Thesis (Ph.D.)--University of Melbourne, Dept. of Mechanical Engineering, School of Engineering, 2009. / Typescript. Includes bibliographical references (p. 177-184)

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Ghassan AlRegib; Committee Member: Elliot Moore; Committee Member: Monson H. Hayes; Committee Member: Paul A. Work; Committee Member: Ying Zhang. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (M.S.)--Rochester Institute of Technology, 1994. / Typescript. Includes bibliographical references (leaves 77-80).

Thesis (Ph. D.)--Drexel University, 2005. / Includes abstract and vita. Includes bibliographical references (leaves 121-129).

Cardiac arrhythmias occur when the normal pattern of electrical signals in the heart breaks down. A premature ventricular contraction (PVC) is a common type of arrhythmia that occurs when a heartbeat originates from an ectopic focus within the ventricles rather than from the sinus node in the right atrium. This and other arrhythmias are often diagnosed with the help of an electrocardiogram, or ECG, which records the electrical activity of the heart using electrodes placed on the skin. In an ECG signal, a PVC is characterized by both timing and morphological differences from a normal sinus beat. An implantable cardiac monitor (ICM) is a device used to help physicians diagnose and monitor infrequent cardiac arrhythmias that may not be observed during an ECG recording performed during a normal clinic visit. These devices are implanted under the skin of the chest and simply monitor and record the electrical activity of the heart. The recorded signal is referred to as a subcutaneous electrocardiogram, or SECG. This thesis proposes and tests a novel algorithm that uses an SECG signal to perform PVC detection and is suitable for implementation within an implantable cardiac monitoring device. The proposed algorithm uses a combination of morphological and timing criteria to identify PVCs in near real time. Current commercially-available ICMs do not provide a PVC detection feature, so the proposed algorithm could help provide physicians with valuable additional diagnostic information about a clinically-significant arrhythmia.

Published Article / People have tried different ways to make machines intelligent. One option is to use a simulated neural net as a platform for Genetic Algorithms. Neural nets are a combination of neurons in a certain pattern. Neurons in a neural net system are a simulation of neurons in an organism's brain. Genetic Algorithms represent an emulation of evolution in nature. The question arose as to why write a program to simulate neurons if a program can execute the functions a combination of neurons would generate. For this reason a virtual robot indicated in Figure 1 was made "intelligent" by developing a process where the robot creates a program for itself. Although Genetic Algorithms might have been used in the past to generate a program, a new method called Single-Chromosome-Evolution-Algorithms (SCEA) was introduced and compared to Genetic Algorithms operation. Instructions in the program were changed by using either Genetic Algorithms or alternatively with SCEA where only one simulation was needed per generation to be tested by the fitness of the system.

Today's computer systems often contains several different processing units aside from the CPU. Among these the GPU is a very common processing unit with an immense compute power that is available in almost all computer systems. How do we make use of this processing power that lies within our machines? One answer is the OpenCL framework that is designed for just this, to open up the possibilities of using all the different types of processing units in a computer system. This thesis will discuss the advantages and disadvantages of using the integrated GPU available in a basic workstation computer for computation of image processing and sorting algorithms. These tasks are computationally intensive and the authors will analyze if an integrated GPU is up to the task of accelerating the processing of these algorithms. The OpenCL framework makes it possible to run one implementation on different processing units, to provide perspective we will benchmark our implementations on both the GPU and the CPU and compare the results. A heterogeneous approach that combines the two above mentioned processing units will also be tested and discussed. The OpenCL framework is analyzed from a development perspective and what advantages and disadvantages it brings to the development process will be presented.

This thesis discusses the development and performance of a novel evolutionary algorithm, the Targeted Estimation of Distribution Algorithm (TEDA). TEDA takes the concept of targeting, an idea that has previously been shown to be effective as part of a Genetic Algorithm (GA) called Fitness Directed Crossover (FDC), and introduces it into a novel hybrid algorithm that transitions from a GA to an Estimation of Distribution Algorithm (EDA). Targeting is a process for solving optimisation problems where there is a concept of control points, genes that can be said to be active, and where the total number of control points found within a solution is as important as where they are located. When generating a new solution an algorithm that uses targeting must first of all choose the number of control points to set in the new solution before choosing which to set. The hybrid approach is designed to take advantage of the ability of EDAs to exploit patterns within the population to effectively locate the global optimum while avoiding the tendency of EDAs to prematurely converge. This is achieved by initially using a GA to effectively explore the search space before transitioning into an EDA as the population converges on the region of the global optimum. As targeting places an extra restriction on the solutions produced by specifying their size, combining it with the hybrid approach allows TEDA to produce solutions that are of an optimal size and of a higher quality than would be found using a GA alone without risking a loss of diversity. TEDA is tested on three different problem domains. These are optimal control of cancer chemotherapy, network routing and Feature Subset Selection (FSS). Of these problems, TEDA showed consistent advantage over standard EAs in the routing problem and demonstrated that it is able to find good solutions faster than untargeted EAs and non evolutionary approaches at the FSS problem. It did not demonstrate any advantage over other approaches when applied to chemotherapy. The FSS domain demonstrated that in large and noisy problems TEDA’s targeting derived ability to reduce the size of the search space significantly increased the speed with which good solutions could be found. The routing domain demonstrated that, where the ideal number of control points is deceptive, both targeting and the exploitative capabilities of an EDA are needed, making TEDA a more effective approach than both untargeted approaches and FDC. Additionally, in none of the problems was TEDA seen to perform significantly worse than any alternative approaches.

The available sources have, to some extent, determined the form of this thesis, which was undertaken in the hope that a more detailed study of the relations between London and the Crown during the years 1 1400_1 1150 would place in perspective the crises with which it begins and ends. The most important source of material for this study has been the Journals of the Court of Aldermen and Common Council which survive from 1416 (the years 1429- 1436 are missing). Historians with the help of a nineteenth century index have quarried in these Journals, but they have never been read through systematically. Journals nos. 3 and 6, having been wrongly bound up, could not be used until, their pages bad been sorted into the correct order from the internal evidence of their contents. The scribes who compiled the Journals were both careless and cautious which increases the difficulty in interpreting their crabbed notes. From studying the Journals dominant themes emerged which were then followed up at the Public Record Office and elsewhere. The conclusions from this study fall into three main categories. The Journals provided a great deal of material from which it was possible to draw a much more detailed picture of the machinery and business of the government of medieval London. T1'e Aldermen and civic officials emerge as conservative, but conscientious, men who might press hardly upon minority interests, but had constantly before their eyes the needs of the City as a whole. Secondly it has been possible to tidy up the chronology of the crises themselves. At such times as Bolingbroke' s usurpation and Cade' a revolt the civic scribes were least active and most cautious. But it seems clear that the London support for both these men has been exaggerated and that the fundamental conservatism of the City governors was not easily rocked, whether by royal scions or Kentish peasants. But this study has proved most useful where the more mundane contact between the Crown and the citizens could be examined, In this way it has been possible to place the financial relations between the King and the City in perspective, and to realize that the King did not come as a beggar to the Londoners, since he had at his disposal all the chartered freedoms and privileges which were essential to the communal and economic life of the City. London, in spite of its great prestige and financial importance, still operated in the fifteenth century within a framework of royal privilege. While the memory of Richard II's action in 1392 was still green the Londoners were in no position to demand redress of grievances before supply. In understanding the delicate balance of the relationship between the Crown and the Londoners it is easier to understand the survival of the Lancastrian dynasty.

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