T H E aim of histoand cytochemical studies is to identify and eventually to quantitate substances on a microscopic level. This necessitates isolating extremely small areas for analysis, preferably in the intact biological tissue. Physical methods have proven to be of value in this respect, in particular the radiant energy micro-absorption techniques (Fitzgerald & Engstrom, 1952). The field of h...

Growing interest in providing and improving radio coverage for mobile phones and wireless LANs inside buildings has recently emerged. The need of such coverage appears mainly in office buildings, shopping malls in very complex environment. Although the three dimensional FDTD method has shown great promise, the calculation time is very environment dependent and exceeds the calculation time of ra...

Ambient occlusion has proven to be a useful tool for producing realistic images, both in offline rendering and interactive applications. In production rendering, ambient occlusion is typically computed by casting a large number of short shadow rays from each visible point, yielding unparalleled quality but long rendering times. Interactive applications typically use screen-space approximations ...

In recent years, interactive ray tracing has become realisable, albeit mainly using clustered workstations and sophisticated acceleration structures. On nonclustered computer architectures this is still not an easy task to achieve, especially when rendering animated scenes, even though the computation power of modern workstations is increasing rapidly. In this paper we propose commonly known im...

The generation of photorealistic images is one of the major topics in computer graphics. By using the principles of physical light propagation, images that are indistinguishable from real photographs can be generated. This computation, however, is a very time-consuming task. When simulating the real behavior of light, individual images can take hours to be of sufficient quality. For this reason...

X-Ray diffraction is the only method currently available for the determination of the detailed three-dimensional structure of macromolecules. In this article, the principles behind the use of X-ray crystallography in the study of protein structure are presented. The results obtained in its application to several enzymes are discussed, as well as the limitations of the method.

During the last years, a number of novel X-ray imaging and data processing methods have been developed. This work gives an overview of some selected X-ray computed tomography (CT)-developments, which are relevant for research and industry: 1) Advanced CT-data processing and visualization methods: Only through processing, segmentation, evaluation and visualization of CT data, insights of a sampl...

We study the performance of affine arithmetic as a replacement for interval arithmetic in interval methods for ray casting implicit surfaces. Affine arithmetic is a variant of interval arithmetic designed to handle the dependency problem, and which has improved several interval algorithms in computer graphics.