In this master’s thesis we focus on the basic properties of computer curves and their practical applicability. We explain how the curve can be understood in general, what are polynomial curves and their composing possibilities. Then we focus on the description of Bezier curves, especially the Bezier cubic. We discuss in more detail some of fundamental algorithms that are used for modelling these curves on computers and then we will show their practical interpretation. Then we explain non uniform rational B-spline curves and De Boor algorithm. In the end we discuss topic rasterization of segment, thick line, circle and ellipse. The aim of master’s thesis is the creation of the set of interactive applets, simulating some of the methods and algorithm we discussed in theoretical part. This applets will help facilitate understanding and will make the teaching more effective.

Today, many organisations are adopting offices that have an open design with or without flexible seating. While advocates of open-plan offices propose that these office types lead to cost savings and aid inter and intra-team communication, opponents argue that these office types are associated with decreased performance and worsened health among employees. This thesis investigates how the type of office (cell offices, shared room offices, small open-plan offices, medium-sized open plan offices, large open-plan offices and flex offices) influences employee health and performance, and whether this is different for different personalities and jobs with different concentration demands. Data were gathered by means of surveys and cognitive tests from five organisations with different office types. In Study I (N=1241), the aim was to investigate the main effect of office type on indicators of health and performance and the interaction effect of office type with the need to concentrate in order to carry out work tasks. Office type alone was associated with distraction and cognitive stress in such a way that cell offices were associated with fewest problems, followed by flex offices, while open-plan offices were associated with the most problems. While employees in open-plan offices and employees in flex offices reported more problems as the need for concentration increased, employees in cell offices reported the same level of problems regardless of the need of concentration. Study II (N=527) investigated how performance on a memory test was affected during normal working conditions as compared to a quiet baseline. There was a negative dose-response relationship between the size of the open-plan office environment and the drop in word recall during the normal working condition. However, Study II also showed that individuals working in cell offices had as high a drop in performance during normal working conditions as did those working in large open-plan office environments. Study III (N=1133–1171) focused on the interaction effect between office type and individual differences in personality. The personality trait agreeableness interacted with office type on the outcome variables distraction and job satisfaction. Specifically, Study III may indicate that as offices get more open and flexible, agreeable people will report more problems. In conclusion, the studies in the present thesis have implications for practice and suggest that office type impacts on employee health and performance, while concentration demands of the job and agreeableness moderate the effects. Although employees report higher level of distraction in open-plan office environments, when performance on a demanding task is measured, cell offices are not as favourable during normal working conditions as self-reported data usually indicate. Organisations should also be aware that, among open-plan offices, small open-plan offices are associated with fewer problems. / Kontorslandskap med eller utan fasta arbetsstationer förekommer idag i många organisationer. Förespråkare för kontorslandskap hänvisar till kostnadsbesparing samt förbättrade förutsättningar för kommunikation, medan motståndare hävdar att kontorslandskap leder till försämrad prestation och hälsa bland medarbetarna. Denna avhandling undersöker om kontorstyp påverkar de anställdas hälsa och prestation, samt om effekten av kontorstyp varierar beroende på de anställdas personlighet och typ av arbetsuppgifter. Data i form av enkätsvar och prestation på kognitiva tester samlades in från fem organisationer med olika typer av kontorslösningar (cellkontor, delade kontorsrum, små kontorslandskap, mellanstora kontorslandskap, stora kontorslandskap och flexkontor). I studie I (N = 1241) var syftet att undersöka huvudeffekten av kontorstyp på indikatorer för hälsa och prestation samt om effekten är beroende av koncentrationskraven i arbetet. Kontorstyp visade samband med distraktion och kognitiv stress på så sätt att medarbetare i cellkontor uppgav minst problem, följt av de i flexkontor, medan kontorslandskap var förknippade med mer problem. Vidare rapporterade anställda som hade arbetsuppgifter som krävde koncentration mer problem i kontorslandskap och flexkontor, medan anställda i cellkontor, oavsett arbetets krav, rapporterade lika mycket problem. I studie II (N = 527) undersöktes hur prestation på ett minnestest påverkades under normala arbetsförhållanden jämfört med en tyst referensmätning i olika kontorstyper. Det fanns ett negativt dos-responssamband mellan storleken på kontorslandskapet och hur många procent sämre medarbetare presterade under normala arbetsförhållanden. Men Studie II visade också att personer som arbetar i cellkontor hade ett lika högt bortfall i prestation under normala arbetsförhållanden som de som arbetade i stora kontorslandskap. I studie III (N = 1133-1171) låg fokus på interaktionseffekten mellan kontorstyp och personlighet. Vänlighet var den enda personlighetsvariabeln som interagerade med kontorstyp på utfallsvariablerna distraktion och arbetstillfredsställelse. Mer specifikt visade Studie III att när kontoret blir mer öppet och flexibelt, så rapporterar människor som skattar sig högt på personlighetsvariabeln vänlighet fler problem. Resultaten i avhandlingen kan få flera praktiska implikationer då den visar att kontorstyp påverkar medarbetarnas hälsa och prestation, medan koncentrationskrävande arbetsuppgifter och vänlighet modererar effekterna. Vidare visar avhandlingen att även om anställda rapporterar mindre distraktion i cellkontor jämfört med i kontorslandskap, behöver inte cellkontor vara lika gynnsamma som självskattade mått visar när prestationen mäts med objektiva mått under normala arbetsförutsättningar, i det här fallet ett minnestest. Slutligen bör organisationer även vara medvetna om att avhandlingen visar en viss tendens att små kontorslandskap är förknippade med mindre problem än stora. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Manuscript.</p>

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In this master’s thesis we focus on the basic properties of computer curves and their practical applicability. We explain how the curve can be understood in general, what are polynomial curves and their composing possibilities. Then we focus on the description of Bezier curves, especially the Bezier cubic. We discuss in more detail some of fundamental algorithms that are used for modelling these curves on computers and then we will show their practical interpretation. Then we explain non uniform rational B-spline curves and De Boor algorithm. In the end we discuss topic rasterization of segment, thick line, circle and ellipse. The aim of master’s thesis is the creation of the set of interactive applets, simulating some of the methods and algorithm we discussed in theoretical part. This applets will help facilitate understanding and will make the teaching more effective.

Konventionelle, optische Transportnetze haben die Bereitstellung von High-Speed-Konnektivität in Form von langfristig installierten Verbindungen konstanter Bitrate ermöglicht. Die Einrichtungszeiten solcher Verbindungen liegen in der Größenordnung von Wochen, da in den meisten Fällen manuelle Eingriffe erforderlich sind. Nach der Installation bleiben die Verbindungen für Monate oder Jahre aktiv. Das Aufkommen von Grid Computing und Cloud-basierten Diensten bringt neue Anforderungen mit sich, die von heutigen optischen Transportnetzen nicht mehr erfüllt werden können. Dies begründet die Notwendigkeit einer Umstellung auf dynamische, optische Netze, welche die kurzfristige Bereitstellung von Bandbreite auf Nachfrage (Bandwidth on Demand - BoD) ermöglichen. Diese Netze müssen Verbindungen mit unterschiedlichen Bitratenanforderungen, mit zufälligen Ankunfts- und Haltezeiten und stringenten Einrichtungszeiten realisieren können. Grid Computing und Cloud-basierte Dienste führen in manchen Fällen zu Verbindungsanforderungen mit Haltezeiten im Bereich von Sekunden, wobei die Einrichtungszeiten im Extremfall in der Größenordnung von Millisekunden liegen können. Bei optischen Netzen für BoD muss der Verbindungsaufbau und -abbau, sowie das Netzmanagement ohne manuelle Eingriffe vonstattengehen. Die dafür notwendigen Technologien sind Flex-Grid-Wellenlängenmultiplexing, rekonfigurierbare optische Add / Drop-Multiplexer (ROADMs) und bandbreitenvariable, abstimmbare Transponder. Weiterhin sind Online-Ressourcenzuweisungsmechanismen erforderlich, um für jede eintreffende Verbindungsanforderung abhängig vom aktuellen Netzzustand entscheiden zu können, ob diese akzeptiert werden kann und welche Netzressourcen hierfür reserviert werden. Dies bedeutet, dass die Ressourcenzuteilung als Online-Optimierungsproblem behandelt werden muss. Die Entscheidungen sollen so getroffen werden, dass auf lange Sicht ein vorgegebenes Optimierungsziel erreicht wird. Die Ressourcenzuweisung bei dynamischen optischen Netzen lässt sich in die Teilfunktionen Routing- und Spektrumszuteilung (RSA), Verbindungsannahmekontrolle (CAC) und Dienstgütesteuerung (GoS Control) untergliedern. In dieser Dissertation wird das Problem der Online-Ressourcenzuteilung in dynamischen optischen Netzen behandelt. Es wird die Theorie der Markov-Entscheidungsprozesse (MDP) angewendet, um die Ressourcenzuweisung als Online-Optimierungsproblem zu formulieren. Die MDP-basierte Formulierung hat zwei Vorteile. Zum einen lassen sich verschiedene Optimierungszielfunktionen realisieren (z.B. die Minimierung der Blockierungswahrscheinlichkeiten oder die Maximierung der wirtschaftlichen Erlöse). Zum anderen lässt sich die Dienstgüte von Gruppen von Verbindungen mit spezifischen Verkehrsparametern gezielt beeinflussen (und damit eine gewisse GoS-Steuerung realisieren). Um das Optimierungsproblem zu lösen, wird in der Dissertation ein schnelles, adaptives und zustandsabhängiges Verfahren vorgestellt, dass im realen Netzbetrieb rekursiv ausgeführt wird und die Teilfunktionen RSA und CAC umfasst. Damit ist das Netz in der Lage, für jede eintreffende Verbindungsanforderung eine optimale Ressourcenzuweisung zu bestimmen. Weiterhin wird in der Dissertation die Implementierung des Verfahrens unter Verwendung eines 3-Way-Handshake-Protokolls für den Verbindungsaufbau betrachtet und ein analytisches Modell vorgestellt, um die Verbindungsaufbauzeit abzuschätzen. Die Arbeit wird abgerundet durch eine Bewertung der Investitionskosten (CAPEX) von dynamischen optischen Netzen. Es werden die wichtigsten Kostenfaktoren und die Beziehung zwischen den Kosten und der Performanz des Netzes analysiert. Die Leistungsfähigkeit aller in der Arbeit vorgeschlagenen Verfahren sowie die Genauigkeit des analytischen Modells zur Bestimmung der Verbindungsaufbauzeit wird durch umfangreiche Simulationen nachgewiesen. / Conventional optical transport networks have leveraged the provisioning of high-speed connectivity in the form of long-term installed, constant bit-rate connections. The setup times of such connections are in the order of weeks, given that in most cases manual installation is required. Once installed, connections remain active for months or years. The advent of grid computing and cloud-based services brings new connectivity requirements which cannot be met by the present-day optical transport network. This has raised awareness on the need for a changeover to dynamic optical networks that enable the provisioning of bandwidth on demand (BoD) in the optical domain. These networks will have to serve connections with different bit-rate requirements, with random interarrival times and durations, and with stringent setup latencies. Ongoing research has shown that grid computing and cloud-based services may in some cases request connections with holding times ranging from seconds to hours, and with setup latencies that must be in the order of milliseconds. To provide BoD, dynamic optical networks must perform connection setup, maintenance and teardown without manual labour. For that, software-configurable networks are needed that are deployed with enough capacity to automatically establish connections. Recently, network architectures have been proposed for that purpose that embrace flex-grid wavelength division multiplexing, reconfigurable optical add/drop multiplexers, and bandwidth variable and tunable transponders as the main technology drivers. To exploit the benefits of these technologies, online resource allocation methods are necessary to ensure that during network operation the installed capacity is efficiently assigned to connections. As connections may arrive and depart randomly, the traffic matrix is unknown, and hence, each connection request submitted to the network has to be processed independently. This implies that resource allocation must be tackled as an online optimization problem which for each connection request, depending on the network state, decides whether the request is admitted or rejected. If admitted, a further decision is made on which resources are assigned to the connection. The decisions are so calculated that, in the long-run, a desired performance objective is optimized. To achieve its goal, resource allocation implements control functions for routing and spectrum allocation (RSA), connection admission control (CAC), and grade of service (GoS) control. In this dissertation we tackle the problem of online resource allocation in dynamic optical networks. For that, the theory of Markov decision processes (MDP) is applied to formulate resource allocation as an online optimization problem. An MDP-based formulation has two relevant advantages. First, the problem can be solved to optimize an arbitrarily defined performance objective (e.g. minimization of blocking probability or maximization of economic revenue). Secondly, it can provide GoS control for groups of connections with different statistical properties. To solve the optimization problem, a fast, adaptive and state-dependent online algorithm is proposed to calculate a resource allocation policy. The calculation is performed recursively during network operation, and uses algorithms for RSA and CAC. The resulting policy is a course of action that instructs the network how to process each connection request. Furthermore, an implementation of the method is proposed that uses a 3-way handshake protocol for connection setup, and an analytical performance evaluation model is derived to estimate the connection setup latency. Our study is complemented by an evaluation of the capital expenditures of dynamic optical networks. The main cost drivers are identified. The performance of the methods proposed in this thesis, including the accuracy of the analytical evaluation of the connection setup latency, were evaluated by simulations. The contributions from the thesis provide a novel approach that meets the requirements envisioned for resource allocation in dynamic optical networks.

This master thesis aims to develop a test methodology for electromechanical linear actuators. A linear actuator acts as a linear motor, converting a power source to linear motion. The electromechanical linear actuator in this project has an electric motor as its power source and uses a rack and pinion system to transfer that power to linear motion.  The test methodology is to impose a force onto the rack of the actuator, to ensure that operation under a load scenario is within specification. To accomplish this, the design of a test rig implementation is analyzed. The test rig consists of the test unit, which is to be tested, the load unit, which is to provide the load force, and a control system for the load unit. The load unit is another linear actuator and is controlled via a load cell. The load cell gives out the load force being applied, and the controller gives out the corresponding appropriate motor command to the load unit to ensure the load force is as desired. This analysis is done through simulation of the setup. Viable options for the setup were first analyzed in order to implement the deemed promising options for a setup into a simulation environment. The simulation environment in this project was Simscape, an extension of MATLAB’s Simulink. In simulation the parameters for the test rig were rigorously analyzed, in order to determine acceptable thresholds. The primary load unit tested was another electromechanical linear actuator from Cascade Drives, the model A-100-8P. Two secondary setups, one using the same model as being tested, and another setup using two of the models being tested. Simulation found that the suggested options’ applied load force have a poor rise time, large overshoot and substantial oscillation errors. The primary source for this was determined to be the latency between load cell input, and motor command output in the controller. The poor metrics from the result could lead to problems when emergency braking, and with a long honing period, which would render most test data unusable.

Mobile robots need to move in the real world for the majority of tasks. Their control is often intertwined with the tasks they have to solve. Unforeseen events must have an adequate and prompt reaction, in order to solve the corresponding task satisfactorily. A robust system must be able to respond to a variety of events with specific solutions and strategies to keep the system running. Robot navigation control systems are essential for this. In this thesis we present a robot navigation control system that fulfills these requirements: Move Base Flex. Furthermore, the map representation used to model the environment is essential for path planning. Depending on the representation of the map, path planners can solve problems like simple 2D indoor navigation, but also complex rough terrain outdoor navigation with multiple levels and varying slopes, if the corresponding representation can model them accurately. With Move Base Flex, we present a middle layer navigation framework for navigation control, that is map independent at its core. Based on this, we present the Mesh Navigation Stack to master path planning in complex outdoor environments using a developed mesh map to model surfaces in 3D. Finally, to solve path planning in complex outdoor environments, we have developed and integrated the Continuous Vector Field Planner with the aforementioned solutions and evaluated it on five challenging and complex outdoor datasets in simulation and in the real-world. Beyond that, the corresponding developed software packages are open source available and have been released to easily reproduce the provided scientific results.