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In application areas that process stream-like data such as multimedia, networking and DSP, the pipelined concurrent processing is frequently represented as a dataflow network of communicating computational kernels connected by FIFO queues. However, while dataflow is a natural medium for conceptualizing and modeling stream-processing systems, its adoption as a programming methodology has been hinde
Monitoring of permafrost has been ongoing since 1978 in the Abisko area, northernmost Sweden, when measurements of active layer thickness started. In 1980, boreholes were drilled in three mires in the area to record permafrost temperatures. Recordings were made twice per year, and the last data were obtained in 2002. During the International Polar Year (2007-2008), new boreholes were drilled withi
The welding procedure to seal copper canisters requires variable power input throughout the 45 minute long weld cycle to keep the probe temperature within the process window. By using a cascaded loop that determines the power input requirement, the controller will not be dependent on repeatability in the necessary power input between weld cycles, and the lag time in the probe temperature measureme
The equation-based Modelica language allows the modeller to specify custom functions. The body of a function is an algorithm that contains procedural code to be executed when the function is called. This language feature is useful for many applications; however, the insertion of a function often prevent model optimizations that require the model to be formulated in purely declarative form by equat
We present a decomposition approach to a class of social welfare optimization problems for optimal power flow in multi-region electricity networks. The electricity network is decomposed into multiple regions which decide independently over the amount of power produced within the region and exchanged with neighboring regions. We decompose the overall power flow (or social welfare) optimization into
Control-Based Operating System Design describes the application of system- and control-theoretical methods to the design of computer operating system components. It argues that computer operating system components should not be first “designed" and then “endowed with control", but rather conceived from the outset as controllers, synthesised and assessed in the system-theoretical world of dynamic m
This paper presents an exploration framework which performs data assignment and access scheduling exploration for applications given a multilayer memory architecture. Our framework uses multiobjective criteria during exploration, such as application execution time, energy, bandwidth, and data size. In order to tackle the complexity of the exploration, it is divided into three phases; Pareto diagra
To improve traffic safety it is important to evaluate the safety of roads and intersections. Today this requires a large amount of manual labor so an automated system using cameras would be very beneficial. We focus on the geometric part of the problem, that is, how to get accurate three-dimensional data from images of a road or an intersection. This is essential in order to correctly identify dif
Utilities, such as steam and cooling water, are often shared between several production areas at industrial sites, and the effects of disturbances in utilities could thus be hard to predict. In addition, production areas could be connected because of the product flow at the site. This paper introduces a simple modeling approach for modeling the relation between utility operation and production. Us
Context: The authors wanted to assess whether the quality of published human-centric software engineering experiments was improving. This required a reliable means of assessing the quality of such experiments. Aims: The aims of the study were to confirm the usability of a quality evaluation checklist, determine how many reviewers were needed per paper that reports an experiment, and specify an ap
Execution trace graph analysis of dataflow programs has been demonstrated to be an effective way for exploring and optimizing the design space of many core applications. In this work a novel transformation from the execution trace graph to an event driven linear system is proposed. It is also illustrated how the trace space of can be effectively reduced and well known system control techniques can
The paper presents a CPS-oriented course that integrates control theory and embedded computing. The course combines concurrent real-time programming and analysis with discrete-time sampled control theory and real-time networking. The contents of course, including the course projects are described in the paper as well as the experiences with the course.
This paper highlights the issues of detecting Java concurrency bugs using static code analysis tools. Concurrency bugs are often hard to find because of interleaving threads and there is need to use static analysis tools to detect the concurrency bugs. In the literature review, we established that there are number of static analysis tools such as FindBugs, JLint and Chord, used in experiments to d
This paper considers switching output feedback control of linear systems and variable structure systems. Theory for stability analysis and design for a class of observer-based feedback control systems is presented. A circle-criterion approach can be used to design an observer-based state feedback control which yields a closed-loop system with specified robustness characteristics. The approach is r
