Nam Tran

2009-01-01

215

Closed form models for dwell point locations in automated storage carousel systems  

Microsoft Academic Search

This research focuses on determining the optimal dwell point location in an automated storage carousel system (ASCS) to minimise the expected response time for incoming service requests (storages and retrievals). This can be achieved by modelling the problem as a minisum location problem on a line segment with two-dimensional existing facilities (demands) using a continuous approximation of the individual storage

T. S. Hale; F. Huq; N. A. Pujari

2008-01-01

216

A revised empirical model to estimate solar radiation using automated surface weather observations  

Microsoft Academic Search

The transition from manual to automated weather observations at US National Weather Service Offices has compromised the ability to use these data as a means for estimating global horizontal and direct solar radiation. The creation of long term model-derived solar radiation climatologies continues to rely on the in situ cloud data that these observations provide, since homogeneous and readily available

Brian N. Belcher; Arthur T. DeGaetano

2007-01-01

217

New Directions in C2 Software Quality Assurance Automation Based on Executable Environment Models  

Microsoft Academic Search

This paper presents some concepts, principles, and techniques for automated testing of real-time reactive software systems based on attributed event grammar (AEG) modeling of the environment in which a system will operate. AEG provides a uniform approach for auto- matic test generation, execution, and analysis. Quantitative and qualitative assessment of the system comprised of the software under test and its

Mikhail Auguston; James Bret Michael; Man-Tak Shing

218

IDEF3 and IDEF4 Automation System Requirements Document and System Environment Models.  

National Technical Information Service (NTIS)

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 re...

T. M. Blinn

1989-01-01

219

Automated Test Assembly for Cognitive Diagnosis Models Using a Genetic Algorithm  

ERIC Educational Resources Information Center

Much recent psychometric literature has focused on cognitive diagnosis models (CDMs), a promising class of instruments used to measure the strengths and weaknesses of examinees. This article introduces a genetic algorithm to perform automated test assembly alongside CDMs. The algorithm is flexible in that it can be applied whether the goal is to…

Finkelman, Matthew; Kim, Wonsuk; Roussos, Louis A.

2009-01-01

220

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

PubMed Central

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.

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

2014-01-01

221

Parallelization of a hydrological model using the message passing interface  

USGS Publications Warehouse

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.

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

2013-01-01

222

Diffuse interface model of multicomponent vesicle adhesion and fusion.  

PubMed

Prefusion and postfusion states of the biological fusion process between lipid bilayer vesicle membranes are studied in this paper. Based on the Helfrich-type continuum theory, a diffuse interface model is developed which describes the phase changes on the deformable vesicles via a scalar phase field function, and incorporates the adhesion effect between the different phases of the vesicles through a nonlocal interaction potential. Various equilibrium configurations in the prefusion and postfusion states are examined. The effects of spontaneous curvatures, bending, and Gaussian rigidities on the fusion process are discussed. Instead of considering only the regions in close contact as in many previous studies, the present approach allows us to include the energetic contributions from all parts of the vesicles. By carrying out simulations based on the gradient flow of the associated energy functional, we are also able to elucidate the dynamic transitions between the prefusion and postfusion states. PMID:21867209

Zhao, Yanxiang; Du, Qiang

2011-07-01

223

An investigation of passivation properties of SiNx-Si interface by an MIS model  

NASA Astrophysics Data System (ADS)

This paper presents a new way to study passivation mechanism of SiNx-Si interface using capacitance-voltage method. Fixed charge density (Nf) near dielectric/Si interface, which is closely related to field effect passivation, and interface trap density (Dit) at dielectric/Si interface, which is closely related to chemical passivation, can be obtained directly from experimental CV characteristics. The passivation properties of SiNx-Si can be studied and optimized by the MIS model.

Wang, Jun; Han, Meijie; Ma, Xueliang; Zhang, Hua; Chen, Ping; Zhu, Haixin

2013-12-01

224

Reliability in Automated Aids for Unmanned Aerial Vehicle Flight Control: Evaluating a Model of Automation Dependence in High Workload.  

National Technical Information Service (NTIS)

Twenty-four participants flew a simulated unmanned aerial vehicle (UAV) through ten mission legs while searching for targets of opportunity and monitoring system parameters. Participants were assisted by automation which provided auditory alerts in respon...

C. D. Wickens S. Dixon

2004-01-01

225

Development of an automated 7-day 96-well Caco-2 cell culture model.  

PubMed

Caco-2 cells are a widely accepted model to predict permeability and absorption of compounds in humans. We built up an automated 96-wellplate Caco-2 permeation model with reduced growth time. Model compounds (metoprolol, ketoprofen, verapamil, naproxen, hydrochlorthiazide), permeability markers (TEER, Lucifer Yellow, D-[1-(14)C]-mannitol) and confocal microscopy were used to assess the utility of our method on Biomek-FX-automation. The confocal imaging data showed that Caco-2 cells formed monolayers when cultured for 7 days with initial cell density of 2.1 x 10(5) cells/cm2. P-Glycoprotein was present in Caco-2 cells, localized on the plasma membrane. Permeation of model compounds was comparable to those obtained from traditional 12-wellplate experiments. PMID:18604991

Galkin, A; Pakkanen, J; Vuorela, P

2008-06-01

226

Algorithm for the Automated Generation of Rheological Models.  

National Technical Information Service (NTIS)

The paper presents a computational approach for generating rheological models. A rheological structure can be analogically described as a set of basic components connected in series or in parallel. The models are automatically created in two different for...

A. C. Capelo L. Ironi S. Tentoni

1990-01-01

227

Automated adaptive model inference to predict biological network dynamics  

NASA Astrophysics Data System (ADS)

Dynamical models of cellular regulation often consist of large and intricate networks of interactions at the molecular scale. Since individual interaction parameters are usually difficult to measure, these parameters are often estimated implicitly, using statistical fits. This can lead to overfitting and degradation in the quality of models' predictions. Here we study phenomenological models that adapt their level of detail to the amount of available data, leading to accurate predictions even when microscopic details are not well understood. The model search is made computationally efficient by testing an ordered, nested set of models and by using a model class that can be solved using linear regression in log-space. We test the method on synthetic data and find that phenomenological models inferred this way often outperform detailed, ``correct'' molecular models in making predictions about responses of the system to signals yet unseen.

Daniels, Bryan; Nemenman, Ilya

2013-03-01

228

Automated dynamic analytical model improvement for damped structures  

NASA Technical Reports Server (NTRS)

A method is described to improve a linear nonproportionally damped analytical model of a structure. The procedure finds the smallest changes in the analytical model such that the improved model matches the measured modal parameters. Features of the method are: (1) ability to properly treat complex valued modal parameters of a damped system; (2) applicability to realistically large structural models; and (3) computationally efficiency without involving eigensolutions and inversion of a large matrix.

Fuh, J. S.; Berman, A.

1985-01-01

229

Computer automation of general-to-specific model selec-tion procedures  

Microsoft Academic Search

Abstract That econometric,methodology,remains in dispute partly reflects the lack of clear evidence on alternative approaches. This paper reconsiders econometric,model selection from a computer- automation perspective, focusing on general-to-specific reduction approaches, as embodied in the program PcGets (general?to?specific). Starting from a general linear, dynamic statistical model, which captures the essential data characteristics, standard testing procedures are applied to elimin- ate statistically-insignificant

H. M Krolzig; D. F. Hendry

2001-01-01

230

Automated Test Case Generation for Web Applications from a Domain Specific Model  

Microsoft Academic Search

Model-based testing is a promising technique for test case design that is used in an increasing number of application domains. However, to fully gain efficiency advantages, intuitive domain-specific notations with comfortable tool support as well as a high degree of automation in the whole testing process are required. In this paper, a model-based testing approach for web application black box

Arne-Michael Torsel

2011-01-01

231

Development of an integrated semi-automated system for in vitro pharmacodynamic modelling  

Microsoft Academic Search

Objectives: The aim of this study was to develop an integrated system for in vitro pharmacodynamic modelling of antimicrobials with greater flexibility, easier control and better accuracy than existing in vitro models. Methods: Custom-made bottle caps, fittings, valve controllers and a modified bench-top shaking incubator were used. A temperature-controlled automated sample collector was built. Computer soft- ware was developed to

Liangsu Wang; Michael K. Wismer; Fred Racine; Donald Conway; Robert A. Giacobbe; Olga Berejnaia; Gary S. Kath

232

Automated Predicate Abstraction for Real-Time Models  

Microsoft Academic Search

Introduction Model checking has been widely successful in validating and debugging hardware de- signs and communication protocols. However, state-space explosion is an intrinsic problem which limits the applicability of model checking tools. To overcome this limitation software model checkers have suggested different approaches, among which abstraction methods have been highly esteemed. modern techniques. Among others, predicate abstraction is a prominent

Bahareh Badban; Stefan Leue; Jan-Georg Smaus

2009-01-01

233

Computer-automated multiparadigm modeling in control systems technology  

Microsoft Academic Search

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

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

2004-01-01

234

Numerical Mantle Convection Models With a Flexible Thermodynamic Interface  

NASA Astrophysics Data System (ADS)

Accurate material properties are needed for deep mantle (P,T) conditions in order to predict the longterm behavior of convection planetary mantles. Also the interpretation of seismological observations concerning the deep mantle in terms of mantle flow models calls for a consistent thermodynamical description of the basic physical parameters. We have interfaced a compressible convection code using the anelastic liquid approach based on finite element methods, to a database containing a full thermodynamic description of mantle silicates (Ita and King, J. Geophys. Res., 99, 15,939-15,940, 1994). The model is based on high resolution (P,T) tables of the relevant thermodynamic properties containing typically 50 million (P,T) table gridpoints to obtain resolution in (P,T) space of 1 K and an equivalent of 1 km. The resulting model is completely flexible such that numerical mantle convection experiments can be performed for any mantle composition for which the thermodynamic database is available. We present results of experiments for 2D cartesian models using a data base for magnesium-iron silicate in a pyrolitic composition (Stixrude and Bukowinski, Geoph.Monogr.Ser., 74, 131-142, 1993) and a recent thermodynamical model for magnesium silicate for the complete mantle (P,T) range, (Jacobs and Oonk, Phys. Chem. Mineral, 269, inpress 2001). Preliminary results of bulksound velocity distribution derived in a consistent way from the convection results and the thermodynamic database show a `realistic' mantle profile with bulkvelocity variations decreasing from several percent in the upper mantle to less than a percent in the deep lower mantle.

van den Berg, A. P.; Jacobs, M. H.; de Jong, B. H.

2001-12-01

235

Graphical User Interface for Simulink Integrated Performance Analysis Model  

NASA Technical Reports Server (NTRS)

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.

Durham, R. Caitlyn

2009-01-01

236

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

PubMed

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

Pizziol, Sergio; Tessier, Catherine; Dehais, Frédéric

2014-03-01

237

A bidirectional interface growth model for cranial interosseous suture morphogenesis  

PubMed Central

Interosseous sutures exhibit highly variable patterns of interdigitation and corrugation. Recent research has identified fundamental molecular mechanisms of suture formation, and computer models have been used to simulate suture morphogenesis. However, the role of bone strain in the development of complex sutures is largely unknown, and measuring suture morphologies beyond the evaluation of fractal dimensions remains a challenge. Here we propose a morphogenetic model of suture formation, which is based on the paradigm of Laplacian interface growth. Computer simulations of suture morphogenesis under various boundary conditions generate a wide variety of synthetic sutural forms. Their morphologies are quantified with a combination of Fourier analysis and principal components analysis, and compared with natural morphological variation in an ontogenetic sample of human interparietal suture lines. Morphometric analyses indicate that natural sutural shapes exhibit a complex distribution in morphospace. The distribution of synthetic sutures closely matches the natural distribution. In both natural and synthetic systems, sutural complexity increases during morphogenesis. Exploration of the parameter space of the simulation system indicates that variation in strain and/or morphogen sensitivity and viscosity of sutural tissue may be key factors in generating the large variability of natural suture complexity.

Zollikofer, Christoph P E; Weissmann, John David

2011-01-01

238

NRCS GeoHydro—A GIS interface for hydrologic modeling  

NASA Astrophysics Data System (ADS)

The US Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) has developed NRCS GeoHydro 9x, a new ArcGIS application, to complement the WinTR-20 application and assist USDA field staff, and other government, private, and foreign organizations. WinTR-20 is a storm event hydrologic model used to evaluate impacts of structural and land treatment measures. NRCS GeoHydro 9x, using geographic information systems (GIS) tools and techniques, performs hydrologic modeling on a drainage area to compute its catchments, drainage points, drainage lines, slope, runoff curve number, longest flow path, time of concentration ( T c), and cross-section details. The application acts as a GIS interface to WinTR-20 by exporting the results of GIS analyses of the drainage area in the input format of WinTR-20. NRCS GeoHydro 9x reinforces the idea that GIS tools and techniques enhance productivity by doing preliminary hydrologic analysis of the drainage area in an objective and accurate manner in a relatively short duration.

Merkel, William H.; Kaushika, Ravichandran M.; Gorman, Eddy

2008-08-01

239

Power system modeling requirements for rotating machine interfaced distributed resources  

Microsoft Academic Search

Rotating machine interfaced power generation equipment today constitute the majority of interconnected distributed resources (DR). Even though new electronically interfaced DR devices, such as fuel cells, photovoltaics and microturbines are rapidly emerging, rotating machines are expected to continue to represent a major sector of interconnected DR capacity for the foreseeable future. To simulate and predict the impacts of these machines

Philip P. Barker; Bradley K. Johnson

2002-01-01

240

Automated Trace Analysis of Discrete-Event System Models  

Microsoft Academic Search

In this paper, we describe a novel technique that helps a modeler gain insight into the dynamic behavior of a complex stochastic discrete event simulation model based on trace analysis. We propose algorithms to distinguish progressive from repetitive behavior in a trace and to extract a minimal progressive fragment of a trace. The implied combinatorial optimization problem for trace reduction

Peter Kemper; Carsten Tepper

2009-01-01

241

Developing Automated Helicopter Models Using Simulated Annealing and Genetic Search  

Microsoft Academic Search

A heuristic technique is presented that applies simulated annealing search to derive mathematical equations that model a pilot for an X-CELL 60 helicopter. The technique uses a pre-defined alphabet of formulas and combines them to create a mathematical model of the system controller or pilot. The proposed technique provides a new tool that can be used to develop an accurate

Namir Aldawoodi; Rafael Perez; Kimon Valavanis; Wendy Alvis

242

Computer Automation of General-to-Specific Model Selection Procedures  

Microsoft Academic Search

Over the last three decades, the LSE methodology (see Hendry, 1993, for an overview) has emerged as a leading approach for pursuing econometrics. One of its main tenets is the concept of general-to-specific modelling: Starting from a general dynamic statistical model, which captures the essential characteristics of the underlying data set, standard testing procedures are used to reduce its complexity

Hans-Martin Krolzig; David Hendry

1999-01-01

243

Automated parameter extraction software for advanced IGBT modeling  

Microsoft Academic Search

A software package for extracting parameters to be used in advanced IGBT models is presented. In addition, new model equations and extraction procedures are introduced that more accurately describe a wide range of IGBT types including the Warp-Speed IGBTs. The parameter extraction software package consists of five programs that extract the 20 physical and structural parameters needed in the most

S. Bouche

2000-01-01

244

Automated Inspection of Textile Fabrics Using Textural Models  

Microsoft Academic Search

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

Fernand S. Cohen; Zhigang Fan; Stephane Attali

1991-01-01

245

Man power/cost estimation model: Automated planetary projects  

NASA Technical Reports Server (NTRS)

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.

Kitchen, L. D.

1975-01-01

246

Automated parametrical antenna modelling for ambient assisted living applications  

NASA Astrophysics Data System (ADS)

In this paper a parametric modeling technique for a fast polynomial extraction of the physically relevant parameters of inductively coupled RFID/NFC (radio frequency identification/near field communication) antennas is presented. The polynomial model equations are obtained by means of a three-step procedure: first, full Partial Element Equivalent Circuit (PEEC) antenna models are determined by means of a number of parametric simulations within the input parameter range of a certain antenna class. Based on these models, the RLC antenna parameters are extracted in a subsequent model reduction step. Employing these parameters, polynomial equations describing the antenna parameter with respect to (w.r.t.) the overall antenna input parameter range are extracted by means of polynomial interpolation and approximation of the change of the polynomials' coefficients. The described approach is compared to the results of a reference PEEC solver with regard to accuracy and computation effort.

Kazemzadeh, R.; John, W.; Mathis, W.

2012-09-01

247

Continental hydrosystem modelling: the concept of nested stream-aquifer interfaces  

NASA Astrophysics Data System (ADS)

Recent developments in hydrological modelling are based on a view of the interface being a single continuum through which water flows. These 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. This notion of a single continuum, which is accepted by the hydrological modellers, originates in the historical modelling of hydrosystems based on the hypothesis of a homogeneous media that led to the Darcy law. There is then a need to first bridge the gap between hydrological and eco-hydrological views of the stream-aquifer interfaces, and, secondly, to rationalise the modelling of stream-aquifer interface within a consistent framework that fully takes into account the multi-dimensionality of the stream-aquifer interfaces. We first define the concept of nested stream-aquifer interfaces as a key transitional component of continental hydrosystem. Based on a literature review, we then demonstrate the usefulness of the concept for the multi-dimensional study of the stream-aquifer interface, with a special emphasis on the stream network, which is identified as the key component for scaling hydrological processes occurring at the interface. Finally we focus on the stream-aquifer interface modelling at different scales, with up-to-date methodologies and give some guidances for the multi-dimensional modelling 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. The outcome of MIM is the localisation in space of the stream-aquifer interface types that can be studied by a given approach. The efficiency of the method is demonstrated with two approaches from the local (~1 m) to the continental (<10 M km2) scale.

Flipo, N.; Mouhri, A.; Labarthe, B.; Biancamaria, S.

2014-01-01

248

A Voyage to Arcturus: A model for automated management of a WLCG Tier-2 facility  

NASA Astrophysics Data System (ADS)

With the current trend towards "On Demand Computing" in big data environments it is crucial that the deployment of services and resources becomes increasingly automated. Deployment based on cloud platforms is available for large scale data centre environments but these solutions can be too complex and heavyweight for smaller, resource constrained WLCG Tier-2 sites. Along with a greater desire for bespoke monitoring and collection of Grid related metrics, a more lightweight and modular approach is desired. In this paper we present a model for a lightweight automated framework which can be use to build WLCG grid sites, based on "off the shelf" software components. As part of the research into an automation framework the use of both IPMI and SNMP for physical device management will be included, as well as the use of SNMP as a monitoring/data sampling layer such that more comprehensive decision making can take place and potentially be automated. This could lead to reduced down times and better performance as services are recognised to be in a non-functional state by autonomous systems.

Roy, Gareth; Crooks, David; Mertens, Lena; Mitchell, Mark; Purdie, Stuart; Cadellin Skipsey, Samuel; Britton, David

2014-06-01

249

A 2-D Interface Element for Coupled Analysis of Independently Modeled 3-D Finite Element Subdomains  

NASA Technical Reports Server (NTRS)

Over the past few years, the development of the interface technology has provided an analysis framework for embedding detailed finite element models within finite element models which are less refined. This development has enabled the use of cascading substructure domains without the constraint of coincident nodes along substructure boundaries. The approach used for the interface element is based on an alternate variational principle often used in deriving hybrid finite elements. The resulting system of equations exhibits a high degree of sparsity but gives rise to a non-positive definite system which causes difficulties with many of the equation solvers in general-purpose finite element codes. Hence the global system of equations is generally solved using, a decomposition procedure with pivoting. The research reported to-date for the interface element includes the one-dimensional line interface element and two-dimensional surface interface element. Several large-scale simulations, including geometrically nonlinear problems, have been reported using the one-dimensional interface element technology; however, only limited applications are available for the surface interface element. In the applications reported to-date, the geometry of the interfaced domains exactly match each other even though the spatial discretization within each domain may be different. As such, the spatial modeling of each domain, the interface elements and the assembled system is still laborious. The present research is focused on developing a rapid modeling procedure based on a parametric interface representation of independently defined subdomains which are also independently discretized.

Kandil, Osama A.

1998-01-01

250

Comparison of Joint Modeling Approaches Including Eulerian Sliding Interfaces  

SciTech Connect

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.

Lomov, I; Antoun, T; Vorobiev, O

2009-12-16

251

An alternative accident prediction model for highway-rail interfaces.  

PubMed

Safety levels at highway/rail interfaces continue to be of major concern despite an ever-increasing focus on improved design and appurtenance application practices. Despite the encouraging trend towards improved safety, accident frequencies remain high, many of which result in fatalities. More than half of these accidents occur at public crossings, where active warning devices (i.e. gates, lights, bells, etc.) are in place and functioning properly. This phenomenon speaks directly to the need to re-examine both safety evaluation (i.e. accident prediction) methods and design practices at highway-rail crossings. With respect to earlier developed accident prediction methods, the Peabody Dimmick Formula, the New Hampshire Index and the National Cooperative Highway Research Program (NCHRP) Hazard Index, all lack descriptive capabilities due to their limited number of explanatory variables. Further, each has unique limitations that are detailed in this paper. The US Department of Transportation's (USDOT) Accident Prediction Formula, which is most widely, also has limitations related to the complexity of the three-stage formula and its decline in accident prediction model accuracy over time. This investigation resulted in the development of an alternate highway-rail crossing accident prediction model, using negative binomial regression that shows great promise. The benefit to be gained through the application of this alternate model is (1) a greatly simplified, one-step estimation process; (2) comparable supporting data requirements and (3) interpretation of both the magnitude and direction of the effect of the factors found to significantly influence highway-rail crossing accident frequencies. PMID:11789573

Austin, Ross D; Carson, Jodi L

2002-01-01

252

Modeling and Formal Verification of Production Automation Systems  

Microsoft Academic Search

This paper presents the real-time model checker RAVEN and related theoretical background. RAVEN augments the efficiency of tra- ditional symbolic model checking with possibilities to describe real-time systems. These extensions rely on multi-terminal binary decision dia- grams to represent time delays and time intervals. The temporal logic CCTL is used to specify properties with time constraints. Another note- worthy feature

Jürgen Ruf; Roland J. Weiss; Thomas Kropf; Wolfgang Rosenstiel

2004-01-01

253

Automated Analysis of Unified Modeling Language (UML) Specifications  

Microsoft Academic Search

Abstract The Unified Modeling,Language,(UML) is a standard language adopted by the Object Management,Group (OMG) for writing object-oriented (OO) descriptions of software systems. UML allows the analyst to add class-level and system-level constraints. However, UML does not describe how to check the correctness of these constraints. Recent studies have shown,that Symbolic Model Checking can effectively verify large software

Meyer C. Tanuan

2001-01-01

254

Automated Internet Trading Based On Optimized Physics Models Of Markets  

Microsoft Academic Search

We describe a real-time, internet-based S&P futures trading system, including a description of general aspects of internet-mediated inter- actions with electronic exchanges. Inner-shell stochastic nonlinear dynamic models are developed, and Canonical Momenta Indicators (CMI) are derived from a fitted Lagrangian used by outer-shell trad- ing models dependent on these indicators. Recursive and adaptive optimization using Adaptive Simulated Annealing (ASA) is

Lester Ingber; Radu Paul Mondescu

2001-01-01

255

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

NASA Astrophysics Data System (ADS)

Aim of the paper is to propose a new coupled interface-body damage model for the study of the detachment process in concrete or masonry structures strengthened with fiber reinforced polymers (FRP). In particular, a model of the FRP-concrete or -masonry interface, accounting for the coupling between the degradation of the cohesive material and the FRP detachment, is presented. To this end, a nonlocal damage model is considered for the quasi-brittle material. Regarding the interface, a model which accounts for damage, unilateral contact and friction is developed. The novelty of the proposed model consists in taking into account the coupling between the body and the interface damage, ensuring that the interface damage is not lower than the body one. Some numerical examples and a comparison with experimental data are presented in order to verify the efficiency of the proposed model in reproducing the FRP decohesion from the support cohesive material.

Marfia, S.; Sacco, E.; Toti, J.

2012-09-01

256

Film rupture in the diffuse interface model coupled to hydrodynamics.  

PubMed

The process of dewetting of a thin liquid film is usually described using a long-wave approximation yielding a single evolution equation for the film thickness. This equation incorporates an additional pressure term-the disjoining pressure-accounting for the molecular forces. Recently a disjoining pressure was derived coupling hydrodynamics to the diffuse interface model [L. M. Pismen and Y. Pomeau, Phys. Rev. E 62, 2480 (2000)]. Using the resulting evolution equation as a generic example for the evolution of unstable thin films, we examine the thickness ranges for linear instability and metastability for flat films, the families of stationary periodic and localized solutions, and their linear stability. The results are compared to simulations of the nonlinear time evolution. From this we conclude that, within the linearly unstable thickness range, there exists a well defined subrange where finite perturbations are crucial for the time evolution and the resulting structures. In the remainder of the linearly unstable thickness range the resulting structures are controlled by the fastest flat film mode assumed up to now for the entire linearly unstable thickness range. Finally, the implications for other forms of disjoining pressure in dewetting and for spinodal decomposition are discussed. PMID:11580344

Thiele, U; Velarde, M G; Neuffer, K; Pomeau, Y

2001-09-01

257

Automated TIMI frame counting using 3-d modeling.  

PubMed

Three dimensional coronary modeling and reconstruction can assist in the quantitative analysis of coronary flow velocity from 2-d coronary images. In this paper a novel method to assess coronary flow velocity is proposed. First, 3-d models of the coronary arteries are estimated from bi-plane X-ray images using epipolar constraint energy minimization for the selected fiducial points like bifurcations, and subsequently 3-d B-spline energy minimization for the arterial segments. A 4-d model is assembled from a set of 3-d models representing different phases of the cardiac cycle. The 4-d model is fitted to the 2-d image sequences containing basal or hyperemic blood flow information. Then, by counting the frames in analogy with TIMI frame counting, an index of the mean coronary flow velocity can be estimated. Our experimental results show that the algorithm correlates with r=0.98 (P<0.0001, 95% CI 0.92-0.99) to the clinical measurements of the TFC. PMID:22867533

ten Brinke, G A; Slump, C H; Stoel, M G

2012-10-01

258

Morphology based cohesive zone modeling of the cement-bone interface from postmortem retrievals.  

PubMed

In cemented total hip arthroplasty, the cement-bone interface can be considerably degenerated after less than one year in vivo service; this makes the interface much weaker relative to the direct post-operative situation. It is, however, still unknown how these degenerated interfaces behave under mixed-mode loading and how this is related to the interface morphology. In this study, we used a finite element (FE) approach to analyze the mixed-mode response of the cement-bone interface taken from postmortem retrievals. We investigated whether it was feasible to generate a fully elastic and a failure cohesive model based on only morphological input parameters. Computed tomography-based FE-models of postmortem cement-bone interfaces were generated and the interface morphology was determined. The models were loaded until failure in multiple directions by allowing cracking of the bone and cement components and including periodic boundary conditions. The resulting stiffness was related to the interface morphology. A closed form mixed-mode cohesive model that included failure was determined and related to the interface morphology. The responses of the FE-simulations compare satisfactorily with experimental observations, albeit the magnitude of the strength and stiffness are somewhat overestimated. Surprisingly, the FE-simulations predict no failure under shear loading and a considerable normal compression is generated which prevents dilation of the interface. The obtained mixed-mode stiffness response could subsequently be related to the interface morphology and subsequently be formulated into an elastic cohesive zone model. Finally, the acquired data could be used as an input for a cohesive model that also includes interface failure. PMID:21783159

Waanders, Daan; Janssen, Dennis; Mann, Kenneth A; Verdonschot, Nico

2011-10-01

259

A project model for an automated building system: design and planning phases  

Microsoft Academic Search

The purpose of an automated building system (ABS) is to automatically generate maximum information and the related documents for the preliminary design, detailed design and construction planning of a building project. The ABS under development, described in this paper, includes features such as: representation of project information by a tri-hierarchical project model, step-by-step progress through predefined design and construction planning

Rafael Sacks; Abraham Warszawski

1997-01-01

260

Automated Texture Registration and Stitching for Real World Models  

Microsoft Academic Search

In this paper a system is presented which automati- cally registers and stitches textures acquired from mul- tiple photographic images onto the surface of a given corresponding 3D model. Within this process the cam- era position, direction and eld of view must be deter- mined for each of the images. For this registration, which aligns a 2D image to a

Hendrik P. A. Lensch; Wolfgang Heidrich; Hans-peter Seidel

2000-01-01

261

Evaluation of an Automated Pressure Ulcer Risk Assessment Model  

Microsoft Academic Search

The key to timely interventions and reducing avoidable incidence is the early identification of patients at risk for developing pressure ulcers. To enable the automatic detection of such patients and inform acute care interdisciplinary providers, a filter feature model using heuristic statistical methods was applied to a relational database of retrospective patient data including demographics, medications, and clinical visit details.

Tara Borlawsky; George Hripcsak

2007-01-01

262

Automated biowaste sampling system urine subsystem operating model, part 1  

NASA Technical Reports Server (NTRS)

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.

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

1973-01-01

263

Building hierarchical automation solutions in the IEC 61499 modeling language  

Microsoft Academic Search

The IEC 61499 modeling language pursues a component-based approach with modular building blocks coupled by ports and arranged in a hierarchical manner. However, as in similar approaches, the IEC 61499 language does not define how functional hierarchies of upper- and lower-level functional entities should be built. In this paper, motivated by our previous work, structuring principles for IEC 61499 for

Alois Zoitl; Herbert Prahofer

2011-01-01

264

Automated volumetric breast density derived by shape and appearance modeling  

NASA Astrophysics Data System (ADS)

The image shape and texture (appearance) estimation designed for facial recognition is a novel and promising approach for application in breast imaging. The purpose of this study was to apply a shape and appearance model to automatically estimate percent breast fibroglandular volume (%FGV) using digital mammograms. We built a shape and appearance model using 2000 full-field digital mammograms from the San Francisco Mammography Registry with known %FGV measured by single energy absorptiometry method. An affine transformation was used to remove rotation, translation and scale. Principal Component Analysis (PCA) was applied to extract significant and uncorrelated components of %FGV. To build an appearance model, we transformed the breast images into the mean texture image by piecewise linear image transformation. Using PCA the image pixels grey-scale values were converted into a reduced set of the shape and texture features. The stepwise regression with forward selection and backward elimination was used to estimate the outcome %FGV with shape and appearance features and other system parameters. The shape and appearance scores were found to correlate moderately to breast %FGV, dense tissue volume and actual breast volume, body mass index (BMI) and age. The highest Pearson correlation coefficient was equal 0.77 for the first shape PCA component and actual breast volume. The stepwise regression method with ten-fold cross-validation to predict %FGV from shape and appearance variables and other system outcome parameters generated a model with a correlation of r2 = 0.8. In conclusion, a shape and appearance model demonstrated excellent feasibility to extract variables useful for automatic %FGV estimation. Further exploring and testing of this approach is warranted.

Malkov, Serghei; Kerlikowske, Karla; Shepherd, John

2014-03-01

265

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

PubMed

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

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

2012-12-21

266

Automation based on knowledge modeling theory and its applications in engine diagnostic systems using Space Shuttle Main Engine vibrational data  

NASA Astrophysics Data System (ADS)

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).

Kim, Jonnathan H.

1995-04-01

267

An Improvement in Thermal Modelling of Automated Tape Placement Process  

SciTech Connect

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.

Barasinski, Anaies; Leygue, Adrien; Poitou, Arnaud [GEM, UMR CNRS-Centrale Nantes 1 rue de la Noe, BP 92101, F-44321 Nantes cedex 3 (France); Soccard, Eric [EADS IW, Techno campus EMC2, Allee du Chaffault, 44340 Bouguenais (France)

2011-01-17

268

Model-based automation of baker's yeast production  

Microsoft Academic Search

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

Knut Ringbom; Anette Rothberg; Björn Saxén

1996-01-01

269

ADGEN: a system for automated sensitivity analysis of predictive models  

SciTech Connect

A system that can automatically enhance computer codes with a sensitivity calculation capability is presented. With this new system, named ADGEN, rapid and cost-effective calculation of sensitivities can be performed in any FORTRAN code for all input data or parameters. The resulting sensitivities can be used in performance assessment studies related to licensing or interactions with the public to systematically and quantitatively prove the relative importance of each of the system parameters in calculating the final performance results. A general procedure calling for the systematic use of sensitivities in assessment studies is presented. The procedure can be used in modelling and model validation studies to avoid ''over modelling,'' in site characterization planning to avoid ''over collection of data,'' and in performance assessment to determine the uncertainties on the final calculated results. The added capability to formally perform the inverse problem, i.e., to determine the input data or parameters on which to focus additional research or analysis effort in order to improve the uncertainty of the final results, is also discussed.

Pin, F.G.; Horwedel, J.E.; Oblow, E.M.; Lucius, J.L.

1986-09-01

270

A polygonal finite element method for modeling arbitrary interfaces in large deformation problems  

NASA Astrophysics Data System (ADS)

In this paper, a polygonal-FEM technique is presented in modeling of arbitrary interfaces in large deformations. The method is used to model the internal interfaces and arbitrary geometries using a uniform non-conformal mesh. The technique is applied to capture discontinuous deformations in the non-conformal elements, which are cut by the interface in a uniform regular mesh. In this approach, a uniform non-conformal mesh is decomposed into sub-elements that conform to the internal interfaces. The geometry of interface is used to produce various triangular, quadrilateral and pentagonal elements at the intersection of interface with regular FE mesh, in which the extra degrees-of-freedom are defined along the interface. The level set method is employed to describe the material geometry on the background mesh. The technique is used to extrude any arbitrary geometry from an initial background mesh and model under different external effects. An important feature of the technique is the decomposition of the uniform non-conformal mesh to the polygonal-FEM mesh, which is conformed to the material interfaces. Finally, several numerical examples are analyzed to demonstrate the efficiency of proposed technique in modeling arbitrary interfaces in large deformations.

Biabanaki, S. O. R.; Khoei, A. R.

2012-07-01

271

Automated Hardware-in-the-Loop Modeling and Simulation in Active Sensor Imaging Using T16713 DSP Units  

Microsoft Academic Search

This paper presents a new methodology for the modeling and simulation of active sensor imaging systems using a hardware-in-the-loop technique based on TI6713 digital signal processor (DSP) units. The methodology centers on procedures to enhance the degree of automation in the modeling and simulation processes by taking the following actions: (1) improving the automated development of algorithms to compute the

Ana B. Ramirez; Domingo Rodriguez

2006-01-01

272

Detecting solid liquid interface properties with mechanical slip modelling for quartz crystal microbalance operating in liquid  

Microsoft Academic Search

Quartz crystal microbalances (QCMs) provide sensitive probes for changes at solid-solid or solid-liquid interfaces. It is essential to obtain a physical insight into the details of the interface loading mechanism to interpret the observed behaviour leading to fresh applications of AT-cut quartz resonators. In this work, a mechanical slip model of the interface between a quartz plate and a viscoelastic

F. Lu; H. P. Lee; S. P. Lim

2004-01-01

273

Automated Test Input Generation for Software That Consumes ORM Models  

NASA Astrophysics Data System (ADS)

Software tools that analyze and generate code from ORM conceptual schemas are highly susceptible to feature interaction bugs. When testing such tools, test suites are needed that cover many combinations of features, including combinations that rarely occur in practice. Manually creating such a test suite is extremely labor-intensive, and the tester may fail to cover feasible feature combinations that are counter-intuitive or that rarely occur. This paper describes ATIG, a prototype tool for automatically generating test suites that cover diverse combinations of ORM features. ATIG makes use of combinatorial testing to optimize coverage of select feature combinations within constraints imposed by the need to keep the sizes of test suites manageable. We have applied ATIG to generate test inputs for an industrial strength ORM-to-Datalog code generator. Initial results suggest that it is useful for finding feature interaction errors in tools that operate on ORM models.

McGill, Matthew J.; Stirewalt, R. E. Kurt; Dillon, Laura K.

274

User modeling in expert man-machine interfaces: a case study in intelligent information retrieval  

Microsoft Academic Search

The requirements of a user modeling component for an expert interface are analyzed, and the main points of a proposed approach to user modeling are stated. The authors focus on a knowledge-based system, called UM-tool, devoted to creating, maintaining, and using explicit user models within an expert interface. UM-tool supports a novel approach to user modeling, which is based both

GIORGIO BRAJNIK; GIOVANNI GUIDA; CARLO TASSO

1990-01-01

275

A comparison of automated anatomical-behavioural mapping methods in a rodent model of stroke.  

PubMed

Neurological damage, due to conditions such as stroke, results in a complex pattern of structural changes and significant behavioural dysfunctions; the automated analysis of magnetic resonance imaging (MRI) and discovery of structural-behavioural correlates associated with these disorders remains challenging. Voxel lesion symptom mapping (VLSM) has been used to associate behaviour with lesion location in MRI, but this analysis requires the definition of lesion masks on each subject and does not exploit the rich structural information in the images. Tensor-based morphometry (TBM) has been used to perform voxel-wise structural analyses over the entire brain; however, a combination of lesion hyper-intensities and subtle structural remodelling away from the lesion might confound the interpretation of TBM. In this study, we compared and contrasted these techniques in a rodent model of stroke (n=58) to assess the efficacy of these techniques in a challenging pre-clinical application. The results from the automated techniques were compared using manually derived region-of-interest measures of the lesion, cortex, striatum, ventricle and hippocampus, and considered against model power calculations. The automated TBM techniques successfully detect both lesion and non-lesion effects, consistent with manual measurements. These techniques do not require manual segmentation to the same extent as VLSM and should be considered part of the toolkit for the unbiased analysis of pre-clinical imaging-based studies. PMID:23727124

Crum, William R; Giampietro, Vincent P; Smith, Edward J; Gorenkova, Natalia; Stroemer, R Paul; Modo, Michel

2013-09-15

276

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

PubMed Central

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.

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

2013-01-01

277

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

278

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

PubMed

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

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

2013-01-01

279

IDEF3 and IDEF4 automation system requirements document and system environment models  

NASA Technical Reports Server (NTRS)

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.

Blinn, Thomas M.

1989-01-01

280

Automated Finite Element Modeling of Wing Structures for Shape Optimization  

NASA Technical Reports Server (NTRS)

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.

Harvey, Michael Stephen

1993-01-01

281

A semi-automated vascular access system for preclinical models  

NASA Astrophysics Data System (ADS)

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.

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

282

Industrial data monitoring using intranet-based high level of a hierarchical model of an automated system of industrial enterprise maintenance and control  

Microsoft Academic Search

It's difficult now to disclaim the availability of application of Internet technologies in industry. Originally not intended for industrial automation they nevertheless can be used as a part of a multilevel hierarchical automation system. The paper shows one of the possible solutions. A way to construct Intranet based high level of a hierarchical model of an automated system for a

Konstantin I. Budnikov

2001-01-01

283

Model for Hydrodynamic Instabilities of a Fluid Interface Using Coupled Conformal Mappings  

Microsoft Academic Search

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

Igor Sokolov; Alexender Velikovich

2003-01-01

284

A Structural Model for the Solid-Liquid Interface in Monatomic Systems.  

National Technical Information Service (NTIS)

A structural model for the solid-liquid interface has been developed by applying the construction rules for the liquid to the boundary condition of a crystal plane. In particular, an interface has been created between a dense random packing of hard sphere...

F. Spaepen

1975-01-01

285

Cohesive Zone Model Applied to Creep Crack Initiation at an Interface Edge between Submicron Thick Films  

Microsoft Academic Search

A crack initiates at an interface edge between submicron thick films and leads to the malfunction of microelectronic devices. In this study, the cohesive zone model method with a cohesive law based on the damage mechanics concept is developed to simulate the creep crack initiation at an interface edge between tin and silicon films. Experiments on delamination at the Sn\\/Si

Do Van Truong; Takayuki Kitamura

2010-01-01

286

A thick-interface model for diffusive and massive phase transformation in substitutional alloys  

Microsoft Academic Search

Based on the application of the thermodynamic extremal principle, a new model for the diffusive and massive phase transformation in multicomponent substitutional alloys is developed. Interfacial reactions such as the rearrangement of the lattice, solute drag and trans-interface diffusion are automatically considered by assigning a finite thickness and a finite mobility to the interface region. As an application of the

J. Svoboda; J. Vala; E. Gamsjäger; F. D. Fischer

2006-01-01

287

Transition Layer in a Lattice-Gas Model of a Solid-Melt Interface.  

National Technical Information Service (NTIS)

The equilibrium solid-melt interface in a lattice-gas model of a single-component system is shown to be isomorphous with an earlier calculation of an interface between ordered and disordered structures. When the surface is parallel to a plane that is not ...

J. W. Cahn R. Kikuchi

1985-01-01

288

Modeling Auditory-Haptic Interface Cues from an Analog Multi-line Telephone  

NASA Technical Reports Server (NTRS)

The Western Electric Company produced a multi-line telephone during the 1940s-1970s using a six-button interface design that provided robust tactile, haptic and auditory cues regarding the "state" of the communication system. This multi-line telephone was used as a model for a trade study comparison of two interfaces: a touchscreen interface (iPad)) versus a pressure-sensitive strain gauge button interface (Phidget USB interface controllers). The experiment and its results are detailed in the authors' AES 133rd convention paper " Multimodal Information Management: Evaluation of Auditory and Haptic Cues for NextGen Communication Dispays". This Engineering Brief describes how the interface logic, visual indications, and auditory cues of the original telephone were synthesized using MAX/MSP, including the logic for line selection, line hold, and priority line activation.

Begault, Durand R.; Anderson, Mark R.; Bittner, Rachael M.

2012-01-01

289

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

NASA Technical Reports Server (NTRS)

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.

Corker, Kevin M.; Smith, Barry R.

1993-01-01

290

Combat Automation for Airborne Weapon Systems: Man/Machine Interface Trends and Technologies (L'Automatisation du Combat Aerien: Tendances et Technologies pour l'Interface Homme/Machine).  

National Technical Information Service (NTIS)

Recent advances in combat automation technologies offer significant potential for improving overall mission effectiveness. Development of advanced situational awareness display concepts, parallel distributed computer architecture and tactical information ...

1993-01-01

291

ESDDM: A Software Evolution Process Model Based on Evolution Behavior Interface  

NASA Astrophysics Data System (ADS)

According to "Software processes are software too" proposed by L.Osterweil, we assume a software process model with independent functions as a component. To fully describe the evolution behavior of process-based components, the concept of evolution behavior interface is introduced and a Petri net based ESDDM model is discussed. By applying on a realistic case, we conclude that ESDDM, a software evolution process model based on evolution behavior interface, is able to effectively support the concurrent engineering.

Zhao, Na; Wang, Jian; Li, Tong; Yu, Yong; Dai, Fei; Xie, Zhongwen

292

Sliding drops in the diffuse interface model coupled to hydrodynamics  

Microsoft Academic Search

Using a film thickness evolution equation derived recently combining long-wave approximation and diffuse interface theory [L. M. Pismen and Y. Pomeau, Phys. Rev. E 62, 2480 (2000)] we study one-dimensional surface profiles for a thin film on an inclined plane. We discuss stationary flat film and periodic solutions including their linear stability. Flat sliding drops are identified as universal profiles,

Uwe Thiele; Manuel G. Velarde; Kai Neuffer; Michael Bestehorn; Yves Pomeau

2001-01-01

293

Interface-modified random circuit breaker network model applicable to both bipolar and unipolar resistance switching  

NASA Astrophysics Data System (ADS)

We observed reversible-type changes between bipolar (BRS) and unipolar resistance switching (URS) in one Pt/SrTiOx/Pt capacitor. To explain both BRS and URS in a unified scheme, we introduce the ``interface-modified random circuit breaker network model,'' in which the bulk medium is represented by a percolating network of circuit breakers. To consider interface effects in BRS, we introduce circuit breakers to investigate resistance states near the interface. This percolation model explains the reversible-type changes in terms of connectivity changes in the circuit breakers and provides insights into many experimental observations of BRS which are under debate by earlier theoretical models.

Lee, S. B.; Lee, J. S.; Chang, S. H.; Yoo, H. K.; Kang, B. S.; Kahng, B.; Lee, M.-J.; Kim, C. J.; Noh, T. W.

2011-01-01

294

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

PubMed

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

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

2014-03-01

295

Nonlinear phase-field model for electrode-electrolyte interface evolution  

NASA Astrophysics Data System (ADS)

A nonlinear phase-field model is proposed for modeling microstructure evolution during highly nonequilibrium processes. We consider electrochemical reactions at electrode-electrolyte interfaces leading to electroplating and electrode-electrolyte interface evolution. In contrast to all existing phase-field models, the rate of temporal phase-field evolution and thus the interface motion in the current model is considered nonlinear with respect to the thermodynamic driving force. It produces Butler-Volmer-type electrochemical kinetics for the dependence of interfacial velocity on the overpotential at the sharp-interface limit. At the low overpotential it recovers the conventional Allen-Cahn phase-field equation. This model is generally applicable to many other highly nonequilibrium processes where linear kinetics breaks down.

Liang, Linyun; Qi, Yue; Xue, Fei; Bhattacharya, Saswata; Harris, Stephen J.; Chen, Long-Qing

2012-11-01

296

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

NASA Astrophysics Data System (ADS)

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.

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

297

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

298

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

NASA Technical Reports Server (NTRS)

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.

Milligan, James R.; Dutton, James E.

1993-01-01

299

Effects of modeling errors on trajectory predictions in air traffic control automation  

NASA Technical Reports Server (NTRS)

Air traffic control automation synthesizes aircraft trajectories for the generation of advisories. Trajectory computation employs models of aircraft performances and weather conditions. In contrast, actual trajectories are flown in real aircraft under actual conditions. Since synthetic trajectories are used in landing scheduling and conflict probing, it is very important to understand the differences between computed trajectories and actual trajectories. This paper examines the effects of aircraft modeling errors on the accuracy of trajectory predictions in air traffic control automation. Three-dimensional point-mass aircraft equations of motion are assumed to be able to generate actual aircraft flight paths. Modeling errors are described as uncertain parameters or uncertain input functions. Pilot or autopilot feedback actions are expressed as equality constraints to satisfy control objectives. A typical trajectory is defined by a series of flight segments with different control objectives for each flight segment and conditions that define segment transitions. A constrained linearization approach is used to analyze trajectory differences caused by various modeling errors by developing a linear time varying system that describes the trajectory errors, with expressions to transfer the trajectory errors across moving segment transitions. A numerical example is presented for a complete commercial aircraft descent trajectory consisting of several flight segments.

Jackson, Michael R. C.; Zhao, Yiyuan; Slattery, Rhonda

1996-01-01

300

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

301

A micromechanically-based interface model for the periodontal ligament  

Microsoft Academic Search

An interface, 3D finite element is presented, specifically designed to simulate the mechanical behavior of the periodontal\\u000a ligament (hereafter shortened into PDL). The PDL is a thin layer (about 0.25 mm in adult humans) of soft tissue that connects\\u000a the root of a tooth to the surrounding alveolar bone. From the mechanical viewpoint, it can be considered as a thin

Francesco Genna

302

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

NASA Technical Reports Server (NTRS)

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.

Rubin, Carol

2002-01-01

303

Navy Atmospheric Boundary Layer (NABL) model system: Software/Interface requirements specification  

NASA Astrophysics Data System (ADS)

The engineering and external interface requirements for the Navy Atmospheric Boundary Layer (NABL) Model System are specified. This document will be used as a basis for detailed system design and testing.

Petit, Pierre A.

1991-11-01

304

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 ...

305

Ontology and SWRL-Based Learning Model for Home Automation Controlling  

Microsoft Academic Search

\\u000a In the present paper we describe IntelliDomo’s learning model, an ontology-based expert system able to control a home automation\\u000a system and to learn user’s behaviour. This system obtains its own data from the user’s daily activities. From these data,\\u000a IntelliDomo can detect behaviour periodic patterns and it can be able to generate SWRL rules that anticipate the user’s day-to-day\\u000a activities.

Pablo A. Valiente-Rocha; Adolfo Lozano Tello

2010-01-01

306

A Study on Automated Context-aware Access Control Model Using Ontology  

NASA Astrophysics Data System (ADS)

Applications in context-aware computing environment will be connected wireless network and various devices. According to, recklessness access of information resource can make trouble of system. So, access authority management is very important issue both information resource and adapt to system through founding security policy of needed system. But, existing security model is easy of approach to resource through simply user ID and password. This model has a problem that is not concerned about user's environment information. In this paper, propose model of automated context-aware access control using ontology that can more efficiently control about resource through inference and judgment of context information that collect user's information and user's environment context information in order to ontology modeling.

Jang, Bokman; Jang, Hyokyung; Choi, Euiin

307

Applications software for modeling distribution automation operations on the Athens Utilities Board  

SciTech Connect

This paper discusses the development of applications software called the System Reconfiguration Analysis Program (SYSRAP) for modeling distribution automation operations on the Athens Utilities Board (AUB). The first phase of development involved the testing of algorithms that combine a radial power flow analysis, short- circuit analysis and data base structuring of input and calculated values in a data base management program. In the second phase, the algorithms were written in a Pascal program and feeder data was dynamically allocated to system memory to speed computation and access time. During the last phase of development, the program was linked with the real-time data monitored by the distribution automation system at AUB so that SYSRAP could model the real-time behavior of the distribution system as closely as possible. The paper discusses the data base techniques that SYSRAP uses to speed up data base access and computation time and the data requirements for modeling the real-time operation of an electric distribution system.

Patton, J.B.; Rizy, D.T. (Oak Ridge National Lab., TN (USA). Energy Div.); Lawler, J.S. (Tennessee Univ., Knoxville, TN (USA). Dept. of Electrical and Computer Engineering)

1990-04-01

308

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

PubMed Central

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.

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

2012-01-01

309

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

PubMed

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

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

2012-11-01

310

A conceptual model of the automated credibility assessment of the volunteered geographic information  

NASA Astrophysics Data System (ADS)

The use of Volunteered Geographic Information (VGI) in collecting, sharing and disseminating geospatially referenced information on the Web is increasingly common. The potentials of this localized and collective information have been seen to complement the maintenance process of authoritative mapping data sources and in realizing the development of Digital Earth. The main barrier to the use of this data in supporting this bottom up approach is the credibility (trust), completeness, accuracy, and quality of both the data input and outputs generated. The only feasible approach to assess these data is by relying on an automated process. This paper describes a conceptual model of indicators (parameters) and practical approaches to automated assess the credibility of information contributed through the VGI including map mashups, Geo Web and crowd - sourced based applications. There are two main components proposed to be assessed in the conceptual model - metadata and data. The metadata component comprises the indicator of the hosting (websites) and the sources of data / information. The data component comprises the indicators to assess absolute and relative data positioning, attribute, thematic, temporal and geometric correctness and consistency. This paper suggests approaches to assess the components. To assess the metadata component, automated text categorization using supervised machine learning is proposed. To assess the correctness and consistency in the data component, we suggest a matching validation approach using the current emerging technologies from Linked Data infrastructures and using third party reviews validation. This study contributes to the research domain that focuses on the credibility, trust and quality issues of data contributed by web citizen providers.

Idris, N. H.; Jackson, M. J.; Ishak, M. H. I.

2014-02-01

311

XML Web Services Automation: A Software Engineering Approach  

Microsoft Academic Search

XML Web services are a mechanism for exposing program functionality over the Web, typically to other services. In this paper we analyse the interactions of standalone applications and Web services and investigate modeling role-based interactions. From this investigation, we engineer a tool that automates the process of generating Web services based on an application's set of compliant interface primitives. These

Nicholas Nicoloudis; Christine Mingins

2002-01-01

312

Measurement and Modeling of Thermal Contact Resistance at a Plastic-Metal Interface  

NASA Astrophysics Data System (ADS)

Themal contact resistance(TCR) is a resistance to the flow of heat across the interface of 2 surfaces due to imperfect contact. The TCR at the metal-plastic interface has been shown to affect the modeling of injection molding processes. Its value is strongly dependent on a number of interface parameters including pressure, temperature, the nature of plastic material, the metal surface characteristics and the presence of interstitial medium such as the mold releasing agents used in injection molding. This study focuses on identifying the inter-relationships among these parameters, by measuring the TCR values for various plastic-metal interfaces under different experimental conditions in order to establish a model that could be used in process modeling and analysis.

Sridhar, L.; Narh, Kwabena A.

1996-03-01

313

Effective Automated Prediction of Vertebral Column Pathologies Based on Logistic Model Tree with SMOTE Preprocessing.  

PubMed

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

Karabulut, Esra Mahsereci; Ibrikci, Turgay

2014-05-01

314

Toward the virtual cell: Automated approaches to building models of subcellular organization "learned" from microscopy images  

PubMed Central

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.

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

2012-01-01

315

TOBAGO — a semi-automated approach for the generation of 3-D building models  

NASA Astrophysics Data System (ADS)

3-D city models are in increasing demand for a great number of applications. Photogrammetry is a relevant technology that can provide an abundance of geometric, topologic and semantic information concerning these models. The pressure to generate a large amount of data with high degree of accuracy and completeness poses a great challenge to phtogrammetry. The development of automated and semi-automated methods for the generation of those data sets is therefore a key issue in photogrammetric research. We present in this article a strategy and methodology for an efficient generation of even fairly complex building models. Within this concept we request the operator to measure the house roofs from a stereomodel in form of an unstructured point cloud. According to our experience this can be done very quickly. Even a non-experienced operator can measure several hundred roofs or roof units per day. In a second step we fit generic building models fully automatically to these point clouds. The structure information is inherently included in these building models. In such a way geometric, topologic and even semantic data can be handed over to a CAD-system, in our case AutoCad, for further visualization and manipulation. The structuring is achieved in three steps. In a first step a classifier is initiated which recognizes the class of houses a particular roof point cloud belongs to. This recognition step is primarily based on the analysis of the number of ridge points. In the second and third steps the concrete topological relations between roof points are investigated and generic building models are fitted to the point clouds. Based on the technique of constraint-based reasoning two geometrical parsers are solving this problem. We have tested the methodology under a variety of different conditions in several pilot projects. The results will indicate the good performance of our approach. In addition we will demonstrate how the results can be used for visualization (texture mapping) and animation (walk-throughs and fly-overs).

Gruen, Armin

316

Closed-Loop Modeling in Future Automation System Engineering and Validation  

Microsoft Academic Search

This paper presents a new framework for design and validation of industrial automation systems based on systematic application of formal methods. The engineering methodology proposed in this paper is based on the component design of automated manufacturing systems from intelligent mechatronic components. Foundations of such componentspsila information infrastructure are the new IEC 61499 architecture and the automation object concept. It

Valeriy Vyatkin; Hans-Michael Hanisch; Cheng Pang; Chia-Han Yang

2009-01-01

317

A Wireless Sensor Network Communication Model for Automation of Electric Power Distribution  

Microsoft Academic Search

Automation of electric power distribution in a cost-efficient and reliable manner can be accomplished by complete automation of the load dispatch centers and substations on a large scale. For efficient load balancing among the feed lines, a continuous monitoring of parameters, such as voltage, current in the line, temperature, pressure, and oil level of the transformers is required. Currently, automation

M. Muthukumar; N. Sureshkumar

318

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

NASA Technical Reports Server (NTRS)

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.

Belknap, Shannon; Zhang, Michael

2013-01-01

319

An Evaluation of Autoregressive Spectral Estimation Model Order for Brain-Computer Interface Applications  

Microsoft Academic Search

Autoregressive (AR) spectral estimation is a popular method for modeling the electroencephalogram (EEG), and therefore the frequency domain EEG phenomena that are used for control of a brain-computer interface (BCI). Several studies have been conducted to evaluate the optimal AR model order for EEG, but the criteria used in these studies does not necessarily equate to the optimal AR model

Dean J. Krusienski; Dennis J. McFarland; Jonathan R. Wolpaw

2006-01-01

320

GASP! A Standardized Performance Analysis Tool Interface for Global Address Space Programming Models  

Microsoft Academic Search

The global address space (GAS) programming model pro- vides important potential productivity advantages over traditional par- allel programming models. Languages using the GAS model currently have insucient support from existing performance analysis tools, due in part to their implementation complexity. We have designed the Global Address Space Performance (GASP) tool interface that is flexible enough to support instrumentation of any

Hung-hsun Su; Dan Bonachea; Adam Leko; Hans Sherburne; Max Billingsley; Alan D. George

2006-01-01

321

FE Modeling of Guided Wave Propagation in Structures with Weak Interfaces  

NASA Astrophysics Data System (ADS)

This paper describes the use of a Finite Element code for modeling the effects of weak interfaces on the propagation of low order Lamb modes. The variable properties of the interface are modeled by uniform repartitions of compression and shear springs that insure the continuity of the stresses and impose a discontinuity in the displacement field. The method is tested by comparison with measurements that were presented in a previous QNDE conference (B.W.Drinkwater, M.Castaings, and B.Hosten ``The interaction of Lamb waves with solid-solid interfaces'', Q.N.D.E. Vol. 22, (2003) 1064-1071). The interface was the contact between a rough elastomer with high internal damping loaded against one surface of a glass plate. Both normal and shear stiffnesses of the interface were quantified from the attenuation of A0 and S0 Lamb waves caused by leakage of energy from the plate into the elastomer and measured at each step of a compressive loading. The FE model is made in the frequency domain, thus allowing the viscoelastic properties of the elastomer to be modeled by using complex moduli as input data. By introducing the interface stiffnesses in the code, the predicted guided waves attenuations are compared to the experimental results to validate the numerical FE method.

Hosten, Bernard; Castaings, Michel

2005-04-01

322

An automated shell for management of parametric dispersion/deposition modeling  

SciTech Connect

In 1993, the US Army tasked Argonne National Laboratory to perform a study of chemical agent dispersion and deposition for the Chemical Stockpile Emergency Preparedness Program using an existing Army computer model. The study explored a wide range of situations in terms of six parameters: agent type, quantity released, liquid droplet size, release height, wind speed, and atmospheric stability. A number of discrete values of interest were chosen for each parameter resulting in a total of 18,144 possible different combinations of parameter values. Therefore, the need arose for a systematic method to assemble the large number of input streams for the model, filter out unrealistic combinations of parameter values, run the model, and extract the results of interest from the extensive model output. To meet these needs, we designed an automated shell for the computer model. The shell processed the inputs, ran the model, and reported the results of interest. By doing so, the shell compressed the time needed to perform the study and freed the researchers to focus on the evaluation and interpretation of the model predictions. The results of the study are still under review by the Army and other agencies; therefore, it would be premature to discuss the results in this paper. However, the design of the shell could be applied to other hazards for which multiple-parameter modeling is performed. This paper describes the design and operation of the shell as an example for other hazards and models.

Paddock, R.A.; Absil, M.J.G.; Peerenboom, J.P.; Newsom, D.E.; North, M.J.; Coskey, R.J. Jr.

1994-03-01

323

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

NASA Astrophysics Data System (ADS)

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.

Orouji, Ali A.; Mehrad, Mahsa

2014-08-01

324

Large strain elasto-plasticity for diffuse interface models  

NASA Astrophysics Data System (ADS)

Most solid-state phase transformations are accompanied by large deformations, stemming either from external load, transformation strains or plasticity. The consideration of such large deformations will affect the numerical treatment of such transformations. In this paper, we present a new scheme to embed large deformations in an explicit phase-field scheme and its implementation in the open-source framework OpenPhase. The suggested scheme combines the advantages of a spectral solver to calculate the mechanical boundary value problem in a small strain limit and an advection procedure to transport field variables over the calculation grid. Since the developed approach should be used for various sets of problems, e.g. simulations of thermodynamically driven phase transformations, the mechanic formulation is kept general. However, to ensure compatibility with phase-field methods using the concept of diffuse interface, the latter is treated with special care in the present work.

Borukhovich, E.; Engels, P. S.; Böhlke, T.; Shchyglo, O.; Steinbach, I.

2014-04-01

325

Sliding drops in the diffuse interface model coupled to hydrodynamics.  

PubMed

Using a film thickness evolution equation derived recently combining long-wave approximation and diffuse interface theory [L. M. Pismen and Y. Pomeau, Phys. Rev. E 62, 2480 (2000)] we study one-dimensional surface profiles for a thin film on an inclined plane. We discuss stationary flat film and periodic solutions including their linear stability. Flat sliding drops are identified as universal profiles, whose main properties do not depend on mean film thickness. The flat drops are analyzed in detail, especially how their velocity, advancing and receding dynamic contact angles and plateau thicknesses depend on the inclination of the plane. A study of nonuniversal drops shows the existence of a dynamical wetting transition with hysteresis between droplike solutions and a flat film with small amplitude nonlinear waves. PMID:11736194

Thiele, U; Velarde, M G; Neuffer, K; Bestehorn, M; Pomeau, Y

2001-12-01

326

Modeling and automation of sequencing-based characterization of RNA structure  

PubMed Central

Sequence census methods reduce molecular measurements such as transcript abundance and protein-nucleic acid interactions to counting problems via DNA sequencing. We focus on a novel assay utilizing this approach, called selective 2?-hydroxyl acylation analyzed by primer extension sequencing (SHAPE-Seq), that can be used to characterize RNA secondary and tertiary structure. We describe a fully automated data analysis pipeline for SHAPE-Seq analysis that includes read processing, mapping, and structural inference based on a model of the experiment. Our methods rely on the solution of a series of convex optimization problems for which we develop efficient and effective numerical algorithms. Our results can be easily extended to other chemical probes of RNA structure, and also generalized to modeling polymerase drop-off in other sequence census-based experiments.

Aviran, Sharon; Trapnell, Cole; Lucks, Julius B.; Mortimer, Stefanie A.; Luo, Shujun; Schroth, Gary P.; Doudna, Jennifer A.; Arkin, Adam P.; Pachter, Lior

2011-01-01

327

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

SciTech Connect

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.

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

328

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

NASA Astrophysics Data System (ADS)

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.

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

329

Interfaces with internal structures in generalized rock-paper-scissors models  

NASA Astrophysics Data System (ADS)

In this work we investigate the development of stable dynamical structures along interfaces separating domains belonging to enemy partnerships in the context of cyclic predator-prey models with an even number of species N ?8. We use both stochastic and field theory simulations in one and two spatial dimensions, as well as analytical arguments, to describe the association at the interfaces of mutually neutral individuals belonging to enemy partnerships and to probe their role in the development of the dynamical structures at the interfaces. We identify an interesting behavior associated with the symmetric or asymmetric evolution of the interface profiles depending on whether N /2 is odd or even, respectively. We also show that the macroscopic evolution of the interface network is not very sensitive to the internal structure of the interfaces. Although this work focuses on cyclic predator-prey models with an even number of species, we argue that the results are expected to be quite generic in the context of spatial stochastic May-Leonard models.

Avelino, P. P.; Bazeia, D.; Losano, L.; Menezes, J.; de Oliveira, B. F.

2014-04-01

330

Toward automated model building from video in computer-assisted diagnoses in colonoscopy  

NASA Astrophysics Data System (ADS)

A 3D colon model is an essential component of a computer-aided diagnosis (CAD) system in colonoscopy to assist surgeons in visualization, and surgical planning and training. This research is thus aimed at developing the ability to construct a 3D colon model from endoscopic videos (or images). This paper summarizes our ongoing research in automated model building in colonoscopy. We have developed the mathematical formulations and algorithms for modeling static, localized 3D anatomic structures within a colon that can be rendered from multiple novel view points for close scrutiny and precise dimensioning. This ability is useful for the scenario when a surgeon notices some abnormal tissue growth and wants a close inspection and precise dimensioning. Our modeling system uses only video images and follows a well-established computer-vision paradigm for image-based modeling. We extract prominent features from images and establish their correspondences across multiple images by continuous tracking and discrete matching. We then use these feature correspondences to infer the camera's movement. The camera motion parameters allow us to rectify images into a standard stereo configuration and calculate pixel movements (disparity) in these images. The inferred disparity is then used to recover 3D surface depth. The inferred 3D depth, together with texture information recorded in images, allow us to construct a 3D model with both structure and appearance information that can be rendered from multiple novel view points.

Koppel, Dan; Chen, Chao-I.; Wang, Yuan-Fang; Lee, Hua; Gu, Jia; Poirson, Allen; Wolters, Rolf

2007-03-01

331

Continuity-based interfacing of models for wastewater systems described by Petersen matrices.  

PubMed

In this paper the Petersen and composition matrices that modellers are now familiar with are used as a basis to construct interfacing models between subsystems considered in wastewater treatment. Starting from continuity considerations and a set of transformation reactions between components used in the two models of the subsystems to be interfaced, a set of linear algebraic equations needs to be solved. The theoretical development is illustrated using a simplified integrated model of an activated sludge system coupled to an anaerobic digester. Continuity-guaranteed interfacing of subsystems will facilitate optimization studies of the within-the-fence process units of a wastewater treatment plant or of the integrated urban wastewater system. PMID:16180469

Vanrolleghem, P A; Rosen, C; Zaher, U; Copp, J; Benedetti, L; Ayesa, E; Jeppsson, Ulf

2005-01-01

332

General MACOS Interface for Modeling and Analysis for Controlled Optical Systems  

NASA Technical Reports Server (NTRS)

The General MACOS Interface (GMI) for Modeling and Analysis for Controlled Optical Systems (MACOS) enables the use of MATLAB as a front-end for JPL s critical optical modeling package, MACOS. MACOS is JPL s in-house optical modeling software, which has proven to be a superb tool for advanced systems engineering of optical systems. GMI, coupled with MACOS, allows for seamless interfacing with modeling tools from other disciplines to make possible integration of dynamics, structures, and thermal models with the addition of control systems for deformable optics and other actuated optics. This software package is designed as a tool for analysts to quickly and easily use MACOS without needing to be an expert at programming MACOS. The strength of MACOS is its ability to interface with various modeling/development platforms, allowing evaluation of system performance with thermal, mechanical, and optical modeling parameter variations. GMI provides an improved means for accessing selected key MACOS functionalities. The main objective of GMI is to marry the vast mathematical and graphical capabilities of MATLAB with the powerful optical analysis engine of MACOS, thereby providing a useful tool to anyone who can program in MATLAB. GMI also improves modeling efficiency by eliminating the need to write an interface function for each task/project, reducing error sources, speeding up user/modeling tasks, and making MACOS well suited for fast prototyping.

Sigrist, Norbert; Basinger, Scott A.; Redding, David C.

2012-01-01

333

RuleBender: a visual interface for rule-based modeling  

PubMed Central

Summary: Rule-based modeling (RBM) is a powerful and increasingly popular approach to modeling intracellular biochemistry. Current interfaces for RBM are predominantly text-based and command-line driven. Better visual tools are needed to make RBM accessible to a broad range of users, to make specification of models less error prone and to improve workflows. We present RULEBENDER, an open-source visual interface that facilitates interactive debugging, simulation and analysis of RBMs. Availability: RULEBENDER is freely available for Mac, Windows and Linux at http://rulebender.org. Contact: faeder@pitt.edu; marai@cs.pitt.edu Supplementary information: Supplementary data are available at Bioinformatics online.

Xu, Wen; Smith, Adam M.; Faeder, James R.; Marai, G. Elisabeta

2011-01-01

334

Electronegativity equalization model for interface barrier formation at reactive metal/organic contacts  

NASA Astrophysics Data System (ADS)

A general model based on electronegativity equalization method (EEM) is proposed for a quantitative formulation of barrier formation at reactive metal/organic interfaces. The present model predicts for molecular bonding formation a linear dependence of barrier heights on the degree of partial charge transfer, which is determined by the electronegativity difference between metals and molecules. Also, the calculated barrier heights show good agreement with the empirical values. It suggests that the EEM-based electronegativity model has captured the essence of barrier formation at reactive metal/organic interfaces, and that electronegativity is a fundamental factor in characterizing the chemical trend of barrier heights.

Tang, J. X.; Li, Y. Q.; Wang, S. D.; Lee, C. S.; Lee, S. T.

2009-10-01

335

The GIS Weasel: An interface for the development of geographic information used in environmental simulation modeling  

Microsoft Academic Search

The GIS Weasel is a freely available, open-source software package built on top of ArcInfo Workstation® [ESRI, Inc., 2001, ArcInfo Workstation (8.1 ed.), Redlands, CA] for creating maps and parameters of geographic features used in environmental simulation models. The software has been designed to minimize the need for GIS expertise and automate the preparation of the geographic information as much

Roland J. Viger

2008-01-01

336

Interface characteristics of carbon nanotube reinforced polymer composites using an advanced pull-out model  

NASA Astrophysics Data System (ADS)

An advanced pull-out model is presented to obtain the interface characteristics of carbon nanotube (CNT) in polymer composite. Since, a part of the CNT/matrix interface near the crack tip is considered to be debonded, there must present adhesive van der Waals (vdW) interaction which is generally presented in the form of Lennard-Jones potential. A separate analytical model is also proposed to account normal cohesive stress caused by the vdW interaction along the debonded CNT/polymer interface. Analytical solutions for axial and interfacial shear stress components are derived in closed form. The analytical result shows that contribution of vdW interaction is very significant and also enhances stress transfer potential of CNT in polymer composite. Parametric studies are also conducted to obtain the influence of key composite factors on bonded and debonded interface. The result reveals that the parameter dependency of interfacial stress transfer is significantly higher in the perfectly bonded interface than that of the debonded interface.

Ahmed, Khondaker Sakil; Keng, Ang Kok

2014-02-01

337

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

NASA Astrophysics Data System (ADS)

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.

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

338

Combining language models in the input interface of a spoken dialogue system  

Microsoft Academic Search

This paper presents a new technique to enhance the performance of the input interface of spoken dia- logue systems based on a procedure that combines during speech recognition the advantages of using prompt-dependent language models with those of using a language model independent of the prompts gen- erated by the dialogue system. The technique proposes to create a new speech

Ramón López-cózar; Zoraida Callejas

2006-01-01

339

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

ERIC Educational Resources Information Center

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…

Ding, Suining

2008-01-01

340

Semi-ionic Model for Metal Oxides and Their Interfaces with Organic Molecules  

Microsoft Academic Search

A semi-ionic model is proposed for simulations of bulk metal oxides and interfaces between metal oxides and organic molecules. In this model, the electrostatic interactions are represented by partial charges on atoms; the covalent contributions are represented by a Morse function, and the van der Waals interactions are represented by a Lennard-Jones (LJ) function. Four potential functions are parametrized, using

Lifeng Zhao; Lianchi Liu; Huai Sun

2007-01-01

341

A surface complexation model of the carbonate mineral-aqueous solution interface  

Microsoft Academic Search

A surface complexation model for the chemical structure and reactivity of the carbonatewater interface is presented. The model postulates the formation of the hydration species >CO 3 H 0 and >MeOH 0 at the surface of a divalent metal carbonate MeCO 3 (Me = Ca, Mn, Fe, etc.). The existence of these primary hydration species is supported by spectroscopic data.

Philippe van Cappellen; Laurent Charlet; Werner Stumm; Paul Wersin

1993-01-01

342

Interfacing environmental simulation models and databases using XML  

Microsoft Academic Search

Typically in environmental management tasks one needs to examine and explore data from several sources, use simulation models, develop scenarios, assess impacts, and provide support for decision makers. Here we consider the eXtensible Markup Language (XML) standard in developing information transfer techniques between databases and simulation models. Suitability of XML as the agreed data transfer format is studied in a

Teemu Kokkonen; Ari Jolma; Harri Koivusalo

2003-01-01

343

A Graphical User Interface for handling IFC Partial Model Exchange  

Microsoft Academic Search

This paper is concerned with the interoperability problem between AEC software applications and actors representing multidisciplinary collaborative domains. The idea of creating a central model that is used as a base for interoperability between multidisciplinary software applications has been recently developing under the BIM (Building Information Model) concept. The IFC (Industry Foundation Classes) initiative from the IAI (International Alliance of

Mohamed Nour

344

Random-tiling model of membranes and interfaces  

NASA Astrophysics Data System (ADS)

A class of random tiling membrane models with an intrinsic self-diffusion mechanism is introduced. As an illustration, a random Wieringa roof model is constructed and investigated by means of Monte Carlo simulations. The long time transport is found to be consistent with normal diffusion both at low and high temperatures.

Jari?, Marko Vukobrat; Johnson, Steven L.

1996-02-01

345

Finite elements methods for modeling the guided waves propagation in structures with weak interfaces  

NASA Astrophysics Data System (ADS)

This paper describes two methods using a finite element (FE) code for modeling the effects of weak interfaces on the propagation of low-order Lamb modes. The variable properties of the interfaces are modeled by either a thin layer or a uniform repartition of compression and shear springs that insure the continuity of the stresses and impose a discontinuity in the displacement field. The method is tested by comparison with measurements that were presented in a previous paper [J. Acoust. Soc. Am. 113(6) 3161-3170 (2003)]. The interface was the contact between a rough elastomer with high internal damping loaded against one surface of a glass plate. Both normal and shear stiffnesses of the interface were quantified from the attenuation of A0 and S0 Lamb waves caused by leakage of energy from the plate into the elastomer and measured at each step of a compressive loading. The FE model is made in the frequency domain, thus allowing the viscoelastic properties of the elastomer to be modeled by using complex moduli as input data. By introducing the interface stiffnesses in the code, the predicted guided waves attenuations are compared to the experimental results to validate the numerical FE methods. .

Hosten, Bernard; Castaings, Michel

2005-03-01

346

Electronic structure of the SiNx/TiN interface: A model system for superhard nanocomposites  

NASA Astrophysics Data System (ADS)

Nanostructured materials such as nanocomposites and nanolaminates—subjects of intense interest in modern materials research—are defined by internal interfaces, the nature of which is generally unknown. Nevertheless, the interfaces often determine the bulk properties. An example of this is superhard nanocomposites with hardness approaching that of diamond. TiN/Si3N4 nanocomposites (TiN nanocrystals encapsulated in a fully percolated SiNx tissue phase) and nanolaminates, in particular, have attracted much attention as model systems for the synthesis of such superhard materials. Here, we use in situ angle-resolved x-ray photoelectron spectroscopy to probe the electronic structure of Si3N4/TiN(001), Si/TiN(001), and Ti/TiN(001) bilayer interfaces, in which 4-ML-thick overlayers are grown in an ultrahigh vacuum system by reactive magnetron sputter deposition onto epitaxial TiN layers on MgO(001). The thickness of the Si3N4, Si, and Ti overlayers is chosen to be thin enough to insure sufficient electron transparency to probe the interfaces, while being close to values reported in typical nanocomposites and nanolaminates. The results show that these overlayer/TiN(001) interfaces have distinctly different bonding characteristics. Si3N4 exhibits interface polarization through the formation of an interlayer, in which the N concentration is enhanced at higher substrate bias values during Si3N4 deposition. The increased number of Ti-N bonds at the interface, together with the resulting polarization, strengthens interfacial bonding. In contrast, overlayers of Si and, even more so, metallic Ti weaken the interface by minimizing the valence band energy difference between the two phases. A model is proposed that provides a semiquantitative explanation of the interfacial bond strength in nitrogen-saturated and nitrogen-deficient Ti-Si-N nanocomposites.

Patscheider, Jörg; Hellgren, Niklas; Haasch, Richard T.; Petrov, Ivan; Greene, J. E.

2011-03-01

347

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

Microsoft Academic Search

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

Martin A. Fischler; Robert C. Bolles

1981-01-01

348

Interface reduction of flexible bodies for efficient modeling of body flexibility in multibody dynamics  

Microsoft Academic Search

The floating frame of reference techniques is an established technique to incorporate flexibility in multibody models. The\\u000a model dimension of the body flexibility models can be reduced by model reduction techniques such as Component Mode Synthesis\\u000a (CMS) or Krylov subspace-based techniques, but the efficiency of these techniques is limited by the number of interface nodes\\u000a in which the flexible body

Gert H. K. Heirman; Wim Desmet

2010-01-01

349

Modeling and matching of landmarks for automation of Mars Rover localization  

NASA Astrophysics Data System (ADS)

The Mars Exploration Rover (MER) mission, begun in January 2004, has been extremely successful. However, decision-making for many operation tasks of the current MER mission and the 1997 Mars Pathfinder mission is performed on Earth through a predominantly manual, time-consuming process. Unmanned planetary rover navigation is ideally expected to reduce rover idle time, diminish the need for entering safe-mode, and dynamically handle opportunistic science events without required communication to Earth. Successful automation of rover navigation and localization during the extraterrestrial exploration requires that accurate position and attitude information can be received by a rover and that the rover has the support of simultaneous localization and mapping. An integrated approach with Bundle Adjustment (BA) and Visual Odometry (VO) can efficiently refine the rover position. However, during the MER mission, BA is done manually because of the difficulty in the automation of the cross-sitetie points selection. This dissertation proposes an automatic approach to select cross-site tie points from multiple rover sites based on the methods of landmark extraction, landmark modeling, and landmark matching. The first step in this approach is that important landmarks such as craters and rocks are defined. Methods of automatic feature extraction and landmark modeling are then introduced. Complex models with orientation angles and simple models without those angles are compared. The results have shown that simple models can provide reasonably good results. Next, the sensitivity of different modeling parameters is analyzed. Based on this analysis, cross-site rocks are matched through two complementary stages: rock distribution pattern matching and rock model matching. In addition, a preliminary experiment on orbital and ground landmark matching is also briefly introduced. Finally, the reliability of the cross-site tie points selection is validated by fault detection, which considers the mapping capability of MER cameras and the reason for mismatches. Fault detection strategies are applied in each step of the cross-site tie points selection to automatically verify the accuracy. The mismatches are excluded and localization errors are minimized. The method proposed in this dissertation is demonstrated with the datasets from the 2004 MER mission (traverse of 318 m) as well as the simulated test data at Silver Lake (traverse of 5.5 km), California. The accuracy analysis demonstrates that the algorithm is efficient at automatically selecting a sufficient number of well-distributed high-quality tie points to link the ground images into an image network for BA. The method worked successfully along with a continuous 1.1 km stretch. With the BA performed, highly accurate maps can be created to help the rover to navigate precisely and automatically. The method also enables autonomous long-range Mars rover localization.

Wang, Jue

350

Automated Multi-model Reconstruction from Single-Particle Electron Microscopy Data  

PubMed Central

Biological macromolecules can adopt multiple conformational and compositional states due to structural flexibility and alternative subunit assemblies. This structural heterogeneity poses a major challenge in the study of macromolecular structure using single particle electron microscopy. We propose a fully automated, unsupervised method for the three-dimensional reconstruction of multiple structural models from heterogeneous data. As a starting reference, our method employs an initial structure that does not account for any heterogeneity. Then, a multi-stage clustering is used to create multiple models representative of the heterogeneity within the sample. The multi-stage clustering combines an existing approach based on Multivariate Statistical Analysis to perform clustering within individual Euler angles, and a newly developed approach to sort out class-averages from individual Euler angles into homogeneous groups. Structural models are computed from individual clusters. The whole data classification is further refined using an iterative multi-model projection matching approach. We tested our method on one synthetic and three distinct experimental datasets. The tests include the cases where a macromolecular complex exhibits structural flexibility and cases where a molecule is found in ligand-bound and unbound states. We propose the use of our approach as an efficient way to reconstruct distinct multiple models from heterogeneous data.

Shatsky, Maxim; Hall, Richard J.; Nogales, Eva; Malik, Jitendra; Brenner, Steven E.

2010-01-01

351

Classification of mouse sperm motility patterns using an automated multiclass support vector machines model.  

PubMed

Vigorous sperm motility, including the transition from progressive to hyperactivated motility that occurs in the female reproductive tract, is required for normal fertilization in mammals. We developed an automated, quantitative method that objectively classifies five distinct motility patterns of mouse sperm using Support Vector Machines (SVM), a common method in supervised machine learning. This multiclass SVM model is based on more than 2000 sperm tracks that were captured by computer-assisted sperm analysis (CASA) during in vitro capacitation and visually classified as progressive, intermediate, hyperactivated, slow, or weakly motile. Parameters associated with the classified tracks were incorporated into established SVM algorithms to generate a series of equations. These equations were integrated into a binary decision tree that sequentially sorts uncharacterized tracks into distinct categories. The first equation sorts CASA tracks into vigorous and nonvigorous categories. Additional equations classify vigorous tracks as progressive, intermediate, or hyperactivated and nonvigorous tracks as slow or weakly motile. Our CASAnova software uses these SVM equations to classify individual sperm motility patterns automatically. Comparisons of motility profiles from sperm incubated with and without bicarbonate confirmed the ability of the model to distinguish hyperactivated patterns of motility that develop during in vitro capacitation. The model accurately classifies motility profiles of sperm from a mutant mouse model with severe motility defects. Application of the model to sperm from multiple inbred strains reveals strain-dependent differences in sperm motility profiles. CASAnova provides a rapid and reproducible platform for quantitative comparisons of motility in large, heterogeneous populations of mouse sperm. PMID:21349820

Goodson, Summer G; Zhang, Zhaojun; Tsuruta, James K; Wang, Wei; O'Brien, Deborah A

2011-06-01

352

Classification of Mouse Sperm Motility Patterns Using an Automated Multiclass Support Vector Machines Model1  

PubMed Central

Vigorous sperm motility, including the transition from progressive to hyperactivated motility that occurs in the female reproductive tract, is required for normal fertilization in mammals. We developed an automated, quantitative method that objectively classifies five distinct motility patterns of mouse sperm using Support Vector Machines (SVM), a common method in supervised machine learning. This multiclass SVM model is based on more than 2000 sperm tracks that were captured by computer-assisted sperm analysis (CASA) during in vitro capacitation and visually classified as progressive, intermediate, hyperactivated, slow, or weakly motile. Parameters associated with the classified tracks were incorporated into established SVM algorithms to generate a series of equations. These equations were integrated into a binary decision tree that sequentially sorts uncharacterized tracks into distinct categories. The first equation sorts CASA tracks into vigorous and nonvigorous categories. Additional equations classify vigorous tracks as progressive, intermediate, or hyperactivated and nonvigorous tracks as slow or weakly motile. Our CASAnova software uses these SVM equations to classify individual sperm motility patterns automatically. Comparisons of motility profiles from sperm incubated with and without bicarbonate confirmed the ability of the model to distinguish hyperactivated patterns of motility that develop during in vitro capacitation. The model accurately classifies motility profiles of sperm from a mutant mouse model with severe motility defects. Application of the model to sperm from multiple inbred strains reveals strain-dependent differences in sperm motility profiles. CASAnova provides a rapid and reproducible platform for quantitative comparisons of motility in large, heterogeneous populations of mouse sperm.

Goodson, Summer G.; Zhang, Zhaojun; Tsuruta, James K.; Wang, Wei; O'Brien, Deborah A.

2011-01-01

353

Toward Automated FAÇADE Texture Generation for 3d Photorealistic City Modelling with Smartphones or Tablet Pcs  

NASA Astrophysics Data System (ADS)

An automated model-image fitting algorithm is proposed in this paper for generating façade texture image from pictures taken by smartphones or tablet PCs. The façade texture generation requires tremendous labour work and thus, has been the bottleneck of 3D photo-realistic city modelling. With advanced developments of the micro electro mechanical system (MEMS), camera, global positioning system (GPS), and gyroscope (G-sensors) can all be integrated into a smartphone or a table PC. These sensors bring the possibility of direct-georeferencing for the pictures taken by smartphones or tablet PCs. Since the accuracy of these sensors cannot compared to the surveying instruments, the image position and orientation derived from these sensors are not capable of photogrammetric measurements. This paper adopted the least-squares model-image fitting (LSMIF) algorithm to iteratively improve the image's exterior orientation. The image position from GPS and the image orientation from gyroscope are treated as the initial values. By fitting the projection of the wireframe model to the extracted edge pixels on image, the image exterior orientation elements are solved when the optimal fitting achieved. With the exact exterior orientation elements, the wireframe model of the building can be correctly projected on the image and, therefore, the façade texture image can be extracted from the picture.

Wang, S.

2012-07-01

354

Tape-Drop Transient Model for In-Situ Automated Tape Placement of Thermoplastic Composites  

NASA Technical Reports Server (NTRS)

Composite parts of nonuniform thickness can be fabricated by in-situ automated tape placement (ATP) if the tape can be started and stopped at interior points of the part instead of always at its edges. This technique is termed start/stop-on-the-part, or, alternatively, tape-add/tape-drop. The resulting thermal transients need to be managed in order to achieve net shape and maintain uniform interlaminar weld strength and crystallinity. Starting-on-the-part has been treated previously. This paper continues the study with a thermal analysis of stopping-on-the-part. The thermal source is switched off when the trailing end of the tape enters the nip region of the laydown/consolidation head. The thermal transient is determined by a Fourier-Laplace transform solution of the two-dimensional, time-dependent thermal transport equation. This solution requires that the Peclet number Pe (the dimensionless ratio of inertial to diffusive heat transport) be independent of time and much greater than 1. Plotted isotherms show that the trailing tape-end cools more rapidly than the downstream portions of tape. This cooling can weaken the bond near the tape end; however the length of the affected region is found to be less than 2 mm. To achieve net shape, the consolidation head must continue to move after cut-off until the temperature on the weld interface decreases to the glass transition temperature. The time and elapsed distance for this condition to occur are computed for the Langley ATP robot applying PEEK/carbon fiber composite tape and for two upgrades in robot performance. The elapsed distance after cut-off ranges from about 1 mm for the present robot to about 1 cm for the second upgrade.

Costen, Robert C.; Marchello, Joseph M.

1998-01-01

355

A Demonstration of Automated DNA Sequencing.  

ERIC Educational Resources Information Center

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)

Latourelle, Sandra; Seidel-Rogol, Bonnie

1998-01-01

356

Blockm-a block diagram modelling interface and its applications  

Microsoft Academic Search

A MATLAB-based menu-driven multi-input multi-output linear system block diagram modeling program called BLOCKM is presented. This program can be used very easily to enter complicated models described in block diagram form. The state-space representation of the system can then easily be found and processed in the MATLAB environment. The F-14 benchmark problem is used as an example to show the

D. Xue; D. P. Atherton

1992-01-01

357

Atomistic Cohesive Zone Models for Interface Decohesion in Metals  

NASA Technical Reports Server (NTRS)

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.

Yamakov, Vesselin I.; Saether, Erik; Glaessgen, Edward H.

2009-01-01

358

Sloan Digital Sky Survey photometric telescope automation and observing software  

SciTech Connect

The photometric telescope (PT) provides observations necessary for the photometric calibration of the Sloan Digital Sky Survey (SDSS). Because the attention of the observing staff is occupied by the operation of the 2.5 meter telescope which takes the survey data proper, the PT must reliably take data with little supervision. In this paper we describe the PT's observing program, MOP, which automates most tasks necessary for observing. MOP's automated target selection is closely modeled on the actions a human observer might take, and is built upon a user interface that can be (and has been) used for manual operation. This results in an interface that makes it easy for an observer to track the activities of the automating procedures and intervene with minimum disturbance when necessary. MOP selects targets from the same list of standard star and calibration fields presented to the user, and chooses standard star fields covering ranges of airmass, color, and time necessary to monitor atmospheric extinction and produce a photometric solution. The software determines when additional standard star fields are unnecessary, and selects survey calibration fields according to availability and priority. Other automated features of MOP, such as maintaining the focus and keeping a night log, are also built around still functional manual interfaces, allowing the observer to be as active in observing as desired; MOP's automated features may be used as tools for manual observing, ignored entirely, or allowed to run the telescope with minimal supervision when taking routine data.

Eric H. Neilsen, Jr. et al.

2002-10-16

359

Mesoscale modeling of the water liquid-vapor interface: A surface tension calculation  

NASA Astrophysics Data System (ADS)

We report a mesoscale modeling of the liquid-vapor interface of water. A mesoscopic model of water has been established in dissipative particle dynamics (DPD) to reproduce the interfacial properties of water. The surface tension and coexisting densities are compared between atomistic and mesoscopic simulations. Simple scaling relations have been established to link the atomistic and mesoscopic length and time scales. Our study demonstrates the capability of the DPD method to explore the interfacial properties of a planar water liquid-vapor interface and a water nanodroplet. This constitutes an important step toward the calculation of the surface tension of larger and more complex interfacial systems.

Ghoufi, A.; Malfreyt, P.

2011-05-01

360

Model for Deformation, Stress and Contact at Interfaces - Implications for Ultrasonic Measurements  

NASA Astrophysics Data System (ADS)

An analytical model is presented for calculating deformation, contact area, stiffness, and the distribution of stress across joints and interfaces that can be described as two rough surfaces in partial contact. Analytical, modeling, and experimental results are presented that demonstrate the role that deformation of the bulk material surrounding the joint and mechanical interaction between contact points play in joint properties and the propagation of acoustic waves across the interface. Results are applied to help interpret C-scans of spot-welded joints.

Hopkins, Deborah; Reverdy, Frédéric

2004-02-01

361

Delft FEWS: an open interface that connects models and data streams for operational forecasting systems  

NASA Astrophysics Data System (ADS)

Many of the operational forecasting systems that are in use today are centred around a single modelling suite. Over the years these systems and the required data streams have been tailored to provide a closed-knit interaction with their underlying modelling components. However, as time progresses it becomes a challenge to integrate new technologies into these model centric operational systems. Often the software used to develop these systems is out of date, or the original designers of these systems are no longer available. Additionally, the changing of the underlying models may requiring the complete system to be changed. This then becomes an extensive effort, not only from a software engineering point of view, but also from a training point of view. Due to significant time and resources being committed to re-training the forecasting teams that interact with the system on a daily basis. One approach to reducing the effort required in integrating new models and data is through an open interface architecture, and through the use of defined interfaces and standards in data exchange. This approach is taken by the Delft-FEWS operational forecasting shell, which has now been applied in some 40 operational forecasting centres across the world. The Delft-FEWS framework provides several interfaces that allow models and data in differing formats to be flexibly integrated with the system. The most common approach to the integration of modes is through the Delft-FEWS Published Interface. This is an XML based data exchange format that supports the exchange of time series data, as well as vector and gridded data formats. The Published Interface supports standardised data formats such as GRIB and the NetCDF-CF standard. A wide range of models has been integrated with the system through this approach, and these are used operationally across the forecasting centres using Delft FEWS. Models can communicate directly with the interface of Delft-FEWS, or through a SOAP service. This giving the flexibility required for a state-of-the-art operational forecasting service. While Delft-FEWS comes with a user-friendly GIS based interface, a time series viewer and editor, and a wide range of tools for visualization, analysis, validation and data conversion, the available graphical display can be extended. New graphical components can be seamlessly integrated with the system through the SOAP service. Thanks to this open infrastructure, new models can easily be incorporated into an operational system without having to change the operational process. This allows the forecaster to focus on the science instead of having to worry about model details and data formats. Furthermore all model formats introduced to the Delft-FEWS framework will in principle become available to the Delft-FEWS community (in some cases subject to the licence conditions of the model supplier). Currently a wide range of models has been integrated and is being used operationally; Mike 11, HEC-RAS & HEC-RESSIM, HBV, MODFLOW, SOBEK and more. In this way Delft-FEWS not only provides a modelling interface but also a platform for model inter-comparison or multi-model ensembles, as well as a knowledge interface that allows forecasters throughout the world to exchange their views and ideas on operational forecasting. Keywords: FEWS; forecasting; modelling; timeseries; data; XML; NetCDF; interface; SOAP

de Rooij, Erik; Werner, Micha

2010-05-01

362

Context based mixture model for cell phase identification in automated fluorescence microscopy  

PubMed Central

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.

Wang, Meng; Zhou, Xiaobo; King, Randy W; Wong, Stephen TC

2007-01-01

363

The Role of Model Interfaces for Participation in Water Management  

Microsoft Academic Search

Despite the increasing complexity in water management decision processes the actual use of models in those processes is not\\u000a very common. Particularly in participatory water management the potential participants do not seem to find access to models\\u000a used or usable for decision-making. The article discusses up to which degree computer- and Internet-based tools and complementary\\u000a instruments can help to \\u000a \\u000a \\u000a \\u000a \\u000a • 

Thomas Horlitz

2007-01-01

364

Automated brain structure segmentation based on atlas registration and appearance models.  

PubMed

Accurate automated brain structure segmentation methods facilitate the analysis of large-scale neuroimaging studies. This work describes a novel method for brain structure segmentation in magnetic resonance images that combines information about a structure's location and appearance. The spatial model is implemented by registering multiple atlas images to the target image and creating a spatial probability map. The structure's appearance is modeled by a classifier based on Gaussian scale-space features. These components are combined with a regularization term in a Bayesian framework that is globally optimized using graph cuts. The incorporation of the appearance model enables the method to segment structures with complex intensity distributions and increases its robustness against errors in the spatial model. The method is tested in cross-validation experiments on two datasets acquired with different magnetic resonance sequences, in which the hippocampus and cerebellum were segmented by an expert. Furthermore, the method is compared to two other segmentation techniques that were applied to the same data. Results show that the atlas- and appearance-based method produces accurate results with mean Dice similarity indices of 0.95 for the cerebellum, and 0.87 for the hippocampus. This was comparable to or better than the other methods, whereas the proposed technique is more widely applicable and robust. PMID:21937346

van der Lijn, Fedde; de Bruijne, Marleen; Klein, Stefan; den Heijer, Tom; Hoogendam, Yoo Y; van der Lugt, Aad; Breteler, Monique M B; Niessen, Wiro J

2012-02-01

365

A Sketching Interface for Freeform 3D Modeling  

NASA Astrophysics Data System (ADS)

This chapter introduces Teddy, a sketch-based modeling system to quickly and easily design freeform models such as stuffed animals and other rotund objects. The user draws several 2D freeform strokes interactively on the screen and the system automatically constructs plausible 3D polygonal surfaces. Our system supports several modeling operations, including the operation to construct a 3D polygonal surface from a 2D silhouette drawn by the user: it inflates the region surrounded by the silhouette making a wide area fat, and a narrow area thin. Teddy, our prototype system, is implemented as a Java program, and the mesh construction is done in real-time on a standard PC. Our informal user study showed that a first-time user masters the operations within 10 minutes, and can construct interesting 3D models within minutes. We also report the result of a case study where a high school teacher taught various 3D concepts in geography using the system.

Igarashi, Takeo

366

Modeling and Analysis Generic Interface for eXternal numerical codes (MAGIX)  

NASA Astrophysics Data System (ADS)

The Modeling and Analysis Generic Interface for eXternal numerical codes (MAGIX) is a model optimizer developed under the framework of the coherent set of astrophysical tools for spectroscopy (CATS) project. The MAGIX package provides a framework of an easy interface between existing codes and an iterating engine that attempts to minimize deviations of the model results from available observational data, constraining the values of the model parameters and providing corresponding error estimates. Many models (and, in principle, not only astrophysical models) can be plugged into MAGIX to explore their parameter space and find the set of parameter values that best fits observational/experimental data. MAGIX complies with the data structures and reduction tools of Atacama Large Millimeter Array (ALMA), but can be used with other astronomical and with non-astronomical data. http://www.astro.uni-koeln.de/projects/schilke/MAGIX

Möller, T.; Bernst, I.; Panoglou, D.; Muders, D.; Ossenkopf, V.; Röllig, M.; Schilke, P.

2013-01-01

367

Automated generation of high-quality training data for appearance-based object models  

NASA Astrophysics Data System (ADS)

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.

Becker, Stefan; Voelker, Arno; Kieritz, Hilke; Hübner, Wolfgang; Arens, Michael

2013-11-01

368

Automated estimation of fetal cardiac timing events from Doppler ultrasound signal using hybrid models.  

PubMed

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

Marzbanrad, Faezeh; Kimura, Yoshitaka; Funamoto, Kiyoe; Sugibayashi, Rika; Endo, Miyuki; Ito, Takuya; Palaniswami, Marimuthu; Khandoker, Ahsan H

2014-07-01

369

Automated rodent in situ muscle contraction assay and myofiber organization analysis in sarcopenia animal models.  

PubMed

Age-related sarcopenia results in frailty and decreased mobility, which are associated with increased falls and long-term disability in the elderly. Given the global increase in lifespan, sarcopenia is a growing, unmet medical need. This report aims to systematically characterize muscle aging in preclinical models, which may facilitate the development of sarcopenia therapies. Naïve rats and mice were subjected to noninvasive micro X-ray computed tomography (micro-CT) imaging, terminal in situ muscle function characterizations, and ATPase-based myofiber analysis. We developed a Definiens (Parsippany, NJ)-based algorithm to automate micro-CT image analysis, which facilitates longitudinal in vivo muscle mass analysis. We report development and characterization of translational in situ skeletal muscle performance assay systems in rat and mouse. The systems incorporate a custom-designed animal assay stage, resulting in enhanced force measurement precision, and LabVIEW (National Instruments, Austin, TX)-based algorithms to support automated data acquisition and data analysis. We used ATPase-staining techniques for myofibers to characterize fiber subtypes and distribution. Major parameters contributing to muscle performance were identified using data mining and integration, enabled by Labmatrix (BioFortis, Columbia, MD). These technologies enabled the systemic and accurate monitoring of muscle aging from a large number of animals. The data indicated that longitudinal muscle cross-sectional area measurement effectively monitors change of muscle mass and function during aging. Furthermore, the data showed that muscle performance during aging is also modulated by myofiber remodeling factors, such as changes in myofiber distribution patterns and changes in fiber shape, which affect myofiber interaction. This in vivo muscle assay platform has been applied to support identification and validation of novel targets for the treatment of sarcopenia. PMID:22461442

Weber, H; Rauch, A; Adamski, S; Chakravarthy, K; Kulkarni, A; Dogdas, B; Bendtsen, C; Kath, G; Alves, S E; Wilkinson, H A; Chiu, C-S

2012-06-01

370

An Agent-Based Interface to Terrestrial Ecological Forecasting  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

371

Automated geography  

SciTech Connect

Analytical methods and computer technology for spatial analysis have advanced rapidly. Geographers can now consider a general form of automated geography which integrates all of the new techniques into an analytical whole. Computer cartography, computer graphics, digital remote sensing, geographic information systems, spatial statistics, and quantitative spatial modeling can be combined eclectically with traditional manual techniques to address geographic problems that are too large and complex for manual treatment alone. Small systems are widely available to facilitate small, less complex problems. Automation can assist in all forms of geography - scientific and humanistic, nomothetic and idiographic, basic and applied - but its adoption is likely to be highest among applied scientists. The immediate challenge is to prepare for a major shift toward computer instruction and automated geography in the late 1980s. Long term effects will include improved contributions by geographers to national and international policy analyses, a greater emphasis on team-work and sharing, stronger ties with other disciplines, and a generally more viable discipline. 27 references.

Dobson, J.E.

1983-05-01

372

Modeling Nitrogen Cycle at the Surface-Subsurface Water Interface  

NASA Astrophysics Data System (ADS)

Anthropogenic activities, primarily food and energy production, have altered the global nitrogen cycle, increasing reactive dissolved inorganic nitrogen, Nr, chiefly ammonium NH4+ and nitrate NO3-, availability in many streams worldwide. Increased Nr promotes biological activity often with negative consequences such as water body eutrophication and emission of nitrous oxide gas, N2O, an important greenhouse gas as a by-product of denitrification. The hyporheic zone may play an important role in processing Nr and returning it to the atmosphere. Here, we present a process-based three-dimensional semi-analytical model, which couples hyporheic hydraulics with biogeochemical reactions and transport equations. Transport is solved by means of particle tracking with negligible local dispersion and biogeochemical reactions modeled by linearized Monod's kinetics with temperature dependant reaction rate coefficients. Comparison of measured and predicted N2O emissions from 7 natural stream shows a good match. We apply our model to gravel bed rivers with alternate bar morphology to investigate the role of hyporheic hydraulic, depth of alluvium, relative availability of stream concentration of NO3- and NH4+ and water temperature on nitrogen gradients within the sediment. Our model shows complex concentration dynamics, which depend on hyporheic residence time distribution and consequently on streambed morphology, within the hyporheic zone. Nitrogen gas emissions from the hyporheic zone increase with alluvium depth in large low-gradient streams but not in small steep streams. On the other hand, hyporheic water temperature influences nitrification/denitrification processes mainly in small-steep than large low-gradient streams, because of the long residence times, which offset the slow reaction rates induced by low temperatures in the latter stream. The overall conclusion of our analysis is that river morphology has a major impact on biogeochemical processes such as nitrification and denitrification with a direct impact on the stream nutrient removal and transport.

Marzadri, A.; Tonina, D.; Bellin, A.

2011-12-01

373

NRCS GeoHydro—A GIS interface for hydrologic modeling  

Microsoft Academic Search

The US Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) has developed NRCS GeoHydro 9x, a new ArcGIS application, to complement the WinTR–20 application and assist USDA field staff, and other government, private, and foreign organizations. WinTR–20 is a storm event hydrologic model used to evaluate impacts of structural and land treatment measures. NRCS GeoHydro 9x, using geographic information

William H. Merkel; Ravichandran M. Kaushika; Eddy Gorman

2008-01-01

374

Model analyses of visual biofeedback training for EEG-based brain-computer interface  

Microsoft Academic Search

The primary goal of this study was to construct a simulation model of a biofeedback brain-computer interface (BCI) system to analyze the effect of biofeedback training on BCI users. A mathematical model of a man-machine visual-biofeedback\\u000a BCI system was constructed to simulate a subject using a BCI system to control cursor movements. The model consisted of a\\u000a visual tracking system,

Chih-Wei Chen; Ming-Shaung Ju; Yun-Nien Sun; Chou-Ching K. Lin

2009-01-01

375

Modeling and identification of frictional forces at a contact interface experiencing micro-vibro-impacts  

NASA Astrophysics Data System (ADS)

Modeling and identification of restoring forces at contact interfaces is an inevitable part of investigating the dynamic characteristics of mechanical systems. As the vibration amplitude increases, various nonlinear mechanisms such as micro/macro-slip and micro-impacts activate in the interface. This paper considers the nonlinear behavior of a frictional contact in situations where micro-impacts develop in the normal direction to the friction surface. It investigates the effect of variable normal load on the contact frictional forces, and defines a friction model capable of taking into account this effect. In an experimental case study, the contact is excited using a dual sine force to allow a reliable dual-mode identification procedure. The measured data and the normal modes of the corresponding linear system are employed to define the system nonlinear modes used to expand the system response. This provides a reduced order model containing dominant nonlinear effects in the contact interface. Force state mapping method is employed to identify the contact restoring forces. The experimentally obtained forces are employed to determine the parameters of a new friction law defied by modifying the Valanis model. It is shown the model is capable of predicting the main nonlinear characteristics of the contact interface and regenerates the experimental results at different vibration response levels.

Pourahmadian, Fatemeh; Ahmadian, Hamid; Jalali, Hassan

2012-06-01

376

Model studies of Rayleigh instabilities via microdesigned interfaces  

SciTech Connect

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.

Glaeser, Andreas M.

2000-10-17

377

Accident prediction model for railway-highway interfaces.  

PubMed

Considerable past research has explored relationships between vehicle accidents and geometric design and operation of road sections, but relatively little research has examined factors that contribute to accidents at railway-highway crossings. Between 1998 and 2002 in Korea, about 95% of railway accidents occurred at highway-rail grade crossings, resulting in 402 accidents, of which about 20% resulted in fatalities. These statistics suggest that efforts to reduce crashes at these locations may significantly reduce crash costs. The objective of this paper is to examine factors associated with railroad crossing crashes. Various statistical models are used to examine the relationships between crossing accidents and features of crossings. The paper also compares accident models developed in the United States and the safety effects of crossing elements obtained using Korea data. Crashes were observed to increase with total traffic volume and average daily train volumes. The proximity of crossings to commercial areas and the distance of the train detector from crossings are associated with larger numbers of accidents, as is the time duration between the activation of warning signals and gates. The unique contributions of the paper are the application of the gamma probability model to deal with underdispersion and the insights obtained regarding railroad crossing related vehicle crashes. PMID:16297846

Oh, Jutaek; Washington, Simon P; Nam, Doohee

2006-03-01

378

Interface modeling to predict well casing damage for big hill strategic petroleum reserve.  

SciTech Connect

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.

Ehgartner, Brian L.; Park, Byoung Yoon

2012-02-01

379

Distribution automation applications of fiber optics  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

380

Semi-automated DIRSIG scene modeling from three-dimensional lidar and passive imagery  

NASA Astrophysics Data System (ADS)

The Digital Imaging and Remote Sensing Image Generation (DIRSIG) model is an established, first-principles based scene simulation tool that produces synthetic multispectral and hyperspectral images from the visible to long wave infrared (0.4 to 20 microns). Over the last few years, significant enhancements such as spectral polarimetric and active Light Detection and Ranging (lidar) models have also been incorporated into the software, providing an extremely powerful tool for multi-sensor algorithm testing and sensor evaluation. However, the extensive time required to create large-scale scenes has limited DIRSIG's ability to generate scenes "on demand." To date, scene generation has been a laborious, time-intensive process, as the terrain model, CAD objects and background maps have to be created and attributed manually. To shorten the time required for this process, this research developed an approach to reduce the man-in-the-loop requirements for several aspects of synthetic scene construction. Through a fusion of 3D lidar data with passive imagery, we were able to semi-automate several of the required tasks in the DIRSIG scene creation process. Additionally, many of the remaining tasks realized a shortened implementation time through this application of multi-modal imagery. Lidar data is exploited to identify ground and object features as well as to define initial tree location and building parameter estimates. These estimates are then refined by analyzing high-resolution frame array imagery using the concepts of projective geometry in lieu of the more common Euclidean approach found in most traditional photogrammetric references. Spectral imagery is also used to assign material characteristics to the modeled geometric objects. This is achieved through a modified atmospheric compensation applied to raw hyperspectral imagery. These techniques have been successfully applied to imagery collected over the RIT campus and the greater Rochester area. The data used include multiple-return point information provided by an Optech lidar linescanning sensor, multispectral frame array imagery from the Wildfire Airborne Sensor Program (WASP) and WASP-lite sensors, and hyperspectral data from the Modular Imaging Spectrometer Instrument (MISI) and the COMPact Airborne Spectral Sensor (COMPASS). Information from these image sources was fused and processed using the semi-automated approach to provide the DIRSIG input files used to define a synthetic scene. When compared to the standard manual process for creating these files, we achieved approximately a tenfold increase in speed, as well as a significant increase in geometric accuracy.

Lach, Stephen R.

381

Automated Probing and Inference of Analytical Models for Metabolic Network Dynamics  

NASA Astrophysics Data System (ADS)

We introduce a method to automatically construct mathematical models of a biological system, and apply this technique to infer a seven-dimensional nonlinear model of glycolytic oscillations in yeast -- based only on noisy observational data obtained from in silico experiments. Graph-based symbolic encoding, fitness prediction, and estimation-exploration can for the first time provide the level of symbolic regression required for biological applications. With no a priori knowledge of the system, the Cornell algorithm in several hours of computation correctly identified all seven ordinary nonlinear differential equations, the most complicated of which was dA3dt=-1.12.A3-192.24.A3S11+12.50.A3^4+124.92.S3+31.69.A3S3, where A3 = [ATP], S1= [glucose], and S3 = [cytosolic pyruvate and acetaldehyde pool]. Errors on the 26 parameters ranged from 0 to 14.5%. The algorithm also automatically identified new and potentially useful chemical constants of the motion, e.g. -k1N2+K2v1+k2S1A3-(k4-k5v1)A3^4+k6 0. This approach may enable automated design, control and analysis of wet-lab experiments for model identification/refinement.

Wikswo, John; Schmidt, Michael; Jenkins, Jerry; Hood, Jonathan; Lipson, Hod

2010-03-01

382

Project Independence Evaluation System (PIES) Documentation. Volume X. Automation of Finding Rate and Discount Rates in the FEA Gas Supply Model.  

National Technical Information Service (NTIS)

This report describes the methodology used to automate, within the model, the straight-forward but laborious calculation of finding rates and discount rates. Early versions of the model required these calculations to be done by hand.

1976-01-01

383

Contaminant analysis automation demonstration proposal  

SciTech Connect

The nation-wide and global need for environmental restoration and waste remediation (ER&WR) presents significant challenges to the analytical chemistry laboratory. The expansion of ER&WR programs forces an increase in the volume of samples processed and the demand for analysis data. To handle this expanding volume, productivity must be increased. However. The need for significantly increased productivity, faces contaminant analysis process which is costly in time, labor, equipment, and safety protection. Laboratory automation offers a cost effective approach to meeting current and future contaminant analytical laboratory needs. The proposed demonstration will present a proof-of-concept automated laboratory conducting varied sample preparations. This automated process also highlights a graphical user interface that provides supervisory, control and monitoring of the automated process. The demonstration provides affirming answers to the following questions about laboratory automation: Can preparation of contaminants be successfully automated?; Can a full-scale working proof-of-concept automated laboratory be developed that is capable of preparing contaminant and hazardous chemical samples?; Can the automated processes be seamlessly integrated and controlled?; Can the automated laboratory be customized through readily convertible design? and Can automated sample preparation concepts be extended to the other phases of the sample analysis process? To fully reap the benefits of automation, four human factors areas should be studied and the outputs used to increase the efficiency of laboratory automation. These areas include: (1) laboratory configuration, (2) procedures, (3) receptacles and fixtures, and (4) human-computer interface for the full automated system and complex laboratory information management systems.

Dodson, M.G.; Schur, A.; Heubach, J.G.

1993-10-01

384

The Slow Bow Shock Model of the Heliospheric Interface  

NASA Astrophysics Data System (ADS)

Recent IBEX observations indicate that the pristine interstellar wind is most likely subfast and sub-Alfvenic, which means that no regular fast magnetosonic bow shock can form upstream of the heliosphere. Nevertheless, a slow magnetosonic bow shock can still exist in the local interstellar medium, provided that the angle between the interstellar magnetic field and the interstellar plasma flow velocity (alpha_Bv) is sufficiently small. The latter is supported by a number of kinetic-gasdynamic and multi-fluid MHD simulations that used the Voyager termination shock crossings to constrain the magnitude (3 to 4 microG) and direction (alpha_Bv= 15 to 30 degrees) of the interstellar magnetic field. We propose a quasi-parallel slow bow shock model as a likely alternative of the currently prevailing no bow shock model. The theoretically expected slow bow shock is self-consistently reproduced in our multi-fluid MHD simulations. Since slow-mode information can propagate mainly along the magnetic field, the slow bow shock is significantly shifted from the nose of the heliosphere toward the flank in the direction of the interstellar magnetic field. Such a displaced slow bow shock results in a dense and highly asymmetric hydrogen wall that is expected to produce detectable extra Lyman alpha absorption not only around the nose direction but also in some preferential tailward directions. This could explain among others the puzzling blue shift observed in the Lyman alpha absorption profile of Sirius. The slow bow shock model could easily explain the hotter and slower secondary interstellar hydrogen population observed by IBEX, which is thought to originate from the outer heliosheath. Thus both Lyman alpha and IBEX observations seem to be more consistent with a slow bow shock rather than a shock-free fast bow wave. Voyager 1 is most likely heading towards the slow bow shock, while Voyager 2 is not, which means that the two spacecraft are expected to encounter fundamentally different interstellar plasma populations beyond the heliopause.

Zieger, B.; Opher, M.

2013-05-01

385

Computational modeling and experimental investigation of effects of compositional elements on interface and design aesthetics  

Microsoft Academic Search

This article describes computational modeling and two corresponding experimental investigations of the effects of symmetry, balance and quantity of construction elements on interface aesthetic judgments. In the first experiment, 30 black and white geometric images were developed by systematically varying these three attributes in order to validate computational aesthetic quantification algorithms with subject ratings. The second experiment employed the same

Michael Bauerly; Yili Liu

2006-01-01

386

AgRISTARS: Yield model development/soil moisture. Interface control document  

NASA Technical Reports Server (NTRS)

The interactions and support functions required between the crop Yield Model Development (YMD) Project and Soil Moisture (SM) Project are defined. The requirements for YMD support of SM and vice-versa are outlined. Specific tasks in support of these interfaces are defined for development of support functions.

1980-01-01

387

A Monthly Water-Balance Model Driven By a Graphical User Interface  

USGS Publications Warehouse

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.

McCabe, Gregory J.; Markstrom, Steven L.

2007-01-01

388

Time integration for diffuse interface models for two-phase flow  

NASA Astrophysics Data System (ADS)

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.

Aland, Sebastian

2014-04-01

389

A penalty-based interface technology for coupling independently modeled 3D finite element meshes  

Microsoft Academic Search

An effective and robust 2D interface element able to connect independently modeled 3D finite element subdomains is presented. This method has been developed using a hybrid variational formulation with the penalty constraints, which leads to a computational approach that is very efficient. A significant effort has been directed toward developing an automatic calculation of the proper penalty parameter for each

Antonio Pantano; Ronald C. Averill

2007-01-01

390

FLAIR - Flux line-segment model for advection and interface reconstruction  

Microsoft Academic Search

A technique of interface transport and reconstruction is derived for the numerical models utilizing the volume of fluid method. For surface advection and its reconstruction, a new and more accurate FLAIR algorithm is developed. This technique is applied to the capillary driven viscous flow of an initially elliptic, two-dimensional fluid zone. The problem considered involves the solution of the Navier-Stokes

N. Ashgriz; J. Y. Poo

1991-01-01

391

Support of surgical process modeling by using adaptable software user interfaces  

NASA Astrophysics Data System (ADS)

Surgical Process Modeling (SPM) is a powerful method for acquiring data about the evolution of surgical procedures. Surgical Process Models are used in a variety of use cases including evaluation studies, requirements analysis and procedure optimization, surgical education, and workflow management scheme design. This work proposes the use of adaptive, situation-aware user interfaces for observation support software for SPM. We developed a method to support the modeling of the observer by using an ontological knowledge base. This is used to drive the graphical user interface for the observer to restrict the search space of terminology depending on the current situation. In the evaluation study it is shown, that the workload of the observer was decreased significantly by using adaptive user interfaces. 54 SPM observation protocols were analyzed by using the NASA Task Load Index and it was shown that the use of the adaptive user interface disburdens the observer significantly in workload criteria effort, mental demand and temporal demand, helping him to concentrate on his essential task of modeling the Surgical Process.

Neumuth, T.; Kaschek, B.; Czygan, M.; Goldstein, D.; Strauß, G.; Meixensberger, J.; Burgert, O.

2010-03-01

392

Self-organized criticality in an interface-growth model with quenched randomness.  

PubMed

We study a modified model of the Kardar-Paris-Zhang equation with quenched disorder, in which the driving force decreases as the interface rises up. A critical state is self-organized, and the anomalous scaling law with roughness exponent ??0.63 is numerically obtained. PMID:21230119

Sakaguchi, Hidetsugu

2010-09-01

393

Seismic traveltime inversion of 3D velocity model with triangulated interfaces  

NASA Astrophysics Data System (ADS)

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.

Li, Fei; Xu, Tao; Zhang, Minghui; Wu, Zhenbo; Wu, Chenglong; Zhang, Zhongjie; Teng, Jiwen

2014-04-01

394

Modeling the washboard effect at the head/disk interface  

NASA Astrophysics Data System (ADS)

A model is presented that accounts for the observation of periodic lubricant ripples formed when a slider is flying on-track over a lubricated disk surface. It is shown that lubricant flow modulation from the air shear stress due to the low flying slider acting as a spring is responsible for the observed corrugation, as repeated flying over the same track enhances the effect. This is somewhat moderated by the relaxation of the lubricant perturbation, by surface diffusion. Depending on the relative magnitude of the shear and diffusion processes, the system can find itself into regions of stability where small perturbations decay away, or regions of instability where they increase exponentially. Instability is enhanced for lower fly height and higher disk rotational frequency, making it a challenge for future growth in disk drive performance and areal density.

Dai, Qing; Hendriks, Ferdi; Marchon, Bruno

2004-07-01

395

Time sequence ordering extensions to the Entity-Relationship model and their application to the automated manufacturing process  

Microsoft Academic Search

Moyne, J.R., T.J. Teorey and L.C. McAfee, Jr., Time sequence ordering extensions to the entity relationship model and their application to the automated manufacturing process, Data & Knowledge Engineering 6 (1991) 421-443. New extensions to the entity-relationship (E-R) model have been developed to represent time sequencing and ordering aspects of information flow, and to represent the integration of control (programming)

James R. Moyne; Toby J. Teorey; Leo C. McAfee Jr.

1991-01-01

396

Automated Weather Research and Forecasting (WRF)-Based Nowcasting System: Software Description.  

National Technical Information Service (NTIS)

A Web service/Web interface software package has been engineered to address the need for an automated means to run the Weather Research and Forecasting (WRF) model with four-dimensional data assimilation. The user provides a model center point and selects...

B. P. Reen R. E. Dumais S. F. Kirby

2013-01-01

397

Mapping local laboratory interface terms to LOINC at a German university hospital using RELMA V.5: a semi-automated approach  

PubMed Central

Objective Logical Observation Identifiers Names and Codes (LOINC) mapping of laboratory data is often a question of the effort of mapping compared with the benefits of the structure achieved. The new LOINC mapping assistant RELMA (version 2011) has the potential to reduce the effort required for semi-automated mapping. We examined quality, time effort, and sustainability of such mapping. Methods To verify the mapping quality, two samples of 100 laboratory terms were extracted from the laboratory system of a German university hospital and processed in a semi-automated fashion with RELMA V.5 and LOINC V.2.34 German translation DIMDI to obtain LOINC codes. These codes were reviewed by two experts from each of two laboratories. Then all 2148 terms used in these two laboratories were processed in the same way. Results In the initial samples, 93 terms from one laboratory system and 92 terms from the other were correctly mapped. Of the total 2148 terms, 1660 could be mapped. An average of 500 terms per day or 60 terms per hour could be mapped. Of the laboratory terms used in 2010, 99% could be mapped. Discussion Semi-automated LOINC mapping of non-English laboratory terms has become promising in terms of effort and mapping quality using the new version RELMA V.5. The effort is probably lower than for previous manual mapping. The mapping quality equals that of manual mapping and is far better than that reported with previous automated mapping activities. Conclusion RELMA V.5 and LOINC V.2.34 offer the opportunity to start thinking again about LOINC mapping even in non-English languages, since mapping effort is acceptable and mapping results equal those of previous manual mapping reports.

Burkle, Thomas; Prokosch, Hans-Ulrich; Ganslandt, Thomas

2013-01-01

398

Modelling discontinuous metal matrix composite behavior under creep conditions: Effect of interface diffusional matter transport and interface sliding  

SciTech Connect

The continuum mechanics analysis of creep behavior of metal matrix composites is presented in this paper. The analysis includes elasticity, power law creep and diffusional matter transport and sliding along the reinforcement/matrix interfaces. The solution of the problem requires development of original mathematical and numerical methods. The present results indicate a significant influence of reinforcement/matrix interface properties on macroscopic behavior of the composite as well as on stress distribution in the composite under creep conditions.

Vala, J.; Svoboda, J.; Kozak, V.; Cadek, J. (Academy of Sciences of Czech Republic, Brno (Czechoslovakia). Inst. of Physical Metallurgy)

1994-05-01

399

A computational model for stress reduction at the skin-implant interface of osseointegrated prostheses.  

PubMed

Osseointegrated implants (OI)s for transfemoral prosthetic attachment offer amputees an alternative to the traditional socket attachment. Potential benefits include a natural transfer of loads directly to the skeleton via the percutaneous abutment, relief of pain and discomfort of residual limb soft tissues by eliminating sockets, increased sensory feedback, and improved function. Despite the benefits, the skin-implant interface remains a critical limitation, as it is highly prone to bacterial infection. One approach to improve clinical outcomes is to minimize stress concentrations at the skin-implant interface due to shear loading, reducing soft tissue breakdown and subsequent risk of infection. We hypothesized that broadening the bone base at the distal end of the femur would provide added surface area for skin adhesion and reduce stresses at the skin-implant interface. We tested this hypothesis using finite element models of an OI in a residual limb. Results showed a dramatic decrease in stress reduction, with up to ~90% decrease in stresses at the skin-implant interface as cortical bone thickness increased from 2 to 8 mm. The findings in this study suggests that surgical techniques could stabilize the skin-implant interface, thus enhancing a skin-to-bone seal around the percutaneous device and minimizing infection. PMID:22275149

Yerneni, Srinivasu; Dhaher, Yasin; Kuiken, Todd A

2012-04-01

400

Nuclear Reactor/Hydrogen Process Interface Including the HyPEP Model  

SciTech Connect

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.

Steven R. Sherman

2007-05-01

401

NURBS- and T-spline-based isogeometric cohesive zone modeling of interface debonding  

NASA Astrophysics Data System (ADS)

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.

Dimitri, R.; De Lorenzis, L.; Wriggers, P.; Zavarise, G.

2014-02-01

402

A software model and specification language for non-WIMP user interfaces  

Microsoft Academic Search

We present a software model and language for describing and programming the fine-grained aspects of interaction in a non-WIMP user interface, such as a virtual environment. Our approach is based on our view that the essence of a non-WIMP dialogue is a set of continuous relationships—most of which are temporary. The model combines a data-flow or constraint-like component for the

Robert J. K. Jacob; Leonidas Deligiannidis; Stephen Morrison

1999-01-01

403

Modelling and simulations of multi-component lipid membranes and open membranes via diffuse interface approaches  

Microsoft Academic Search

Diffuse interface (phase field) models are developed for multi-component vesicle membranes with different lipid compositions\\u000a and membranes with free boundary. These models are used to simulate the deformation of membranes under the elastic bending\\u000a energy and the line tension energy with prescribed volume and surface area constraints. By comparing our numerical simulations\\u000a with recent biological experiments, it is demonstrated that

Xiaoqiang Wang; Qiang Du

2008-01-01

404

Psychovegetative syndrome diagnosis: an automated psychophysiological investigation and mathematical modeling approach.  

PubMed

1. INTRODUCTION. The main purpose of our work was to create the informational expert system of psychovegetative syndrome diagnosis by applying clinical data and estimating the functioning of the central and peripheral part of regulatory apparatus of the human organism, taking into consideration parallel and consecutive sensory, motor, associative, emotional drive systems, and internal body state. We used automatized psychophysiological investigation and mathematical models. For this purpose the following principal tasks have been prepared: the creation of database of quantifiable estimation patient state; the definition and automation of psychophysiological investigation; mathematical modeling of vegetative functions using a non-invasive sample and its connection with real psychophysiological experiment; mathematical modeling of organisms inner medium homeostasis; and the creation of an informational-expert system of psychovegetative syndrome diagnosis. 2. DATABASE OF ESTIMATION OF PATIENTS STATE. The medical records of the DB "PATIENT" contain data on patient psychic and somatoneurological status. 3. AUTOMATED PSYCHOPHYSIOLOGICAL INVESTIGATION. Psychophysiological investigation enables estimation of the functioning of several subsystems of the human organism and establishes an interrelationship between them by means of electrophysiological data and performance parameters. The study of psychophysiological provision of behavior by psychophysiological investigation enables us to get information about adaptational mechanisms of the patient under certain environmental loads. By means of special mathematical provision, the mathematical elaboration of biosignals as performance parameters has been realized; also realized were the formation of received parameters in the database, the estimation of separated parameters in the view of informativity, and the establishment of diagnostic patterns. 4. MATHEMATICAL MODELS FOR ESTIMATION INTERNAL BODY STATE. The proposed mathematical models allow investigation of homeostatic regulation in various intensities of the metabolic processes and external load. This approach in mathematical models allows us to characterize the relations between the central and peripheral parts of the regulatory mechanisms, using non-invasive samples under psychophysiological investigation and the simulation of different surroundings for brain cells functioning. 5. INFORMATION-EXPERT SYSTEM. Proceeding from the principle of psychoneural unity, we characterized the functioning mechanisms of CNS by means of automatized EEG analysis, visually evoked potential analysis, estimated psychic status, and the characteristics of neural system biochemical processes received by mathematical modeling. By using the indices of the viscero-vegetative and somatolocomotor system (as well as parameters received by automatized analysis of ECG), the EEG respiratory signal--from mathematical models of vegetative functions decision support system applied in estimation of a peripheral block of the regulatory system--is reflected in diagnosis of certain syndromes. The informational expert system, proceeding from the functioning of the human organism's regulatory apparatus, diagnosed psychovegetative syndrome and described the mechanisms of its development. 6. CONCLUSION. The informational expert system enables estimation of the functioning of a human organism as a whole and can be introduced in the sphere of practical medicine and professional orientation as well as in laboratories of experimental psychology and neurosciences. PMID:8591596

Brelidze, Z; Samadashvili, Z; Khachapuridze, G; Kubaneishvili, E; Nozadze, Z; Benidze, I; Tsitskishvili, N

1995-01-01

405

Numerical modeling of flow in a differential chamber of the gas-dynamic interface of a portable mass-spectrometer  

NASA Astrophysics Data System (ADS)

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.

Pivovarova, E. A.; Smirnovsky, A. A.; Schmidt, A. A.

2013-11-01

406

Automated phantom assay system  

SciTech Connect

This paper describes an automated phantom assay system developed for assaying phantoms spiked with minute quantities of radionuclides. The system includes a computer-controlled linear-translation table that positions the phantom at exact distances from a spectrometer. A multichannel analyzer (MCA) interfaces with a computer to collect gamma spectral data. Signals transmitted between the controller and MCA synchronize data collection and phantom positioning. Measured data are then stored on disk for subsequent analysis. The automated system allows continuous unattended operation and ensures reproducible results.

Sisk, D.R.; Nichols, L.L.; Olsen, P.C.

1991-11-01

407

Developing Novel Automated Apparatus for Studying Battery of Social Behaviors in Mutant Mouse Models for Autism.  

National Technical Information Service (NTIS)

We have constructed general-purpose, automated, quantitative behavioral phenotyping platform for cohort socially interacting group of mice. The system is designed for identification and quantification of a large battery of locomotion and social behavioral...

T. Kimchi

2013-01-01

408

Simple model for linear and nonlinear mixing at unstable fluid interfaces in spherical geometry  

NASA Astrophysics Data System (ADS)

A simple model was recently described for predicting linear and nonlinear mixing at an unstable planar fluid interface subjected to an arbitrary time-dependent variable acceleration history [J. D. Ramshaw, Phys. Rev. E 58, 5834 (1998)]. Here we present an analogous model for describing the mixing of two adjacent spherical fluid shells of different density resulting from an arbitrary time-dependent mean interface radius R(t). As in the planar case, the model is based on a heuristic expression for the kinetic energy of the system. This expression is based on that for the kinetic energy of a linearly perturbed interface, but with a dynamically renormalized effective wavelength which becomes proportional to the half-width a(t) of the mixing layer in the nonlinear regime. An equation of motion for s=R2a is then derived from Lagrange's equations. This evolution equation properly reduces to Plesset's equation for small perturbations, and to the previous planar model in the limit of very large R. The conservation properties of the model are established, and a suitable numerical scheme which preserves these properties is proposed.

Ramshaw, John D.

1999-08-01

409

Simple model for linear and nonlinear mixing at unstable fluid interfaces in spherical geometry  

SciTech Connect

A simple model was recently described for predicting linear and nonlinear mixing at an unstable planar fluid interface subjected to an arbitrary time-dependent variable acceleration history [J. D. Ramshaw, Phys. Rev. E {bold 58}, 5834 (1998)]. Here we present an analogous model for describing the mixing of two adjacent spherical fluid shells of different density resulting from an arbitrary time-dependent mean interface radius R(t). As in the planar case, the model is based on a heuristic expression for the kinetic energy of the system. This expression is based on that for the kinetic energy of a linearly perturbed interface, but with a dynamically renormalized effective wavelength which becomes proportional to the half-width a(t) of the mixing layer in the nonlinear regime. An equation of motion for s=R{sup 2}a is then derived from Lagrange{close_quote}s equations. This evolution equation properly reduces to Plesset{close_quote}s equation for small perturbations, and to the previous planar model in the limit of very large R. The conservation properties of the model are established, and a suitable numerical scheme which preserves these properties is proposed. {copyright} {ital 1999} {ital The American Physical Society}

Ramshaw, J.D. [Lawrence Livermore National Laboratory, University of California, P.O. Box 808, Livermore, California 94551 (United States)] [Lawrence Livermore National Laboratory, University of California, P.O. Box 808, Livermore, California 94551 (United States)

1999-08-01

410

The treatment of flat areas and depressions in automated drainage analysis of raster digital elevation models  

NASA Astrophysics Data System (ADS)

Methods developed to process raster digital elevation models (DEM) automatically in order to delineate and measure the properties of drainage networks and drainage basins are being recognized as potentially valuable tools for the topographic parameterization of hydrological models. All of these methods ultimately rely on some form of overland flow simulation to define drainage courses and catchment areas and, therefore, have difficulty dealing with closed depressions and flat areas on digital land surface models. Some fundamental assumptions about the nature of these problem topographic features in DEM are implicit in the various techniques developed to deal with them in automated drainage analysis. The principal assumptions are: (1) that closed depressions and flat areas are spurious features that arise from data errors and limitations of DEM resolution; (2) that flow directions across flat areas are determined solely by adjacent cells of lower elevation; and (3) that closed depressions are caused exclusively by the underestimation of DEM elevations. It is argued that while the first of these assumptions is reasonable, given the quality of DEMs generally available for hydrological analysis, the others are not. Rather it seems more likely that depressions are caused by both under- and overestimation errors and that flow directions across flat areas are determined by the distribution of both higher and lower elevations surrounding flat areas. Two new algorithms are introduced that are based on more reasonable assumptions about the nature of flat areas and depressions, and produce more realistic results in application. These algorithms allow breaching of depression outlets and consider the distribution of both higher and lower elevations in assigning flow directions on flat areas. The results of applying these algorithms to some real and hypothetical landscapes are presented.

Martz, Lawrence W.; Garbrecht, Jurgen

1998-05-01

411

A DIFFUSE-INTERFACE APPROACH FOR MODELING TRANSPORT, DIFFUSION AND ADSORPTION/DESORPTION OF MATERIAL QUANTITIES ON A DEFORMABLE INTERFACE*  

PubMed Central

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.

Teigen, Knut Erik; Li, Xiangrong; Lowengrub, John; Wang, Fan; Voigt, Axel

2010-01-01

412

Towards Automated Seismic Moment Tensor Inversion in Australia Using 3D Structural Model  

NASA Astrophysics Data System (ADS)

There is significant seismic activity in the region around Australia, largely due to the plate boundaries to the north and to the east of the mainland. This seismicity poses serious seismic and tsunamigenic hazard in a wider region, and risk to coastal areas of Australia, and is monitored by Geoscience Australia (GA) using a network of permanent broadband seismometers within Australia. Earthquake and tsunami warning systems were established by the Australian Government and have been using the waveforms from the GA seismological network. The permanent instruments are augmented by non-GA seismic stations based both within and outside of Australia. In particular, seismic moment tensor (MT) solutions for events around Australia as well as local distances are useful for both warning systems and geophysical studies in general. These monitoring systems, however, currently use only one dimensional, spherically-symmetric models of the Earth for source parameter determination. Recently, a novel 3D model of Australia and the surrounding area has been developed from spectral element simulations [1], taking into account not only velocity heterogeneities, but also radial anisotropy and seismic attenuation. This development, inter alia, introduces the potential of providing significant improvements in MT solution accuracy. Allowing reliable MT solutions with reduced dependence on non-GA stations is a secondary advantage. We studied the feasibility of using 1D versus 3D structural models. The accuracy of the 3D model has been investigated, confirming that these models are in most cases superior to the 1D models. A full MT inversion method using a point source approximation was developed as the first step, keeping in mind that for more complex source time functions, a finite source inversion will be needed. Synthetic experiments have been performed with random noise added to the signal to test the code in the both 1D and 3D setting, using a precomputed library of structural Greens functions. Implementation of this 3D model will improve warning systems, and we present results that are an important step towards automated MT inversion in Australia. [1] Fichtner, A., Kennett, B.L.N., Igel, H., Bunge, H.-P., 2009. Full seismic waveform tomography for upper-mantle structure in the Australasian region using adjoint methods. Geophys. J. Int., in press.

Hingee, M.; Tkalcic, H.; Fichtner, A.; Sambridge, M.; Kennett, B. L.; Gorbatov, A.

2009-12-01

413

Automated Biometrics  

Microsoft Academic Search

Identity verification becomes a challenging task when it has to be automated with high accuracy and non-repudiability. The existing methods such as passwords and photo identity cards are inadequate to meet such heavy demands. Automated biometrics-based authentication methods can meet all the demands. An overview of the fast developing and exciting area of automated biometrics is provided in this paper.

Nalini K. Ratha; Andrew W. Senior; Ruud M. Bolle

2001-01-01

414

User's Manual for the Model Interface and Plugboard Cabinets in the 14- by 22-Foot Subsonic Tunnel.  

National Technical Information Service (NTIS)

The primary method of connection between the wind tunnel model instrumentation and the data acquisition system in the 14- by 22-Foot Subsonic Tunnel is through the Model Interface (MIF) and Plugboard cabinets. The MIF and Plugboard cabinets allow versatil...

R. B. Askew P. F. Quinto

1994-01-01

415

A Study of the Subject-Oriented Approach for Automation and Process Modeling of a Service Company  

Microsoft Academic Search

\\u000a Nowadays business requirements can be met through a subject oriented approach to modeling and process automation of enterprise\\u000a services. As a consequence of the wide-ranging implementation of IT infrastructure, the time needed for an employee to adapt\\u000a to a new environment is continually increasing. The subject-oriented approach can reduce this time substantially and as a\\u000a result significantly improve enterprise relationship

Yuliya Stavenko; Alexander Gromoff

416

FunFOLD: an improved automated method for the prediction of ligand binding residues using 3D models of proteins  

Microsoft Academic Search

Background  The accurate prediction of ligand binding residues from amino acid sequences is important for the automated functional annotation\\u000a of novel proteins. In the previous two CASP experiments, the most successful methods in the function prediction category were\\u000a those which used structural superpositions of 3D models and related templates with bound ligands in order to identify putative\\u000a contacting residues. However, whilst

Daniel B. Roche; Stuart J. Tetchner; Liam J. McGuffin

2011-01-01

417

Detecting solid–liquid interface properties with mechanical slip modelling for quartz crystal microbalance operating in liquid  

Microsoft Academic Search

Quartz crystal microbalances (QCMs) provide sensitive probes for changes at solid–solid or solid–liquid interfaces. It is essential to obtain a physical insight into the details of the interface loading mechanism to interpret the observed behaviour leading to fresh applications of AT-cut quartz resonators. In this work, a mechanical slip model of the interface between a quartz plate and a viscoelastic

F Lu; H P Lee; S P Lim

2004-01-01

418

Mixed-level optical-system simulation incorporating component-level modeling of interface elements  

NASA Astrophysics Data System (ADS)

While system-level simulation can allow designers to assess optical system performance via measures such as signal waveforms, spectra, eye diagrams, and BER calculations, component-level modeling can provide a more accurate description of coupling into and out of individual devices, as well as their detailed signal propagation characteristics. In particular, the system-level simulation of interface components used in optical systems, including splitters, combiners, grating couplers, waveguides, spot-size converters, and lens assemblies, can benefit from more detailed component-level modeling. Depending upon the nature of the device and the scale of the problem, simulation of optical transmission through these components can be carried out using either electromagnetic device-level simulation, such as the beampropagation method, or ray-based approaches. In either case, system-level simulation can interface to such componentlevel modeling via a suitable exchange of optical signal data. This paper presents the use of a mixed-level simulation flow in which both electromagnetic device-level and ray-based tools are integrated with a system-level simulation environment in order to model the use of various interface components in optical systems for a range of purposes, including, for example, coupling to and from optical transmission media such as single- and multimode optical fiber. This approach enables case studies on the impact of physical and geometric component variations on system performance, and the sensitivity of system behavior to misalignment between components.

Mena, Pablo V.; Stone, Bryan; Heller, Evan; Herrmann, Dan; Ghillino, Enrico; Scarmozzino, Rob

2014-03-01

419

Multiscale Modeling of Intergranular Fracture in Aluminum: Constitutive Relation For Interface Debonding  

NASA Technical Reports Server (NTRS)

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.

Yamakov, V.; Saether, E.; Glaessgen, E. H.

2008-01-01

420

The DaveMLTranslator: An Interface for DAVE-ML Aerodynamic Models  

NASA Technical Reports Server (NTRS)

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.

Hill, Melissa A.; Jackson, E. Bruce

2007-01-01

421

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)

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).

Kim, Jonnathan H.

1995-01-01

422

Automating ground-fixed target modeling with the smart target model generator  

Microsoft Academic Search

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

D. Verner; R. Dukes

2007-01-01

423

Evaluation of automated statistical shape model based knee kinematics from biplane fluoroscopy.  

PubMed

State-of-the-art fluoroscopic knee kinematic analysis methods require the patient-specific bone shapes segmented from CT or MRI. Substituting the patient-specific bone shapes with personalizable models, such as statistical shape models (SSM), could eliminate the CT/MRI acquisitions, and thereby decrease costs and radiation dose (when eliminating CT). SSM based kinematics, however, have not yet been evaluated on clinically relevant joint motion parameters. Therefore, in this work the applicability of SSMs for computing knee kinematics from biplane fluoroscopic sequences was explored. Kinematic precision with an edge based automated bone tracking method using SSMs was evaluated on 6 cadaveric and 10 in-vivo fluoroscopic sequences. The SSMs of the femur and the tibia-fibula were created using 61 training datasets. Kinematic precision was determined for medial-lateral tibial shift, anterior-posterior tibial drawer, joint distraction-contraction, flexion, tibial rotation and adduction. The relationship between kinematic precision and bone shape accuracy was also investigated. The SSM based kinematics resulted in sub-millimeter (0.48-0.81mm) and approximately 1° (0.69-0.99°) median precision on the cadaveric knees compared to bone-marker-based kinematics. The precision on the in-vivo datasets was comparable to that of the cadaveric sequences when evaluated with a semi-automatic reference method. These results are promising, though further work is necessary to reach the accuracy of CT-based kinematics. We also demonstrated that a better shape reconstruction accuracy does not automatically imply a better kinematic precision. This result suggests that the ability of accurately fitting the edges in the fluoroscopic sequences has a larger role in determining the kinematic precision than that of the overall 3D shape accuracy. PMID:24207131

Baka, Nora; Kaptein, Bart L; Giphart, J Erik; Staring, Marius; de Bruijne, Marleen; Lelieveldt, Boudewijn P F; Valstar, Edward

2014-01-01

424

An Automated Method to Identify Mesoscale Convective Complexes in the Regional Climate Model Evaluation System  

NASA Astrophysics Data System (ADS)

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.

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

425

Properties of the interfaces generated by the competition between stable and unstable growth models  

NASA Astrophysics Data System (ADS)

Two different growing mechanisms, given by the Eden model (EM) and the unstable Eden model (UEM), are used to numerically explore the properties of the interface generated by a competitive dynamic process in which particles are aggregated according to the rules of the EM with probability (1-p) and following the UEM with probability p . Based on extensive numerical simulations, it is shown that the interface width exhibits a growing regime that at time tx2 crosses over to a saturation state such that the width (Wsat) remains stationary. It is shown that Wsat and tx2 depend on both the lattice size L and the probability p . This behavior can be rationalized by proposing new scaling relationships, which are tested numerically. Furthermore, the relevant exponents are determined showing that the instabilities of the UEM dominate the dynamics of the growing process.

Irurzun, Isabel; Horowitz, Claudio M.; Albano, Ezequiel V.

2005-09-01

426

Modeling of ultrasound transmission through a solid-liquid interface comprising a network of gas pockets  

SciTech Connect

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.

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

427

A user interface for the Kansas Geological Survey slug test model.  

PubMed

The Kansas Geological Survey (KGS) developed a semianalytical solution for slug tests that incorporates the effects of partial penetration, anisotropy, and the presence of variable conductivity well skins. The solution can simulate either confined or unconfined conditions. The original model, written in FORTRAN, has a text-based interface with rigid input requirements and limited output options. We re-created the main routine for the KGS model as a Visual Basic macro that runs in most versions of Microsoft Excel and built a simple-to-use Excel spreadsheet interface that automatically displays the graphical results of the test. A comparison of the output from the original FORTRAN code to that of the new Excel spreadsheet version for three cases produced identical results. PMID:19583592

Esling, Steven P; Keller, John E

2009-01-01

428

Ergonomic Models of Anthropometry, Human Biomechanics and Operator-Equipment Interfaces  

NASA Technical Reports Server (NTRS)

The Committee on Human Factors was established in October 1980 by the Commission on Behavioral and Social Sciences and Education of the National Research Council. The committee is sponsored by the Office of Naval Research, the Air Force Office of Scientific Research, the Army Research Institute for the Behavioral and Social Sciences, the National Aeronautics and Space Administration, and the National Science Foundation. The workshop discussed the following: anthropometric models; biomechanical models; human-machine interface models; and research recommendations. A 17-page bibliography is included.

Kroemer, Karl H. E. (editor); Snook, Stover H. (editor); Meadows, Susan K. (editor); Deutsch, Stanley (editor)

1988-01-01

429

Modelling of the ultrasonic field by the angular spectrum method in presence of interface.  

PubMed

We present a numerical modelling of the harmonic sound in two isotropic media, one liquid and the other solid separated by a plane interface. This numerical modelling is carried out by the angular spectrum method. This latter is applied to calculate the displacement potential generated by a rectangular transducer with a Gaussian profile and with an uniform profile. The rigorous modelling of the field needed to find the optimal parameters of the decomposition according to the transducer aperture and the ultrasonic wave frequency. PMID:12159951

Belgroune, D; de Belleval, J F; Djelouah, H

2002-05-01

430

Model of traveling wave formed by autonomous motion of contact line with oil/water interface  

NASA Astrophysics Data System (ADS)

A model for the spontaneous traveling wave in oil/water system is proposed. The present model is to explain the traveling wave generated by chemical reactions between a cationic surfactant and oil-soluble anions. This is an extension of the previous model which describes the oscillatory motion of the contact line formed by the oil/water interface and a glass surface. The oscillations at different places are coupled to each other by an effect that diminishes the interfacial energy. The numerical calculations reveal that the traveling wave with a specified direction is reproduced under several assumptions for the noise term.

Shioi, Akihisa; Ban, Takahiko; Suzuki, Sho

2008-12-01

431

Object-Based Integration of Photogrammetric and LiDAR Data for Automated Generation of Complex Polyhedral Building Models  

PubMed Central

This research is concerned with a methodology for automated generation of polyhedral building models for complex structures, whose rooftops are bounded by straight lines. The process starts by utilizing LiDAR data for building hypothesis generation and derivation of individual planar patches constituting building rooftops. Initial boundaries of these patches are then refined through the integration of LiDAR and photogrammetric data and hierarchical processing of the planar patches. Building models for complex structures are finally produced using the refined boundaries. The performance of the developed methodology is evaluated through qualitative and quantitative analysis of the generated building models from real data.

Kim, Changjae; Habib, Ayman

2009-01-01

432

Modeling Geometry and Progressive Failure of Material Interfaces in Plain Weave Composites  

NASA Technical Reports Server (NTRS)

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.

Hsu, Su-Yuen; Cheng, Ron-Bin

2010-01-01

433

Characterizing and Modeling Brittle Bi-material Interfaces Subjected to Shear  

NASA Astrophysics Data System (ADS)

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.

Anyfantis, Konstantinos N.; Berggreen, Christian

2014-04-01

434

Hybrid Interface Automata for Component Interfaces  

Microsoft Academic Search

The modelling and verifying of hybrid systems attract more and more attentions recently. Hybrid automaton is widely used to model discrete and continuous behaviors of hybrid systems. In this paper, a hybrid interface automaton(HIA) is proposed based on hybrid automaton to model the interface behaviors of hybrid components. According to the interface type of components, we define two kinds of

Dehui Du; Jing Liu

2011-01-01

435

Arcgis-swat: a Geodata Model and GIS Interface for Swat  

NASA Astrophysics Data System (ADS)

This paper presents ArcGIS-SWAT, a geodata model and geographic information system (GIS) interface for the Soil and Water Assessment Tool (SWAT). The ArcGIS-SWAT data model is a system of geodatabases that store SWAT geographic, numeric, and text input data and results in an organized fashion. Thus, it is proposed that a single and comprehensive geodatabase be used as the repository of a SWAT simulation. The ArcGIS-SWAT interface uses programming objects that conform to the Component Object Model (COM) design standard, which facilitate the use of functionality of other Windows-based applications within ArcGIS-SWAT. In particular, the use of MS Excel and MATLAB functionality for data analysis and visualization of results is demonstrated. Likewise, it is proposed to conduct hydrologic model integration through the sharing of information with a not-model-specific hub data model where information common to different models can be stored and from which it can be retrieved. As an example, it is demonstrated how the Hydrologic Modeling System (HMS) ­ a computer application for flood analysis ­ can use information originally developed by ArcGIS-SWAT for SWAT. The application of ArcGIS-SWAT to the Seco Creek watershed in Texas is presented.

Olivera, Francisco; Valenzuela, Milver; Srinivasan, R.; Cho, Janghwoan I.

2006-04-01

436

Diffuse interface model for compressible fluid - Compressible elastic-plastic solid interaction  

NASA Astrophysics Data System (ADS)

An Eulerian hyperbolic diffuse interface model for elastic-plastic solid-fluid interaction is constructed. The system of governing equations couples Euler equations of compressible fluids and a visco-plastic model of Maxwell type materials (the deviatoric part of the stress tensor decreases during plastic deformations) in the same manner as models of multicomponent fluids. In particular, the model is able to create interfaces which were not present initially.The model is thermodynamically compatible: it verifies the entropy inequality. However, a numerical treatment of the model is particularly challenging. Indeed, the model is non-conservative, so a special numerical splitting is proposed to overcome this difficulty. The numerical algorithm contains two relaxation procedures. One of them is physical and is related to the plastic relaxation mechanism (relaxation toward the yield surface). The second one is numerical. It consists in replacing the algebraic equation expressing a mechanical equilibrium between components by a partial differential equation with a short relaxation time. The numerical method was tested in 1D case (Wilkins' flying plate problem), 2D plane case (impact of a projectile on a plate) and axisymmetrical case (Taylor test problem, impact with penetration effects, etc.). Numerical examples show the ability of the model to deal with real physical phenomena.

Favrie, N.; Gavrilyuk, S. L.

2012-04-01

437

Degenerate Ising model for atomistic simulation of crystal-melt interfaces  

NASA Astrophysics Data System (ADS)

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.

Schebarchov, D.; Schulze, T. P.; Hendy, S. C.

2014-02-01