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1

Nordic School of Public Health Computer Software in Epidemiology / Statistical Methods in Epidemiology  

E-print Network

Nordic School of Public Health Computer Software in Epidemiology / Statistical Methods in Epidemiology Open Source Solutions - # Mark Myatt, December 2001 &RS\\ULJKW0DUN0\\DWW : Permission is granted the 5 environment for data analysis and graphics to work with epidemiological data. Topics covered

Gallagher, Colin

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

BPO crude oil analysis data base user`s guide: Methods, publications, computer access correlations, uses, availability  

SciTech Connect

The Department of Energy (DOE) has one of the largest and most complete collections of information on crude oil composition that is available to the public. The computer program that manages this database of crude oil analyses has recently been rewritten to allow easier access to this information. This report describes how the new system can be accessed and how the information contained in the Crude Oil Analysis Data Bank can be obtained.

Sellers, C.; Fox, B.; Paulz, J.

1996-03-01

4

Computer Science and Technology Publications. NBS Publications List 84.  

ERIC Educational Resources Information Center

This bibliography lists publications of the Institute for Computer Sciences and Technology of the National Bureau of Standards. Publications are listed by subject in the areas of computer security, computer networking, and automation technology. Sections list publications of: (1) current Federal Information Processing Standards; (2) computer

National Bureau of Standards (DOC), Washington, DC. Inst. for Computer Sciences and Technology.

5

An Analysis of Natural Computing Publication Venues  

E-print Network

An Analysis of Natural Computing Publication Venues Michael O'Neill Natural Computing Research an analysis of different publication venues across the field of Natural Computing and compare of invaluable resources exist within the Natural Computing commu- nity, perhaps most notable is the Genetic

Fernandez, Thomas

6

Computing in Public Administration: Practice and Education.  

ERIC Educational Resources Information Center

Presents a survey of common and leading-edge computer use practices followed by municipal government personnel and the directors of 12 masters degree programs in public administration. Concludes by suggesting directions for future developments both in public agencies and in the academy. (GEA)

Norris, Donald F.; Thompson, Lyke

1988-01-01

7

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

8

TIMEINTEGRATION METHODS IN COMPUTATIONAL AERODYNAMICS  

E-print Network

' $ TIME­INTEGRATION METHODS IN COMPUTATIONAL AERODYNAMICS Antony Jameson Department of Aeronautics methods for unsteady problems 4. Conclusions & % #12;' $ Some Examples of Aerodynamic Calculations flow & % #12;' $ Aerodynamic Flow computations AIRPLANE DENSITY from 0.6250 to 1.1000 AIRPLANE CP from

Stanford University

9

Computational Methods Development at Ames  

NASA Technical Reports Server (NTRS)

This viewgraph presentation outlines the development at Ames Research Center of advanced computational methods to provide appropriate fidelity computational analysis/design capabilities. Current thrusts of the Ames research include: 1) methods to enhance/accelerate viscous flow simulation procedures, and the development of hybrid/polyhedral-grid procedures for viscous flow; 2) the development of real time transonic flow simulation procedures for a production wind tunnel, and intelligent data management technology; and 3) the validation of methods and the flow physics study gives historical precedents to above research, and speculates on its future course.

Kwak, Dochan; Smith, Charles A. (Technical Monitor)

1998-01-01

10

Computational Methods For Composite Structures  

NASA Technical Reports Server (NTRS)

Selected methods of computation for simulation of mechanical behavior of fiber/matrix composite materials described in report. For each method, report describes significance of behavior to be simulated, procedure for simulation, and representative results. Following applications discussed: effects of progressive degradation of interply layers on responses of composite structures, dynamic responses of notched and unnotched specimens, interlaminar fracture toughness, progressive fracture, thermal distortions of sandwich composite structure, and metal-matrix composite structures for use at high temperatures. Methods demonstrate effectiveness of computational simulation as applied to complex composite structures in general and aerospace-propulsion structural components in particular.

Chamis, Christos C.

1988-01-01

11

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

12

Computational Methods for Simulating Quantum Computers  

E-print Network

This review gives a survey of numerical algorithms and software to simulate quantum computers.It covers the basic concepts of quantum computation and quantum algorithms and includes a few examples that illustrate the use of simulation software for ideal and physical models of quantum computers.

H. De Raedt; K. Michielsen

2004-06-27

13

Computational Methods for Ramsey Numbers.  

National Technical Information Service (NTIS)

The Ramsey number R(k,l) is the least integer in such that all graphs on n or more vertices contain a clique of k vertices or an independent set of 1 vertices as an induced subgraph. In this work we investigate computational methods for finding lower boun...

H. Haanpaeae

2000-01-01

14

Special Publication 500-293 US Government Cloud Computing  

E-print Network

Special Publication 500-293 (Draft) US Government Cloud Computing Technology Roadmap Volume II and Dawn Leaf NIST Cloud Computing Program Information Technology Laboratory #12;This page left Publication 500-293 (Draft) US Government Cloud Computing Technology Roadmap Volume II Release 1.0 (Draft

15

Cryptography Challenges for Computational Privacy in Public Clouds  

E-print Network

Cryptography Challenges for Computational Privacy in Public Clouds Sashank Dara Cisco Systems into the underpinnings of Computational Privacy and lead to better solutions. I. INTRODUCTION Cloud computing came out, the cryptographic techniques for solving cloud computational privacy problems are micro- scopic, in the sense that

16

Relative status of journal and conference publications in computer science  

Microsoft Academic Search

Though computer scientists agree that conference publications enjoy greater status in computer science than in other disciplines, there is little quantitative evidence to support this view. The importance of journal publication in academic promotion makes it a highly personal issue, since focusing exclusively on journal papers misses many significant papers published by CS conferences. Here, we aim to quantify the

Jill Freyne; Lorcan Coyle; Barry Smyth; Padraig Cunningham

2010-01-01

17

Geometric methods in quantum computation  

NASA Astrophysics Data System (ADS)

Recent advances in the physical sciences and engineering have created great hopes for new computational paradigms and substrates. One such new approach is the quantum computer, which holds the promise of enhanced computational power. Analogous to the way a classical computer is built from electrical circuits containing wires and logic gates, a quantum computer is built from quantum circuits containing quantum wires and elementary quantum gates to transport and manipulate quantum information. Therefore, design of quantum gates and quantum circuits is a prerequisite for any real application of quantum computation. In this dissertation we apply geometric control methods from differential geometry and Lie group representation theory to analyze the properties of quantum gates and to design optimal quantum circuits. Using the Cartan decomposition and the Weyl group, we show that the geometric structure of nonlocal two-qubit gates is a 3-Torus. After further reducing the symmetry, the geometric representation of nonlocal gates is seen to be conveniently visualized as a tetrahedron. Each point in this tetrahedron except on the base corresponds to a different equivalent class of nonlocal gates. This geometric representation is one of the cornerstones for the discussion on quantum computation in this dissertation. We investigate the properties of those two-qubit operations that can generate maximal entanglement. It is an astonishing finding that if we randomly choose a two-qubit operation, the probability that we obtain a perfect entangler is exactly one half. We prove that given a two-body interaction Hamiltonian, it is always possible to explicitly construct a quantum circuit for exact simulation of any arbitrary nonlocal two-qubit gate by turning on the two-body interaction for at most three times, together with at most four local gates. We also provide an analytic approach to construct a universal quantum circuit from any entangling gate supplemented with local gates. Closed form solutions have been derived for each step in this explicit construction procedure. Moreover, the minimum upper bound is found to construct a universal quantum circuit from any Controlled-Unitary gate. A near optimal explicit construction of universal quantum circuits from a given Controlled-Unitary is provided. For the Controlled-NOT and Double-CNOT gate, we then develop simple analytic ways to construct universal quantum circuits with exactly three applications, which is the least possible for these gates. We further discover a new quantum gate (named B gate) that achieves the desired universality with minimal number of gates. Optimal implementation of single-qubit quantum gates is also investigated. Finally, as a real physical application, a constructive way to implement any arbitrary two-qubit operation on a spin electronics system is discussed.

Zhang, Jun

18

Public participation: more than a method?  

PubMed Central

While it is important to support the development of methods for public participation, we argue that this should not be at the expense of a broader consideration of the role of public participation. We suggest that a rights based approach provides a framework for developing more meaningful approaches that move beyond public participation as synonymous with consultation to value the contribution of lay knowledge to the governance of health systems and health research. PMID:25337604

Boaz, Annette; Chambers, Mary; Stuttaford, Maria

2014-01-01

19

Computational Methods for Hyperbolic Equations  

NASA Astrophysics Data System (ADS)

This is an introduction to some of the basic concepts on modern numerical methods for computing approximate solutions to hyperbolic partial differential equations. This chapter is divided into five sections. Section 1 contains a review of some elementary theoretical concepts on hyperbolic equations, mainly focused on the linear case; the Riemann problem for a general linear system with constant coefficients is solved in detail. Section 2 is an introduction to the basics of discretization methods, including finite difference methods and finite volume methods; concepts such as local truncation error, linear stability and modified equation are included; Godunov's theorem is stated, proved and its implications are discussed. Section 3 contains two approximate Riemann solvers, as applied to the three-dimensional Euler equations, namely HLLC and EVILIN. Section 4 deals with the construction of non-linear (non-oscillatory) numerical methods of the TVD and ENO type, for a scalar conservation law. In Sect. 5 we use the theory developed for scalar equations as a guideline to construct non-linear (quasi non-oscillatory) second-order finite volume schemes for one-dimensional non-linear systems with source terms. Key references for further reading are indicated at the end of each section.

Toro, E. F.

20

Special Publication 500-293 US Government Cloud Computing  

E-print Network

Special Publication 500-293 (Draft) US Government Cloud Computing Technology Roadmap Volume I Release 1.0 (Draft) High-Priority Requirements to Further USG Agency Cloud Computing Adoption Lee Badger Sokol, Jin Tong, Fred Whiteside and Dawn Leaf NIST Cloud Computing Program Information Technology

21

High-performance Computing Methods for Computational Genomics  

Microsoft Academic Search

The article consists of a Powerpoint presentation on high performance computing methods for computational genomics. The areas discussed include: sequence alignment; database querying; EST clustering; genome assembly; evolutionary history reconstruction.

Srinivas Aluru; D. A. Bader; Ananth Kalyanaraman

2007-01-01

22

Acceptance of Computer Technology in the Corporate Public Affairs Function.  

ERIC Educational Resources Information Center

A survey of 160 top "Fortune" 500 companies was conducted in 1979 to determine the extent to which computers were being used in public affairs/government relations research and analysis. The survey instrument was divided into six sections, containing a total of 26 closed-end questions. The six sections elicited information on (1) public affairs…

Glenn, Martha Cole; And Others

23

Evolution as Computation Evolutionary Theory (accepted for publication)  

E-print Network

1/21/05 1 Evolution as Computation Evolutionary Theory (accepted for publication) By: John E: jemayf@iastate.edu Key words: Evolution, Computation, Complexity, Depth Running head: Evolution of evolution must include life and also non-living processes that change over time in a manner similar

Mayfield, John

24

Computer-Assisted Management of Instruction in Veterinary Public Health  

ERIC Educational Resources Information Center

Reviews a course in Food Hygiene and Public Health at the University of Illinois College of Veterinary Medicine in which students are sequenced through a series of computer-based lessons or autotutorial slide-tape lessons, the computer also being used to route, test, and keep records. Since grades indicated mastery of the subject, the course will…

Holt, Elsbeth; And Others

1975-01-01

25

Computational methods in wind power meteorology  

E-print Network

Computational methods in wind power meteorology Bo Hoffmann Jørgensen, Søren Ott, Niels Nørmark, Jakob Mann and Jake Badger Title: Computational methods in wind power meteorology Department: Wind in connection with the project called Computational meth- ods in wind power meteorology which was supported

26

Computational methods for probability of instability calculations  

NASA Technical Reports Server (NTRS)

This paper summarizes the development of the methods and a computer program to compute the probability of instability of a dynamic system than can be represented by a system of second-order ordinary linear differential equations. Two instability criteria based upon the roots of the characteristics equation or Routh-Hurwitz test functions are investigated. Computational methods based on system reliability analysis methods and importance sampling concepts are proposed to perform efficient probabilistic analysis. Numerical examples are provided to demonstrate the methods.

Wu, Y.-T.; Burnside, O. H.

1990-01-01

27

Methods and applications in computational protein design  

E-print Network

In this thesis, we summarize our work on applications and methods for computational protein design. First, we apply computational protein design to address the problem of degradation in stored proteins. Specifically, we ...

Biddle, Jason Charles

2010-01-01

28

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

Code of Federal Regulations, 2011 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...

2011-07-01

29

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

Code of Federal Regulations, 2010 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...

2010-07-01

30

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

31

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

Code of Federal Regulations, 2012 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...

2012-07-01

32

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. PMID:23204927

Loomis, Cynthia A.; Curchoe, Carol Lynn

2012-01-01

33

A computer method for perspective drawing  

E-print Network

A COMPUTER METHOD FOR PERSPECTIVE DRAWING A Thesis By' HERBERT RAY HAYNES Submitted to the Graduate College of' the Texas A8cM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1966 Major... Subject: Computer Science A COMPUTER METHOD FOR PERSPECTIVE DRAWING A Thesis HERBERT RAY HAYNES Approved as to style and content by: Chairman oi' Committee M er Member August 1966 ACKNOWLEDGEMENTS The assistance of the following members of my...

Haynes, Herbert Ray

2012-06-07

34

Theoretical and computational methods in statistical mechanics  

E-print Network

Theoretical and computational methods in statistical mechanics Shmuel Friedland Univ. Illinois and computational methods in statistical mechanicsBerkeley, October 26, 2009 1 / 32 #12;Overview Motivation: Ising in statistical mechanicsBerkeley, October 26, 2009 2 / 32 #12;Figure: Uri Natan Peled, Photo - December 2006

Friedland, Shmuel

35

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

36

32 CFR 310.52 - Computer matching publication and review requirements.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Computer matching publication and review requirements... PRIVACY PROGRAM DOD PRIVACY PROGRAM Computer Matching Program Procedures § 310.52 Computer matching publication and review...

2012-07-01

37

32 CFR 310.52 - Computer matching publication and review requirements.  

...2014-07-01 2014-07-01 false Computer matching publication and review requirements... PRIVACY PROGRAM DOD PRIVACY PROGRAM Computer Matching Program Procedures § 310.52 Computer matching publication and review...

2014-07-01

38

32 CFR 310.52 - Computer matching publication and review requirements.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Computer matching publication and review requirements... PRIVACY PROGRAM DOD PRIVACY PROGRAM Computer Matching Program Procedures § 310.52 Computer matching publication and review...

2010-07-01

39

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

40

32 CFR 310.52 - Computer matching publication and review requirements.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Computer matching publication and review requirements... PRIVACY PROGRAM DOD PRIVACY PROGRAM Computer Matching Program Procedures § 310.52 Computer matching publication and review...

2011-07-01

41

Simulation methods for advanced scientific computing  

SciTech Connect

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The objective of the project was to create effective new algorithms for solving N-body problems by computer simulation. The authors concentrated on developing advanced classical and quantum Monte Carlo techniques. For simulations of phase transitions in classical systems, they produced a framework generalizing the famous Swendsen-Wang cluster algorithms for Ising and Potts models. For spin-glass-like problems, they demonstrated the effectiveness of an extension of the multicanonical method for the two-dimensional, random bond Ising model. For quantum mechanical systems, they generated a new method to compute the ground-state energy of systems of interacting electrons. They also improved methods to compute excited states when the diffusion quantum Monte Carlo method is used and to compute longer time dynamics when the stationary phase quantum Monte Carlo method is used.

Booth, T.E.; Carlson, J.A.; Forster, R.A. [and others

1998-11-01

42

PA 540: #35741 RESEARCH METHODS FOR PUBLIC ADMINISTRATION  

E-print Network

1 PA 540: #35741 RESEARCH METHODS FOR PUBLIC ADMINISTRATION FALL SEMESTER, 2013 Class Meeting of these methods. Fowler, Floyd J., 2008. Survey Research Methods, 4th. (Sage Publications). $35 Gerring, John

Illinois at Chicago, University of

43

Transonic wing analysis using advanced computational methods  

NASA Technical Reports Server (NTRS)

This paper discusses the application of three-dimensional computational transonic flow methods to several different types of transport wing designs. The purpose of these applications is to evaluate the basic accuracy and limitations associated with such numerical methods. The use of such computational methods for practical engineering problems can only be justified after favorable evaluations are completed. The paper summarizes a study of both the small-disturbance and the full potential technique for computing three-dimensional transonic flows. Computed three-dimensional results are compared to both experimental measurements and theoretical results. Comparisons are made not only of pressure distributions but also of lift and drag forces. Transonic drag rise characteristics are compared. Three-dimensional pressure distributions and aerodynamic forces, computed from the full potential solution, compare reasonably well with experimental results for a wide range of configurations and flow conditions.

Henne, P. A.; Hicks, R. M.

1978-01-01

44

BOOK REVIEW Computational Photography: Methods and Applications.  

E-print Network

BOOK REVIEW Computational Photography: Methods and Applications. By Rastislav Lukac, Boca Raton, FL of computational photography is given by Wikipedia, which is also used by the book's Editor to begin his editorial that was deliber- ately omitted in the taxonomy proposed by Shree K. Nayar.1 This book illustrates recent advances

Schettini, Raimondo

45

A Computer-Assisted Method of Counseling.  

ERIC Educational Resources Information Center

A computer-assisted method of counseling was applied to cases of stuttering and hypertension. Although both symptom complexes had previously resisted therapy, results indicated that computer-assisted counseling eliminated the stuttering and reduced diastolic blood pressure to normal levels. (Author)

Parente, Frederick J.; And Others

1981-01-01

46

Computational methods for global/local analysis  

NASA Technical Reports Server (NTRS)

Computational methods for global/local analysis of structures which include both uncoupled and coupled methods are described. In addition, global/local analysis methodology for automatic refinement of incompatible global and local finite element models is developed. Representative structural analysis problems are presented to demonstrate the global/local analysis methods.

Ransom, Jonathan B.; Mccleary, Susan L.; Aminpour, Mohammad A.; Knight, Norman F., Jr.

1992-01-01

47

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

48

Computing Discharge Using the Index Velocity Method.  

National Technical Information Service (NTIS)

Application of the index velocity method for computing continuous records of discharge has become increasingly common, especially since the introduction of low-cost acoustic Doppler velocity meters (ADVMs) in 1997. Presently (2011), the index velocity met...

K. A. Oberg, V. A. Levesque

2012-01-01

49

Reform of Computer Graphics Teaching Method  

Microsoft Academic Search

In this paper, we propose an approach for teaching method of computer graphics course that has the benefit of offering simple and interesting study. The approach aim at improving undergraduate student's practical ability and comprehensive ability, which only need we change the teaching method a little. We illustrate this idea by presenting a three dimension (3D) tree modeling case, which

Jun Zhou; Ming Ye; Chun-Lun Huang

2010-01-01

50

Computing discharge using the index velocity method  

USGS Publications Warehouse

Application of the index velocity method for computing continuous records of discharge has become increasingly common, especially since the introduction of low-cost acoustic Doppler velocity meters (ADVMs) in 1997. Presently (2011), the index velocity method is being used to compute discharge records for approximately 470 gaging stations operated and maintained by the U.S. Geological Survey. The purpose of this report is to document and describe techniques for computing discharge records using the index velocity method. Computing discharge using the index velocity method differs from the traditional stage-discharge method by separating velocity and area into two ratings—the index velocity rating and the stage-area rating. The outputs from each of these ratings, mean channel velocity (V) and cross-sectional area (A), are then multiplied together to compute a discharge. For the index velocity method, V is a function of such parameters as streamwise velocity, stage, cross-stream velocity, and velocity head, and A is a function of stage and cross-section shape. The index velocity method can be used at locations where stage-discharge methods are used, but it is especially appropriate when more than one specific discharge can be measured for a specific stage. After the ADVM is selected, installed, and configured, the stage-area rating and the index velocity rating must be developed. A standard cross section is identified and surveyed in order to develop the stage-area rating. The standard cross section should be surveyed every year for the first 3 years of operation and thereafter at a lesser frequency, depending on the susceptibility of the cross section to change. Periodic measurements of discharge are used to calibrate and validate the index rating for the range of conditions experienced at the gaging station. Data from discharge measurements, ADVMs, and stage sensors are compiled for index-rating analysis. Index ratings are developed by means of regression techniques in which the mean cross-sectional velocity for the standard section is related to the measured index velocity. Most ratings are simple-linear regressions, but more complex ratings may be necessary in some cases. Once the rating is established, validation measurements should be made periodically. Over time, validation measurements may provide additional definition to the rating or result in the creation of a new rating. The computation of discharge is the last step in the index velocity method, and in some ways it is the most straight-forward step. This step differs little from the steps used to compute discharge records for stage-discharge gaging stations. The ratings are entered into database software used for records computation, and continuous records of discharge are computed.

Levesque, Victor A.; Oberg, Kevin A.

2012-01-01

51

Updated Panel-Method Computer Program  

NASA Technical Reports Server (NTRS)

Panel code PMARC_12 (Panel Method Ames Research Center, version 12) computes potential-flow fields around complex three-dimensional bodies such as complete aircraft models. Contains several advanced features, including internal mathematical modeling of flow, time-stepping wake model for simulating either steady or unsteady motions, capability for Trefftz computation of drag induced by plane, and capability for computation of off-body and on-body streamlines, and capability of computation of boundary-layer parameters by use of two-dimensional integral boundary-layer method along surface streamlines. Investigators interested in visual representations of phenomena, may want to consider obtaining program GVS (ARC-13361), General visualization System. GVS is Silicon Graphics IRIS program created to support scientific-visualization needs of PMARC_12. GVS available separately from COSMIC. PMARC_12 written in standard FORTRAN 77, with exception of NAMELIST extension used for input.

Ashby, Dale L.

1995-01-01

52

A method of computing fast cosine transforms  

NASA Astrophysics Data System (ADS)

Several methods of computing fast cosine transforms (FCTs) have been suggested but, in general, either they do not fully exploit the savings in memory occupation or they require additional software modules to be implemented. In this paper we show that the FCT can be implemented using well-known existing software (e.g. bit reversal, complex FFT), thus freeing the computer memory from scratch arrays and the end user from major software changes.

Mencaraglia, F.; Natale, V.

1984-11-01

53

Method and system for benchmarking computers  

DOEpatents

A testing system and method for benchmarking computer systems. The system includes a store containing a scalable set of tasks to be performed to produce a solution in ever-increasing degrees of resolution as a larger number of the tasks are performed. A timing and control module allots to each computer a fixed benchmarking interval in which to perform the stored tasks. Means are provided for determining, after completion of the benchmarking interval, the degree of progress through the scalable set of tasks and for producing a benchmarking rating relating to the degree of progress for each computer.

Gustafson, John L. (Ames, IA)

1993-09-14

54

Stochastic Lagrangian Method for Downscaling Problems in Computational Fluid Dynamics  

E-print Network

Stochastic Lagrangian Method for Downscaling Problems in Computational Fluid Dynamics Fr downscaling technique applied to computational fluid dynamics. Our method consists in building a local model for the downscaling in Computational Fluid Dynamics (CFD). For numerous practical reasons (computational cost

Paris-Sud XI, Université de

55

Semiempirical methods for computing turbulent flows  

NASA Technical Reports Server (NTRS)

Two semiempirical theories which provide a basis for determining the turbulent friction and heat exchange near a wall are presented: (1) the Prandtl-Karman theory, and (2) the theory utilizing an equation for the energy of turbulent pulsations. A comparison is made between exact numerical methods and approximate integral methods for computing the turbulent boundary layers in the presence of pressure, blowing, or suction gradients. Using the turbulent flow around a plate as an example, it is shown that, when computing turbulent flows with external turbulence, it is preferable to construct a turbulence model based on the equation for energy of turbulent pulsations.

Belov, I. A.; Ginzburg, I. P.

1986-01-01

56

Computers for Learning: The Uses of Computer-Assisted Instruction (CAI) in California Public Schools.  

ERIC Educational Resources Information Center

Implications of and resource information on the use of computer assisted instruction (CAI) in California public schools are presented under the following headings: (1) definition of CAI, (2) effectiveness of CAI, (3) obstacles to the use of CAI, (4) the turnaround in CAI acceptance and use, (5) instructional potential of CAI, and (6) how to obtain…

Grimes, Don Marston

57

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

58

Evolutionary computation methods for helicopter loads estimation  

Microsoft Academic Search

The accurate estimation of component loads in a helicopter is an important goal for life cycle management and life extension efforts. This paper explores the use of evolutionary computational methods to help estimate some of these helicopter dynamic loads. Thirty standard time-dependent flight state and control system parameters were used to construct a set of 180 input variables to estimate

Julio J. Valdes; Catherine Cheung; Weichao Wang

2011-01-01

59

Design methods for ethical persuasive computing  

Microsoft Academic Search

Value Sensitive Design and Participatory Design are two methodological frameworks that account for ethical issues throughout the process of technology design. Through anal- ysis and case studies, this paper argues that such methods should be applied to persuasive technology—computer sys- tems that are intended to change behaviors and attitudes.

Janet Davis

2009-01-01

60

Computational Methods for Structural Mechanics and Dynamics  

NASA Technical Reports Server (NTRS)

Topics addressed include: transient dynamics; transient finite element method; transient analysis in impact and crash dynamic studies; multibody computer codes; dynamic analysis of space structures; multibody mechanics and manipulators; spatial and coplanar linkage systems; flexible body simulation; multibody dynamics; dynamical systems; and nonlinear characteristics of joints.

Stroud, W. Jefferson (editor); Housner, Jerrold M. (editor); Tanner, John A. (editor); Hayduk, Robert J. (editor)

1989-01-01

61

Computer-assisted analysis of public discourse: a case study of the precautionary principle in the US and UK press  

Microsoft Academic Search

Content analysis of newspaper publications has become a major scientific method of the analysis of public discourse. Within\\u000a the framework of content analysis, we suggest a computer-assisted method to extract the most important topics of this discourse\\u000a in an objective, quantifiable manner. The method combines frequency and proximity analysis of the text population, selection\\u000a of the key words, text modification

Andrei Kirilenko; Svetlana Stepchenkova; Rebecca Romsdahl; Kristine Mattis

2012-01-01

62

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

63

A method to compute periodic sums  

NASA Astrophysics Data System (ADS)

In a number of problems in computational physics, a finite sum of kernel functions centered at N particle locations located in a box in three dimensions must be extended by imposing periodic boundary conditions on box boundaries. Even though the finite sum can be efficiently computed via fast summation algorithms, such as the fast multipole method (FMM), the periodized extension is usually treated via a different algorithm, Ewald summation, accelerated via the fast Fourier transform (FFT). A different approach to compute this periodized sum just using a blackbox finite fast summation algorithm is presented in this paper. The method splits the periodized sum into two parts. The first, comprising the contribution of all points outside a large sphere enclosing the box, and some of its neighbors, is approximated inside the box by a collection of kernel functions (“sources”) placed on the surface of the sphere or using an expansion in terms of spectrally convergent local basis functions. The second part, comprising the part inside the sphere, and including the box and its immediate neighborhood, is treated via available summation algorithms. The coefficients of the sources are determined by least squares collocation of the periodicity condition of the total potential, imposed on a circumspherical surface for the box. While the method is presented in general, details are worked out for the case of evaluating electrostatic potentials and forces. Results show that when used with the FMM, the periodized sum can be computed to any specified accuracy, at an additional cost of the order of the free-space FMM. Several technical details and efficient algorithms for auxiliary computations are provided, as are numerical comparisons.

Gumerov, Nail A.; Duraiswami, Ramani

2014-09-01

64

Preprint accepted for publication in Computers and Education Computer-Assisted Assignments in a Large Physics Class  

E-print Network

1 Preprint accepted for publication in Computers and Education Computer-Assisted Assignments tool to implementa Computer-Assisted Personalized Approach for homework assignments and examinations interactivecontact with the students. 1. Introduction The use of computers in education is very widespread

65

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

66

Parallel computer methods for eigenvalue extraction  

NASA Technical Reports Server (NTRS)

A new numerical algorithm for the solution of large-order eigenproblems typically encountered in linear elastic finite element systems is presented. The architecture of parallel processing is used in the algorithm to achieve increased speed and efficiency of calculations. The algorithm is based on the frontal technique for the solution of linear simultaneous equations and the modified subspace eigenanalysis method for the solution of the eigenproblem. The advantages of this new algorithm in parallel computer architecture are discussed.

Akl, Fred

1988-01-01

67

Analytic Method for Computing Instrument Pointing Jitter  

NASA Technical Reports Server (NTRS)

A new method of calculating the root-mean-square (rms) pointing jitter of a scientific instrument (e.g., a camera, radar antenna, or telescope) is introduced based on a state-space concept. In comparison with the prior method of calculating the rms pointing jitter, the present method involves significantly less computation. The rms pointing jitter of an instrument (the square root of the jitter variance shown in the figure) is an important physical quantity which impacts the design of the instrument, its actuators, controls, sensory components, and sensor- output-sampling circuitry. Using the Sirlin, San Martin, and Lucke definition of pointing jitter, the prior method of computing the rms pointing jitter involves a frequency-domain integral of a rational polynomial multiplied by a transcendental weighting function, necessitating the use of numerical-integration techniques. In practice, numerical integration complicates the problem of calculating the rms pointing error. In contrast, the state-space method provides exact analytic expressions that can be evaluated without numerical integration.

Bayard, David

2003-01-01

68

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

69

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 toexamine the interrelationship between different selling strategies for going public. A greatdeal of recent empirical evidence suggests that to maximise the revenue raised from theshares sold in the public offering, it is fundamental to choose the appropriate design for thesale which, in turn, reflects the final ownership structure. This

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

2001-01-01

70

Computational method for free surface hydrodynamics  

SciTech Connect

There are numerous flow phenomena in pressure vessel and piping systems that involve the dynamics of free fluid surfaces. For example, fluid interfaces must be considered during the draining or filling of tanks, in the formation and collapse of vapor bubbles, and in seismically shaken vessels that are partially filled. To aid in the analysis of these types of flow phenomena, a new technique has been developed for the computation of complicated free-surface motions. This technique is based on the concept of a local average volume of fluid (VOF) and is embodied in a computer program for two-dimensional, transient fluid flow called SOLA-VOF. The basic approach used in the VOF technique is briefly described, and compared to other free-surface methods. Specific capabilities of the SOLA-VOF program are illustrated by generic examples of bubble growth and collapse, flows of immiscible fluid mixtures, and the confinement of spilled liquids.

Hirt, C.W.; Nichols, B.D.

1980-01-01

71

Recommendations for evaluation of computational methods  

PubMed Central

The field of computational chemistry, particularly as applied to drug design, has become increasingly important in terms of the practical application of predictive modeling to pharmaceutical research and development. Tools for exploiting protein structures or sets of ligands known to bind particular targets can be used for binding-mode prediction, virtual screening, and prediction of activity. A serious weakness within the field is a lack of standards with respect to quantitative evaluation of methods, data set preparation, and data set sharing. Our goal should be to report new methods or comparative evaluations of methods in a manner that supports decision making for practical applications. Here we propose a modest beginning, with recommendations for requirements on statistical reporting, requirements for data sharing, and best practices for benchmark preparation and usage. PMID:18338228

2008-01-01

72

Review of Computational Stirling Analysis Methods  

NASA Technical Reports Server (NTRS)

Nuclear thermal to electric power conversion carries the promise of longer duration missions and higher scientific data transmission rates back to Earth for both Mars rovers and deep space missions. A free-piston Stirling convertor is a candidate technology that is considered an efficient and reliable power conversion device for such purposes. While already very efficient, it is believed that better Stirling engines can be developed if the losses inherent its current designs could be better understood. However, they are difficult to instrument and so efforts are underway to simulate a complete Stirling engine numerically. This has only recently been attempted and a review of the methods leading up to and including such computational analysis is presented. And finally it is proposed that the quality and depth of Stirling loss understanding may be improved by utilizing the higher fidelity and efficiency of recently developed numerical methods. One such method, the Ultra HI-Fl technique is presented in detail.

Dyson, Rodger W.; Wilson, Scott D.; Tew, Roy C.

2004-01-01

73

Evolutionary Computing Methods for Spectral Retrieval  

NASA Technical Reports Server (NTRS)

A methodology for processing spectral images to retrieve information on underlying physical, chemical, and/or biological phenomena is based on evolutionary and related computational methods implemented in software. In a typical case, the solution (the information that one seeks to retrieve) consists of parameters of a mathematical model that represents one or more of the phenomena of interest. The methodology was developed for the initial purpose of retrieving the desired information from spectral image data acquired by remote-sensing instruments aimed at planets (including the Earth). Examples of information desired in such applications include trace gas concentrations, temperature profiles, surface types, day/night fractions, cloud/aerosol fractions, seasons, and viewing angles. The methodology is also potentially useful for retrieving information on chemical and/or biological hazards in terrestrial settings. In this methodology, one utilizes an iterative process that minimizes a fitness function indicative of the degree of dissimilarity between observed and synthetic spectral and angular data. The evolutionary computing methods that lie at the heart of this process yield a population of solutions (sets of the desired parameters) within an accuracy represented by a fitness-function value specified by the user. The evolutionary computing methods (ECM) used in this methodology are Genetic Algorithms and Simulated Annealing, both of which are well-established optimization techniques and have also been described in previous NASA Tech Briefs articles. These are embedded in a conceptual framework, represented in the architecture of the implementing software, that enables automatic retrieval of spectral and angular data and analysis of the retrieved solutions for uniqueness.

Terrile, Richard; Fink, Wolfgang; Huntsberger, Terrance; Lee, Seugwon; Tisdale, Edwin; VonAllmen, Paul; Tinetti, Geivanna

2009-01-01

74

Robust level set method for computer vision  

NASA Astrophysics Data System (ADS)

Level set method provides powerful numerical techniques for analyzing and solving interface evolution problems based on partial differential equations. It is particularly appropriate for image segmentation and other computer vision tasks. However, there exists noise in every image and the noise is the main obstacle to image segmentation. In level set method, the propagation fronts are apt to leak through the gaps at locations of missing or fuzzy boundaries that are caused by noise. The robust level set method proposed in this paper is based on the adaptive Gaussian filter. The fast marching method provides a fast implementation for level set method and the adaptive Gaussian filter can adapt itself to the local characteristics of an image by adjusting its variance. Thus, the different parts of an image can be smoothed in different way according to the degree of noisiness and the type of edges. Experiments results demonstrate that the adaptive Gaussian filter can greatly reduce the noise without distorting the image and made the level set methods more robust and accurate.

Si, Jia-rui; Li, Xiao-pei; Zhang, Hong-wei

2005-12-01

75

User's guide to SAC, a computer program for computing discharge by slope-area method  

USGS Publications Warehouse

This user's guide contains information on using the slope-area program, SAC. SAC can be used to compute peak flood discharges from measurements of high-water marks along a stream reach. The Slope-area method used by the program is the U.S. Geological Survey (USGS) procedure presented in Techniques of Water Resources Investigations of the U.S. Geological Survey, beok 3, chapter A2, "Measurement of Peak Discharge by the Slope-Area Method." The program uses input files that have formats compatible with those used by the water-surface profile program (WSPRO) described in the Federal Highways Administration publication FHWA-IP-89-027. The guide briefly describes the slope-area method documents the input requirements and the output produced, and demonstrates use of SAC.

Fulford, Janice M.

1994-01-01

76

A computationally efficient optimal maintenance scheduling method  

SciTech Connect

This paper addresses the optimal preventive maintenance scheduling problem (OMSP). The importance of OMSP is due to the fact that system reliability and operating cost of an electric utility are affected by the maintenance outage of generating facilities. The authors present a multi-component objective function consisting of reliability and production cost which incorporates uncertainties such as load uncertainties and forced outages of generating units. Dynamic Programming (DP) which is most suitable for sequential decision problems is used as a framework to solve the OMSP. The dimensionality problem, a serious drawback of DP, is reduced by converting it into an iteratively, monotonically converging technique of DP successive approximations (DPSA). To further reduce the computational time, the stage cost function (reliability index LOLP and production cost) is evaluated by cumulant method. This method is an order of magnitude faster than the classical Booth-Baleriaux method. The approach has been programmed on a VAX 11/780 and applied to a twenty-one unit system. A scheduling horizon of one year and a stage length of one week were used. The results show that reliability is a more appropriate objective function than production cost.

Yamayee, Z.; Sidenblad, K.; Yoshimura, M.

1983-02-01

77

Domain decomposition methods in computational fluid dynamics  

NASA Technical Reports Server (NTRS)

The divide-and-conquer paradigm of iterative domain decomposition, or substructuring, has become a practical tool in computational fluid dynamic applications because of its flexibility in accommodating adaptive refinement through locally uniform (or quasi-uniform) grids, its ability to exploit multiple discretizations of the operator equations, and the modular pathway it provides towards parallelism. These features are illustrated on the classic model problem of flow over a backstep using Newton's method as the nonlinear iteration. Multiple discretizations (second-order in the operator and first-order in the preconditioner) and locally uniform mesh refinement pay dividends separately, and they can be combined synergistically. Sample performance results are included from an Intel iPSC/860 hypercube implementation.

Gropp, William D.; Keyes, David E.

1991-01-01

78

Modules and methods for all photonic computing  

DOEpatents

A method for all photonic computing, comprising the steps of: encoding a first optical/electro-optical element with a two dimensional mathematical function representing input data; illuminating the first optical/electro-optical element with a collimated beam of light; illuminating a second optical/electro-optical element with light from the first optical/electro-optical element, the second optical/electro-optical element having a characteristic response corresponding to an iterative algorithm useful for solving a partial differential equation; iteratively recirculating the signal through the second optical/electro-optical element with light from the second optical/electro-optical element for a predetermined number of iterations; and, after the predetermined number of iterations, optically and/or electro-optically collecting output data representing an iterative optical solution from the second optical/electro-optical element.

Schultz, David R. (Knoxville, TN); Ma, Chao Hung (Oak Ridge, TN)

2001-01-01

79

Computer-Assisted Writing Instruction in Public Community Colleges.  

ERIC Educational Resources Information Center

A study explored the status of computer aided instruction (CAI) in writing programs offered by community colleges identified as using CAI. The questionnaire, completed in the winter of 1986 by 198 English instructors, measured accessibility of computers to faculty and students, types of hardware and software, computer locations, computer facility…

Saunders, Pearl I.

80

Three fast computational approximation methods in hypersonic aerothermodynamics  

E-print Network

Three fast computational approximation methods in hypersonic aerothermodynamics V.V. Riabov* Rivier analyzed to study nonequilibrium hypersonic viscous flows near blunt bodies. These approximations allow; Nonequilibrium hypersonic flows 1. Introduction Numerous methods [1,2] that require significant computational

Riabov, Vladimir V.

81

Multiresolution Reproducing Kernel Particle Method for Computational Fluid Dynamics  

E-print Network

Multiresolution Reproducing Kernel Particle Method for Computational Fluid Dynamics Wing Kam Liu (RKPM) is developed for computational fluid dynamics. An algorithm incorporating multiple scale adaptive in fluid dynamics. KEY WORDS: meshless kernel particle method, multiresolution analysis, wavelets

Liu, Wing Kam

82

IBEISEVIER Comput. Methods Appl. Mech. Engrg. 167 ( 1998) 261-273 Computer methods  

E-print Network

save considerable computational time and storage. Numerical examples are presented to illustrate the performance of the method. Some guidelines are suggested to further increase the efficiency of the proposed-structure interaction problems. A typical example is the analysis of dam-reservoir interaction. The reservoir can

Guddati, Murthy N.

83

Public Health 439 (section 20) Qualitative Research Methods  

E-print Network

Public Health 439 (section 20) Qualitative Research Methods Spring 2012 1 PUB HLTH 439 (section 20) Qualitative Research Methods Spring 2011 Day/Time: Tuesdays, 6:00 ­ 9:00 PM Classroom Location: McGaw 2 research deals with words, spoken and written. This course will focus on qualitative research methods

Chisholm, Rex L.

84

Computational Methods in Biomechanics and Physics A Dissertation  

E-print Network

Computational Methods in Biomechanics and Physics A Dissertation Presented to the Faculty Doctor of Philosophy By Serguei Lapin May 2005 #12;Computational Methods in Biomechanics and Physics;Computational Methods in Biomechanics and Physics. An Abstract of a Dissertation Presented to the Faculty

Lapin, Sergey

85

Computational Evaluation of the Traceback Method  

ERIC Educational Resources Information Center

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,…

Kol, Sheli; Nir, Bracha; Wintner, Shuly

2014-01-01

86

Resource management for global public computing: many policies are better than (n)one  

E-print Network

Resource management for global public computing: many policies are better than (n)one Evangelos- centralised way. Our work makes the following contri- butions: · Federation of policies. Our system embraces Research Cambridge Abstract The federation of authority in global public computing systems poses major

Harris, Timothy

87

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

88

Computationally Efficient Methods for Selecting Among Mixtures of Graphical Models  

E-print Network

Computationally Efficient Methods for Selecting Among Mixtures of Graphical Models B. THIESSON, C efficient methods for Bayesian model selection. The methods select among mixtures in which each component. Keywords : Model selection, asymptotic methods, mixture models, directed acyclic graphs, hidden variables

Heckerman, David

89

Computer Science without computers: new outreach methods from old tricks  

Microsoft Academic Search

A disturbing gap is emerging as the demand for qualified computer scientists increases, yet enrolments in CS courses have dropped dramatically since 2000. One of the reasons often given for this is the mismatch between what school students understand the subject to be, and what it really is. A major project based at Canterbury University is underway for school outreach

Tim Bell; Isaac Freeman; Mick Grimley

90

to appear in Behavior Research Methods, Instruments and Computers A Computational Model  

E-print Network

to appear in Behavior Research Methods, Instruments and Computers A Computational Model,version1-1Apr2008 Author manuscript, published in "Behavior Research Methods 38, 4 (2006) 628-637" #12;to appear in Behavior Research Methods, Instruments and Computers Abstract This paper describes

Paris-Sud XI, Université de

91

Computer methods for structural neurological systems analysis  

E-print Network

of the digital computer has allowed our progress to increase enormously. Unfortunately, this great tool has shown many limitations. In the early 1960's, researchers in the area of artificial intelligence made wild predictions about computers emulating... and neuroscientists together to study the brain itself. In general, the artificial intelligence approach attempts to make computers exhibit "intelligent" behavior, without correlating This Thesis follows the style and format of Communications of rhe ACM...

Lo?pez, Roberto Eugenio

2012-06-07

92

Scientific Methods in Computer Science Gordana Dodig-Crnkovic  

E-print Network

Scientific Methods in Computer Science Gordana Dodig-Crnkovic Department of Computer Science M scientific aspects of Computer Science. First it defines science and scientific method in general. It gives a dis- cussion of relations between science, research, development and technology. The existing theory

Cunningham, Conrad

93

Computational Methods for Protein Identification from Mass Spectrometry Data  

Microsoft Academic Search

Protein identification using mass spectrometry is an indispensable computational tool in the life sciences. A dramatic increase in the use of proteomic strategies to understand the biology of living systems generates an ongoing need for more effective, efficient, and accurate computational methods for protein identification. A wide range of computational methods, each with various implementations, are available to complement different

Leo McHugh; Jonathan W. Arthur; Johanna McEntyre

2008-01-01

94

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

E-print Network

Enabling Public Auditability and Data Dynamics for Storage Security in Cloud Computing Qian Wang, IEEE, and Jin Li Abstract--Cloud Computing has been envisioned as the next-generation architecture the integrity of data storage in Cloud Computing. In particular, we consider the task of allowing a third party

Hou, Y. Thomas

95

Privacy-Preserving Public Auditing for Data Storage Security in Cloud Computing  

E-print Network

Privacy-Preserving Public Auditing for Data Storage Security in Cloud Computing Cong Wang, Qian large size of outsourced data makes the data integrity protection in Cloud Computing a very challenging efficient. I. INTRODUCTION Cloud Computing has been envisioned as the next- generation architecture

Hou, Y. Thomas

96

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

E-print Network

1 Enabling Public Auditability and Data Dynamics for Storage Security in Cloud Computing Qian Wang, IEEE, and Jin Li Abstract--Cloud Computing has been envisioned as the next-generation architecture the integrity of data storage in Cloud Computing. In particular, we consider the task of allowing a third party

Hou, Y. Thomas

97

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

98

Weaving Formal Methods into the Undergraduate Computer Science Curriculum  

E-print Network

alongside other mathematical, scienti c, and engineering methods already taught. Formal methods would simply. Just as we use simple mathematics in our daily life, computer scientists would use formal methods of having computer scientists use formal methods without their even realizing it. 1 Philosophy Ratherthan

Wing, Jeannette M.

99

Computational structural mechanics methods research using an evolving framework  

NASA Technical Reports Server (NTRS)

Advanced structural analysis and computational methods that exploit high-performance computers are being developed in a computational structural mechanics research activity sponsored by the NASA Langley Research Center. These new methods are developed in an evolving framework and applied to representative complex structural analysis problems from the aerospace industry. An overview of the methods development environment is presented, and methods research areas are described. Selected application studies are also summarized.

Knight, N. F., Jr.; Lotts, C. G.; Gillian, R. E.

1990-01-01

100

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

101

Computational methods in sequence and structure prediction  

NASA Astrophysics Data System (ADS)

This dissertation is organized into two parts. In the first part, we will discuss three computational methods for cis-regulatory element recognition in three different gene regulatory networks as the following: (a) Using a comprehensive "Phylogenetic Footprinting Comparison" method, we will investigate the promoter sequence structures of three enzymes (PAL, CHS and DFR) that catalyze sequential steps in the pathway from phenylalanine to anthocyanins in plants. Our result shows there exists a putative cis-regulatory element "AC(C/G)TAC(C)" in the upstream of these enzyme genes. We propose this cis-regulatory element to be responsible for the genetic regulation of these three enzymes and this element, might also be the binding site for MYB class transcription factor PAP1. (b) We will investigate the role of the Arabidopsis gene glutamate receptor 1.1 (AtGLR1.1) in C and N metabolism by utilizing the microarray data we obtained from AtGLR1.1 deficient lines (antiAtGLR1.1). We focus our investigation on the putatively co-regulated transcript profile of 876 genes we have collected in antiAtGLR1.1 lines. By (a) scanning the occurrence of several groups of known abscisic acid (ABA) related cisregulatory elements in the upstream regions of 876 Arabidopsis genes; and (b) exhaustive scanning of all possible 6-10 bps motif occurrence in the upstream regions of the same set of genes, we are able to make a quantative estimation on the enrichment level of each of the cis-regulatory element candidates. We finally conclude that one specific cis-regulatory element group, called "ABRE" elements, are statistically highly enriched within the 876-gene group as compared to their occurrence within the genome. (c) We will introduce a new general purpose algorithm, called "fuzzy REDUCE1", which we have developed recently for automated cis-regulatory element identification. In the second part, we will discuss our newly devised protein design framework. With this framework we have developed a software package which is capable of designing novel protein structures at the atomic resolution. This software package allows us to perform protein structure design with a flexible backbone. The backbone flexibility includes loop region relaxation as well as a secondary structure collective mode relaxation scheme. (Abstract shortened by UMI.)

Lang, Caiyi

102

User-based CPU Verification Scheme for Public Cloud Computing  

E-print Network

scheme is proposed for cloud cheating detection. In this scheme, a predefined computational task is constructed for the cloud to execute in our cheating detection process. Then we compare the difference the cloud is cheating or not. A time-lock puzzle is introduced to construct the predefined computational

Wu, Jie

103

Wing analysis using a transonic potential flow computational method  

NASA Technical Reports Server (NTRS)

The ability of the method to compute wing transonic performance was determined by comparing computed results with both experimental data and results computed by other theoretical procedures. Both pressure distributions and aerodynamic forces were evaluated. Comparisons indicated that the method is a significant improvement in transonic wing analysis capability. In particular, the computational method generally calculated the correct development of three-dimensional pressure distributions from subcritical to transonic conditions. Complicated, multiple shocked flows observed experimentally were reproduced computationally. The ability to identify the effects of design modifications was demonstrated both in terms of pressure distributions and shock drag characteristics.

Henne, P. A.; Hicks, R. M.

1978-01-01

104

Method of performing computational aeroelastic analyses  

NASA Technical Reports Server (NTRS)

Computational aeroelastic analyses typically use a mathematical model for the structural modes of a flexible structure and a nonlinear aerodynamic model that can generate a plurality of unsteady aerodynamic responses based on the structural modes for conditions defining an aerodynamic condition of the flexible structure. In the present invention, a linear state-space model is generated using a single execution of the nonlinear aerodynamic model for all of the structural modes where a family of orthogonal functions is used as the inputs. Then, static and dynamic aeroelastic solutions are generated using computational interaction between the mathematical model and the linear state-space model for a plurality of periodic points in time.

Silva, Walter A. (Inventor)

2011-01-01

105

Atomistic Method Applied to Computational Modeling of Surface Alloys  

NASA Technical Reports Server (NTRS)

The formation of surface alloys is a growing research field that, in terms of the surface structure of multicomponent systems, defines the frontier both for experimental and theoretical techniques. Because of the impact that the formation of surface alloys has on surface properties, researchers need reliable methods to predict new surface alloys and to help interpret unknown structures. The structure of surface alloys and when, and even if, they form are largely unpredictable from the known properties of the participating elements. No unified theory or model to date can infer surface alloy structures from the constituents properties or their bulk alloy characteristics. In spite of these severe limitations, a growing catalogue of such systems has been developed during the last decade, and only recently are global theories being advanced to fully understand the phenomenon. None of the methods used in other areas of surface science can properly model even the already known cases. Aware of these limitations, the Computational Materials Group at the NASA Glenn Research Center at Lewis Field has developed a useful, computationally economical, and physically sound methodology to enable the systematic study of surface alloy formation in metals. This tool has been tested successfully on several known systems for which hard experimental evidence exists and has been used to predict ternary surface alloy formation (results to be published: Garces, J.E.; Bozzolo, G.; and Mosca, H.: Atomistic Modeling of Pd/Cu(100) Surface Alloy Formation. Surf. Sci., 2000 (in press); Mosca, H.; Garces J.E.; and Bozzolo, G.: Surface Ternary Alloys of (Cu,Au)/Ni(110). (Accepted for publication in Surf. Sci., 2000.); and Garces, J.E.; Bozzolo, G.; Mosca, H.; and Abel, P.: A New Approach for Atomistic Modeling of Pd/Cu(110) Surface Alloy Formation. (Submitted to Appl. Surf. Sci.)). Ternary alloy formation is a field yet to be fully explored experimentally. The computational tool, which is based on the BFS (Bozzolo, Ferrante, and Smith) method for the calculation of the energetics, consists of a small number of simple PCbased computer codes that deal with the different aspects of surface alloy formation. Two analysis modes are available within this package. The first mode provides an atom-by-atom description of real and virtual stages 1. during the process of surface alloying, based on the construction of catalogues of configurations where each configuration describes one possible atomic distribution. BFS analysis of this catalogue provides information on accessible states, possible ordering patterns, and details of island formation or film growth. More importantly, it provides insight into the evolution of the system. Software developed by the Computational Materials Group allows for the study of an arbitrary number of elements forming surface alloys, including an arbitrary number of surface atomic layers. The second mode involves large-scale temperature-dependent computer 2. simulations that use the BFS method for the energetics and provide information on the dynamic processes during surface alloying. These simulations require the implementation of Monte-Carlo-based codes with high efficiency within current workstation environments. This methodology capitalizes on the advantages of the BFS method: there are no restrictions on the number or type of elements or on the type of crystallographic structure considered. This removes any restrictions in the definition of the configuration catalogues used in the analytical calculations, thus allowing for the study of arbitrary ordering patterns, ultimately leading to the actual surface alloy structure. Moreover, the Monte Carlo numerical technique used for the large-scale simulations allows for a detailed visualization of the simulated process, the main advantage of this type of analysis being the ability to understand the underlying features that drive these processes. Because of the simplicity of the BFS method for e energetics used in these calculations, a detailed atom-by-atom analysis can be performed at any

Bozzolo, Guillermo H.; Abel, Phillip B.

2000-01-01

106

Aircraft Engine Gas Path Diagnostic Methods: Public Benchmarking Results  

NASA Technical Reports Server (NTRS)

Recent technology reviews have identified the need for objective assessments of aircraft engine health management (EHM) technologies. To help address this issue, a gas path diagnostic benchmark problem has been created and made publicly available. This software tool, referred to as the Propulsion Diagnostic Method Evaluation Strategy (ProDiMES), has been constructed based on feedback provided by the aircraft EHM community. It provides a standard benchmark problem enabling users to develop, evaluate and compare diagnostic methods. This paper will present an overview of ProDiMES along with a description of four gas path diagnostic methods developed and applied to the problem. These methods, which include analytical and empirical diagnostic techniques, will be described and associated blind-test-case metric results will be presented and compared. Lessons learned along with recommendations for improving the public benchmarking processes will also be presented and discussed.

Simon, Donald L.; Borguet, Sebastien; Leonard, Olivier; Zhang, Xiaodong (Frank)

2013-01-01

107

Workplace Ergonomics Reference Guide 2nd Edition: A Publication of the Computer/Electronic Accommodations Program.  

National Technical Information Service (NTIS)

This is a publication of the Computer/Electronic Accommodations Program (CAP) Work Life Wellness Program. This guide provides illustrations of proper workstation ergonomics and a checklist for implementation of these strategies as well as tips for prevent...

2013-01-01

108

Computer-Aided Dispatch System as a Decision Making Tool in Public and Private Sectors  

E-print Network

We describe in detail seven distinct areas in both public and private sectors in which a real-time computer-aided dispatch system is applicable to the allocation of scarce resources. Characteristics of a real-time ...

Lee, I-Jen

109

Analytic and simulation methods in computer network design*  

E-print Network

Analytic and simulation methods in computer network design* by LEONARD KLEINROCK University of California Los Angeles, California INTRODUCTION 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

Kleinrock, Leonard

110

Computational Anatomy, Object Matching, and the Level Set Method  

E-print Network

Computational Anatomy, Object Matching, and the Level Set Method Wei-Hsun Liao1, Luminita Vese2 matching in computational anatomy. We present a new framework for warping pairs of overlapping and non and the infinite dimensional group actions is discussed. 1 Introduction Computational anatomy [1, 2] is an emerging

Soatto, Stefano

111

The LATIN multiscale computational method and the Proper Generalized Decomposition  

E-print Network

, parallel computing, homogenization 1. Introduction Today, in structural mechanics, there is a growing- fore, one of today's main challenges is to derive computational strategies capable of solving in "Computer Methods in Applied Mechanics and Engineering 199, 21-22 (2009) 1287-1296" DOI : 10.1016/j.cma.2009

Paris-Sud XI, Université de

112

COMPUTATIONAL METHODS FOR PREDICTING TRANSMEMBRANE ALPHA HELICES  

E-print Network

: COMPUTATIONAL MOLECULAR BIOLOGY FINAL PROJECT DECEMBER 6TH , 2002 #12;Introduction: Protein crystal structures. Their importance is illustrated by the high occurrence of journal articles publishing protein structures in highly respected journals such as Science and Nature. While the number of known protein crystal structures has

113

COMPUTER MODELS AND METHODS FOR A DISABLED ACCESS ANALYSIS DESIGN ENVIRONMENT  

E-print Network

COMPUTER MODELS AND METHODS FOR A DISABLED ACCESS ANALYSIS DESIGN ENVIRONMENT A DISSERTATION access analysis tools to test the usability of a facility. Among the usability constraints, building code of minimum standards to safeguard life or limb, health, property and public welfare. The statements

Stanford University

114

Studies on the zeros of Bessel functions and methods for their computation  

NASA Astrophysics Data System (ADS)

The zeros of Bessel functions play an important role in computational mathematics, mathematical physics, and other areas of natural sciences. Studies addressing these zeros (their properties, computational methods) can be found in various sources. This paper offers a detailed overview of the results concerning the real zeros of the Bessel functions of the first and second kinds and general cylinder functions. The author intends to publish several overviews on this subject. In this first publication, works dealing with real zeros are analyzed. Primary emphasis is placed on classical results, which are still important. Some of the most recent publications are also discussed.

Kerimov, M. K.

2014-09-01

115

Computing methods in applied sciences and engineering. VII  

SciTech Connect

The design of computers with fast memories, capable of up to one billion floating point operations per second, is important for the attempts being made to solve problems in Scientific Computing. The role of numerical algorithm designers is important due to the architectures and programming necessary to utilize the full potential of these machines. Efficient use of such computers requires sophisticated programming tools, and in the case of parallel computers algorithmic concepts have to be introduced. These new methods and concepts are presented.

Glowinski, R.; Lions, J.L.

1986-01-01

116

Laser imaging method using computational holography  

Microsoft Academic Search

To form a laser image, there usually are two kinds of image forming methods. One is to direct slender laser beams to special points by light directing element (LDE). The other one is light blocking method where amplitude spatial light modulator (SLM) used to form laser image. The former method has high light efficiency for none light is blocked, however

Tao Wang; Yingjie Yu; Huadong Zheng

2010-01-01

117

Computer Technology Standards of Learning for Virginia's Public Schools  

ERIC Educational Resources Information Center

The Computer/Technology Standards of Learning identify and define the progressive development of essential knowledge and skills necessary for students to access, evaluate, use, and create information using technology. They provide a framework for technology literacy and demonstrate a progression from physical manipulation skills for the use of…

Virginia Department of Education, 2005

2005-01-01

118

Lecture Notes in Computer Science 7058 Commenced Publication in 1973  

E-print Network

, Switzerland C. Pandu Rangan Indian Institute of Technology, Madras, India Bernhard Steffen TU Dortmund the hiatus theoreticus, and as a means to bring technology and medicine closer together. While some aspects and computers is of increasing importance in medicine and healthcare. The daily actions of medical professionals

Hammerton, James

119

Soft Computing Methods in Design of Superalloys  

NASA Technical Reports Server (NTRS)

Soft computing techniques of neural networks and genetic algorithms are used in the design of superalloys. The cyclic oxidation attack parameter K(sub a), generated from tests at NASA Lewis Research Center, is modelled as a function of the superalloy chemistry and test temperature using a neural network. This model is then used in conjunction with a genetic algorithm to obtain an optimized superalloy composition resulting in low K(sub a) values.

Cios, K. J.; Berke, L.; Vary, A.; Sharma, S.

1996-01-01

120

Soft computing methods in design of superalloys  

NASA Technical Reports Server (NTRS)

Soft computing techniques of neural networks and genetic algorithms are used in the design of superalloys. The cyclic oxidation attack parameter K(sub a), generated from tests at NASA Lewis Research Center, is modeled as a function of the superalloy chemistry and test temperature using a neural network. This model is then used in conjunction with a genetic algorithm to obtain an optimized superalloy composition resulting in low K(sub a) values.

Cios, K. J.; Berke, L.; Vary, A.; Sharma, S.

1995-01-01

121

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

122

Computational methods for physical mapping of chromosomes  

SciTech Connect

A standard technique for mapping a chromosome is to randomly select pieces, to use restriction enzymes to cut these pieces into fragments, and then to use the fragments for estimating the probability of overlap of these pieces. Typically, the order of the fragments within a piece is not determined, and the observed fragment data from each pair of pieces must be permuted N1 {times} N2 ways to evaluate the probability of overlap, N1 and N2 being the observed number of fragments in the two selected pieces. We will describe computational approaches used to substantially reduce the computational complexity of the calculation of overlap probability from fragment data. Presently, about 10{sup {minus}4} CPU seconds on one processor of an IBM 3090 is required for calculation of overlap probability from the fragment data of two randomly selected pieces, with an average of ten fragments per piece. A parallel version has been written using IBM clustered FORTRAN. Parallel measurements for 1, 6, and 12 processors will be presented. This approach has proven promising in the mapping of chromosome 16 at Los Alamos National Laboratory. We will also describe other computational challenges presented by physical mapping. 4 refs., 4 figs., 1 tab.

Torney, D.C.; Schenk, K.R. (Los Alamos National Lab., NM (USA)); Whittaker, C.C. (International Business Machines Corp., Albuquerque, NM (USA) Los Alamos National Lab., NM (USA)); White, S.W. (International Business Machines Corp., Kingston, NY (USA))

1990-01-01

123

Domain identification in impedance computed tomography by spline collocation method  

NASA Technical Reports Server (NTRS)

A method for estimating an unknown domain in elliptic boundary value problems is considered. The problem is formulated as an inverse problem of integral equations of the second kind. A computational method is developed using a splice collocation scheme. The results can be applied to the inverse problem of impedance computed tomography (ICT) for image reconstruction.

Kojima, Fumio

1990-01-01

124

Overview of computational structural methods for modern military aircraft  

NASA Technical Reports Server (NTRS)

Computational structural methods are essential for designing modern military aircraft. This briefing deals with computational structural methods (CSM) currently used. First a brief summary of modern day aircraft structural design procedures is presented. Following this, several ongoing CSM related projects at Northrop are discussed. Finally, shortcomings in this area, future requirements, and summary remarks are given.

Kudva, J. N.

1992-01-01

125

Computational study and comparisons of LFT reducibility methods  

Microsoft Academic Search

A set of computationally tractable model reduction algorithms are described which may be used to determine minimal realization dimensions for uncertain systems represented by linear fractional transformations on structured uncertainty sets; these computational tools are also applicable to multi-dimensional systems. The methods described utilize linear matrix inequality methods, in addition to straightforward coordinate transformations and truncations. These algorithms are evaluated

Carolyn Beck; R. D'Andrea

1998-01-01

126

Methodology for successful undergraduate recruiting in computer science at comprehensive public universities  

Microsoft Academic Search

This paper presents a methodology for increasing undergraduate Computer Science (CS) major enrollment at comprehensive public universities, particularly those that have first generation college students or students from underrepresented populations in professional computer science in the United States. While there has been significant prior discussion of undergraduate recruiting to increase major enrollment in CS, this is the first identification of

Patricia Morreale; Stan Kurkovsky; George Chang

2009-01-01

127

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.

128

Computer Literacy in Public Education: Implications for Libraries and Librarians/Media Specialists.  

ERIC Educational Resources Information Center

In order to study the concept of computer literacy and its implications for education, a review was made of the relevant professional, trade, and technical literature, with emphasis on information printed from 1978 to the present which highlights the development, growth, and present status of computer literacy in public schools. Recent…

Geib, Jerry H. E.

129

36 CFR 1254.32 - What rules apply to public access use of the Internet on NARA-supplied computers?  

Code of Federal Regulations, 2012 CFR

...access use of the Internet on NARA-supplied computers? 1254.32 Section 1254.32 Parks...access use of the Internet on NARA-supplied computers? (a) Public access computers (workstations) are available for...

2012-07-01

130

36 CFR 1254.32 - What rules apply to public access use of the Internet on NARA-supplied computers?  

Code of Federal Regulations, 2010 CFR

...access use of the Internet on NARA-supplied computers? 1254.32 Section 1254.32 Parks...access use of the Internet on NARA-supplied computers? (a) Public access computers (workstations) are available for...

2010-07-01

131

36 CFR 1254.32 - What rules apply to public access use of the Internet on NARA-supplied computers?  

Code of Federal Regulations, 2013 CFR

...access use of the Internet on NARA-supplied computers? 1254.32 Section 1254.32 Parks...access use of the Internet on NARA-supplied computers? (a) Public access computers (workstations) are available for...

2013-07-01

132

36 CFR 1254.32 - What rules apply to public access use of the Internet on NARA-supplied computers?  

Code of Federal Regulations, 2011 CFR

...access use of the Internet on NARA-supplied computers? 1254.32 Section 1254.32 Parks...access use of the Internet on NARA-supplied computers? (a) Public access computers (workstations) are available for...

2011-07-01

133

36 CFR 1254.32 - What rules apply to public access use of the Internet on NARA-supplied computers?  

...access use of the Internet on NARA-supplied computers? 1254.32 Section 1254.32 Parks...access use of the Internet on NARA-supplied computers? (a) Public access computers (workstations) are available for...

2014-07-01

134

Machine Vision Methods in Computer Games  

Microsoft Academic Search

This paper surveys machine vision and image processing methods that can be used in games and also shows how machine vi- sion applications may beneflt from the graphics hardware developed for game applications. By observing image space rendering algorithms, we come to the conclusion that image processing and rendering methods require similar algorithms and hardware support.

Laszlo Szirmay-Kalos; BME IIT

135

An experimental unification of reservoir computing methods.  

PubMed

Three different uses of a recurrent neural network (RNN) as a reservoir that is not trained but instead read out by a simple external classification layer have been described in the literature: Liquid State Machines (LSMs), Echo State Networks (ESNs) and the Backpropagation Decorrelation (BPDC) learning rule. Individual descriptions of these techniques exist, but a overview is still lacking. Here, we present a series of experimental results that compares all three implementations, and draw conclusions about the relation between a broad range of reservoir parameters and network dynamics, memory, node complexity and performance on a variety of benchmark tests with different characteristics. Next, we introduce a new measure for the reservoir dynamics based on Lyapunov exponents. Unlike previous measures in the literature, this measure is dependent on the dynamics of the reservoir in response to the inputs, and in the cases we tried, it indicates an optimal value for the global scaling of the weight matrix, irrespective of the standard measures. We also describe the Reservoir Computing Toolbox that was used for these experiments, which implements all the types of Reservoir Computing and allows the easy simulation of a wide range of reservoir topologies for a number of benchmarks. PMID:17517492

Verstraeten, D; Schrauwen, B; D'Haene, M; Stroobandt, D

2007-04-01

136

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

137

Public health surveillance: historical origins, methods and evaluation.  

PubMed Central

In the last three decades, disease surveillance has grown into a complete discipline, quite distinct from epidemiology. This expansion into a separate scientific area within public health has not been accompanied by parallel growth in the literature about its principles and methods. The development of the fundamental concepts of surveillance systems provides a basis on which to build a better understanding of the subject. In addition, the concepts have practical value as they can be used in designing new systems as well as understanding or evaluating currently operating systems. This article reviews the principles of surveillance, beginning with a historical survey of the roots and evolution of surveillance, and discusses the goals of public health surveillance. Methods for data collection, data analysis, interpretation, and dissemination are presented, together with proposed procedures for evaluating and improving a surveillance system. Finally, some points to be considered in establishing a new surveillance system are presented. PMID:8205649

Declich, S.; Carter, A. O.

1994-01-01

138

Lattice gas methods for computational aeroacoustics  

NASA Technical Reports Server (NTRS)

This paper presents the lattice gas solution to the category 1 problems of the ICASE/LaRC Workshop on Benchmark Problems in Computational Aeroacoustics. The first and second problems were solved for Delta t = Delta x = 1, and additionally the second problem was solved for Delta t = 1/4 and Delta x = 1/2. The results are striking: even for these large time and space grids the lattice gas numerical solutions are almost indistinguishable from the analytical solutions. A simple bug in the Mathematica code was found in the solutions submitted for comparison, and the comparison plots shown at the end of this volume show the bug. An Appendix to the present paper shows an example lattice gas solution with and without the bug.

Sparrow, Victor W.

1995-01-01

139

Computational Neuroimaging: Analysis methods W12-PSYCH-204B-01  

E-print Network

; Experimental design and analysis methods Advanced methods: High resolution fMRI. Multivoxel pattern analyses, fComputational Neuroimaging: Analysis methods W12-PSYCH-204B-01 Basic MR physics and BOLD signals focusing on understanding analysis methods for neuroimaging data using real and simulated data sets. Topics

Grill-Spector, Kalanit

140

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

141

Fast calculation method for spherical computer-generated holograms  

Microsoft Academic Search

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

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

2006-01-01

142

Numerical Geodynamics An introduction to computational methods  

E-print Network

Thorsten W. Becker Department of Earth Sciences University of Southern California Los Angeles CA, USA Boris J. P. Kaus Department of Earth Sciences ETH Z¨urich, Switzerland Editing and additions by Francois . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3 Introduction to Numerical Geodynamics 34 3.1 Numerical methods in the Earth Sciences

Becker, Thorsten W.

143

[The method and development of computer-assisted surgery].  

PubMed

The methodology and the state of the art of Computer-Assisted Surgery (CAS) are introduced in this paper. Computer-assisted surgery is a new high technology which uses computer science, biomedical engineering, mechanism, mathematics, surgery, and so on. Its objective is to help surgeons use multimodal data, such as CT, MRI, DSA, PET, et al. in a rational and quantitative way in order to plan and perform medical intervention. Stereotactic localization method and registration are two cruxes in computer-assisted surgery. There are several methods for localization and registration. In recent ten years, computer-assisted surgery has been a cynosure of scientists. Some computer-assisted surgery systems have been used in clinical practice. PMID:12548915

Fei, B; Zhuang, T

1998-06-01

144

Transonic Flow Computations Using Nonlinear Potential Methods  

NASA Technical Reports Server (NTRS)

This presentation describes the state of transonic flow simulation using nonlinear potential methods for external aerodynamic applications. The presentation begins with a review of the various potential equation forms (with emphasis on the full potential equation) and includes a discussion of pertinent mathematical characteristics and all derivation assumptions. Impact of the derivation assumptions on simulation accuracy, especially with respect to shock wave capture, is discussed. Key characteristics of all numerical algorithm types used for solving nonlinear potential equations, including steady, unsteady, space marching, and design methods, are described. Both spatial discretization and iteration scheme characteristics are examined. Numerical results for various aerodynamic applications are included throughout the presentation to highlight key discussion points. The presentation ends with concluding remarks and recommendations for future work. Overall. nonlinear potential solvers are efficient, highly developed and routinely used in the aerodynamic design environment for cruise conditions. Published by Elsevier Science Ltd. All rights reserved.

Holst, Terry L.; Kwak, Dochan (Technical Monitor)

2000-01-01

145

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

146

Checklist and Pollard Walk butterfly survey methods on public lands  

USGS Publications Warehouse

Checklist and Pollard Walk butterfly survey methods were contemporaneously applied to seven public sites in North Dakota during the summer of 1995. Results were compared for effect of method and site on total number of butterflies and total number of species detected per hour. Checklist searching produced significantly more butterfly detections per hour than Pollard Walks at all sites. Number of species detected per hour did not differ significantly either among sites or between methods. Many species were detected by only one method, and at most sites generalist and invader species were more likely to be observed during checklist searches than during Pollard Walks. Results indicate that checklist surveys are a more efficient means for initial determination of a species list for a site, whereas for long-term monitoring the Pollard Walk is more practical and statistically manageable. Pollard Walk transects are thus recommended once a prairie butterfly fauna has been defined for a site by checklist surveys.

Royer, R.A.; Austin, J.E.; Newton, W.E.

1998-01-01

147

Evolutionary Computational Methods for Identifying Emergent Behavior in Autonomous Systems  

NASA Technical Reports Server (NTRS)

A technique based on Evolutionary Computational Methods (ECMs) was developed that allows for the automated optimization of complex computationally modeled systems, such as autonomous systems. The primary technology, which enables the ECM to find optimal solutions in complex search spaces, derives from evolutionary algorithms such as the genetic algorithm and differential evolution. These methods are based on biological processes, particularly genetics, and define an iterative process that evolves parameter sets into an optimum. Evolutionary computation is a method that operates on a population of existing computational-based engineering models (or simulators) and competes them using biologically inspired genetic operators on large parallel cluster computers. The result is the ability to automatically find design optimizations and trades, and thereby greatly amplify the role of the system engineer.

Terrile, Richard J.; Guillaume, Alexandre

2011-01-01

148

Analytical and numerical methods; advanced computer concepts  

SciTech Connect

This past year, two projects have been completed and a new is under way. First, in joint work with R. Kohn, we developed a numerical algorithm to study the blowup of solutions to equations with certain similarity transformations. In the second project, the adaptive mesh refinement code of Berger and Colella for shock hydrodynamic calculations has been parallelized and numerical studies using two different shared memory machines have been done. My current effort is towards the development of Cartesian mesh methods to solve pdes with complicated geometries. Most of the coming year will be spent on this project, which is joint work with Prof. Randy Leveque at the University of Washington in Seattle.

Lax, P D

1991-03-01

149

Computational Methods in Quantum Field Theory  

E-print Network

After a brief introduction to the statistical description of data, these lecture notes focus on quantum field theories as they emerge from lattice models in the critical limit. For the simulation of these lattice models, Markov chain Monte-Carlo methods are widely used. We discuss the heat bath and, more modern, cluster algorithms. The Ising model is used as a concrete illustration of important concepts such as correspondence between a theory of branes and quantum field theory or the duality map between strong and weak couplings. The notes then discuss the inclusion of gauge symmetries in lattice models and, in particular, the continuum limit in which quantum Yang-Mills theories arise.

Kurt Langfeld

2007-11-19

150

Democratizing Computer Science Knowledge: Transforming the Face of Computer Science through Public High School Education  

ERIC Educational Resources Information Center

Despite the fact that computer science (CS) is the driver of technological innovations across all disciplines and aspects of our lives, including participatory media, high school CS too commonly fails to incorporate the perspectives and concerns of low-income students of color. This article describes a partnership program -- Exploring Computer

Ryoo, Jean J.; Margolis, Jane; Lee, Clifford H.; Sandoval, Cueponcaxochitl D. M.; Goode, Joanna

2013-01-01

151

Level Set and PDE Methods for Computer Graphics  

E-print Network

on Visualization and Computer Graphics, and Communications in Mathematical Sciences, and participatesLevel Set and PDE Methods for Computer Graphics Notes for SIGGRAPH 2004 Course #27 Los Angeles, CA August 10, 2004 Organizer David Breen Drexel University Speakers David Breen Drexel University Ron Fedkiw

152

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

153

Python for Education: Computational Methods for Nonlinear Systems  

E-print Network

We describe a novel, interdisciplinary, computational methods course that uses Python and associated numerical and visualization libraries to enable students to implement simulations for a number of different course modules. Problems in complex networks, biomechanics, pattern formation, and gene regulation are highlighted to illustrate the breadth and flexibility of Python-powered computational environments.

Christopher R. Myers; James. P. Sethna

2007-04-24

154

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

155

A Comparative Assessment of Computer Literacy of Private and Public Secondary School Students in Lagos State, Nigeria  

ERIC Educational Resources Information Center

The aim of this study was to conduct a comparative assessment of computer literacy of private and public secondary school students. Although the definition of computer literacy varies widely, this study treated computer literacy in terms of access to, and use of, computers and the internet, basic knowledge and skills required to use computers and…

Osunwusi, Adeyinka Olumuyiwa; Abifarin, Michael Segun

2013-01-01

156

IEEE TRANSACTIONS ON CLOUD COMPUTING, VOL. X, NO. X, XXXX 201X 1 Oruta: Privacy-Preserving Public Auditing  

E-print Network

IEEE TRANSACTIONS ON CLOUD COMPUTING, VOL. X, NO. X, XXXX 201X 1 Oruta: Privacy-Preserving Public--Public auditing, privacy-preserving, shared data, cloud computing. 1 INTRODUCTION CLOUD service providers offer verifiers. In this paper, we propose a novel privacy-preserving mechanism that supports public auditing

Li, Baochun

157

Computational Simulations and the Scientific Method  

NASA Technical Reports Server (NTRS)

As scientific simulation software becomes more complicated, the scientific-software implementor's need for component tests from new model developers becomes more crucial. The community's ability to follow the basic premise of the Scientific Method requires independently repeatable experiments, and model innovators are in the best position to create these test fixtures. Scientific software developers also need to quickly judge the value of the new model, i.e., its cost-to-benefit ratio in terms of gains provided by the new model and implementation risks such as cost, time, and quality. This paper asks two questions. The first is whether other scientific software developers would find published component tests useful, and the second is whether model innovators think publishing test fixtures is a feasible approach.

Kleb, Bil; Wood, Bill

2005-01-01

158

Computational Methods for Measuring the Difference of Empirical Distributions  

Microsoft Academic Search

This paper presents a simple computational method for measuring the difference of independent empirical distributions estimated by bootstrapping or other resampling approaches. Using data from a field test of external scope in contingent valuation, this complete combinatorial method is compared with other methods (empirical convolutions, repeated sampling, normality, nonoverlapping confidence intervals) that have been suggested in the literature. Tradeoffs between

Gregory L. Poe; Kelly L. Giraud; John B. Loomis

2005-01-01

159

Experience Papers Introducing Research Methods to Computer Science Honours  

E-print Network

Experience Papers Introducing Research Methods to Computer Science Honours Students Vashti Galpina research methods Honours course to increase our students' exposure to research and to help them cope better of the problems we encountered with the Honours research reports prior to the introduction of the research methods

Galpin, Vashti

160

MATH 131 COMPUTER LAB 2: NUMERICAL METHODS W. GARRETT MITCHENER  

E-print Network

MATH 131 COMPUTER LAB 2: NUMERICAL METHODS W. GARRETT MITCHENER Please type your report, but if you: September, 2004. 1 #12;2 W. GARRETT MITCHENER 3. Logistic Population with Periodic Harvesting (This part

Mitchener, W. Garrett

161

Computer method for identification of boiler transfer functions  

NASA Technical Reports Server (NTRS)

Iterative computer aided procedure was developed which provides for identification of boiler transfer functions using frequency response data. Method uses frequency response data to obtain satisfactory transfer function for both high and low vapor exit quality data.

Miles, J. H.

1972-01-01

162

Platform-independent method for computer aided schematic drawings  

DOEpatents

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

163

2.093 Computer Methods in Dynamics, Fall 2002  

E-print Network

Formulation of finite element methods for analysis of dynamic problems in solids, structures, fluid mechanics, and heat transfer. Computer calculation of matrices and numerical solution of equilibrium equations by direct ...

Bathe, Klaus-Jürgen

164

A memory based method for computing robot-arm configuration  

E-print Network

A MEMORY BASED METHOD FOR COMPUTING ROBOT-ARM CONFIGURATION A Thesis by SALEEM KARIMJEE Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1985... Major Subject: Mechanical Engineering A MEMORY BASED METHOD FOR COMPUTING ROBOT-ARM CONFIGURATION A Thesis by SALEEM KARIMJEE Approved as to style and content by: B jamin O'. Moo i (Chairman of Committee) Make McDermott (Member) , Norman C...

Karimjee, Saleem

2012-06-07

165

Method and computer program product for maintenance and modernization backlogging  

SciTech Connect

According to one embodiment, a computer program product for determining future facility conditions includes a computer readable medium having computer readable program code stored therein. The computer readable program code includes computer readable program code for calculating a time period specific maintenance cost, for calculating a time period specific modernization factor, and for calculating a time period specific backlog factor. Future facility conditions equal the time period specific maintenance cost plus the time period specific modernization factor plus the time period specific backlog factor. In another embodiment, a computer-implemented method for calculating future facility conditions includes calculating a time period specific maintenance cost, calculating a time period specific modernization factor, and calculating a time period specific backlog factor. Future facility conditions equal the time period specific maintenance cost plus the time period specific modernization factor plus the time period specific backlog factor. Other embodiments are also presented.

Mattimore, Bernard G; Reynolds, Paul E; Farrell, Jill M

2013-02-19

166

A New Characterization of Elfving's Method for High Dimensional Computation  

E-print Network

We give a new characterization of Elfving's (1952) method for computing c-optimal designs in k dimensions which gives explicit formulae for the k unknown optimal weights and k unknown signs in Elfving's characterization. This eliminates the need to search over these parameters to compute c-optimal designs, and thus reduces the computational burden from solving a family of optimization problems to solving a single optimization problem for the optimal finite support set. We give two illustrative examples: a high dimensional polynomial regression model and a logistic regression model, the latter showing that the method can be used for locally optimal designs in nonlinear models as well.

Bartroff, Jay

2011-01-01

167

Convergence acceleration of the Proteus computer code with multigrid methods  

NASA Technical Reports Server (NTRS)

Presented here is the first part of a study to implement convergence acceleration techniques based on the multigrid concept in the Proteus computer code. A review is given of previous studies on the implementation of multigrid methods in computer codes for compressible flow analysis. Also presented is a detailed stability analysis of upwind and central-difference based numerical schemes for solving the Euler and Navier-Stokes equations. Results are given of a convergence study of the Proteus code on computational grids of different sizes. The results presented here form the foundation for the implementation of multigrid methods in the Proteus code.

Demuren, A. O.; Ibraheem, S. O.

1992-01-01

168

Methods for operating parallel computing systems employing sequenced communications  

DOEpatents

A parallel computing system and method 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 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.

Benner, Robert E. (Albuquerque, NM); Gustafson, John L. (Albuquerque, NM); Montry, Gary R. (Albuquerque, NM)

1999-01-01

169

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

170

Computer Anti-forensics Methods and Their Impact on Computer Forensic Investigation  

Microsoft Academic Search

Electronic crime is very difficult to investigate and prosecute, mainly due to the fact that investigators have to build their\\u000a cases based on artefacts left on computer systems. Nowadays, computer criminals are aware of computer forensics methods and\\u000a techniques and try to use countermeasure techniques to efficiently impede the investigation processes. In many cases investigation\\u000a with such countermeasure techniques in

Przemyslaw Pajek; Elias Pimenidis

171

An efficient method for computation of the manipulator inertia matrix  

NASA Technical Reports Server (NTRS)

An efficient method of computation of the manipulator inertia matrix is presented. Using spatial notations, the method leads to the definition of the composite rigid-body spatial inertia, which is a spatial representation of the notion of augmented body. The previously proposed methods, the physical interpretations leading to their derivation, and their redundancies are analyzed. The proposed method achieves a greater efficiency by eliminating the redundancy in the intrinsic equations as well as by a better choice of coordinate frame for their projection. In this case, removing the redundancy leads to greater efficiency of the computation in both serial and parallel senses.

Fijany, Amir; Bejczy, Antal K.

1989-01-01

172

A computing method for spatial accessibility based on grid partition  

NASA Astrophysics Data System (ADS)

An accessibility computing method and process based on grid partition was put forward in the paper. As two important factors impacting on traffic, density of road network and relative spatial resistance for difference land use was integrated into computing traffic cost in each grid. A* algorithms was inducted to searching optimum traffic cost of grids path, a detailed searching process and definition of heuristic evaluation function was described in the paper. Therefore, the method can be implemented more simply and its data source is obtained more easily. Moreover, by changing heuristic searching information, more reasonable computing result can be obtained. For confirming our research, a software package was developed with C# language under ArcEngine9 environment. Applying the computing method, a case study on accessibility of business districts in Guangzhou city was carried out.

Ma, Linbing; Zhang, Xinchang

2007-06-01

173

Method for implementation of recursive hierarchical segmentation on parallel computers  

NASA Technical Reports Server (NTRS)

A method, computer readable storage, and apparatus for implementing a recursive hierarchical segmentation algorithm on a parallel computing platform. The method includes setting a bottom level of recursion that defines where a recursive division of an image into sections stops dividing, and setting an intermediate level of recursion where the recursive division changes from a parallel implementation into a serial implementation. The segmentation algorithm is implemented according to the set levels. The method can also include setting a convergence check level of recursion with which the first level of recursion communicates with when performing a convergence check.

Tilton, James C. (Inventor)

2005-01-01

174

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

175

Solution-adaptive finite element method in computational fracture mechanics  

NASA Technical Reports Server (NTRS)

Some recent results obtained using solution-adaptive finite element method in linear elastic two-dimensional fracture mechanics problems are presented. The focus is on the basic issue of adaptive finite element method for validating the applications of new methodology to fracture mechanics problems by computing demonstration problems and comparing the stress intensity factors to analytical results.

Min, J. B.; Bass, J. M.; Spradley, L. W.

1993-01-01

176

Comparison of Computational Learning Methods on a Diagnostic Cytological Application  

E-print Network

Comparison of Computational Learning Methods on a Diagnostic Cytological Application K. Koutroumbas methods on a problem of diagnostic cytology and more specifically on the classification of gastric cells. INTRODUCTION Cytology has been proved a powerful tool for the diagnosis of gastric lesions. In recent years

Paliouras, George

177

Artificial Intelligence Methods: Challenge in Computer Based Polymer Design  

NASA Astrophysics Data System (ADS)

This paper deals with the use of Artificial Intelligence Methods (AI) in the design of new molecules possessing desired physical, chemical and biological properties. This is an important and difficult problem in the chemical, material and pharmaceutical industries. Traditional methods involve a laborious and expensive trial-and-error procedure, but computer-assisted approaches offer many advantages in the automation of molecular design.

Rusu, Teodora; Pinteala, Mariana; Cartwright, Hugh

2009-08-01

178

Monte Carlo Methods: A Computational Pattern for Our Pattern Language  

E-print Network

Monte Carlo Methods: A Computational Pattern for Our Pattern Language Jike Chong University@eecs.berkeley.edu Kurt Keutzer University of California, Berkeley keutzer@eecs.berkeley.edu ABSTRACT The Monte Carlo for a particular data working set. This paper presents the Monte Carlo Methods software pro- gramming pattern

California at Berkeley, University of

179

Efficient Computation of Truncated Power Direct Approach versus Newton's Method  

E-print Network

(explicit) compu- tation. Keywords: Implicit functions; computation of Taylor polynomials; Newton-Raphson Figure 1: Graphical representation of the Newton-Raphson method starting at x0 2. Iterating or the Newton-Raphson method. It turns out that this scheme converges locally (i. e. if x0 is near enough

Koepf, Wolfram

180

Calculating PI Using Historical Methods and Your Personal Computer.  

ERIC Educational Resources Information Center

Provides a software program for determining PI to the 15th place after the decimal. Explores the history of determining the value of PI from Archimedes to present computer methods. Investigates Wallis's, Liebniz's, and Buffon's methods. Written for Tandy GW-BASIC (IBM compatible) with 384K. Suggestions for Apple II's are given. (MVL)

Mandell, Alan

1989-01-01

181

Computer-Simulation Methods in Human Linkage Analysis  

Microsoft Academic Search

In human linkage analysis, many statistical problems without analytical solution could be solved by ad hoc Monte Carlo procedures were efficient computer-simulation methods available for members of family pedigrees. In this paper, a general method is described for randomly generating genotypes at one or more marker loci, given observed phenotypes at loci linked among themselves and with the markers. The

Jurg Ott

1989-01-01

182

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

183

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

184

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

185

Negotiating knowledge contribution to multiple discourse communities: A doctoral student of computer science writing for publication  

Microsoft Academic Search

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 student's alternate forms of one paper, i.e., its Chinese version aimed at publication

Yongyan Li

2006-01-01

186

An Exploratory Study of Malaysian Publication Productivity in Computer Science and Information Technology.  

ERIC Educational Resources Information Center

Explores the Malaysian computer science and information technology publication productivity as indicated by data collected from three Web-based databases. Relates possible reasons for the amount and pattern of contributions to the size of researcher population, the availability of refereed scholarly journals, and the total expenditure allocated to…

Gu, Yinian

2002-01-01

187

DataSteward: Using Dedicated Compute Nodes for Scalable Data Management on Public Clouds  

E-print Network

DataSteward: Using Dedicated Compute Nodes for Scalable Data Management on Public Clouds Radu on clouds to build on their inherent elasticity and scalability. One of the critical needs in order to deal by cloud providers suffer from high latencies, trading performance for availability. One alternative

Paris-Sud XI, Université de

188

Publications Forrest M. Hoffman and William W. Hargrove. Cluster computing: Linux taken to *  

E-print Network

Publications Forrest M. Hoffman and William W. Hargrove. Cluster computing: Linux taken to * *the extreme. Linux Magazine, 1(1):56-59, 1999. Forrest M. Hoffman. Concepts in Beowulfery. Linux Magazine, 4(1):40-41, January* * 2002a. Forrest M. Hoffman. Configuring a Beowulf Cluster. Linux Magazine

Hoffman, Forrest M.

189

Publications Forrest M. Hoffman and William W. Hargrove. Cluster computing: Linux taken to the extreme. Linux  

E-print Network

Publications Forrest M. Hoffman and William W. Hargrove. Cluster computing: Linux taken to the extreme. Linux Magazine, 1(1):56­59, 1999. Forrest M. Hoffman. Concepts in Beowulfery. Linux Magazine, 4(1):40­41, January 2002a. Forrest M. Hoffman. Configuring a Beowulf Cluster. Linux Magazine, 4(2):42­45, February

Hoffman, Forrest M.

190

Publics in Practice: Ubiquitous Computing at a Shelter for Homeless Mothers  

E-print Network

Publics in Practice: Ubiquitous Computing at a Shelter for Homeless Mothers Christopher A. Le} @us.ibm.com ABSTRACT Today, commodity technologies like mobile phones--once symbols of status at a shelter for homeless mothers. Our system connects mobile phones, a shared display, and a Web application

Edwards, Keith

191

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

192

Under consideration for publication in Formal Aspects of Computing Verifying Anonymity in Voting  

E-print Network

Under consideration for publication in Formal Aspects of Computing Verifying Anonymity in Voting Abstract. We present formal definitions of anonymity for voting protocols using the process algebra CSP. We strong, whereas the weak anonymity definition is shown to be a suitable property for analysing voting

Doran, Simon J.

193

Methods and systems for providing reconfigurable and recoverable computing resources  

NASA Technical Reports Server (NTRS)

A method for optimizing the use of digital computing resources to achieve reliability and availability of the computing resources is disclosed. The method comprises providing one or more processors with a recovery mechanism, the one or more processors executing one or more applications. A determination is made whether the one or more processors needs to be reconfigured. A rapid recovery is employed to reconfigure the one or more processors when needed. A computing system that provides reconfigurable and recoverable computing resources is also disclosed. The system comprises one or more processors with a recovery mechanism, with the one or more processors configured to execute a first application, and an additional processor configured to execute a second application different than the first application. The additional processor is reconfigurable with rapid recovery such that the additional processor can execute the first application when one of the one more processors fails.

Stange, Kent (Inventor); Hess, Richard (Inventor); Kelley, Gerald B (Inventor); Rogers, Randy (Inventor)

2010-01-01

194

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

195

ILLICO; A nodal neutron diffusion method for modern computer architectures  

Microsoft Academic Search

A nodal multigroup neutron diffusion method for modern computer architectures has been developed and implemented in the ILLICO code. Vectorization and parallelization strategies that are successful in speeding up modern nodal computations on commercially available supercomputers have been identified and applied. Realistic three-dimensional benchmark problems can be solved in the vectorized mode in >0.73 s (33.86 Mflops). Vector-concurrent implementations are

H. L. Rajic; A. M. Ougouag

1989-01-01

196

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

197

A stochastic method for computing hadronic matrix elements  

We present a stochastic method for the calculation of baryon 3-point functions which is an alternative to the typically used sequential method offering more versatility. We analyze the scaling of the error of the stochastically evaluated 3-point function with the lattice volume and find a favorable signal to noise ratio suggesting that the stochastic method can be extended to large volumes providing an efficient approach to compute hadronic matrix elements and form factors.

Drach, Vincent [DESY, Zeuthen (Germany); Jansen, Karl [DESY, Zeuthen (Germany); Alexandrou, Constantia [University of Cyprus, Nicosia (Cyprus); Constantinou, Marth [University of Cyprus, Nicosia (Cyprus); Dinter, Simon [DESY, Zeuthen (Germany); Hadjiyiannakou, Kyriakos [University of Cyprus, Nicosia (Cyprus); Renner, Dru B. [JLAB, Newport News, VA (United States)

2014-01-01

198

Fully consistent CFD methods for incompressible flow computations  

NASA Astrophysics Data System (ADS)

Nowadays collocated grid based CFD methods are one of the most efficient tools for computations of the flows past wind turbines. To ensure the robustness of the methods they require special attention to the well-known problem of pressure-velocity coupling. Many commercial codes to ensure the pressure-velocity coupling on collocated grids use the so-called momentum interpolation method of Rhie and Chow [1]. As known, the method and some of its widely spread modifications result in solutions, which are dependent of time step at convergence. In this paper the magnitude of the dependence is shown to contribute about 0.5% into the total error in a typical turbulent flow computation. Nevertheless if coarse grids are used, the standard interpolation methods result in much higher non-consistent behavior. To overcome the problem, a recently developed interpolation method, which is independent of time step, is used. It is shown that in comparison to other time step independent method, the method may enhance the convergence rate of the SIMPLEC algorithm up to 25 %. The method is verified using turbulent flow computations around a NACA 64618 airfoil and the roll-up of a shear layer, which may appear in wind turbine wake.

Kolmogorov, D. K.; Shen, W. Z.; Sørensen, N. N.; Sørensen, J. N.

2014-06-01

199

SAR/QSAR methods in public health practice  

SciTech Connect

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.

Demchuk, Eugene, E-mail: edemchuk@cdc.gov; Ruiz, Patricia; Chou, Selene; Fowler, Bruce A.

2011-07-15

200

Determinant Computation on the GPU using the Condensation Method  

NASA Astrophysics Data System (ADS)

We report on a GPU implementation of the condensation method designed by Abdelmalek Salem and Kouachi Said for computing the determinant of a matrix. We consider two types of coefficients: modular integers and floating point numbers. We evaluate the performance of our code by measuring its effective bandwidth and argue that it is numerical stable in the floating point number case. In addition, we compare our code with serial implementation of determinant computation from well-known mathematical packages. Our results suggest that a GPU implementation of the condensation method has a large potential for improving those packages in terms of running time and numerical stability.

Anisul Haque, Sardar; Moreno Maza, Marc

2012-02-01

201

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

202

Computer controlled fluorometer device and method of operating same  

DOEpatents

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means. 13 figs.

Kolber, Z.; Falkowski, P.

1990-07-17

203

Computational Methods for Dynamic Stability and Control Derivatives  

NASA Technical Reports Server (NTRS)

Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.

Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.

2004-01-01

204

Computational Methods for Dynamic Stability and Control Derivatives  

NASA Technical Reports Server (NTRS)

Force and moment measurements from an F-16XL during forced pitch oscillation tests result in dynamic stability derivatives, which are measured in combinations. Initial computational simulations of the motions and combined derivatives are attempted via a low-order, time-dependent panel method computational fluid dynamics code. The code dynamics are shown to be highly questionable for this application and the chosen configuration. However, three methods to computationally separate such combined dynamic stability derivatives are proposed. One of the separation techniques is demonstrated on the measured forced pitch oscillation data. Extensions of the separation techniques to yawing and rolling motions are discussed. In addition, the possibility of considering the angles of attack and sideslip state vector elements as distributed quantities, rather than point quantities, is introduced.

Green, Lawrence L.; Spence, Angela M.; Murphy, Patrick C.

2003-01-01

205

Computer controlled fluorometer device and method of operating same  

DOEpatents

A computer controlled fluorometer device and method of operating same, said device being made to include a pump flash source and a probe flash source and one or more sample chambers in combination with a light condenser lens system and associated filters and reflectors and collimators, as well as signal conditioning and monitoring means and a programmable computer means and a software programmable source of background irradiance that is operable according to the method of the invention to rapidly, efficiently and accurately measure photosynthetic activity by precisely monitoring and recording changes in fluorescence yield produced by a controlled series of predetermined cycles of probe and pump flashes from the respective probe and pump sources that are controlled by the computer means.

Kolber, Zbigniew (Shoreham, NY); Falkowski, Paul (Stony Brook, NY)

1990-01-01

206

Computational Methods for CLIP-seq Data Processing  

PubMed Central

RNA-binding proteins (RBPs) are at the core of post-transcriptional regulation and thus of gene expression control at the RNA level. One of the principal challenges in the field of gene expression regulation is to understand RBPs mechanism of action. As a result of recent evolution of experimental techniques, it is now possible to obtain the RNA regions recognized by RBPs on a transcriptome-wide scale. In fact, CLIP-seq protocols use the joint action of CLIP, crosslinking immunoprecipitation, and high-throughput sequencing to recover the transcriptome-wide set of interaction regions for a particular protein. Nevertheless, computational methods are necessary to process CLIP-seq experimental data and are a key to advancement in the understanding of gene regulatory mechanisms. Considering the importance of computational methods in this area, we present a review of the current status of computational approaches used and proposed for CLIP-seq data. PMID:25336930

Reyes-Herrera, Paula H; Ficarra, Elisa

2014-01-01

207

PSD computations using Welch's method. [Power Spectral Density (PSD)  

SciTech Connect

This report describes Welch's method for computing Power Spectral Densities (PSDs). We first describe the bandpass filter method which uses filtering, squaring, and averaging operations to estimate a PSD. Second, we delineate the relationship of Welch's method to the bandpass filter method. Third, the frequency domain signal-to-noise ratio for a sine wave in white noise is derived. This derivation includes the computation of the noise floor due to quantization noise. The signal-to-noise ratio and noise flood depend on the FFT length and window. Fourth, the variance the Welch's PSD is discussed via chi-square random variables and degrees of freedom. This report contains many examples, figures and tables to illustrate the concepts. 26 refs.

Solomon, Jr, O M

1991-12-01

208

COMPUTATIONAL METHODS FOR LEAST SQUARES PROBLEMS AND CLINICAL TRIALS  

E-print Network

COMPUTATIONAL METHODS FOR LEAST SQUARES PROBLEMS AND CLINICAL TRIALS A DISSERTATION SUBMITTED (rather than estimating the sensitivity of the data). Clinical trials generate much incomplete data. In the second part of the thesis we study clinical trials with time-to-event endpoints, in which the most

Stanford University

209

On optimal control methods in computer vision and image processing  

Microsoft Academic Search

Abstract: In this paper, we discuss the employment of methods from optimal control for problemsin computer vision and image processing. The underlying principle will be that of dynamicprogramming and the associated Hamilton-Jacobi equation which allows a unied approachto tackle a number of dierent issues in vision. In particular, we will consider problemsconcerning shape theory, morphology, optical ow, nonlinear scale-spaces, and

B. Kimia; A. Tannenbaum; S. Zucker

1994-01-01

210

IE 496: Computational Methods in Optimization Dr. Ted Ralphs  

E-print Network

IE 496: Computational Methods in Optimization Syllabus Dr. Ted Ralphs Spring 2012 1 Miscellaneous Course Information Instructor: Dr. Ted Ralphs Office: 473 Mohler Lab Phone: 8-4784 E-mail: ted@lehigh.edu Office Hour: TR 11:00-12:00 or by appointment Web page: http://coral.ie.lehigh.edu/~ted Course web page

Ralphs, Ted

211

ISE 407: Computational Methods in Optimization Dr. Ted Ralphs  

E-print Network

ISE 407: Computational Methods in Optimization Syllabus Dr. Ted Ralphs Fall 2013 1 Miscellaneous Course Information Instructor: Dr. Ted Ralphs Office: 473 Mohler Lab Phone: 8-4784 E-mail: ted@lehigh.edu Office Hour: TR 11:00-12:00 or by appointment Web page: http://coral.ie.lehigh.edu/~ted Course web page

Ralphs, Ted

212

Computational methods for transcriptional regulation Eric D Siggia  

E-print Network

? Computational methods that fit incomplete noisy data provide the outlines of regulatory pathways, but the errors merely getting something right to not getting anything wrong. Success should be measured not by whether expression analysis [5]; the error in an experiment­ gene­probe triplet is a combination of three fitting

Siggia, Eric

213

Computational Methods for Learning Population History from Large Scale Genetic  

E-print Network

Computational Methods for Learning Population History from Large Scale Genetic Variation Datasets of Philosophy. Copyright 2013 Ming-Chi Tsai #12;Keywords: Population Genetics, Minimum Description Length is a fundamental question in population genetics with numerous implications for basic and applied research

Matsuda, Noboru

214

Computational methods for bird strike simulations: A review  

Microsoft Academic Search

Bird strikes are a major threat to aircraft structures, as a collision with a bird during flight can lead to serious structural damage. Computational methods have been used for more than 30 years for the bird-proof design of such structures, being an efficient tool compared to the expensive physical certification tests with real birds. At the velocities of interest, the

Sebastian Heimbs

2011-01-01

215

Applications of the Discrete Adjoint Method Computational Fluid Dynamics  

E-print Network

. In this thesis two applications of this method in the context of computational fluid dynamics are con- sidered the utility of the approach. The second application, in adaptive mesh design, allows efficient evaluation the automatic design of adaptive meshes. Special emphasis is given to problems with anisotropic solution

Jimack, Peter

216

Computational method for evaluating meteorites as sources of sonic boom  

E-print Network

Computational method for evaluating meteorites as sources of sonic boom M. Hennetona , P. Delormea- tinguished from natural sources of infrasounds such as meteorite atmospheric entries. With a view to investigate meteorites as an infrasound source, numerical simulations of Euler equations are performed around

Paris-Sud XI, Université de

217

Computational Methods for Semiclassical and Quantum Transport in Semiconductor Devices  

E-print Network

Computational Methods for Semiclassical and Quantum Transport in Semiconductor Devices Christian The progressive miniaturization of semiconductor devices, and the use of bulk materials other than silicon, necessitates the use of a wide variety of models in semiconductor device simulation. These include

Ringhofer, Christian

218

ICAS2002 CONGRESS COMPUTATIONAL AND ANALYTICAL METHODS IN  

E-print Network

ICAS2002 CONGRESS COMPUTATIONAL AND ANALYTICAL METHODS IN THE AIRCRAFT DESIGN CURRICULUM Vladimir V. Riabov Rivier College, Nashua, New Hampshire 03060, USA Keywords: aircraft design curriculum, design Aircraft Design classes with the University of New Hampshire and Worcester Polytechnic Institute [3

Riabov, Vladimir V.

219

12 CFR 227.25 - Unfair balance computation method.  

Code of Federal Regulations, 2010 CFR

12 ? Banks and Banking ? 3 ? 2010-01-01 ? 2010-01-01 ? false ? Unfair balance computation method. ? 227.25 ? Section 227.25 ? Banks and Banking ? FEDERAL RESERVE SYSTEM (CONTINUED) ? BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM ? UNFAIR OR DECEPTIVE ACTS OR PRACTICES (REGULATION AA) ?...

2010-01-01

220

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

221

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

222

Convergence acceleration of the Proteus computer code with multigrid methods  

NASA Technical Reports Server (NTRS)

This report presents the results of a study to implement convergence acceleration techniques based on the multigrid concept in the two-dimensional and three-dimensional versions of the Proteus computer code. The first section presents a review of the relevant literature on the implementation of the multigrid methods in computer codes for compressible flow analysis. The next two sections present detailed stability analysis of numerical schemes for solving the Euler and Navier-Stokes equations, based on conventional von Neumann analysis and the bi-grid analysis, respectively. The next section presents details of the computational method used in the Proteus computer code. Finally, the multigrid implementation and applications to several two-dimensional and three-dimensional test problems are presented. The results of the present study show that the multigrid method always leads to a reduction in the number of iterations (or time steps) required for convergence. However, there is an overhead associated with the use of multigrid acceleration. The overhead is higher in 2-D problems than in 3-D problems, thus overall multigrid savings in CPU time are in general better in the latter. Savings of about 40-50 percent are typical in 3-D problems, but they are about 20-30 percent in large 2-D problems. The present multigrid method is applicable to steady-state problems and is therefore ineffective in problems with inherently unstable solutions.

Demuren, A. O.; Ibraheem, S. O.

1995-01-01

223

Advanced Computing Initiative To Study Methods of Improving Fusion  

E-print Network

Advanced Computing Initiative To Study Methods of Improving Fusion July 10, 2014 Science motivation be ASCR). Motivation similar to previous FSP proposal ($25M/y), but smaller funding & more modular better than 1990 analytic turbulence theories Plot made in 1990. Analytic theories disagreed

224

A higher order iterative method for computing the Drazin inverse.  

PubMed

A method with high convergence rate for finding approximate inverses of nonsingular matrices is suggested and established analytically. An extension of the introduced computational scheme to general square matrices is defined. The extended method could be used for finding the Drazin inverse. The application of the scheme on large sparse test matrices alongside the use in preconditioning of linear system of equations will be presented to clarify the contribution of the paper. PMID:24222747

Soleymani, F; Stanimirovi?, Predrag S

2013-01-01

225

A new mixed finite element method for computing viscoelastic flows  

Microsoft Academic Search

A new mixed finite element method for computing viscoelastic flows is presented. The mixed formulation is based on the introduction of the rate of deformation tensor as an additional unknown. Contrary to the popular EVSS method [D. Rajagopalan, R.A. Brown and R.C. Armstrong, J. Non-Newtonian Fluid Mech., 36 (1990) 159], no change of variable is performed into the constitutive equation.

Robert Guénette; Michel Fortin

1995-01-01

226

Convergence of adaptive finite element methods in computational mechanics  

Microsoft Academic Search

The a priori convergence of finite element methods is based on the density property of the sequence of finite element spaces which essentially assumes a quasi-uniform mesh-refining. The advantage is guaranteed convergence for a large class of data and solutions; the disadvantage is a global mesh refinement everywhere accompanied by large computational costs.Adaptive finite element methods (AFEMs) automatically refine exclusively

Carsten Carstensen

2009-01-01

227

Analysis and optimization of cyclic methods in orbit computation  

NASA Technical Reports Server (NTRS)

The mathematical analysis and computation of the K=3, order 4; K=4, order 6; and K=5, order 7 cyclic methods and the K=5, order 6 Cowell method and some results of optimizing the 3 backpoint cyclic multistep methods for solving ordinary differential equations are presented. Cyclic methods have the advantage over traditional methods of having higher order for a given number of backpoints while at the same time having more free parameters. After considering several error sources the primary source for the cyclic methods has been isolated. The free parameters for three backpoint methods were used to minimize the effects of some of these error sources. They now yield more accuracy with the same computing time as Cowell's method on selected problems. This work is being extended to the five backpoint methods. The analysis and optimization are more difficult here since the matrices are larger and the dimension of the optimizing space is larger. Indications are that the primary error source can be reduced. This will still leave several parameters free to minimize other sources.

Pierce, S.

1973-01-01

228

Computation of cascade flutter by uncoupled and coupled methods  

NASA Astrophysics Data System (ADS)

A computational method for flutter prediction of turbomachinery cascades is presented. The flow through multiple blade passages is calculated using a time-domain approach with coupled aerodynamic and structural models. The unsteady Euler/Navier-Stokes equations are solved in quasi-three-dimensions using a second-order implicit scheme with dual time-stepping and a multigrid method. A structural model for the blades with bending and torsion degrees of freedom is integrated in time together with the flow field. Information between structural and aerodynamic models is exchanged until convergence in each real-time step. Computational results for a cascade are presented and compared with those obtained by the conventional energy method and with experimental and numerical data by other authors. Significant differences are found between the coupled and uncoupled methods at low mass ratios. A transonic test case with strong nonlinear phenomena is investigated with the fluid structure coupled method. Results for inviscid flow are compared with results of Navier-Stokes computations.

Sadeghi, Mani; Liu, Feng

2005-11-01

229

Consensus methods: review of original methods and their main alternatives used in public health  

PubMed Central

Summary Background Consensus-based studies are increasingly used as decision-making methods, for they have lower production cost than other methods (observation, experimentation, modelling) and provide results more rapidly. The objective of this paper is to describe the principles and methods of the four main methods, Delphi, nominal group, consensus development conference and RAND/UCLA, their use as it appears in peer-reviewed publications and validation studies published in the healthcare literature. Methods A bibliographic search was performed in Pubmed/MEDLINE, Banque de Données Santé Publique (BDSP), The Cochrane Library, Pascal and Francis. Keywords, headings and qualifiers corresponding to a list of terms and expressions related to the consensus methods were searched in the thesauri, and used in the literature search. A search with the same terms and expressions was performed on Internet using the website Google Scholar. Results All methods, precisely described in the literature, are based on common basic principles such as definition of subject, selection of experts, and direct or remote interaction processes. They sometimes use quantitative assessment for ranking items. Numerous variants of these methods have been described. Few validation studies have been implemented. Not implementing these basic principles and failing to describe the methods used to reach the consensus were both frequent reasons contributing to raise suspicion regarding the validity of consensus methods. Conclusion When it is applied to a new domain with important consequences in terms of decision making, a consensus method should be first validated. PMID:19013039

Bourrée, Fanny; Michel, Philippe; Salmi, Louis Rachid

2008-01-01

230

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

231

Computer-aided methods of determining thyristor thermal transients  

SciTech Connect

An accurate tracing of the thyristor thermal response is investigated. This paper offers several alternatives for thermal modeling and analysis by using an electrical circuit analog: topological method, convolution integral method, etc. These methods are adaptable to numerical solutions and well suited to the use of the digital computer. The thermal analysis of thyristors was performed for the 1000 MVA converter system at the Princeton Plasma Physics Laboratory. Transient thermal impedance curves for individual thyristors in a given cooling arrangement were known from measurements and from manufacturer's data. The analysis pertains to almost any loading case, and the results are obtained in a numerical or a graphical format. 6 refs., 9 figs.

Lu, E.; Bronner, G.

1988-08-01

232

Accepted for publication at the Human Computer Interaction International 2009 Annual Conference. July 19-24, San Diego, CA  

E-print Network

Accepted for publication at the Human Computer Interaction International 2009 Annual Conference. July 19-24, San Diego, CA A Computational Implementation of a Human Attention Guiding Mechanism of a physical anthropometric character, to a computational cognitive structure that represents human

233

Alternate Methods of Measuring Public Radio Audiences: A Pilot Project.  

ERIC Educational Resources Information Center

A pilot project was undertaken to explore ways to profile public radio audiences inexpensively and simply. The major effort was through use of the station's monthly programing guide mailing list. Persons found in this list were interviewed and their listening habits compared with a general survey (baseline) group. The survey showed that public

Williams, Wenmouth, Jr.; LeRoy, David J.

234

Fast calculation method for computer-generated cylindrical holograms.  

PubMed

Since a general flat hologram has a limited viewable area, we usually cannot see the other side of a reconstructed object. There are some holograms that can solve this problem. A cylindrical hologram is well known to be viewable in 360 deg. Most cylindrical holograms are optical holograms, but there are few reports of computer-generated cylindrical holograms. The lack of computer-generated cylindrical holograms is because the spatial resolution of output devices is not great enough; therefore, we have to make a large hologram or use a small object to fulfill the sampling theorem. In addition, in calculating the large fringe, the calculation amount increases in proportion to the hologram size. Therefore, we propose what we believe to be a new calculation method for fast calculation. Then, we print these fringes with our prototype fringe printer. As a result, we obtain a good reconstructed image from a computer-generated cylindrical hologram. PMID:18594581

Yamaguchi, Takeshi; Fujii, Tomohiko; Yoshikawa, Hiroshi

2008-07-01

235

Approximate Quantum Mechanical Methods for Rate Computation in Complex Systems  

NASA Astrophysics Data System (ADS)

The last 20 years have seen qualitative leaps in the complexity of chemical reactions that have been studied using theoretical methods. While methodologies for small molecule scattering are still of great importance and under active development [1], two important trends have allowed the theoretical study of the rates of reaction in complex molecules, condensed phase systems, and biological systems. First, there has been the explicit recognition that the type of state to state information obtained by rigorous scattering theory is not only not possible for complex systems, but more importantly, not meaningful. Thus, methodologies have been developed that compute averaged rate data directly from a Hamiltonian. Perhaps the most influential of these approaches has been the correlation function formalisms developed by Bill Miller et al. [2]. While these formal expressions for rate theories are certainly not the only correlation function descriptions of quantum rates [3, 4], these expressions of rates directly in terms of evolution operators, and in their coordinate space representations as Feynman Propagators, have lent themselves beautifully to complex systems because many of the approximation methods that have been devised are for Feynman propagator computation. This fact brings us to the second contributor to the blossoming of these approximate methods, the development of a wide variety of approximate mathematical methods to compute the time evolution of quantum systems. Thus the marriage of these mathematical developments has created the necessary powerful tools needed to probe systems of complexity unimagined just a few decades ago.

Schwartz, Steven D.

236

Domain decomposition methods for the parallel computation of reacting flows  

NASA Technical Reports Server (NTRS)

Domain decomposition is a natural route to parallel computing for partial differential equation solvers. Subdomains of which the original domain of definition is comprised are assigned to independent processors at the price of periodic coordination between processors to compute global parameters and maintain the requisite degree of continuity of the solution at the subdomain interfaces. In the domain-decomposed solution of steady multidimensional systems of PDEs by finite difference methods using a pseudo-transient version of Newton iteration, the only portion of the computation which generally stands in the way of efficient parallelization is the solution of the large, sparse linear systems arising at each Newton step. For some Jacobian matrices drawn from an actual two-dimensional reacting flow problem, comparisons are made between relaxation-based linear solvers and also preconditioned iterative methods of Conjugate Gradient and Chebyshev type, focusing attention on both iteration count and global inner product count. The generalized minimum residual method with block-ILU preconditioning is judged the best serial method among those considered, and parallel numerical experiments on the Encore Multimax demonstrate for it approximately 10-fold speedup on 16 processors.

Keyes, David E.

1988-01-01

237

Design and Analysis of Computational Methods for Structural Acoustics  

NASA Astrophysics Data System (ADS)

The application of finite element methods to problems in structural acoustics (the vibration of an elastic structure coupled to an acoustic medium) is considered. New methods are developed which yield dramatic improvement in accuracy over the standard Galerkin finite element approach. The goal of the new methods is to decrease the computational burden required to achieve a desired accuracy level at a particular frequency thereby enabling larger scale, higher frequency computations for a given platform. A new class of finite element methods, Galerkin Generalized Least-Squares (GGLS) methods, are developed and applied to model the in vacuo and fluid-loaded vibration response of Reissner-Mindlin plates. Through judicious selection of the design parameters inherent to GGLS methods, this formulation provides a consistent framework for enhancing the accuracy of finite elements. An optimal GGLS method is designed such that the complex wave-number finite element dispersion relations are identical to the analytic relations. Complex wave-number dispersion analysis and numerical experiments demonstrate the dramatic superiority of the new optimal method over the standard finite element approach for coupled and uncoupled plate vibrations. The new method provides for a dramatic decrease in discretization requirements over previous methods. The canonical problem of a baffled, fluid-loaded, finite cylindrical shell is also studied. The finite element formulation for this problem is developed and the results are compared to an analytic solution based on an expansion of the displacement using in vacuo mode shapes. A novel high resolution parameter estimation technique, based on Prony's method, is used to obtain the complex wave-number dispersion relations for the finite structure. The finite element dispersion relations enable the analyst to pinpoint the source of errors and form discretization rules. The stationary phase approximation is used to obtain the dependence of the far field pressure on the surface displacement. This analysis allows for the study of the propagation of errors into the far field as well as the determination of important mechanisms of sound radiation.

Grosh, Karl

238

47 CFR 90.483 - Permissible methods and requirements of interconnecting private and public systems of...  

Code of Federal Regulations, 2012 CFR

...requirements of interconnecting private and public systems of communications. 90.483 Section... Transmitter Control Interconnected Systems § 90.483 Permissible methods and...requirements of interconnecting private and public systems of communications....

2012-10-01

239

47 CFR 90.483 - Permissible methods and requirements of interconnecting private and public systems of...  

Code of Federal Regulations, 2013 CFR

...requirements of interconnecting private and public systems of communications. 90.483 Section... Transmitter Control Interconnected Systems § 90.483 Permissible methods and...requirements of interconnecting private and public systems of communications....

2013-10-01

240

Characterization of Meta-Materials Using Computational Electromagnetic Methods  

NASA Technical Reports Server (NTRS)

An efficient and powerful computational method is presented to synthesize a meta-material to specified electromagnetic properties. Using the periodicity of meta-materials, the Finite Element Methodology (FEM) is developed to estimate the reflection and transmission through the meta-material structure for a normal plane wave incidence. For efficient computations of the reflection and transmission over a wide band frequency range through a meta-material a Finite Difference Time Domain (FDTD) approach is also developed. Using the Nicholson-Ross method and the Genetic Algorithms, a robust procedure to extract electromagnetic properties of meta-material from the knowledge of its reflection and transmission coefficients is described. Few numerical examples are also presented to validate the present approach.

Deshpande, Manohar; Shin, Joon

2005-01-01

241

Computational methods for efficient structural reliability and reliability sensitivity analysis  

NASA Technical Reports Server (NTRS)

This paper presents recent developments in efficient structural reliability analysis methods. The paper proposes an efficient, adaptive importance sampling (AIS) method that can be used to compute reliability and reliability sensitivities. The AIS approach uses a sampling density that is proportional to the joint PDF of the random variables. Starting from an initial approximate failure domain, sampling proceeds adaptively and incrementally with the goal of reaching a sampling domain that is slightly greater than the failure domain to minimize over-sampling in the safe region. Several reliability sensitivity coefficients are proposed that can be computed directly and easily from the above AIS-based failure points. These probability sensitivities can be used for identifying key random variables and for adjusting design to achieve reliability-based objectives. The proposed AIS methodology is demonstrated using a turbine blade reliability analysis problem.

Wu, Y.-T.

1993-01-01

242

Implementation of an ADI method on parallel computers  

NASA Technical Reports Server (NTRS)

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 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.

Fatoohi, Raad A.; Grosch, Chester E.

1987-01-01

243

Computation of the magnetic flux in the finite elements method  

NASA Astrophysics Data System (ADS)

For designers, calculation of local fluxes can be very useful. In the vector potential formulation, the local fluxes can be easily deduced. In the scalar potential formulation, the determination of these fluxes presents some difficulties. In this paper, we present three methods to compute a flux through any surface in the scalar potential formulation. These are compared with the one used in the vector potential formulation for two application examples.

Henneron, T.; Clénet, S.; Piriou, F.

2007-08-01

244

Computer method for identification of boiler transfer functions  

NASA Technical Reports Server (NTRS)

An iterative computer method is described for identifying boiler transfer functions using frequency response data. An objective penalized performance measure and a nonlinear minimization technique are used to cause the locus of points generated by a transfer function to resemble the locus of points obtained from frequency response measurements. Different transfer functions can be tried until a satisfactory empirical transfer function to the system is found. To illustrate the method, some examples and some results from a study of a set of data consisting of measurements of the inlet impedance of a single tube forced flow boiler with inserts are given.

Miles, J. H.

1971-01-01

245

On a method computing transient wave propagation in ionospheric regions  

NASA Technical Reports Server (NTRS)

A consequence of an exoatmospheric nuclear burst is an electromagnetic pulse (EMP) radiated from it. In a region far enough away from the burst, where nonlinear effects can be ignored, the EMP can be represented by a large-amplitude narrow-time-width plane-wave pulse. If the ionosphere intervenes the origin and destination of the EMP, frequency dispersion can cause significant changes in the original pulse upon reception. A method of computing these dispersive effects of transient wave propagation is summarized. The method described is different from the standard transform techniques and provides physical insight into the transient wave process. The method, although exact, can be used in approximating the early-time transient response of an ionospheric region by a simple integration with only explicit knowledge of the electron density, electron collision frequency, and electron gyrofrequency required. As an illustration of the method, it is applied to a simple example and contrasted with the corresponding transform solution.

Gray, K. G.; Bowhill, S. A.

1978-01-01

246

A bibliography on finite element and related methods analysis in reactor physics computations (1971--1997)  

SciTech Connect

This bibliography provides a list of references on finite element and related methods analysis in reactor physics computations. These references have been published in scientific journals, conference proceedings, technical reports, thesis/dissertations and as chapters in reference books from 1971 to the present. Both English and non-English references are included. All references contained in the bibliography are sorted alphabetically by the first author`s name and a subsort by date of publication. The majority of the references relate to reactor physics analysis using the finite element method. Related topics include the boundary element method, the boundary integral method, and the global element method. All aspects of reactor physics computations relating to these methods are included: diffusion theory, deterministic radiation and neutron transport theory, kinetics, fusion research, particle tracking in finite element grids, and applications. For user convenience, many of the listed references have been categorized. The list of references is not all inclusive. In general, nodal methods were purposely excluded, although a few references do demonstrate characteristics of finite element methodology using nodal methods (usually as a non-conforming element basis). This area could be expanded. The author is aware of several other references (conferences, thesis/dissertations, etc.) that were not able to be independently tracked using available resources and thus were not included in this listing.

Carpenter, D.C.

1998-01-01

247

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

248

Evaluation of computational methods for the reconstruction of HLA haplotypes.  

PubMed

Human leukocyte antigen (HLA) haplotypes are frequently evaluated for population history inferences and association studies. However, the available typing techniques for the main HLA loci usually do not allow the determination of the allele phase and the constitution of a haplotype, which may be obtained by a very time-consuming and expensive family-based segregation study. Without the family-based study, computational inference by probabilistic models is necessary to obtain haplotypes. Several authors have used the expectation-maximization (EM) algorithm to determine HLA haplotypes, but high levels of erroneous inferences are expected because of the genetic distance among the main HLA loci and the presence of several recombination hotspots. In order to evaluate the efficiency of computational inference methods, 763 unrelated individuals stratified into three different datasets had their haplotypes manually defined in a family-based study of HLA-A, -B, -DRB1 and -DQB1 segregation, and these haplotypes were compared with the data obtained by the following three methods: the Expectation-Maximization (EM) and Excoffier-Laval-Balding (ELB) algorithms using the arlequin 3.11 software, and the PHASE method. When comparing the methods, we observed that all algorithms showed a poor performance for haplotype reconstruction with distant loci, estimating incorrect haplotypes for 38%-57% of the samples considering all algorithms and datasets. We suggest that computational haplotype inferences involving low-resolution HLA-A, HLA-B, HLA-DRB1 and HLA-DQB1 haplotypes should be considered with caution. PMID:20670352

Castelli, E C; Mendes-Junior, C T; Veiga-Castelli, L C; Pereira, N F; Petzl-Erler, M L; Donadi, E A

2010-12-01

249

Computational methods of the Advanced Fluid Dynamics Model  

SciTech Connect

To more accurately treat severe accidents in fast reactors, a program has been set up to investigate new computational models and approaches. The product of this effort is a computer code, the Advanced Fluid Dynamics Model (AFDM). This paper describes some of the basic features of the numerical algorithm used in AFDM. Aspects receiving particular emphasis are the fractional-step method of time integration, the semi-implicit pressure iteration, the virtual mass inertial terms, the use of three velocity fields, higher order differencing, convection of interfacial area with source and sink terms, multicomponent diffusion processes in heat and mass transfer, the SESAME equation of state, and vectorized programming. A calculated comparison with an isothermal tetralin/ammonia experiment is performed. We conclude that significant improvements are possible in reliably calculating the progression of severe accidents with further development.

Bohl, W.R.; Wilhelm, D.; Parker, F.R.; Berthier, J.; Maudlin, P.J.; Schmuck, P.; Goutagny, L.; Ichikawa, S.; Ninokata, H.; Luck, L.B.

1987-01-01

250

COMSAC: Computational Methods for Stability and Control. Part 2  

NASA Technical Reports Server (NTRS)

The unprecedented advances being made in computational fluid dynamic (CFD) technology have demonstrated the powerful capabilities of codes in applications to civil and military aircraft. Used in conjunction with wind-tunnel and flight investigations, many codes are now routinely used by designers in diverse applications such as aerodynamic performance predictions and propulsion integration. Typically, these codes are most reliable for attached, steady, and predominantly turbulent flows. As a result of increasing reliability and confidence in CFD, wind-tunnel testing for some new configurations has been substantially reduced in key areas, such as wing trade studies for mission performance guarantees. Interest is now growing in the application of computational methods to other critical design challenges. One of the most important disciplinary elements for civil and military aircraft is prediction of stability and control characteristics. CFD offers the potential for significantly increasing the basic understanding, prediction, and control of flow phenomena associated with requirements for satisfactory aircraft handling characteristics.

Fremaux, C. Michael (Compiler); Hall, Robert M. (Compiler)

2004-01-01

251

Algebraic methods for image processing and computer vision.  

PubMed

Many important problems in image processing and computer vision can be formulated as the solution of a system of simultaneous polynomial equations. Crucial issues include the uniqueness of solution and the number of solutions (if not unique), and how to find numerically all the solutions. The goal of this paper is to introduce to engineers and scientists some mathematical tools from algebraic geometry which are very useful in resolving these issues. Three-dimensional motion/structure estimation is used as the context. However, these tools should also be helpful in other areas including surface intersection in computer-aided design, and inverse position problems in kinematics/robotics. The tools to be described are Bezout numbers, Grobner bases, homotopy methods, and a powerful theorem which states that under rather general conditions one can draw general conclusions on the number of solutions of a polynomial system from a single numerical example. PMID:18285185

Holt, R J; Huang, T S; Netravali, A N

1996-01-01

252

Exploring and accounting for publication bias in mental health: a brief overview of methods.  

PubMed

OBJECTIVE Publication bias undermines the integrity of published research. The aim of this paper is to present a synopsis of methods for exploring and accounting for publication bias. METHODS We discussed the main features of the following methods to assess publication bias: funnel plot analysis; trim-and-fill methods; regression techniques and selection models. We applied these methods to a well-known example of antidepressants trials that compared trials submitted to the Food and Drug Administration (FDA) for regulatory approval. RESULTS The funnel plot-related methods (visual inspection, trim-and-fill, regression models) revealed an association between effect size and SE. Contours of statistical significance showed that asymmetry in the funnel plot is probably due to publication bias. Selection model found a significant correlation between effect size and propensity for publication. CONCLUSIONS Researchers should always consider the possible impact of publication bias. Funnel plot-related methods should be seen as a means of examining for small-study effects and not be directly equated with publication bias. Possible causes for funnel plot asymmetry should be explored. Contours of statistical significance may help disentangle whether asymmetry in a funnel plot is caused by publication bias or not. Selection models, although underused, could be useful resource when publication bias and heterogeneity are suspected because they address directly the problem of publication bias and not that of small-study effects. PMID:24477532

Mavridis, Dimitris; Salanti, Georgia

2014-02-01

253

PREFACE: Theory, Modelling and Computational methods for Semiconductors  

NASA Astrophysics Data System (ADS)

These conference proceedings contain the written papers of the contributions presented at the 2nd International Conference on: Theory, Modelling and Computational methods for Semiconductors. The conference was held at the St Williams College, York, UK on 13th-15th Jan 2010. The previous conference in this series took place in 2008 at the University of Manchester, UK. The scope of this conference embraces modelling, theory and the use of sophisticated computational tools in Semiconductor science and technology, where there is a substantial potential for time saving in R&D. The development of high speed computer architectures is finally allowing the routine use of accurate methods for calculating the structural, thermodynamic, vibrational and electronic properties of semiconductors and their heterostructures. This workshop ran for three days, with the objective of bringing together UK and international leading experts in the field of theory of group IV, III-V and II-VI semiconductors together with postdocs and students in the early stages of their careers. The first day focused on providing an introduction and overview of this vast field, aimed particularly at students at this influential point in their careers. We would like to thank all participants for their contribution to the conference programme and these proceedings. We would also like to acknowledge the financial support from the Institute of Physics (Computational Physics group and Semiconductor Physics group), the UK Car-Parrinello Consortium, Accelrys (distributors of Materials Studio) and Quantumwise (distributors of Atomistix). The Editors Acknowledgements Conference Organising Committee: Dr Matt Probert (University of York) and Dr Max Migliorato (University of Manchester) Programme Committee: Dr Marco Califano (University of Leeds), Dr Jacob Gavartin (Accelrys Ltd, Cambridge), Dr Stanko Tomic (STFC Daresbury Laboratory), Dr Gabi Slavcheva (Imperial College London) Proceedings edited and compiled by Dr Max Migliorato and Dr Matt Probert

Migliorato, Max; Probert, Matt

2010-04-01

254

Structure-based Methods for Computational Protein Functional Site Prediction  

PubMed Central

Due to the advent of high throughput sequencing techniques and structural genomic projects, the number of gene and protein sequences has been ever increasing. Computational methods to annotate these genes and proteins are even more indispensable. Proteins are important macromolecules and study of the function of proteins is an important problem in structural bioinformatics. This paper discusses a number of methods to predict protein functional site especially focusing on protein ligand binding site prediction. Initially, a short overview is presented on recent advances in methods for selection of homologous sequences. Furthermore, a few recent structural based approaches and sequence-and-structure based approaches for protein functional sites are discussed in details. PMID:24688745

Dukka, B KC

2013-01-01

255

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.

256

A Novel Automated Method for Analyzing Cylindrical Computed Tomography Data  

NASA Technical Reports Server (NTRS)

A novel software method is presented that is applicable for analyzing cylindrical and partially cylindrical objects inspected using computed tomography. This method involves unwrapping and re-slicing data so that the CT data from the cylindrical object can be viewed as a series of 2-D sheets in the vertical direction in addition to volume rendering and normal plane views provided by traditional CT software. The method is based on interior and exterior surface edge detection and under proper conditions, is FULLY AUTOMATED and requires no input from the user except the correct voxel dimension from the CT scan. The software is available from NASA in 32- and 64-bit versions that can be applied to gigabyte-sized data sets, processing data either in random access memory or primarily on the computer hard drive. Please inquire with the presenting author if further interested. This software differentiates itself in total from other possible re-slicing software solutions due to complete automation and advanced processing and analysis capabilities.

Roth, D. J.; Burke, E. R.; Rauser, R. W.; Martin, R. E.

2011-01-01

257

Annotated Bibliography of Publications concerning Computers in Education: Emphasis on Microcomputers in ESL and Language Learning. Revised Edition.  

ERIC Educational Resources Information Center

An annotated bibliography of material in the fields of education, languages and linguistics, and computer technology is presented. The bibliography describes over 250 journal articles, books, conference and workshop proceedings, booklets, and pieces from diverse publications. The entries are organized by date of publication (1960s and 1970s as a…

Stevens, Vance, Ed.

258

Method and apparatus for managing transactions with connected computers  

DOEpatents

The present invention provides a method and apparatus that make use of existing computer and communication resources and that reduce the errors and delays common to complex transactions such as international shipping. The present invention comprises an agent-based collaborative work environment that assists geographically distributed commercial and government users in the management of complex transactions such as the transshipment of goods across the U.S.-Mexico border. Software agents can mediate the creation, validation and secure sharing of shipment information and regulatory documentation over the Internet, using the World-Wide Web to interface with human users.

Goldsmith, Steven Y. (Albuquerque, NM); Phillips, Laurence R. (Corrales, NM); Spires, Shannon V. (Albuquerque, NM)

2003-01-01

259

Applications of Computational Methods for Dynamic Stability and Control Derivatives  

NASA Technical Reports Server (NTRS)

Initial steps in the application o f a low-order panel method computational fluid dynamic (CFD) code to the calculation of aircraft dynamic stability and control (S&C) derivatives are documented. Several capabilities, unique to CFD but not unique to this particular demonstration, are identified and demonstrated in this paper. These unique capabilities complement conventional S&C techniques and they include the ability to: 1) perform maneuvers without the flow-kinematic restrictions and support interference commonly associated with experimental S&C facilities, 2) easily simulate advanced S&C testing techniques, 3) compute exact S&C derivatives with uncertainty propagation bounds, and 4) alter the flow physics associated with a particular testing technique from those observed in a wind or water tunnel test in order to isolate effects. Also presented are discussions about some computational issues associated with the simulation of S&C tests and selected results from numerous surface grid resolution studies performed during the course of the study.

Green, Lawrence L.; Spence, Angela M.

2004-01-01

260

Deterministic point inclusion methods for computational applications with complex geometry  

SciTech Connect

A fundamental problem in computation is finding practical and efficient algorithms for determining if a query point is contained within a model of a three-dimensional solid. The solid is modeled using a general boundary representation that can contain polygonal elements and/or parametric patches.We have developed two such algorithms: the first is based on a global closest feature query, and the second is based on a local intersection query. Both algorithms work for two- and three-dimensional objects. This paper presents both algorithms, as well as the spatial data structures and queries required for efficient implementation of the algorithms. Applications for these algorithms include computational geometry, mesh generation, particle simulation, multiphysics coupling, and computer graphics. These methods are deterministic in that they do not involve random perturbations of diagnostic rays cast from the query point in order to avoid ‘unclean’ or ‘singular’ intersections of the rays with the geometry. Avoiding the necessity of such random perturbations will become increasingly important as geometries become more convoluted and complex.

Khamayseh, Ahmed; Kuprat, Andrew P.

2008-11-21

261

DETERMINISTIC POINT INCLUSION METHODS FOR COMPUTATIONAL APPLICATIONS WITH COMPLEX GEOMETRY.  

SciTech Connect

A fundamental problem in computation is finding practical and efficient algorithms for determining if a query point is contained within a model of a three-dimensional solid. The solid is modeled using a general boundary representation that can contain polygonal elements and/or parametric patches. We have developed two such algorithms: the first is based on a global closest feature query, and the second is based on a local intersection query. Both algorithms work for two- and three-dimensional objects. This paper presents both algorithms, as well as the spatial data structures and queries required for efficient implementation of the algorithms. Applications for these algorithms include computational geometry, mesh generation, particle simulation, multiphysics coupling, and computer graphics. These methods are deterministic in that they do not involve random perturbations of diagnostic rays cast from the query point in order to avoid "unclean" or "singular" intersections of the rays with the geometry. Avoiding the necessity of such random perturbations will become increasingly important as geometries become more convoluted and complex.

Khamayseh, Ahmed K [ORNL; Kuprat, Andrew [Los Alamos National Laboratory (LANL)

2008-01-01

262

Deterministic point inclusion methods for computational applications with complex geometry  

NASA Astrophysics Data System (ADS)

A fundamental problem in computation is finding practical and efficient algorithms for determining if a query point is contained within a model of a three-dimensional solid. The solid is modeled using a general boundary representation that can contain polygonal elements and/or parametric patches. We have developed two such algorithms: the first is based on a global closest feature query, and the second is based on a local intersection query. Both algorithms work for two- and three-dimensional objects. This paper presents both algorithms, as well as the spatial data structures and queries required for efficient implementation of the algorithms. Applications for these algorithms include computational geometry, mesh generation, particle simulation, multiphysics coupling, and computer graphics. These methods are deterministic in that they do not involve random perturbations of diagnostic rays cast from the query point in order to avoid 'unclean' or 'singular' intersections of the rays with the geometry. Avoiding the necessity of such random perturbations will become increasingly important as geometries become more convoluted and complex.

Khamayseh, Ahmed; Kuprat, Andrew

2008-10-01

263

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. PMID:11266290

Rose, R. I.

2001-01-01

264

Computing thermal Wigner densities with the phase integration method  

NASA Astrophysics Data System (ADS)

We discuss how the Phase Integration Method (PIM), recently developed to compute symmetrized time correlation functions [M. Monteferrante, S. Bonella, and G. Ciccotti, Mol. Phys. 109, 3015 (2011)], can be adapted to sampling/generating the thermal Wigner density, a key ingredient, for example, in many approximate schemes for simulating quantum time dependent properties. PIM combines a path integral representation of the density with a cumulant expansion to represent the Wigner function in a form calculable via existing Monte Carlo algorithms for sampling noisy probability densities. The method is able to capture highly non-classical effects such as correlation among the momenta and coordinates parts of the density, or correlations among the momenta themselves. By using alternatives to cumulants, it can also indicate the presence of negative parts of the Wigner density. Both properties are demonstrated by comparing PIM results to those of reference quantum calculations on a set of model problems.

Beutier, J.; Borgis, D.; Vuilleumier, R.; Bonella, S.

2014-08-01

265

Ventricular hemodynamics using cardiac computed tomography and optical flow method.  

PubMed

Ventricular hemodynamics plays an important role in assessing cardiac function in clinical practice. The aim of this study was to determine the ventricular hemodynamics based on contrast movement in the left ventricle (LV) between the phases in a cardiac cycle recorded using an electrocardiography (ECG) with cardiac computed tomography (CT) and optical flow method. Cardiac CT data were acquired at 120 kV and 280 mA with a 350 ms gantry rotation, which covered one cardiac cycle, on the 640-slice CT scanner with ECG for a selected patient without heart disease. Ventricular hemodynamics (mm/phase) were calculated using the optical flow method based on contrast changes with ECG phases in anterior-posterior, lateral and superior-inferior directions. Local hemodynamic information of the LV with color coating was presented. The visualization of the functional information made the hemodynamic observation easy. PMID:24463391

Lin, Yang-Hsien; Huang, Yung-Hui; Lin, Kang-Ping; Liu, Juhn-Cherng; Huang, Tzung-Chi

2014-01-01

266

Radiation Transport Computation in Stochastic Media: Method and Application  

NASA Astrophysics Data System (ADS)

Stochastic media, characterized by the stochastic distribution of inclusions in a background medium, are typical radiation transport media encountered in natural or engineering systems. In the community of radiation transport computation, there is always a demand of accurate and efficient methods that can account for the nature of the stochastic distribution. In this dissertation, we focus on methodology development for the radiation transport computation that is applied to neutronic analyses of nuclear reactor designs characterized by the stochastic distribution of particle fuel. Reactor concepts with the employment of a fuel design consisting of a random heterogeneous mixture of fissile material and non-fissile moderator are constantly proposed. Key physical quantities such as core criticality and power distribution, reactivity control design parameters, depletion and fuel burn-up need to be carefully evaluated. In order to meet these practical requirements, we first need to develop accurate and fast computational methods that can effectively account for the stochastic nature of double heterogeneity configuration. A Monte Carlo based method called Chord Length Sampling (CLS) method is considered to be a promising method for analyzing those TRISO-type fueled reactors. Although the CLS method has been proposed for more than two decades and much research has been conducted to enhance its applicability, further efforts are still needed to address some key research gaps that exist for the CLS method. (1) There is a general lack of thorough investigation of the factors that give rise to the inaccuracy of the CLS method found by many researchers. The accuracy of the CLS method depends on the optical and geometric properties of the system. In some specific scenarios, considerable inaccuracies have been reported. However, no research has been providing a clear interpretation of the reasons responsible for the inaccuracy in the reported scenarios. Furthermore, no any correction methods have been proposed or developed to improve the accuracy of the CLS in all the applied scenarios. (2) Previous CLS method only deals with the on-the-fly sample of fuel particles in analyzing TRISO-type fueled reactors. Within the fuel particle, which consists of a fuel kernel and a coating, conventional Monte Carlo simulations apply. This strategy may not fully achieve the highest computational efficiency since extra simulation time is taken for tracking neutrons in the coating region. The coating region has negligible neutronic effect on the overall reactor core performance. This indicates a possible strategy to further increase the computational efficiency by directly sampling fuel kernels on-the-fly in the CLS simulations. In order to test the new strategy, a new model of the chord length distribution function is needed, which requires new research effort to develop and test the new model. (3) The previous evaluations and applications of the CLS method have been limited to single-type single-size fuel particle systems, i.e. only one type of fuel particles with constant size is assumed in the fuel zone, which is the case for typical VHTR designs. In practice, however, for different application purposes, two or more types of TRISO fuel particles may be loaded in the same fuel zone, e.g. fissile fuel particles and fertile fuel particles are used for transmutation purpose in some reactors. Moreover, the fuel particle size may not be kept constant and can vary with a range. Typical design containing such fuel particles can be found in the FSV reactor. Therefore, it is desired to develop new computational model to treat multi-type poly-sized particle systems in the neutornic analysis. This requires extending the current CLS method to on-the-fly sample not only the location of the fuel particle, but also the type and size of the fuel particles in order to be applied to a broad range of reactor designs in neutronic analyses. New sampling functions need to be developed for the extended on-the-fly sampling strategy. This Ph.D. dissertation addressed these

Liang, Chao

267

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

268

Parallel computation of multigroup reactivity coefficient using iterative method  

SciTech Connect

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 [Center for Development of Nuclear Informatics, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia)] [Center for Development of Nuclear Informatics, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia); Dewayatna, Winter [Center for Nuclear Fuel Technology, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia)] [Center for Nuclear Fuel Technology, National Nuclear Energy Agency of Indonesia PUSPIPTEK Area, Tangerang (Indonesia)

2013-09-09

269

Publicity.  

ERIC Educational Resources Information Center

Publicity for preschool cooperatives is described. Publicity helps produce financial support for preschool cooperatives. It may take the form of posters, brochures, newsletters, open house, newspaper coverage, and radio and television. Word of mouth and general good will in the community are the best avenues of publicity that a cooperative nursery…

Chisholm, Joan

270

"State of the Art Computational Methods and Software for Computer-Aided Electrical and Mechanical Control Systems"  

E-print Network

, based on that study, will be made for the engineers. Mathematical and computational jargon that seem to be distractive for most engineers and other applied scientists to learn these techniques will be avoided"State of the Art Computational Methods and Software for Computer-Aided Electrical and Mechanical

Rimon, Elon

271

A stochastic collocation method combined with a reduced basis method to compute uncertainties in numerical dosimetry  

E-print Network

uncertainties in numerical dosimetry M. A. Drissaoui1,2 , S. Lanteri3 , P. Lévêque4 , F. Musy2 , L. Nicolas1 , R with a stochastic problem in a numerical dosimetry application in which the field solutions are computed using--Finite-element methods, numerical analysis, dosimetry. I. INTRODUCTION he lack of knowledge on the electric parameters

Paris-Sud XI, Université de

272

Fundamental studies in hypersonic aeroelasticity using computational methods  

NASA Astrophysics Data System (ADS)

This dissertation describes the aeroelastic analysis of a generic hypersonic vehicle using methods in computational aeroelasticity. This objective is achieved by first considering the behavior of a representative configuration, namely a two degree-of-freedom typical cross-section, followed by that of a three-dimensional model of the generic vehicle, operating at very high Mach numbers. The typical cross-section of a hypersonic vehicle is represented by a double-wedge cross-section, having pitch and plunge degrees of freedom. The flutter boundaries of the typical cross-section are first generated using third-order piston theory, to serve as a basis for comparison with the refined calculations. Prior to the refined calculations, the time-step requirements for the reliable computation of the unsteady airloads using Euler and Navier-Stokes aerodynamics are identified. Computational aeroelastic response results are used to obtain frequency and damping characteristics, and compared with those from piston theory solutions for a variety of flight conditions. A parametric study of offsets, wedge angles; and static angle of attack is conducted. All the solutions are fairly close below the flutter boundary, and differences between the various models increase when the flutter boundary is approached. For this geometry, differences between viscous and inviscid aeroelastic behavior are not substantial. The effects of aerodynamic heating on the aeroelastic behavior of the typical cross-section are incorporated in an approximate manner, by considering the response of a heated wing. Results indicate that aerodynamic heating reduces aeroelastic stability. This analysis was extended to a generic hypersonic vehicle, restrained such that the rigid-body degrees of freedom are absent. The aeroelastic stability boundaries of the canted fin alone were calculated using third-order piston theory. The stability boundaries for the generic vehicle were calculated at different altitudes using piston theory for comparison. The flutter boundaries using first-order piston theory were found to be much higher than those calculated using third-order piston theory. Computational aeroelastic response of the complete vehicle using Euler aerodynamics was found to predict a significantly higher flutter boundary as compared to third-order piston theory, due to substantial three-dimensional flow effects. Also, both methods predicted an increase in the flutter boundary with increasing altitude.

Thuruthimattam, Biju James

273

Computing Equilibria in General Equilibrium Models via Interior-point Methods  

Microsoft Academic Search

In this paper we study new computational methods to find equilibria in generalequilibrium models. We first survey the algorithms to compute equilibria thatcan be found in the literature on computational economics and we indicate howthese algorithms can be improved from the computational point of view. We alsoprovide alternative algorithms that are able to compute the equilibria in anefficient manner even

Mercedes Esteban-Bravo

2004-01-01

274

Computational Methods for MicroRNA Target Prediction  

PubMed Central

MicroRNAs (miRNAs) have been identified as one of the most important molecules that regulate gene expression in various organisms. miRNAs are short, 21–23 nucleotide-long, single stranded RNA molecules that bind to 3' untranslated regions (3' UTRs) of their target mRNAs. In general, they silence the expression of their target genes via degradation of the mRNA or by translational repression. The expression of miRNAs, on the other hand, also varies in different tissues based on their functions. It is significantly important to predict the targets of miRNAs by computational approaches to understand their effects on the regulation of gene expression. Various computational methods have been generated for miRNA target prediction but the resulting lists of candidate target genes from different algorithms often do not overlap. It is crucial to adjust the bioinformatics tools for more accurate predictions as it is equally important to validate the predicted target genes experimentally. PMID:25153283

Ekimler, Semih; Sahin, Kaniye

2014-01-01

275

Inter-Domain Redundancy Path Computation Methods Based on PCE  

NASA Astrophysics Data System (ADS)

This paper evaluates three inter-domain redundancy path computation methods based on PCE (Path Computation Element). Some inter-domain paths carry traffic that must be assured of high quality and high reliability transfer such as telephony over IP and premium virtual private networks (VPNs). It is, therefore, important to set inter-domain redundancy paths, i. e. primary and secondary paths. The first scheme utilizes an existing protocol and the basic PCE implementation. It does not need any extension or modification. In the second scheme, PCEs make a virtual shortest path tree (VSPT) considering the candidates of primary paths that have corresponding secondary paths. The goal is to reduce blocking probability; corresponding secondary paths may be found more often after a primary path is decided; no protocol extension is necessary. In the third scheme, PCEs make a VSPT considering all candidates of primary and secondary paths. Blocking probability is further decreased since all possible candidates are located, and the sum of primary and secondary path cost is reduced by choosing the pair with minimum cost among all path pairs. Numerical evaluations show that the second and third schemes offer only a few percent reduction in blocking probability and path pair total cost, while the overheads imposed by protocol revision and increase of the amount of calculation and information to be exchanged are large. This suggests that the first scheme, the most basic and simple one, is the best choice.

Hayashi, Rie; Oki, Eiji; Shiomoto, Kohei

276

Computational carbohydrate chemistry: what theoretical methods can tell us  

PubMed Central

Computational methods have had a long history of application to carbohydrate systems and their development in this regard is discussed. The conformational analysis of carbohydrates differs in several ways from that of other biomolecules. Many glycans appear to exhibit numerous conformations coexisting in solution at room temperature and a conformational analysis of a carbohydrate must address both spatial and temporal properties. When solution nuclear magnetic resonance data are used for comparison, the simulation must give rise to ensemble-averaged properties. In contrast, when comparing to experimental data obtained from crystal structures a simulation of a crystal lattice, rather than of an isolated molecule, is appropriate. Molecular dynamics simulations are well suited for such condensed phase modeling. Interactions between carbohydrates and other biological macromolecules are also amenable to computational approaches. Having obtained a three-dimensional structure of the receptor protein, it is possible to model with accuracy the conformation of the carbohydrate in the complex. An example of the application of free energy perturbation simulations to the prediction of carbohydrate-protein binding energies is presented. PMID:9579797

Woods, Robert J.

2014-01-01

277

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. PMID:15576347

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

2004-01-01

278

Computational and experimental methods to decipher the epigenetic code  

PubMed Central

A multi-layered set of epigenetic marks, including post-translational modifications of histones and methylation of DNA, is finely tuned to define the epigenetic state of chromatin in any given cell type under specific conditions. Recently, the knowledge about the combinations of epigenetic marks occurring in the genome of different cell types under various conditions is rapidly increasing. Computational methods were developed for the identification of these states, unraveling the combinatorial nature of epigenetic marks and their association to genomic functional elements and transcriptional states. Nevertheless, the precise rules defining the interplay between all these marks remain poorly characterized. In this perspective we review the current state of this research field, illustrating the power and the limitations of current approaches. Finally, we sketch future avenues of research illustrating how the adoption of specific experimental designs coupled with available experimental approaches could be critical for a significant progress in this area.

de Pretis, Stefano; Pelizzola, Mattia

2014-01-01

279

Modern wing flutter analysis by computational fluid dynamics methods  

NASA Technical Reports Server (NTRS)

The application and assessment of the recently developed CAP-TSD transonic small-disturbance code for flutter prediction is described. The CAP-TSD code has been developed for aeroelastic analysis of complete aircraft configurations and was previously applied to the calculation of steady and unsteady pressures with favorable results. Generalized aerodynamic forces and flutter characteristics are calculated and compared with linear theory results and with experimental data for a 45 deg sweptback wing. These results are in good agreement with the experimental flutter data which is the first step toward validating CAP-TSD for general transonic aeroelastic applications. The paper presents these results and comparisons along with general remarks regarding modern wing flutter analysis by computational fluid dynamics methods.

Cunningham, Herbert J.; Batina, John T.; Bennett, Robert M.

1988-01-01

280

Modern wing flutter analysis by computational fluid dynamics methods  

NASA Technical Reports Server (NTRS)

The application and assessment of the recently developed CAP-TSD transonic small-disturbance code for flutter prediction is described. The CAP-TSD code has been developed for aeroelastic analysis of complete aircraft configurations and was previously applied to the calculation of steady and unsteady pressures with favorable results. Generalized aerodynamic forces and flutter characteristics are calculated and compared with linear theory results and with experimental data for a 45 deg sweptback wing. These results are in good agreement with the experimental flutter data which is the first step toward validating CAP-TSD for general transonic aeroelastic applications. The paper presents these results and comparisons along with general remarks regarding modern wing flutter analysis by computational fluid dynamics methods.

Cunningham, Herbert J.; Batina, John T.; Bennett, Robert M.

1987-01-01

281

A new hybrid interpolation method for information exchange in computational aeroelasticity  

Microsoft Academic Search

Interpolation methods are very important in computational aeroelasticity in both the closely and loosely coupled analysis method. In this paper, the characteristics of thin plate splines (TPS), multiquadrics surface spline methods(MQ) and kriging method were first analyzed for interface data interpolation in computational aeroelasticity. Through the analysis of different methods, a hybrid interpolation method is proposed which combines the thin

Xiao-liang Wang; Wenbin Song

2010-01-01

282

A Fast New Public Code for Computing Photon Orbits in a Kerr Spacetime  

NASA Astrophysics Data System (ADS)

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; Agol, Eric

2009-05-01

283

Benchmarking Gas Path Diagnostic Methods: A Public Approach  

NASA Technical Reports Server (NTRS)

Recent technology reviews have identified the need for objective assessments of engine health management (EHM) technology. The need is two-fold: technology developers require relevant data and problems to design and validate new algorithms and techniques while engine system integrators and operators need practical tools to direct development and then evaluate the effectiveness of proposed solutions. This paper presents a publicly available gas path diagnostic benchmark problem that has been developed by the Propulsion and Power Systems Panel of The Technical Cooperation Program (TTCP) to help address these needs. The problem is coded in MATLAB (The MathWorks, Inc.) and coupled with a non-linear turbofan engine simulation to produce "snap-shot" measurements, with relevant noise levels, as if collected from a fleet of engines over their lifetime of use. Each engine within the fleet will experience unique operating and deterioration profiles, and may encounter randomly occurring relevant gas path faults including sensor, actuator and component faults. The challenge to the EHM community is to develop gas path diagnostic algorithms to reliably perform fault detection and isolation. An example solution to the benchmark problem is provided along with associated evaluation metrics. A plan is presented to disseminate this benchmark problem to the engine health management technical community and invite technology solutions.

Simon, Donald L.; Bird, Jeff; Davison, Craig; Volponi, Al; Iverson, R. Eugene

2008-01-01

284

Dynamically Adaptive Wavelet Collocation Method for Shock Computations  

NASA Astrophysics Data System (ADS)

Most explicit TVD schemes make use of artificial viscosity to reduce oscillations and avoid the stability requirements that an explicitly written dissipation term would require when solving hyperbolic conservation equations. In this talk an adaptive wavelet collocation method for shock computation is described. The method for determining a shock's location is similar to Harten's multiresolution algorithm, but its implementation is more continuous. The presence of wavelet coefficients on the finest level of resolution indicates that the maximum allowed resolution has been reached and localized artificial viscous terms should be added to smooth the solution. The localized viscosity is constructed by creating a mask of the wavelet coefficients on the finest level that are greater than a given threshold parameter. The mask is smoothed to reduce oscillations that can be induced due to spatial discontinuities in the second derivative. The main advantage of this technique are its generality and zero losses away from shocks. Since the viscosity is written explicitly, sonic points are no longer problematic and there is no need to track wind direction or introduce flux splitting. One- and two-dimensional examples are given and discussed.

Regele, Jonathan

2005-11-01

285

The Public’s Archaeology: Utilizing Ethnographic Methods to Link Public Education with Accountability in Archaeological Practice  

Microsoft Academic Search

This paper discusses exploratory PhD research which utilized ethnographic methods in an attempt to understand the myriad connections\\u000a to archaeology, history, and heritage in a small Indiana town. I rejected an initial hypothesis that archaeological resources\\u000a are an integral part of collective cultural identities and, instead, discovered that talking with living people can facilitate\\u000a more effective communication and collaboration between

Dru McGill

2010-01-01

286

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

287

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

288

A stoichiometric calibration method for dual energy computed tomography  

NASA Astrophysics Data System (ADS)

The accuracy of radiotherapy dose calculation relies crucially on patient composition data. The computed tomography (CT) calibration methods based on the stoichiometric calibration of Schneider et al (1996 Phys. Med. Biol. 41 111-24) are the most reliable to determine electron density (ED) with commercial single energy CT scanners. Along with the recent developments in dual energy CT (DECT) commercial scanners, several methods were published to determine ED and the effective atomic number (EAN) for polyenergetic beams without the need for CT calibration curves. This paper intends to show that with a rigorous definition of the EAN, the stoichiometric calibration method can be successfully adapted to DECT with significant accuracy improvements with respect to the literature without the need for spectrum measurements or empirical beam hardening corrections. Using a theoretical framework of ICRP human tissue compositions and the XCOM photon cross sections database, the revised stoichiometric calibration method yields Hounsfield unit (HU) predictions within less than ±1.3 HU of the theoretical HU calculated from XCOM data averaged over the spectra used (e.g., 80 kVp, 100 kVp, 140 kVp and 140/Sn kVp). A fit of mean excitation energy (I-value) data as a function of EAN is provided in order to determine the ion stopping power of human tissues from ED-EAN measurements. Analysis of the calibration phantom measurements with the Siemens SOMATOM Definition Flash dual source CT scanner shows that the present formalism yields mean absolute errors of (0.3 ± 0.4)% and (1.6 ± 2.0)% on ED and EAN, respectively. For ion therapy, the mean absolute errors for calibrated I-values and proton stopping powers (216 MeV) are (4.1 ± 2.7)% and (0.5 ± 0.4)%, respectively. In all clinical situations studied, the uncertainties in ion ranges in water for therapeutic energies are found to be less than 1.3 mm, 0.7 mm and 0.5 mm for protons, helium and carbon ions respectively, using a generic reconstruction algorithm (filtered back projection). With a more advanced method (sinogram affirmed iterative technique), the values become 1.0 mm, 0.5 mm and 0.4 mm for protons, helium and carbon ions, respectively. These results allow one to conclude that the present adaptation of the stoichiometric calibration yields a highly accurate method for characterizing tissue with DECT for ion beam therapy and potentially for photon beam therapy.

Bourque, Alexandra E.; Carrier, Jean-François; Bouchard, Hugo

2014-04-01

289

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

290

Profiling animal toxicants by automatically mining public bioassay data: a big data approach for computational toxicology.  

PubMed

In vitro bioassays have been developed and are currently being evaluated as potential alternatives to traditional animal toxicity models. Already, the progress of high throughput screening techniques has resulted in an enormous amount of publicly available bioassay data having been generated for a large collection of compounds. When a compound is tested using a collection of various bioassays, all the testing results can be considered as providing a unique bio-profile for this compound, which records the responses induced when the compound interacts with different cellular systems or biological targets. Profiling compounds of environmental or pharmaceutical interest using useful toxicity bioassay data is a promising method to study complex animal toxicity. In this study, we developed an automatic virtual profiling tool to evaluate potential animal toxicants. First, we automatically acquired all PubChem bioassay data for a set of 4,841 compounds with publicly available rat acute toxicity results. Next, we developed a scoring system to evaluate the relevance between these extracted bioassays and animal acute toxicity. Finally, the top ranked bioassays were selected to profile the compounds of interest. The resulting response profiles proved to be useful to prioritize untested compounds for their animal toxicity potentials and form a potential in vitro toxicity testing panel. The protocol developed in this study could be combined with structure-activity approaches and used to explore additional publicly available bioassay datasets for modeling a broader range of animal toxicities. PMID:24950175

Zhang, Jun; Hsieh, Jui-Hua; Zhu, Hao

2014-01-01

291

Publications  

NSDL National Science Digital Library

This is an article from The Physiologist. "If you have published an article in one of the APS research journals in the second half of 2007, you may have noticed that the time it took from acceptance of your manuscript to final publication was much shorter than in the past. That is because the Publications Department decreased that time from an average of four months to two and a half months."

2008-02-01

292

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

293

Recent advances in computational structural reliability analysis methods  

NASA Technical Reports Server (NTRS)

The goal of structural reliability analysis is to determine the probability that the structure will adequately perform its intended function when operating under the given environmental conditions. Thus, the notion of reliability admits the possibility of failure. Given the fact that many different modes of failure are usually possible, achievement of this goal is a formidable task, especially for large, complex structural systems. The traditional (deterministic) design methodology attempts to assure reliability by the application of safety factors and conservative assumptions. However, the safety factor approach lacks a quantitative basis in that the level of reliability is never known and usually results in overly conservative designs because of compounding conservatisms. Furthermore, problem parameters that control the reliability are not identified, nor their importance evaluated. A summary of recent advances in computational structural reliability assessment is presented. A significant level of activity in the research and development community was seen recently, much of which was directed towards the prediction of failure probabilities for single mode failures. The focus is to present some early results and demonstrations of advanced reliability methods applied to structural system problems. This includes structures that can fail as a result of multiple component failures (e.g., a redundant truss), or structural components that may fail due to multiple interacting failure modes (e.g., excessive deflection, resonate vibration, or creep rupture). From these results, some observations and recommendations are made with regard to future research needs.

Thacker, Ben H.; Wu, Y.-T.; Millwater, Harry R.; Torng, Tony Y.; Riha, David S.

1993-01-01

294

Established and emerging dose reduction methods in cardiac computed tomography.  

PubMed

Cardiac computed tomography (CT) is a non-invasive modality that is commonly used as an alternative to invasive coronary angiography for the investigation of coronary artery disease. The enthusiasm for this technology has been tempered by a growing appreciation of the potential risks of malignancy associated with the use of ionising radiation. In the spirit of minimizing patient risk, the medical profession and industry have worked hard to developed methods and protocols to reduce patient radiation exposure while maintaining excellent diagnostic accuracy. A complete understanding of radiation reduction techniques will allow clinicians to reduce patient risk while providing an important diagnostic service. This review will consider the established and emerging techniques that may be adopted to reduce patient absorbed doses from x-ray CT. By modifying (1) x-ray tube output, (2) imaging time (scan duration), (3) imaging distance (scan length) and (4) the appropriate use of shielding, clinicians will be able to adhere to the 'as low as reasonably achievable (ALARA)' principle. PMID:21630110

Small, Gary R; Kazmi, Mustapha; Dekemp, Robert A; Chow, Benjamin J W

2011-08-01

295

Computational methods for microRNA target prediction.  

PubMed

MicroRNAs (miRNAs) are important players in gene regulation. The final and maybe the most important step in their regulatory pathway is the targeting. Targeting is the binding of the miRNA to the mature RNA via the RNA-induced silencing complex. Expression patterns of miRNAs are highly specific in respect to external stimuli, developmental stage, or tissue. This is used to diagnose diseases such as cancer in which the expression levels of miRNAs are known to change considerably. Newly identified miRNAs are increasing in number with every new release of miRBase which is the main online database providing miRNA sequences and annotation. Many of these newly identified miRNAs do not yet have identified targets. This is especially the case in animals where the miRNA does not bind to its target as perfectly as it does in plants. Valid targets need to be identified for miRNAs in order to properly understand their role in cellular pathways. Experimental methods for target validations are difficult, expensive, and time consuming. Having considered all these facts it is of crucial importance to have accurate computational miRNA target predictions. There are many proposed methods and algorithms available for predicting targets for miRNAs, but only a few have been developed to become available as independent tools and software. There are also databases which collect and store information regarding predicted miRNA targets. Current approaches to miRNA target prediction produce a huge amount of false positive and an unknown amount of false negative results, and thus the need for better approaches is evermore evident. This chapter aims to give some detail about the current tools and approaches used for miRNA target prediction, provides some grounds for their comparison, and outlines a possible future. PMID:24272439

Hamzeiy, Hamid; Allmer, Jens; Yousef, Malik

2014-01-01

296

16.901 Computational Methods in Aerospace Engineering, Spring 2003  

E-print Network

Introduction to computational techniques arising in aerospace engineering. Applications drawn from aerospace structures, aerodynamics, dynamics and control, and aerospace systems. Techniques include: numerical integration ...

Darmofal, David L.

297

Lanczos eigensolution method for high-performance computers  

NASA Technical Reports Server (NTRS)

The theory, computational analysis, and applications are presented of a Lanczos algorithm on high performance computers. The computationally intensive steps of the algorithm are identified as: the matrix factorization, the forward/backward equation solution, and the matrix vector multiples. These computational steps are optimized to exploit the vector and parallel capabilities of high performance computers. The savings in computational time from applying optimization techniques such as: variable band and sparse data storage and access, loop unrolling, use of local memory, and compiler directives are presented. Two large scale structural analysis applications are described: the buckling of a composite blade stiffened panel with a cutout, and the vibration analysis of a high speed civil transport. The sequential computational time for the panel problem executed on a CONVEX computer of 181.6 seconds was decreased to 14.1 seconds with the optimized vector algorithm. The best computational time of 23 seconds for the transport problem with 17,000 degs of freedom was on the the Cray-YMP using an average of 3.63 processors.

Bostic, Susan W.

1991-01-01

298

Geokerr: A Fast New Public Code for Computing Photon Orbits in a Kerr Spacetime  

NASA Astrophysics Data System (ADS)

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 semi-analytically 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; Agol, Eric

2010-11-01

299

Process and Computer-Based Elementary Writing Curriculum: A Review of Methods and Assessments.  

ERIC Educational Resources Information Center

The purpose of this review of literature was to synthesize a wide range of both quantitative and qualitative studies of teacher implementation of computer-assisted writing curriculum methods. Studies on the effect of computer-assisted learning, the relationship of computers and children's writing, and assessment methods for traditional and…

Mott, Michael S.; Sumrall, William J.; Hodges, M. Lee

300

Computer Physics Communications 66(1991) 243-258 Function parametrization: a fast inverse mapping method  

E-print Network

1 Computer Physics Communications 66(1991) 243-258 Function parametrization: a fast inverse mapping (FP) is a method to invert computer models that map physical parameters describing the state that requires little computing time to evaluate. The major advantages of FP over other analysis methods are

van Milligen, Boudewijn

301

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

302

Intelligence Computing Methods in Electronic Commerce and Security  

Microsoft Academic Search

This paper consists of a survey of various e-business, e-marketplaces, graphics and imaging processing, pattern recognition, computer vision, access control, authentication, authorization, etc. applications based on the intelligent computing, and also a summary of the recent techniques such as still artificial neural networks, swarm intelligence, artificial immune systems, fractal geometry, artificial life, ant colony algorithm, genetic algorithm, evolutionary algorithm, quantum

Jing Zhang

2009-01-01

303

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 those…

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

2005-01-01

304

Methods, Metrics and Motivation for a Green Computer Science Program  

E-print Network

OF COMPUTING AND INFORMATION SYSTEMS ­ Installation Management. General Terms Economics, Measurement of a truly paperless office [11] has yet to be realized, it certainly began a movement toward Green Computing files have reduced paper in the modern office, although the truly paperless office is rarely realized

Way, Thomas

305

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

306

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

Microsoft Academic Search

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), associate (A), and regulate (R). There were 2 experiments. In Experiment 1,

Dharmananda Jairam; Kenneth A. Kiewra

2010-01-01

307

Accepted for publication in Computers & Education on 24-09-09 Formative e-assessment: practitioner cases  

E-print Network

of formative e-assessment were developed during the project by a collaborative methodology involvingAccepted for publication in Computers & Education on 24-09-09 Formative e-assessment Information Systems Committee (JISC)-funded project 'Scoping a vision of formative e-assessment', namely

Paris-Sud XI, Université de

308

Publications Forrest M. Ho#man and William W. Hargrove. Cluster computing: Linux taken to the extreme. Linux  

E-print Network

Publications Forrest M. Ho#man and William W. Hargrove. Cluster computing: Linux taken to the extreme. Linux Magazine, 1(1):56--59, 1999. Forrest M. Ho#man. Concepts in Beowulfery. Linux Magazine, 4(1):40--41, January 2002a. Forrest M. Ho#man. Configuring a Beowulf Cluster. Linux Magazine, 4(2):42--45, February

Hoffman, Forrest M.

309

The Repeated Replacement Method: A Pure Lagrangian Meshfree Method for Computational Fluid Dynamics  

PubMed Central

In this paper we describe the repeated replacement method (RRM), a new meshfree method for computational fluid dynamics (CFD). RRM simulates fluid flow by modeling compressible fluids’ tendency to evolve towards a state of constant density, velocity, and pressure. To evolve a fluid flow simulation forward in time, RRM repeatedly “chops out” fluid from active areas and replaces it with new “flattened” fluid cells with the same mass, momentum, and energy. We call the new cells “flattened” because we give them constant density, velocity, and pressure, even though the chopped-out fluid may have had gradients in these primitive variables. RRM adaptively chooses the sizes and locations of the areas it chops out and replaces. It creates more and smaller new cells in areas of high gradient, and fewer and larger new cells in areas of lower gradient. This naturally leads to an adaptive level of accuracy, where more computational effort is spent on active areas of the fluid, and less effort is spent on inactive areas. We show that for common test problems, RRM produces results similar to other high-resolution CFD methods, while using a very different mathematical framework. RRM does not use Riemann solvers, flux or slope limiters, a mesh, or a stencil, and it operates in a purely Lagrangian mode. RRM also does not evaluate numerical derivatives, does not integrate equations of motion, and does not solve systems of equations. PMID:22866175

Walker, Wade A.

2012-01-01

310

ICRP Publication 116—the first ICRP/ICRU application of the male and female adult reference computational phantoms  

NASA Astrophysics Data System (ADS)

ICRP Publication 116 on ‘Conversion coefficients for radiological protection quantities for external radiation exposures’, provides fluence-to-dose conversion coefficients for organ-absorbed doses and effective dose for various types of external exposures (ICRP 2010 ICRP Publication 116). The publication supersedes the ICRP Publication 74 (ICRP 1996 ICRP Publication 74, ICRU 1998 ICRU Report 57), including new particle types and expanding the energy ranges considered. The coefficients were calculated using the ICRP/ICRU computational phantoms (ICRP 2009 ICRP Publication 110) representing the reference adult male and reference adult female (ICRP 2002 ICRP Publication 89), together with a variety of Monte Carlo codes simulating the radiation transport in the body. Idealized whole-body irradiation from unidirectional and rotational parallel beams as well as isotropic irradiation was considered for a large variety of incident radiations and energy ranges. Comparison of the effective doses with operational quantities revealed that the latter quantities continue to provide a good approximation of effective dose for photons, neutrons and electrons for the ‘conventional’ energy ranges considered previously (ICRP 1996, ICRU 1998), but not at the higher energies of ICRP Publication 116.

Petoussi-Henss, Nina; Bolch, Wesley E.; Eckerman, Keith F.; Endo, Akira; Hertel, Nolan; Hunt, John; Menzel, Hans G.; Pelliccioni, Maurizio; Schlattl, Helmut; Zankl, Maria

2014-09-01

311

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

312

Publicly Verifiable Delegation of Large Polynomials and Matrix Computations, with Applications  

E-print Network

@cs.nyu.edu 2 City College of New York, USA rosario@cs.ccny.cuny.edu Abstract. Outsourced computations (where Computing (a computational infrastructure that allows businesses to lease comput- ing resources from important for mobile devices, such as smart phones and netbooks, which might resort to a network server

313

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

314

Methodical failure: the use of case study method by public relations researchers  

Microsoft Academic Search

Case studies comprise up to a third of published articles in the public relations literature. There has, however, been little discussion in the literature of their methodological advantages or shortcomings as a research tool, or reflection on the quality of published case studies. This paper reviews the literature on case-study research, and surveys 5 years of case studies published in

Andrew Cutler

2004-01-01

315

A Computational Method for Compressible Flows with Condensation in Power Plant Condensers  

Microsoft Academic Search

A computational method for compressible flows with condensation was developed. Condensation was formulated by two thermodynamic equations of state for pressure and energy. These equations of state were simultaneously solved with the Euler equation and heat transfer equations. A finite volume method based on an approximate Riemann solver was adopted to solve the Euler equation. The computational method was applied

Fumio Takahashi; Iwao Harada

2008-01-01

316

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

317

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

318

arXiv:cond-mat/0401348v39Sep2004 Method for Computing Protein Binding Affinity  

E-print Network

arXiv:cond-mat/0401348v39Sep2004 Method for Computing Protein Binding Affinity Charles F. F. Karney is given to compute the binding affinity of a ligand to a protein. The method involves extending estimate of the free energy of binding. Keywords: free energy; binding affinity; Monte Carlo methods

Karney, Charles

319

Method for Computing Protein Binding Affinity CHARLES F. F. KARNEY,1  

E-print Network

Method for Computing Protein Binding Affinity CHARLES F. F. KARNEY,1 JASON E. FERRARA,1 STEPHAN to compute the binding affinity of a ligand to a protein. The method involves extending configuration space; binding affinity; Monte Carlo methods; equilibrium constants; proteins Introduction Many drugs work

Karney, Charles

320

A novel computational method for inferring dynamic genetic regulatory trajectories  

E-print Network

We present a novel method called Time Series Affinity Propagation (TSAP) for inferring regulatory states and trajectories from time series genomic data. This method builds on the Affinity Propagation method of Frey and ...

Reeder, Christopher Campbell

2008-01-01

321

A method for computing the leading-edge suction in a higher-order panel method  

NASA Technical Reports Server (NTRS)

Experimental data show that the phenomenon of a separation induced leading edge vortex is influenced by the wing thickness and the shape of the leading edge. Both thickness and leading edge shape (rounded rather than point) delay the formation of a vortex. Existing computer programs used to predict the effect of a leading edge vortex do not include a procedure for determining whether or not a vortex actually exists. Studies under NASA Contract NAS1-15678 have shown that the vortex development can be predicted by using the relationship between the leading edge suction coefficient and the parabolic nose drag. The linear theory FLEXSTAB was used to calculate the leading edge suction coefficient. This report describes the development of a method for calculating leading edge suction using the capabilities of the higher order panel methods (exact boundary conditions). For a two dimensional case, numerical methods were developed using the double strength and downwash distribution along the chord. A Gaussian quadrature formula that directly incorporates the logarithmic singularity in the downwash distribution, at all panel edges, was found to be the best method.

Ehlers, F. E.; Manro, M. E.

1984-01-01

322

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

323

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

324

Managing Public-Access Computers: A How-To-Do-It Manual for Librarians. How-To-Do-It Manuals for Librarians, Number 96.  

ERIC Educational Resources Information Center

This book, while necessarily concerning itself with computer technology, approaches technology as a tool for providing public-service and helps librarians and others effectively manage public-access computers. The book is organized to progress from more technological to more managerial topics. The first chapter--which answers the question, "What…

Barclay, Donald A.

325

Towards the Development of Computational Tools for Evaluating Phylogenetic Network Reconstruction Methods  

E-print Network

Towards the Development of Computational Tools for Evaluating Phylogenetic Network Reconstruction NETWORK RECONSTRUCTION METHODS LUAY NAKHLEH, JERRY SUN, TANDY WARNOW Dept. of Computer Sciences, U on Biocomputing 8:315-326(2003) #12;TOWARDS THE DEVELOPMENT OF COMPUTATIONAL TOOLS FOR EVALUATING PHYLOGENETIC

Babu, M. Madan

326

Distributed privacy-preserving network size computation: A system-identification based method  

E-print Network

Distributed privacy-preserving network size computation: A system-identification based method Federica Garin and Ye Yuan Abstract-- In this study, we propose an algorithm for comput- ing the network to correctly compute the number of nodes in the network. Moreover, numerical implementation has been taken

Paris-Sud XI, Université de

327

A Block Lanczos Method for Computing the Singular Values and Corresponding Singular Vectors of a Matrix  

Microsoft Academic Search

We present a block Lanczos method for computing the greatest singular values and associated vectors of a large and sparse matrix, say A. Our algorithm does not transform A but accesses it through a user-supplied routine that computes the product AX or A tX for a given matrix X. This paper includes a discussion of the various ways to compute

Gene H. Golub; Franklin T. Luk; Michael L. Overton

1981-01-01

328

Enforcing Trust-based Intrusion Detection in Cloud Computing Using Algebraic Methods  

E-print Network

Enforcing Trust-based Intrusion Detection in Cloud Computing Using Algebraic Methods Amira Bradai scheme for hybrid cloud computing is proposed. We consider a trust metric based on honesty, cooperation detection, Perron Frobenius, cloud computing, hybrid execution, false alarms, security scores. I

Paris-Sud XI, Université de

329

Computer Game Scene-Generation Projects Using "Particle Methods"  

E-print Network

correct appearing behaviour of various material and scene components in movie special effects with existing or integrated 3D rendering software. An ideal system would integrate particle trajectory is the basis for many of the clothes effects you may have seen in computer-generated effects in movies

Hawick, Ken

330

Simple computer method provides contours for radiological images  

NASA Technical Reports Server (NTRS)

Computer is provided with information concerning boundaries in total image. Gradient of each point in digitized image is calculated with aid of threshold technique; then there is invoked set of algorithms designed to reduce number of gradient elements and to retain only major ones for definition of contour.

Newell, J. D.; Keller, R. A.; Baily, N. A.

1975-01-01

331

New Methods of Mobile Computing: From Smartphones to Smart Education  

ERIC Educational Resources Information Center

Every aspect of our daily lives has been touched by the ubiquitous nature of mobile devices. We have experienced an exponential growth of mobile computing--a trend that seems to have no limit. This paper provides a report on the findings of a recent offering of an iPhone Application Development course at Sheridan College, Ontario, Canada. It…

Sykes, Edward R.

2014-01-01

332

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

333

DEVELOPING METHODS FOR COMPUTER PROGRAMMING BY MUSICAL PERFORMANCE AND COMPOSITION  

E-print Network

process, allowing music to be used to write computer programs. Such an approach would be less language similarities to program structure, music contains another form of less explicit structure ­ an emotional structure. Music has often been described as a language of emotions [5]. It has been shown that affective

Miranda, Eduardo Reck

334

Quantum-chemical methods for massively parallel computers  

Microsoft Academic Search

For many years it has been recognized that fundamental physical constraints such as the speed of light will limit the ultimate speed of single-processor computers to less than about three billion floating point operations per second. This limitation is becoming increasingly restrictive as commercially available machines are now within an order of magnitude of this asymptotic limit. A natural way

Colvin

1986-01-01

335

COMPUTATION OF AIRCRAFT FLOW FIELDS BY A MULTIGRID EULER METHOD  

E-print Network

the aircraft is discretized with a single-block H-0 mesh which is generated by the union of separate O- meshes-dimensional and three-dimensional flow. In general, they require substantially more computer memory storage than. The running times of three-dimensional Euler codes must be reduced, however, if they are to be used routinely

Jameson, Antony

336

Introducing Research Methods to Computer Science Honours Students  

Microsoft Academic Search

Research skills are important for any academic and can be of great benefit to any professional person. These skills are, however, difficult to teach and to learn. In the Department of Computer Science at the University of the Witwatersrand we have for a number of years included the completion of a research report as part of our Honours programme. This

Vashti Galpin; Scott Hazelhurst; Conrad Mueller; Ian Sanders

337

Final Project IE 407 Computational Methods in Optimization  

E-print Network

a literature review and detailed computational results, (2) well-commented source code and instructions on how. The final product of the project will be (1) a detailed report presented as a research paper that includes architectures. · For the case of shared memory, the study could examine the effects of details

Ralphs, Ted

338

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

339

Verifying a computational method for predicting extreme ground motion  

USGS Publications Warehouse

In situations where seismological data is rare or nonexistent, computer simulations may be used to predict ground motions caused by future earthquakes. This is particularly practical in the case of extreme ground motions, where engineers of special buildings may need to design for an event that has not been historically observed but which may occur in the far-distant future. Once the simulations have been performed, however, they still need to be tested. The SCEC-USGS dynamic rupture code verification exercise provides a testing mechanism for simulations that involve spontaneous earthquake rupture. We have performed this examination for the specific computer code that was used to predict maximum possible ground motion near Yucca Mountain. Our SCEC-USGS group exercises have demonstrated that the specific computer code that was used for the Yucca Mountain simulations produces similar results to those produced by other computer codes when tackling the same science problem. We also found that the 3D ground motion simulations produced smaller ground motions than the 2D simulations.

Harris, R.A.; Barall, M.; Andrews, D.J.; Duan, B.; Ma, S.; Dunham, E.M.; Gabriel, A.-A.; Kaneko, Y.; Kase, Y.; Aagaard, B.T.; Oglesby, D.D.; Ampuero, J.-P.; Hanks, T.C.; Abrahamson, N.

2011-01-01

340

A MEASURE-THEORETIC COMPUTATIONAL METHOD FOR INVERSE SENSITIVITY PROBLEMS I: METHOD AND ANALYSIS  

PubMed Central

We consider the inverse sensitivity analysis problem of quantifying the uncertainty of inputs to a deterministic map given specified uncertainty in a linear functional of the output of the map. This is a version of the model calibration or parameter estimation problem for a deterministic map. We assume that the uncertainty in the quantity of interest is represented by a random variable with a given distribution, and we use the law of total probability to express the inverse problem for the corresponding probability measure on the input space. Assuming that the map from the input space to the quantity of interest is smooth, we solve the generally ill-posed inverse problem by using the implicit function theorem to derive a method for approximating the set-valued inverse that provides an approximate quotient space representation of the input space. We then derive an efficient computational approach to compute a measure theoretic approximation of the probability measure on the input space imparted by the approximate set-valued inverse that solves the inverse problem. PMID:23637467

Breidt, J.; Butler, T.; Estep, D.

2012-01-01

341

Methods for Computationally Efficient Structured CFD Simulations of Complex Turbomachinery Flows  

NASA Technical Reports Server (NTRS)

This research presents more efficient computational methods by which to perform multi-block structured Computational Fluid Dynamics (CFD) simulations of turbomachinery, thus facilitating 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 flow passages and rotor tip clearance regions than is typically practiced with structured codes. The paradigm presented herein facilitates CFD simulation of previously impractical geometries and flows. These methods are validated and demonstrate improved computational efficiency when applied to complicated geometries and flows.

Herrick, Gregory P.; Chen, Jen-Ping

2012-01-01

342

Computer Literacy. Part II--A Teacher's Guide. A Staff Development Publication.  

ERIC Educational Resources Information Center

This teacher's guide, consisting of learning modules, lists of resources, and assessment recommendations, is designed as a tool for developing a computer literacy component of an existing prevocational course or in teaching a free-standing computer literacy course. A list of aims and objectives for a computer literacy course is provided first.…

Lloyd, Jo; And Others

343

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

344

Computational experiments on the weighted linear discontinuous method  

E-print Network

]amours is and st the Indira Gandhi Atomic Research Centre in India. s Some of the specific methods considered in these studies included the dismond-difi'ereuce, step characteristic, linear characteristic and linear discon- tinuous methods. Vaidyanathau even...]amours is and st the Indira Gandhi Atomic Research Centre in India. s Some of the specific methods considered in these studies included the dismond-difi'ereuce, step characteristic, linear characteristic and linear discon- tinuous methods. Vaidyanathau even...

Rodriguez, Gabriel

2012-06-07

345

Spring 2014: Computational and Variational Methods for Inverse Problems  

E-print Network

's method for optimization problems can also be seen as a method to find stationary points x of the gradient that implements the inexact Newton-conjugate gradient method as de- scribed in class3 and use it to solve 397 Assignment 2 (due Feb. 26, 2014) 1. Consider the unconstrained optimization problem min f(x, y

Ghattas, Omar

346

Thermal radiation view factor: Methods, accuracy and computer-aided procedures  

NASA Technical Reports Server (NTRS)

The computer aided thermal analysis programs which predicts the result of predetermined acceptable temperature range prior to stationing of these orbiting equipment in various attitudes with respect to the Sun and the Earth was examined. Complexity of the surface geometries suggests the use of numerical schemes for the determination of these viewfactors. Basic definitions and standard methods which form the basis for various digital computer methods and various numerical methods are presented. The physical model and the mathematical methods on which a number of available programs are built are summarized. The strength and the weaknesses of the methods employed, the accuracy of the calculations and the time required for computations are evaluated. The situations where accuracies are important for energy calculations are identified and methods to save computational times are proposed. Guide to best use of the available programs at several centers and the future choices for efficient use of digital computers are included in the recommendations.

Kadaba, P. V.

1982-01-01

347

Application of traditional CFD methods to nonlinear computational aeroacoustics problems  

NASA Technical Reports Server (NTRS)

This paper describes an implementation of a high order finite difference technique and its application to the category 2 problems of the ICASE/LaRC Workshop on Computational Aeroacoustics (CAA). Essentially, a popular Computational Fluid Dynamics (CFD) approach (central differencing, Runge-Kutta time integration and artificial dissipation) is modified to handle aeroacoustic problems. The changes include increasing the order of the spatial differencing to sixth order and modifying the artificial dissipation so that it does not significantly contaminate the wave solution. All of the results were obtained from the CM5 located at the Numerical Aerodynamic Simulation Laboratory. lt was coded in CMFortran (very similar to HPF), using programming techniques developed for communication intensive large stencils, and ran very efficiently.

Chyczewski, Thomas S.; Long, Lyle N.

1995-01-01

348

Methods for the Accurate Computations of Hypersonic Flows  

Microsoft Academic Search

In order to overcome some difficulties observed in the computation of hypersonic flows, a robust, accurate and efficient numerical scheme based on AUSM-type splitting is developed. Typical symptoms appearing in the application of AUSM-type schemes for high-speed flows, such as pressure wiggles near a wall and overshoots across a strong shock, are cured by introducing weighting functions based on pressure

Kyu Hong Kim; Chongam Kim; Oh-Hyun Rho

2001-01-01

349

A New Method for Online Scheduling in Computational Grid Environments  

Microsoft Academic Search

\\u000a A crucial issue for the efficient deployment of distributed applications on the grid is that of scheduling. In this paper,\\u000a a modified cost-based online scheduling algorithm is presented for computational grids with theoretical guarantee. Firstly,\\u000a a scheduling framework is described, where the grid environment is characterized, and the online job model is defined. Secondly,\\u000a the modified cost-based online scheduling algorithm

Chuliang Weng; Minglu Li; Xinda Lu

2005-01-01

350

Frequency response modeling and control of flexible structures: Computational methods  

NASA Technical Reports Server (NTRS)

The dynamics of vibrations in flexible structures can be conventiently modeled in terms of frequency response models. For structural control such models capture the distributed parameter dynamics of the elastic structural response as an irrational transfer function. For most flexible structures arising in aerospace applications the irrational transfer functions which arise are of a special class of pseudo-meromorphic functions which have only a finite number of right half place poles. Computational algorithms are demonstrated for design of multiloop control laws for such models based on optimal Wiener-Hopf control of the frequency responses. The algorithms employ a sampled-data representation of irrational transfer functions which is particularly attractive for numerical computation. One key algorithm for the solution of the optimal control problem is the spectral factorization of an irrational transfer function. The basis for the spectral factorization algorithm is highlighted together with associated computational issues arising in optimal regulator design. Options for implementation of wide band vibration control for flexible structures based on the sampled-data frequency response models is also highlighted. A simple flexible structure control example is considered to demonstrate the combined frequency response modeling and control algorithms.

Bennett, William H.

1989-01-01

351

Analysis of multigrid methods on massively parallel computers: Architectural implications  

NASA Technical Reports Server (NTRS)

We study the potential performance of multigrid algorithms running on massively parallel computers with the intent of discovering whether presently envisioned machines will provide an efficient platform for such algorithms. We consider the domain parallel version of the standard V cycle algorithm on model problems, discretized using finite difference techniques in two and three dimensions on block structured grids of size 10(exp 6) and 10(exp 9), respectively. Our models of parallel computation were developed to reflect the computing characteristics of the current generation of massively parallel multicomputers. These models are based on an interconnection network of 256 to 16,384 message passing, 'workstation size' processors executing in an SPMD mode. The first model accomplishes interprocessor communications through a multistage permutation network. The communication cost is a logarithmic function which is similar to the costs in a variety of different topologies. The second model allows single stage communication costs only. Both models were designed with information provided by machine developers and utilize implementation derived parameters. With the medium grain parallelism of the current generation and the high fixed cost of an interprocessor communication, our analysis suggests an efficient implementation requires the machine to support the efficient transmission of long messages, (up to 1000 words) or the high initiation cost of a communication must be significantly reduced through an alternative optimization technique. Furthermore, with variable length message capability, our analysis suggests the low diameter multistage networks provide little or no advantage over a simple single stage communications network.

Matheson, Lesley R.; Tarjan, Robert E.

1993-01-01

352

The Ulam Index: Methods of Theoretical Computer Science Help in Identifying Chemical Substances  

NASA Technical Reports Server (NTRS)

In this paper, we show how methods developed for solving a theoretical computer problem of graph isomorphism are used in structural chemistry. We also discuss potential applications of these methods to exobiology: the search for life outside Earth.

Beltran, Adriana; Salvador, James

1997-01-01

353

ADVANCED METHODS FOR THE COMPUTATION OF PARTICLE BEAM TRANSPORT AND THE COMPUTATION OF ELECTROMAGNETIC FIELDS AND MULTIPARTICLE PHENOMENA  

SciTech Connect

Since 1980, under the grant DEFG02-96ER40949, the Department of Energy has supported the educational and research work of the University of Maryland Dynamical Systems and Accelerator Theory (DSAT) Group. The primary focus of this educational/research group has been on the computation and analysis of charged-particle beam transport using Lie algebraic methods, and on advanced methods for the computation of electromagnetic fields and multiparticle phenomena. This Final Report summarizes the accomplishments of the DSAT Group from its inception in 1980 through its end in 2011.

Alex J. Dragt

2012-08-31

354

Fast Fourier transform method of computing difference equations and simulating filters  

Microsoft Academic Search

Two methods for using the fast Fourier transform to reduce the number of arithmetic operations and, therefore the time required for computing discrete, preformulated, and finite convolutions are listed and justified. Under the idealistic assumption that the impulse response of a preformulated difference equation terminates, a theorem is proved that these two methods can be modified to compute such difference

H. Helms

1967-01-01

355

26 CFR 1.669(a)-3 - Tax computed by the exact throwback method.  

Code of Federal Regulations, 2010 CFR

...computed by the exact throwback method. 1.669(a)-3 Section 1.669(a)-3 Internal Revenue INTERNAL REVENUE SERVICE...Years Beginning Before January 1, 1969 § 1.669(a)-3 Tax computed by the exact throwback method....

2010-04-01

356

26 CFR 1.669(a)-3 - Tax computed by the exact throwback method.  

Code of Federal Regulations, 2012 CFR

...computed by the exact throwback method. 1.669(a)-3 Section 1.669(a)-3 Internal Revenue INTERNAL REVENUE SERVICE...Years Beginning Before January 1, 1969 § 1.669(a)-3 Tax computed by the exact throwback method....

2012-04-01

357

26 CFR 1.669(a)-3 - Tax computed by the exact throwback method.  

Code of Federal Regulations, 2011 CFR

...computed by the exact throwback method. 1.669(a)-3 Section 1.669(a)-3 Internal Revenue INTERNAL REVENUE SERVICE...Years Beginning Before January 1, 1969 § 1.669(a)-3 Tax computed by the exact throwback method....

2011-04-01

358

26 CFR 1.669(a)-3 - Tax computed by the exact throwback method.  

...computed by the exact throwback method. 1.669(a)-3 Section 1.669(a)-3 Internal Revenue INTERNAL REVENUE SERVICE...Years Beginning Before January 1, 1969 § 1.669(a)-3 Tax computed by the exact throwback method....

2014-04-01

359

26 CFR 1.669(a)-3 - Tax computed by the exact throwback method.  

Code of Federal Regulations, 2013 CFR

...computed by the exact throwback method. 1.669(a)-3 Section 1.669(a)-3 Internal Revenue INTERNAL REVENUE SERVICE...Years Beginning Before January 1, 1969 § 1.669(a)-3 Tax computed by the exact throwback method....

2013-04-01

360

Advocacy and evidence for sustainable public computer access : Experiences from the Global Libraries Initiative  

Microsoft Academic Search

Purpose – This paper aims to draw together the evidence-based advocacy experience of five national programs focused on developing public access information and communications technologies (ICT) via public libraries as grantees of the Bill & Melinda Gates Foundation's Global Libraries Initiative. Design\\/methodology\\/approach – The authors describe a common approach to strategic advocacy and to impact planning and assessment. They then

Janet Sawaya; Tshepo Maswabi; Resego Taolo; Pablo Andrade; Máximo Moreno Grez; Pilar Pacheco; Kristine Paberza; Sandra Vigante; Agniete Kurutyte; Ugne Rutkauskiene; Jolanta Je?owska; Maciej Kochanowicz

2011-01-01

361

Public participation: more than a method?: Comment on "Harnessing the potential to quantify public preferences for healthcare priorities through citizens' juries".  

PubMed

While it is important to support the development of methods for public participation, we argue that this should not be at the expense of a broader consideration of the role of public participation. We suggest that a rights based approach provides a framework for developing more meaningful approaches that move beyond public participation as synonymous with consultation to value the contribution of lay knowledge to the governance of health systems and health research. PMID:25337604

Boaz, Annette; Chambers, Mary; Stuttaford, Maria

2014-10-01

362

A strong coupled CFD-CSD method on computational aeroelastity  

Microsoft Academic Search

In this paper, a strong coupled CFD-CSD method is developed to simulate the aeroelastic phenomena. The CFD solver is based on the finite-volume algorithm for the Navier-Stokes equations on unstructured grid. The CSD solver solves the aeroelastic governing equations in the modal space. Their coupling is realized by a dual-time method. The spring-based smoothing method is adopted to deform and

Rui Xi; Hongguang Jia

2011-01-01

363

Computational Method Speeds Mapping of Cell Signaling Networks  

NSF Publications Database

... Mapping of Cell Signaling Networks Method helps decode molecular chat inside cells External ... of cells to the control centers inside them that trigger particular responses. But cell signaling ...

364

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

365

Relationship of Instructional Methods to Student Engagement in Two Public High Schools  

ERIC Educational Resources Information Center

This study investigated the argument that schools that emphasize relational learning are better able to serve the motivational needs of adolescents. Matched-pair samples (n=80) from two public secondary schools were compared using the experience sampling method (ESM). Students attending a "non-traditional" school (which employed group decision…

Johnson, Lisa S.

2008-01-01

366

Simulated Exchange Value Method: Applying Green National Accounting to Forest Public Recreation  

Microsoft Academic Search

While applied national accounts are based on market costs and outputs, non-market valuation techniques yield estimates for consumer or Hicksian surplus. To integrate non-market values in national accounts we propose the Simulated Exchange Value method, which simulates the whole market (demand and cost functions) to obtain exchange values. We focus on forest public recreational services because they are relatively close

Jose L. Oviedo; Pablo Campos; Alejandro Caparrós

2010-01-01

367

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

368

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

PubMed Central

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 3 Å. 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

2013-01-01

369

ACM Journal of Educational Resources in Computing, Vol. 7, No. 3, Art. 2. Publication Date: November 2007. Cognitive Science Implications for Enhancing  

E-print Network

ACM Journal of Educational Resources in Computing, Vol. 7, No. 3, Art. 2. Publication Date application in the domain of cyber security education. Categories and Subject Descriptors: I.6 [Simulation Information Systems - Animation; Evaluation/Methodology; K.3 [Computers and Education]: Computer Uses

370

A modified Jiles method for hysteresis computation including minor loops  

NASA Astrophysics Data System (ADS)

This work presents a new methodology for determination of hysteresis curves based on the Jiles-Atherton method. The magnetic induction is adopted as an independent variable which is available in the vector potential magnetic field formulation. The presented method can be directly incorporated in a finite element software.

Koltermann, P. I.; Righi, L. A.; Bastos, J. P. A.; Carlson, R.; Sadowski, N.; Batistela, N. J.

2000-01-01

371

Fast calculation method for cylindrical computer-generated holograms  

Microsoft Academic Search

We propose a fast calculation method for diffraction to nonplanar surfaces using the fast-Fourier transform (FFT) algorithm. In his method, the diffracted wavefront on a cylindrical surface is expressed as a convolution between the point response function and the spatial distribution of objects wherein the convolution is calculated using FFT. The principle of the fast calculation and the simulation results

Yusuke Sando; Masahide Itoh; Toyohiko Yatagai

2005-01-01

372

Computational intelligence methods for information understanding and information management  

E-print Network

importance. These changes could be summarized by a simple rule: IF fossil fuels are burned THEN climate warms acquisition methods for extraction of knowledge from data. Statistical methods traditionally used for data in large databases. Although the main goal of statistics is to derive knowledge from empirical data

Jankowski, Norbert

373

Are Private Schools Better Than Public Schools? Appraisal for Ireland by Methods for Observational Studies  

PubMed Central

In observational studies the assignment of units to treatments is not under control. Consequently, the estimation and comparison of treatment effects based on the empirical distribution of the responses can be biased since the units exposed to the various treatments could differ in important unknown pretreatment characteristics, which are related to the response. An important example studied in this article is the question of whether private schools offer better quality of education than public schools. In order to address this question we use data collected in the year 2000 by OECD for the Programme for International Student Assessment (PISA). Focusing for illustration on scores in mathematics of 15-years old pupils in Ireland, we find that the raw average score of pupils in private schools is higher than of pupils in public schools. However, application of a newly proposed method for observational studies suggests that the less able pupils tend to enroll in public schools, such that their lower scores is not necessarily an indication of bad quality of the public schools. Indeed, when comparing the average score in the two types of schools after adjusting for the enrollment effects, we find quite surprisingly that public schools perform better on average. This outcome is supported by the methods of instrumental variables and latent variables, commonly used by econometricians for analyzing and evaluating social programs. PMID:22242110

Pfeffermann, Danny; Landsman, Victoria

2011-01-01

374

Computational method for thermoviscoelasticity with application to rock mechanics  

NASA Astrophysics Data System (ADS)

Large scale numerical computations associated with rock mechanics problems have required efficient and economical models for predicting temperature, stress, failure, and deformed structural configuration under various loafing conditions. To meet this requirement, the complex dependence of the properties of geological materials on the time and temperature is modified to yield a reduced time scale as a function of time and temperature under the thermorheologically simple material (TSM) postulate. The thermorheologically linear concept is adopted in the finite element formulation by uncoupling thermal and mechanical responses. The thermal responses, based on transient heat conduction or convective diffusion, are formulated by using the two point recurrence scheme and the upwinding scheme, respectively. An incremental solution procedure with the implicit time stepping scheme is proposed for the solution of the thermoviscoelastic response. The proposed thermoviscoelastic solution algorithm is based on the uniaxial creep experimental data and the corresponding temperature shift functions, and is intended to minimize computational efforts by allowing large time step size with stable solutions. A thermoelastic fracture formulation is also presented by introducing the degenerate quadratic isoparametric singular element for the thermally induced line crack problems.

Lee, S. C.

1984-01-01

375

Systems, computer-implemented methods, and tangible computer-readable storage media for wide-field interferometry  

NASA Technical Reports Server (NTRS)

Disclosed herein are systems, computer-implemented methods, and tangible computer-readable storage media for wide field imaging interferometry. The method includes for each point in a two dimensional detector array over a field of view of an image: gathering a first interferogram from a first detector and a second interferogram from a second detector, modulating a path-length for a signal from an image associated with the first interferogram in the first detector, overlaying first data from the modulated first detector and second data from the second detector, and tracking the modulating at every point in a two dimensional detector array comprising the first detector and the second detector over a field of view for the image. The method then generates a wide-field data cube based on the overlaid first data and second data for each point. The method can generate an image from the wide-field data cube.

Lyon, Richard G. (Inventor); Leisawitz, David T. (Inventor); Rinehart, Stephen A. (Inventor); Memarsadeghi, Nargess (Inventor)

2012-01-01

376

Comparison of computation methods for CBM production performance  

E-print Network

methane production is somewhat complicated and has led to numerous methods of approximating production performance. Many CBM reservoirs go through a dewatering period before significant gas production occurs. With dewatering, desorption of gas...

Mora, Carlos A.

2009-06-02

377

The variational multiscale method—a paradigm for computational mechanics  

Microsoft Academic Search

We present a general treatment of the variational multiscale method in the context of an abstract Dirichlet problem. We show how the exact theory represents a paradigm for subgrid-scale models and a posteriori error estimation. We examine hierarchical p-methods and bubbles in order to understand and, ultimately, approximate the ‘fine-scale Green's function’ which appears in the theory. We review relationships

Thomas J. R. Hughes; Gonzalo R. Feijóo; Luca Mazzei; Jean-Baptiste Quincy

1998-01-01

378

Comparison of Two Numerical Methods for Computing Fractal Dimensions  

NASA Astrophysics Data System (ADS)

From cosmology to economics, the examples of fractals can be found virtually everywhere. However, since few fractals permit the analytical evaluation of generalized fractal dimensions or R'enyi dimensions, the search for effective numerical methods is inevitable. In this project two promising numerical methods for obtaining generalized fractal dimensions, based on the distribution of distances within a set, are examined. They can be applied, in principle, to any set even if no closed-form expression is available. The biggest advantage of these methods is their ability to generate a spectrum of generalized dimensions almost simultaneously. It should be noted that this feature is essential to the analysis of multifractals. As a test of their effectiveness, here the methods were applied to the generalized Cantor set and the multiplicative binomial process. The generalized dimensions of both sets can be readily derived analytically, thus enabling the accuracy of the numerical methods to be verified. Here we will present a comparison of the analytical results and the predictions of the methods. We will show that, while they are effective, care must be taken in their interpretation.

Shiozawa, Yui; Miller, Bruce; Rouet, Jean-Louis

2012-10-01

379

Solution NMR and Computational Methods for Understanding Protein Allostery  

PubMed Central

Allosterism is an essential biological regulatory mechanism. In enzymes, allosteric regulation results in an activation or inhibition of catalytic turnover. The mechanisms by which this is accomplished are unclear and vary significantly depending on the enzyme. It is commonly the case that a metabolite binds to the enzyme at a site distant from the catalytic site yet its binding is coupled to and sensed by the active site. This coupling can manifest in changes in structure, dynamics, or both at the active site. These interactions between allosteric and active site, which are often quite distant from one another involve numerous atoms as well as complex conformational rearrangements of the protein secondary and tertiary structure. Interrogation of this complex biological phenomenon necessitates multiple experimental approaches. In this article, we outline a combined solution NMR spectroscopic and computational approach using molecular dynamics and network models to uncover mechanistic aspects of allostery in the enzyme imidazole glycerol phosphate synthase. PMID:23445323

Manley, Gregory; Rivalta, Ivan

2014-01-01

380

Publication Series of the John von Neumann Institute for Computing (NIC) NIC Series Volume 8  

E-print Network

) of the International Union of Pure and Applied Physics (IUPAP), the Computational Physics Group of the European of portions of this work for personal or classroom use is granted provided that the copies are not made). The CCP series is held jointly under the auspices of the Commission on Computational Physics (C20

Marro, Joaquín

381

Munster Programming Training (MPT) PUBLICITY [COMPUTER SCIENCE, UCC 30/11/2011  

E-print Network

, Computer Science at UCC decided to offer a significant introduction into the field in educating students systems, home electronics and much more. Computer Science offers value in a very wide range of careers by some of our MPT students, they were selected as Irish Panel participants at International Olympiads

Schellekens, Michel P.

382

Scalable game design and the development of a checklist for getting computational thinking into public schools  

Microsoft Academic Search

Game design appears to be a promising approach to interest K-12 students in Computer Science. Unfortunately, balancing motivational and educational concerns is truly challenging. Over a number of years, we have explored how to achieve a functional balance by creating a curriculum that combines increasingly complex game designs, computational thinking patterns and authoring tools. Scalable Game Design is a research

Alexander Repenning; David C. Webb; Andri Ioannidou

2010-01-01

383

Computation of separated flow on a ramp using the space marching conservative supra-characteristics method  

NASA Technical Reports Server (NTRS)

Steady, hypersonic viscous flows over compression corners with streamwise separation have been computed using the space marching Conservative Supra-Characteristics Method (CSCM-S) of Lombard. The CSCM-S method permits stable space marching of the parabolized Navier-Stokes (PNS) equations through large separated flow regions. The present method has been used to compute surface pressure, heat transfer, and skin friction coefficients for two compression corner cases studied experimentally by Holden and Moselle. The computed results compare favorably with previous Navier-Stokes results and the experimental data. The present method has also been compared with the conventional Beam-Warming scheme for solving the PNS equations. Comparison are made for accuracy, computer time, and computer storage.

Stookesberry, D. C.; Tannehill, J. C.

1986-01-01

384

New Computational Methods for the Prediction and Analysis of Helicopter Noise  

NASA Technical Reports Server (NTRS)

This paper describes several new methods to predict and analyze rotorcraft noise. These methods are: 1) a combined computational fluid dynamics and Kirchhoff scheme for far-field noise predictions, 2) parallel computer implementation of the Kirchhoff integrations, 3) audio and visual rendering of the computed acoustic predictions over large far-field regions, and 4) acoustic tracebacks to the Kirchhoff surface to pinpoint the sources of the rotor noise. The paper describes each method and presents sample results for three test cases. The first case consists of in-plane high-speed impulsive noise and the other two cases show idealized parallel and oblique blade-vortex interactions. The computed results show good agreement with available experimental data but convey much more information about the far-field noise propagation. When taken together, these new analysis methods exploit the power of new computer technologies and offer the potential to significantly improve our prediction and understanding of rotorcraft noise.

Strawn, Roger C.; Oliker, Leonid; Biswas, Rupak

1996-01-01

385

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 PMID:9336178

Liang, J; Subramaniam, S

1997-01-01

386

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

387

A Fully Conservative Ghost Fluid Method & Stiff Detonation Waves Computer Science Department  

E-print Network

A Fully Conservative Ghost Fluid Method & Stiff Detonation Waves Duc Nguyen Computer Science University Stanford, CA 94305 We present a new, fully conservative version of the ghost fluid method the level set method to track the location of the detonation wave and the ghost fluid method to treat

Fedkiw, Ron

388

METHOD FOR COMPUTING THE RADIAL DISTRIBUTION OF EMITTERS IN A CYLINDRICAL SOURCE  

Microsoft Academic Search

A method for computing the distribution of emitters from the observed ; projected intensity profile is described. The method is applicable to optically ; thin volume sources with cylindrical symmetry. Unlike previous methods, this ; method yields results which are relatively insensitive to small random errors in ; the data. (auth)

WILLIAM L. BARR

1962-01-01

389

Quasi-Hamiltonian Method for Computation of Decoherence Rates  

NASA Astrophysics Data System (ADS)

We present a general formalism for the dissipative dynamics of an arbitrary quantum system in the presence of a classical stochastic process. It is applicable to a wide range of physical situations, and in particular it can be used for qubit arrays in the presence of classical two-level systems (TLS). In this formalism, all decoherence rates appear as eigenvalues of an evolution matrix. Thus the method is linear, and the close analogy to Hamiltonian systems opens up a toolbox of well-developed methods such as perturbation theory and mean-field theory. We apply the method to the problem of a single qubit in the presence of TLS that give rise to pure dephasing 1/f noise and solve this problem exactly.

Joynt, Robert; Zhou, Dong; Wang, Qiang-Hua

390

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

391

Computational methods for estimation of parameters in hyperbolic systems  

NASA Technical Reports Server (NTRS)

Approximation techniques for estimating spatially varying coefficients and unknown boundary parameters in second order hyperbolic systems are discussed. Methods for state approximation (cubic splines, tau-Legendre) and approximation of function space parameters (interpolatory splines) are outlined and numerical findings for use of the resulting schemes in model "one dimensional seismic inversion' problems are summarized.

Banks, H. T.; Ito, K.; Murphy, K. A.

1983-01-01

392

Poster Presentation Thread 1: Computational Methods in Biomechanics and Mechanobiology  

E-print Network

patients were associated with risk for foot ulceration, however, in the clinic, only interfacial pressures are being measured to evaluate susceptibly to ulcers [1]. This study aims at developing a method for deep's contact theory. The biomechanical model considers the heel and metatarsal head pads, where most ulcers

Gefen, Amit

393

Combination of Thin Lenses--A Computer Oriented Method.  

ERIC Educational Resources Information Center

Suggests a method treating geometric optics using a microcomputer to do the calculations of image formation. Calculations are based on the connection between the composition of lenses and the mathematics of fractional linear equations. Logic of the analysis and an example problem are included. (JM)

Flerackers, E. L. M.; And Others

1984-01-01

394

CS 335 Fall 2011 Computational Methods in Business and Finance  

E-print Network

assignments, two in-class midterms and a final examination. The assignments will involve Matlab coding methods used in financial applications. Topics covered include: · Introduction to Matlab · No, determination of implied volatility · Floating point issues: stability, error propagation · Portfolio

Waterloo, University of

395

Computational Intelligence Methods for Rule-Based Data Understanding  

E-print Network

the changes is of even greater importance. These changes could be summarized by a rule: IF fossil fuels networks, decision trees, machine learning, and statistical methods are introduced. Optimization in the next few days, is a goal in itself. Black-box statistical approaches to data analysis that offer

Setiono, Rudy

396

An Improved Computer Vision Method for White Blood Cells Detection  

PubMed Central

The automatic detection of white blood cells (WBCs) still remains as an unsolved issue in medical imaging. The analysis of WBC images has engaged researchers from fields of medicine and computer vision alike. Since WBC can be approximated by an ellipsoid form, an ellipse detector algorithm may be successfully applied in order to recognize such elements. This paper presents an algorithm for the automatic detection of WBC embedded in complicated and cluttered smear images that considers the complete process as a multiellipse detection problem. The approach, which is based on the differential evolution (DE) algorithm, transforms the detection task into an optimization problem whose individuals represent candidate ellipses. An objective function evaluates if such candidate ellipses are actually present in the edge map of the smear image. Guided by the values of such function, the set of encoded candidate ellipses (individuals) are evolved using the DE algorithm so that they can fit into the WBCs which are enclosed within the edge map of the smear image. Experimental results from white blood cell images with a varying range of complexity are included to validate the efficiency of the proposed technique in terms of its accuracy and robustness. PMID:23762178

Cuevas, Erik; Diaz, Margarita; Manzanares, Miguel; Zaldivar, Daniel; Perez-Cisneros, Marco

2013-01-01

397

Modern Electrophysiological Methods for Brain-Computer Interfaces  

PubMed Central

Modern electrophysiological studies in animals show that the spectrum of neural oscillations encoding relevant information is broader than previously thought and that many diverse areas are engaged for very simple tasks. However, EEG-based brain-computer interfaces (BCI) still employ as control modality relatively slow brain rhythms or features derived from preselected frequencies and scalp locations. Here, we describe the strategy and the algorithms we have developed for the analysis of electrophysiological data and demonstrate their capacity to lead to faster accurate decisions based on linear classifiers. To illustrate this strategy, we analyzed two typical BCI tasks. (1) Mu-rhythm control of a cursor movement by a paraplegic patient. For this data, we show that although the patient received extensive training in mu-rhythm control, valuable information about movement imagination is present on the untrained high-frequency rhythms. This is the first demonstration of the importance of high-frequency rhythms in imagined limb movements. (2) Self-paced finger tapping task in three healthy subjects including the data set used in the BCI-2003 competition. We show that by selecting electrodes and frequency ranges based on their discriminative power, the classification rates can be systematically improved with respect to results published thus far. PMID:18288256

Grave de Peralta Menendez, Rolando; Noirhomme, Quentin; Cincotti, Febo; Mattia, Donatella; Aloise, Fabio; Gonzalez Andino, Sara

2007-01-01

398

Pragmatic approaches to using computational methods to predict xenobiotic metabolism.  

PubMed

In this study the performance of a selection of computational models for the prediction of metabolites and/or sites of metabolism was investigated. These included models incorporated in the MetaPrint2D-React, Meteor, and SMARTCyp software. The algorithms were assessed using two data sets: one a homogeneous data set of 28 Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and paracetamol (DS1) and the second a diverse data set of 30 top-selling drugs (DS2). The prediction of metabolites for the diverse data set (DS2) was better than for the more homogeneous DS1 for each model, indicating that some areas of chemical space may be better represented than others in the data used to develop and train the models. The study also identified compounds for which none of the packages could predict metabolites, again indicating areas of chemical space where more information is needed. Pragmatic approaches to using metabolism prediction software have also been proposed based on the results described here. These approaches include using cutoff values instead of restrictive reasoning settings in Meteor to reduce the output with little loss of sensitivity and for directing metabolite prediction by preselection based on likely sites of metabolism. PMID:23718189

Piechota, Przemyslaw; Cronin, Mark T D; Hewitt, Mark; Madden, Judith C

2013-06-24

399

CLOUD COMPUTING TECHNOLOGIES PROGRAM An eleven-week in-depth program in the principles, methods, and technologies of Cloud Computing  

E-print Network

CLOUD COMPUTING TECHNOLOGIES PROGRAM An eleven-week in-depth program in the principles, methods, and technologies of Cloud Computing DePaul University's Cloud Computing Technologies Program provides a broad understanding of the different leading Cloud Computing technologies. The program is designed to quickly educate

Schaefer, Marcus

400

CLOUD COMPUTING FUNDAMENTALS PROGRAM An eleven-week in-depth program in the principles, methods, and technologies of Cloud Computing  

E-print Network

CLOUD COMPUTING FUNDAMENTALS PROGRAM An eleven-week in-depth program in the principles, methods, and technologies of Cloud Computing DePaul University's Cloud Computing Fundamentals Program provides a comprehensive introduction to essential aspects of Cloud Computing. The program is designed to quickly educate

Schaefer, Marcus

401

Computational methods to compute wavefront error due to aero-optic effects  

NASA Astrophysics Data System (ADS)

Aero-optic effects can have deleterious effects on high performance airborne optical sensors that must view through turbulent flow fields created by the aerodynamic effects of windows and domes. Evaluating aero-optic effects early in the program during the design stages allows mitigation strategies and optical system design trades to be performed to optimize system performance. This necessitates a computationally efficient means to evaluate the impact of aero-optic effects such that the resulting dynamic pointing errors and wavefront distortions due to the spatially and temporally varying flow field can be minimized or corrected. To this end, an aero-optic analysis capability was developed within the commercial software SigFit that couples CFD results with optical design tools. SigFit reads the CFD generated density profile using the CGNS file format. OPD maps are then created by converting the three-dimensional density field into an index of refraction field and then integrating along specified paths to compute OPD errors across the optical field. The OPD maps may be evaluated directly against system requirements or imported into commercial optical design software including Zemax® and Code V® for a more detailed assessment of the impact on optical performance from which design trades may be performed.

Genberg, Victor; Michels, Gregory; Doyle, Keith; Bury, Mark; Sebastian, Thomas

2013-09-01

402

Personal, Public: Using DIY to explore citizen-led efforts in urban computing  

E-print Network

As communities develop technological literacy and explore how technology can impact their lives, the future. Such hybrid digital-physical approaches to urban computing are not uncommon. Recent work exists in, among

Paulos, Eric

403

ACCEPTED FOR PUBLICATION IN IEEE TRANSACTION ON VISUALIZATION AND COMPUTER GRAPHICS 1 Filtering and Rendering of  

E-print Network

AND COMPUTER GRAPHICS 3 Fig. 1. The changing reflectance characteristics of a desert scene at different is defined as the ratio of the reflected radiance in the direction towards the viewer to the irradiance

Tan, Ping

404

Development of supersonic computational aerodynamic program using panel method  

NASA Technical Reports Server (NTRS)

An aerodynamic program for steady supersonic linearized potential flow using a higher order panel method was developed. Boundary surface is divided into planar triangular panels on each of which a linearly varying doublet and a constant or linearly varying source are distributed. Distributions of source and doublet on the panel assemblies of the panels can be determined by their strengths at nodal points, which are placed at the vertices of the panels for linear distribution or on each panel for constant distribution.

Maruyama, Y.; Akishita, S.; Nakamura, A.

1987-01-01

405

Singularity computations. [finite element methods for elastoplastic flow  

NASA Technical Reports Server (NTRS)

Direct descriptions of the structure of a singularity would describe the radial and angular distributions of the field quantities as explicitly as practicable along with some measure of the intensity of the singularity. This paper discusses such an approach based on recent development of numerical methods for elastoplastic flow. Attention is restricted to problems where one variable or set of variables is finite at the origin of the singularity but a second set is not.

Swedlow, J. L.

1978-01-01

406

A Survey of Synchronization Methods for Parallel Computers  

Microsoft Academic Search

An examination is given of how traditional synchronization methods influence the design of MIMD (multiple-instruction multiple-data-stream) multiprocessors. She provides an overview of MIMD multiprocessing and goes on to discuss semaphore-based implementations (Ultracomputers, Cedar, and the Sequent Balance\\/21000), monitor-based implementations (the HM\\/sup 2\\/p) and implementations based on message-passing (HEP, the BBN Butterfly and the Transputer).

Anne Dinning

1989-01-01

407

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 involving molecular species that occur in hydrocarbon combustion. These potential energy surfaces require an accurate and balanced treatment of reactants, intermediates, and products. This difficult challenge is met with 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 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. [Argonne National Laboratory, IL (United States)

1993-12-01

408

Computational observers and visualization methods for stereoscopic medical imaging.  

PubMed

As stereoscopic display devices become common, their image quality assessment evaluation becomes increasingly important. Most studies conducted on 3D displays are based on psychophysics experiments with humans rating their experience based on detection tasks. The physical measurements do not map to effects on signal detection performance. Additionally, human observer study results are often subjective and difficult to generalize. We designed a computational stereoscopic observer approach inspired by the mechanisms of stereopsis in human vision for task-based image assessment that makes binary decisions based on a set of image pairs. The stereo-observer is constrained to a left and a right image generated using a visualization operator to render voxel datasets. We analyze white noise and lumpy backgrounds using volume rendering techniques. Our simulation framework generalizes many different types of model observers including existing 2D and 3D observers as well as providing flexibility to formulate a stereo model observer approach following the principles of stereoscopic viewing. This methodology has the potential to replace human observer studies when exploring issues with stereo display devices to be used in medical imaging. We show results quantifying the changes in performance when varying stereo angle as measured by an ideal linear stereoscopic observer. Our findings indicate that there is an increase in performance of about 13-18% for white noise and 20-46% for lumpy backgrounds, where the stereo angle is varied from 0 to 30. The applicability of this observer extends to stereoscopic displays used for in the areas of medical and entertainment imaging applications. PMID:25321697

Zafar, Fahad; Yesha, Yaacov; Badano, Aldo

2014-09-22

409

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

PubMed Central

Background Computational models play an increasingly important role in the assessment and control of public health crises, as demonstrated during the 2009 H1N1 influenza pandemic. Much research has been done in recent years in the development of sophisticated data-driven models for realistic computer-based simulations of infectious disease spreading. However, only a few computational tools are presently available for assessing scenarios, predicting epidemic evolutions, and managing health emergencies that can benefit a broad audience of users including policy makers and health institutions. Results We present "GLEaMviz", a publicly available software system that simulates the spread of emerging human-to-human infectious diseases across the world. The GLEaMviz tool comprises three components: the client application, the proxy middleware, and the simulation engine. The latter two components constitute the GLEaMviz server. The simulation engine leverages on the Global Epidemic and Mobility (GLEaM) framework, a stochastic computational scheme that integrates worldwide high-resolution demographic and mobility data to simulate disease spread on the global scale. The GLEaMviz design aims at maximizing flexibility in defining the disease compartmental model and configuring the simulation scenario; it allows the user to set a variety of parameters including: compartment-specific features, transition values, and environmental effects. The output is a dynamic map and a corresponding set of charts that quantitatively describe the geo-temporal evolution of the disease. The software is designed as a client-server system. The multi-platform client, which can be installed on the user's local machine, is used to set up simulations that will be executed on the server, thus avoiding specific requirements for large computational capabilities on the user side. Conclusions The user-friendly graphical interface of the GLEaMviz tool, along with its high level of detail and the realism of its embedded modeling approach, opens up the platform to simulate realistic epidemic scenarios. These features make the GLEaMviz computational tool a convenient teaching/training tool as well as a first step toward the development of a computational tool aimed at facilitating the use and exploitation of computational models for the policy making and scenario analysis of infectious disease outbreaks. PMID:21288355

2011-01-01

410

Analysis of the direct Fourier method for computer tomography.  

PubMed

We develop a direct Fourier method (DFM) for reconstructing a function from its X-ray projections. We introduce a framework that can be used to get a quantitative comparison between different choices of basis functions in the step of resampling from polar to Cartesian coordinates. We use the framework to compare polynomial interpolation, approximated sinc-functions, Gaussians, splines, and Kaiser-Bessel functions. The resulting algorithm is very fast, requiring 12.5N2 log2 N + 49N2 flops. Numerical experiments show it to be efficient. PMID:10875705

Waldén, J

2000-03-01

411

A computational method for determination of the individual anaerobic threshold.  

PubMed

The individual anaerobic threshold (IAT) has received attention recently in the field of exercise physiology. The IAT is defined as the point during progressive exercise when lactate elimination from the blood is both maximal and equal to the diffusion from the working muscles. It has been theorized that an individual can maintain exercise for relatively long periods when working at the IAT. A common method for determination of the IAT is to perform a visual determination from plots of lactate concentration versus power output. This paper briefly describes the theoretical basis for determination of the IAT and presents an algorithm for its accurate calculation. PMID:8375156

Prusaczyk, W K; Jacobs, I; Bowden, T; McLellan, T M

1993-07-01

412

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

413

Fast methods for computing scene raw signals in millimeter-wave sensor simulations  

NASA Astrophysics Data System (ADS)

Modern millimeter wave (mmW) radar sensor systems employ wideband transmit waveforms and efficient receiver signal processing methods for resolving accurate measurements of targets embedded in complex backgrounds. Fast Fourier Transform processing of pulse return signal samples is used to resolve range and Doppler locations, and amplitudes of scattered RF energy. Angle glint from RF scattering centers can be measured by performing monopulse arithmetic on signals resolved in both delta and sum antenna channels. Environment simulations for these sensors - including all-digital and hardware-in-the-loop (HWIL) scene generators - require fast, efficient methods for computing radar receiver input signals to support accurate simulations with acceptable execution time and computer cost. Although all-digital and HWIL simulations differ in their representations of the radar sensor (which is itself a simulation in the all-digital case), the signal computations for mmW scene modeling are closely related for both types. Engineers at the U.S. Army Aviation and Missile Research, Development and Engineering Center (AMRDEC) have developed various fast methods for computing mmW scene raw signals to support both HWIL scene projection and all-digital receiver model input signal synthesis. These methods range from high level methods of decomposing radar scenes for accurate application of spatially-dependent nonlinear scatterer phase history, to low-level methods of efficiently computing individual scatterer complex signals and single precision transcendental functions. The efficiencies of these computations are intimately tied to math and memory resources provided by computer architectures. The paper concludes with a summary of radar scene computing performance on available computer architectures, and an estimate of future growth potential for this computational performance.

Olson, Richard F.; Reynolds, Terry M.; Satterfield, H. Dewayne

2010-04-01

414

Parallel Störmer-Cowell methods for high-precision orbit computations.  

NASA Astrophysics Data System (ADS)

Many orbit problems in celestial mechanics are described by (nonstiff) initial-value problems (IVPs) for second-order ordinary differential equations of the form y?= f(y). The authors consider high-order parallel methods which fit into the class of general linear methods. In each step, these methods compute blocks of k approximate solution values (or stage values) at k different points using the whole previous block of solution values. The k stage values can be computed in parallel, so that on a k-processor computer system such methods effectively perform as a one-value method. The block methods considered in this paper are such that each equation defining a stage value resembles a linear multistep equation of the familiar Störmer-Cowell type. For k = 4 and k = 5 they constructed explicit PSC methods with stage order q = k and step point order p = k+1 and implicit PSC methods with q = k+1 and p = k+2. For k ? 6 one can construct explicit PSC methods with q = k and p = k+2 and implicit PSC methods with q = k+1 and p = k+3. It turns out that for k ? 5 the abscissae of the stage values can be chosen such that only k-1 stage values in each block have to be computed, so that the number of computational stages, and hence the number of processors and the number of starting values needed, reduces to k* = k-1.

van der Houwen, P. J.; Messina, E.; de Swart, J. J. B.

1999-11-01

415

A new method to compute standard-weight equations that reduces length-related bias  

USGS Publications Warehouse

We propose a new method for developing standard-weight (Ws) equations for use in the computation of relative weight (Wr) because the regression line-percentile (RLP) method often leads to length-related biases in Ws equations. We studied the structural properties of W s equations developed by the RLP method through simulations, identified reasons for biases, and compared Ws equations computed by the RLP method and the new method. The new method is similar to the RLP method but is based on means of measured weights rather than on means of weights predicted from regression models. The new method also models curvilinear W s relationships not accounted for by the RLP method. For some length-classes in some species, the relative weights computed from Ws equations developed by the new method were more than 20 Wr units different from those using Ws equations developed by the RLP method. We recommend assessment of published Ws equations developed by the RLP method for length-related bias and use of the new method for computing new Ws equations when bias is identified. ?? Copyright by the American Fisheries Society 2005.

Gerow, K.G.; Anderson-Sprecher, R. C.; Hubert, W.A.

2005-01-01

416

A computer-aided detection and classification method for concealed targets in hyperspectral imagery  

Microsoft Academic Search

Detecting concealed targets in an unknown environment presents a great challenge in hyperspectral image analysis since the prior knowledge about targets, the background and environment is not available. In this paper, a computer-aided detection and classification method (CADCM) for concealed targets is proposed. It is fully computer-automated and requires no a priori information at all. It consists of three successive

Hsuan Ren; Chein-I Chang

1998-01-01

417

Applications of level set methods in computational biophysics Emmanuel Maitre1  

E-print Network

Applications of level set methods in computational biophysics Emmanuel Maitre1 , Thomas Milcent1 to fluid-structure problems arising in biophysics. The first one is concerned with three computational tools in biophysics applications. 1 Introduction Biophysics and biomechanics are two fields where

Cottet, Georges-Henri

418

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

419

A Moving Least Squares method for implant model deformation in Computer Aided Orthopedic Surgery for  

E-print Network

A Moving Least Squares method for implant model deformation in Computer Aided Orthopedic Surgery. In past years, a vari- ety of software systems used on orthopedic surgeries have been developed, where CAOS (Computer Aided Orthopedic Surgery). In a CAOS system the surgeon can load X-Ray images

Coto, Ernesto

420

The computational complexity of elliptic curve integer sub-decomposition (ISD) method  

NASA Astrophysics Data System (ADS)

The idea of the GLV method of Gallant, Lambert and Vanstone (Crypto 2001) is considered a foundation stone to build a new procedure to compute the elliptic curve scalar multiplication. This procedure, that is integer sub-decomposition (ISD), will compute any multiple kP of elliptic curve point P which has a large prime order n with two low-degrees endomorphisms ?1 and ?2 of elliptic curve E over prime field Fp. The sub-decomposition of values k1 and k2, not bounded by ±C?n , gives us new integers k11, k12, k21 and k22 which are bounded by ±C?n and can be computed through solving the closest vector problem in lattice. The percentage of a successful computation for the scalar multiplication increases by ISD method, which improved the computational efficiency in comparison with the general method for computing scalar multiplication in elliptic curves over the prime fields. This paper will present the mechanism of ISD method and will shed light mainly on the computation complexity of the ISD approach that will be determined by computing the cost of operations. These operations include elliptic curve operations and finite field operations.

Ajeena, Ruma Kareem K.; Kamarulhaili, Hailiza

2014-07-01

421

Pre-calculated object light-based fast calculation method for computer-generated hologram  

Microsoft Academic Search

Computer generated holograms are expected to be an ideal three-dimensional display system. Enormous computation time, however, is required to calculate holograms. There are fast calculation methods based on fast Fourier transforms using a patch model, but they require two-dimensional fast Fourier transforms for each patch. Therefore, calculating the object light from a complex object that has many patches takes much

Hironobu Sakata; Yuji Sakamoto

2010-01-01

422

A Survey of Methods for Computing (un)Stable Manifolds of Vector Fields  

Microsoft Academic Search

The computation of global invariant manifolds has seen renewed interest in recent years. We survey dieren t approaches for computing a global stable or unstable mani- fold of a vector eld, where we concentrate on the case of a two-dimensional manifold. All methods are illustrated with the same example | the two-dimensional stable man- ifold of the origin in the

Bernd Krauskopf; Hinke M. Osinga; Eusebius J. Doedel; M. E. Henderson; John Guckenheimer; A. Vladimirsky; M. Dellnitz; O. Junge

2005-01-01

423

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

424

Methods and guidelines for the design and development of domestic ubiquitous computing applications  

Microsoft Academic Search

Bringing ubiquitous computing applications to home environments is a great challenge. In our research we investigate how applications can be conceived, designed, and implemented that fit into people's lives. In particular we describe our experiments on how methods of user centered design and participatory design can be appropriated to find users' requirements and design ideas for ubiquitous computing applications for

Albrecht Schmidt; Lucia Terrenghi

2006-01-01

425

Methods and Guidelines for the Design and Development of Domestic Ubiquitous Computing Applications  

Microsoft Academic Search

Bringing ubiquitous computing applications to home environments is a great challenge. In our research we investigate how applications can be conceived, designed, and implemented that fit into people's lives. In particular we describe our experiments on how methods of user centered design and participatory design can be appropriated to find users' requirements and design ideas for ubiquitous computing applications for

Albrecht Schmidt; Lucia Terrenghi; Paul Holleis

2007-01-01

426

A Rule-based Computer System to Facilitate Public Health Surveillance during the 2002 Olympic Winter Games  

PubMed Central

We describe our preliminary experience in using a computer rule-based system to assist real-time public health surveillance. The rules operated on HL7 messages transmitted by hospital information systems and included laboratory test ordering, results, radiology reports, emergency room & outpatient clinic visits and hospital admissions. Data elements were mapped to standard vocabularies and then run through the inference engine, in a data-driven process. The aim of the system was to detect events of possible public health significance, as well as reportable infectious diseases. The program has been actively used by the University-based infection control team, beginning with the 2002 Olympic Winter Games. It represents a novel surveillance system that uses objective, quantifiable events to support monitoring of community populations.

Gundlapalli, Adi V.; Olson, Jonathan; Smith, Sean P.; Baza, Michael; Hausam, Robert R.; Eutropius, Louise J.; Pestotnik, Stanley L.; Duncan, Karen; Staggers, Nancy; Pincetl, Pierre; Samore, Matthew H.

2002-01-01

427

Social Networking Services for Public Spaces University of Oulu, Finland, Department of Computer Science and Engineering  

E-print Network

the possibilities of new technologies from a more practical viewpoint. Mechanism for distributing user interfaces application that blurs the boundaries of online and offline spaces by sharing social media content in public & Riekki J (2010) Social Surroundings: Bridging the Virtual and Physical Divide. IEEE MultiMedia 17

Chaudhuri, Surajit

428

Computational methods for preliminary design and geometry definition in turbomachinery  

NASA Astrophysics Data System (ADS)

A review of the turbomachinery preliminary design process is given with particular emphasis on axial and radial compressors. The review covers the selection of machine type, mean-line analysis and correlations, stagestacking calculations and the use of design charts and optimization techniques to find optimum values for design parameters. A comparison is made between the most successful correlations for endwall losses in axial compressors to highlight the different approaches that are possible. The preliminary design process provides an initial definition of the skeletal geometry of the blading and the annulus of the turbomachine. Turbomachinery design systems are then based on design by analysis, whereby the blading is assessed using CFD codes and is iteratively refined. A numerically based parametric blade geometry definition system makes the use of CFD considerably more effective. Examples of modern turbomachinery geometry definition methods involving Bezier surfaces and B-splines are described.

Casey, M. V.

1994-05-01

429

Computational methods for estimating energy expenditure in human physical activities.  

PubMed

Accurate and reliable methods for assessing human physical activity (PA) energy expenditure (PAEE) are informative and essential for understanding individual behaviors and quantifying the effect of PA on disease, for PA surveillance, and for examining determinants of PA in different populations. This article reviews recent advances in the estimation of PAEE in three interrelated areas: 1) types of sensors worn by human subjects, 2) features extracted from the measured sensor signals, and 3) modeling techniques to estimate the PAEE using these features. The review illustrates three directions in the PAEE studies and provides recommendations for future research, with the aim to produce valid, reliable, and accurate assessment of PAEE from wearable sensors. PMID:22617402

Liu, Shaopeng; Gao, Robert X; Freedson, Patty S

2012-11-01

430

Using computational methods to explore improvements to Knölker's iron catalyst.  

PubMed

Knölker's iron catalyst is characterized by low toxicity and relatively low price in comparison with precious metal catalysts. Density functional theory was used to explore improvements to this catalyst. It was found that electron-withdrawing substituents on the CpOH ring are favorable for improving the efficiency of iron catalysts. Increasing the acidity of CpOH is also an available means of improving the catalytic efficiency. However, replacing the hydroxyl of CpOH with the amino group is not a valid choice for improvement. In contrast, substituting phosphine ligands for carbonyls is the most effective method for improving the catalytic activity of the iron catalyst. But the PR3 ligand must have electron-donating groups and its steric effect should be controlled in a suitable range. Replacing carbonyl groups by PH3 and PPhH2 ligands can effectually improve the catalytic activity for hydrogenation of ketones. PMID:24840123

Lu, Xi; Zhang, Yawei; Turner, Nicholas; Zhang, Mingtao; Li, Tonglei

2014-07-01

431

THE LOS ALAMOS SUPERNOVA LIGHT-CURVE PROJECT: COMPUTATIONAL METHODS  

SciTech Connect

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. [Department of Computer Science, University of New Mexico, Albuquerque, NM 87131 (United States); Even, Wesley; Hungerford, Aimee L. [XTD-6, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Whalen, Daniel J. [Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fontes, Christopher J. [XCP-5, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Colgan, James [T-1, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2013-02-15

432

Combining associative computing and distributed arithmetic methods for efficient implementation of multiple inner products  

NASA Astrophysics Data System (ADS)

Many multimedia processing algorithms as well as communication algorithms implemented in mobile devices are based on intensive implementation of linear algebra methods, in particular, implying implementation of a large number of inner products in real time. Among most efficient approaches to perform inner products are the Associative Computing (ASC) approach and Distributed Arithmetic (DA) approach. In ASC, computations are performed on Associative Processors (ASP), where Content-Addressable memories (CAMs) are used instead of traditional processing elements to perform basic arithmetic operations. In the DA approach, computations are reduced to look-up table reads with respect to binary planes of inputs. In this work, we propose a modification of Associative processors that supports efficient implementation of the DA method. Thus, the two powerful methods are combined to further improve the efficiency of multiple inner product computation. Computational complexity analysis of the proposed method illustrates significant speed-up when computing multiple inner products as compared both to the pure ASC method and to the pure DA method as well as to other state-of the art traditional methods for inner product calculation.

Guevorkian, David; Yli-Pietilä, Timo; Liuha, Petri; Egiazarian, Karen

2012-02-01

433

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

434

An overview of computational simulation methods for composite structures failure and life analysis  

NASA Technical Reports Server (NTRS)

Three parallel computational simulation methods are being developed at the LeRC Structural Mechanics Branch (SMB) for composite structures failure and life analysis: progressive fracture CODSTRAN; hierarchical methods for high-temperature composites; and probabilistic evaluation. Results to date demonstrate that these methods are effective in simulating composite structures failure/life/reliability.

Chamis, Christos C.

1993-01-01

435

An overview of computational simulation methods for composite structures failure and life analysis  

SciTech Connect

Three parallel computational simulation methods are being developed at the LeRC Structural Mechanics Branch (SMB) for composite structures failure and life analysis: progressive fracture CODSTRAN; hierarchical methods for high-temperature composites; and probabilistic evaluation. Results to date demonstrate that these methods are effective in simulating composite structures failure/life/reliability.

Chamis, C.C.

1993-10-01

436

A Monte Carlo method to compute the exchange coefficient in the double porosity model  

E-print Network

A Monte Carlo method to compute the exchange coefficient in the double porosity model Fabien: Monte Carlo methods, double porosity model, ran- dom walk on squares, fissured media AMS Classification: 76S05 (65C05 76M35) Published in Monte Carlo Methods Appl.. Proc. of Monte Carlo and probabilistic

Paris-Sud XI, Université de

437

Nonparaxial method for computing the gradient field of a wavefront using moiré deflectometry  

Microsoft Academic Search

A nonparaxial method in moiré deflectometry to obtain the gradient field of a wavefront under test is proposed. This method uses only two deflectograms without any information about the phase object. As a result, director cosines of the gradient field are computed from moiré fringe deviations on both deflectograms without ambiguities. The method is proved by using a synthetic wavefront

Ricardo Legarda-Sáenz; Ramón Rodr??guez-Vera; Mariano Rivera

1999-01-01

438

Using Survey Methods for Design and Evaluation in Child Computer Interaction  

E-print Network

Using Survey Methods for Design and Evaluation in Child Computer Interaction Janet Read Child@aol.com ABSTRACT This paper begins with a review of some of the current literature on the use of survey methods with children. It then presents four known concerns with using survey methods and reflects on how these may

439

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...

440

Novel methods in computational analysis and design of protein-protein interactions : applications to phosphoregulated interactions  

E-print Network

This thesis presents a number of novel computational methods for the analysis and design of protein-protein complexes, and their application to the study of the interactions of phosphopeptides with phosphopeptide-binding ...

Joughin, Brian Alan

2007-01-01

441

AMSC/CMSC 660 Scientific Computing I UNIT 6: Nonlinear Systems and Continuation Methods  

E-print Network

AMSC/CMSC 660 Scientific Computing I Fall 2008 UNIT 6: Nonlinear Systems and Continuation Methods . Note: The one-dimensional case (n = 1) is covered in CMSC/AMSC 460. The best software for this problem

O'Leary, Dianne P.

442

NEWTON METHOD FOR RIEMANNIAN CENTROID COMPUTATION IN NATURALLY REDUCTIVE HOMOGENEOUS SPACES  

E-print Network

.1 Applications of Center of Mass Computation Moakher in his study of SO(3) [3] mentions the study of plate methods. For example Moakher has a study [3] of the problem in SO(3) in which he presents solutions

Instituto de Sistemas e Robotica

443

Principled computational methods for the validation discovery of genetic regulatory networks  

E-print Network

As molecular biology continues to evolve in the direction of high-throughput collection of data, it has become increasingly necessary to develop computational methods for analyzing observed data that are at once both ...

Hartemink, Alexander J. (Alexander John), 1972-

2001-01-01

444

Computational Method for Drug Target Search and Application in Drug Discovery  

E-print Network

Ligand-protein inverse docking has recently been introduced as a computer method for identification of potential protein targets of a drug. A protein structure database is searched to find proteins to which a drug can bind ...

Chen, Yuzong

445

Systematic Use of Computational Methods Allows Stratifying Treatment Responders in Glioblastoma Multiforme  

E-print Network

Systematic Use of Computational Methods Allows Stratifying Treatment Responders in Glioblastoma. ABSTRACT Cancers are complex diseases whose comprehensive characterization requires genome-scale molecular variables at miRNA, copy number variation, expression, methylation and pathway level in glioblastoma

Kaski, Samuel

446

Computational Methods for Stability and Control (COMSAC): The Time Has Come  

NASA Technical Reports Server (NTRS)

Powerful computational fluid dynamics (CFD) tools have emerged that appear to offer significant benefits as an adjunct to the experimental methods used by the stability and control community to predict aerodynamic parameters. The decreasing costs for and increasing availability of computing hours are making these applications increasingly viable as time goes on and the cost of computing continues to drop. This paper summarizes the efforts of four organizations to utilize high-end computational fluid dynamics (CFD) tools to address the challenges of the stability and control arena. General motivation and the backdrop for these efforts will be summarized as well as examples of current applications.

Hall, Robert M.; Biedron, Robert T.; Ball, Douglas N.; Bogue, David R.; Chung, James; Green, Bradford E.; Grismer, Matthew J.; Brooks, Gregory P.; Chambers, Joseph R.

2005-01-01

447

8th. World Congress on Computational Mechanics (WCCM8) 5th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2008)  

E-print Network

8th. World Congress on Computational Mechanics (WCCM8) 5th European Congress on Computational-mail: marino.arroyo@upc.edu Key Words: meshfree methods, point­sampled surfaces, thin shell analysis ABSTRACT

Huerta, Antonio

448

8th. World Congress on Computational Mechanics (WCCM8) 5th European Congress on Computational Methods in Applied Sciences and Engineeering (ECCOMAS 2008)  

E-print Network

8th. World Congress on Computational Mechanics (WCCM8) 5th European Congress on Computational-adaptivity, meshfree methods, finite-deformation elasticity, optimization ABSTRACT An attractive feature of meshfree

Huerta, Antonio

449

European Congress on Computational Methods in Applied Sciences and Engineering ECCOMAS Computational Fluid Dynamics Conference 2001  

E-print Network

-dimensional Generalised Navier-Stokes equations for incompressible flows. This involves a so-called Taylor-Galerkin finite and a two-step predictor-corrector scheme is assumed. This, in conjunction with a second-order pressure correction method to accommodate the incompressibility constraint, produces a fractional-staged equation

Grant, P. W.

450

Factors Affecting Texas Farm Commodity Prices and Index Computation Methods, 1910-58.  

E-print Network

Factors Affecting Texas Farm Commodity Prices and Index Computation Methods, 1910-58 I. A. Kincannon and G. B. strong* RICE RELATIONSHIPS GREATLY CONCERN THE shown graphically. Figures 1 through 3 illustrate P farmer. Each farmer produces a product... Factors Affecting Texas Farm Commodity Prices and Index Computation Methods, 1910-58 I. A. Kincannon and G. B. strong* RICE RELATIONSHIPS GREATLY CONCERN THE shown graphically. Figures 1 through 3 illustrate P farmer. Each farmer produces a product...

Strong, G. B.; Kincannon, J. A.

1959-01-01

451

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

452

Analysis of the computed torque drive method and comparison with conventional position servo for a computer-controlled manipulator  

NASA Technical Reports Server (NTRS)

A manipulator and its control system (modeled after a Stanford design) is being developed as part of an artificial intelligence project. This development includes an analytical study of the control system software. A comparison is presented of the computed torque method and the conventional position servo. No conclusion is made as to the perference of one system over the other, as it is dependent upon the application and the results of a sampled data analysis.

Markiewicz, B. R.

1973-01-01

453

Reducing computation time in DFP (Davidon, Fletcher & Powell) update method for solving unconstrained optimization problems  

NASA Astrophysics Data System (ADS)

Solving the unconstrained optimization problems is not easy and DFP update method is one of the methods that we can work with to solve the problems. In unconstrained optimization, the time computing needed by the method's algorithm to solve the problems is very vital and because of that, we proposed a hybrid search direction for DFP update method in order to reduce the computation time needed for solving unconstrained optimization problems. Some convergence analysis and numerical results of the hybrid search direction were analyzed and the results showed that the proposed hybrid search direction strictly reduce the computation time needed by DFP update method and at the same time increase the method's efficiency which is sometimes fail for some complicated unconstrained optimization problems.

Sofi, A. Z. M.; Mamat, M.; Ibrahim, M. A. H.

2013-04-01

454

Methods for computing weighting tables based on local power expansion for tristimulus values computations.  

PubMed

In this paper, two types of weighting tables are derived by applying the local power expansion method proposed by Oleari [Color Res. Appl. 25, 176 (2000)]. Both tables at two different levels consider the deconvolution of the spectrophotometric data for monochromator triangular transmittance. The first one, named zero-order weighting table, is similar to weighting table 5 of American Society for Testing and Materials (ASTM) used with the measured spectral reflectance factors (SRFs) corrected by the Stearns and Stearns formula. The second one, named second-order weighting table, is similar to weighting table 6 of ASTM and must be used with the undeconvoluted SRFs. It is hoped that the results of this paper will aid the International Commission on Illumination TC 1-71 on tristimulus integration in focusing on ongoing methods, testing, and recommendations. PMID:22048291

Li, Changjun; Oleari, Claudio; Melgosa, Manuel; Xu, Yang

2011-11-01

455

Simplified methods for computing total sediment discharge with the modified Einstein procedure  

USGS Publications Warehouse

A procedure was presented in 1950 by H. A. Einstein for computing the total discharge of sediment particles of sizes that are in appreciable quantities in the stream bed. This procedure was modified by the U.S. Geological Survey and adapted to computing the total sediment discharge of a stream on the basis of samples of bed sediment, depth-integrated samples of suspended sediment, streamflow measurements, and water temperature. This paper gives simplified methods for computing total sediment discharge by the modified Einstein procedure. Each of four homographs appreciably simplifies a major step in the computations. Within the stated limitations, use of the homographs introduces much less error than is present in either the basic data or the theories on which the computations of total sediment discharge are based. The results are nearly as accurate mathematically as those that could be obtained from the longer and more complex arithmetic and algebraic computations of the Einstein procedure.

Colby, Bruce R.; Hubbell, David Wellington

1961-01-01

456

Under consideration for publication in Formal Aspects of Computing Deriving Dense Linear Algebra  

E-print Network

I, Castell´on, Spain Abstract. Starting in the late 1960s computer scientists including Dijkstra and Hoare advocated goal- oriented programming and the formal derivation of algorithms. The chief impediment to realizing this for loop-based programs was that a priori determination of loop-invariants, a prerequisite

Batory, Don

457

Under consideration for publication in Formal Aspects of Computing Advanced Features of Duration Calculus  

E-print Network

. Davis, A.W. Roscoe and J.C.P Woodcock editors, Millennial Perspectives in Computer Science, Proceedings is inspired by the pioneering work presented in PaR95, PaD88, PWX98, ZH96]. The main contribution

Xu, Qiwen

458

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

459

A publication for College of Computing and Digital Media alumni IN THE LOOP  

E-print Network

notes. On the first day of CSEdWeek, Mayor Rahm Emanuel and Barbara Byrd-Bennett, the CEO of Chicago to the announcement, jobs in computing are among the highest-paid positions for new college graduates, but fewer than skills that are valuable in any field--how to think logically and coherently, how to look at problems

Schaefer, Marcus

460

Current Journals Athena Computers  

E-print Network

BOOKS SCORES Current Journals Athena Computers Group Study Rooms Information Desk Media Computers Reference Collection Restrooms-outside of library Scanner, Copier, Public Printer Special REFERENCE STUDY SPACE PUBLIC COMPUTERS CURRENT JOURNALS SCANNER, COPIER, PUBLIC PRINTER, ATHENA COMPUTER

461

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

462

An Accurate Method for Computing the Absorption of Solar Radiation by Water Vapor  

NASA Technical Reports Server (NTRS)

The method is based upon molecular line parameters and makes use of a far wing scaling approximation and k distribution approach previously applied to the computation of the infrared cooling rate due to water vapor. Taking into account the wave number dependence of the incident solar flux, the solar heating rate is computed for the entire water vapor spectrum and for individual absorption bands. The accuracy of the method is tested against line by line calculations. The method introduces a maximum error of 0.06 C/day. The method has the additional advantage over previous methods in that it can be applied to any portion of the spectral region containing the water vapor bands. The integrated absorptances and line intensities computed from the molecular line parameters were compared with laboratory measurements. The comparison reveals that, among the three different sources, absorptance is the largest for the laboratory measurements.

Chou, M. D.

1980-01-01

463

Methods to identify standard data elements in clinical and public health forms.  

PubMed

The fragmentation of clinical and public health systems results in divergent information collection practices, presenting challenges to standardization and EHR certification efforts. Data forms employed in public health jurisdictions nationwide reflect these differences in patient treatment, monitoring and evaluation, and follow-up, presenting challenges for data integration. To study these variations, we surveyed tuberculosis contact investigation forms from all fifty states, three municipalities and two countries. We apply statistics and cluster analysis to analyze the divergent content of contact investigation forms with the goal of characterizing normative practices and identifying a common core of data fields. We found widespread variation in data elements between states in the study, with the "Name" field being the only ubiquitous data element. Our method reveals distinct groupings of data fields employed in certain regions, allowing the simultaneous identification of core standard data fields as well as variations in practice. PMID:22195051

Abernethy, Neil F; DeRimer, Kathy; Small, Peter M

2011-01-01

464

Distributed-Lagrange-Multiplier-based computational method for particulate flow with collisions  

Microsoft Academic Search

A Distributed-Lagrange-Multiplier-based computational method is developed for colliding particles in a solid-fluid system. A numerical simulation is conducted in two dimensions using the finite volume method. The entire domain is treated as a fluid but the fluid in the particle domains satisfies a rigidity constraint. We present an efficient method for predicting the collision between particles. In earlier methods, a

Arezoo Ardekani; Roger Rangel

2006-01-01

465

Using Survey Methods for Design and Evaluation in Child Computer Interaction  

E-print Network

This paper begins with a review of some of the current literature on the use of survey methods with children. It then presents four known concerns with using survey methods and reflects on how these may impact on studies in Child Computer Interaction. The paper presents some guidelines for HCI researchers and developers intending to use survey methods in their studies with children, and closes with some thoughts about the use of survey methods in this interesting but complex area.

Janet Read

466

Nuclear Instruments and Methods in Physics Research A 558 (2006) 163167 Applications of parallel computational methods to charged-particle  

E-print Network

computational methods to charged-particle beam dynamics$ A. Kabela,Ã?,1 , Y. Caia,1 , M. Dohlusb , T. Senc , R dynamics problems accessible to numerical simulations. We describe recent progress in code development Radiation (CSR) occurs when short bunches travel along strongly bent trajectories, leading to a tail

Sen, Tanaji

467

A fast method to compute Three-Dimensional Infrared Radiative Transfer in non scattering medium  

NASA Astrophysics Data System (ADS)

The Atmospheric Radiation field has seen the development of more accurate and faster methods to take into account absoprtion in participating media. Radiative fog appears with clear sky condition due to a significant cooling during the night, so scattering is left out. Fog formation modelling requires accurate enough method to compute cooling rates. Thanks to High Performance Computing, multi-spectral approach of Radiative Transfer Equation resolution is most often used. Nevertheless, the coupling of three-dimensionnal radiative transfer with fluid dynamics is very detrimental to the computational cost. To reduce the time spent in radiation calculations, the following method uses analytical absorption functions fitted by Sasamori (1968) on Yamamoto's charts (Yamamoto,1956) to compute a local linear absorption coefficient. By averaging radiative properties, this method eliminates the spectral integration. For an isothermal atmosphere, analytical calculations lead to an explicit formula between emissivities functions and linear absorption coefficient. In the case of cooling to space approximation, this analytical expression gives very accurate results compared to correlated k-distribution. For non homogeneous paths, we propose a two steps algorithm. One-dimensional radiative quantities and linear absorption coefficient are computed by a two-flux method. Then, three-dimensional RTE under the grey medium assumption is solved with the DOM. Comparisons with measurements of radiative quantities during ParisFOG field (2006) shows the cability of this method to handle strong vertical variations of pressure/temperature and gases concentrations.

Makke, Laurent; Musson-Genon, Luc; Carissimo, Bertrand

2014-05-01

468

A Computationally Efficient Meshless Local Petrov-Galerkin Method for Axisymmetric Problems  

NASA Technical Reports Server (NTRS)

The Meshless Local Petrov-Galerkin (MLPG) method is one of the recently developed element-free methods. The method is convenient and can produce accurate results with continuous secondary variables, but is more computationally expensive than the finite element method. To overcome this disadvantage, a simple Heaviside test function is chosen. The computational effort is significantly reduced by eliminating the domain integral for the axisymmetric potential problems and by simplifying the domain integral for the axisymmetric elasticity problems. The method is evaluated through several patch tests for axisymmetric problems and example problems for which the exact solutions are available. The present method yielded very accurate solutions. The sensitivity of several parameters of the method is also studied.

Raju, I. S.; Chen, T.

2003-01-01

469

A comparison of computational methods for three-dimensional, turbulent turbomachinery flow fields  

NASA Technical Reports Server (NTRS)

A space-marching method and a time-marching method have been used to compute the three-dimensional turbulent flow in an end wall cascade of airfoils. Using an identical grid and turbulence model, the two codes were used to predict a variety of flow quantities. Predictions by the two methods are compared to each other and to experimental data. In general both methods predict measured quantities well, with a small edge in prediction accuracy going to the space-marching method. Secondary flow comparisons show the time-marching solution more accurately predicting the underturning of the flow in the outer portion of the end wall boundary layer while the space-marching method more accurately predicted the overturning of the flow very near the end wall. The prediction comparisons are discussed along with computational details and other attributes of the two methods.

Kirtley, K. R.; Warfield, M.; Lakshminarayana, B.

1986-01-01

470

A computational method to model radar return range in a polygonally based, computer-generated-imagery simulation  

NASA Technical Reports Server (NTRS)

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 visible to the radar to facilitate the real-time simulation of the radar return. This rapid rejection of the nonvisible polygons requires the precalculation and storage of a set of parameters that do not vary during the simulation. The calculation of a radar range as a function of the radar forward-looking angle to the CGI terrain is carried out only for the visible polygons. This method was used as part of a simulation for terrain-following helicopter operations on the vertical motion simulator at the NASA Ames Research Center. It proved to be an efficient means for returning real-time simulated radar range data.

Moran, F. J.; Phillips, J. D.

1986-01-01

471

Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow computations  

E-print Network

Multiple temperature kinetic model and gas-kinetic method for hypersonic non-equilibrium flow. For the non-equilibrium flow computations, i.e., the nozzle flow and hypersonic rarefied flow over flat plate-kinetic method; Hypersonic and rarefied flows 1. Introduction The development of aerospace technology has

Xu, Kun

472

Applications of Computer Simulation Methods in Plastic Forming Technologies for Magnesium Alloys  

Microsoft Academic Search

Applications of computer simulation methods in plastic forming of magnesium alloy parts are discussed. As magnesium alloys possess very poor plastic formability at room temperature, various methods have been tried to improve the formability, for example, suitable rolling process and annealing procedures should be found to produce qualified magnesium alloy sheets, which have the reduced anisotropy and improved formability. The

S. H. Zhang; W. T. Zheng; Y. L. Shang; X. Wu; G. Palumbo; L. Tricarico

2007-01-01

473

Investigating the Limits of Monte Carlo Tree Search Methods in Computer Go  

E-print Network

Investigating the Limits of Monte Carlo Tree Search Methods in Computer Go Shih-Chieh Huang1, University of Alberta, Edmonton, Canada T6G 2E8 Abstract Monte Carlo Tree Search methods have led to huge- tion of simulations and tree search in Monte Carlo Tree Search is much stronger than either simulation

Müller, Martin

474

A Preconditioned Newton-Krylov Method for Computing Stationary Pulse Solutions of Mode-locked Lasers  

E-print Network

A Preconditioned Newton-Krylov Method for Computing Stationary Pulse Solutions of Mode-locked laser cavity using a preconditioned matrix-implicit Newton-Krylov solver. Solutions are obtained two solving the periodic boundary value problem for the nonlinear cavity using a Newton-Raphson method

Polz, Martin

475

JOURNAL OF COMPUTATIONAL PHYSICS 39, 201-225 (1981) Volume of Fluid (VOF) Method for the  

E-print Network

JOURNAL OF COMPUTATIONAL PHYSICS 39, 201-225 (1981) Volume of Fluid (VOF) Method for the Dynamics the concept of a fractional volume of fluid (VOF). This method is shown to be more flexible and efftcient than, a description is given for an incompressible hydrodynamics code, SOLA-VOF, that usesthe VOF technique to track

Frey, Pascal

476

Computation of incompressible bubble dynamics with a stabilized finite element level set method  

E-print Network

; Bubble dynamics 0045-7825/$ - see front matter � 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.cma), laheyr@rpi.edu (R.T. Lahey Jr.). Comput. Methods Appl. Mech. Engrg. 194 (2005) 4565­4587 www.elsevier.com/locate/cma, combustion and biological industries today. Owing to the advances in numerical methods and as well

Frey, Pascal

477

A new computational method to fit the weighted euclidean distance model  

Microsoft Academic Search

This paper describes a computational method for weighted euclidean distance scaling which combines aspects of an analytic solution with an approach using loss functions. We justify this new method by giving a simplified treatment of the algebraic properties of a transformed version of the weighted distance model. The new algorithm is much faster than INDSCAL yet less arbitrary than other

Jan de Leeuw; Sandra Pruzansky

1978-01-01

478

Adaptive finite element methods for two-dimensional problems in computational fracture mechanics  

NASA Technical Reports Server (NTRS)

Some recent results obtained using solution-adaptive finite element methods in two-dimensional problems in linear elastic fracture mechanics are presented. The focus is on the basic issue of adaptive finite element methods for validating the new methodology by computing demonstration problems and comparing the stress intensity factors to analytical results.

Min, J. B.; Bass, J. M.; Spradley, L. W.

1994-01-01

479

Using Stochastic Approximation Methods to Compute Optimal Base-Stock Levels in Inventory Control Problems  

E-print Network

Using Stochastic Approximation Methods to Compute Optimal Base-Stock Levels in Inventory Control, 2007 Abstract In this paper, we consider numerous inventory control problems for which the base-stock base-stock levels. The existing stochastic approximation methods in the literature guarantee

Topaloglu, Huseyin

480

Computational Methods and Function Theory Volume 11 (2011), No. 2, 655669  

E-print Network

Computational Methods and Function Theory Volume 11 (2011), No. 2, 655­669 Conformal Welding a numerical implementation of conformal welding for finitely connected regions using the geodesic zipper welding, numerical conformal mapping, geodesic al- gorithm, zipper algorithm, Koebe's method. 2000 MSC

481

Method for fast computation of infrared radiation from heated turbulent jets viewed through thick atmospheric layers  

Microsoft Academic Search

The simple effective method for computing the spectral thermal radiation intensity from jets of hydrocarbon fuel combustion products viewing through thick atmosphere layers is proposed. The method is based on (1) similarity of radiation characteristics of optically thin turbulent jets and (2) three-group approximation. The first approach can be used because jet radiation filtered by sufficiently thick atmospheric layer is

Andrey I. Bril; Vitaliy P. Kabashnikov; Yuri V. Khodyko; Natalya V. Kuzmina

1998-01-01

482

Methods, systems, and computer program products for network firewall policy optimization  

DOEpatents

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

483

Monte Carlo methods designed for parallel computation Sheldon B. Opps and Jeremy Scho eld  

E-print Network

Monte Carlo methods designed for parallel computation Sheldon B. Opps and Jeremy Scho#12;eld of these methods is that individual Monte Carlo chains, which are run on a separate nodes, are coupled together- rate calculation, for example to improve the statistics of a Monte Carlo simulation, one inherent bene

Schofield, Jeremy

484

Monte Carlo Methods for Computation and Optimization (048715) Winter 2013/4  

E-print Network

Monte Carlo Methods for Computation and Optimization (048715) Winter 2013/4 Lecture Notes Nahum Shimkin i #12;PREFACE These lecture notes are intended for a first, graduate-level, course on Monte-Carlo, Simulation and the Monte Carlo Method, Wiley, 2008. (2) S. Asmussen and P. Glynn, Stochastic Simulation

Shimkin, Nahum

485

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

486

Phenomenography and Grounded Theory as Research Methods in Computing Education Research Field  

ERIC Educational Resources Information Center

This paper discusses two qualitative research methods, phenomenography and grounded theory. We introduce both methods' data collection and analysis processes and the type or results you may get at the end by using examples from computing education research. We highlight some of the similarities and differences between the aim, data collection and…

Kinnunen, Paivi; Simon, Beth

2012-01-01

487

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) [Ardsley, NY; Blumrich, Matthias Augustin (Ridgefield, CT) [Ridgefield, CT; Chen, Dong (Croton-On-Hudson, NY) [Croton-On-Hudson, NY; Coteus, Paul (Yorktown, NY) [Yorktown, NY; Gara, Alan (Mount Kisco, NY) [Mount Kisco, NY; Giampapa, Mark E. (Irvington, NY) [Irvington, NY; Heidelberger, Philip (Cortlandt Manor, NY) [Cortlandt Manor, NY; Hoenicke, Dirk I. (Ossining, NY) [Ossining, NY; Singh, Sarabjeet (Mississauga, CA) [Mississauga, CA; Steinmacher-Burow, Burkhard D. (Wernau, DE) [Wernau, DE; Takken, Todd (Brewster, NY) [Brewster, NY; Vranas, Pavlos (Bedford Hills, NY) [Bedford Hills, NY

2008-06-03

488

A CLASS OF RECONSTRUCTED DISCONTINUOUS GALERKIN METHODS IN COMPUTATIONAL FLUID DYNAMICS  

SciTech Connect

A class of reconstructed discontinuous Galerkin (DG) methods is presented to solve compressible flow problems on arbitrary grids. The idea is to combine the efficiency of the reconstruction methods in finite volume methods and the accuracy of the DG methods to obtain a better numerical algorithm in computational fluid dynamics. The beauty of the resulting reconstructed discontinuous Galerkin (RDG) methods is that they provide a unified formulation for both finite volume and DG methods, and contain both classical finite volume and standard DG methods as two special cases of the RDG methods, and thus allow for a direct efficiency comparison. Both Green-Gauss and least-squares reconstruction methods and a least-squares recovery method are presented to obtain a quadratic polynomial representation of the underlying linear discontinuous Galerkin solution on each cell via a so-called in-cell reconstruction process. The devised in-cell reconstruction is aimed to augment the accuracy of the discontinuous Galerkin method by increasing the order of the underlying polynomial solution. These three reconstructed discontinuous Galerkin methods are used to compute a variety of compressible flow problems on arbitrary meshes to assess their accuracy. The numerical experiments demonstrate that all three reconstructed discontinuous Galerkin methods can significantly improve the accuracy of the underlying second-order DG method, although the least-squares reconstructed DG method provides the best performance in terms of both accuracy, efficiency, and robustness.

Hong Luo; Yidong Xia; Robert Nourgaliev

2011-05-01

489

Increasing quality of computer-generated kinoforms using direct search with random trajectory method  

NASA Astrophysics Data System (ADS)

Method of increase of quality of computer generated kinoforms is proposed. It is simple direct search method similar to direct binary search method for binary holograms generation. Main difference is that proposed direct search with random trajectory method designed to process arrays with multiple phase levels. First, kinoform is generated with conventional method such as Gerchberg-Saxton. Then, elements of kinoform are sequentially switched to obtain lower normalized standard deviation (NSTD) of reconstructed image from desired image. This process goes on until minimum NSTD drop level is reached. Proposed method provides average NSTD decrease 26%.

Bondareva, Alyona P.; Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Rodin, Vladislav G.; Starikov, Sergey N.

2014-09-01

490

Opinions of the Dutch public on palliative sedation: a mixed-methods approach  

PubMed Central

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 i