Theory, Software and Testing Examples in Decision Support Systems

This volume summarizes the results of a four-year cooperative contracted study "Theory, Software and Testing Examples for Decision Support Systems" conducted in Poland by four institutions: the Institute of Automatic Control, Warsaw University of Technology, the System Research Institute of the Polish Academy of Sciences, the Institute of Control and Systems Engineering, Academy of Mining and Metallurgy in Cracow, and the Institute of Informatics, University of Warsaw in cooperation with the Methodology of the Decision Analysis Project of the System and Decision Sciences Program at IIASA. This research was supported mostly by IIASA funds in Polish national currency, but also by other sources and research grants in Poland, such as the grant RP.1.02 of the Ministry of Education for research in optimization and automatic control; totally, it represents the results of a part-time work of about 30 researchers from these institutions. This volume concentrates on the theoretical and methodological advances of this cooperative study, although it describes also experiences of applications in the area of programming the development of chemical industry together with a decision support system for such purposes as well as presents short descriptions of eight software packages (prototype decision support systems, multiobjective mathematical programming packages and a pilot negotiation support system) that are available together with more detailed documentation as scientific software constituting a part of results of this study. The research on the Polish side was coordinated by Professor Andrzej P. Wierzbicki and on IIASA's side by Dr. Andrzej Lewandowski, the project leader of the Methodology of Decision Analysis; they served also as the editors of this volume

Animating Coupling between Inviscid Free-Surface Liquids and Elastic Deformable Bodies

Driven by demand for high-fidelity computer-generated imagery, physics-based animation has become an exciting frontier of research in computer science. Simulations of fluids and their interactions with other objects in the environment have particularly enjoyed much attention and investigation. Consequently, effective techniques have been developed to efficiently simulate two-way coupling between fluids and rigid bodies, allowing for convincing animation of, for instance, ships on the ocean. On the other hand, accurately capturing interactions between fluids and deformable solids has proven to be much more elusive. In particular, satisfaction of boundary conditions poses a significant difficulty, as the straightforward voxelized treatment suffers from visible grid artefacts, whereas use of a conforming mesh greatly increases the computational overhead of a simulation. This thesis investigates the problem of animating two-way coupling effects between free-surface liquids and linearly elastic solids. Aside from presenting simulation techniques for such liquids and solids separately, we introduce a new approach to simulating their interactions that exhibits several notable advantages over previous techniques. By fully incorporating the dynamics of the solid into pressure projection, we simultaneously handle fluid incompressibility and solid elasticity and damping. Thanks to this strong coupling, our method does not suffer from instability, even in very taxing scenarios. Furthermore, use of a cut-cell discretization methodology allows us to accurately apply proper free-slip boundary conditions at the exact solid-fluid interface. Consequently, our method is capable of correctly simulating inviscid tangential flow, devoid of grid artefacts or artificial sticking. Lastly, we present an efficient algebraic transformation to convert the indefinite coupled pressure projection system into positive-definite form. The thesis also contains an evaluation of our proposed method, including several animation scenarios, as well as comparisons to previous techniques

Aspiration Based Decision Support Systems

This book focuses the methodology of decision analysis and support related to the principle of reference point optimization (developed by the editors of this volume and called also variously: aspiration-led decision support, quasi-satisfying framework of rationality, DIDAS methodology etc.). The selection principle applied for this volume was to concentrate on advances of theory and methodology, related to the focusing theme, to supplement them by experiences and methodological advances gained through wide applications and tests in one particular application area - the programming of development of industrial structures in chemical industry, and finally to give a very short description of various software products developed in the contracted study agreement

2D finite volume model for groundwater flow simulations : integrating non-orthogonal grid capability into modflow

The modular finite-difference groundwater flow model MODFLOW is one of the most widely used groundwater modelling programs, and is applicable to most types of flow problems in its field. However, its finite difference formulation decreases its ability to simulate accurately natural aquifer geometries. To enhance its capability in simulating such boundaries, a finite volume scheme has been developed for inclusion in MODFLOW. In this study, the two-dimensional formulation has been considered. Three discretisations of the two-dimensional diffusion equation, governing groundwater flow and for use with structured quadrilateral meshes, have been developed. The three methods rely on a cell-centred finite volume approach, but show distinct differences in the choice of: gradient approximation, head interpolations and control volume. A time implicit formulation has been used in each model. The sparse system of linear equations that result from the implicit formulation has been solved by using an iterative solver, based on the strongly implicit procedure. Five test examples have been undertaken to compare the performance of the newly developed methods against MODFLOW predictions and analytical results. The accuracy of the results obtained was found to depend on the spatial and temporal discretisations. One of the three developed methods proved its robustness, with regard to mesh non-orthogonality and skewness, and was called the GWFV method. In a second step of studies, a field case study was used to test the preferred model. A mesh generator using a structured quadrilateral grid was used to produce the finite volume mesh of the simulated area. The results of MODFLOW and the GWFV model simulations were compared against field observations. A discussion about the performance of the new developed model has been included and the model has been shown to perform well in comparison with MODFLOW. Keywords: numerical models, finite volume discretisations, groundwater flow models, MODFLOW, non-orthogonal grid

Treatment of Later Humoral Rejection with Anti-CD20 Monoclonal Antibody Rituximab: A Single Centre Experience

Humoral or vascular rejection is a B cell-mediated production of immunoglobulin (Ig) G antibody against a transplanted organ that results in immune complex deposition on the vascular endothelium, activation of the complement cascade, production of endothelial dysfunction and regional ischaemic injury