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We present a framework for the solution of control and estimation problems under a signal-to-noise (SNR) ratio constraint. The framework can be used to design optimal linear controllers, based on output feedback, with two degrees of freedom: One part of the controller is placed before the communication channel and represents sensing and encoding operations. The other part represents decoding and i

In his licentiate thesis, Calle Sjöström sums up his own and Certec's experience from almost five years' work on haptic interfaces for people with disabilities. The haptic technology tested have great potential for future development, but need refinement

Evaluation of IT investments is a difficult and complicated issue. This chapter presents a framework for control of IT investments with the aim of providing decision-makers with a clear picture of individual IT investments as well as an aggregated level where all IT investments are combined into a total picture. The framework has been developed using an action–research approach.In a number of work

High-level modeling languages are receiving increased industrial and academic interest within several domains, such as chemical engineering, thermo-fluid systems and automotive systems. One such modeling language is Modelica. Modelica is an open language, specifically targeted at multi-domain modeling and model re-use. Key features of Modelica include object oriented modeling, declarative equation

An analytical stiffness and eigenfrequency model of symmetric parallel 6-6 Stewart platforms (hexapods) is developed based on geometrical design variables to optimize the dynamical performance. The model is based upon Lagrangean dynamics in which the Bryant angles are used for the kinematics formulation. With the analytical eigenfrequency model, optimum stiffness characteristics can be obtained fo

This paper presents current results of an ongoing project to develop a Modelica base library for thermohydraulic systems. There are many different aspects to the development of such a library, fromthe basic physics of fluids and heat to the structuring of model classes in the library and the actual implementation in the Modelica language. The structuring should define interfaces and partial classe

A new chemical reactor, the Open Plate Reactor (OPR), is being developed by Alfa Laval AB. It has a very flexible configuration with distributed inlet ports, cooling zones and internal sensors. This gives the OPR improved control capabilities compared to standard chemical reactors in addition to better heat transfer capacity. In this paper, we address the relationship between the process design,

This paper reports the work on implementing a parallel version of Pascal on a small scale multiprocessor computer. A few simple primitives were included to support parallel programming. The code generation, linking and loading procedures are described. An overview of the hardware is included. Finally some programming experience with the system is reported.

A bilinear system model of a continuous tank reactor from a biotechnology application (F. Mandenius et al., 1987) is studied. The concentrations of the substrate sugar and the product ethanol were measured on-line and utilized to control the flow-rate through the fermenter. The system can be integrated analytically making it possible to describe the reachable sets. Limited controllability is found

Composition is a practice of key importance in software engineering. When real-time applications are composed it is necessary that their timing properties (such as meeting the deadlines) are guaranteed. The composition is performed by establishing an interface between the application and the physical platform. Such an interface does typically contain information about the amount of computing capac