The focus of this thesis is research on the performance of very low speed direct drive permanent magnet generators for energy conversion from marine and tidal currents. Various aspects involved in the design of these generators and their electromagnetic modelling using the finite element simulations are presented. For a detailed study, a 5 kW prototype generator has been designed and constructed based on finite element based simulations. Several experiments were conducted on the prototype generator. The experimental results were compared with the corresponding case simulations on the designed generator. The differences between the results predicted by the simulations and those predicted by the measurements were less than 10%. The part and overload performance of the generator has been investigated and it is found from both simulations and measurements that the generator is capable to efficiently operate at varying speeds. The tests on the experimental generator were made for speeds between 2 and 16 rpm and for load variations of 0.5 to 2 per unit. In this thesis it is shown that it is possible to design a very low speed direct drive generator for more or less any given marine current site and this is beneficial for projects aiming to develop a technical and economical viable marine current energy conversion system.

Psykoanalysen är ingen vetenskap eftersom den saknar kunskapsobjekt. Med syftet att finna detta objekt och därmed grunda en vetenskap togs avstamp i Freuds begrepp Det Omedvetna. Genom begreppsanalys av Freuds texter och med hjälp av matematisk mängdlära samt nedslag i filosofi och ontologi kunde en första beskrivning av objektet göras. Freuds begrepp visade sig då syfta på ett inlärt men bortträngt Omedvetet som i sin uppbyggnad ligger nära vårt medvetna tänkande. Det sökta objektet däremot, var ett medfött och inte bortträngt psykiskt system med en egen logik, symmetrisk logik, och sannolikt också vårt känslocentrum. Studier av neuropsykoanalys band sedan objektet till Limbiska systemet och det implicita minnet. Här bekräftades att systemet bär våra känslor. Ur författarens praktik hade samtidigt vuxit en idé om att vi föds med en uppsättning bilder av oss själva som är systematiskt ordnade i ett självbildssystem och av grandios natur. Till systemet kunde en livsåskådning knytas som primärt är en idealism. Självbildssystemet skyddades av en homeostatiskt fungerande sjävbildsbevarande drift. Denna drift framstod som vår viktigaste drift. Sexualdrift och självbevarelsedrift intog en sekundär roll. Det fanns sedan fog för att sammanföra det inte bortträngda Omedvetna och självbildssystemet till en enhet och betrakta kombinationen som psykoanalysens kunskapsobjekt. Resultatet hade inflytande på frågor som: den fria viljan, moral, determinism och kunskapssubjektets status. / Psychoanalysis is not a science since it does not have an object of knowledge. With the objective to find such an object and thereby establish a science Freud´s concept the Unconscious was taken as a point of departure with concept analysis of some of Freud´s texts and with help of mathematical set theory and the impact of philosophy and ontology an initial description of the object was made. What Freud had in mind with his concept was a system that was learned and then repressed, a repressed Unconscious, which in its structure is close to our conscious thinking. The requested object of knowledge of psychoanalysis was shown to be an inborn psychical system, which is not repressed, and with its own logic, symmetrical logic, and probably also our centre of feeling/emotion. Studies of neuro-psychoanalysis situated the object in the Limbic system and the implicit memory. This confirmed that the system carries our feelings and emotions. From the author´s practice had grown, at the same time, an idea that we are born with a set of images of ourselves that are systematically arranged in a self-image system of a grandiose nature. The system could be associated with a philosophy that primarily is an idealism. The self-image system was protected by a homeostatic subsystem which aim was conservation of the system. This subsystem took its power from a self-image protecting drive. This drive was found to be our most powerful drive. Sexual desire and self-preservation took a secondary role. It was substantiated that the unrepressed unconscious and the system of self-images shall be treated as one unit and that this combination is the sought for object of knowledge of psychoanalysis. The result had influence on the issues: free will, morality, determinism and the status of the subject of knowledge.

This thesis compares the impact on disk performance in a GNU/Linux  environmentwith three encryption algorithms: AES,  Serpent and Twofish in three different implementations: DM-crypt, Loop-AES and Truecrypt. For all three algorithms a key length of 256 bits is used. The thesis shows that the least performance impact during data encryption, and thus file writing, is reached by using AES or Twofish encryption implemented in DM-crypt or TrueCrypt. The thesis shows that some data operations with a sufficiently low processor utilization barely affects disk performance at all if encrypted using the optimal implementation and algorithm. It is also discovered that the performance impact during data decryption, or file reading, can be minimized by using the most efficient implementation and algorithm. The best results are met with the AES or Twofish cipher, regardless of implementation. An important conclusion that  is  drawn is that it is hard to determine a superior encryption solution for all purposes. However, by reviewing and examining the collected data from all aspects of disk performance the AES implementation in TrueCrypt is, with small marginals, determined to be the most optimal. / Undersökningen jämför hur krypteringsalgoritmerna AES, Serpent och Twofish implementerade i DM-crypt, Loop-AES och TrueCrypt påverkar diskprestandan i en GNU/Linux-miljö. Samtliga krypteringsalgoritmer tillämpas med en nyckellängd på 256 bitar. Undersökningen visar att högst skrivhastighet och således krypteringshastighet uppnås med algoritmerna AES och Twofish i DM-crypt eller Truecrypt. Krypteringens påverkan på diskprestanda är beroende av vilka typer av operationer som utförs och hur hög processorsysselsättningsgraden är. Vid  simplare  I/O-operationer har  den mest optimala  krypteringslösningen knappt någon påverkan på diskprestandan överhuvudtaget. Undersökningen visar också att påverkan av prestanda vid dekryptering är minst vid tillämpning av AES eller Twofish oavsett implementering. En viktig slutsats som dras är att det inte finns en överlägsen krypteringslösning för samtliga användningsområden. Genom att sammanställa och granska insamlad data gällande samtliga aspekter beträffande diskprestanda fastställs TrueCrypts implementation av AES till att vara den mest optimala, trots små marginaler.

Diese Arbeit entstand an der Professur für Fahrzeugmodellierung und –simulation der TU Dresden in Zusammenarbeit mit der Fa. Bombardier Transportation („Bombardier Center of Competence“). In einem Teilprojekt dieser Kooperation wird die Einführung technischer Funktionen und Systeme zur Energieeinsparung bei Lokomotiven untersucht. Die Nutzung von Speichertechnologien ist neben der Abwärmenutzung und der energiesparenden Fahrweise die effizienteste Maßnahme zur Senkung des Kraftstoffverbrauchs bei Dieselfahrzeugen. Zusätzlich zur Rekuperation von Bremsarbeit können die Funktionen Lastpunktverschiebung und emissionsfreier Betrieb mit Hilfe eines Energiespeichers realisiert werden. Der Einsatz elektrischer Energiespeicher erweist sich als geeignet für dieselelektrische Schienenfahrzeuge im Personenverkehr, da diese durch die bereits vorhandenen elektrischen Antriebskomponenten relativ einfach zu hybridisieren sind und eine nutzungsgerechte Speicherauslegung aufgrund weitgehend bekannter Fahraufgaben möglich ist. In der Arbeit wird ein durchgängiges Verfahren zur Auslegung von dieselelektrischen Lokomotiven mit Energiespeichern im Personenverkehr beschrieben. Im Fokus liegt dabei der Einsatz von Optimierungsalgorithmen zur Verbesserung des Generatorsystems und des Einsatzes von elektrischen Energiespeichern im Hinblick auf den Kraftstoffverbrauch und die weiteren Anteile der Lebenszykluskosten. Das im Rahmen der Arbeit erstellte Programm zur energetischen Simulation bildet die Basis zur Untersuchung verschiedener Strategien für die Fahrtgestaltung unter Berücksichtigung der Fahrzeitreserven, den Betrieb des Energiespeichers und der Steuerung von Anlagen mit mehreren Dieselmotorgeneratorsätzen. Neben der Nutzung regelbasierter Strategien werden dabei auch vorausschauende Betriebsstrategien eingesetzt, welche die Möglichkeiten der bei Schienenfahrzeugen im Vorfeld bekannten Streckengeschwindigkeit und -topologie nutzen. Die dafür angewandten Methoden sind die Dynamische Programmierung nach BELLMANN und der äquivalenzkostenbasierte Betrieb. Die Optimierung der Fahrzeugkonfiguration wird durch einen Programmbaustein realisiert, welcher unter Berücksichtigung der Lokkonfiguration und der Energiesimulation für ein vorgegebenes Streckenprofil die Verbrauchs-, Instandhaltungs- und Anschaffungskosten für das Fahrzeug berechnet.

An electrostatic actuator driven by conventional voltage control and charge control requires high actuation voltage and suffers from the pull-in phenomenon that limits its operation range, much less than its entire gap. To provide effective solutions to these problems, we present complete analytical and numerical models of various electrostatic actuators coupled with resonant drive circuits that are able to drive electrostatic actuators at much lower input voltage than that of conventional actuation methods and to extend their operation range beyond their conventional pull-in points in the presence of high parasitic capacitance. Moreover, in order to validate the analytical and numerical models of various electrostatic actuators coupled with the resonant drive circuits, we perform the experiment on the microplate and the micromirror coupled with the resonant drive circuit. For instance, using a high voltage amplifier, we manage to rotate the micromirror with sidewall electrodes by 6 ° at 180 V. However, using the resonant drive circuit, we are able to rotate the same micromirror by 6 ° at much lower input voltage, 8.5 V. In addition, the presented work also facilitates the stability analysis of electrostatic actuators coupled with the resonant drive circuits and provides how the effect of the parasitic capacitance can be minimized. For example, the resonant drive circuit placed within a positive feedback loop of a variable gain amplifier is able to extend the operation range much further even in the presence of very high parasitic capacitance. The resonant drive circuit with the proposed feedback controllers is also able to minimize the detrimental effects of the parasitic capacitance and to displace a parallel-plate actuator over its entire gap without the saddle-node bifurcation. Finally, we present a new displacement measurement method of electrostatic actuators coupled with the resonant drive circuits by sensing the phase delay of an actuation voltage with respect to an input voltage. This new measurement method allows us to easily implement feedback control into existent systems employing an electrostatic actuator without any modification or alteration to the electrostatic actuator itself. Hence, this research work presents the feasibility of electrostatic actuators coupled with the resonant drive circuit in various industrial and medical applications, in which the advantages of miniaturization, low supply voltage, and low power consumption are greatly appreciated.

This thesis focuses on the Blood Drive which takes place during the spring Greek Week event at Western Kentucky University. I primarily investigate the varying methods of negotiating issues of altruism and egoism in terms of the Blood Drive as well as way that the Blood Drive fits into the WKU Greek yearly cycle. I focus on issues of the process of identity in social Greek-letter organizations and how the process of this identity is renegotiated during the Blood Drive and other Greek events. I interviewed people from several groups for this paper. Initially, I interviewed Blood Donor Recruitment Representatives from the American Red Cross, WKU students associated with the social Greek-letter system and the Blood Drive of Greek Week, and employees of WKU associated with the social Greek-letter system and the Blood Drive of Greek Week. At the event itself I widened my scope to include information provided by Mobile Unit Assistants (MUAs) and other employees of the American Red Cross. Key conclusions of this paper include that while people may all participate or be involved in the same event, their methods of understanding concepts of altruism and egoism vary with their kinds of association. In turn, their conceptualizations mirror those developed by social scientists in the last two hundred years. Also, the issues of separation and integration, processes to do with identity, are central to the events of the Greek calendar year and the Blood Drive event in particular.

A robust servo control system based on Integral Variable Structure Model Following Control (IVSMFC) is proposed. The IVSMFC approach comprises a reference model part for specifying the design requirements and an Integral Variable Structure Control (IVSC) part for minimizing the errors between the plant and the model. Sliding mode thus obtained features robustness against external disturbances and parameter variations. Design procedures in both continuous-time and discrete-time have been detailed. The IVSMFC-based servo control system has been successfully applied to a DSP-based brushless DC motor drive for globoidal cam indexing system and to power system. Simulation and experimental results demonstrate that the proposed scheme can achieve fast and robust responses.

The servo mechatronic system design process usually covers two different engineering domains: structure design and system control. The relationship between these two domains is much closed. In order to reduce the disturbance caused by parameters in either one, the domain knowledge from those two different fields needs to be integrated. Thus, in order to reduce the disturbance caused by parameters in either one, the mechanical and controller design domains need to be integrated. Therefore, the integrated design method Design For Control (DFC), will be employed in this thesis. In this connect, it is not only applied to achieve minimal power consumption but also enhance structural performance and system response at same time. To investigate for the integrated design method, there are two common servo mechatronic systems: feed drive system and legged servo mechatronic system are used as the design platform. 1. Mechatronic Feed Drive System To investigate the method for integrated optimization, a mechatronic feed drive system of the machine tools is used as a design platform. The 3D software, Pro/Engineer is first used to build the 3D model to analyze and design structure parameters such as elastic deformation, nature frequency and component size, based on their effects and sensitivities to the structure. Additionally, in order to achieve system robust, Quantitative Feedback Theory (QFT), will be applied to determine proper control parameters for the controller. Therefore, overall physical properties of the machine tool will be obtained in the initial stage. Following this Design Then Control process, the iterative design process is following to enhance some of system performance. Finally, the technology design for control will be carried out to modify the structural and control parameters to achieve overall system performance. Hence, the corresponding productivity is expected to be greatly improved. 2. Legged Servo Mechatronic System The goal of this study is to develop a one-degree-of-freedom (DOF) legged servo mechatronic system with DFC. For this system, the kinematics and control dynamic analysis of legged servo mechatronic system have been solved by using four bar linkage with symmetrical coupler point, pantograph, and common position and velocity controller. In addition, in order to improvement system dynamic performance and reduce the control cost, the counterweight, that base on mass redistribution is employed to integrate structure and control into one design step for reduce shaking moment. Additionally, in order to improvement the system performance, the complete force balance is not only to take advantage of control cost, but also easy to control.

Although the design principles of the Switched Reluctance Machines (SRMs) are available in different fragments in numerous bibliography positions, there no exists the complex design procedure of whole drive system taking into account the SR Machine, control system and supply device as well. The hybrid design method for SRM drives with application of new analytical calculation methods, finite element method and simulation models is proposed in this thesis. The calculation/design system is characterised by important effectivity and reliability. The new possibilities in analytical determination of saturation effects and core losses under various modes of control, including sensorless method, are also taken into account. The correctness of the proposed design algorithms are verified by laboratory tests made on three motor prototypes manufactured in industry for concrete application. This dissertation provides the elements indispensable for more accurate and complex analysis and design of drives with switch reluctance motors. The elements of electrical motor and control system design as well as the considerations on the choice of supply device and controller subsystems are jointed in the thesis for final receiving of the design tool for considered industrial drive system.

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