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Configuration Management for Reusable Software ?
Get PDFThis paper discusses the configuration management of reusable software, and proposes a software libarary architecture that incorporates configuration management.
A Domain Decomposition Preconditioner for Hermite Collocation Problems
Get PDFWe propose a preconditioning method for linear systems of equations arising from piecewise Hermite bicubic collocation applied to two dimensional elliptic PDEs with mixed boundary conditions. We construct an efficient, parallel preconditioner for the GMRES method. The main contribution of the paper is a novel interface preconditioner derived in the framework of substructuring and employing a local Hermite collocation discretization for the interface subproblems based on a hybrid fine-coarse mesh. Interface equations based on this mesh depend only weakly on unknowns associated with subdomains. The effectiveness of the proposed method is highlighted by numerical experiments that cover a variety of problems
Multiple Foci Drill-Down through Tuple and Attribute Polyarchies in Tabular Data.
Get PDFInformation analysis often involves decomposing data into sub-groups to allow for comparison and identification of relationships. Breakdown Visualization provides a mechanism to support this analysis through user guided drill-down of polyarchical metadata. This metadata describes multiple hierarchical structures for organizing tuple aggregation and table attributes. This structure is seen in sport statistics, financial data, organizational structures, and other fields. A spreadsheet format enables comparison of visualizations at each level of the hierarchy. Breakdown Visualization allows users to drill-down a single hierarchy then pivot into another hierarchy within the same view. We utilize a fix and move technique that allows users to select multiple foci for drill-down. We present an analysis scenario that demonstrates how Breakdown Visualization can be used to perform financial statement analysi
Probabilistic Modeling of Errors from Structural Optimization Based on Multiple Starting Points
Get PDFWith optimization increasingly used in engineering applications, a series of optimization runs may be required, and
it may be too expensive to converge them to very high accuracy. A procedure for estimating average optimization
convergence errors from a set of poorly converged optimization runs is developed. A probabilistic model is fitted to
the errors in optimal objective function values of poorly converged runs. The Weibull distribution was identified as
a reasonable error model both for the Rosenbrock function problem and the structural optimization of a high speed
civil transport. Once a statistical model for the error is identified, it can be used to estimate average errors from a set
of pairs of runs. In particular, by performing pairs of optimization runs from two starting points, accurate estimates
of the mean and standard deviation of the convergence errors can be obtained
Usability Inspection Report of NCSTRL
Get PDFAn evaluation report of the www.ncstrl.org site outlining usability problems and solutions to these problems
WBCSim: An Environment for Modeling Wood-Based Composites Manufacturing
No full textThis paper describes a computing environment WBCSim that increases the productivity of wood scientists conducting research on wood-based composite materials and manufacturing processes. WBCSim integrates Fortran 90 simulation codes with a Web-based graphical front end, an optimization tool, and various visualization tools. WBCSim serves as an example for the design, construction, and evaluation of small-scale problem solving environments. WBCSim supports six models. A detailed description of the system architecture and a typical scenario of usage are presented, along with optimization and visualization features
XML for ETDs
Get PDFThe main objective of this project was to devise a tool/procedure to aid students at Virginia Tech in developing their electronic theses and dissertations (ETDs) in eXtensible Markup Language (XML) and to document properly all the work that was done at Virginia Tech in this regard. The project began by studying the other ETD-XML projects done earlier. Both the approaches (DTD and XSD) explored at Virginia Tech were studied and an attempt was made to improve the XSD approach using VBA (Visual Basic for Applications). The proposed approach was completely implemented and documented in a way that should be easy for the students to comprehend. This should help ease student efforts to prepare theses in XML
DIVERSE: a Software Toolkit to Integrate Distributed Simulations with Heterogeneous Virtual Environments
Get PDFWe present DIVERSE (Device Independent Virtual Environments- Reconfigurable, Scalable, Extensible), which is a modular collection of complimentary software packages that we have developed to facilitate the creation of distributed operator-in-the-loop simulations. In DIVERSE we introduce a novel implementation of remote shared memory (distributed shared memory) that uses Internet Protocol (IP) networks. We also introduce a new method that automatically extends hardware drivers (not in the operating system kernel driver sense) into inter-process and Internet hardware services. Using DIVERSE, a program can display in a CAVEâ„¢, ImmersaDeskâ„¢, head mounted display (HMD), desktop or laptop without modification. We have developed a method of configuring user programs at run-time by loading dynamic shared objects (DSOs), in contrast to the more common practice of creating interpreted configuration languages. We find that by loading DSOs the development time, complexity and size of DIVERSE and DIVERSE user applications is significantly reduced. Configurations to support different I/O devices, device emulators, visual displays, and any component of a user application including interaction techniques, can be changed at run-time by loading different sets of DIVERSE DSOs. In addition, interpreted run-time configuration parsers have been implemented using DIVERSE DSOs; new ones can be created as needed.
DIVERSE is free software, licensed under the terms of the GNU General Public License (GPL) and the GNU Lesser General Public License (LGPL) licenses.
We describe the DIVERSE architecture and demonstrate how DIVERSE was used in the development of a specific application, an operator-in-the-loop Navy ship-board crane simulator, which runs unmodified on a desktop computer and/or in a CAVE with motion base motion queuing
Usability Evaluation in Virtual Environments: Classification and Comparison of Methods
Get PDFVirtual environments (VEs) are a relatively new type of human-computer interface in which users perceive and act in a three-dimensional world. The designers of such systems cannot rely solely on design guidelines for traditional two-dimensional interfaces, so usability evaluation is crucial for VEs. We present an overview of VE usability evaluation. First, we discuss some of the issues that differentiate VE usability evaluation from evaluation of traditional user interfaces such as GUIs. We also present a review of VE evaluation methods currently in use, and discuss a simple classification space for VE usability evaluation methods. This classification space provides a structured means for comparing evaluation methods according to three key characteristics: involvement of representative users, context of evaluation, and types of results produced. To illustrate these concepts, we compare two existing evaluation approaches: testbed evaluation [Bowman, Johnson, & Hodges, 1999], and sequential evaluation [Gabbard, Hix, & Swan, 1999]. We conclude by presenting novel ways to effectively link these two approaches to VE usability evaluation