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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

BROAD BANDWIDTH HIGH RESOLUTION ANALOG TO DIGITAL CONVERTERS: THEORY, ARCHITECTURE AND IMPLEMENTATION

Ren, Saiyu, Dr. 31 March 2008 (has links)
No description available.
42

A small-signal modeling of GaAs FET and broad band amplifier design

Tan, Tiow Heng January 1991 (has links)
No description available.
43

The Broad Autism Phenotype in the General Population: Evidence Through Eye-Tracking

Maddox, Brenna Burns 07 May 2012 (has links)
The broad autism phenotype (BAP) has been defined both behaviorally and biologically. There has been little research on the association of the BAP, behaviorally defined, with neural or cognitive biomarkers typically associated with Autism Spectrum Disorder (ASD). People diagnosed with ASD tend to show reduced gaze fixation toward the eye region, but much less eye-tracking research has been done related to the BAP (Boraston & Blakemore, 2007). In this study, we sought to assess eye gaze patterns in people with the behaviorally defined BAP, as defined by a score of 30 or above on the Autism Spectrum Quotient (AQ; Baron-Cohen et al., 2001). It was hypothesized that the BAP group participants would exhibit longer average fixation duration to the eye region during an emotion recognition condition, relative to a free-viewing condition, whereas the comparison group participants (defined as an AQ score of 24 and below) would not show a difference in fixation duration to the eye region between conditions. Nine hundred and thirty-nine undergraduates completed an online survey, and 45 of these students (15 BAP group and 30 comparison group) participated in the eye-tracking session, where they viewed a series of human faces, each presented twice within a condition. Results revealed a significant negative relationship between social anxiety and eye region fixation duration in the free-viewing condition, for both presentations of faces. Contrary to expectation, BAP predicted longer eye region fixation duration in the free-viewing condition, for the second presentation of faces. Possible explanations for these surprising findings are discussed. / Master of Science
44

Caracterização de aspectos da fala e da linguagem oral em pais de autistas.

Mendes, Silvia Carolina Teixeira 05 December 2008 (has links)
Made available in DSpace on 2016-01-26T12:51:27Z (GMT). No. of bitstreams: 1 silviacarolinateixeiramendes_dissert.pdf: 3230897 bytes, checksum: 9cec9035ff4564008d0f6d5d7135945b (MD5) Previous issue date: 2008-12-05 / Autism is a neuropsychiatric disorder that develops during early childhood and is part of a group of psychiatric conditions denominated Pervasive Developmental Disorders (PDD). Diagnosis is clinical, mainly based on the presence of social interaction disorders, restricted interests, stereotyped behavior and communication disorders. Communication is an important aspect of the disease as it is invariably present in autism. Psychiatric alterations of speech and language are commoner in autistic families, thus suggesting a broad phenotype and possible genetic anticipation in autism. This study aimed at analyzing the oral language and the speech of parents of autistic and control individuals and to correlate the results to a possible broad phenotype and genetic anticipation in autism. Eighteen couples, mothers and fathers, of autistic patients were investigated. A control group was composed of nine men and nine women, paired by age and education. The participants were submitted to a clinical evaluation of speech and language and to the Test of Language Competence (TLC-E). The results showed a poorer performance by the parents of autistic patients when compared to the controls in respect to language but not to speech. The presence of alterations in oral language in couples with autistic children supports the hypothesis of a broad phenotype of this disease and of the existence of genetic anticipation in autism. / O autismo é um transtorno neuropsiquiátrico que se desenvolve na infância precoce e é parte de um grupo de condições psiquiátricas denominado Transtornos Invasivos do Desenvolvimento TID (Pervasive Developmental Disorders PDD). O diagnóstico é clínico e baseado principalmente na presença de distúrbios de interação social, interesses restritos, padrões estereotipados do comportamento e distúrbios de comunicação. A comunicação é um aspecto importante da doença por estar invariavelmente alterada no autista. Alterações psiquiátricas, de fala e linguagem são mais freqüentes em familiares de autistas, o que sugere o fenótipo broad e possível antecipação genética no autismo. Este estudo teve como objetivos analisar a linguagem oral e a fala em pais de autistas e em controles, e de relacionar os resultados obtidos à possibilidade do fenótipo broad e de antecipação genética em autismo. Foram investigados 18 casais, mães pais de autistas (Grupo I). O grupo controle foi composto de nove homens e nove mulheres, pareados por sexo, idade e escolaridade. Os grupos foram submetidos a avaliação clínica da fala e da linguagem e ao teste de competência de linguagem (TLC-E). Os resultados mostraram um pior desempenho dos pais de autistas em relação a seus controles quanto a aspectos da linguagem e não da fala. A presença de alterações de linguagem oral em casais com filho autista reforçam a hipótese do fenótipo broad desta doença e da existência de antecipação genética em autismo.
45

Caracterización molecular y desarrollo de métodos de diagnóstico del género Fabavirus Evaluación de BTH como método de control

Ferrer Gual, Rosa Margarita 24 May 2010 (has links)
El género Fabavirus pertenece a la familia Comoviridae e incluye tres especies: Broad bean wilt virus 1 (BBWV-1), BBWV-2 y Lamium mild mosaic virus (LMMV), aunque recientemente se ha propuesto una nueva especie, Gentian mosaic virus (GeMV). Estos virus afectan a un gran número de especies hortícolas y ornamentales y son transmitidos de manera no persistente por unas veinte especies de pulgones. El genoma está formado por dos cadenas de RNA monocatenario de polaridad positiva que se encapsidan separadamente con dos proteínas de cápsida formando viriones isométricos. BBWV-1 y BBWV-2 están distribuidos por todo el mundo. En España se ha encontrado BBWV-1 en cultivos de pimiento de Aragón, Cataluña, Castilla León, C. Valenciana, Murcia, Navarra, País Vasco y La Rioja. Los fabavirus son un grupo viral muy poco estudiado. Al comienzo de esta tesis, sólo se había determinado la secuencia nucleotídica del genoma completo de seis aislados de BBWV-2 procedentes de Extremo Oriente, mientras que no se disponía de ninguna secuencia completa de BBWV-1. Para desarrollar métodos rápidos, sensibles y específicos de detección, diferenciar aislados con secuencias divergentes y evaluar en su caso la efectividad de distintas estrategias de control se consideró necesario obtener la secuencia completa de al menos un aislado de BBWV-1 y secuencias parciales de aislados de distintos países. En esta tesis, se determinó la secuencia nucleotídica completa del genoma del aislado español 1S1 de BBWV-1 y se dedujo su organización genómica. El genoma está formado por dos moléculas de RNA monocatenario de polaridad positiva de 5814 y 3431 nt, respectivamente, con la organización genómica descrita para otros miembros de la familia Comoviridae. Al comparar esta secuencia con la única secuencia disponible de BBWV-1 correspondiente al aislado 1U2 de EEUU (publicado durante el desarrollo de esta tesis), se comprobó que los genomas de ambos aislados eran muy divergentes. / Ferrer Gual, RM. (2008). Caracterización molecular y desarrollo de métodos de diagnóstico del género Fabavirus Evaluación de BTH como método de control [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8313 / Palancia
46

Considering the impact of BEE procurement policy on entrepreneurial activities in Fezile Dabi District / Molahlehi Peterson Molukanelo

Molukanelo, Molahlehi Peterson January 2014 (has links)
The post-1994 South African government has introduced multiple initiatives, programmes and passed various legislations which were aimed at assisting previously disadvantaged individuals to participate in the mainstream economy. These interventions by government are aimed at advancing mass participation in the economy by all groups of the society. Because of the laws during the apartheid regime, blacks in particular found themselves excluded in business opportunities and thus prohibiting them to actively participate in the economy. This study was therefore aimed at considering the impact made by BEE procurement policy on the BEE entrepreneurial activities in Fezile Dabi District. Fezile District is one of the four District Municipalities within the Free State province. The study aims to assess the impact of procurement policy as one of the elements towards BEE entrepreneurship activities. The study used both literature review as well as the empirical study to come to the conclusions revealed in the last chapter. The empirical study which was conducted using the questionnaires surveys over the four local municipalities within the District revealed that small business owners agree and believe that the BEE procurement policies introduced by government are very good instruments to enable them to enter the business sector and participate actively in the economy. However the challenge acknowledged by the small businesses is that despite this good legislation the implementation at the Fezile Dabi District is not properly executed. Lack of transparency and favouritism in awarding contracts and tenders were revealed as the biggest challenges facing the District. Practical recommendations were made to address these challenges and improving the system. / MBA, North-West University, Potchefstroom Campus, 2015
47

Considering the impact of BEE procurement policy on entrepreneurial activities in Fezile Dabi District / Molahlehi Peterson Molukanelo

Molukanelo, Molahlehi Peterson January 2014 (has links)
The post-1994 South African government has introduced multiple initiatives, programmes and passed various legislations which were aimed at assisting previously disadvantaged individuals to participate in the mainstream economy. These interventions by government are aimed at advancing mass participation in the economy by all groups of the society. Because of the laws during the apartheid regime, blacks in particular found themselves excluded in business opportunities and thus prohibiting them to actively participate in the economy. This study was therefore aimed at considering the impact made by BEE procurement policy on the BEE entrepreneurial activities in Fezile Dabi District. Fezile District is one of the four District Municipalities within the Free State province. The study aims to assess the impact of procurement policy as one of the elements towards BEE entrepreneurship activities. The study used both literature review as well as the empirical study to come to the conclusions revealed in the last chapter. The empirical study which was conducted using the questionnaires surveys over the four local municipalities within the District revealed that small business owners agree and believe that the BEE procurement policies introduced by government are very good instruments to enable them to enter the business sector and participate actively in the economy. However the challenge acknowledged by the small businesses is that despite this good legislation the implementation at the Fezile Dabi District is not properly executed. Lack of transparency and favouritism in awarding contracts and tenders were revealed as the biggest challenges facing the District. Practical recommendations were made to address these challenges and improving the system. / MBA, North-West University, Potchefstroom Campus, 2015
48

ROBUST ADAPTIVE BEAMFORMING WITH BROAD NULLS

Yudong, He, Xianghua, Yang, Jie, Zhou, Banghua, Zhou, Beibei, Shao 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Robust adaptive beamforming using worst-case performance optimization is developed in recent years. It had good performance against array response errors, but it cannot reject strong interferences. In this paper, we propose a scheme for robust adaptive beamforming with broad nulls to reject strong interferences. We add a quadratic constraint to suppress the power of the array response over a spatial region of the interferences. The optimal weighting vector is then obtained by minimizing the power of the array output subject to quadratic constrains on the desired signal and interferences, respectively. We derive the formulations for the optimization problem and solve it efficiently using Newton recursive algorithm. Numerical examples are presented to compare the performances of the robust adaptive beamforming with no null constrains, sharp nulls and broad nulls. The results show its powerful ability to reject strong interferences.
49

Design and analysis of MAC protocols for wireless multi-hop sensor and terahertz networks

Lin, Jian 27 May 2016 (has links)
The contributions of this thesis include designing and analyzing novel medium access control (MAC) protocols for two types of wireless networks: (1) duty-cycling cooperative multi-hop wireless sensor networks (MHWSNs), and (2) single-hop Terahertz networks (TeraNets). For MHWSNs, the specific contributions are two new scalable MAC protocols for alleviating the “energy-hole” problem with cooperative transmission (CT). The energy-hole is known to limit the life of battery-powered MHWSNs. The hole occurs when nodes near the Sink exhaust their energy first because their load is heavier: they must transmit packets they originate and relay packets from and to other nodes farther from the Sink. Effective techniques for extending lifetime in MHWSNs include duty cycling (DC) and, more recently introduced, cooperative transmission (CT) range extension. However, a scalable MAC protocol has not been presented that combines both. From the MAC perspective, conducting CT in an asynchronous duty-cycling network is extremely challenging. On the one hand, the source, the cooperators and the destination need to reach consensus about a wake-up period, during which CT can be performed. This dissertation develops novel MAC protocols that solve the challenge and enable CT in an asynchronous duty-cycling network. On the other hand, the question arises, “Does the energy cost of the MAC cancel out the lifetime benefits of CT range extension?” We show that CT still gives as much as 200% increase in lifetime, in spite of the MAC overhead. The second contribution of this dissertation is a comprehensive analytical framework for MHWSNs. The network performance of a MHWSN is a complex function of the traffic volume, routing protocol, MAC technique, and sensors' harvested energy if sensors are energy-harvesting (EH) enabled. The optimum performance provides a benchmark for heuristic routing and MAC protocols. However, there does not exist such an optimization framework that is able to capture all of these protocol aspects. The problems and performance metrics of non-EH networks and EH networks are different. Because the non-EH nodes depend on a battery, a suitable performance metric is the lifetime, defined as the number of packets delivered upon the first or a portion of nodes' death. Thus, the lifetime is governed by the absorbing states in a controlled dynamic system with finite decision horizon. On the other hand, the lifetime of an EH network is theoretically infinite unless the sensors are broken or destroyed. Therefore, an infinite horizon problem is formulated towards the performance of EH networks. The proposed model departs significantly from past analyses for single-hop networks that do not capture routing and past analyses for multi-hop networks that miss MAC aspects. To our knowledge, this is the first work to model the optimal performance of MHWSNs, by jointly considering MAC layer link admission, routing queuing, energy evolution, and cooperative transmission. The third contribution of this dissertation is a novel MAC protocol for Terahertz (THz) Band wireless networks, which captures the peculiarities of the THz channel and takes advantage of large antenna arrays with fast beam steering capabilities. Communication in THz Band (0.1-10THz) is envisioned as a key wireless technology in the next decade to provide Terabits-per-second links, however, the enabling technology is still in its infancy. Existing MAC protocols designed for classical wireless networks that provide Megabits-per-second to Gigabits-per-second do not scale to THz networks, because they do not capture the peculiarities of the THz Band, e.g., the very high molecular absorption loss or the very high reflection loss at THz Band frequencies. In addition, to overcome the high path loss and extend communication range, the proposed MAC design takes advantage of fast beam steering capabilities provided by the large antenna arrays, in particular, beam-switching at the pulse level.
50

Epicuria: The Dichotomy of Richmond's Urban and Suburban Landscape in a Market Environment

Canale, Kate 27 April 2011 (has links)
This thesis examines the dichotomy of Richmond’s suburban and urban environments within a market environment. In our quest to make our lives more convenient, we have moved outside of cities, increased commutes and cut ourselves off from one another. Ultimately we have lowered our standards of quality in food, products and services by allowing big retailers and chain restaurants to determine a new standard of living. The goal of this works is to create a food hall and market environment that will act as a catalyst to improve the quality of life of Richmonders as well as to draw residents from the suburbs back into the city and revitalize the run down urban areas. The market and food hall will showcase the best that Richmond has to offer. It will support local farmers and business, integrate and encourage community by connecting people, encourage a slower pace of life and act as a center of revenue for the neighborhood and city of Richmond.

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