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Last update: November 12, 2013.
1

Computation Methods.  

National Technical Information Service (NTIS)

The computation methods described in this section are for use in fatigue analyses. The functions to be computed are the Gamma Function, the two Incomplete Gamma Functions, an Error Function and its Inverse, a Probability of Failure Function, and a transce...

R. G. Lambert

1980-01-01

2

Communicating the Impact of Free Access to Computers and the Internet in Public Libraries: A Mixed Methods Approach to Developing Outcome Indicators  

Microsoft Academic Search

The U.S. IMPACT studies have two research projects underway that employ a mixed method research design to develop and validate performance indicators related specifically to the outcomes of public access computing (PAC) use in public libraries. Through the use of a nationwide telephone survey (n  =  1130), four case studies, and a nationwide Internet survey of PAC users administered through

Samantha Becker; Michael D. Crandall; Karen E. Fisher

2009-01-01

3

Publication-quality computer graphics  

SciTech Connect

A user-friendly graphic software package is being used at Oak Ridge National Laboratory to produce publication-quality computer graphics. Close interaction between the graphic designer and computer programmer have helped to create a highly flexible computer graphics system. The programmer-oriented environment of computer graphics has been modified to allow the graphic designer freedom to exercise his expertise with lines, form, typography, and color. The resultant product rivals or surpasses that work previously done by hand. This presentation of computer-generated graphs, charts, diagrams, and line drawings clearly demonstrates the latitude and versatility of the software when directed by a graphic designer.

Slabbekorn, M.H.; Johnston, R.B. Jr.

1981-01-01

4

List of Free Computer-Related Publications  

NSDL National Science Digital Library

The List of Free Computer-Related Publications includes hardcopy magazines, newspapers, and journals related to computing which can be subscribed to free of charge. Each entry contains a brief overview of that publication, including its primary focus, typical content, publication frequency, subscription information, as well as an (admittedly) subjective overall rating. Note that some publications have qualifications you must meet in order for the subscription to be free.

5

Methods of Computational Intelligence  

Microsoft Academic Search

Comparison of various methods of computational intelligence are presented and illustrated with exampIes. These methods include neural networks, fuzzy systems, and evolutionary computation. The presentation is focused on neural networks, their learning algorithms and special architectures. General learning rule as a function of the incoming signals is discussed. Other learning rules such as Hebbian learning, perceptron learning, LMS - Least

Bogdan M. Wilamowski

2009-01-01

6

Methods of computational intelligence  

Microsoft Academic Search

Comparison of various methods of computational intelligence are presented and illustrated with examples. These methods include neural networks, fuzzy systems, and evolutionary computation. The presentation is focused on neural networks, their learning algorithms and special architectures. General learning rule as a function of the incoming signals is discussed. Other learning rules such as Hebbian learning, perceptron learning, LMS (least mean

Bogdan M. Wilamowski

2004-01-01

7

Computational methods for NDT  

NASA Astrophysics Data System (ADS)

Development of ultrasound nondestructive evaluation techniques (NDT) has involved a combination of both analytic and experimental methods. In contrast, relatively little work has been done on the use of computational methods for experimental design and analysis in NDT. This is due to the relative lack of availability of software for such computations. While computational methods and associated software implementations abound in the electromagnetic and structural analysis engineering communities, no such paradigm exists for ultrasound researchers and engineers. This paper demonstrates a software package, Wave2000, which computes the full solution to the 2D viscoelastic wave equation. 2D objects are represented by graphical images and are comprised of a number of solids and/or liquids. Each material is specified in terms of its material density, the first and second Lame constants, and the first and second viscosities. The program computers the displacement vector was a function of Cartesian coordinates x and y and of time t, and the solution includes effects of diffraction, scattering, reflection, and attenuation of the propagating wave. Wave2000 implements a finite difference solution on a standard personal computer running Microsoft Windows 95 or NT. Sources and receivers may be located anywhere in or on the surface of the object. The source waveform can be practically any temporal function desired, including data collected from an actual transducer, and the receiver data can be sorted in a data file for subsequent processing. Several examples of the use of Wave2000 are given, including simulations of scattering from cracks and propagation through layers of materials and fluid-filled porous structures. Results demonstrate that computational methods can play an important can play an important role in NDT specifically and in ultrasonics in general.

Kaufman, Jonathan J.; Luo, Gangming; Bianco, Bruno; Chiabrera, Alessandro; Siffert, Robert S.

1999-02-01

8

Computer intensive statistical methods  

NASA Astrophysics Data System (ADS)

The special session “Computer-Intensive Statistical Methods” was held in morning and afternoon parts at the 1985 AGU Fall Meeting in San Francisco. Calif. Its mission was to provide a forum for hydrologists and statisticians who are active in bringing unconventional, algorithmic-oriented statistical techniques to bear on problems of hydrology. Statistician Emanuel Parzen (Texas A&M University, College Station, Tex.) opened the session by relating recent developments in quantile estimation methods and showing how properties of such methods can be used to advantage to categorize runoff data previously analyzed by I. Rodriguez-Iturbe (Universidad Simon Bolivar, Caracas, Venezuela). Statistician Eugene Schuster (University of Texas, El Paso) discussed recent developments in nonparametric density estimation which enlarge the framework for convenient incorporation of prior and ancillary information. These extensions were motivated by peak annual flow analysis. Mathematician D. Myers (University of Arizona, Tucson) gave a brief overview of “kriging” and outlined some recently developed methodology.

Yakowitz, S.

9

Trustworthy and personalized computing on public kiosks  

Microsoft Academic Search

Many people desire ubiquitous access to their personal com- puting environments. We present a system in which a user leverages a personal mobile device to establish trust in a public computing device, or kiosk, prior to resuming her environment on the kiosk. We have designed a protocol by which the mobile device determines the identity and in- tegrity of all

Scott Garriss; Ramón Cáceres; Stefan Berger; Reiner Sailer; Leendert Van Doorn; Xiaolan Zhang

2008-01-01

10

Protecting Public-Access Computers in Libraries.  

ERIC Educational Resources Information Center

|Describes one public library's development of a computer-security plan, along with helpful products used. Discussion includes Internet policy, physical protection of hardware, basic protection of the operating system and software on the network, browser dilemmas and maintenance, creating clear intuitive interface, and administering fair use and…

King, Monica

1999-01-01

11

Closing the "Digital Divide": Building a Public Computing Center  

ERIC Educational Resources Information Center

The public computing center offers an economical and environmentally friendly model for providing additional public computer access when and where it is needed. Though not intended to be a replacement for a full-service branch, the public computing center does offer a budget-friendly option for quickly expanding high-demand services into the…

Krebeck, Aaron

2010-01-01

12

A Computational Framework to Study Public Health Epidemiology  

Microsoft Academic Search

Public health professionals require computational support to study disease outbreak dynamics and to facilitate policy and decision-making. Modeling disease outbreaks in large realistic populations is a data-intensive task that requires tremendous computational resources. This paper presents a framework of multiple source and computational modules to evaluate what-if scenarios and quantify public health actions.

Courtney D. Corley; Armin R. Mikler

2009-01-01

13

Integrating Public Health and Computer Science Theoretical Perspectives for Developing Tailored Health Messages  

Microsoft Academic Search

In this paper, we review current approaches employed by both public health and computer science to develop tailored persuasive messages to foster health-related behavior change. It is based on this review that we propose an integrated framework for merging public health and computer science approaches. We believe that such a framework can lead to new methods to extend current tailoring

Rita Kukafka; Frances Morrison; Stephen B. Johnson

14

Methods for computing color anaglyphs  

NASA Astrophysics Data System (ADS)

A new computation technique is presented for calculating pixel colors in anaglyph images. The method depends upon knowing the RGB spectral distributions of the display device and the transmission functions of the filters in the viewing glasses. It requires the solution of a nonlinear least-squares program for each pixel in a stereo pair and is based on minimizing color distances in the CIEL*a*b* uniform color space. The method is compared with several techniques for computing anaglyphs including approximation in CIE space using the Euclidean and Uniform metrics, the Photoshop method and its variants, and a method proposed by Peter Wimmer. We also discuss the methods of desaturation and gamma correction for reducing retinal rivalry.

McAllister, David F.; Zhou, Ya; Sullivan, Sophia

2010-02-01

15

SEMINAR ON COMPUTATIONAL LINGUISTICS. PUBLIC HEALTH SERVICE PUBLICATION NUMBER 1716.  

ERIC Educational Resources Information Center

IN OCTOBER 1966 A SEMINAR WAS HELD IN BETHESDA, MARYLAND ON THE USE OF COMPUTERS IN LANGUAGE RESEARCH. THE ORGANIZERS OF THE CONFERENCE, THE CENTER FOR APPLIED LINGUISTICS AND THE NATIONAL INSTITUTES OF HEALTH, ATTEMPTED TO BRING TOGETHER EMINENT REPRESENTATIVES OF THE MAJOR SCHOOLS OF CURRENT LINGUISTIC RESEARCH. THE PAPERS PRESENTED AT THE…

PRATT, ARNOLD W.; AND OTHERS, Eds.

16

Computational methods for stellerator configurations  

SciTech Connect

This project had two main objectives. The first one was to continue to develop computational methods for the study of three dimensional magnetic confinement configurations. The second one was to collaborate and interact with researchers in the field who can use these techniques to study and design fusion experiments. The first objective has been achieved with the development of the spectral code BETAS and the formulation of a new variational approach for the study of magnetic island formation in a self consistent fashion. The code can compute the correct island width corresponding to the saturated island, a result shown by comparing the computed island with the results of unstable tearing modes in Tokamaks and with experimental results in the IMS Stellarator. In addition to studying three dimensional nonlinear effects in Tokamaks configurations, these self consistent computed island equilibria will be used to study transport effects due to magnetic island formation and to nonlinearly bifurcated equilibria. The second objective was achieved through direct collaboration with Steve Hirshman at Oak Ridge, D. Anderson and R. Talmage at Wisconsin as well as through participation in the Sherwood and APS meetings.

Betancourt, O.

1992-01-01

17

Computers and Telecommunications: Issues in Public Policy.  

ERIC Educational Resources Information Center

The rapid growth of data communications and remote-access computing has outpaced the ability of industrial organizations to adapt to change, and at the same time has outpaced the ability of government policy making organizations to guide the evolution of this new technology. This book focuses on a number of important issues awaiting resolution by…

Mathison, Stuart L.; Walker, Philip M.

18

How You Can Protect Public Access Computers "and" Their Users  

ERIC Educational Resources Information Center

|By providing the public with online computing facilities, librarians make available a world of information resources beyond their traditional print materials. Internet-connected computers in libraries greatly enhance the opportunity for patrons to enjoy the benefits of the digital age. Unfortunately, as hackers become more sophisticated and…

Huang, Phil

2007-01-01

19

37 CFR 201.26 - Recordation of documents pertaining to computer shareware and donation of public domain computer...  

Code of Federal Regulations, 2013 CFR

... Recordation of documents pertaining to computer shareware and donation of public domain computer software. 201.26 Section 201.26... Recordation of documents pertaining to computer shareware and donation of public...

2013-07-01

20

Method for monitoring computer programs  

US Patent & Trademark Office Database

As disclosed in this patent disclosure, I have invented a method for substantially disabling at least one cheat program, referred to as the anti-cheat software, used in conjunction with at least one online competitive game program involving at least two players, each player using at least one computer that are in online communication with each other. My invention allows the players' remote terminal to continue to function and operate independent of the host server, while at the same time having the host server, in conjunction with the anti-cheat software, substantially disable programs not required to operate the remote terminal and not required to play the online game--the programs that are substantially disabled may or may not be "cheat programs", but essentially any program not required for the operation of the remote terminal and the online game.

2013-09-10

21

Funding Public Computing Centers: Balancing Broadband Availability and Expected Demand  

ERIC Educational Resources Information Center

|The National Broadband Plan (NBP) recently announced by the Federal Communication Commission visualizes a significantly enhanced commitment to public computing centers (PCCs) as an element of the Commission's plans for promoting broadband availability. In parallel, the National Telecommunications and Information Administration (NTIA) has…

Jayakar, Krishna; Park, Eun-A

2012-01-01

22

Gender and Public Access Computing: An International Perspective  

Microsoft Academic Search

Information and Communication Technologies (ICTs), and public access to computers with Internet connectivity in particular, can assist community development efforts and help bridge the so-called digital divide. However, use of ICT is not gender neutral. Technical, social, and cultural barriers emphasize women’s exclusion from the benefits of ICT for development. This paper offers a qualitative analysis of the benefits of

Allison Terry; Ricardo Gomez

2011-01-01

23

BOINC: A System for Public-Resource Computing and Storage  

Microsoft Academic Search

BOINC (Berkeley Open Infrastructure for Network Com- puting) is a software system that makes it easy for scientists to create and operate public-resource computing projects. It supports diverse applications, including those with large storage or communication requirements. PC owners can participate in multiple BOINC projects, and can specify how their resources are allocated among these projects. We describe the goals

David P. Anderson

2004-01-01

24

Reconfigurable computing: architectures and design methods  

Microsoft Academic Search

Reconfigurable computing is becoming increasingly attractive for many applications. This survey covers two aspects of reconfigurable computing: architectures and design methods. The paper includes recent advances in reconfigurable architectures, such as the Alters Stratix II and Xilinx Virtex 4 FPGA devices. The authors identify major trends in general-purpose and special- purpose design methods. It is shown that reconfigurable computing designs

T. J. Todman; G. A. Constantinides; S. J. E. Wilton; O. Mencer; W. Luk; P. Y. K. Cheung

2005-01-01

25

Computational methods for reversed-field equilibrium  

SciTech Connect

Investigating the temporal evolution of reversed-field equilibrium caused by transport processes requires the solution of the Grad-Shafranov equation and computation of field-line-averaged quantities. The technique for field-line averaging and the computation of the Grad-Shafranov equation are presented. Application of Green's function to specify the Grad-Shafranov equation boundary condition is discussed. Hill's vortex formulas used to verify certain computations are detailed. Use of computer software to implement computational methods is described.

Boyd, J.K.; Auerbach, S.P.; Willmann, P.A.; Berk, H.L.; McNamara, B.

1980-04-15

26

32 CFR 310.52 - Computer matching publication and review requirements.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Computer matching publication and review requirements... PRIVACY PROGRAM DOD PRIVACY PROGRAM Computer Matching Program Procedures § 310.52 Computer matching publication and review...

2013-07-01

27

Forecasting Methods for Computer Technology.  

National Technical Information Service (NTIS)

How well the computer site manager avoids future dangers and takes advantage of future opportunities depends to a considerable degree on how much anticipatory information he has available. People who rise in management are expected with each successive pr...

W. J. Worlton

1978-01-01

28

Method for Tracking Core-Contributed Publications  

PubMed Central

Accurately tracking core-contributed publications is an important and often difficult task. Many core laboratories are supported by programmatic grants (such as Cancer Center Support Grant and Clinical Translational Science Awards) or generate data with instruments funded through S10, Major Research Instrumentation, or other granting mechanisms. Core laboratories provide their research communities with state-of-the-art instrumentation and expertise, elevating research. It is crucial to demonstrate the specific projects that have benefited from core services and expertise. We discuss here the method we developed for tracking core contributed publications.

Loomis, Cynthia A.; Curchoe, Carol Lynn

2012-01-01

29

Meshless methods in computational mechanics  

Microsoft Academic Search

In this thesis, two meshless methods, the element free Galerkin (EFG) method and the meshless method based on the local boundary integral equation (LBIE), are described. The first part (Chapters II and III) of the thesis is to propose efficient methods in enforcing the essential boundary conditions in the EFG method. A modified collocation method has been proposed for enforcing

Tulong Zhu

1998-01-01

30

Computational methods for passive solar simulation  

Microsoft Academic Search

The use of network models and a range of computational methods for the simulation of passive solar buildings are described, compared, and assessed. The following methods are considered: (i) steady-state methods; (ii) finite difference methods, explicit and implicit; (iii) modal or analytic spectral methods; (iv) Fourier series methods. Methods (ii) to (iv) are compared by applying them to a series

C CARTER

1990-01-01

31

47 CFR 61.20 - Method of filing publications.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Method of filing publications. 61.20 Section 61.20... § 61.20 Method of filing publications. (a) All issuing carriers...tariffs shall file all tariff publications and associated...

2011-10-01

32

47 CFR 61.20 - Method of filing publications.  

Code of Federal Regulations, 2012 CFR

...2012-10-01 false Method of filing publications. 61.20 Section 61.20... § 61.20 Method of filing publications. (a) All issuing carriers...tariffs shall file all tariff publications and associated...

2012-10-01

33

47 CFR 61.32 - Method of filing publications.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Method of filing publications. 61.32 Section 61.32 Telecommunication...Dominant Carriers § 61.32 Method of filing publications. (a) Publications sent for filing must be addressed to...

2011-10-01

34

Research methods for computer applications  

Microsoft Academic Search

This paper identifies issues and techniques useful to psychologists interested in applied research for computer applications.\\u000a Applied research includes guideline research, product development evaluation, and field trial evaluation. Suggestions for\\u000a improved guideline research involve screening the problem to determine its potential usefulness and screening the design to\\u000a make sure it involves sufficiently representative tasks, subjects, and materials for the desired

Jo W. Tombaugh

1983-01-01

35

Computational methods of neutron transport  

Microsoft Academic Search

This books presents a balanced overview of the major methods currently available for obtaining numerical solutions in neutron and gamma ray transport. It focuses on methods particularly suited to the complex problems encountered in the analysis of reactors, fusion devices, radiation shielding, and other nuclear systems. Derivations are given for each of the methods showing how the transport equation is

E. E. Lewis; W. F. Miller

1984-01-01

36

A new computational method for Laplace transforms by decomposition method  

Microsoft Academic Search

In this paper, Adomian decomposition method is applied to develop a new computational method for Laplace transforms. Some examples are provided to illustrate the simplicity and reliability of the new method.

E. Babolian; J. Biazar; A. R. Vahidi

2004-01-01

37

Computational Aspects of Glimm's Method.  

National Technical Information Service (NTIS)

The application of Glimm's method to the equations of gas dynamics is considered. In particular, its advantages are discussed for situations in which chemical reactions occur in the gas. 1 figure. (ERA citation 03:022000)

A. J. Chorin

1977-01-01

38

ComputerTown, USA?? Using Personal Computers in the Public Library.  

ERIC Educational Resources Information Center

|Describes the development of a project to disseminate information about and provide hands-on experience with personal computers through classes and workshops for both adults and children at the Menlo Park Public Library. Funding and implementation are discussed, as well as how such projects can be started by other libraries. (BK)|

Zamora, Ramon

1981-01-01

39

Numerical Methods for Computing Casimir Interactions  

Microsoft Academic Search

\\u000a We review several different approaches for computing Casimir forces and related fluctuation-induced interactions between bodies\\u000a of arbitrary shapes and materials. The relationships between this problem and well known computational techniques from classical\\u000a electromagnetism are emphasized. We also review the basic principles of standard computational methods, categorizing them\\u000a according to three criteria—choice of problem, basis, and solution technique—that can be used

Steven G. Johnson

40

Computer methods in electric network analysis  

SciTech Connect

The computational algorithms utilized in power system analysis have more than just a minor overlap with those used in electronic circuit computer aided design. This paper describes the computer methods that are common to both areas and highlights the differences in application through brief examples. Recognizing this commonality has stimulated the exchange of useful techniques in both areas and has the potential of fostering new approaches to electric network analysis through the interchange of ideas.

Saver, P.; Hajj, I.; Pai, M.; Trick, T.

1983-06-01

41

Simulating quantum computers with probabilistic methods  

Microsoft Academic Search

We investigate the boundary between classical and quantum computational power. This work consists of two parts. First we develop new classical simulation algorithms that are centered on sampling methods. Using these techniques we generate new classes of classically simulatable quantum circuits where standard techniques relying on the exact computation of measurement probabilities fail to provide efficient simulations. For example, we

M. Van den Nest

2009-01-01

42

Teacher Perspectives on the Current State of Computer Technology Integration into the Public School Classroom  

ERIC Educational Resources Information Center

|Since the introduction of computers into the public school arena over forty years ago, educators have been convinced that the integration of computer technology into the public school classroom will transform education. Joining educators are state and federal governments. Public schools and others involved in the process of computer technology…

Zuniga, Ramiro

2009-01-01

43

Computational Chemistry Using Modern Electronic Structure Methods  

ERIC Educational Resources Information Center

|Various modern electronic structure methods are now days used to teach computational chemistry to undergraduate students. Such quantum calculations can now be easily used even for large size molecules.|

Bell, Stephen; Dines, Trevor J.; Chowdhry, Babur Z.; Withnall, Robert

2007-01-01

44

Epistemic divergence and the publicity of scientific methods  

Microsoft Academic Search

Epistemic divergence occurs when different investigators give different answers to the same question using evidence-collecting methods that are not public. Without following the principle that scientific methods must be public, scientific communities risk epistemic divergence. I explicate the notion of public method and argue that, to avoid the risk of epistemic divergence, scientific communities should (and do) apply only methods

Gualtiero Piccinini

2003-01-01

45

Computational evaluation of the Traceback Method.  

PubMed

ABSTRACT Several models of language acquisition have emerged in recent years that rely on computational algorithms for simulation and evaluation. Computational models are formal and precise, and can thus provide mathematically well-motivated insights into the process of language acquisition. Such models are amenable to robust computational evaluation, using technology that was developed for Information Retrieval and Computational Linguistics. In this article we advocate the use of such technology for the evaluation of formal models of language acquisition. We focus on the Traceback Method, proposed in several recent studies as a model of early language acquisition, explaining some of the phenomena associated with children's ability to generalize previously heard utterances and generate novel ones. We present a rigorous computational evaluation that reveals some flaws in the method, and suggest directions for improving it. PMID:23343571

Kol, Sheli; Nir, Bracha; Wintner, Shuly

2013-01-24

46

Projection for the Future of Instructional Computing in the Montgomery County Public Schools.  

National Technical Information Service (NTIS)

This report summarizes the findings of a one man-month study of the current status and future direction of instructional computing in the Montgomery County, Maryland, Public Schools including computer assisted instruction, computer managed instruction, co...

J. P. Fennell

1977-01-01

47

32 CFR 310.52 - Computer matching publication and review requirements.  

Code of Federal Regulations, 2010 CFR

...PRIVACY PROGRAM DOD PRIVACY PROGRAM Computer Matching Program Procedures § 310.52 Computer matching publication and review requirements...disclosures are made (see subpart G of this part). (b) If a computer matching program is...

2009-07-01

48

32 CFR 310.52 - Computer matching publication and review requirements.  

Code of Federal Regulations, 2010 CFR

...PRIVACY PROGRAM DOD PRIVACY PROGRAM Computer Matching Program Procedures § 310.52 Computer matching publication and review requirements...disclosures are made (see subpart G of this part). (b) If a computer matching program is...

2010-07-01

49

Advanced computational methods for nonlinear spin dynamics  

Microsoft Academic Search

We survey methods for the accurate computation of the dynamics of spin in general nonlinear accelerator lattices. Specifically, we show how it is possible to compute high-order nonlinear spin transfer maps in SO(3) or SU(2) representations in parallel with the corresponding orbit transfer maps. Specifically, using suitable invariant subspaces of the coupled spin-orbit dynamics, it is possible to develop a

Martin Berz; Kyoko Makino

2011-01-01

50

Simulating quantum computers with probabilistic methods  

Microsoft Academic Search

We investigate the boundary between classical and quantum computational\\u000apower. This work consists of two parts. First we develop new classical\\u000asimulation algorithms that are centered on sampling methods. Using these\\u000atechniques we generate new classes of classically simulatable quantum circuits\\u000awhere standard techniques relying on the exact computation of measurement\\u000aprobabilities fail to provide efficient simulations. For example, we

Maarten Van den Nest

2009-01-01

51

QMR methods in computational fluid dynamics  

SciTech Connect

We examine the application of QMR methods to the solution of linear systems of equations arising from the use of implicit solution methods in computational fluid dynamics. We will deal with implicit finite difference schemes for solving the Euler equations. These schemes may arise from the implicit treatment of the time dependent equations or from the use of Newton`s method for the solution of the steady state equations. In both situations it is necessary to solve a large sparse nonsymmetric linear system of equations at each iteration. We will examine the effectiveness of QMR in the solution of these systems. W e compare the resulting methods to methods which rely on some other simplifying technique to solve the linear systems. Our goal is to show that the QMR method is a viable alternative to the more ad-hoc schemes for solving implicit computational fluid dynamics problems.

Nachtigal, N.M.; Semeraro, B.D.

1994-12-31

52

Meshless methods for computational fluid dynamics  

NASA Astrophysics Data System (ADS)

While the generation of meshes has always posed challenges for computational scientists, the problem has become more acute in recent years. Increased computational power has enabled scientists to tackle problems of increasing size and complexity. While algorithms have seen great advances, mesh generation has lagged behind, creating a computational bottleneck. For industry and government looking to impact current and future products with simulation technology, mesh generation imposes great challenges. Many generation procedures often lack automation, requiring many man-hours, which are becoming far more expensive than computer hardware. More automated methods are less reliable for complex geometry with sharp corners, concavity, or otherwise complex features. Most mesh generation methods to date require a great deal of user expertise to obtain accurate simulation results. Since the application of computational methods to real world problems appears to be paced by mesh generation, alleviating this bottleneck potentially impacts an enormous field of problems. Meshless methods applied to computational fluid dynamics is a relatively new area of research designed to help alleviate the burden of mesh generation. Despite their recent inception, there exists no shortage of formulations and algorithms for meshless schemes in the literature. A brief survey of the field reveals varied approaches arising from diverse mathematical backgrounds applied to a wide variety of applications. All meshless schemes attempt to bypass the use of a conventional mesh entirely or in part by discretizing governing partial differential equations on scattered clouds of points. A goal of the present thesis is to develop a meshless scheme for computational fluid dynamics and evaluate its performance compared with conventional methods. The meshless schemes developed in this work compare favorably with conventional finite volume methods in terms of accuracy and efficiency for the Euler and Navier-Stokes equations. The success of these schemes may be largely attributeed their sound mathematical foundation based on a local extremum diminishing property, which has been generalized to handle local clouds of points instead of mesh-based topologies. In addition, powerful algorithms are developed to accelerate convergence for meshless schemes, which also apply to mesh based schemes in a mesh transparent manner. The convergence acceleration technique, termed "multicloud," produces schemes with convergence rates rivaling structured multigrid. However, the advantage of multicloud is that it makes no assumptions regarding mesh topology or discretization used on the finest level. Thus, multicloud is extrememly general and widely applicable. Finally, a unique application of meshless methods is demonstrated for overset grids in which a meshless method is used to seamlessly connect different types of grids. It is shown that meshless methods provide significant advantages over conventional interpolation procedures for overset grids. This application serves to highlight the practical utility of meshless schemes for computational fluid dynamics.

Katz, Aaron Jon

53

Going Public and the Sale of Shares with Heterogeneous Investors: Agent?Based Computational Modelling and Computer Simulations  

Microsoft Academic Search

In this paper we use agent-based computational modelling and computer simulations to examine the interrelationship between different selling strategies for going public. A great deal of recent empirical evidence suggests that to maximise the revenue raised from the shares sold in the public offering, it is fundamental to choose the appropriate design for the sale which, in turn, reflects the

Pietro Panzarasa; Nicholas R. Jennings; Timothy J. Norman

2001-01-01

54

Teaching Practical Public Health Evaluation Methods  

ERIC Educational Resources Information Center

Human service fields, and more specifically public health, are increasingly requiring evaluations to prove the worth of funded programs. Many public health practitioners, however, lack the required background and skills to conduct useful, appropriate evaluations. In the late 1990s, the Centers for Disease Control and Prevention (CDC) created the…

Davis, Mary V.

2006-01-01

55

A Tableau Method for Public Announcement Logics  

Microsoft Academic Search

Public announcement logic is an extension of multi-agent epistemic logic with dynamic operators to model the informational con- sequences of announcements to the entire group of agents. We propose a labelled tableau-calculus for this logic. We also present an extension of the calculus for a logic of arbitrary announcements. Public announcement logic (PAL) was originally proposed in (1). This is

Philippe Balbiani; Hans P. Van Ditmarsch; Andreas Herzig; Tiago De Lima

2007-01-01

56

Understanding Nuclear Receptors Using Computational Methods  

PubMed Central

Nuclear receptors (NRs) are important targets for therapeutic drugs. NRs regulate transcriptional activities through binding to ligands and interacting with a number of regulating proteins. Computational methods can provide insights into essential ligand-receptor and protein-protein interactions. These in turn have facilitated the discovery of novel agonists and antagonists with high affinity and specificity as well as aiding in the prediction of toxic side effects of drugs by identifying possible off-target interactions. Here, we review the application of computational methods towards several clinically important NRs (with special emphasis on PXR) and discuss their use for screening and predicting the toxic side effects of xenobiotics.

Ai, Ni; Krasowski, Matthew D.; Welsh, William J; Ekins, Sean

2010-01-01

57

An Efficient Method for Computing All Reducts  

NASA Astrophysics Data System (ADS)

In the process of data mining of decision table using Rough Sets methodology, the main computational effort is associated with the determination of the reducts. Computing all reducts is a combinatorial NP-hard computational problem. Therefore the only way to achieve its faster execution is by providing an algorithm, with a better constant factor, which may solve this problem in reasonable time for real-life data sets. The purpose of this presentation is to propose two new efficient algorithms to compute reducts in information systems. The proposed algorithms are based on the proposition of reduct and the relation between the reduct and discernibility matrix. Experiments have been conducted on some real world domains in execution time. The results show it improves the execution time when compared with the other methods. In real application, we can combine the two proposed algorithms.

Bao, Yongguang; Du, Xiaoyong; Deng, Mingrong; Ishii, Naohiro

58

Survey of the Computer Users of the Upper Arlington Public Library.  

ERIC Educational Resources Information Center

The Computer Services Department of the Upper Arlington Public Library in Franklin County, Ohio, provides microcomputers for public use, including IBM compatible and Macintosh computers, a laser printer, and dot-matrix printers. Circulation statistics provide data regarding the frequency and amount of computer use, but these statistics indicate…

Tsardoulias, L. Sevim

59

Computationally efficient method to construct scar functions  

NASA Astrophysics Data System (ADS)

The performance of a simple method [E. L. Sibert III, E. Vergini, R. M. Benito, and F. Borondo, New J. Phys.NJOPFM1367-263010.1088/1367-2630/10/5/053016 10, 053016 (2008)] to efficiently compute scar functions along unstable periodic orbits with complicated trajectories in configuration space is discussed, using a classically chaotic two-dimensional quartic oscillator as an illustration.

Revuelta, F.; Vergini, E. G.; Benito, R. M.; Borondo, F.

2012-02-01

60

Subspace methods and equilibration in computer vision  

Microsoft Academic Search

Many computer vision problems (e.g. the estimation of the fundamental matrix, the homography matrix, or camera cal- ibration as well as the factorization method) belong to the class of subspace problems which are well-known in sig- nal processing. They essentially consist in dividing a vector space into a lower dimensional data space and an orthogonal error space, based on the

Matthias Muhlich; Rudolf Mester

1999-01-01

61

Computational Thermochemistry and Benchmarking of Reliable Methods  

SciTech Connect

During the first and second years of the Computational Thermochemistry and Benchmarking of Reliable Methods project, we completed several studies using the parallel computing capabilities of the NWChem software and Molecular Science Computing Facility (MSCF), including large-scale density functional theory (DFT), second-order Moeller-Plesset (MP2) perturbation theory, and CCSD(T) calculations. During the third year, we continued to pursue the computational thermodynamic and benchmarking studies outlined in our proposal. With the issues affecting the robustness of the coupled cluster part of NWChem resolved, we pursued studies of the heats-of-formation of compounds containing 5 to 7 first- and/or second-row elements and approximately 10 to 14 hydrogens. The size of these systems, when combined with the large basis sets (cc-pVQZ and aug-cc-pVQZ) that are necessary for extrapolating to the complete basis set limit, creates a formidable computational challenge, for which NWChem on NWMPP1 is well suited.

Feller, David F.; Dixon, David A.; Dunning, Thom H.; Dupuis, Michel; McClemore, Doug; Peterson, Kirk A.; Xantheas, Sotiris S.; Bernholdt, David E.; Windus, Theresa L.; Chalasinski, Grzegorz; Fosada, Rubicelia; Olguim, Jorge; Dobbs, Kerwin D.; Frurip, Donald; Stevens, Walter J.; Rondan, Nelson; Chase, Jared M.; Nichols, Jeffrey A.

2006-06-20

62

Efficient methods to compute genomic predictions.  

PubMed

Efficient methods for processing genomic data were developed to increase reliability of estimated breeding values and to estimate thousands of marker effects simultaneously. Algorithms were derived and computer programs tested with simulated data for 2,967 bulls and 50,000 markers distributed randomly across 30 chromosomes. Estimation of genomic inbreeding coefficients required accurate estimates of allele frequencies in the base population. Linear model predictions of breeding values were computed by 3 equivalent methods: 1) iteration for individual allele effects followed by summation across loci to obtain estimated breeding values, 2) selection index including a genomic relationship matrix, and 3) mixed model equations including the inverse of genomic relationships. A blend of first- and second-order Jacobi iteration using 2 separate relaxation factors converged well for allele frequencies and effects. Reliability of predicted net merit for young bulls was 63% compared with 32% using the traditional relationship matrix. Nonlinear predictions were also computed using iteration on data and nonlinear regression on marker deviations; an additional (about 3%) gain in reliability for young bulls increased average reliability to 66%. Computing times increased linearly with number of genotypes. Estimation of allele frequencies required 2 processor days, and genomic predictions required <1 d per trait, and traits were processed in parallel. Information from genotyping was equivalent to about 20 daughters with phenotypic records. Actual gains may differ because the simulation did not account for linkage disequilibrium in the base population or selection in subsequent generations. PMID:18946147

VanRaden, P M

2008-11-01

63

The Contingent Valuation Method in Public Libraries  

ERIC Educational Resources Information Center

This study aims to present a new model measuring the economic value of public libraries, combining the dissonance minimizing (DM) and information bias minimizing (IBM) format in the contingent valuation (CV) surveys. The possible biases which are tied to the conventional CV surveys are reviewed. An empirical study is presented to compare the model…

Chung, Hye-Kyung

2008-01-01

64

The Contingent Valuation Method in Public Libraries  

ERIC Educational Resources Information Center

|This study aims to present a new model measuring the economic value of public libraries, combining the dissonance minimizing (DM) and information bias minimizing (IBM) format in the contingent valuation (CV) surveys. The possible biases which are tied to the conventional CV surveys are reviewed. An empirical study is presented to compare the…

Chung, Hye-Kyung

2008-01-01

65

Validating New Tuberculosis Computational Models with Public Whole Cell Screening Aerobic Activity Datasets  

Microsoft Academic Search

Purpose  The search for small molecules with activity against Mycobacterium tuberculosis (Mtb) increasingly uses high throughput screening and computational methods. Several public datasets from the Collaborative\\u000a Drug Discovery Tuberculosis (CDD TB) database have been evaluated with cheminformatics approaches to validate their utility\\u000a and suggest compounds for testing.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Previously reported Bayesian classification models were used to predict a set of 283 Novartis

Sean Ekins; Joel S. Freundlich

66

Computer based media access method and system  

US Patent & Trademark Office Database

The disclosed system and method includes a global computer network facility which provides a platform allowing artists to quickly and easily promote their music. A method and system of uploading songs establishes unique characteristics of each song with audio-analytical tools, and stores the analyzed songs on an online cloud computing storage facility. The artist-users can efficiently promote their music directly to the right suited audience in a fair fashion, providing a platform for all artists, including lesser known and popular artists. Simultaneously, the system allows listeners to readily access their entire music library from any mobile device via syncing music to devices with the invention's client application. At the same time, listener-users are automatically prompted with new or recommended music based on audio/acoustical characteristics of the song that they are currently listening to.

2013-06-25

67

Computational methods in noncoding RNA research  

Microsoft Academic Search

Non protein-coding RNAs (ncRNAs) are a research hotspot in bioinformatics. Recent discoveries have revealed new ncRNA families\\u000a performing a variety of roles, from gene expression regulation to catalytic activities. It is also believed that other families\\u000a are still to be unveiled. Computational methods developed for protein coding genes often fail when searching for ncRNAs. Noncoding\\u000a RNAs functionality is often heavily

Ariane Machado-Lima; Hernando A. del Portillo; Alan Mitchell Durham

2008-01-01

68

Computational methods of electron/photon transport  

SciTech Connect

A review of computational methods simulating the non-plasma transport of electrons and their attendant cascades is presented. Remarks are mainly restricted to linearized formalisms at electron energies above 1 keV. The effectiveness of various metods is discussed including moments, point-kernel, invariant imbedding, discrete-ordinates, and Monte Carlo. Future research directions and the potential impact on various aspects of science and engineering are indicated.

Mack, J.M.

1983-01-01

69

Advanced computational methods for nonlinear spin dynamics  

NASA Astrophysics Data System (ADS)

We survey methods for the accurate computation of the dynamics of spin in general nonlinear accelerator lattices. Specifically, we show how it is possible to compute high-order nonlinear spin transfer maps in SO(3) or SU(2) representations in parallel with the corresponding orbit transfer maps. Specifically, using suitable invariant subspaces of the coupled spin-orbit dynamics, it is possible to develop a differential algebraic flow operator in a similar way as in the symplectic case of the orbit dynamics. The resulting high-order maps can be utilized for a variety of applications, including long-term spin-orbit tracking under preservation of the symplectic-orthonormal structure and the associated determination of depolarization rates. Using normal form methods, it is also possible to determine spin-orbit invariants of the motion, in particular the nonlinear invariant axis as well as the associated spin-orbit tune shifts. The methods are implemented in the code COSY INFINITY [1] and available for spin-orbit computations for general accelerator lattices, including conventional particle optical elements including their fringe fields, as well as user specified field arrangements.

Berz, Martin; Makino, Kyoko

2011-05-01

70

Computations of entropy bounds: Multidimensional geometric methods  

SciTech Connect

The entropy bounds for constructive upper bound on the needed number-of-bits for solving a dichotomy is represented by the quotient of two multidimensional solid volumes. For minimization of this upper bound exact calculation of the volume of this quotient is needed. Three methods for exact computing of the volume of a given nD volume are presented: (1) general method for calculation any nD volume by slicing it into volumes of decreasing dimension is presented; (2) a method applying appropriate curvilinear coordinate system is described for volume bounded by symmetrical curvilinear hypersurfaces (spheres, cones, hyperboloids, ellipsoids, cylinders, etc.); and (3) an algorithm for dividing any nD complex into simplices and computing of the volume of the simplices is presented, supplemented by a general formula for calculation of volume of an nD simplex. These mathematical methods enable exact calculation of volume of any complicated multidimensional solids. The methods allow for the calculation of the minimal volume and lead to tighter bounds on the needed number-of-bits.

Makaruk, H.E.

1998-02-01

71

[Methods of computer-assisted molecular modeling].  

PubMed

We present an overview on modern computer methods of molecular modelling. After treating three main steps of drug evaluation, namely target identification, lead identification and lead optimisation, we shortly discuss molecular graphics, molecular mechanics, molecular orbital and molecular dynamics methods. These are suitable for the more-or-less adequate modelling of real molecular processes both at the microscopic and the macroscopic levels. Molecular graphics provides beautiful pictures for the specialist that allow inspection and manipulation of detailed molecular models. An especially useful tool for the visualisation of molecular entities is the display of various properties on the molecular surface that allows rapid recognition of important relationships. Molecular mechanics is able to predict properties (e.g. geometric parameters, conformer stability) of several classes of molecules with an accuracy close to the experimental one, therefore it plays an important role in complementing molecular graphics. The performance of molecular orbital methods increased considerably in the last decade thus we can calculate parameters for isolated or interacting molecules that are not easily amenable to experiment (e.g. structure and energetics of unstable species or activation energies of elementary processes). Computer simulation methods provide a link between gas-phase models of microscopic structures or processes and macroscopic properties or events that may be derived from the former. Thus, it became possible to apply computerised methods for an adequate simulation of important events, like chemical and biochemical reactions, drug-target interactions, drug delivery and the similar that determine drug action. It is stressed that the hardware and software for computer-aided molecular modelling may not be absent from the arsenal of a drug designer. PMID:9528144

Náray-Szabó, G

1998-01-01

72

Motivation for Green computer, methods used in computer science program  

Microsoft Academic Search

Computer science educators are uniquely positioned to promote greater awareness of Green computing, using the academic setting to encourage environmentally conscious use of technology. This paper reports on practical techniques that can engage faculty and students, enabling Green computing to be integrated into the classroom and research laboratory. Analysis and empirical evaluation of each reported technique is given, comparing the

V. Chauhan; A. Chauhan; S. Kapoor; S. Agrawal; R. R. Singh

2011-01-01

73

Numerical methods for problems in computational aeroacoustics  

NASA Astrophysics Data System (ADS)

A goal of computational aeroacoustics is the accurate calculation of noise from a jet in the far field. This work concerns the numerical aspects of accurately calculating acoustic waves over large distances and long time. More specifically, the stability, efficiency, accuracy, dispersion and dissipation in spatial discretizations, time stepping schemes, and absorbing boundaries for the direct solution of wave propagation problems are determined. Efficient finite difference methods developed by Tam and Webb, which minimize dispersion and dissipation, are commonly used for the spatial and temporal discretization. Alternatively, high order pseudospectral methods can be made more efficient by using the grid transformation introduced by Kosloff and Tal-Ezer. Work in this dissertation confirms that the grid transformation introduced by Kosloff and Tal-Ezer is not spectrally accurate because, in the limit, the grid transformation forces zero derivatives at the boundaries. If a small number of grid points are used, it is shown that approximations with the Chebyshev pseudospectral method with the Kosloff and Tal-Ezer grid transformation are as accurate as with the Chebyshev pseudospectral method. This result is based on the analysis of the phase and amplitude errors of these methods, and their use for the solution of a benchmark problem in computational aeroacoustics. For the grid transformed Chebyshev method with a small number of grid points it is, however, more appropriate to compare its accuracy with that of high- order finite difference methods. This comparison, for an order of accuracy 10-3 for a benchmark problem in computational aeroacoustics, is performed for the grid transformed Chebyshev method and the fourth order finite difference method of Tam. Solutions with the finite difference method are as accurate. and the finite difference method is more efficient than, the Chebyshev pseudospectral method with the grid transformation. The efficiency of the Chebyshev pseudospectral method is further improved by developing Runge-Kutta methods for the temporal discretization which maximize imaginary stability intervals. Two new Runge-Kutta methods, which allow time steps almost twice as large as the maximal order schemes, while holding dissipation and dispersion fixed, are developed. In the process of studying dispersion and dissipation, it is determined that maximizing dispersion minimizes dissipation, and vice versa. In order to determine accurate and efficient absorbing boundary conditions, absorbing layers are studied and compared with one way wave equations. The matched layer technique for Maxwell equations is equivalent to the absorbing layer technique for the acoustic wave equation introduced by Kosloff and Kosloff. The numerical implementation of the perfectly matched layer for the acoustic wave equation with a large damping parameter results in a small portion of the wave transmitting into the absorbing layer. A large damping parameter also results in a large portion of the wave reflecting back into the domain. The perfectly matched layer is implemented on a single domain for the solution of the second order wave equation, and when implemented in this manner shows no advantage over the matched layer. Solutions of the second order wave equation, with the absorbing boundary condition imposed either by the matched layer or by the one way wave equations, are compared. The comparison shows no advantage of the matched layer over the one way wave equation for the absorbing boundary condition. Hence there is no benefit to be gained by using the matched layer, which necessarily increases the size of the computational domain.

Mead, Jodi Lorraine

1998-12-01

74

Methods for fast computation of integral transforms  

SciTech Connect

This paper is concerned with two aspects of the numerical calculation of integral transforms. The first is finding a necessary and sufficient condition that enables converting an integral transform into a correlation (convolution) form. The condition and the transformation that implements it are generalizations of the Gardner transformation and derived in the paper. This technique can be applied to a wide class of integral transforms and is shown to reduce the computational complexity and storage requirements of the resulting algorithm. The second issue addressed in the paper is the accuracy of the calculation of the correlation integral, obtained by the above transformation, for a given number of samples. It is shown how the standard FFT method can be applied in combination with various numerical integration rules. This proves to be an important factor in expediting the computations, reducing the storage requirements, an improving the accuracy. 21 refs., 1 tab.

Gueron, S. (Cornell Univ., Ithaca, NY (United States))

1994-01-01

75

Development and publication of new gravimetric methods of analysis.  

PubMed

A review is made of the factors affecting the accuracy of gravimetric methods, and which need to be investigated in the development of new methods. Recommendations are made for writing up such investigations for publication. PMID:18960845

Erdey, L; Pólos, L; Chalmers, R A

1970-12-01

76

Saving lives: a computer simulation game for public education about emergencies  

SciTech Connect

One facet of the Information Revolution in which the nation finds itself involves the utilization of computers, video systems, and a variety of telecommunications capabilities by those who must cope with emergency situations. Such technologies possess a significant potential for performing emergency public education and transmitting key information that is essential for survival. An ''Emergency Public Information Competitive Challenge Grant,'' under the aegis of the Federal Emergency Management Agency (FEMA), has sponsored an effort to use computer technology - both large, time-sharing systems and small personal computers - to develop computer games which will help teach techniques of emergency management to the public at large. 24 references.

Morentz, J.W.

1985-01-01

77

Public Perceptions of the Computer Impact on Society.  

ERIC Educational Resources Information Center

Presents the feelings and considered opinions of noncomputer professionals in an effort to provide information to computer professionals who are concerned with defining their responsibility in the area of the effects of computer technology on human society. (Author/IRT)

Mathews, Walter M.; Sullivan, Kathleen

1979-01-01

78

Solar heating and cooling computer analysis - A simplified sizing design method for non-thermal specialists  

Microsoft Academic Search

Emphasis on solar energy for use in space heating and cooling presents a problem for many architects, heating, ventilating and air conditioning engineers, and contractors because they lack expertise in solar applications. This paper describes two public-domain computer design programs, written for use by the solar community. SOLCOST, a simplified sizing design method for nonthermal specialist users, computes an optimum

M. Connolly; R. Giellis; C. Jensen; R. McMordie

1976-01-01

79

Computationally Expensive Methods in Statistics: An Introduction  

Microsoft Academic Search

\\u000a Assuming a twodimensional data set with N observations (rows) and n variables (columns) there are two types of large scale data which require intensive computational work: \\u000a \\u000a \\u000a \\u000a 1 \\u000a \\u000a N >> n: traditional statistical methods: many points in low or medium dimensional space;  many  observations  but  moderate  number\\u000a  of variables; traditional ANOVA, L2, L1, and L? regression; discriminance analysis etc. applications in

Wolfgang M. Hartmann

2004-01-01

80

Linking computational methods across different length scales  

NASA Astrophysics Data System (ADS)

Throughout the Plenary and Break-Out Sessions at the Workshop the issue was frequently brought up of linking together computational approaches which traditionally operate on distinct length scales. In response to this interest, an informal discussion was held to examine the prospects for a collaborative initiative on coupling atomistic and continuum methods. At this gathering everyone agreed that for materials modeling to be predictive it must be firmly based on realistic physical descriptions of the underlying processes, and that such realism should exist at all levels of the computational hierarchy. There was strong consensus that the integration of computational approaches across different levels (length scales) is a critical issue facing the materials modeling community. While the need to couple the atomistic and continuum methods is now quite widely recognized, few studies have been carried out to sufficient extent as to provide useful guidance for further work. All participants agreed that the next course of action should focus on specific problems. To acknowledge the fact that many participants have made contributions to a discussion session that did not follow any organized format, we have decided to use citations. However, the reader should be fore-warned that our intention is to refer to contributions in the spirit of an informal discussion rather than any prepared and documented presentation. Under the circumstances, omissions and misinterpretations on our part are almost inevitable; for these we apologize. More accurate descriptions of the various views expressed on the issue of multiscale modeling can be found in the papers contained in Part III of these Proceedings.

Bulatov, V. V.; Yip, Sidney; Arias, Tomás

1996-08-01

81

Computationally sound mechanized proofs for basic and public-key Kerberos  

Microsoft Academic Search

We present a computationally sound mechanized analysis of Kerberos 5, both with and without its public-key extension PKINIT. We prove authentication and key secrecy proper- ties using the prover CryptoVerif, which works directly in the computational model; these are the first mechanical proofs of a full industrial protocol at the computational level. We also generalize the notion of key usability

Buno Blanchet; Aaron D. Jaggard; Andre Scedrov; Joe-kai Tsay

2008-01-01

82

Enhanced visualization methods for computed radiography images.  

PubMed

This paper focuses on the application of two image enhancement techniques for the picture archiving and communications systems imaging diagnostic workstation applied to computed radiography (CR) and digital radiography images. The first method is a contrast enhancement technique based on a class of nonlinear intensity transformations described by analytic transfer functions derived from Hurter and Driffield characteristic curves. The second method employs antialiasing techniques preventing the formation of Moiré patterns on subsampled CR images containing antiscatter grid lines, designed to achieve a good balance between artifact suppression and resolution degradation. These techniques are likely to become standard features for all high-end medical imaging workstations in the near future, and thus, we are suggesting that more powerful descriptions of these types of processing should be included in the Digital Imaging and Communications in Medicine standard. PMID:16341634

Bonciu, Cristian; Rezaee, Mahmoud R; Edwards, Warren

2006-06-01

83

An Inframarginal Analysis Based Resource Allocation Method in Distributed Computing  

Microsoft Academic Search

The key of distributed computing is to fully utilize computing resources. However, the efficiency of distributed computing can always be affected by volatility of available nodes and uncertainty of network environment. In order to enhance resource allocation efficiency in distributed computing, this paper presents an inframarginal analysis based resource allocation method, which distributes computing task to the node with more

Liu Jun; Wang En Ze; Qiao Jian Zhong; Lin Shu Kuan

2010-01-01

84

Optical design teaching by computing graphic methods  

NASA Astrophysics Data System (ADS)

One of the key challenges in the teaching of Optics is that students need to know not only the math of the optical design, but also, and more important, to grasp and understand the optics in a three-dimensional space. Having a clear image of the problem to solve is the first step in order to begin to solve that problem. Therefore to achieve that the students not only must know the equation of refraction law but they have also to understand how the main parameters of this law are interacting among them. This should be a major goal in the teaching course. Optical graphic methods are a valuable tool in this way since they have the advantage of visual information and the accuracy of a computer calculation.

Vazquez-Molini, D.; Muñoz-Luna, J.; Fernandez-Balbuena, A. A.; Garcia-Botella, A.; Belloni, P.; Alda, J.

2012-10-01

85

Public Workshop - Use of Computer Simulation of the United ...  

Center for Biologics Evaluation and Research (CBER)

... Use of Computer Simulation of the United States Blood Supply in Support of Planning for Emergency Preparedness and Medical Countermeasures. ... More results from www.fda.gov/biologicsbloodvaccines/newsevents/workshopsmeetingsconferences

86

Method for Computing Subjective Dissimilarities Among Discrete Entities.  

National Technical Information Service (NTIS)

A method for computing subjective dissimilarities among discrete entities is provided. The method includes the steps of presenting a plurality of entities to a perceiver, determining discrimination probabilities among the entities, and computing Fechneria...

E. Dzhafaroy H. Columus

2005-01-01

87

Computational methods for finite temperature quantum magnets  

NASA Astrophysics Data System (ADS)

Quantum spin models are of great interest because they describe the behavior of real magnetic materials and provide a simple context for understanding exotic quantum phases. Experimental results on the triangular lattice antiferromagnet NiGa2S4 in particular have motivated the study of S = 1 models having strong biquadratic interactions that favor a spin nematic ground state. We describe a scenario where the presence of such interactions in NiGa2S4 could be responsible for tuning it into the vicinity of a zero temperature critical point such that two distinct temperature scales emerge in its thermodynamic properties. We also observe that the likely presence of strong third-neighbor exchange interactions in this material leads to a finite temperature phase transition into a classical spin disordered phase that breaks lattice rotational symmetry. To confirm these predictions, we devise an approach in which the model is treated in a semi-classical approximation amenable to Monte Carlo simulations. Unlike a standard classical approximation, our method retains all of the symmetries of the quantum Hamiltonian and succeeds in correctly capturing the effects of biquadratic interactions. However, it is not able to make quantitatively accurate predictions. In order to address this shortcoming, we turn to a second method that is able to fully treat both quantum and classical thermal effects. In this method, thermal averages are computed by sampling a set of wave-functions known as minimally entangled typical thermal states, or METTS. We describe each step of the sampling process in detail and present efficient algorithms for working with matrix product states and matrix product operators. The METTS themselves can be studied to observe characteristic order and excitations of a system, and their properties reveal that they make an especially efficient basis for sampling. Finally, we explore the extent to which the average entanglement of a METTS ensemble is minimal. Future possibilities for both the semi-classical and METTS methods are discussed.

Stoudenmire, Edwin Miles

88

Study of basic computer competence among public health nurses in Taiwan.  

PubMed

Rapid advances in information technology and media have made distance learning on the Internet possible. This new model of learning allows greater efficiency and flexibility in knowledge acquisition. Since basic computer competence is a prerequisite for this new learning model, this study was conducted to examine the basic computer competence of public health nurses in Taiwan and explore factors influencing computer competence. A national cross-sectional randomized study was conducted with 329 public health nurses. A questionnaire was used to collect data and was delivered by mail. Results indicate that basic computer competence of public health nurses in Taiwan is still needs to be improved (mean = 57.57 +- 2.83, total score range from 26-130). Among the five most frequently used software programs, nurses were most knowledgeable about Word and least knowledgeable about PowerPoint. Stepwise multiple regression analysis revealed eight variables (weekly number of hours spent online at home, weekly amount of time spent online at work, weekly frequency of computer use at work, previous computer training, computer at workplace and Internet access, job position, education level, and age) that significantly influenced computer competence, which accounted for 39.0 % of the variance. In conclusion, greater computer competence, broader educational programs regarding computer technology, and a greater emphasis on computers at work are necessary to increase the usefulness of distance learning via the Internet in Taiwan. Building a user-friendly environment is important in developing this new media model of learning for the future. PMID:15136958

Yang, Kuei-Feng; Yu, Shu; Lin, Ming-Sheng; Hsu, Chia-Ling

2004-03-01

89

Computational methods in calculating superconducting current problems  

NASA Astrophysics Data System (ADS)

Various computational problems in treating superconducting currents are examined. First, field inversion in spatial Fourier transform space is reviewed to obtain both one-dimensional transport currents flowing down a long thin tape, and a localized two-dimensional current. The problems associated with spatial high-frequency noise, created by finite resolution and experimental equipment, are presented, and resolved with a smooth Gaussian cutoff in spatial frequency space. Convergence of the Green's functions for the one-dimensional transport current densities is discussed, and particular attention is devoted to the negative effects of performing discrete Fourier transforms alone on fields asymptotically dropping like 1/r. Results of imaging simulated current densities are favorably compared to the original distributions after the resulting magnetic fields undergo the imaging procedure. The behavior of high-frequency spatial noise, and the behavior of the fields with a 1/r asymptote in the imaging procedure in our simulations is analyzed, and compared to the treatment of these phenomena in the published literature. Next, we examine calculation of Mathieu and spheroidal wave functions, solutions to the wave equation in elliptical cylindrical and oblate and prolate spheroidal coordinates, respectively. These functions are also solutions to Schrodinger's equations with certain potential wells, and are useful in solving time-varying superconducting problems. The Mathieu functions are Fourier expanded, and the spheroidal functions expanded in associated Legendre polynomials to convert the defining differential equations to recursion relations. The infinite number of linear recursion equations is converted to an infinite matrix, multiplied by a vector of expansion coefficients, thus becoming an eigenvalue problem. The eigenvalue problem is solved with root solvers, and the eigenvector problem is solved using a Jacobi-type iteration method, after preconditioning the truncated matrix. The convergence of these methods, the methods' possible failure modes, and the run time of these algorithms are all discussed. Finally, the results of these algorithms are compared to the standard tables in the literature, to excellent agreement.

Brown, David John, II

90

A public data hub for benchmarking common brain-computer interface algorithms  

NASA Astrophysics Data System (ADS)

Methods of statistical machine learning have recently proven to be very useful in contemporary brain-computer interface (BCI) research based on the discrimination of electroencephalogram (EEG) patterns. Because of this, many research groups develop new algorithms for both feature extraction and classification. However, until now, no large-scale comparison of these algorithms has been accomplished due to the fact that little EEG data is publicly available. Therefore, we at Team PhyPA recorded 32-channel EEGs, electromyograms and electrooculograms of 36 participants during a simple finger movement task. The data are published on our website www.phypa.org and are freely available for downloading. We encourage BCI researchers to test their algorithms on these data and share their results. This work also presents exemplary benchmarking procedures of common feature extraction methods for slow cortical potentials and event-related desynchronization as well as for classification algorithms based on these features.

Zander, Thorsten O.; Ihme, Klas; Gärtner, Matti; Rötting, Matthias

2011-04-01

91

The performance of public key-enabled kerberos authentication in mobile computing applications  

Microsoft Academic Search

Authenticating mobile computing users can require a significant amount of processing and communications resources-particularly when protocols based on public key encryption are invoked. These resource requirements can result in unacceptable response times for the user. In this paper, we analyze adaptations of the public key-enabled Kerberos network authentication protocol to a mobile platform by measuring the service time of a

Alan Harbitter; Daniel A. Menascé

2001-01-01

92

The Use of Public Computing Facilities by Library Patrons: Demography, Motivations, and Barriers  

ERIC Educational Resources Information Center

Public libraries play an important part in the development of a community. Today, they are seen as more than store houses of books; they are also responsible for the dissemination of online, and offline information. Public access computers are becoming increasingly popular as more and more people understand the need for internet access. Using a…

DeMaagd, Kurt; Chew, Han Ei; Huang, Guanxiong; Khan, M. Laeeq; Sreenivasan, Akshaya; LaRose, Robert

2013-01-01

93

Public library computer training for older adults to access high-quality Internet health information  

Microsoft Academic Search

An innovative experiment to develop and evaluate a public library computer training program to teach older adults to access and use high-quality Internet health information involved a productive collaboration among public libraries, the National Institute on Aging and the National Library of Medicine of the National Institutes of Health (NIH), and a Library and Information Science (LIS) academic program at

Bo Xie; Julie M. Bugg

2009-01-01

94

Computer Methods in Stochastic Modeling (Komputerowe metody w modelowaniu stochastycznym)  

Microsoft Academic Search

The book can be classified as a work from a new quickly developing domain of applied and computational mathematics called numerical probability or computational stochastics. Authors present new computer methods of construction and investigation of various stochastic models describing problems arising in finance, economics, biology, physics and engineering, providing accurate descriptions of real-life phenomena. Enclosed original computer software package SDE-Solver

Aleksander Janicki; Adam Izydorczyk

95

Computers in Public Schools: Changing the Image with Image Processing.  

ERIC Educational Resources Information Center

|The kinds of educational technologies selected can make the difference between uninspired, rote computer use and challenging learning experiences. University of Arizona's Image Processing for Teaching Project has worked with over 1,000 teachers to develop image-processing techniques that provide students with exciting, open-ended opportunities…

Raphael, Jacqueline; Greenberg, Richard

1995-01-01

96

Object Orientated Methods in Computational Fluid Dynamics.  

NASA Astrophysics Data System (ADS)

We outline the aims of the FOAM code, a Finite Volume Computational Fluid Dynamics code written in C++, and discuss the use of Object Orientated Programming (OOP) methods to achieve these aims. The intention when writing this code was to make it as easy as possible to alter the modelling : this was achieved by making the top level syntax of the code as close as possible to conventional mathematical notation for tensors and partial differential equations. Object orientation enables us to define classes for both types of objects, and the operator overloading possible in C++ allows normal symbols to be used for the basic operations. The introduction of features such as automatic dimension checking of equations helps to enforce correct coding of models. We also discuss the use of OOP techniques such as data encapsulation and code reuse. As examples of the flexibility of this approach, we discuss the implementation of turbulence modelling using RAS and LES. The code is used to simulate turbulent flow for a number of test cases, including fully developed channel flow and flow around obstacles. We also demonstrate the use of the code for solving structures calculations and magnetohydrodynamics.

Tabor, Gavin; Weller, Henry; Jasak, Hrvoje; Fureby, Christer

1997-11-01

97

The Administrative Impact of Computers on the British Columbia Public School System.  

ERIC Educational Resources Information Center

|This case study analyzes and evaluates the administrative computer systems in the British Columbia public school organization in order to investigate the costs and benefits of computers, their impact on managerial work, their influence on centralization in organizations, and the relationship between organizational objectives and the design of…

Gibbens, Trevor P.

98

Program Documentation of a Computer Model for Variable Calculations of the Public School Foundation Program. Revised.  

ERIC Educational Resources Information Center

This publication documents the revised Alaska Finance Foundation Simulation Program, a computer finance simulation package for the Alaska School District Foundation Formula. The introduction briefly describes the program, which was written in Fortran for a Honeywell '66' computer located at the University of Alaska, Fairbanks, and allows…

Fullam, T. J.

99

Computers for Political Change: PeaceNet and Public Data Access.  

ERIC Educational Resources Information Center

|Describes two computer communication projects: PeaceNet, devoted to peace issues; and Public Data Access, devoted to making U.S. government information more broadly available. Discusses the potential of new technology (computer communication) for grass-roots political movements. (SR)|

Downing, John D. H.

1989-01-01

100

Grid and Distributed Public Computing Schemes for Structural Proteomics: A Short Overview  

Microsoft Academic Search

Grid and distributed public computing schemes has become an essential tool for many scientific fields including bioinformatics, computational biology and systems biology. The adoption of these technologies has given rise to a wide range of projects and contributions that provide various ways of setting up these environments and exploiting their potential resources and services for different domains of applications. This

Azhar Ali Shah; Daniel Barthel; Natalio Krasnogor

2007-01-01

101

Small Towns and Small Computers: Can a Match Be Made? A Public Policy Seminar.  

ERIC Educational Resources Information Center

A public policy seminar discussed how to match small towns and small computers. James K. Coyne, Special Assistant to the President and Director of the White House Office of Private Sector Initiatives, offered opening remarks and described a database system developed by his office to link organizations and communities with small computers to…

National Association of Towns and Townships, Washington, DC.

102

Improved Computational Methods for Ray Tracing  

Microsoft Academic Search

This paper describes algorithmic procedures that have been implemented to reduce the computational expense of producing ray-traced images. The selection of bounding volumes is examined to reduce the computational cost of the ray-intersection test. The use of object coherence, which relies on a hierarchical description of the environment, is then presented. Finally, since the building of the ray- intersection trees

Hank Weghorst; Gary Hooper; Donald P. Greenberg

1984-01-01

103

Python for Education: Computational Methods for Nonlinear Systems  

NSDL National Science Digital Library

The authors' interdisciplinary computational methods course uses Python and associated numerical and visualization libraries to enable students to implement simulations for several different course modules, which highlight the breadth and flexibility of Python-powered computational environments.

Myers, Christopher; Sethna, James

2008-07-23

104

Element-free Galerkin method for electromagnetic field computations  

Microsoft Academic Search

Although numerically very efficient the finite element method exhibits difficulties whenever the remeshing of the analysis domain must be performed. For such problems utilizing meshless computation methods is very promising. In this paper, a kind of meshless method called the element-free Galerkin method is introduced for electromagnetic field computation. The mathematical background for the moving least square approximation employed in

Vlatko CINGOSKI; Naoki MIYAMOTO; Hideo Yamashita

1998-01-01

105

Fast Multipole Methods for Scattering Computations.  

National Technical Information Service (NTIS)

The purpose of this phase of the project was to develop fast algorithms for computations of electromagnetic scattering (radar), and assist in the implementation and development of fast engineering software using these algorithms by the team at Hughes Rese...

V. Rokhlin R. R. Coifman V. Wickerhauser

1994-01-01

106

Computational aeroacoustics: Its methods and applications  

NASA Astrophysics Data System (ADS)

The first part of this thesis deals with the methodology of computational aeroacoustics (CAA). It is shown that although the overall accuracy of a broadband optimized upwind scheme can be improved to some degree, a scheme that is accurate everywhere in a wide range is not possible because increasing the accuracy for large wavenumbers is always at the expense of decreasing that for smaller wavenumbers. Partially for avoiding such a dilemma, optimized multi-component schemes are proposed that are superior to optimized broadband schemes for a sound field with dominant wavenumbers. The Fourier analysis shows that even for broadband waves an optimized central multi-component scheme is at least comparable to an optimized central broadband scheme. Numerical implementation of the impedance boundary condition in the time domain is a unique and challenging topic in CAA. A benchmark problem is proposed for such implementation and its analytical solution is derived. A CAA code using Tam and Auriault's formulation of broadband time-domain impedance boundary condition accurately reproduces the analytical solution. For the duct environment, the code also accurately predicts the analytical solution of a semi-infinite impedance duct problem and the experimental data from the NASA Langley Flow Impedance Tube Facility. In the second part of the thesis are applications of the developed CAA codes. A time-domain method is formulated to separate the instability waves from the acoustic waves of the linearized Euler equations in a critical sheared mean flow. Its effectiveness is demonstrated with the CAA code solving a test problem. Other applications are concerned with optimization using the CAA codes. A noise prediction and optimization system for turbofan engine inlet duct design is developed and applied in three scenarios: liner impedance optimization, duct geometry optimization and liner layout optimization. The results show that the system is effective in finding design variable values in favor of a given objective. In a different context of optimization, a conceptual design for adaptive noise control is developed. It consists of a liner with controllable impedance and an expert system realized with an optimizer coupled with the CAA code. The expert system is shown to be able to find impedance properties that minimize the difference between the current and the desired acoustic fields.

Zheng, Shi

107

Linking learning methods to outcomes in public health leadership development  

Microsoft Academic Search

Purpose – The purpose of this research is to present evaluation findings from the National Public Health Leadership Institute (PHLI) regarding how the curriculum's learning methods work singly and together to produce outcomes for learners and their organizations. Design\\/methodology\\/approach – Six months after graduation from PHLI, four recent cohorts of PHLI graduates were asked to report overall reactions to PHLI

Delesha L. Miller; Karl E. Umble; Steve L. Frederick; Donna R. Dinkin

2007-01-01

108

The Diffusion of Evaluation Methods among Public Relations Practitioners.  

ERIC Educational Resources Information Center

|A study explored the relationships between public relations practitioners' organizational roles and the type of evaluation methods they used on the job. Based on factor analysis of role data obtained from an earlier study, four organizational roles were defined and ranked: communication manager, media relations specialist, communication liaison,…

Dozier, David M.

109

The Diffusion of Evaluation Methods among Public Relations Practitioners.  

ERIC Educational Resources Information Center

A study explored the relationships between public relations practitioners' organizational roles and the type of evaluation methods they used on the job. Based on factor analysis of role data obtained from an earlier study, four organizational roles were defined and ranked: communication manager, media relations specialist, communication liaison,…

Dozier, David M.

110

Real-Time Optic Flow Computation with Variational Methods  

Microsoft Academic Search

Variational methods for optic flow computation have the rep- utation of producing good results at the expense of being too slow for real-time applications. We show that real-time variational computation of optic flow fields is possible when appropriate methods are combined with modern numerical techniques. We consider the CLG method, a re- cent variational technique that combines the quality of

Andrés Bruhn; Joachim Weickert; Christian Feddern; Timo Kohlberger; Christoph Schnörr

2003-01-01

111

Methods Towards Invasive Human Brain Computer Interfaces  

Microsoft Academic Search

During the last ten years there has been growing interest in the develop- ment of Brain Computer Interfaces (BCIs). The eld has mainly been driven by the needs of completely paralyzed patients to communicate. With a few exceptions, most human BCIs are based on extracranial elec- troencephalography (EEG). However, reported bit rates are still low. One reason for this is

Thomas Navin Lal; Thilo Hinterberger; Guido Widman; Michael Schröder; N. Jeremy Hill; Wolfgang Rosenstiel; Christian Erich Elger; Bernhard Schölkopf; Niels Birbaumer

2004-01-01

112

Methods towards invasive human brain computer interfaces  

Microsoft Academic Search

Abstract During the last ten years there has been growing interest in the development of Brain Computer Interfaces (BCIs). The eld,has mainly been driven by the needs of completely paralyzed patients to communicate. With a few exceptions, most human BCIs are based on extracranial electroencephalography (EEG). However, reported bit rates are still low. One reason for this is the low

T. N. Lal; T. Hinterberger; G. Widman; N. J. Hill; W. Rosenstiel; C. E. Elger; N. Birbaum

2005-01-01

113

Methods for multiphase computational fluid dynamics  

Microsoft Academic Search

This paper presents an overview of the physical models for computational fluid dynamic (CFD) predictions of multiphase flows. The governing equations and closure models are derived and presented for fluid–solid flows and fluid–fluid flows, both in an Eulerian and a Lagrangian framework. Some results obtained with these equations are presented. Finally, the capabilities and limitations of multiphase CFD are discussed.

B. G. M. van Wachem; A. E. Almstedt

2003-01-01

114

Zoom lens design methods for small computers  

Microsoft Academic Search

Zoom lens design is complicated. The application of rapid and disciplined procedures in nested iterative loops, with the designer interactively included is the best chance we have to be creative in this situation. This feature of the design process gives the opportunity to use small computers. The complete zoom lens design procedure is presented from this standpoint with details of

A. Osawa; J. Maxwell; M. J. Salter

1989-01-01

115

Investigation of Human-Computer Task Markets: Methods and Prototype  

Microsoft Academic Search

We lay out the challenges and opportunities of defining and optimizing the operation of human-computer task markets where planning and learning methods are used to identify and enlist both computational and human expertise to jointly contribute to the solution of problems, based on the competencies, availabilities, and pricing of different problem-solving resources. The approach melds the area of human computation

Dafna Shahaf; Eric Horvitz

2009-01-01

116

A Quantitative Method for Estimating Probable Public Costs of Hurricanes.  

PubMed

/ A method is presented for estimating probable public costs resulting from damage caused by hurricanes, measured as local government expenditures approved for reimbursement under the Stafford Act Section 406 Public Assistance Program. The method employs a multivariate model developed through multiple regression analysis of an array of independent variables that measure meteorological, socioeconomic, and physical conditions related to the landfall of hurricanes within a local government jurisdiction. From the regression analysis we chose a log-log (base 10) model that explains 74% of the variance in the expenditure data using population and wind speed as predictors. We illustrate application of the method for a local jurisdiction-Lee County, Florida, USA. The results show that potential public costs range from $4.7 million for a category 1 hurricane with winds of 137 kilometers per hour (85 miles per hour) to $130 million for a category 5 hurricane with winds of 265 kilometers per hour (165 miles per hour). Based on these figures, we estimate expected annual public costs of $2.3 million. These cost estimates: (1) provide useful guidance for anticipating the magnitude of the federal, state, and local expenditures that would be required for the array of possible hurricanes that could affect that jurisdiction; (2) allow policy makers to assess the implications of alternative federal and state policies for providing public assistance to jurisdictions that experience hurricane damage; and (3) provide information needed to develop a contingency fund or other financial mechanism for assuring that the community has sufficient funds available to meet its obligations. KEY WORDS: Hurricane; Public costs; Local government; Disaster recovery; Disaster response; Florida; Stafford Act PMID:9950698

BOSWELL; DEYLE; SMITH; BAKER

1999-04-01

117

Approximate Method for Computing Backwater Profiles in Corrugated Metal Pipes.  

National Technical Information Service (NTIS)

The determination of the shape and characteristics of a backwater profile in a closed conduit is generally a lengthy and tedious procedure without the use of a computer. By using the charts and tables of this publication and a few simple calculations, it ...

P. N. Zelensky

1976-01-01

118

Secure Encapsulation and Publication of Biological Services in the Cloud Computing Environment  

PubMed Central

Secure encapsulation and publication for bioinformatics software products based on web service are presented, and the basic function of biological information is realized in the cloud computing environment. In the encapsulation phase, the workflow and function of bioinformatics software are conducted, the encapsulation interfaces are designed, and the runtime interaction between users and computers is simulated. In the publication phase, the execution and management mechanisms and principles of the GRAM components are analyzed. The functions such as remote user job submission and job status query are implemented by using the GRAM components. The services of bioinformatics software are published to remote users. Finally the basic prototype system of the biological cloud is achieved.

Zhang, Weizhe; Wang, Xuehui; Lu, Bo; Kim, Tai-hoon

2013-01-01

119

Computational Methods for Collisional Plasma Physics  

SciTech Connect

Modeling the high density, high temperature plasmas produced by intense laser or particle beams requires accurate simulation of a large range of plasma collisionality. Current simulation algorithms accurately and efficiently model collisionless and collision-dominated plasmas. The important parameter regime between these extremes, semi-collisional plasmas, has been inadequately addressed to date. LLNL efforts to understand and harness high energy-density physics phenomena for stockpile stewardship require accurate simulation of such plasmas. We have made significant progress towards our goal: building a new modeling capability to accurately simulate the full range of collisional plasma physics phenomena. Our project has developed a computer model using a two-pronged approach that involves a new adaptive-resolution, ''smart'' particle-in-cell algorithm: complex particle kinetics (CPK); and developing a robust 3D massively parallel plasma production code Z3 with collisional extensions. Our new CPK algorithms expand the function of point particles in traditional plasma PIC models by including finite size and internal dynamics. This project has enhanced LLNL's competency in computational plasma physics and contributed to LLNL's expertise and forefront position in plasma modeling. The computational models developed will be applied to plasma problems of interest to LLNL's stockpile stewardship mission. Such problems include semi-collisional behavior in hohlraums, high-energy-density physics experiments, and the physics of high altitude nuclear explosions (HANE). Over the course of this LDRD project, the world's largest fully electromagnetic PIC calculation was run, enabled by the adaptation of Z3 to the Advanced Simulation and Computing (ASCI) White system. This milestone calculation simulated an entire laser illumination speckle, brought new realism to laser-plasma interaction simulations, and was directly applicable to laser target physics. For the first time, magnetic fields driven by Raman scatter have been observed. Also, Raman rescatter was observed in 2D. This code and its increased suite of dedicated diagnostics are now playing a key role in studies of short-pulse, high-intensity laser matter interactions. In addition, a momentum-conserving electron collision algorithm was incorporated into Z3. Finally, Z3's portability across diverse MPP platforms enabled it to serve the LLNL computing community as a tool for effectively utilizing new machines.

Lasinski, B F; Larson, D J; Hewett, D W; Langdon, A B; Still, C H

2004-02-18

120

Computational Methods for Analyzing Health News Coverage  

ERIC Educational Resources Information Center

|Researchers that investigate the media's coverage of health have historically relied on keyword searches to retrieve relevant health news coverage, and manual content analysis methods to categorize and score health news text. These methods are problematic. Manual content analysis methods are labor intensive, time consuming, and inherently…

McFarlane, Delano J.

2011-01-01

121

A typology of health marketing research methods--combining public relations methods with organizational concern.  

PubMed

Research plays a critical role throughout virtually every conduit of the health services industry. The key terms of research, public relations, and organizational interests are discussed. Combining public relations as a strategic methodology with the organizational concern as a factor, a typology of four different research methods emerges. These four health marketing research methods are: investigative, strategic, informative, and verification. The implications of these distinct and contrasting research methods are examined. PMID:19042536

Rotarius, Timothy; Wan, Thomas T H; Liberman, Aaron

2007-01-01

122

A Comparison of Computational Methods for Identifying Virulence Factors  

PubMed Central

Bacterial pathogens continue to threaten public health worldwide today. Identification of bacterial virulence factors can help to find novel drug/vaccine targets against pathogenicity. It can also help to reveal the mechanisms of the related diseases at the molecular level. With the explosive growth in protein sequences generated in the postgenomic age, it is highly desired to develop computational methods for rapidly and effectively identifying virulence factors according to their sequence information alone. In this study, based on the protein-protein interaction networks from the STRING database, a novel network-based method was proposed for identifying the virulence factors in the proteomes of UPEC 536, UPEC CFT073, P. aeruginosa PAO1, L. pneumophila Philadelphia 1, C. jejuni NCTC 11168 and M. tuberculosis H37Rv. Evaluated on the same benchmark datasets derived from the aforementioned species, the identification accuracies achieved by the network-based method were around 0.9, significantly higher than those by the sequence-based methods such as BLAST, feature selection and VirulentPred. Further analysis showed that the functional associations such as the gene neighborhood and co-occurrence were the primary associations between these virulence factors in the STRING database. The high success rates indicate that the network-based method is quite promising. The novel approach holds high potential for identifying virulence factors in many other various organisms as well because it can be easily extended to identify the virulence factors in many other bacterial species, as long as the relevant significant statistical data are available for them.

Zheng, Lu-Lu; Li, Yi-Xue; Ding, Juan; Guo, Xiao-Kui; Feng, Kai-Yan; Wang, Ya-Jun; Hu, Le-Le; Cai, Yu-Dong; Hao, Pei; Chou, Kuo-Chen

2012-01-01

123

Caller behaviour classification using computational intelligence methods.  

PubMed

A classification system that accurately categorizes caller interaction within Interactive Voice Response systems is essential in determining caller behaviour. Field and call performance classifier for pay beneficiary application are developed. Genetic Algorithms, Multi-Layer Perceptron neural network, Radial Basis Function neural network, Fuzzy Inference Systems and Support Vector Machine computational intelligent techniques were considered in this research. Exceptional results were achieved. Classifiers with accuracy values greater than 90% were developed. The preferred models for field 'Say amount', 'Say confirmation' and call performance classification are the ensemble of classifiers. However, the Multi-Layer Perceptron classifiers performed the best in field 'Say account' and 'Select beneficiary' classification. PMID:20180256

Patel, Pretesh B; Marwala, Tshilidzi

2010-02-01

124

Graphical electromagnetic computing method combined with IGES files import  

Microsoft Academic Search

In this paper, the graphical electromagnetic computing (GRECO) method combined with an interface that can identify and read IGES files is presented. Graphical electromagnetic computing (GRECO) is an effective method of predicting the radar cross section (RCS) of complex targets, but there must beforehand be a model file from which the shape parameter can be easily obtained. Based on the

Fang Xiang; Su Donglin; Liu Yan

2007-01-01

125

Applications of meshless methods for damage computations with finite strains  

Microsoft Academic Search

Material defects such as cavities have great effects on the damage process in ductile materials. Computations based on finite element methods (FEMs) often suffer from instability due to material failure as well as large distortions. To improve computational efficiency and robustness the element-free Galerkin (EFG) method is applied in the micro-mechanical constitute damage model proposed by Gurson and modified by

Xiaofei Pan; Huang Yuan

2009-01-01

126

An augmented Fast Marching Method for computing skeletons and centerlines  

Microsoft Academic Search

We present a simple and robust method for computing skeletons for arbitrary planar objects and centerlines for 3D objects. We augment the Fast Marching Method (FMM) widely used in level set applications by computing the paramterized boundary location every pixel came from during the boundary evolution. The resulting parameter field is then thresholded to produce the skeleton branches created by

Alexandru Telea; Jarke J. van Wijk

2002-01-01

127

A Meshless Method for Computational Stochastic Mechanics  

NASA Astrophysics Data System (ADS)

This paper presents a stochastic meshless method for probabilistic analysis of linear-elastic structures with spatially varying random material properties. Using Karhunen-Loève (K-L) expansion, the homogeneous random field representing material properties was discretized by a set of orthonormal eigenfunctions and uncorrelated random variables. Two numerical methods were developed for solving the integral eigenvalue problem associated with K-L expansion. In the first method, the eigenfunctions were approximated as linear sums of wavelets and the integral eigenvalue problem was converted to a finite-dimensional matrix eigenvalue problem that can be easily solved. In the second method, a Galerkin-based approach in conjunction with meshless discretization was developed in which the integral eigenvalue problem was also converted to a matrix eigenvalue problem. The second method is more general than the first, and can solve problems involving a multi-dimensional random field with arbitrary covariance functions. In conjunction with meshless discretization, the classical Neumann expansion method was applied to predict second-moment characteristics of the structural response. Several numerical examples are presented to examine the accuracy and convergence of the stochastic meshless method. A good agreement is obtained between the results of the proposed method and the Monte Carlo simulation. Since mesh generation of complex structures can be far more time-consuming and costly than the solution of a discrete set of equations, the meshless method provides an attractive alternative to the finite element method for solving stochastic-mechanics problems.

Rahman, S.; Xu, H.

2005-03-01

128

Discontinuous Galerkin Methods: Theory, Computation and Applications  

SciTech Connect

This volume contains a survey article for Discontinuous Galerkin Methods (DGM) by the editors as well as 16 papers by invited speakers and 32 papers by contributed speakers of the First International Symposium on Discontinuous Galerkin Methods. It covers theory, applications, and implementation aspects of DGM.

Cockburn, B.; Karniadakis, G. E.; Shu, C-W (Eds.)

2000-12-31

129

Computer decision-support systems for public argumentation: assessing deliberative legitimacy  

Microsoft Academic Search

Recent proposals for computer-assisted argumentation have drawn on dialectical models of argumentation. When used to assist public policy planning, such systems also raise questions of political legitimacy. Drawing on deliberative democratic theory, we elaborate normative criteria for deliberative legitimacy and illustrate their use for assessing two argumentation systems. Full assessment of such systems requires experiments in which system designers draw

William Rehg; Peter Mcburney; Simon Parsons

2005-01-01

130

Perceptions of Connectedness: Public Access Computing and Social Inclusion in Colombia  

Microsoft Academic Search

Of all the benefits public access computers (PAC) offer users, one stands apart: stronger personal connections with friends and family. A closer look at the results of a qualitative study among users of libraries, telecenters, and cybercafes in Colombia, South America, shows that social media and personal relationships can also have an important community and sociopolitical dimension. By fostering a

Luis Fernando Baron; Ricardo Gomez

2012-01-01

131

Bridging between organizations and the public: volunteer coordinators' uneasy relationship with social computing  

Microsoft Academic Search

We present the results of a qualitative study of the use of social computing technologies by volunteer coordinators at nonprofit organizations. The work of volunteer coordinators is bridge-building work - bringing together numerous public constituencies as well as constituencies within their organizations. One might expect this class of work to be well supported by social software, some of which has

Amy Voida; Ellie Harmon; Ban Al-Ani

2012-01-01

132

Advanced Telecommunications and Computer Technologies in Georgia Public Elementary School Library Media Centers.  

ERIC Educational Resources Information Center

The purpose of this study was to determine what recent progress had been made in Georgia public elementary school library media centers regarding access to advanced telecommunications and computer technologies as a result of special funding. A questionnaire addressed the following areas: automation and networking of the school library media center…

Rogers, Jackie L.

133

Computer crime and abuse: A survey of public attitudes and awareness  

Microsoft Academic Search

In recent years, a number of surveys have indicated a significant escalation in reported incidents of computer crime and abuse. This rise is coupled with increasing attention to the issue in the mass media, which has the effect of heightening public perceptions of problems with IT and may represent a barrier to the adoption of technologies such as the Internet

Paul Dowland; Steven Furnell; H. M. Illingworth; Paul L. Reynolds

1999-01-01

134

Trends in Access to Computing Technology and Its Use in Chicago Public Schools, 2001-2005  

ERIC Educational Resources Information Center

|Five years after Consortium on Chicago School Research (CCSR) research revealed a "digital divide" among Chicago Public Schools (CPS) and limited computer usage by staff and students, this new study shows that district schools have overcome many of these obstacles, particularly in terms of technology access and use among teachers and…

Coca, Vanessa; Allensworth, Elaine M.

2007-01-01

135

Teacher Use of Computers and the Internet in Public Schools. Stats in Brief.  

ERIC Educational Resources Information Center

|To address the need to understand the extent and types of teacher use of computers and the Internet, as well as teachers' perceptions of their own preparedness to use these tools in their classes, a National Center for Education Statistics (NCES) survey was commissioned. The survey found that 99% of full-time regular public school teachers…

Rowand, Cassandra

136

Computing what the public wants: Some issues in road safety cost–benefit analysis  

Microsoft Academic Search

In road safety, as in other fields, cost–benefit analysis (CBA) is used to justify the investment of public money and to establish priority between projects. It amounts to a computation by which ‘few’ – the CB analysts – aim to determine what the ‘many’ – those on behalf of which the choice is to be made – would choose. The

Ezra Hauer

2011-01-01

137

Computational Intelligence, Bioinformatics and Computational Biology: A Brief Overview of Methods, Problems and Perspectives  

Microsoft Academic Search

The paper is an overview of methods of computational intelligence (CI) used in the area of Bioin- formatics (BI) for the purpose of advancing the area Computational Biology (CB) and facilitating discoveries from biological data. CI is the area of developing generic intelligent information pro- cessing methods and systems with wider applications, one of them being Bioinformatics. CI adopts many

Nikola Kasabov; Igor A. Sidorov; Dimiter S. Dimitrov

2005-01-01

138

Phase Field Method: Spinodal Decomposition Computer Laboratory  

NSDL National Science Digital Library

In this lab, spinodal decomposition is numerically implemented in FiPy. A simple example python script (spinodal.py) summarizes the concepts. This lab is intended to complement the "Phase Field Method: An Introduction" lecture

Garcã­a, R. E.

2008-08-25

139

A Meshless Method for Computational Stochastic Mechanics  

Microsoft Academic Search

This paper presents a stochastic meshless method for probabilistic analysis of linear-elastic structures with spatially varying random material properties. Using Karhunen-Loève (K-L) expansion, the homogeneous random field representing material properties was discretized by a set of orthonormal eigenfunctions and uncorrelated random variables. Two numerical methods were developed for solving the integral eigenvalue problem associated with K-L expansion. In the first

S. Rahman; H. Xu

2005-01-01

140

A Meshless Method for Computational Stochastic Mechanics  

Microsoft Academic Search

This paper presents a stochastic meshless method for proba- bilistic analysis of linear-elastic structures with spatially varying random material properties. Using Karhunen-Loeve (K-L) expan- sion, the homogeneous random field representing material prop- erties was discretized by a set of orthonormal eigenfunctions and uncorrelated random variables. Two numerical methods were de- veloped for solving the integral eigenvalue problem associated with K-L

S. Rahman; H. Xu

2005-01-01

141

Assessment of gene order computing methods for Alzheimer's disease  

PubMed Central

Background Computational genomics of Alzheimer disease (AD), the most common form of senile dementia, is a nascent field in AD research. The field includes AD gene clustering by computing gene order which generates higher quality gene clustering patterns than most other clustering methods. However, there are few available gene order computing methods such as Genetic Algorithm (GA) and Ant Colony Optimization (ACO). Further, their performance in gene order computation using AD microarray data is not known. We thus set forth to evaluate the performances of current gene order computing methods with different distance formulas, and to identify additional features associated with gene order computation. Methods Using different distance formulas- Pearson distance and Euclidean distance, the squared Euclidean distance, and other conditions, gene orders were calculated by ACO and GA (including standard GA and improved GA) methods, respectively. The qualities of the gene orders were compared, and new features from the calculated gene orders were identified. Results Compared to the GA methods tested in this study, ACO fits the AD microarray data the best when calculating gene order. In addition, the following features were revealed: different distance formulas generated a different quality of gene order, and the commonly used Pearson distance was not the best distance formula when used with both GA and ACO methods for AD microarray data. Conclusion Compared with Pearson distance and Euclidean distance, the squared Euclidean distance generated the best quality gene order computed by GA and ACO methods.

2013-01-01

142

A Unified Method for Iterative Computation of Modular Multiplication and Reduction Operations  

Microsoft Academic Search

In this paper, a unified methodology is introduced for the computation of modular multiplication and reduction operations, which are fundamental to numerous public-key cryptography systems. First, a general theory is presented which aides the construction of arbitrary most-significant-digit first and least-significant-digit first iterative modular reduction methods. Utilizing this foundation, new methods are presented which are not premised in division techniques.

William L. Freking; Keshab K. Parhi

1999-01-01

143

Fast car/human classification methods in the computer vision tasks  

NASA Astrophysics Data System (ADS)

In this paper we propose a method for classification of moving objects of "human" and "car" types in computer vision systems using statistical hypotheses and integration of the results using two different decision rules. FAR-FRR graphs for all criteria and the decision rule are plotted. Confusion matrix for both ways of integration is presented. The example of the method application to the public video databases is provided. Ways of accuracy improvement are proposed.

Vishnyakov, Boris V.; Malin, Ivan K.; Vizilter, Yuri V.; Huang, Shih-Chia; Kuo, Sy-Yen

2013-04-01

144

Fast calculation method for spherical computer-generated holograms.  

PubMed

The synthesis of spherical computer-generated holograms is investigated. To deal with the staggering calculation times required to synthesize the hologram, a fast calculation method for approximating the hologram distribution is proposed. In this method, the diffraction integral is approximated as a convolution integral, allowing computation using the fast-Fourier-transform algorithm. The principles of the fast calculation method, the error in the approximation, and results from simulations are presented. PMID:16708098

Tachiki, Mark L; Sando, Yusuke; Itoh, Masahide; Yatagai, Toyohiko

2006-05-20

145

Identification of Parasitic Genes by Computational Methods  

Microsoft Academic Search

A number of parasite genome projects are under way, and large amounts of nucleotide sequence data are becoming available for analysis. There is an urgent need for development of theoretical tools to analyze the genome data, including identification of protein-coding sequences. The majority of the methods developed to date require prior information about the genome before accurate predictions can be

A. Bhattacharya; S. Bhattacharya; A. Joshi; S. Ramachandran; R. Ramaswamy

2000-01-01

146

Fast Method for Computer Image Enhancement.  

National Technical Information Service (NTIS)

The conventional method adopted for the contrast enhancement of an m x n pixel image involves m x n multiplications and hence the time required for the enhancement is proportional to the total number of pixels. The number of multiplications required for t...

P. Muralikrishna

1984-01-01

147

Automatic detection of lung nodules in computed tomography images: training and validation of algorithms using public research databases  

NASA Astrophysics Data System (ADS)

Lung cancer is one of the main public health issues in developed countries. Lung cancer typically manifests itself as non-calcified pulmonary nodules that can be detected reading lung Computed Tomography (CT) images. To assist radiologists in reading images, researchers started, a decade ago, the development of Computer Aided Detection (CAD) methods capable of detecting lung nodules. In this work, a CAD composed of two CAD subprocedures is presented: , devoted to the identification of parenchymal nodules, and , devoted to the identification of the nodules attached to the pleura surface. Both CADs are an upgrade of two methods previously presented as Voxel Based Neural Approach CAD . The novelty of this paper consists in the massive training using the public research Lung International Database Consortium (LIDC) database and on the implementation of new features for classification with respect to the original VBNA method. Finally, the proposed CAD is blindly validated on the ANODE09 dataset. The result of the validation is a score of 0.393, which corresponds to the average sensitivity of the CAD computed at seven predefined false positive rates: 1/8, 1/4, 1/2, 1, 2, 4, and 8 FP/CT.

Camarlinghi, Niccolò

2013-09-01

148

Public participation GIS: a method for identifying ecosystems services  

USGS Publications Warehouse

This study evaluated the use of an Internet-based public participation geographic information system (PPGIS) to identify ecosystem services in Grand County, Colorado. Specific research objectives were to examine the distribution of ecosystem services, identify the characteristics of participants in the study, explore potential relationships between ecosystem services and land use and land cover (LULC) classifications, and assess the methodological strengths and weakness of the PPGIS approach for identifying ecosystem services. Key findings include: (1) Cultural ecosystem service opportunities were easiest to identify while supporting and regulatory services most challenging, (2) participants were highly educated, knowledgeable about nature and science, and have a strong connection to the outdoors, (3) some LULC classifications were logically and spatially associated with ecosystem services, and (4) despite limitations, the PPGIS method demonstrates potential for identifying ecosystem services to augment expert judgment and to inform public or environmental policy decisions regarding land use trade-offs.

Brown, Greg; Montag, Jessica; Lyon, Katie

2012-01-01

149

Curriculum modules, software laboratories, and an inexpensive hardware platform for teaching computational methods to undergraduate computer science students  

Microsoft Academic Search

Computational methods are increasingly important to 21st century research and education; bioinformatics and climate change are just two examples of this trend. In this context computer scientists play an important role, facilitating the development and use of the methods and tools used to support computationally-based approaches. The undergraduate curriculum in computer science is one place where computational tools and methods

Charles Franklin Peck

2009-01-01

150

Low-Rank Incremental Methods for Computing Dominant Singular Subspaces  

SciTech Connect

Computing the singular values and vectors of a matrix is a crucial kernel in numerous scientific and industrial applications. As such, numerous methods have been proposed to handle this problem in a computationally efficient way. This paper considers a family of methods for incrementally computing the dominant SVD of a large matrix A. Specifically, we describe a unification of a number of previously disparate methods for approximating the dominant SVD via a single pass through A. We tie the behavior of these methods to that of a class of optimization-based iterative eigensolvers on A'*A. An iterative procedure is proposed which allows the computation of an accurate dominant SVD via multiple passes through A. We present an analysis of the convergence of this iteration, and provide empirical demonstration of the proposed method on both synthetic and benchmark data.

Baker, Christopher G [ORNL; Gallivan, Dr. Kyle A [Florida State University; Van Dooren, Dr. Paul [Universite Catholique de Louvain

2012-01-01

151

I LIKE Computers versus I LIKERT Computers: Rethinking Methods for Assessing the Gender Gap in Computing.  

ERIC Educational Resources Information Center

There is a burgeoning body of research on gender differences in computing attitudes and behaviors. After a decade of experience, researchers from both inside and outside the field of educational computing research are raising methodological and conceptual issues which suggest that perhaps researchers have shortchanged girls and women in…

Morse, Frances K.; Daiute, Colette

152

Computer Controlled Oral Test Administration: A Method and Example.  

ERIC Educational Resources Information Center

A computer/tape recorder interface was designed, which permits automatic oral adminstration of "true-false" or "multiple-choice" type tests. This paper describes the hardware and control program software, which were developed to implement the method on a DEC PDP 11 computer. (Author/JKS)

Milligan, W. Lloyd

1978-01-01

153

Evaluation of Tracking Methods for Human-Computer Interaction  

Microsoft Academic Search

Tracking methods are evaluated in a real-time feature tracking system used for human- computer interaction (HCI). The Camera Mouse, a HCI system that uses video input to manipulate the mouse cursor, was used as the test platform for this study. The Camera Mouse was developed to assist individuals with severe disabilities in using computers, but the technology may be used

Christopher Fagiani; Margrit Betke; James Gips

2002-01-01

154

Simple method for computing power systems maximum loading conditions  

Microsoft Academic Search

A very simple and fast method for computing power systems maximum loading points is proposed in this paper. These points are simply computed through repeated load flow solutions. The main contribution resides in the appropriate use of a special load flow with step size optimization and the extraction of useful information from it, which guides the search for the desired

C. H. Fujisawa; C. A. Castro

2009-01-01

155

Computational methods for Traditional Chinese Medicine: A survey  

Microsoft Academic Search

Traditional Chinese Medicine (TCM) has been actively researched through various approaches, including computational techniques. A review on basic elements of TCM is provided to illuminate various challenges and progresses in its study using computational methods. Information on various TCM formulations, in particular resources on databases of TCM formulations and their integration to Western medicine, are analyzed in several facets, such

Suryani Lukman; Yulan He; Siu-Cheung Hui

2007-01-01

156

Computer systems and methods for visualizing data  

DOEpatents

A method for forming a visual plot using a hierarchical structure of a dataset. The dataset comprises a measure and a dimension. The dimension consists of a plurality of levels. The plurality of levels form a dimension hierarchy. The visual plot is constructed based on a specification. A first level from the plurality of levels is represented by a first component of the visual plot. A second level from the plurality of levels is represented by a second component of the visual plot. The dataset is queried to retrieve data in accordance with the specification. The data includes all or a portion of the dimension and all or a portion of the measure. The visual plot is populated with the retrieved data in accordance with the specification.

Stolte, Chris (Palo Alto, CA); Hanrahan, Patrick (Portola Valley, CA)

2010-07-13

157

Computer based safety training: an investigation of methods  

PubMed Central

Background: Computer based methods are increasingly being used for training workers, although our understanding of how to structure this training has not kept pace with the changing abilities of computers. Information on a computer can be presented in many different ways and the style of presentation can greatly affect learning outcomes and the effectiveness of the learning intervention. Many questions about how adults learn from different types of presentations and which methods best support learning remain unanswered. Aims: To determine if computer based methods, which have been shown to be effective on younger students, can also be an effective method for older workers in occupational health and safety training. Methods: Three versions of a computer based respirator training module were developed and presented to manufacturing workers: one consisting of text only; one with text, pictures, and animation; and one with narration, pictures, and animation. After instruction, participants were given two tests: a multiple choice test measuring low level, rote learning; and a transfer test measuring higher level learning. Results: Participants receiving the concurrent narration with pictures and animation scored significantly higher on the transfer test than did workers receiving the other two types of instruction. There were no significant differences between groups on the multiple choice test. Conclusions: Narration with pictures and text may be a more effective method for training workers about respirator safety than other popular methods of computer based training. Further study is needed to determine the conditions for the effective use of this technology.

Wallen, E; Mulloy, K

2005-01-01

158

Explicit Building Block Multiobjective Evolutionary Computation: Methods and Applications.  

National Technical Information Service (NTIS)

This dissertation presents principles, techniques, and performance of evolutionary computation optimization methods. Concentration is on concepts, design formulation, and prescription for multiobjective problem solving and explicit building block (BB) mul...

R. O. Day

2005-01-01

159

Platform-independent method for computer aided schematic drawings  

SciTech Connect

A CAD/CAM method is disclosed for a computer system to capture and interchange schematic drawing and associated design information. The schematic drawing and design information are stored in an extensible, platform-independent format.

Vell, Jeffrey L. (Slingerlands, NY); Siganporia, Darius M. (Clifton Park, NY); Levy, Arthur J. (Fort Lauderdale, FL)

2012-02-14

160

An Innovative Method for Evaluating Strategic Goals in a Public Agency: Conservation Leadership in the U.S. Forest Service.  

ERIC Educational Resources Information Center

|Presents an innovative methodology for evaluating strategic goals in a public agency. The method involves computer content analysis of online news media text to evaluate expressed attitudes. Provides a way to assess the views of a wide range of stakeholders quickly and efficiently. (SLD)|

Bengston, David N.; Fan, David P.

1999-01-01

161

Methods for operating parallel computing systems employing sequenced communications  

DOEpatents

A parallel computing system and method are disclosed having improved performance where a program is concurrently run on a plurality of nodes for reducing total processing time, each node having a processor, a memory, and a predetermined number of communication channels connected to the node and independently connected directly to other nodes. The present invention improves performance of the parallel computing system by providing a system which can provide efficient communication between the processors and between the system and input and output devices. A method is also disclosed which can locate defective nodes with the computing system. 15 figs.

Benner, R.E.; Gustafson, J.L.; Montry, G.R.

1999-08-10

162

Using Computational Methods to Reinvigorate an Undergraduate Physics Curriculum  

NSDL National Science Digital Library

The increased importance of computational methods in physics has made it a must-have skill for undergraduate physics majors. The Austin Peay State University (APSU) Department of Physics and Astronomy has recently reinvigorated its program with the help of the Department of Mathematics by adding small computational components to classes across our curricula, as well as adding a single, required Computational Methods class to the physics major. In addition, we now emphasize a front-to-back problem management approach within our classes; this has required a significant change in the way in which we assess our students performance.

Taylor, Jaime; King, Alex

2008-06-07

163

Computer algebra methods in the study of nonlinear differential systems  

NASA Astrophysics Data System (ADS)

Some issues concerning computer algebra methods as applied to the qualitative analysis of differential equations with first integrals are discussed. The problems of finding stationary sets and analyzing their stability and bifurcations are considered. Special attention is given to algorithms for finding and analyzing peculiar stationary sets. It is shown that computer algebra tools, combined with qualitative analysis methods for differential equations, make it possible not only to enhance the computational efficiency of classical algorithms, but also to implement new approaches to the solution of well-known problems and, in this way, to obtain new results.

Irtegov, V. D.; Titorenko, T. N.

2013-06-01

164

Secure encapsulation and publication of biological services in the cloud computing environment.  

PubMed

Secure encapsulation and publication for bioinformatics software products based on web service are presented, and the basic function of biological information is realized in the cloud computing environment. In the encapsulation phase, the workflow and function of bioinformatics software are conducted, the encapsulation interfaces are designed, and the runtime interaction between users and computers is simulated. In the publication phase, the execution and management mechanisms and principles of the GRAM components are analyzed. The functions such as remote user job submission and job status query are implemented by using the GRAM components. The services of bioinformatics software are published to remote users. Finally the basic prototype system of the biological cloud is achieved. PMID:24078906

Zhang, Weizhe; Wang, Xuehui; Lu, Bo; Kim, Tai-Hoon

2013-09-01

165

Demand forecasting using fuzzy neural computation, with special emphasis on weekend and public holiday forecasting  

SciTech Connect

This paper describes the implementation and forecasting results of a hybrid fuzzy neural technique, which combines neural network modeling, and techniques from fuzzy logic and fuzzy set theory for electric load forecasting. The strengths of this powerful technique lie in its ability to forecast accurately on weekdays, as well as, on weekends, public holidays, and days before and after public holidays. Furthermore, use of fuzzy logic effectively handles the load variations due to special events. The Fuzzy-Neural Network (FNN) has been extensively tested on actual data obtained from a power system for 24-hour ahead prediction based on forecast weather information. Very impressive results, with an average error of 0.62% on weekdays, 0.83% on Saturdays and 1.17% on Sundays and public holidays have been obtained. This approach avoids complex mathematical calculations and training on many years of data, and is simple to implement on a personal computer.

Srinivasan, D.; Chang, C.S.; Liew, A.C. [National Univ. of Singapore (Singapore). Dept. of Electrical Engineering

1995-11-01

166

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm  

NASA Astrophysics Data System (ADS)

An image hiding method based on cascaded iterative Fourier transform and public-key encryption algorithm was proposed. Firstly, the original secret image was encrypted into two phase-only masks M1 and M2 via cascaded iterative Fourier transform (CIFT) algorithm. Then, the public-key encryption algorithm RSA was adopted to encrypt M2 into M2' . Finally, a host image was enlarged by extending one pixel into 2×2 pixels and each element in M1 and M2' was multiplied with a superimposition coefficient and added to or subtracted from two different elements in the 2×2 pixels of the enlarged host image. To recover the secret image from the stego-image, the two masks were extracted from the stego-image without the original host image. By applying public-key encryption algorithm, the key distribution was facilitated, and also compared with the image hiding method based on optical interference, the proposed method may reach higher robustness by employing the characteristics of the CIFT algorithm. Computer simulations show that this method has good robustness against image processing.

Zhang, B.; Sang, Jun; Alam, Mohammad S.

2013-03-01

167

Discrete fractional Fourier transform computation by adaptive method  

NASA Astrophysics Data System (ADS)

The continuous fractional Fourier transform (FRFT) can be interpreted as a rotation of a signal in the time-frequency plane and is a powerful tool for analyzing and processing nonstationary signals. Because of the importance of the FRFT, the discrete fractional Fourier transform (DFRFT) has recently become an important issue. We present the computation method for the DFRFT using the adaptive least-mean-square algorithm. First, the DFRFT computation scheme with single angle parameter of the signal block using the adaptive filter system is introduced. Second, considering the transform angles always change in practical applications, the DFRFT computation scheme with adjustable-angle parameter of the signal block using the adaptive filter system is presented. Then we construct two realization structures of the DFRFT computation with simultaneous multiple-angle parameters for each signal block. The proposed computation approaches have the inherent parallel structures, which make them suitable for efficient very large scale integration implementations.

Zhang, Feng; Tao, Ran; Wang, Yue

2013-06-01

168

A literature review of neck pain associated with computer use: public health implications  

PubMed Central

Prolonged use of computers during daily work activities and recreation is often cited as a cause of neck pain. This review of the literature identifies public health aspects of neck pain as associated with computer use. While some retrospective studies support the hypothesis that frequent computer operation is associated with neck pain, few prospective studies reveal causal relationships. Many risk factors are identified in the literature. Primary prevention strategies have largely been confined to addressing environmental exposure to ergonomic risk factors, since to date, no clear cause for this work-related neck pain has been acknowledged. Future research should include identifying causes of work related neck pain so that appropriate primary prevention strategies may be developed and to make policy recommendations pertaining to prevention.

Green, Bart N

2008-01-01

169

Analysing Privacy-Invasive Software Using Computer Forensic Methods  

Microsoft Academic Search

User privacy is widely affected by the occurrence of privacy-in- vasive software (PIS) on the Internet. We present a computer forensic inves- tigation method for detecting and analysing PIS. In an experiment we use this method to evaluate both the evolution of PIS and associated countermeas- ures, over a four year period. Background information on both PIS and coun- termeasure

Martin Boldt; Bengt Carlsson

170

A robust method for computing vehicle ego-motion  

Microsoft Academic Search

We describe a robust method for computing the ego-motion of the vehicle relative to the road using input from a single camera mounted next to the rear view mirror. Since feature points are unreliable in cluttered scenes we use direct methods where image values in the two images are combined in a global probability function. Combined with the use of

Gideon P. Stein; Ofer Mano; Amnon Shashua

2000-01-01

171

Linear and nonlinear methods for brain-computer interfaces  

Microsoft Academic Search

At the recent Second International Meeting on Brain-Computer Interfaces (BCIs) held in June 2002 in Rensselaerville, NY, a formal debate was held on the pros and cons of linear and nonlinear methods in BCI research. Specific examples applying EEG data sets to linear and nonlinear methods are given and an overview of the various pros and cons of each approach

Klaus-Robert Müller; Charles W. Anderson; Gary E. Birch

2003-01-01

172

Computer Subroutines for Analytic Rotation by Two Gradient Methods.  

ERIC Educational Resources Information Center

|Two computer subroutine packages for the analytic rotation of a factor matrix, A(p x m), are described. The first program uses the Flectcher (1970) gradient method, and the second uses the Polak-Ribiere (Polak, 1971) gradient method. The calculations in both programs involve the optimization of a function of free parameters. The result is a…

van Thillo, Marielle

173

Multiresolution reproducing kernel particle method for computational fluid dynamics  

Microsoft Academic Search

Multiresolution analysis based on the reproducing kernel particle method (RKPM) is developed for computational fluid dynamics. An algorithm incorporating multiple-scale adaptive refinement is introduced. The concept of using a wavelet solution as an error indicator is also presented. A few representative numerical examples are solved to illustrate the performance of this new meshless method. Results show that the RKPM is

Sukky Jun; Dirk Thomas Sihling; Yijung Chen; Wei Hao

1997-01-01

174

Toward a method of selecting among computational models of cognition  

Microsoft Academic Search

The question of how one should decide among competing explanations of data is at the heart of the scientific enterprise. Computational models of cognition are increasingly being advanced as explanations of behavior. The success of this line of inquiry depends on the development of robust methods to guide the evaluation and selection of these models. This article introduces a method

Mark A. Pitt; In Jae Myung; Shaobo Zhang

2002-01-01

175

Computer Subroutines for Analytic Rotation by Two Gradient Methods.  

ERIC Educational Resources Information Center

Two computer subroutine packages for the analytic rotation of a factor matrix, A(p x m), are described. The first program uses the Flectcher (1970) gradient method, and the second uses the Polak-Ribiere (Polak, 1971) gradient method. The calculations in both programs involve the optimization of a function of free parameters. The result is a…

van Thillo, Marielle

176

Reconnection methods for an arbitrary polyhedral computational grid  

SciTech Connect

The paper suggests a method for local reconstructions of a 3D irregular computational grid and the algorithm of its program implementation. Two grid reconstruction operations are used as basic: paste of two cells having a common face and cut of a certain cell into two by a given plane. This paper presents criteria to use one or another operation, the criteria are analyzed. A program for local reconstruction of a 3D irregular grid is used to conduct two test computations and the computed results are given.

Rasskazova, V.V.; Sofronov, I.D.; Shaporenko, A.N. [Russian Federal Nuclear Center (Russian Federation); Burton, D.E.; Miller, D.S. [Lawrence Livermore National Lab., CA (United States)

1996-08-01

177

An adaptive sequential Monte Carlo method for approximate Bayesian computation  

Microsoft Academic Search

Approximate Bayesian computation (ABC) is a popular approach to address inference problems where the likelihood function is\\u000a intractable, or expensive to calculate. To improve over Markov chain Monte Carlo (MCMC) implementations of ABC, the use of\\u000a sequential Monte Carlo (SMC) methods has recently been suggested. Most effective SMC algorithms that are currently available\\u000a for ABC have a computational complexity that

Pierre Del Moral; Arnaud Doucet; Ajay Jasra

178

Implementation of an ADI Method on parallel computers  

Microsoft Academic Search

In this paper we discuss the implementation of an ADI method for solving the diffusion equation on three parallel\\/vector computers. The computers were chosen so as to encompass a variety of architectures. They are the MPP, an SIMD machine with 16-Kbit serial processors; Flex\\/32, an MIMD machine with 20 processors; and Cray\\/2, an MIMD machine with four vector processors. The

Raad A. Fatoohi; Chester E. Grosch

1987-01-01

179

Extrapolation methods for accelerating PageRank computations  

Microsoft Academic Search

We present a novel algorithm for the fast computation of PageRank, a hyperlink-based estimate of the ''importance'' of Web pages. The original PageRank algorithm uses the Power Method to compute successive iterates that converge to the principal eigenvector of the Markov matrix representing the Web link graph. The algorithm presented here, called Quadratic Extrapolation, accelerates the convergence of the Power

Sepandar D. Kamvar; Taher H. Haveliwala; Christopher D. Manning; Gene H. Golub

2003-01-01

180

Public involvement in multi-objective water level regulation development projects-evaluating the applicability of public involvement methods  

SciTech Connect

Public involvement is a process that involves the public in the decision making of an organization, for example a municipality or a corporation. It has developed into a widely accepted and recommended policy in environment altering projects. The EU Water Framework Directive (WFD) took force in 2000 and stresses the importance of public involvement in composing river basin management plans. Therefore, the need to develop public involvement methods for different situations and circumstances is evident. This paper describes how various public involvement methods have been applied in a development project involving the most heavily regulated lake in Finland. The objective of the project was to assess the positive and negative impacts of regulation and to find possibilities for alleviating the adverse impacts on recreational use and the aquatic ecosystem. An exceptional effort was made towards public involvement, which was closely connected to planning and decision making. The applied methods were (1) steering group work, (2) survey, (3) dialogue, (4) theme interviews, (5) public meeting and (6) workshops. The information gathered using these methods was utilized in different stages of the project, e.g., in identifying the regulation impacts, comparing alternatives and compiling the recommendations for regulation development. After describing our case and the results from the applied public involvement methods, we will discuss our experiences and the feedback from the public. We will also critically evaluate our own success in coping with public involvement challenges. In addition to that, we present general recommendations for dealing with these problematic issues based on our experiences, which provide new insights for applying various public involvement methods in multi-objective decision making projects.

Vaentaenen, Ari [Department of Sociology, FIN 20014 University of Turku (Finland)]. E-mail: armiva@utu.fi; Marttunen, Mika [Department for Expert Services, Finnish Environment Institute, P.O. Box 140 FIN 00251 Helsinki (Finland)]. E-mail: Mika.Marttunen@ymparisto.fi

2005-04-15

181

Novel Methods for Communicating Plasma Science to the General Public  

NASA Astrophysics Data System (ADS)

The broader implications of Plasma Science remains an elusive topic that the general public rarely discusses, regardless of their relevance to energy, the environment, and technology. Recently, we have looked beyond print media for methods to reach large numbers of people in creative and informative ways. These have included video, art, images, and music. For example, our submission to the ``What is a Flame?'' contest was ranked in the top 15 out of 800 submissions. Images of plasmas have won 3 out of 5 of the Princeton University ``Art of Science'' competitions. We use a plasma speaker to teach students of all ages about sound generation and plasma physics. We report on the details of each of these and future videos and animations under development.

Zwicker, Andrew; Merali, Aliya; Wissel, S. A.; Delooper, John

2012-10-01

182

Curriculum modules, software laboratories, and an inexpensive hardware platform for teaching computational methods to undergraduate computer science students  

NASA Astrophysics Data System (ADS)

Computational methods are increasingly important to 21st century research and education; bioinformatics and climate change are just two examples of this trend. In this context computer scientists play an important role, facilitating the development and use of the methods and tools used to support computationally-based approaches. The undergraduate curriculum in computer science is one place where computational tools and methods can be introduced to facilitate the development of appropriately prepared computer scientists. To facilitate the evolution of the pedagogy, this dissertation identifies, develops, and organizes curriculum materials, software laboratories, and the reference design for an inexpensive portable cluster computer, all of which are specifically designed to support the teaching of computational methods to undergraduate computer science students. Keywords. computational science, computational thinking, computer science, undergraduate curriculum.

Peck, Charles Franklin

183

SAR/QSAR methods in public health practice.  

PubMed

Methods of (Quantitative) Structure-Activity Relationship ((Q)SAR) modeling play an important and active role in ATSDR programs in support of the Agency mission to protect human populations from exposure to environmental contaminants. They are used for cross-chemical extrapolation to complement the traditional toxicological approach when chemical-specific information is unavailable. SAR and QSAR methods are used to investigate adverse health effects and exposure levels, bioavailability, and pharmacokinetic properties of hazardous chemical compounds. They are applied as a part of an integrated systematic approach in the development of Health Guidance Values (HGVs), such as ATSDR Minimal Risk Levels, which are used to protect populations exposed to toxic chemicals at hazardous waste sites. (Q)SAR analyses are incorporated into ATSDR documents (such as the toxicological profiles and chemical-specific health consultations) to support environmental health assessments, prioritization of environmental chemical hazards, and to improve study design, when filling the priority data needs (PDNs) as mandated by Congress, in instances when experimental information is insufficient. These cases are illustrated by several examples, which explain how ATSDR applies (Q)SAR methods in public health practice. PMID:21034766

Demchuk, Eugene; Ruiz, Patricia; Chou, Selene; Fowler, Bruce A

2010-10-27

184

PBL and Computer Programming — The Seven Steps Method with Adaptations  

NASA Astrophysics Data System (ADS)

Problem-Based Learning (PBL) method emphasizes students' own activity in learning about problems, setting up their own learning goals and actively searching for and analyzing information. In this paper, we describe and discuss our experiences on applying PBL, especially the seven steps method widely used in medical faculties, in an introductory computer programming course. We explain how the method is implemented, give examples and identify different kinds of PBL cases, and describe how the method is supplemented by other learning methods in our course. According to our experience, the PBL method increases the commitment of the students which results in a significantly lower drop-out rate: the average is 17% versus 45% in our traditional programming courses. In addition to computer programming, students also learn generic skills related to group work, collaborative design work, independent studying, and externalization of their knowledge.

Nuutila, Esko; Törmä, Seppo; Malmi, Lauri

2005-06-01

185

Computational Method to Model Radar Return Range in a Polygonally Based, Computer-Generated-Imagery Simulation.  

National Technical Information Service (NTIS)

Described is a method for modeling a ground-mapping radar system for use in simulations where the terrain is in a polygonal form commonly used with computer generated imagery (CGI). The method employs a unique approach for rapidly rejecting polygons not v...

F. J. Moran J. D. Phillips

1986-01-01

186

The Spectral-Element Method, Beowulf Computing, and Global Seismology  

Microsoft Academic Search

The propagation of seismic waves through Earth can now be modeled accurately with the recently developed spectral-element method. This method takes into account heterogeneity in Earth models, such as three-dimensional variations of seismic wave velocity, density, and crustal thickness. The method is implemented on relatively inexpensive clusters of personal computers, so-called Beowulf machines. This combination of hardware and software enables

Dimitri Komatitsch; Jeroen Ritsema; Jeroen Tromp

2002-01-01

187

Efficient algorithm for computing orbital energies within elongation method  

NASA Astrophysics Data System (ADS)

We developed a new approach for solving eigenvalue problem for the oligomer chain systems based on localized molecular orbitals (LMO) of the separated fragments within elongation method. The method performed in this work and implemented in elongation scheme yields excellent agreement with the conventional results. It has been demonstrated that the proposed algorithm for computing orbital energies and eigenvectors in elongation method reduces the CPU time usage up to 50%.

Loboda, Oleksandr; Gu, Feng Long; Pomogaeva, Anna V.; Makowski, Marcin; Aoki, Yuriko

2012-12-01

188

Geometrical MTF computation method based on the irradiance model  

NASA Astrophysics Data System (ADS)

The Modulation Transfer Function (MTF) is a measure of an optical system's ability to transfer contrast from the specimen to the image plane at a specific resolution. It can be computed either numerically by geometrical optics or measured experimentally by imaging a knife edge or a bar-target pattern of varying spatial frequency. Previously, MTF accuracy was generally affected by the size of the mesh on the image plane. This paper presents a new MTF computation method based on the irradiance model, without counting the number of rays hitting each grid. To verify the method, the MTF in the sagittal and meridional directions of an axis-symmetrical optical system is computed by both the ray-counting and the proposed methods. It is found that the grid size meshed on the image plane significantly affects the MTF of the ray-counting method, sometimes with significantly negative results. The proposed irradiance method is immune to issues of grid size. The CPU computation time for the two methods is approximately the same.

Lin, P.-D.; Liu, C.-S.

2011-01-01

189

a Computationally Efficient Particle Simulation Method Suited to Vector Computer Architectures.  

NASA Astrophysics Data System (ADS)

Recent interest in a National Aero-Space Plane (NASP) and various Aero-assisted Space Transfer Vehicles (ASTVs) presents the need for a greater understanding of high-speed rarefied flight conditions. Particle simulation techniques such as the Direct Simulation Monte Carlo (DSMC) method are well suited to such problems, but the high cost of computation limits the application of the methods to two-dimensional or very simple three-dimensional problems. This research re-examines the algorithmic structure of existing particle simulation methods and re-structures them to allow efficient implementation on vector-oriented supercomputers. A brief overview of the DSMC method and the Cray-2 vector computer architecture are provided, and the elements of the DSMC method that inhibit substantial vectorization are identified. One such element is the collision selection algorithm. A complete reformulation of underlying kinetic theory shows that this may be efficiently vectorized for general gas mixtures. The mechanics of collisions are vectorizable in the DSMC method, but several optimizations are suggested that greatly enhance performance. Also this thesis proposes a new mechanism for the exchange of energy between vibration and other energy modes. The developed scheme makes use of quantized vibrational states and is used in place of the Borgnakke-Larsen model. Finally, a simplified representation of physical space and boundary conditions is utilized to further reduce the computational cost of the developed method. Comparison to solutions obtained from the DSMC method for the relaxation of internal energy modes in a homogeneous gas, as well as single and multiple specie shock wave profiles, are presented. Additionally, a large scale simulation of the flow about the proposed Aero-assisted Flight Experiment (AFE) vehicle is included as an example of the new computational capability of the developed particle simulation method. It is concluded that efficient vectorization of a particle simulation method is possible and up to two orders of magnitude improvement in computational performance can be attained.

McDonald, Jeffrey Douglas

1990-01-01

190

Computational methods for predicting protein-protein interactions.  

PubMed

Protein-protein interactions (PPIs) play a critical role in many cellular functions. A number of experimental techniques have been applied to discover PPIs; however, these techniques are expensive in terms of time, money, and expertise. There are also large discrepancies between the PPI data collected by the same or different techniques in the same organism. We therefore turn to computational techniques for the prediction of PPIs. Computational techniques have been applied to the collection, indexing, validation, analysis, and extrapolation of PPI data. This chapter will focus on computational prediction of PPI, reviewing a number of techniques including PIPE, developed in our own laboratory. For comparison, the conventional large-scale approaches to predict PPIs are also briefly discussed. The chapter concludes with a discussion of the limitations of both experimental and computational methods of determining PPIs. PMID:18202838

Pitre, Sylvain; Alamgir, Md; Green, James R; Dumontier, Michel; Dehne, Frank; Golshani, Ashkan

2008-01-01

191

Numerical methods to compute optical errors due to stress birefringence  

Microsoft Academic Search

A method to compute polarization changes and wavefront error due to mechanical stress in transmissive optical elements is presented. In general, stress produces an anisotropic and inhomogeneous optical medium where the magnitude and direction of the indices of refraction vary at every point. Jones calculus is used to incrementally evaluate the effects of stress for a grid of rays traced

Keith B. Doyle; Victor L. Genberg; Gregory J. Michels

2002-01-01

192

Cluster variation method in the computational materials science  

Microsoft Academic Search

Cluster Variation Method (CVM) has been very successful in the computations of alloy phase diagrams as well as in many problems of the materials science related to the phase transitions. Originally, CVM was developed in the framework of the so-called rigid lattice approximation, but it has recently been extended to include continuous atomic displacements due to thermal lattice vibration and

R. Kikuchi; K. Masuda-Jindo

2002-01-01

193

EQUILIBRIUM AND NONEQUILIBRIUM FOUNDATIONS OF FREE ENERGY COMPUTATIONAL METHODS  

SciTech Connect

Statistical mechanics provides a rigorous framework for the numerical estimation of free energy differences in complex systems such as biomolecules. This paper presents a brief review of the statistical mechanical identities underlying a number of techniques for computing free energy differences. Both equilibrium and nonequilibrium methods are covered.

C. JARZYNSKI

2001-03-01

194

Plane Couette Flow Computations by TRMC and MFS Methods.  

National Technical Information Service (NTIS)

A new class of schemes of the DSMC type for computing near-continuum flows has been recently suggested: the time-relaxed Monte Carlo (TRMC) methods. An important step preceding the wide use of these schemes is their validation by classical homogeneous and...

G. Russo L. Pareschi S. Trazzi A. A. Shevyrin Y. A. Bondar

2005-01-01

195

A computationally practical method for stochastic groundwater modeling  

Microsoft Academic Search

Stochastic theories of subsurface flow and transport have changed the way we think about heterogeneity but have not had much impact on practical groundwater modeling. Most numerical models still provide no information on prediction uncertainty. This gap between theory and practice is due largely to the excessive computational demands of available numerical methods for solving stochastic problems. The two primary

Shu-Guang Li; Dennis McLaughlin; Hua-Sheng Liao

2003-01-01

196

Computational method for radar absorbing composite lattice grids  

Microsoft Academic Search

Composite lattice grids reinforced by glass fibers (GFRC) and carbon fibers (CFRC) filled with spongy materials can be designed as lightweight radar absorbing structures (RAS). In the present paper, a computational approach based on periodic moment method (PMM) has been developed to calculate reflection coefficients of radar absorbing composite lattice grids. Total reflection backing (TRB) is considered directly in our

Mingji Chen; Yongmao Pei; Daining Fang

2009-01-01

197

Three dimensional traveltime computation using the Fast Marching Method  

Microsoft Academic Search

We present a fast algorithm for solving the eikonal equation in three dimensions,based on the Fast Marching Method (FMM). The algorithm is of order O(N log N ),where N is the total number of grid points in the computational domain. The algorithmcan be used in any orthogonal coordinate system, and globaly constructs thesolution to the eikonal equation for each point

James A. Sethian; Alexander Mihai Popovici

1998-01-01

198

Computational Methods for Sparse Solution of Linear Inverse Problems  

Microsoft Academic Search

The goal of the sparse approximation problem is to approximate a target signal using a linear combination of a few elementary signals drawn from a fixed collection. This paper surveys the major practical algorithms for sparse approximation. Specific attention is paid to computational issues, to the circumstances in which individual methods tend to perform well, and to the theoretical guarantees

Joel A. Tropp; Stephen J. Wright

2010-01-01

199

Computer method and apparatus for aggregating and segmenting probabilistic distributions  

US Patent & Trademark Office Database

Computer method and apparatus that permits a sensory oriented interactive real time aggregation and segmentation of probabilistic distributions derived from quantitative and qualitative data of one or more sources with a feedback mechanism that describes distribution attributes in a variety of visual, kinetic, and aural contexts.

2008-11-18

200

Micro-computed tomography: an alternative method for shark ageing.  

PubMed

Micro-computed tomography (microCT) produced 3D reconstructions of shark Carcharhinus brevipinna vertebrae that could be virtually sectioned along any desired plane, and upon which growth bands were readily visible. When compared to manual sectioning, it proved to be a valid and repeatable means of ageing and offers several distinct advantages over other ageing methods. PMID:22497384

Geraghty, P T; Jones, A S; Stewart, J; Macbeth, W G

2012-02-16

201

Using hierarchical soft computing method to discriminate microcyte anemia  

Microsoft Academic Search

Anemia is the most common hematological disorder. The complete blood count (CBC) is used to identify anemia and others disorder relative to hematology. However, discriminating both of iron deficiency anemias (IDA) and thalassemia (THA) depend on the mean cell volume (MCV) less than 80fL (fluid ounces) that is imprecision and uncertain. Recently, more literatures applied soft computing methods to solved

Jehn-shan Yeh; Ching-hsue Cheng

2005-01-01

202

Computational methods for creep fracture analysis by damage mechanics  

Microsoft Academic Search

Some mechanical problems of the computational method of creep fracture analysis based on continuum damage mechanics are discussed. After brief review of the local approach to creep crack growth analysis by means of finite element analysis and continuum damage mechanics, intrinsic feature of the fracture analysis in the framework of continuum theory and the causes of mesh-dependence of the numerical

S. Murakami; Y. Liu; M. Mizuno

2000-01-01

203

Computational methods for calculating geometric parameters of tectonic plates  

Microsoft Academic Search

Present day and ancient plate tectonic configurations can be modelled in terms of non-overlapping polygonal regions, separated by plate boundaries, on the unit sphere. The computational methods described in this article allow an evaluation of the area and the inertial tensor components of a polygonal region on the unit sphere, as well as an estimation of the associated errors. These

Antonio Schettino

1999-01-01

204

Nongradient minimization methods for parallel processing computers, part 1  

Microsoft Academic Search

This paper attempts to provide minimization algorithms which are adapted to execution on parallel computers. For this purpose, three well-known nongradient methods are examined. From these, three parallel iterative procedures are derived, by discussing in detail their mathematical behavior, when the cooperating processes are either synchronous or asynchronous.

C. Sutti

1983-01-01

205

COMPUTER-BASED TRIZ - SYSTEMATIC INNOVATION METHODS FOR ARCHITECTURE  

Microsoft Academic Search

The Russian Theory of Inventive Problem Solving, TRIZ, is the most comprehensive systematic innovation and creativity methodology available. Essentially the method consists of restating a specific design task in a more general way and then selecting generic solutions from databases of patents and solutions from a wide range of technologies. The development of computer databases greatly facilitates this task. Since

Darrell L Mann; Conall Ó Catháin

206

An Introduction to Computer Simulation Methods Third Edition (draft)  

NSDL National Science Digital Library

Draft chapters for An Introduction to Computer Simulation Methods (CSM) Third Edition. The third edition of CSM is Java-based and uses the object-oriented Open Source Physics code library. Examples described in this book are distributed in a ready-to-run Launcher package. Source code is available in an Eclipse workspace under the GNU GPL open source license.

Gould, Harvey; Tobochnik, Jan; Christian, Wolfgang

2008-06-05

207

Boundary method for attenuation correction in positron computed tomography  

SciTech Connect

A new method for attenuation correction in positron computed tomography (PCT) has been developed, and it can improve the quality of PCT images. The method requires a short transmission scan by the PCT system. Then boundaries between tissues with significantly different attenuation coefficients are determined from the transmission image by edge-finding techniques. Attenuation correction factors (ACF) are then calculated using these boundaries and the average attenuation coefficients within the enclosed regions. The method has been tested on computer-simulated data, on scans of phantoms, and on patient studies, and has been found effective in reducing the random noise in transmission measurements and in providing more accurate ACFs than the method using geometric attenuation correction. As a result, transmission scan times can be shortened, inconvenience to patients is reduced, and PCT images are improved.

Huang, S.C.; Carson, R.E.; Phelps, M.E.; Hoffman, E.J.; Schelbert, H.R.; Kuhl, D.E.

1981-07-01

208

Global spherical harmonic computation by two-dimensional Fourier methods  

Microsoft Academic Search

A method is presented for performing global spherical harmonic computation by two-dimensional Fourier transformations. The method goes back to old literature (Schuster 1902) and tackles the problem of non-orthogonality of Legendre-functions, when discretized on an equi-angular grid. Both analysis and synthesis relations are presented, which link the spherical harmonic spectrum to a two-dimensional Fourier spectrum. As an alternative, certain functions

Nico Sneeuw; Richard Bun

1996-01-01

209

Computationally intensive methods warrant reconsideration of pedagogy in statistics  

Microsoft Academic Search

Computationally intensive methods of statistical inference do not fit the current canon of pedagogy in statistics. To accommodate\\u000a these methods and the logic underlying them, I propose seven pedagogical principles: (1) Define inferential statistics as\\u000a techniques for reckoning with chance. (2) Distinguish three types of research: sample surveys, in which statistics affords\\u000a generalization from the cases studied; experiments, in which

Gordon Bear; Ramapo CoUege

1995-01-01

210

Computing the Casimir energy using the point-matching method  

SciTech Connect

We use a point-matching approach to numerically compute the Casimir interaction energy for a two perfect-conductor waveguide of arbitrary section. We present the method and describe the procedure used to obtain the numerical results. At first, our technique is tested for geometries with known solutions, such as concentric and eccentric cylinders. Then, we apply the point-matching technique to compute the Casimir interaction energy for new geometries such as concentric corrugated cylinders and cylinders inside conductors with focal lines.

Lombardo, F. C.; Mazzitelli, F. D. [Departamento de Fisica Juan Jose Giambiagi, FCEyN University of Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); Vazquez, M. [Computer Applications on Science and Engineering Department, Barcelona Supercomputing Center (BSC), 29, Jordi Girona 08034 Barcelona (Spain); Villar, P. I. [Departamento de Fisica Juan Jose Giambiagi, FCEyN University of Buenos Aires, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina); Computer Applications on Science and Engineering Department, Barcelona Supercomputing Center (BSC), 29, Jordi Girona 08034 Barcelona (Spain)

2009-09-15

211

Application of finite element method to hypersonic nozzle flow computations  

NASA Astrophysics Data System (ADS)

An explicit Taylor-Galerkin Finite Element Method (FEM) algorithm, used for the solution of Euler/Navier-Stokes equations, is applied for the computation of steady-state frozen equilibrium flow in single expansion ramp nozzles (SERN) and in plug nozzles for hypersonic propulsion systems. External flow conditions are taken into account. For the determination of nozzle performance a detailed 2D/3D-flow analysis in regions with complex geometries was performed using unstructured computational grids with adaptive mesh refinement. Some results for the investigated nozzle configurations at different flight conditions are presented and discussed. Additionally, thrust vectoring by modification of the lower nozzle flap shape was studied.

Koschel, W.; Rick, W.; Bikker, S.

1992-02-01

212

An effective method for computing the noise in biochemical networks  

NASA Astrophysics Data System (ADS)

We present a simple yet effective method, which is based on power series expansion, for computing exact binomial moments that can be in turn used to compute steady-state probability distributions as well as the noise in linear or nonlinear biochemical reaction networks. When the method is applied to representative reaction networks such as the ON-OFF models of gene expression, gene models of promoter progression, gene auto-regulatory models, and common signaling motifs, the exact formulae for computing the intensities of noise in the species of interest or steady-state distributions are analytically given. Interestingly, we find that positive (negative) feedback does not enlarge (reduce) noise as claimed in previous works but has a counter-intuitive effect and that the multi-OFF (or ON) mechanism always attenuates the noise in contrast to the common ON-OFF mechanism and can modulate the noise to the lowest level independently of the mRNA mean. Except for its power in deriving analytical expressions for distributions and noise, our method is programmable and has apparent advantages in reducing computational cost.

Zhang, Jiajun; Nie, Qing; He, Miao; Zhou, Tianshou

2013-02-01

213

An effective method for computing the noise in biochemical networks.  

PubMed

We present a simple yet effective method, which is based on power series expansion, for computing exact binomial moments that can be in turn used to compute steady-state probability distributions as well as the noise in linear or nonlinear biochemical reaction networks. When the method is applied to representative reaction networks such as the ON-OFF models of gene expression, gene models of promoter progression, gene auto-regulatory models, and common signaling motifs, the exact formulae for computing the intensities of noise in the species of interest or steady-state distributions are analytically given. Interestingly, we find that positive (negative) feedback does not enlarge (reduce) noise as claimed in previous works but has a counter-intuitive effect and that the multi-OFF (or ON) mechanism always attenuates the noise in contrast to the common ON-OFF mechanism and can modulate the noise to the lowest level independently of the mRNA mean. Except for its power in deriving analytical expressions for distributions and noise, our method is programmable and has apparent advantages in reducing computational cost. PMID:23464139

Zhang, Jiajun; Nie, Qing; He, Miao; Zhou, Tianshou

2013-02-28

214

Method of computer-aided measurement in a shooting range  

NASA Astrophysics Data System (ADS)

In the view of the blindness of photoelectric measurement scheme argument and the danger of live shell measurement in shooting range, this paper provided a computer aided measurement method guiding the measurement scheme argument and equipment researching and producing and driving the measurement process visiblization and standardization. The computer aided measurement in shooting range can be divided into the mathematical simulation of targets moving, the mathematical simulation of measurement method, the mathematical simulation of photoelectric system, the animated displaying of measurement process, and so on. By adding random jamming, Gaussian white noise and so on, the live measurement environment and condition was built. By using mathematical discretization, the time series pictures was obtained. By controlling the time changing and time unifying of several equipment, the animated displaying of measurement process was built. The programming language was MATLAB. The method was proved through simulating the intersection measurement trajectory of antiaircraft gun's shell successfully.

Liu, Chanlao; Zhang, Yun; Xiong, Rensheng; Sun, Yishang

2000-10-01

215

COMPUTATIONAL STUDIES OF CLUSTERS:Methods and Results  

NASA Astrophysics Data System (ADS)

The experimental and computational study of clusters has been an active field of research for over a decade. This review provides an overview of some of the methods that have been developed to study clusters and some of the results that have been obtained. Included are computational approaches to explore the potential energy surface for clusters, methods to extract thermodynamic properties from the potential surface information and approaches to insure simulation studies are performed in an ergodic fashion. The methods have proved to be useful in studying the structural transition from clusters to bulk phases, phase changes in small clusters and the importance of quantum effects. The review ends with a discussion of problems in cluster chemistry and physics that are of interest for future investigations.

Freeman, David L.; Doll, J. D.

1996-10-01

216

A Critical Review of Computer-Assisted Learning in Public Health via the Internet, 1999-2008  

ERIC Educational Resources Information Center

|Computers and the internet have been utilized as viable avenues for public health education delivery. Yet the effectiveness, e.g., behavior change, from use of these tools has been limited. Previous reviews have focused on single health topics such as smoking cessation and weight loss. This review broadens the scope to consider computer-assisted…

Corda, Kirsten W.; Polacek, Georgia N. L. J.

2009-01-01

217

Computational methods for coupling microstructural and micromechanical materials response simulations  

SciTech Connect

Computational materials simulations have traditionally focused on individual phenomena: grain growth, crack propagation, plastic flow, etc. However, real materials behavior results from a complex interplay between phenomena. In this project, the authors explored methods for coupling mesoscale simulations of microstructural evolution and micromechanical response. In one case, massively parallel (MP) simulations for grain evolution and microcracking in alumina stronglink materials were dynamically coupled. In the other, codes for domain coarsening and plastic deformation in CuSi braze alloys were iteratively linked. this program provided the first comparison of two promising ways to integrate mesoscale computer codes. Coupled microstructural/micromechanical codes were applied to experimentally observed microstructures for the first time. In addition to the coupled codes, this project developed a suite of new computational capabilities (PARGRAIN, GLAD, OOF, MPM, polycrystal plasticity, front tracking). The problem of plasticity length scale in continuum calculations was recognized and a solution strategy was developed. The simulations were experimentally validated on stockpile materials.

HOLM,ELIZABETH A.; BATTAILE,CORBETT C.; BUCHHEIT,THOMAS E.; FANG,HUEI ELIOT; RINTOUL,MARK DANIEL; VEDULA,VENKATA R.; GLASS,S. JILL; KNOROVSKY,GERALD A.; NEILSEN,MICHAEL K.; WELLMAN,GERALD W.; SULSKY,DEBORAH; SHEN,YU-LIN; SCHREYER,H. BUCK

2000-04-01

218

Computational Methods for Predicting Sites of Functionally Important Dynamics  

PubMed Central

Understanding and controlling biological function of proteins at the atomic level is of great importance; allosteric mechanisms provide such an interface. Experimental and computational methods have been developed to search for residue mutations that produce changes in function by altering sites of correlated motion. These methods are often observational in that altered motions are achieved by random sampling without revealing the underlying mechanism(s). We present two deterministic methods founded on structure-function relationships that predict dynamic control sites (i.e. locations that experience correlated motions as a result of altered dynamics). The first method (“static”) is based on a single structure conformation (e.g. the wild type (WT)) and utilizes a graph description of atomic connectivity. The local atomic interactions are used to compute the propagation of contact paths. This description of structure connectivity reveals flexible locations that are susceptible to altered dynamics. The second method (“dynamic”) is a comparative analysis between the normal modes of a WT structure and a mutant structure. A mapping function is defined that quantifies the significance of the motions in one structure projected onto the motions of the other. Each mode is considered up- or down-regulated according to its change in relative significance. This description of altered dynamics is the basis for a motion correlation analysis, from which the dynamic control sites are readily identified. The methods are theoretically derived and applied using the canonical system dihydrofolate reductase (DHFR). Both methods demonstrate a very high predictive value (p < 0.005) in identifying known dynamic control sites. The dynamic method also produces a new hypothesis regarding the mechanism by which the DHFR mutant achieves hyperactivity. These tools are suitable for allosteric investigations and may greatly enhance the speed and effectiveness of other computational and experimental methods.

Schuyler, Adam D.; Carlson, Heather A.; Feldman, Eva L.

2009-01-01

219

Investigation of Ultrasonic Wave Scattering Effects using Computational Methods  

NASA Astrophysics Data System (ADS)

Advances in computational power and expanded access to computing clusters has made mathematical modeling of complex wave effects possible. We have used multi-core and cluster computing to implement analytical and numerical models of ultrasonic wave scattering in fluid and solid media (acoustic and elastic waves). We begin by implementing complicated analytical equations that describe the force upon spheres immersed in inviscid and viscous fluids due to an incident plane wave. Two real-world applications of acoustic force upon spheres are investigated using the mathematical formulations: emboli removal from cardiopulmonary bypass circuits using traveling waves and the micromanipulation of algal cells with standing waves to aid in biomass processing for algae biofuels. We then move on to consider wave scattering situations where analytical models do not exist: scattering of acoustic waves from multiple scatterers in fluids and Lamb wave scattering in solids. We use a numerical method called finite integration technique (FIT) to simulate wave behavior in three dimensions. The 3D simulations provide insight into experimental results for situations where 2D simulations would not be sufficient. The diverse set of scattering situations explored in this work show the broad applicability of the underlying principles and the computational tools that we have developed. Overall, our work shows that the movement towards better availability of large computational resources is opening up new ways to investigate complicated physics phenomena.

Campbell Leckey, Cara Ann

220

The spectral-element method, Beowulf computing, and global seismology.  

PubMed

The propagation of seismic waves through Earth can now be modeled accurately with the recently developed spectral-element method. This method takes into account heterogeneity in Earth models, such as three-dimensional variations of seismic wave velocity, density, and crustal thickness. The method is implemented on relatively inexpensive clusters of personal computers, so-called Beowulf machines. This combination of hardware and software enables us to simulate broadband seismograms without intrinsic restrictions on the level of heterogeneity or the frequency content. PMID:12459579

Komatitsch, Dimitri; Ritsema, Jeroen; Tromp, Jeroen

2002-11-29

221

The GLEaMviz computational tool, a publicly available software to explore realistic epidemic spreading scenarios at the global scale  

Microsoft Academic Search

Background  Computational models play an increasingly important role in the assessment and control of public health crises, as demonstrated\\u000a during the 2009 H1N1 influenza pandemic. Much research has been done in recent years in the development of sophisticated data-driven\\u000a models for realistic computer-based simulations of infectious disease spreading. However, only a few computational tools are\\u000a presently available for assessing scenarios, predicting

Van den Wouter Broeck; Corrado Gioannini; Bruno Gonçalves; Marco Quaggiotto; Vittoria Colizza; Alessandro Vespignani

2011-01-01

222

Pretrial Publicity and the Jury: Research and Methods  

Microsoft Academic Search

\\u000a Research conducted over the past 40 years demonstrates that pretrial publicity (PTP) can negatively influence jurors’ perceptions\\u000a of parties in criminal and civil cases receiving substantial news coverage. Changes in the news media over the same period\\u000a of time have made news coverage more accessible to the public as traditional media including newspapers, television, and radio\\u000a are complemented with new

Lisa M. Spano; Jennifer L. Groscup; Steven D. Penrod

223

37 CFR 201.26 - Recordation of documents pertaining to computer shareware and donation of public domain computer...  

Code of Federal Regulations, 2010 CFR

...dissemination or other use of computer shareware. Documents transferring...rights under the copyright law of computer shareware and security interests in such software should...Definitions â(1) The term computer shareware is...

2009-07-01

224

37 CFR 201.26 - Recordation of documents pertaining to computer shareware and donation of public domain computer...  

Code of Federal Regulations, 2010 CFR

...dissemination or other use of computer shareware. Documents transferring...rights under the copyright law of computer shareware and security interests in such software should...Definitions â(1) The term computer shareware is...

2010-07-01

225

A fast method for fully nonlinear water-wave computations  

NASA Astrophysics Data System (ADS)

A fast computational method for fully nonlinear non-overturning water waves is derived in two and three dimensions. A corresponding time-stepping scheme is developed in the two-dimensional case. The essential part of the method is a fast converging iterative solution procedure of the Laplace equation. One part of the solution is obtained by fast Fourier transform, while another part is highly nonlinear and consists of integrals with kernels that decay quickly in space. The number of operations required is asymptotically O(N log N), where N is the number of nodes at the free surface. While any accuracy of the computations is achieved by a continued iteration of the equations, one iteration is found to be sufficient for practical computations, while maintaining high accuracy. The resulting explicit approximation of the scheme is tested in two versions. Simulations of nonlinear wave fields with wave slope even up to about unity compare very well with reference computations. The numerical scheme is formulated in such a way that aliasing terms are partially or completely avoided.

Clamond, Didier; Grue, John

2001-11-01

226

Computational methods to determine the structure of hydrogen storage materials  

NASA Astrophysics Data System (ADS)

To understand the mechanisms and thermodynamics of material-based hydrogen storage, it is important to know the structure of the material and the positions of the hydrogen atoms within the material. Because hydrogen can be difficult to resolve experimentally computational research has proven to be a valuable tool to address these problems. We discuss different computational methods for identifying the structure of hydrogen materials and the positions of hydrogen atoms, and we illustrate the methods with specific examples. Through the use of ab-initio molecular dynamics, we identify molecular hydrogen binding sites in the metal-organic framework commonly known as MOF-5 [1]. We present a method to identify the positions of atomic hydrogen in imide structures using a novel type of effective Hamiltonian. We apply this new method to lithium imide (Li2NH), a potentially important hydrogen storage material, and demonstrate that it predicts a new ground state structure [2]. We also present the results of a recent computational study of the room-temperature structure of lithium imide in which we suggest a new structure that reconciles the differences between previous experimental and theoretical studies. [4pt] [1] T. Mueller and G. Ceder, Journal of Physical Chemistry B 109, 17974 (2005). [0pt] [2] T. Mueller and G. Ceder, Physical Review B 74 (2006).

Mueller, Tim

2009-03-01

227

Implementation of an ADI method on parallel computers  

SciTech Connect

In this paper the implementation of an ADI method for solving the diffusion equation on three parallel/vector computers is discussed. The computers were chosen so as to encompass a variety of architectures. They are the MPP, an SIMD machine with 16-Kbit serial processors; Flex/32, an MIMD machine with 20 processors; and Cray/2, an MIMD machine with four vector processors. The Gaussian elimination algorithm is used to solve a set of tridiagonal systems on the Flex/32 and Cray/2 while the cyclic elimination algorithm is used to solve these systems on the MPP. The implementation of the method is discussed in relation to these architectures and measures of the performance on each machine are given. Simple performance models are used to describe the performance. These models highlight the bottlenecks and limiting factors for this algorithm on these architectures. Finally conclusions are presented. 10 references.

Fatoohi, R.A.; Grosch, C.E.

1987-06-01

228

RTS&T Monte Carlo code (facilities and computation methods)  

Microsoft Academic Search

The paper describes facilities and computation methods of the new RTS&T Monte Carlo code. This code performs simulations of three dimensional electromagnetic shower development and low energy neutron production and transport in accelerator and in shielding components with a calculation of the isotope transmutation problem. RTS&T is based on a compilation from ENDF\\/B-VI, JENDL-3, EAF, FENDL and EPNDL evaluated data

A. I. Blokhiny; I. I. Degtyarev; A. E. Lokhovitskii; M. A. Maslov; I. A. Yazynin

1997-01-01

229

Application of finite element method to hypersonic nozzle flow computations  

Microsoft Academic Search

An explicit Taylor-Galerkin Finite Element Method (FEM) algorithm, used for the solution of Euler\\/Navier-Stokes equations, is applied for the computation of steady-state frozen equilibrium flow in single expansion ramp nozzles (SERN) and in plug nozzles for hypersonic propulsion systems. External flow conditions are taken into account. For the determination of nozzle performance a detailed 2D\\/3D-flow analysis in regions with complex

W. Koschel; W. Rick; S. Bikker

1992-01-01

230

A method for computing flows over an ogival body  

Microsoft Academic Search

A method for computing three-dimensional flow over an ogival body at angle of attack is described. An approximate set of governing equations is given for viscous flows which have a primary flow direction. A two-level second-order accurate marching procedure is presented for general equations. With this procedure, a three-dimensional turbulent flow can be solved in any coordinate system by marching

P. R. Eiseman; R. Levy; H. McDonald

1977-01-01

231

Experiences using DAKOTA stochastic expansion methods in computational simulations.  

SciTech Connect

Uncertainty quantification (UQ) methods bring rigorous statistical connections to the analysis of computational and experiment data, and provide a basis for probabilistically assessing margins associated with safety and reliability. The DAKOTA toolkit developed at Sandia National Laboratories implements a number of UQ methods, which are being increasingly adopted by modeling and simulation teams to facilitate these analyses. This report disseminates results as to the performance of DAKOTA's stochastic expansion methods for UQ on a representative application. Our results provide a number of insights that may be of interest to future users of these methods, including the behavior of the methods in estimating responses at varying probability levels, and the expansion levels for the methodologies that may be needed to achieve convergence.

Templeton, Jeremy Alan; Ruthruff, Joseph R.

2012-01-01

232

Hindered settling computations using a parallel boundary element method  

SciTech Connect

This paper presents a parallel implementation of the boundary element method (BEM) for multiple instruction multiple data (MIMD) computer architectures to determine the hindered settling function for a suspension of sedimenting rigid particles in Stokes flow. The hindered settling function is a measure of the average sedimentation velocity of the suspension. This function can be determined numerically by performing statistical analyses of several random realizations of a physical system characterized by a set of defining parameters. These defining parameters can include the volume fraction of the solid phase, shape factors, orientation characteristics, and others. The boundary element method is particularly well suited for studying such systems because of the simplification in the discretization associated with the method. However, as the number of solid particles to be modeled is increased so are the computational demands. Parallel computation offers the opportunity to model systems of greater complexity. We discuss a parallel boundary element formulation based on the torus-wrap mapping. In this approach, blocks of the coefficient matrix associated with the discretized boundary element equations are assigned to processors as opposed to more traditional parallel boundary element implementations where rows or columns are assigned to processors. The torus-wrap mapping can be shown to minimize the communication volume between processors during the LU factorization. Therefore, the present formulation scales well with increases in the number of processors.

Ingber, M.S. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Mechanical Engineering; Womble, D.E. [Sandia National Labs., Albuquerque, NM (United States)

1994-07-01

233

Plane Couette Flow Computations by TRMC and MFS Methods  

NASA Astrophysics Data System (ADS)

A new class of schemes of the DSMC type for computing near-continuum flows has been recently suggested: the time-relaxed Monte Carlo (TRMC) methods. An important step preceding the wide use of these schemes is their validation by classical homogeneous and one-dimensional problems of gas dynamics. For this purpose, a plane Couette flow is considered in the present paper. A comparison of TRMC results with the data obtained by time-proved schemes of the DSMC method (here we used the Majorant Frequency Scheme) in a wide range of Knudsen numbers and for different values of wall velocity is presented.

Russo, G.; Pareschi, L.; Trazzi, S.; Shevyrin, A. A.; Bondar, Ye. A.; Ivanov, M. S.

2005-05-01

234

Oxford textbook of public health. Volume 3. Investigative methods in public health  

SciTech Connect

This book contains 31 chapters. Some of the chapter titles are: Cross-sectional studies; Viral diseases of public health importance; Arboviruses; The principles of an epidemic field investigation; Field investigations in air; Radiation; Iatrogenic hazards; and Field investigations of noise hazards.

Holland, W.W.; Detels, R.; Knox, G.

1985-01-01

235

GRACE: Public Health Recovery Methods Following an Environmental Disaster  

Microsoft Academic Search

Different approaches are necessary when community-based participatory research (CBPR) of environmental illness is initiated after an environmental disaster within a community. Often such events are viewed as golden scientific opportunities to do epidemiological studies. However, the authors believe that in such circumstances, community engagement and empowerment needs to be integrated into the public health service efforts in order for both

Erik R. Svendsen; Nancy C. Whittle; Robert E. McKeown; Karen Sprayberry; Margaret Heim; Richard Caldwell; James J. Gibson; John E. Vena

2010-01-01

236

Public Participation GIS: A Method for Identifying Ecosystem Services  

Microsoft Academic Search

This study evaluated the use of an Internet-based public participation geographic information system (PPGIS) to identify ecosystem services in Grand County, Colorado. Specific research objectives were to examine the distribution of ecosystem services, identify the characteristics of participants in the study, explore potential relationships between ecosystem services and land use and land cover (LULC) classifications, and assess the methodological strengths

Greg Brown; Jessica M. Montag; Katie Lyon

2011-01-01

237

Public Participation GIS: A Method for Identifying Ecosystem Services  

Microsoft Academic Search

This study evaluated the use of an Internet-based public participation geographic information system (PPGIS) to identify ecosystem services in Grand County, Colorado. Specific research objectives were to examine the distribution of ecosystem services, identify the characteristics of participants in the study, explore potential relationships between ecosystem services and land use and land cover (LULC) classifications, and assess the methodological strengths

Greg Brown; Jessica M. Montag; Katie Lyon

2012-01-01

238

On Improving Qualitative Methods in Public Administration Research  

Microsoft Academic Search

What do exemplary qualitative accounts look like, and how do they convince readers of their correctness? What sort of standards can be used to assess qualitative research accounts for public administration? To address these questions, the authors examined 72 recent qualitative research journal articles. Proceeding from a set of preliminary guidelines, they worked iteratively between articles and the emergent template

Ralph S. Brower; Mitchel Y. Abolafia; Jered B. Carr

2000-01-01

239

Pedagogical Methods of Teaching "Women in Public Speaking."  

ERIC Educational Resources Information Center

|A course on women in public speaking, developed at the University of Cincinnati, focuses on the rhetoric of selected women who have been involved in various movements and causes in the United States in the twentieth century. Women studied include educator Mary McLeod Bethune, Congresswoman Jeannette Rankin, suffragette Carrie Chapman Catt, Helen…

Pederson, Lucille M.

240

A numerical method to compute interior transmission eigenvalues  

NASA Astrophysics Data System (ADS)

In this paper the numerical calculation of eigenvalues of the interior transmission problem arising in acoustic scattering for constant contrast in three dimensions is considered. From the computational point of view existing methods are very expensive, and are only able to show the existence of such transmission eigenvalues. Furthermore, they have trouble finding them if two or more eigenvalues are situated closely together. We present a new method based on complex-valued contour integrals and the boundary integral equation method which is able to calculate highly accurate transmission eigenvalues. So far, this is the first paper providing such accurate values for various surfaces different from a sphere in three dimensions. Additionally, the computational cost is even lower than those of existing methods. Furthermore, the algorithm is capable of finding complex-valued eigenvalues for which no numerical results have been reported yet. Until now, the proof of existence of such eigenvalues is still open. Finally, highly accurate eigenvalues of the interior Dirichlet problem are provided and might serve as test cases to check newly derived Faber-Krahn type inequalities for larger transmission eigenvalues that are not yet available.

Kleefeld, Andreas

2013-10-01

241

A FAST NEW PUBLIC CODE FOR COMPUTING PHOTON ORBITS IN A KERR SPACETIME  

SciTech Connect

Relativistic radiative transfer problems require the calculation of photon trajectories in curved spacetime. We present a novel technique for rapid and accurate calculation of null geodesics in the Kerr metric. The equations of motion from the Hamilton-Jacobi equation are reduced directly to Carlson's elliptic integrals, simplifying algebraic manipulations and allowing all coordinates to be computed semianalytically for the first time. We discuss the method, its implementation in a freely available FORTRAN code, and its application to toy problems from the literature.

Dexter, Jason [Department of Physics, University of Washington, Seattle, WA 98195-1560 (United States); Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States)], E-mail: jdexter@u.washington.edu

2009-05-10

242

Computation of multi-material interactions using point method  

SciTech Connect

Calculations of fluid flows are often based on Eulerian description, while calculations of solid deformations are often based on Lagrangian description of the material. When the Eulerian descriptions are used to problems of solid deformations, the state variables, such as stress and damage, need to be advected, causing significant numerical diffusion error. When Lagrangian methods are used to problems involving large solid deformat ions or fluid flows, mesh distortion and entanglement are significant sources of error, and often lead to failure of the calculation. There are significant difficulties for either method when applied to problems involving large deformation of solids. To address these difficulties, particle-in-cell (PIC) method is introduced in the 1960s. In the method Eulerian meshes stay fixed and the Lagrangian particles move through the Eulerian meshes during the material deformation. Since its introduction, many improvements to the method have been made. The work of Sulsky et al. (1995, Comput. Phys. Commun. v. 87, pp. 236) provides a mathematical foundation for an improved version, material point method (MPM) of the PIC method. The unique advantages of the MPM method have led to many attempts of applying the method to problems involving interaction of different materials, such as fluid-structure interactions. These problems are multiphase flow or multimaterial deformation problems. In these problems pressures, material densities and volume fractions are determined by satisfying the continuity constraint. However, due to the difference in the approximations between the material point method and the Eulerian method, erroneous results for pressure will be obtained if the same scheme used in Eulerian methods for multiphase flows is used to calculate the pressure. To resolve this issue, we introduce a numerical scheme that satisfies the continuity requirement to higher order of accuracy in the sense of weak solutions for the continuity equations. Numerical examples are given to demonstrate the new scheme.

Zhang, Duan Z [Los Alamos National Laboratory; Ma, Xia [Los Alamos National Laboratory; Giguere, Paul T [Los Alamos National Laboratory

2009-01-01

243

Pesticides and public health: integrated methods of mosquito management.  

PubMed Central

Pesticides have a role in public health as part of sustainable integrated mosquito management. Other components of such management include surveillance, source reduction or prevention, biological control, repellents, traps, and pesticide-resistance management. We assess the future use of mosquito control pesticides in view of niche markets, incentives for new product development, Environmental Protection Agency registration, the Food Quality Protection Act, and improved pest management strategies for mosquito control.

Rose, R. I.

2001-01-01

244

Public websites and human–computer interaction: an empirical study of measurement of website quality and user satisfaction  

Microsoft Academic Search

The focus of this paper is to investigate measurement of website quality and user satisfaction. More specifically, the paper reports on a study investigating whether users of high-quality public websites are more satisfied than those of low-quality websites. Adopting a human–computer interaction perspective, we have gathered data from the 2009 public website awards in Scandinavia. Our analysis of Norwegian and

Hanne Sørum; Kim Normann Andersen; Ravi Vatrapu

2011-01-01

245

Public websites and human–computer interaction: an empirical study of measurement of website quality and user satisfaction  

Microsoft Academic Search

The focus of this paper is to investigate measurement of website quality and user satisfaction. More specifically, the paper reports on a study investigating whether users of high-quality public websites are more satisfied than those of low-quality websites. Adopting a human–computer interaction perspective, we have gathered data from the 2009 public website awards in Scandinavia. Our analysis of Norwegian and

Hanne Sørum; Kim Normann Andersen; Ravi Vatrapu

2012-01-01

246

Assessment of nonequilibrium radiation computation methods for hypersonic flows  

NASA Astrophysics Data System (ADS)

The present understanding of shock-layer radiation in the low density regime, as appropriate to hypersonic vehicles, is surveyed. Based on the relative importance of electron excitation and radiation transport, the hypersonic flows are divided into three groups: weakly ionized, moderately ionized, and highly ionized flows. In the light of this division, the existing laboratory and flight data are scrutinized. Finally, an assessment of the nonequilibrium radiation computation methods for the three regimes in hypersonic flows is presented. The assessment is conducted by comparing experimental data against the values predicted by the physical model.

Sharma, Surendra

1993-01-01

247

How to Delegate and Verify in Public: Verifiable Computation from Attribute-based Encryption  

Microsoft Academic Search

The wide variety of small, computationally weak devices, and the growing number of computationally intensive tasks makes it appealing to delegate computation to data centers. However, outsourcing computation is useful only when the returned result can be trusted, which makes verifiable computation (VC) a must for such scenarios. In this work we extend the definition of verifiable computation in two

Bryan Parno; Mariana Raykova; Vinod Vaikuntanathan

2012-01-01

248

[A new method of measuring temporal resolution for computed tomography].  

PubMed

In this study, we proposed a new method of measuring temporal resolution using an impulse signal in the time domain in computed tomography (CT). We employed a metal ball with a diameter of 11 mm as the source of the impulse signal, which was shot to a slice plane at a very fast speed during scanning, along the perpendicular direction to the plane. A 4-slice multi detector-row CT (MDCT) system was employed to evaluate the new method, and images for region of interest (ROI) measurement were reconstructed with a z-increment corresponding to a very short time (< or = 0.03 sec). Temporal sensitivity profiles (TSPs) for various helical beam-pitches were obtained by plotting averaged CT values within the ROIs against the temporal axis. The accuracy of the method was examined by comparing the measured TSPs with theoretical TSPs corresponding to respective helical beam-pitches. As a result, the theoretical TSPs and measured TSPs demonstrated high coincidence in all beam-pitches. Since the TSPs indicated the profiles with sharp shapes faithful to the theoretical TSPs, it was proved that the new method had sufficient inherent temporal resolution. It was indicated that the new method we proposed would be an effective method for evaluating temporal resolution in CT. PMID:18840955

Ichikawa, Katsuhiro; Takada, Tadanori; Hara, Takanori; Ohashi, Kazuya; Niwa, Shinji

2008-09-20

249

A fast phase space method for computing creeping rays  

SciTech Connect

Creeping rays can give an important contribution to the solution of medium to high frequency scattering problems. They are generated at the shadow lines of the illuminated scatterer by grazing incident rays and propagate along geodesics on the scatterer surface, continuously shedding diffracted rays in their tangential direction. In this paper, we show how the ray propagation problem can be formulated as a partial differential equation (PDE) in a three-dimensional phase space. To solve the PDE we use a fast marching method. The PDE solution contains information about all possible creeping rays. This information includes the phase and amplitude of the field, which are extracted by a fast post-processing. Computationally, the cost of solving the PDE is less than tracing all rays individually by solving a system of ordinary differential equations. We consider an application to mono-static radar cross section problems where creeping rays from all illumination angles must be computed. The numerical results of the fast phase space method and a comparison with the results of ray tracing are presented.

Motamed, Mohammad [Department of Numerical Analysis and Computer Science, Royal Institute of Technology (KTH), Lindstadsvagen 3, 10044 Stockholm (Sweden)]. E-mail: mohamad@nada.kth.se; Runborg, Olof [Department of Numerical Analysis and Computer Science, Royal Institute of Technology (KTH), Lindstadsvagen 3, 10044 Stockholm (Sweden)]. E-mail: olofr@nada.kth.se

2006-11-20

250

A computer method for the automatic reduction of spectroscopic data.  

PubMed

A computer program, written in Fortran IV and for use with an associated spectral comparator, has been developed at The Naval Research Laboratory for the purpose of automatically reducing spectroscopic data. A Datex digitalizing magnetic tape recorder in conjunction with a modified Jarrell-Ash microphotometer allows the reading of spectral information from a photographic plate at the rate of twentyfive data pairs per second. Spectra of local interest analyzed by this method are (1) absorption, (2) emission, (3) plasma type, obtained from time-resolved spectroscopic techniques, and (4) solar echellegrams obtained from rocket probings of the upper atmosphere. Markedly useful features of the program are its capabilities of (a) recognizing spectral peaks from a background of variable density, (b) obtaining absolute values for the radiance or irradiance. An essential characteristic of the method is the saving of significant amounts of time in the reduction of photographic spectroscopic data. PMID:20062364

Ditzel, E F; Giddings, L E

1967-12-01

251

A rigorous method for computation of ferrite toroidal phase shifters  

NASA Astrophysics Data System (ADS)

Coupled-wave theory is used to calculate the performance of twin-toroidal phase shifters. Computation results show that this method is effective, rather simple, and easy to handle. In comparison with the single-toroid phase shifter, the twin-toroidal model's phase shift is considerably larger and its production is simpler. The wires carrying magnetizing currents are located in the weak microwave electric field area. Hence, their influence on the performance of the phase shifter is negligible; this also facilitates production. The loss factors of these two kinds of toroid phase shifters are about the same. Experimental results are in good agreement with theoretical analysis. On this basis, it is concluded that coupled-wave theory is a powerful method for treating electromagnetic problems of waveguides loaded with magnetized ferrites.

Xu, Yansheng; Zhang, Guangchuang

1988-06-01

252

Computational methods for ab initio detection of microRNAs  

PubMed Central

MicroRNAs are small RNA sequences of 18–24 nucleotides in length, which serve as templates to drive post-transcriptional gene silencing. The canonical microRNA pathway starts with transcription from DNA and is followed by processing via the microprocessor complex, yielding a hairpin structure. Which is then exported into the cytosol where it is processed by Dicer and then incorporated into the RNA-induced silencing complex. All of these biogenesis steps add to the overall specificity of miRNA production and effect. Unfortunately, their modes of action are just beginning to be elucidated and therefore computational prediction algorithms cannot model the process but are usually forced to employ machine learning approaches. This work focuses on ab initio prediction methods throughout; and therefore homology-based miRNA detection methods are not discussed. Current ab initio prediction algorithms, their ties to data mining, and their prediction accuracy are detailed.

Allmer, Jens; Yousef, Malik

2012-01-01

253

Quantitative methods of measuring restorative components in urban public parks  

Microsoft Academic Search

The paper demonstrates how quantitative methods can be used in a landscape architecture study. Three different methods to determine how people evaluate the psychological restoration\\/relaxation potential of small urban parks, as described in attention restoration theory, were assessed. The methods presented and evaluated are: ratings of environments based on quantified photos, eye tracking and choice-based conjoint analysis. Ratings of environments

Helena Nordh

2012-01-01

254

Parallel computation of multigroup reactivity coefficient using iterative method  

NASA Astrophysics Data System (ADS)

One of the research activities to support the commercial radioisotope production program is a safety research target irradiation FPM (Fission Product Molybdenum). FPM targets form a tube made of stainless steel in which the nuclear degrees of superimposed high-enriched uranium. FPM irradiation tube is intended to obtain fission. The fission material widely used in the form of kits in the world of nuclear medicine. Irradiation FPM tube reactor core would interfere with performance. One of the disorders comes from changes in flux or reactivity. It is necessary to study a method for calculating safety terrace ongoing configuration changes during the life of the reactor, making the code faster became an absolute necessity. Neutron safety margin for the research reactor can be reused without modification to the calculation of the reactivity of the reactor, so that is an advantage of using perturbation method. The criticality and flux in multigroup diffusion model was calculate at various irradiation positions in some uranium content. This model has a complex computation. Several parallel algorithms with iterative method have been developed for the sparse and big matrix solution. The Black-Red Gauss Seidel Iteration and the power iteration parallel method can be used to solve multigroup diffusion equation system and calculated the criticality and reactivity coeficient. This research was developed code for reactivity calculation which used one of safety analysis with parallel processing. It can be done more quickly and efficiently by utilizing the parallel processing in the multicore computer. This code was applied for the safety limits calculation of irradiated targets FPM with increment Uranium.

Susmikanti, Mike; Dewayatna, Winter

2013-09-01

255

Computation vs. cloning: evaluation of two methods for haplotype determination.  

PubMed

Nuclear sequence data, often from multiple loci, are increasingly being employed in analyses of population structure and history, yet there has been relatively little evaluation of methods for accurately and efficiently separating the alleles or haplotypes in heterozygous individuals. We compared the performance of a computational method of haplotype reconstruction and standard cloning methods using a highly variable intron (ornithine decarboxylase, intron 6) in three closely related species of dabbling ducks (genus Anas). Cloned sequences from 32 individuals were compared to results obtained from phase 2.1.1 . phase correctly identified haplotypes in 28 of 30 heterozygous individuals when the underlying model assumed no recombination. Haplotypes of the remaining two individuals were also inferred correctly except for unique polymorphisms, the phase of which was appropriately indicated as uncertain (phase probability = 0.5). For a larger set of 232 individuals, results were essentially identical regardless of the recombination model used and haplotypes for all 30 of the tested heterozygotes were correctly inferred, with the exception of uncertain phase for unique polymorphisms in one individual. In contrast, initial sequences of one clone per sample yielded accurate haplotype determination in only 26 of 30 individuals; polymerase chain reaction (PCR)/cloning errors resulting from misincorporation of individual nucleotides could be recognized and avoided by comparison to direct sequences, but errors due to PCR recombination resulted in incorrect haplotype reconstruction in four individuals. The accuracy of haplotypes reconstructed by phase, even when dealing with a relatively small number of samples and numerous variable sites, suggests broad utility of computational approaches for reducing the cost and improving the efficiency of data collection from nuclear sequence loci. PMID:21586011

Harrigan, Ryan J; Mazza, Maureen E; Sorenson, Michael D

2008-11-01

256

78 FR 54453 - Notice of Public Meeting-Intersection of Cloud Computing and Mobility Forum and Workshop  

Federal Register 2010, 2011, 2012, 2013

...Notice of Public Meeting--Intersection of Cloud Computing and Mobility Forum and Workshop...NIST) announces the Intersection of Cloud and Mobility Forum and Workshop to be held...held each day. The NIST Intersection of Cloud and Mobility Forum and Workshop will...

2013-09-04

257

Graphical Methods: A Review of Current Methods and Computer Hardware and Software. Technical Report No. 27.  

ERIC Educational Resources Information Center

|Graphical methods for displaying data, as well as available computer software and hardware, are reviewed. The authors have emphasized the types of graphs which are most relevant to the needs of the National Center for Education Statistics (NCES) and its readers. The following types of graphs are described: tabulations, stem-and-leaf displays,…

Bessey, Barbara L.; And Others

258

A multiscale discontinuous galerkin method with the computational structure of a continuous galerkin method.  

SciTech Connect

Proliferation of degrees-of-freedom has plagued discontinuous Galerkin methodology from its inception over 30 years ago. This paper develops a new computational formulation that combines the advantages of discontinuous Galerkin methods with the data structure of their continuous Galerkin counterparts. The new method uses local, element-wise problems to project a continuous finite element space into a given discontinuous space, and then applies a discontinuous Galerkin formulation. The projection leads to parameterization of the discontinuous degrees-of-freedom by their continuous counterparts and has a variational multiscale interpretation. This significantly reduces the computational burden and, at the same time, little or no degradation of the solution occurs. In fact, the new method produces improved solutions compared with the traditional discontinuous Galerkin method in some situations.

Sangalli, Giancarlo (University of Pavia, Italy); Buffa, Annalisa (University of Pavia, Italy); Bochev, Pavel Blagoveston; Scovazzi, Guglielmo; Hughes, Thomas J. R. (The University of Texas at Austin)

2005-07-01

259

A multiscale discontinuous Galerkin method with the computational structure of a continuous Galerkin method.  

SciTech Connect

Proliferation of degrees-of-freedom has plagued discontinuous Galerkin methodology from its inception over 30 years ago. This paper develops a new computational formulation that combines the advantages of discontinuous Galerkin methods with the data structure of their continuous Galerkin counterparts. The new method uses local, element-wise problems to project a continuous finite element space into a given discontinuous space, and then applies a discontinuous Galerkin formulation. The projection leads to parameterization of the discontinuous degrees-of-freedom by their continuous counterparts and has a variational multiscale interpretation. This significantly reduces the computational burden and, at the same time, little or no degradation of the solution occurs. In fact, the new method produces improved solutions compared with the traditional discontinuous Galerkin method in some situations.

Buffa, Annalisa (IMATI - Consiglio Nazionale delle Ricerche, Pavia, Italy); Bochev, Pavel Blagoveston; Scovazzi, Guglielmo; Hughes, Thomas J. R. (The University of Texas at Austin)

2005-03-01

260

The Parallel Improved Lanczos Method for Integer Factorization over Finite Fields for Public Key Cryptosystems  

Microsoft Academic Search

The integer factorization and discrete logarithm problems are of practical importance because of the widespread use of public key cryptosystems whose security depends on the presumed difficulty of solving these problems. Factoring integers and computing discrete logarithms often require solving large and sparse systems of linear equations over finite fields. In this paper, we propose an improved version of the

Laurence Tianruo Yangtz; Richard P. Brent

2001-01-01

261

Helping Students Soar to Success on Computers: An Investigation of the Soar Study Method for Computer-Based Learning  

ERIC Educational Resources Information Center

This study used self-report and observation techniques to investigate how students study computer-based materials. In addition, it examined if a study method called SOAR can facilitate computer-based learning. SOAR is an acronym that stands for the method's 4 theoretically driven and empirically supported components: select (S), organize (O),…

Jairam, Dharmananda; Kiewra, Kenneth A.

2010-01-01

262

Computational Methods and Challenges for Large-Scale Circuit Mapping  

PubMed Central

Summary The connectivity architecture of neuronal circuits is essential to understand how brains work, yet our knowledge about the neuronal wiring diagrams remains limited and partial. Technical breakthroughs in labeling and imaging methods starting more than a century ago have advanced knowledge in the field. However, the volume of data associated with imaging a whole brain or a significant fraction thereof, with electron or light microscopy, has only recently become amenable to digital storage and analysis. A mouse brain imaged at light microscopic resolution is about a terabyte of data, and 1 mm3 of the brain at EM resolution is about half a petabyte. This has given rise to a new field of research, computational analysis of large scale neuroanatomical data sets, with goals that include reconstructions of the morphology of individual neurons as well as entire circuits. The problems encountered include large data management, segmentation and 3D reconstruction, computational geometry and workflow management allowing for hybrid approaches combining manual and algorithmic processing. Here we review this growing field of neuronal data analysis with emphasis on reconstructing neurons from EM data cubes.

Helmstaedter, Moritz; Mitra, Partha

2012-01-01

263

A comprehensive method for optical-emission computed tomography  

NASA Astrophysics Data System (ADS)

Optical-computed tomography (CT) and optical-emission computed tomography (ECT) are recent techniques with potential for high-resolution multi-faceted 3D imaging of the structure and function in unsectioned tissue samples up to 1-4 cc. Quantitative imaging of 3D fluorophore distribution (e.g. GFP) using optical-ECT is challenging due to attenuation present within the sample. Uncorrected reconstructed images appear hotter near the edges than at the center. A similar effect is seen in SPECT/PET imaging, although an important difference is attenuation occurs for both emission and excitation photons. This work presents a way to implement not only the emission attenuation correction utilized in SPECT, but also excitation attenuation correction and source strength modeling which are unique to optical-ECT. The performance of the correction methods was investigated by the use of a cylindrical gelatin phantom whose central region was filled with a known distribution of attenuation and fluorophores. Uncorrected and corrected reconstructions were compared to a sectioned slice of the phantom imaged using a fluorescent dissecting microscope. Significant attenuation artifacts were observed in uncorrected images and appeared up to 80% less intense in the central regions due to attenuation and an assumed uniform light source. The corrected reconstruction showed agreement throughout the verification image with only slight variations (~5%). Final experiments demonstrate the correction in tissue as applied to a tumor with constitutive RFP.

Thomas, Andrew; Bowsher, James; Roper, Justin; Oliver, Tim; Dewhirst, Mark; Oldham, Mark

2010-07-01

264

Publications  

Cancer.gov

Publications News Updates PLCO Update Suggests Positive Predictive Value of Prostate Screening Drops over Time (Posted 01/13/2009) Report from Large NCI Study Suggests PSA Testing Could Be Done at Longer Intervals for Men Who Choose to Test(Posted

265

Publications  

Cancer.gov

Publications View All  |  2013-2010  |  2009-2000  |  1999-1990  |  1989-1980  |  1979-1970 2013 2012 2011 2010 Baker SG, Kramer BS. Surrogate endpoint analysis: an exercise in extrapolation. J Natl Cancer Inst 2013;105(5):316-320.[ PubMed

266

Density functional methods as computational tools in materials design  

NASA Astrophysics Data System (ADS)

This article gives a brief overview of density functional theory and discusses two specific implementations: a numerical localized basis approach (DMol) and the pseudopotential plane-wave method. Characteristic examples include Cu, clusters, CO and NO dissociation on copper surfaces, Li-, K-, and O-endohedral fullerenes, tris-quaternary ammonium cations as zeolite template, and oxygen defects in bulk SiO2. The calculations reveal the energetically favorable structures (estimated to be within ± 0.02 Å of experiment), the energetics of geometric changes, and the electronic structures underlying the bonding mechanisms. A characteristic DMo1 calculation on a 128-node nCUBE 2 parallel computer shows a speedup of about 107 over a single processor. A plane-wave calculation on a unit cell with 64 silicon atoms using 1024 nCUBE 2 processors runs about five times faster than on a single-processor CRAY YMP.

Li, Y. S.; van Daelen, M. A.; Wrinn, M.; King-Smith, D.; Newsam, J. M.; Delley, B.; Wimmer, E.; Klitsner, T.; Sears, M. P.; Carlson, G. A.; Nelson, J. S.; Allan, D. C.; Teter, M. P.

1994-04-01

267

Computational method for discovery of estrogen responsive genes  

PubMed Central

Estrogen has a profound impact on human physiology and affects numerous genes. The classical estrogen reaction is mediated by its receptors (ERs), which bind to the estrogen response elements (EREs) in target gene's promoter region. Due to tedious and expensive experiments, a limited number of human genes are functionally well characterized. It is still unclear how many and which human genes respond to estrogen treatment. We propose a simple, economic, yet effective computational method to predict a subclass of estrogen responsive genes. Our method relies on the similarity of ERE frames across different promoters in the human genome. Matching ERE frames of a test set of 60 known estrogen responsive genes to the collection of over 18?000 human promoters, we obtained 604 candidate genes. Evaluating our result by comparison with the published microarray data and literature, we found that more than half (53.6%, 324/604) of predicted candidate genes are responsive to estrogen. We believe this method can significantly reduce the number of testing potential estrogen target genes and provide functional clues for annotating part of genes that lack functional information.

Tang, Suisheng; Tan, Sin Lam; Ramadoss, Suresh Kumar; Kumar, Arun Prashanth; Tang, Man-Hung Eric; Bajic, Vladimir B.

2004-01-01

268

Matching wind turbine rotors and loads: Computational methods for designers  

NASA Astrophysics Data System (ADS)

A comprehensive method for matching wind energy conversion system (WECS) rotors with the load characteristics of common electrical and mechanical applications was reported. A method was developed to convert the data into useful results: (1) from turbine efficiency and load torque characteristics, turbine power is predicted as a function of windspeed; (2) it is decided how turbine power is to be governed to insure safety of all components; (3) mechanical conversion efficiency comes into play to predict how useful delivered power varies with windspeed; (4) wind statistics are used to predict longterm energy output. Most systems are approximated by a graph and calculator approach. The method leads to energy predictions, and to insight into modeled processes. A computer program provides more sophisticated calculations where a highly unusual system is to be modeled, where accuracy is at a premium, or where error analysis is required. The analysis is fleshed out with in depth case studies for induction generator and inverter utility systems; battery chargers; resistance heaters; positive displacement pumps; including three different load compensation strategies; and centrifugal pumps with unregulated electric power transmission from turbine to pump.

Seale, J. B.

1983-04-01

269

Computing Transport coefficients from the Microscopic Response Method  

NASA Astrophysics Data System (ADS)

If an external perturbation to a system may be expressed as additional terms in the Hamiltonian, the microscopic response is determined by the the wave function of the system. To obtain the macroscopic response, an ensemble average can be carried out at the final stage. With the help of a systematic diagrammatic expansion, one is able to consistently compute the corresponding transport coefficient. If the spatial fluctuation of the carrier distribution is small, the microscopic response method reduces to the usual Kubo-Greenwood formula (KGF). We illustrate with the conductivity and Hall mobility of amorphous semiconductors. Because the direction of the Lorentz force is determined by the line connecting the initial and final localized states, the sign of Hall mobility in a-Si:H can be anomalous. The method is being implemented in an ab initio code, and it is applicable to any temperature. Thus it significantly improves upon the usual method which averages KGF over a trajectory of classical molecular dynamics. [4pt] M.-L. Zhang and D. A. Drabold, Phys. Rev. Lett. 105, 186602 (2010); Eur. Phys. J. B. 77, 7-23, (2010); arXiv: 1008.1067.

Zhang, Mingliang; Drabold, David A.

2011-03-01

270

A simple method to estimate renal volume from computed tomography  

PubMed Central

Introduction: Renal parenchymal volume can be used clinically to estimate differential renal function. Unfortunately, conventional methods to determine renal volume from computed tomography (CT) are time-consuming or difficult due to software limitations. We evaluated the accuracy of simple renal measurements to estimate renal volume as compared with estimates made using specialized CT volumetric software. Methods: We reviewed 28 patients with contrast-enhanced abdominal CT. Using a standardized technique, one urologist and one urology resident independently measured renal length, lateral diameter and anterior-posterior diameter. Using the ellipsoid method, the products of the linear measurements were compared to 3D volume measurements made by a radiologist using specialized volumetric software. Results: Linear kidney measurements were highly consistent between the urologist and the urology resident (intraclass correlation coefficients: 0.97 for length, 0.96 for lateral diameter, and 0.90 for anterior-posterior diameter). Average renal volume was 170 (SD: 36) cm3 using the ellipsoid method compared with 186 (SD 37) cm3 using volumetric software, for a mean absolute bias of ?15.2 (SD 15.0) cm3 and a relative volume bias of ?8.2% (p < 0.001). Thirty-one of 56 (55.3%) estimated volumes were within 10% of the 3D measured volume and 54 of 56 (96.4%) were within 30%. Conclusion: Renal volume can be easily approximated from contrast-enhanced CT scans using the ellipsoid method. These findings may obviate the need for 3D volumetric software analysis in certain cases. Prospective validation is warranted.

Breau, Rodney H.; Clark, Edward; Bruner, Bryan; Cervini, Patrick; Atwell, Thomas; Knoll, Greg; Leibovich, Bradley C.

2013-01-01

271

29 CFR 794.123 - Method of computing annual volume of sales.  

Code of Federal Regulations, 2013 CFR

...false Method of computing annual volume of sales. 794.123 Section 794.123 Labor...3) of the Act Annual Gross Volume of Sales § 794.123 Method of computing annual volume of sales. (a) Where the enterprise,...

2013-07-01

272

A method for obtaining digital signatures and public-key cryptosystems  

Microsoft Academic Search

An encryption method is presented with the novel property that publicly re- vealing an encryption key does not thereby reveal the corresponding decryption key. This has two important consequences: 1. Couriers or other secure means are not needed to transmit keys, since a message can be enciphered using an encryption key publicly revealed by the intended recipient. Only he can

Ronald L. Rivest; Adi Shamir; Leonard M. Adleman

1978-01-01

273

A METHOD FOR OBTAINING DIGITAL SIGNATURES AND PUBLIC-KEY CRYP-TOSYSTEMS  

Microsoft Academic Search

Abstract An encryption method is presented with the novel property that publicly revealing an encryption key does not thereby reveal the corresponding decryption key. This has two important consequences: 1. Couriers or other secure means are not needed to transmit keys, since a message can be enciphered using an encryption key publicly revealed by the intended recipient. Only he can

R. L. Rivest; A. Shamir; L. M. Adelman

1977-01-01

274

Analytic and simulation methods in computer network design  

Microsoft Academic Search

The Seventies are here and so are computer networks! The time sharing industry dominated the Sixties and it appears that computer networks will play a similar role in the Seventies. The need has now arisen for many of these time-shared systems to share each others' resources by coupling them together over a communication network thereby creating a computer network. The

Leonard Kleinrock

1970-01-01

275

Methods for Improving the User-Computer Interface.  

National Technical Information Service (NTIS)

Numerous examples have been cited of deficiencies in the user-computer interface on Navy computers, both ashore and aboard ship. The computer system designer often overlooks the user's perspective in his desire to provide the user with a system that is a ...

P. H. McCann

1983-01-01

276

Optimal Joint Multiple Resource Allocation Method for Cloud Computing Environments  

Microsoft Academic Search

Cloud computing is a model for enabling convenient, on-demand network access to a shared pool of configurable computing resources. To provide cloud computing services economically, it is important to optimize resource allocation under the assumption that the required resource can be taken from a shared resource pool. In addition, to be able to provide processing ability and storage capacity, it

Shin-ichi Kuribayashi

2011-01-01

277

Methods, metrics and motivation for a green computer science program  

Microsoft Academic Search

Computer science educators are uniquely positioned to promote greater awareness of Green Computing, using the academic setting to encourage environmentally conscious use of technology. This paper reports on practical techniques that can engage faculty and students, enabling Green Computing to be integrated into the classroom and research laboratory. Analysis and empirical evaluation of each reported technique is given, comparing the

Mujtaba Talebi

2009-01-01

278

Computational Methods for Analyzing Fluid Flow Dynamics from Digital Imagery  

SciTech Connect

The main goal (long term) of this work is to perform computational dynamics analysis and quantify uncertainty from vector fields computed directly from measured data. Global analysis based on observed spatiotemporal evolution is performed by objective function based on expected physics and informed scientific priors, variational optimization to compute vector fields from measured data, and transport analysis proceeding with observations and priors. A mathematical formulation for computing flow fields is set up for computing the minimizer for the problem. An application to oceanic flow based on sea surface temperature is presented.

Luttman, A.

2012-03-30

279

A method for computing unsteady fully nonlinear interfacial waves  

NASA Astrophysics Data System (ADS)

We derive a time-stepping method for unsteady fully nonlinear two-dimensional motion of a two-layer fluid. Essential parts of the method are: use of Taylor series expansions of the prognostic equations, application of spatial finite difference formulae of high order, and application of Cauchy's theorem to solve the Laplace equation, where the latter is found to be advantageous in avoiding instability. The method is computationally very efficient. The model is applied to investigate unsteady trans-critical two-layer flow over a bottom topography. We are able to simulate a set of laboratory experiments on this problem described by Melville & Helfrich (1987), finding a very good agreement between the fully nonlinear model and the experiments, where they reported bad agreement with weakly nonlinear Korteweg de Vries theories for interfacial waves. The unsteady transcritical regime is identified. In this regime, we find that an upstream undular bore is generated when the speed of the body is less than a certain value, which somewhat exceeds the critical speed. In the remaining regime, a train of solitary waves is generated upstream. In both cases a corresponding constant level of the interface behind the body is developed. We also perform a detailed investigation of upstream generation of solitary waves by a moving body, finding that wave trains with amplitude comparable to the thickness of the thinner layer are generated. The results indicate that weakly nonlinear theories in many cases have quite limited applications in modelling unsteady transcritical two-layer flows, and that a fully nonlinear method in general is required.

Grue, John; André Friis, Helmer; Palm, Enok; Olav Rusås, Per

1997-11-01

280

Polyp segmentation method for CT colonography computer-aided detection  

NASA Astrophysics Data System (ADS)

We have developed a new method employing the Canny edge detector and Radon transformation to segment images of polyp candidates for CT colonography (CTC) computer aided polyp detection and obtain features useful for distinguishing true polyps from false positive detections. The technique is applied to two-dimensional subimages of polyp candidates selected using various 3-D shape and curvature characteristics. We detect boundaries using the Canny operator. The baseline of the colon wall is detected by applying the Radon transform to the edge image and locating the strongest peak in the resulting transform matrix. The following features are calculated and used to classify detections as true positives (TP) and false positives (FP): polyp boundary length, polyp base length, polyp internal area, average intensity, polyp height, and inscribed circle radius. The segmentation technique was applied to a data set of 15 polyps larger than 3 mm and 617 false positives taken from 80 CTC studies (supine and prone screening of 40 patients). The sensitivity was 100% (15 of 15). 58% of the FP's were eliminated leaving an average of 3 false positives per study. Our method is able to segment polyps and quantitatively measure polyp features independently of orientation and shape.

Jerebko, Anna K.; Teerlink, Sheldon; Franaszek, Marek; Summers, Ronald M.

2003-05-01

281

Improved Methods for Operating Public Transportation Services. Final August 1, 2011-January 31, 2013.  

National Technical Information Service (NTIS)

In this joint project, West Virginia University and the University of Maryland collaborated in developing improved methods for analyzing and managing public transportation services. Transit travel time data were collected using GPS tracking services and t...

A. Sanchez A. Unnikrishan D. Martinelli M. E. Kim P. Schonfeld

2013-01-01

282

Description of a method to support public health information management: organizational network analysis  

PubMed Central

In this case study we describe a method that has potential to provide systematic support for public health information management. Public health agencies depend on specialized information that travels throughout an organization via communication networks among employees. Interactions that occur within these networks are poorly understood and are generally unmanaged. We applied organizational network analysis, a method for studying communication networks, to assess the method’s utility to support decision making for public health managers, and to determine what links existed between information use and agency processes. Data on communication links among a health department’s staff was obtained via survey with a 93% response rate, and analyzed using Organizational Risk Analyzer (ORA) software. The findings described the structure of information flow in the department’s communication networks. The analysis succeeded in providing insights into organizational processes which informed public health managers’ strategies to address problems and to take advantage of network strengths.

Merrill, Jacqueline; Bakken, Suzanne; Rockoff, Maxine; Gebbie, Kristine; Carley, Kathleen

2007-01-01

283

Interactive computer methods for generating mineral-resource maps  

USGS Publications Warehouse

Inasmuch as maps are a basic tool of geologists, the U.S. Geological Survey's CRIB (Computerized Resources Information Bank) was constructed so that the data it contains can be used to generate mineral-resource maps. However, by the standard methods used-batch processing and off-line plotting-the production of a finished map commonly takes 2-3 weeks. To produce computer-generated maps more rapidly, cheaply, and easily, and also to provide an effective demonstration tool, we have devised two related methods for plotting maps as alternatives to conventional batch methods. These methods are: 1. Quick-Plot, an interactive program whose output appears on a CRT (cathode-ray-tube) device, and 2. The Interactive CAM (Cartographic Automatic Mapping system), which combines batch and interactive runs. The output of the Interactive CAM system is final compilation (not camera-ready) paper copy. Both methods are designed to use data from the CRIB file in conjunction with a map-plotting program. Quick-Plot retrieves a user-selected subset of data from the CRIB file, immediately produces an image of the desired area on a CRT device, and plots data points according to a limited set of user-selected symbols. This method is useful for immediate evaluation of the map and for demonstrating how trial maps can be made quickly. The Interactive CAM system links the output of an interactive CRIB retrieval to a modified version of the CAM program, which runs in the batch mode and stores plotting instructions on a disk, rather than on a tape. The disk can be accessed by a CRT, and, thus, the user can view and evaluate the map output on a CRT immediately after a batch run, without waiting 1-3 days for an off-line plot. The user can, therefore, do most of the layout and design work in a relatively short time by use of the CRT, before generating a plot tape and having the map plotted on an off-line plotter.

Calkins, James Alfred; Crosby, A. S.; Huffman, T. E.; Clark, A. L.; Mason, G. T.; Bascle, R. J.

1980-01-01

284

Computer-stored faculty publication file using the MT/ST in a medium-sized medical center library.  

PubMed

The Bowman Gray School of Medicine Library has implemented a computerized faculty publication file adapted from an existing system that utilized a Magnetic Tape/Selectric Typewriter for catalog card production and computer storage. The faculty publication file has provided printouts for the school's annual report and monthly faculty bulletins. After the data for all faculty bibliographies have been stored in the file, it will be possible to retrieve complete author and departmental listings. The file will be continuously updated by adding current citations and the bibliographies of new faculty members and by deleting data when faculty members leave the staff. PMID:1247706

Lee, S; Gratz, P; White, J

1976-01-01

285

Computer Aids for Aerospace Design and Engineering: Innovation, Economics and Public Policy.  

National Technical Information Service (NTIS)

A discussion of the applications of computer systems to the weapons systems development process, with emphasis on the role that the government might play in promoting, supporting, and implementing development of new computer-based systems for engineering ...

C. P. McLaughlin

1967-01-01

286

Human-computer interaction: The usability test methods and design principles in the human-computer interface design  

Microsoft Academic Search

This paper has analyzed and summarized the usability research in the human computer interface design and the relations between these researches and the usability of interface, and according to the usability research, this paper has summarized the usability test methods in the human computer interface design. At the end of this paper, it has analyzed and put forward some principles

Gong Chao

2009-01-01

287

Effects of numerical formulation on magnetic field computation using meshless methods  

Microsoft Academic Search

Meshless methods have some advantages over their counterparts such as the finite-element method (FEM). However, existing meshless methods for computational electromagnetic fields are still not as efficient as FEM. In this paper, we compare two meshless methods of discretizing the computational domain of Poisson-like problems; namely, the point collocation and Galerkin methods (which use the strong and weak forms of

Kok-Meng Lee; Qiang Li; Hungson Sun

2006-01-01

288

Improved computational methods for simulating inertial confinement fusion  

NASA Astrophysics Data System (ADS)

This dissertation describes the development of two multidimensional Lagrangian code for simulating inertial confinement fusion (ICF) on structured meshes. The first is DRACO, a production code primarily developed by the Laboratory for Laser Energetics. Several significant new capabilities were implemented including the ability to model radiative transfer using Implicit Monte Carlo [Fleck et al., JCP 8, 313 (1971)]. DRACO was also extended to operate in 3D Cartesian geometry on hexahedral meshes. Originally the code was only used in 2D cylindrical geometry. This included implementing thermal conduction and a flux-limited multigroup diffusion model for radiative transfer. Diffusion equations are solved by extending the 2D Kershaw method [Kershaw, JCP 39, 375 (1981)] to three dimensions. The second radiation-hydrodynamics code developed as part of this thesis is Cooper, a new 3D code which operates on structured hexahedral meshes. Cooper supports the compatible hydrodynamics framework [Caramana et al., JCP 146, 227 (1998)] to obtain round-off error levels of global energy conservation. This level of energy conservation is maintained even when two temperature thermal conduction, ion/electron equilibration, and multigroup diffusion based radiative transfer is active. Cooper is parallelized using domain decomposition, and photon energy group decomposition. The Mesh Oriented datABase (MOAB) computational library is used to exchange information between processes when domain decomposition is used. Cooper's performance is analyzed through direct comparisons with DRACO. Cooper also contains a method for preserving spherical symmetry during target implosions [Caramana et al., JCP 157, 89 (1999)]. Several deceleration phase implosion simulations were used to compare instability growth using traditional hydrodynamics and compatible hydrodynamics with/without symmetry modification. These simulations demonstrate increased symmetry preservation errors when traditional hydrodynamics is used. The symmetry preservation errors are not as significant when physical instability growth dominates numerical instability growth. In this case, traditional and compatible hydrodynamics produce similar results.

Fatenejad, Milad

289

Formulations and computational methods for contact problems in solid mechanics  

NASA Astrophysics Data System (ADS)

A study of existing formulations and computational methods for contact problems is conducted. The purpose is to gain insights into the solution procedures and pinpoint their limitations so that alternate procedures can be developed. Three such procedures based on the augmented Lagrangian method (ALM) are proposed. Small-scale benchmark problems are solved analytically as well as numerically to study the existing and proposed methods. The variational inequality formulation for frictionless contact is studied using the two bar truss-wall problem in a closed form. Sub-differential formulation is investigated using the spring-wall contact and the truss-wall friction problems. A two-phase analytical procedure is developed for solving the truss-wall frictional contact benchmark problem. The variational equality formulation for contact problems is studied using the penalty method along with the Newton-Raphson procedure. Limitations of such procedures, mainly due to their dependence on the user defined parameters (i.e., the penalty values and the number of time steps), are identified. Based on the study it is concluded that alternate formulations need to be developed. Frictionless contact formulation is developed using the basic concepts of ALM from optimization theory. A new frictional contact formulation (ALM1) is then developed employing ALM. Automatic penalty update procedure is used to eliminate dependence of the solution on the penalty values. Dependence of the solution on the number of time steps in the existing as well as ALM1 formulations is attributed to a flaw in the return mapping procedure for friction. Another new frictional contact formulation (ALM2) is developed to eliminate the dependence of solution on the number of time steps along with the penalty values. Effectiveness of ALM2 is demonstrated by solving the two bar and five bar truss-wall problems. The solutions are compared with the analytical and existing formulations. Design sensitivity analysis of frictional contact problems is also studied and potential advantages of ALM2 over the existing formulations to obtain the sensitivity coefficients are identified. Finally, future directions of the research and conclusions are given.

Mirar, Anand Ramchandra

290

Computational methods in solid-state numerical quantum chemistry  

Microsoft Academic Search

The application of computational quantum chemistry towards the design of functional materials has been identified as one of the grand challenges in the art of high performance computing, offering substantial benefit to those who are able to make progress in the art and to those who are able to utilize the results of such techniques on a production scale economic

Armin Liebchen

1997-01-01

291

Methods in computational physics. Volume 14 - Radio astronomy  

Microsoft Academic Search

Papers are presented which deal with the special computational problems in radioastronomical studies, studying the chief problems of data acquisition, reduction, and interpretation for selected types of observations. The specific topics studied are the principles of radioheliography with emphasis on the Culgoora radioheliograph, pulsar signal processing, aperture synthesis (in particular, earth rotation aperture synthesis), and computations in radio-frequency spectroscopy. Individual

B. Alder; S. Fernbach; M. Rotenberg

1975-01-01

292

PROPOSAL OFSHARED MEMORYACCESS METHODS FOR LAMBDA COMPUTING ENVIRONMENT  

Microsoft Academic Search

Optical transmission technology is studied actively in order to realize high- speed transmission and broadband networks. However, conventional packet- based switching technology cannot realize the true high quality communication for each connection. Then we propose new ? computing environment which has the virtual channels utilizing optical fibers connecting computing nodes. So we can offer the high-speed and reliable connection path\\/pipe

Hirohisa Nakamoto; Ken-ichi Baba; Masayuki Murat

293

Students' Attitudes towards Control Methods in Computer-Assisted Instruction.  

ERIC Educational Resources Information Center

Describes study designed to investigate dental students' attitudes toward computer-assisted teaching as applied in programs for oral radiology in Denmark. Programs using personal computers and slide projectors with varying degrees of learner and teacher control are described, and differences in attitudes between male and female students are…

Hintze, Hanne; And Others

1988-01-01

294

Evaluating Computer Automated Scoring: Issues, Methods, and an Empirical Illustration  

ERIC Educational Resources Information Center

|With the continual progress of computer technologies, computer automated scoring (CAS) has become a popular tool for evaluating writing assessments. Research of applications of these methodologies to new types of performance assessments is still emerging. While research has generally shown a high agreement of CAS system generated scores with…

Yang, Yongwei; Buckendahl, Chad W.; Juszkiewicz, Piotr J.; Bhola, Dennison S.

2005-01-01

295

Students' Attitudes towards Control Methods in Computer-Assisted Instruction.  

ERIC Educational Resources Information Center

|Describes study designed to investigate dental students' attitudes toward computer-assisted teaching as applied in programs for oral radiology in Denmark. Programs using personal computers and slide projectors with varying degrees of learner and teacher control are described, and differences in attitudes between male and female students are…

Hintze, Hanne; And Others

1988-01-01

296

Four-stage computational technology with adaptive numerical methods for computational aerodynamics  

NASA Astrophysics Data System (ADS)

Computational aerodynamics is a key technology in aircraft design which is ahead of physical experiment and complements it. Of course all three components of computational modeling are actively developed: mathematical models of real aerodynamic processes, numerical algorithms, and high-performance computing. The most impressive progress has been made in the field of computing, though with a considerable complication of computer architecture. Numerical algorithms are developed more conservative. More precisely, they are offered and theoretically justified for more simple mathematical problems. Nevertheless, computational mathematics now has amassed a whole palette of numerical algorithms that can provide acceptable accuracy and interface between modern mathematical models in aerodynamics and high-performance computers. A significant step in this direction was the European Project ADIGMA whose positive experience will be used in International Project TRISTAM for further movement in the field of computational technologies for aerodynamics. This paper gives a general overview of objectives and approaches intended to use and a description of the recommended four-stage computer technology.

Shaydurov, V.; Liu, T.; Zheng, Z.

2012-10-01

297

Small Scale Distance Education; "The Personal (Computer) Touch"; Tutorial Methods for TMA's Using a Computer.  

ERIC Educational Resources Information Center

|The authors present reports of current research on distance education at the FernUniversitat in West Germany. Fritsch discusses adapting distance education techniques for small classes. Kuffner describes procedures for providing feedback to students using personalized computer-generated letters. Klute discusses using a computer with tutorial…

Fritsch, Helmut; And Others

1989-01-01

298

Computer Science Instruction in Elementary Grades, an Exploration of Computer-Based Learning Methods. Final Report.  

ERIC Educational Resources Information Center

|During the exploratory phase of this two-year project, 234 instructional computer programs were written by 167 junior and senior high school students, instructed as individuals, in small groups, and in whole classes. Then a doctoral study investigated the effectiveness of computer-assisted instruction in the development of problem solving skills.…

Starkweather, John A.

299

Do Examinees Understand Score Reports for Alternate Methods of Scoring Computer Based Tests?  

ERIC Educational Resources Information Center

|This study assessed the interpretability of scaled scores based on either number correct (NC) scoring for a paper-and-pencil test or one of two methods of scoring computer-based tests: an item pattern (IP) scoring method and a method based on equated NC scoring. The equated NC scoring method for computer-based tests was proposed as an alternative…

Whittaker, Tiffany A.; Williams, Natasha J.; Dodd, Barbara G.

2011-01-01

300

A computational method for optimizing fuel treatment locations  

Treesearch

International Institute of Tropical Forestry ... Fire growth from the upwind edge of the landscape is then computed using a minimum travel time algorithm. This identifies major fire travel routes (areas needing treatment) and their intersections  ...

301

Progress Towards Computational Method for Circulation Control Airfoils.  

National Technical Information Service (NTIS)

The compressible Reynold-averaged Navier-Stokes equations are solved for circulation control airfoil flows. Numerical solutions are computed with both structured and unstructured grid solvers. Several turbulence models are considered, including the Spalar...

R. C. Swanson C. L. Rumsey S. G. Anders

2005-01-01

302

Leading Computational Methods on Scalar and Vector HEC Platforms  

Microsoft Academic Search

The last decade has witnessed a rapid proliferation of superscalar cache-based microprocessors to build high-end computing (HEC) platforms, primarily because of their generality, scalability, and cost effectiveness. However, the growing gap between sustained and peak performance for full-scale scientific applications on conventional supercomputers has become a major concern in high performance computing, requiring significantly larger systems and application scalability than

Leonid Oliker; Jonathan Carter; Michael Wehner; Andrew Canning; Stéphane Ethier; Arthur Mirin; David Parks; Patrick H. Worley; Shigemune Kitawaki; Yoshinori Tsuda

2005-01-01

303

Computationally efficient method for analyzing guard channel schemes  

Microsoft Academic Search

Call admission control (CAC) is important for cellular wireless networks in order to provide quality of service (QoS) requirements\\u000a to users. Guard channel scheme is one of the CAC schemes. There are different computational models for analyzing the guard\\u000a channel scheme which make unrealistic assumption of exponential distribution for both call holding duration and cell residence\\u000a time for computational tractability.

Attahiru Sule Alfa

2009-01-01

304

26 CFR 1.9001-1 - Change from retirement to straight-line method of computing depreciation.  

Code of Federal Regulations, 2010 CFR

... Change from retirement to straight-line method of computing depreciation... Change from retirement to straight-line method of computing depreciation...from the retirement to the straight-line method of computing the...

2010-04-01

305

26 CFR 1.9001-1 - Change from retirement to straight-line method of computing depreciation.  

Code of Federal Regulations, 2010 CFR

... Change from retirement to straight-line method of computing depreciation... Change from retirement to straight-line method of computing depreciation...from the retirement to the straight-line method of computing the...

2009-04-01

306

Methods of Conserving Heating Energy Utilized in Thirty-One Public School Systems.  

ERIC Educational Resources Information Center

|The Memphis City School System was notified by Memphis Light, Gas, and Water that it was necessary to reduce its consumption of natural gas during the winter of 1975-76. A survey was developed and sent to 44 large public school systems to determine which methods of heating energy conservation were used most frequently and which methods were most…

Davis, Kathy Eggers

307

Public Computer Assisted Learning Facilities for Children with Visual Impairment: Universal Design for Inclusive Learning  

ERIC Educational Resources Information Center

|Although computer assisted learning (CAL) is becoming increasingly popular, people with visual impairment face greater difficulty in accessing computer-assisted learning facilities. This is primarily because most of the current CAL facilities are not visually impaired friendly. People with visual impairment also do not normally have access to…

Siu, Kin Wai Michael; Lam, Mei Seung

2012-01-01

308

Toward dynamic and attribute based publication, discovery and selection for cloud computing  

Microsoft Academic Search

Cloud computing is an emerging paradigm where computing resources are offered over the Internet as scalable, on-demand (Web) services. While cloud vendors have concentrated their efforts on the improvement of performance, resource consumption and scalability, other cloud characteristics have been neglected. On the one hand cloud service providers face difficult problems of publishing services that expose resources, and on the

Andrzej Goscinski; Michael Brock

2010-01-01

309

Computer-Aided Transcription in the Courts. Executive Summary. National Center Publication No. R-0058.  

National Technical Information Service (NTIS)

This report summarizes the findings of the Computer-Aided Transcription (CAT) Project, which conducted a 14-month study of the technology and use of computer systems for translating into English the shorthand notes taken by court reporters on stenotype ma...

1981-01-01

310

Public Computer Assisted Learning Facilities for Children with Visual Impairment: Universal Design for Inclusive Learning  

ERIC Educational Resources Information Center

Although computer assisted learning (CAL) is becoming increasingly popular, people with visual impairment face greater difficulty in accessing computer-assisted learning facilities. This is primarily because most of the current CAL facilities are not visually impaired friendly. People with visual impairment also do not normally have access to…

Siu, Kin Wai Michael; Lam, Mei Seung

2012-01-01

311

The Status of Computing in Public Schools in the West Kootenay Region of British Columbia.  

ERIC Educational Resources Information Center

|The purpose of this study was to determine the status of the use of computers in the schools within the West Kootenay region of southeastern British Columbia (Canada). Thirty teachers, librarians, principals, and senior district administrators were interviewed to determine the computing background of the interviewees and how they were using…

Perra, Leonel L.

312

Fast Computational Methods for Computing Quantum Transport in Nanowires and Nanotubes.  

National Technical Information Service (NTIS)

Nanowires and nanotubes are promising building blocks for designing nanoscale devices for sensing warfare agents. Computer models are key to designing and improving such sensors. Due to their nanoscale size, quantum models are needed to model the transpor...

D. E. Petersen E. Darve K. Stokbro S. Li

2008-01-01

313

A Computer Method for the Calibration of a Photographic Emulsion for Spectrographic Analysis.  

National Technical Information Service (NTIS)

A computer method to calibrate emulsion-covered glass plates used to interpret densities of lines for quantitative spectrographic work is reported. This method follows a slightly modified ASTM graphic method, which is also described, and allows one to sim...

B. H. Strauss

1977-01-01

314

Method for simulating paint mixing on computer monitors  

NASA Astrophysics Data System (ADS)

Computer programs like Adobe Photoshop can generate a mixture of two 'computer' colors by using the Gradient control. However, the resulting colors diverge from the equivalent paint mixtures in both hue and value. This study examines why programs like Photoshop are unable to simulate paint or pigment mixtures, and offers a solution using Photoshops existing tools. The article discusses how a library of colors, simulating paint mixtures, is created from 13 artists' colors. The mixtures can be imported into Photoshop as a color swatch palette of 1248 colors and as 78 continuous or stepped gradient files, all accessed in a new software package, Chromafile.

Carabott, Ferdinand; Lewis, Garth; Piehl, Simon

2002-06-01

315

Public health education for midwives and midwifery students: a mixed methods study  

PubMed Central

Background Current national and international maternity policy supports the importance of addressing public health goals and investing in early years. Health care providers for women during the reproductive and early postnatal period have the opportunity to encourage women to make choices that will impact positively on maternal and fetal health. Midwives are in a unique position, given the emphasis of the philosophy of midwifery care on building relationships and incorporating a holistic approach, to support women to make healthy choices with the aim of promoting health and preventing ill health. However, exploration of the educational preparation of midwives to facilitate public health interventions has been relatively limited. The aim of the study was to identify the scope of current midwifery pre registration educational provision in relation to public health and to explore the perspectives of midwives and midwifery students about the public health role of the midwife. Methods This was a mixed methods study incorporating a survey of Higher Educational Institutions providing pre registration midwifery education across the UK and focus groups with midwifery students and registered midwives. Results Twenty nine institutions (53% response) participated in the survey and nine focus groups were conducted (59 participants). Public health education was generally integrated into pre registration midwifery curricula as opposed to taught as a discrete subject. There was considerable variation in the provision of public health topics within midwifery curricula and the hours of teaching allocated to them. Focus group data indicated that it was consistently difficult for both midwifery students and midwives to articulate clearly their understanding and definition of public health in relation to midwifery. Conclusions There is a unique opportunity to impact on maternal and infant health throughout the reproductive period; however the current approach to public health within midwifery education should be reviewed to capitalise on the role of the midwife in delivering public health interventions. It is clear that better understanding of midwifery public health roles and the visibility of public health within midwifery is required in order to maximise the potential contribution of midwives to achieving short and long term public health population goals.

2012-01-01

316

A method for wave decomposition in computations for nonlinear dynamical three-dimensional towing systems  

Microsoft Academic Search

We propose a new method for computing multimode wave interactions in towing systems; our method is based on wave splitting\\u000a of the equations of a model in such a way that each computational step requires computation for only one mode. The efficiency\\u000a of the method is demonstrated by analysis of a concrete towing system with a turning towboat.

Yu. I. Kalyukh; I. T. Selezov

1998-01-01

317

Computational disease gene identification: a concert of methods prioritizes type 2 diabetes and obesity candidate genes  

Microsoft Academic Search

Genome-wide experimental methods to identify disease genes, such as linkage analysis and association studies, generate increasingly large candidate gene sets for which comprehensive empirical analysis is impractical. Computational methods employ data from a variety of sources to identify the most likely candidate disease genes from these gene sets. Here, we review seven independent computational disease gene prioritization methods, and then

Nicki Tiffin; Euan Adie; Frances Turner; Han G. Brunner; Marc A. van Driel; Martin Oti; Nuria Lopez-Bigas; Christos Ouzounis; Carolina Perez-Iratxeta; Miguel A. Andrade-Navarro; Adebowale Adeyemo; Mary Elizabeth Patti; Colin A. M. Semple; Winston Hide

2006-01-01

318

An improved physical optics method for the computation of radar cross section of electrically large objects  

Microsoft Academic Search

An improved physical optics method for the computation of radar cross section of electrically large objects is presented. The method is quite general to compute the radar cross section (RCS) of arbitrarily shaped metal structures by rigorously transforming the radiation surface integral in the traditional PO method to a line integral along the metal boundary. Since the line integral is

Chonghua Fang; Xiaonan Zhao; Qian Liu

2008-01-01

319

Minimizing the Free Energy: A Computer Method for Teaching Chemical Equilibrium Concepts.  

ERIC Educational Resources Information Center

Presents a computer method for teaching chemical equilibrium concepts using material balance conditions and the minimization of the free energy. Method for the calculation of chemical equilibrium, the computer program used to solve equilibrium problems and applications of the method are also included. (HM)

Heald, Emerson F.

1978-01-01

320

A Computer Assisted Method for Analyzing Curriculum Content.  

ERIC Educational Resources Information Center

A computer-assisted curriculum evaluation effort at Pacific University assessed the extent to which the existing curriculum addressed the Association of Schools and Colleges of Optometry's (ASCO) recommendations, possible duplication of effort, and areas taught but not included in the ASCO models. (MSE)

Septon, Richard D.

1983-01-01

321

COMPUTER VISION BASED METHOD FOR FIRE DETECTION IN COLOR VIDEOS  

Microsoft Academic Search

This paper presents a computer vision based system for automatically detecting the presence of fire in stable video sequences. The algorithm is based not only on the color and movement attributes of fire but also analyzes the temporal variation of fire intensity, the spatial color variation of fire and the tendency of fire to be grouped around a central point.

Jessica Ebert; Jennie Shipley

322

An auction method for resource allocation in computational grids  

Microsoft Academic Search

A computational grid is composed of a set of resource consumers and resources providers. Usually these entities are independent and making decisions autonomously based on their policies and resource allocation in such systems is a challenging problem. In such systems using market-like techniques for this problem regulates the supply and demand for resources, provides an incentive for providers, and motivates

Hesam Izakian; Ajith Abraham; Behrouz Tork Ladani

2010-01-01

323

Computational methods for image restoration, image segmentation, and texture modeling  

Microsoft Academic Search

This work is devoted to new computational models for image segmentation, image restoration and image de- composition. In particular, we partition an image into piecewise-constant regions using energy minimization and curve evolution approaches. Applications of denoising-segmentation in polar coordinates (motivated by impedance tomography) and of segmentation of brain images will be presented. Also, we decompose a natural image into a

Ginmo Chung; Linh H. Lieu; Nicolay M. Tanushev; Luminita A. Vese

2006-01-01

324

Volume rendering methods for computational fluid dynamics visualization  

Microsoft Academic Search

This paper describes three alternative volume rendering approaches to visualizing computational fluid dynamics (CFD) data. One new approach uses realistic volumetric gas rendering techniques to produce photo-realistic images and animations from scalar CFD data. The second uses ray casting that is based on a simpler illumination model and is mainly centered around a versatile new tool for the design of

David S. Ebert; Roni Yagel; James N. Scott; Yair Kurzion

1994-01-01

325

THE ROLE OF STATISTICAL METHODS IN COMPUTER SCIENCE AND BIOINFORMATICS  

Microsoft Academic Search

This article discusses the links between computer science, statistics and biology education on the basis of research at the Latvia University of Agriculture. Bioinformatics study is considered from two aspects - as one for biologists learning Information Technologies (IT) to use within their speciality, or for IT specialists learning biology so they can apply their skills to biological problems. The

Irina Arhipova

2006-01-01

326

Computer Training and Individual Differences: When Method Matters.  

ERIC Educational Resources Information Center

Interviews were conducted with 263 licensed users of training software, 68 of whom had used computer-based training (CBT), instructor-led training, and video tutorials. Videos were deemed the least useful. Instructor-led training had the most feedback and media richness, but CBT was an effective low-cost alternative. (SK)

Harp, Candace G.; Taylor, Sandra C.; Satzinger, John W.

1998-01-01

327

A new era in scientific computing: Domain decomposition methods in hybrid CPU–GPU architectures  

Microsoft Academic Search

Recent advances in graphics processing units (GPUs) technology open a new era in high performance computing. Applications of GPUs to scientific computations are attracting a lot of attention due to their low cost in conjunction with their inherently remarkable performance features and the recently enhanced computational precision and improved programming tools. Domain decomposition methods (DDM) constitute today an important category

M. Papadrakakis; G. Stavroulakis; A. Karatarakis

2011-01-01

328

Finite volume methods applied to the computational modelling of welding phenomena  

Microsoft Academic Search

This paper presents the computational modelling of welding phenomena within a versatile numerical framework. The framework embraces models from both the fields of computational fluid dynamics (CFD) and computational solid mechanics (CSM). With regard to the CFD modelling of the weld pool fluid dynamics, heat transfer and phase change, cell-centred finite volume (FV) methods are employed. Additionally, novel vertex-based FV

Gareth A. TAYLOR; Michael Hughes; Nadia Strusevich; Koulis Pericleous

2002-01-01

329

Meshless method based on orthogonal basis for computational electromagnetics  

Microsoft Academic Search

This paper discovers and researches problems on numerical oscillations of the solution in element-free Galerkin method (EFGM) when it uses high order polynomial basis, and puts forward the meshless method based on orthogonal basis (MLMBOB), which is composed of essential boundary conditions with Penalty method, then gets the numerical solutions of the partial differential equations. This method holds nearly all

Yong Zhang; K. R. Shao; D. X. Xie; J. D. Lavers

2005-01-01

330

3D modeling method for computer animate based on modified weak structured light method  

NASA Astrophysics Data System (ADS)

A simple and affordable 3D scanner is designed in this paper. Three-dimensional digital models are playing an increasingly important role in many fields, such as computer animate, industrial design, artistic design and heritage conservation. For many complex shapes, optical measurement systems are indispensable to acquiring the 3D information. In the field of computer animate, such an optical measurement device is too expensive to be widely adopted, and on the other hand, the precision is not as critical a factor in that situation. In this paper, a new cheap 3D measurement system is implemented based on modified weak structured light, using only a video camera, a light source and a straight stick rotating on a fixed axis. For an ordinary weak structured light configuration, one or two reference planes are required, and the shadows on these planes must be tracked in the scanning process, which destroy the convenience of this method. In the modified system, reference planes are unnecessary, and size range of the scanned objects is expanded widely. A new calibration procedure is also realized for the proposed method, and points cloud is obtained by analyzing the shadow strips on the object. A two-stage ICP algorithm is used to merge the points cloud from different viewpoints to get a full description of the object, and after a series of operations, a NURBS surface model is generated in the end. A complex toy bear is used to verify the efficiency of the method, and errors range from 0.7783mm to 1.4326mm comparing with the ground truth measurement.

Xiong, Hanwei; Pan, Ming; Zhang, Xiangwei

2010-11-01

331

Study on computer-aided alignment method of Cassegrain system  

NASA Astrophysics Data System (ADS)

To realize the fast, efficient alignment of Cassegrain system, the scheme of computer-aided alignment is proposed. The misalignment state of Cassegrain system was simulated in Zemax, corresponding relationship between the misalignments and Zernike polynomial coefficients is analyzed and the misalignment characteristics of Cassegrain system were summarized by Matlab. Finally, the alignment scheme is determined by analysis. In order to verify the scheme, the Cassegrain system was aligned according to the value which was calculated in accordance with the alignment scheme. The result demonstrates that the alignment scheme is feasible to Cassegrain system. Satisfactory results are achieved in applying the scheme of computer-aided alignment to the alignment of 1.2m and 1.8m telescopes.

Bin, Wang; Lei, Jiang Shi; Tian, Qiu

2010-05-01

332

Counting hard-to-count populations: the network scale-up method for public health  

PubMed Central

Estimating sizes of hidden or hard-to-reach populations is an important problem in public health. For example, estimates of the sizes of populations at highest risk for HIV and AIDS are needed for designing, evaluating and allocating funding for treatment and prevention programmes. A promising approach to size estimation, relatively new to public health, is the network scale-up method (NSUM), involving two steps: estimating the personal network size of the members of a random sample of a total population and, with this information, estimating the number of members of a hidden subpopulation of the total population. We describe the method, including two approaches to estimating personal network sizes (summation and known population). We discuss the strengths and weaknesses of each approach and provide examples of international applications of the NSUM in public health. We conclude with recommendations for future research and evaluation.

Bernard, H Russell; Hallett, Tim; Iovita, Alexandrina; Johnsen, Eugene C; Lyerla, Rob; McCarty, Christopher; Mahy, Mary; Salganik, Matthew J; Saliuk, Tetiana; Scutelniciuc, Otilia; Shelley, Gene A; Sirinirund, Petchsri; Weir, Sharon

2010-01-01

333

Parallel computations based on modified numerical integration methods  

NASA Astrophysics Data System (ADS)

Even though the idea of parallel computing and parallel connection of high amount of microprocessors is attractive, it is not easy to reach big increase in performance compared to single processor approach. The potential of parallel data processing has already been studied. It was found, that even a small percentage of sequential steps may lead to high reduction of performance of the entire system. This is the consequence of the fact, that most algorithms were not developed for heavy parallel systems.

Kunovský, Ji?í; Kraus, Michal; Šátek, Václav; Szöllös, Alexandr

2012-09-01

334

Computer methods and ecological validity in reading research  

Microsoft Academic Search

Computer-based procedures for obtaining word-by-word reading times are evaluated in terms of criteria for basic research and\\u000a for ecologically valid research. Ecological validity can sometimes compromise experimental designs that should control extraneous\\u000a variables or separate confounded factors. Two reading paradigms that were developed for basic research on linguistic coding\\u000a mechanisms are also shown to meet many of the criteria for

Doris Aaronson

1984-01-01

335

Synergic Combinations of Computational Methods and Experiments for Structural Diagnoses  

Microsoft Academic Search

\\u000a The mechanical characterization of materials and the non-destructive assessment of possible damages in industrial plant components\\u000a and in civil engineering structures and infrastructures is a problem which at present arises more and more frequently and\\u000a acquires growing importance in both experimental and computational mechanics. The survey presented here concerns some representative,\\u000a practically meaningful typical problems of this kind recently or

Giulio Maier; Gabriella Bolzon; Vladimir Buljak; Tomasz Garbowski; Bartosz Miller

336

Computational Methods for the Analysis of Array Comparative Genomic Hybridization  

PubMed Central

Array comparative genomic hybridization (array CGH) is a technique for assaying the copy number status of cancer genomes. The widespread use of this technology has lead to a rapid accumulation of high throughput data, which in turn has prompted the development of computational strategies for the analysis of array CGH data. Here we explain the principles behind array image processing, data visualization and genomic profile analysis, review currently available software packages, and raise considerations for future software development.

Chari, Raj; Lockwood, William W.; Lam, Wan L.

2006-01-01

337

An Overview of Public Access Computer Software Management Tools for Libraries  

ERIC Educational Resources Information Center

|An IT decision maker gives an overview of public access PC software that's useful in controlling session length and scheduling, Internet access, print output, security, and the latest headaches: spyware and adware. In this article, the author describes a representative sample of software tools in several important categories such as setup…

Wayne, Richard

2004-01-01

338

Computing Science: Organised Chaos Learning Outcomes from Trialling Active Learning Methods in Computing Science.  

National Technical Information Service (NTIS)

Active Learning in Computing is a 5 year CETL project funded by HEFCE (UK). It involves a consortium of Universities from the North West of England, comprising Durham University as project lead and Newcastle University, University of Leeds and Leeds Metro...

C. Phillips L. Marshall M. Devlin

2008-01-01

339

ZOOM: a generic personal computer-based teaching program for public health and its application in schistosomiasis control.  

PubMed Central

Schistosomiasis, a group of parasitic diseases caused by Schistosoma parasites, is associated with water resources development and affects more than 200 million people in 76 countries. Depending on the species of parasite involved, disease of the liver, spleen, gastrointestinal or urinary tract, or kidneys may result. A computer-assisted teaching package has been developed by WHO for use in the training of public health workers involved in schistosomiasis control. The package consists of the software, ZOOM, and a schistosomiasis information file, Dr Schisto, and uses hypermedia technology to link pictures and text. ZOOM runs on the IBM-PC and IBM-compatible computers, is user-friendly, requires a minimal hardware configuration, and can interact with the user in English, French, Spanish or Portuguese. The information files for ZOOM can be created or modified by the instructor using a word processor, and thus can be designed to suit the need of students. No programming knowledge is required to create the stacks.

Martin, G. T.; Yoon, S. S.; Mott, K. E.

1991-01-01

340

Multi-Level iterative methods in computational plasma physics  

SciTech Connect

Plasma physics phenomena occur on a wide range of spatial scales and on a wide range of time scales. When attempting to model plasma physics problems numerically the authors are inevitably faced with the need for both fine spatial resolution (fine grids) and implicit time integration methods. Fine grids can tax the efficiency of iterative methods and large time steps can challenge the robustness of iterative methods. To meet these challenges they are developing a hybrid approach where multigrid methods are used as preconditioners to Krylov subspace based iterative methods such as conjugate gradients or GMRES. For nonlinear problems they apply multigrid preconditioning to a matrix-few Newton-GMRES method. Results are presented for application of these multilevel iterative methods to the field solves in implicit moment method PIC, multidimensional nonlinear Fokker-Planck problems, and their initial efforts in particle MHD.

Knoll, D.A.; Barnes, D.C.; Brackbill, J.U.; Chacon, L.; Lapenta, G.

1999-03-01

341

Permeability computation on a REV with an immersed finite element method  

SciTech Connect

An efficient method to compute permeability of fibrous media is presented. An immersed domain approach is used to represent the porous material at its microscopic scale and the flow motion is computed with a stabilized mixed finite element method. Therefore the Stokes equation is solved on the whole domain (including solid part) using a penalty method. The accuracy is controlled by refining the mesh around the solid-fluid interface defined by a level set function. Using homogenisation techniques, the permeability of a representative elementary volume (REV) is computed. The computed permeabilities of regular fibre packings are compared to classical analytical relations found in the bibliography.

Laure, P. [Laboratoire J.-A. Dieudonne, CNRS UMR 6621, Universite de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice, Cedex 02 (France); Puaux, G.; Silva, L.; Vincent, M. [MINES ParisTech, CEMEF-Centre de Mise en Forme des Materiaux, CNRS UMR 7635, BP 207 1 rue Claude, Daunesse 06904 Sophia Antipolis cedex (France)

2011-05-04

342

Evaluation of construction methods and performance for high rise public housing construction in Hong Kong  

Microsoft Academic Search

Time, cost and resource usage are some of the most important production performance issues in the construction industry. This paper investigates the impact of using different construction methods or techniques on production performance in the context of high-rise public housing construction in Hong Kong. Three different construction schemes with the same standard “Harmony” design were investigated. These schemes differ in

C. M Tam; Z. M Deng; S. X Zeng

2002-01-01

343

Weeding the Forest Hill Branch of Toronto Public Library by the Slote Method: A Test Case.  

ERIC Educational Resources Information Center

|Describes a two-part book circulation use study conducted to find a simple inexpensive and effective method of weeding a public library branch collection, to determine whether weeding increases circulation, and to compare results with Slote's results. Seven tables, one appendix, and 32 references are provided. (RBF)|

McKee, Penelope

1981-01-01

344

Public-private sector wage differentials around the world: Methods and evidence  

Microsoft Academic Search

My intention, in this (rather unambitiously titled) paper, is to present a brief overview of work on the rationale and evidence for the existence of pay premia or penalties associated with working in the public sector. Many studies have found evidence of such premia or penalties (and mostly the former, especially for women) using econometric methods that are not dissimilar

Richard Disney

2007-01-01

345

Applications of the CASE\\/MULTICASE SAR Method to Environmental and Public Health Situations  

Microsoft Academic Search

The availability of validated and characterized SAR models of toxicological phenomena provides a method to apply SAR technology to a variety of environmental, public health and industrial situations. These include (i) the prioritization of environmental pollutants for control and or regulation, (ii) the design of multi-action optimized therapeutics from which the potential for unwanted side-effects have been engineered out, (iii)

H. S. Rosenkranz; A. R. Cunningham; Y. P. Zhang; G. Klopman

1999-01-01

346

The Role of Public Extension in Introducing Environment-Friendly Farming Methods in Turkey.  

ERIC Educational Resources Information Center

Currently, the Turkish extension service plays a minimal role in reducing adverse environmental effects of farming methods. Public investment in research and extension on sustainable agriculture is needed to ensure long-term production practices that maintain the food supply without damaging the environment. (SK)

Kumuk, T.; Akgungor, S.

1995-01-01

347

Fusion Method for Designing Computer-Based Learning Game  

Microsoft Academic Search

Combination Method, game phases and learning phases are separated, and the results of the learning are used to play the game. Although this method is general and simple because it is independent of the properties of the learning activity, the learning phases itself often remains boring. In Fusion Method, learning activity and game activity are fused together. Therefore, in the

Takanobu Umetsu; Tsukasa Hirashima; Akira Takeuchi

2002-01-01

348

Geographical Information Systems (GIS): Their Use as Decision Support Tools in Public Libraries and the Integration of GIS with Other Computer Technology  

Microsoft Academic Search

Describes the the use of Geographical Information Systems (GIS) as decision support tools in public libraries in England. A GIS is a computer software system that represents data in a geographic dimension. GIS as a decision support tool in public libraries is in its infancy; only seven out of 40 libraries contacted in the survey have GIS projects, three of

Andrew M. Hawkins

1994-01-01

349

A multigrid pseudospectral method for steady flow computation  

NASA Astrophysics Data System (ADS)

In this work two-dimensional steady flow problems are cast into a fixed-point formulation, Q = F(Q). The non-linear operator, F, is an approximate pseudospectral solver to the Navier-Stokes equations. To search the solution we employ Picard iteration together with a one-dimensional error minimization and a random perturbation in case of getting stuck. A monotone convergence is brought out, and is greatly improved by using a multigrid strategy. The efficacy of this approach is demonstrated by computing flow between eccentric rotating cylinders, and the regularized lid-driven cavity flow with Reynolds number up to 1000.

Chou, Mo-Hong

2003-09-01

350

Shielding analysis methods available in the scale computational system  

SciTech Connect

Computational tools have been included in the SCALE system to allow shielding analysis to be performed using both discrete-ordinates and Monte Carlo techniques. One-dimensional discrete ordinates analyses are performed with the XSDRNPM-S module, and point dose rates outside the shield are calculated with the XSDOSE module. Multidimensional analyses are performed with the MORSE-SGC/S Monte Carlo module. This paper will review the above modules and the four Shielding Analysis Sequences (SAS) developed for the SCALE system. 7 refs., 8 figs.

Parks, C.V.; Tang, J.S.; Hermann, O.W.; Bucholz, J.A.; Emmett, M.B.

1986-01-01

351

Improved methods for computing masses from numerical simulations  

SciTech Connect

An important advance in the computation of hadron and glueball masses has been the introduction of non-local operators. This talk summarizes the critical signal-to-noise ratio of glueball correlation functions in the continuum limit, and discusses the case of (q{bar q} and qqq) hadrons in the chiral limit. A new strategy for extracting the masses of excited states is outlined and tested. The lessons learned here suggest that gauge-fixed momentum-space operators might be a suitable choice of interpolating operators. 15 refs., 2 tabs.

Kronfeld, A.S.

1989-11-22

352

A two-Factor Authentication System using Mobile Devices to Protect against Untrusted Public Computers  

Microsoft Academic Search

This paper discusses a two-Factor authentication system that allows both the user and the server to assure that the other is the correct entity. This system also allows a user to use unprotected computers with no concern of revealing information to attacks such as phishing, key logging and wire listening. This is accomplished by placing the entering and encrypting of

Abdullah Alqattan; Nima Kaviani; Patrick Lewis; Nicholas Pearson

353

The Evolution of Computer Forensic Best Practices: An Update on Programs and Publications  

Microsoft Academic Search

The field of computer forensics is one of the newer disciplines in the area of forensic science. Like all of the others, it is going through a transition from an art practiced by individuals to a more standardized set of techniques for which “best practices” can be defined. Over the past few years, a number of documents have been published

Alan E. Brill; Mark Pollitt; Carrie Morgan Whitcomb

2006-01-01

354

Enabling Public Auditability and Data Dynamics for Storage Security in Cloud Computing  

Microsoft Academic Search

Cloud Computing has been envisioned as the next-generation architecture of IT Enterprise. It moves the application software and databases to the centralized large data centers, where the management of the data and services may not be fully trustworthy. This unique paradigm brings about many new security challenges, which have not been well understood. This work studies the problem of ensuring

Qian Wang; Cong Wang; Kui Ren; Wenjing Lou; Jin Li

2011-01-01

355

Senses working overtime: on sensuous experiences and public computer game play  

Microsoft Academic Search

In this article we will discuss players' experience of computer games in terms of sight, sound, taste, smell, and touch. We discuss how senses shape and give meaning to players' game play experiences in the game café and a mass LAN party. We also discuss how the social environments in which games are played impact on the experience of playing

Fatima Jonsson; Harko Verhagen

2011-01-01

356

Negotiating Knowledge Contribution to Multiple Discourse Communities: A Doctoral Student of Computer Science Writing for Publication  

ERIC Educational Resources Information Center

|Despite the rich literature on disciplinary knowledge construction and multilingual scholars' academic literacy practices, little is known about how novice scholars are engaged in knowledge construction in negotiation with various target discourse communities. In this case study, with a focused analysis of a Chinese computer science doctoral…

Li, Yongyan

2006-01-01

357

Failure case study: An instructive method for teaching computer network engineering  

Microsoft Academic Search

The computer network engineering course, one of essential and popular courses to train the network engineer, requires students to master comprehensive theories on network engineering and experienced practice skills. In this paper, we propose the failure case study method for teaching the computer network engineering course. The applications of the failure case study method are presented with six examples both

Liyang Yu; Wei Zhang

2010-01-01

358

Comparison of methods of computing lognormal sum distributions and outages for digital wireless applications  

Microsoft Academic Search

Four methods that can be used to approximate the distribution function (DF) of a sum of independent lognormal random variables (RVs) are investigated and compared. The aim is to determine the best method to compute the DF considering both accuracy and computational effort. The investigation focuses on values of the dB spread, ?, valid for practical problems in wireless transmission

Norman C. Beaulieu; Adnan A. Abu-Dayya; P. J. McLane

1994-01-01

359

An efficient and general numerical method to compute steady uniform vortices  

Microsoft Academic Search

Steady uniform vortices are widely used to represent high Reynolds number flows, yet their efficient computation still presents some challenges. Existing Newton iteration methods become inefficient as the vortices develop fine-scale features; in addition, these methods cannot, in general, find solutions with specified Casimir invariants. On the other hand, available relaxation approaches are computationally inexpensive, but can fail to converge

Paolo Luzzatto-Fegiz; Charles H. K. Williamson

2011-01-01

360

Application of the Discrete Ordinates Method to Compute Radiant Heat Loss in a Diesel Engine  

Microsoft Academic Search

A three-dimensional model for computing flows, sprays, and combustion in internal combustion engines is modified to include radiant heat loss. Radiant heat loss is computed by solving the radiative transport equation using a discrete ordinates approximation method. Such a method solves the radiative transport equation for a set of discrete directions spanning the range of 4 ? solid angle. Angular

John Abraham; Vinicio Magi

1997-01-01

361

Quasi-Monte Carlo Methods in Computer Graphics, Part II: The Radiance Equation  

Microsoft Academic Search

The radiance equation, which describes the global illumination problem in computer graphics, is a high dimensional integral equation. Estimates of the solu- tion are usually computed on the basis of Monte Carlo methods. In this paper we propose and investigate quasi-Monte Carlo methods, which means that we replace (pseudo-) random samples by low discrepancy sequences, yielding deterministic algorithms. We carry

Stefan Heinrich; Alexander Keller

1994-01-01

362

Method for Expressing Public Opinions Concerning the Introduction of an Emerging Technology to Society  

NASA Astrophysics Data System (ADS)

Emerging technology may have considerable social impact. Because emerging technology has not yet been introduced in society, it is needed general public express its opinions on emerging technology. It is important that expressing opinion must have social spirit. A method to limit facility of the Internet and activate social spirit is proposed. Evaluation experiment were conducted to test the effectiveness of the proposed method, and the participant could express opinion with social spirit.

Yamamoto, Satoshi; Ito, Kyoko; Ohnishi, Satoshi; Nishida, Shogo

363

New Semiempirical Method for Computing Nonlinear Missile Aerodynamics. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

New methods have been developed to compute inviscid surface pressures and temperatures for both perfect and equilibrium chemically reacting flows on pointed and blunt bodies of revolution. These new methods include an improved shock-expansion theory, an i...

F. G. Moore L. Devan T. Hymer

1993-01-01

364

Advanced methods for the computation of particle beam transport and the computation of electromagnetic fields and beam-cavity interactions  

SciTech Connect

The University of Maryland Dynamical Systems and Accelerator Theory Group carries out research in two broad areas: the computation of charged particle beam transport using Lie algebraic methods and advanced methods for the computation of electromagnetic fields and beam-cavity interactions. Important improvements in the state of the art are believed to be possible in both of these areas. In addition, applications of these methods are made to problems of current interest in accelerator physics including the theoretical performance of present and proposed high energy machines. The Lie algebraic method of computing and analyzing beam transport handles both linear and nonlinear beam elements. Tests show this method to be superior to the earlier matrix or numerical integration methods. It has wide application to many areas including accelerator physics, intense particle beams, ion microprobes, high resolution electron microscopy, and light optics. With regard to the area of electromagnetic fields and beam cavity interactions, work is carried out on the theory of beam breakup in single pulses. Work is also done on the analysis of the high behavior of longitudinal and transverse coupling impendances, including the examination of methods which may be used to measure these impedances. Finally, work is performed on the electromagnetic analysis of coupled cavities and on the coupling of cavities to waveguides.

Dragt, A.J.; Gluckstern, R.L.

1990-11-01

365

Multiple leaf tracking using computer vision methods with shape constraints  

NASA Astrophysics Data System (ADS)

Accurate monitoring of leaves and plants is a necessity for research on plant physiology. To aid this biological research, we propose a new active contour method to track individual leaves in chlorophyll fluorescence time laps sequences. The proposed active contour algorithm is developed such that it can handle sequences with low temporal resolution. This paper proposes a novel optimization method which incorporates prior knowledge about the plant shape. Tests show that the proposed framework outperforms state of the art tracking methods.

De Vylder, Jonas; Van Der Straeten, Dominique; Philips, Wilfried

2013-05-01

366

Computational methods for constructing protein structure models from 3D electron microscopy maps.  

PubMed

Protein structure determination by cryo-electron microscopy (EM) has made significant progress in the past decades. Resolutions of EM maps have been improving as evidenced by recently reported structures that are solved at high resolutions close to 3Å. Computational methods play a key role in interpreting EM data. Among many computational procedures applied to an EM map to obtain protein structure information, in this article we focus on reviewing computational methods that model protein three-dimensional (3D) structures from a 3D EM density map that is constructed from two-dimensional (2D) maps. The computational methods we discuss range from de novo methods, which identify structural elements in an EM map, to structure fitting methods, where known high resolution structures are fit into a low-resolution EM map. A list of available computational tools is also provided. PMID:23796504

Esquivel-Rodríguez, Juan; Kihara, Daisuke

2013-06-21

367

Log analysis of subsurface geology: Concepts and computer methods  

Microsoft Academic Search

This is a text for engineers\\/graduate students studying petroleum engineering. It provides introduction to log analysis and review of logging tools. It describes common graphical methods of multiple log interpretation, basic concepts of matrix algebra, and examples of statistical analysis and signal processing techniques. It reviews remedial methods directed to the suppression of measurement error associated with logs. The mapping

Doveton

1986-01-01

368

Ab initio electronic-structure computations with the recursion method  

Microsoft Academic Search

An accurate and efficient algorithm for using the recursion method in ab initio electronic-structure calculations with nonorthogonal real-space basis sets is presented. The matrix representation of the Hamiltonian operator in a localized basis is shown to possess a sparse represention, and is constructed from the Hamiltonian and overlap matrices, but without the full inverse of the overlap matrix. A method

Andrew Gibson; Roger Haydock; John P. Lafemina

1993-01-01

369

Nongradient minimization methods for parallel processing computers, part 2  

Microsoft Academic Search

This paper analyzes the mathematical behavior of nongradient parallel minimization algorithms. The convergence of parallel synchronous iterative procedures corresponding to linearly independent direction methods and to mutually conjugate direction methods is discussed. For the latter, convergence with finite termination on quadratic objective functions and convergence on sufficiently smooth nonquadratic objective functions is proved.

C. Sutti

1983-01-01

370

Yeast Ancestral Genome Reconstructions: The Possibilities of Computational Methods  

NASA Astrophysics Data System (ADS)

In 2006, a debate has risen on the question of the efficiency of bioinformatics methods to reconstruct mammalian ancestral genomes. Three years later, Gordon et al. (PLoS Genetics, 5(5), 2009) chose not to use automatic methods to build up the genome of a 100 million year old Saccharomyces cerevisiae ancestor. Their manually constructed ancestor provides a reference genome to test whether automatic methods are indeed unable to approach confident reconstructions. Adapting several methodological frameworks to the same yeast gene order data, I discuss the possibilities, differences and similarities of the available algorithms for ancestral genome reconstructions. The methods can be classified into two types: local and global. Studying the properties of both helps to clarify what we can expect from their usage. Both methods propose contiguous ancestral regions that come very close (> 95% identity) to the manually predicted ancestral yeast chromosomes, with a good coverage of the extant genomes.

Tannier, Eric

371

Structural and mechanistic investigations of photosystem II through computational methods.  

PubMed

The advent of oxygenic photosynthesis through water oxidation by photosystem II (PSII) transformed the planet, ultimately allowing the evolution of aerobic respiration and an explosion of ecological diversity. The importance of this enzyme to life on Earth has ironically been paralleled by the elusiveness of a detailed understanding of its precise catalytic mechanism. Computational investigations have in recent years provided more and more insights into the structural and mechanistic details that underlie the workings of PSII. This review will present an overview of some of these studies, focusing on those that have aimed at elucidating the mechanism of water oxidation at the CaMn? cluster in PSII, and those exploring the features of the structure and dynamics of this enzyme that enable it to catalyse this energetically demanding reaction. This article is part of a Special Issue entitled: Photosystem II. PMID:21565158

Ho, Felix M

2011-05-01

372

Methods for the Accurate Computations of Hypersonic Flows  

NASA Astrophysics Data System (ADS)

In order to eliminate or minimize the numerical error by shock waves due to grid distribution in multidimensional hypersonic flows, a new grid reconstruction scheme, the shock-aligned grid technique (SAGT), is proposed. The error due to shock waves in a non-shock-aligned grid system magnifies in proportion to the Mach number and propagates on the downstream side of the flow field to contaminate sensitive aerodynamic coefficients or flow quantities. SAGT, combined with the AUSMPW+ scheme proposed in Part I of the present work, not only provides an accurate solution but also reduces the grid dependency of a numerical scheme without a substantial increase in computational cost. In addition, SAGT is robust and flexible enough to deal with complex flow problems involving shock interaction and reflection and equilibrium and nonequilibrium effects. Extensive numerical tests from a hypersonic blunt body flow to hypersonic nonequilibrium flows validate the accuracy, efficiency, robustness, and convergence characteristics of SAGT.

Kim, Kyu Hong; Kim, Chongam; Rho, Oh-Hyun

2001-11-01

373

Public bookmarks and private benefits: An analysis of incentives in social computing  

Microsoft Academic Search

Users of social computing websites are both producers and consumers of the information found on the site. This creates a novel problem for web-based software applications: how can website designers induce users to produce information that is useful for others? We study this question by interviewing users of the social bookmarking website del.icio.us. We find that for the users in

Rick Wash; Emilee Rader

2007-01-01

374

Reference computations of public dose and cancer risk from airborne releases of plutonium. Nuclear safety technical report  

SciTech Connect

This report presents results of computations of doses and the associated health risks of postulated accidental atmospheric releases from the Rocky Flats Plant (RFP) of one gram of weapons-grade plutonium in a form that is respirable. These computations are intended to be reference computations that can be used to evaluate a variety of accident scenarios by scaling the dose and health risk results presented here according to the amount of plutonium postulated to be released, instead of repeating the computations for each scenario. The MACCS2 code has been used as the basis of these computations. The basis and capabilities of MACCS2 are summarized, the parameters used in the evaluations are discussed, and results are presented for the doses and health risks to the public, both the Maximum Offsite Individual (a maximally exposed individual at or beyond the plant boundaries) and the population within 50 miles of RFP. A number of different weather scenarios are evaluated, including constant weather conditions and observed weather for 1990, 1991, and 1992. The isotopic mix of weapons-grade plutonium will change as it ages, the {sup 241}Pu decaying into {sup 241}Am. The {sup 241}Am reaches a peak concentration after about 72 years. The doses to the bone surface, liver, and whole body will increase slightly but the dose to the lungs will decrease slightly. The overall cancer risk will show almost no change over this period. This change in cancer risk is much smaller than the year-to-year variations in cancer risk due to weather. Finally, x/Q values are also presented for other applications, such as for hazardous chemical releases. These include the x/Q values for the MOI, for a collocated worker at 100 meters downwind of an accident site, and the x/Q value integrated over the population out to 50 miles.

Peterson, V.L.

1993-12-23

375

On the Probabilistic Computation Method with Reliability for the Weight Distribution of LDPC Codes  

NASA Astrophysics Data System (ADS)

In the analysis of maximum-likelihood decoding performance of low-density parity-check (LDPC) codes, the weight distribution is an important factor. We presented a probabilistic method for computing the weight distribution of LDPC codes, and showed results of computing the weight distribution of several LDPC codes. In this paper, we improve our previously presented method and propose a probabilistic computation method with reliability for the weight distribution of LDPC codes. Using the proposed method, we can determine the weight distribution with small failure probability.

Hirotomo, Masanori; Mohri, Masami; Morii, Masakatu

376

Computational Methods for Dynamic Optimization and Pursuit-Evasion Games.  

National Technical Information Service (NTIS)

The thesis deals with the numerical solution of deterministic optimal control problems and pursuit-evasion games that emerge in the field of aircraft trajectory optimization. In the optimization framework, the thesis presents a continuation method for min...

T. Raivio

2000-01-01

377

Analog Computer Methods for Scoring Continuous Performance Records.  

National Technical Information Service (NTIS)

Methods for scoring continuous records of tracking performance with analog signal correlator and frequency analysis systems are described. An index of lead-lag obtained from the correlator output is compared with discrete lead-lag scores obtained by hand ...

D. Trumbo M. Noble F. Baganoff

1965-01-01

378

Matching Wind Turbine Rotors and Loads: Computational Methods for Designers.  

National Technical Information Service (NTIS)

This report provides a comprehensive method for matching wind energy conversion system (WECS) rotors with the load characteristics of common electrical and mechanical applications. The user must supply: (1) turbine aerodynamic efficiency as a function of ...

J. B. Seale

1983-01-01

379

Stability of computational methods for constrained dynamics systems  

Microsoft Academic Search

Many methods have been proposed for numerically integrating the differential-algebraic systems arising from the Euler-Lagrange equations for constrained motion. These are based on various problem formulations and discretizations. The authors offer a critical evaluation of these methods from the standpoint of stability. Considering a linear model, the authors first give conditions under which the differential-algebraic problem is well conditioned. This

Uri M. Ascher; Linda R. Petzold

1993-01-01

380

Method, system, and computer readable storage for affiliate group searching  

US Patent & Trademark Office Database

A method for allowing an information seeker to utilize affiliate group searching involving human searchers who are members of particular information affiliate groups. Each affiliate group has an area of expertise in which they are particularly skilled. In at least one embodiment, the method includes accepting designation of an affiliate group for providing information searching and presenting search results produced by a member of the affiliate group to an information seeker.

Jones; Scott A. (Carmel, IN)

2010-09-21

381

The Voronoi Implicit Interface Method for computing multiphase physics  

PubMed Central

We introduce a numerical framework, the Voronoi Implicit Interface Method for tracking multiple interacting and evolving regions (phases) whose motion is determined by complex physics (fluids, mechanics, elasticity, etc.), intricate jump conditions, internal constraints, and boundary conditions. The method works in two and three dimensions, handles tens of thousands of interfaces and separate phases, and easily and automatically handles multiple junctions, triple points, and quadruple points in two dimensions, as well as triple lines, etc., in higher dimensions. Topological changes occur naturally, with no surgery required. The method is first-order accurate at junction points/lines, and of arbitrarily high-order accuracy away from such degeneracies. The method uses a single function to describe all phases simultaneously, represented on a fixed Eulerian mesh. We test the method’s accuracy through convergence tests, and demonstrate its applications to geometric flows, accurate prediction of von Neumann’s law for multiphase curvature flow, and robustness under complex fluid flow with surface tension and large shearing forces.

Saye, Robert I.; Sethian, James A.

2011-01-01

382

A unified computer program for assessment of attenuation correction and data acquisition methods in single photon emission computed tomography (SPECT).  

PubMed

A computer based simulation program was developed to assess the usefulness of various attenuation correction algorithms and data acquisition methods in single photon emission computed tomography (SPECT) in a unified approach. The program analytically calculated projection ray sums from a mathematical model with various distributions of activities and either uniform or non uniform attenuation coefficients by using the line integrals including the effect of attenuation. Data acquisition starting at arbitrary angles, various acquisition angles, including a 180 degree scan and a non circular orbit of a gamma camera, including an elliptical orbit can readily be taken into consideration in our simulation program. To simulate non circular orbit data acquisition, the resolution dependence on the object distance from the collimator surface was incorporated into the simulation. This computer based simulation program allows various combinations of attenuation correction algorithms such as hybrid methods, and data acquisition methods can be evaluated under a large number of study conditions. The usefulness of this computer based simulation program is shown with several representative examples. PMID:2788088

Murase, K; Tanada, S; Higashino, H; Yamada, M; Miyagawa, M; Iio, A; Hamamoto, K

1989-01-01

383

Computation of molecular electrostatics with boundary element methods.  

PubMed Central

In continuum approaches to molecular electrostatics, the boundary element method (BEM) can provide accurate solutions to the Poisson-Boltzmann equation. However, the numerical aspects of this method pose significant problems. We describe our approach, applying an alpha shape-based method to generate a high-quality mesh, which represents the shape and topology of the molecule precisely. We also describe an analytical method for mapping points from the planar mesh to their exact locations on the surface of the molecule. We demonstrate that derivative boundary integral formulation has numerical advantages over the nonderivative formulation: the well-conditioned influence matrix can be maintained without deterioration of the condition number when the number of the mesh elements scales up. Singular integrand kernels are characteristics of the BEM. Their accurate integration is an important issue. We describe variable transformations that allow accurate numerical integration. The latter is the only plausible integral evaluation method when using curve-shaped boundary elements. Images FIGURE 3 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8

Liang, J; Subramaniam, S

1997-01-01

384

Computer-aided diagnosis system: A Bayesian hybrid classification method.  

PubMed

A novel method to classify multi-class biomedical objects is presented. The method is based on a hybrid approach which combines pairwise comparison, Bayesian regression and the k-nearest neighbor technique. It can be applied in a fully automatic way or in a relevance feedback framework. In the latter case, the information obtained from both an expert and the automatic classification is iteratively used to improve the results until a certain accuracy level is achieved, then, the learning process is finished and new classifications can be automatically performed. The method has been applied in two biomedical contexts by following the same cross-validation schemes as in the original studies. The first one refers to cancer diagnosis, leading to an accuracy of 77.35% versus 66.37%, originally obtained. The second one considers the diagnosis of pathologies of the vertebral column. The original method achieves accuracies ranging from 76.5% to 96.7%, and from 82.3% to 97.1% in two different cross-validation schemes. Even with no supervision, the proposed method reaches 96.71% and 97.32% in these two cases. By using a supervised framework the achieved accuracy is 97.74%. Furthermore, all abnormal cases were correctly classified. PMID:23932384

Calle-Alonso, F; Pérez, C J; Arias-Nicolás, J P; Martín, J

2013-08-07

385

Method for computing the maximum water temperature in a fuel pool containing spent nuclear fuel  

SciTech Connect

A method is proposed for computing the upper bound on the local water temperature rise with respect to the bulk temperature in a spent fuel pool. The solution involves casting the continuity and momentum relationships in integral form in terms of the unknown velocity functions. The method of collocation is used to solve the problem. Computer application of this method shows it to be an efficient and cost-effective design tool.

Singh, K.P.; Soler, A.I.; Gupta, J.P.

1986-01-01

386

On the computer intensive methods in model selection  

Microsoft Academic Search

Bootstrap-based model selection has been shown in many practical instances to be superior to classical methods such the AIC and MDL. This is particularly noticeable when the distribution of modelling noise is unknown and\\/or when the available data samples are small. One of the main problems of using bootstrap model selection with real data is the necessity of tuning the

D. Robert Iskander; Weaam Alkhaldi; Abdelhak M. Zoubir

2008-01-01

387

An Evolutionary Computational Method for N-Connection Subgraph Discovery  

Microsoft Academic Search

The problem of n-connection subgraph discovery (n-CSDP for short) is to find a small sized subgraph that can well capture the relationship among the n given nodes in a large graph. However there have been very few researches directly addressing the CSDP problem. Furthermore the currently available methods, for example, the electricity analogues based algorithm can only be suitable for

Enhong Chen; Xujia Chen; Phillip C.-Y. Sheu; Tieyun Qian

2006-01-01

388

Domain decomposition methods on nonmatching grids in electromagnetic field computation  

Microsoft Academic Search

Summary form only given. We consider domain decomposition methods on nonmatching grids using mortar edge elements in the numerical solution of interior domain problems for the time-harmonic Maxwell equations and the eddy current equations in three space dimensions. As an application for the time-harmonic Maxwell equations, we consider a benchmark problem for an LWD (logging while drilling) tool used in

R. H. W. Hoppe

2004-01-01

389

Applications of level set methods in computational biophysics  

Microsoft Academic Search

We describe in this paper two applications of Eulerian level set methods to uid-structure problems arising in biophysics. The rst one is concerned with three-dimensional equilibrium shapes of phospholipidic vesicles. This is a complex problem which can be recast as the minimization of the curvature energy of an immersed elastic membrane, under a constant area constraint. The second deals with

Emmanuel Maitre; Thomas Milcent; Georges-Henri Cottet; Annie Raoult; Yves Usson

2009-01-01

390

On computer simulation methods to model Zener pinning  

Microsoft Academic Search

We compare the ability of three types of microstructural model to simulate particle pinning by performing simulations using the front tracking model, the phase field model and the Monte Carlo Potts model. The same three-dimensional test geometries are simulated using each method and compared with theory. The pinning force acting on the migrating curved grain boundary is calculated and compared

Azmir Harun; Elizabeth A. Holm; Mike P. Clode; Mark A. Miodownik

2006-01-01

391

Phase-field method for computationally efficient modeling of solidification with arbitrary interface kinetics  

Microsoft Academic Search

We present mathematical results which dramatically enhance the computational efficiency of the phase-field method for modeling the solidification of a pure material. These results make it possible to resolve a smaller capillary length to interface thickness ratio and thus render smaller undercooling and three-dimensional computations accessible. Furthermore, they allow one to choose computational parameters to produce a Gibbs-Thomson condition with

Alain Karma; Wouter-Jan Rappel

1996-01-01

392

Methods for Computationally Efficient Structured CFD Simulations of Complex Turbomachinery Flows  

Microsoft Academic Search

This research presents more efficient computational methods by which to perform multiple-block structured CFD simulations of turbomachinery, thus enabling higher-fidelity solutions of complicated geometries and their associated flows. This computational framework offers flexibility in allocating resources to balance process count and wall-clock computation time, while facilitating research interests of simulating axial compressor stall inception with more complete gridding of the

Gregory Herrick; Jen-Ping Chen

2011-01-01

393

A comparison of the computational efficiency of three inverse scattering methods  

Microsoft Academic Search

This paper presented three inverse scattering methods. Based on the provided data, it is clear that the distorted Born iterative method provides the most accurate reconstructions. However, the cost of such accuracy is computation time. Because this is a direct implementation of the method, one expects reduced times from a more clever design. While both the linear sampling method and

A. J. Hesford; W. C. Chew

2005-01-01

394

Fast computation of invariant geometric moments: a new method giving correct results  

Microsoft Academic Search

Invariant geometric moments have been widely used in shape analysis and pattern recognition. Using a discrete version of Green's theorem, the authors propose a method for fast computation of the moments in binary images. The method is similar to-and as efficient as-the previous method of Li and Shen (1991). But the precision is largely improved. The new method gives exactly

Luren Yang; Fritz Albregtsen

1994-01-01

395

An efficient method for computer aided analysis of noisy electromagnetic fields  

Microsoft Academic Search

This work presents an efficient method for the numerical simulation of noisy electromagnetic fields, accounting for arbitrary correlations between the noise radiation sources. It allows us to compute the spatial distribution of the spectral energy density. Method of moments is applied to model noisy electromagnetic fields by network methods using correlation matrix techniques. The method can be combined with available

Johannes A. Russer; Peter Russer

2011-01-01

396

A Simplified Quadrature Element Method to compute the natural frequencies of multispan beams and frame structures  

Microsoft Academic Search

In this paper a new version of the Modified Quadrature Element Method (MQEM) is proposed. Like MQEM, the proposed method overcomes the drawback of the distance ? of the Quadrature Element Method (QEM) without introducing further degrees of freedom at the ends of the element as in the Differential Quadrature Element Method (DQEM), but it makes the computational cost of

S. Tomasiello

2011-01-01

397

Systematic Methods for the Computation of the Directional Fields and Singular Points of Fingerprints  

Microsoft Academic Search

The first subject of the paper is the estimation of a high resolution directional field of fingerprints. Traditional methods are discussed and a method, based on principal component analysis, is proposed. The method not only computes the direction in any pixel location, but its coherence as well. It is proven that this method provides exactly the same results as the

Asker M. Bazen; Sabih H. Gerez

2002-01-01

398

Intelligent classification methods of grain kernels using computer vision analysis  

NASA Astrophysics Data System (ADS)

In this paper, a digital image analysis method was developed to classify seven kinds of individual grain kernels (common rice, glutinous rice, rough rice, brown rice, buckwheat, common barley and glutinous barley) widely planted in Korea. A total of 2800 color images of individual grain kernels were acquired as a data set. Seven color and ten morphological features were extracted and processed by linear discriminant analysis to improve the efficiency of the identification process. The output features from linear discriminant analysis were used as input to the four-layer back-propagation network to classify different grain kernel varieties. The data set was divided into three groups: 70% for training, 20% for validation, and 10% for testing the network. The classification experimental results show that the proposed method is able to classify the grain kernel varieties efficiently.

Lee, Choon Young; Yan, Lei; Wang, Tianfeng; Lee, Sang Ryong; Park, Cheol Woo

2011-06-01

399

Possibilities of the Particle Finite Element Method in Computational Mechanics  

Microsoft Academic Search

\\u000a We present some developments in the formulation of the Particle Finite Element Method (PFEM) for analysis of complex coupled\\u000a problems in fluid and solid mechanics accounting for fluid-structure interaction and coupled thermal effects. The PFEM uses\\u000a an updated Lagrangian description to model the motion of nodes (particles) in both the fluid and the structure domains. Nodes\\u000a are viewed as material

Eugenio Oñate; Sergio R. Idelsohn; Miguel Angel Celigueta; Riccardo Rossi; Salvador Latorre

400

Computational methods for the verification of adaptive control systems  

Microsoft Academic Search

Intelligent and adaptive control systems will significantly challenge current verification and validation (V&V) processes, tools, and methods for flight certification. Although traditional certification practices have produced safe and reliable flight systems, they will not be cost effective for next-generation autonomous unmanned air vehicles (UAVs) due to inherent size and complexity increases from added functionality. Affordable V&V of intelligent control systems

Ravi K. Prasanth; Jovan Boskovic; Raman K. Mehra

2004-01-01

401

Computer-aided engineering methods for successful VHSIC application  

NASA Astrophysics Data System (ADS)

Through the example of a VHSIC implementation of a MIL-STD-1750A avionic processor subsystem, an effective approach has applied CAE methods tailored to the job of VHSIC integration. Structured hierarchical design organization combined with rigorous mixed-mode digital simulation permitted an entire VHSIC-based subsystem and its integral application-specific IC design to be verified with a high degree of confidence. Accurate performance data were obtained well in advance of fabrication.

Wood, R. Gary

402

Measuring Public Access to the Shoreline: The Boat-Based Offset Survey Method  

Microsoft Academic Search

As cities redevelop underutilized waterfronts, opportunities exist to promote public access to the shoreline. However, planning for access is hampered by a lack of reliable data on how people utilize a specific shoreline. The boat-based offset transect survey (B-BOTS) method allows researchers to accurately record, map, and analyze shoreline access. This article discusses the use of B-BOTS along the northern

Robert Thompson; Tracy Dalton

2010-01-01

403

Attitudes to health care prioritisation methods and criteria among nurses, doctors, politicians and the general public  

Microsoft Academic Search

The aim of this postal questionnaire study was to measure attitudes to health care prioritisation criteria among the Finnish general public (n=1156), politicians (n=1096), doctors (n=803) and nurses (n=667), altogether 3722 subjects. The questionnaire consisted of questions on background data, a list of seven alternative prioritisation methods and a list of 11 possible criteria for health care prioritisation.The most acceptable

Olli-Pekka Ryynänen; Markku Myllykangas; Juha Kinnunen; Jorma Takala

1999-01-01

404

Theoretical studies of potential energy surfaces and computational methods.  

SciTech Connect

This project involves the development, implementation, and application of theoretical methods for the calculation and characterization of potential energy surfaces (PES) involving molecular species that occur in hydrocarbon combustion. These potential energy surfaces require an accurate and balanced treatment of reactants, intermediates, and products. Most of our work focuses on general multiconfiguration self-consistent-field (MCSCF) and multireference single- and double-excitation configuration interaction (MRSDCI) methods. In contrast to the more common single-reference electronic structure methods, this approach is capable of describing accurately molecular systems that are highly distorted away from their equilibrium geometries, including reactant, fragment, and transition-state geometries, and of describing regions of the potential surface that are associated with electronic wave functions of widely varying nature. The MCSCF reference wave functions are designed to be sufficiently flexible to describe qualitatively the changes in the electronic structure over the broad range of molecular geometries of interest. The necessary mixing of ionic, covalent, and Rydberg contributions, along with the appropriate treatment of the different electron-spin components (e.g. closed shell, high-spin open-shell, low-spin open shell, radical, diradical, etc.) of the wave functions are treated correctly at this level. Further treatment of electron correlation effects is included using large scale multireference CI wave functions, particularly including the single and double excitations relative to the MCSCF reference space. This leads to the most flexible and accurate large-scale MRSDCI wave functions that have been used to date in global PES studies.

Shepard, R. (Chemistry)

2006-01-01

405

A method to decrease computation time for fourth order Lucas sequence  

NASA Astrophysics Data System (ADS)

The fourth order Lucas sequence is a linear recurrence relation related to quartic polynomial and based on Lucas function. This sequence had been used to develop the LUC4,6 cryptosystem. As we know, the efficiency is one of the crucial parts of the cryptosystem and it is depended on computation time for Lucas sequence which is used to develop the process encryption and decryption in the LUC4.6 cryptosystem. In this paper, a method will be proposed to decrease the computation time for fourth order Lucas sequence. This method omits some terms of the sequence to decrease the computation time. Thus, if the LUC4,6 cryptosystem is using this method to compute the plaintexts and cipher texts, then the computation time had been decreased.

Jin, Wong Tze; Md. Said, Mohd. Rushdan; Othman, Mohamed; Feng, Koo Lee

2013-09-01

406

3D modeling method for computer animate based on modified weak structured light method  

Microsoft Academic Search

A simple and affordable 3D scanner is designed in this paper. Three-dimensional digital models are playing an increasingly important role in many fields, such as computer animate, industrial design, artistic design and heritage conservation. For many complex shapes, optical measurement systems are indispensable to acquiring the 3D information. In the field of computer animate, such an optical measurement device is

Hanwei Xiong; Ming Pan; Xiangwei Zhang

2010-01-01

407

Single trial method for brain-computer interface.  

PubMed

Electroencephalogram (EEG) related to fast eye movement (saccade), has been the subject of application oriented research by our group toward developing a brain-computer interface (BCI). Our goal is to develop novel BCI based on eye movements system employing EEG signals online. Most of the analysis of the saccade-related EEG data has been performed using ensemble averaging approaches. However, ensemble averaging is not suitable for BCI. In order to process raw EEG data in real time, we performed saccade-related EEG experiments and processed data by using the non-conventional fast ICA with reference signal (FICAR). The FICAR algorithm can extract desired independent components (IC) which have strong correlation against a reference signal. Visually guided saccade tasks and auditory guided saccade tasks were performed and the EEG signal generated in the saccade was recorded. The EEG processing was performed in three stages: PCA preprocessing and noise reduction, extraction of the desired IC using Wiener filter with reference signal, and post-processing using higher order statistics fast ICA based on maximization of kurtosis. Form the experimental results and analysis we found that using FICAR it is possible to extract form raw EEG data the saccade-related ICs and to predict saccade in advance by about 10 [ms] before real movements of eyes occurs. For single trail EEG data we have successfully extracted the desire ICs with recognition rate about 70%. In next steps, saccade-related EEG signals and saccade-related ICs in visually and auditory guided saccade task are compared in the point of the latency between starting time of a saccade and time when a saccade-related EEG signal or an IC has maximum value and in the point of the peak scale where a saccade-related EEG signal or an IC has maximum value. As results, peak time when saccade-related ICs have maximum amplitude is earlier than peak time when saccade-related EEG signals have maximum amplitude. This is very important advantage for developing our BCI. However, S/N ratio in being processed by FICAR is not improved comparing S/N ratio in being processed by ensemble averaging. PMID:17947135

Funase, Arao; Yagi, Tohru; Barros, Allan K; Cichocki, Andrzej; Takumi, Ichi

2006-01-01

408

Computations for Group Sequential Boundaries Using the Lan-DeMets Spending Function Method  

Microsoft Academic Search

We describe an interactive Fortran program which performs computations related to the design and analysis of group sequential clinical trials using Lan-DeMets spending functions. Many clinical trials include interim analyses of accumulating data and rely on group sequential methods to avoid consequent inflation of the type I error rate. The computations are appropriate for interim test statistics whose distribution or

David M. Reboussin; David L. DeMets; KyungMann Kim; K. K. Gordon Lan

2000-01-01

409

Nonlinear dynamic simulation of single- and multispool core engines, part 1: Computational method  

Microsoft Academic Search

A new computational method for accurate simulation of the nonlinear, dynamic behavior of single- and multispool core engines, turbofan engines, and power-generation gas turbine engines is presented in part 1. In order to perform the simulation, a modularly structured computer code has been developed that includes individual mathematical modules representing various engine components. The generic structure of the code enables

M. T. Schobeiri; M. Attia; C. Lippke

1994-01-01

410

FCC (Federal Communications Commission) Methods of Measurement of Radio Noise Emissions from Computing Devices.  

National Technical Information Service (NTIS)

This standard sets forth uniform methods of measurement of radio noise emitted from computing devices defined in section 15.4 of FCC Rules. The technical standards for computing devices are set forth in Subpart J of Part 15 of FCC Rules (47 CFR Part 15J)....

1983-01-01

411

A computationally efficient method for solving the redundant problem in biomechanics  

Microsoft Academic Search

Determining the optimal set of musculotendon forces with which to produce a forward dynamic simulation of movement typically involves a huge investment of time and computational resources. A new, computationally efficient method is proposed that simultaneously achieves the desired trajectory and the dynamically optimized set of muscle stresses, and hence forces, according to the maximal endurance criterion function of Crowninshield

G. T. Yamaguchi; D. W. Moran; J. Si

1995-01-01

412

Computational methods for transcriptome annotation and quantification using RNA-seq  

Microsoft Academic Search

High-throughput RNA sequencing (RNA-seq) promises a comprehensive picture of the transcriptome, allowing for the complete annotation and quantification of all genes and their isoforms across samples. Realizing this promise requires increasingly complex computational methods. These computational challenges fall into three main categories: (i) read mapping, (ii) transcriptome reconstruction and (iii) expression quantification. Here we explain the major conceptual and practical

Manfred G Grabherr; Mitchell Guttman; Cole Trapnell; Manuel Garber

2011-01-01

413

MHRDRing Z-Pinches and Related Geometries: Four Decades of Computational Modeling Using Still Unconventional Methods  

SciTech Connect

For approximately four decades, Z-pinches and related geometries have been computationally modeled using unique Alternating Direction Implicit (ADI) numerical methods. Computational results have provided illuminating and often provocative interpretations of experimental results. A number of past and continuing applications are reviewed and discussed.

Lindemuth, Irvin R. [University of Nevada Reno NV USA (United States)

2009-01-21

414

Implementation of an ADI (Alternating Direction Implicit) Method on Parallel Computers.  

National Technical Information Service (NTIS)

The implementation of an ADI method for solving the diffusion equation on three parallel/vector computers is discussed. The computers were chosen so as to encompass a variety of architectures. They are: the MPP, an SIMD machine with 16K bit serial process...

R. A. Fatoohi C. E. Grosch

1987-01-01

415

Combination of MLFMA and an iterative method to compute large scattering or radiation problems  

Microsoft Academic Search

An efficient approach for the computation of large scattering or radiation problems is presented in this work. The underlying technique analyzes different parts of the geometry separately, and then it computes different effects or interactions between these parts. We show in the results section good agreement with conventional rigorous methods for a number of test cases.

Carlos Delgado; Eliseo Garcia; Ivan Gonzalez; Felipe Catedra

2010-01-01

416

ANN statistical image recognition method for computer vision in agricultural mobile robot navigation  

Microsoft Academic Search

The main application area in this project, is to deploy image processing and segmentation techniques in computer vision through an omnidirectional vision system to agricultural mobile robots (AMR) used for trajectory navigation problems, as well as localization matters. Thereby, computational methods based on the JSEG algorithm were used to provide the classification and the characterization of such problems, together with

Luciano C. Lulio; Mario L. Tronco; Arthur J. V. Porto

2010-01-01

417

Feature selective validation (FSV) for validation of computational electromagnetics (CEM). part I-the FSV method  

Microsoft Academic Search

A goal for the validation of computational electromagnetics (CEM) is to provide the community with a simple computational method that can be used to predict the assessment of electromagnetic compatibility (EMC) data as it would be undertaken by individuals or teams of engineers. The benefits of being able to do this include quantifying the comparison of data that has hitherto

Alistair P. Duffy; Anthony J. M. Martin; Antonio Orlandi; G. Antonini; T. M. Benson; M. S. Woolfson

2006-01-01

418

A Method for Identifying Contours in Processing Digital Images from Computer Tomograph  

NASA Astrophysics Data System (ADS)

The first step in digital processing of two-dimensional computed tomography images is to identify the contour of component elements. This paper deals with the collective work of specialists in medicine and applied mathematics in computer science on elaborating new algorithms and methods in medical 2D and 3D imagery.

Ro?u, ?erban; Pater, Flavius; Costea, Dan; Munteanu, Mihnea; Ro?u, Doina; Fratila, Mihaela

2011-09-01

419

The Use of Qsar and Computational Methods in Drug Design  

Microsoft Academic Search

\\u000a The application of quantitative structure–activity relationships (QSARs) has significantly impacted the paradigm of drug discovery.\\u000a Following the successful utilization of linear solvation free-energy relationships (LSERs), numerous 2D- and 3D-QSAR methods\\u000a have been developed, most of them based on descriptors for hydrophobicity, polarizability, ionic interactions, and hydrogen\\u000a bonding. QSAR models allow for the calculation of physicochemical properties (e.g., lipophilicity), the prediction

Fania Bajot

2010-01-01

420

Novel systems biology and computational methods for lipidomics  

NASA Astrophysics Data System (ADS)

The analysis and interpretation of large lipidomic data sets requires the development of new dynamical systems, data mining and visualization approaches. Traditional techniques are insufficient to study corregulations and stochastic fluctuations observed in lipidomic networks and resulting experimental data. The emphasis of this paper lies in the presentation of novel approaches for the dynamical analysis and projection representation. Different paradigms describing kinetic models and providing context-based information are described and at the same time their interrelations are revealed. These qualitative and quantitative methods are applied to the lipidomic analysis of U87 MG glioblastoma cells. The achieved provide a more detailed insight into the data structure of the lipidomic system.

Meyer-Bäse, Anke; Lespinats, Sylvain

2010-04-01

421

Some methods of computing platform transmitter terminal location estimates  

NASA Astrophysics Data System (ADS)

A position estimation algorithm was developed to track a humpback whale tagged with an ARGOS platform after a transmitter deployment failure and the whale's diving behavior precluded standard methods. The algorithm is especially useful where a transmitter location program exists; it determines the classical keplarian elements from the ARGOS spacecraft position vectors included with the probationary file messages. A minimum of three distinct messages are required. Once the spacecraft orbit is determined, the whale is located using standard least squares regression techniques. Experience suggests that in instances where circumstances inherent in the experiment yield message data unsuitable for the standard ARGOS reduction, (message data may be too sparse, span an insufficient period, or include variable-length messages). System ARGOS can still provide much valuable location information if the user is willing to accept the increased location uncertainties.

Hoisington, C. M.

422

The Los Alamos Supernova Light-curve Project: Computational Methods  

NASA Astrophysics Data System (ADS)

We have entered the era of explosive transient astronomy, in which current and upcoming real-time surveys such as the Large Synoptic Survey Telescope, the Palomar Transient Factory, and the Panoramic Survey Telescope and Rapid Response System will detect supernovae in unprecedented numbers. Future telescopes such as the James Webb Space Telescope may discover supernovae from the earliest stars in the universe and reveal their masses. The observational signatures of these astrophysical transients are the key to unveiling their central engines, the environments in which they occur, and to what precision they will pinpoint cosmic acceleration and the nature of dark energy. We present a new method for modeling supernova light curves and spectra with the radiation hydrodynamics code RAGE coupled with detailed monochromatic opacities in the SPECTRUM code. We include a suite of tests that demonstrate how the improved physics and opacities are indispensable to modeling shock breakout and light curves when radiation and matter are tightly coupled.

Frey, Lucille H.; Even, Wesley; Whalen, Daniel J.; Fryer, Chris L.; Hungerford, Aimee L.; Fontes, Christopher J.; Colgan, James

2013-02-01

423

A coarse-grid projection method for accelerating incompressible flow computations  

NASA Astrophysics Data System (ADS)

We present a coarse-grid projection (CGP) method for accelerating incompressible flow computations, which is applicable to methods involving Poisson equations as incompressibility constraints. The CGP methodology is a modular approach that facilitates data transfer with simple interpolations and uses black-box solvers for the Poisson and advection-diffusion equations in the flow solver. After solving the Poisson equation on a coarsened grid, an interpolation scheme is used to obtain the fine data for subsequent time stepping on the full grid. A particular version of the method is applied here to the vorticity-stream function, primitive variable, and vorticity-velocity formulations of incompressible Navier-Stokes equations. We compute several benchmark flow problems on two-dimensional Cartesian and non-Cartesian grids, as well as a three-dimensional flow problem. The method is found to accelerate these computations while retaining a level of accuracy close to that of the fine resolution field, which is significantly better than the accuracy obtained for a similar computation performed solely using a coarse grid. A linear acceleration rate is obtained for all the cases we consider due to the linear-cost elliptic Poisson solver used, with reduction factors in computational time between 2 and 42. The computational savings are larger when a suboptimal Poisson solver is used. We also find that the computational savings increase with increasing distortion ratio on non-Cartesian grids, making the CGP method a useful tool for accelerating generalized curvilinear incompressible flow solvers.

San, Omer; Staples, Anne E.

2013-01-01

424

Application of Computer-Assisted Learning Methods in the Teaching of Chemical Spectroscopy.  

ERIC Educational Resources Information Center

Discusses the application of computer-assisted learning methods to the interpretation of infrared, nuclear magnetic resonance, and mass spectra; and outlines extensions into the area of integrated spectroscopy. (Author/CMV)

Ayscough, P. B.; And Others

1979-01-01

425

System, Method and Computer-Readable Medium for Locating Physical Phenomena.  

National Technical Information Service (NTIS)

A method, system and computer product for detecting the location of a deformation of a structure includes baselining a defined energy transmitting characteristic for each of the plurality of laterally adjacent conductors attached to the structure. Each of...

M. T. Weseman D. T. Rohrbaugh J. G. Richardson

2005-01-01

426

38 CFR 3.25 - Parent's dependency and indemnity compensation (DIC)-Method of payment computation.  

Code of Federal Regulations, 2013 CFR

...DIC. (c) Two parents not living together. The rate computation method...1) Two parents who are not living together, or (2) An unremarried parent...section. (d) Two parents living together or remarried parents living...

2013-07-01

427

Method, Systems, and Computer Program Products for Implementing Function-Parallel Network Firewall.  

National Technical Information Service (NTIS)

Methods, systems, and computer program products for providing function-parallel firewalls are disclosed. According to one aspect, a function-parallel firewall includes a first firewall node for filtering received packets using a first portion of a rule se...

E. W. Fulp R. J. Farley

2005-01-01

428

COMPUTATIONAL METHODS FOR STUDYING THE INTERACTION BETWEEN POLYCYCLIC AROMATIC HYDROCARBONS AND BIOLOGICAL MACROMOLECULES  

EPA Science Inventory

Computational Methods for Studying the Interaction between Polycyclic Aromatic Hydrocarbons and Biological Macromolecules . The mechanisms for the processes that result in significant biological activity of PAHs depend on the interaction of these molecules or their metabol...

429

A high order explicit method for the computation of flow about a circular cylinder  

SciTech Connect

In this paper a finite difference method for computing the solutions of the incompressible Navier-Stokes equations for flow about a circular cylinder in two dimensions is presented. A stream function/vorticity formulation of the equation is used and the numerical method incorporates recent developments in the computation of vorticity boundary conditions as well as far field boundary conditions. Three schemes are described, one of second order accuracy, one of fourth order accuracy, and a hybrid method which is second order accurate in the computation of the vorticity transport and fourth order accurate in the determination of the stream function. Fully resolved solutions for flow past a cylinder have been computed over a range of Reynolds numbers from 1000 to 9500. Comparisons are made between the results obtained with methods of different orders of accuracy as well as of the effectiveness of the vorticity and far field boundary conditions. 28 refs., 10 figs., 7 tabs.

Anderson, C.R. [Univ. of California, Los Angeles, CA (United States); Reider, M.C. [IBM T.J. Watson Research Center, Yorktown Heights, NY (United States)

1996-04-01

430

Computational Methods for Determining Lower Bounds for Eigenvalues of Operators in Hilbert Space.  

National Technical Information Service (NTIS)

A survey of computational methods for determining lower bounds for eigenvalues of semibounded, self-adjoint operators in Hilbert space, in particular, of many operators associated with boundary value problems for ordinary and partial differential equation...

D. W. Fox W. C. Rheinboldt

1966-01-01

431

Accuracy, Resolution, and Computational Complexity of a Discontinuous Galerkin Finite Element Methods.  

National Technical Information Service (NTIS)

An analysis of the balance between the computational complexity, accuracy, and resolution requirements of a discontinuous Galerkin finite element method for the solution of the compressible Euler equations of gas dynamics is presented. The discontinuous G...

H. van der Ven J. J. W. van der Vegt

2002-01-01

432

Advanced Methods for the Computer-Aided Diagnosis of Lesions in Digital Mammograms.  

National Technical Information Service (NTIS)

The objective of the proposed research is to develop computer-aided diagnosis methods for use in mammography in order to increase the diagnostic accuracy of radiologists and to aid in mammographic screening programs. We have increased the detection accura...

M. L. Giger

1999-01-01

433

A dental public health approach based on computational mathematics: Monte Carlo simulation of childhood dental decay.  

PubMed

This study developed a Monte Carlo simulation approach to examining the prevalence and incidence of dental decay using Australian children as a test environment. Monte Carlo simulation has been used for a half a century in particle physics (and elsewhere); put simply, it is the probability for various population-level outcomes seeded randomly to drive the production of individual level data. A total of five runs of the simulation model for all 275,000 12-year-olds in Australia were completed based on 2005-2006 data. Measured on average decayed/missing/filled teeth (DMFT) and DMFT of highest 10% of sample (Sic10) the runs did not differ from each other by more than 2% and the outcome was within 5% of the reported sampled population data. The simulations rested on the population probabilities that are known to be strongly linked to dental decay, namely, socio-economic status and Indigenous heritage. Testing the simulated population found DMFT of all cases where DMFT<>0 was 2.3 (n = 128,609) and DMFT for Indigenous cases only was 1.9 (n = 13,749). In the simulation population the Sic25 was 3.3 (n = 68,750). Monte Carlo simulations were created in particle physics as a computational mathematical approach to unknown individual-level effects by resting a simulation on known population-level probabilities. In this study a Monte Carlo simulation approach to childhood dental decay was built, tested and validated. PMID:23410020

Tennant, Marc; Kruger, Estie

2013-01-07

434

The Use of Qsar and Computational Methods in Drug Design  

NASA Astrophysics Data System (ADS)

The application of quantitative structure-activity relationships (QSARs) has significantly impacted the paradigm of drug discovery. Following the successful utilization of linear solvation free-energy relationships (LSERs), numerous 2D- and 3D-QSAR methods have been developed, most of them based on descriptors for hydrophobicity, polarizability, ionic interactions, and hydrogen bonding. QSAR models allow for the calculation of physicochemical properties (e.g., lipophilicity), the prediction of biological activity (or toxicity), as well as the evaluation of absorption, distribution, metabolism, and excretion (ADME). In pharmaceutical research, QSAR has a particular interest in the preclinical stages of drug discovery to replace tedious and costly experimentation, to filter large chemical databases, and to select drug candidates. However, to be part of drug discovery and development strategies, QSARs need to meet different criteria (e.g., sufficient predictivity). This chapter describes the foundation of modern QSAR in drug discovery and presents some current challenges and applications for the discovery and optimization of drug candidates

Bajot, Fania

435

Problem-solving method with semantic net based on DNA computing in artificial intelligence  

Microsoft Academic Search

Semantic Net is among the problem solving systems in artificial intelligence fields. In this paper, we demonstrate how to design DNA-typed Semantic Net in order to apply DNA computing to artificial intelligence. Moreover, we propose a problem-solving method with DNA-typed Semantic Net. In this method, it is possible to reason out a reference object by using DNA computing algorithm. Proposed

Yusei Tsuboi; Zuwairie Ibrahim; Osamu Ono

2004-01-01

436

Multiscale segmentation method for small inclusion detection in 3D industrial computed tomography  

Microsoft Academic Search

In this paper a new segmentation method for highly precise inclusion detection in 3D X-ray computed tomography (CT), based on multiresolution denoising methods, is presented. The aim of this work is the automatic 3D-segmentation of small graphite inclusions in cast iron samples. Industrial X-ray computed tomography of metallic samples often suffers from imaging artifacts (e.g. cupping effects) which result in

G. Zauner; B. Harrer; D. Angermaier; M. Reiter; J. Kastner

2007-01-01

437

Computer simulations of 2-dimensional photonic crystal waveguide by method of moment  

Microsoft Academic Search

In this paper, we perform computer simulation of 2-dimensional photonic crystal waveguide composed of photonic crystal and slab waveguides. The slab waveguides work as input\\/output ports. Computer simulations are performed by the method of moment based on the guided-mode extracted integral equations, which had been proposed by the authors [1], [2]. We also apply the fast multipole method [3] on

Masahiro Tanaka; Kazuo Tanaka

2010-01-01

438

Preparing ultra-thin nano-MnO 2 electrodes using computer jet-printing method  

Microsoft Academic Search

Computer jet-printing method was developed to prepare ultra-thin film nano-MnO2 electrodes using a computer with a jetprinter. Special emulsion ink containing nano-MnO2 particles was jet-printed on the gold covered paper to form a thin film electrode. Scanning electron microscopy (SEM), voltammetry and electrochemical impedance methods were used to investigate the morphologies and electrochemical properties of electrodes. It is found that

Fan Xu; Tao Wang; Wenrong Li; Zhiyu Jiang

2003-01-01

439

A new computer method for the storage and manipulation of DNA gel reading data.  

PubMed Central

This paper describes a new way of storing DNA gel reading data and an accompanying set of computer programs. These programs will perform all the manipulations that are required on data gained by the so-called 'shotgun' method of DNA sequencing. This system simplifies the computer processing involved with this sequencing method and also has the capability of being able at any time during a project to display, lined up in register, all the gel reading covering any section of the sequence.

Staden, R

1980-01-01

440

ZOOM: a generic personal computer-based teaching program for public health and its application in schistosomiasis control.  

PubMed

Schistosomiasis, a group of parasitic diseases caused by Schistosoma parasites, is associated with water resources development and affects more than 200 million people in 76 countries. Depending on the species of parasite involved, disease of the liver, spleen, gastrointestinal or urinary tract, or kidneys may result. A computer-assisted teaching package has been developed by WHO for use in the training of public health workers involved in schistosomiasis control. The package consists of the software, ZOOM, and a schistosomiasis information file, Dr Schisto, and uses hypermedia technology to link pictures and text. ZOOM runs on the IBM-PC and IBM-compatible computers, is user-friendly, requires a minimal hardware configuration, and can interact with the user in English, French, Spanish or Portuguese. The information files for ZOOM can be created or modified by the instructor using a word processor, and thus can be designed to suit the need of students. No programming knowledge is required to create the stacks. PMID:1786618

Martin, G T; Yoon, S S; Mott, K E

1991-01-01

441

Computational methods for improving the resolution of subsurface seismic images. Final report  

Microsoft Academic Search

The original goal is to devise computational methods for improving the resolution of subsurface seismic images. Initially the research emphasis was primarily on developing methods for efficient ray- theoretic modeling of acoustic waves in triangulated representations of media and on efficient means of modeling waves that travel sub- horizontally in horizontally layered media. Subsequent directions included new efficient methods for

Larner

1994-01-01

442

Computations of electromagnetic fields by the multiple multipole method (generalized multipole technique)  

Microsoft Academic Search

In this paper a numerical method for computations of electromagnetic fields is presented, which has been developed by the authors and their colleagues since 1978 under the name of the multiple multipole (MMP) method. In the meantime several groups are working independently on similar methods (with sometimes different approaches and different names). The majority of them agreed to use the

C. Hafner; N. Kuster

1991-01-01

443

A computer method for the calibration of a photographic emulsion for spectrographic analysis  

Microsoft Academic Search

A computer method to calibrate emulsion-covered glass plates used to interpret densities of lines for quantitative spectrographic work is reported. This method follows a slightly modified ASTM graphic method, which is also described, and allows one to simply input dark and light data points to establish preliminary and emulsion calibration curves. After the curves are established, by inputting percent transmission

B. H. Strauss

1977-01-01

444

A Numerov-type Method for Computing Eigenvalues and Resonances of the Radial Schrödinger Equation  

Microsoft Academic Search

A two-step method is developed for computing eigenvalues and resonances of the radial Schrödinger equation. Numerical results obtained for the integration of the eigenvalue and the resonance problems for several potentials show that this new method is better than other similar methods.

Tom E. Simos; G. Tougelidis

1996-01-01

445

Computation of Energy Consumption in Apartment Buildings. The Methods EFB 2 and EFB 3.  

National Technical Information Service (NTIS)

On the basis of a previous EFB 1 method a new computation method has been developed in order to predict heat consumption and losses in apartment buildings. The method comprises two variations: EFB 2, where the whole building is constantly heated (to diffe...

A. Nielsen

1980-01-01

446

Computer-supported G2G collaboration for public policy and decision-making  

Microsoft Academic Search

Purpose – This paper investigates whether and how G2G collaboration for policy and decision-making can be effectively supported by an appropriately developed information system. Design\\/methodology\\/approach – The research method adopted in this paper follows the “Design Science Paradigm”, which has been extensively used in information systems research. Findings – As resulted from the case study described in this paper, the

Nikos Karacapilidis; Euripides Loukis; Stavros Dimopoulos

2005-01-01

447

Applying social science and public health methods to community-based pandemic planning.  

PubMed

Pandemic influenza is a unique threat to communities, affecting schools, businesses, health facilities and individuals in ways not seen in other emergency events. This paper aims to outline a local government project which utilised public health and social science research methods to facilitate the creation of an emergency response plan for pandemic influenza coincidental to the early stages of the 2009 H1N1 ('swine flu') outbreak. A multi-disciplinary team coordinated the creation of a pandemic influenza emergency response plan which utilised emergency planning structure and concepts and encompassed a diverse array of county entities including schools, businesses, community organisations, government agencies and healthcare facilities. Lessons learned from this project focus on the need for (1) maintaining relationships forged during the planning process, (2) targeted public health messaging, (3) continual evolution of emergency plans, (4) mutual understanding of emergency management concepts by business and community leaders, and (5) regional coordination with entities outside county boundaries. PMID:21177224

Danforth, Elizabeth J; Doying, Annette; Merceron, Georges; Kennedy, Laura

2010-11-01

448

A filtered convolution method for the computation of acoustic wave fields in very large spatiotemporal domains.  

PubMed

The full-wave computation of transient acoustic fields with sizes in the order of 100 x 100 x 100 wavelengths by 100 periods requires a numerical method that is extremely efficient in terms of storage and computation. Iterative integral equation methods offer a good performance on these points, provided that the recurring spatiotemporal convolutions are computed with a coarse sampling and relatively few computational operations. This paper describes a method for the numerical evaluation of very large-scale, four-dimensional convolutions that employs a fast Fourier transformation and that uses a sampling rate close to or at the limit of two points per wavelength and per period. To achieve this, the functions involved are systematically filtered, windowed, and zero-padded with respect to all relevant coordinates prior to sampling. The method is developed in the context of the Neumann iterative solution of the acoustic contrast source problem for an inhomogeneous medium. The implementation of the method on a parallel computer is discussed. The obtained numerical results have a relative root mean square error of a few percent when sampling at two points per wavelength and per period. Further, the results prove that the method enables the computation of transient fields in the order of the indicated size. PMID:19354362

Verweij, Martin D; Huijssen, Jacob

2009-04-01

449

Moving finite elements: A continuously adaptive method for computational fluid dynamics  

SciTech Connect

Moving Finite Elements (MFE), a recently developed method for computational fluid dynamics, promises major advances in the ability of computers to model the complex behavior of liquids, gases, and plasmas. Applications of computational fluid dynamics occur in a wide range of scientifically and technologically important fields. Examples include meteorology, oceanography, global climate modeling, magnetic and inertial fusion energy research, semiconductor fabrication, biophysics, automobile and aircraft design, industrial fluid processing, chemical engineering, and combustion research. The improvements made possible by the new method could thus have substantial economic impact. This paper describes the mathematical formulation and illustrates its use.

Glasser, A.H. (Los Alamos National Lab., NM (USA)); Miller, K.; Carlson, N. (California Univ., Berkeley, CA (USA))

1991-01-01

450

The Perceptions of Globalization at a Public Research University Computer Science Graduate Department  

NASA Astrophysics Data System (ADS)

Based on a qualitative methodological approach, this study focuses on the understanding of a phenomenon called globalization in a research university computer science department. The study looks into the participants' perspectives about the department, its dynamics, culture and academic environment as related to globalization. The economic, political, academic and social/cultural aspects of the department are taken into consideration in investigating the influences of globalization. Three questions guide this inquiry: 1) How is the notion of globalization interpreted in this department? 2) How does the perception of globalization influence the department in terms of finances, academics, policies and social life And 3) How are these perceptions influence the selection of students? Globalization and neo-institutional view of legitimacy is used as theoretical lenses to conceptualize responses to these questions. The data include interviews, field notes, official and non-official documents. Interpretations of these data are compared to findings from prior research on the impact of globalization in order to clarify and validate findings. Findings show that there is disagreement in how the notion of globalization is interpreted between the doctoral students and the faculty in the department. This disagreement revealed the attitudes and interpretations of globalization in the light of the policies and procedures related to the department. How the faculty experience globalization is not consistent with the literature in this project. The literature states that globalization is a big part of higher education and it is a phenomenon that causes the changes in the goals and missions of higher education institutions (Knight, 2003, De Witt, 2005). The data revealed that globalization is not the cause for change but more of a consequence of actions that take place in achieving the goals and missions of the department.

Nielsen, Selin Yildiz

451

Numerical methods and comparison for computing dark and bright solitons in the nonlinear Schrödinger equation  

NASA Astrophysics Data System (ADS)

In this paper, we propose new efficient and accurate numerical methods for computing dark solitons and review some existing numerical methods for bright and/or dark solitons in the nonlinear Schrödinger equation (NLSE), and compare them numerically in terms of accuracy and efficiency. We begin with a review of dark and bright solitons of NLSE with defocusing and focusing cubic nonlinearities, respectively. For computing dark solitons, to overcome the nonzero and/or non-rest (or highly oscillatory) phase background at far field, we design efficient and accurate numerical methods based on accurate and simple artificial boundary conditions or a proper transformation to rest the highly oscillatory phase background. Stability and conservation laws of these numerical methods are analyzed. For computing interactions between dark and bright solitons, we compare the efficiency and accuracy of the above numerical methods and different existing numerical methods for computing bright solitons of NLSE, and identify the most efficient and accurate numerical methods for computing dark and bright solitons as well as their interactions in NLSE. These numerical methods are applied to study numerically the stability and interactions of dark and bright solitons in NLSE. Finally, they are extended to solve NLSE with general nonlinearity and/or external potential and coupled NLSEs with vector solitons.

Bao, Weizhu; Tang, Qinglin; Xu, Zhiguo

2013-02-01

452

The effectiveness of smoking cessation methods for smokers in public health maternity clinics: a randomized trial.  

PubMed Central

Little insight is available in the literature on how best to assist the pregnant smoker in public health maternity clinics to quit during pregnancy. A randomized pretest/posttest experiment was used to evaluate the effectiveness of two different self-help cessation methods. Three hundred and nine pregnant women from three public health maternity clinics were assigned randomly to one of three groups with one-third assigned to each: a control group; a group receiving the American Lung Association's Freedom From Smoking Manual; and those receiving A Pregnant Woman's Self-Help Guide to Quit Smoking. Using a saliva thiocyanate (SCN) and behavioral report at mid-pregnancy and end of pregnancy to confirm cessation or reduction, 2 per cent in the control group quit and 7 per cent reduced their SCN levels substantially. Of the women assigned to the ALA method, 6 per cent quit and 14 per cent reduced their SCN levels substantially. Of the women who used the Guide, 14 per cent quit and 17 per cent reduced their SCN levels substantially. Results of this trial indicate that health education methods tailored to the pregnant smoker are more effective in changing smoking behavior than the standard clinic information and advice to quit and/or the use of smoking cessation methods not tailored to the needs of the pregnant smoker.

Windsor, R A; Cutter, G; Morris, J; Reese, Y; Manzella, B; Bartlett, E E; Samuelson, C; Spanos, D

1985-01-01

453

Methods for Studying the Use of Public Spaces in Libraries \\/ Les méthodes d'étude de l'utilisation des espaces publics dans les bibliothèques  

Microsoft Academic Search

This review examines selected methods for studying the use of public spaces in libraries, including mental mapping, observation, questionnaires, and interviews. Although use-of-space research often features more than one method of inquiry, observation (in its various forms) is a key method. Information gathered from use-of-space research can be used for a variety of purposes, from feeding into design and renovation

Francine May

2011-01-01

454

Computational aeroacoustics of phonation, part I: Computational methods and sound generation mechanisms.  

PubMed

The aerodynamic generation of sound during phonation was studied using direct numerical simulations of the airflow and the sound field in a rigid pipe with a modulated orifice. Forced oscillations with an imposed wall motion were considered, neglecting fluid-structure interactions. The compressible, two-dimensional, axisymmetric form of the Navier-Stokes equations were numerically integrated using highly accurate finite difference methods. A moving grid was used to model the effects of the moving walls. The geometry and flow conditions were selected to approximate the flow within an idealized human glottis and vocal tract during phonation. Direct simulations of the flow and farfield sound were performed for several wall motion programs, and flow conditions. An acoustic analogy based on the Ffowcs Williams-Hawkings equation was then used to decompose the acoustic source into its monopole, dipole, and quadrupole contributions for analysis. The predictions of the farfield acoustic pressure using the acoustic analogy were in excellent agreement with results from the direct numerical simulations. It was found that the dominant sound production mechanism was a dipole induced by the net force exerted by the surfaces of the glottis walls on the fluid along the direction of sound wave propagation. A monopole mechanism, specifically sound from the volume of fluid displaced by the wall motion, was found to be comparatively weak at the frequency considered (125 Hz). The orifice geometry was found to have only a weak influence on the amplitude of the radiated sound. PMID:12430825

Zhao, Wei; Zhang, Cheng; Frankel, Steven H; Mongeau, Luc

2002-11-01

455

Efficient Computational Methods to Treat Multiple Scattering in Electron Diffraction by Nanostructures  

NASA Astrophysics Data System (ADS)

Our purpose is to extend the capabilities of surface structure determination methods, such as Low Energy Electron Diffraction, so they can be used for nanostructures. To treat non-periodic systems, a cluster approach is used. The main computational challenge consists in solving a Ax=b matrix-vector equation of large dimension. Since matrix inversion is both memory and compute-time demanding, we have developed and tested two fast iterative methods to solve the above equation: the Sparse-Matrix Canonical Grid (SMCG) method shifts the atoms to a regular space grid and makes use of FFT transformations while the Multi-Level Singular-Value Decomposition (MLSVD) performs fast rank determination and SV decomposition of A. For both these methods, the compute time scales as N x log2N per iteration, where N is the number of atoms. These two methods complement each other in terms of the types of nanostructures that they handle best.

Gavaza, G. M.; Yu, Z. X.; Tsang, L.; Chan, C. H.; van Hove, M. A.

2005-03-01

456

A direct matrix method for computing analytical Jacobians of discretized nonlinear integro-differential equations  

NASA Astrophysics Data System (ADS)

In this article, we present a simple direct matrix method for analytically computing the Jacobian of nonlinear algebraic equations that arise from the discretization of nonlinear integro-differential equations. The method is based on a formulation of the discretized equations in vector form using only matrix-vector products and component-wise operations. By applying simple matrix-based differentiation rules, the matrix form of the analytical Jacobian can be calculated with little more difficulty than required to compute derivatives in single-variable calculus. After describing the direct matrix method, we present numerical experiments demonstrating the computational performance of the method, discuss its connection to the Newton-Kantorovich method and apply it to illustrative 1D and 2D example problems from electrochemical transport.

Chu, Kevin T.

2009-08-01

457

[Identification of Legionella spp. by means of cultural and molecular methods in a public hospital].  

PubMed

An epidemiologic study on the isolation of Legionella spp from the sanitary water of a public Hospital in Cagliari (Italy) has been performed. The aim of the study was the comparison between the isolation of various Legionella spp from different hospital sources and the real hazard of Legionella infection of the inpatients. Two test methods were used for Legionella detection: a) the culture on selective media, that has the disadvantage of being quite time-consuming and of isolating also other bacterial species. Furthermore, the culture method often fails the isolation of vital but not culturable bacteria (VBNC); b) the PCR molecular method, which is rapid and precise and recognizes also VBNC cells. The most relevant result of this work was that, in spite of the isolation of a considerable number of Legionella spp (even Legionella pneumophila), no case of infection was detected in the Hospital during the period of the study. PMID:19385336

Madeddu, M A; Carta, F; Muggianu, R; Meloni, P; Ingianni, A; Contu, A; Pompei, R

458

Opinions of the Dutch public on palliative sedation: a mixed-methods approach.  

PubMed

Background Palliative sedation is defined as deliberately lowering a patient's consciousness, to relieve intolerable suffering from refractory symptoms at the end of life. Palliative sedation is considered a last resort intervention in end-of-life care that should not be confused with euthanasia. Aim To inform healthcare professionals about attitudes of the general public regarding palliative sedation. Design and setting A cross-sectional survey among members of the Dutch general public followed by qualitative interviews. Method One thousand nine hundred and sixty members of the general public completed the questionnaire, which included a vignette describing palliative sedation (response rate 78%); 16 participants were interviewed. Results In total, 22% of the responders indicated knowing the term 'palliative sedation'. Qualitative data showed a variety of interpretations of the term. Eighty-one per cent of the responders agreed with the provision of sedatives as described in a vignette of a patient with untreatable pain and a life expectancy of <1 week who received sedatives to alleviate his suffering. This percentage was somewhat lower for a patient with a life expectancy of <1 month (74%, P = 0.007) and comparable in the case where the physician gave sedatives with the aim of ending the patient's life (79%, P = 0.54). Conclusion Most of the general public accept the use of palliative sedation at the end of life, regardless of a potential life-shortening effect. However, confusion exists about what palliative sedation represents. This should be taken into account by healthcare professionals when communicating with patients and their relatives on end-of-life care options. PMID:24152482

van der Kallen, Hilde Th; Raijmakers, Natasja Jh; Rietjens, Judith Ac; van der Male, Alex A; Bueving, Herman J; van Delden, Johannes Jm; van der Heide, Agnes

2013-10-01

459

Krylov subspace methods for computing hydrodynamic interactions in Brownian dynamics simulations  

NASA Astrophysics Data System (ADS)

Hydrodynamic interactions play an important role in the dynamics of macromolecules. The most common way to take into account hydrodynamic effects in molecular simulations is in the context of a Brownian dynamics simulation. However, the calculation of correlated Brownian noise vectors in these simulations is computationally very demanding and alternative methods are desirable. This paper studies methods based on Krylov subspaces for computing Brownian noise vectors. These methods are related to Chebyshev polynomial approximations, but do not require eigenvalue estimates. We show that only low accuracy is required in the Brownian noise vectors to accurately compute values of dynamic and static properties of polymer and monodisperse suspension models. With this level of accuracy, the computational time of Krylov subspace methods scales very nearly as O(N2) for the number of particles N up to 10 000, which was the limit tested. The performance of the Krylov subspace methods, especially the ``block'' version, is slightly better than that of the Chebyshev method, even without taking into account the additional cost of eigenvalue estimates required by the latter. Furthermore, at N = 10 000, the Krylov subspace method is 13 times faster than the exact Cholesky method. Thus, Krylov subspace methods are recommended for performing large-scale Brownian dynamics simulations with hydrodynamic interactions.

Ando, Tadashi; Chow, Edmond; Saad, Yousef; Skolnick, Jeffrey

2012-08-01

460

Krylov subspace methods for computing hydrodynamic interactions in brownian dynamics simulations.  

PubMed

Hydrodynamic interactions play an important role in the dynamics of macromolecules. The most common way to take into account hydrodynamic effects in molecular simulations is in the context of a brownian dynamics simulation. However, the calculation of correlated brownian noise vectors in these simulations is computationally very demanding and alternative methods are desirable. This paper studies methods based on Krylov subspaces for computing brownian noise vectors. These methods are related to Chebyshev polynomial approximations, but do not require eigenvalue estimates. We show that only low accuracy is required in the brownian noise vectors to accurately compute values of dynamic and static properties of polymer and monodisperse suspension models. With this level of accuracy, the computational time of Krylov subspace methods scales very nearly as O(N(2)) for the number of particles N up to 10 000, which was the limit tested. The performance of the Krylov subspace methods, especially the "block" version, is slightly better than that of the Chebyshev method, even without taking into account the additional cost of eigenvalue estimates required by the latter. Furthermore, at N = 10,000, the Krylov subspace method is 13 times faster than the exact Cholesky method. Thus, Krylov subspace methods are recommended for performing large-scale brownian dynamics simulations with hydrodynamic interactions. PMID:22897254

Ando, Tadashi; Chow, Edmond; Saad, Yousef; Skolnick, Jeffrey

2012-08-14

461

Krylov subspace methods for computing hydrodynamic interactions in Brownian dynamics simulations  

PubMed Central

Hydrodynamic interactions play an important role in the dynamics of macromolecules. The most common way to take into account hydrodynamic effects in molecular simulations is in the context of a Brownian dynamics simulation. However, the calculation of correlated Brownian noise vectors in these simulations is computationally very demanding and alternative methods are desirable. This paper studies methods based on Krylov subspaces for computing Brownian noise vectors. These methods are related to Chebyshev polynomial approximations, but do not require eigenvalue estimates. We show that only low accuracy is required in the Brownian noise vectors to accurately compute values of dynamic and static properties of polymer and monodisperse suspension models. With this level of accuracy, the computational time of Krylov subspace methods scales very nearly as O(N2) for the number of particles N up to 10 000, which was the limit tested. The performance of the Krylov subspace methods, especially the “block” version, is slightly better than that of the Chebyshev method, even without taking into account the additional cost of eigenvalue estimates required by the latter. Furthermore, at N = 10 000, the Krylov subspace method is 13 times faster than the exact Cholesky method. Thus, Krylov subspace methods are recommended for performing large-scale Brownian dynamics simulations with hydrodynamic interactions.

Ando, Tadashi; Chow, Edmond; Saad, Yousef; Skolnick, Jeffrey

2012-01-01

462

Shaking hands with a computer: an examination of two methods of organizational newcomer orientation.  

PubMed

The current study investigated the effects of using a computer-based orientation program on organizational socialization and attitudinal outcomes. In a quasi-experimental field study, 261 newcomers either participated in a group, social-based orientation session or an individual, computer-based orientation session. Consistent with hypotheses, results indicated that participation in the computer-based orientation session led to lower levels of socialization in the more socially rich content areas, whereas the more information-based content areas were not affected. Levels of socialization mediated the effects of computer-based orientation on the more distal attitudinal outcomes of affective organizational commitment and job satisfaction. Computer-based orientation participation also negatively affected supervisor ratings of socialization. The results demonstrate the importance of newcomer orientations and socialization outcomes during organizational entry and that training method can be an important moderator of orientation practices. PMID:16162074

Wesson, Michael J; Gogus, Celile Itir

2005-09-01

463

Acceleration Method of 3D Medical Images Registration Based on Compute Unified Device Architecture.  

PubMed

Compute Unified Device Architecture (CUDA) is a parallel computing platform and programming model invented by NVIDIA. It enables dramatic increase in computing performance via the power of the graphics processing unit (GPU). In medical image analysis, 3D image registration generally takes relatively long time, which is not feasible for clinical applications. To solve this problem, this paper proposed a high performance computational method based on CUDA, which took full advantage of GPU parallel computing under CUDA architecture combined with image multiple scale and maximum mutual information. Experiments showed that this algorithm can not only maintain the registration accuracy but also greatly increase the speed of registration process and meet the real-time requirement of clinical application. PMID:24092080

Meng, Lu

2013-01-01

464

Methods and apparatus using commutative error detection values for fault isolation in multiple node computers  

DOEpatents

Methods and apparatus perform fault isolation in multiple node computing systems using commutative error detection values for--example, checksums--to identify and to isolate faulty nodes. When information associated with a reproducible portion of a computer program is injected into a network by a node, a commutative error detection value is calculated. At intervals, node fault detection apparatus associated with the multiple node computer system retrieve commutative error detection values associated with the node and stores them in memory. When the computer program is executed again by the multiple node computer system, new commutative error detection values are created and stored in memory. The node fault detection apparatus identifies faulty nodes by comparing commutative error detection values associated with reproducible portions of the application program generated by a particular node from different runs of the application program. Differences in values indicate a possible faulty node.

Almasi, Gheorghe (Ardsley, NY); Blumrich, Matthias Augustin (Ridgefield, CT); Chen, Dong (Croton-On-Hudson, NY); Coteus, Paul (Yorktown, NY); Gara, Alan (Mount Kisco, NY); Giampapa, Mark E. (Irvington, NY); Heidelberger, Philip (Cortlandt Manor, NY); Hoenicke, Dirk I. (Ossining, NY); Singh, Sarabjeet (Mississauga, CA); Steinmacher-Burow, Burkhard D. (Wernau, DE); Takken, Todd (Brewster, NY); Vranas, Pavlos (Bedford Hills, NY)

2008-06-03

465

Parallel Computing of Multi-scale Finite Element Sheet Forming Analyses Based on Crystallographic Homogenization Method  

SciTech Connect

Since the multi-scale finite element analysis (FEA) requires large computation time, development of the parallel computing technique for the multi-scale analysis is inevitable. A parallel elastic/crystalline viscoplastic FEA code based on a crystallographic homogenization method has been developed using PC cluster. The homogenization scheme is introduced to compute macro-continuum plastic deformations and material properties by considering a polycrystal texture. Since the dynamic explicit method is applied to this method, the analysis using micro crystal structures computes the homogenized stresses in parallel based on domain partitioning of macro-continuum without solving simultaneous linear equations. The micro-structure is defined by the Scanning Electron Microscope (SEM) and the Electron Back Scan Diffraction (EBSD) measurement based crystal orientations. In order to improve parallel performance of elastoplasticity analysis, which dynamically and partially increases computational costs during the analysis, a dynamic workload balancing technique is introduced to the parallel analysis. The technique, which is an automatic task distribution method, is realized by adaptation of subdomain size for macro-continuum to maintain the computational load balancing among cluster nodes. The analysis code is applied to estimate the polycrystalline sheet metal formability.

Kuramae, Hiroyuki; Okada, Kenji; Uetsuji, Yasutomo; Nakamachi, Eiji [Osaka Institute of Technology, 5-16-1, Omiya, Asahi-ku, Osaka 535-8585 (Japan); Tam, Nguyen Ngoc; Nakamura, Yasunori [Osaka Sangyou University, 3-1-1, Nakagaito, Daito, Osaka 574-8530 (Japan)

2005-08-05

466

FDM-FEM zonal method for viscous flow computations over multiple-bodies  

Microsoft Academic Search

A hybrid method between a finite-difference method (FDM) and a finite-element method (FEM) is developed for computations of two and three dimensional viscous flowfields over multiple bodies. In this scheme, an implicit finite-difference method is applied to viscous flow regions bodies with body-fitted grids, and those FDM-zones are patched together by solving the remaining region using an explicit FEM. With

Kozuhiro Nakahashi; Shigeru Obayashi

1987-01-01

467

Application of the discrete ordinates method to compute radiant heat loss in a diesel engine  

SciTech Connect

A three-dimensional model for computing flows, sprays, and combustion in internal combustion engines is modified to include radiant heat loss. Radiant heat loss is computed by solving the radiative transport equation using a discrete ordinates approximation method. Such a method solves the radiative transport equation for a set of discrete directions spanning the range of 4{pi} solid angle. Angular integrals of intensity are discretized by numerical quadrature. The resulting discrete ordinates equations are numerically solved by using a finite volume approach in contravariant formulation. Computations are made with and without radiant heat loss in a diesel engine, and the effects of the radiant heat loss on the computed temperature and NO and soot concentrations are discussed. Inclusion of radiant heat loss reduces the peak temperature by about 10%. As a result, the predicted frozen NO concentrations are found to be lowered. However, the soot concentrations are not significantly altered.

Abraham, J. [Purdue Univ., West Lafayette, IN (United States); Magi, V. [Univ. of Basilicata, Potenza (Italy). Dept. of Environmental Engineering and Physics

1997-05-09

468

Computation of the acoustic radiation force using the finite-difference time-domain method.  

PubMed

The computational details related to calculating the acoustic radiation force on an object using a 2-D grid finite-difference time-domain method (FDTD) are presented. The method is based on propagating the stress and velocity fields through the grid and determining the energy flow with and without the object. The axial and radial acoustic radiation forces predicted by FDTD method are in excellent agreement with the results obtained by analytical evaluation of the scattering method. In particular, the results indicate that it is possible to trap the steel cylinder in the radial direction by optimizing the width of Gaussian source and the operation frequency. As the sizes of the relating objects are smaller than or comparable to wavelength, the algorithm presented here can be easily extended to 3-D and include torque computation algorithms, thus providing a highly flexible and universally usable computation engine. PMID:20968334

Cai, Feiyan; Meng, Long; Jiang, Chunxiang; Pan, Yu; Zheng, Hairong

2010-10-01

469

Private and Public Sector Enterprise Resource Planning System Post-Implementation Practices: A Comparative Mixed Method Investigation  

ERIC Educational Resources Information Center

|While private sector organizations have implemented enterprise resource planning (ERP) systems since the mid 1990s, ERP implementations within the public sector lagged by several years. This research conducted a mixed method, comparative assessment of post "go-live" ERP implementations between public and private sector organization. Based on a…

Bachman, Charles A.

2010-01-01

470

Breastfeeding Rates Differ Significantly by Method Used: A Cause for Concern for Public Health Measurement  

PubMed Central

Abstract Objective Accurate measurements of prevalence of “any” breastfeeding and “exclusive” breastfeeding help assess progress toward public health goals. We compared two commonly used data sources for measuring breastfeeding rates to assess agreement. Methods The National Immunization Survey (NIS) is used by the Centers for Disease Control and Prevention to measure progress toward national breastfeeding goals and obtains breastfeeding outcomes retrospectively at 19–35 months. The California Newborn Screen (CNS) is a contemporaneous measure of breastfeeding during birth hospitalization and measures progress toward public health goals in California. We compared results for “any breastfeeding” and “exclusive breastfeeding” for California infants in the NIS to those in the CNS using descriptive statistics. Results Our results show that the two methods produce similar results for “any” breastfeeding at <4 days: 82.7%, 95% confidence interval (79.6%, 85.8%) in the NIS and 86.1% (86.0%, 86.2%) in the CNS. However, the two methods produce very different results for “exclusive” breastfeeding at <4 days: 60.4% (56.6%, 64.1%) in the NIS and 41.6% (41.5%, 41.7%) in the CNS. Rates of “exclusive” breastfeeding varied more for some subgroups; for Hispanics, estimates were 61.1% (56.1%, 66.1%) in the NIS and 29.7% (29.5%, 29.9%) in the CNS. Conclusions There is good agreement between two disparate methods for assessing “any” breastfeeding rates. However, our findings suggest that the NIS, the CNS, or both are flawed measures of “exclusive” breastfeeding. Validated methods for measuring “exclusive” breastfeeding would allow improved monitoring of breastfeeding prevalence.

Chien, Alyna T.; McCulloch, Charles E.; Dudley, R. Adams

2011-01-01

471

Characteristics method with cubic-spline interpolation for open channel flow computation  

NASA Astrophysics Data System (ADS)

In the framework of the specified-time-interval scheme, the accuracy of the characteristic method is greatly related to the form of the interpolation. The linear interpolation was commonly used to couple the characteristics method (LI method) in open channel flow computation. The LI method is easy to implement, but it leads to an inevitable smoothing of the solution. The characteristics method with the Hermite cubic interpolation (HP method, originally developed by Holly and Preissmann, 1977) was then proposed to largely reduce the error induced by the LI method. In this paper, the cubic-spline interpolation on the space line or on the time line is employed to integrate with characteristics method (CS method) for unsteady flow computation in open channel. Two hypothetical examples, including gradually and rapidly varied flows, are used to examine the applicability of the CS method as compared with the LI method, the HP method, and the analytical solutions. The simulated results show that the CS method is comparable to the HP method and more accurate than the LI method. Without tackling the additional equations for spatial or temporal derivatives, the CS method is easier to implement and more efficient than the HP method.

Tsai, Tung-Lin; Chiang, Shih-Wei; Yang, Jinn-Chuang

2004-10-01

472

A survey of computational and physical methods applied to solid-state fermentation  

Microsoft Academic Search

During the last decade, significant effort has been made to apply computational and physical methods to solid-state fermentation (SSF). This had positive impact both on our understanding of the basic principles underlying this old technology, and on the latest progress made in industrial bioengineering. Guidelines on bioreactor design and operation including scale-up, new methods for biomonitoring and advanced control strategies

J. Lenz; M. Höfer; J.-B. Krasenbrink; U. Hölker

2004-01-01

473

A new method for time domain computation of the steady state in nonlinear circuits  

Microsoft Academic Search

A new method for solving the periodic steady state computation of circuits with nonlinear resistors and linear dynamic elements is presented. Any nonlinear resistor is replaced by equivalent sources controlled by its terminal voltages or currents. The convergence of this procedure is assured, unlike the cases of the harmonic balance and shooting methods. Its high convergence speed allows the fast

Florea Ioan Hantila; Mihai Maricaru; Florin Constantinescu; Radu Ciuceanu

2011-01-01

474

A Runge-Kutta method for computing guaranteed solutions of ODEs  

Microsoft Academic Search

In this article we present a new approach for the computation of guar- anteed solutions of ODEs, based on a classical Runge-Kutta method with a precise error approximation. The interest in validated methods for solving ODEs has recently in- creased in many areas, such as state estimation (9) or validation of hybrid systems (6). In these applications, it is crucial

Olivier Bouissou; Matthieu Martel

475

Computing singular solutions of the Navier-Stokes equations with the Chebyshev-collocation method  

Microsoft Academic Search

The solution of fluid flow problems exhibits a singular behaviour when the conditions imposed on the boundary display some discontinuities or change in type. A treatment of these singularities has to be considered in order to preserve the accuracy of high-order methods, such as spectral methods. The present work concerns the computation of a singular solution of the Navier-Stokes equations

O. Botella; R. Peyret

2001-01-01

476

An amortized-complexity method to compute the Riemann zeta function  

Microsoft Academic Search

A practical method to compute the Riemann zeta function is presented. The method can locate all zeta zeros in [T,T+T^{1\\/4}] using an average time of T^{1\\/4+o(1)} per zero. This is the same complexity as the Odlyzko-Sch\\\\\\

G. A. Hiary

2010-01-01

477

Methods, systems, and computer program products for network firewall policy optimization  

SciTech Connect

Methods, systems, and computer program products for firewall policy optimization are disclosed. According to one method, a firewall policy including an ordered list of firewall rules is defined. For each rule, a probability indicating a likelihood of receiving a packet matching the rule is determined. The rules are sorted in order of non-increasing probability in a manner that preserves the firewall policy.

Fulp, Errin W. (Winston-Salem, NC); Tarsa, Stephen J. (Duxbury, MA)

2011-10-18

478

Comparison of atomic-level simulation methods for computing thermal conductivity  

Microsoft Academic Search

We compare the results of equilibrium and nonequilibrium methods to compute thermal conductivity. Using Sillinger-Weber silicon as a model system, we address issues related to nonlinear response, thermal equilibration, and statistical averaging. In addition, we present an analysis of finite-size effects and demonstrate how reliable results can be obtained when using nonequilibrium methods by extrapolation to an infinite system size.

Patrick K. Schelling; Simon R. Phillpot; Pawel Keblinski

2002-01-01

479

CCAM: A Connectivity-Clustered Access Method for Networks and Network Computations  

Microsoft Academic Search

Current spatial database management systems (SDBMS) provide efficient access methods and operators for point and range queries over collections of spatial points, line segments, and polygons. However, it is not clear if existing spatial access methods can efficiently support network computations which traverse line segments in a spatial network based on connectivity rather than geographic proximity. The expected I\\/O cost

Shashi Shekhar; Duen-ren Liu

1997-01-01

480

Level set and fast marching methods in image processing and computer vision  

Microsoft Academic Search

Level set methods have been used in a variety of settings for problems in computer vision and image processing. A related numerical methodology, known as “fast marching methods”, has been developed to solve static Hamilton-Jacobi equations extremely quickly; the techniques rely on conversion to a static problem, and are based on a marriage between narrow band techniques for level set

R. Malladi; J. A. Sethian

1996-01-01

481

Leader Progression Analysis Model for Shielding Failure Computation by Using the Charge Simulation Method  

Microsoft Academic Search

Shielding failure has long been recognized as a possible mode of lightning flashover. This paper reports the development of a method for estimating the shielding failure number of transmission lines using the charge simulation method. The effects of towers, sags of conductors, and a perfectly conducting ground are represented in 3-D computation. In addition, the stepwise descending nature of a

Behrooz Vahidi; Mostafa Yahyaabadi; Mohammad Reza Bank Tavakoli; S. M. Ahadi

2008-01-01

482

An advanced computer-aided geometric modeling and fabrication method for human middle ear  

Microsoft Academic Search

This paper presents a practical and systematic method for reconstructing accurate computer and physical models of the entire human middle ear. The proposed method starts with the histological section preparation of human temporal bone. Through tracing outlines of the middle ear components on the sections, a set of discrete points is obtained and employed to construct B-spline curves that represent

Qunli Sun; Kuang-Hua Chang; Kenneth J. Dormer; Robert K. Dyer; Rong Z. Gan

2002-01-01

483

Traumatic pulmonary pathology measured with computed tomography and a semiautomated analytic method  

Microsoft Academic Search

The goal of this study is to develop a controlled approach to quantifying the amount of lung damage after blunt chest trauma. The presented method is used to analyze computed tomography scans and to assess patients' risk for developing acute respiratory distress syndrome (ARDS). When used to predict which patients were at risk for ARDS, the method presented in this

Melissa Daly; Preston R. Miller; J. Jeffrey Carr; F. Scott Gayzik; J. Jason Hoth; J. Wayne Meredith; Joel D. Stitzel

2008-01-01

484

A Computational Method for Solving the Schrodinger Equation for a System of N Interacting Fermions  

Microsoft Academic Search

We introduce here a computational method aimed at finding numerically the solutions of the one-dimensional Schrodinger equation for a system of N fermions. The method is based on a discretization scheme of the wave function as well as on the Numerov algorithm which offers an approximate treatment of the second derivative using the three-point difference formula. After discretizing the wave

Nouredine Zettili

2002-01-01

485

Numerical Optimization of Computing Algorithms of the Variational Nodal Method Based on Transformation of Variables  

Microsoft Academic Search

Numerical methods based on transformation of variables are developed to improve the computational efficiency of the variational nodal method (VNM). Reordering and orthogonal transformations of the nodal unknowns are found to reduce the coefficient matrices of VNM into block-diagonal forms. These forms make it possible to reduce greatly the number of floating-point operations in matrix manipulations and hence to reduce

W. S. Yang; G. Palmiotti; E. E. Lewis

2001-01-01

486

Tensors-structured numerical methods in scientific computing: Survey on recent advances  

Microsoft Academic Search

In the present paper, we give a survey of the recent results and outline future prospects of the tensor-structured numerical methods in applications to multidimensional problems in scientific computing. The guiding principle of the tensor methods is an approximation of multivariate functions and operators relying on a certain separation of variables. Along with the traditional canonical and Tucker models, we

Boris N. Khoromskij

487

A Front-Tracking Method for the Computations of Multiphase Flow  

Microsoft Academic Search

Direct numerical simulations of multiphase flows, using a front-tracking method, are presented. The method is based on writing one set of governing equations for the whole computational domain and treating the different phases as one fluid with variable material properties. Interfacial terms are accounted for by adding the appropriate sources as ? functions at the boundary separating the phases. The

G. Tryggvason; B. Bunner; A. Esmaeeli; D. Juric; N. Al-Rawahi; W. Tauber; J. Han; S. Nas; Y.-J. Janz

2001-01-01

488

Method for measuring the public's appreciation and knowledge of bank notes  

NASA Astrophysics Data System (ADS)

No matter how sophisticated a banknotes' security features are, they are only effective if the public uses them. Surveys conducted by the De Nederlandsche Bank (the Dutch central bank, hereinafter: DNB) in the period 1989-1999 have shown that: the more people like a banknote, the more they know about it, including its security features; there is a positive correlation between the appreciation of a banknote (beautiful or ugly) and the knowledge of its security features, its picture and text elements; hardly anybody from the general public knows more than 4 security features by heart, which is why the number of security features for the public should be confined to a maximum of 4; the average number of security features known to a Dutchman was about 1.7 in 1999; over the years, the awareness of banknote security features gradually increased from 1.03 to 1983 to 1.7 in 1999, as a result of new banknote design and information campaigns. In 1999, DNB conducted its last opinion poll on NLG-notes. After the introduction of the euro banknotes on 1 January 2002, a new era of measurements will start. It is DNB's intention to apply the same method for the euro notes as it is used to for the NLG-notes, as this will permit: A comparison of the results of surveys on Dutch banknotes with those of surveys on the new euro notes (NLG) x (EUR); a comparison between the results of similar surveys conducted in other euro countries: (EUR1)x(EUR2). Furthermore, it will enable third parties to compare their banknote model XXX with the euro: (XXX)x(EUR). This article deals with the survey and the results regarding the NLG- notes and is, moreover, intended as an invitation to use the survey method described.

de Heij, Hans A.

2002-04-01

489

Automated Method for Improving System Performance of Computer-Aided Diagnosis in Breast Ultrasound  

Microsoft Academic Search

The purpose of this research was to demonstrate the feasibility of a computerized auto-assessment method in which a computer-aided diagnosis (CADx) system itself provides a level of confidence for its estimate for the probability of malignancy for each radiologist-identified lesion. The computer performance was assessed within a leave-one-case-out protocol using a database of sonographic images from 542 patients (19% cancer

Karen Drukker; Charlene A. Sennett; Maryellen L. Giger

2009-01-01