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Thesis (M.Sc.). / Written for the Dept. of Physics. Title from title page of PDF (viewed 2008/05/29). Includes bibliographical references.

Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Cressler, John D.; Committee Member: Laskar, Joy; Committee Member: Shen, Shyh-Chiang. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis (Ph.D.)--University of Texas at Dallas, 2007. / Includes vita. Includes bibliographical references (leaves 147-152)

abstract: The front end of almost all ADCs consists of a Sample and Hold Circuit in order to make sure a constant analog value is digitized at the end of ADC. The design of Track and Hold Circuit (THA) mainly focuses on following parameters: Input frequency, Sampling frequency, dynamic Range, hold pedestal, feed through error. This thesis will discuss the importance of these parameters of a THA to the ADCs and commonly used architectures of THA. A new architecture with SiGe HBT transistors in BiCMOS 130 nm technology is presented here. The proposed topology without complicated circuitry achieves high Spurious Free Dynamic Range(SFDR) and Total Harmonic Distortion (THD).These are important figure of merits for any THA which gives a measure of non-linearity of the circuit. The proposed topology is implemented in IBM8HP 130 nm BiCMOS process combines typical emitter follower switch in bipolar THAs and output steering technique proposed in the previous work. With these techniques and the cascode transistor in the input which is used to isolate the switch from the input during the hold mode, better results have been achieved. The THA is designed to work with maximum input frequency of 250 MHz at sampling frequency of 500 MHz with input currents not more than 5mA achieving an SFDR of 78.49 dB. Simulation and results are presented, illustrating the advantages and trade-offs of the proposed topology. / Dissertation/Thesis / M.S. Electrical Engineering 2012

abstract: Visual attention (VA) is the study of mechanisms that allow the human visual system (HVS) to selectively process relevant visual information. This work focuses on the subjective and objective evaluation of computational VA models for the distortion-free case as well as in the presence of image distortions. Existing VA models are traditionally evaluated by using VA metrics that quantify the match between predicted saliency and fixation data obtained from eye-tracking experiments on human observers. Though there is a considerable number of objective VA metrics, there exists no study that validates that these metrics are adequate for the evaluation of VA models. This work constructs a VA Quality (VAQ) Database by subjectively assessing the prediction performance of VA models on distortion-free images. Additionally, shortcomings in existing metrics are discussed through illustrative examples and a new metric that uses local weights based on fixation density and that overcomes these flaws, is proposed. The proposed VA metric outperforms all other popular existing metrics in terms of the correlation with subjective ratings. In practice, the image quality is affected by a host of factors at several stages of the image processing pipeline such as acquisition, compression, and transmission. However, none of the existing studies have discussed the subjective and objective evaluation of visual saliency models in the presence of distortion. In this work, a Distortion-based Visual Attention Quality (DVAQ) subjective database is constructed to evaluate the quality of VA maps for images in the presence of distortions. For creating this database, saliency maps obtained from images subjected to various types of distortions, including blur, noise and compression, and varying levels of distortion severity are rated by human observers in terms of their visual resemblance to corresponding ground-truth fixation density maps. The performance of traditionally used as well as recently proposed VA metrics are evaluated by correlating their scores with the human subjective ratings. In addition, an objective evaluation of 20 state-of-the-art VA models is performed using the top-performing VA metrics together with a study of how the VA models’ prediction performance changes with different types and levels of distortions. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2016

Les transformées sont un élément clé dans les systèmes de codage vidéo par blocs. Cette thèse approfondit les schémas d’apprentissage à multiples transformées. Une première contribution de ce travail est consacrée à l’évaluation de schémas d’apprentissage de transformées de deux types en ligne et hors ligne. Les deux approches sont comparées en détail et leur pertinence respective révélées. Nous proposons ensuite plusieurs techniques afin d’améliorer la stabilité du système d’apprentissage et réduire le coût de la signalisation. Une seconde contribution concerne les schémas d’apprentissage multi-transformées hors ligne déjà connus qui sont étendus avec pour objectifs de 1) fournir des transformées plus génériques et moins biaisées, 2) obtenir des gains de compression plus élevés, 3) réduire la complexité d’encodage et de décodage. On propose un schéma dit IMDTC (Improved Mode Dependent Transform Competition) qui offre un gain de codage très significatif, plus de 5% par rapport à HEVC standard sous la configuration All Intra (AI), avec une augmentation de complexité raisonnable. Enfin, l’adaptabilité au contenu de l’apprentissage hors ligne est étendue en explorant une nouvelle approche d’apprentissage des transformées basée sur des jeux de transformées adaptées à des contenus. Plusieurs ensembles contenant de multiples transformées sont appris sur différents contenus et regroupés en jeu. Lors du codage d’une région donnée d’une image, un ensemble de transformées est sélectionné localement à partir du jeu. Les résultats numériques montrent le potentiel élevé de cette approche par rapport aux approches classiques en ligne et hors ligne. / Transforms are a key element in block-based video coding systems which, in conjugation with quantization, is important for the overall compression efficiency of the system. This thesis explores multipletransform- based learning schemes. A first contribution of this work is dedicated to the evaluation of transform learning schemes with two flavors 1) online learning, and 2) offline learning. The two approaches are compared against each other and their respective appropriability is studied in detail. Some novel techniques are proposed in this work to 1) improve the stability of the learning scheme and 2) to reduce the signaling cost. In a second contribution of this thesis, the offline multiple-transform learning schemes already known in the literature are further extended with the aims to altogether 1) provide more generic transforms that are less biased towards specific classes of contents, 2) achieve higher compression gains, 3) reduce encoding and decoding computational complexity. An improved Mode Dependent Transform Competition (IMDTC) scheme is proposed which provides a considerable gain of over 5% compared to standard HEVC under All Intra (AI) configuration at a complexity just 2.9 times the standard HEVC. Finally, the content adaptability aspect of the offline learning is explored through a novel content-adapted pool-based transform learning approach where several multiple-transform sets are learned on different contents and pooled together. During the coding of a given region of an image, one transform set is selected locally from the pool. Numerical results show the high potential of this approach against the conservative online and offline approaches.

Made available in DSpace on 2014-06-11T19:22:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-08-27Bitstream added on 2014-06-13T20:27:08Z : No. of bitstreams: 1 carvalho_ac_me_ilha.pdf: 884948 bytes, checksum: 678386f50d74fa0271afe8eabfc08a7f (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho tem por objetivo a proposição de um estudo de caso realizado em uma planta industrial, cuja linha de produção se concentra na área da metalurgia. O principal enfoque foi direcionado na avaliação e nos efeitos causados pelas correntes distorcidas, geradas por cargas não lineares, nos barramentos e alimentadores da industria. Com o objetivo de avaliar o impacto das cargas elétricas, com características não lineares, as instalada e a serem instaladas no sistema elétrico da industria. Foi realizada também uma avaliação geral da planta da indústria através da análise das faturas de energia elétrica buscando identificar nos principais indicadores, os desvios no sistema elétrico da planta. Entre estes, podemos destacar a demanda, o consumo, os reativos excedentes e outros. Todos os procedimentos desenvolvidos neste trabalho foram direcionados no sentido de se usar racionalmente a energia elétrica e controlar o seu desperdício. / This work aims to study a case carried out in an industrial plant, whose production line is concentrated on the metallurgy field. The main objective was addressed in the evaluation and in the effects caused by the distortion of the currents, due to nonlinear loads connected at the industry busbar and feeders. With the objective of evaluating the impact of the electric loads, with non- linear characteristics, or installed in the industry electric system. It was also accomplished a general evaluation of the industry plant by analyzing the electric power invoices looking for identifying, in the main quality power indicators, the deviations in the electric plant system. Among these, we can mention the demand, the consumption, the exceeding reactives and others. All the procedures developed in this work were addressed aiming to use the electric power rationally and to control its waste.

One of the fundamental underlying assumptions of selection procedures is that the information gathered from applicants is accurate, and thus, will predict performance on the job (Donovan, Dwight, & Schneider, 2014; Schmitt & Sinha, 2011). As self-report instruments such as paper-and-pencil tests and unsupervised online surveys become more prevalent in organizational selection contexts (Truxillo & Bauer, 2011) due to ease of use and cost efficiency, the concern of applicants faking responses to inaccurately portray themselves as more highly desirable is increasingly critical (Hough, Oswald, & Ployhart, 2001). Depending on the exact magnitude of the particular selection event, this compromise of validity may cost an organization just as much as they stand to gain from an accurate self-report selection tool. The aim of this study is to test the viability of a video game platform designed to aid personnel selection by reducing faking. This thesis first outlines the most widely assessed predictors of job performance and briefly review the state-of-the-science of personality research in the context of employee selection. Then, a review of faking, drawing upon a model of faking proposed by McFarland & Ryan (2000), describes the impact it has on employee selection based on personality tests. Drawing upon Malone’s (1981) theory of intrinsic motivation as well as Sweller’s (1994) theory of cognitive load, I proposed the use of a video game platform as a counter-measure to faking selection assessments. Results suggest that participants are less able to fake personality assessments when assessed via video games as compared to online surveys.

This project includes survey of various methods ECG signal filtering, to suppress of powerline interference. It is specialized especially on properties which affecting the quality of filtration. The main essence of project is evaluation of the proposed methods in terms of quality and the least possible distortion of the resulting ECG signal. The work is focused on linear, adaptive filtering and filtering using discrete wavelet trans-form. Signal processing and evaluation of descriptive parameters are transferred using the graphical interface GUI in the program Matlab 7.7.0 ( R2008b ).