Hans J. W. Spoelder

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The Distributed ASCI Supercomputer (DAS) is a homogeneous wide-area distributed system consisting of four cluster computers at different locations. DAS has been used for research on communication software, parallel languages and programming systems, schedulers, parallel applications, and distributed applications. The paper gives a preview of the most(More)
This paper presents an innovative method to analyze and visualize time-dependent evolution of features. The analysis and visualization of time-dependent data are complicated because of the immense number of data involved. However, if the scientist's main interest is the evolution of certain features, it suffices to show the evolution of these features. The(More)
The estimation of protein secondary structure from circular dichroism spectra is described by a multivariate linear model with noise (Gauss-Markoff model). With this formalism the adequacy of the linear model is investigated, paying special attention to the estimation of the error in the secondary structure estimates. It is shown that the linear model is(More)
Most research in parallel rendering has focused on widely used immediate mode interfaces (mainly OpenGL) or on retained mode interfaces designed for parallel rendering only. In this paper, we describe parallel implementations of the Aura API which provides a multi-platform graphics interface using a retained mode paradigm. Using several test applications in(More)
The Polder Computing Environment, a system for interactive distributed simulation K. A. Iskra1, , R. G. Belleman, G. D. van Albada, J. Santoso, P. M. A. Sloot, H. E. Bal, H. J. W. Spoelder and M. Bubak4,5 1 Section Computational Science, Universiteit van Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands 2 Division of Mathematics and Computer(More)
We present the CAVEStudy system that enables scientists to interactively steer a simulation from a virtual reality (VR) environment. No modification to the source code is necessary. CAVEStudy allows interactive and immersive analysis of a simulation running on a remote computer. We describe three case-studies implemented with CAVEStudy.
This paper presents an innovative method to analyze and visualize time-dependent evolutions of features. The analysis and visualization of time-dependent data is complicated because of the immense amount of data involved. However, if the scientist's main interest is the evolution of certain features, it suffices to show the evolution of these features. The(More)
OBJECTIVES To prove the feasibility of a local CT system as a method of CT suitable for use in dentistry. METHODS Using an experimental set-up consisting of an X-ray source, a turntable and a charge-coupled device (CCD) detector connected to a PC, CT scans were made of a single molar and a dry mandible. Slices were reconstructed using filtered(More)
We describe a Virtual Reality system that allows users at different locations to interact with a multi-agent system in a natural way. We use RoboCup (robot soccer) as a case study. A human player who is immersed in a CAVE can interact with the RoboCup simulation in its natural domain, by playing along with a virtual soccer game. The system supports(More)