In this work, a novel method is proposed to optimize the array geometry for DOA estimation. The method is based on minimization of fine error variances with the constraint that the gross error probability is below a certain threshold. For this purpose, a metric function that reflects the gross and fine error characteristics of the array is offered. Theoretical analyses show that the minimization of this metric function leads to small DOA estimation error variance and small gross error probability. Analyses have been carried out under the assumptions of planar array geometry, isotropic array elements and AWGN. Genetic algorithm is used as an optimization tool and performance simulation is performed by comparing the DOA estimation errors of optimized array to a uniform circular array (UCA). Computer simulations support the theoretical analyses and show that the method proposed leads to significant improvement in array geometry in terms of DOA estimation performance.

This work deals with the further development of a method for Direction of Arrival (DOA) estimation based on the Discrete Fourier Transform (DFT) of the sensor array output. In the existing DFT-based algorithm, relatively high SNR is considered, and it is assumed that a large number of sensors are available. In this study an overview of some of the most commonly used DOA estimation techniques will be presented. Then the performance of the DFT method will be analyzed and compared with the performance of existing techniques. Two main objectives will be studied, firstly the reduction of the number of sensors and secondly the performance of the DFT based technique in the presence of noise. Experimental simulations will be presented to illustrate that in absence of noise, the proposed method is very fast and using just one snapshot is sufficient to accurately estimate DOAs. Also, in presence of noise, the method is still relatively fast and using a small number of snapshots, it can accurately estimate DOAs. The above mentioned properties are the result of taking an average of the peaks of the DFTs, X_n (k), obtained from a sequence of N_s snapshots. With N_s sufficiently large, the average over N_s snapshots approaches expected value. Also, the conditions that should be satisfied to avoid overlapping of main-lobes, and thus loosing the DOA of some signals, in the DFT spectrum are examined. This study further analyzes the performance of the proposed method as well as two other commonly used algorithms, MUSIC and conventional beamformer. An extensive simulation was conducted and different features of the spatial DFT technique, such as accuracy, resolution, sensitivity to noise, effect of multiple snapshots and the number of sensors were evaluated and compared with those of existing techniques. The simulations indicate that in most aspects the proposed spatial DFT algorithm outperforms the other techniques. / Graduate

Made available in DSpace on 2014-12-17T14:13:38Z (GMT). No. of bitstreams: 1 HerlaineRND_TESE.pdf: 771785 bytes, checksum: 4ae27df46d2162daa74c541e0abcf535 (MD5) Previous issue date: 2010-12-10 / This study aimed at examining the representation and the level of knowledge as well as getting acquainted whether there had been significant divergence among three social groups of 3rd year Law students, 7th period Medical students at UFPB and a group of people from the Catholic Church in vila dos pescadores in Jo?o Pessoa - about organ donation, transplant law and ethical issues that raise questions. In order to accomplish the qualitative analysis, Bardin?s content analysis technique was applied in conjunction with the Chisquare test which was applied with significance level of 5% to quantitative data. The data revealed that most informants agree with organ donation, Although they are not acquainted with the law of transplants, and with the lack of confidence in the single list of recipients. The problem is that there is an encouragement to trades with organs and the possibility of any person legally authorized to donate organs in life. The statistically significant difference was observed in only two questions, ie, in response to the confidence in the diagnosis of brain death: 64% of 7th period Medical students at UFPB trust this diagnosis versus 12% of the evangelizing group of vila dos pescadores. The other difference refers to the answer about the confidence in the single list of recipients: 36% of the 7th period Medical students of UFPB said to trust the list versus 12% of the 3rd law students of UFPB. This is was a multidisciplinary study with Involvement of lawyers and doctors / O presente estudo teve por objetivo analisar a representa??o, o n?vel de conhecimento, bem como saber se existia diverg?ncia significativa entre tr?s grupos sociais estudantes de direito do 3? ano e de medicina do 7? per?odo da UFPB e um grupo de pessoas da igreja cat?lica na vila dos pescadores em Jo?o Pessoa-PB sobre a doa??o de ?rg?os, lei dos transplantes e temas que suscitam questionamentos ?ticos. Aplicou-se a t?cnica de an?lise de conte?do de Bardin para a an?lise qualitativa e o teste Qui-quadrado com n?vel de signific?ncia de 5% para os dados quantitativos. Os dados mostraram que a maioria dos entrevistados ? favor?vel a doa??o de ?rg?os, que n?o conhece a lei de transplantes, como tamb?m n?o confia na lista ?nica de receptores. E que h? um favorecimento ao com?rcio de ?rg?os, a possibilidade de qualquer pessoa autorizada judicialmente ser doador de ?rg?os em vida. A diferen?a estatisticamente significativa s? foi observada em dois questionamentos, ou seja, na resposta sobre a confian?a no diagn?stico de morte encef?lica: 64% dos estudantes de medicina do 7? per?odo da UFPB confiam nesse diagn?stico versus 12% do grupo evangelizador da vila dos pescadores. A outra diferen?a foi na resposta sobre a confian?a na lista ?nica de receptores: 36% dos estudantes do 7? per?odo de medicina da UFPB afirmaram confiar na lista versus 12% dos estudantes de direito do 3? ano da UFPB. A realiza??o desse estudo teve car?ter multidisciplinar com envolvimento de advogados e m?dicos

The study involves an assessment of the effectiveness of Employment Equity Act, 55 of 1998 (EEA) in the South African public service, with specific reference to the Department of Agriculture (DoA) and problems the DoA encounters in realising the main objectives of the abovementioned Act. The research comprises both normative and empirical aspects of the EEA in the public service (specifically DoA). Employment Equity Act (Act 55 of 1998), in the agriculture sector has produced mixed results. There is a perception that the number of women in middle and senior management positions has slightly improved, as appears in the DoA organisational chart. Others perceive the Act as flawed in its design and implementation, due to the fact that the number of disabled employees in the middle and senior management levels is hardly visible on the organisational chart. The purpose of this research is to ascertain whether the DoA has been able to meet or implement the dictates of the EEA. Mostly, this research aims to look at ways in which the EEA can best be implemented, so that it functions as effectively as possible and to ensure that the Act yields the desired results. The fact that the DoA has not managed to reach the EEA target to employ disabled and women (though the number of women in senior positions has slightly improved) to senior positions, necessitates the need of this study. And mostly by the fact that EEA plays a pivotal role in ensuring equity in the DoA, which has in the past been perceived by some as the one dominated by a certain racial group. The specific objectives of this study are: <ul> <li>To explore difficulties that adversely impact on the effectiveness of the Employment Equity Act, 55 of 1998 in Department of Agriculture especially with regards to disabled officials.</li> <li>To determine if there is a disparity in the views of management and employees (both able-bodies and disabled employees) with regard to the effectiveness of Employment Equity Act, 55 of 1998 and problems experienced.</li> <li>To established levels of satisfaction of employees (designated groups)with the Employment Equity Act, 55 of 1998 and employees within the work environment.</li> </ul> This study will also make use of qualitative and quantitative research methods. Both Primary and Secondary research will be conducted to obtain the information needed to meet the objectives of the research. This research is important for the DoA because, the issue of EEA and other related issues such as Affirmative Action (AA) have been a thorny issue to others, while others embrace it. The importance of this research is further exacerbated by the fact that it sets forth a clear picture of the impact the Act in question made in its quest to ensure equity in the workplace. In summary this study attempts to shed some light on the effectiveness of EEA and to determine whether the desired effects of EEA have been achieved by the DoA. / Dissertation (MAdmin)--University of Pretoria, 2010. / School of Public Management and Administration (SPMA) / unrestricted

As human settlement expands into the natural habitats of wild animals, the conflict between humans and wildlife increases. The human-elephant conflict is one that causes a tremendous amount of damage, often to poor villages close to the savannah. In this master's thesis, a system is developed, that is intended to detect, localise and track elephants from seismic vibrations generated from footsteps. The system consists of multiple devices, with three geophones, and a microprocessor each. To detect the footsteps, two different methods are evaluated. One that analyses features consistion of the normalised standard deviation, frequency peak, spectral centroid and low compared to high frequency content of a signal. These features of the signal are then compared to those of an elephant footstep. The other one compares the frequency content of the seismic wave from a footstep to an computed average of known elephant footsteps. The signal feature method performed the best with an accuracy of 89 %, and detecting 54 % of the footsteps. The detected footstep is sent to a backend where further calculations are done. With one device, estimations of the direction of arrival (DOA) angle can be made. This is done using a delay and sum algorithm. By using a Kalman filter on the DOA estimates, the bearing to the elephant can be tracked over time. From the detected elephant footsteps it has been shown that it is possible to estimate the direction of an elephant with quite high performance and by applying a Kalman filter to track the elephant, it has been shown that the filter gives better and more reasonable estimates. With two devices, a location can be estimated with triangulation and also an elephant's position can be tracked. With triangulation, where the easting position estimated to some extent, but the northing position did not give good results. By using these localisations estimates in a Kalman filter the elephant could be tracked in most of the cases with high enough performance and especially when there weren't too many high northing estimates. By using separate DOA estimations in an extended Kalman filter the easting position could be tracked fairly well, while the northing updates had some strange behaviours, most probably because of implementation error. / Project Ngulia

Made available in DSpace on 2015-04-14T14:48:30Z (GMT). No. of bitstreams: 1 393788.pdf: 178340 bytes, checksum: c62b060341c1d65db14d176e4d3191cc (MD5) Previous issue date: 2007-12-11 / A disserta??o visou abordar os procedimentos de transplanta??o humana, especificamente a tutela penal relativa ao com?rcio de ?rg?os humanos que tem sido dispensada n?o s? pelo legislador p?trio (Lei 9.434/97), como tamb?m em rela??o ao direito comparado a esta revolucion?ria t?cnica. Tal objetivo foi desenvolvido atrav?s de an?lise eminentemente interdisciplinar, com a abordagem de elementos da hist?ria das id?ias, psiquiatria, filosofia, etnografia, bio?tica e direito. Primeiramente buscou-se investigar a transi??o das vis?es de corpo na modernidade e contemporaneidade: indo desde uma id?ia de sacralidade at? a de profana??o. Ap?s, buscou-se, al?m da realiza??o de an?lise hist?rico-comparativa dos principais avan?os cient?ficos na ?rea com a evolu??o legislativa, principalmente em nosso pa?s, a defini??o de conceitos relacionados ? tem?tica, como o de transplante, suas modalidades e a pol?mica relativa a morte encef?lica. A quest?o de escassez demonstrou-se essencial ? discuss?o, j? que ensejadora de um dos mais debatidos e controversos temas relativos aos transplantes de ?rg?o na atualidade: o com?rcio de ?rg?os humanos. Ap?s discuss?o de casos documentados sobre a pr?tica, foi realizada a confronta??o entre os argumentos favor?veis e contr?rios, chegando-se ? conclus?o de que uma an?lise ? luz da dignidade humana e da ?tica da alteridade ? suficiente para recha?ar a disposi??o remunerada de ?rg?os humanos. Sob a ?tica dos bens jur?dicos envolvidos e do consentimento do ofendido, a conclus?o n?o ? outra. Por ?ltimo atrav?s de pesquisa de campo em que foram entrevistadas 450 pessoas, evidenciou-se a avers?o majorit?ria ao com?rcio de ?rg?os, fundada em um crit?rio moral, em tr?s grupos diferentes (profissionais e acad?micos de Medicina e outras ci?ncias da sa?de; profissionais e acad?micos do Direito e comunidade em geral). O desejo de salvar vidas precisa estar em conson?ncia com o necess?rio respeito ? dignidade humana.

Made available in DSpace on 2014-12-17T15:38:59Z (GMT). No. of bitstreams: 1 IsraelLLF_DISSERT.pdf: 3244558 bytes, checksum: e46a1b6adc42426356bdca03afd3f98b (MD5) Previous issue date: 2012-08-06 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The context of blood donation in Brazil faces problems since the start of its operations in the 1940, in the beginning the biggest obstacle was obtain safe and qualified blood, and then, established criteria for donations, the barrier is the low number of suitable candidates for donation. This suitability is associated with the good health of those who goes to the services of blood banks and the return of the donor is often conditioned by the way care is given and perceived by the user. The quality of life, defined as a perception that a person has of her/his position in the world, can influence the health and emerges as a way to focus on the subjectivity in a context dominated by objective and practical exams; listen to the views about the received services increases the focus on the user and provides feedback to the institution, guiding and planning its future actions. The purpose of this study was to verify the quality of life in blood donors and their perceptions of care in a blood center in Natal/RN. This is a descriptive cross sectional study conducted with blood donors from Dalton Cunha Barbosa blood center. The used protocols were: a structures questionnaire with questions on sociodemographic and services perception data, and SF-36 quality of life instrument. The sociodemographic and SF-36 data ware analyzed using descriptive and inferential statistics, using the statistical package PASW 18.0; those related to treatment were submitted to thematic content analysis. The results revealed a sample mainly composed by men, married people, who attended high school and had already made previous donations, with the first two groups returning more often for donations. The scores of the SF-36 confirm the certificated of good health of the screens, beind high in all areas and featuring a healthy population; statistically significant differences were denoted between sexes, levels of education and marital status. The speeches about the service were mostly positive and had as main focus acess, agility, technical aspects and subjective feelings. The data regarding the Rio Grande do Norte blood donors profile confirmed some characteristics of the Brazilian ones, those data of the SF-36 were similar to those found in studies with healthy groups and the impressions about the care received show similarities with national and international studies about the attendance at blood banks / O campo de doa??o de sangue no Brasil enfrenta problemas desde o in?cio de sua atua??o na d?cada de 1940, se a princ?pio o maior entrave era conseguir sangue seguro e de qualidade, depois de estabelecidos crit?rios para doa??es, o obst?culo est? no baixo n?mero de candidatos aptos ? doa??o. A aptid?o est? relacionada ? boa sa?de daqueles que buscam os servi?os de hemocentros e o retorno do doador, muitas vezes, condicionado ? forma como o atendimento ? prestado e percebido pelo usu?rio. A qualidade de vida, percep??o que o indiv?duo tem de sua posi??o no contexto no qual se insere, pode influenciar a sa?de e emerge como forma de enfocar a subjetividade em um contexto de exames e pr?ticas objetivas; audi??o de impress?es sobre o atendimento recebido amplia o foco sobre o usu?rio e permite um feedback a institui??o para que esta oriente e planeje sua atua??o. O presente estudo objetivou verificar a qualidade de vida em doadores de sangue e sua percep??o do atendimento em um hemocentro de Natal/RN. Trata-se de um estudo descritivo de corte transversal, realizado com doadores de sangue usu?rios dos servi?os do Hemocentro Dalton Barbosa Cunha (HEMONORTE). Foram utilizados como protocolos: um question?rio estruturado, com quest?es sociodemogr?ficas e sobre o atendimento, e o instrumento de Qualidade de Vida SF-36. Os dados sociodemogr?ficos e do SF-36 foram analisados utilizando-se estat?stica descritiva e inferencial, com auxilio do pacote estat?stico PASW 18.0; aqueles referentes ao atendimento foram submetidos ? an?lise de conte?do tem?tica. Os resultados revelaram uma amostra essencialmente composta por homens, pessoas casadas, que estudaram at? o segundo grau e j? tinham feito doa??es anteriores, com os dois primeiros grupos retornando mais frequentemente para doa??es. Os escores obtidos no SF-36 confirmam o atestado de boa sa?de das triagens, sendo elevados em todos os dom?nios e caracterizando uma popula??o saud?vel; denotaram-se diferen?as estat?sticas significativas entre os sexos, n?veis de escolaridade e estados civis. Os discursos sobre o atendimento foram em sua maioria positivos e tiveram como focos principais o acesso, agilidade, aspectos t?cnicos e sensa??es subjetivas. Dados referentes ao perfil do doador potiguar confirmam caracter?sticas algumas do doador brasileiro, aqueles do SF-36 assemelham-se aos encontrados em estudos com grupos de indiv?duos saud?veis e as impress?es sobre o atendimento recebido t?m similaridades com estudos nacionais e estrangeiros sobre o atendimento em bancos de sangue

Ce travail de thèse traite du développement d’une antenne microphonique compacte et d’une chaîne de traitement du signal dédiée, pour la reconnaissance et la localisation angulaire de cibles aériennes. L’approche globale proposée consiste en une détection initiale de cible potentielle, la localisation et le suivi de la cible, et une détection affinée par un filtrage spatial adaptatif informé par la localisation de la cible. Un algorithme original de localisation goniométrique est proposé. Il utilise l’algorithme RANSAC sur des données pression-vitesse large bande [100 Hz - 10 kHz], estimées en temps réel, dans le domaine temporel, par des différences et sommes finies avec des doublets de microphones à espacements inter-microphoniques adaptés à la fréquence. L’extension de la bande passante de l’antenne en hautes fréquences est rendue possible par l’utilisation de différences finies d’ordre élevé, ou de variantes de la méthode PAGE (Phase and Amplitude Gradient Estimation) adaptées à l’antenne développée. L’antenne acoustique compacte ainsi développée utilise 32 microphones MEMS numériques répartis dans le plan horizontal sur une zone de 7.5 centimètres, selon une géométrie d’antenne adaptée aux l’algorithmes de localisation et de filtrage spatial employés. Des essais expérimentaux de localisation et de suivi de trajectoire contrôlée par une sphère de spatialisation dans le domaine ambisonique ont montré une erreur de localisation moyenne de 4 degrés. Une base de données de signatures acoustiques de drones en vol a été créée, avec connaissance de la position du drone par rapport à l’antenne microphonique apportée par des mesures GPS. L’augmentation des données par bruitage artificiel, et la sélection dedescripteurs acoustiques par des algorithmes évolutionnistes, ont permis de détecter un drone inconnu dans un environnement sonore inconnu jusqu’à 200 mètres avec le classifieur JRip. Afin de faciliter la détection et d’en augmenter la portée, l’étape de détection initiale est précédée d’une formation de voies différentielle dans 4 directions principales (nord, sud, est, ouest), et l’étape de détection affinée est précédée d’une formation de voies de Capon informée par la localisation et le suivi de la cible à identifier. / This thesis deals with the development of a compact microphone array and a dedicated signal processing chain for aerialtarget recognition and direction of arrival (DOA) estimation. The suggested global approach consists in an initial detection ofa potential target, followed by a DOA estimation and tracking process, along with a refined detection, facilitated by adaptivespatial filtering. An original DOA estimation algorithm is proposed. It uses the RANSAC algorithm on real-time time-domainbroadband [100 Hz - 10 kHz] pressure and particle velocity data which are estimated using finite differences and sums ofsignals of microphone pairs with frequency-dependent inter-microphone spacings. The use of higher order finite differences, or variants of the Phase and Amplitude Gradient Estimation (PAGE) method adapted to the designed antenna, can extend its bandwidth at high frequencies. The designed compact microphone array uses 32 digital MEMS microphones, horizontally disposed over an area of 7.5 centimeters. This array geometry is suitable to the implemented algorithms for DOA estimation and spatial filtering. DOA estimation and tracking of a trajectory controlled by a spatialization sphere in the Ambisonic domain have shown an average DOA estimation error of 4 degrees. A database of flying drones acoustic signatures has been set up, with the knowledge of the drone’s position in relation to the microphone array set out by GPS measurements. Adding artificial noise to the data, and selecting acoustic features with evolutionary programming have enabled the detection of an unknown drone in an unknown soundscape within 200 meters with the JRip classifier. In order to facilitate the detection and extend its range, the initial detection stage is preceded by differential beamforming in four main directions (north, south, east, west), and the refined detection stage is preceded by MVDR beamforming informed by the target’s DOA.

Le cadre d'étude de ce travail est celui du traitement d'antenne appliqué au modèle linéaire. Dans divers domaines, comme en bio-médical ou encore en RADAR, le nombre de Directions D'Arrivées (DDA) d'intérêts est un ensemble réduit de toutes les directions constituant le modèle. Nous optons donc pour un modèle structuré s'écrivant <br /><br />Observation = Signal d'intérêt + Interférence structurée + Bruit<br /><br />Où l'interférence structurée est composée d'un certain nombre de Directions D'Arrivées connues ou estimées. De ce modèle, nous proposons deux types d'approches : (1) nous supposons disposer de la connaissance de M-S DDA sur un total de M et (2) nous souhaitons estimer de manière séquentielle M DDA.<br /><br />La littérature fournit des solutions pour résoudre le problème d'estimation de S DDA d'intérêts sur un total de M. Les solutions proposées utilisent une déflation orthogonale du sous-espace signal bruité. Nous donnons alors une nouvelle Borne de Cramér-Rao (CRB) que nous nommons Prior-CRB associée à ce type modèle et nous montrons sous quelles conditions (très restrictives) cette borne est inférieure à une CRB classique issue du modèle linéaire composé de M DDA. Pour s'absoudre des contraintes liées au modèle à déflation orthogonale nous proposons alors d'employer une déflation oblique en place de la déflation orthogonale. Nous construisons alors de nouveau estimateurs des DDA d'intérêts. A la vue des simulations, les performances sont bien meilleures que les algorithmes à déflation orthogonale et nous proposons d'expliquer ces performances par la dérivation des variances théoriques de chacun des estimateurs proposés. Ainsi, via l'analyse de ces variances, nous montrons pourquoi la projection oblique est plus appropriée et nous donnons une relation d'ordre de chacune des variances associées aux algorithmes étudiés.<br /><br />Ici encore le problème de l'estimation séquentielle de M DDA est un problème suscitant un grand intérêt. Seulement, les solutions proposées dans la littérature utilisent une déflation orthogonale pour annuler séquentiellement les directions préalablement estimées via un critère MUSIC modifié. Nous nous démarquons en proposant un algorithme qui pondère, par une fonction quadratique de forçage à zéro, le pseudo-spectre de MUSIC. Cette approche montre de bien meilleures performances que les méthodes à déflation orthogonale et permet de s'affranchir très nettement de la résolution de Rayleigh grâce au contrôle de la fonction de pondération. Nous montrons de plus que cet algorithme est efficace et que l'erreur de propagation peut s'annuler via le réglage d'un paramètre de la fonction de pondération. Pour caractériser au mieux les performances de cet algorithme nous proposons une CRB, que nous nommons la Interfering-CRB issue d'un modèle linéaire constitué d'une DDA d'intérêt et de M-1 DDA interférentes (DDA estimées préalablement ou restant à estimer). Nous montrons que cette borne « reflète » bien l'algorithme ZF-MUSIC.

Signal acquisition, signal reconstruction and analysis of spectrum of the signal are the three most important steps in signal processing and they are found in almost all of the modern day hardware. In most of the signal processing hardware, the signal of interest is sampled at uniform intervals satisfying some conditions like Nyquist rate. However, in some cases the privilege of having uniformly sampled data is lost due to some constraints on the hardware resources. In this thesis an important problem of signal reconstruction and spectral analysis from nonuniformly sampled data is addressed and a variety of methods are presented. The proposed methods are tested via numerical experiments on both artificial and real-life data sets. The thesis starts with a brief review of methods available in the literature for signal reconstruction and spectral analysis from non uniformly sampled data. The methods discussed in the thesis are classified into two broad categories - dense and sparse methods, the classification is based on the kind of spectra for which they are applicable. Under dense spectral methods the main contribution of the thesis is a non-parametric approach named LIMES, which recovers the smooth spectrum from non uniformly sampled data. Apart from recovering the spectrum, LIMES also gives an estimate of the covariance matrix. Under sparse methods the two main contributions are methods named SPICE and LIKES - both of them are user parameter free sparse estimation methods applicable for line spectral estimation. The other important contributions are extensions of SPICE and LIKES to multivariate time series and array processing models, and a solution to the grid selection problem in sparse estimation of spectral-line parameters. The third and final part of the thesis contains applications of the methods discussed in the thesis to the problem of radial velocity data analysis for exoplanet detection. Apart from the exoplanet application, an application based on Sudoku, which is related to sparse parameter estimation, is also discussed.