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Using Virtual Environments in the Teaching of Computer Graphics
Get PDFEducation has long been touted as an appropriate
application area for immersive virtual environments
(VEs), but few immersive applications have actually been
used in the classroom, and even fewer have been
compared empirically with other teaching methods. This
paper presents VENTS, a novel immersive VE application
intended to teach the concept of the three-dimensional
(3D) normalizing transformation in an undergraduate
computer graphics class. VENTS was developed based on
key principles for the use of VEs in education,
systematically evaluated for usability, and refined based
on the results of this evaluation. Students in a university
course used VENTS, and their learning was compared to
that of other students who either attended a lecture on the
topic or used a 3D desktop application covering the same
material. The results of pre- and post-tests showed a
larger percent increase in test score for the VE group
than the desktop or lecture groups, although these
differences are not statistically significant
A Genetic Algorithm for Mixed Integer Nonlinear Programming Problems Using Separate Constraint Approximations
Get PDFThis paper describes a new approach for reducing the number of the fitness and constraint function evaluations required by a genetic algorithm (GA) for optimization problems with mixed continuous and discrete design variables. The proposed additions to the GA make the search more effective and rapidly improve the fitness value from generation to generation.The additions involve memory as a function of both discrete and continuous design variables, and multivariate approximation of the individual functions' responses in terms of several continuous design variables. The approximation is demonstrated for the minimum weight design of a composite cylindrical shell with grid stiffeners
Testbed Evaluation of Navigation and Text Display Techniques in an Information-Rich Virtual Environment
Get PDFInformation-Rich Virtual Environment (IRVE) is a virtual environment (VE) that is enhanced with the addition of related abstract information. Such an environment conveys rich information set that can make the VE more useful if provided with a useful interface and efficient interaction techniques. This motivates our current research goals to investigate the interface and interaction issues involved in IRVE. The fundamental question is how to access and display information in an effective way. This paper presents the first controlled experiment using a travel testbed based on our text layout taxonomy. We investigated two manipulation-based navigation techniques: Hand-Centered Object Manipulation Extending Ray0casting (HOMER) and Go-Go based navigation, and two text layout techniques; within-the-world display (WWD) and heads-up display (HUD). Four search tasks with repeated measures were performed to measure subjects performance in a densely packed environment. We found that using Go-Go based navigation combined with HUD techniques is significantly better than the other three combinations for difficulty search tasks. HUD enabled better performance than WWD and Go-Go technique enabled better performance than HOMER technique ro most of the tasks. Also users preferred the combination of Go-Go and HUD for all tasks. Such results on their own, or combined with specific application characteristics, can provide valuable design guidelines for IRVEs
Claims Reuse for Notification Systems Design: LINK-UP Vision and IRC Equations
Get PDFExtending previous work on the concept of claims reuse, an approach for cataloging and reusing design knowledge in human-computer interaction, we introduce a vision for a system, LINK-UP. The system is intended to parallel a usability engineering process that involves claims analysis. While we initially target notification system design support, we believe that the general method is extensible to other design concerns. A key aspect of the LINK-UP system is its iterative assessment of critical parameters---essential target values that describe anticipated user goals. In notification systems design, three critical parameters are interruption, reaction, and comprehension, referred to as IRC. While the parameter values represent abstract concepts, a pivotal challenge in the development of LINK-UP is determining methods for consistent and accurate parameter specification. To this end, we introduce equations for calculating user's model IRC parameters, either from analytical or empirical data. Presented here are details of variable justification and equation behavior. Future work will assess consistency and accuracy of artifact classifications using the equations
Designing of a Community-based Translation Center
Get PDFInterfaces that support multi-lingual content can reach a broader community. We wish to extend the reach of CITIDEL, a digital library for computing education materials, to support multiple languages. By doing so, we hope that it will increase the number of users, and in turn the number of resources. This paper discusses three approaches to translation (automated translation, developer-based, and community-based), and a brief evaluation of these approaches. It proposes a design for an online community translation center where volunteers help translate interface components and educational materials available in CITIDEL
Requirements Management Tools: A Quantitative Assessment
Get PDFThis report is primarily aimed at people with some background in Requirements Engineering or practitioners wishing to assess tools available for managing requirements. We provide a starting point for this assessment, by presenting a brief survey of existing Requirements Management tools. As a part of the survey, we characterize a set of requirements management tools by outlining their features, capabilities and goals. The characterization offers a foundation to select and possibly customize a requirements engineering tool for a software project. This report consists of three parts. In Part I we define the terms requirements and requirements engineering and briefly point out the main components of the requirements engineering process. In Part II, we survey the characteristics and capabilities of 6 popular requirements management tools, available in the market. We enumerate the salient features of each of theses tools. In Part III, we briefly describe a Synergistic Environment for Requirement Generation. This environment captures additional tools augmenting the requirements generation process. A description of these tools is provided. In the concluding section, we present a discussion defining the ideal set of characteristics that should be embodied in a requirements management tool. This report is adapted from a compendium of assignments that were prepared by the students in a Requirements Engineering class offered in the Department of Computer Science at Virginia Tech
Pipeline Implementation of Cellular Automata for Structural Design on Message-Passing Multiprocessors
No full textThe inherent structure of cellular automata is trivially parallelizable and can directly benefit from massively parallel machines in computationally intensive problems. This paper presents both synchronous and pipeline parallel implementations of cellular automata on distributed memory (message-passing) architectures. A structural design problem is considered to study the performance of the various cellular automata implementations. The synchronous parallel implementation is a mixture of Jacobi and Gauss-Seidel style iteration, where it is more Jacobi like as the number of processors increase. Therefore, it exhibits divergence because of the mathematical characteristics of Jacobi matrix iteration for the structural problem as the number of processors increases. The proposed pipeline implementation preserves convergence by simulating a pure Gauss-Seidel iteration. Numerical results for analysis and design of a cantilever plate made of composite material show that the pipeline update scheme is convergent and successfully generates optimal designs
Digital Library logging using XML
Get PDFThis project explores the various ways in which relevant statistics can be extracted from digital library logs collected in XML. A set of potential statistics that can be used for performing clickstream analysis are listed. Clickstream analysis deals with the path taken by the user when he/she is using the digital library site.
This project also involves visualization of the statistics collected. Visualizations are an intuitive way to represent raw data and they can help in gaining more insight into the statistics.
The target digital library was CITIDEL and the XML logs collected from this digital library were used in the project. We also designed and developed a prototype for collection of statistics and visualizing them. Implementation of the tools was done using Java and PHP. JpGraph was used for building visualizations in PHP
Design and Display of Enhancing Information in Desktop Information-Rich Virtual Environments: Challenges and Techniques
Get PDFInformation-Rich Virtual Environments (IRVEs) have been described as environments in which perceptual information is enhanced with abstract (or symbolic) information such as text, numbers, images, audio, video, or hyperlinked resources. Desktop VE applications present the same information design and layout challenges as immersive VEs, but in addition, they may also be integrated with external windows or frames commonly used in desktop interfaces. This paper enumerates design approaches for the display of enhancing information both internal and external to the virtual world?s render volume. Using standard web-based software frameworks, we explore a number of implicit and explicit spatial layout methods for the display and linking of abstract information, especially text. Within the virtual environment view, we demonstrate both Heads-Up-Displays and encapsulated scenegraph behaviors we call Semantic Objects. For desktop displays, which support information display venues external to the scene, we demonstrate the linking and integration of the scene with web browsers and the Snap-Together visualization a system. Finally, we describe the application of these techniques in the PathSim Visualizer, an IRVE interface for the biomedical domain. These design techniques are relevant for instructional and informative interfaces for a wide variety of desktop VE applications
Optimization and Blending of Composite Laminates Using Guide based Genetic Algorithms
No full textComposite panel structure optimization is commonly decomposed
into panel optimization subproblems, with specified local loads,
resulting in manufacturing incompatibilities between adjacent
panel designs. A new method proposed here for constructing
globally blended panel designs uses a parallel decomposition
antithetical to that of earlier work. Rather than performing
concurrent panel genetic optimizations, a single genetic
optimization is conducted for the entire structure with the
parallelism solely within the fitness evaluations. A guide
based genetic algorithm approach is introduced to exclusively
generate and evaluate valid globally blended designs, utilizing
a simple master-slave parallel implementation, implicitly
reducing the size of the problem design space and increasing
the quality of discovered local optima