International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / It can be challenging to select the best architecture for DSP filters for a given application. Design constraints often include both objective and subjective information. This paper discusses the initial results of an investigation into using expert system techniques to address this problem. The goal is a system that allows users to specify traditional constraints such as impulse response, frequency response, stability, SNR, etc., but they may also constrain the filter’s cost, complexity, or any parameter which can be clearly identified for the specific application.

In this thesis, a class of combinatorial optimization methods rooted in statistical mechanics and their use in signal processing applications will be discussed. The thesis consists of two separate parts. The first part deals with the rationale for my work and also covers the background information necessary to put the second part, which consists of a number of papers, in context. There are (at least) two sides to an optimization problem---the problem statement arising from an application or a design and the selection of an algorithm to solve the problem. In this work the problem statements are practical problems, of combinatorial nature, frequently encountered in signal processing and the algorithms of choice are annealing based algorithms, founded in statistical mechanics. From my work, it is my experience that solving a particular problem often leads to new developments on the part of the algorithm which, in turn, open up possibilities to apply the modified algorithm to a new set of problems, leading to a continuously improving algorithm and a growing field of applications. The included papers deal with the application of annealing optimization methods to the problems of configuring active noise and vibration control systems, digital filter design and adaptive filtering. They also describe the successive development of a highly efficient entropy-directed deterministic annealing (EDDA) optimization algorithm detailed in the final paper.

In this dissertation, several algorithms to design linear phase Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) filters have been discussed.<br /> Contrary to various already existing standard algorithms,the proposed methods approximate magnitude and phase characteristics simultaneously. The basic mechanism used in this study is polynomial based design of digital filters. We have used several already existing polynomials; e.g., Chebyshev polynomials, Legendre polynomials, to develop linear phase digital filters and developed some two dimensional polynomials following orthogonal properties to design digital filters for image processing, their design methodology have also been discussed.<br /> Filters of proposed type can be used for applications where exact linear phase is required. Another application of this type of filters is the design of filters with zero group delay. IIR filters are designed with absolute linear phase and zero group delay.<br /> The algorithms proposed in the present thesis allow user to design filters with his set of constraints, which is required in practical filter design problems. Very narrow band 1D and 2D linear phase FIR filters can easily be designed by the proposed methodology. The IIR filters proposed provide the guarantee to result in a stable filter.<br /> All the algorithms have been discussed stepwise to make sure that any one with basic programming capability can easily design them. We have not used any standard routine of any particular platform, therefore any freely available programming platform (like C, C++, Scilab, Octave, etc.) can be used to design these filters.

The objective of this thesis is to enhance the efficiency of Mass Rapid Transit (MRT) system and improve the power quality by reducing harmonic distortion. The energy consumption of an MRT system by considering the annual ridership and the stochastic operation characteristics of train sets are used to find the optimal placement of traction substations to enhance the operation efficiency of MRT systems. To mitigate the harmonic distortion, the installation location and capacity of harmonic filters are designed and verified by computer simulation. The software programs for AC/DC load flow study and harmonic distortion analysis have been developed and integrated to perform power system simulation of MRT operation. The mathematical model of 12-pulse uncontrolled rectifiers without interphase transformers is derived and implemented in the programs to obtain more accurate simulation results. The optimal inverter substation planning is solved by minimizing the overall cost of power consumption and inverter investment for mass rapid transit power systems with immune algorithm. The objective function and constraints are expressed as antigen, and all feasible solutions are expressed as antibody. The diversity of antibody is then enhanced by proximity of antigen so that the global optimization during the solution process can be obtained. It is found that the energy regeneration can be restored effectively with the optimal planning of inverters by the proposed immune algorithm. Based on the computer simulation of Taipei MRT system, the voltage harmonic distortion is varied dramatically with the dynamic load behavior of train sets. The stochastic harmonic load flow analysis is performed to investigate the power quality problem for an electrified rapid transit system. Different strategies of harmonic distortion mitigation have been proposed by minimizing the objective function to solve the optimal sizes and locations of harmonic filters so that the harmonic distortion can be reduced and reactive power compensation can be obtained at the same time. By performing the immune algorithm, the harmonic filters with proper capacity and the corresponding switching time for filter commitment are determined. It is found that the harmonic distortion can be effectively reduced for the MRT system by the proper design of harmonic filters.

Although many devices can be used to capture images of high resolution, there is still a need to show these images on displays with low resolution. Existing methods of subpixel-based down-sampling are reviewed in this thesis and their limitations are described. A new approach to optimizing sampling structure conversion for color mosaic displays is developed. Full color images are filtered by a set of optimal filters before down-sampling, resulting in better image quality according to the SCIELAB measure, a spatial extension of the CIELAB metric measuring perceptual color difference. The typical RGB stripe display pattern is tested to get the optimal filters using least-squares filter design. The new approach is also implemented on a widely used two-dimensional display pattern, the Pentile RGBG. Clear images are produced and color fringing artifacts are reduced. Quality of down-sampled images are compared using SCIELAB and by visual inspection.

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In industry, adjustable speed drives (ASDs) are widely employed in driving AC motors for variable speed applications due to the high performance and high energy efficiency obtained in such systems. However, ASDs have an impact on the power quality and utilisation of AC power feeds by injecting current harmonics and causing resonances, additional losses, and voltage distortion at the point of common coupling. Due to these problems, electric power utilities have established stringent rules and regulations to limit the effects of this distortion. As a result, efficient, reliable, and economical harmonic mitigation techniques must now be implemented in practical systems to achieve compliance at reasonable cost. A variety of techniques exist to control the harmonic current injected by ASDs, and allow three-phase AC-line-connected medium-power systems to meet stringent power quality standards. Of these, the broadband harmonic passive filter deserves special attention because of its good harmonic mitigation and reactive power compensation abilities, and low cost. It is also relatively free from harmonic resonance problems, has relatively simple structural complexity and involves considerably less engineering effort when compared to systems of single tuned shunt passive filters or active filters and active rectifier solutions. In this thesis, passive broadband harmonic filters are investigated. In particular, the improved broadband filter (IBF) which has superior overall performance and examples of its application are increasing rapidly. During this research project, the IBF operating principle is reviewed and its design principles are established. As the main disadvantage of most passive harmonic filters is the large-sized components, the first proposed design attempts to optimize the size of the filter components (L and C) utilized in the existing IBF topology. The second proposed design attempts to optimize the number and then the size of filter components resulting in an Advanced Broadband passive Filter (ABF) novel structure. The proposed design methods are based on frequency domain modelling of the system and then using a genetic algorithm optimization technique to search for optimal filter component values. The results obtained are compared with the results of a linear searching approach. The measured performance of the optimal filter designs (IBF and ABF) is evaluated under different loading conditions with typical levels of background voltage distortion. This involves assessing input current total harmonic distortion, input power factor, rectifier voltage regulation, efficiency, size and cost. The potential resonance problem is addressed and the influence of voltage imbalance on performance is investigated. The assessment is based on analysis, computer simulations and experimental results. The measured performance is compared to various typical passive harmonic filters for three-phase diode rectifier front-end type adjustable speed drives. Finally, the broadband filter design’s effectiveness and performance are evaluated by involving them in a standard IEEE distribution network operating under different penetration levels of connected nonlinear total loads (ASD system). The study is conducted via detailed modelling of the distribution network and the linked nonlinear loads using computer simulations.

<p>Saab Aerosystems, a part of Saab AB, has the overall responsibility for the development of the fourth generation fighter aircraft JAS 39 Gripen. When planning a mission for one or more aircrafts, a computer program called Mission Support System is used. Some of the data from the planning is then transferred to the actual aircraft. Today there are some unwanted restrictions in the planning software. One of these restrictions is about the fact that a number of parameters that controls the output from a planned mission are not configurable runtime, i.e. a reinstallation at customers location is needed to change this. The main purpose of this thesis was to propose a new design and a new framework that solves the inflexibility described above. The design should also be validated by a test implementation. A number of different designs were proposed and four of these were selected to be candidates for being implemented. An important tool used when developing the designs was the theory of design patterns. To choose one of the four a ranking system, based on both measurable metrics and non-measurable experience, was used. One design was selected to be the best and after implementing of the design it was considered to be valid. Future work can consist of rewriting all modules in the software to use the new framework.</p>

This thesis analyzes design criteria&rsquo / s, performance evaluation of fuel filter. Fundamental concepts, definition and systems has been discussed at literature survey parts. Fundamentals of filter design tests and calculations are discussed. In Addition Frequency and amplitude effect on fuel filter efficiency investigated with different particle sizes by preparing special test set up. Test results has been analyzed by using Regression, Anova and Analyze of Variance methods with Minitab software.

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