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An Empirical Study of Representation Methods for Reusable SoftwareComponents
No full textAn empirical study of methods for representing reusable software components is described. Thirty-five subjects searched for reusable components in a database of UNIX tools using four different representation methods: attribute-value, enumerated, faceted, and keyword. The study used Proteus, a reuse library system that supports multiple representation methods. Searching effectiveness was measured with recall, precision, and overlap. Search time for the four methods was also compared. Subjects rated the methods in terms of preference and helpfulness in understanding components. Some principles for constructing reuse libraries, based on the results of this study, are discussed
Situational Analysis with the Task Mapping Model (TMM): A Tutorial
No full textThe Task Mapping Model (TMM) is a user-centered analysis technique providing methods and notations for use in human-computer interaction (HCI) task analysis (Mayo & Hartson, 1993). The primary function of the TMM is to synthesize new design requirements based on usability problems, user task descriptions, user class profiles, user knowledge requirements, and current user interface designs. The TMM does not, however, derive new design specifications or high/low level interface designs
Software Reuse Metrics and Models: A Survey
No full textThis paper is no longer available. It has been replaced by TR-95-07
Nonlinear Thermal Waves: Part II - Analytical Solutions for Pulses
No full textThe weak shock theory developed by Cramer (1994) is used to derive explicit solutions for the evolution of one-dimensional weakly, nonlinear, weakly relaxing heat pulses in rigid conductors. Formulas and differential equations governing the evolution of general heat inputs are derived and applied to the special cases of a square-wave heat input and a finite width sine-wave heat input. Numerical solutions to the exact Maxwell-Cattaneo theory are also presented and show excellent agreement with these analytical solutions
Parallel Discrete Event Simulation: A Modeling MethodologicalPerspective
No full textThe field of parallel discrete event simulation is entering a period of self-assessment. Fifteen years of investigation has seen great strides in techniques for efficiently executing discrete event simulations on parallel and distributed machines. Still, the discrete event simulation community at large has failed to recognize much of these results. One reason for this is perhaps a disagreement in the focus and purpose of the parallel discrete event simulation research community (primarily computer scientists) and the discrete event simulation community (a widely diverse group including operations researchers, statisticians, as well as computer scientists). An examination of the parallel discrete event simulation problem from a modeling methodological perspective illustrates some of these differences and reveals potentials for their resolution
Improved Genetic Algorithm for the Design of Stiffened Composite Panels
No full textThe design of composite structures against buckling presents two major challenges to the designer. First, the problem of laminate stacking sequence design is discrete in nature, involving a small set of fiber orientations, which complicates the solution process. Therefore, the design of the stacking sequence is a combinatorial optimization problem which is suitable for genetic algorithms. Second, many local optima with comparable performance may be found. Most optimization algorithms find only a single optimum, while often a designer would want to obtain all the local optima with performance close to the global optimum. Genetic algorithms can easily find many near optimal solutions. However, they usually require very large computational costs. Previous work by the authors on the use of genetic algorithms for designing stiffened composite panels revealed both the above strength and weakness of the genetic algorithm. The present paper suggests several changes to the basic genetic algorithm developed previously, and demonstrates reduced computational cost and increased reliability of the algorithm due to these changes. Additionally, for a stiffened composite panel used in this study, designs lighter by about 4 percent compared to previous results were obtained
Reuse Level Metrics
No full textReuse level is an abstract metric that can be applied to any reusable asset. This paper presents extensions to the reuse level metric, defines the metric formally, and discusses an implementation of the abstract metric for C in an enhanced version of the rl program
Seeing Things Your Way: Information Visualization for a User-Centered Database of Computer Science Literature
No full textProject Envision is a user-centered multimedia database of computer science literature. Envision features powerful information visualization by displaying search results as a matrix of icons, with layout semantics under user control. Its Graphic View interacts with Item Summary and Preview Item windows to give users access to bibliographic information and abstracts. The concepts underlying these windows are being extended to a Graphical Browser for the full database and for hierarchical structures. This paper describes the development process and information visualization facilities in Envision search results and browsing displays
Validation, Verification, and Testing Techniques Throughout the Life Cycle of a Simulation Study
No full textLife cycle validation, verification, and testing (VV&T) is extremely important for the success of a simulation study. This paper surveys current software VV&T techniques and current simulation model VV&T techniques and describes how they can all be applied throughout the life cycle of a simulation study. The processes and credibility assessment stages of the life cycle are described and the applicability of the VV&T techniques for each stage is stated. A glossary is provided to explicitly define important terms and VV&T techniques
Detecting Delaminations in Composite Structures Using Anti-Optimization
No full textThe present study proposes a detection technique for delaminations in a laminated composite structure. The proposed technique optimizes the spatial distribution of harmonic excitation so as to magnify the difference between the delaminated and intact structure. The technique is evaluated by numerical simulation of two-layered aluminum beams. Effects of measurement and geometric noises are included in the analysis. A finite element model for a delaminated composite, based on the layer-wise laminated plate theory in conjunction with a step function to simulate delaminations, is used