Search results

The two major aims of this study are (1) To test the performance of the Landscape Reconstruction Algorithm (LRA) to quantify past landscape changes using historical maps and related written sources, and (2) to use the LRA and map reconstructions for a better understanding of the origin of landscape diversity and the recent loss of species diversity. Southern Sweden, hemiboreal vegetation zone. The

This thesis covers areas within estimation and optimal control of vehicles, in particular four-wheeled vehicles. One topic is how to handle delayed and out-of-sequence measurements (OOSMs) in tracking systems. The motivation for this is that with technological development and exploitation of more sensors in tracking systems, OOSMs gain more significance in various applications. The thesis derives

This work describes the two-way coupling performed between the regional atmospheric model Brazilian Regional Atmospheric Modeling System (BRAMS) and the hydrological model MGB-IPH. As a first step of the atmosphere-hydrology coupling, only the water balance variables were coupled. Differences in temporal and spatial scales between MGH-IPH and BRAMS were analyzed. By default, MGB-IPH has a daily ti

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

We consider an optimization problem of joint link rate assignment and transmission scheduling in wireless mesh networks. We assume that each radio link uses (when active) one selected link-dependent modulation and coding scheme. For finding an exact optimum, the problem requires a complicated branch-and-price algorithm that becomes excessively time consuming for networks of practical size. Therefo

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

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.