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1

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

2

Automated Fluid Interface System (AFIS)  

NASA Technical Reports Server (NTRS)

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 and the receiving satellite is needed. The objective of the Automated Fluid Interface System (AFIS) program is to design, fabricate, and functionally demonstrate compliance with all design requirements for an automated fluid interface system. A description and documentation of the Fairchild AFIS design is provided.

1990-01-01

3

Service delivery and learning in automated interfaces  

E-print Network

This dissertation analyzes the strategic implications of customization policies available to companies that must simultaneously provide service and learn about their customers through automated interfaces. The first part ...

Oliveira, Paulo Rocha e, 1974-

2002-01-01

4

Human-Machine Interface in Building Automation Systems  

E-print Network

problem between the non-computer knowledgeable operator and the computer based Building Automation System. One of the solutions to this problem is the design and implementation of a human machine interface which educates the operator to utilize the system...

Sobczak, N. L.

1981-01-01

5

Automation Interfaces of the Orion GNC Executive Architecture  

NASA Technical Reports Server (NTRS)

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

Hart, Jeremy

2009-01-01

6

Microphone Array Front-End Interface for Home Automation  

Microsoft Academic Search

In this paper we present a microphone array (MA) interface to a Spoken Dialog System. Our goal is to create a hands- free home automation system with a vocal interface to control home devices. The user establishes a dialog with a virtual butler that is able to control a plethora of home devices, such as ceiling lights, air-conditioner, windows shades,

G. E. Coelho; A. J. Serralheiro; J. P. Netti

2008-01-01

7

Guidelines for an accessible web automation interface  

Microsoft Academic Search

In recent years, the Web has become an ever more sophisticated and irreplaceable tool in our daily lives. While the visual Web has been advancing at a rapid pace, assistive technology has not been able to keep up, increasingly putting visually impaired users at a disadvantage. Web automation has the potential to bridge the accessibility divide between the ways blind

Yury Puzis; Eugene Borodin; Faisal Ahmed; Valentine Melnyk; I. V. Ramakrishnan

2011-01-01

8

An intuitive accessible web automation user interface  

Microsoft Academic Search

In recent years, the Web has become an ever more sophisticated and irreplaceable tool in our daily lives. While the visual Web has advanced at a rapid pace, assistive technology has not been able to keep up, increasingly putting visually impaired users at a disadvantage. Web automation has the potential to bridge the accessibility divide between the ways blind and

Yury Puzis; Yevgen Borodin; Faisal Ahmed; I. V. Ramakrishnan

2012-01-01

9

Modeling Dynamic Component Interfaces  

E-print Network

In this paper we adopt a component model based on object-oriented systems, introducing the concepts of components and their structure. A component consists of a dynamically changing set of connected objects. Only some of these objects are interface objects, and are thus accessible from the environment. During the component lifetime not only the number of objects, but also that of interface objects, and their connections change. To describe this situation, we introduce Component Interface Diagrams (CIDs) -- an adaption of UML diagrams -- as a notation to characterize interfaces of components, their structure, and their navigability. We show how CIDs can be used to describe the in-house developed Open Editor Framework (OEF). Finally, we give guidelines that allow to map components described with CIDs directly to several component technologies, like ActiveX, CORBA, or Java Beans. 1: Introduction Today, on top of object-oriented techniques, an additional layer of software development, ba...

Franz Huber; Andreas Rausch; Bernhard Rumpe

1998-01-01

10

Space station automation and robotics study. Operator-systems interface  

NASA Technical Reports Server (NTRS)

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

1984-01-01

11

Modeling Reality Based Interfaces  

Microsoft Academic Search

The last decade has seen a wave of HCI research aimed at integrating the physical and digital worlds. This work has led to the development of a range of interaction styles such as tangible user interfaces (6), mixed reality interfaces and sensing interfaces (1). Common to these interfaces is that they change the interaction with computers from a segregated specialized

Orit Shaer

12

Feeder Automation modeling in IEC61850  

Microsoft Academic Search

Feeder Automation is one important part of distribution automation. Considering frequent change of network due to rapid growing of system, it is necessary to find a high efficient configuration way. Open and interoperability feature of IEC61850 makes it possible to model the feeder automation in IEC61850. This paper introduced the modeling of FA in IEC61850, including architecture, data, topology and

Zhao Wang; Lei Jing; Wenxiao Ma

2008-01-01

13

ATAM - Automated Trade Assessment Modeling  

NASA Technical Reports Server (NTRS)

Automated Trade Assessment Modeling program, ATAM, one of software tools designed to assess candidate architectures for data-management system of Space Station. Designed to discriminate among candidates having equally acceptable performance and reliability characteristics. Utilizes data base, defined by user, containing information on candidate architecture. Assesses such trade factors of system as weight, power consumption, and life-cycle cost. Produces detailed parameter assessments as well as single figure of merit for candidate architecture. Written in Microsoft FORTRAN.

Vallone, Antonio; Wu, Mei-Zong; Hogie, Keith

1989-01-01

14

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

15

User interface design for an automated part recognition system  

E-print Network

the five interfaces. The interfaces investigated are described below. One interface utilized a menu command layout with a mouse for command selection (Menu ? Mouse interface) . In another, commands placed on screen buttons were selected using a touch... screen (Button ? Touch interface). The button screen design was also tested with a mouse (Button ? Mouse interface) as a third alternative. Two of the interface alternatives involved the use of a new touch pad device, the UnMouse~. One such interface...

Avitts, Tommie Annette

2012-06-07

16

View Planning for Automated Site Modeling  

Microsoft Academic Search

We present a systematic method for constructing 3-D models of large outdoor sites. The method is designed for a mobile robot platform and incorporates automated acquisition of scanned data as well as automated view planning and model construction. In our modeling process, we first use a preliminary view or set of preplanned views to yield an initial, approximate, 3-D model

Paul S. Blaer; Peter K. Allen

2006-01-01

17

Finite element estimates of interface stress in the trans-tibial prosthesis using gap elements are different from those using automated contact  

Microsoft Academic Search

When compared with automated contact methods of finite element (FE) analyses, gap elements have certain inherent disadvantages in simulating large slip of compliant materials on stiff surfaces. However, automated contact has found limited use in the biomechanical literature. A non-linear, three-dimensional, geometrically accurate, FE analysis of the trans-tibial limb–socket prosthetic system was used to compare an automated contact interface model

S. G Zachariah; J. E Sanders

2000-01-01

18

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

E-print Network

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

Gray, Jeffrey G.

19

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

E-print Network

THE DESIGN OF THE COMPUTER-HUMAN INTERFACE OF INTEGRATED RESOURCE MANAGEMENT AUTOMATION (IRMA) A Thesis DAVID RUSSELL HOLTFRERICH Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1991 Major subject: Computer Science THE DESIGN OF THE COMPUTER-HUMAN INTERFACE OF INTEGRATED RESOURCE MANAGEMENT AUTOMATION (IRMA) A Thesis DAVID RUSSELL HOLTFRERICH Approved as to style and content by: Bart...

Holtfrerich, David Russell

2012-06-07

20

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

21

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

22

Automated Usability Evaluation of WIMP and Web Interfaces  

Microsoft Academic Search

Usability evaluation is an increasingly important part of the iterative design process. Automated usability eval- uation (AUE) has great promise as a way to augment existing evaluation techniques, but is greatly underex- plored. We present a new taxonomy for automated us- ability analysis and illustrate it with an extensive survey. We discuss ways to expand the application of AUE to

Marti A. Hearst

23

Hierarchical interface-enriched finite element method: An automated technique for mesh-independent simulations  

NASA Astrophysics Data System (ADS)

A hierarchical interface-enriched finite element method (HIFEM) is introduced for the mesh-independent treatment of problems with complex morphologies. The proposed method provides an automated framework to capture gradient discontinuities associated with multiple materials interfaces that are in a close proximity or contact, while using finite element meshes that do not conform to the problem geometry. While yielding an optimal precision and convergence rate, other principal advantages of HIFEM include the ease of implementation and the ability to compute enriched solutions for a variety of complex materials interface configurations. Moreover, the construction of enrichment functions in this method is independent of the number and sequence of materials interfaces introduced to the nonconforming mesh. An immediate benefit of this feature is the ability to add new materials phases to already enriched nonconforming elements, without the need to remove/modify existing enrichments or sub-elements. In addition to detailed convergence study, several example problems are presented to show the application of HIFEM for modeling various engineering problems, including woven composites, heterogeneous materials systems, and actively-cooled microvascular systems.

Soghrati, Soheil

2014-10-01

24

Automated Construction of Web Accessibility Models from Transaction Click-streams  

E-print Network

Automated Construction of Web Accessibility Models from Transaction Click-streams Jalal Mahmud. In this paper we present a fully automated process that syner- gistically combines several techniques H.3.3 [Information Systems]: Search and Retrieval; H.5.2 [Information Interfaces and Presentation

Ramakrishnan, C. R.

25

Designing effective human-automation-plant interfaces: a control-theoretic perspective.  

PubMed

In this article, we propose the application of a control-theoretic framework to human-automation interaction. The framework consists of a set of conceptual distinctions that should be respected in automation research and design. We demonstrate how existing automation interface designs in some nuclear plants fail to recognize these distinctions. We further show the value of the approach by applying it to modes of automation. The design guidelines that have been proposed in the automation literature are evaluated from the perspective of the framework. This comparison shows that the framework reveals insights that are frequently overlooked in this literature. A new set of design guidelines is introduced that builds upon the contributions of previous research and draws complementary insights from the control-theoretic framework. The result is a coherent and systematic approach to the design of human-automation-plant interfaces that will yield more concrete design criteria and a broader set of design tools. Applications of this research include improving the effectiveness of human-automation interaction design and the relevance of human-automation interaction research. PMID:15960084

Jamieson, Greg A; Vicente, Kim J

2005-01-01

26

SWISS-MODEL: an automated protein homology-modeling server  

Microsoft Academic Search

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

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

2003-01-01

27

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

28

Interface Model of Cold Fusion  

Microsoft Academic Search

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

Talbot A. Chubb

29

Alloy Interface Interdiffusion Modeled  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

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

ITR -(ASE + NHS) -(int): Intelligent Human-Machine Interface & Control for Highly Automated Chemical Screening Processes  

E-print Network

ITR - (ASE + NHS) - (int): Intelligent Human-Machine Interface & Control for Highly Automated for communication delay conditions in predicting human operator robot control actions. 2006 Spring Prototype. Use CELISCA operators for informal usability tests. Assemble collection of prototypes in graph for use

Kaber, David B.

32

Designing a mobile user interface for automated species identification  

Microsoft Academic Search

Biological research in the field is constrained by the speed and difficulty of species determination, as well as by access to relevant information about the species encountered. However, recent work on vision-based algorithms raises the promise of rapid botanical species identification. The potential for mobile vision-based identification provides opportunities for new user interface techniques. To explore these issues, we present

Sean Michael White; Dominic Marino; Steven Feiner

2007-01-01

33

Automation and Accountability in Decision Support System Interface Design  

ERIC Educational Resources Information Center

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

Cummings, Mary L.

2006-01-01

34

Automating the 3D Modeling Pipeline  

Microsoft Academic Search

We describe advances in automating the 3D modeling pipeline to create rich 3D textured models. Our work is aimed at large scale site modeling, where much manual ef- fort is often needed to create complete models. We present i) an automatic 2D-3D registration method for texture using cast shadows as a cue to refine the registration parameters, ii) methods for

Peter Allen; Alejandro Troccoli; Paul Blaer

35

Flexible software architecture for user-interface and machine control in laboratory automation.  

PubMed

We describe a modular, layered software architecture for automated laboratory instruments. The design consists of a sophisticated user interface, a machine controller and multiple individual hardware subsystems, each interacting through a client-server architecture built entirely on top of open Internet standards. In our implementation, the user-interface components are built as Java applets that are downloaded from a server integrated into the machine controller. The user-interface client can thereby provide laboratory personnel with a familiar environment for experiment design through a standard World Wide Web browser. Data management and security are seamlessly integrated at the machine-controller layer using QNX, a real-time operating system. This layer also controls hardware subsystems through a second client-server interface. This architecture has proven flexible and relatively easy to implement and allows users to operate laboratory automation instruments remotely through an Internet connection. The software architecture was implemented and demonstrated on the Acapella, an automated fluid-sample-processing system that is under development at the University of Washington. PMID:9793655

Arutunian, E B; Meldrum, D R; Friedman, N A; Moody, S E

1998-10-01

36

Models for Automated Earthmoving Howard Cannon  

E-print Network

based control scheme given initial conditions, some of which can be controlled (excavator control models are used to both estimate soil properties and predict contact forces between the excavator developed a robotic earthmoving system that completely automates the task of mass excavation and truck

Singh, Sanjiv

37

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

38

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

39

AVENUE: Automated Site Modeling in Urban Environments  

Microsoft Academic Search

This paper is an overview of the AVENUE project at Columbia University. AVENUE's main goal is to automate the site modeling process in urban environments. The first component of AVENUE is a 3-D modeling system which constructs complete 3-D geometric models with photometric texture mapping acquired from different viewpoints. The second component is a planning system that plans the Next-Best-View

Peter K. Allen; Ioannis Stamos; Atanas Gueorguiev; Ethan Gold; Paul Blaer

2001-01-01

40

Automated detection of chorio-scleral interface using polarization-sensitive optical coherence tomography  

NASA Astrophysics Data System (ADS)

A polarization sensitive optical coherence tomography based automated algorithm for segmentation of the chorio-scleral interface is presented. The algorithm employs a two-step segmentation approach. At first, local birefringence based segmentation with low precision is performed to roughly distinguish the choroid and sclera. Successively, a depth oriented slope fitting to phase retardation is applied in both the choroid and sclera. The interface is determined as the cross-point of the two phase retardation slope lines. The algorithm shows potential for functional, objective, and volumetric choroid thickness measurement.

Duan, Lian; Yamanari, Masahiro; Yasuno, Yoshiaki

2012-01-01

41

A Succinct Memory Model for Automated Design Debugging  

E-print Network

. SAT-based automated design debugging [4], [5] has proven to be an effective technique compared Checking (BMC). The technique eliminates memory arrays but keeps the memory interface and the control logic

Veneris, Andreas

42

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

43

CollageMachine: Model of ``Interface Ecology''  

E-print Network

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

Mohri, Mehryar

44

Automating risk analysis of software design models.  

PubMed

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

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

2014-01-01

45

Atomistic modeling of dislocation-interface interactions  

SciTech Connect

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

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

2011-01-31

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

MINIMUM MODELS: REASONING AND AUTOMATION  

E-print Network

by means of toy Blocks World theories. 4 #12;Declaration No portion of the work referred . . . . . . . . . . . . . . . . . . . . . . 17 2.3.1 A blocks world example . . . . . . . . . . . . . . . . . . . 18 2.3.2 A boolean circuit, as well as the main difficulties involved when building a proof system for minimum model reasoning

Rydeheard, David

48

Automation model of sewerage rehabilitation planning.  

PubMed

The major steps of sewerage rehabilitation include inspection of sewerage, assessment of structural conditions, computation of structural condition grades, and determination of rehabilitation methods and materials. Conventionally, sewerage rehabilitation planning relies on experts with professional background that is tedious and time-consuming. This paper proposes an automation model of planning optimal sewerage rehabilitation strategies for the sewer system by integrating image process, clustering technology, optimization, and visualization display. Firstly, image processing techniques, such as wavelet transformation and co-occurrence features extraction, were employed to extract various characteristics of structural failures from CCTV inspection images. Secondly, a classification neural network was established to automatically interpret the structural conditions by comparing the extracted features with the typical failures in a databank. Then, to achieve optimal rehabilitation efficiency, a genetic algorithm was used to determine appropriate rehabilitation methods and substitution materials for the pipe sections with a risk of mal-function and even collapse. Finally, the result from the automation model can be visualized in a geographic information system in which essential information of the sewer system and sewerage rehabilitation plans are graphically displayed. For demonstration, the automation model of optimal sewerage rehabilitation planning was applied to a sewer system in east Taichung, Chinese Taiwan. PMID:17302324

Yang, M D; Su, T C

2006-01-01

49

Development of a commercial Automated Laser Gas Interface (ALGI) for AMS  

NASA Astrophysics Data System (ADS)

National Electrostatics Corporation (NEC), Massachusetts Institute of Technology (MIT), and GlaxoSmithKline (GSK) collectively have been developing an interface to introduce CO2 produced by the laser combustion of liquid chromatograph eluate deposited on a CuO substrate directly into the ion source of an AMS system, thereby bypassing the customary graphitization process. The Automated Laser Gas Interface (ALGI) converts dried liquid samples to CO2 gas quickly and efficiently, allowing 96 samples to be measured in as little as 16 h. 14C:12C ratios stabilize typically within 2 min of analysis time per sample. Presented is the recent progress of NEC’s ALGI, a stand-alone accessory to an NEC gas-enabled multi-cathode source of negative ions by Cs sputtering (MC-SNICS) ion source.

Daniel, R.; Mores, M.; Kitchen, R.; Sundquist, M.; Hauser, T.; Stodola, M.; Tannenbaum, S.; Skipper, P.; Liberman, R.; Young, G.; Corless, S.; Tucker, M.

2013-01-01

50

Using Domain Speci c Knowledge for Automated Modeling  

E-print Network

understand the behavior of real world systems. Mathematical models have the ability to integrate potentially behavior of the selected system variables. A framework for automated modeling of real world systems for integration of theoretical and empirical approaches to automated modeling of real world systems. To achieve

Dzeroski, Saso

51

Software tool for automated analysis of conceptual data model  

Microsoft Academic Search

This paper describes implementation of a software system for analyzing data model correctness. Proposed system is based on integration of an automated reasoning system with CASE tool output in aim to automate the process of data model evaluation. The system is based on transformation of XML form of a conceptual data model to predicate logic form and merging with data

Z. Kazi; B. Radulovic

2011-01-01

52

A Diffuse Interface Model with Immiscibility Preservation  

PubMed Central

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

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

2013-01-01

53

A Model for Evaluating Interface Terminologies  

PubMed Central

Objective Evaluations of individual terminology systems should be driven in part by the intended usages of such systems. Clinical interface terminologies support interactions between healthcare providers and computer-based applications. They aid practitioners in converting clinical “free text” thoughts into the structured, formal data representations used internally by application programs. Interface terminologies also serve the important role of presenting existing stored, encoded data to end users in human-understandable and actionable formats. The authors present a model for evaluating functional utility of interface terminologies based on these intended uses. Design Specific parameters defined in the manuscript comprise the metrics for the evaluation model. Measurements Parameters include concept accuracy, term expressivity, degree of semantic consistency for term construction and selection, adequacy of assertional knowledge supporting concepts, degree of complexity of pre-coordinated concepts, and the “human readability” of the terminology. The fundamental metric is how well the interface terminology performs in supporting correct, complete, and efficient data encoding or review by humans. Results Authors provide examples demonstrating performance of the proposed evaluation model in selected instances. Conclusion A formal evaluation model will permit investigators to evaluate interface terminologies using a consistent and principled approach. Terminology developers and evaluators can apply the proposed model to identify areas for improving interface terminologies. PMID:17947616

Rosenbloom, S. Trent; Miller, Randolph A.; Johnson, Kevin B.; Elkin, Peter L.; Brown, Steven H.

2008-01-01

54

Parallel computing for automated model calibration  

SciTech Connect

Natural resources model calibration is a significant burden on computing and staff resources in modeling efforts. Most assessments must consider multiple calibration objectives (for example magnitude and timing of stream flow peak). An automated calibration process that allows real time updating of data/models, allowing scientists to focus effort on improving models is needed. We are in the process of building a fully featured multi objective calibration tool capable of processing multiple models cheaply and efficiently using null cycle computing. Our parallel processing and calibration software routines have been generically, but our focus has been on natural resources model calibration. So far, the natural resources models have been friendly to parallel calibration efforts in that they require no inter-process communication, only need a small amount of input data and only output a small amount of statistical information for each calibration run. A typical auto calibration run might involve running a model 10,000 times with a variety of input parameters and summary statistical output. In the past model calibration has been done against individual models for each data set. The individual model runs are relatively fast, ranging from seconds to minutes. The process was run on a single computer using a simple iterative process. We have completed two Auto Calibration prototypes and are currently designing a more feature rich tool. Our prototypes have focused on running the calibration in a distributed computing cross platform environment. They allow incorporation of?smart? calibration parameter generation (using artificial intelligence processing techniques). Null cycle computing similar to SETI@Home has also been a focus of our efforts. This paper details the design of the latest prototype and discusses our plans for the next revision of the software.

Burke, John S.; Danielson, Gary R.; Schulz, Douglas A.; Vail, Lance W.

2002-07-29

55

Automated phase retardation oriented segmentation of chorio-scleral interface by polarization sensitive optical coherence tomography.  

PubMed

An automated chorio-scleral interface (CSI) detection algorithm based on polarization sensitive optical coherence tomography (PS-OCT) is presented. This algorithm employs a two-step scheme based on the phase retardation variation detected by PS-OCT. In the first step, a rough CSI segmentation is implemented to distinguish the choroid and sclera by using depth-oriented second derivative of the phase retardation. Second, the CSI is further finely defined as the intersection of lines fitted to the phase retardation in the choroid and sclera. This algorithm challenges the current back-scattering intensity based CSI segmentation approaches that are not fully based on anatomical and morphological evidence, and provides a rational segmentation method for the morphological investigation of the choroid. Applications of this algorithm are demonstrated on in vivo posterior images acquired by a PS-OCT system with 1-?m probe. PMID:22330573

Duan, Lian; Yamanari, Masahiro; Yasuno, Yoshiaki

2012-01-30

56

Automated Security Test Generation with Formal Threat Models  

Microsoft Academic Search

Security attacks typically result from unintended behaviors or invalid inputs. Security testing is labor intensive because a real-world program usually has too many invalid inputs. It is highly desirable to automate or partially automate security-testing process. This paper presents an approach to automated generation of security tests by using formal threat models represented as Predicate\\/Transition nets. It generates all attack

Dianxiang Xu; Manghui Tu; Michael Sanford; Lijo Thomas; Daniel Woodraska; Weifeng Xu

2012-01-01

57

Interface sharpness in the Potts model  

SciTech Connect

A simple proof is given for the existence of a sharp interface between two ordered phases for the three-dimensional 2{double prime}-state Potts model (n integer). The results show that the roughening temperature of the three-dimensional Potts model is greater than the transition temperature of the two-dimensional Potts model. For a large arbitrary spin integer, it is expected that this roughening temperature is equal to the transition temperature (of the 3D model), i.e., that the interface between two ordered phases is harp up to the transition temperature, at which it is wetted by a film of the disordered phase. It is also expected that for a large arbitrary spin integer, the a-f interface (between an ordered and the disordered phase) is sharp at the transition temperature.

Ruiz, J. (CNRS-Luming, Marseille (France))

1989-09-01

58

Automated neuron model optimization techniques: a review.  

PubMed

The increase in complexity of computational neuron models makes the hand tuning of model parameters more difficult than ever. Fortunately, the parallel increase in computer power allows scientists to automate this tuning. Optimization algorithms need two essential components. The first one is a function that measures the difference between the output of the model with a given set of parameter and the data. This error function or fitness function makes the ranking of different parameter sets possible. The second component is a search algorithm that explores the parameter space to find the best parameter set in a minimal amount of time. In this review we distinguish three types of error functions: feature-based ones, point-by-point comparison of voltage traces and multi-objective functions. We then detail several popular search algorithms, including brute-force methods, simulated annealing, genetic algorithms, evolution strategies, differential evolution and particle-swarm optimization. Last, we shortly describe Neurofitter, a free software package that combines a phase-plane trajectory density fitness function with several search algorithms. PMID:19011918

Van Geit, W; De Schutter, E; Achard, P

2008-11-01

59

Model-Driven Configuration of Automated Parking Facilities  

E-print Network

be entering and leaving the facility concurrently. Determination of parking location and maneuveringModel-Driven Configuration of Automated Parking Facilities Abstract Purpose Methodology the context of an automated parking facility, whereby a driver may drop a car off at the entrance to a garage

Gray, Jeffrey G.

60

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

PubMed Central

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

Bass, Ellen J.

2011-01-01

61

SUBMARINE AUTOMATION: DEMONSTRATION #5  

Microsoft Academic Search

This paper describes the results obtained in the final performing period of the ARPA sponsored submarine automation project1. Efforts on the mapping between the submarine operational environment and the RCS software architecture lead to the result of three watch station graphic user interface panels. The submarine automation model has been expanded to include some engineering systems control capability. On the

Hui-Min Huang; Richard Quintero

62

An interface tracking model for droplet electrocoalescence.  

SciTech Connect

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

Erickson, Lindsay Crowl

2013-09-01

63

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

64

Modeling the User Interface of Multimedia Applications  

E-print Network

not change over time, like a still image, while temporal media is time dependent like audio or video conventional user interface modeling approaches are not sufficient, as they do not cover the media el- ements as well. Thus, we first propose a solution for the media-specific part. Second, we

65

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

66

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

67

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

68

MSG: A Computer System for Automated Modeling of Heat Transfer  

E-print Network

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

Steinberg, Louis

69

Using Enterprise Reference Models for Automated ISO 9000 Compliance Evaluation  

E-print Network

1 Using Enterprise Reference Models for Automated ISO 9000 Compliance Evaluation Henry M. Kim1, and then compared to a reference model of "good" processes and structures, such as the ISO 9000 standards. In this paper, the TOVE ISO 9000 Micro-Theory is presented as a formal reference model of quality goodness. ISO

Fox, Mark S.

70

Perspectives of Interfacing People with Technology in the Development of Office Automation.  

ERIC Educational Resources Information Center

Noting the increasing impact of office automation on the workings of both people and organizations, this paper purposes the need for implementation methodologies, termed "self-actualizing systems," to introduce automation technologies into the office environment with a minimum of trauma to workers. Such methodologies, it contends, allow users to…

Conroy, Thomas R.; Ewbank, Ray V. K.

71

ASPOGAMO: Automated Sports Game Analysis Models Michael Beetz1  

E-print Network

benefit of this system is its possibility to model even cognitive abstractions based on an automatically of comparing the final results only after the end of the game. In computer vision, video indexingASPOGAMO: Automated Sports Game Analysis Models Michael Beetz1 , Nicolai v. Hoyningen-Huene1

Cremers, Daniel

72

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

PubMed

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

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

2004-12-24

73

Automated particulate sampler field test model operations guide  

SciTech Connect

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

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

1996-10-01

74

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

75

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

76

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...

77

A cost model for small scale automated digital preservation archives  

E-print Network

media for digital materials are vulnerable to dete- rioration and catastrophic loss. More challenging neglected. The rapid development of file formats and the strong dependency between digital objectsA cost model for small scale automated digital preservation archives Stephan Strodl Secure Business

78

The Application of Automated Reasoning to Formal Models of  

E-print Network

the techniques can be studied. In 1989 Helman [9] presented a common formalism that captures dynamic programThe Application of Automated Reasoning to Formal Models of Combinatorial Optimization Paul Helman formalisms have been proposed over the years to capture combi­ natorial optimization algorithms

Veroff, Robert

79

Interactive Assessment of User Preference Models: The Automated Travel Assistant  

Microsoft Academic Search

This paper presents the candidate\\/critique model of interactive problem solv - ing, in which an automated problem solver communicates candidate solutions to the user and the user critiques those solutions. The system starts with minimal in formation about the user's preferences, and preferences are elicite d and inferred incrementally by analyz- ing the critiques. The system's goal is to present

Greg Linden; Steve Hanks; Neal Lesh

80

On automation of the procedure for crystal structure model refinement  

SciTech Connect

The methods of automation of the procedure for crystal structure model refinement from experimental diffraction data, implemented in the ASTRA program package, are described. Such tools as statistical tests, parameter scanning, and data scanning reduce the time necessary for structural investigation. At strong correlations between parameters, especially when the data set is limited, parameter scanning has an advantage over the full-matrix refinement.

Dudka, A. P. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)], E-mail: dudka@ns.crys.ras.ru

2008-03-15

81

Automating sensitivity analysis of computer models using computer calculus  

SciTech Connect

An automated procedure for performing sensitivity analyses has been developed. The procedure uses a new FORTRAN compiler with computer calculus capabilities to generate the derivatives needed to set up sensitivity equations. The new compiler is called GRESS - Gradient Enhanced Software System. Application of the automated procedure with ''direct'' and ''adjoint'' sensitivity theory for the analysis of non-linear, iterative systems of equations is discussed. Calculational efficiency consideration and techniques for adjoint sensitivity analysis are emphasized. The new approach is found to preserve the traditional advantages of adjoint theory while removing the tedious human effort previously needed to apply this theoretical methodology. Conclusions are drawn about the applicability of the automated procedure in numerical analysis and large-scale modelling sensitivity studies. 24 refs., 2 figs.

Oblow, E.M.; Pin, F.G.

1985-01-01

82

Computational design of patterned interfaces using reduced order models  

PubMed Central

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

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

2014-01-01

83

Computational design of patterned interfaces using reduced order models  

NASA Astrophysics Data System (ADS)

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

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

2014-08-01

84

Multiscale modeling of polymers at interfaces  

E-print Network

A brief review of modeling and simulation methods for a study of polymers at interfaces is provided. When studying truly multiscale problems as provided by realistic polymer systems, coarse graining is practically unavoidable. In this process, degrees of freedom on smaller scales are eliminated to the favor of a model suitable for efficient study of the system behavior on larger length and time scales. We emphasize the need to distinguish between dynamic and static properties regarding the model validation. A model which accurately reproduces static properties may fail completely, when it comes to the dynamic behavior of the system. Furthermore, we comment on the use of Monte Carlo method in polymer science as compared to molecular dynamics simulations. Using the latter approach, we also discuss results of recent computer simulations on the properties of polymers close to solid substrates. This includes both generic features (as also observed in the case of simpler molecular models) as well as polymer specific properties. Predictive power of computer simulations is highlighted by providing experimental evidence for these observations. Some important implications of these results for an understanding of mechanical properties of thin polymer films and coatings are also worked out.

Fathollah Varnik; Kurt Binder

2009-10-16

85

Model coupling friction and adhesion for steel-concrete interfaces  

E-print Network

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

Boyer, Edmond

86

The Automated Digital Network System (ADNS) Interface to Transformational Satellite Communications System (TSAT)  

Microsoft Academic Search

The U. S. Department of Defense (DoD) is in the initial phase of building the Global Information Grid (GIG), a private secure internetwork connecting a number of its joint and service-specific IP networks. Two of these networks are the Automated Digital Network System (ADNS) and the Transformational Satellite Communications System (TSAT). ADNS provides network services and entry into the Defense

Joanna N. Ptasinski; Yenchi Congtang

2007-01-01

87

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

88

Modeling, Analysis, Simulation and Control of Laboratory Automation Systems Using Petri Nets: Part 1. Modeling  

Microsoft Academic Search

A move from fixed, statically scheduled laboratory automation systems to more dynamic and adaptive behavior introduces complexities and challenges that have not been thoroughly explored in the field of laboratory automation. Powerful tools are required for the systematic modeling, analysis, simulation, and control of such systems. In this first part of a tutorial series, we introduce and explore Petri nets

Mark F. Russo; Alan Sasso

2005-01-01

89

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

90

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

91

Automated Optic Disk Boundary Detection by Modified Active Contour Model  

Microsoft Academic Search

This paper presents a novel deformable-model-based algorithm for fully automated detection of optic disk boundary in fundus images. The proposed method improves and extends the original snake (deforming-only technique) in two aspects: clustering and smoothing update. The contour points are first self-separated into edge-point group or uncertain-point group by clustering after each deformation, and these contour points are then updated

Juan Xu; Opas Chutatape; Paul Chew

2007-01-01

92

Development of an automated core model for nuclear reactors  

Microsoft Academic Search

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

Mosteller

1998-01-01

93

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

94

SAIDE: A Semi-Automated Interface for Hydrogen/Deuterium Exchange Mass Spectrometry  

PubMed Central

Deuterium/hydrogen exchange in combination with mass spectrometry (DH MS) is a sensitive technique for detection of changes in protein conformation and dynamics. Since temperature, pH and timing control are the key elements for reliable and efficient measurement of hydrogen/deuterium content in proteins and peptides, we have developed a small, semiautomatic interface for deuterium exchange that interfaces the HPLC pumps with a mass spectrometer. This interface is relatively inexpensive to build, and provides efficient temperature and timing control in all stages of enzyme digestion, HPLC separation and mass analysis of the resulting peptides. We have tested this system with a series of standard tryptic peptides reconstituted in a solvent containing increasing concentration of deuterium. Our results demonstrate the use of this interface results in minimal loss of deuterium due to back exchange during HPLC desalting and separation. For peptides reconstituted in a buffer containing 100% deuterium, and assuming that all amide linkages have exchanged hydrogen with deuterium, the maximum loss of deuterium content is only 17% of the label, indicating the loss of only one deuterium molecule per peptide.

Villar, Maria T.; Miller, Danny E.; Fenton, Aron W.; Artigues, Antonio

2011-01-01

95

Automating test program generation in STIL - expectations and experiences using IEEE 1450 [standard test interface language  

Microsoft Academic Search

At the International Test Conference 2002 several low cost test solutions were presented. All of these solutions promised to establish a close link between automatic test pattern generation, ATE based testing and fault diagnosis\\/analysis by using the IEEE 1450 standard test interface language (STIL). However, the reality is different. This paper describes the integration of a STIL based tester into

Helmut Lang; B. Pande; H. Ahrens

2003-01-01

96

Server Interface Descriptions for Automated Testing of JavaScript Web Applications  

E-print Network

. With this so-called Ajax style of structuring web applications, the server mostly acts as a central database seen from the client's point of view. The server interface comprises a collection of operations function goto_page(id, q) { 2 jQuery.ajax(GET_PAGE_URL + '?page=' + id + 3 '&query=' + q, 4 {'data

Su, Zhendong

97

Modelling melt-solid interfaces in Bridgman growth  

NASA Technical Reports Server (NTRS)

Doped epoxy models with abrupt interfaces were prepared to test radiographic and computer enhancement procedures used to study the images of melt-solid interfaces during crystal growth in Bridgman furnaces. A column averaging procedure resulted in improved images that faithfully reproduced the positions and shapes of interfaces even at very low density differences. These techniques were applied to lead tin telluride growing in Bridgman furnaces.

Barber, Patrick G.; Berry, Robert F.; Debnam, William J.; Fripp, Archibald F.; Huang, YU

1989-01-01

98

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

99

A case study for modelling and design of distributed automation systems  

Microsoft Academic Search

In the paper, the problem of modelling and designing of reconfigurable and reusable distributed automation systems is addressed. Such systems are characterized by the distribution of hardware, software, and physical components for the control and automation systems implementation, following the trend to distributed intelligence into the controlled plant and to integrate Information and Communication Technologies into automation systems. Through the

Luca Ferrarini; Carlo Veber; K. Lorentz

2003-01-01

100

Diffuse-Interface Model for Smoothed Particle Hydrodynamics  

SciTech Connect

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

Zhijie Xu; Paul Meakin; Alexandre Tartakovsky

2009-03-01

101

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

102

Diffuse-interface model for smoothed particle hydrodynamics  

SciTech Connect

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

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

2009-03-01

103

Automated Decomposition of Model-based Learning Problems  

NASA Technical Reports Server (NTRS)

A new generation of sensor rich, massively distributed autonomous systems is being developed that has the potential for unprecedented performance, such as smart buildings, reconfigurable factories, adaptive traffic systems and remote earth ecosystem monitoring. To achieve high performance these massive systems will need to accurately model themselves and their environment from sensor information. Accomplishing this on a grand scale requires automating the art of large-scale modeling. This paper presents a formalization of [\\em decompositional model-based learning (DML)], a method developed by observing a modeler's expertise at decomposing large scale model estimation tasks. The method exploits a striking analogy between learning and consistency-based diagnosis. Moriarty, an implementation of DML, has been applied to thermal modeling of a smart building, demonstrating a significant improvement in learning rate.

Williams, Brian C.; Millar, Bill

1996-01-01

104

Multibody dynamics model building using graphical interfaces  

NASA Technical Reports Server (NTRS)

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

Macala, Glenn A.

1989-01-01

105

A continuum model of colloid-stabilized interfaces  

NASA Astrophysics Data System (ADS)

Colloids that are partially wetted by two immiscible fluids can become confined to fluid-fluid interfaces. At sufficiently high volume fractions, the colloids may jam and the interface may crystallize. Examples include bicontinuous interfacially jammed emulsion gels (``bijels''), which were proposed in Stratford et al. (Science (2005) 309:2198) as a hypothetical new class of soft materials in which interpenetrating, continuous domains of two immiscible viscous fluids are maintained in a rigid state, by a jammed layer of colloidal particles at their interface. We develop a continuum model for such a system that is capable of simulating the long-time evolution. A Navier-Stokes- Cahn-Hilliard model for the macroscopic two-phase flow system is combined with a surface Phase- Field-Crystal model for the microscopic colloidal system along the interface. The presence of colloids introduces elastic forces at the interface between the two immiscible fluid phases. An adaptive finite element method is used to solve the model numerically. Using a variety of flow configurations, we demonstrate that as colloids jam on the interface and the interface crystallizes, the elastic force may be strong enough to make the interface sufficiently rigid to resist external forces, such as an applied shear flow, as well as surface tension induced coarsening in bicontinuous structures.

Lowengrub, John

2012-02-01

106

A continuum model of colloid-stabilized interfaces  

NASA Astrophysics Data System (ADS)

Colloids that are partially wetted by two immiscible fluids can become confined to fluid-fluid interfaces. At sufficiently high volume fractions, the colloids may jam and the interface may crystallize. Examples include bicontinuous interfacially jammed emulsion gels (bijels), which were proposed in this study by Stratford et al. [Science 309, 2198 (2005)] as a hypothetical new class of soft materials in which interpenetrating, continuous domains of two immiscible viscous fluids are maintained in a rigid state by a jammed layer of colloidal particles at their interface. We develop a continuum model for such a system that is capable of simulating the long-time evolution. A Navier-Stokes-Cahn-Hilliard model for the macroscopic two-phase flow system is combined with a surface phase-field-crystal model for the microscopic colloidal system along the interface. The presence of colloids introduces elastic forces at the interface between the two immiscible fluid phases. An adaptive finite element method is used to solve the model numerically. Using a variety of flow configurations in two dimensions, we demonstrate that as colloids jam on the interface and the interface crystallizes, the elastic force may be strong enough to make the interface sufficiently rigid to resist external forces, such as an applied shear flow, as well as surface tension induced coarsening in bicontinuous structures.

Aland, Sebastian; Lowengrub, John; Voigt, Axel

2011-06-01

107

Smooth surface meshing for automated finite element model generation from 3D image data.  

PubMed

Finite element (FE) modelling based on data from three-dimensional high-resolution computed tomography (CT) imaging systems provides a non-invasive method to assess structural mechanics. Automated mesh generation from these voxel based image data can be achieved by direct conversion to hexahedron elements, however these model representations have jagged edges. This paper proposes an automated method to generate smoothed FE meshes from voxel-based image data. Mesh fairing processes are utilized that allow constraints that control the smoothing process, and are computationally efficient. Surfaces of the mesh on the exterior, as well as interfaces between two tissues, can be smoothed by varying fairing parameters and constraint criteria. The method was tested on a variety of real and simulated three-dimensional data sets, resulting in both hexahedron and tetrahedron meshes. It was shown that the fairing process is linearly related to the number of smoothing iterations, and that peak stresses are reduced in FE simulations of the smoothed models. Although developed for micro-CT data sets, this fast and reliable mesh smoothing method could be applied to any three-dimensional image data where node and element connectivity have been defined. PMID:15922348

Boyd, Steven K; Müller, Ralph

2006-01-01

108

Percolation Model of Adhesion at Polymer Interfaces  

NASA Astrophysics Data System (ADS)

Adhesion at polymer interfaces is treated as a percolation problem, where an areal density of chains ?, of length L, contribute a number of entanglements to the interface of thickness X. The fracture energy G, is determined by the fraction of entanglements P, fractured or disentangled in the deformation zone preceding the crack tip, via G ~ P-P_c, where Pc is the percolation threshold, given by Pc = 1- M_e/Mc . For incompatible A/B interfaces reinforced with ? diblocks or random A-B copolymers of effective length L'(L' ~ 0 for brushes and strongly adsorbed chains), we obtain P ~ ?L/X, Pc ~ ? _cL/X, such that G = K(? - ? _c)+ G_o, where K and Go ~ 1 J/m^2 are constants. Note that Log G vs Log ? will have an apparent slope of about 2, incorrectly suggesting that G ~ ? ^2. For cohesive fracture, disentanglement dominates at M M*, G = G*[1-M_c/M]. For fatigue crack propagation da/dN, at welding interfaces, we obtain da/dN ~ M-5/2(t/Tr)-5/4, where t is the welding time and Tr is the reptation time. For polymer-solid interfaces, G ~ (X/R)^2. where X is the conformational width of the first layer of chains of random coil size R. The fractal nature of the percolation process is relevant to the fracture mechanism and fractography.

Wool, Richard P.

1998-03-01

109

Automated Physico-Chemical Cell Model Development through Information Theory  

SciTech Connect

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

Peter J. Ortoleva

2005-11-29

110

Automated semiconductor equipment modeling and model parameter estimation using MES data  

Microsoft Academic Search

Driven by upcoming simulation and optimization applications with increasing complexity, the demand for more detailed equipment models is growing. The effort to create and to parameterize practicable equipment models by providing capacity limitations and predicting processing times increases as well. Automated modeling strategies based on MES data using data mining techniques increase the efficiency of today's modeling policies remarkably.

Robert Kohn; S. Werner

2010-01-01

111

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

112

T:XML: A Tool Supporting User Interface Model Transformation  

NASA Astrophysics Data System (ADS)

Model driven development of user interfaces is based on the transformation of an abstract specification into the final user interface the user will interact with. The design of transformation rules to carry out this transformation process is a key issue in any model-driven user interface development approach. In this paper, we introduce T:XML, an integrated development environment for managing, creating and previewing transformation rules. The tool supports the specification of transformation rules by using a graphical notation that works on the basis of the transformation of the input model into a graph-based representation. T:XML allows the design and execution of transformation rules in an integrated development environment. Furthermore, the designer can also preview how the generated user interface looks like after the transformations have been applied. These previewing capabilities can be used to quickly create prototypes to discuss with the users in user-centered design methods.

López-Jaquero, Víctor; Montero, Francisco; González, Pascual

113

MESA: An Interactive Modeling and Simulation Environment for Intelligent Systems Automation  

NASA Technical Reports Server (NTRS)

This report describes MESA, a software environment for creating applications that automate NASA mission opterations. MESA enables intelligent automation by utilizing model-based reasoning techniques developed in the field of Artificial Intelligence. Model-based reasoning techniques are realized in Mesa through native support of causal modeling and discrete event simulation.

Charest, Leonard

1994-01-01

114

Molecular modeling of cracks at interfaces in nanoceramic composites  

NASA Astrophysics Data System (ADS)

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

Pavia, F.; Curtin, W. A.

2013-10-01

115

Providing user models direct access to interfaces: an exploratory study of a simple interface with implications for HRI and HCI  

Microsoft Academic Search

Models of users are a way to understand and improve the usability of computer interfaces. We present here a model in ACT-R cognitive-modeling language that interacts with a publicly available driving simulation as a simple analog for robot inter- faces. The model interacts with the unmodified Java interface by incorporating a novel use of bitmap parsing. The model's structure starts

Frank E. Ritter; Dirk Van Rooy; Robert St. Amant; K. Simpson

2006-01-01

116

Automated geo/ortho registered aerial imagery product generation using the mapping system interface card (MSIC)  

NASA Astrophysics Data System (ADS)

The development concept paper for the MSIC system was first introduced in August 2012 by these authors. This paper describes the final assembly, testing, and commercial availability of the Mapping System Interface Card (MSIC). The 2.3kg MSIC is a self-contained, compact variable configuration, low cost real-time precision metadata annotator with embedded INS/GPS designed specifically for use in small aircraft. The MSIC was specifically designed to convert commercial-off-the-shelf (COTS) digital cameras and imaging/non-imaging spectrometers with Camera Link standard data streams into mapping systems for airborne emergency response and scientific remote sensing applications. COTS digital cameras and imaging/non-imaging spectrometers covering the ultraviolet through long-wave infrared wavelengths are important tools now readily available and affordable for use by emergency responders and scientists. The MSIC will significantly enhance the capability of emergency responders and scientists by providing a direct transformation of these important COTS sensor tools into low-cost real-time aerial mapping systems.

Bratcher, Tim; Kroutil, Robert; Lanouette, André; Lewis, Paul E.; Miller, David; Shen, Sylvia; Thomas, Mark

2013-05-01

117

Automated smoother for the numerical decoupling of dynamics models  

PubMed Central

Background Structure identification of dynamic models for complex biological systems is the cornerstone of their reverse engineering. Biochemical Systems Theory (BST) offers a particularly convenient solution because its parameters are kinetic-order coefficients which directly identify the topology of the underlying network of processes. We have previously proposed a numerical decoupling procedure that allows the identification of multivariate dynamic models of complex biological processes. While described here within the context of BST, this procedure has a general applicability to signal extraction. Our original implementation relied on artificial neural networks (ANN), which caused slight, undesirable bias during the smoothing of the time courses. As an alternative, we propose here an adaptation of the Whittaker's smoother and demonstrate its role within a robust, fully automated structure identification procedure. Results In this report we propose a robust, fully automated solution for signal extraction from time series, which is the prerequisite for the efficient reverse engineering of biological systems models. The Whittaker's smoother is reformulated within the context of information theory and extended by the development of adaptive signal segmentation to account for heterogeneous noise structures. The resulting procedure can be used on arbitrary time series with a nonstationary noise process; it is illustrated here with metabolic profiles obtained from in-vivo NMR experiments. The smoothed solution that is free of parametric bias permits differentiation, which is crucial for the numerical decoupling of systems of differential equations. Conclusion The method is applicable in signal extraction from time series with nonstationary noise structure and can be applied in the numerical decoupling of system of differential equations into algebraic equations, and thus constitutes a rather general tool for the reverse engineering of mechanistic model descriptions from multivariate experimental time series. PMID:17711581

Vilela, Marco; Borges, Carlos CH; Vinga, Susana; Vasconcelos, Ana Tereza R; Santos, Helena; Voit, Eberhard O; Almeida, Jonas S

2007-01-01

118

From Workflow Models to Executable Web Service Interfaces  

Microsoft Academic Search

Workflow models have been used and refined for years to execute processes within organisations. To deal with col- laborative processes (choreographies) these internal work- flow models have to be aligned with the external behaviour advertised through Web service interfaces. However, tra- ditional workflow management systems (WfMS) do not of- fer this functionality. Simply sharing and merging process models is often

Armin Haller; Mateusz Marmolowski; Walid Gaaloul; Eyal Oren; Brahmananda Sapkota; Manfred Hauswirth

2009-01-01

119

Modeling Explicit and Implicit Service Request for Intelligent Interface Design  

Microsoft Academic Search

We propose a goal-driven approach to model explicit and implicit service requests for intelligent interface design. This approach starts the system construction from the view of software requirements engineering. Requirements of the system are generated by the goal-based requirements analysis in which functional and nonfunctional requirements will be represented by a set of goal models. These goal models are used

Chiung-hon Leon Lee; Alan Liu

2009-01-01

120

Towards Artifact Models as Process Interfaces in Distributed Software Projects  

E-print Network

abstracting from the diverse local software processes. Index Terms--agile methods; artifact model; distributed in agile methods, such as Scrum, as they do not explicitly define an artifact model at allTowards Artifact Models as Process Interfaces in Distributed Software Projects Marco Kuhrmann

121

A sharp-interface phase change model for a mass-conservative interface tracking method  

NASA Astrophysics Data System (ADS)

A new phase-change model has been developed for a mass-conservative interface tracking method. The mass transfer rate is directly calculated from the heat flux at the liquid-vapor interface, and the phase change takes place only in the cells which include this interface. As a consequence of the sharpness of the mass transfer rate distribution, the velocity jump across the interface can be captured, and high accuracy can be maintained. The method has been implemented in an incompressible Navier-Stokes equations solver employing a projection method based on a staggered finite-volume algorithm on Cartesian grids. The model has been verified for one-dimensional phase-change problems and a three-dimensional simulation of a growing vapor bubble in a superheated liquid under zero gravity condition. The computed results agree with theoretical solutions, and the accuracy of the model is confirmed to be of second-order in space using a grid refinement study. A three-dimensional simulation of a rising vapor bubble in a superheated liquid under gravity has been performed as a validation case, and good agreement with experimental data is obtained for the bubble growth rate. As a demonstration of the applicability of the method to engineering problems, a nucleate boiling simulation is presented with a comparison to experimental data. Good agreement is obtained for the bubble shapes and the bubble departure period. In all the simulation cases, strict mass conservation is satisfied.

Sato, Yohei; Ni?eno, Bojan

2013-09-01

122

Diffuse interface model of diffusion-limited crystal growth  

Microsoft Academic Search

A general approach to diffusion-limited crystal growth is proposed. It consists of a modified (nonequilibrium) Cahn-Hilliard representation of the interface coupled to a diffusion equation. Arguments are given as to its superiority over previous models. These are illlustrated in a one-dimensional solution which shows how the system selects a unique interface velocity. The selection can be interpreted as the requirement

Joseph B. Collins; Herbert Levine

1985-01-01

123

Author's personal copy Modelling and automation of water and wastewater treatment processes  

E-print Network

Author's personal copy Preface Modelling and automation of water and wastewater treatment processes on the applications of modelling and automation to water and wastewater treatment processes. The session, under purification systems. Many papers showed a considerable effort to extend the analysis from the single plant

124

A Bond Graph Based Modular Modeling Approach towards an Automated Modeling Environment for Reconfigurable Machine Tools  

Microsoft Academic Search

As is well known, due to their graphical and acausal nature, bond graphs naturally lend themselves to a modular approach to physical based modeling of dynamic systems. In this paper we present a bond graph based modular approach for modeling reconfigurable machine tools (RMTs) as a multi-domain system. This approach is the basis of an effort towards developing an automated

Tulga Ersal; Jeffrey L. Stein; Loucas S. Louca

125

INTERFACE  

E-print Network

Allows use of any input range Easy to drive with the ADA4941 No pipeline delay Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic interface Serial interface SPI®-/QSPI™-/MICROWIRE™-/DSP-compatible Ability to daisy-chain multiple ADCs and busy indicator 10-lead package: MSOP (MSOP-8 size) and 3 mm × 3 mm QFN (LFCSP), SOT-23 size APPLICATIONS Battery-powered equipment Data acquisition systems Medical instruments Seismic data acquisition systems

Low Power Dissipation

126

Model-based automated detection of mammalian cell colonies  

NASA Astrophysics Data System (ADS)

Manually counting cell colonies, especially those that originate from fibroblast cell lines, is a time-consuming, eye-straining and tedious task in which consistency of counting is difficult to maintain. In this paper we present a novel model-based image segmentation method, which employs prior knowledge about the shape of a colony with the aim to automatically detect isolated, touching and overlapping cell colonies of various sizes and intensities. First, a set of hypothetical model instances is generated by using a robust statistical approach to estimate the model parameters and a novel confidence measure to quantify the difference between a model instance and the underlying image. Second, the model instances matching the individual colonies in the image are selected from the set by a minimum description length principle. The procedure was applied to images of Chinese hamster lung fibroblast cell line DC3F, which forms poorly defined or 'fuzzy' colonies. The correlation with manual counting was determined and the cell survival curves obtained by automated and manual counting were compared. The results obtained show that the proposed automatic procedure was capable to correctly identify 91% of cell colonies typical of mammalian cell lines.

Bernard, Rok; Kanduser, Masa; Pernus, Franjo

2001-11-01

127

A new dynamic modeling method to fixed machined joint interface  

NASA Astrophysics Data System (ADS)

The concept of virtual material was developed for the first time when the flexible joint interface may be considered as a virtual material with the same cross area. The virtual material is rigidly connected with two components situated in both sides of flexible joint interface. By adding an element, a complex assembled part including a joint interface could be equaled as a simple component without any joint interface in order to simplify the complicated problem about flexible joint interface. The interaction between normal and tangential characteristics of fixed interface taken into account, a series of exact analytical solutions of elastic modulus, shear modulus, Poisson ratio and density were deduced from virtual material through Hertz contact theory and fractal theory. By using experimental results about a series of test specimens, the exact analytic expressions for virtual material's parameters were verified in terms of qualitative comparison principle of resembling vibration shapes and quantitative comparison principle of the natural frequencies. The virtual material model vibration shapes are in excellent agreement with the experimental results. The relative errors between the virtual material model natural frequencies and the experimental ones are between -3% and 10%.

Tian, Hongliang; Li, Bin; Mao, Kuanmin; Gu, Peihua

2013-07-01

128

The variable and conserved interfaces of modeled olfactory receptor proteins  

E-print Network

The variable and conserved interfaces of modeled olfactory receptor proteins YITZHAK PILPEL models of other G-protein-coupled receptors, allows us to analyze the OR amino acid variability patterns postions in other G-protein-coupled receptors, the rest are suggested to form an olfactory-unique aspect

Church, George M.

129

Automated piecewise power-law modeling of biological systems.  

PubMed

Recent trends suggest that future biotechnology will increasingly rely on mathematical models of the biological systems under investigation. In particular, metabolic engineering will make wider use of metabolic pathway models in stoichiometric or fully kinetic format. A significant obstacle to the use of pathway models is the identification of suitable process descriptions and their parameters. We recently showed that, at least under favorable conditions, Dynamic Flux Estimation (DFE) permits the numerical characterization of fluxes from sets of metabolic time series data. However, DFE does not prescribe how to convert these numerical results into functional representations. In some cases, Michaelis-Menten rate laws or canonical formats are well suited, in which case the estimation of parameter values is easy. However, in other cases, appropriate functional forms are not evident, and exhaustive searches among all possible candidate models are not feasible. We show here how piecewise power-law functions of one or more variables offer an effective default solution for the almost unbiased representation of uni- and multivariate time series data. The results of an automated algorithm for their determination are piecewise power-law fits, whose accuracy is only limited by the available data. The individual power-law pieces may lead to discontinuities at break points or boundaries between sub-domains. In many practical applications, these boundary gaps do not cause problems. Potential smoothing techniques, based on differential inclusions and Filippov's theory, are discussed in Appendix A. PMID:20060428

Machina, Anna; Ponosov, Arkady; Voit, Eberhard O

2010-09-01

130

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.

131

INTERFACE  

E-print Network

INL: ±2.25 LSB maximum Dynamic range: 99.7 dB typical True differential analog input range: ±VREF 0 V to VREF with VREF between 2.9 V to 5.0 V Allows use of any input range Easy to drive with the ADA4941 No pipeline delay Single-supply 2.5 V operation with 1.8 V/2.5 V/3 V/5 V logic interface Serial interface SPI-/QSPI™-/MICROWIRE™-/DSP-compatible Ability to daisy-chain multiple ADCs and busy indicator 10-lead MSOP (MSOP-8 size) and 10-lead 3 mm × 3 mm QFN (LFCSP), SOT-23 size APPLICATIONS Battery-powered equipment Data acquisition systems Medical instruments Seismic data acquisition systems

Daisy Chain

132

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...

133

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

EPA Science Inventory

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

134

Automated macromolecular model building for X-ray crystallography using ARP/wARP version 7  

PubMed Central

ARP/wARP is a software suite to build macromolecular models in X-ray crystallography electron density maps. Structural genomics initiatives and the study of complex macromolecular assemblies and membrane proteins all rely on advanced methods for 3D structure determination. ARP/wARP meets these needs by providing the tools to obtain a macromolecular model automatically, with a reproducible computational procedure. ARP/wARP 7.0 tackles several tasks: iterative protein model building including a high-level decision-making control module; fast construction of the secondary structure of a protein; building flexible loops in alternate conformations; fully automated placement of ligands, including a choice of the best fitting ligand from a “cocktail”; and finding ordered water molecules. All protocols are easy to handle by a non-expert user through a graphical user interface or a command line. The time required is typically a few minutes although iterative model building may take a few hours. PMID:18600222

Langer, Gerrit G; Cohen, Serge X; Lamzin, Victor S; Perrakis, Anastassis

2008-01-01

135

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

136

EMPIRICAL TESTS OF HUNTER–COVEY INTERFACE MODELS  

Microsoft Academic Search

Abstract: Quail hunting consists of a complex set of behaviors that involve humans, pointing dogs, and wild birds. The recent development,of models,known,as Hunter–Covey,Interface (HCI) theory provides an opportunity,to analyze how we perceive, understand, and manage quail hunting. There are 2 groups of HCI models: static and dynamic. The static HCI model,predicts daily hunting,mortality based on the velocity of the hunt

JASON B. HARDIN; LEONARD A. BRENNAN; FIDEL HERNÁNDEZ; ERIC J. REDEKER; WILLIAM P. KUVLESKY; Raphael

2005-01-01

137

NASA: Model development for human factors interfacing  

NASA Technical Reports Server (NTRS)

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

Smith, L. L.

1984-01-01

138

Automated parameter fitting of two-port network transducer models.  

PubMed

Networks of linear lumped-parameter components, as may be simulated in electronic circuit design software such as SPICE, are a lightweight, fast, and convenient means of predicting the behavior of electroacoustic transducers in practical application. The development of these models can be quite burdensome. The selection and networking of the equivalent electronic components requires specialized domain knowledge of the transduction mechanisms and design of a transducer. Previously, a general network synthesis approach was proposed [Warren, Daniel, "Applications of network synthesis and zero-pole analysis in transducer modeling," J. Acoust. Soc. Am. 133, 3360-3360 (2013)] but was deemed to be an unreliable and awkward means of developing transducer networks in practice. However, networks that represent transducer behavior are generally well-known for a given transducer type and design. The more difficult task, or, at least, the more often performed and thereby repetitive task, is the selection of component parameter values which correctly predict the transducer's behavior under all electrical drive and acoustical loading conditions which may be encountered in practical application. The approach taken here is to assume that the network itself is already known and seek to develop an automated means of determining the correct parameter values. PMID:25235737

Warren, Daniel M

2014-04-01

139

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

140

A Geometric Interface for Solid Modelling Specification and Report  

E-print Network

Interface for Solid Modelling Specification and Report Cecil Armstrong Adrian Bowyer Stephen Cameron Jonathan Corney Graham Jared Ralph Martin Alan Middleditch Malcolm Sabin Jonathan Salmon THE GEOMETRIC Library. Typeset and designed by Ralph Martin, John Woodwark, and Stephen Cameron. Printed in Great

Martin, Ralph R.

141

MATHEMATICAL MODEL OF DELAMINATION CRACKS ON IMPERFECT INTERFACES  

E-print Network

of Liverpool Liverpool L69 3BX, UK Abstract A mathematical model of a crack along a thin and soft interface in dissimilar media (where ideal contact conditions are speci#12;ed outside the crack), in our case the gradient;rmly bound to the ceramic support structure during this process. If it cracks and shears, then catalyst

Bath, University of

142

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

143

Model-driven embedded systems design environment for the industrial automation sector  

Microsoft Academic Search

The aim of this paper is to describe a model-driven embedded systems design approach which is applied to Industrial Automation and Control Systems (IACS). Therefore, an overview on existing model-driven approaches is given and their applicability for IACS is discussed. The special requirements of the industrial automation sector are taken into account by a novel architecture, utilizing existing model-driven techniques.

Thomas Strasser; Christoph Sünder; Antonio Valentini

2008-01-01

144

First-principles modeling of magnetic misfit interfaces  

NASA Astrophysics Data System (ADS)

We investigate the structural and magnetic properties of interfaces with large lattice mismatch, choosing Pt/Co and Au/Co as prototypes. For our first-principles calculations, we reduce the lattice mismatch to 0.2% by constructing Moiré supercells. Our results show that the roughness and atomic density, and thus the magnetic properties, depend strongly on the substrate and thickness of the Co slab. An increasing thickness leads to the formation of a Co transition layer at the interface, especially for Pt/Co due to strong Pt-Co interaction. A Moiré supercell with a transition layer is found to reproduce the main experimental findings and thus turns out to be the appropriate model for simulating magnetic misfit interfaces.

Grytsyuk, Sergiy; Schwingenschlögl, Udo

2013-10-01

145

Modeling and Automation of Diagnosis and Treatment of Diabetes  

Microsoft Academic Search

\\u000a The present work aims at designing and implementing an automated decision making system for the treatment of diabetes. The\\u000a automated medical tool has been equipped to handle the decisions regarding the care plan of the patient and also helps in\\u000a diagnosis. It takes in essential parameters like glucose, cholesterol, blood pressure and devises a care plan for the patient.\\u000a Fuzzy

Abhirami Baskaran; Dhivya Karthikeyan; Anusha T. Swamy

2010-01-01

146

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

Microsoft Academic Search

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

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

2008-01-01

147

Universality in Sandpiles, Interface Depinning, and Earthquake Models  

SciTech Connect

Recent numerical results for a model describing dispersive transport in ricepiles are explained by mapping the model to the depinning transition of an elastic interface that is dragged at one end through a random medium. The average velocity of transport vanishes with system size {ital L} as {l_angle}{ital v}{r_angle}{approximately}{ital L}{sup 2{minus}{ital D}}{approximately}{ital L}{sup {minus}0.23}, and the avalanche size distribution exponent {tau}=2{minus}1/{ital D}{approx_equal}1.55, where {ital D}{approx_equal}2.23 from interface depinning. We conjecture that the purely deterministic Burridge-Knopoff {open_quote}{open_quote}train{close_quote}{close_quote} model for earthquakes is in the same universality class. {copyright} {ital 1996 The American Physical Society.}

Paczuski, M.; Boettcher, S. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States)] [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973 (United States); [Department of Physics and Astronomy, The University of Oklahoma, Norman, Oklahoma 73019-0225 (United States)

1996-07-01

148

A DIS interface for the Joint Conflict Model simulation  

SciTech Connect

A Distributed Interactive Simulation (DIS) 2.0.3 compatible interface has been added to the Joint Conflict Model (JCM) simulation. JCM is a multi-player, multi-sided, joint, entity-based, stochastic, constructive simulation. A DIS interface allows JCM to engage itself, other constructive simulations, virtual simulators and/or real players in real-time training exercises. A real-time demonstration between multiple JCM simulations and Special Operations Forces Network (SOFNET) helicopter trainers was demonstrated 8 June 1994 at the 58th Special Operations Wing (SOW) at Kirtland AFB. This paper will examine issues of interest that were raised as a result of the JCM/SOFNET demonstration: munition modeling, terrain correlation, terrain clamping, coordinate conversion, transfer of entity modeling control, and mounting and dismounting entities.

Matone, J.; Pimper, J.; Uzelac, M.

1994-08-01

149

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

150

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

National Technical Information Service (NTIS)

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 p...

R. C. Costen

2000-01-01

151

BUSINESS PROCESSES MODELLING AND AUTOMATION IN THE BANKING SECTOR: A CASE STUDY  

Microsoft Academic Search

The banking sector is a competitive environment, where business process re-engineering is constantly needed. Business process modelling and automation are effective tools towards this direction, improving the performance of business activities and enabling enterprise-wide monitoring and coordination. In this paper, we present a case study of modelling and automating business processes in the Loan Monitoring Department of a medium-sized Bank.

MARA NIKOLAIDOU; DIMOSTHENIS ANAGNOSTOPOULOS; APHRODITE TSALGATIDOU

152

Dynamic behavior of interfaces: modeling with nonequilibrium thermodynamics.  

PubMed

In multiphase systems the transfer of mass, heat, and momentum, both along and across phase interfaces, has an important impact on the overall dynamics of the system. Familiar examples are the effects of surface diffusion on foam drainage (Marangoni effect), or the effect of surface elasticities on the deformation of vesicles or red blood cells in an arterial flow. In this paper we will review recent work on modeling transfer processes associated with interfaces in the context of nonequilibrium thermodynamics (NET). The focus will be on NET frameworks employing the Gibbs dividing surface model, in which the interface is modeled as a two-dimensional plane. This plane has excess variables associated with it, such as a surface mass density, a surface momentum density, a surface energy density, and a surface entropy density. We will review a number of NET frameworks which can be used to derive balance equations and constitutive models for the time rate of change of these excess variables, as a result of in-plane (tangential) transfer processes, and exchange with the adjoining bulk phases. These balance equations must be solved together with mass, momentum, and energy balances for the bulk phases, and a set of boundary conditions coupling the set of bulk and interface equations. This entire set of equations constitutes a comprehensive continuum model for a multiphase system, and allows us to examine the role of the interfacial dynamics on the overall dynamics of the system. With respect to the constitutive equations we will focus primarily on equations for the surface extra stress tensor. PMID:23672962

Sagis, Leonard M C

2014-04-01

153

Modeling the Photoionized Interface in Blister HII Regions  

E-print Network

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

Ravi Sankrit; J. Jeff Hester

2000-01-20

154

Test Automation Test Automation  

E-print Network

Test Automation Test Automation Mohammad Mousavi Eindhoven University of Technology, The Netherlands Software Testing 2013 Mousavi: Test Automation #12;Test Automation Outline Test Automation Mousavi: Test Automation #12;Test Automation Why? Challenges of Manual Testing Test-case design: Choosing inputs

Mousavi, Mohammad

155

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

156

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

157

Numerical study of a non-equilibrium interface model  

NASA Astrophysics Data System (ADS)

We have carried out extensive computer simulations of one-dimensional models related to the low noise (solid-on-solid) non-equilibrium interface of a two-dimensional anchored Toom model with unbiased and biased noise. For the unbiased case the computed fluctuations of the interface in this limit provide new numerical evidence for the logarithmic correction to the subnormal 0305-4470/29/23/014/img5 variance which was predicted by the dynamic renormalization group calculations on the modified Edwards - Wilkinson equation. In the biased case the simulations are in close quantitative agreement with the predictions of the collective variable approximation (CVA), which gives the same 0305-4470/29/23/014/img6 behaviour of the variance as the KPZ equation.

Subramanian, Balakrishna; Barkema, G. T.; Lebowitz, J. L.; Speer, E. R.

1996-12-01

158

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

159

A Multiple Agent Model of Human Performance in Automated Air Traffic Control and Flight Management Operations  

NASA Technical Reports Server (NTRS)

A predictive model of human operator performance (flight crew and air traffic control (ATC)) has been developed and applied in order to evaluate the impact of automation developments in flight management and air traffic control. The model is used to predict the performance of a two person flight crew and the ATC operators generating and responding to clearances aided by the Center TRACON Automation System (CTAS). The purpose of the modeling is to support evaluation and design of automated aids for flight management and airspace management and to predict required changes in procedure both air and ground in response to advancing automation in both domains. Additional information is contained in the original extended abstract.

Corker, Kevin; Pisanich, Gregory; Condon, Gregory W. (Technical Monitor)

1995-01-01

160

Modeling and Extracting Deep-Web Query Interfaces  

E-print Network

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

Meng, Weiyi

161

Model-Based Testing with a General Purpose Keyword-Driven Test Automation Framework  

Microsoft Academic Search

Model-based testing (MBT) is a relatively new approach to software testing that extends test automation from test execution to test design using automatic test generation from models. The effective use of the new approach requires new skills and knowledge, such as test modeling skills, but also good tool support. This paper focuses upon the integration of the TEMA model-based graphical

Tuomas Pajunen; Tommi Takala; Mika Katara

2011-01-01

162

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.

163

Bacterial Adhesion to Hexadecane (Model NAPL)-Water Interfaces  

NASA Astrophysics Data System (ADS)

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

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

2009-05-01

164

Building Project Model Support for Automated Labor Monitoring  

E-print Network

. Experimental data were collected, using an ADC system, from the job site of a reinforced concrete building of the automated project perfor- mance control APPC initiative. Project performance control broadly refers of the project is as close as possible to a set of desirable values. Perfor- mance is measured in terms

Sacks, Rafael

165

ShowFlow: A practical interface for groundwater modeling  

SciTech Connect

ShowFlow was created to provide a user-friendly, intuitive environment for researchers and students who use computer modeling software. What traditionally has been a workplace available only to those familiar with command-line based computer systems is now within reach of almost anyone interested in the subject of modeling. In the case of this edition of ShowFlow, the user can easily experiment with simulations using the steady state gaussian plume groundwater pollutant transport model SSGPLUME, though ShowFlow can be rewritten to provide a similar interface for any computer model. Included in this thesis is all the source code for both the ShowFlow application for Microsoft{reg sign} Windows{trademark} and the SSGPLUME model, a User's Guide, and a Developer's Guide for converting ShowFlow to run other model programs. 18 refs., 13 figs.

Tauxe, J.D.

1990-12-01

166

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. PMID:24675760

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

2014-01-01

167

AUTOMATED E-BUSINESS NEGOTIATION: MODEL, LIFE CYCLE, AND SYSTEM ARCHITECTURE  

Microsoft Academic Search

How to apply negotiation principles to E-business is an important topic for both negotiation research and E-business research. Automation of E-business negotiation is even more challenging due to the inherent complexity of business negotiations. Some research has been done in this area, but a comprehensive model for automated E-business negotiation is still missing. Furthermore, existing work in this area does

HAIFEI LI; Stanley Y. W. Su; Herman Lam; Yihua Huang

168

a Deformable Template Model with Feature Tracking for Automated Ivus Segmentation  

NASA Astrophysics Data System (ADS)

Intravascular Ultrasound (IVUS) can be used to create a 3D vascular profile of arteries for preventative prediction of Coronary Heart Disease (CHD). Segmentation of individual B-scan frames is a crucial step for creating profiles. Manual segmentation is too labor intensive to be of routine use. Automated segmentation algorithms are not yet accurate enough. We present a method of tracking features across frames of ultrasound data to increase automated segmentation accuracy using a deformable template model.

Manandhar, Prakash; Hau Chen, Chi

2010-02-01

169

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

170

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

171

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

172

An automated technique to support the verification and validation of simulation models  

Microsoft Academic Search

Simulation modeling requires model validation and verification to ensure that computed results are worth being considered. While we cannot expect a magic solution to the general problem, automated techniques for particular aspects of validation and verification are feasible. In this paper, we propose a technique to deduce model properties automatically from simulation runs performed for verification and validation and to

Samuel K. Klock; Peter Kemper

2010-01-01

173

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

174

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

175

Teallach: a model-based user interface development environment for object databases  

Microsoft Academic Search

Model-based user interface development environments show promise for improving the productivityof user interface developers, and possibly for improving the quality of developed interfaces.While model-based techniques have previously been applied to the area of database interfaces, theyhave not been specifically targeted at the important area of object database applications. Suchapplications make use of models that are semantically richer than their relational

Tony Griffiths; Peter J. Barclay; Norman W. Paton; Jo Mckirdy; Jessie B. Kennedy; Philip D. Gray; Richard Cooper; Carole A. Goble; Paulo Pinheiro Da Silva

2001-01-01

176

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

E-print Network

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

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

2014-04-28

177

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

178

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

E-print Network

GLEAN: A Computer-Based Tool for Rapid GOMS Model Usability Evaluation of User Interface Designs-2110 ABSTRACT Engineering models of human performance permit some aspects of usability of interface designs in predicting usability of the procedural aspects of interface designs. This paper describes a computer

Kieras, David E.

179

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

NASA Technical Reports Server (NTRS)

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

Hansen, R. F. (principal investigator)

1981-01-01

180

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

E-print Network

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

Xie, Tao

181

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

182

Markov Models for Automated ECG Interval Nicholas P. Hughes, Lionel Tarassenko and Stephen J. Roberts  

E-print Network

Markov Models for Automated ECG Interval Analysis Nicholas P. Hughes, Lionel Tarassenko and Stephen of real ECG features, and we investigate the use of hidden semi­Markov models for improved state duration which may be brought about by the drug. Of particular interest is the electrocardiogram (ECG 1

Hughes, Nick

183

Markov Models for Automated ECG Interval Nicholas P. Hughes, Lionel Tarassenko and Stephen J. Roberts  

E-print Network

Markov Models for Automated ECG Interval Analysis Nicholas P. Hughes, Lionel Tarassenko and Stephen of real ECG features, and we investigate the use of hidden semi-Markov models for improved state duration which may be brought about by the drug. Of particular interest is the electrocardiogram (ECG1

Roberts, Stephen

184

Automated Software Engineering Process Assessment: Supporting Diverse Models using an Ontology  

E-print Network

assessment tooling; semantic technology; Capability Maturity Model Integration; ISO/IEC 15504; ISO 9000 I assessment while simultaneously supporting diverse process assessment reference models (CMMI, ISO/IEC 15504, ISO 9001). It also provides an in-the-loop automated process assessment capability that can help

Ulm, Universität

185

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

186

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

Microsoft Academic Search

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

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

1999-01-01

187

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

EPA Science Inventory

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

188

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

189

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

NASA Astrophysics Data System (ADS)

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

Nguyen, Duc Duy; Zhao, Shan

2014-12-01

190

Fluctuations of interface statistical physics models applied to a stock market model  

Microsoft Academic Search

In this paper, applying the theory of fluctuations of the interfaces for statistical physics lattice models, we construct a financial model and use this financial model to describe the behavior or fluctuations of a stock price process in a stock market. By using the methods of statistical physics and under some conditions, we show that the finite dimensional distribution of

Jun Wang; Song Deng

2008-01-01

191

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

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

192

An intracardiac navigation interface for electrophysiology modeling tools  

E-print Network

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

Ocholi, Ojonimi A

2006-01-01

193

The use of analytical models in human-computer interface design  

NASA Technical Reports Server (NTRS)

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

Gugerty, Leo

1991-01-01

194

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.

195

Deconstructing classical water models at interfaces and in bulk  

E-print Network

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

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

2011-07-27

196

Coulomb frictional interfaces in modeling cemented total hip replacements: a more realistic model.  

PubMed

Loosening of cemented femoral hip stems could be initiated by failure of the cement mantle due to high cement stresses. The goals of this study were to determine if realistic stem-cement interface characteristics could result in high cement stresses when compared to a bonded stem-cement interface and to determine if stem design parameters could be chosen to reduce peak cement stresses. Three-dimensional finite-element models of cemented femoral hip components were studied with bonded or realistic Coulomb friction stem-cement interfaces. The results showed that the use of a non-bonded, non-linear Coulomb friction interface resulted in substantially different stress fields in the cement when compared to a bonded stem-cement interface. Tensile stresses in the proximal cement mantel for the Coulomb friction interface case (10.8 MPa) were greater than the fatigue strength of the cement. In contrast, the tensile stresses in the cement mantle were not greater than the fatigue strength for the bonded case (7.5 MPa). Failure of the cement mantle in the proximal femur could therefore be initiated by a lack of a bond at the stem-cement interface. The effect of different cross-sectional stem geometries (medial radii of 3.0, 4.9 and 5.5 mm and antero-posterior widths of 9.8 and 13.7 mm) and different elastic moduli (cobalt chromium alloy and titanium alloy) for the stem material were also evaluated for models with a Coulomb friction interface. Changes in the stem cross-section and elastic modulus had only limited effects on the stress distributions in the cement. Of the parameters evaluated in this study, the characteristics of the stem-cement interface had the largest effect on cement mantle stresses. PMID:7559676

Mann, K A; Bartel, D L; Wright, T M; Burstein, A H

1995-09-01

197

FULLY AUTOMATED NON-NATIVE SPEECH RECOGNITION USING CONFUSION-BASED ACOUSTIC MODEL INTEGRATION AND GRAPHEMIC CONSTRAINTS  

E-print Network

FULLY AUTOMATED NON-NATIVE SPEECH RECOGNITION USING CONFUSION-BASED ACOUSTIC MODEL INTEGRATION automated approach for the recognition of non-native speech based on acoustic model modification. For a na improvements. 1. INTRODUCTION The drastic drop in performance for automatic speech recognition (ASR) systems

Paris-Sud XI, Université de

198

A five-equation model for the numerical simulation of interfaces in two-phase flows  

Microsoft Academic Search

In the Eulerian approach for simulating interfaces in two-phase flows, the main difficulties arise from the fixed character of the mesh which does not follow the interface. Therefore, near the interface there are computational cells containing both fluids which require a suitable modelling of the mixture. Furthermore, most numerical algorithms, such as the volume of fluid or the level set

Grégoire Allaire; Sébastien Clerc; Samuel Kokh

2000-01-01

199

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

EPA Science Inventory

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

200

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

201

Infrared detector arrays: Electronic interface analysis, design, and modeling  

NASA Astrophysics Data System (ADS)

Advances in infrared (IR) detector technology coupled with advances in analog Si CMOS technology have resulted in on-focal-plane hybrid integration of high performance Si readout circuitry with high density IR detector arrays made from a variety of low bandgap semiconductor materials. This dissertation focuses on characterizations or several linear IR photodiode arrays employing on- focal-plane Si CMOS readout circuitry. Significant performance improvements are reported using buffered capacitive transimpedance amplifiers (CTIA) to interconnect with photodiode arrays instead of reverse- biased, self-integrating techniques. Near zero volt detector bias is maintained by buffered interfacing techniques which greatly reduce dark currents and improve linearity. Key performance issues are CMOS op amp input offset voltage and input voltage noise. Emphasis has been placed on noise analysis as improved modeling has revealed dominating noise sources to be preamp white noise and preamp 1/f noise. Preamp white noise dominates at shorter exposure times while preamp 1/f noise dominates at longer exposure times on InGaAs arrays evaluated. Under small detector bias conditions (<20 mV) applied by CMOS op amp input offset voltage, detector 1/f noise limits sensitivity of Ge arrays at longer exposure times. Analytical tools developed explain direct increases in noise equivalent input charge or noise equivalent electrons with exposure time. Detector thermal shot noise, with a square root dependence On exposure time never limits sensitivity of devices evaluated. Improved models for the critical interface between IR detector and readout circuitry will greatly assist evaluating recommended improvements in IR detector and CMOS op amp design.

Howard, Steven G.

1998-11-01

202

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

203

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

NASA Technical Reports Server (NTRS)

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

Brat, Guillaume

2012-01-01

204

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

E-print Network

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

Memon, Atif M.

205

Automated Modelling of Cartridge Valve Flow Mapping Song Liu and Bin Yao  

E-print Network

Automated Modelling of Cartridge Valve Flow Mapping Song Liu and Bin Yao Abstract-- Proportional on the pressure dynamics in the hydraulic cylinder with consideration of some unknown parameters like effective is the proportional poppet type cartridge valve, a low accuracy but fast response valve widely used in industry due

Yao, Bin

206

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

E-print Network

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

Schindler, Konrad

207

Automated sorting of genetically engineered embryonic stem cells for generation of mouse models  

E-print Network

Automated sorting of genetically engineered embryonic stem cells for generation of mouse models of such mice via homologous recombination in embryonic stem cells (ESCs) is a tedious process. A combination of embryonic stem mouse generation using CellProcessor technology. (a) The F1 Hybrid ESC Art4.12 was chosen

Cai, Long

208

Evolving car designs using model-based automated safety analysis and optimisation techniques  

E-print Network

-effective and flexible design solutions and for reduc- ing production costs further. Note that cost reduction has becomeEvolving car designs using model-based automated safety analysis and optimisation techniques Yiannis Papadopoulos a,*, Christian Grante b a Department of Computer Science, University of Hull, Hull HU

Papadopoulos, Yiannis

209

LT Tyson Scofield, USCG and Dr. Alan Brown Manning and Automation Model for Naval Ship  

E-print Network

1 LT Tyson Scofield, USCG and Dr. Alan Brown Manning and Automation Model for Naval Ship Analysis and Optimization ABSTRACT The manning of a ship is a major driver of total ownership cost. The Government Accounting Office (GAO) states that "the cost of the ship's crew is the largest expense incurred over

Brown, Alan

210

A model-based approach to automated testing of access control policies  

Microsoft Academic Search

Access control policies in software systems can be implemented incorrectly for various reasons. This paper presents a model-based approach for automated testing of access control implementation. To feed the model-based testing process, test models are constructed by integrating declarative access control rules and contracts (preconditions and post-conditions) of the associated activities. The access control tests are generated from the test

Dianxiang Xu; Lijo Thomas; Michael Kent; Tejeddine Mouelhi; Yves Le Traon

2012-01-01

211

AUTOMATED RECONSTRUCTION OF BOND GRAPH MODELS BASED ON FREQUENTIAL SPECIFICATIONS  

Microsoft Academic Search

This study proposes a method for automatic reconstruction of models that present modelling inconsistencies. It first describes a general procedure, derived from the bond graph modelling process, which builds generic (independent of physical and technological domains) models. By applying different elimination criteria we extract those models that comply with our demands. This general algorithm is adapted for the reconstruction of

Anca-Maria PIRVU; Geneviève DAUPHIN-TANGUY; Philippe KUBIAK

212

Automated Measurement and Statistical Modeling of Elastic Laminae in Arteries  

PubMed Central

Structural features of elastic laminae within arteries can provide vital information for both the mechanobiology and the biomechanics of the wall. In this paper, we propose, test, and illustrate a new computer-based scheme for automated analysis of regional distributions of elastic laminae thickness, inter-lamellar distances, and fragmentation (furcation points) from standard histological images. Our scheme eliminates potential artifacts produced by tissue cutting, automatically aligns tissue according to physiologic orientations, and performs cross-sectional measurements along radial directions. A statistical randomized complete block design (RCBD) and F-test were used to assess potential (non)-uniformity of lamellar thicknesses and separations along both radial and circumferential directions. Illustrative results for both normotensive and hypertensive thoracic porcine aorta revealed marked heterogeneity along the radial direction in nearly stress-free samples. Clearly, regional measurements can provide more detailed information about morphologic changes that cannot be gained by globally averaged evaluations alone. We also found that quantifying Furcation Point densities offers new information about potential elastin fragmentation, particularly in response to increased loading due to hypertension. PMID:20221934

Xu, Hai; Hu, Jin-Jia; Humphrey, Jay D.; Liu, Jyh-Charn

2010-01-01

213

Automated Measurement of UML Models: an open toolset approach  

Microsoft Academic Search

The Unified Modeling Language (UML) is the de facto standard language for modeling object-oriented software systems. As the importance of UML within organizations increases, the need for measuring UML models arises. This paper describes a UML measurement tool that not only fully supports the measurement of models according to the most popular metrics definitions, but also provides an open measurement

Luigi Lavazza; Alberto Agostini

2005-01-01

214

Efficient Model Checking by Automated Ordering of Transition Relation Partitions  

Microsoft Academic Search

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

Daniel Geist; Ilan Beer

1994-01-01

215

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

Microsoft Academic Search

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

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

2005-01-01

216

Micromechanical modeling of composites with mechanical interface – Part II: Damage mechanics assessment  

Microsoft Academic Search

Continuing the work initiated in the Part I [Bonora N, Ruggiero A. Micromechanical modeling of composites with mechanical interface – Part I: unit cell model development and manufacturing process effects. Compos Sci Technol 2003], in this paper the possibility to account for different damage mechanisms, in the unit cell model (UCM), explicitly developed for composites with mechanical interface, is discussed

Nicola Bonora; Andrew Ruggiero

2006-01-01

217

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

218

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. PMID:21539540

Zollikofer, Christoph P E; Weissmann, John David

2011-01-01

219

Automated Nonlinear Regression Modeling for HCI Antti Oulasvirta  

E-print Network

for Informatics and Saarland University ABSTRACT Predictive models in HCI, such as models of user perfor- mance literature provides useful introduction [9]). As a concrete example, consider Fitts' law. Although at times

220

Modeling Automated Highway Systems with VeriJ Universite Pierre & Marie Curie, CNRS-UMR7606 (LIP6/MoVe)  

E-print Network

Modeling Automated Highway Systems with VeriJ ZHANG Yan Universit´e Pierre & Marie Curie, CNRS of an automated highway system is used to present the basic constructs of the language. 1 Introduction Modeling to handle low level models or complex specification formalisms. The area of automated highway systems

Paris-Sud XI, Université de

221

Modelling the inhomogeneous SiC Schottky interface  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

222

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

PubMed Central

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

Zhu, Xiang; Zhang, Dianwen

2013-01-01

223

IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION, VOL. 13, NO. 1, FEBRUARY 1997 105 Adaptive Model-Based Hybrid Control of  

E-print Network

IEEE TRANSACTIONS ON ROBOTICS AND AUTOMATION, VOL. 13, NO. 1, FEBRUARY 1997 105 Adaptive Model either manually of by fixed automation equipment. The new algorithm evaluated in this paper employs. The practical advantages and disadvantages of control algo- rithms, however, can most clearl

Whitcomb, Louis L.

224

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

225

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

226

Reduced complexity structural modeling for automated airframe synthesis  

NASA Technical Reports Server (NTRS)

A procedure is developed for the optimum sizing of wing structures based on representing the built-up finite element assembly of the structure by equivalent beam models. The reduced-order beam models are computationally less demanding in an optimum design environment which dictates repetitive analysis of several trial designs. The design procedure is implemented in a computer program requiring geometry and loading information to create the wing finite element model and its equivalent beam model, and providing a rapid estimate of the optimum weight obtained from a fully stressed design approach applied to the beam. The synthesis procedure is demonstrated for representative conventional-cantilever and joined wing configurations.

Hajela, Prabhat

1987-01-01

227

A linear program model for the automation of network management  

Microsoft Academic Search

A linear program model is developed to represent the problem of real-time control of traffic in an overloaded circuit-switched network. Circuit groups and exchanges are modeled approximately as saturating devices. Circuit groups saturate with respect to carried traffic, and exchanges saturate with respect to the rate of attempts served. A linear objective function is chosen. Methods for the size of

R. Warfield; D. McMillan

1988-01-01

228

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

229

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

230

Automated protein model building combined with iterative structure refinement  

Microsoft Academic Search

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

Richard Morris; Victor S. Lamzin; Anastassis Perrakis

1999-01-01

231

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

232

Modeling a Shock-Accelerated Fluid - Multiphase Fluid Interface  

NASA Astrophysics Data System (ADS)

The hydrocode SHAMRC has been used in the past to study the formation and growth of the Richtmyer-Meshkov Instability (RMI). While RMI involves impulsively accelerating two continuous fluids of differing densities, a similar class of instabilities has recently been described for multiphase flow. In this scenario, a shock wave passes through a region containing ambient air seeded with particles which have a non-trivial mass and density much greater than that of the surrounding and embedding fluid. In this scenario, no baroclinic vorticity is generated due to the lack of a fluid-fluid density interface. After the shock passage, the particles or droplets lag behind the surrounding gas. Momentum exchange between the embedded phase and the embedding phase leads to non-uniform local equilibrium velocity distribution, and thus to shear and vortex formation. As the primary mechanism for this instability formation is momentum transfer via drag, the morphology of the instability is strongly dependent of the sizes of the particles in the initial conditions. The simulations described here attempt to model the effects of changing the particle size on the morphology and growth rate of this instability.

Anderson, Michael; Vorobieff, Peter; White, Ross; Conroy, Joseph; Truman, C. Randall; Kumar, Sanjay

2011-11-01

233

A Performance Model of Selection Techniques for P300-Based Brain-Computer Interfaces  

E-print Network

A Performance Model of Selection Techniques for P300-Based Brain-Computer Interfaces Jean [2], and to move a wheelchair [6]. Studies on the design and evaluation of P300-based interac- tive propose a model to predict the performance of selection techniques using Brain-Computer Interfaces based

Casiez, Géry

234

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

E-print Network

and improves the flexibility and usability of eye-based interfaces. Fixation tracing uses hidden Markov models to map user actions to the sequential predictions of a cognitive process model. In a study of eye typing methods and allows for more flexibility in designing usable interfaces. Implications for future research

Salvucci, Dario D.

235

Automated mask creation from a 3D model using Faethm.  

SciTech Connect

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

Schiek, Richard Louis; Schmidt, Rodney Cannon

2007-11-01

236

Model-based metrics of human-automation function allocation in complex work environments  

NASA Astrophysics Data System (ADS)

Function allocation is the design decision which assigns work functions to all agents in a team, both human and automated. Efforts to guide function allocation systematically has been studied in many fields such as engineering, human factors, team and organization design, management science, and cognitive systems engineering. Each field focuses on certain aspects of function allocation, but not all; thus, an independent discussion of each does not address all necessary issues with function allocation. Four distinctive perspectives emerged from a review of these fields: technology-centered, human-centered, team-oriented, and work-oriented. Each perspective focuses on different aspects of function allocation: capabilities and characteristics of agents (automation or human), team structure and processes, and work structure and the work environment. Together, these perspectives identify the following eight issues with function allocation: 1) Workload, 2) Incoherency in function allocations, 3) Mismatches between responsibility and authority, 4) Interruptive automation, 5) Automation boundary conditions, 6) Function allocation preventing human adaptation to context, 7) Function allocation destabilizing the humans' work environment, and 8) Mission Performance. Addressing these issues systematically requires formal models and simulations that include all necessary aspects of human-automation function allocation: the work environment, the dynamics inherent to the work, agents, and relationships among them. Also, addressing these issues requires not only a (static) model, but also a (dynamic) simulation that captures temporal aspects of work such as the timing of actions and their impact on the agent's work. Therefore, with properly modeled work as described by the work environment, the dynamics inherent to the work, agents, and relationships among them, a modeling framework developed by this thesis, which includes static work models and dynamic simulation, can capture the issues with function allocation. Then, based on the eight issues, eight types of metrics are established. The purpose of these metrics is to assess the extent to which each issue exists with a given function allocation. Specifically, the eight types of metrics assess workload, coherency of a function allocation, mismatches between responsibility and authority, interruptive automation, automation boundary conditions, human adaptation to context, stability of the human's work environment, and mission performance. Finally, to validate the modeling framework and the metrics, a case study was conducted modeling four different function allocations between a pilot and flight deck automation during the arrival and approach phases of flight. A range of pilot cognitive control modes and maximum human taskload limits were also included in the model. The metrics were assessed for these four function allocations and analyzed to validate capability of the metrics to identify important issues in given function allocations. In addition, the design insights provided by the metrics are highlighted. This thesis concludes with a discussion of mechanisms for further validating the modeling framework and function allocation metrics developed here, and highlights where these developments can be applied in research and in the design of function allocations in complex work environments such as aviation operations.

Kim, So Young

237

Drivers' communicative interactions: on-road observations and modelling for integration in future automation systems.  

PubMed

Social interactions with other road users are an essential component of the driving activity and may prove critical in view of future automation systems; still up to now they have received only limited attention in the scientific literature. In this paper, it is argued that drivers base their anticipations about the traffic scene to a large extent on observations of social behaviour of other 'animate human-vehicles'. It is further argued that in cases of uncertainty, drivers seek to establish a mutual situational awareness through deliberate communicative interactions. A linguistic model is proposed for modelling these communicative interactions. Empirical evidence from on-road observations and analysis of concurrent running commentary by 25 experienced drivers support the proposed model. It is suggested that the integration of a social interactions layer based on illocutionary acts in future driving support and automation systems will improve their performance towards matching human driver's expectations. Practitioner Summary: Interactions between drivers on the road may play a significant role in traffic coordination. On-road observations and running commentaries are presented as empirical evidence to support a model of such interactions; incorporation of drivers' interactions in future driving support and automation systems may improve their performance towards matching driver's expectations. PMID:25204887

Portouli, Evangelia; Nathanael, Dimitris; Marmaras, Nicolas

2014-12-01

238

An automated in vitro model for the evaluation of ultrasound modalities measuring myocardial deformation  

PubMed Central

Background Echocardiography is the method of choice when one wishes to examine myocardial function. Qualitative assessment of the 2D grey scale images obtained is subjective, and objective methods are required. Speckle Tracking Ultrasound is an emerging technology, offering an objective mean of quantifying left ventricular wall motion. However, before a new ultrasound technology can be adopted in the clinic, accuracy and reproducibility needs to be investigated. Aim It was hypothesized that the collection of ultrasound sample data from an in vitro model could be automated. The aim was to optimize an in vitro model to allow for efficient collection of sample data. Material & Methods A tissue-mimicking phantom was made from water, gelatin powder, psyllium fibers and a preservative. Sonomicrometry crystals were molded into the phantom. The solid phantom was mounted in a stable stand and cyclically compressed. Peak strain was then measured by Speckle Tracking Ultrasound and sonomicrometry. Results We succeeded in automating the acquisition and analysis of sample data. Sample data was collected at a rate of 200 measurement pairs in 30 minutes. We found good agreement between Speckle Tracking Ultrasound and sonomicrometry in the in vitro model. Best agreement was 0.83 ± 0.70%. Worst agreement was -1.13 ± 6.46%. Conclusions It has been shown possible to automate a model that can be used for evaluating the in vitro accuracy and precision of ultrasound modalities measuring deformation. Sonomicrometry and Speckle Tracking Ultrasound had acceptable agreement. PMID:20822532

2010-01-01

239

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

240

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

241

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

242

Automated Decomposition of Model-based Learning Problems  

Microsoft Academic Search

A new generation of sensor rich, massively distributed autonomous systems is being developed that has the potential for unprecedented performance, such as smart buildings, reconfigurable factories, adaptive traffic systems and remote earth ecosystem monitor- ing. To achieve high performance these massive sys- tems will need to accurately model themselves and their environment from sensor information. Accom- plishing this on a

Brian C. Williams; Bill Millar

1996-01-01

243

TOWARDS AUTOMATED MODEL REVISION FOR FAULT-TOLERANT SYSTEMS  

E-print Network

is a testament in itself of her unyielding devotion and love. I would like to thank our three children, Haya is especially beneficial in the development of systems that need high assurance. To apply model revision in practice, we need to develop tools that are user friendly, comprehensive, and efficient. However, due

Kulkarni, Sandeep

244

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

245

Defect Identification with Model-Based Test Automation  

Microsoft Academic Search

Software is an integral part of automotive products, but organizations face many problems that impede rapid development of software systems critical to their operations and growth. Manual processes to generate tests for software will become increasingly insufficient as automotive software becomes more complex, and more safety-critical. A method exists to develop tests automatically from formal, precise requirement and design models.

Mark Blackburn; Aaron Nauman; Bob Busser; Bryan Stensvad

2002-01-01

246

A computational model of the motivation-learning interface Manish Saggar (mishu@cs.utexas.edu)  

E-print Network

A computational model of the motivation-learning interface Manish Saggar (mishu the influence of motivation on learning observed by Markman, Baldwin and Maddox (2005). They showed influences learning and cognition. Keywords: Computational modeling, Motivation, Learning, Regulatory focus

Maddox, W. Todd

247

Developing a TeraGrid Based Land Surface Hydrology and Weather Modeling Interface  

E-print Network

on the quality of air, land, and water resources. The computation-intensive models are supported by resourcesDeveloping a TeraGrid Based Land Surface Hydrology and Weather Modeling Interface Hsin-I Chang1

Jiang, Wen

248

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

249

Automated Volumetric Breast Density derived by Shape and Appearance Modeling  

PubMed Central

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. PMID:25083119

Malkov, Serghei; Kerlikowske, Karla; Shepherd, John

2014-01-01

250

Flashover of a vacuum-insulator interface: A statistical model  

NASA Astrophysics Data System (ADS)

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, and that the average rate at which flashovers occur is a power-law function of the instantaneous value of the electric field. Under these conditions, we find that the flashover probability is given by 1-exp(-E?pteffC/k?), where Ep is the peak value in time of the spatially averaged electric field E(t), teff??[E(t)/Ep]?dt is the effective pulse width, C is the insulator circumference, k?exp(?/d), and ? and ? are constants. We define E(t) as V(t)/d, where V(t) is the voltage across the insulator and d is the insulator thickness. Since the model assumes that flashovers occur at random azimuthal locations along the insulator, it does not apply to systems that have a significant defect, i.e., a location contaminated with debris or compromised by an imperfection at which flashovers repeatedly take place, and which prevents a random spatial distribution. The model is consistent with flashover measurements to within 7% for pulse widths between 0.5 ns and 10 ?s, and to within a factor of 2 between 0.5 ns and 90 s (a span of over 11 orders of magnitude). For these measurements, Ep ranges from 64 to 651 kV/cm, d from 0.50 to 4.32 cm, and C from 4.96 to 95.74 cm. The model is significantly more accurate, and is valid over a wider range of parameters, than the J. C. Martin flashover relation that has been in use since 1971 [J. C. Martin on Pulsed Power, edited by T. H. Martin, A. H. Guenther, and M. Kristiansen (Plenum, New York, 1996)]. We have generalized the statistical model to estimate the total-flashover probability of an insulator stack (i.e., an assembly of insulator-electrode systems connected in series). The expression obtained is consistent with the measured flashover performance of a stack of five 5.72-cm-thick, 1003-cm-circumference insulators operated at 100 and 158 kV/cm. The expression predicts that the total-flashover probability is a strong function of the ratio Ep/k, and that under certain conditions, the performance improves as the capacitance between the stack grading rings is increased. In addition, the expression suggests that given a fixed stack height, there exists an optimum number of insulator rings that maximizes the voltage at which the stack can be operated. The results presented can be applied to any system (or any set of systems connected in series) subject to random failures, when the characteristic statistical delay time of a failure is much greater than its formative time.

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

2004-07-01

251

Simplified cusum model for automated control of fab processes  

NASA Astrophysics Data System (ADS)

Advanced process control can be achieved using basic math to create a simplified cumulative sum (cusum) chart. The method is simple: plot the difference between the measured value and the desired target (error value). Each new data point is summed with the last data point. A process that is only slightly off target will be evidenced by a gradual trend towards the control limits. The farther from target the process is the steeper the slope will be, and the sooner it will breach the control limits. Subtracting a noise threshold value from the error value can control the sensitivity of the cusum chart. For example, if the threshold is 5 and the measured value is 8, the plotted value would be 3. Measured values of less than the threshold considered on-target and plotted as zero. Substantial improvements in process capability were realized using an APC system built on this simple cusum model.

Downing, John T.; Sorenson, Tracey

2002-07-01

252

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

USGS Publications Warehouse

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

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

2003-01-01

253

Diffuse-interface model for rapid phase transformations in nonequilibrium systems  

NASA Astrophysics Data System (ADS)

A thermodynamic approach to rapid phase transformations within a diffuse interface in a binary system is developed. Assuming an extended set of independent thermodynamic variables formed by the union of the classic set of slow variables and the space of fast variables, we introduce finiteness of the heat and solute diffusive propagation at the finite speed of the interface advancing. To describe transformations within the diffuse interface, we use the phase-field model which allows us to follow steep but smooth changes of phase within the width of the diffuse interface. Governing equations of the phase-field model are derived for the hyperbolic model, a model with memory, and a model of nonlinear evolution of transformation within the diffuse interface. The consistency of the model is proved by the verification of the validity of the condition of positive entropy production and by outcomes of the fluctuation-dissipation theorem. A comparison with existing sharp-interface and diffuse-interface versions of the model is given.

Galenko, Peter; Jou, David

2005-04-01

254

A Multilayered Sharp Interface Model of Coupled Freshwater and Saltwater Flow in Coastal Systems: Model Development and Application  

Microsoft Academic Search

A quasi three-dimensional, finite difference model, that simulates freshwater and saltwater flow separated by a sharp interface, has been developed to study layered coastal aquifer systems. The model allows for regional simulation of coastal groundwater conditions, including the effects of saltwater dynamics on the freshwater system. Vertically integrated freshwater and saltwater flow equations incorporating the interface boundary condition are solved

Hedeff I. Essaid

1990-01-01

255

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

Microsoft Academic Search

A quasi three-dimensional, finite difference model, that simulates freshwater and saltwater flow separated by a sharp interface, has been developed to study layered coastal aquifer systems. The model allows for regional simulation of coastal groundwater conditions, including the effects of saltwater dynamics on the freshwater system. Vertically integrated freshwater and saltwater flow equations incorporating the interface boundary condition are solved

Hedeff I. Essaid

1990-01-01

256

Automated drusen detection in retinal images using analytical modelling algorithms  

PubMed Central

Background Drusen are common features in the ageing macula associated with exudative Age-Related Macular Degeneration (ARMD). They are visible in retinal images and their quantitative analysis is important in the follow up of the ARMD. However, their evaluation is fastidious and difficult to reproduce when performed manually. Methods This article proposes a methodology for Automatic Drusen Deposits Detection and quantification in Retinal Images (AD3RI) by using digital image processing techniques. It includes an image pre-processing method to correct the uneven illumination and to normalize the intensity contrast with smoothing splines. The drusen detection uses a gradient based segmentation algorithm that isolates drusen and provides basic drusen characterization to the modelling stage. The detected drusen are then fitted by Modified Gaussian functions, producing a model of the image that is used to evaluate the affected area. Twenty two images were graded by eight experts, with the aid of a custom made software and compared with AD3RI. This comparison was based both on the total area and on the pixel-to-pixel analysis. The coefficient of variation, the intraclass correlation coefficient, the sensitivity, the specificity and the kappa coefficient were calculated. Results The ground truth used in this study was the experts' average grading. In order to evaluate the proposed methodology three indicators were defined: AD3RI compared to the ground truth (A2G); each expert compared to the other experts (E2E) and a standard Global Threshold method compared to the ground truth (T2G). The results obtained for the three indicators, A2G, E2E and T2G, were: coefficient of variation 28.8 %, 22.5 % and 41.1 %, intraclass correlation coefficient 0.92, 0.88 and 0.67, sensitivity 0.68, 0.67 and 0.74, specificity 0.96, 0.97 and 0.94, and kappa coefficient 0.58, 0.60 and 0.49, respectively. Conclusions The gradings produced by AD3RI obtained an agreement with the ground truth similar to the experts (with a higher reproducibility) and significantly better than the Threshold Method. Despite the higher sensitivity of the Threshold method, explained by its over segmentation bias, it has lower specificity and lower kappa coefficient. Therefore, it can be concluded that AD3RI accurately quantifies drusen, using a reproducible method with benefits for ARMD evaluation and follow-up. PMID:21749717

2011-01-01

257

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

258

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

259

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

E-print Network

the attended character. Due to the low SNR and variability of EEG signals, P300-based BCI typing systems needINCORPORATION OF A LANGUAGE MODEL INTO A BRAIN COMPUTER INTERFACE BASED SPELLER THROUGH HMMs Ã?ada, 34956 Istanbul, Turkey ABSTRACT Brain computer interface (BCI) research deals with the problem

Yanikoglu, Berrin

260

A User-Oriented Interface for Generalised Informetric Analysis Based on Applying Advanced Data Modelling Techniques.  

ERIC Educational Resources Information Center

Presents a user-oriented interface for generalized informetric analysis and demonstrates how informetric calculations can be specified through advanced data modeling techniques. Topics include bibliographic data; online information retrieval systems; citation networks; query interface; impact factors; data restructuring; and multi-level…

Jarvelin, Kalervo; Ingwersen, Peter; Niemi, Timo

2000-01-01

261

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

PubMed

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

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

2007-01-01

262

A New Tool for Inundation Modeling: Community Modeling Interface for Tsunamis (ComMIT)  

NASA Astrophysics Data System (ADS)

Almost 5 years after the 26 December 2004 Indian Ocean tragedy, the 10 August 2009 Andaman tsunami demonstrated that accurate forecasting is possible using the tsunami community modeling tool Community Model Interface for Tsunamis (ComMIT). ComMIT is designed for ease of use, and allows dissemination of results to the community while addressing concerns associated with proprietary issues of bathymetry and topography. It uses initial conditions from a precomputed propagation database, has an easy-to-interpret graphical interface, and requires only portable hardware. ComMIT was initially developed for Indian Ocean countries with support from the United Nations Educational, Scientific, and Cultural Organization (UNESCO), the United States Agency for International Development (USAID), and the National Oceanic and Atmospheric Administration (NOAA). To date, more than 60 scientists from 17 countries in the Indian Ocean have been trained and are using it in operational inundation mapping.

Titov, V. V.; Moore, C. W.; Greenslade, D. J. M.; Pattiaratchi, C.; Badal, R.; Synolakis, C. E.; Kâno?lu, U.

2011-11-01

263

INTERFACING ACOUSTIC MODELS WITH NATURAL LANGUAGE PROCESSING SYSTEMS  

E-print Network

to accom- plish this interface is of great significance, because this choice determines how word on implementation and ef- ficiency issues associated with the use of word graphs for inter- facing acoustic speech for graph construction is examined, as well as techniques for word graph compression. In addition, the word

Johnson, Michael T.

264

Model-driven reverse engineering of legacy graphical user interfaces  

Microsoft Academic Search

Businesses are more and more modernizing the legacy systems they developed with Rapid Application Development (RAD), so that they can benefit from the new platforms and technologies. In these systems, the Graphical User Interface (GUI) layout is implicitly given by the position of the GUI elements (i.e. coordinates). However, taking advantage of current features of GUI technologies often requires an

Óscar Sánchez Ramón; Jesús Sánchez Cuadrado; Jesús García Molina

2010-01-01

265

Cognitive garment design interface using user behavior tree model  

Microsoft Academic Search

An effective user interface helps to hinge on ideas and imagination from fashion designers and most importantly express their artworks with their flair. Shape, material, color, movement and flow - all these qualities give a piece of clothing its uniqueness, and the designer uses drawings to communicate his intentions. Sketches of various views of the garment provide the preliminary clues

Shuang Liang; E. C. L. Chan; G. Baciu; Rong-Hua Li

2010-01-01

266

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

267

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

268

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

SciTech Connect

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

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

2012-03-15

269

Development of Multi-scale Multiphase Flow Equation and Thermodynamic Modeling of Gas-liquid Interface  

NASA Astrophysics Data System (ADS)

A gas-liquid interface contains various complex physics and unknown phenomena related to thermodynamics, electromagnetics, hydrodynamics, and heat and mass transfer. Therefore, a modeling of gas-liquid interface is one of key issues of the numerical research on multiphase flows. Currently, the Continuum Surface Force model (CSF) is popular to model a gas-liquid interface in computational fluid dynamics. However, the CSF model cannot explain the physics of the gas-liquid interface because it is derived through a mechanical energy balance at the interface. In this study, by assuming a gas-liquid interface as a fluid-membrane with a thin but finite thickness, we develop a new gas-liquid interface model based on thermodynamics via mathematical approach. In particular, we derive an equation of free energy based on a lattice gas model including the effect of the electric double layer caused by a contamination on the interaction between the bubble interfaces. Finally, we derive a set of new governing equations for fluid motion based on a mesoscopic concept. The free energy is incorporated into the Navier-Stokes equation as new terms by using Chapman-Enskog expansion. Moreover, by using the new governing equation, we derive the jump condition at the gas-liquid interface based on thermodynamics. Then, we compare the obtained thermodynamic jump condition with the conventional one. As a result, we reveal that the conventional jump condition is true under a specific condition and that thermodynamic jump condition provides more general formalism than the conventional one.

Yonemoto, Yukihiro; Kunugi, Tomoaki

270

Toward adaptive conversational interfaces: Modeling speech convergence with animated personas  

Microsoft Academic Search

The design of robust interfaces that process conversational speech is a challenging research direction largely because users' spoken language is so variable. This research explored a new dimension of speaker stylistic variation by examining whether users' speech converges systematically with the text-to-speech (TTS) heard from a software partner. To pursue this question, a study was conducted in which twenty-four 7

Sharon L. Oviatt; Courtney Darves; Rachel Coulston

2004-01-01

271

Sketch-based interfaces for modeling and users' needs: Redefining connections  

E-print Network

The goal of this paper is to reexamine assumptions about sketch-based interfaces for modeling in the context of designers' needs and practices. Research questions examine (a) the type of sketch support and (b) the timing ...

Elsen, Catherine

272

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 ...

273

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

PubMed

An automated 3D finite element (FE) modeling procedure for direct fiber reinforced dental bridge is established on the basis of computer tomography (CT) scan data. The model presented herein represents a two-unit anterior cantilever bridge that includes a maxillary right incisor as an abutment and a maxillary left incisor as a cantilever pontic bonded by adhesive and reinforced fibers. The study aims at gathering fundamental knowledge for design optimization of this type of innovative composite dental bridges. To promote the automatic level of numerical analysis and computational design of new dental biomaterials, this report pays particular attention to the mathematical modeling, mesh generation, and validation of numerical models. To assess the numerical accuracy and to validate the model established, a convergence test and experimental verification are also presented. PMID:15912531

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

2005-07-01

274

Using Multidisciplinary Expert Evaluations to Test and Improve Cognitive Model Interfaces  

E-print Network

has been the TacAir-Soar system [24] which employs cognitive models developed with the Soar cognitiveUsing Multidisciplinary Expert Evaluations to Test and Improve Cognitive Model Interfaces Marios N, situation awareness, cognitive models ABSTRACT: Typically, the design of cognitive models has not emphasized

Ritter, Frank

275

Modeling Speech Disfluency to Predict Conceptual Misalignment in Speech Survey Interfaces  

ERIC Educational Resources Information Center

Computer-based interviewing systems could use models of respondent disfluency behaviors to predict a need for clarification of terms in survey questions. This study compares simulated speech interfaces that use two such models--a generic model and a stereotyped model that distinguishes between the speech of younger and older speakers--to several…

Ehlen, Patrick; Schober, Michael F.; Conrad, Frederick G.

2007-01-01

276

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

277

Modeling interface roughness scattering in a layered seabed for normal-incident chirp sonar signals.  

PubMed

Downward looking sonar, such as the chirp sonar, is widely used as a sediment survey tool in shallow water environments. Inversion of geo-acoustic parameters from such sonar data precedes the availability of forward models. An exact numerical model is developed to initiate the simulation of the acoustic field produced by such a sonar in the presence of multiple rough interfaces. The sediment layers are assumed to be fluid layers with non-intercepting rough interfaces. PMID:22502485

Tang, Dajun; Hefner, Brian T

2012-04-01

278

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

PubMed

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

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

2015-03-01

279

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

PubMed Central

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

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

2013-01-01

280

From Proceedings of the Seventh International Conference on User Modeling. Banff, Alberta: Springer. User Modeling in Adaptive Interfaces  

E-print Network

. User Modeling in Adaptive Interfaces Pat Langley? Adaptive Systems Group DaimlerChrysler Research and Technology Center 1510 Page Mill Road, Palo Alto, CA 94304 USA LANGLEY@RTNA.DAIMLERCHRYSLER.COM Abstract. In this paper we examine the notion of adaptive user interfaces, interactive sys- tems that invoke machine

Langley, Pat

281

An Analytical Model for Solute Segregation at Liquid Metal/Solid Substrate Interface  

NASA Astrophysics Data System (ADS)

In this paper, we present an analytical model for describing the equilibrium solute segregation at the interface between metallic liquid (an A-B solution, where A is solvent and B is solute) and a solid substrate (S) using approaches of thermodynamics and statistical mechanics. This analytical model suggests that the interfacial solute segregation is governed by the difference in interfacial energies between the pure B/S and pure A/S interfaces, the heat of mixing of the A-B solution and the difference in entropies of fusion between pure solute and solvent. The calculated solute segregations at the interface in the liquid Al-Ti/TiB2 and liquid Sn-Al/Al2O3 systems are in qualitative agreement with the experimental observations. It is demonstrated that the present analytical model can be used to predict the solute segregation at the liquid/substrate interface, at least qualitatively.

Men, Hua; Fan, Zhongyun

2014-11-01

282

A useful automated rainfall-runoff model for engineering applications in semi-arid regions  

NASA Astrophysics Data System (ADS)

This research develops a useful GIS-based automated Semi-Distributed Time-Area model (SDISTA) that is intended for engineering applications in semi-arid regions. SDISTA is a simple model that reconsiders the time-area technique using an improved approach that deals with each grid cell as a completely independent hydrologic unit. Travel times through the grid cells are estimated using a spatially varied grid-based Manning's formula that relates the hydraulic radius at each grid cell to the characteristics of its upstream catchment area and excess rainfall depth. SDISTA is tested in this research on cases from semi-arid regions including Sinai Peninsula. The results show that SDISTA can be as accurate as HEC-1/HEC-HMS using a very dense network. SDISTA is fully automated and requires minimum effort from the user which is very favorable for engineering applications. The most attractive feature of SDISTA is its ability to automatically delineate and simulate any number of catchment areas simultaneously on digital elevation models.

Gad, Mohamed A.

2013-03-01

283

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

284

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. PMID:23105914

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

2012-01-01

285

A performance model of selection techniques for p300-based brain-computer interfaces  

Microsoft Academic Search

In this paper, we propose a model to predict the performance of selection techniques using Brain-Computer Interfaces based on P300 signals. This model is based on Markov the- ory and can compute both the time required to select a target and the number of visual flashes needed. We illustrate how to use this model with three different interaction techniques to

Jean-baptiste Sauvan; Anatole Lécuyer; Fabien Lotte; Géry Casiez

2009-01-01

286

MODELING FRACTURES AND BARRIERS AS INTERFACES FOR FLOW IN POROUS MEDIA  

E-print Network

MODELING FRACTURES AND BARRIERS AS INTERFACES FOR FLOW IN POROUS MEDIA VINCENT MARTIN, J Vol. 26, No. 5, pp. 1667­1691 Abstract. We consider a fractured porous medium that is studied at a scale such that the fractures can be modeled individually. Models for flow in which the fractures

287

The use of analytical models in human-computer interface design  

NASA Technical Reports Server (NTRS)

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

Gugerty, Leo

1993-01-01

288

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. PMID:22777818

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

2012-01-01

289

Bayesian student modeling, user interfaces and feedback: A sensitivity analysis  

Microsoft Academic Search

The Andes physics tutoring system has a student modeler that uses Bayesian networks. Although the student modeler was evaluated once with positive results, in order to better understand it and student modeling in general, a sensitivity analysis was conducted. That is, we studied the effects on accuracy of varying both numerical parameters of the student modeler (e.g., the prior probabilities)

Zhendong Niu

290

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

291

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

292

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

Microsoft Academic Search

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

K. Horio; H. Yanai

1990-01-01

293

77 FR 20835 - National Customs Automation Program (NCAP) Test Concerning Automated Commercial Environment (ACE...  

Federal Register 2010, 2011, 2012, 2013

...gov. For technical questions related to ABI transmissions, contact your assigned client...trade/automated/automated_systems/abi/getting_started/getting_started...FTP, Secure Web Services, existing EDI ABI MQ interfaces. All responses back to...

2012-04-06

294

78 FR 44142 - Modification of Two National Customs Automation Program (NCAP) Tests Concerning Automated...  

Federal Register 2010, 2011, 2012, 2013

...gov. For technical questions related to ABI transmissions, contact your assigned client...trade/automated/automated_systems/abi/getting_started/getting_started...Secure Web Services, or existing EDI ABI MQ interfaces. All responses back to...

2013-07-23

295

Squashing Cubes: Automating Deformable Model Construction for Graphics Doug L. James Jernej Barbic Christopher D. Twigg (Carnegie Mellon University)  

E-print Network

displacement fields can be obtained for many animation purposes. One practical benefit of voxelization models remains a tedious process for animators. Squashing Cubes (SC) automates the construction are interpolated back onto the original model, thus producing the final animation. Such domain embedding schemes

James, Doug L.

296

Drawing interfaces : building geometric models with hand-drawn sketches  

E-print Network

Architects work on drawings and models, not buildings. Today, in many architectural practices, drawings and models are produced in digital format using Computer-aided Design (CAD) tools. Unquestionably, digital media have ...

Branda, Ewan E. (Ewan Edward), 1964-

1998-01-01

297

Practical Software Model Checking via Dynamic Interface Reduction  

E-print Network

- sion. DEMETER makes software model checking more practical with the following contributions: (i model checking. We have integrated DEMETER into two existing model checkers, MACEMC and MODIST, each centers for years to manage tens of thousands of machines, DEMETER manages to explore completely

Yang, Junfeng

298

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

299

Automated detection of new or evolving melanocytic lesions using a 3D body model.  

PubMed

Detection of new or rapidly evolving melanocytic lesions is crucial for early diagnosis and treatment of melanoma. We propose a fully automated pre-screening system for detecting new lesions or changes in existing ones, on the order of 2 - 3mm, over almost the entire body surface. Our solution is based on a multi-camera 3D stereo system. The system captures 3D textured scans of a subject at different times and then brings these scans into correspondence by aligning them with a learned, parametric, non-rigid 3D body model. This means that captured skin textures are in accurate alignment across scans, facilitating the detection of new or changing lesions. The integration of lesion segmentation with a deformable 3D body model is a key contribution that makes our approach robust to changes in illumination and subject pose. PMID:25333167

Bogo, Federica; Romero, Javier; Peserico, Enoch; Black, Michael J

2014-01-01

300

Vertical leakage in sharp-interface seawater intrusion models of layered coastal aquifers  

NASA Astrophysics Data System (ADS)

Previous sharp-interface studies of seawater intrusion (SWI) adopt various approaches to the treatment of vertical fluxes in regions where alternating saltwater and freshwater are found in overlying aquifers. In this study, we compare dispersive modeling and sand-tank experiments to the results of sharp-interface models to evaluate assumptions regarding vertical fluxes in coastal multi-aquifer systems. The sand-tank experiments (one transient and two steady-state cases) consist of two coarse sand layers separated by a lower-permeability layer of fine sand. Vertical freshwater leakage in sharp-interface models is treated in one of three ways. Case 1: upward freshwater leakage flows only into freshwater in the aquifer above, bypassing any overlying saltwater; Case 2: no upward freshwater leakage occurs if there is overlying saltwater; Case 3: freshwater leaks into any overlying saltwater without modifying the saltwater salinity. Sharp-interface models over-predicted the toe position of the saltwater wedge in both the experiments and numerical models (regardless of the vertical leakage assumption), in agreement with previous studies. Nonetheless, Case 1 produced improved prediction of the sand-tank results relative to Cases 2 and 3. Freshwater leakage fluxes in areas where the interface was absent were reasonably well represented by all three sharp-interface leakage assumptions, compared to those of the dispersive model. In regions where saltwater overlies freshwater, the upward freshwater fluxes predicted by dispersive modeling were found to be consistently closest to the upward freshwater flux of Case 1, compared to Cases 2 and 3. Saltwater-to-saltwater leakages from the dispersive models were poorly represented by the sharp-interface models. Vertical flux assumptions were then evaluated for idealized field-scale situations, and Case 1 again best matched the dispersive modeling results. Streamlines from dispersive modeling show that upward freshwater leakage tends to flow around and bypass overlying saltwater. This matches optimally the assumption of Case 1. We conclude that Case 1 is the ideal approach to the treatment of upward freshwater fluxes in sharp-interface models of multiple-aquifer systems, whereas Cases 2 and 3 may create unrealistic SWI predictions, especially for situations where overlying aquifers are separated by a layer of low conductance.

Mehdizadeh, S. Sadjad; Werner, Adrian D.; Vafaie, Freydoon; Badaruddin, Sugiarto

2014-11-01

301

Aspects of automation mode confusion  

E-print Network

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

Wheeler, Paul H. (Paul Harrison)

2007-01-01

302

The Raise and Peel Model of a Fluctuating Interface  

NASA Astrophysics Data System (ADS)

We propose a one-dimensional nonlocal stochastic model of adsorption and desorption depending on one parameter, the adsorption rate. At a special value of this parameter, the model has some interesting features. For example, the spectrum is given by conformal field theory, and the stationary non-equilibrium probability distribution is given by the two-dimensional equilibrium distribution of the ice model with domain wall type boundary conditions. This connection is used to find exact analytic expressions for several quantities of the stochastic model. Vice versa, some understanding of the ice model with domain wall type boundary conditions can be obtained by the study of the stochastic model. At the special point we study several properties of the model, such as the height fluctuations as well as cluster and avalanche distributions. The latter has a long tail which shows that the model exhibits self organized criticality. We also find in the stationary state a special surface phase transition without enhancement and with a crossover exponent ?=2/3. Furthermore, we study the phase diagram of the model as a function of the adsorption rate and find two massive phases and a scale invariant phase where conformal invariance is broken.

de Gier, Jan; Nienhuis, Bernard; Pearce, Paul A.; Rittenberg, Vladimir

2004-01-01

303

Dynamic Distribution and Layouting of Model-Based User Interfaces in Smart Environments  

NASA Astrophysics Data System (ADS)

The developments in computer technology in the last decade change the ways of computer utilization. The emerging smart environments make it possible to build ubiquitous applications that assist users during their everyday life, at any time, in any context. But the variety of contexts-of-use (user, platform and environment) makes the development of such ubiquitous applications for smart environments and especially its user interfaces a challenging and time-consuming task. We propose a model-based approach, which allows adapting the user interface at runtime to numerous (also unknown) contexts-of-use. Based on a user interface modelling language, defining the fundamentals and constraints of the user interface, a runtime architecture exploits the description to adapt the user interface to the current context-of-use. The architecture provides automatic distribution and layout algorithms for adapting the applications also to contexts unforeseen at design time. Designers do not specify predefined adaptations for each specific situation, but adaptation constraints and guidelines. Furthermore, users are provided with a meta user interface to influence the adaptations according to their needs. A smart home energy management system serves as running example to illustrate the approach.

Roscher, Dirk; Lehmann, Grzegorz; Schwartze, Veit; Blumendorf, Marco; Albayrak, Sahin

304

Development of tangible user interface for linking context modeling and 3D map in smartphone  

Microsoft Academic Search

Their combined smartphone image processing, recognition and communication capabilities in a smartphone device make them an ideal platform for embedding computer vision in the pursuit of new mobile applications. This paper, we present a novel approach of collaborative interaction model combining tangible user interface and mobile augmented reality. This model is aware of a user's context through the user-centric integration

Jin-Suk Kang; Byeong-Hee Roh

2010-01-01

305

The Amulet Environment: New Models for Effective User Interface Software Development  

E-print Network

of the Amulet design is that all graphical objects and behaviors of those objects are explicitly represented. The undo model also supports new designs. The widgets are implemented in an open fashion using the Amulet­interactive, graphical user interface software for Unix, Windows or Macintosh. Amulet uses new models for objects

Myers, Brad A.

306

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

307

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

E-print Network

Three-Dimensional Modeling of Complex Fusion Devices Using CAD-MCNPX Interface Mengkuo Wang 1 , Timothy J. Tautges 2 , Douglass L. Henderson 3 , Laila El-Guebaly 4 , Xueren Wang 5 1 University, wang@fusion.ucsd.edu MCNPX's [1] geometric modeling capabilities are limited to Boolean combinations

California at San Diego, University of

308

A sketch on Sketch-Based Interfaces and Modeling. Leandro Moraes V. Cruz  

E-print Network

be manufactured. Some examples of modeling software, in this line, are AutoCAD and SolidWorks. Over time, besides, clothing, and other representations of objects and scenarios. In such cases, the aim of modeling). These applications are powerful and accurate, but they have com- plicated interfaces which increase the learning time

309

3D-2 Application of a Micromechanical Model to Wave Propagation Through Nonlinear Rough Interfaces Under Stress  

Microsoft Academic Search

Imperfect interfaces between two rough solids are known to exhibit nonlinear, anisotropic behavior under static normal and shear stresses. We expect this nonlinear, anisotropic behavior to have a profound effect on wave propagation through such interfaces. A micromechanical methodology is applied to explicitly model the initial normal and shear stiffness behavior of interfaces. The calculated initial normal and shear stiffness

Anil Misra; Orestes Marangos

2006-01-01

310

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

E-print Network

, building an interface between implant and bone regions. Microscopically, two interfaces canBone-cement interface micromechanical model under cyclic loading J.A. Sanz-Herrera1, a , H descubrimientos s/n 41092 Seville (Spain) a jsanz@us.es, b helgaem@gmail.com, c mpariza@us.es Keywords: Bone

Ariza Moreno, Pilar

311

Automated home cage assessment shows behavioral changes in a transgenic mouse model of spinocerebellar ataxia type 17.  

PubMed

Spinocerebellar Ataxia type 17 (SCA17) is an autosomal dominantly inherited, neurodegenerative disease characterized by ataxia, involuntary movements, and dementia. A novel SCA17 mouse model having a 71 polyglutamine repeat expansion in the TATA-binding protein (TBP) has shown age related motor deficit using a classic motor test, yet concomitant weight increase might be a confounding factor for this measurement. In this study we used an automated home cage system to test several motor readouts for this same model to confirm pathological behavior results and evaluate benefits of automated home cage in behavior phenotyping. Our results confirm motor deficits in the Tbp/Q71 mice and present previously unrecognized behavioral characteristics obtained from the automated home cage, indicating its use for high-throughput screening and testing, e.g. of therapeutic compounds. PMID:23665119

Portal, Esteban; Riess, Olaf; Nguyen, Huu Phuc

2013-08-01

312

Atomistic modeling of the Au droplet-GaAs interface for size-selective nanowire growth  

NASA Astrophysics Data System (ADS)

Density functional theory calculations within both the local density approximation and the generalized gradient approximation are used to study Au-catalyzed growth under near-equilibrium conditions. We discuss both the chemical equilibrium of a GaAs nanowire with an As2 gas atmosphere and the mechanical equilibrium between the capillary forces at the nanowire tip. For the latter goal, the interface between the gold nanoparticle and the nanowire is modeled atomically within a slab approach, and the interface energies are evaluated from the total energies of the model systems. We discuss three growth regimes, one catalyzed by an (almost) pure Au particle, an intermediate alloy-catalyzed growth regime, and a Ga-catalyzed growth regime. Using the interface energies calculated from the atomic models, as well as the surface energies of the nanoparticle and the nanowire sidewalls, we determine the optimized geometry of the nanoparticle-capped nanowire by minimizing the free energy of a continuum model. Under typical experimental conditions of 10-4 Pa As2 and 700 K, our results in the local density approximation are insensitive to the Ga concentration in the nanoparticle. In these growth conditions, the energetically most favored interface has an interface energy of around 45 meV/Å2, and the correspondingly optimized droplet on top of a GaAs nanowire is somewhat larger than a hemisphere and forms a contact angle around 130? for both pure Au and Au-Ga alloy nanoparticles.

Sakong, Sung; Du, Yaojun A.; Kratzer, Peter

2013-10-01

313

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

314

A Multilayered Sharp Interface Model of Coupled Freshwater and Saltwater Flow in Coastal Systems: Model Development and Application  

NASA Astrophysics Data System (ADS)

A quasi three-dimensional, finite difference model, that simulates freshwater and saltwater flow separated by a sharp interface, has been developed to study layered coastal aquifer systems. The model allows for regional simulation of coastal groundwater conditions, including the effects of saltwater dynamics on the freshwater system. Vertically integrated freshwater and saltwater flow equations incorporating the interface boundary condition are solved within each aquifer. Leakage through confining layers is calculated by Darcy's law, accounting for density differences across the layer. The locations of the interface tip and toe, within grid blocks, are tracked by linearly extrapolating the position of the interface. The model has been verified using available analytical solutions and experimental results. Application of the model to the Soquel-Aptos basin, Santa Cruz County, California, illustrates the use of the quasi three-dimensional, sharp interface approach for the examination of freshwater-saltwater dynamics in regional systems. Simulation suggests that the interface, today, is still responding to long-term Pleistocene sea level fluctuations and has not achieved equilibrium with present day sea level conditions.

Essaid, Hedeff I.

1990-07-01

315

SENSPECTRA : an elastic, strain-aware physical modeling interface  

E-print Network

Senspectra is a computationally augmented physical modeling toolkit designed for sensing and visualization of structural strain. The system functions as a distributed sensor network consisting of nodes, embedded with ...

Leclerc, Vincent, S.M. Massachusetts Institute of Technology

2006-01-01

316

Static Reservoir Model Upgridding and Design of User Interface  

E-print Network

calculations such that the heterogeneity measure of a defined static property is minimized within the layers. In addition, the geological model coarsening will also rely on preserving geological marker information. This combination of static calculation...

Du, Song

2011-02-22

317

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

318

Finite element analysis of thermal residual stresses at graded ceramic-metal interfaces. I - Model description and geometrical effects. II- Interface optimization for residual stress reduction  

Microsoft Academic Search

An elastic FEM numerical model for simulating residual stresses at graded ceramic-metal interfaces during cooling, which accounts for the effect of plasticity, was developed and used to investigate residual stresses at ceramic-metal graded and nongraded interfaces in Al2O3-Ni system. Specimen geometries were designed to provide information related to joining, coating, and thick-film applications. The results demonstrate the importance of accounting

R. L. Williamson; B. H. Rabin; J. T. Drake

1993-01-01

319

Smart Frameworks and Self-Describing Models: Model Metadata for Automated Coupling of Hydrologic Process Components (Invited)  

NASA Astrophysics Data System (ADS)

Model coupling frameworks like CSDMS (Community Surface Dynamics Modeling System) and ESMF (Earth System Modeling Framework) have developed mechanisms that allow heterogeneous sets of process models to be assembled in a plug-and-play manner to create composite "system models". These mechanisms facilitate code reuse, but must simultaneously satisfy many different design criteria. They must be able to mediate or compensate for differences between the process models, such as their different programming languages, computational grids, time-stepping schemes, variable names and variable units. However, they must achieve this interoperability in a way that: (1) is noninvasive, requiring only relatively small and isolated changes to the original source code, (2) does not significantly reduce performance, (3) is not time-consuming or confusing for a model developer to implement, (4) can very easily be updated to accommodate new versions of a given process model and (5) does not shift the burden of providing model interoperability to the model developers, e.g. by requiring them to provide their output in specific forms that meet the input requirements of other models. In tackling these design challenges, model framework developers have learned that the best solution is to provide each model with a simple, standardized interface, i.e. a set of standardized functions that make the model: (1) fully-controllable by a caller (e.g. a model framework) and (2) self-describing. Model control functions are separate functions that allow a caller to initialize the model, advance the model's state variables in time and finalize the model. Model description functions allow a caller to retrieve detailed information on the model's input and output variables, its computational grid and its timestepping scheme. If the caller is a modeling framework, it can compare the answers to these queries with similar answers from other process models in a collection and then automatically call framework service components as necessary to mediate the differences between the coupled models. This talk will first review two key products of the CSDMS project, namely a standardized model interface called the Basic Model Interface (BMI) and the CSDMS Standard Names. The standard names are used in conjunction with BMI to provide a semantic matching mechanism that allows output variables from one process model to be reliably used as input variables to other process models in a collection. They include not just a standardized naming scheme for model variables, but also a standardized set of terms for describing the attributes and assumptions of a given model. To illustrate the power of standardized model interfaces and metadata, a smart, light-weight modeling framework written in Python will be introduced that can automatically (without user intervention) couple a set of BMI-enabled hydrologic process components together to create a spatial hydrologic model. The same mechanisms could also be used to provide seamless integration (import/export) of data and models.

Peckham, S. D.

2013-12-01

320

A graphical user interface for numerical modeling of acclimation responses of vegetation to climate change  

NASA Astrophysics Data System (ADS)

Ecophysiological models that vertically resolve vegetation canopy states are becoming a powerful tool for studying the exchange of mass, energy, and momentum between the land surface and the atmosphere. A mechanistic multilayer canopy-soil-root system model (MLCan) developed by Drewry et al. (2010a) has been used to capture the emergent vegetation responses to elevated atmospheric CO2 for both C3 and C4 plants under various climate conditions. However, processing input data and setting up such a model can be time-consuming and error-prone. In this paper, a graphical user interface that has been developed for MLCan is presented. The design of this interface aims to provide visualization capabilities and interactive support for processing input meteorological forcing data and vegetation parameter values to facilitate the use of this model. In addition, the interface also provides graphical tools for analyzing the forcing data and simulated numerical results. The model and its interface are both written in the MATLAB programming language. Finally, an application of this model package for capturing the ecohydrological responses of three bioenergy crops (maize, miscanthus, and switchgrass) to local environmental drivers at two different sites in the Midwestern United States is presented.

Le, Phong V. V.; Kumar, Praveen; Drewry, Darren T.; Quijano, Juan C.

2012-12-01

321

Automated and reproducible read-across like models for predicting carcinogenic potency.  

PubMed

Several qualitative (hazard-based) models for chronic toxicity prediction are available through commercial and freely available software, but in the context of risk assessment a quantitative value is mandatory in order to be able to apply a Margin of Exposure (predicted toxicity/exposure estimate) approach to interpret the data. Recently quantitative models for the prediction of the carcinogenic potency have been developed, opening some hopes in this area, but this promising approach is currently limited by the fact that the proposed programs are neither publically nor commercially available. In this article we describe how two models (one for mouse and one for rat) for the carcinogenic potency (TD50) prediction have been developed, using lazar (Lazy Structure Activity Relationships), a procedure similar to read-across, but automated and reproducible. The models obtained have been compared with the recently published ones, resulting in a similar performance. Our aim is also to make the models freely available in the near future thought a user friendly internet web site. PMID:25047023

Lo Piparo, Elena; Maunz, Andreas; Helma, Christoph; Vorgrimmler, David; Schilter, Benoît

2014-10-01

322

Modelling, Formality and the PhoneticsPhonology Interface Julian Bradfield  

E-print Network

predictions about reality; and the sciences of artificial systems, such as software design and verification of formal models. A pitfall common in the `artificial' sciences is `throwing the baby out with the bathwater': in the necessary process of abstracting to a level that one can deal with formally, one accidentally defines away

Bradfield, Julian

323

The Need for an Interaction Cost Model in Adaptive Interfaces  

E-print Network

Experiment · Direction, Size, Opacity, Proximity, Intersection · Task completion time · 12 participants 14;Model of Occlusion Opacity Blocked Overlap Frustration Cost of Occlusion 16 #12;Objective Occlusion Function · Overlap = f(Blocked, Opacity) · Blocked=0: · overlap = constant · Blocked=1: · Cubic in Opacity

324

The impact of acceleration\\/deceleration on travel-time models for automated storage\\/retrieval systems  

Microsoft Academic Search

In this note we propose a travel-time model of automated storage\\/retrieval (S\\/R) machines by considering the speed profiles that exist in real-world applications. Compact forms of expected travel-times under randomized storage conditions have been determined for both single and dual command cycles.

DING-TSAIR CHANG; UE-PYNG WEN; JAMES T. LIN

1995-01-01

325

A Method and Tool Support for Model-based Semi-automated Failure Modes and Effects Analysis of Engineering Designs  

E-print Network

: model-based FMEA, fault tree synthesis, steer- by-wire systems, automated safety analysis. 1 earlier work on fault tree synthesis. The tool constructs FMEAs from engineering diagrams (e.g. developed FMEA, the tool first generates a "forest" of interconnected system fault trees by traversing the system

Papadopoulos, Yiannis

326

Laboratory measurements and theoretical modeling of seismoelectric interface response and coseismic wave fields  

SciTech Connect

A full-waveform seismoelectric numerical model incorporating the directivity pattern of a pressure source is developed. This model provides predictions of coseismic electric fields and the electromagnetic waves that originate from a fluid/porous-medium interface. An experimental setup in which coseismic electric fields and interface responses are measured is constructed. The seismo-electric origin of the signals is confirmed. The numerically predicted polarity reversal of the interfacial signal and seismoelectric effects due to multiple scattering are detected in the measurements. Both the simulated coseismic electric fields and the electromagnetic waves originating from interfaces agree with the measurements in terms of travel times, waveform, polarity, amplitude, and spatial amplitude decay, demonstrating that seismoelectric effects are comprehensively described by theory.

Schakel, M. D.; Slob, E. C.; Heller, H. K. J. [Department of Geotechnology, Delft University of Technology, PO Box 5048, 2600 GA, Delft (Netherlands); Smeulders, D. M. J. [Department of Geotechnology, Delft University of Technology, PO Box 5048, 2600 GA, Delft (Netherlands); Department of Mechanical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB, Eindhoven (Netherlands)

2011-04-01

327

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. In the common case that the equations for interface and flow are coupled explicitly, we find a time step restriction which is very different to other two-phase flow models and in particular is independent of the grid size. We also show that the proposed stabilization techniques can lift this time step restriction. Even more pronounced is the performance of the proposed fully implicit scheme which is stable for arbitrarily large time steps. We demonstrate in a Taylor-flow application that this superior coupling between flow and interface equation can decrease the computation time by several orders of magnitude.

Aland, Sebastian

2014-04-01

328

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

329

Automated Geospatial Watershed Assessment  

EPA Science Inventory

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

330

Diffuse interface models of locally inextensible vesicles in a viscous fluid  

NASA Astrophysics Data System (ADS)

We present a new diffuse interface model for the dynamics of inextensible vesicles in a viscous fluid with inertial forces. A new feature of this work is the implementation of the local inextensibility condition in the diffuse interface context. Local inextensibility is enforced by using a local Lagrange multiplier, which provides the necessary tension force at the interface. We introduce a new equation for the local Lagrange multiplier whose solution essentially provides a harmonic extension of the multiplier off the interface while maintaining the local inextensibility constraint near the interface. We also develop a local relaxation scheme that dynamically corrects local stretching/compression errors thereby preventing their accumulation. Asymptotic analysis is presented that shows that our new system converges to a relaxed version of the inextensible sharp interface model. This is also verified numerically. To solve the equations, we use an adaptive finite element method with implicit coupling between the Navier-Stokes and the diffuse interface inextensibility equations. Numerical simulations of a single vesicle in a shear flow at different Reynolds numbers demonstrate that errors in enforcing local inextensibility may accumulate and lead to large differences in the dynamics in the tumbling regime and smaller differences in the inclination angle of vesicles in the tank-treading regime. The local relaxation algorithm is shown to prevent the accumulation of stretching and compression errors very effectively. Simulations of two vesicles in an extensional flow show that local inextensibility plays an important role when vesicles are in close proximity by inhibiting fluid drainage in the near contact region.

Aland, Sebastian; Egerer, Sabine; Lowengrub, John; Voigt, Axel

2014-11-01

331

Applying Meta-Modeling for the Definition of Model-Driven Development Methods of Advanced User Interfaces  

NASA Astrophysics Data System (ADS)

The user interfaces of interactive systems become increasingly complex due to new interaction paradigms, required adaptability, use of innovative technologies, multi-media and interaction modalities. Their development thus demands for sophisticated processes and methods, as they are deployed in software engineering. Model-driven development is a promising candidate for mastering the complex development task in a systematic, precise and appropriately formal way. Although diverse models of advanced user interfaces are deployed in a development process to specify, design and implement the user interface, it is not standardized which models to use, how to combine them, and how to proceed in the course of development. Rather, this has to be defined by methods in the context of organizations, domains, projects. To cope with the definition of model-driven development methods for advanced user interfaces, we propose a meta-method for method engineering. It can be used for modeling and tailoring such development methods. We show how to apply this meta-method for designing development methods in the domain of advanced user interfaces.

Sauer, Stefan

332

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

333

Automated method for modeling seven-helix transmembrane receptors from experimental data.  

PubMed Central

A rule-based automated method is presented for modeling the structures of the seven transmembrane helices of G-protein-coupled receptors. The structures are generated by using a simulated annealing Monte Carlo procedure that positions and orients rigid helices to satisfy structural restraints. The restraints are derived from analysis of experimental information from biophysical studies on native and mutant proteins, from analysis of the sequences of related proteins, and from theoretical considerations of protein structure. Calculations are presented for two systems. The method was validated through calculations using appropriate experimental information for bacteriorhodopsin, which produced a model structure with a root mean square (rms) deviation of 1.87 A from the structure determined by electron microscopy. Calculations are also presented using experimental and theoretical information available for bovine rhodopsin to assign the helices to a projection density map and to produce a model of bovine rhodopsin that can be used as a template for modeling other G-protein-coupled receptors. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 8 FIGURE 11 PMID:8599649

Herzyk, P; Hubbard, R E

1995-01-01

334

CIMplementation™: Evaluating Manufacturing Automation  

E-print Network

or computer may perform an individual operation better than humanly pos sible, we must consider two major implications of installing these automation tools in industry. First, it is easier to plan an automated facility than to install and operate one.... The key featu res of thi s model are the degree of automation made pps sible by the computer, the flexibility of'the system, and the common database which will permit integration of information. 3.0 CHANGES IN MANUFACTURING RESULTING F...

Krakauer, J.

335

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

336

Self-Observation Model Employing an Instinctive Interface for Classroom Active Learning  

ERIC Educational Resources Information Center

In a classroom, obtaining active, whole-focused, and engaging learning results from a design is often difficult. In this study, we propose a self-observation model that employs an instinctive interface for classroom active learning. Students can communicate with virtual avatars in the vertical screen and can react naturally according to the…

Chen, Gwo-Dong; Nurkhamid; Wang, Chin-Yeh; Yang, Shu-Han; Chao, Po-Yao

2014-01-01

337

P300 based brain-computer interface using Hidden Markov Models  

Microsoft Academic Search

This paper reports on preliminary work on the use of hidden Markov models (HMMs) approach for tasks classification in P300-based brain-computer interface (BCI) system. Every HMM is trained on a set of electroencephalogram (EEG) records issued from different sessions corresponding to the same task. The HMMs that has been built take into account the variability of EEGs during different sessions.

Salah Helmy; Tarik Al-ani; Yskandar Hamam; Essam El-madbouly

2008-01-01

338

Medical palpation of deformable tissue using physics-based model for haptic interface robot (HIRO)  

Microsoft Academic Search

Medical education has a strong need for palpation training. Haptic sense is indispensable for the detection of subsurface tumor. A virtual reality (VR) training for breast palpation simulation was created utilizing the newly designed multi-fingered haptic interface robot (HIRO). The simulation allows the user to perform breast palpation. A realistic model of the breast was developed and a physically based

Vytautas Daniulaitis; M. Osama Alhalabi; Haruhisa Kawasaki; Yuji Tanaka

2004-01-01

339

Modeling fractures as interfaces for flow and transport in porous media  

E-print Network

Modeling fractures as interfaces for flow and transport in porous media Clarisse Alboin J´er^ome Jaffr´e Jean E. Roberts Christophe Serres § September 10, 2001 Abstract Fractures in a porous medium into account interaction between the fracture and the surrounding rock. We proved existence and uniqueness

340

Point process modeling on decoding and encoding for Brain Machine Interfaces  

Microsoft Academic Search

Point process modeling has the potential to capture the specificity of neural firing where the information is contained in the spike time occurrence. We aim at building an adaptive signal processing framework for brain machine interfaces working directly in the spike domain. However, the signal processing tools for continuous stochastic processes faces challenge when implemented directly on point processes. Under

Yiwen Wang; Jose C. Principe

2009-01-01

341

Using Cognitive Models to Transfer the Strengths of Computer Games into Human Computer Interfaces  

E-print Network

can apply successful features of computer games to support other forms of human computer interaction1 Using Cognitive Models to Transfer the Strengths of Computer Games into Human Computer Interfaces into the motivational appeal that often distinguishes computer games from other forms of human computer interaction

Johnson, Chris

342

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

343

An Interface for Targeted Collection of Common Sense Knowledge Using a Mixture Model  

E-print Network

the throughput of new knowledge when interacting with a user. The symbiotic relationship between user interfaces and acquisition. Author Keywords Common sense reasoning, human computation, hierarchical Bayes model, knowledge of information about the world that human users take for granted. This information, which people often take

Herr, Hugh

344

Developing a user-centered mobile service interface based on a cognitive model of attention allocation  

E-print Network

by the driver at all times. This poses on the one hand a large challenge to designers and developers of in-carDeveloping a user-centered mobile service interface based on a cognitive model of attention sometimes even against legal restriction - e.g. in the car. Services running on these devices (e.g. email

Boyer, Edmond

345

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

E-print Network

Outline Modeling primary atomization and interface evaporation in turbulent two-phase flows Simulation of Primary Atomization 3 Asymptotic Analysis 4 Summary #12;Outline Outline 1 Introduction 2 Simulation of Primary Atomization 3 Asymptotic Analysis 4 Summary #12;Outline Outline 1 Introduction 2

Helluy, Philippe

346

The integrity of welded interfaces in ultra high molecular weight polyethylene: Part 1-Model.  

PubMed

The difficulty of eradicating memory of powder-particle interfaces in UHMWPE for bearing surfaces for hip and knee replacements is well-known, and 'fusion defects' have been implicated frequently in joint failures. During processing the polymer is formed into solid directly from the reactor powder, under pressure and at temperatures above the melting point, and two types of inter-particle defect occur: Type 1 (consolidation-deficient) and Type 2 (diffusion-deficient). To gain quantitative information on the extent of the problem, the formation of macroscopic butt welds in this material was studied, by (1) modelling the process and (2) measuring experimentally the resultant evolution of interface toughness. This paper reports on the model. A quantitative measure of interface structural integrity is defined, and related to the "maximum reptated molecular weight" introduced previously. The model assumes an idealised surface topography. It is used to calculate the evolution of interface integrity during welding, for given values of temperature, pressure, and parameters describing the surfaces, and a given molar mass distribution. Only four material properties are needed for the calculation; all of them available for polyethylene. The model shows that, for UHMWPE typically employed in knee transplants, the rate of eradication of Type 1 defects is highly sensitive to surface topography, process temperature and pressure. Also, even if Type 1 defects are prevented, Type 2 defects heal extremely slowly. They must be an intrinsic feature of UHMWPE for all reasonable forming conditions, and products and forming processes should be designed accordingly. PMID:16490249

Buckley, C Paul; Wu, Junjie; Haughie, David W

2006-06-01

347

Of Men, Women, and Computers: Data-Driven Gender Modeling for Improved User Interfaces  

E-print Network

Of Men, Women, and Computers: Data-Driven Gender Modeling for Improved User Interfaces Hugo Liu Massachusetts Institute of Technology hugo@media.mit.edu Rada Mihalcea University of North Texas rada@cs.unt.edu Abstract Men and women have unique sensibilities for information, which can be tapped to create gender

Mihalcea, Rada

348

inTouch: Interactive Multiresolution Modeling and 3D Painting with a Haptic Interface  

E-print Network

by an artist using (semi-) automatic digitizing systems. One of the limitations of existing commercial modeling- ple VR interfaces for selection and movement rather than on force-feedback devices. In the last fewAble Technologies [Mas98]. Though its ability to feel the ob- jects while placing or adding new objects provides

North Carolina at Chapel Hill, University of

349

Automated inter-model parameter connection synthesis for simulation model integration  

E-print Network

New simulation modeling environments have been developed such that multiple models can be integrated into a single model. This conglomeration of model data allows designers to better understand the physical phenomenon being ...

Ligon, Thomas (Thomas Crumrine)

2007-01-01

350

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

Microsoft Academic Search

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

Meng Wang; Xiaobo Zhou; Randy W. King; Stephen T. C. Wong

2007-01-01

351

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

352

Evaluation of Automated Model Calibration Techniques for Residential Building Energy Simulation  

SciTech Connect

This simulation study adapts and applies the general framework described in BESTEST-EX (Judkoff et al 2010) for self-testing residential building energy model calibration methods. BEopt/DOE-2.2 is used to evaluate four mathematical calibration methods in the context of monthly, daily, and hourly synthetic utility data for a 1960's-era existing home in a cooling-dominated climate. The home's model inputs are assigned probability distributions representing uncertainty ranges, random selections are made from the uncertainty ranges to define 'explicit' input values, and synthetic utility billing data are generated using the explicit input values. The four calibration methods evaluated in this study are: an ASHRAE 1051-RP-based approach (Reddy and Maor 2006), a simplified simulated annealing optimization approach, a regression metamodeling optimization approach, and a simple output ratio calibration approach. The calibration methods are evaluated for monthly, daily, and hourly cases; various retrofit measures are applied to the calibrated models and the methods are evaluated based on the accuracy of predicted savings, computational cost, repeatability, automation, and ease of implementation.

Robertson, J.; Polly, B.; Collis, J.

2013-09-01

353

Microwave landing system modeling with application to air traffic control automation  

NASA Technical Reports Server (NTRS)

Compared to the current instrument landing system, the microwave landing system (MLS), which is in the advanced stage of implementation, can potentially provide significant fuel and time savings as well as more flexibility in approach and landing functions. However, the expanded coverage and increased accuracy requirements of the MLS make it more susceptible to the features of the site in which it is located. An analytical approach is presented for evaluating the multipath effects of scatterers that are commonly found in airport environments. The approach combines a multiplane model with a ray-tracing technique and a formulation for estimating the electromagnetic fields caused by the antenna array in the presence of scatterers. The model is applied to several airport scenarios. The reduced computational burden enables the scattering effects on MLS position information to be evaluated in near real time. Evaluation in near real time would permit the incorporation of the modeling scheme into air traffic control automation; it would adaptively delineate zones of reduced accuracy within the MLS coverage volume, and help establish safe approach and takeoff trajectories in the presence of uneven terrain and other scatterers.

Poulose, M. M.

1992-01-01

354

Towards Automated Bargaining in Electronic Markets: A Partially Two-Sided Competition Model  

NASA Astrophysics Data System (ADS)

This paper focuses on the prominent issue of automating bargaining agents within electronic markets. Models of bargaining in literature deal with settings wherein there are only two agents and no model satisfactorily captures settings in which there is competition among buyers, being they more than one, and analogously among sellers. In this paper, we extend the principal bargaining protocol, i.e. the alternating-offers protocol, to capture bargaining in markets. The model we propose is such that, in presence of a unique buyer and a unique seller, agents' equilibrium strategies are those in the original protocol. Moreover, we game theoretically study the considered game providing the following results: in presence of one-sided competition (more buyers and one seller or vice versa) we provide agents' equilibrium strategies for all the values of the parameters, in presence of two-sided competition (more buyers and more sellers) we provide an algorithm that produce agents' equilibrium strategies for a large set of the parameters and we experimentally evaluate its effectiveness.

Gatti, Nicola; Lazaric, Alessandro; Restelli, Marcello

355

Automated multi-body system dynamics via bond graph modelling and interactive graphics  

NASA Astrophysics Data System (ADS)

For all but the simplest multi-body systems, it is necessary to solve the kinematics and dynamics by computer simulation. The development of algorithms for automating the modelling process for general multi-body systems via the bond graph formalism and the implementaion of these algorithms in a computer program for multi-body dynamical analysis and simulation are discussed. The program, which is implemented to operate in the Sun Suntools environment, encompasses the entire range of operations required for analyzing multi-body systems, from interpretation of a physical model description, through the bond graph representation, to the determination and presentation of results. Interactive graphics, automatic bond graph generation, automatic graph indexing, power flow, and casual assignment are employed to generate the equations of motion for a wide range of mechanical systems. Equations of motion are written in advanced continuous simulation language (ACSL) format, so that solution of these equations of motion can be carried out in a convenient fashion. The program was used to model and study the kinematic and dynamic behavior of robotic manipulators and is being employed in the analysis of other multi-body systems.

McInnis, J. B.; Elmaraghy, W. H.

1989-05-01

356

Automated Geometric Model Builder Using Range Image Sensor Data: Final Acquistion  

SciTech Connect

This report documents a data collection where we recorded redundant range image data from multiple views of a simple scene, and recorded accurate survey measurements of the same scene. Collecting these data was a focus of the research project Automated Geometric Model Builder Using Range Image Sensor Data (96-0384), supported by Sandia's Laboratory-Directed Research and Development (LDRD) Program during fiscal years 1996, 1997, and 1998. The data described here are available from the authors on CDROM, or electronically over the Internet. Included in this data distribution are Computer-Aided Design (CAD) models we constructed from the survey measurements. The CAD models are compatible with the SolidWorks 98 Plus system, the modern Computer-Aided Design software system that is central to Sandia's DeskTop Engineering Project (DTEP). Integration of our measurements (as built) with the constructive geometry process of the CAD system (as designed) delivers on a vision of the research project. This report on our final data collection will also serve as a final report on the project.

Diegert, C.; Sackos, J.

1999-02-01

357

Interface tension of the 3d 4-state Potts model using the Wang-Landau algorithm  

E-print Network

We study the interface tension of the 4-state Potts model in three dimensions using the Wang- Landau algorithm. The interface tension is given by the ratio of the partition function with a twisted boundary condition in one direction and periodic boundary conditions in all other directions over the partition function with periodic boundary conditions in all directions. With the Wang-Landau algorithm we can explicitly calculate both partition functions and obtain the result for all temperatures. We find solid numerical evidence for perfect wetting. Our algorithm is tested by calculating thermodynamic quantities at the phase transition point.

A. Hietanen; B. Lucini

2011-11-21

358

Molecular modeling of the green leaf volatile methyl salicylate on atmospheric air/water interfaces.  

PubMed

Methyl salicylate (MeSA) is a green leaf volatile (GLV) compound that is emitted in significant amounts by plants, especially when they are under stress conditions. GLVs can then undergo chemical reactions with atmospheric oxidants, yielding compounds that contribute to the formation of secondary organic aerosols (SOAs). We investigated the adsorption of MeSA on atmospheric air/water interfaces at 298 K using thermodynamic integration (TI), potential of mean force (PMF) calculations, and classical molecular dynamics (MD) simulations. Our molecular models can reproduce experimental results of the 1-octanol/water partition coefficient of MeSA. A deep free energy minimum was found for MeSA at the air/water interface, which is mainly driven by energetic interactions between MeSA and water. At the interface, the oxygenated groups in MeSA tend to point toward the water side of the interface, with the aromatic group of MeSA lying farther away from water. Increases in the concentrations of MeSA lead to reductions in the height of the peaks in the MeSA-MeSA g(r) functions, a slowing down of the dynamics of both MeSA and water at the interface, and a reduction in the interfacial surface tension. Our results indicate that MeSA has a strong thermodynamic preference to remain at the air/water interface, and thus chemical reactions with atmospheric oxidants are more likely to take place at this interface, rather than in the water phase of atmospheric water droplets or in the gas phase. PMID:23668770

Liyana-Arachchi, Thilanga P; Hansel, Amie K; Stevens, Christopher; Ehrenhauser, Franz S; Valsaraj, Kalliat T; Hung, Francisco R

2013-05-30

359

Modeling a Shock-Accelerated Fluid - Multiphase Fluid Interface  

NASA Astrophysics Data System (ADS)

The hydrocode SHAMRC has been used in the past to study the formation and growth of the Richtmyer Meshkov Instability (RMI). While RMI involves impulsively accelerating two continuous fluids of differing densities, a similar class of instabilities has been recently described for multiphase flow. In this scenario, a shock wave passes through a region seeded with particles which have a non-trivial mass and density much greater than that of the surrounding and embedding fluid, resulting in a higher effective density in the seeded region. As the volume of the particles is small, there is no pressure gradient between the two regions. The simulations described here attempt to model the first order formation and growth phenomenon of this new class of instability by approximating the second phase as a continuous fluid with an averaged density. The strength of the shock and the packing density of the tracer particles are varied to provide a wide range of instability growth rates. Finally, these growth rates are scaled and compared to experimental data.

Anderson, Michael; Conroy, Joseph; Truman, C. Randall; Vorobieff, Peter; Kumar, Sanjay

2010-11-01

360

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

361

Modeling Rayleigh and Stoneley waves and other interface and boundary effects with the parabolic equation.  

PubMed

An improved approach for handling boundaries, interfaces, and continuous depth dependence with the elastic parabolic equation is derived and benchmarked. The approach is applied to model the propagation of Rayleigh and Stoneley waves. Depending on the choice of dependent variables, the operator in the elastic wave equation may not factor or the treatment of interfaces may be difficult. These problems are resolved by using a formulation in terms of the vertical displacement and the range derivative of the horizontal displacement. These quantities are continuous across horizontal interfaces, which permits the use of Galerkin's method to discretize in depth. This implementation extends the capability of the elastic parabolic equation to handle arbitrary depth dependence and should lead to improvements for range-dependent problems. PMID:16018454

Jerzak, Wayne; Siegmann, William L; Collins, Michael D

2005-06-01

362

Modeling Rayleigh and Stoneley waves and other interface and boundary effects with the parabolic equation  

NASA Astrophysics Data System (ADS)

An improved approach for handling boundaries, interfaces, and continuous depth dependence with the elastic parabolic equation is derived and benchmarked. The approach is applied to model the propagation of Rayleigh and Stoneley waves. Depending on the choice of dependent variables, the operator in the elastic wave equation may not factor or the treatment of interfaces may be difficult. These problems are resolved by using a formulation in terms of the vertical displacement and the range derivative of the horizontal displacement. These quantities are continuous across horizontal interfaces, which permits the use of Galerkin's method to discretize in depth. This implementation extends the capability of the elastic parabolic equation to handle arbitrary depth dependence and should lead to improvements for range-dependent problems. .

Jerzak, Wayne; Siegmann, William L.; Collins, Michael D.

2005-06-01

363

Perturbative approach to the structure of a planar interface in the Landau-de Gennes model.  

PubMed

The structure of nearly static planar interfaces is studied within the framework of the Landau-de Gennes model with the dynamics governed by the time-dependent Ginzburg-Landau equation. To account for the full elastic anisotropy the free energy expansion is extended to include a third order gradient term. The solutions corresponding to the in-plane or homeotropic director alignment at the interface are sought. For this purpose a consistent perturbative scheme is constructed which enables one to calculate successive corrections to the velocity and the order parameter of the interface. The implications of the solutions are discussed. The elastic anisotropy introduces asymmetry into the order parameter and free energy profiles, even for the high symmetry homeotropic configuration. The velocity of the interface with the homeotropic or in-plane alignment is enhanced or reduced, respectively. There is no reorientation of the optical axis in the boundary layer. For the class of nematogens with approximate splay-bend degeneracy the temperature dependence of the interface velocity is weakly affected by the remaining twist anisotropy. PMID:17155076

Pe?ka, Robert; Saito, Kazuya

2006-10-01

364

Non-Redundant Unique Interface Structures as Templates for Modeling Protein Interactions  

PubMed Central

Improvements in experimental techniques increasingly provide structural data relating to protein-protein interactions. Classification of structural details of protein-protein interactions can provide valuable insights for modeling and abstracting design principles. Here, we aim to cluster protein-protein interactions by their interface structures, and to exploit these clusters to obtain and study shared and distinct protein binding sites. We find that there are 22604 unique interface structures in the PDB. These unique interfaces, which provide a rich resource of structural data of protein-protein interactions, can be used for template-based docking. We test the specificity of these non-redundant unique interface structures by finding protein pairs which have multiple binding sites. We suggest that residues with more than 40% relative accessible surface area should be considered as surface residues in template-based docking studies. This comprehensive study of protein interface structures can serve as a resource for the community. The dataset can be accessed at http://prism.ccbb.ku.edu.tr/piface. PMID:24475173

Cukuroglu, Engin; Gursoy, Attila; Nussinov, Ruth; Keskin, Ozlem

2014-01-01

365

Modeling the electrode-electrolyte interface for recording and stimulating electrodes.  

PubMed

The design of metal microelectrodes that produce minimal damage to tissue and can successfully record from and stimulate targeted neural structures necessitates a thorough understanding of the electrical phenomena generated in the tissue surrounding the electrodes. Computational modeling has been a primary strategy used to study these phenomena, and the Finite Element Method has proven to be a powerful approach. Much research has been directed toward the development of models for electrode recording and stimulation, but very few models reported in the literature thus far incorporate the effects of the electrode-electrolyte interface, which can be a source of very high impedance, and thus likely a key component of the system. To explore the effects that the electrode-electrolyte interface has upon the electric potential and current density surrounding metal microelectrodes, simulations of electrode-saline systems in which the electrodes were driven at AC potentials ranging from 10 mV to 500 mV and frequencies of 100 Hz to 10 kHz have been performed using the Finite Element Method. Solutions obtained using the thin layer approximation for the electrode-electrolyte interface was compared with those generated using a thin uniform layer, a representation that has previously appeared in the literature. Solutions using these two methods were similar in the linear regime of the interface however, the thin layer approximation has important advantages over its competitor including ease of application and low computational cost. PMID:17945606

Troy, John B; Cantrell, Donald R; Taflove, Allen; Ruoff, Rodney S

2006-01-01

366

Coulomb frictional interfaces in modeling cemented total hip replacements: A more realistic model  

Microsoft Academic Search

Loosening of cemented femoral hip stems could be initiated by failure of the cement mantle due to high cement stresses. The goals of this study were to determine if realistic stem-cement interface characteristics could result in high cement stresses when compared to a bonded stem-cement interface and to determine if stem design parameters could be chosen to reduce peak cement

K. A. Mann; D. L. Bartel; T. M. Wright; A. H. Burstein

1995-01-01

367

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

368

Modeling the interface of Li metal and Li solid electrolytes from first principles Nicholas Lepley, N. A. W. Holzwarth  

E-print Network

Modeling the interface of Li metal and Li solid electrolytes from first principles Nicholas Lepley battery electrolytes. Simplified theoretical models often fail to agree with experimental observations of the stability of electrode electrolyte interfaces. An example of this disagreement is the thiophosphate

Holzwarth, Natalie

369

An elasto-viscoplastic interface model for investigating the constitutive behavior of nacre  

NASA Astrophysics Data System (ADS)

In order to better understand the strengthening mechanism observed in nacre, we have developed an interface computational model to simulate the behavior of the organic present at the interface between aragonite tablets. In the model, the single polymer-chain behavior is characterized by the worm-like-chain (WLC) model, which is in turn incorporated into the eight-chain cell model developed by Arruda and Boyce [Arruda, E.M., Boyce, M.C., 1993a. A three-dimensional constitutive model for the large stretches, with application to polymeric glasses. Int. J. Solids Struct. 40, 389-412] to achieve a continuum interface constitutive description. The interface model is formulated within a finite-deformation framework. A fully implicit time-integration algorithm is used for solving the discretized governing equations. Finite element simulations were performed on a representative volume element (RVE) to investigate the tensile response of nacre. The staggered arrangement of tablets and interface waviness obtained experimentally by Barthelat et al. [Barthelat, F., Tang, H., Zavattieri, P.D., Li, C.-M., Espinosa, H.D., 2007. On the mechanics of mother-of-pearl: a key feature in the material hierarchical structure. J. Mech. Phys. Solids 55 (2), 306-337] was included in the RVE simulations. The simulations showed that both the rate-dependence of the tensile response and hysteresis loops during loading, unloading and reloading cycles were captured by the model. Through a parametric study, the effect of the polymer constitutive response during tablet-climbing and its relation to interface hardening was investigated. It is shown that stiffening of the organic material is not required to achieve the experimentally observed strain hardening of nacre during tension. In fact, when ratios of contour length/persistent length experimentally identified are employed in the simulations, the predicted stress-strain behavior exhibits a deformation hardening consistent with the one measured experimentally and also captured by the phenomenological cohesive model used in the study carried out by Barthelat et al. [Barthelat, F., Tang, H., Zavattieri, P.D., Li, C.-M., Espinosa, H.D., 2007. On the mechanics of mother-of-pearl: a key feature in the material hierarchical structure. J. Mech. Phys. Solids 55 (2), 306-337]. The simulation results also reveal that the bulk modulus of the polymer controls the rate of hardening, feature not captured by more simple cohesive laws.

Tang, H.; Barthelat, F.; Espinosa, H. D.

2007-07-01

370

Fully automated segmentation of oncological PET volumes using a combined multiscale and statistical model  

SciTech Connect

The widespread application of positron emission tomography (PET) in clinical oncology has driven this imaging technology into a number of new research and clinical arenas. Increasing numbers of patient scans have led to an urgent need for efficient data handling and the development of new image analysis techniques to aid clinicians in the diagnosis of disease and planning of treatment. Automatic quantitative assessment of metabolic PET data is attractive and will certainly revolutionize the practice of functional imaging since it can lower variability across institutions and may enhance the consistency of image interpretation independent of reader experience. In this paper, a novel automated system for the segmentation of oncological PET data aiming at providing an accurate quantitative analysis tool is proposed. The initial step involves expectation maximization (EM)-based mixture modeling using a k-means clustering procedure, which varies voxel order for initialization. A multiscale Markov model is then used to refine this segmentation by modeling spatial correlations between neighboring image voxels. An experimental study using an anthropomorphic thorax phantom was conducted for quantitative evaluation of the performance of the proposed segmentation algorithm. The comparison of actual tumor volumes to the volumes calculated using different segmentation methodologies including standard k-means, spatial domain Markov Random Field Model (MRFM), and the new multiscale MRFM proposed in this paper showed that the latter dramatically reduces the relative error to less than 8% for small lesions (7 mm radii) and less than 3.5% for larger lesions (9 mm radii). The analysis of the resulting segmentations of clinical oncologic PET data seems to confirm that this methodology shows promise and can successfully segment patient lesions. For problematic images, this technique enables the identification of tumors situated very close to nearby high normal physiologic uptake. The use of this technique to estimate tumor volumes for assessment of response to therapy and to delineate treatment volumes for the purpose of combined PET/CT-based radiation therapy treatment planning is also discussed.

Montgomery, David W. G.; Amira, Abbes; Zaidi, Habib [School of Electronics, Electrical Engineering and Computer Science, ECIT, The Queen's University of Belfast, Belfast, Northern Ireland (United Kingdom); School of Engineering and Design, Brunel University, London, Uxbridge (United Kingdom); Division of Nuclear Medicine, Geneva University Hospital, CH-1211 Geneva 4 (Switzerland)

2007-02-15

371

Interfacing MATLAB and Python Optimizers to Black-Box Environmental Simulation Models  

NASA Astrophysics Data System (ADS)

A common approach for utilizing environmental models in a management or policy-analysis context is to incorporate them into a simulation-optimization framework - where an underlying process-based environmental model is linked with an optimization search algorithm. The optimization search algorithm iteratively adjusts various model inputs (i.e. parameters or design variables) in order to minimize an application-specific objective function computed on the basis of model outputs (i.e. response variables). Numerous optimization algorithms have been applied to the simulation-optimization of environmental systems and this research investigated the use of optimization libraries and toolboxes that are readily available in MATLAB and Python - two popular high-level programming languages. Inspired by model-independent calibration codes (e.g. PEST and UCODE), a small piece of interface software (known as PIGEON) was developed. PIGEON allows users to interface Python and MATLAB optimizers with arbitrary black-box environmental models without writing any additional interface code. An initial set of benchmark tests (involving more than 20 MATLAB and Python optimization algorithms) were performed to validate the interface software - results highlight the need to carefully consider such issues as numerical precision in output files and enforcement (or not) of parameter limits. Additional benchmark testing considered the problem of fitting isotherm expressions to laboratory data - with an emphasis on dual-mode expressions combining non-linear isotherms with a linear partitioning component. With respect to the selected isotherm fitting problems, derivative-free search algorithms significantly outperformed gradient-based algorithms. Attempts to improve gradient-based performance, via parameter tuning and also via several alternative multi-start approaches, were largely unsuccessful.

Matott, L. S.; Leung, K.; Tolson, B.

2009-12-01

372

Interaction of IAPP and Insulin with Model Interfaces Studied Using Neutron Reflectometry  

PubMed Central

The islet amyloid polypeptide (IAPP) and insulin are coproduced by the ?-cells of the pancreatic islets of Langerhans. Both peptides can interact with negatively charged lipid membranes. The positively charged islet amyloid polypeptide partially inserts into these membranes and subsequently forms amyloid fibrils. The amyloid fibril formation of insulin is also accelerated by the presence of negatively charged lipids, although insulin has a negative net charge at neutral pH-values. We used water-polymer model interfaces to differentiate between the hydrophobic and electrostatic interactions that can drive these peptides to adsorb at an interface. By applying neutron reflectometry, the scattering-length density profiles of IAPP and insulin, as adsorbed at three different water-polymer interfaces, were determined. The islet amyloid polypeptide most strongly adsorbed at a hydrophobic poly-(styrene) surface, whereas at a hydrophilic, negatively charged poly-(styrene sulfonate) interface, the degree of adsorption was reduced by 50%. Almost no IAPP adsorption was evident at this negatively charged interface when we added 100 mM NaCl. On the other hand, negatively charged insulin was most strongly attracted to a hydrophilic, negatively charged interface. Our results suggest that IAPP is strongly attracted to a hydrophobic surface, whereas the few positive charges of IAPP cannot warrant a permanent immobilization of IAPP at a hydrophilic, negatively charged surface at an ionic strength of 100 mM. Furthermore, the interfacial accumulation of insulin at a hydrophilic, negatively charged surface may represent a favorable precondition for nucleus formation and fibril formation. PMID:19186147

Jeworrek, Christoph; Hollmann, Oliver; Steitz, Roland; Winter, Roland; Czeslik, Claus

2009-01-01

373

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. PMID:21373370

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

2010-01-01

374

An alternative model to boundary and\\/or interface layers correctors in plasma physics: derivation and existence theory  

Microsoft Academic Search

In this paper we propose and study alternative models to boundary and\\/or interface layers correctors in plasma physics. These new models consist of coupling the Fokker–Planck equations with their hydrodynamics approximations.

Moulay D. Tidriri

2000-01-01

375

CS 525: Advanced Database Organization Study of relational, semantic, and object-oriented data models and interfaces. Database management system  

E-print Network

CS 525: Advanced Database Organization Objectives Study of relational, semantic, and object-oriented data models and interfaces. Database management system techniques for query optimization, concurrency History of database management. Goals of database system development. Relational systems Data models

Heller, Barbara

376

Wall modeling for implicit large-eddy simulation and immersed-interface methods  

NASA Astrophysics Data System (ADS)

We propose and analyze a wall model based on the turbulent boundary layer equations (TBLE) for implicit large-eddy simulation (LES) of high Reynolds number wall-bounded flows in conjunction with a conservative immersed-interface method for mapping complex boundaries onto Cartesian meshes. Both implicit subgrid-scale model and immersed-interface treatment of boundaries offer high computational efficiency for complex flow configurations. The wall model operates directly on the Cartesian computational mesh without the need for a dual boundary-conforming mesh. The combination of wall model and implicit LES is investigated in detail for turbulent channel flow at friction Reynolds numbers from Re ? = 395 up to Re ? =100,000 on very coarse meshes. The TBLE wall model with implicit LES gives results of better quality than current explicit LES based on eddy viscosity subgrid-scale models with similar wall models. A straightforward formulation of the wall model performs well at moderately large Reynolds numbers. A logarithmic-layer mismatch, observed only at very large Reynolds numbers, is removed by introducing a new structure-based damping function. The performance of the overall approach is assessed for two generic configurations with flow separation: the backward-facing step at Re h = 5,000 and the periodic hill at Re H = 10,595 and Re H = 37,000 on very coarse meshes. The results confirm the observations made for the channel flow with respect to the good prediction quality and indicate that the combination of implicit LES, immersed-interface method, and TBLE-based wall modeling is a viable approach for simulating complex aerodynamic flows at high Reynolds numbers. They also reflect the limitations of TBLE-based wall models.

Chen, Zhen Li; Hickel, Stefan; Devesa, Antoine; Berland, Julien; Adams, Nikolaus A.

2014-02-01

377

Micromechanical modeling of composites with mechanical interface – Part 1: Unit cell model development and manufacturing process effects  

Microsoft Academic Search

Micromechanical modeling has been demonstrated to be a powerful tool to predict macroscopic constitutive response especially for those materials having periodic microstructure. In the past decades, this methodology has been widely applied to composites often neglecting the role of stress\\/strain histories due to manufacturing. In this first paper, looking at those classes of composite materials having a mechanical interface, the

Nicola Bonora; Andrew Ruggiero

2006-01-01

378

The diamond-vacuum interface: I. A model of the interface between an n-type semiconductor, with negative electron affinity, and the vacuum  

Microsoft Academic Search

It is generally believed that if an n-type semiconductor with negative electron affinity could be found, it would act as an ideal 'cold cathode'. A model is proposed to describe the conditions at an ideal surface between such a semiconductor and the vacuum. When such an interface is created, electrons will have to exit the semiconductor owing to the difference

Johan F. Prins

2003-01-01

379

Automated computation of functional vascular density using laser speckle imaging in a rodent window chamber model.  

E-print Network

speckle contrast maps K typically is computed from raw speckle images with algorithmsspeckle contrast maps Nine maps of K were acquired as described above and used to compute FVD manually and using an automated algorithm.

White, Sean M; George, Steven C; Choi, Bernard

2011-01-01

380

76 FR 34740 - Agency Information Collection Activities: Automated Clearinghouse  

Federal Register 2010, 2011, 2012, 2013

...Number: CBP Form 400. Abstract: The Automated Clearinghouse (ACH) allows participants in the Automated Broker Interface (ABI) to transmit daily statements, deferred tax, and bill payments electronically through a financial institution directly...

2011-06-14

381

76 FR 19121 - Agency Information Collection Activities: Automated Clearinghouse  

Federal Register 2010, 2011, 2012, 2013

...Number: CBP Form 400. Abstract: The Automated Clearinghouse (ACH) allows participants in the Automated Broker Interface (ABI) to transmit daily statements, deferred tax, and bill payments electronically through a financial institution directly...

2011-04-06

382

Automated segmentation and geometrical modeling of the tricuspid aortic valve in 3D echocardiographic images.  

PubMed

The aortic valve has been described with variable anatomical definitions, and the consistency of 2D manual measurement of valve dimensions in medical image data has been questionable. Given the importance of image-based morphological assessment in the diagnosis and surgical treatment of aortic valve disease, there is considerable need to develop a standardized framework for 3D valve segmentation and shape representation. Towards this goal, this work integrates template-based medial modeling and multi-atlas label fusion techniques to automatically delineate and quantitatively describe aortic leaflet geometry in 3D echocardiographic (3DE) images, a challenging task that has been explored only to a limited extent. The method makes use of expert knowledge of aortic leaflet image appearance, generates segmentations with consistent topology, and establishes a shape-based coordinate system on the aortic leaflets that enables standardized automated measurements. In this study, the algorithm is evaluated on 11 3DE images of normal human aortic leaflets acquired at mid systole. The clinical relevance of the method is its ability to capture leaflet geometry in 3DE image data with minimal user interaction while producing consistent measurements of 3D aortic leaflet geometry. PMID:24505702

Pouch, Alison M; Wang, Hongzhi; Takabe, Manabu; Jackson, Benjamin M; Sehgal, Chandra M; Gorman, Joseph H; Gorman, Robert C; Yushkevich, Paul A

2013-01-01

383

Including nonequilibrium interface kinetics in a continuum model for melting nanoscaled particles  

PubMed Central

The melting temperature of a nanoscaled particle is known to decrease as the curvature of the solid-melt interface increases. This relationship is most often modelled by a Gibbs–Thomson law, with the decrease in melting temperature proposed to be a product of the curvature of the solid-melt interface and the surface tension. Such a law must break down for sufficiently small particles, since the curvature becomes singular in the limit that the particle radius vanishes. Furthermore, the use of this law as a boundary condition for a Stefan-type continuum model is problematic because it leads to a physically unrealistic form of mathematical blow-up at a finite particle radius. By numerical simulation, we show that the inclusion of nonequilibrium interface kinetics in the Gibbs–Thomson law regularises the continuum model, so that the mathematical blow up is suppressed. As a result, the solution continues until complete melting, and the corresponding melting temperature remains finite for all time. The results of the adjusted model are consistent with experimental findings of abrupt melting of nanoscaled particles. This small-particle regime appears to be closely related to the problem of melting a superheated particle. PMID:25399918

Back, Julian M.; McCue, Scott W.; Moroney, Timothy J.

2014-01-01

384

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

385

Including nonequilibrium interface kinetics in a continuum model for melting nanoscaled particles.  

PubMed

The melting temperature of a nanoscaled particle is known to decrease as the curvature of the solid-melt interface increases. This relationship is most often modelled by a Gibbs-Thomson law, with the decrease in melting temperature proposed to be a product of the curvature of the solid-melt interface and the surface tension. Such a law must break down for sufficiently small particles, since the curvature becomes singular in the limit that the particle radius vanishes. Furthermore, the use of this law as a boundary condition for a Stefan-type continuum model is problematic because it leads to a physically unrealistic form of mathematical blow-up at a finite particle radius. By numerical simulation, we show that the inclusion of nonequilibrium interface kinetics in the Gibbs-Thomson law regularises the continuum model, so that the mathematical blow up is suppressed. As a result, the solution continues until complete melting, and the corresponding melting temperature remains finite for all time. The results of the adjusted model are consistent with experimental findings of abrupt melting of nanoscaled particles. This small-particle regime appears to be closely related to the problem of melting a superheated particle. PMID:25399918

Back, Julian M; McCue, Scott W; Moroney, Timothy J

2014-01-01

386

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

387

Deterministic contact mechanics model applied to electrode interfaces in polymer electrolyte fuel cells and interfacial water accumulation  

NASA Astrophysics Data System (ADS)

An elastic deterministic contact mechanics model is applied to the compressed micro-porous (MPL) and catalyst layer (CL) interfaces in polymer electrolyte fuel cells (PEFCs) to elucidate the interfacial morphology. The model employs measured two-dimensional surface profiles and computes local surface deformation and interfacial gap, average contact resistance, and percent contact area as a function of compression pressure. Here, we apply the model to one interface having a MPL with cracks and one with a crack-free MPL. The void size distributions and water retention curves for the two sets of CL|MPL interfaces under compression are also computed. The CL|MPL interfaces with cracks are observed to have higher roughness, resulting in twice the interfacial average gap compared to the non-cracked interface at a given level of compression. The results indicate that the interfacial contact resistance is roughly the same for cracked or non-cracked interfaces due to cracks occupying low percentage of overall area. However, the cracked CL|MPL interface yields higher liquid saturation levels at all capillary pressures, resulting in an order of magnitude higher water storage capacity compared to the smooth interface. The van Genuchten water retention curve correlation for log-normal void size distributions is found to fit non-cracked CL|MPL interfaces well.

Zenyuk, I. V.; Kumbur, E. C.; Litster, S.

2013-11-01

388

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

NASA Astrophysics Data System (ADS)

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.; Moysan, J.; Chatain, D.; Corneloup, G.; Baqué, F.

2011-08-01

389

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

NASA Astrophysics Data System (ADS)

Coupled hydrological-hydrogeological models, emphasising the importance of the stream-aquifer interface, are more and more used in hydrological sciences for pluri-disciplinary studies aiming at investigating environmental issues. Based on an extensive literature review, stream-aquifer interfaces are described at five different scales: local [10 cm-~10 m], intermediate [~10 m-~1 km], watershed [10 km2-~1000 km2], regional [10 000 km2-~1 M km2] and continental scales [>10 M km2]. This led us to develop the concept of nested stream-aquifer interfaces, which extends the well-known vision of nested groundwater pathways towards the surface, where the mixing of low frequency processes and high frequency processes coupled with the complexity of geomorphological features and heterogeneities creates hydrological spiralling. This conceptual framework allows the identification of a hierarchical order of the multi-scale control factors of stream-aquifer hydrological exchanges, from the larger scale to the finer scale. The hyporheic corridor, which couples the river to its 3-D hyporheic zone, is then identified as the key component for scaling hydrological processes occurring at the interface. The identification of the hyporheic corridor as the support of the hydrological processes scaling is an important step for the development of regional studies, which is one of the main concerns for water practitioners and resources managers. In a second part, the modelling of the stream-aquifer interface at various scales is investigated with the help of the conductance model. Although the usage of the temperature as a tracer of the flow is a robust method for the assessment of stream-aquifer exchanges at the local scale, there is a crucial need to develop innovative methodologies for assessing stream-aquifer exchanges at the regional scale. After formulating the conductance model at the regional and intermediate scales, we address this challenging issue with the development of an iterative modelling methodology, which ensures the consistency of stream-aquifer exchanges between the intermediate and regional scales. Finally, practical recommendations are provided for the study of the interface using the innovative methodology MIM (Measurements-Interpolation-Modelling), which is graphically developed, scaling in space the three pools of methods needed to fully understand stream-aquifer interfaces at various scales. In the MIM space, stream-aquifer interfaces that can be studied by a given approach are localised. The efficiency of the method is demonstrated with two examples. The first one proposes an upscaling framework, structured around river reaches of ~10-100 m, from the local to the watershed scale. The second example highlights the usefulness of space borne data to improve the assessment of stream-aquifer exchanges at the regional and continental scales. We conclude that further developments in modelling and field measurements have to be undertaken at the regional scale to enable a proper modelling of stream-aquifer exchanges from the local to the continental scale.

Flipo, N.; Mouhri, A.; Labarthe, B.; Biancamaria, S.; Rivière, A.; Weill, P.

2014-08-01

390

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

391

Formulation of consumables management models: Mission planning processor payload interface definition  

NASA Technical Reports Server (NTRS)

Consumables models required for the mission planning and scheduling function are formulated. The relation of the models to prelaunch, onboard, ground support, and postmission functions for the space transportation systems is established. Analytical models consisting of an orbiter planning processor with consumables data base is developed. A method of recognizing potential constraint violations in both the planning and flight operations functions, and a flight data file storage/retrieval of information over an extended period which interfaces with a flight operations processor for monitoring of the actual flights is presented.

Torian, J. G.

1977-01-01

392

A study of the ice-water interface using the TIP4P/2005 water model  

E-print Network

In this work we study the ice-water interface under coexistence conditions by means of molecular simulations using the TIP4P/2005 water model. Following the methodology proposed by Hoyt and co-workers [J. J. Hoyt, M. Asta and A. Karma, Phys. Rev. Lett., 86, 5530, (2001)] we measure the interfacial free energy of ice with liquid water by analysing the spectrum of capillary fluctuations of the interface. We get an orientationally averaged interfacial free energy of 27(2) mN/m, in good agreement with a recent estimate obtained from simulation data of the size of critical clusters [E. Sanz, C. Vega, J. R. Espinosa, R. Caballero-Bernal, J. L. F. Abascal and C. Valeriani, JACS, 135, 15008, (2013)]. We also estimate the interfacial free energy of different planes and obtain 27(2), 28(2)and 28(2) mN/m for the basal, the primary prismatic and the secondary prismatic planes respectively. Finally, we inspect the structure of the interface and find that its thickness is of approximately 4-5 molecular diameters. Moreover, we find that when the basal plane is exposed to the fluid the interface alternates regions of cubic ice with regions of hexagonal ice.

Jorge Benet; Luis G. MacDowell; Eduardo Sanz

2014-10-01

393

Of Men, Women, and Computers: Data-Driven Gender Modeling for Improved User Interfaces  

Microsoft Academic Search

Men and women have unique sensibilities for information, which can be tapped to create gender-sensitive user interfaces that appeal more specifically to each sex. Building on previous research in gen- der psychology and also in user modeling, we take a data-driven ap- proach to understanding gender preferences by mining a large corpus of 150,000 weblog entries- half authored by men,

Hugo Liu; Rada Mihalcea

2007-01-01

394

Towards Asynchronous Brain-computer Interfaces: A P300-based Approach with Statistical Models  

Microsoft Academic Search

Asynchronous control is a critical issue in developing brain-computer interfaces for real-life applications, where the machine should be able to detect the occurrence of a mental command. In this paper we propose a computational approach for robust asynchronous control using the P300 signal, in a variant of oddball paradigm. First, we use Gaussian models in the support vector margin space

Haihong Zhang; Chuanchu Wang; Cuntai Guan

2007-01-01

395

Towards Asynchronous Brain-computer Interfaces: A P300-based Approach with Statistical Models  

Microsoft Academic Search

Asynchronous control is a critical issue in devel- oping brain-computer interfaces for real-life applications, where the machine should be able to detect the occurrence of a mental command. In this paper we propose a computational approach for robust asynchronous control using the P300 signal, in a variant of oddball paradigm. First, we use Gaussian models in the support vector margin

Haihong Zhang; Chuanchu Wang; Cuntai Guan

2008-01-01

396

An approximate model and empirical energy function for solute interactions with a water-phosphatidylcholine interface.  

PubMed Central

An empirical model of a liquid crystalline (L alpha phase) phosphatidylcholine (PC) bilayer interface is presented along with a function which calculates the position-dependent energy of associated solutes. The model approximates the interface as a gradual two-step transition, the first step being from an aqueous phase to a phase of reduced polarity, but which maintains a high enough concentration of water and/or polar head group moieties to satisfy the hydrogen bond-forming potential of the solute. The second transition is from the hydrogen bonding/low polarity region to an effectively anhydrous hydrocarbon phase. The "interfacial energies" of solutes within this variable medium are calculated based upon atomic positions and atomic parameters describing general polarity and hydrogen bond donor/acceptor propensities. This function was tested for its ability to reproduce experimental water-solvent partitioning energies and water-bilayer partitioning data. In both cases, the experimental data was reproduced fairly well. Energy minimizations carried out on beta-hexyl glucopyranoside led to identification of a global minimum for the interface-associated glycolipid which exhibited glycosidic torsion angles in agreement with prior results (Hare, B.J., K.P. Howard, and J.H. Prestegard. 1993. Biophys. J. 64:392-398). Molecular dynamics simulations carried out upon this same molecule within the simulated interface led to results which were consistent with a number of experimentally based conclusions from previous work, but failed to quantitatively reproduce an available NMR quadrupolar/dipolar coupling data set (Sanders, C.R., and J.H. Prestegard. 1991. J. Am. Chem. Soc. 113:1987-1996). The proposed model and functions are readily incorporated into computational energy modeling algorithms and may prove useful in future studies of membrane-associated molecules. PMID:8241401

Sanders, C R; Schwonek, J P

1993-01-01

397

Non-reactive metal\\/oxide interfaces: from model calculations towards realistic simulations  

Microsoft Academic Search

In the last decade two principal factors have stimulated the progressive regain of interest for non-reactive metal\\/oxide interfaces. On one hand, the eorts invested by the community of model catalysis in analysing the reactivity properties of supported metal nano-clusters have resulted in an abundance of high quality experimental data. They have also risen several precise questions on the direct and

Jacek Goniakowski; Christine Mottet; Claudine Noguera

2006-01-01

398

A Model-Driven Engineering Approach for the Usability of Plastic User Interfaces  

Microsoft Academic Search

Plastic User Interfaces (UI) are able to adapt to their context of use while preserving usability. Research efforts have focused\\u000a so far, on the functional aspect of UI adaptation, while neglecting the usability dimension. This paper investigates how the\\u000a notion of mapping as promoted by Model Driven Engineering (MDE), can be exploited to control UI adaptation according to explicit\\u000a usability

Jean-Sébastien Sottet; Gaëlle Calvary; Joëlle Coutaz; Jean-Marie Favre

399

Raise and Peel Models of fluctuating interfaces and combinatorics of Pascal's hexagon  

E-print Network

The raise and peel model of a one-dimensional fluctuating interface (model A) is extended by considering one source (model B) or two sources (model C) at the boundaries. The Hamiltonians describing the three processes have, in the thermodynamic limit, spectra given by conformal field theory. The probability of the different configurations in the stationary states of the three models are not only related but have interesting combinatorial properties. We show that by extending Pascal's triangle (which gives solutions to linear relations in terms of integer numbers), to an hexagon, one obtains integer solutions of bilinear relations. These solutions give not only the weights of the various configurations in the three models but also give an insight to the connections between the probability distributions in the stationary states of the three models. Interestingly enough, Pascal's hexagon also gives solutions to a Hirota's difference equation.

Pavel Pyatov

2004-06-14

400

Experiments and modeling of freshwater lenses in layered aquifers: Steady state interface geometry  

NASA Astrophysics Data System (ADS)

The interface geometry of freshwater lenses in layered aquifers was investigated by physical 2D laboratory experiments. The resulting steady-state geometries of the lenses were compared to existing analytical expressions from Dupuit-Ghyben-Herzberg (DGH) analysis of strip-island lenses for various cases of heterogeneity. Despite the vertical exaggeration of the physical models, which would seem to vitiate the assumption of vertical equipotentials, the fits with the DGH models were generally satisfactory. Observed deviations between the analytical and physical models can be attributed mainly to outflow zones along the shore line, which are not considered in the analytical models. As unconfined natural lenses have small outflow zones compared to their overall dimensions, and flow is mostly horizontal, the DGH analytical models should perform even better at full scale. Numerical models that do consider the outflow face generally gave a good fit to the physical models.

Dose, Eduardo J.; Stoeckl, Leonard; Houben, Georg J.; Vacher, H. L.; Vassolo, Sara; Dietrich, Jörg; Himmelsbach, Thomas

2014-02-01

401

Reduction of nonlinear embedded boundary models for problems with evolving interfaces  

NASA Astrophysics Data System (ADS)

Embedded boundary methods alleviate many computational challenges, including those associated with meshing complex geometries and solving problems with evolving domains and interfaces. Developing model reduction methods for computational frameworks based on such methods seems however to be challenging. Indeed, most popular model reduction techniques are projection-based, and rely on basis functions obtained from the compression of simulation snapshots. In a traditional interface-fitted computational framework, the computation of such basis functions is straightforward, primarily because the computational domain does not contain in this case a fictitious region. This is not the case however for an embedded computational framework because the computational domain typically contains in this case both real and ghost regions whose definitions complicate the collection and compression of simulation snapshots. The problem is exacerbated when the interface separating both regions evolves in time. This paper addresses this issue by formulating the snapshot compression problem as a weighted low-rank approximation problem where the binary weighting identifies the evolving component of the individual simulation snapshots. The proposed approach is application independent and therefore comprehensive. It is successfully demonstrated for the model reduction of several two-dimensional, vortex-dominated, fluid-structure interaction problems.

Balajewicz, Maciej; Farhat, Charbel

2014-10-01

402

Charge transfer in photoelectrochemical devices via interface states - unified model and comparison with experimental data  

SciTech Connect

A simple, unified model is presented for the mediation of charge transfer across the semiconductor/electrolyte interface by states localized in the bandgap of the semiconductor. These states are interpreted to arise from specific adsorption of anionic species from the electrolyte. The adsorbed ions could be either one of the components of a regenerative redox couple or comprise the constituent ions of the supporting electrolyte. The role of the interphasial layer in photoelectrochemical (PEC) devices is examined in the light of the above model. The key factor in determining the efficacy of energy conversion in the PEC system is identified as the competition between tunneling of photogenerated holes across the interphasial layer and their recombination with the majority carriers in the semiconductor conduction band. The extent of matching between the interface state and the reduced (filled) energy levels in the electrolyte is shown to be important in this regard. Experimental data on the n-GaAs/room temperature molten salt electrolyte and the n-CdSe/polysulfide interfaces are discussed in the light of this model. 28 refs.

Rajeshwar, K.

1982-05-01

403

Finite element modeling of laminated composite plates with locally delaminated interface subjected to impact loading.  

PubMed

This paper investigates the effects of localized interface progressive delamination on the behavior of two-layer laminated composite plates when subjected to low velocity impact loading for various fiber orientations. By means of finite element approach, the laminae stiffnesses are constructed independently from their interface, where a well-defined virtually zero-thickness interface element is discreetly adopted for delamination simulation. The present model has the advantage of simulating a localized interfacial condition at arbitrary locations, for various degeneration areas and intensities, under the influence of numerous boundary conditions since the interfacial description is expressed discretely. In comparison, the model shows good agreement with existing results from the literature when modeled in a perfectly bonded state. It is found that as the local delamination area increases, so does the magnitude of the maximum displacement history. Also, as top and bottom fiber orientations deviation increases, both central deflection and energy absorption increase although the relative maximum displacement correspondingly decreases when in contrast to the laminates perfectly bonded state. PMID:24696668

Abo Sabah, Saddam Hussein; Kueh, Ahmad Beng Hong

2014-01-01

404

Evidence evaluation in fingerprint comparison and automated fingerprint identification systems--Modeling between finger variability.  

PubMed

In the context of the investigation of the use of automated fingerprint identification systems (AFIS) for the evaluation of fingerprint evidence, the current study presents investigations into the variability of scores from an AFIS system when fingermarks from a known donor are compared to fingerprints that are not from the same source. The ultimate goal is to propose a model, based on likelihood ratios, which allows the evaluation of mark-to-print comparisons. In particular, this model, through its use of AFIS technology, benefits from the possibility of using a large amount of data, as well as from an already built-in proximity measure, the AFIS score. More precisely, the numerator of the LR is obtained from scores issued from comparisons between impressions from the same source and showing the same minutia configuration. The denominator of the LR is obtained by extracting scores from comparisons of the questioned mark with a database of non-matching sources. This paper focuses solely on the assignment of the denominator of the LR. We refer to it by the generic term of between-finger variability. The issues addressed in this paper in relation to between-finger variability are the required sample size, the influence of the finger number and general pattern, as well as that of the number of minutiae included and their configuration on a given finger. Results show that reliable estimation of between-finger variability is feasible with 10,000 scores. These scores should come from the appropriate finger number/general pattern combination as defined by the mark. Furthermore, strategies of obtaining between-finger variability when these elements cannot be conclusively seen on the mark (and its position with respect to other marks for finger number) have been presented. These results immediately allow case-by-case estimation of the between-finger variability in an operational setting. PMID:24447455

Egli Anthonioz, N M; Champod, C

2014-02-01

405

EzGal: A Flexible Interface for Stellar Population Synthesis Models  

NASA Astrophysics Data System (ADS)

We present EzGal, a flexible Python program designed to easily generate observable parameters (magnitudes, colors, and mass-to-light ratios) for arbitrary input stellar population synthesis (SPS) models. As has been demonstrated by various authors, for many applications the choice of input SPS models can be a significant source of systematic uncertainty. A key strength of EzGal is that it enables simple, direct comparison of different model sets so that the uncertainty introduced by choice of model set can be quantified. Its ability to work with new models will allow EzGal to remain useful as SPS modeling evolves to keep up with the latest research (such as varying IMFs). EzGal is also capable of generating composite stellar population models (CSPs) for arbitrary input star-formation histories and reddening laws, and it can be used to interpolate between metallicities for a given model set. To facilitate use, we have created an online interface to run EzGal and quickly generate magnitude and mass-to-light ratio predictions for a variety of star-formation histories and model sets. We make many commonly used SPS models available from the online interface, including the canonical Bruzual & Charlot models, an updated version of these models, the Maraston models, the BaSTI models, and the Flexible Stellar Population Synthesis (FSPS) models. We use EzGal to compare magnitude predictions for the model sets as a function of wavelength, age, metallicity, and star-formation history. From this comparison we quickly recover the well-known result that the models agree best in the optical for old solar-metallicity models, with differences at the ˜0.1 level. Similarly, the most problematic regime for SPS modeling is for young ages (?2 Gyr) and long wavelengths (??7500 Å), where thermally pulsating AGB stars are important and scatter between models can vary from 0.3 mag (Sloan i) to 0.7 mag (Ks). We find that these differences are not caused by one discrepant model set and should therefore be interpreted as general uncertainties in SPS modeling. Finally, we connect our results to a more physically motivated example by generating CSPs with a star-formation history matching the global star-formation history of the universe. We demonstrate that the wavelength and age dependence of SPS model uncertainty translates into a redshift-dependent model uncertainty, highlighting the importance of a quantitative understanding of model differences when comparing observations with models as a function of redshift.

Mancone, Conor L.; Gonzalez, Anthony H.

2012-06-01

406

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

407

Electrochemical Surface Potential Due to Classical Point Charge Models Drives Anion Adsorption to the Air-Water Interface  

E-print Network

electrostatic surface potential should favor the desorption of anions at the air-water interface. The resultsElectrochemical Surface Potential Due to Classical Point Charge Models Drives Anion Adsorption to the Air-Water Interface Marcel D. Baer, Abraham C. Stern, Yan Levin,*,§ Douglas J. Tobias

Levin, Yan

408

Cockpit automation  

NASA Technical Reports Server (NTRS)

The aims and methods of aircraft cockpit automation are reviewed from a human-factors perspective. Consideration is given to the mixed pilot reception of increased automation, government concern with the safety and reliability of highly automated aircraft, the formal definition of automation, and the ground-proximity warning system and accidents involving controlled flight into terrain. The factors motivating automation include technology availability; safety; economy, reliability, and maintenance; workload reduction and two-pilot certification; more accurate maneuvering and navigation; display flexibility; economy of cockpit space; and military requirements.

Wiener, Earl L.

1988-01-01

409

Configuring a Graphical User Interface for Managing Local HYSPLIT Model Runs Through AWIPS  

NASA Technical Reports Server (NTRS)

Responding to incidents involving the release of harmful airborne pollutants is a continual challenge for Weather Forecast Offices in the National Weather Service. When such incidents occur, current protocol recommends forecaster-initiated requests of NOAA's Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model output through the National Centers of Environmental Prediction to obtain critical dispersion guidance. Individual requests are submitted manually through a secured web site, with desired multiple requests submitted in sequence, for the purpose of obtaining useful trajectory and concentration forecasts associated with the significant release of harmful chemical gases, radiation, wildfire smoke, etc., into local the atmosphere. To help manage the local HYSPLIT for both routine and emergency use, a graphical user interface was designed for operational efficiency. The interface allows forecasters to quickly determine the current HYSPLIT configuration for the list of predefined sites (e.g., fixed sites and floating sites), and to make any necessary adjustments to key parameters such as Input Model. Number of Forecast Hours, etc. When using the interface, forecasters will obtain desired output more confidently and without the danger of corrupting essential configuration files.

Wheeler, mark M.; Blottman, Peter F.; Sharp, David W.; Hoeth, Brian; VanSpeybroeck, Kurt M.

2009-01-01

410

Dynamic and spatial behavior of a corrugated interface in the driven lattice gas model  

NASA Astrophysics Data System (ADS)

The spatiotemporal behavior of an initially corrugated interface in the two-dimensional driven lattice gas (DLG) model with attractive nearest-neighbors interactions is investigated via Monte Carlo simulations. By setting the system in the ordered phase, with periodic boundary conditions along the external field axis. i.e. horizontal, and open along the vertical directions respectively, an initial interface was imposed, that consists in a series of sinusoidal profiles with amplitude A0 and wavelength ? set parallel to the applied driving field axis. We studied the dynamic behavior of its statistical width or roughness W(t), defined as the root mean square of the interface position. We found that W(t) decays exponentially for all ? and lattice longitudinal sizes Lx, i.e., the lattice side that runs along the axis of the external field. We determined its relaxation time ?, and found that depends on ? as a power law ???p, where p depends on the temperature and Lx. At low T’s ( T?Tc(E)) and large Lx, p approaches to p=3/2. At intermediate T’s ( Tinterface stabilizes faster than in the equilibrium model, i. e. the Ising lattice gas (E=0) where p=3. At higher T’s p increases for T?Tc(E), and the finite size dependence is recovered. Also, if T is fixed, p increases with Lx until it saturates at large values of it, while this regime is vanishing at T?Tc(E). In this way, the dynamic relaxation process of a sinusoidal interface is improved by the external driving field with respect to its equilibrium counterpart, if the system is set in an intermediate temperature stage far from Tc(E) and in a lattice with a sufficiently large longitudinal side. The behavior of ? was also investigated as a function of E and in the intermediate stage Tinterface, and the Fourier coefficients corresponding to the same wave vector of the initial profile. The obtained results allowed us to conclude that the spatial evolution of the profile maintains its initial wavelength, does not travel along the external field axis, and its shape is preserved over all the relaxation process.

Saracco, Gustavo P.; Albano, Ezequiel V.

2010-09-01

411

Definition of common support equipment and space station interface requirements for IOC model technology experiments  

NASA Technical Reports Server (NTRS)

A study was conducted to identify the common support equipment and Space Station interface requirements for the IOC (initial operating capabilities) model technology experiments. In particular, each principal investigator for the proposed model technology experiment was contacted and visited for technical understanding and support for the generation of the detailed technical backup data required for completion of this study. Based on the data generated, a strong case can be made for a dedicated technology experiment command and control work station consisting of a command keyboard, cathode ray tube, data processing and storage, and an alert/annunciator panel located in the pressurized laboratory.

Russell, Richard A.; Waiss, Richard D.

1988-01-01

412

Testing of Environmental Satellite Bus-Instrument Interfaces Using Engineering Models  

NASA Technical Reports Server (NTRS)

This paper discusses the formulation and execution of a laboratory test of the electrical interfaces between multiple atmospheric scientific instruments and the spacecraft bus that carries them. The testing, performed in 2002, used engineering models of the instruments and the Aura spacecraft bus electronics. Aura is one of NASA s Earth Observatory System missions. The test was designed to evaluate the complex interfaces in the command and data handling subsystems prior to integration of the complete flight instruments on the spacecraft. A problem discovered during the flight integration phase of the observatory can cause significant cost and schedule impacts. The tests successfully revealed problems and led to their resolution before the full-up integration phase, saving significant cost and schedule. This approach could be beneficial for future environmental satellite programs involving the integration of multiple, complex scientific instruments onto a spacecraft bus.

Gagnier, Donald; Hayner, Rick; Nosek, Thomas; Roza, Michael; Hendershot, James E.; Razzaghi, Andrea I.

2004-01-01

413

Improved modeling of electrified interfaces using the effective screening medium method  

NASA Astrophysics Data System (ADS)

An update of the effective screening medium (ESM) method [Otani and Sugino, Phys. Rev. BPRBMDO1098-012110.1103/PhysRevB.73.115407 73, 115407 (2006)] is presented, extending the ability to simulate electrified interfaces in an efficient and flexible way. The need for an artificial vacuum buffer between the molecular system and the screening medium is removed by defining a smooth transition of the ESM dielectric permittivity (smooth ESM), precluding numerical instabilities when molecules come in contact with the ESM. Moreover, at short distances, the smooth ESM acts as a repulsive wall, and thus the simulation cell can serve as a natural container for molecules in molecular-dynamics simulations. Consequently, the smooth ESM method is a substantial advancement in modeling solid-liquid interfaces under electric bias.

Hamada, Ikutaro; Sugino, Osamu; Bonnet, Nicéphore; Otani, Minoru

2013-10-01

414

ISMARA: automated modeling of genomic signals as a democracy of regulatory motifs  

PubMed Central

Accurate reconstruction of the regulatory networks that control gene expression is one of the key current challenges in molecular biology. Although gene expression and chromatin state dynamics are ultimately encoded by constellations of binding sites recognized by regulators such as transcriptions factors (TFs) and microRNAs (miRNAs), our understanding of this regulatory code and its context-dependent read-out remains very limited. Given that there are thousands of potential regulators in mammals, it is not practical to use direct experimentation to identify which of these play a key role for a particular system of interest. We developed a methodology that models gene expression or chromatin modifications in terms of genome-wide predictions of regulatory sites and completely automated it into a web-based tool called ISMARA (Integrated System for Motif Activity Response Analysis). Given only gene expression or chromatin state data across a set of samples as input, ISMARA identifies the key TFs and miRNAs driving expression/chromatin changes and makes detailed predictions regarding their regulatory roles. These include predicted activities of the regulators across the samples, their genome-wide targets, enriched gene categories among the targets, and direct interactions between the regulators. Applying ISMARA to data sets from well-studied systems, we show that it consistently identifies known key regulators ab initio. We also present a number of novel predictions including regulatory interactions in innate immunity, a master regulator of mucociliary differentiation, TFs consistently disregulated in cancer, and TFs that mediate specific chromatin modifications. PMID:24515121

Balwierz, Piotr J.; Pachkov, Mikhail; Arnold, Phil; Gruber, Andreas J.; Zavolan, Mihaela; van Nimwegen, Erik

2014-01-01

415

Temperature Control of Fimbriation Circuit Switch in Uropathogenic Escherichia coli: Quantitative Analysis via Automated Model Abstraction  

PubMed Central

Uropathogenic Escherichia coli (UPEC) represent the predominant cause of urinary tract infections (UTIs). A key UPEC molecular virulence mechanism is type 1 fimbriae, whose expression is controlled by the orientation of an invertible chromosomal DNA element—the fim switch. Temperature has been shown to act as a major regulator of fim switching behavior and is overall an important indicator as well as functional feature of many urologic diseases, including UPEC host-pathogen interaction dynamics. Given this panoptic physiological role of temperature during UTI progression and notable empirical challenges to its direct in vivo studies, in silico modeling of corresponding biochemical and biophysical mechanisms essential to UPEC pathogenicity may significantly aid our understanding of the underlying disease processes. However, rigorous computational analysis of biological systems, such as fim switch temperature control circuit, has hereto presented a notoriously demanding problem due to both the substantial complexity of the gene regulatory networks involved as well as their often characteristically discrete and stochastic dynamics. To address these issues, we have developed an approach that enables automated multiscale abstraction of biological system descriptions based on reaction kinetics. Implemented as a computational tool, this method has allowed us to efficiently analyze the modular organization and behavior of the E. coli fimbriation switch circuit at different temperature settings, thus facilitating new insights into this mode of UPEC molecular virulence regulation. In particular, our results suggest that, with respect to its role in shutting down fimbriae expression, the primary function of FimB recombinase may be to effect a controlled down-regulation (rather than increase) of the ON-to-OFF fim switching rate via temperature-dependent suppression of competing dynamics mediated by recombinase FimE. Our computational analysis further implies that this down-regulation mechanism could be particularly significant inside the host environment, thus potentially contributing further understanding toward the development of novel therapeutic approaches to UPEC-caused UTIs. PMID:20361050

Kuwahara, Hiroyuki; Myers, Chris J.; Samoilov, Michael S.

2010-01-01

416

Fracture permeability and seismic wave scattering--Poroelastic linear-slip interface model for heterogeneous fractures  

SciTech Connect

Schoenberg's Linear-slip Interface (LSI) model for single, compliant, viscoelastic fractures has been extended to poroelastic fractures for predicting seismic wave scattering. However, this extended model results in no impact of the in-plane fracture permeability on the scattering. Recently, we proposed a variant of the LSI model considering the heterogeneity in the in-plane fracture properties. This modified model considers wave-induced, fracture-parallel fluid flow induced by passing seismic waves. The research discussed in this paper applies this new LSI model to heterogeneous fractures to examine when and how the permeability of a fracture is reflected in the scattering of seismic waves. From numerical simulations, we conclude that the heterogeneity in the fracture properties is essential for the scattering of seismic waves to be sensitive to the permeability of a fracture.

Nakagawa, S.; Myer, L.R.

2009-06-15

417

Substation automation systems in review  

Microsoft Academic Search

Screen-based substation automation projects are becoming increasingly common. Computerized substation automation systems have been installed for at least 5 years. In response to a number of issues, such as the safety of operational staff that operates a diverse range of equipment, operational efficiencies, and space savings, many electric utilities have incorporated with these systems a screen-based person-machine interface (PMI, which

S. Humphreys

1998-01-01

418

Numerical-analytical interfacing in two dimensions with applications to modeling NTS seismograms  

NASA Astrophysics Data System (ADS)

A new method for interfacing numerical and integral techniques allows greater flexibility in seismic modeling. Specifically, numerical calculations in laterally varying structure are interfaced with analytic methods that enable propagation to great distances. Such modeling is important for studying situations containing localized complex regions not easily handled by analytic means. The calculations involved are entirely two-dimensional, but the use of an appropriate source in combination with a filter applied to the resulting seismograms produces synthetic seismograms which are point-source responses in three dimensions. The integral technique is called two-dimensional Kirchhoff because its form is similar to the classical three-dimensional Kirchhoff. Data from Yucca Flat at the Nevada Test Site are modeled as a demonstration of the usefulness of the new method. In this application, both local and teleseismic records are modeled simultaneously from the same model with the same finite-difference run. This application indicates the importance of locally scattered Rayleigh waves in the production of teleseismic body-wave complexity and coda.

Stead, Richard J.; Helmberger, Donald V.

1988-03-01

419

Cockpit automation - In need of a philosophy  

NASA Technical Reports Server (NTRS)

Concern has been expressed over the rapid development and deployment of automatic devices in transport aircraft, due mainly to the human interface and particularly the role of automation in inducing human error. The paper discusses the need for coherent philosophies of automation, and proposes several approaches: (1) flight management by exception, which states that as long as a crew stays within the bounds of regulations, air traffic control and flight safety, it may fly as it sees fit; (2) exceptions by forecasting, where the use of forecasting models would predict boundary penetration, rather than waiting for it to happen; (3) goal-sharing, where a computer is informed of overall goals, and subsequently has the capability of checking inputs and aircraft position for consistency with the overall goal or intentions; and (4) artificial intelligence and expert systems, where intelligent machines could mimic human reason.

Wiener, E. L.

1985-01-01

420

A Cognitive System Model for Human/Automation Dynamics in Airspace Management  

NASA Technical Reports Server (NTRS)

NASA has initiated a significant thrust of research and development focused on providing the flight crew and air traffic managers automation aids to increase capacity in en route and terminal area operations through the use of flexible, more fuel-efficient routing, while improving the level of safety in commercial carrier operations. In that system development, definition of cognitive requirements for integrated multi-operator dynamic aiding systems is fundamental. In order to support that cognitive function definition, we have extended the Man Machine Integrated Design and Analysis System (MIDAS) to include representation of multiple cognitive agents (both human operators and intelligent aiding systems) operating aircraft, airline operations centers and air traffic control centers in the evolving airspace. The demands of this application require representation of many intelligent agents sharing world-models, and coordinating action/intention with cooperative scheduling of goals and actions in a potentially unpredictable world of operations. The MIDAS operator models have undergone significant development in order to understand the requirements for operator aiding and the impact of that aiding in the complex nondeterminate system of national airspace operations. The operator model's structure has been modified to include attention functions, action priority, and situation assessment. The cognitive function model has been expanded to include working memory operations including retrieval from long-term store, interference, visual-motor and verbal articulatory loop functions, and time-based losses. The operator's activity structures have been developed to include prioritization and interruption of multiple parallel activities among multiple operators, to provide for anticipation (knowledge of the intention and action of remote operators), and to respond to failures of the system and other operators in the system in situation-specific paradigms. The model's internal representation has been be modified so that multiple, autonomous sets of equipment will function in a scenario as the single equipment sets do now. In order to support the analysis requirements with multiple items of equipment, it is necessary for equipment to access the state of other equipment objects at initialization time (a radar object may need to access the position and speed of aircraft in its area, for example), and as a function of perception and sensor system interaction. The model has been improved to include multiple world-states as a function of equipment am operator interaction. The model has been used -1o predict the impact of warning and alert zones in aircraft operation, and, more critic-ally, the interaction of flight-deck based warning mechanisms and air traffic controller action in response to ground-based conflict prediction and alerting systems. In this operation, two operating systems provide alerting to two autonomous, but linked sets of operators, whose view of the system and whose dynamics in response are radically different. System stability and operator action was predicted using the MIDAS model.

Corker, Kevin M.; Pisanich, Gregory; Lebacqz, J. Victor (Technical Monitor)

1997-01-01

421

Automation of one-loop QCD corrections  

E-print Network

We present the complete automation of the computation of one-loop QCD corrections, including UV renormalization, to an arbitrary scattering process in the Standard Model. This is achieved by embedding the OPP integrand reduction technique, as implemented in CutTools, into the MadGraph framework. By interfacing the tool so constructed, which we dub MadLoop, with MadFKS, the fully automatic computation of any infrared-safe observable at the next-to-leading order in QCD is attained. We demonstrate the flexibility and the reach of our method by calculating the production rates for a variety of processes at the 7 TeV LHC.

Valentin Hirschi; Rikkert Frederix; Stefano Frixione; Maria Vittoria Garzelli; Fabio Maltoni; Roberto Pittau

2011-03-03

422

Particles at fluid-fluid interfaces: A new Navier-Stokes-Cahn-Hilliard surface-phase-field-crystal model  

PubMed Central

Colloid particles that are partially wetted by two immiscible fluids can become confined to fluid-fluid interfaces. At sufficiently high volume fractions, the colloids may jam and the interface may crystallize. The fluids together with the interfacial colloids form an emulsion with interesting material properties and offer an important route to new soft materials. A promising approach to simulate these emulsions was presented in Aland et al. [Phys. Fluids 23, 062103 (2011)], where a Navier-Stokes-Cahn-Hilliard model for the macroscopic two-phase fluid system was combined with a surface phase-field-crystal model for the microscopic colloidal particles along the interface. Unfortunately this model leads to spurious velocities which require very fine spatial and temporal resolutions to accurately and stably simulate. In this paper we develop an improved Navier-Stokes-Cahn-Hilliard-surface phase-field-crystal model based on the principles of mass conservation and thermodynamic consistency. To validate our approach, we derive a sharp interface model and show agreement with the improved diffuse interface model. Using simple flow configurations, we show that the new model has much better properties and does not lead to spurious velocities. Finally, we demonstrate the solid-like behavior of the crystallized interface by simulating the fall of a solid ball through a colloid-laden multiphase fluid. PMID:23214691

Aland, Sebastian; Lowengrub, John; Voigt, Axel

2013-01-01

423

Work Practice Simulation of Complex Human-Automation Systems in Safety Critical Situations: The Brahms Generalized berlingen Model  

NASA Technical Reports Server (NTRS)

The transition from the current air traffic system to the next generation air traffic system will require the introduction of new automated systems, including transferring some functions from air traffic controllers to on­-board automation. This report describes a new design verification and validation (V&V) methodology for assessing aviation safety. The approach involves a detailed computer simulation of work practices that includes people interacting with flight-critical systems. The research is part of an effort to develop new modeling and verification methodologies that can assess the safety of flight-critical systems, system configurations, and operational concepts. The 2002 Ueberlingen mid-air collision was chosen for analysis and modeling because one of the main causes of the accident was one crew's response to a conflict between the instructions of the air traffic controller and the instructions of TCAS, an automated Traffic Alert and Collision Avoidance System on-board warning system. It thus furnishes an example of the problem of authority versus autonomy. It provides a starting point for exploring authority/autonomy conflict in the larger system of organization, tools, and practices in which the participants' moment-by-moment actions take place. We have developed a general air traffic system model (not a specific simulation of Überlingen events), called the Brahms Generalized Ueberlingen Model (Brahms-GUeM). Brahms is a multi-agent simulation system that models people, tools, facilities/vehicles, and geography to simulate the current air transportation system as a collection of distributed, interactive subsystems (e.g., airports, air-traffic control towers and personnel, aircraft, automated flight systems and air-traffic tools, instruments, crew). Brahms-GUeM can be configured in different ways, called scenarios, such that anomalous events that contributed to the Überlingen accident can be modeled as functioning according to requirements or in an anomalous condition, as occurred during the accident. Brahms-GUeM thus implicitly defines a class of scenarios, which include as an instance what occurred at Überlingen. Brahms-GUeM is a modeling framework enabling "what if" analysis of alternative work system configurations and thus facilitating design of alternative operations concepts. It enables subsequent adaption (reusing simulation components) for modeling and simulating NextGen scenarios. This project demonstrates that BRAHMS provides the capacity to model the complexity of air transportation systems, going beyond idealized and simple flights to include for example the interaction of pilots and ATCOs. The research shows clearly that verification and validation must include the entire work system, on the one hand to check that mechanisms exist to handle failures of communication and alerting subsystems and/or failures of people to notice, comprehend, or communicate problematic (unsafe) situations; but also to understand how people must use their own judgment in relating fallible systems like TCAS to other sources of information and thus to evaluate how the unreliability of automation affects system safety. The simulation shows in particular that distributed agents (people and automated systems) acting without knowledge of each others' actions can create a complex, dynamic system whose interactive behavior is unexpected and is changing too quickly to comprehend and control.

Clancey, William J.; Linde, Charlotte; Seah, Chin; Shafto, Michael

2013-01-01

424

A knowledge- and model-based system for automated weaning from mechanical ventilation: technical description and first clinical application.  

PubMed

To describe the principles and the first clinical application of a novel prototype automated weaning system called Evita Weaning System (EWS). EWS allows an automated control of all ventilator settings in pressure controlled and pressure support mode with the aim of decreasing the respiratory load of mechanical ventilation. Respiratory load takes inspired fraction of oxygen, positive end-expiratory pressure, pressure amplitude and spontaneous breathing activity into account. Spontaneous breathing activity is assessed by the number of controlled breaths needed to maintain a predefined respiratory rate. EWS was implemented as a knowledge- and model-based system that autonomously and remotely controlled a mechanical ventilator (Evita 4, Dräger Medical, Lübeck, Germany). In a selected case study (n = 19 patients), ventilator settings chosen by the responsible physician were compared with the settings 10 min after the start of EWS and at the end of the study session. Neither unsafe ventilator settings nor failure of the system occurred. All patients were successfully transferred from controlled ventilation to assisted spontaneous breathing in a mean time of 37 ± 17 min (± SD). Early settings applied by the EWS did not significantly differ from the initial settings, except for the fraction of oxygen in inspired gas. During the later course, EWS significantly modified most of the ventilator settings and reduced the imposed respiratory load. A novel prototype automated weaning system was successfully developed. The first clinical application of EWS revealed that its operation was stable, safe ventilator settings were defined and the respiratory load of mechanical ventilation was decreased. PMID:23892513

Schädler, Dirk; Mersmann, Stefan; Frerichs, Inéz; Elke, Gunnar; Semmel-Griebeler, Thomas; Noll, Oliver; Pulletz, Sven; Zick, Günther; David, Matthias; Heinrichs, Wolfgang; Scholz, Jens; Weiler, Norbert

2014-10-01

425

AUTOMATED ACTIN FILAMENT SEGMENTATION, TRACKING AND TIP ELONGATION MEASUREMENTS BASED ON OPEN ACTIVE CONTOUR MODELS  

E-print Network

an automated method for actin fila- ment segmentation and tracking for measuring tip elongation rates in Total-assemble into long fila- ments of over 10 m in length and 7 nm in thickness is important for eukaryotic cells: actin of individual actin fila- ments growing on a glass surface in vitro [2, 3, 7]. The two ends of an actin filament

Huang, Xiaolei

426

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

National Technical Information Service (NTIS)

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, ...

R. C. Costen, J. M. Marchello

1998-01-01

427

BEM solution of delamination problems using an interface damage and plasticity model  

NASA Astrophysics Data System (ADS)

The problem of quasistatic and rate-independent evolution of elastic-plastic-brittle delamination at small strains is considered. Delamination processes for linear elastic bodies glued by an adhesive to each other or to a rigid outer surface are studied. The energy amounts dissipated in fracture Mode I (opening) and Mode II (shear) at an interface may be different. A concept of internal parameters is used here on the delaminating interfaces, involving a couple of scalar damage variable and a plastic tangential slip with kinematic-type hardening. The so-called energetic solution concept is employed. An inelastic process at an interface is devised in such a way that the dissipated energy depends only on the rates of internal parameters and therefore the model is associative. A fully implicit time discretization is combined with a spatial discretization of elastic bodies by the BEM to solve the delamination problem. The BEM is used in the solution of the respective boundary value problems, for each subdomain separately, to compute the corresponding total potential energy. Sample problems are analysed by a collocation BEM code to illustrate the capabilities of the numerical procedure developed.

Panagiotopoulos, C. G.; Manti?, V.; Roubí?ek, T.

2013-04-01

428

Numerical investigation of the interface in a continuous steel casting mold water model  

NASA Astrophysics Data System (ADS)

In this study, the steady-state Navier-Stokes equations are solved on a curvilinear nonorthogonal grid, following the finite volume approximation, with a pressure prediction-correction method, for the case of a flow in a model steel casting mold. The steel flow is simulated by water flow and the slag layer by an oil film, following conditions of previous experimental studies. The simulation aims at the understanding of the free wave and the interface surface wave behavior and the mechanism that leads to the breakup of the steel-slag interface, and thus induction of impurities inside the final steel product. Boundary conditions are set on the free and the interface surfaces, and an adaptive grid mechanism is used in order to update the grid’s shape so as to follow the wave formation. Several cases have been considered with the inlet velocity parameter, and results concerning the velocity field and the generated waves are reported. It is shown that a critical casting speed exists that leads to wave instability, which may be associated with emulsification phenomena.

Theodorakakos, A.; Bergeles, G.

1998-12-01

429

A study of the ice-water interface using the TIP4P/2005 water model  

E-print Network

In this work we study the ice-water interface under coexistence conditions by means of molecular simulations using the TIP4P/2005 water model. Following the methodology proposed by Hoyt and co-workers [J. J. Hoyt, M. Asta and A. Karma, Phys. Rev. Lett., 86, 5530, (2001)] we measure the interfacial free energy of ice with liquid water by analysing the spectrum of capillary fluctuations of the interface. We get an orientationally averaged interfacial free energy of 27(2) mN/m, in good agreement with a recent estimate obtained from simulation data of the size of critical clusters [E. Sanz, C. Vega, J. R. Espinosa, R. Caballero-Bernal, J. L. F. Abascal and C. Valeriani, JACS, 135, 15008, (2013)]. We also estimate the interfacial free energy of different planes and obtain 27(2), 28(2)and 28(2) mN/m for the basal, the primary prismatic and the secondary prismatic planes respectively. Finally, we inspect the structure of the interface and find that its thickness is of approximately 4-5 molecular diameters. Moreover,...

Benet, Jorge; Sanz, Eduardo

2014-01-01

430

Diffuse-interface modeling of liquid-vapor coexistence in equilibrium drops using smoothed particle hydrodynamics.  

PubMed

We study numerically liquid-vapor phase separation in two-dimensional, nonisothermal, van der Waals (vdW) liquid drops using the method of smoothed particle hydrodynamics (SPH). In contrast to previous SPH simulations of drop formation, our approach is fully adaptive and follows the diffuse-interface model for a single-component fluid, where a reversible, capillary (Korteweg) force is added to the equations of motion to model the rapid but smooth transition of physical quantities through the interface separating the bulk phases. Surface tension arises naturally from the cohesive part of the vdW equation of state and the capillary forces. The drop models all start from a square-shaped liquid and spinodal decomposition is investigated for a range of initial densities and temperatures. The simulations predict the formation of stable, subcritical liquid drops with a vapor atmosphere, with the densities and temperatures of coexisting liquid and vapor in the vdW phase diagram closely matching the binodal curve. We find that the values of surface tension, as determined from the Young-Laplace equation, are in good agreement with the results of independent numerical simulations and experimental data. The models also predict the increase of the vapor pressure with temperature and the fitting to the numerical data reproduces very well the Clausius-Clapeyron relation, thus allowing for the calculation of the vaporization pressure for this vdW fluid. PMID:25122383

Sigalotti, Leonardo Di G; Troconis, Jorge; Sira, Eloy; Peña-Polo, Franklin; Klapp, Jaime

2014-07-01

431

Test Automation Ant JUnit Test Automation  

E-print Network

Test Automation Ant JUnit Test Automation Mohammad Mousavi Eindhoven University of Technology, The Netherlands Software Testing 2012 Mousavi: Test Automation #12;Test Automation Ant JUnit Outline Test Automation Ant JUnit Mousavi: Test Automation #12;Test Automation Ant JUnit Why? Challenges of Manual Testing

Mousavi, Mohammad

432

Development and implementation of (Q)SAR modeling within the CHARMMing web-user interface.  

PubMed

Recent availability of large publicly accessible databases of chemical compounds and their biological activities (PubChem, ChEMBL) has inspired us to develop a web-based tool for structure activity relationship and quantitative structure activity relationship modeling to add to the services provided by CHARMMing (www.charmming.org). This new module implements some of the most recent advances in modern machine learning algorithms-Random Forest, Support Vector Machine, Stochastic Gradient Descent, Gradient Tree Boosting, so forth. A user can import training data from Pubchem Bioassay data collections directly from our interface or upload his or her own SD files which contain structures and activity information to create new models (either categorical or numerical). A user can then track the model generation process and run models on new data to predict activity. © 2014 Wiley Periodicals, Inc. PMID:25362883

Weidlich, Iwona E; Pevzner, Yuri; Miller, Benjamin T; Filippov, Igor V; Woodcock, H Lee; Brooks, Bernard R

2015-01-01

433

Validation of a digital mammographic unit model for an objective and highly automated clinical image quality assessment.  

PubMed

In mammography, image quality assessment has to be directly related to breast cancer indicator (e.g. microcalcifications) detectability. Recently, we proposed an X-ray source/digital detector (XRS/DD) model leading to such an assessment. This model simulates very realistic contrast-detail phantom (CDMAM) images leading to gold disc (representing microcalcifications) detectability thresholds that are very close to those of real images taken under the simulated acquisition conditions. The detection step was performed with a mathematical observer. The aim of this contribution is to include human observers into the disc detection process in real and virtual images to validate the simulation framework based on the XRS/DD model. Mathematical criteria (contrast-detail curves, image quality factor, etc.) are used to assess and to compare, from the statistical point of view, the cancer indicator detectability in real and virtual images. The quantitative results given in this paper show that the images simulated by the XRS/DD model are useful for image quality assessment in the case of all studied exposure conditions using either human or automated scoring. Also, this paper confirms that with the XRS/DD model the image quality assessment can be automated and the whole time of the procedure can be drastically reduced. Compared to standard quality assessment methods, the number of images to be acquired is divided by a factor of eight. PMID:23207102

Perez-Ponce, Hector; Daul, Christian; Wolf, Didier; Noel, Alain

2013-08-01

434

Interface Generation and Compositional Verification in JavaPathfinder  

NASA Technical Reports Server (NTRS)

We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.

Giannakopoulou, Dimitra; Pasareanu, Corina

2009-01-01

435

Molecules to modeling: Toxoplasma gondii oocysts at the human-animal-environment interface  

PubMed Central

Environmental transmission of extremely resistant Toxoplasma gondii oocysts has resulted in infection of diverse species around the world, leading to severe disease and deaths in human and animal populations. This review explores T. gondii oocyst shedding, survival, and transmission, emphasizing the importance of linking laboratory and landscape from molecular characterization of oocysts to watershed-level models of oocyst loading and transport in terrestrial and aquatic systems. Building on discipline-specific studies, a One Health approach incorporating tools and perspectives from diverse fields and stakeholders has contributed to an advanced understanding of T. gondii and is addressing transmission at the rapidly changing human–animal–environment interface. PMID:23218130

VanWormer, Elizabeth; Fritz, Heather; Shapiro, Karen; Mazet, Jonna A.K.; Conrad, Patricia A.

2013-01-01

436

Some neurobiological applications of the BBC Model B microcomputer and Unilab 8-bit interface.  

PubMed

Four computer programs written for the BBC Model B microcomputer (coupled to a Unilab 8-bit interface) are discussed. These programs enable the system to be used as (1) a transient recorder, (2) a rapid signal averager, (3) a spike-train analyser and (4) an instrument for measuring the amplitude of single channel currents. Flow-charts illustrating the operation of each program are given along with a detailed discussion of how the programs may be used in the laboratory. The discussion is illustrated using recordings taken from experiments conducted on a range of neurobiological preparations. PMID:2581102

Cottrell, G A; Duff, D A; Dunbar, S J; Green, K A

1985-03-01

437

LUI: Lovely MEGA User Interface  

Microsoft Academic Search

The capabilities of a automated theorem prover's interface are essential for the effective use of (interactive) proof systems. L?UI is the multi-modal interface that combines several features: a graphical display of information in a proof graph, a selective term browser with hypertext facilities, proof and proof plan presentation in natural language, and an editor for adding and maintaining the knowledge

Jörg H. Siekmann; Christoph Benzmüller; Lassaad Cheikhrouhou; Armin Fiedler; Helmut Horacek; Michael Kohlhase; Karsten Konrad; Andreas Meier; Erica Melis; Martin Pollet; Volker Sorge

1999-01-01

438

Integrating and Interfacing Library Systems.  

ERIC Educational Resources Information Center

This overview of local library online systems that integrate several functions covers functional integration, benefits of integrated systems, turnkey systems, minicomputer and microcomputer-based systems, interfacing automated systems, types of interfaces, linking homogenous and heterogeneous systems, role of vendors, library applications, linking…

Boss, Richard W.

1985-01-01

439

Development of a semi-automated method for mitral valve modeling with medial axis representation using 3D ultrasound  

PubMed Central

Purpose: Precise 3D modeling of the mitral valve has the potential to improve our understanding of valve morphology, particularly in the setting of mitral regurgitation (MR). Toward this goal, the authors have developed a user-initialized algorithm for reconstructing valve geometry from transesophageal 3D ultrasound (3D US) image data. Methods: Semi-automated image analysis was performed on transesophageal 3D US images obtained from 14 subjects with MR ranging from trace to severe. Image analysis of the mitral valve at midsystole had two stages: user-initialized segmentation and 3D deformable modeling with continuous medial representation (cm-rep). Semi-automated segmentation began with user-identification of valve location in 2D projection images generated from 3D US data. The mitral leaflets were then automatically segmented in 3D using the level set method. Second, a bileaflet deformable medial model was fitted to the binary valve segmentation by Bayesian optimization. The resulting cm-rep provided a visual reconstruction of the mitral valve, from which localized measurements of valve morphology were automatically derived. The features extracted from the fitted cm-rep included annular area, annular circumference, annular height, intercommissural width, septolateral length, total tenting volume, and percent anterior tenting volume. These measurements were compared to those obtained by expert manual tracing. Regurgitant orifice area (ROA) measurements were compared to qualitative assessments of MR severity. The accuracy of valve shape representation with cm-rep was evaluated in terms of the Dice overlap between the fitted cm-rep and its target segmentation. Results: The morphological features and anatomic ROA derived from semi-automated image analysis were consistent with manual tracing of 3D US image data and with qualitative assessments of MR severity made on clinical radiology. The fitted cm-reps accurately captured valve shape and demonstrated patient-specific differences in valve morphology among subjects with varying degrees of MR severity. Minimal variation in the Dice overlap and morphological measurements was observed when different cm-rep templates were used to initialize model fitting. Conclusions: This study demonstrates the use of deformable medial modeling for semi-automated 3D reconstruction of mitral valve geometry using transesophageal 3D US. The proposed algorithm provides a parametric geometrical representation of the mitral leaflets, which can be used to evaluate valve morphology in clinical ultrasound images. PMID:22320803

M. Pouch, Alison; A. Yushkevich, Paul; M. Jackson, Benjamin; S. Jassar, Arminder; Vergnat, Mathieu; H. Gorman, Joseph; C. Gorman, Robert; M. Sehgal, Chandra

2012-01-01

440

Design of an automated cocktail mixing experience  

E-print Network

This thesis describes the design concept development of an automated cocktail mixing device and user interface that is capable of dispensing a variety of alcoholic and non-alcoholic ingredients to produce a myriad of drink ...

Aguirre, Alejandro, S.B. Massachusetts Institute of Technology

2013-01-01

441

Establishing a Novel Modeling Tool: A Python-Based Interface for a Neuromorphic Hardware System  

PubMed Central

Neuromorphic hardware systems provide new possibilities for the neuroscience modeling community. Due to the intrinsic parallelism of the micro-electronic emulation of neural computation, such models are highly scalable without a loss of speed. However, the communities of software simulator users and neuromorphic engineering in neuroscience are rather disjoint. We present a software concept that provides the possibility to establish such hardware devices as valuable modeling tools. It is based on the integration of the hardware interface into a simulator-independent language which allows for unified experiment descriptions that can be run on various simulation platforms without modification, implying experiment portability and a huge simplification of the quantitative comparison of hardware and simulator results. We introduce an accelerated neuromorphic hardware device and describe the implementation of the proposed concept for this system. An example setup and results acquired by utilizing both the hardware system and a software simulator are demonstrated. PMID:19562085

Bruderle, Daniel; Muller, Eric; Davison, Andrew; Muller, Eilif; Schemmel, Johannes; Meier, Karlheinz

2008-01-01

442

Modeling and simulation of electronic structure, material interface and random doping in nano-electronic devices  

SciTech Connect

The miniaturization of nano-scale electronic devices, such as metal oxide semiconductor field effect transistors (MOSFETs), has given rise to a pressing demand in the new theoretical understanding and practical tactic for dealing with quantum mechanical effects in integrated circuits. Modeling and simulation of this class of problems have emerged as an important topic in applied and computational mathematics. This work presents mathematical models and computational algorithms for the simulation of nano-scale MOSFETs. We introduce a unified two-scale energy functional to describe the electrons and the continuum electrostatic potential of the nano-electronic device. This framework enables us to put microscopic and macroscopic descriptions in an equal footing at nano-scale. By optimization of the energy functional, we derive consistently coupled Poisson-Kohn-Sham equations. Additionally, layered structures are crucial to the electrostatic and transport properties of nano-transistors. A material interface model is proposed for more accurate description of the electrostatics governed by the Poisson equation. Finally, a new individual dopant model that utilizes the Dirac delta function is proposed to understand the random doping effect in nano-electronic devices. Two mathematical algorithms, the matched interface and boundary (MIB) method and the Dirichlet-to-Neumann mapping (DNM) technique, are introduced to improve the computational efficiency of nano-device simulations. Electronic structures are computed via subband decomposition and the transport properties, such as the I-V curves and electron density, are evaluated via the non-equilibrium Green's functions (NEGF) formalism. Two distinct device configurations, a double-gate MOSFET and a four-gate MOSFET, are considered in our three-dimensional numerical simulations. For these devices, the current fluctuation and voltage threshold lowering effect induced by the discrete dopant model are explored. Numerical convergence and model well-posedness are also investigated in the present work.

Chen Duan [Department of Mathematics, Michigan State University, East Lansing, MI 48824 (United States); Wei Guowei [Department of Mathematics, Michigan State University, East Lansing, MI 48824 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824 (United States)], E-mail: wei@math.msu.edu

2010-06-20

443