Volume rendering is a computerized visualization technique that can be used to identify critical portions and specific regions of interest in various applications including medicine or biology. Localization and segmentations can be conducted and rendered dynamically such that navigation and operations within the volumetric dataset can be implemented. This paper describes our work on immersive VR image processing and visualization. A system is being developed with motion tracking and a pen-like stylus in this project in order to assist the bio-medical science research. This will provide a six degree-of-freedom 3D motion control that eases the control for volume manipulation and data extraction in a 3D environment. Together with a stereovision system, it will provide the user with a full 3D interactive environment in virtual reality (VR) for medical and cell biological applications

Anti-aliasing in form factor computation and precise determination of shadow boundaries are important issues for radiosity method. A-buffer is a technique introduced by L. Carpenter (1984) for anti-aliasing in hidden surface removal. In this paper, we propose a method based on the A-buffer to replace the Z-buffer in the computation of form factors using the Hemicube for anti-aliasing. The method directly computes shadow boundaries in contrast to the adaptive re-meshing approach. Though the processing of shadow boundaries is not fast, only one discontinuity meshing (no iteration) is required. We implement the method in an infrastructure building design system.

This paper presents the results of a propagation survey and the actual performance of a subsequently installed troposcatter system between East and West Malaysia, a distance of 739 km (463 mi), mainly over water. The survey was carried out at 1840 MHz and the installed system uses the 900-MHz band. The path attenuation results are compared with predictions based on the International Radio Consultative Committee (CCIR) method. The noise performances of the installed system with a capacity of 48 voice channels are compared against CCIR objectives for the hypothetical reference circuit.