Vinesh Raja

Cybersphere: the fully immersive spherical projection system

The computer generated virtual environments made possible by virtual reality (VR) may be moved through and manipulated by users in real time [1], but most display methods, including computer monitors, head-mounted displays, or projection screens, have an important limitation—they do not allow users to move around the virtual environment in a natural way. Efforts to remove this limitation include the development in the U.S. of a device similar to a stationary unicycle [3], which attempts to simulate the walking motion of a person sitting upon it. But this lessthan-ideal solution introduces its own restrictions on freedom of movement. By contrast, freedom of movement is not restricted with the fully immersive spherical projection system known as the Cybersphere, developed through joint research by VR Systems and the University of Warwick, both in the U.K. Users who enter this spherical system—which represents a new approach to VR visualization—can walk, run, jump, or crawl in any direction, while at the same time being able to observe an allencompassing virtual environment. In this article we describe where the Cybersphere fits in the world of virtual reality interfaces, and discuss ways it can be applied to a cross-sectional audience, ranging from simple component visualization to highly complex military simulations. Since the advent into VR in 1965, when Ivan Sutherland presented a paper describing the concepts of the Head Mounted Display (HMD), several systems have been developed to “perceive” physical objects. The Cybersphere, launched in October 2000, is the latest such system; others include the cathode ray tube (CRT), the head mounted display (HMD), the binocular omni-oriented monitor (BOOM), and a projection screen environment known as a CAVE. Following is a brief description of each.

Incorporated tool selection system using object technology

Abstract Tool selection is perhaps one of the most important functions in a process planning system because the selection of a tool affects the selection of machining parameters, jig and fixture selection, production rate, cost of the product, and the resulting accuracy. Therefore computer-aided tool selection (CATS) is an essential element within a computer-aided process planning (CAPP) system (C. Koulamas, Tool requirements in multi-level machining systems, International Journal of Production Research, 29 (2) (1991) 417–437.), and in turn in a Computer Integrated Manufacturing (CIM) environment. This paper proposes an object–oriented methodology for selecting the tooling parameters for parts in a CIM environment. As this system can be incorporated into both static and dynamic process planning systems, it is termed as Incorporated Tool Selection Systems (ITSS). The steps of the methodology are discussed in detail, together with an example.

Applications of virtual reality in product design evaluation

Product evaluation throughout various stages of a design process is crucial to the final products success, and this may be a costly, time consuming and logistically complex process. Currently there are limited product design evaluation tools available to provide better support to the whole product design and development process. Virtual reality (VR) has matured to become useful technology to support efficient and effective product design and development applications. This paper reports an investigation on applying VR technologies to computer aided product evaluation. The research work has concentrated on: i) investigating the potential of emerging VR based technologies such as three dimensional (3D) haptic interaction and 3D stereoscopic viewing, ii) integrating and implementing these VR based technologies into a computer aided product evaluation application and iii) exploring the efficiency and effectiveness of these VR based technologies in comparison with traditional techniques used during the product design evaluation process.

Rapid prototyping models and their quality evaluation using reverse engineering

Abstract This paper presents the results of a systematic research project carried out for evaluating the quality of a wide range of rapid prototyping (RP) models used in the manufacture of wax patterns for investment casting. The evaluation was based on geometrical accuracy, surface finish, visual inspection of RP patterns and the final casting process, compatibility with the standard casting process and casting quality based on X-ray analysis. A real high-integrity aerospace component was selected for these trials. Eight RP models of this component were constructed for each of the six different RP technologies. Based upon the requirements of the industrial applications, eight geometrical parameters for the example component have been chosen for the evaluation. These are four orientation angles, two diameters, one roundness and one surface flatness. Reverse engineering technology has been applied for the measurement of these eight parameters to overcome the difficulties faced by conventional inspection methods. In this paper it is hoped to present a comprehensive evaluation of the quality of the RP models for each RP method investigated. The findings provide meaningful information for industry to select RP technology best suited to their production requirements in order to reduce the leading time of product development.

Introduction to reverse engineering

This chapter introduces readers to the term reverse engineering (RE), and to the associated techniques that can be used for scanning physical parts. In addition, the chapter presents the process of reverse engineering and the strategy for scanning and converting the scanned data into a 3-D surface or solid model.

Exercise improvement after pectus excavatum repair is not related to chest wall function

OBJECTIVES In patients undergoing corrective surgery for pectus excavatum, there is evidence of improvement in cardiopulmonary function. It is unclear how much of this improvement is attributable to improved chest wall function. Thus, we observed changes in chest wall function in response to an incremental load exercise pre- and postoperatively. METHODS Using optoelectronic plethysmography, total and regional chest wall volumes were measured in 7 male patients with severe pectus excavatum who underwent a Nuss correction. Rib cage and abdominal volumes were recorded at rest and during exercise (incremental cycle ergometry), pre- and postoperatively in conjunction with spirometry. RESULTS Tidal volume increases during exercise are blunted compared with baseline measurements at 6 days (-36 ± 7%) partially recovering at 6 months postoperatively (-18 ± 22%). This is mirrored by changes in spirometry. Tidal volume decreased during exercise initially in all compartments, but persisted in the rib cage compartment. An increase of 44% (P = 0.009) in exercise tolerance was found 6 months after surgical correction. CONCLUSIONS Six months after Nuss correction in pectus patients, there was a decrease in rib cage mobility. Despite reduction, patients had a significant improvement in exercise tolerance. Therefore, we conclude that early postoperative improvement in exercise capacity is not due to changes in chest wall function. The longer term effects on chest wall function are yet to be defined.

A practical knowledge transfer system: a case study

This research paper is concerned with the problem of making “knowledge flow” practical for a wide variety of companies. The paper discusses the need for a practical solution to knowledge transfer and demonstrates how the challenges of knowledge transfer were overcome in a cross‐functional environment using the principles of object technology. The proposed concept, by offering a structured approach to knowledge transfer, allows organisations to create systems based on simple but effective knowledge transfer processes, which will integrate with legacy computing systems.

Optimum level of goal mapping in a reengineering environment

Today’s business world is facing a plethora of managerial and technological changes which are beyond the capacity of any firm to control or absorb. Customer satisfaction, development of new products, and introduction of new technologies are well‐known driving forces, but their fast mutation and turmoil are making them unpredictable. Companies have to radically alter their strategic and process goals to keep up with this volatile market. In this turbulent environment, business process reengineering (BPR) has evolved as the most promising approach for designing organizations. It is extremely important for reengineers to understand the “driving” forces in this environment. One of the most important and fundamental drivers is understanding the goals (goal mapping) of the organization. Typically the goals of organizations are derived from the “voice of the customer”. In this paper we address a procedure by which optimum level of goal mapping can be considered in the preliminary stages of BPR. A cost optimization model for goal mapping is proposed using an example from the Space Shuttle Testing Facility at the SSC‐National Aeronautics and Space Administration.

Chapter 4: Simulating a Deformable Object Using a Surface Mass Spring System

This paper introduces volume springs that provide the volume effect to a surface model when it is deformed. The estimation of the properties of the model takes the real material properties into consideration, where each spring stiffness is derived based on the elasticity, rigidity and compressibility modulus. The proposed model can be adopted to simulate soft objects such as a deformable human breast, and it can be further extended to address other material properties.

Collaborative design review in a distributed environment

Publisher Summary This chapter investigates how collaborative environment technology can be used to integrate geographically dispersed design teams and other technical and non-technical members from within and outside the organization to support collaborative product design reviews. The creation of such a collaborative environment for design allows participants from different phases of the product development cycle to collaborate and form a virtual team. The chapter proposes a new framework to extend the current advances in collaborative technologies to provide access to local and global resources within design teams and the deployment of private and public design review workspaces to provide an efficient collaborative design environment. Also, a prototype collaborative computer-aided design (CAD) environment has been developed and the results are discussed.