Algorithms and VLSI architectures for parametric additive synthesis

A parametric additive synthesis approach to sound synthesis is advantageous as it can model sounds in a large scale manner, unlike the classical sinusoidal additive based synthesis paradigms. It is known that a large body of naturally occurring sounds are resonant in character and thus fit the concept well. This thesis is concerned with the computational optimisation of a super class of form ant synthesis which extends the sinusoidal parameters with a spread parameter known as band width. Here a modified formant algorithm is introduced which can be traced back to work done at IRCAM, Paris. When impulse driven, a filter based approach to modelling a formant limits the computational work-load. It is assumed that the filter's coefficients are fixed at initialisation, thus avoiding interpolation which can cause the filter to become chaotic. A filter which is more complex than a second order section is required. Temporal resolution of an impulse generator is achieved by using a two stage polyphase decimator which drives many filterbanks. Each filterbank describes one formant and is composed of sub-elements which allow variation of the formant’s parameters. A resource manager is discussed to overcome the possibility of all sub- banks operating in unison. All filterbanks for one voice are connected in series to the impulse generator and their outputs are summed and scaled accordingly. An explorative study of number systems for DSP algorithms and their architectures is investigated. I invented a new theoretical mechanism for multi-level logic based DSP. Its aims are to reduce the number of transistors and to increase their functionality. A review of synthesis algorithms and VLSI architectures are discussed in a case study between a filter based bit-serial and a CORDIC based sinusoidal generator. They are both of similar size, but the latter is always guaranteed to be stable

Support vector machine based classification in condition monitoring of induction motors

Continuous and trouble-free operation of induction motors is an essential part of modern power and production plants. Faults and failures of electrical machinery may cause remarkable economical losses but also highly dangerous situations. In addition to analytical and knowledge-based models, application of data-based models has established a firm position in the induction motor fault diagnostics during the last decade. For example, pattern recognition with Neural Networks (NN) is widely studied. Support Vector Machine (SVM) is a novel machine learning method introduced in early 90's. It is based on the statistical learning theory presented by V.N. Vapnik, and it has been successfully applied to numerous classification and pattern recognition problems such as text categorization, image recognition and bioinformatics. SVM based classifier is built to minimize the structural misclassification risk, whereas conventional classification techniques often apply minimization of the empirical risk. Therefore, SVM is claimed to lead enhanced generalisation properties. Further, application of SVM results in the global solution for a classification problem. Thirdly, SVM based classification is attractive, because its efficiency does not directly depend on the dimension of classified entities. This property is very useful in fault diagnostics, because the number of fault classification features does not have to be drastically limited. However, SVM has not yet been widely studied in the area of fault diagnostics. Specifically, in the condition monitoring of induction motor, it does not seem to have been considered before this research. In this thesis, a SVM based classification scheme is designed for different tasks in induction motor fault diagnostics and for partial discharge analysis of insulation condition monitoring. Several variables are compared as fault indicators, and forces on rotor are found to be important in fault detection instead of motor current that is currently widely studied. The measurement of forces is difficult, but easily measurable vibrations are directly related to the forces. Hence, vibration monitoring is considered in more detail as the medium for the motor fault diagnostics. SVM classifiers are essentially 2-class classifiers. In addition to the induction motor fault diagnostics, the results of this thesis cover various methods for coupling SVMs for carrying out a multi-class classification problem.reviewe

Applications of MATLAB in Science and Engineering

The book consists of 24 chapters illustrating a wide range of areas where MATLAB tools are applied. These areas include mathematics, physics, chemistry and chemical engineering, mechanical engineering, biological (molecular biology) and medical sciences, communication and control systems, digital signal, image and video processing, system modeling and simulation. Many interesting problems have been included throughout the book, and its contents will be beneficial for students and professionals in wide areas of interest

Modern VLSI Analogue Filter Design: Methodology and Software Development

This thesis describes various approaches for the design of modern analogue filters and provides a practical filter and equaliser design aids system XFILT. The thesis begins by placing the analogue filter design technique and software into a historical and technology perspective. The evolution of the analogue filter is traced from early work, through the passive-RLC to transconductor-C and switched-current realisations. The software development in VLSI analogue filter automation is reviewed. For SC filter design, a cascade SC design approach which includes a novel pole-zero pairing method and a comprehensive comparison of SC filter realisation using different biquads are presented. Very useful guidelines for the choice of a suitable biquad structure according to the nature of the filter problem are presented. The canonical realisations of SC filter are studied. The multirate SC system design is described. Several strategies and the algorithms for multirate SC system design are proposed. In transconductor-C filter design research, the definition of a canonical ladder based transconductor-C filter is introduced, and two canonical ladder based transconductor-C filter design approaches are proposed. The ladder based transconductor-C equaliser design is also discussed. A practical video frequency transconductor-C filter and equaliser design is given to demonstrate the utility of the matrix design method and the design software. A new approach to realise exact ladder based SI filter with first and second generation memory cell has been proposed. The bilinear transformation is used in the design procedure. Eight different SI ladder based structures can be obtained for one prototype ladder. Therefore it provides SI filter designers with various circuit choices based on different requirement such as area, maximum ratio of transistor aspect ratio limit, sensitivity or noise performance. Techniques to improve dynamic range and reduce circuit parameter spread are also presented. The proposed approach is well suited for a computer compiler implementation. A suitability study of each decomposition method for different filtering applications is also carried out and a general guideline for the choice of different decomposition methods is obtained. A comparison study on SI filter sensitivity performance based on first generation and second generation memory cells is carried out. Using four filter examples, it is demonstrated that SI filters based on a second generation SI memory cell have good sensitivity performance. For SI filters based on first generation memory cells, it is shown that a high ratio of clock frequency to cutoff frequency in the lowpass case, or a high ratio of clock frequency to midband frequency in the bandpass case would introduce high sensitivity. A novel approach for SI ladder filter based on the S2I integrator is also proposed and a canonical realisation for SI filter based on S2I integrator is developed. Examination of SI equaliser design reveals that cascade structure is a better candidate than ladder based structure. Multirate SI filter system design is also studied. Finally, a very brief introduction to the assembly of the design methods in this thesis into a software package XHLT for VLSI analogue filter and equaliser design is given. The user aspects of XFILT have been discussed and various capabilities of XFILT are demonstrated. Several advanced facilities which remove traditional design limitations are illustrated. The philosophy of the system is explained. It is shown that the distinguished features of XFILT are Ease of Use. General Applicability, and Ease of Extension. The system structure is described and the graphics interface which acts both as user friendly interface and a system manager of all the software is outlined. Fabricated SC, transconductor-C, and SI filter and equaliser have been designed by using XFILT. The system is under further enhancement toward a commercial product