In this thesis, we present a design for computing moments of a binary horizontally/vertically convex image on an FPGA chip, using run-time reconfiguration. We compute the moments of up to third order for a total of 16 moments. We address how run-time reconfiguration speeds up moment computations without taking up huge hardware resources. Since we are considering a binary horizontally/vertically convex image, we look at an alternative method in moment computations that utilizes constant coefficient multipliers. We divide the image into segments and process one segment at a time. We reconfigure the constant coefficient multipliers before processing the next segment. This thesis also looks at the interactions between different logic units for moment computations. We provide an estimate of the total number of CLBs used to implement this design on an FPGA chip. Finally, we address variations of this particular type of image, such as non-binary and non-convex and determine whether this design is still applicable in those instances.

Resonant harmonic filters (RHFs), are the most common devices installed in distribution systems for reducing distortion caused by harmonic generating loads. When such filters are applied in systems with a distorted distribution voltage their effectiveness may decline drastically. This dissertation explores the causes of degradation of RHFs effectiveness and suggests methods of their improvement both by optimization algorithms and by modification of the filter structure. An optimization based design method is developed for the conventional RHF. It takes into consideration the interaction of the filter with the distribution system and provides a filter which gives the maximum effectiveness with respect to harmonic suppression. The results for the optimized filters, applied in some typical cases, are given, and the limits of effectiveness for a common application are explored. For cases where the conventional RHF cannot be applied due to low effectiveness, a resonant harmonic suppressor, referred to as a RHF with line inductor, is investigated. It is formed by the addition of a line inductor to a conventional RHF, and it has a higher effectiveness in the presence distribution voltage distortion. A similar method of optimization based design is developed and evaluated for the RHF with line inductor as for the conventional RHF. Also, the limits of its effectiveness are explored. One major disadvantage of the RHF with line inductor is the load voltage reduction due to the additional impedance between the distribution system and load. For loads with variable reactive power, the voltage drop across the line inductor may reach an unacceptable level. Also, the fluctuation of the load voltage could increase. In order to reduce these effects, an adaptive capability with respect to load reactive power compensation is added to the filter. Such a filter, referred to as a semi-adaptive RHF, is obtained when a RHF is combined with a thyristor switched inductor (TSI). The addition of the TSI also increases flexibility in the design of the filter with respect to the line inductors value. Design aspects of the semi-adaptive RHF are explored and simulation results are presented.

In this dissertation we try to achieve secrecy enhancement in communications by resorting to both cryptographic and information theoretic secrecy tools and metrics. Our objective is to unify tools and measures from cryptography community with techniques and metrics from information theory community that are utilized to provide privacy and confidentiality in communication systems. For this purpose we adopt encryption techniques accompanied with privacy amplification tools in order to achieve secrecy goals that are determined based on information theoretic and cryptographic metrics. Every secrecy scheme relies on a certain advantage for legitimate users over adversaries viewed as an asymmetry in the system to deliver the required security for data transmission. In all of the proposed schemes in this dissertation, we resort to either inherently existing asymmetry in the system or proactively created advantage for legitimate users over a passive eavesdropper to further enhance secrecy of the communications. This advantage is manipulated by means of privacy amplification and encryption tools to achieve secrecy goals for the system evaluated based on information theoretic and cryptographic metrics. In our first work discussed in Chapter 2 and the third work explained in Chapter 4, we rely on a proactively established advantage for legitimate users based on eavesdroppers lack of knowledge about a shared source of data. Unlike these works that assume an errorfree physical channel, in the second work discussed in Chapter 3 correlated erasure wiretap channel model is considered. This work relies on a passive and internally existing advantage for legitimate users that is built upon statistical and partial independence of eavesdroppers channel errors from the errors in the main channel. We arrive at this secrecy advantage for legitimate users by exploitation of an authenticated but insecure feedback channel. From the perspective of the utilized tools, the first work discussed in Chapter 2 considers a specific scenario where secrecy enhancement of a particular block cipher called Data Encryption standard (DES) operating in cipher feedback mode (CFB) is studied. This secrecy enhancement is achieved by means of deliberate noise injection and wiretap channel encoding as a technique for privacy amplification against a resource constrained eavesdropper. Compared to the first work, the third work considers a more general framework in terms of both metrics and secrecy tools. This work studies secrecy enhancement of a general cipher based on universal hashing as a privacy amplification technique against an unbounded adversary. In this work, we have achieved the goal of exponential secrecy where information leakage to adversary, that is assessed in terms of mutual information as an information theoretic measure and Eves distinguishability as a cryptographic metric, decays at an exponential rate. In the second work generally encrypted data frames are transmitted through Automatic Repeat reQuest (ARQ) protocol to generate a common random source between legitimate users that later on is transformed into information theoretically secure keys for encryption by means of privacy amplification based on universal hashing. Towards the end, future works as an extension of the accomplished research in this dissertation are outlined. Proofs of major theorems and lemmas are presented in the Appendix.

A novel method is described in detail for steering light in many directions without moving mechanical parts. The method involves a combination of liquid crystal cells and polarizing beam splitters. The polarization at each beam splitter is controlled by applying a signal to its corresponding liquid crystal cell. A study of light steering techniques is described for efficient beam placement, in a line and plane. These techniques permit accurate, non-mechanical, beam steering limited by the response time of the liquid crystal cells. A theoretical limit to the number of discrete directions is described and closely approached for a one dimensional system.

Performance of induction motor supplied with asymmetrical and nonsinusoidal supply voltages is studied in this thesis. Theory of induction motor is first presented for sinusoidal symmetrical supply voltages. Equations for the torque, losses, currents and efficiency are derived. Appropriate changes are made to apply this theory to induction motors operating at nonsinusoidal and asymmetrical supply voltages. Single phase equivalent circuit of the induction motor is presented for both asymmetrical and nonsinusoidal supply voltages. The equations governing operating characteristics are presented. Machine torque, losses, current and efficiency for asymmetrical and nonsinusoidal supply voltages are compared with the same for sinusoidal symmetrical supply voltages. Computer simulation in MATLAB is used to study the impacts of asymmetrical and nonsinusoidal supply voltages on induction machines. Machine torque, losses, current and efficiency are calculated for various levels of voltage asymmetry and distortion. Results of computer simulation are presented.

Fast and reliable Spectrum Sensing (SS) plays a crucial role in the cognitive radio (CR) technology in order to prevent unwanted interference to the primary users (PU) and to reliably and quickly detect the white spaces in the spectrum for opportunistic access by the secondary users (SU). Spectrum Sensing must often be performed in the absence of information such as PU signaling scheme, noise level and channel fading coefficients. While these parameters can be estimated in the SU, estimation errors significantly deteriorates the performance of SS techniques. In this thesis, we introduce and evaluate the performance of two novel blind spectrum sensing algorithms which do not rely on knowledge of these parameters. The first is a SS technique for signaling schemes which introduce controlled intersymbol interference in the transmitter. The second is for cases when the receiver of the SU is equipped with a multiantenna system. This approach exploits the path correlation among the signals received at different antennas. Next we analyze the performance of Spectrum Monitoring (SM), an new technique which allows the SU to detect the presence of the PU using its own receiver statistics. In contrast to SS, with SM, the SU does not need to interrupt its own transmission in order to detect the presence of the PU. We carefully construct the decision statistics for SM and evaluate its performance. The performance of a hybrid SM/SS system shows a significant improvement over SS alone.

Most communication systems use a finite signal set as their alphabet set to form a codebook to transmit data over a communication channel in a reliable fashion. The problem with Conventional methods which implement Coded Modulation (CM) schemes such as Trellis Coded Modulation or Multi-level Coding Multi-Stage Decoding is their complexity of dealing with codes with different rates in each level which makes the design and implementation a difficult task. One simple way to implement Coded Modulation is Bit-Interleaved Coded Modulation (BICM) which uses only a single binary encoder to transmit data. Although BICM is a suboptimal scheme compared to CM, its simplicity, from a practical point of view, is a great motivation to design BICM scheme achieving rates close to those obtained by CM. Lots of efforts have been taken place in the past twenty years to design optimal constellation for different snr regimes in CM under various constraints. Some of them are revisited in this study. A novel approach, called Adjustable Weights Model (AWM), will be presented to design constellations which work very well in both CM and BICM schemes. The model also induces a particular labelling on the constellation. In this work, some properties of AWM are studied. AWM is used to facilitate design of near optimal signalling for CM and BICM schemes. An optimization problem is formed to find the optimal parameters of the proposed model. Global optimization methods are used to solve the optimization problems. It is shown that the optimal points are always on the boundary of the domain by using data processing inequality . Some suboptimal solutions are provided by moment and cumulants matching techniques. The model has the ability to produce different constellations by adjusting its weights. It is well established that the optimal constellation for high snr region is equillattice. This model also converges to an equillattice constellation in high snr region. Number of nonzero weight parameters in the model can vary according to snr, help us to circumvent the saturation problem with conventional CM scheme. BICM capacity is presented and its relation with CM capacity is discussed. BICM capacity, as a function of snr, is expanded around zero snr. Different constellations and their labeling can be characterized based on the coefficients in the Taylor expansion. The most important difference between CM and BICM is the effect of labelling in the former scheme. Labelling is irrelevant in CM, but greatly influences the system performance in BICM. Effect of labelling and how to search for optimal labeling is part of this study. It is shown that AWM is optimal at medium and low snr regimes. The model coupled with its underlying labelling is first order optimal. Although Gray labelling is optimal at high snr, it is not optimal in the low snr regime. Higher order optimal constellations are defined to be the constellations that have more than one coefficient in their Taylor expansion matched with CM capacity coefficients. It gives us a powerful tool to study constellation in medium snr regime which has not been already discovered. In addition, optimality criterion is provided.

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This dissertation is concentrated mainly on the newest PMTF machine topology proposed and patented by Jacek F. Gieras in March 4, 2010. Such a topology (topology of 2010) is an object of this dissertation. A prototype that was built with 3D Finite Element Method (FEM) modeling of PMTF generator proves that the generator that was built on the basis of topology of 2010 has several significant disadvantages among which the greatest impact have high leakage flux losses. Applying FEM modeling, various steps to improve machine performance have been undertaken. Results obtained from modeling show, that keeping the same diameter and lengths of the machine as well as number of turns of the winding, output power of the machine can be two times higher and the negative flux linkage that is established by inactive PMs significantly reduced. This was achieved by introducing magnetic shunts to the stator structure. These shunts also reduce cogging torque. Modifications include changing machine stator structure, slot shape, and implementation of magnetic shunts which play a vital role in preventing flux leakage losses and reducing cogging torque. During modifications a big attention was paid to simplifying a manufacturing process. Modifications do not complicate machine design and count all aspects which may arise when manufacturing. Modified version of the PMTF machine was built by Polish manufacturer Komel for University of Nevada-Reno. This project was supported by National Science Foundation. The prototype results prove that the magnetic shunts block almost 70% of negative magnetic flux coming from inactive magnets. The induced voltage of the machine calculated using 3D FEM model is the same what was obtained during prototype laboratory test. However, the laboratory test also shows that if magnetic shunts are made of pure iron, generator has significant power losses. These power losses are caused by eddy currents induced on the magnetic shunts. To prevent eddy currents flowing on the magnetic shunts surface, instead of pure iron, laminated steel or magnetic powder has to be selected as a material for shunts. Combining the ideas of topologies [1-3] a new version of PMTF machine is introduced in this dissertation. Its electromechanical parameters are calculated. Three different designs of PMTF generator are compared in terms of output power to volume ratio.

The study of multi-agent systems (MAS) focuses on systems in which many intelligent agents interact within an environment. The agents are considered to be autonomous entities. MAS can be used to solve problems that are difficult or impossible for an individual agent to solve. The main feature which is achieved when developing MAS, if they work, is flexibility, since MAS can be added to, modified and reconstructed, without the need for detailed rewriting of the application. MAS can manifest self-organization as well as self-steering related complex behaviors even when the individual strategies of all their agents are simple. The goal of MAS research is to find methods that allow us to build complex systems composed of autonomous agents who, while operating on local knowledge and possessing only limited abilities, are nonetheless capable of enacting the desired global behaviors. We want to know how to take a description of what a system of agents should do and break it down into individual agent behaviors. This thesis investigates the problem when discrete-time MAS are consensusable under undirected graph. A discussion is provided to show how the problem differs from continuous time system. Then a consensusability condition is derived in terms of the Mahler measure of the agent system for single input single out systems (SISO) and result shows that there is an improved consensusability by a power of two. An algorithm is proposed for distributed consensus feedback control law when the consensusability holds. Also the case of output feedback is considered in which the consensusability problem becomes more complicated. To solve this we decompose the problem into two parts i.e. state feedback and state estimation. Simulation results demonstrate the effectiveness of the established results.