651,920 research outputs found

    Development of a Collaborative Design Tool for Structural Analysis in an Immersive Virtual Environment

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    This paper contains the results of an on-going collaborative research effort by the departments of Architecture and Computer Science of Virginia Polytechnic Institute and State University, U.S.A., to develop a computer visualization application for the structural analysis of building structures. The VIRTUAL-SAP computer program is being developed by linking PC-SAP4 (Structural Analysis Program), and virtual environment software developed using the SVE (Simple Virtual Environment) library. VIRTUAL-SAP is intended for use as a collaborative design tool to facilitate the interaction between the architect, engineer, and contractor by providing an environment that they can walk-through and observe the consequences of design alterations. Therefore, this software can be used as an interactive computer-aided analysis of building systems

    Understanding Next-Generation VR: Classifying Commodity Clusters for Immersive Virtual Reality

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    Commodity clusters offer the ability to deliver higher performance computer graphics at lower prices than traditional graphics supercomputers. Immersive virtual reality systems demand notoriously high computational requirements to deliver adequate real-time graphics, leading to the emergence of commodity clusters for immersive virtual reality. Such clusters deliver the graphics power needed by leveraging the combined power of several computers to meet the demands of real-time interactive immersive computer graphics.However, the field of commodity cluster-based virtual reality is still in early stages of development and the field is currently adhoc in nature and lacks order. There is no accepted means for comparing approaches and implementers are left with instinctual or trial-and-error means for selecting an approach.This paper provides a classification system that facilitates understanding not only of the nature of different clustering systems but also the interrelations between them. The system is built from a new model for generalized computer graphics applications, which is based on the flow of data through a sequence of operations over the entire context of the application. Prior models and classification systems have been too focused in context and application whereas the system described here provides a unified means for comparison of works within the field

    On the simulation of interactive non-verbal behaviour in virtual humans

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    Development of virtual humans has focused mainly in two broad areas - conversational agents and computer game characters. Computer game characters have traditionally been action-oriented - focused on the game-play - and conversational agents have been focused on sensible/intelligent conversation. While virtual humans have incorporated some form of non-verbal behaviour, this has been quite limited and more importantly not connected or connected very loosely with the behaviour of a real human interacting with the virtual human - due to a lack of sensor data and no system to respond to that data. The interactional aspect of non-verbal behaviour is highly important in human-human interactions and previous research has demonstrated that people treat media (and therefore virtual humans) as real people, and so interactive non-verbal behaviour is also important in the development of virtual humans. This paper presents the challenges in creating virtual humans that are non-verbally interactive and drawing corollaries with the development history of control systems in robotics presents some approaches to solving these challenges - specifically using behaviour based systems - and shows how an order of magnitude increase in response time of virtual humans in conversation can be obtained and that the development of rapidly responding non-verbal behaviours can start with just a few behaviours with more behaviours added without difficulty later in development

    C-Sheep: Controlling Entities in a 3D Virtual World as a Tool for Computer Science Education

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    One of the challenges in teaching computer science in general and computer programming in particular is to maintain the interest of students, who often perceive the subject as difficult and tedious. To this end, we introduce C-Sheep, a mini-language-like system for computer science education, using a state of the art rendering engine, usually found in entertainment systems. The intention is to motivate students to spend more time programming, which can be achieved by providing an enjoyable experience. Computer programming is an essential skill for software developers and as such is always an integral part of every computer science curriculum. However, even if students are pursuing a computer science related degree, it can be very difficult to interest them in the act of computer programming, the writing of software, itself. In the C-Sheep system this is addressed by using the visual gimmickry of modern computer games, which allows programs to provide instant visualisation of algorithms. This visual feedback is invaluable to the understanding of how the algorithm works, and - if there are unintended results - how errors in the program can be debugged. The C-Sheep programming language is a (100% compatible) subset of the ANSI C programming language. Apart from just being a tool for learning the basics of the C programming language, C-Sheep implements the C control structures that are required for teaching the basic computer science principles encountered in structured programming. Unlike other teaching languages which have minimal syntax and which are variable free to provide an environment with minimal complexity, C-Sheep allows the declaration and use of variables. C-Sheep also supports the definition of sub-routines (functions) which can be called recursively. "The Meadow" virtual environment is the virtual world in which entities (in our case sheep) controlled by C-Sheep programs exist. This micro world provides a graphical representation of the algorithms used in the programs controlling the virtual entities. Their position and orientation within the virtual world visualise the current state of the program. "The Meadow" is based on our proprietary "Crossbow" game engine which incorporates a virtual machine for executing CSheep programs. The Crossbow Engine is a compact game engine which is flexible in design and offers a number of features common to more complex engines. The Crossbow Virtual Machine used with C-Sheep in "The Meadow" - an improvement on the ZBL/0 virtual machine - is a module of the Crossbow Engine. The C-Sheep system also provides a counterpart library for C, mirroring the CSheep library functions of the virtual machine. This allows C-Sheep programs to be compiled into an executable using a normal off-the-shelf C/C++ compiler. This executable can then be run from within the native working environment of the operating system. The purpose of this library is to simplify the migration from the educational mini-language to real-world systems by allowing novice programmers to make an easy transition from using the C-Sheep system to using the C programming language

    Virtual acoustic system with a multichannel headphone

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    The performance of current virtual acoustic systems is highly sensitive to the geometry of the individual ear at high frequencies. The objective of this paper is to study a virtual acoustic system which may be not sensitive to individual ear shape. The incident sound field around the ear is reproduced by using a multichannel headphone. The results of computer simulations show that the desired sound pressure at the eardrum can be successfully replicated in a virtual acoustic environment by using a multichannel headphone

    Evaluation of usage patterns for web-based educational systems using web mining

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    Virtual courses often separate teacher and student physically from one another, resulting in less direct feedback. The evaluation of virtual courses and other computer-supported educational systems is therefore of major importance in order to monitor student progress, guarantee the quality of the course and enhance the learning experience for the student. We present a technique for the usage evaluation of Web-based educational systems focussing on behavioural analysis, which is based on Web mining technologies. Sequential patterns are extracted from Web access logs and compared to expected behaviour

    Using teleporting, awareness and multiple views to improve teamwork in collaborative virtual environments

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    Mobile Group Dynamics (MGDs) are a suite of techniques that help people work together in large-scale collaborative virtual environments (CVEs). The present paper describes the implementation and evaluation of three additional MGDs techniques (teleporting, awareness and multiple views) which, when combined, produced a 4 times increase in the amount that participants communicated in a CVE and also significantly increased the extent to which participants communicated over extended distances in the CVE. The MGDs were evaluated using an urban planning scenario using groups of either seven (teleporting + awareness) or eight (teleporting + awareness + multiple views) participants. The study has implications for CVE designers, because it provides quantitative and qualitative data about how teleporting, awareness and multiple views improve groupwork in CVEs. Categories and Subject Descriptors (according to ACM CCS): C.2.4 [Computer-Communication Networks]: Distributed Systems – Distributed applications; H.1.2 [Models and Principles]: User/Machine Systems – Human factors; Software psychology; H.5.1 [Information Interfaces and Presentation]: Multimedia Information Systems – Artificial, augmented and virtual realities; H.5.3 [Information Interfaces and Presentation]: Group and Organization Interfaces – Collaborative computing; Computer-supported cooperative work; Synchronous interaction; I.3.7[Computer Graphics]: Three Dimensional Graphics and Realism – Virtual Realit

    Implementation of NASTRAN on the IBM/370 CMS operating system

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    The NASA Structural Analysis (NASTRAN) computer program is operational on the IBM 360/370 series computers. While execution of NASTRAN has been described and implemented under the virtual storage operating systems of the IBM 370 models, the IBM 370/168 computer can also operate in a time-sharing mode under the virtual machine operating system using the Conversational Monitor System (CMS) subset. The changes required to make NASTRAN operational under the CMS operating system are described

    Agent mediation and management of virtual communities: a redefinition of the traditional community concept

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    The paper explores the evolution of the concept of community in the light of computer mediated immersive virtual environments. The traditional concept of community has become strained in its attempts to capture the evolving virtual community. We believe the concept of the virtual community is of paramount importance and examine the extent to which this is being redefined to cater for it. We examine the management and mediation of such an environment and specifically the social process associated with the cohabited users. We advocate the use of multi-agent systems in delivering this functionalit