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Addressing the challenges of extreme scale computing re- quires holistic design of new programming models and sys- tems that support those models. This paper discusses the Angstrom processor, which is designed to support a new Self-aware Computing (SEEC) model. In SEEC, applications explicitly state goals, while other systems components provide actions that the SEEC runtime system can use to meet
We consider the classical 3-state Moore-Greitzer model, which is commonly used for approximating dynamics of deviations of flow and pressure variables in an axial compressor from their nominal steady-state values. The linearization of the nonlinear system is not controllable and, therefore, even local asymptotic stability cannot be achieved using methods of linear control theory. We propose a fami
Distributed Decision Making and Control is a mathematical treatment of relevant problems in distributed control, decision and multi-agent systems, The research reported was prompted by the recent rapid development in large-scale networked and embedded systems and communications. One of the main reasons for the growing complexity in such systems is the dynamics introduced by computation and communi
Popular Abstract in Swedish Denna avhandling presenterar nya metoder för att analysera bilder på hjärtat för att utesluta eller bekräfta kranskärlssjukdom. Hjärtat har en livsviktig uppgift, att pumpa runt blodet för att förse alla kroppens organ med energi och syre. Vid förträngningar i kärlen som försörjer hjärtmuskeln med blod (kranskärlen) uppkommer ett tillstånd som kallas ischemisk hjärtsjukIn this thesis, methods for automated analysis of myocardial perfusion single photon emission computer tomography (myocardial perfusion SPECT, MPS) images have been successfully developed and evaluated. MPS images show the perfusion of the myocardium and are used for diagnosing patients with suspected ischemic heart disease. The disease is characterized by reduced perfusion to a region of the myoc
A particle filter based solution to the out-of-sequence measurement (OOSM) problem is proposed. The solution is storage efficient, while being computationally fast. The filter approaches the multi-OOSM problem by not only updating the estimate at the most recent time, but also for all times between the OOSM time and the most recent time. This is done by exploiting the complete in-sequence informat
To the purpose of marine seismic acquisition, new acoustic sources have been developed to reduce the environmental impact. The use of marine vibrators makes it possible to define emission frequency ranges, consequently allowing limitation of the frequencies that disturb marine animal life. Constructing marine vibrators with high efficiency and linear dynamics is however difficult, and the vibrator
Abstract in UndeterminedStabilization and optimal control is studied for state space systems with nonnegative coefficients (positive systems). In particular, we show that a stabilizing distributed feedback controller, when it exists, can be computed using linear programming. The same methods are also used to minimize the closed loop input-output gain. An example devoted to distributed control of a
In absence of covariance data, Kalman filters are usually initialized by guessing the initial state. Making the variance of the initial state estimate large makes sure that the estimate converges quickly and that the influence of the initial guess soon will be negligible. If, however, only very few measurements are available during the estimation process and an estimate is wanted as soon as possib
The application of feedback control to computing systems is a promising research area, but has to date been hindered by the almost unanimously perceived complexity in creating control-oriented system models. Computing systems are in fact considered very hard to describe with dynamic models allowing for simple and powerful control design tools, so that complex ones need bringing in to the detriment
Decentralised and scalable conditions for robust stability of networks of heterogenous linear time-invariant (LTI) systems are derived based on integral quadratic constraints. These generalise previous works in the literature with an increased flexibility in the choice of multipliers employed. The results allow for arbitrary interconnection matrices and accommodate multi-input-multi-output systems
To fulfill increasing requirements in the manufacturing sector, companies are faced with several challenges. Three major challenges have been identified regarding time-to-market, vertical feedback loops and level of automation. Grafchart, a graphical language aimed for supervisory control applications, can be used from the process-planning phase, through the implementation phase and all the way to
When a feedback controller is implemented in a networked embedded system, the computations and communications induce delays and jitter, which may destabilize the control loop. The majority of previous work on analysis of control loops with time-varying delays has focused on output (actuation) jitter. In many embedded systems, input (sampling) jitter is also an issue. In this paper, we analyze the
We consider a wind power plant of megawatt wind turbines operating in derated mode. When operating in this mode, the wind power plant controller is free to distribute power set-points to the individual turbines, as long as the total power demand is met. In this work, we design a controller that exploits this freedom to reduce the fatigue on the turbines in the wind power plant. We show that the co
Advances in Intelligent Transport Systems (ITS), intelligent vehicles and cooperative systems are enabling traffic and transport solutions that are both safer and more environmentally acceptable. While it is well known that high dependability is a desirable feature it has a price, and the level of dependability needed varies from application to application. Typical examples are cooperative safety
Three approaches of iterative learning control (ILC) applied to a Gantry-Tau parallel kinematic robot aC algorithms using 1) measured motor angles, 2) tool-position estimates, and for evaluation purposes, 3l position. The approaches are compared experimentally, with the tool performance evaluated using extert is concluded that the tool performance can be improved using tool-position estimates in t
In this paper an order reduction method for spatially distributed models is presented. Such systems may be modeled as two nodes interacting with each other through feedback. A model of one of the nodes reduced in such a way, that the closed loop performance is approximated. The method exploits a coprime factor description of the closed loop model and semidefinite programming. The method is related
Clock synchronization is a necessary component in modern distributed systems, especially WSN. Despite the great effort and the numerous improvements, the existing synchronization schemes do not yet address the cancellation of propagation delays. Up to a few years ago, this was not perceived as a problem, because the time-stamping precision was a more limiting factor for the accuracy achievable wit
